CCM3基因与砷暴露交互作用对血管发育的影响及机制研究

Early vascular damage and adult health effects caused by low-dose arsenic exposure in early life have attracted much attention, but the specific mechanism is unclear. CCM3 gene plays an important role in vascular development and remodeling, and it can also interact with a variety of proteins to regulate vascular development. CCM3 gene also plays an important role in cell proliferation, differentiation and apoptosis, and it is an important environmental response gene. We found that arsenic can regulate the up-regulation of CCM3 by miR-425-5p, and Notch/p38/VEGF signaling pathway play an important role in arsenic inhibition of angiogenesis. Recent results showed that CCM3 gene knockout mouse brain microvascular endothelial cell proliferation and inhibit pericyte in vitro, knockdown of CCM3 in endothelial cells and pericyte were also observed the different outcomes, suggesting that there are closely relation between CCM3 deficiency and vascular abnormalities. This project will be based on the previous study, observe the deletion of CCM3 in sodium arsenite exposure on embryonic vascular development and vascular abnormalities in adult offspring with CCM3 gene knockout mice; investigate mechanism of arsenic exposure and CCM3 defects in abnormal vascular development via separation of offspring mouse brain microvascular endothelial cells and pericytes; uncover the biological function of CCM3 and its molecular mechanism via regulating Notch signaling pathway in vascular development, which will provide a theoretical basis for prevention of vascular dysplasia from the interaction of genetic and environmental.

生命早期低剂量砷暴露引起的血管损伤效应及成年后健康效应已引起关注，然而具体机制不明。CCM3基因作为一种重要的环境应答基因在血管发育重塑中有重要作用。我们发现砷可经由miR-425-5p诱导CCM3表达进而调控Notch/p38/VEGF信号通路，在砷抑制血管生成中发挥重要作用；CCM3基因敲除小鼠脑血管内皮细胞增生而周细胞则抑制，体外敲除CCM3的内皮细胞和周细胞也观察到一样的结果。以上结果提示CCM3缺失与血管发育异常有密切关系，但是CCM3调控Notch信号通路在砷致血管发育中的生物学作用及机制尚不清楚。本项目将在前期研究基础上，采用CCM3基因敲除小鼠和细胞模型，在动物和细胞水平上观察砷与CCM3基因交互作用在血管发育异常中的作用；进而从转录调控和蛋白质相互作角度深入探讨CCM3调控Notch信号通路在砷致血管发育异常的分子机制，以期为血管发育异常病因及防治提供理论依据。

背景：. 生命早起低剂量砷暴露引起的血管损伤效应及成年的健康效应已引起关注，然而具体机制不明。CCM3基因作为一种重要的环境应答基因在血管发育重塑中有重要作用。我们发现砷可经由miR-425-5p诱导CCM3表达进而调控Notch/p38/VEGF信号通路，在砷抑制血管生成中发挥重要作用；CCM3基因敲除小鼠脑血管内皮细胞增生而周细胞则抑制，体外敲除CCM3的内皮和周细胞也观察到一样的结果，我们的研究结果提示CCM3缺失与血管发育异常有密切关系。.研究内容：. 本项目将在前期研究基础上，采用CCM3基因敲除小鼠，观察CCM3缺失在亚砷酸钠暴露后胚胎血管发育及成年子代血管异常中的作用；体外分离砷暴露子代小鼠脑微血管内皮细胞和周细胞，构建体外CCM3基因敲除的HUVEC和pericyte细胞模型；从蛋白互作角度深入探讨CCM3调控Notch信号通路在血管发育异常的分子机制，从基因和环境相互作用的角度防治血管发育异常提供理论依据。 .结果及意义：. 结果显示：CCM3敲低后在HUVEC和pericyte中介导的血管形成效应不同，在HUVEC中起促进作用，而pericyte中则发挥抑制作用；氧化应激在其血管生成效应中发挥一定作用；且Notch、p38，ERK1/2信号分子在CCM3敲低后HUVEC和pericyte细胞中介导的血管形成起调控作用。. 1ppm亚砷酸钠饮水染毒整个孕期及出生后3个月后，视网膜血管可见明显增生，而10ppm则可抑制血管生成。血清中氧化应激损伤指标MDA在1ppm和10ppm时则显著增高，而GSH则降低，缺陷型小鼠比野生型小鼠降低或增高更敏感，提示CCM3缺陷可导致对化学物处理更加敏感。CCM3基因缺陷的小鼠对照组和1ppm染毒组中视网膜血管生成增多，而10ppm则缺陷型比野生型血管生成降低，在一定范围内，CCM3敲低后可维持机体平衡，但是损伤达到一定程度后，CCM3缺陷反而会对化学物更加敏感。CCM3缺失小鼠中分离的内皮细胞中Notch1表达降低，分离的内皮细胞和周细胞中高剂量组ERK1/2信号通路显著降低，提示Notch及ERK1/2信号通路在砷导致的血管生成中发挥作用，可为从基因和环境相互作用的角度防治血管发育异常提供理论依据。