脑出血患者血肿周围脑组织中P75NTR、TrkA的表达及其与细胞凋亡的关系

Expressions of P75NTR and TrkA in tissues surrounding the hematoma in patients with intracerebral hemorrhage and their association with cell apoptosis

目的通过对人脑出血后血肿周围不同区域组织中的P75NTR、TrkA表达的检测，探讨其在脑出血后血肿周围组织细胞凋亡中的作用。方法采集脑出血血肿清除术患者的脑组织标本，分别运用DNA断裂原位末端标记（TUNEL）法及免疫组化技术检测血肿周围及远隔部位组织中细胞凋亡率与P75NTR、TrkA的表达。结果相对于远隔部位组织．脑出血后血肿周围组织中的细胞凋亡率与P75NTR的表达水平明显增加（P〈0．05），而TrkA的表达水平并没有明显变化（P〉0．05），P75NTR的阳性细胞率与TUNEL阳性细胞率呈正相关（r=0．628，P=-0．000）。结论脑出血后血肿周围组织中凋亡细胞明显增多，P75NTR介导的细胞凋亡通路可能发挥了重要的作用：TrkA在脑出血发生后并没有增量表达以增加细胞存活，未起到拮抗P75NTR介导的细胞凋亡作用。

Objective To detect the expressions of P75NTR and TrkA in different brain tissues surrounding the hematoma in patients with intracerebral hemorrhage （ICH） and their roles in cell apoptosis following ICH. Methods The brain tissue samples were collected from patients with ICH during hematoma evacuation. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling （TUNEL） and immunohistochemistry were employed to detect the cell apoptosis and expressions of P75NTR and TrkA in the surrounding and distant tissues of the hematoma, respectively. Results Compared with the distant tissues, the tissues surrounding the hematoma showed significantly increased cell apoptotic rate and P75NTR expression （P〈0.05）, but the expression level of TrkA remained unchanged （P〉0.05）. A significant positive correlation was found between P75NTR expression and TUNEL-positive cells （r=0.628, P=0.000）. Conclusion Cell apoptosis increases significantly in the tissues surrounding the hematoma after ICH, in which P75NTR-mediated apoptosis pathway may play a key role. TrkA is not upregulated after ICH to antagonize P75NTR-mediated cell apoptosis.