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Galanin receptor ligands
Abstracts
neuropeptides as therapeutics has been challenging due to poor metabolic stability and lack of blood-brain barrier penetration. Furthermore, activation of peripheral GalR1 receptors results in hyperglycemia due to inhibition of insulin release. We have applied a novel technology platform to develop galanin analogs that are metabolically stable, maintain low nanomolar affinity for galanin receptors, and following systemic administration are potently active in preventing induced seizures. Subsequent studies have led to the discovery of NAX 810-2, a GalR2-preferring agonist that displays potent anticonvulsant activity in several seizure and epilepsy models. NAX 810-2 is a GalR2-preferring agonist (GalR2 Ki 32 nM, GalR1 Ki 494 nM) that shows a high level of plasma protein binding (99.5%) and displays potent anti-seizure activity in the mouse 6Hz model (ED50, 32mA: 2.5 mg/kg i.p.), the Frings Audiogenic model (ED50: 9.2 mg/kg i.p.), and the mouse corneal kindling model (ED50: 7.4 mg/kg i.p.). Pharmacokinetic studies show that the plasma halflife of the analog is approximately 1.25h following systemic (i.v.) administration. Repeated administration of NAX 810-2 (8 mg/kg b.i.d., 3 days) shows that the analog retains full efficacy. Further studies have also shown that NAX 810-2 exhibits a favorable CYP inhibition profile. In summary, NAX 810-2 is a potential first-in-class neuropeptide therapeutic for epilepsy.
OF
Galanin neurons in the preoptic area gained recent interest as they demonstrate Fos activation in response to pup exposure and their selective ablation led to the cessation of maternal behaviors. Here, we identified distinct populations of galanin neurons in the preoptic area of rat dams, which also contain oxytocin. Injecting retrograde tracer around preoptic galanin neurons led to the appearance of labeled cells in a distinct part of the posterior thalamus, the posterior intralaminar nucleus (PIL). These cells contain tuberoinfundibular peptide 39 (TIP39) and convey suckling information to the hypothalamus. Anterograde labeling of the PIL resulted in an ipsilateral appearance of fibers in preoptic area whose distribution resembled that of the galanin neurons, which were in turn innervated by TIP39 terminals as demonstrated by electron microscopy. While these results suggest that galanin neurons receive information on suckling through a direct neuronal pathway, we also addressed the hormonal influence of prolactin on galanin neurons. The majority of galanin neurons in the anterior commissural nucleus but not in other parts of the preoptic area contained a phosphorylated signal transduction protein of the prolactin receptor (pSTAT5) 2 hours following suckling or 30 min following intracerebroventricular prolactin injection suggesting that only this population of galanin neurons is affected by the hormone. In summary, we identified different populations of galanin neurons in the maternal preoptic area, implied that all galanin cell groups receive neuronal input from pup suckling but only one of them is affected by prolactin.
RO
150
doi:10.1016/j.npep.2017.02.071
DP
Acknowledgements: OTKA K100319 research grant and KTIA_NAP_B_13-22014-0004 Program. doi:10.1016/j.npep.2017.02.069
G8
TE
THE GALANIN RECEPTOR 3 ANTAGONIST SNAP 37889 INDUCES APOPTOSIS IN VITRO
G6 GALANIN RECEPTOR LIGANDS
EC
Ulo Langel; Stockholm University, Stockholm, Sweden; Tartu University, Tartu, Estonia
Andreas Kollera, Raphaela Ridd, Marlena Beyreisb,c, Rodolfo Bianchinia, Barbara S. Holuba, Andreas Langa, Felix Lockera, Bernhard Brodowicza, Ognjen Velickovicd, Martin Jakabc, Hubert Kerschbaumb, Kamil Önderd, Barbara Koflera; aLaura Bassi Centre of Expertise THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria; bDepartment of Cell Biology, University of Salzburg, Salzburg, Austria; cInstitute of Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria; dDivision of Molecular Dermatology, Department of Dermatology, Paracelsus Medical University, Salzburg, Austria
CO
RR
The effect of galanin is mediated through three GPCR subtypes, GalR1-3. The limited number of specific ligands to the galanin receptor subtypes has hindered the understanding of the individual effects of each receptor subtype. This review summarizes the current data of the importance of the galanin receptor subtypes and receptor subtype specific agonists and antagonists and their involvement in different biological and pathological functions.
