- Email: [email protected]
Adipose tissue insulin resistance is associated with macrophage activation in non-diabetic patients with non-alcoholic fatty liver disease
e12
Abstracts / Digestive and Liver Disease 48S (2016) e1–e17
OC-21
OC-22
ADIPOSE TISSUE INSULIN RESISTANCE IS ASSOCIATED WITH MACROPHAGE ACTIVATION IN NON-DIABETIC PATIENTS WITH NON-ALCOHOLIC FATTY LIVER DISEASE
NLRP3 INFLAMMASOME ACTIVATION BY MICROBIAL PRODUCTS LEADS TO IL-18 SYNTHESIS AND IMPAIRED EPITHELIAL BARRIER FUNCTION IN CHOLANGIOCYTES
M. Marietti 1 , C. Rosso 1 , M. Gaggini 2 , C. Saponaro 2 , K. Kazankov 3 , E. Buzzigoli 2 , H.J. Møller 4 , G.P. Caviglia 1 , M.L. Abate 1 , A. Smedile 1 , G.M. Saracco 5,6 , H. Vilstrup 3 , J. George 5,6 , H. Grønbæk 3 , A. Gastaldelli 3 , E. Bugianesi 1
L. Maroni 1 , L. Agostinelli 1 , S. Saccomanno 1 , E. Mingarelli 1 , C. Rychlicki 1 , S. De Minicis 2 , J.M. Banales 3 , A. Benedetti 1 , G. Svegliati Baroni 1 , M. Marzioni 1
1 Department of Medical Sciences, University of Torino, Torino, Italy 2 Cardiometabolic Risk Unit, Institute of Clinical Physiology, CNR, Pisa, Italy 3 Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark 4 Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark 5 The Storr Liver Centre, University of Sydney and Westmead Hospital, Westmead, Australia 6 Department of Oncology, University of Turin, Turin, Italy
Introduction: Non-alcoholic fatty liver disease (NAFLD) has a bidirectional relationship with insulin resistance (IR): the liver is the target of an increased flux of free fatty acids (FFAs) and adipokines stemming from a dysfunctional adipose tissue (AT) but a fatty liver actively contributes to the dyslipidemic profile and to the chronic low grade inflammation. Soluble CD163 (sCD163), a marker of hepatic macrophages activation, has been associated with fibrosis in NAFLD. Aim: To elucidate the link between IR in the liver and in the AT, sCD163 and liver damage in 40 non-diabetic patients with NAFLD. Material and methods: All study subjects underwent tracers studies with [2 H5 ]glycerol and [2 H2 ]glucose in fasting conditions. AT-IR was calculated as FFAs*insulin (INS) (AT-IR1) and as GlycerolRa*INS (AT-IR2). Hepatic-IR was derived from endogenous glucose production*INS. sCD163 levels were measured by an enzyme-linked immunosorbent assay. Hepatic fat was assessed by liver biopsy. Histology was scored according to Kleiner. Results: AT-IR showed a significant association with hepatic fat (AT-IR1: r = 0.50, p = 0.001; AT-IR2: r = 0.44, p = 0.004), NAS score (p = 0.006 and 0.05 respectively) and fibrosis (p = 0.001 for both) at liver biopsy. Plasma levels of sCD163 were significantly associated with fasting plasma levels of FFAs and with lipolysis (r = 0.35, p = 0.026; r = 0.35, p = 0.028, respectively) while no association with INS levels was found. sCD163 levels were directly related to ATIR (AT-IR1 r = 0.38, p = 0.016 and AT-IR2 r = 0.31, p = 0.005) and with liver fat (r = 0.53; p = 0.005), while no correlation was found with Hepatic-IR. Among histological features, sCD163 plasma levels increased in proportion to the NAS score (r = 0.54; p = 0.003) and to the degree of fibrosis (p < 0.001). At logistic regression analysis, sCD163 plasma levels better predict fibrosis ≥ 2 than AT-IR (OR = 5.2, 95% CI: 1.1-24.6). Conclusions: We hypothesize that in NAFLD, AT-IR can stimulate hepatic macrophage activation via an increased flux of FFAs thus concurring to liver damage. Funding: FP7/2007-2013under grant agreement no.HEALTHF2-2009-241762,FLIP; PRIN2009ARYX4T; Horizon2020 under grant agreement no.634413,EPoS. http://dx.doi.org/10.1016/j.dld.2015.12.038
1 Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy 2 Augusto Murri Hospital - Department of Gastroenterology, Università Politecnica delle Marche, Fermo, Italy 3 Biodonostia Research Institute, Donostia University Hospital, San Sebastian, Spain
