MAPK介导外源性硫化氢对大鼠肾缺血再灌注引起的肾脏和远位心脏损伤的保护作用

目的探讨外源性硫化氢(H 2S)对大鼠肾缺血再灌注损伤(renal ischemia-reperfusion injury, RIRI)引起的肾脏和远位心脏损伤的保护作用及可能机制。方法 Wistar雄性大鼠30只,随机分为5组,分别为假手术组、I/R A组、I/R B组、NaHS A组和NaHS B组,每组6只。采用单侧肾动脉结扎建立RIRI大鼠模型,其中I/R A组和I/R B组分别缺血30 min和60 min后再灌注180 min,NaHS A组和NaHS B组在I/R A组和I/R B组的基础上于再灌注前30 min腹腔注射NaHS(100 μg/Kg)。实验结束后检测大鼠肾脏和心脏的形态学变化,ELISA法检测血清肌酐(Scr)、尿素氮(BUN)和心肌肌钙蛋白I(TnI)的水平。TUNEL实验检测肾脏和心脏细胞凋亡,再采用ELISA法检测H 2S、EPK、JNK、p38MAPK和Caspase 3的水平。结果 与假手术组相比,I/R A组肾脏和心脏形态学损伤较轻,I/R B组损伤较重,I/R A组和I/R B组大鼠Scr和BUN水平明显增加,心脏组织TnI水平明显下降( P <0.01),分别与I/R A组和I/R B组相比,NaHS A组和NaHS B组肾脏和心脏损伤明显减轻,Scr、BUN和心脏TnI水平进一步改善,差异有统计学意义( P <0.01)。另外,与假手术组相比,I/R A组和I/R B组肾小管上皮细胞和心肌细胞呈不同程度的凋亡,H 2S水平明显下降,ERK、JNK、p38MAPK和Caspase 3的水平显著增加;分别与I/R A组和I/R B组相比,NaHS A组和NaHS B组上述细胞凋亡程度明显减少,H 2S、ERK、JNK、p38MAPK和Caspase 3水平显著改善,差异有统计学意义( P <0.05或 P <0.01)。结论 外源性NaHS可明显减轻RIRI引起的大鼠肾脏和远位心脏的损伤,其机制可能与H 2S下调p38MAPK、JNK和ERK蛋白的表达,从而抑制肾脏和心肌细胞的凋亡进程有关。

Protective effect of MAPK-mediated exogenous hydrogen sulfide on renal and remote heart injury induced by renal ischemia-reperfusion in rats

Purpose To investigate the protective effect of exogenous hydrogen sulfide (H 2S) on renal and remote heart damages induced by renal ischemia-reperfusion injury (RIRI) and its possible mechanism in rats. Methods 30 male Wistar rats were randomly divided into 5 groups: sham operation group, I/R A group, I/R B group, NaHS A group and NaHS B group. RIRI rat model was established by ligation of unilateral renal artery. The I/R A group and I/R B group were reperfused for 180 min after ischemia for 30 min and 60 min, respectively. NaHS A group and NaHS B group were reperfused by NaHS (100 μg/Kg) for 30 min based on I/R A and I/R B groups ion. At the end of the experiments, the morphological changes of kidney and heart were detected. The levels of serum creatinine (Scr),blood urea nitrogen (BUN) and troponin I (TnI) were detected by ELISA. TUNEL assay was used to detect the cell apoptosis of kidney and heart. In addition to, the content of H 2S, EPK, JNK, p38MAPK and Caspase 3 were also detected by ELISA. Results Compared with the sham group, the morphological damage of kidney and heart in I/R A group was mild and the I/R B group was severe. The levels of serum Scr and BUN were significantly higher, and TnI decreased significantly in heart tissue ( P <0.01). Compared with I/R A group and I/R B group, the renal and cardiac injury of NaHS A group and NaHS B group were reduced, while the levels of Scr and BUN were decreased and cardiac TnI obviously increased ( P <0.01). In addition, in I/R A group and I/R B group, tubular epithelial cells and cardiomyocytes showed different degrees of apoptosis. The level of H 2S decreased significantly, and ERK, JNK, p38MAPK and Caspase 3 increased significantly. Compared with I/R A group and I/R B group, the apoptosis of NaHS A group and NaHS B group were significantly reduced, and the levels of H 2S, ERK, JNK, p38MAPK and Caspase 3 were significantly improved ( P <0.05 or P <0.01). Conclusion Exogenous NaHS can significantly reduce the RIRI-induced injury of rat kidney and distal heart. The mechanism may be related to the down-regulation of p38MAPK, JNK and ERK expression, thereby inhibiting the apoptosis of kidney and myocardial cells.