卒中再灌注期脑血管病变引起SCG交感神经元凋亡：脑血管平滑肌神经营养作用的新发现

自主神经功能紊乱是卒中预后不良的独立危险因素，脑缺血再灌注引起自主神经功能障碍的病因是当下研究的难点。申请人在小鼠缺血再灌注后发现脑血管去交感支配、颈上神经节(SCG)交感神经元凋亡，提示脑部损伤继发外周神经元凋亡。进一步实验发现，脑vSMC分泌上清有效促进成年SCG神经元存活，质谱提示脑膜vSMC至少稳定分泌27种基质蛋白，其中22种在缺氧缺糖后不表达。我们发现，脑膜vSMC分泌上清促进成年SCG交感神经元存活。申请人决定另辟蹊径，从血管─神经互作的角度，解析再灌注期“交感神经─脑vSMC”单元病变机制。我们推测：脑vSMC是卒中引起SCG神经元损伤的“感受器”，即缺血再灌注后脑vSMC源性神经营养因子减少，引起SCG交感神经元凋亡。本课题拟在原代细胞、SCG外植体、小鼠模型层面，应用流式分选、体外共培养、转基因动物等技术，从“血管营养神经”的角度阐释脑血管损伤后交感神经紊乱的病因。

Autonomic dysfunction is an independent risk factor for poor prognosis of stroke. The etiology of autonomic dysfunction caused by cerebral ischemia-reperfusion is the current research difficulty. After ischemia-reperfusion in mice, the applicant found sympathetic denervation in cerebral arteries, then neuron apoptosis in superior cervical ganglion (SCG). The phenomenon suggested that brain injury led to peripheral neuron apoptosis. Further experiments showed that the secreted supernatant of brain vascular smooth muscle cell (vSMC) effectively promoted adult SCG neurons survival. Mass spectrometry showed that meningeal vSMC could stably secrete at least 27 proteins, of which 22 matrix proteins were not expressed after hypoxia and glucose deprivation. We found that the supernatant secreted by meningeal vSMC promoted the survival of adult SCG sympathetic neurons. The applicant decided to find another way to analyze the pathological mechanism of "sympathetic neuron - brain vSMC" unit in reperfusion period from the perspective of vessel - neuron interaction. We speculate that brain vSMC is the "sensor" of stroke induced SCG neuron damage, that is, the decrease of brain vSMC derived neurotrophic factors after ischemia-reperfusion leads to the apoptosis of SCG sympathetic neurons. The purpose of this project is to explain the etiology of sympathetic disorder after cerebrovascular injury from the perspective of "vessel supported neuron" by using flow cytometry, co-culture in vitro and transgenic animal technology at the level of primary cells, SCG explants and mouse models.