桂枝汤调控NLRP3炎性小体改善糖尿病心脏自主神经病变的作用及机制研究

Diabetic cardiac autonomic neuropathy (DCAN) is composed of high glucose, oxidative and inflammation leading to neuronal ischemia and necrosis, a diabetic complications caused by cardiac sympathetic and vagus nerve dysfunction, clinical often asymptomatic myocardial ischemia or myocardial infarction, ventricular arrhythmia and even sudden death. Recent reports of antioxidant therapy such as alpha lipoic acid and aldose reductase inhibitors do not prevent the progress of DCAN. The activation of NLRP3 inflammasome and the increase of the downstream inflammatory factors IL-18 and IL-1β were found in DCAN patients, but the related mechanisms were not clear. Therefore, we hypothesized that inhibition of the activation of NLRP3 inflammasome corpuscle can improve cardiac autonomic neuropathy. In our previous study, Guizhi Decoction could improve cardiac autonomic nerve remodeling in diabetic rats, adjust the imbalance of sympathetic and vagus nerve, and improve DCAN. The project aims to observe effect of NLRP3 gene silence improving cardiac autonomic neuropathy, and observe the molecular intervention of Guizhi Decoction NLRP3 inflammasome and its downstream pathway and regulation mechanism of DCAN, from the angle of anti-inflammatory TCM to provide reliable experimental basis for Guizhi Decoction in the treatment of DCAN.

糖尿病心脏自主神经病变（DCAN）是由高血糖、氧化及炎症等导致神经元缺血、坏死，引起的心脏交感、迷走神经功能障碍的一种糖尿病并发症，临床常发生无症状性心肌缺血或心肌梗死、致命性室性心律失常、甚至猝死。近期报道α-硫辛酸、醛糖还原酶抑制剂等抗氧化治疗并没有阻止DCAN的进展。DCAN患者发现NLRP3炎性小体激活及其下游炎症因子IL-18、IL-1β升高，但相关机制并不明确。因此，我们假设抑制NLRP3炎性小体激活能够改善心脏自主神经病变。我们前期研究桂枝汤能够改善糖尿病大鼠心脏自主神经重构，调整交感、迷走神经失衡，改善心脏自主神经病变。本项目利用NLRP3-miRNA慢病毒沉默NLRP3基因，观察NLRP3炎症小体及其下游通路对心脏自主神经病变的影响，同时观察桂枝汤干预NLRP3炎性小体及其下游通路防治DCAN的分子调节机制，从中药抗炎角度为桂枝汤治疗DCAN提供可靠实验依据

糖尿病心脏自主神经病变（DCAN)是由高血糖、氧化及炎症等导致神经元缺血、坏死，引起的心脏自主神经功能障碍的一种糖尿病并发症，临床常发生无症状性心肌缺血或心肌梗死、致命性室性心律失常、甚至猝死。研究指出，DCAN患者心脏心率变异性降低，心脏交感神经兴奋性增加，心脏交感/迷走神经支配失衡，同时，NLRP3炎性小体及IL-1β、IL-18炎性因子表达升高，但是NLRP3炎性小体与心脏交感/迷走神经支配失衡的相关机制不明确。因此,我们假设干预NLRP3炎性小体能够改善心脏交感/迷走神经支配失衡状态。本项目主要研究NLRP3炎性小体与心脏交感/迷走神经功能学/解剖学支配失衡的关系及探索桂枝汤干预NLRP3炎性小体防治DCAN的作用机制。研究结果显示：糖尿病前期及糖尿病期NLRP3炎性小体及IL-1β、IL-18炎性因子表达升高，并随病程进展，心脏交感/迷走神经功能学/解剖学支配失衡状态逐渐加重，促进DCAN疾病进展。注射NLRP3-shRNA干扰NLRP3-mRNA表达，能够抑制NLRP3炎性小体及IL-1β、IL-18炎性因子表达，改善心率变异性（LF/HF），降低心脏交感/迷走神经（TH/CHAT）支配密度比例，改善心脏交感/迷走神经功能学/解剖学支配失衡状态。桂枝汤干预后能够降低NLRP3炎性小体激活程度及IL-1β、IL-18炎性因子表达，改善心率变异性（LF/HF），改善心脏交感/迷走神经功能学/解剖学支配失衡状态，延缓DCAN疾病的进展。本研究揭示了NLRP3炎性小体在糖尿病心脏自主神经病变中的作用机制，阐释了经方桂枝汤干预NLRP3炎性通路改善DCAN的作用机制，为中医药防治心脏自主神经病变提供新思路及科学依据。