circRNA SIPA1L1修饰牙髓干细胞来源外泌体促血管生成能力的机制

Study on the angiogenic ability of exosomes derived from dental pulp stem cells modified by circRNA SIPA1L1

目的 探究环状RNA(circRNA)信号诱导增殖相关蛋白1样蛋白1(SIPA1L1)修饰的人牙髓干细胞(hDPSC)来源外泌体(Exo)对人脐静脉内皮细胞(HUVEC)血管生成能力的影响及机制。方法 从牙髓组织分离培养hDPSC,将circSIPA1L1过表达质粒载体转染至hDPSC后,分离Exo并进行鉴定。将HUVEC分为对照组、hDPSC Exo组、circSIPA1L1-hDPSC Exo组,培养48 h后,Matrigel基质胶血管形成实验检测血管形成能力,qRT-PCR和Western blot测定血管内皮细胞生长因子(VEGF)、血管内皮细胞生长因子受体2(VEGFR2)、胎盘生长因子(PGF)的表达水平。结果 从未转染的hDPSC与转染circSIPA1L1的hDPSC中成功分离出Exo,且相较于h DPSC来源的Exo,转染circSIPA1L1的hDPSC来源的Exo中circSIPA1L1相对表达量显著上调(P <0.05)。与hDPSC Exo组比较,circSIPA1L1-hDPSC Exo组HUVEC的管样结构形成数目显著增加(P <0.05),VEGF、VEGFR2、PGF mRNA与蛋白相对表达量也显著上调(P<0.05)。结论 circRNA SIPA1L1修饰hDPSC来源的Exo能够促进血管生成,其机制可能与上调VEGF、VEGFR2、PGF的表达水平有关。

Objective To investigate the effect of human pulp stem cells(hDPSC)-derived exosomes(Exo)modified by circRNA(circRNA)signal-induced proliferation-associated protein-like 1(SIPA1L1)on the angiogenesis of human umbilical vein endothelial cells(HUVEC).Methods hDPSC was isolated and cultured from pulp tissue,the circSIPA1L1 overexpression plasmid was transfected into hDPSC,and Exo was isolated and identified.HUVEC was divided into control group,hDPSC Exo group and circSIPA1L1-hDPSC Exo group.After culture for 48 h,the vasculoformation ability was detected by Matrigel matrix gel vasculoformation test,the expres⁃sion levels of vascular endothelial growth factor(VEGF),vascular endothelial growth factor receptor 2(VEGFR2)and placental growth factor(PGF)were determined by qRT-PCR and Western blot.Results The Exo was success⁃fully isolated from the untransfected hDPSC and the hDPSC transfected with circSIPA1L1,and compared with the HDPSC-derived Exo,the relative expression of circSIPA1L1 in the hDPSC Exo transfected with circSIPA1L1 was significantly up-regulated(P<0.05).Compared with hDPSC Exo group,the number of HUVEC tubular structures in circSIPA1L1-hDPSC Exo group was significantly increased(P<0.05),and the mRNA and protein relative expressions of VEGF,VEGFR2 and PGF were also significantly up-regulated(P<0.05).Conclusions Modification of hDPSC-derived Exo by circRNA SIPA1L1 can promote angiogenesis,and the mechanism may be related to up-regulation of VEGF,VEGFR2 and PGF expression levels.