CREG基因沉默诱导小鼠ESCs来源的EBs自发性凋亡

目的: 探讨E1A激活基因阻遏子(CREG)基因沉默诱导鼠源性胚胎干细胞(ESCs)来源的胚胎小体(EBs)自发性凋亡的作用。方法: 应用pDS-shRNA-CREG逆转录病毒真核表达载体和绿色荧光蛋白(GFP)的对照载体,感染鼠源性胚胎干细胞R1,筛选获得稳定的细胞克隆(R1-shCREG和R1-GFP);用小鼠胚胎成纤维细胞株STO作为饲养细胞,进行R1、R1-shCREG和R1-GFP细胞培养。倒置显微镜观察3种ESCs的生长情况。碱性磷酸酶(AKP)染色和小鼠心肌接种畸胎瘤形成实验检测转染后ESCs分化情况。当ESCs生长至亚融合状态时进行传代,去除白血病抑制因子(LIF)并悬浮培养制备EBs。用RT-PCR技术和Western blotting方法分别检测3组EBs培养7 d时CREG和cleaved caspase-3蛋白和mRNA的表达, Annexin V/PI流式细胞术检测EBs细胞凋亡情况。结果: 经pDS-shRNA-CREG逆转录病毒真核表达载体及 GFP的质粒载体转染获得稳定转染的细胞克隆。AKP染色证实R1、R1-GFP和R1-shCREG 3组ESCs均保持未分化状态。同时,体内和体外分化研究证实,R1和R1-GFP组细胞具有三胚层分化能力,小鼠心肌内注射的ESCs形成畸胎瘤组织;而R1-shCREG则不能够形成畸胎瘤类似物,细胞分化能力降低,且细胞死亡现象增加。培养7 d的R1-shCREG/EB组 CREG蛋白表达量较R1/EB组和R1-GFP/EB组均降低; CREG的mRNA表达下降;而cleaved caspase-3 mRNA和蛋白表达均显著升高;同时, R1-shCREG/EB细胞凋亡率明显升高。结论: 下调CREG表达可抑制ESCs分化,促进ESCs来源的EBs细胞凋亡的发生。

CREG gene silencing induces spontaneous apoptosis of ESCs-derived EBs

AIM: To investigate the effect of cellular repressor of E1A-stimulated genes(CREG) on the spontaneous apoptosis of murine embryonic stem cells(ESCs)-derived embryoid bodies(EBs).METHODS: The murine ESCs R1 were infected with pDS-shRNA-CREG and pDS-shRNA-GFP retrovirus,respectively.R1,R1-GFP and R1-shCREG were cultured on STO feeder cells in DMEM supplied with leukemia inhibitory factor(LIF).Alkaline phosphatase(AKP) staining and teratoma formation assay inoculated into mouse myocardium were used to detect s...