G7
UN
doi:10.1016/j.npep.2017.02.070
NAX 810-2, A NOVEL GALANIN-BASED THERAPY FOR EPILEPSY Cameron Metcalfa, Brian Kleina,b, Daniel McDouglea, Liuyin Zhangc, Grzegorz Bulaja,c, H. Steve Whitea,b; aNeuroAdjuvants, Inc, Salt Lake City, UT, USA; bUniversity of Utah, Dept. of Pharmacology and Toxicology, Salt Lake City, UT, USA; cUniversity of Utah, Dept. of Medicinal Chemistry, Salt Lake City, UT, USA The endogenous neuropeptide galanin and its associated receptors play an important role in the control of seizures and are therefore an attractive therapeutic target. However, developing
Galanin and its receptors (GAL1-3) modulate a range of neuronal, immune and vascular activities. In vivo administration of SNAP 37889 a potent small non-peptidergic antagonist of GAL3, reportedly reduces anxiety- and depression-related behavior in rodent models. Accordingly, SNAP 37889 has been proposed as a potential therapeutic agent to treat anxiety and depression related disorders. Therefore, we evaluated the toxicity of SNAP 37889 to different cell types. The epithelial cell line HMCB expressed GAL1 and GAL3. The myeloid cell line HL-60 and peripheral blood mononuclear cells (PBMCs) expressed GAL2 only. The neuroblastoma cell line SH-SY5Y did not express any GAL receptors. The murine microglial cell line BV-2 expressed GAL2 and GAL3. The cell viability of HMCB, SH-SY5Y, HL-60 and BV-2 cell lines was measured by ATP quantification upon SNAP 37889 treatment and showed that the toxicity of SNAP 37889 was concentration and cell density dependent. At high cell density SNAP 37889 up to 100 μM had almost no effect on all cell lines. At lower densities SNAP 37889 diminished the cell viability and the IC50 of the compound ranged from 15 - 70 μM. PBMCs, HL-60 and BV-2 cells showed a significant increase of caspase-3/7 activity and Annexin V positive cells upon 10 μM SNAP 37889 treatment for 4 hours.
neuropeptides as therapeutics has been challenging due to poor metabolic stability and lack of blood-brain barrier penetration. Furthermore, activation of peripheral GalR1 receptors results in hyperglycemia due to inhibition of insulin release. We have applied a novel technology platform to develop galanin analogs that are metabolically stable, maintain low nanomolar affinity for galanin receptors, and following systemic administration are potently active in preventing induced seizures. Subsequent studies have led to the discovery of NAX 810-2, a GalR2-preferring agonist that displays potent anticonvulsant activity in several seizure and epilepsy models. NAX 810-2 is a GalR2-preferring agonist (GalR2 Ki 32 nM, GalR1 Ki 494 nM) that shows a high level of plasma protein binding (99.5%) and displays potent anti-seizure activity in the mouse 6Hz model (ED50, 32mA: 2.5 mg/kg i.p.), the Frings Audiogenic model (ED50: 9.2 mg/kg i.p.), and the mouse corneal kindling model (ED50: 7.4 mg/kg i.p.). Pharmacokinetic studies show that the plasma halflife of the analog is approximately 1.25h following systemic (i.v.) administration. Repeated administration of NAX 810-2 (8 mg/kg b.i.d., 3 days) shows that the analog retains full efficacy. Further studies have also shown that NAX 810-2 exhibits a favorable CYP inhibition profile. In summary, NAX 810-2 is a potential first-in-class neuropeptide therapeutic for epilepsy.
OF
Galanin neurons in the preoptic area gained recent interest as they demonstrate Fos activation in response to pup exposure and their selective ablation led to the cessation of maternal behaviors. Here, we identified distinct populations of galanin neurons in the preoptic area of rat dams, which also contain oxytocin. Injecting retrograde tracer around preoptic galanin neurons led to the appearance of labeled cells in a distinct part of the posterior thalamus, the posterior intralaminar nucleus (PIL). These cells contain tuberoinfundibular peptide 39 (TIP39) and convey suckling information to the hypothalamus. Anterograde labeling of the PIL resulted in an ipsilateral appearance of fibers in preoptic area whose distribution resembled that of the galanin neurons, which were in turn innervated by TIP39 terminals as demonstrated by electron microscopy. While these results suggest that galanin neurons receive information on suckling through a direct neuronal pathway, we also addressed the hormonal influence of prolactin on galanin neurons. The majority of galanin neurons in the anterior commissural nucleus but not in other parts of the preoptic area contained a phosphorylated signal transduction protein of the prolactin receptor (pSTAT5) 2 hours following suckling or 30 min following intracerebroventricular prolactin injection suggesting that only this population of galanin neurons is affected by the hormone. In summary, we identified different populations of galanin neurons in the maternal preoptic area, implied that all galanin cell groups receive neuronal input from pup suckling but only one of them is affected by prolactin.
