iPSC-MSCs抑制ApoE(-/-)小鼠动脉粥样硬化斑块形成及其机制

Inhibitory effect of iPSC-MSCs on atherosclerotic plaque formation in Apo E(-/-) mice and its mechanism

目的探究诱导性多能干细胞源性间充质干细胞(iPSC-MSCs)对高脂饲养的ApoE(-/-)小鼠的动脉粥样硬化抑制作用及其相关机制。方法 40只8周的ApoE-/-小鼠随机分为4组,每组10只:普通饲料组:给予普通饲料喂养,高脂饲料组:给予高脂饲料喂养,干细胞组:给予高脂喂养同时尾静脉注射iPSC-MSCs,PBS组:给予高脂喂养同时尾静脉注射PBS。12周后观察小鼠主动脉粥样硬化斑块形成情况、血脂水平、炎症因子水平以及Nothc1蛋白的表达情况。结果高脂喂养后,高脂组ApoE(-/-)小鼠的斑块面积较普通饲料组明显增多,且小鼠总胆固醇(CHOL)、低密度脂蛋白(LDL)、TNF-α、IL-6分别为(32.02±2.32)mmol/L、(20.36±0.90)mmol/L、(534.30±89.51)pg/ml、(32.69±1.86)pg/ml均较普通饲料组明显升高,差异具有统计学意义(P<0.01);注射iPSC-MSCs后斑块面积明显减小,小鼠的CHOL、LDL、TNF-α、IL-6水平分别为(24.98±1.18)mmol/L、(15.34±1.54)mmol/L、(230.6±13.31)pg/ml、(8.54±2.02)pg/ml,较高脂组明显下降,差异具有统计学意义(P<0.05)。且高脂组中ApoE(-/-)小鼠的Notch1蛋白水平要明显高于普通饲料组(P<0.01),iPSC-MSCs干预后Notch1蛋白表达水平要明显低于高脂组(P<0.05),PBS对于ApoE(-/-)小鼠Notch1蛋白表达无影响(P>0.05)。结论 iPSC-MSC可以抑制ApoE(-/-)小鼠动脉粥样硬化斑块形成,可能与iPSC-MSCs可以减轻ApoE(-/-)小鼠TNF-a、IL-6等炎症因子水平,降低胆固醇含量,下调Notch1的蛋白表达有关。

Objective This study is to investigate whether mesenchymal stem cells derived from induced pluripotent stemcells（iPSC-MSCs）could alleviate atherosclerosis and its possible modulating mechanism in high-fat fed ApoE（-/-）mice.Methods 40 8-week old ApoE（-/-）mice were divided into four groups. Regular diet group：10 mice were fed withregular diet. High fat diet（HFD）group：10 mice were fed with high fat diet. iPSC-MSCs group ：iPSC-MSCs wereintravenously administered to ApoE-/-mice fed on a HFD. PBS group ：PBS was intravenously administered to ApoE（-/-）mice fed on a HFD. After 12 weeks,aortas and serum were obtained from ApoE（-/-） mice to detect the sizes ofatherosclerotic plaques,lipid levels,cytokines levels and the expression of Notch1. Results After fed with HFD,the ApoE（-/-）mice in HFD group have larger plaque size than RD group. What＇s more,the total cholesterol、LDL、TNF-α、IL-6concentrations are（32.02±2.32）mmol/L、（20.36±0.90）mmol/L、（534.30±89.51）pg/ml、（32.69±1.86）pg/ml,which are allhigher than those in RD group（P〈0.01）. Systematically administering iPSC-MSCs clearly reduced the size of plaques.Thetotal cholesterol、LDL、TNF-α、IL-6 concentrations are（24.98±1.18）mmol/L、（15.34±1.54）mmol/L、（230.60±13.31）pg/ml、（8.54±2.02）pg/ml,which are all lower than those in HFD group（P〈0.05）. In addition,the expression of Notch1 protein inHFD group is higher than that in RD group（P〈0.01）. after injecting iPSC-MSCs,we found that the the expression of Notch1 protein were down-regulated（P〈0.05）,PBS has no effect on Notch1 protein（P〉0.05）. Conclusion Systemicallyadministration of iPSC-MSCs suppressed the atherosclerotic lesions in ApoE（-/-）mice,which was probably related to thereduction of inflammatory cytokines,amelioration of lipid disorder and down-regulation of Notch signaling pathway.