17β-雌二醇对大鼠肾缺血再灌注损伤肾小管细胞凋亡及炎症的影响

摘要

Purpose To investigate the effects and mechanism of 17β-estradiol on the apoptosis and inflammation of renal tubular cells in rats with renal ischemia/reperfusion injury. Methods All the female Sprague-Dawley rats were ovariectomized and randomly divided into four groups: Control group, Sham group, I/R group and estrogen plus I/R (E2 + I/R) group (n = 8). Right kidney of the rat was excised and artery of the left kidney was blockaded for 45 min.24 h after the reperfusion, we collected the blood and nephridial tissue of each group. An automatic biochemical analyzer was used to measure the expression level of BUN and Cr in blood. Hematoxylin-eosin (HE) staining was used to observe the pathological changes and the degree of inflammatory reaction of the ischemia/reperfusion injury kidney. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) method was used to detect the apoptosis of renal tubular cells. The expression levels of Cleaved-Caspase-3 protein were measured by Western blot, while the numbers of CD4+ T lymphocyte infiltration in each group were tested by immunofluorescence (IF). Results Compared with the Sham group, expression level of BUN, Cr and Cleaved-Caspase-3 in I/R group significantly increased (P＜0.05) as well as the number of apoptotic cells (P＜0.05). In the meantime, inflammatory reaction significantly aggravated (P＜0.05) and the number of CD4 + T lymphocytes increased remarkably (P＜0.05). However, expression level of BUN, Cr and Gleaved-Caspase-3 in E2 + I/R group decreased significantly (P＜0.05) and the pathological damage in the kidney was alleviated (P＜0.05) compared with I/R group, furthermore, the number of apoptotic cells decreased (P＜0.05) compared with I/R group. The inflammatory reaction significantly blunted (P＜0.05) and the infiltration of CD4 + T lymphocytes decreased remarkably (P＜0.05) compared with I/R group. Conclusion Estrogen can inhibit the expression of Cleaved-Caspase-3 in renal tissue during ischemia/reperfusion injury and reduce the apoptosis of renal tubular cells. It can also reduce the infiltration of CD4 + T lymphocytes, thus playing a protective role on renal ischemia/reperfusion injury.%目的 探讨17β-雌二醇对肾缺血再灌注损伤大鼠肾小管细胞凋亡及炎症的影响及机制.方法 将所有去卵巢处理后的雌性SD大鼠随机分为正常组(Control)、假手术组(Sham组)、缺血再灌注损伤组(I/R组)及缺血再灌注雌激素治疗组(E2+I/R)(每组8只).切除右肾,夹闭左侧肾动脉45 min,再灌注24 h后留取各组大鼠血和肾脏标本.全自动生化分析仪测定血尿素氮(BUN)及血肌酐(Cr)水平,采用HE染色观察肾组织病理学形态,原位末端标记法(TUNEL)检测肾小管细胞凋亡率,Western blot法检测肾组织Cleaved-Caspase-3蛋白表达水平,肾组织病理学观察炎性反应及免疫荧光法检测各组肾组织 CD4 + T淋巴细胞的浸润数量.结果 与Sham组相比,I/R组血BUN和Cr水平升高(P＜0.05),肾组织病理学损伤明显(P＜0.05),凋亡细胞数增加(P＜0.05),Cleaved-Caspase-3蛋白表达显著升高(P＜0.01),炎症反应加重(P＜0.05),CD4+ T淋巴细胞浸润增加(P＜0.05);与I/R组相比,E2 + I/R组血BUN和Cr水平降低(P＜0.05),肾组织病理学损伤减轻(P＜0.05),凋亡细胞数减少(P＜0.05),Cleaved-Caspase-3蛋白表达水平降低(P＜0.01),炎症反应减轻(P＜0. 05) , CD4 + T淋巴细胞浸润减少(P＜0.05).结论 雌激素可抑制缺血再灌注损伤后肾组织Cleaved-Caspase-3蛋白表达,减少肾小管细胞凋亡,并且可以减轻炎症反应和CD4 + T淋巴细胞浸润,对肾缺血再灌注损伤发挥保护作用.