臭氧后处理对大鼠肾脏HIF-1α的表达及细胞凋亡的影响

Effect of Ozone Postconditioning on Renal Hypoxic Inducible Factor-Alpha in Rats and Its Regulation in Cell Apoptosis

目的:探讨臭氧后处理对大鼠肾脏缺血再灌注损伤(IRI)中缺氧诱导因子-1α(HIF-1α)及肾小管上皮细胞凋亡的影响。方法:随机将36只SD大鼠分为假手术组、缺血再灌注组和臭氧后处理组,每组12只,进行如下实验:①假手术组:切除大鼠右肾后缝合腹壁;②缺血再灌注组:切除大鼠右肾后,用无创伤血管夹夹闭左肾动、静脉45min进行缺血,然后开放血管夹进行再灌注;③臭氧后处理组:手术步骤与缺血再灌注组相同,但在术后10d内,每天对该组大鼠经直肠吹入氧气和臭氧的混合气体2.5-3.0ml[臭氧浓度为50mg/L,0.5mg/(kg·d)]。全自动生化分析仪检测大鼠血清肌酐和尿素氮,观察大鼠肾组织的病理改变和细胞凋亡情况,蛋白免疫印迹法(Western blot)检测各组大鼠HIF-1α的含量。结果:与假手术组相比,缺血再灌注组和臭氧后处理组血清尿素氮、肌酐水平均显著升高,而缺血再灌注组的尿素氮、肌酐表达量又明显高于臭氧后处理组。臭氧后处理组的肾组织病理学改变较缺血再灌注组轻。假手术组、缺血再灌注组、缺血后处理组大鼠肾组织的细胞凋亡指数分别为4.32±1.84、39.28±4.06和27.42±2.83,3组间比较,差异均有统计学意义(P<0.05)。Western Blot结果显示,在假手术组、缺氧再灌注组和臭氧后处理组中HIF-1α表达量依次增加,差异有统计学意义(P<0.05)。结论:臭氧后处理可能通过显著增加HIF-1α的表达而抑制肾小管上皮细胞的凋亡,从而发挥肾脏保护作用。

Objective： To investigate the effect of ozone postconditioning（OP） on the rat kidney activity of HIF-la and renal tubular epithelial cell apoptosis after renal ischemia and reperfusion injury （IRI）. Methods： 36 SD rats were randomly divided into three groups, control group, IRI group and OP group. Each group had 12 rats. In sham operation group, the right kidneys of rats were excised. In IRI group, with no wound vascular clamp, left renal arteries and veins of rats were clamped for 45 min, then opened vascular clamp and the rats subjected reperfusion. In OP groups, operation steps were the same as the IRI group. But within 10 d after surgery, the renal OP was induced by rectal insufflation of oxygen and ozone 2.5-3.0 ml （ozone 50 mg/L, 0.5 mg/ [kg. d],once everyday）. The parameters （blood urea nitrogen and creatine） of renal function were determined by auto-biochemieal analyzer. The changes of renal tissue were examined by a microscope and the apoptosis of in the nephridial tissue was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling（TUNEL）. The expression of the HIF-la was de- tected by Western blot. Results. Compared with sham operation group, BUN and Cr were signifi- cantly increased in IRI group and OP group. However, these targets in IRI group were signifi- cantly increased compared with those in OP group. The pathology change of renal tissue in IRI group was more serious than that in OP group. And the apoptosis index in sham operation group, IRI group and OP group rats kidney cell apoptosis index were 4. 32 ±1. 84,39. 28±4.06, and 27.42±2.83 respectively （P〈0.05）. The result of Western blot showed that the expression of HIF-1α increased in turn in sham group, IRI group and OP group. The difference was statistical- ly significant. Conclusion： One of the mechanisms of kidney protection by ozone postconditioning may be due to increase activity level of HIF-1α and decrease renal tubular epithelial cell apoptosis.