Bombesin receptor subtype-3-expressing neurons regulate energy homeostasis through a novel neuronal pathway in the hypothalamus.

Objectives: Bombesin receptor subtype-3 (BRS-3) has been suggested to play a potential role in energy homeostasis. However, the physiological mechanism of BRS-3 on energy homeostasis remains unknown. Thus, we investigated the BRS-3-mediated neuronal pathway involved in food intake and energy expenditure.

A Selective Bombesin Receptor Subtype 3 Agonist Promotes Weight Loss in Male Diet-Induced-Obese Rats With Circadian Rhythm Change.

Bombesin receptor subtype 3 (BRS-3) is an orphan G protein-coupled receptor. Based on the obese phenotype of male BRS-3-deficient mice, BRS-3 has been considered an attractive target for obesity treatment. Here, we developed a selective BRS-3 agonist (compound-A) and evaluated its antiobesity effects.

Development of a Novel Carbon-11 Labeled PET Radioligand for Melanin- Concentrating Hormone Receptor 1.

Background And Objective: Melanin-concentrating hormone (MCH) is an attractive target for antiobesity agents and many drug discovery programs have been dedicated to identify smallmolecule antagonists of melanin-concentrating hormone receptor 1 (MCHR1). The aim of this study was to develop a positron emission tomography (PET) tracer for MCHR1 for translation of preclinical pharmacology to clinic to enhance success rate of drug discovery programs.

Methods: We identified 4-(cyclopropylmethoxy)-N-[8-methyl-3-({[(1-methyl-1H-pyrrol-2-yl)methyl] amino}ethyl)quinolin-7-yl]benzamide (Compound II) from Takeda MCHR1 antagonist library by utilizing binding affinity, log D value, physicochemical parameters ideal for a central nerve system agent, and synthetic feasibility of corresponding carbon-11 labeled radioligands as selection parameters for tracer candidates.

A novel and selective melanin-concentrating hormone receptor 1 antagonist ameliorates obesity and hepatic steatosis in diet-induced obese rodent models.

Melanin-concentrating hormone (MCH), a cyclic neuropeptide expressed predominantly in the lateral hypothalamus, plays an important role in the control of feeding behavior and energy homeostasis. Mice lacking MCH or MCH receptor are resistant to diet-induced obesity (DIO) and MCH receptor antagonists show potent anti-obesity effects in preclinical studies, indicating that MCH receptor is a promising target for anti-obesity drugs. Moreover, recent studies have suggested the potential of MCH receptor antagonists for treatment of non-alcoholic fatty liver disease (NAFLD).

Amine-free melanin-concentrating hormone receptor 1 antagonists: Novel non-basic 1-(2H-indazole-5-yl)pyridin-2(1H)-one derivatives and mitigation of mutagenicity in Ames test.

To develop non-basic melanin-concentrating hormone receptor 1 (MCHR1) antagonists with a high probability of target selectivity and therapeutic window, we explored neutral bicyclic motifs that could replace the previously reported imidazo[1,2-a]pyridine or 1H-benzimidazole motif. The results indicated that the binding affinity of a chemically neutral 2H-indazole derivative 8a with MCHR1 (hMCHR1: IC50=35nM) was comparable to that of the imidazopyridine and benzimidazole derivatives (1 and 2, respectively) reported so far. However, 8a was positive in the Ames test using TA1537 in S9- condition.

Amine-free melanin-concentrating hormone receptor 1 antagonists: Novel 1-(1H-benzimidazol-6-yl)pyridin-2(1H)-one derivatives and design to avoid CYP3A4 time-dependent inhibition.

Melanin-concentrating hormone (MCH) is an attractive target for antiobesity agents, and numerous drug discovery programs are dedicated to finding small-molecule MCH receptor 1 (MCHR1) antagonists. We recently reported novel pyridine-2(1H)-ones as aliphatic amine-free MCHR1 antagonists that structurally featured an imidazo[1,2-a]pyridine-based bicyclic motif. To investigate imidazopyridine variants with lower basicity and less potential to inhibit cytochrome P450 3A4 (CYP3A4), we designed pyridine-2(1H)-ones bearing various less basic bicyclic motifs.

Melanin-Concentrating Hormone Receptor 1 Antagonists Lacking an Aliphatic Amine: Synthesis and Structure-Activity Relationships of Novel 1-(Imidazo[1,2-a]pyridin-6-yl)pyridin-2(1H)-one Derivatives.

