JNK信号通路在横纹肌溶解致急性肾损伤中的作用及桦木酸的干预效应

The function of JNK signaling pathway in rhabdomyolysis-induced acute kidney injury and the interfering effects of betulinic acid

目的观察JNK信号通路在横纹肌溶解致急性肾损伤中的变化和作用,以及桦木酸的干预效果。方法将32只Wistar大鼠随机分为4组:正常对照组(C,n=8),甘油肌注组(G,n=8),甘油+桦木酸组(GB,n=8),甘油+SP600125组(GS,n=8),通过大鼠后肢肌内注射甘油建立横纹肌溶解模型,GB、GS组分别给予腹腔注射桦木酸和SP600125;24 h后,血肌酐和尿素水平采用生化分析仪检测,通过HE染色观察肾脏病理变化,采用Western Blot法检测肾组织p JNK、JNK、NF-κB和Cleaved Caspase-3表达,肾组织IL-1β水平采用ELISA法进行检测。结果甘油注射后,肾脏出现急性损伤,p JNK/JNK比值升高;BA和SP600125干预后,p JNK/JNK比值降低,肾功能指标、病理损伤评分、细胞凋亡、炎性因子水平均下降;在本实验剂量下,BA对JNK通路和炎性因子的抑制作用弱于SP600125,但对肾病理损伤和细胞凋亡的治疗效果较好。结论在横纹肌溶解致急性肾损伤中,JNK通路被激活,使用SP600125抑制JNK通路可降低肌酐尿素水平,抑制肾脏炎性反应,减轻肾病理损伤和细胞凋亡,桦木酸至少部分通过抑制JNK通路的激活发挥肾脏保护作用。

Objective To investigate the change and effect of JNK pathway in rhabdomyolysis-induced acute kidney injury( AKI) and the interfered effect of betulinic acid( BA). Methods 32 Wistar rats were randomly divided into 4 groups:control group( C,n = 8),glycerol injection group( G,n = 8),group glycerol + BA( GB,n = 8),group glycerol + SP600125( GS,n =8). The experimental model of rhabdomyolysis-induced AKI was established by injecting 50% glycerin intramuscular into the hind limbs. Group GB,GS were administered intraperitoneally with BA and SP600125 separately. 24 hours after glycerin injection,the venous blood and kidney samples were taken. The serum creatinine( CR),blood urea nitrogen( BUN)were detected with automatic biochemistry analyzer. The expression of p JNK,JNK,NF-κB and Cleaved Caspase-3 in kidney were assayed by Western Blot. The pathological changes were examined by H&E staining. The levels of IL-1βwas measured by ELISA. Results Glycerin injection induced acute injury and higher p JNK/JNK ratio in the kidney,which were ameliorated by administration of BA and SP600125. After the administration of BA and SP600125,the renal function indexes,pathological damage score,apoptosis degree and inflammatory factor reduced. In the dosage of this experiment,BA had better curative effect on renal injury and apoptosis degree. But the inhibition of JNK phosphorylation of SP600125 was stronger than BA.Conclusion In rhabdomyolysis-induced AKI,JNK pathway was activated. Inhibition of JNK phosphorylation by SP600125 could reduce the level of Cr and BUN,suppress renal inflammation,alleviate the pathological damage and apoptosis. BA played a renoprotective role at least partially through inhibiting JNK pathway.