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Direct and rapid effects of 3,5-diiodo-L-thyronine (T2)
Accepted Manuscript Direct and rapid effects of 3,5-diiodo-L-thyronine (T2) Maria Moreno, Antonia Giacco, Celia di Munno, Fernando Goglia PII:
S0303-7207(17)30092-8
DOI:
10.1016/j.mce.2017.02.012
Reference:
MCE 9839
To appear in:
Molecular and Cellular Endocrinology
Received Date: 18 October 2016 Revised Date:
2 January 2017
Accepted Date: 8 February 2017
Please cite this article as: Moreno, M., Giacco, A., di Munno, C., Goglia, F., Direct and rapid effects of 3,5-diiodo-L-thyronine (T2), Molecular and Cellular Endocrinology (2017), doi: 10.1016/ j.mce.2017.02.012. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Direct and rapid effects of 3,5-diiodo-L-thyronine (T2)
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Maria Moreno, Antonia Giacco, Celia di Munno, Fernando Goglia°
Department of Science and Technologies, University of Sannio, Benevento. Italy
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°Corresponding author
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Email [email protected] Tel. +380824305100
Address: Via Port’Arsa 11, 82100 Benevento. Italy
Key words: 3,5-diiodothyronine; energy metabolism; mitochondria; thyroid hormone action;
ABSTRACT
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metabolic rate; short-term effects.
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A growing number of researchers are focusing their attention on the possibility that thyroid hormone metabolites, particularly 3,5-diiodothyronine (T2), may actively regulate energy
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metabolism at the cellular, rather than the nuclear, level. Due to their biochemical features, mitochondria have been the focus of research on the thermogenic effects of thyroid hormones. Indeed, mitochondrial activities have been shown to be regulated both directly and indirectly by T2specific pathways. Herein, we describe the effects of T2 on energy metabolism.
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ACCEPTED MANUSCRIPT INTRODUCTION Thyroid hormones (THs) have a great impact on many processes that are essential for development and normal growth, as well as energy metabolism in adult (Brent, 2012; Cheng et al., 2010; Davis et
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al., 2016). THs stimulate energy metabolism in most tissues, leading to an increase in basal metabolic rate [minimal rate of energy required for breathing, heart rate, blood circulation, etc.] (Johnstone et al., 2005; Danforth and Burger,1984; Silva 2003). For example, at the heart level, THs induce: a) an increase of the force and the speed of both systolic contraction and diastolic
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relaxation and b) either a decrease of vascular resistance or an increase of coronary arteriolar
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angiogenesis (Klein et al., 2001; Grais and Sowers, 2014). In addition, resting energy expenditure (amount of energy required over a 24-h period by the body at rest) is highly sensitive to THs, especially in athyreotic individuals (Al-Adsani et al., 1997). More recent data further support this idea showing effects of THs in euthyroid subjects both in healthy (Johannsen et al., 2012) and in pathological conditions such as obesity and anorexia (for review, see Reinehr 2010). Although it is
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well established that THs affect energy expenditure (Fox et al., 2008; Iwen et al., 2013; Knudsen et al., 2005), the cellular and molecular events underlying this essential function are not yet
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understood (Kim, 2008; Vaitkus et al., 2015). It is now recognized that other iodothyronines and TH metabolites exert relevant biological actions on energy metabolism (for recent reviews see
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Moreno et al., 2008; Senese et al., 2014a; Senese et al., 2014b; Zucchi et al., 2014; Goglia, 2015; Davis et al., 2016). Among these, an endogenous TH metabolite 3,5-diiodo-L-thyronine (T2) has been shown to exert several metabolic effects. As far as it concerns the process involved in the in vivo production of T2 there is still no knowledge. One in vivo study likely supported the production of T2 from T3 as increased serum and hepatic levels of T2 were detected following T3 injection into euthyroid rats only when all three deiodinase enzymes were not inhibited (Moreno et al., 2002). Serum and hepatic levels of T2 in euthyroid rats have been estimated to be around 5 pM and 1.0 fmol/100 mg, respectively (Moreno et al., 2002). In humans, mean T2 serum levels are estimated to be 16.2 ± 6.4 pM in healthy subjects, 21.6 ± 4.8 pM in patients with brain tumors, and 46.7 ± 48.8 2
ACCEPTED MANUSCRIPT pM in septic patients (Pinna et al., 1997). However, due to several technical problems (i.e. low specific activities of the probes labelled in the inner ring) T2 measurements via these methods have been abandoned. Recent developments and optimization of a chemiluminescent immunoassay (Lehmphul et al., 2014) allowed to obtain new information on T2 levels (Pietzner et al., 2015a,
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Pietzner et al., 2015b, Dietrich et al., 2015). Moreover, mass spectrometry techniques (Hopley et al., 2004; Van Uytfanghe et al., 2004; Soukhova et al., 2004; Tai et al., 2004; Hantson et al., 2004; De Angelis et al., 2016) as well as Electrospray ionization tandem mass spectrometry (ESI-MS/MS)
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has been applied to identify and quantify T3 and T2 isomers (Zhang et al., 2005; Zhang et al., 2006; Hansen et al., 2016). Routine application of these approaches must be implemented (Köhrle et al.,
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2013).
In vivo studies
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Some decades ago, “surprising results” were published showing that, among several iodothyronines tested (i.e., T4 and T3), very low concentrations of T2 (pM range) rapidly stimulated oxygen consumption in perfused livers isolated from hypothyroid rats (Horst et al., 1989). The effects
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exerted by T2 were rapid and cycloheximide-independent, suggesting the nucleus did not contribute (Horst et al., 1989). Although in this study T3 showed a similar effect, which was largely abolished
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by deiodinase 1 inhibition, T2 exerted its effect more rapidly than T3 and independent of deiodinase 1 activity. This strongly indicates that caution should be taken when analysing metabolic data following T3 administration. These results, together with others showing an interaction between T2 and mitochondria (Goglia et al.,1981), have led to the idea that T2 may be able to stimulate cellular respiration via pathways involving mitochondria and bioenergetic mechanisms as major targets. Accordingly, several studies have demonstrated that T2 is able to stimulate mitochondrial respiratory activities (Lanni et al. 1992, 1993, 1994; Goglia, 2005), rapidly and directly stimulate bovine heart-isolated cytochrome c oxidase (COX) activity [barely any detectable stimulation was
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ACCEPTED MANUSCRIPT exerted by T3] (Goglia et al., 1994), and specifically bind the Va subunit of the COX complex, suggesting Va is one mitochondrial site through which T2 directly affects this organelle’s activity (Arnold et al., 1998). Moreover, T2 binding to the COX complex has been shown to abolish allosteric ATP inhibition of COX, thus decreasing the respiratory control ratio of the complex
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(Kadenbach et al., 2000) and consequently leading to heat production (i.e., calorigenic effect). In light of these effects, researchers began investigating whether T2 influences resting metabolic rate (RMR) in vivo employing rats made hypothyroid by simultaneous administration of
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propylthiouracil and iopanoic acid (which results in severe hypothyroidism and inhibition of all the
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deiodinase activities; referred to as P+I). P+I rats injected intraperitoneally with either T2 or T3 showed increased RMR with the time course of T2 effects being more rapid than that of T3 (Moreno et al., 1997). Indeed, T2 increased RMR within 1 h and reached a maximal effect at 30 h; T3 increased RMR at 20 h after injection, reached a peak at 65 h and its effect declined after a week (Moreno et al., 1997). Interestingly, only the T3’s effect on RMR were abolished by
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actinomycin D, leading to the conclusion that the effects of T2 on RMR are independent of de novo transcription. A further study showed that acute injection of T3 had an evident effect on the RMR
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25 h earlier in euthyroid animals (with physiologically active deiodinases) than in P+I rats (Moreno et al., 1997). This effect was accompanied by a later effect (after 24 h) which was abolished by
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actinomycin D. From these studies it was suggested that T2 and T3, via different mechanisms, might cooperate in vivo in the control of RMR. T2’s improved cold tolerance, energy expenditure, and oxidative capacity in cold-exposed P+I rats. While P+I rats survived the cold for 3-4 d, intraperitoneal injection of 10 µg T2/100 g body weight increased survival toward the end of the 3week experiment, with an increased energy expenditure and tissue-specific oxidative capacity (Lanni et al., 1998). A top-down elasticity analysis applied to mitochondria showed that T2 rapidly (i.e.1 h after its injection into euthyroid rats) stimulated the hepatic activity of both cytochrome coxidizing and -reducing components of the respiratory chain, in line with previous evidence of a
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ACCEPTED MANUSCRIPT direct interaction with COX (Lombardi et al., 1998). In addition to liver oxidative capacity, T2 also stimulated skeletal muscle mitochondrial uncoupling (Lombardi et al., 2007, 2009), mitochondrial translocation of the fatty acid transporter CD36 and fatty acid oxidation (Lombardi et al., 2012,
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2015, an effect that may explain, at least in part, the effect of T2 on RMR. Consequent to the above results, many studies have investigated the hypothesis that the T2 could counterbalance weight gain and lipid accumulation. In one rat model of high-fat diet (HFD)-induced lipid accumulation, T2 administration (25 µg/100 g body weight for 4 weeks) was able to prevent
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body weight gain, liver adiposity, hyperlipidemia, and insulin resistance, (Lanni et al. 2005, de
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Lange et al., 2011, Moreno et al., 2011). At this dose-regimen, no signs of thyrotoxicosis (tachycardia, cardiac hyperplasia, and decreased thyroid stimulating hormone levels) were detected (Lanni et al., 2005; de Lange et al., 2011). T2 administrations to HFD-overweight rats were shown to significantly reduce pre-existing hepatic fat accumulation, as well as hyperlipidaemia, through increased hepatic mitochondrial fatty acid oxidation coupled with uncoupling and reduced
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mitochondrial oxidative stress (Mollica et al., 2009). The aforementioned beneficial effects of T2 are reminiscent of those caused by physical exercise
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which renders this thyroid hormone metabolite a potential exercise mimetic (see, for review, Jaspers et al., 2016). The above results were confirmed in animals fed a standard laboratory diet and
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prolonged treatment duration (Padron et al., 2014). Of note, in this last study, TSH levels remained normal in rats receiving 25 µg of T2/100 g BW but were slightly lower in rats that received 50 and 75 µg of T2/100 g BW (Padron et al., 2014). At the dose of 75 µg of T2/100 g BW no changes in heart mass but, due to a decrease of body mass, an increase in the relative heart mass (g heart/100 g BW) was observed (Padron et al., 2014). Administration of T2 to rats fed a HFD rapidly (within 6 h) increased hepatic fatty acid oxidation via sirtuin 1 activation leading to deacetylation of peroxisome proliferator activated receptor α 5
ACCEPTED MANUSCRIPT coactivator-1α and sterol receptor element binding protein-1c and, thus, to induction and reduction of expression of genes involved in fatty acid oxidation and lipogenesis, respectively (de Lange et al., 2011). By a proteomic analysis it has been shown that mitochondria are the principal target of T2 with Blue Native-page (BN-PAGE) analysis revealing that T2 partially restored respiratory
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complex I and II levels affected by the HFD (Silvestri et al., 2010, 2014). Additionally, BN-PAGEbased histochemical in-gel measurements showed increased activities of all respiratory complexes affected by HFD (except complex V) and in chow fed animals [except complex IV] in response to
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T2 (Silvestri et al., 2010).
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On the other hand, T2 administration to Sprague Dawley rats fed a safflower-oil based HFD, failed to improve non-alcoholic fatty liver disease (NAFLD) producing only a trend (not significant) to ameliorate whole body insulin sensitivity (Vatner et al., 2015). The contrast with previous data, however, might only be apparent due to the differences in diet-fatty acids composition (i.e. unsaturated fat-predominant plant oil vs. saturated fat-predominant animal fat), to housing
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temperature (i.e. 22°C vs. 28°C) and to strain-specific differences in metabolic features, such as lipoprotein metabolism (Galan et al., 1994).
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T2 rapidly (within 1 h) affects mitochondrial F(o)F (1)-ATP synthase synthetic and hydrolytic activity in the liver of hypothyroid rats (Cavallo et al., 2011). This effect, being associated with no
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change in F(o)F (1)-ATP synthase β-subunit mRNA accumulation or α-β subunit protein amounts, indicates a direct T2 effect which, as suggested by the authors, may depend on an increase in the level of mitochondrial cardiolipin (CL) and decreased CL peroxidation (Cavallo et al., 2011). When chronically injecting hypothyroid rats with T2, upregulated protein levels of ATP synthase subunits were detected by Mangiullo et al. (2010) who suggested that activation of the transcription of αsubunit of GA-binding protein/nuclear respiratory factor-2 by T2 may be the mediator of the T2transcriptional activity (Mangiullo et al., 2010). These data, as a whole, demonstrate that depending on the dose of T2 administered, treatment schedule, and animal model utilized, several end-points 6
ACCEPTED MANUSCRIPT have been reached concerning the effects of T2, which likely occurred via different mechanisms (described below).
