Calcitonin gene-related peptide (CGRP) is thought to be a prominent neuropeptide in cardiovascular regulation and neuroimmune modulation. There are two isoforms of CGRP (␣CGRP and ␤CGRP), and the main CGRP receptors are probably composed of a calcitonin receptor-like receptor (CLR) and a receptor activity-modifying protein (RAMP)1. However, the physiological functions of CGRP that are mediated through the CLR/RAMP1 receptors remain to be clarified. For an improved understanding of the functions, we generated mice deficient in RAMP1, a specific subunit of CGRP receptors, by a conditional gene-targeting technique. The RAMP1-deficient mice (RAMP1 ؊/؊ ) exhibited high blood pressure, with no changes in heart rate. ␣CGRP was found to have a potent vascular relaxant activity compared with ␤CGRP in the artery of the WT (RAMP1 ؉/؉ ) mice. The activities of both CGRP isoforms were remarkably suppressed in the arteries of the RAMP1 ؊/؊ mice. The LPS-induced inflammatory responses of the RAMP1 ؊/؊ mice revealed a transient and significant increase in the serum CGRP levels and high serum levels of proinflammatory cytokines compared with the RAMP1 ؉/؉ mice. ␣CGRP and ␤CGRP equally suppressed the production of TNF-␣ and IL-12 in bone marrow-derived dendritic cells stimulated with lipopolysaccharide. Their inhibitory effects were not observed in the bone marrow-derived dendritic cells of the RAMP1 ؊/؊ mice. These results indicate that CGRP signaling through CLR/RAMP1 receptors plays a crucial role in the regulation of both blood pressure by vascular relaxation and proinflammatory cytokine production from dendritic cells.gene-disrupted mice ͉ calcitonin gene-related peptide ͉ adrenomedullin ͉ neuropeptide ͉ dendritic cells C alcitonin gene-related peptide (CGRP) is a 37-aa neuropeptide that is produced in the neural body of dorsal root ganglion cells and released from sensory nerve endings. There are two isoforms of CGRP: ␣ and ␤ in rats and mice and I and II in humans. These differ in their peptide sequences by 1 aa (rats) and 3 aa (mice and humans) of the 37 aa (1). ␣CGRP is produced mainly in the nervous system by the tissue-specific alternative splicing of the primary RNA transcript of the calcitonin/CGRP gene. On the other hand, ␤CGRP is produced not only in the neuronal tissues but also in the enteric nerves of the intestine (2) and in immune cells such as T cells (3). Pharmacologically, ␣CGRP is known to have the most potent vasodilatory activity (4). Most blood vessels are surrounded by a dense perivascular CGRPergic neural network, suggesting the physiological importance of CGRP in vasodilatory regulation (5). ␣CGRP also contributes to local neurogenic inflammation and nociception (6). Moreover, the functions of immune cells such as macrophages (7,8), Langerhans cells (8), and T cells (9, 10) are modulated by ␣CGRP. However, the precise functional differences between ␣CGRP and ␤CGRP remain unclear.Historically, CGRP receptors have been classified into two classes: CGRP 1 and CGRP 2 receptors. The CGRP 1 receptors are m...

Malic enzyme 1 (ME1) regulates one of the main pathways that provide nicotinamide adenine dinucleotide phosphate (NADPH), which is essential for cancer cell growth through maintenance of redox balance and biosynthesis processes in the cytoplasm. In this study, we found that ME1 inhibition disrupted metabolism in cancer cells and inhibited cancer cell growth by inducing senescence or apoptosis. In glucose-restricted culture conditions, cancer cells increased ME1 expression, and tracer experiments with labelled glutamine revealed that the flux of ME1-derived pyruvate to citrate was enhanced. In addition, cancer cells showed higher sensitivity to ME1 depletion in glucose-restricted conditions compared to normal culture conditions. These results suggest that in a low-glucose environment, where glycolysis and the pentose phosphate pathway (PPP) is attenuated, cancer cells become dependent on ME1 for the supply of NADPH and pyruvate. Our data demonstrate that ME1 is a promising target for cancer treatment, and a strategy using ME1 inhibitors combined with inhibition of glycolysis, PPP or redox balance regulators may provide an effective therapeutic option.

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Monoacylglycerol O-acyltransferase 2 (MGAT2) catalyzes the synthesis of diacylglycerol (DG), a triacylglycerol precursor and potential peripheral target for novel anti-obesity therapeutics. High-throughput screening identified lead compounds with MGAT2 inhibitory activity. Through structural modification, a potent, selective, and orally bioavailable MGAT2 inhibitor, compound A (compA), was discovered. CompA dose-dependently inhibited postprandial increases in plasma triglyceride (TG) levels. Metabolic flux analysis revealed that compA inhibited triglyceride/diacylglycerol resynthesis in the small intestine and increased free fatty acid and acyl-carnitine with shorter acyl chains than originally labelled fatty acid. CompA decreased high-fat diet (HFD) intake in C57BL/6J mice. MGAT2-null mice showed a similar phenotype as compA-treated mice and compA did not suppress a food intake in MGAT2 KO mice, indicating that the anorectic effects were dependent on MGAT2 inhibition. Chronic administration of compA significantly prevented body weight gain and fat accumulation in mice fed HFD. MGAT2 inhibition by CompA under severe diabetes ameliorated hyperglycemia and fatty liver in HFD-streptozotocin (STZ)-treated mice. Homeostatic model assessments (HOMA-IR) revealed that compA treatment significantly improved insulin sensitivity. The proximal half of the small intestine displayed weight gain following compA treatment. A similar phenomenon has been observed in Roux-en-Y gastric bypass-treated animals and some studies have reported that this intestinal remodeling is essential to the anti-diabetic effects of bariatric surgery. These results clearly demonstrated that MGAT2 inhibition improved dyslipidemia, obesity, and diabetes, suggesting that compA is an effective therapeutic for obesity-related metabolic disorders.