氧化型低密度脂蛋白通过下调TET2抑制人脐静脉内皮细胞增殖和迁移

Oxidized Low Density Lipoprotein Inhibits Human Umbilical Vein Endothelial Cell Proliferation and Migration via Downregulation of TET2

目的探讨TET2在氧化型低密度脂蛋白(ox-LDL)抑制人脐静脉内皮细胞(HUVEC)增殖和迁移中的作用及其机制。方法分别以0、25、50、75 mg/L ox-LDL孵育HUVEC 24 h,Western blot检测ox-LDL对HUVEC TET2表达的影响。噻唑蓝法检测TET2对ox-LDL处理的HUVEC增殖的影响;Transwell实验和划痕实验检测TET2干预对HUVEC迁移的影响;免疫荧光法检测TET2干预对HUVEC细胞骨架的影响;Western blot检测HUVEC总Rac1及磷酸化Rac1的表达。结果 ox-LDL呈浓度依赖性地下调TET2的表达。过表达TET2改善ox-LDL对HUVEC增殖和迁移的抑制,低表达TET2进一步抑制HUVEC增殖和迁移。免疫荧光结果表明,ox-LDL促进HUVEC周边致密带的形成,过表达TET2抑制致密带的形成,低表达TET2进一步加强致密带的形成。Western blot结果表明,ox-LDL抑制HUVEC Rac1蛋白的表达,过表达TET2上调HUVEC总Rac1及磷酸化Rac1的水平,低表达TET2进一步降低总Rac1及磷酸化Rac1的水平。结论 ox-LDL通过下调TET2的表达影响细胞骨架,从而抑制HUVEC的增殖和迁移。

Aim To investigate the effect of ten-eleven translocation oncogene family member 2( TET2) on oxidized low density lipoprotein( ox-LDL)-treated human umbilical vein endothelial cell( HUVEC) proliferation and migration. Methods HUVEC was incubated with 0,25,50,75 ox-LDL mg / L respectively for 24 h,and Western blot was used to detect HUVEC TET2 protein expression. Methyl thiazolyl tetrazolium( MTT) method was used to detect the effect of TET2 on ox-LDL-treated HUVEC proliferation. Transwell experiment and scratch experiment were used to detect the effect of TET2 intervention on ox-LDL-treated HUVEC migration. Immunofluorescence was used to detect the effect of TET2 intervention on HUVEC cytoskeleton,and Western blot was used to detect the expressions of total Rac1( tRac1) and phosphorylated Rac1( pRac1) in HUVEC. Results Oxidized low density lipoprotein inhibited HUVEC TET2 expression with a dose-dependent manner. TET2 overexpression improved the ox-LDL-induced HUVEC proliferation and migration inhibition,while TET2 low expression( TET2 shRNA) further inhibited HUVEC proliferation and migration. Immunofluorescence showed that ox-LDL induced the formation of HUVEC peripheral compact zone. TET2 overexpression inhibited the formation of compact zone induced by ox-LDL,while TET2 shRNA strengthened the compact zone formation.Western blot showed that ox-LDL inhibited the expression of Rac1 protein in HUVEC. TET2 overexpression increased the levels of tRac1 and pRac1 in HUVEC,while TET2 shRNA further decreased the levels of tRac1 and pRac1. Conclusion Oxidized low density lipoprotein can inhibit the expression of TET2,which regulate HUVEC cytoskeleton,so as to inhibit the proliferation and migration of HUVEC.