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In vitro studies Several in vitro studies have investigated whether T2 directly acts on the liver apart from endocrine and/or metabolic pathway involvement by exposing primary rat hepatocytes to a mixture of oleate/palmitate (fatty hepatocytes) and treating them with T2 (10-5 M) (Grasselli et al., 2011a). In
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such conditions, T2 reduced lipid droplets and down-regulated the expression of adipose-
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differentiation-related protein, peroxisome proliferator-activated receptor γ, acyl-coenzyme A oxidase, Cu/Zn superoxide dismutase as well as catalase activities. More recently, T2 has been shown to reduce lipid excess in fatty hepatocytes by recruiting triglyceride lipase (ATGL) on the LD surface and to modulate the LD-associated proteins Rab18 and TIP47. ATGL recruitment is followed by up-regulation of carnitin palmitoyl-transferase (CPT1) expression and stimulation of
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COX activity, indexes of mitochondrial functions (Grasselli et al., 2016). T2 also reduces lipid content and triggers phosphorylation of Akt in an insulin receptor-independent manner when
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incubated with NAFLD-like rat primary hepatocytes (Gnocchi et al., 2014). Rat hepatoma cell lines (FAO), defective for functional TRs, when exposed to an oleate/palmitate (2:1 ratio) mixture and
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treated with T2 (doses of 10-7-10-5M for 24h) showed reduced TG content, reduced number and size of LDs, down-regulated expression of PPARα and PPAR-γ, and stimulated mitochondrial uncoupling (Grasselli et al., 2011b). Hence, these results suggest that the lipid-lowering actions of T2 occur through “non-receptor-mediated” mechanisms and involve short-term action through stimulation of mitochondrial uncoupled respiratory activity (Grasselli et al., 2011b). In HepG2 cells, T2 blocks the proteolytic cleavage of SREBP-1 without affecting its expression at the transcriptional or translational level, thus reducing fatty acid synthase expression (Rochira et al., 2013); this effect is dependent on the concurrent activation of MAPK, ERK, and p38 and Akt and
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ACCEPTED MANUSCRIPT PKC-δ pathways (Rochira et al., 2013). T2 acts very rapidly also in avian cells during differentiation and fetal development (Incerpi et al., 2002; Alisi et al., 2004; Incerpi et al., 2005), by affecting the Na+/H+-exchanger and the amino acid transport through a signal transduction pathway involving protein kinase C, the mitogen-activated protein kinase pathway, and phosphatidylinositol-
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3-kinase (Incerpi et al., 2002). Moreover, T2, via activation of protein kinases A and C and phosphatidylinositol-3-kinase, inhibits the Na+/K+-ATPase (Scapin et al., 2009). In addition, in pituitary GH3 cells, T2 rapidly affects intracellular Ca2+ and NO via plasma membrane and
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mitochondrial pathways and by interacting with different mitochondrial complexes activates the
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mitochondrial Na+/Ca2+-exchanger (Del Viscovo et al., 2012).
Biological effects in non-mammalian species
Interestingly, T2 also rapidly influences mitochondrial activities in liver and muscle from various
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non-terrestrial vertebrates. Within 5 min after incubation with T2 (0.3 nM), an increase in mitochondrial respiration has been shown in liver and muscle from the goldfish Carassius auratus (Leary et al., 1996). Short-term effects of T4, T3, and T2 exposure (0.1 µM for 12 or 24 h) on
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deiodinase1 and deiodinase 2 activities and mRNA in killifish liver have been examined as well (Garcia et al., 2004). Although none of these iodothyronines (T2-T4) had any effect on deiodinase 1
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activity, they were all found to decrease deiodinase 2 activity, with T2 effects being evident after 12-h, and T4 and T3 effects manifesting after 24 h. T2 was also shown to regulate thermal acclimation in zebrafish (Danio renio) with an efficiency comparable to T3 (Little et al., 2013). In tilapia, T2 has been shown to be an alternative ligand for the so called “long” TRβ1 isoform (containing a 9-amino-acid insert in its ligand-binding domain) present in this species, isoform that, interestingly, in the liver, is the predominant one (i.e. it has been estimated that the expression level of the long TRβ1 is 106-fold higher than that of short TRβ1) (Mendoza et al., 2013). From the functional point of view, it has been demonstrated that T2, in vivo, negatively modulates the 8
ACCEPTED MANUSCRIPT expression of this long TRβ1 isoform (Mendoza et al., 2013; Hernández-Puga et al., 2016) and through its binding and transactivation stimulates tilapia growth (Navarrete-Ramirez et al., 2014).
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Mechanism of action Based on reports available to date, it is unlikely that TH receptor (TR) activation represents a central mechanism in T2’s effects on metabolism, at least at low concentrations and when the effects are rapid. Evidence supporting this notion comes from the rapid time-course of some T2
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effects (likely precluding transcription and protein synthesis), as well as from its utilization of
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mitochondria and plasma membrane signalling pathways, lack of dependence on the presence of nuclear TRs, and structure-activity correlations that are different from those observed for nuclear TRs (for review see Davis et al., 2016 and references therein). Indeed, Va subunit of the COX complex is a binding site for T2 (Goglia et al., 1994; Arnold et al., 1998) which accounts for the rapid stimulatory effects of T2 of the mitochondrial activity (Kadenbach et al., 2000). Moreover,
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results obtained with FAO cells support the concept that the actions of T2 in these cells are independent of transcriptionally functional TRs (Grasselli et al., 2011b). However, at higher doses
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and when administered for longer time periods, it is not possible to exclude TRs as mediators of some T2’s considering that, although significantly lower than that of T3, an affinity of T2 for TRβ
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has been measured in cells and tissues (Leeson et al., 1988; Ball et al., 1997). As stated above, data from tilapia showed that T2’s effects may be mediated by the long TRβ1 isoform (Mendoza et al., 2013; Navarrete-Ramirez et al., 2014; Hernández-Puga et al., 2016) and that the T2-induced downregulation of the long TRβ1 prevents the effect of cortisol to increase the expression of the receptor isoform (Hernández-Puga et al., 2016). However, T2 shows a weaker
affinity for the human TRβ isoform [about 40-fold less than T3] (Mendoza et al., 2013) and as well as a weak transactivation capacity relative to T3 (Ball et al.,1997; Mendoza et al., 2013; de Lange et al., 2011). 9
ACCEPTED MANUSCRIPT Of note, a study in the eighties had previously reported hepatic nuclei of human, rat, chick embryo, amphibian larva, and salmon to have similar affinities for THs and similar relative affinities for several thyroid hormone analogues, including, among the other, T2, thus suggesting that the TR
recent advance in the field do not confirm such a conclusion.
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molecule has been highly conserved during evolution (Darling et al., 1982). As discussed above,
Thus, with T2 displaying a broad spectrum of mechanisms involving classical interaction with TR and rapid effects at the cell membrane and mitochondria, it is possible that T2 effects may be
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dependent upon various experimental factors among which, at least in animals, i) mode of
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administration (e.g. oral, i.p., s.c., gavage); ii) duration of treatment; iii) dosage; iv) age; and v) differences in strains and distinct composition of diets (de Lange et al., 2011; Lanni et al., 2005; Moreno et al., 2011; Ball et al.,1997; Baur et al., 1997; Horst et al., 1995; Garcia et al., 2007, 2009; Kvetny, 1992; Mendoza et al., 2013; Vatner et al., 2015). Few studies in mice using unusually high doses of T2 have indicated that T2 might have thyrotoxic effects (Goldberg et al., 2012; Jonas et al.,
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2014; da Silva Teixeira et al., 2016), likely due to unspecific interaction of T2 with TRs. Beneficial effects on body fat mass, serum leptin, and energy expenditure have been reported when T2 is
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administrated daily (at the dose of 250 µg/100g BW for 14 or 28 days i.p.) to diet-induced obese male mice (Jonas et al., 2015), an effect comparable with that showed in rats (for review, see
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Coppola et al., 2014). However, data on mice suggest a risk of toxic side-effects of the very high doses of T2 used (Jonas et al., 2015). T2 is effective in reducing cholesterol in Western type diet fed low-density lipoprotein receptor (Ldlr) knockout mice by reducing the liver level of apoB and circulating levels of both apoB48 and apoB100 (Goldberg et al., 2012; Moreno et al., 2016). T2, at the high dose used (1.25 mg/100 g BW via daily gavage), dramatically reduced circulating total and LDL cholesterol (-70% vs. controls), but at the same time, reduced plasma T4 levels. At the same dose, T2, while decreasing body weight and blood glucose levels, has been shown to produce signs of thyrotoxicosis also when injected in obese mice (da Silva Teixeira et al., 2016).
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ACCEPTED MANUSCRIPT These data as a whole might suggest that the species, among the others, can be an important factor in defining the differential effects of T2, a signalling molecule that during the evolution may have acquired as well as lost metabolic functions. Indeed, it must be taken into consideration that when comparing results obtained in different animal models (i.e. rat vs. mouse), the sign and the entity of
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the effects elicited by T2 may depend on other factors such as body size and composition, surface
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area/volume ratio as well as basal metabolic rate and, not last, housing temperature.
Conclusion and Perspectives
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Thirty years of research using mammalian and non-mammalian in vivo and in vitro models has generated substantial data on the effects and mechanisms of T2 action clearly indicating the existence of a new level in the TH signaling cascade. Moreover, the discovery that TH metabolites exert biological actions, together with the identification of several non-nuclear TH binding sites,
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have led to a reinterpretation of traditional assumptions about the TH mechanisms of action mediated by altered gene expression. Currently, several mechanisms are thought to be mediated by direct, non-genomic mechanisms involving cellular compartments other than the nucleus and
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occurring generally more rapidly (short-term) than those mediated by genomic/nuclear mechanisms
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(long-term). Actually, this scenario is much more complicated when considering the paradigm of the overlapping non-genomic and genomic mechanisms of action, so that short-term-activated signalling pathways still may play a role in the regulation of downstream genomic effects (Davis et al., 2016) as well as genomic actions may occur rapidly (Seeling et al., 1982). Notably, evidence of mitochondrial regulation by TH’s via short- and long-term mechanisms, rather than exclusive dependence on synthesis of new mitochondrial components, has led to the idea that TH’s regulate sudden physiological changes in energy requirements via short-term mechanisms and prolonged stimuli (such as long periods of cold exposure or changes in diet or development) via long-term mechanisms. In this view, the effects of T2 make it a peripheral mediator of THs’ rapid 11
ACCEPTED MANUSCRIPT effects on energy metabolism, with the mitochondrial compartment being the principal target. This new information serves to further our understanding of the functional relevance of T2 bioactivity and its role in thyroid endocrinology. However, considering the need for larger cohorts to test the time of use- and dose-dependent actions, undesirable side effects cannot be a priori excluded for
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long-term treatments and at high doses, which is of relevance in order to translate results obtained
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in animal models to humans.
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ACCEPTED MANUSCRIPT References Al-Adsani, H., Hoffer, L.J., Silva, J.E., 1997. Resting energy expenditure is sensitive to small dose changes in patients on chronic thyroid hormone replacement. J. Clin. Endocrinol. Metab. 82,1118– 1125.
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Alisi, A., Spagnuolo, S., Napoletano, S., Spaziani, A., Leoni, S., 2004. Thyroid hormones regulate DNA-synthesis and cell-cycle proteins by activation of PKCalpha and p42/44 MAPK in chick embryo hepatocytes. J. Cellular Physiol. 201, 259-265.
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Arnold, S., Goglia, F., Kadenbach, B., 1998. 3,5-Diiodothyronine binds to subunit Va of cytochrome-c oxidase and abolishes the allosteric inhibition of respiration by ATP. Eur. J. Biochem. 252, 325-330.
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Ball, S., Sokolov, J., Chin, W., 1997. 3,5-Diiodo-L-thyronine (T2) has selective thyromimetic effects in vivo and in vitro. J. Mol. Endocrinol. 19, 137–147. Baur, A., Bauer, K., Jarry H., Köhrle J., 1997. 3,5-Diiodo-L-thyronine stimulates type 1 5′ deiodinase activity in rat anterior pituitaries in vivo and in reaggregate cultures and GH3 cells in vitro. Endocrinol. 138, 3242–3248. Brent, G.A., 2012. Mechanisms of thyroid hormone action. J. Clin. Invest. 122, 3035–3043.
