Division of Emergency Medicine, Department of General Internal Medicine, Department of Emergency Intensive Care Unit, The First Affiliated Hospital of Sun Yat-sen University, No.58, Zhongshan 2nd Road, Guangzhou 510080, China.
Department of Cardiology, The First Affiliated Hospital of Sun Yat-sen University, No.58, Zhongshan 2nd Road, Guangzhou 510080, China.
Exp Cell Res. 2019 Feb 1;375(1):42-51. doi: 10.1016/j.yexcr.2018.12.009. Epub 2018 Dec 14.
Protein kinase RNA-like Endoplasmic Reticulum Kinase (PERK) is an endoplasmic reticulum stress sensor that possesses pro-survival capability and contributes to cell homeostasis and survival. Leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5) has been recognized as a stem cell marker in intestinal epithelial cells. To determine whether PERK modulates the proliferation of intestinal stem cells, we investigated the effects of PERK knock-down on intestinal Lgr5-positive stem cells in mice. Lgr5-EGFP knock-in mice were fed with lentivirus-PERK shRNA twice a day for three days. Isolated intestinal Lgr5-positive stem cells were treated with lentivirus-PERK shRNA. The number of Lgr5-positive cells, the proliferation and apoptotic indices, several biomarkers for proliferation and differentiation, and Akt expression in intestinal stem cells were detected in vivo, in vitro and in two intestinal epithelial injury models caused by radiotherapy and sepsis. PERK knock-down could significantly diminish the number and proliferation of Lgr5-positive cells, induce the low expression of several proliferation markers and the high expression of several differentiation markers in Lgr5-positive cells, enhance the apoptotic Lgr5-positive cells, and reduce the Akt expression in intestinal Lgr5-positive stem cells. Similar results were observed in radiotherapy- and sepsis-induced intestinal injuries. Moreover, PERK inhibition markedly decreased the survival of mice in response to radiation and sepsis. These results suggest a critical role for PERK in the proliferation and survival of intestinal stem cells in mice.
蛋白激酶 RNA 样内质网激酶 (PERK) 是内质网应激传感器，具有促生存能力，并有助于细胞内稳态和存活。富含亮氨酸重复的 G 蛋白偶联受体 5 (Lgr5) 已被认为是肠上皮细胞中的干细胞标志物。为了确定 PERK 是否调节肠干细胞的增殖，我们研究了 PERK 敲低对小鼠肠 Lgr5 阳性干细胞的影响。将 Lgr5-EGFP 敲入小鼠每天两次用慢病毒-PERK shRNA 喂养三天。用慢病毒-PERK shRNA 处理分离的肠 Lgr5 阳性干细胞。在体内、体外和两种由放疗和脓毒症引起的肠上皮损伤模型中检测肠干细胞中的 Lgr5 阳性细胞数量、增殖和凋亡指数、几种增殖和分化标志物以及 Akt 表达。PERK 敲低可显著减少 Lgr5 阳性细胞的数量和增殖，诱导 Lgr5 阳性细胞中几种增殖标志物的低表达和几种分化标志物的高表达，增加凋亡的 Lgr5 阳性细胞，并降低肠 Lgr5 阳性干细胞中的 Akt 表达。在放疗和脓毒症引起的肠损伤中也观察到类似的结果。此外，PERK 抑制显著降低了小鼠对辐射和脓毒症的存活。这些结果表明 PERK 在小鼠肠干细胞的增殖和存活中起关键作用。
