尿毒清颗粒对糖尿病肾病大鼠肾脏抗炎抗氧化保护作用及对TGF-β_1/p38MAPK信号通路影响的研究

Effect of Uremic Granule on Renal Anti-inflammatory and Antioxidant Protection of Diabetic Nephropathy Rats and on TGF-β_1/p38MAPK Signaling Pathway

目的探讨尿毒清胶囊对糖尿病肾病大鼠的抗炎、抗氧化作用及对糖尿病肾病大鼠肾组织TGF-β_1/p38MAPK信号通路的影响。方法 70只雄性SD大鼠,随机分为10只正常组,60只模型组。模型组大鼠腹腔注射45 mg·kg^(-1)链脲佐菌素(STZ)造模,取造模成功的60只大鼠随机分为12只模型组,12只厄贝沙坦阳性组,12只尿毒清颗粒低剂量组(0.04 mg·kg^(-1)),12只尿毒清颗粒中剂量组(0.08 mg·kg^(-1)),12只尿毒清颗粒高剂量(0.16 mg·kg^(-1)),灌胃给药12周,模型组和空白组给予生理盐水。每周称量体质量,每周检测24 h尿蛋白量。给药治疗12周后,取血检测血尿素氮(BUN)、血清肌酐(SCr)、丙二醛(MDA)、一氧化氮(NO)、甘油三酯(TG)、超氧化物歧化酶(SOD)含量;麻醉处死大鼠,各取8只对肾组织行HE染色,观察肾组织的病理形态;并取肾组织进行RT-PCR和免疫组化观察TGF-β_1/p38MAPK信号转导等转化因子的mRNA及蛋白表达。结果与正常组比较,模型组大鼠尿蛋白及血清BUN、SCr、TG、MDA含量显著增高(P<0.05),NO、SOD含量显著降低(P<0.01),肾组织胞浆中TGF-β_1、p38MAPK、Caspase-3 mRNA及蛋白表达显著升高(P<0.05);通过治疗后,与模型组对比,尿毒清颗粒高剂量组和阳性组肾脏病理损害明显减轻,尿蛋白及血清BUN、SCr、TG、MDA含量显著降低(P<0.05),NO、SOD含量明显增高(P<0.05),肾组织内TGF-β_1、p38MAPK、Caspase-3 m RNA及蛋白表达明显减少(P<0.05)。结论尿毒清颗粒能降低24 h尿蛋白量,降低TG和MDA含量及升高NO、SOD含量,通过调控TGF-β_1/p38MAPK从而治疗糖尿病肾病的肾组织受损部位,改善肾功能和减轻病理损伤,能有效地保护糖尿病肾病组织。

Objective To explore effects of uremic granule on the treatment of diabetic nephropathy rats and TGF-β1/p38 MAPK signaling pathway. Methods Seventy male SD rats were randomly divided into normal group(10 rats),model group(60 rats). After models successfully established by intraperitoneal injection of 45 mg?kg^-1streptozotocin(STZ), the model rats were randomly divided into model group, positive control group(irbesartan, 12 rats),uremic granule low,medium,and high dose groups(0.04,0.08,0.16 mg?kg^-1,12 rats each,respectively).Rats were gavage fed with correspondent drugs for 12 weeks,the model group and normal(blank) group rats weregiven saline solution. The body weights were weighed every week;and 24 h urine protein contents were measuredevery week. At the end of drug treatment,blood urea nitrogen(BUN),serum creatinine(SCr),malondialdehyde(MDA), nitric oxide(NO), serum creatinine(SCr), triglycerides(TG) contents and activity of superoxidedismutase(SOD) in rats’ blood were detected. Rats were anesthesia executed,and kidney tissues HE staining of8 rats from each group was carried out to observed the pathological morphology. Transforming growth factor β1(TGF-β1), p38 MAPK, Caspase 3mRNAs and proteins expression in kidney tissues were detected by RT-PCR andimmunohistochemistry. Results Compared with normal group,urinary protein and serum BUN,SCr,TG and MDAcontents of model group rats increased significantly(P<0.05),NO content and SOD activity decreased significantly(P<0.01);cytoplasm TGF-β1, p38 MAPK, Caspase 3 mRNA and protein expression of kidney tissues weresignificantly higher(P<0.05). After treatment,compared with model group,uremic granule high-dose group andpositive group showed significantly reduced renal pathological damage,and the urine protein and serum BUN,SCr,TG, MDA contents decreased significantly(P<0.05);NO content and SOD activity increased obviously(P<0.05),TGF-β1,p38 MAPK,Caspase 3 mRNAs and proteins expression in renal tissues decreased significantly(P<0.05). Conclusion Uremic granule can lower the 24 h urine protein level, lower TG and MDA contents,increase the NO content and SOD activity,effectively protect the diabetic nephropathy,improve renal function andreduce the pathological damage through regulating the TGF-β1/p38 MAPK signaling pathway.