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Cavallo, A., Priore, P., Gnoni, G.V., Papa, S., Zanotti, F., Gnoni, A., 2013. 3,5-Diiodo-L-thyronine administration to hypothyroid rats rapidly enhances fatty acid oxidation rate and bioenergetic parameters in liver cells. PLoS One. 8, e52328. Coppola, M., Glinni, D., Moreno, M., Cioffi, F., Silvestri, E., Goglia, F. 2014. Thyroid hormone
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analogues and derivatives: Actions in fatty liver. World J. Hepatol. 6, 114-129.
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Cheng, S.Y., Leonard, J.L., Davis, P.J., 2010. Molecular aspects of thyroid hormone actions. Endocr. Rev. 31, 139–170.
da Silva Teixeira, S., Filgueira, C., Sieglaff, DH., Benod, C., Villagomez, R., Minze, LJ., Zhang, A., Webb, P., Nunes, MT. 2016. 3,5-diiodothyronine (3,5-T2) reduces blood glucose independently of insulin sensitization in obese mice. Acta Physiol (Oxf). doi: 10.1111/apha.12821
Danforth, E. Jr., Burger, A., 1984. The role of thyroid hormones in the control of energy expenditure. Clin. Endocrinol. Metab. 13, 581–595. Davis, P.J., Goglia, F., Leonard, J.L., 2016. Nongenomic actions of thyroid hormone. Nat. Rev. Endocrinol. 12, 111-121.
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De Angelis, M., Giesert, F., Finan, B., Clemmensen, C., Müller, T., Vogt-Weisenhorn, D., Tschöp, M.H., Schramm, K.W., 2016. Determination of thyroid hormones in mouse tissues by isotopedilution microflow liquid chromatography-mass spectrometry method. J Chromatogr B Analyt Technol Biomed Life Sci. 1033-1034, 413-420.
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de Lange, P., Cioffi, F., Senese, R., Moreno, M., Lombardi, A., Silvestri, E., De Matteis, R., Lionetti, L., Mollica, M.P., Goglia, F., Lanni, A., 2011. Nonthyrotoxic prevention of diet-induced insulin resistance by 3,5-diiodo-L-thyronine in rats. Diabetes. 60, 2730–2739.
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Del Viscovo, A., Secondo, A., Esposito, A., Goglia, F., Moreno, M., Canzoniero, L.M., 2012. Intracellular and plasma membrane-initiated pathways involved in the [Ca2+]i elevations induced by iodothyronines (T3 and T2) in pituitary GH3 cells. Am. J. Physiol. Endocrinol. Metab. 302, E1419–1430. Dietrich, J.W., Müller, P., Schiedat, F., Schlömicher, M., Strauch, J., Chatzitomaris, A., Klein,
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H.H., Mügge, A., Köhrle, J., Rijntjes, E., Lehmphul, I. 2015. Nonthyroidal Illness Syndrome in Cardiac Illness Involves Elevated Concentrations of 3,5-Diiodothyronine and Correlates with Atrial Remodeling. Eur. Thyroid J. 4, 129-137.
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Fox, C.S., Pencina, M.J., D'Agostino, R.B., Murabito, J.M., Seely, E.W., Pearce, E.N., Vasan, R.S., 2008. Relations of thyroid function to body weight: cross-sectional and longitudinal observations in a community-based sample. Arch. Intern. Med. 168, 587–592. García, G.C., Jeziorski, M.C., Valverde, R.C., Orozco, A., 2004. Effects of iodothyronines on the hepatic outer-ring deiodinating pathway in killifish. Gen. Comp. Endocrinol. 135, 201-209.
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Garcia, G.C., Lopez-Bojorquez, L., Nunez, J., Valverde, R.C., Orozco, A., 2007. 3,5Diiodothyronine in vivo maintains euthyroidal expression of type 2 iodothyronine deiodinase, growth hormone, and thyroid hormone receptor beta1 in the killifish. Am. J. Physiol. Regul. Integr. Comp. Physiol. 293, R877–883. Gnocchi D, Steffensen KR, Bruscalupi G, Parini P. 2016. Emerging role of thyroid hormone metabolites. Acta Physiol (Oxf). 217, 184-216.
Goglia, F., Torresani, J., Bugli, P., Barletta, A., Liverini, G., 1981, In vitro binding of triiodothyronine to rat liver mitochondria. Pflugers Arch. 390, 120-124. Goglia, F., Lanni, A., Barth, J., Kadenbach, B., 1994. Interaction of diiodothyronines with isolated cytochrome c oxidase. FEBS Lett. 346, 295-298. Goglia, F., 2005. Biological effects of 3,5-diiodothyronine (T2). Biochemistry (Moscow). 70, 164172. 14
ACCEPTED MANUSCRIPT Goglia, F., 2015. The effects of 3,5-diiodothyronine on energy balance. Front. Physiol. 5, 528. Goldberg, I.J., Huang, L.S., Huggins, L.A., Yu, S., Nagareddy, P.R., Scanlan, T.S., Ehrenkranz, J.R., 2012. Thyroid hormone reduces cholesterol via a non-LDL receptor-mediated pathway. Endocrinol. 153, 5143-5149.
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Grais IM, Sowers JR. 2014. Thyroid and the heart. Am. J. Med. 127, 691-698. Grasselli, E., Voci, A., Canesi, L., De Matteis, R., Goglia, F., Cioffi, F., Fugassa, E., Gallo, G., Vergani, L., 2011. Direct effects of iodothyronines on excess fat storage in rat hepatocytes. J. Hepatol. 54, 1230-1236.
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Grasselli, E., Voci, A., Canesi, L., Goglia, F., Ravera, S., Panfoli, I., Gallo, G., Vergani, L., 2011. Non-receptor-mediated actions are responsible for the lipid-lowering effects of iodothyronines in FaO rat hepatoma cells. J. Endocrinol. 21, 59-69.
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Grasselli, E., Voci, A., Demori, I., Vecchione, G., Compalati, A.D., Gallo, G., Goglia, F., De Matteis, R., Silvestri, E., Vergani, L., 2016. Triglyceride Mobilization from Lipid Droplets Sustains the Anti-Steatotic Action of Iodothyronines in Cultured Rat Hepatocytes. Front. Physiol. 6, 418.
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Hansen, M., Luong, X., Sedlak, D.L., Helbing, C.C., Hayes, T., 2016. Quantification of 11 thyroid hormones and associated metabolites in blood using isotope-dilution liquid chromatography tandem mass spectrometry. Anal Bioanal Chem. 408, 5429-5442.
EP
Hantson, A.L., De Meyer, M., Guérit, N. 2004. Simultaneous determination of endogenous and 13C-labelled thyroid hormones in plasma by stable isotope dilution mass spectrometry. J. Chromatogr. B Analyt .Technol. Biomed. Life Sci. 807, 185-192.
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Hernández-Puga, G., Navarrete-Ramírez, P., Mendoza, A., Olvera, A.,Villalobos, P., Orozco, A. 2016. 3,5-Diiodothyronine-mediated transrepression of the thyroid hormone receptor beta gene in tilapia. Insights on cross-talk between the thyroid hormone and cortisol signaling pathways. Mol. Cell. Endocrinol. 425, 103-110. Hopley, C.J., Stokes, P., Webb, K.S., Baynham, M. 2004. The analysis of thyroxine in human serum by an ‘exact matching’ isotope dilution method with liquid chromatography/tandem mass spectrometry. Rapid. Commun. Mass Spectrom. 18, 1033-1038. Horst, C., Rokos, H., Seitz, H.J., 1989. Rapid stimulation of hepatic oxygen consumption by 3,5-diiodo-L-thyronine. Biochem. J. 261, 945-950. Horst, C., Harneit, A., Seitz, H.J., Rokos, H., 1995. 3,5-Di-iodo-L-thyronine suppresses TSH in rats in vivo and in rat pituitary fragments in vitro. J. Endocrinol. 145, 291–297. Incerpi, S., De Vito, P., Luly, P., Spagnuolo, S., Leoni, S., 2002. Short-term effects of thyroid hormones and 3,5-diiodothyronine on membrane transport systems in chick embryo hepatocytes. Endocrinol. 143, 1660-1668. 15
ACCEPTED MANUSCRIPT Incerpi, S., Scapin, S., D'Arezzo, S., Spagnuolo, S., Leoni, S., 2005. Short-term effects of thyroid hormone in prenatal development and cell differentiation. Steroids 70, 434-443. Iwen, K.A., Schroder, E., Brabant, G., 2013. Thyroid hormone and the metabolic syndrome. Eur. Thyroid. J. 2, 83–92.
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Jaspers, R.T., Zillikens, M.C., Friesema, E.C., delli Paoli, G.D., Bloch, W., Uitterlinden, A.G., Goglia, F., Lanni, A., de Lange, P., 2016. Exercise, fasting, and mimetics: toward beneficial combinations? FASEB J. pii: fj.201600652R.
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Johannsen, D.L., Galgani, J.E., Johannsen, N.M., Zhang, Z., Covington, J.D., Ravussin, E. 2012 Effect of short-term thyroxine administration on energy metabolism and mitochondrial efficiency in humans. PLoS One. 7:e40837.
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Johnstone, A.M., Murison, S.D., Duncan, J.S., Rance, K.A., Speakman, J.R., 2005. Factors influencing variation in basal metabolic rate include fat-free mass, fat mass, age, and circulating thyroxine but not sex, circulating leptin, or triiodothyronine. Am. J. Clin. Nutr. 82, 941–948. Jonas, W., Lietzow, J., Wohlgemuth, F., Hoefig, C.S., Wiedmer, P., Schweizer, U., Köhrle, J., Schürmann, A., 2015. 3,5-Diiodo-L-thyronine (3,5-T2) exerts thyromimetic effects on hypothalamus-pituitary-thyroid axis, body composition, and energy metabolism in male dietinduced obese mice. Endocrinol. 156, 389-399.
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Kadenbach, B., Hüttemann, M., Arnold, S., Lee, I., Bender, E., 2000. Mitochondrial energy metabolism is regulated via nuclear-coded subunits of cytochrome c oxidase. Free Radic. Biol. Med. 29, 211–221.
EP
Kim, B., 2008. Thyroid hormone as a determinant of energy expenditure and the basal metabolic rate. Thyroid 18, 141–144. Klein, I., Ojamaa, K. 2001. Thyroid hormone and the cardiovascular system. N. Engl. J. Med. 344, 501-509.
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Knudsen, N., Laurberg, P., Rasmussen, L.B., Bulow, I., Perrild, H., Ovesen, L., Jorgensen, T., 2005. Small differences in thyroid function may be important for body mass index and the occurrence of obesity in the population. J. Clin. Endocrinol. Metab. 90, 4019–4024. Köhrle, J., Martin, C., Renko, K., Hoefig, C.S. 2013. Simultaneous analysis of all nine possible iodothyronines by liquid chromatography-tandem mass spectrometry. In: Smit J, Visser T, editors. 37th Annual Meeting of European Thyroid Association; 2013 Sep 7-11; Leiden, The Netherlands. Basel, Reinhhardt Druck: Karger, 2013: P241 p.176
Kvetny, J., 1992. 3,5-T2 stimulates oxygen consumption, but not glucose uptake in human mononuclear blood cells. Horm. Metab. Res. 24, 322–325.
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ACCEPTED MANUSCRIPT Lanni, A., Moreno, M., Cioffi, M., Goglia, F., 1992. Effect of 3,3'-diiodothyronine and 3,5diiodothyronine on rat liver oxidative capacity. Mol. Cell. Endocrinol. 86, 143-148. Lanni, A., Moreno, M., Cioffi, M., Goglia, F., 1993. Effect of 3,3'-di-iodothyronine and 3,5-diiodothyronine on rat liver mitochondria. J. Endocrinol. 136, 59-64.
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Lanni, A., Moreno, M., Horst, C., Lombardi, A., Goglia, F., 1994. Specific binding sites for 3,3'diiodo-L-thyronine (3,3'-T2) in rat liver mitochondria. FEBS Lett. 351, 237-240. Lanni, A., Moreno, M., Lombardi, A., Goglia, F., 1996. Calorigenic effect of diiodothyronines in the rat. J. Physiol. 494, 831-837.
