TRPA1 Physiology in Diabetes, Metabolic Syndrome, and Metabolism

摘要 胰腺功能是代谢综合征(MS)的中心，患者表现为长期的高胰岛素血症 胰腺通过过量生产胰岛素来补偿营养过载。胰岛β细胞衰竭，胰岛素 这种慢性高胰岛素血症会导致抵抗力和糖尿病。瞬时受体电位(Trp)阳离子 通道是MS的几个后遗症(例如心血管疾病)的可用药靶点，而TRPA1 最近的研究表明，TRPA1直接参与了MS潜在的胰腺功能障碍。 引导钙离子控制胰岛素在胰腺的释放，提供TRPA1作为调节的治疗靶点 胰岛素输出量。TRPA1被认为是伤害性感受通道。一种有趣的人类可遗传突变 TRPA1(OMIM：615040)引起对禁食的严重阵发性疼痛，建立了另一种联系 TRPA1与新陈代谢。然而，关于以下方面的重大知识差距仍然存在：(1) 代谢/内分泌输入与TRPA1活性的偶联，以及(2)药物调节是否 TRPA1转译为调节整个生物体的代谢途径。 我们新的初步数据证实了TRPA1在胰腺和其他组织中的表达，并直接联系 TRPA1与代谢和线粒体有关。三种独立技术(EM、IF和亚细胞分离) 表明TRPA1定位于线粒体(MT)。此外，我们还证明了内源和内源之间的相互作用 TRPA1和肌酸激酶(CK)的所有同工酶，以及丙酮酸脱氢酶(PDH)亚基。令人惊讶的是， 前者抑制TRPA1通道活性，表明TRPA1受代谢酶调节。这些 研究结果表明，TRPA1转导了其激活剂(温度、钙、氧和辛辣)的作用 化合物)进入代谢途径，直接连接到线粒体的过程和状态。这些发现 提出新的问题，这些问题将通过一套全面的TRPA1实现三个具体目标 PI的实验室提供调节剂、抗体和体内基因敲除和基因编辑工具。这些 问题是：胰岛β细胞功能与TRPA1活性偶联的机制基础是什么？ 这是否严重地涉及到肌酸激酶或PDH？(目标1)；这一规定和职能在哪里 对β细胞功能的贡献存在于质膜、线粒体和其他组织中 胰腺？(目标2)；TRPA1的药理调节是否转化为代谢调节 整个生物体水平上的途径和疾病结果？(目标3)。

Abstract Pancreatic function is central to Metabolic Syndrome (MS) and patients exhibit long-term hyperinsulinemia as the pancreas compensates for nutrient overload through insulin over-production. Beta cell exhaustion, insulin resistance and diabetes follow this chronic hyperinsulinemia. Transient Receptor Potential (TRP) cation channels are druggable targets in several sequelae of the MS (e.g., cardiovascular disease), and TRPA1 has recently been directly implicated in the pancreatic dysfunction underlying MS. Recent studies show that TRPA1 conducts Ca2+ to controls insulin release in the pancreas, offering TRPA1 as a therapeutic target for regulation of insulin output. TRPA1 is best understood as nocioceptive channel. An intriguing human heritable mutation in TRPA1 (OMIM: 615040) causes serious episodic pain in response to fasting, establishing another link between TRPA1 and metabolism. However, significant knowledge gaps remain concerning (1) the mechanistic basis for coupling of metabolic/endocrine inputs to TRPA1 activity, and (2) whether pharmacological regulation of TRPA1 translates to modulation of metabolic pathways in whole organisms. Our new preliminary data validate expression of TRPA1 in the pancreas, and other tissues, and directly link TRPA1 to metabolism and mitochondria. Three independent techniques (EM, IF and subcellular fractionation) show that TRPA1 localizes to mitochondria (Mt). Moreover, we demonstrate interactions between endogenous TRPA1 and all isoenzymes of creatine kinase (CK), plus pyruvate dehydrogenase (PDH) subunits. Strikingly, the former inhibit TRPA1 channel activity, indicating that TRPA1 is regulated by metabolic enzymes. These findings suggest TRPA1 transduces the effects of its activators (temperature, Ca2+, O2, and pungent compounds) into metabolic pathways, linking directly to mitochondrial processes and status. These findings raise new questions that will be addressed in three Specific Aims, enabled by a comprehensive set of TRPA1 modulators, antibodies, and in vivo knockout and gene editing tools available in the PI's laboratory. These questions are: What is the mechanistic basis for coupling of pancreatic beta cell function to TRPA1 activity, does this critically involve Creatine Kinase or PDH? (Aim 1); Where does this regulation and functional contribution to beta cell function reside, in the plasma membrane, mitochondria, and in other tissues than the pancreas? (Aim 2); and Does pharmacological regulation of TRPA1 translate to modulation of metabolic pathways and disease outcomes at the whole organism level? (Aim 3).