抑制PDGFRα活化对小鼠脑损伤后胶质细胞增殖和瘢痕形成的影响

doi:10.13481/j.1671-587x.20200520

摘要/Abstract

摘要： 目的：探讨抑制血小板衍生生长因子受体α（PDGFRα）活化对小鼠脑损伤后胶质细胞增殖和小鼠脑损伤后瘢痕形成的影响，并阐明其作用机制。方法：选取48只8周龄BALB/c小鼠，制备小鼠黑质纹状体通路损伤模型，分为PDGFRα抑制剂AG1296组（AG1296组）和二甲基亚砜（DMSO）对照组（DMSO组），每组24只。AG1296组小鼠手术后连续3 d应用微量注射器沿损伤部位注入抑制剂AG1296，每日5 μL（5 mmol·L^-1），DMSO对照组小鼠注入同等剂量的DMSO。术后第1、4、7和14天各取6只小鼠脑损伤前后2 mm脑组织用于检测。应用免疫组织化学染色和Western blotting法检测各组小鼠脑组织中磷酸化PDGFRα（p-PDGFRα）、星形胶质细胞标志物胶质纤维酸性蛋白（GFAP）和小胶质细胞标志物离子钙接头蛋白分子1（IBA-1）蛋白表达水平。免疫组织化学染色检测各组小鼠脑组织中NG2、CD45、纤连蛋白（FN）和Ⅳ型胶原蛋白（ColⅣ）蛋白表达。结果：免疫组织化学染色，在损伤后4 d小鼠脑组织中p-PDGFRα棕黄色阳性表达细胞数最多，GFAP蛋白在损伤后14 d表达量最多，IBA-1蛋白在伤后7 d表达量最多。各时间点AG1296组小鼠脑组织中p-PDGFRα、GFAP和IBA-1蛋白表达水平明显低于DMSO组。Western blotting法检测，AG1296组小鼠脑组织中p-PDGFRα、GFAP和IBA-1蛋白表达水平明显低于DMSO组（P<0.01）。损伤后14 d，免疫组织化学染色结果显示AG1296组NG2、CD45、FN和ColⅣ阳性表达细胞数较DMSO组明显减少；瘢痕形成情况，AG1296组大鼠脑组织损伤中心的大空洞消失，仅留下一条缝隙，损伤周边虽然仍有许多GFAP阳性表达的胶质细胞，但未形成明显的境界膜，其他阳性表达细胞明显少于DMSO组。结论：抑制PDGFRα的活化可以降低小鼠脑损伤后胶质细胞的增殖，进而减少瘢痕组织形成。

关键词: 血小板衍生生长因子受体, 脑损伤, 星形胶质细胞, 小胶质细胞, 瘢痕

Abstract: Objective: To investigate the effect of inhibiting the activation of platelet-derived growth factor receptor α(PDGFRα) on the proliferation of glial cells and the scar formation after brain injury in the mice,and to clarify its mechanism. Methods: A total of 48 8-weeks-old BALB/c mice were selected to establish the damage models of nigra striatum pathway. The model mice were divided into PDGFRα inhibitor AG1296 group(AG1296 group) and DMSO control group (DMSO group) (n=24); the mice in AG1296 group were injected with inhibitor AG1296 along the injured site for 3 d after operation, 5 μ L (5 mmol·L^-1) every day,and the mice in DMSO group were injected with the same dose of DMSO. On the 1st, 4th, 7th and 14th days after operation, 2 mm brain tissues were taken before and after brain injury of every 6 mice were obtained. The expression levels of phosphorylated PDGFRα (p-PDGFRα), glial fibrilary acidic protein(GFAP) and ionized calcium binding adaptor molecle 1(IBA-1) proteins were detected by immunohistochemistry and Western blotting method. The expressions of NG2,CD45,fibronectin (FN) and type Ⅳ collagen (Col Ⅳ) in brain tissue of the mice were detected by immunohistochemistry. Results: The results of immunohistochemistry showed that the number of cells with the brownish yellow positive expression of p-PDGFRα in brain tissue of the mice was the most 4 d after injury,the GFAP perotein had the highest positive expression 14 d after injury,and IBA-1 protein had the highest positive expression 7 d after injury. The expression levels of p-PDGFRα, GFAP,and IBA-1 proteins in brain tissue of the mice in AG1296 group were significantly lower than those in DMSO group at different time points. The results of Western blotting showed that the expression of p-PDGFRα, GFAP and IBA-1 in AG1296 group were significantly lower than those in DMSO control group (P<0.01). The immunohistochemistry staining results showed that the number of NG2,CD45,FN,and ColⅣ positive expression cells in AG1296 group was significantly decreasesd compared with DMSO group 14 d after injury.The scar formation results showed that in AG1296 group, the large cavity in the injury center of brain tissue of the mice disappeared, leaving only a gap; there were still many GFAP positive glial cells around the injury, but there was no obvious boundary membrane, and the number of other positive cells was significantly less than that in DMSO group. Conclusion: Inhibiting the activation of PDGFRα can reduce the proliferation of glial cells after brain injury, and then reduce the formation of scar tissue.

Key words: platelet-derived growth factor receptor, brain injury, astrocytes, microglia, scar

中图分类号:

R322.81

裴丹, 刘学. 抑制PDGFRα活化对小鼠脑损伤后胶质细胞增殖和瘢痕形成的影响[J]. 吉林大学学报(医学版), 2020, 46(05): 1023-1028.

PEI Dan, LIU Xue. Effect of inhibition of PDGFRα activation on glial cell proliferation and scar formation after brain injury in mice[J]. Journal of Jilin University(Medicine Edition), 2020, 46(05): 1023-1028.

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