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Lanni, A., Moreno, M., Lombardi, A., Goglia, F., 1998. 3,5-Diiodo-L-thyronine and 3,5,3'-triiodoL-thyronine both improve the cold tolerance of hypothyroid rats, but possibly via different mechanisms. Pflug. Archiv. Eur. J. Physiol. 436, 407-414.
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Lanni, A., Moreno, M., Lombardi, A., de Lange, P., Silvestri, E., Ragni, M., Farina, P., Baccari Chieffi, G., Fallahi, P., Antonelli, A., Goglia, F., 2005. 3,5-Diiodo-L-thyronine powerfully reduces adiposity in rats by increasing the burning of fats. FASEB J. 19,1552–1554. Leary, S.C., Barton, K.N., Ballantyne, J.S., 1996. Direct effects of 3,5,3'-triiodothyronine and 3,5diiodothyronine on mitochondrial metabolism in the goldfish Carassius auratus. Gen. Comp. Endocrinol. 104, 61-66.
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Leeson, P.D., Ellis, D., Emmett, J.C., Shah, V.P., Showell, G.A., Underwood, AH., 1988. Thyroid hormone analogues. Synthesis of 3'-substituted 3,5-diiodo-L-thyronines and quantitative structureactivity studies of in vitro and in vivo thyromimetic activities in rat liver and heart. J. Med. Chem. 31, 37-54.
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Lehmphul,I., Brabant, G., Wallaschofski, H., Ruchala, M., Strasburger, C.J., Köhrle, J., Wu, Z., 2014. Detection of 3,5-diiodothyronine in sera of patients with altered thyroid status using a new monoclonal antibody-based chemiluminescence immunoassay. Thyroid. 24, 1350-1360.
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Little, A.G., Kunisue, T., Kannan, K., Seebacher, F., 2013. Thyroid hormone actions are temperature-specific and regulate thermal acclimation in zebrafish (Danio rerio). BMC Biology 26, 11-26. Lombardi, A., Lanni, A., Moreno, M., Brand, M.D., Goglia, F., 1998. Effect of 3,5-di-iodo-Lthyronine on the mitochondrial energy-transduction apparatus. Biochem. J. 330, 521-526. Lombardi, A., Lanni, A., de Lange, P., Silvestri, E., Grasso, P., Senese, R., Goglia, F., Moreno, M., 2007. Acute administration of 3,5-diiodo-L-thyronine to hypothyroid rats affects bioenergetic parameters in rat skeletal muscle mitochondria. FEBS Lett. 581, 5911-5916. Lombardi, A., de Lange, P., Silvestri, E., Busiello, R.A., Lanni, A., Goglia, F., Moreno, M. 2009. 3,5-Diiodo-L-thyronine rapidly enhances mitochondrial fatty acid oxidation rate and thermogenesis in rat skeletal muscle: AMP-activated protein kinase involvement. Am. J. Physiol. Endocrinol. Metab. 296, E497-502.
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ACCEPTED MANUSCRIPT Lombardi, A., De Matteis, R., Moreno, M., Napolitano, L., Busiello, R.A., Senese, R., de Lange, P., Lanni, A., Goglia, F., 2012. Responses of skeletal muscle lipid metabolism in rat gastrocnemius to hypothyroidism and iodothyronine administration: a putative role for FAT/CD36. Am. J. Physiol. Endocrinol. Metab. 303, E1222-1233.
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Lombardi, A., Moreno, M., de Lange, P., Iossa, S., Busiello, R.A., Goglia, F., 2015. Regulation of skeletal muscle mitochondrial activity by thyroid hormones: focus on the "old" triiodothyronine and the "emerging" 3,5-diiodothyronine. Front. Physiol. 6, 237.
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Mangiullo, R., Gnoni, A., Damiano, F., Siculella, L., Zanotti, F., Papa, S., Gnoni, G.V., 2010. 3,5diiodo-L-thyronine upregulates rat-liver mitochondrial F(o)F(1)-ATP synthase by GA-binding protein/nuclear respiratory factor-2. Biochim. Biophys. Acta 1797, 233-240.
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Mendoza, A., Navarrete-Ramirez, P., Hernandez-Puga, G., Villalobos, P., Holzer, G., Renaud, J.P., Laudet, V., Orozco, A., 2013. 3,5-T2 is an alternative ligand for the thyroid hormone receptor beta1. Endocrinol. 154, 2948–2958. Mollica, M.P., Lionetti, L., Moreno, M., Lombardi, A., de Lange, P., Antonelli, A., Lanni, A., Cavaliere, G., Barletta, A., Goglia, F., 2009. 3,5-diiodo-L-thyronine, by modulating mitochondrial functions, reverses hepatic fat accumulation in rats fed a high-fat diet. J. Hepatol. 51, 363–370. Moreno, M., Lanni, A., Lombardi, A., Goglia, F., 1997. How the thyroid controls metabolism in the rat: different roles for triiodothyronine and diiodothyronines. J. Physiol. 505, 529-538.
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Moreno, M., Lombardi, A., Beneduce, L., Silvestri, E., Pinna, G., Goglia, F., Lanni, A., 2002. Are the effects of T3 on resting metabolic rate in euthyroid rats entirely caused by T3 itself? Endocrinol. 143, 504–510.
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Moreno, M., de Lange, P., Lombardi, A., Silvestri, E., Lanni, A., Goglia, F., 2008. Metabolic effects of thyroid hormone derivatives. Thyroid. 18, 239-253.
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Moreno, M., Silvestri, E., De Matteis, R., de Lange, P., Lombardi, A., Glinni, D., Senese, R., Cioffi, F., Salzano, A.M., Scaloni, A., Lanni, A., Goglia, F., 2011. 3,5-Diiodo-L-thyronine prevents highfat-diet-induced insulin resistance in rat skeletal muscle through metabolic and structural adaptations. FASEB J. 25, 3312–3324. Moreno, M., Silvestri, E., Coppola, M., Goldberg, I.J., Huang, L.S., Salzano, A.M., D'Angelo, F., Ehrenkranz, J.R., Goglia, F., 2016 3,5,3'-Triiodo-L-Thyronine- and 3,5-Diiodo-L-ThyronineAffected Metabolic Pathways in Liver of LDL Receptor Deficient Mice. Frontiers Physiology; 7:545.
Navarrete-Ramírez, P., Luna, M., Valverde, R.C., Orozco, A. 2014. 3,5-di-iodothyronine stimulates tilapia growth through an alternate isoform of thyroid hormone receptor β1. J. Mol. Endocrinol. 52, 1-9. Padron, A.S., Neto, R.A., Pantaleão, T.U., de Souza dos Santos, M.C., Araujo, R.L., de Andrade, B.M., da Silva Leandro, M., de Castro, J.P., Ferreira, A.C., de Carvalho, D.P. 2014. Administration 18
ACCEPTED MANUSCRIPT of 3,5-diiodothyronine (3,5-T2) causes central hypothyroidism and stimulates thyroid-sensitive tissues. J. Endocrinol. 221, 415–427. Pietzner, M., Lehmphul, I., Friedrich, N., Schurmann, C., Ittermann, T., Dörr, M., Nauck, M., Laqua, R., Völker, U., Brabant, G., Völzke, H., Köhrle, J., Homuth, G., Wallaschofski, H. 2015. Translating pharmacological findings from hypothyroid rodents to euthyroid humans: is there a
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functional role of endogenous 3,5-T2? Thyroid. 25, 188-197.
Pietzner, M., Homuth, G., Budde, K., Lehmphul, I., Völker, U., Völzke, H., Nauck, M., Köhrle, J., Friedrich, N. 2015. Urine Metabolomics by (1) H-NMR Spectroscopy Indicates Associations
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between Serum 3,5-T2 Concentrations and Intermediary Metabolism in Euthyroid Humans. Eur. Thyroid J. 4 (Suppl 1), 92-100.
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Pinna, G., Meinhold, H., Hiedra, L., Thoma, R., Hoell, T., Gräf, K.J., Stoltenburg-Didinger, G., Eravci, M., Prengel, H., Brödel, O., Finke, R., Baumgartner, A., 1997. Elevated 3,5diiodothyronine concentrations in the sera of patients with nonthyroidal illnesses and brain tumors. Clin. Endocrinol. Metab. 82, 1535-1542.
Reinehr, T. 2010 Obesity and thyroid function. Mol. Cell. Endocrinol. 316, 165-171. Rochira, A., Damiano, F., Marsigliante, S., Gnoni, G.V., Siculella, L., 2013. 3,5-Diiodo-l-thyronine
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induces SREBP-1 proteolytic cleavage block and apoptosis in human hepatoma (Hepg2) cells. Biochim. Biophys. Acta. 1831, 1679-1689.
EP
Scapin, S., Leoni, S., Spagnuolo, S., Fiore, A.M., Incerpi, S., 2009. Short-term effects of thyroid hormones on Na+-K+-ATPase activity of chick embryo hepatocytes during development: focus on signal transduction. Am. J. Physiol. Cell Physiol. 296, C4-12.
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Seelig, S., Jump, D.B., Towle, H.C., Liaw, C., Mariash, C.N., Schwartz, H.L., Oppenheimer, J.H. 1982. Paradoxical effects of cycloheximide on the ultra-rapid induction of two hepatic mRNA sequences by triiodothyronine (T3). Endocrinol. 110, 671-673. Senese, R., Cioffi, F., de Lange, P., Goglia, F., Lanni, A., 2014. Thyroid: biological actions of 'nonclassical' thyroid hormones. J. Endocrinol. 221, R1-12. Senese, R., Lasala, P., Leanza, C., de Lange, P., 2014. New avenues for regulation of lipid metabolism by thyroid hormones and analogs. Front Physiol. 5, 475. Silva, J.E., 2003. The thermogenic effect of thyroid hormone and its clinical implications. Ann. Intern. Med. 139, 205–213. Silvestri, E., Cioffi, F., Glinni, D., Ceccarelli, M., Lombardi, A., de Lange, P., Chambery, A., Severino, V., Lanni, A., Goglia, F., Moreno, M., 2010. Pathways affected by 3,5-diiodo-L19
ACCEPTED MANUSCRIPT thyronine in liver of high fat-fed rats: evidence from two-dimensional electrophoresis, blue-native PAGE, and mass spectrometry. Molecular Biosystems 6, 2256-2271. Silvestri, E., Coppola, M., Cioffi, F., Goglia, F., 2014. Proteomic approaches for the study of tissue specific effects of 3,5,3'-triiodo-L-thyronine and 3,5-diiodo-L-thyronine in conditions of altered energy metabolism. Front Physiol. 5, 491.
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Soukhova, N., Soldin, O.P., Soldin, SJ. 2004. Isotope dilution tandem mass spectrometric method for T4/T3. Clin. Chim. Acta 343, 185-190.
SC
Tai, S.S., Bunk, D.M., White, E., Welch, M.J. 2004. Development and evaluation of a reference measurement procedure for the determination of total 3,3’,5-triiodothyronine in human serum using isotope-dilution liquid chromatography-tandem mass spectrometry. Anal. Chem. 76, 5092-5096.
Vaitkus, J.A., Farrar, J.S., Celi, F.S. 2015. Thyroid Hormone Mediated Modulation of Energy
M AN U
Expenditure. Int. J. Mol. Sci. 16, 16158-16175.
Van Uytfanghe, K., Stöckl, D., Thienpont, L.M. 2004. Development of a simplified sample pretreatment procedure as part of an isotope dilution-liquid chromatography/tandem mass spectrometry candidate reference measurement procedure for serum total thyroxine. Rapid.
TE D
Commun. Mass Spectrom. 18, 1539-1540.
Vatner, D.F., Snikeris, J., Popov, V., Perry, R.J., Rahimi, Y., Samuel, V.T. 2015. 3,5 Diiodo-LThyronine (T2) Does Not Prevent Hepatic Steatosis or Insulin Resistance in Fat-Fed Sprague
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Dawley Rats. PLoS One. 10, e0140837.
Zhang, Y., Conrad, A.H., Conrad, G.W. 2005. Detection and quantification of 3,5,3'-
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triiodothyronine and 3,3',5'-triiodothyronine by electrospray ionization tandem mass spectrometry. J. Am. Soc. Mass Spectrom.16, 1781-1786. Zhang, Y., Conrad, A.H., Thoma, R., Conrad,G.W. 2006. Differentiation of diiodothyronines using electrospray ionization tandem mass spectrometry. J. Mass Spectrom. 41. 162-168. Zucchi, R., Accorroni, A., Chiellini, G., 2014. Update on 3-iodothyronamine and its neurological and metabolic actions. Front Physiol. 5, 402.
