caspase-3限制小鼠脑卒中恢复期齿状回神经前体细胞增殖

 目的  探讨caspase-3对脑卒中恢复期海马齿状回(dentate gyrus,DG)神经前体细胞(neuronal precursor cells,NPCs)增殖的作用。方法  构建小鼠大脑中动脉远端堵塞(distal middle cerebral artery occlusion,dMCAO)缺血模型,取缺血手术后第7天缺血侧DG进行体外细胞培养。研究分为对照组和给药组(caspase-3抑制剂给药组);采用Western blot、免疫细胞化学、流式细胞仪和TUNEL染色检测DG NPCs中caspase-3的表达及NPCs的凋亡和增殖情况。在小鼠脑卒中后第14天,采用免疫组织化学方法检测caspase-3抑制对DG NPCs增殖的影响。结果  体外培养的源自脑缺血后DG的神经球NPCs大量表达激活型caspase-3,但是超过87%的caspase-3阳性细胞与TUNEL阳性没有共定位关系。caspase-3限制了DG NPCs的自我更新,但并未参与细胞的凋亡过程。抑制caspase-3可促进脑卒中恢复期DG NPCs的增殖。结论  caspase-3 可通过细胞凋亡之外的途径调控缺血性脑损伤后的神经再生。

Restricted effect of caspase-3 on proliferation of neuronal precursor cells in dentate gyrus of mice during stroke recovery

Objective  To investigate the effect of caspase-3 on the proliferation of neuronal precursor cells (NPCs) in the dentate gyruse (DG) during stroke recovery. Methods  The stroke model was produced by electrocoagulating the distal middle cerebral artery (dMCA) of mice, then the NPGs were cultered from ischemia DG on the 7th day after stroke. Treatment groups and control groups were assigned in a randomized manner. The expression of caspase-3 and apoptosis and proliferation of NPCs were analyzed by Western blot, immunocytochemistry, flow cytometry analysis and TUNEL staining in NPCs cultured from ischemic DG. Besides, the effects of caspase-3 inhibition on the proliferation of NPCs in the DG was also investigated by immunohistochemistry in the mouse at 14 day after stroke.Results  Caspase-3 was expressed in cultured NPCs,but more than 87% of the caspase-3 positive cells  and TUNEL positive cells were not collocated. Caspase-3 negatively regulated self-renewal of NPCs,but did not participate in cell death in culture DG NPCs. Caspase-3 negatively regulated NPCs proliferation in the DG during stroke recovery.Conclusions  Caspase-3 may possess a novel function that limits the neurogenic response after stroke.