Introduction: Microbial products present in bile are thought to affect cholangiocyte response to injury and to influence the development and progression of cholangiopathies, in particular of Primary Sclerosing Cholangitis (PSC). Inflammasomes are new molecular platforms that respond to microbial products through the synthesis of pro-inflammatory cytokines, such as Il-1 and Il-18. Aim: We sought to verify whether the inflammasome is activated in sclerosing cholangitis and which are its effects in reactive cholangiocytes. Methods: Expression levels of the Nlrp3 inflammasome were tested in cholangiocytes of normal and cholestatic livers. The effects of Nlrp3 activation induced by incubation with LPS/ATP were studied in vitro in normal and siRNA Nlrp3 knockdown cholangiocytes. In vivo, wild type (WT) and Nlrp3A350VneoR (Nlrp3−/− ) mice were fed with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC, a model of sclerosing cholangitis) for 4 weeks. Results: Expression of Nlrp3 and its components is increased in cholangiocytes of mice subjected to DDC and in patients affected by PSC compared to normal conditions. LPS/ATP-induced activation of Nlrp3 in cholangiocytes stimulates the expression of Il-18, but not of Il-6 and Il-1. Nlrp3 activation significantly decreased the expression of Zonulin-1 and E-cadherin but had no effect on cholangiocyte proliferation. The effects of LPS/ATP-induced activation of Nlrp3 in cholangiocytes were neutralized by knockdown of Nlrp3 by siRNA. In vivo, the increases in the liver CK-19-positive parenchyma induced by 4 week DDC in WT animals were reduced in Nlrp3-/− mice and expression of Zonulin-1 tended to be reestablished. Conclusions: Nlrp3 is expressed in reactive cholangiocytes, both in murine models and in PSC. The activation of Nlrp3 leads to the synthesis of pro-inflammatory cytokines and influences the epithelial integrity of cholangiocytes. These findings suggest that microbial products may participate to the development of cholangiopathies by activating the inflammasome in cholangiocytes and altering the barrier function of the biliary epithelium. http://dx.doi.org/10.1016/j.dld.2015.12.039
Abstracts / Digestive and Liver Disease 48S (2016) e1–e17
OC-21
OC-22
ADIPOSE TISSUE INSULIN RESISTANCE IS ASSOCIATED WITH MACROPHAGE ACTIVATION IN NON-DIABETIC PATIENTS WITH NON-ALCOHOLIC FATTY LIVER DISEASE
NLRP3 INFLAMMASOME ACTIVATION BY MICROBIAL PRODUCTS LEADS TO IL-18 SYNTHESIS AND IMPAIRED EPITHELIAL BARRIER FUNCTION IN CHOLANGIOCYTES
M. Marietti 1 , C. Rosso 1 , M. Gaggini 2 , C. Saponaro 2 , K. Kazankov 3 , E. Buzzigoli 2 , H.J. Møller 4 , G.P. Caviglia 1 , M.L. Abate 1 , A. Smedile 1 , G.M. Saracco 5,6 , H. Vilstrup 3 , J. George 5,6 , H. Grønbæk 3 , A. Gastaldelli 3 , E. Bugianesi 1
L. Maroni 1 , L. Agostinelli 1 , S. Saccomanno 1 , E. Mingarelli 1 , C. Rychlicki 1 , S. De Minicis 2 , J.M. Banales 3 , A. Benedetti 1 , G. Svegliati Baroni 1 , M. Marzioni 1
1 Department of Medical Sciences, University of Torino, Torino, Italy 2 Cardiometabolic Risk Unit, Institute of Clinical Physiology, CNR, Pisa, Italy 3 Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark 4 Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark 5 The Storr Liver Centre, University of Sydney and Westmead Hospital, Westmead, Australia 6 Department of Oncology, University of Turin, Turin, Italy
Introduction: Non-alcoholic fatty liver disease (NAFLD) has a bidirectional relationship with insulin resistance (IR): the liver is the target of an increased flux of free fatty acids (FFAs) and adipokines stemming from a dysfunctional adipose tissue (AT) but a fatty liver actively contributes to the dyslipidemic profile and to the chronic low grade inflammation. Soluble CD163 (sCD163), a marker of hepatic macrophages activation, has been associated with fibrosis in NAFLD. Aim: To elucidate the link between IR in the liver and in the AT, sCD163 and liver damage in 40 non-diabetic patients with NAFLD. Material and methods: All study subjects underwent tracers studies with [2 H5 ]glycerol and [2 H2 ]glucose in fasting conditions. AT-IR