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"Highlights"
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An overview of direct and rapid effects of 3,5-diiodothyronine is proposed The mechanism relies on regulation of mitochondrial activities 3,5-diiodothyronine plays a role in thyroid endocrinology
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• • •
S0303-7207(17)30092-8
DOI:
10.1016/j.mce.2017.02.012
Reference:
MCE 9839
To appear in:
Molecular and Cellular Endocrinology
Received Date: 18 October 2016 Revised Date:
2 January 2017
Accepted Date: 8 February 2017
Please cite this article as: Moreno, M., Giacco, A., di Munno, C., Goglia, F., Direct and rapid effects of 3,5-diiodo-L-thyronine (T2), Molecular and Cellular Endocrinology (2017), doi: 10.1016/ j.mce.2017.02.012. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Direct and rapid effects of 3,5-diiodo-L-thyronine (T2)
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Maria Moreno, Antonia Giacco, Celia di Munno, Fernando Goglia°
Department of Science and Technologies, University of Sannio, Benevento. Italy
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°Corresponding author
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Email [email protected] Tel. +380824305100
Address: Via Port’Arsa 11, 82100 Benevento. Italy
Key words: 3,5-diiodothyronine; energy metabolism; mitochondria; thyroid hormone action;
ABSTRACT
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metabolic rate; short-term effects.
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A growing number of researchers are focusing their attention on the possibility that thyroid hormone metabolites, particularly 3,5-diiodothyronine (T2), may actively regulate energy
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metabolism at the cellular, rather than the nuclear, level. Due to their biochemical features, mitochondria have been the focus of research on the thermogenic effects of thyroid hormones. Indeed, mitochondrial activities have been shown to be regulated both directly and indirectly by T2specific pathways. Herein, we describe the effects of T2 on energy metabolism.
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ACCEPTED MANUSCRIPT INTRODUCTION Thyroid hormones (THs) have a great impact on many processes that are essential for development and normal growth, as well as energy metabolism in adult (Brent, 2012; Cheng et al., 2010; Davis et
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al., 2016). THs stimulate energy metabolism in most tissues, leading to an increase in basal metabolic rate [minimal rate of energy required for breathing, heart rate, blood circulation, etc.] (Johnstone et al., 2005; Danforth and Burger,1984; Silva 2003). For example, at the heart level, THs induce: a) an increase of the force and the speed of both systolic contraction and diastolic
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relaxation and b) either a decrease of vascular resistance or an increase of coronary arteriolar
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angiogenesis (Klein et al., 2001; Grais and Sowers, 2014). In addition, resting energy expenditure (amount of energy required over a 24-h period by the body at rest) is highly sensitive to THs, especially in athyreotic individuals (Al-Adsani et al., 1997). More recent data further support this idea showing effects of THs in euthyroid subjects both in healthy (Johannsen et al., 2012) and in pathological conditions such as obesity and anorexia (for review, see Reinehr 2010). Although it is
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well established that THs affect energy expenditure (Fox et al., 2008; Iwen et al., 2013; Knudsen et al., 2005), the cellular and molecular events underlying this essential function are not yet
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understood (Kim, 2008; Vaitkus et al., 2015). It is now recognized that other iodothyronines and TH metabolites exert relevant biological actions on energy metabolism (for recent reviews see
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Moreno et al., 2008; Senese et al., 2014a; Senese et al., 2014b; Zucchi et al., 2014; Goglia, 2015; Davis et al., 2016). Among these, an endogenous TH metabolite 3,5-diiodo-L-thyronine (T2) has been shown to exert several metabolic effects. As far as it concerns the process involved in the in vivo production of T2 there is still no knowledge. One in vivo study likely supported the production of T2 from T3 as increased serum and hepatic levels of T2 were detected following T3 injection into euthyroid rats only when all three deiodinase enzymes were not inhibited (Moreno et al., 2002). Serum and hepatic levels of T2 in euthyroid rats have been estimated to be around 5 pM and 1.0 fmol/100 mg, respectively (Moreno et al., 2002). In humans, mean T2 serum levels are estimated to be 16.2 ± 6.4 pM in healthy subjects, 21.6 ± 4.8 pM in patients with brain tumors, and 46.7 ± 48.8 2
ACCEPTED MANUSCRIPT pM in septic patients (Pinna et al., 1997). However, due to several technical problems (i.e. low specific activities of the probes labelled in the inner ring) T2 measurements via these methods have been abandoned. Recent developments and optimization of a chemiluminescent immunoassay (Lehmphul et al., 2014) allowed to obtain new information on T2 levels (Pietzner et al., 2015a,
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Pietzner et al., 2015b, Dietrich et al., 2015). Moreover, mass spectrometry techniques (Hopley et al., 2004; Van Uytfanghe et al., 2004; Soukhova et al., 2004; Tai et al., 2004; Hantson et al., 2004; De Angelis et al., 2016) as well as Electrospray ionization tandem mass spectrometry (ESI-MS/MS)
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has been applied to identify and quantify T3 and T2 isomers (Zhang et al., 2005; Zhang et al., 2006; Hansen et al., 2016). Routine application of these approaches must be implemented (Köhrle et al.,
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2013).
In vivo studies
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Some decades ago, “surprising results” were published showing that, among several iodothyronines tested (i.e., T4 and T3), very low concentrations of T2 (pM range) rapidly stimulated oxygen consumption in perfused livers isolated from hypothyroid rats (Horst et al., 1989). The effects
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exerted by T2 were rapid and cycloheximide-independent, suggesting the nucleus did not contribute (Horst et al., 1989). Although in this study T3 showed a similar effect, which was largely abolished
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by deiodinase 1 inhibition, T2 exerted its effect more rapidly than T3 and independent of deiodinase 1 activity. This strongly indicates that caution should be taken when analysing metabolic data following T3 administration. These results, together with others showing an interaction between T2 and mitochondria (Goglia et al.,1981), have led to the idea that T2 may be able to stimulate cellular respiration via pathways involving mitochondria and bioenergetic mechanisms as major targets. Accordingly, several studies have demonstrated that T2 is able to stimulate mitochondrial respiratory activities (Lanni et al. 1992, 1993, 1994; Goglia, 2005), rapidly and directly stimulate bovine heart-isolated cytochrome c oxidase (COX) activity [barely any detectable stimulation was
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ACCEPTED MANUSCRIPT exerted by T3] (Goglia et al., 1994), and specifically bind the Va subunit of the COX complex, suggesting Va is one mitochondrial site through which T2 directly affects this organelle’s activity (Arnold et al., 1998). Moreover, T2 binding to the COX complex has been shown to abolish allosteric ATP inhibition of COX, thus decreasing the respiratory control ratio of the complex
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(Kadenbach et al., 2000) and consequently leading to heat production (i.e., calorigenic effect). In light of these effects, researchers began investigating whether T2 influences resting metabolic rate (RMR) in vivo employing rats made hypothyroid by simultaneous administration of
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propylthiouracil and iopanoic acid (which results in severe hypothyroidism and inhibition of all the
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deiodinase activities; referred to as P+I). P+I rats injected intraperitoneally with either T2 or T3 showed increased RMR with the time course of T2 effects being more rapid than that of T3 (Moreno et al., 1997). Indeed, T2 increased RMR within 1 h and reached a maximal effect at 30 h; T3 increased RMR at 20 h after injection, reached a peak at 65 h and its effect declined after a week (Moreno et al., 1997). Interestingly, only the T3’s effect on RMR were abolished by
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actinomycin D, leading to the conclusion that the effects of T2 on RMR are independent of de novo transcription. A further study showed that acute injection of T3 had an evident effect on the RMR
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25 h earlier in euthyroid animals (with physiologically active deiodinases) than in P+I rats (Moreno et al., 1997). This effect was accompanied by a later effect (after 24 h) which was abolished by
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actinomycin D. From these studies it was suggested that T2 and T3, via different mechanisms, might cooperate in vivo in the control of RMR. T2’s improved cold tolerance, energy expenditure, and oxidative capacity in cold-exposed P+I rats. While P+I rats survived the cold for 3-4 d, intraperitoneal injection of 10 µg T2/100 g body weight increased survival toward the end of the 3week experiment, with an increased energy expenditure and tissue-specific oxidative capacity (Lanni et al., 1998). A top-down elasticity analysis applied to mitochondria showed that T2 rapidly (i.e.1 h after its injection into euthyroid rats) stimulated the hepatic activity of both cytochrome coxidizing and -reducing components of the respiratory chain, in line with previous evidence of a
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ACCEPTED MANUSCRIPT direct interaction with COX (Lombardi et al., 1998). In addition to liver oxidative capacity, T2 also stimulated skeletal muscle mitochondrial uncoupling (Lombardi et al., 2007, 2009), mitochondrial translocation of the fatty acid transporter CD36 and fatty acid oxidation (Lombardi et al., 2012,
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2015, an effect that may explain, at least in part, the effect of T2 on RMR. Consequent to the above results, many studies have investigated the hypothesis that the T2 could counterbalance weight gain and lipid accumulation. In one rat model of high-fat diet (HFD)-induced lipid accumulation, T2 administration (25 µg/100 g body weight for 4 weeks) was able to prevent
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body weight gain, liver adiposity, hyperlipidemia, and insulin resistance, (Lanni et al. 2005, de
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Lange et al., 2011, Moreno et al., 2011). At this dose-regimen, no signs of thyrotoxicosis (tachycardia, cardiac hyperplasia, and decreased thyroid stimulating hormone levels) were detected (Lanni et al., 2005; de Lange et al., 2011). T2 administrations to HFD-overweight rats were shown to significantly reduce pre-existing hepatic fat accumulation, as well as hyperlipidaemia, through increased hepatic mitochondrial fatty acid oxidation coupled with uncoupling and reduced
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mitochondrial oxidative stress (Mollica et al., 2009). The aforementioned beneficial effects of T2 are reminiscent of those caused by physical exercise
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which renders this thyroid hormone metabolite a potential exercise mimetic (see, for review, Jaspers et al., 2016). The above results were confirmed in animals fed a standard laboratory diet and
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prolonged treatment duration (Padron et al., 2014). Of note, in this last study, TSH levels remained normal in rats receiving 25 µg of T2/100 g BW but were slightly lower in rats that received 50 and 75 µg of T2/100 g BW (Padron et al., 2014). At the dose of 75 µg of T2/100 g BW no changes in heart mass but, due to a decrease of body mass, an increase in the relative heart mass (g heart/100 g BW) was observed (Padron et al., 2014). Administration of T2 to rats fed a HFD rapidly (within 6 h) increased hepatic fatty acid oxidation via sirtuin 1 activation leading to deacetylation of peroxisome proliferator activated receptor α 5
ACCEPTED MANUSCRIPT coactivator-1α and sterol receptor element binding protein-1c and, thus, to induction and reduction of expression of genes involved in fatty acid oxidation and lipogenesis, respectively (de Lange et al., 2011). By a proteomic analysis it has been shown that mitochondria are the principal target of T2 with Blue Native-page (BN-PAGE) analysis revealing that T2 partially restored respiratory
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complex I and II levels affected by the HFD (Silvestri et al., 2010, 2014). Additionally, BN-PAGEbased histochemical in-gel measurements showed increased activities of all respiratory complexes affected by HFD (except complex V) and in chow fed animals [except complex IV] in response to
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T2 (Silvestri et al., 2010).
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On the other hand, T2 administration to Sprague Dawley rats fed a safflower-oil based HFD, failed to improve non-alcoholic fatty liver disease (NAFLD) producing only a trend (not significant) to ameliorate whole body insulin sensitivity (Vatner et al., 2015). The contrast with previous data, however, might only be apparent due to the differences in diet-fatty acids composition (i.e. unsaturated fat-predominant plant oil vs. saturated fat-predominant animal fat), to housing
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temperature (i.e. 22°C vs. 28°C) and to strain-specific differences in metabolic features, such as lipoprotein metabolism (Galan et al., 1994).
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T2 rapidly (within 1 h) affects mitochondrial F(o)F (1)-ATP synthase synthetic and hydrolytic activity in the liver of hypothyroid rats (Cavallo et al., 2011). This effect, being associated with no
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change in F(o)F (1)-ATP synthase β-subunit mRNA accumulation or α-β subunit protein amounts, indicates a direct T2 effect which, as suggested by the authors, may depend on an increase in the level of mitochondrial cardiolipin (CL) and decreased CL peroxidation (Cavallo et al., 2011). When chronically injecting hypothyroid rats with T2, upregulated protein levels of ATP synthase subunits were detected by Mangiullo et al. (2010) who suggested that activation of the transcription of αsubunit of GA-binding protein/nuclear respiratory factor-2 by T2 may be the mediator of the T2transcriptional activity (Mangiullo et al., 2010). These data, as a whole, demonstrate that depending on the dose of T2 administered, treatment schedule, and animal model utilized, several end-points 6
ACCEPTED MANUSCRIPT have been reached concerning the effects of T2, which likely occurred via different mechanisms (described below).