Aiming to discover melanin-concentrating hormone receptor 1 (MCHR1) antagonists with improved safety profiles, we hypothesized that the aliphatic amine employed in most antagonists reported to date could be removed if the bicyclic motif of the compound scaffold interacted with Asp123 and/or Tyr272 of MCHR1. We excluded aliphatic amines from our compound designs, with a cutoff value of pK(a) < 8, and explored aliphatic amine-free MCHR1 antagonists in a CNS-oriented chemical space limited by four descriptors (TPSA, ClogP, MW, and HBD count). Screening of novel bicyclic motifs with high intrinsic binding affinity for MCHR1 identified the imidazo[1,2-a]pyridine ring (represented in compounds 6a and 6b), and subsequent cyclization of the central aliphatic amide linkage led to the discovery of a potent, orally bioavailable MCHR1 antagonist 4-[(4-chlorobenzyl)oxy]-1-(2-cyclopropyl-3-methylimidazo[1,2-a]pyridin-6-yl)pyridin-2(1H)-one 10a.

Synthesis, structure-activity relationship, and pharmacological studies of novel melanin-concentrating hormone receptor 1 antagonists 3-aminomethylquinolines: reducing human ether-a-go-go-related gene (hERG) associated liabilities.

Recently, we discovered 3-aminomethylquinoline derivative 1, a selective, highly potent, centrally acting, and orally bioavailable human MCH receptor 1 (hMCHR1) antagonist, that inhibited food intake in F344 rats with diet-induced obesity (DIO). Subsequent investigation of 1 was discontinued because 1 showed potent hERG K(+) channel inhibition in a patch-clamp study. To decrease hERG K(+) channel inhibition, experiments with ligand-based drug designs based on 1 and a docking study were conducted.

Melanin-concentrating hormone receptor 1 antagonists. Synthesis and structure-activity relationships of novel 3-(aminomethyl)quinolines.

It was found that 3-(aminomethyl)quinoline derivatives showed high binding affinities for melanin-concentrating hormone receptor 1 (MCHR1) with reduced affinity for serotonin receptor 2c (5-HT2c) when the dihydronaphthalene nucleus of compound 1 (human MCHR1, IC(50) = 1.9 nM; human 5-HT2c receptor, IC(50) = 0.53 nM) was replaced by other bicyclic core scaffolds.

Melanin-concentrating hormone receptor 1 antagonists: synthesis, structure-activity relationship, docking studies, and biological evaluation of 2,3,4,5-tetrahydro-1H-3-benzazepine derivatives.

Melanin-concentrating hormone receptor 1 (MCHR1) antagonists have been studied as potential agents for the treatment of obesity. Initial structure-activity relationship studies of in-house hit compound 1a and subsequent optimization studies resulted in the identification of tetrahydroisoquinoline derivative 23, 1-(2-acetyl-1,2,3,4-tetrahydroisoquinolin-7-yl)-4-[4-(4-chlorophenyl)piperidin-1-yl]butan-1-one, as a potent hMCHR1 antagonist. A homology model of hMCHR1 suggests that these compounds interact with Asn 294 and Asp 123 in the binding site of hMCHR1 to enhance binding affinity.

Discovery, synthesis, and structure-activity relationship of 6-aminomethyl-7,8-dihydronaphthalenes as human melanin-concentrating hormone receptor 1 antagonists.

Human melanin-concentrating hormone receptor 1 (hMCHR1) antagonists are promising targets for obesity treatment. We identified the tetrahydronaphthalene derivative 1a with modest binding affinity for hMCHR1 by screening an in-house G protein-coupled receptor (GPCR) ligand library. We synthesized a series of 6-aminomethyl-5,6,7,8-tetrahydronaphthalenes and evaluated their activity as hMCHR1 antagonists.

Changes in glycated haemoglobin levels in diabetic rats measured with an automatic affinity HPLC.

1. The level of glycated haemoglobin (GHb) in diabetic rats was measured using a newly developed automatic high-performance liquid chromatography (HPLC) with a boronate affinity column that requires only 2.5 min per sample for analysis.

[Ameliorative effects on retinal disorder in diabetic SHRSP (stroke-prone spontaneously hypertensive rat)].

The results of the EUCLID highlighted the importance of the renin-angiotensin system in the pathogenesis of diabetic retinopathy. We aimed to evaluate the effectiveness of candesartan cilexetil(TCV-116), a potent angiotensin II receptor antagonist, in ameliorating retinal disorders in stroke-prone spontaneously hypertensive rats(SHRSP) with storeptozotocin(STZ)-induced diabetes. Retinal VEGF mRNA expression was significantly higher and the latencies of oscillatory potentials were significantly elongated in STZ-treated SHRSP compared with a non-treated SHRSP group matched for age.