Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0344307 (analgesia)
 28,200 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

GPR7 and GPR8 are orphan G protein-coupled receptors that are highly similar to each other. These receptors are expressed predominantly in brain, suggesting roles in central nervous system function. We have purified an endogenous peptide ligand for GPR7 from bovine hypothalamus extracts. This peptide, termed neuropeptide B (NPB), has a C-6-brominated tryptophan residue at the N terminus. It binds and activates human GPR7 or GPR8 with median effective concentrations (EC(50)) of 0.23 nM and 15.8 nM, respectively. In situ hybridization shows distinct localizations of the prepro-NPB mRNA in mouse brain, i.e., in paraventricular hypothalamic nucleus, hippocampus, and several nuclei in midbrain and brainstem. Intracerebroventricular (i.c.v.) injection of NPB in mice induces hyperphagia during the first 2 h, followed by hypophagia. Intracerebroventricular injection of NPB produces analgesia to s.c. formalin injection in rats. Through EST database searches, we identified a putative paralogous peptide. This peptide, termed neuropeptide W (NPW), also has an N-terminal tryptophan residue. Synthetic human NPW binds and activates human GPR7 or GPR8 with EC(50) values of 0.56 nM and 0.51 nM, respectively. The expression of NPW mRNA in mouse brain is confined to specific nuclei in midbrain and brainstem. These findings suggest diverse physiological functions of NPB and NPW in the central nervous system, acting as endogenous ligands on GPR7 andor GPR8.
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PMID:Characterization of a family of endogenous neuropeptide ligands for the G protein-coupled receptors GPR7 and GPR8. 1271 37

In the rat, the neuropeptide B/neuropeptide W (NPB/NPW) system is composed of two ligands, neuropeptide B (NPB) and neuropeptide W (NPW), and one receptor, GPR7. Although preliminary analyses show roles in feeding, hormone secretion, and analgesia, the lack of a detailed anatomical map impairs our understanding of the NPB/NPW system. We demonstrate in this report the expression patterns of GPR7, NPB, and NPW precursor messenger ribonucleic acid (mRNA) in the rat brain by using in situ hybridization and in situ binding experiments. The amygdala expresses the highest levels of GPR7 mRNA and binding signals. Other nuclei with high levels of expression and binding are the suprachiasmatic and the ventral tuberomamillary nuclei. Moderate levels are seen in the dorsal endopiriform, dorsal tenia tecta, bed nucleus, and the red nucleus. Low levels are in the olfactory bulb, parastrial nucleus, hypothalamus, laterodorsal tegmentum, superior colliculus, locus coeruleus, and the nucleus of the solitary tract. Although the NPB precursor is mostly expressed at low levels in the brain, moderate expression is seen in anterior olfactory nucleus, piriform cortex, median preoptic nucleus, basolateral amygdala, hippocampus, medial tuberal nucleus, substantia nigra, dorsal raphe nucleus, Edinger-Westphal nucleus, and the locus coeruleus. To our surprise, the expression of NPW precursor was not detected. Our study greatly expands the preliminary in situ data previously reported. With this map of the NPB/NPW system in the rat brain, a better understanding of the functional implications of the system in various behavioral paradigms is now possible.
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PMID:A study of the rat neuropeptide B/neuropeptide W system using in situ techniques. 1673 66

Neuropeptide B/W receptor 1 (NPBWR1), previously known as G-protein coupled receptor 7 (GPR7), is a class A G-protein coupled receptor implicated in the modulation of several neuroendocrine functions such as feeding behavior, energy homeostasis, epilepsy, and analgesia. In recent years, a few antagonists have been designed that bind to NPBWR1 with high affinity. However, the exact binding modes between the antagonists and the receptor are still unknown. Unraveling the key pharmacophoric features of the receptor will guide the development of novel compounds with increased potency for therapeutic use. Here, we studied the structural organization of NPBWR1 receptor and its antagonist binding modes through computational approaches. Based on the dynamics and energetic features of receptor-ligand interactions, we categorized the binding affinities of the antagonists for NPBWR1 and identified key residues responsible for ligand recognition by NPBWR1. Binding free energy calculations revealed that the residues Trp102(ECL1), Val113(3.29), Gln281(ECL3), and Ala274(6.58) were crucial for ligand interaction. The results of our study will be useful to understand the structure-function relationship of NPBWR1 that may assist future drug discovery initiatives.
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PMID:Computational insights into the binding mechanism of antagonists with neuropeptide B/W receptor 1. 2493 7