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In vitro studies Several in vitro studies have investigated whether T2 directly acts on the liver apart from endocrine and/or metabolic pathway involvement by exposing primary rat hepatocytes to a mixture of oleate/palmitate (fatty hepatocytes) and treating them with T2 (10-5 M) (Grasselli et al., 2011a). In
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such conditions, T2 reduced lipid droplets and down-regulated the expression of adipose-
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differentiation-related protein, peroxisome proliferator-activated receptor γ, acyl-coenzyme A oxidase, Cu/Zn superoxide dismutase as well as catalase activities. More recently, T2 has been shown to reduce lipid excess in fatty hepatocytes by recruiting triglyceride lipase (ATGL) on the LD surface and to modulate the LD-associated proteins Rab18 and TIP47. ATGL recruitment is followed by up-regulation of carnitin palmitoyl-transferase (CPT1) expression and stimulation of
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COX activity, indexes of mitochondrial functions (Grasselli et al., 2016). T2 also reduces lipid content and triggers phosphorylation of Akt in an insulin receptor-independent manner when
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incubated with NAFLD-like rat primary hepatocytes (Gnocchi et al., 2014). Rat hepatoma cell lines (FAO), defective for functional TRs, when exposed to an oleate/palmitate (2:1 ratio) mixture and
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treated with T2 (doses of 10-7-10-5M for 24h) showed reduced TG content, reduced number and size of LDs, down-regulated expression of PPARα and PPAR-γ, and stimulated mitochondrial uncoupling (Grasselli et al., 2011b). Hence, these results suggest that the lipid-lowering actions of T2 occur through “non-receptor-mediated” mechanisms and involve short-term action through stimulation of mitochondrial uncoupled respiratory activity (Grasselli et al., 2011b). In HepG2 cells, T2 blocks the proteolytic cleavage of SREBP-1 without affecting its expression at the transcriptional or translational level, thus reducing fatty acid synthase expression (Rochira et al., 2013); this effect is dependent on the concurrent activation of MAPK, ERK, and p38 and Akt and
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ACCEPTED MANUSCRIPT PKC-δ pathways (Rochira et al., 2013). T2 acts very rapidly also in avian cells during differentiation and fetal development (Incerpi et al., 2002; Alisi et al., 2004; Incerpi et al., 2005), by affecting the Na+/H+-exchanger and the amino acid transport through a signal transduction pathway involving protein kinase C, the mitogen-activated protein kinase pathway, and phosphatidylinositol-
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3-kinase (Incerpi et al., 2002). Moreover, T2, via activation of protein kinases A and C and phosphatidylinositol-3-kinase, inhibits the Na+/K+-ATPase (Scapin et al., 2009). In addition, in pituitary GH3 cells, T2 rapidly affects intracellular Ca2+ and NO via plasma membrane and
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mitochondrial pathways and by interacting with different mitochondrial complexes activates the
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mitochondrial Na+/Ca2+-exchanger (Del Viscovo et al., 2012).
Biological effects in non-mammalian species
Interestingly, T2 also rapidly influences mitochondrial activities in liver and muscle from various
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non-terrestrial vertebrates. Within 5 min after incubation with T2 (0.3 nM), an increase in mitochondrial respiration has been shown in liver and muscle from the goldfish Carassius auratus (Leary et al., 1996). Short-term effects of T4, T3, and T2 exposure (0.1 µM for 12 or 24 h) on
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deiodinase1 and deiodinase 2 activities and mRNA in killifish liver have been examined as well (Garcia et al., 2004). Although none of these iodothyronines (T2-T4) had any effect on deiodinase 1
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activity, they were all found to decrease deiodinase 2 activity, with T2 effects being evident after 12-h, and T4 and T3 effects manifesting after 24 h. T2 was also shown to regulate thermal acclimation in zebrafish (Danio renio) with an efficiency comparable to T3 (Little et al., 2013). In tilapia, T2 has been shown to be an alternative ligand for the so called “long” TRβ1 isoform (containing a 9-amino-acid insert in its ligand-binding domain) present in this species, isoform that, interestingly, in the liver, is the predominant one (i.e. it has been estimated that the expression level of the long TRβ1 is 106-fold higher than that of short TRβ1) (Mendoza et al., 2013). From the functional point of view, it has been demonstrated that T2, in vivo, negatively modulates the 8
ACCEPTED MANUSCRIPT expression of this long TRβ1 isoform (Mendoza et al., 2013; Hernández-Puga et al., 2016) and through its binding and transactivation stimulates tilapia growth (Navarrete-Ramirez et al., 2014).
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Mechanism of action Based on reports available to date, it is unlikely that TH receptor (TR) activation represents a central mechanism in T2’s effects on metabolism, at least at low concentrations and when the effects are rapid. Evidence supporting this notion comes from the rapid time-course of some T2
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effects (likely precluding transcription and protein synthesis), as well as from its utilization of
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mitochondria and plasma membrane signalling pathways, lack of dependence on the presence of nuclear TRs, and structure-activity correlations that are different from those observed for nuclear TRs (for review see Davis et al., 2016 and references therein). Indeed, Va subunit of the COX complex is a binding site for T2 (Goglia et al., 1994; Arnold et al., 1998) which accounts for the rapid stimulatory effects of T2 of the mitochondrial activity (Kadenbach et al., 2000). Moreover,
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results obtained with FAO cells support the concept that the actions of T2 in these cells are independent of transcriptionally functional TRs (Grasselli et al., 2011b). However, at higher doses
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and when administered for longer time periods, it is not possible to exclude TRs as mediators of some T2’s considering that, although significantly lower than that of T3, an affinity of T2 for TRβ
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has been measured in cells and tissues (Leeson et al., 1988; Ball et al., 1997). As stated above, data from tilapia showed that T2’s effects may be mediated by the long TRβ1 isoform (Mendoza et al., 2013; Navarrete-Ramirez et al., 2014; Hernández-Puga et al., 2016) and that the T2-induced downregulation of the long TRβ1 prevents the effect of cortisol to increase the expression of the receptor isoform (Hernández-Puga et al., 2016). However, T2 shows a weaker
affinity for the human TRβ isoform [about 40-fold less than T3] (Mendoza et al., 2013) and as well as a weak transactivation capacity relative to T3 (Ball et al.,1997; Mendoza et al., 2013; de Lange et al., 2011). 9
ACCEPTED MANUSCRIPT Of note, a study in the eighties had previously reported hepatic nuclei of human, rat, chick embryo, amphibian larva, and salmon to have similar affinities for THs and similar relative affinities for several thyroid hormone analogues, including, among the other, T2, thus suggesting that the TR
recent advance in the field do not confirm such a conclusion.
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molecule has been highly conserved during evolution (Darling et al., 1982). As discussed above,
Thus, with T2 displaying a broad spectrum of mechanisms involving classical interaction with TR and rapid effects at the cell membrane and mitochondria, it is possible that T2 effects may be
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dependent upon various experimental factors among which, at least in animals, i) mode of
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administration (e.g. oral, i.p., s.c., gavage); ii) duration of treatment; iii) dosage; iv) age; and v) differences in strains and distinct composition of diets (de Lange et al., 2011; Lanni et al., 2005; Moreno et al., 2011; Ball et al.,1997; Baur et al., 1997; Horst et al., 1995; Garcia et al., 2007, 2009; Kvetny, 1992; Mendoza et al., 2013; Vatner et al., 2015). Few studies in mice using unusually high doses of T2 have indicated that T2 might have thyrotoxic effects (Goldberg et al., 2012; Jonas et al.,
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2014; da Silva Teixeira et al., 2016), likely due to unspecific interaction of T2 with TRs. Beneficial effects on body fat mass, serum leptin, and energy expenditure have been reported when T2 is
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administrated daily (at the dose of 250 µg/100g BW for 14 or 28 days i.p.) to diet-induced obese male mice (Jonas et al., 2015), an effect comparable with that showed in rats (for review, see
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Coppola et al., 2014). However, data on mice suggest a risk of toxic side-effects of the very high doses of T2 used (Jonas et al., 2015). T2 is effective in reducing cholesterol in Western type diet fed low-density lipoprotein receptor (Ldlr) knockout mice by reducing the liver level of apoB and circulating levels of both apoB48 and apoB100 (Goldberg et al., 2012; Moreno et al., 2016). T2, at the high dose used (1.25 mg/100 g BW via daily gavage), dramatically reduced circulating total and LDL cholesterol (-70% vs. controls), but at the same time, reduced plasma T4 levels. At the same dose, T2, while decreasing body weight and blood glucose levels, has been shown to produce signs of thyrotoxicosis also when injected in obese mice (da Silva Teixeira et al., 2016).
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ACCEPTED MANUSCRIPT These data as a whole might suggest that the species, among the others, can be an important factor in defining the differential effects of T2, a signalling molecule that during the evolution may have acquired as well as lost metabolic functions. Indeed, it must be taken into consideration that when comparing results obtained in different animal models (i.e. rat vs. mouse), the sign and the entity of
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the effects elicited by T2 may depend on other factors such as body size and composition, surface
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area/volume ratio as well as basal metabolic rate and, not last, housing temperature.
Conclusion and Perspectives
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Thirty years of research using mammalian and non-mammalian in vivo and in vitro models has generated substantial data on the effects and mechanisms of T2 action clearly indicating the existence of a new level in the TH signaling cascade. Moreover, the discovery that TH metabolites exert biological actions, together with the identification of several non-nuclear TH binding sites,
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have led to a reinterpretation of traditional assumptions about the TH mechanisms of action mediated by altered gene expression. Currently, several mechanisms are thought to be mediated by direct, non-genomic mechanisms involving cellular compartments other than the nucleus and
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occurring generally more rapidly (short-term) than those mediated by genomic/nuclear mechanisms
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(long-term). Actually, this scenario is much more complicated when considering the paradigm of the overlapping non-genomic and genomic mechanisms of action, so that short-term-activated signalling pathways still may play a role in the regulation of downstream genomic effects (Davis et al., 2016) as well as genomic actions may occur rapidly (Seeling et al., 1982). Notably, evidence of mitochondrial regulation by TH’s via short- and long-term mechanisms, rather than exclusive dependence on synthesis of new mitochondrial components, has led to the idea that TH’s regulate sudden physiological changes in energy requirements via short-term mechanisms and prolonged stimuli (such as long periods of cold exposure or changes in diet or development) via long-term mechanisms. In this view, the effects of T2 make it a peripheral mediator of THs’ rapid 11
ACCEPTED MANUSCRIPT effects on energy metabolism, with the mitochondrial compartment being the principal target. This new information serves to further our understanding of the functional relevance of T2 bioactivity and its role in thyroid endocrinology. However, considering the need for larger cohorts to test the time of use- and dose-dependent actions, undesirable side effects cannot be a priori excluded for
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long-term treatments and at high doses, which is of relevance in order to translate results obtained
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in animal models to humans.
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ACCEPTED MANUSCRIPT References Al-Adsani, H., Hoffer, L.J., Silva, J.E., 1997. Resting energy expenditure is sensitive to small dose changes in patients on chronic thyroid hormone replacement. J. Clin. Endocrinol. Metab. 82,1118– 1125.
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Alisi, A., Spagnuolo, S., Napoletano, S., Spaziani, A., Leoni, S., 2004. Thyroid hormones regulate DNA-synthesis and cell-cycle proteins by activation of PKCalpha and p42/44 MAPK in chick embryo hepatocytes. J. Cellular Physiol. 201, 259-265.
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Arnold, S., Goglia, F., Kadenbach, B., 1998. 3,5-Diiodothyronine binds to subunit Va of cytochrome-c oxidase and abolishes the allosteric inhibition of respiration by ATP. Eur. J. Biochem. 252, 325-330.
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Ball, S., Sokolov, J., Chin, W., 1997. 3,5-Diiodo-L-thyronine (T2) has selective thyromimetic effects in vivo and in vitro. J. Mol. Endocrinol. 19, 137–147. Baur, A., Bauer, K., Jarry H., Köhrle J., 1997. 3,5-Diiodo-L-thyronine stimulates type 1 5′ deiodinase activity in rat anterior pituitaries in vivo and in reaggregate cultures and GH3 cells in vitro. Endocrinol. 138, 3242–3248. Brent, G.A., 2012. Mechanisms of thyroid hormone action. J. Clin. Invest. 122, 3035–3043.
