T淋巴细胞缝隙连接通过NF-κB通路介导高血压炎症反应的机制研究

Hypertension is a chronic disease caused by multiple factors. Low grade inflammation, with the abnormality of T lymphocyte subsets ratio and cytokine release, has been recognized to play a crucial pathophysiological role in hypertension. Studies have reported that gap junctions are present in the immune system, and play a key role in regulating important cell functions such as proliferation, activation and cytokine production. However, whether gap junction between lymphocytes participates in hypertension mediated inflammation remains unknown. In our previous research, we found that T lymphocyte subsets ratio of peripheral blood in SHR were abnormal, Cx40 and Cx43 expression in CD4+ or CD8+ T lymphocyte compared to control were significant increase, and there was a positive correlation between inflammatory cytokines IL-2, IL-6 release and Cx40/Cx43. This project will apply the gap junction channels blockers and NF-κB pathway inhibitor in vitro and in vivo experiments, by detecting the ratio of T lymphocyte subsets, inflammatory cytokines, Cx40/Cx43 expression, arterial blood pressure and target organ damage, to clarify the role and mechanism of gap junction channels and NF-κB signaling pathway in the pathogenesis of hypertension.

高血压是一种多因素的慢性疾病，发病过程中伴随着低度炎症反应，以T淋巴细胞亚群比值和细胞因子释放异常为主要特征。有研究报道，T淋巴细胞间存在缝隙连接通道，在细胞增殖、活化及炎症因子释放过程发挥重要作用，但缝隙连接是否参与高血压炎症反应目前尚不清楚。本课题组前期初步观察了自发性高血压大鼠外周血T淋巴细胞上构成缝隙连接通道的连接蛋白（Cx）与炎性因子释放的相关性，结果发现自发性高血压大鼠外周血T淋巴细胞亚群比值异常，CD4+、CD8+T淋巴细胞Cx40和Cx43表达显著高于对照组，且与炎症因子IL-2、IL-6的释放呈正相关。在以上工作基础上，本课题组拟通过体外细胞实验和动物实验，应用缝隙连接通道与NF-κB通路阻断剂，通过检测T淋巴细胞亚群比值，相关炎症因子，Cx40、Cx43的表达，以及动脉血压和靶器官损伤等。阐明缝隙连接通道与NF-κB信号通路在高血压发病过程中的作用及其作用机制。

高血压是一种多因素的慢性疾病，发病过程中伴随着低度炎症反应，以T淋巴细胞亚群比值和细胞因子释放异常为主要特征，T淋巴细胞间存在缝隙连接通道，在细胞增殖、活化及炎症因子释放过程发挥重要作用，但缝隙连接是否参与高血压炎症反应目前尚不清楚。我们的研究发现：（1）原发性高血压患者外周血CD4＋/CD8＋比值显著增加；外周血CD4＋和CD8＋T淋巴细胞Cx40和Cx43表达显著上调；原发性高血压患者血清炎症因子IFN-γ和TNF-ɑ表达水平显著上调，且与Cx40和Cx43高表达呈显著正相关；缝隙连接阻断剂Gap27可显著下调淋巴细胞内以及细胞上清中炎症因子IFN-γ和TNF-ɑ表达。（2）高血压时炎症反应伴随大鼠外周血T淋巴细胞亚群紊乱、炎症细胞因子释放，外源性给予雌激素干预后可改善以上现象；雌激素能够下调ConA活化作用下淋巴细胞连接蛋白的表达和缝隙连接通讯功能。上述研究结果证实高血压通过上调连接蛋白的表达，增强T淋巴细胞间缝隙连接通讯，炎症因子的释放增加。缝隙连接通道阻断剂通过抑制缝隙连接通道信息传递作用，改变缝隙连接介导的T淋巴细胞增殖活化用，降低炎症因子的释放，提示缝隙连接参与调节高血压炎症反应。此外，雌激素可以通过调节T淋巴细胞间缝隙连接通道改善高血压造成的靶器官损害。