was calculated as FFAs*insulin (INS) (AT-IR1) and as GlycerolRa*INS (AT-IR2). Hepatic-IR was derived from endogenous glucose production*INS. sCD163 levels were measured by an enzyme-linked immunosorbent assay. Hepatic fat was assessed by liver biopsy. Histology was scored according to Kleiner. Results: AT-IR showed a significant association with hepatic fat (AT-IR1: r = 0.50, p = 0.001; AT-IR2: r = 0.44, p = 0.004), NAS score (p = 0.006 and 0.05 respectively) and fibrosis (p = 0.001 for both) at liver biopsy. Plasma levels of sCD163 were significantly associated with fasting plasma levels of FFAs and with lipolysis (r = 0.35, p = 0.026; r = 0.35, p = 0.028, respectively) while no association with INS levels was found. sCD163 levels were directly related to ATIR (AT-IR1 r = 0.38, p = 0.016 and AT-IR2 r = 0.31, p = 0.005) and with liver fat (r = 0.53; p = 0.005), while no correlation was found with Hepatic-IR. Among histological features, sCD163 plasma levels increased in proportion to the NAS score (r = 0.54; p = 0.003) and to the degree of fibrosis (p < 0.001). At logistic regression analysis, sCD163 plasma levels better predict fibrosis ≥ 2 than AT-IR (OR = 5.2, 95% CI: 1.1-24.6). Conclusions: We hypothesize that in NAFLD, AT-IR can stimulate hepatic macrophage activation via an increased flux of FFAs thus concurring to liver damage. Funding: FP7/2007-2013under grant agreement no.HEALTHF2-2009-241762,FLIP; PRIN2009ARYX4T; Horizon2020 under grant agreement no.634413,EPoS. http://dx.doi.org/10.1016/j.dld.2015.12.038
1 Department of Gastroenterology and Hepatology, Università Politecnica delle Marche, Ancona, Italy 2 Augusto Murri Hospital - Department of Gastroenterology, Università Politecnica delle Marche, Fermo, Italy 3 Biodonostia Research Institute, Donostia University Hospital, San Sebastian, Spain
Introduction: Microbial products present in bile are thought to affect cholangiocyte response to injury and to influence the development and progression of cholangiopathies, in particular of Primary Sclerosing Cholangitis (PSC). Inflammasomes are new molecular platforms that respond to microbial products through the synthesis of pro-inflammatory cytokines, such as Il-1 and Il-18. Aim: We sought to verify whether the inflammasome is activated in sclerosing cholangitis and which are its effects in reactive cholangiocytes. Methods: Expression levels of the Nlrp3 inflammasome were tested in cholangiocytes of normal and cholestatic livers. The effects of Nlrp3 activation induced by incubation with LPS/ATP were studied in vitro in normal and siRNA Nlrp3 knockdown cholangiocytes. In vivo, wild type (WT) and Nlrp3A350VneoR (Nlrp3−/− ) mice were fed with 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC, a model of sclerosing cholangitis) for 4 weeks. Results: Expression of Nlrp3 and its components is increased in cholangiocytes of mice subjected to DDC and in patients affected by PSC compared to normal conditions. LPS/ATP-induced activation of Nlrp3 in cholangiocytes stimulates the expression of Il-18, but not of Il-6 and Il-1. Nlrp3 activation significantly decreased the expression of Zonulin-1 and E-cadherin but had no effect on cholangiocyte proliferation. The effects of LPS/ATP-induced activation of Nlrp3 in cholangiocytes were neutralized by knockdown of Nlrp3 by siRNA. In vivo, the increases in the liver CK-19-positive parenchyma induced by 4 week DDC in WT animals were reduced in Nlrp3-/− mice and expression of Zonulin-1 tended to be reestablished. Conclusions: Nlrp3 is expressed in reactive cholangiocytes, both in murine models and in PSC. The activation of Nlrp3 leads to the synthesis of pro-inflammatory cytokines and influences the epithelial integrity of cholangiocytes. These findings suggest that microbial products may participate to the development of cholangiopathies by activating the inflammasome in cholangiocytes and altering the barrier function of the biliary epithelium. http://dx.doi.org/10.1016/j.dld.2015.12.039