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Cavallo, A., Priore, P., Gnoni, G.V., Papa, S., Zanotti, F., Gnoni, A., 2013. 3,5-Diiodo-L-thyronine administration to hypothyroid rats rapidly enhances fatty acid oxidation rate and bioenergetic parameters in liver cells. PLoS One. 8, e52328. Coppola, M., Glinni, D., Moreno, M., Cioffi, F., Silvestri, E., Goglia, F. 2014. Thyroid hormone
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analogues and derivatives: Actions in fatty liver. World J. Hepatol. 6, 114-129.
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Cheng, S.Y., Leonard, J.L., Davis, P.J., 2010. Molecular aspects of thyroid hormone actions. Endocr. Rev. 31, 139–170.
da Silva Teixeira, S., Filgueira, C., Sieglaff, DH., Benod, C., Villagomez, R., Minze, LJ., Zhang, A., Webb, P., Nunes, MT. 2016. 3,5-diiodothyronine (3,5-T2) reduces blood glucose independently of insulin sensitization in obese mice. Acta Physiol (Oxf). doi: 10.1111/apha.12821
Danforth, E. Jr., Burger, A., 1984. The role of thyroid hormones in the control of energy expenditure. Clin. Endocrinol. Metab. 13, 581–595. Davis, P.J., Goglia, F., Leonard, J.L., 2016. Nongenomic actions of thyroid hormone. Nat. Rev. Endocrinol. 12, 111-121.
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De Angelis, M., Giesert, F., Finan, B., Clemmensen, C., Müller, T., Vogt-Weisenhorn, D., Tschöp, M.H., Schramm, K.W., 2016. Determination of thyroid hormones in mouse tissues by isotopedilution microflow liquid chromatography-mass spectrometry method. J Chromatogr B Analyt Technol Biomed Life Sci. 1033-1034, 413-420.
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de Lange, P., Cioffi, F., Senese, R., Moreno, M., Lombardi, A., Silvestri, E., De Matteis, R., Lionetti, L., Mollica, M.P., Goglia, F., Lanni, A., 2011. Nonthyrotoxic prevention of diet-induced insulin resistance by 3,5-diiodo-L-thyronine in rats. Diabetes. 60, 2730–2739.
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Del Viscovo, A., Secondo, A., Esposito, A., Goglia, F., Moreno, M., Canzoniero, L.M., 2012. Intracellular and plasma membrane-initiated pathways involved in the [Ca2+]i elevations induced by iodothyronines (T3 and T2) in pituitary GH3 cells. Am. J. Physiol. Endocrinol. Metab. 302, E1419–1430. Dietrich, J.W., Müller, P., Schiedat, F., Schlömicher, M., Strauch, J., Chatzitomaris, A., Klein,
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H.H., Mügge, A., Köhrle, J., Rijntjes, E., Lehmphul, I. 2015. Nonthyroidal Illness Syndrome in Cardiac Illness Involves Elevated Concentrations of 3,5-Diiodothyronine and Correlates with Atrial Remodeling. Eur. Thyroid J. 4, 129-137.
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Fox, C.S., Pencina, M.J., D'Agostino, R.B., Murabito, J.M., Seely, E.W., Pearce, E.N., Vasan, R.S., 2008. Relations of thyroid function to body weight: cross-sectional and longitudinal observations in a community-based sample. Arch. Intern. Med. 168, 587–592. García, G.C., Jeziorski, M.C., Valverde, R.C., Orozco, A., 2004. Effects of iodothyronines on the hepatic outer-ring deiodinating pathway in killifish. Gen. Comp. Endocrinol. 135, 201-209.
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Garcia, G.C., Lopez-Bojorquez, L., Nunez, J., Valverde, R.C., Orozco, A., 2007. 3,5Diiodothyronine in vivo maintains euthyroidal expression of type 2 iodothyronine deiodinase, growth hormone, and thyroid hormone receptor beta1 in the killifish. Am. J. Physiol. Regul. Integr. Comp. Physiol. 293, R877–883. Gnocchi D, Steffensen KR, Bruscalupi G, Parini P. 2016. Emerging role of thyroid hormone metabolites. Acta Physiol (Oxf). 217, 184-216.
Goglia, F., Torresani, J., Bugli, P., Barletta, A., Liverini, G., 1981, In vitro binding of triiodothyronine to rat liver mitochondria. Pflugers Arch. 390, 120-124. Goglia, F., Lanni, A., Barth, J., Kadenbach, B., 1994. Interaction of diiodothyronines with isolated cytochrome c oxidase. FEBS Lett. 346, 295-298. Goglia, F., 2005. Biological effects of 3,5-diiodothyronine (T2). Biochemistry (Moscow). 70, 164172. 14
ACCEPTED MANUSCRIPT Goglia, F., 2015. The effects of 3,5-diiodothyronine on energy balance. Front. Physiol. 5, 528. Goldberg, I.J., Huang, L.S., Huggins, L.A., Yu, S., Nagareddy, P.R., Scanlan, T.S., Ehrenkranz, J.R., 2012. Thyroid hormone reduces cholesterol via a non-LDL receptor-mediated pathway. Endocrinol. 153, 5143-5149.
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Grais IM, Sowers JR. 2014. Thyroid and the heart. Am. J. Med. 127, 691-698. Grasselli, E., Voci, A., Canesi, L., De Matteis, R., Goglia, F., Cioffi, F., Fugassa, E., Gallo, G., Vergani, L., 2011. Direct effects of iodothyronines on excess fat storage in rat hepatocytes. J. Hepatol. 54, 1230-1236.
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Grasselli, E., Voci, A., Canesi, L., Goglia, F., Ravera, S., Panfoli, I., Gallo, G., Vergani, L., 2011. Non-receptor-mediated actions are responsible for the lipid-lowering effects of iodothyronines in FaO rat hepatoma cells. J. Endocrinol. 21, 59-69.
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Grasselli, E., Voci, A., Demori, I., Vecchione, G., Compalati, A.D., Gallo, G., Goglia, F., De Matteis, R., Silvestri, E., Vergani, L., 2016. Triglyceride Mobilization from Lipid Droplets Sustains the Anti-Steatotic Action of Iodothyronines in Cultured Rat Hepatocytes. Front. Physiol. 6, 418.
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Hansen, M., Luong, X., Sedlak, D.L., Helbing, C.C., Hayes, T., 2016. Quantification of 11 thyroid hormones and associated metabolites in blood using isotope-dilution liquid chromatography tandem mass spectrometry. Anal Bioanal Chem. 408, 5429-5442.
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Hantson, A.L., De Meyer, M., Guérit, N. 2004. Simultaneous determination of endogenous and 13C-labelled thyroid hormones in plasma by stable isotope dilution mass spectrometry. J. Chromatogr. B Analyt .Technol. Biomed. Life Sci. 807, 185-192.
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Hernández-Puga, G., Navarrete-Ramírez, P., Mendoza, A., Olvera, A.,Villalobos, P., Orozco, A. 2016. 3,5-Diiodothyronine-mediated transrepression of the thyroid hormone receptor beta gene in tilapia. Insights on cross-talk between the thyroid hormone and cortisol signaling pathways. Mol. Cell. Endocrinol. 425, 103-110. Hopley, C.J., Stokes, P., Webb, K.S., Baynham, M. 2004. The analysis of thyroxine in human serum by an ‘exact matching’ isotope dilution method with liquid chromatography/tandem mass spectrometry. Rapid. Commun. Mass Spectrom. 18, 1033-1038. Horst, C., Rokos, H., Seitz, H.J., 1989. Rapid stimulation of hepatic oxygen consumption by 3,5-diiodo-L-thyronine. Biochem. J. 261, 945-950. Horst, C., Harneit, A., Seitz, H.J., Rokos, H., 1995. 3,5-Di-iodo-L-thyronine suppresses TSH in rats in vivo and in rat pituitary fragments in vitro. J. Endocrinol. 145, 291–297. Incerpi, S., De Vito, P., Luly, P., Spagnuolo, S., Leoni, S., 2002. Short-term effects of thyroid hormones and 3,5-diiodothyronine on membrane transport systems in chick embryo hepatocytes. Endocrinol. 143, 1660-1668. 15
ACCEPTED MANUSCRIPT Incerpi, S., Scapin, S., D'Arezzo, S., Spagnuolo, S., Leoni, S., 2005. Short-term effects of thyroid hormone in prenatal development and cell differentiation. Steroids 70, 434-443. Iwen, K.A., Schroder, E., Brabant, G., 2013. Thyroid hormone and the metabolic syndrome. Eur. Thyroid. J. 2, 83–92.
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Jaspers, R.T., Zillikens, M.C., Friesema, E.C., delli Paoli, G.D., Bloch, W., Uitterlinden, A.G., Goglia, F., Lanni, A., de Lange, P., 2016. Exercise, fasting, and mimetics: toward beneficial combinations? FASEB J. pii: fj.201600652R.
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Johannsen, D.L., Galgani, J.E., Johannsen, N.M., Zhang, Z., Covington, J.D., Ravussin, E. 2012 Effect of short-term thyroxine administration on energy metabolism and mitochondrial efficiency in humans. PLoS One. 7:e40837.
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Johnstone, A.M., Murison, S.D., Duncan, J.S., Rance, K.A., Speakman, J.R., 2005. Factors influencing variation in basal metabolic rate include fat-free mass, fat mass, age, and circulating thyroxine but not sex, circulating leptin, or triiodothyronine. Am. J. Clin. Nutr. 82, 941–948. Jonas, W., Lietzow, J., Wohlgemuth, F., Hoefig, C.S., Wiedmer, P., Schweizer, U., Köhrle, J., Schürmann, A., 2015. 3,5-Diiodo-L-thyronine (3,5-T2) exerts thyromimetic effects on hypothalamus-pituitary-thyroid axis, body composition, and energy metabolism in male dietinduced obese mice. Endocrinol. 156, 389-399.
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Kadenbach, B., Hüttemann, M., Arnold, S., Lee, I., Bender, E., 2000. Mitochondrial energy metabolism is regulated via nuclear-coded subunits of cytochrome c oxidase. Free Radic. Biol. Med. 29, 211–221.
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Kim, B., 2008. Thyroid hormone as a determinant of energy expenditure and the basal metabolic rate. Thyroid 18, 141–144. Klein, I., Ojamaa, K. 2001. Thyroid hormone and the cardiovascular system. N. Engl. J. Med. 344, 501-509.
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Knudsen, N., Laurberg, P., Rasmussen, L.B., Bulow, I., Perrild, H., Ovesen, L., Jorgensen, T., 2005. Small differences in thyroid function may be important for body mass index and the occurrence of obesity in the population. J. Clin. Endocrinol. Metab. 90, 4019–4024. Köhrle, J., Martin, C., Renko, K., Hoefig, C.S. 2013. Simultaneous analysis of all nine possible iodothyronines by liquid chromatography-tandem mass spectrometry. In: Smit J, Visser T, editors. 37th Annual Meeting of European Thyroid Association; 2013 Sep 7-11; Leiden, The Netherlands. Basel, Reinhhardt Druck: Karger, 2013: P241 p.176
Kvetny, J., 1992. 3,5-T2 stimulates oxygen consumption, but not glucose uptake in human mononuclear blood cells. Horm. Metab. Res. 24, 322–325.
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ACCEPTED MANUSCRIPT Lanni, A., Moreno, M., Cioffi, M., Goglia, F., 1992. Effect of 3,3'-diiodothyronine and 3,5diiodothyronine on rat liver oxidative capacity. Mol. Cell. Endocrinol. 86, 143-148. Lanni, A., Moreno, M., Cioffi, M., Goglia, F., 1993. Effect of 3,3'-di-iodothyronine and 3,5-diiodothyronine on rat liver mitochondria. J. Endocrinol. 136, 59-64.
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Lanni, A., Moreno, M., Horst, C., Lombardi, A., Goglia, F., 1994. Specific binding sites for 3,3'diiodo-L-thyronine (3,3'-T2) in rat liver mitochondria. FEBS Lett. 351, 237-240. Lanni, A., Moreno, M., Lombardi, A., Goglia, F., 1996. Calorigenic effect of diiodothyronines in the rat. J. Physiol. 494, 831-837.
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Lanni, A., Moreno, M., Lombardi, A., Goglia, F., 1998. 3,5-Diiodo-L-thyronine and 3,5,3'-triiodoL-thyronine both improve the cold tolerance of hypothyroid rats, but possibly via different mechanisms. Pflug. Archiv. Eur. J. Physiol. 436, 407-414.
