GDNF和NO对局灶性脑缺血大鼠皮质和尾壳核神经干细胞增殖和分化的影响

Effect of GDNF and NO on the proliferation and differentiation of neural stem cells in the cortex and caudoputamen of adult rats after focal cerebral ischemia

目的观察胶质细胞源性神经营养因子(GDNF)对局灶性脑缺血大鼠皮质和尾壳核神经干细胞(NSCs)增殖分化以及nNOS阳性神经元分布的影响,探讨GDNF和NO对内源性NSCs增殖分化影响的作用机制。方法制作右侧局灶性脑缺血模型,左侧脑室注射GDNF,5-溴脱氧尿嘧啶(BrdU)标记DNA合成期(S期)细胞,免疫组化观察正常组、假手术组、脑缺血组、生理盐水组和GDNF组大鼠局灶性脑缺血90min后再灌注时间分别为3d、7d、14d、21d、28d的BrdU/nNOS、BrdU/NeuN、BrdU/GFAP双标阳性细胞。结果GDNF组较脑缺血组和生理盐水组行为学恢复明显;脑缺血后皮质和尾壳核BrdU和nNOS阳性细胞增多,BrdU/nNOS(38．23%±6．87%)、Br- dU/NeuN(52．38%±13．29%)、BrdU/GFAP(13．51%±8．78%)双标细胞阳性率明显增加,与其它组比较均有显著性差异(P＜0．05)。结论局灶性脑缺血激活内源性NSCs,GDNF可调节NO释放,促进NSCs增殖、分化。

Objective To observe the effect of glial cell-lined derived neurotrophic factor（GDNF） on the proliferation and differentiation of endogenetic neural stem cells in the cortex and caudoputamen in adult rats after focal cerebral isehemia,and explore the function of GDNF and NO on endogenetic NSCs in the adult rats after focal cerebral isehemia. Methods The right middle cerebral artery of rats was occluded for 90 minutes to establish transient focal cerebral isehemia reperfusion model. GDNF was injected stereotaxically into the left lateral ventricle. Bromodeoxyuridine （BrdU） was used to label the S phase cells to detect the proliferation of NSCs in every group. The immunohistoehemistry double staining was used to observe the expression positive cells of BrdU/nNOS,BrdU/NeuN and BrdU/GFAP double positive ceils in the cortex and caudoputamen of groups. Results The recovery of the praxiology of rats injected with GDNF was apparently better than the cerebral isehemia group and the saline group. The amount of BrdU and nNOS positive cells of the GDNF group obviously increased,and BrdU/nNOS （ 38.23 % ± 6. 87 % ）, BrdU/NeuN （ 52. 38 % ±13. 29 % ）and BrdU/GFAP （ 13. 51 %± 8. 78 ± ）double positive cells were much more than the corresponding control groups. Conclusion GDNF can enhance the proliferation ability of endogenetie NSCs in the cortex and eaudoputamen and promote the differentiation toward neurons.