RO
150
doi:10.1016/j.npep.2017.02.071
DP
Acknowledgements: OTKA K100319 research grant and KTIA_NAP_B_13-22014-0004 Program. doi:10.1016/j.npep.2017.02.069
G8
TE
THE GALANIN RECEPTOR 3 ANTAGONIST SNAP 37889 INDUCES APOPTOSIS IN VITRO
G6 GALANIN RECEPTOR LIGANDS
EC
Ulo Langel; Stockholm University, Stockholm, Sweden; Tartu University, Tartu, Estonia
Andreas Kollera, Raphaela Ridd, Marlena Beyreisb,c, Rodolfo Bianchinia, Barbara S. Holuba, Andreas Langa, Felix Lockera, Bernhard Brodowicza, Ognjen Velickovicd, Martin Jakabc, Hubert Kerschbaumb, Kamil Önderd, Barbara Koflera; aLaura Bassi Centre of Expertise THERAPEP, Research Program for Receptor Biochemistry and Tumor Metabolism, Department of Pediatrics, Paracelsus Medical University, Salzburg, Austria; bDepartment of Cell Biology, University of Salzburg, Salzburg, Austria; cInstitute of Physiology and Pathophysiology, Paracelsus Medical University, Salzburg, Austria; dDivision of Molecular Dermatology, Department of Dermatology, Paracelsus Medical University, Salzburg, Austria
CO
RR
The effect of galanin is mediated through three GPCR subtypes, GalR1-3. The limited number of specific ligands to the galanin receptor subtypes has hindered the understanding of the individual effects of each receptor subtype. This review summarizes the current data of the importance of the galanin receptor subtypes and receptor subtype specific agonists and antagonists and their involvement in different biological and pathological functions.
G7
UN
doi:10.1016/j.npep.2017.02.070
NAX 810-2, A NOVEL GALANIN-BASED THERAPY FOR EPILEPSY Cameron Metcalfa, Brian Kleina,b, Daniel McDouglea, Liuyin Zhangc, Grzegorz Bulaja,c, H. Steve Whitea,b; aNeuroAdjuvants, Inc, Salt Lake City, UT, USA; bUniversity of Utah, Dept. of Pharmacology and Toxicology, Salt Lake City, UT, USA; cUniversity of Utah, Dept. of Medicinal Chemistry, Salt Lake City, UT, USA The endogenous neuropeptide galanin and its associated receptors play an important role in the control of seizures and are therefore an attractive therapeutic target. However, developing
Galanin and its receptors (GAL1-3) modulate a range of neuronal, immune and vascular activities. In vivo administration of SNAP 37889 a potent small non-peptidergic antagonist of GAL3, reportedly reduces anxiety- and depression-related behavior in rodent models. Accordingly, SNAP 37889 has been proposed as a potential therapeutic agent to treat anxiety and depression related disorders. Therefore, we evaluated the toxicity of SNAP 37889 to different cell types. The epithelial cell line HMCB expressed GAL1 and GAL3. The myeloid cell line HL-60 and peripheral blood mononuclear cells (PBMCs) expressed GAL2 only. The neuroblastoma cell line SH-SY5Y did not express any GAL receptors. The murine microglial cell line BV-2 expressed GAL2 and GAL3. The cell viability of HMCB, SH-SY5Y, HL-60 and BV-2 cell lines was measured by ATP quantification upon SNAP 37889 treatment and showed that the toxicity of SNAP 37889 was concentration and cell density dependent. At high cell density SNAP 37889 up to 100 μM had almost no effect on all cell lines. At lower densities SNAP 37889 diminished the cell viability and the IC50 of the compound ranged from 15 - 70 μM. PBMCs, HL-60 and BV-2 cells showed a significant increase of caspase-3/7 activity and Annexin V positive cells upon 10 μM SNAP 37889 treatment for 4 hours.