Dai Qingqing, Li Shujuan, Liu Ting, Zheng Jiayin, Han Song, Qu Aijuan, Li Junfa
Department of Neurobiology and Center of Stroke, Beijing Institute for Brain Disorders, School of Basic Medical Science, Capital Medical University, Beijing, China.
Department of Neurology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China.
J Cell Biochem. 2019 Jul;120(7):11498-11509. doi: 10.1002/jcb.28429. Epub 2019 Feb 11.
We previously reported that astrocytes are the main sources of interleukin (IL)-17A production that could aggravate neuronal injuries in ischemic stroke. However, the effects of IL-17A on ischemic astrocytes themselves and the underlying molecular mechanism are still unclear. In this study, we found that recombinant mouse (rm) IL-17A could significantly (P < 0.05 or <0.001) alleviate 1-hour oxygen-glucose deprivation (OGD)/reoxygenation (R) 24-hour-induced ischemic injuries in cortical astrocytes with a dose-dependent manner (n = 6 per group). The Western blot and cell cycle analysis results revealed that rmIL-17A significantly ( P < 0.05) inhibited procaspase-3 cleavage without affecting cell proliferation in 1-hour OGD/R 24-hour-treated cortical astrocytes (n = 6 per group). Among the five IL-17 receptor subunits (IL-RA, -RB, -RC, -RD, and -RE), only IL-17RA ( P < 0.01) and -17RC ( P < 0.05) membrane translocation (not messenger RNA and protein) levels were downregulated in cortical astrocytes following 1-hour OGD/reperfusion 24 hours, and rmIL-17A could significantly ( P < 0.05 or <0.001) inhibit this downregulation (n = 6 per group). To further verify the impact of IL-17A on the neurological outcome of ischemic stroke, we found that the intracerebroventricular injection of IL-17A neutralizing monoclonal antibody remarkably ( P < 0.001) reduced the astrocyte activation and improve neurological function ( P < 0.05 or <0.01) of mice following 1-hour middle cerebral artery occlusion/reperfusion (R) 3 to 7 days (n = 6 or 8 per group). These results suggested that IL-17A-mediated alleviation of cortical astrocyte ischemic injuries could affect the neurological outcome of mice with ischemic stroke, which might be mainly dependent on the cell apoptosis pathway through inhibiting the downregulation of IL-17RA and -17RC membrane translocations.
我们之前报道过，星形胶质细胞是白细胞介素（IL）-17A产生的主要来源，其可加重缺血性脑卒中的神经元损伤。然而，IL-17A对缺血性星形胶质细胞自身的影响及其潜在分子机制仍不清楚。在本研究中，我们发现重组小鼠（rm）IL-17A能够以剂量依赖的方式显著（P < 0.05或<0.001）减轻1小时氧糖剥夺（OGD）/复氧（R）24小时诱导的皮质星形胶质细胞缺血性损伤（每组n = 6）。蛋白质印迹和细胞周期分析结果显示，rmIL-17A在1小时OGD/R 24小时处理的皮质星形胶质细胞中显著（P < 0.05）抑制了半胱天冬酶原-3的切割，而不影响细胞增殖（每组n = 6）。在五个IL-17受体亚基（IL-RA、-RB、-RC、-RD和-RE）中，仅IL-17RA（P < 0.01）和-17RC（P < 0.05）的膜转位（而非信使核糖核酸和蛋白质）水平在1小时OGD/再灌注24小时后的皮质星形胶质细胞中下调，且rmIL-17A能够显著（P < 0.05或<0.001）抑制这种下调（每组n = 6）。为进一步验证IL-17A对缺血性脑卒中神经功能结局的影响，我们发现脑室内注射IL-17A中和单克隆抗体可显著（P < 0.001）减少1小时大脑中动脉闭塞/再灌注（R）3至7天后小鼠的星形胶质细胞活化并改善神经功能（P < 0.05或<0.01）（每组n = 6或8）。这些结果表明，IL-17A介导的皮质星形胶质细胞缺血性损伤减轻可能影响缺血性脑卒中小鼠的神经功能结局，这可能主要依赖于通过抑制IL-17RA和-17RC膜转位下调的细胞凋亡途径。
