BDNF对脑缺血大鼠肺组织MEK表达的调节

目的 研究脑源性神经营养因子（BDNF）干扰对脑缺血大鼠肺组织丝裂原细胞外激酶（MEK）表达的影响。 方法 成年SD大鼠分为假手术组、脑缺血肺损伤组及BDNF抗体封闭组（脑缺血术后立即给予BDNF抗体干预，腹腔注射，1 mL/100 g体质量，1次/d，共3 d），每组13只。术后3 d取大鼠肺组织，5只大鼠用于免疫组化以观察MEK在肺组织的定位分布，并测定MEK蛋白的光密度值变化。8只大鼠用RT-PCR检测肺组织MEK mRNA含量变化。 结果 免疫组化染色结果显示，肺组织气管上皮和毛细血管内皮有MEK表达，脑缺血后肺组织上皮细胞和血管内皮细胞MEK光密度值明显增加（P<0.05），而BDNF抗体处理导致MEK光密度值减少（P<0.05）。 RT-PCR结果显示，脑缺血肺组织MKE mRNA表达上调，与假手术组比较差异有统计学意义（P<0.05）；BDNF抗体处理导致MEK mRNA表达上调，与脑缺血肺损伤组比较差异有统计学意义（P<0.05）。 结论 BDNF抗体干预有效减少脑缺血肺组织MEK表达，提示BDNF可能通过调节MEK影响脑缺血肺水肿。

Block Effects of BDNF Antibody on MEK Expression in Lung of Rats with Brain Ischemia

【Abstract】 Objecitve To explore the block effect of brain-derived neurotrophic factor (BDNF) antibody on the mitogen extracellular kinase (MEK) expression in lung tissues of rats with brain ischemia. Methods Adult SD rats were divided into sham group, brain ischemia lung injury (BILI) group, and BDNF antibody treated group. Lung tissues were harvested at 3 days after operation. The distribution of MEK in the lung tissue was studied by immunhistochemistry, and the optical density values of MEK immunostaining was used to compare the difference of each group （n=5）. RT-PCR was used to determine the block effect of BDNF antibody on the level of MEK mRNA （n=8）. Results Immunohistochemistry showed that MEK immunoreactive positive products were observed in endothelia cells of airway and blood vessels. The optical density value in rats with brain ischemia significantly increased, compared with sham one (P<0.05). Moreover, BDNF antibody block could reverse this increase of BDNF immunostaining intensity (P<0.05). RT-PCR showed that BDNF antibody block significantly decreased the expressional level of MEK mRNA in the lung tissues with brain ischemia (P<0.05). Conclusion BDNF antibody block leads to a significant reduction of MEK expression in endothelia cells of lung tissue in the rats with brain ischemia.