白皮杉醇对糖尿病肾病大鼠肾纤维化及HO-1、HIF-1α蛋白表达的影响

EFFECTS OF PICEATANNOL ON RENAL FIBROSIS AND HO-1 AND HIF-1 A EXPRESSIONS IN DIABETIC NEPHROPATHY RATS

目的探究白皮杉醇(PIC)对糖尿病肾病(DN)大鼠血红素氧合酶-1(HO-1)、缺氧诱导因子-1α(HIF-1a)蛋白表达及肾纤维化的影响。方法采用高糖高脂饲料饲养联合腹腔注射链脲佐菌素(STZ)法制备DN大鼠模型。10只一组,成模大鼠被随机分为四组,每组被灌胃以不同剂量的PIC:模型组(M组,等量生理盐水)、PIC低(PIC-L组,PIC 50 mg/kg)、中(PIC-M组,PIC 100 mg/kg)、高(PIC-H组,PIC 200 mg/kg)剂量组。另取10只正常大鼠为对照组(NC组),并被灌胃以等量生理盐水。1/d,持续4w。治疗结束后,检测血糖(FBG)及血清肾功能相关指标;用HE染色观察肾组织病理变化;用Masson染色观察肾组织胶原纤维沉积;用化学发光法检测血清Ⅲ型前胶原(PC Ⅲ)、Ⅳ型胶原(C Ⅳ)水平;用生物化学法检测肾组织丙二醛(MDA)、超氧化物歧化酶(SOD)水平;用蛋白印迹法(WB)测定HIF-1α、HO-1蛋白表达。结果 NC组大鼠肾小球、肾小管结构清晰,基底膜厚度正常,无肾纤维化;M组大鼠肾小球体积增大、肾基底膜增厚,系膜基质增多,肾小管结构紊乱、管腔变大,肾纤维化严重;PIC-L组、PIC-M组、PIC-H组大鼠肾损伤及肾纤维化均减轻。与NC组比较,M组大鼠FBG、血清尿微量白蛋白(UAlb)、血肌酐(Scr)、尿素氮(BUN)、PCⅢ、C Ⅳ水平、肾组织MDA含量、HIF-1α、HO-1蛋白表达均显著升高(P<0.05),肾组织SOD活性显著降低(P<0.05);与M组比较,PIC-L组、PIC-M组、PIC-H组大鼠FBG、血清UAlb、Scr、BUN、PC Ⅲ、C Ⅳ水平、肾组织MDA含量、HIF-1α蛋白表达均依次降低(P<0.05),肾组织SOD活性、HO-1蛋白表达量依次增加(P<0.05)。结论 PIC可减轻DN大鼠肾损伤及肾纤维化,可能与促进HO-1蛋白表达,抑制HIF-1α蛋白表达,提高其抗氧化能力有关。[营养学报,2021,43(1):86-91]

Objective To investigate the effects of piceatannol (PIC) on renal fibrosis and expressions of heme oxygenase-1 (HO-1) and hypoxia inducible factor-1α(HIF-1α) in diabetic nephropathy (DN) rats.Methods A DN rat model was established by feeding the rats with a diet high in sugar and fat and by intraperitoneally injecting the rats with streptozotocin (STZ).The rats were randomly divided into four groups with 10 rats in each group and administrated with different amounts of PIC by gavage:model group (group M,the same amount of saline instead of PIC),low PIC group (PIC-L group,50 mg/kg of PIC),medium PIC group (PIC-M group,100 mg/kg of PIC) and high PIC group (PIC-H group,200 mg/kg of PIC).Another 10 normal rats served as the control group (NC group) and were administrated with the same amount of saline instead of PIC.Gavage was applied once a day and for 4 weeks.After treatment,fasting blood glucose (FGB) and renal function indexes were measured.Pathological changes of renal tissue were observed via HE staining.The deposition of collagen fibers was estimated by Masson staining.The levels of procollagen Ⅲ(PC Ⅲ) and collagen Ⅳ (C Ⅳ) were detected with chemiluminescence.The levels of malondialdehyde (MDA) and superoxide dismutase (SOD) were evaluated using the biochemical methods,and the expressions of HIF-1αand HO-1 were determined by Western blot (WB).Results In the NC group,the structures of glomeruli and renal tubules were clear,the thickness of basement membrane was normal,and no significant renal fibrosis was found.Compared with the NC group,the glomerular volume increased,basement membrane thickened,mesangial matrix increased,renal tubule structure disordered,lumen enlarged and renal fibrosis was serious in group M.In contrast,alleviated renal injury and fibrosis were observed in the PIC-L,PIC-M and PIC-H groups.The levels of FBG,microalbumin,creatinine,urea nitrogen,PC Ⅲ and C Ⅳ in serum,the content of MDA,and the expressions of HIF-1αand HO-1 in renal tissue in group M were significantly higher in the NC group (P<0.05),but the activity of SOD in renal tissue was obviously lower (P<0.05).Compared with group M,the levels of FBG,microalbumin,creatinine,urea nitrogen,PC Ⅲ and C Ⅳ in serum,the content of MDA,and the expression of HIF-1αin renal tissue in the PIC-L,PIC-M and PIC-H groups decreased (P<0.05),and the activity of SOD and expression of HO-1 protein in renal tissue increased (P<0.05).Conclusion PIC can alleviate renal injury and fibrosis in DN rats,which may be related to the increased HO-1 expression,inhibition of HIF-1αexpression and enhancement of antioxidant capacity.[ACTA NUTRIMENTA SINICA,2021,43(1):86-91]