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Lanni, A., Moreno, M., Lombardi, A., de Lange, P., Silvestri, E., Ragni, M., Farina, P., Baccari Chieffi, G., Fallahi, P., Antonelli, A., Goglia, F., 2005. 3,5-Diiodo-L-thyronine powerfully reduces adiposity in rats by increasing the burning of fats. FASEB J. 19,1552–1554. Leary, S.C., Barton, K.N., Ballantyne, J.S., 1996. Direct effects of 3,5,3'-triiodothyronine and 3,5diiodothyronine on mitochondrial metabolism in the goldfish Carassius auratus. Gen. Comp. Endocrinol. 104, 61-66.
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Leeson, P.D., Ellis, D., Emmett, J.C., Shah, V.P., Showell, G.A., Underwood, AH., 1988. Thyroid hormone analogues. Synthesis of 3'-substituted 3,5-diiodo-L-thyronines and quantitative structureactivity studies of in vitro and in vivo thyromimetic activities in rat liver and heart. J. Med. Chem. 31, 37-54.
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Lehmphul,I., Brabant, G., Wallaschofski, H., Ruchala, M., Strasburger, C.J., Köhrle, J., Wu, Z., 2014. Detection of 3,5-diiodothyronine in sera of patients with altered thyroid status using a new monoclonal antibody-based chemiluminescence immunoassay. Thyroid. 24, 1350-1360.
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Little, A.G., Kunisue, T., Kannan, K., Seebacher, F., 2013. Thyroid hormone actions are temperature-specific and regulate thermal acclimation in zebrafish (Danio rerio). BMC Biology 26, 11-26. Lombardi, A., Lanni, A., Moreno, M., Brand, M.D., Goglia, F., 1998. Effect of 3,5-di-iodo-Lthyronine on the mitochondrial energy-transduction apparatus. Biochem. J. 330, 521-526. Lombardi, A., Lanni, A., de Lange, P., Silvestri, E., Grasso, P., Senese, R., Goglia, F., Moreno, M., 2007. Acute administration of 3,5-diiodo-L-thyronine to hypothyroid rats affects bioenergetic parameters in rat skeletal muscle mitochondria. FEBS Lett. 581, 5911-5916. Lombardi, A., de Lange, P., Silvestri, E., Busiello, R.A., Lanni, A., Goglia, F., Moreno, M. 2009. 3,5-Diiodo-L-thyronine rapidly enhances mitochondrial fatty acid oxidation rate and thermogenesis in rat skeletal muscle: AMP-activated protein kinase involvement. Am. J. Physiol. Endocrinol. Metab. 296, E497-502.
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ACCEPTED MANUSCRIPT Lombardi, A., De Matteis, R., Moreno, M., Napolitano, L., Busiello, R.A., Senese, R., de Lange, P., Lanni, A., Goglia, F., 2012. Responses of skeletal muscle lipid metabolism in rat gastrocnemius to hypothyroidism and iodothyronine administration: a putative role for FAT/CD36. Am. J. Physiol. Endocrinol. Metab. 303, E1222-1233.
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Lombardi, A., Moreno, M., de Lange, P., Iossa, S., Busiello, R.A., Goglia, F., 2015. Regulation of skeletal muscle mitochondrial activity by thyroid hormones: focus on the "old" triiodothyronine and the "emerging" 3,5-diiodothyronine. Front. Physiol. 6, 237.
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Mangiullo, R., Gnoni, A., Damiano, F., Siculella, L., Zanotti, F., Papa, S., Gnoni, G.V., 2010. 3,5diiodo-L-thyronine upregulates rat-liver mitochondrial F(o)F(1)-ATP synthase by GA-binding protein/nuclear respiratory factor-2. Biochim. Biophys. Acta 1797, 233-240.
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Mendoza, A., Navarrete-Ramirez, P., Hernandez-Puga, G., Villalobos, P., Holzer, G., Renaud, J.P., Laudet, V., Orozco, A., 2013. 3,5-T2 is an alternative ligand for the thyroid hormone receptor beta1. Endocrinol. 154, 2948–2958. Mollica, M.P., Lionetti, L., Moreno, M., Lombardi, A., de Lange, P., Antonelli, A., Lanni, A., Cavaliere, G., Barletta, A., Goglia, F., 2009. 3,5-diiodo-L-thyronine, by modulating mitochondrial functions, reverses hepatic fat accumulation in rats fed a high-fat diet. J. Hepatol. 51, 363–370. Moreno, M., Lanni, A., Lombardi, A., Goglia, F., 1997. How the thyroid controls metabolism in the rat: different roles for triiodothyronine and diiodothyronines. J. Physiol. 505, 529-538.
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Moreno, M., Lombardi, A., Beneduce, L., Silvestri, E., Pinna, G., Goglia, F., Lanni, A., 2002. Are the effects of T3 on resting metabolic rate in euthyroid rats entirely caused by T3 itself? Endocrinol. 143, 504–510.
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Moreno, M., de Lange, P., Lombardi, A., Silvestri, E., Lanni, A., Goglia, F., 2008. Metabolic effects of thyroid hormone derivatives. Thyroid. 18, 239-253.
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Moreno, M., Silvestri, E., De Matteis, R., de Lange, P., Lombardi, A., Glinni, D., Senese, R., Cioffi, F., Salzano, A.M., Scaloni, A., Lanni, A., Goglia, F., 2011. 3,5-Diiodo-L-thyronine prevents highfat-diet-induced insulin resistance in rat skeletal muscle through metabolic and structural adaptations. FASEB J. 25, 3312–3324. Moreno, M., Silvestri, E., Coppola, M., Goldberg, I.J., Huang, L.S., Salzano, A.M., D'Angelo, F., Ehrenkranz, J.R., Goglia, F., 2016 3,5,3'-Triiodo-L-Thyronine- and 3,5-Diiodo-L-ThyronineAffected Metabolic Pathways in Liver of LDL Receptor Deficient Mice. Frontiers Physiology; 7:545.
Navarrete-Ramírez, P., Luna, M., Valverde, R.C., Orozco, A. 2014. 3,5-di-iodothyronine stimulates tilapia growth through an alternate isoform of thyroid hormone receptor β1. J. Mol. Endocrinol. 52, 1-9. Padron, A.S., Neto, R.A., Pantaleão, T.U., de Souza dos Santos, M.C., Araujo, R.L., de Andrade, B.M., da Silva Leandro, M., de Castro, J.P., Ferreira, A.C., de Carvalho, D.P. 2014. Administration 18
ACCEPTED MANUSCRIPT of 3,5-diiodothyronine (3,5-T2) causes central hypothyroidism and stimulates thyroid-sensitive tissues. J. Endocrinol. 221, 415–427. Pietzner, M., Lehmphul, I., Friedrich, N., Schurmann, C., Ittermann, T., Dörr, M., Nauck, M., Laqua, R., Völker, U., Brabant, G., Völzke, H., Köhrle, J., Homuth, G., Wallaschofski, H. 2015. Translating pharmacological findings from hypothyroid rodents to euthyroid humans: is there a
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functional role of endogenous 3,5-T2? Thyroid. 25, 188-197.
Pietzner, M., Homuth, G., Budde, K., Lehmphul, I., Völker, U., Völzke, H., Nauck, M., Köhrle, J., Friedrich, N. 2015. Urine Metabolomics by (1) H-NMR Spectroscopy Indicates Associations
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between Serum 3,5-T2 Concentrations and Intermediary Metabolism in Euthyroid Humans. Eur. Thyroid J. 4 (Suppl 1), 92-100.
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Pinna, G., Meinhold, H., Hiedra, L., Thoma, R., Hoell, T., Gräf, K.J., Stoltenburg-Didinger, G., Eravci, M., Prengel, H., Brödel, O., Finke, R., Baumgartner, A., 1997. Elevated 3,5diiodothyronine concentrations in the sera of patients with nonthyroidal illnesses and brain tumors. Clin. Endocrinol. Metab. 82, 1535-1542.
Reinehr, T. 2010 Obesity and thyroid function. Mol. Cell. Endocrinol. 316, 165-171. Rochira, A., Damiano, F., Marsigliante, S., Gnoni, G.V., Siculella, L., 2013. 3,5-Diiodo-l-thyronine
TE D
induces SREBP-1 proteolytic cleavage block and apoptosis in human hepatoma (Hepg2) cells. Biochim. Biophys. Acta. 1831, 1679-1689.
EP
Scapin, S., Leoni, S., Spagnuolo, S., Fiore, A.M., Incerpi, S., 2009. Short-term effects of thyroid hormones on Na+-K+-ATPase activity of chick embryo hepatocytes during development: focus on signal transduction. Am. J. Physiol. Cell Physiol. 296, C4-12.
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Seelig, S., Jump, D.B., Towle, H.C., Liaw, C., Mariash, C.N., Schwartz, H.L., Oppenheimer, J.H. 1982. Paradoxical effects of cycloheximide on the ultra-rapid induction of two hepatic mRNA sequences by triiodothyronine (T3). Endocrinol. 110, 671-673. Senese, R., Cioffi, F., de Lange, P., Goglia, F., Lanni, A., 2014. Thyroid: biological actions of 'nonclassical' thyroid hormones. J. Endocrinol. 221, R1-12. Senese, R., Lasala, P., Leanza, C., de Lange, P., 2014. New avenues for regulation of lipid metabolism by thyroid hormones and analogs. Front Physiol. 5, 475. Silva, J.E., 2003. The thermogenic effect of thyroid hormone and its clinical implications. Ann. Intern. Med. 139, 205–213. Silvestri, E., Cioffi, F., Glinni, D., Ceccarelli, M., Lombardi, A., de Lange, P., Chambery, A., Severino, V., Lanni, A., Goglia, F., Moreno, M., 2010. Pathways affected by 3,5-diiodo-L19
ACCEPTED MANUSCRIPT thyronine in liver of high fat-fed rats: evidence from two-dimensional electrophoresis, blue-native PAGE, and mass spectrometry. Molecular Biosystems 6, 2256-2271. Silvestri, E., Coppola, M., Cioffi, F., Goglia, F., 2014. Proteomic approaches for the study of tissue specific effects of 3,5,3'-triiodo-L-thyronine and 3,5-diiodo-L-thyronine in conditions of altered energy metabolism. Front Physiol. 5, 491.
RI PT
Soukhova, N., Soldin, O.P., Soldin, SJ. 2004. Isotope dilution tandem mass spectrometric method for T4/T3. Clin. Chim. Acta 343, 185-190.
SC
Tai, S.S., Bunk, D.M., White, E., Welch, M.J. 2004. Development and evaluation of a reference measurement procedure for the determination of total 3,3’,5-triiodothyronine in human serum using isotope-dilution liquid chromatography-tandem mass spectrometry. Anal. Chem. 76, 5092-5096.
Vaitkus, J.A., Farrar, J.S., Celi, F.S. 2015. Thyroid Hormone Mediated Modulation of Energy
M AN U
Expenditure. Int. J. Mol. Sci. 16, 16158-16175.
Van Uytfanghe, K., Stöckl, D., Thienpont, L.M. 2004. Development of a simplified sample pretreatment procedure as part of an isotope dilution-liquid chromatography/tandem mass spectrometry candidate reference measurement procedure for serum total thyroxine. Rapid.
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Commun. Mass Spectrom. 18, 1539-1540.
Vatner, D.F., Snikeris, J., Popov, V., Perry, R.J., Rahimi, Y., Samuel, V.T. 2015. 3,5 Diiodo-LThyronine (T2) Does Not Prevent Hepatic Steatosis or Insulin Resistance in Fat-Fed Sprague
EP
Dawley Rats. PLoS One. 10, e0140837.
Zhang, Y., Conrad, A.H., Conrad, G.W. 2005. Detection and quantification of 3,5,3'-
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triiodothyronine and 3,3',5'-triiodothyronine by electrospray ionization tandem mass spectrometry. J. Am. Soc. Mass Spectrom.16, 1781-1786. Zhang, Y., Conrad, A.H., Thoma, R., Conrad,G.W. 2006. Differentiation of diiodothyronines using electrospray ionization tandem mass spectrometry. J. Mass Spectrom. 41. 162-168. Zucchi, R., Accorroni, A., Chiellini, G., 2014. Update on 3-iodothyronamine and its neurological and metabolic actions. Front Physiol. 5, 402.
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"Highlights"
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An overview of direct and rapid effects of 3,5-diiodothyronine is proposed The mechanism relies on regulation of mitochondrial activities 3,5-diiodothyronine plays a role in thyroid endocrinology
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