下丘脑室旁核小胶质细胞激活参与高血压发病机制的研究

以往对下丘脑室旁核活动增强引发交感神经过度兴奋参与高血压发病机制的研究多着眼于室旁核神经元，但室旁核小胶质细胞激活在高血压发生发展中的作用及其机制尚不清楚。本项目拟采用高血压模型大鼠、Csf1r条件性基因敲除小鼠，证实室旁核小胶质细胞激活参与高血压的发生发展；采用室旁核小胶质细胞原代培养结合细胞因子芯片及siRNA等分子生物学技术，阐明高血压时室旁核激活的小胶质细胞通过TLR4/MyD88/NF-κB信号通路介导炎性细胞因子释放的机制；采用室旁核原代小胶质细胞和神经元共培养、双侧室旁核慢性给药及小胶质细胞回输等技术明确高血压时室旁核激活的小胶质细胞通过释放炎性细胞因子引起室旁核神经元炎性反应、肾素-血管紧张素系统和NF-κB激活，氧化应激增强和神经递质失平衡进而导致交感神经活动增强和血压升高。本项目可望阐明室旁核小胶质细胞激活参与高血压的发病机制，为高血压的治疗提供新的实验依据和干预靶点。

The hypothalamic paraventricular nucleus (PVN) is an important central site for integration of sympathetic nerve activity. Recent studies have demonstrated that the activation of the PVN contributes to the pathogenesis of hypertension. A growing body of evidence has focused on the effects of neurons in the PVN, however very few studies have explored the role of activated microglia in the PVN in the pathogenesis of hypertension. The relationship between the neurons and the microglia in PVN is unclear. In this study, we will conduct a series of experiments in vivo and in vitro to investigate the microglial mechanisms of hypertension, by using conditional gene knockout techniques, cell co-culture techniques, cytokine chip techniques, siRNA techniques, chronic bilateral PVN infusion techniques, microglial cells transfusion techniques and molecular biology techniques. We will utilize spontaneously hypertensive rats, angiotensin II-induced hypertensive rats and Csf1r conditional knockout mice to determine the involvement of activated microglial cells in the pathogenesis of hypertension. In addition, we will investigate whether microglial cells release proinflammatory cytokines through TLR4/MyD88/NF-κB signaling pathway, and the proinflammatory cytokines released by the activated microglia stimulate PVN neurons; and then activated neurons in PVN induce activation of renin-angiotensin system, overproduction of reactive oxygen species, high levels of proinflammatory cytokines, imbalance of neurotransmitters, and the activation of NF-κB, which cause renal sympathetic hyperactivity, vascular dysfunction and hypertensive responses. Wild type and Csf1r conditional knockout mice will be utilized to confirm this hypothesis. Further exploration of the detailed mechanisms of the interactions between microglial cells and neurons within the PVN may be beneficial towards the development of novel hypertensive therapeutics. The present study will provide new insights into the activated neurons and the activated microglial cells in the PVN in hypertension, which contributes to expand our knowledge about the pathogenesis of hypertension. This study will provide potential targets for prevention and treatment of hypertension and so have important clinical implications.