虎杖苷通过内质网应激相关通路对阿霉素肾病模型大鼠肾脏及心脏的保护作用

Protective effect of polydatin on kidney and heart of model rats with adriamycin nephropathy via endoplasmic reticulum stress related pathway

目的探讨虎杖苷通过内质网应激相关通路对阿霉素肾病模型大鼠肾脏及心脏的保护作用。方法将40只SD雄性大鼠随机分为模型组、虎杖苷组、联合组、对照组,各10只。除对照组外,给予其他3组大鼠建立阿霉素肾病大鼠模型。建模成功后,给予联合组灌胃100 mg/kg虎杖苷及腹腔注射含CCT020312[蛋白激酶R样内质网激酶(PERK)/真核细胞起始因子2α(eIF2α)/CCAAT/增强子结合蛋白同源蛋白(CHOP)通路激活剂]的二甲基亚砜(DMSO),给予虎杖苷组灌胃100 mg/kg虎杖苷及腹腔注射DMSO;给予对照组、模型组灌胃生理盐水及腹腔注射DMSO,均1次/d,共干预7周。观察各组大鼠肾脏及心脏的病理变化。检测各组大鼠的心脏功能指标[左室等容舒张时间(IVRT)、二尖瓣舒张早期峰值速度(E)、舒张晚期峰值速度(A)]、肾功能指标(24 h尿蛋白、血尿素氮、血肌酐),以及肾脏组织PERK、磷酸化PERK(p-PERK)、eIF2α、磷酸化eIF2α(p-eIF2α)、CHOP蛋白表达量。结果(1)模型组大鼠的肾小球肥大变形、增生现象严重、组织结构被破坏,膜外基质增多,血管塌陷,间质存在大量炎性细胞浸润,肾小管萎缩;心肌细胞肿胀变形、排列松散混乱、组织结构被破坏,部分心肌纤维断裂消失,可见大量炎性细胞浸润。虎杖苷组与联合组大鼠上述病理改变均较模型组改善,且虎杖苷组的改善更明显。(2)与对照组比较,模型组的24 h尿蛋白、血尿素氮、血肌酐水平,二尖瓣A值,以及肾脏组织CHOP蛋白表达量、p-PERK/PERK比值、p-eIF2α/eIF2α比值均升高,IVRT延长,二尖瓣E值降低(均P<0.05);与模型组比较,虎杖苷组与联合组的24 h尿蛋白、血尿素氮、血肌酐水平,二尖瓣A值,以及肾脏组织CHOP蛋白表达量、p-PERK/PERK比值、p-eIF2α/eIF2α比值均降低,IVRT均缩短,二尖瓣E值均升高,且虎杖苷组上述指标改善均优于联合组(均P<0.05)。结论虎杖苷可保护阿霉素肾病模型大鼠的肾脏及心脏功能,其作用机制可能与抑制PERK/eIF2α/CHOP信号通路有关。

Objective To explore the protective effect of polydatin on kidney and heart of model rats with adriamycin nephropathy via endoplasmic reticulum stress related pathway.Methods A total of 40 SD male rats were randomly assigned to model group,polydatin group,combination group or control group,with 10 rats in each group.Except for the control group,the adriamycin nephropathy rat model was constructed in the remaining 3 groups.After successful modeling,the combination group received intragastric administration of polydatin with 100 mg/kg,and then received intraperitoneal injection of dimethyl sulfoxide(DMSO)containing CCT020312(protein kinase R-like ER kinase[PERK]/eukaryotic initiation factor 2α[eIF2α]/CCAAT/enhancer-binding protein homologous protein[CHOP]pathway activator),and the polydatin group received intragastric administration of polydatin with 100 mg/kg,and then received intraperitoneal injection of DMSO;furthermore,the control group and the model group received intragastric administration of normal saline,and then received intraperitoneal injection of DMSO.All groups received once a day and a seven-week intervention.The pathological changes of kidney and heart of rats were observed in various groups.The cardiac function indicators with respect to left ventricular isovolumetric relaxation time(IVRT),early peak diastolic velocity(E)and late peak diastolic velocity(A)of mitral valve,and kidney function indicators(24-hour urine protein,blood urea nitrogen and serum creatinine),as well as the expressions of PERK,phosphorylated PERK(p-PERK),eIF2α,phosphorylated eIF2α(p-eIF2α)and CHOP proteins in kidney tissues of rats were detected in various groups.Results(1)In the model group,the rats presented as hypertrophic and hyperplastic glomeruli,destroyed tissue structure of glomeruli,and increased extracellular matrix,vascular collapse,and a large number of inflammatory cells infiltration in mesenchyme,as well as atrophied renal tubules;furthermore,the rats interpreted as swollen and deformed myocardial cells,loose and disorder arrangement of myocardial cells,and destroyed tissue structure of myocardial cells,as well as some broken and disappeared myocardial fibers and a large number of inflammatory cells infiltration in mesenchyme.The above pathological changes in the polydatin group and the combination group were improved compared with the model group,and the improvement in the polydatin group was more obvious.(2)Compared with the control group,the model group exhibited elevated levels of 24-hour urine protein,blood urea nitrogen and serum creatinine,and elevated A value of mitral valve,expression of CHOP protein in kidney tissues,p-PERK/PERK ratio,and p-eIF2α/eIF2αratio,as well as prolonged IVRT and a decreased E value of mitral valve(all P<0.05).Compared with the model group,the polydatin group and the combination group yielded decreased levels of 24-hour urine protein,blood urea nitrogen and serum creatinine,and decreased A value of mitral valve,expression of CHOP protein in kidney tissues,p-PERK/PERK ratio,and p-eIF2α/eIF2αratio,as well as shorter IVRT and an elevated E value of mitral valve,and the improvements of aforementioned indicators in the polydatin group were all superior to those in the combination group(all P<0.05).Conclusion Polydatin can protect kidney and cardiac function in model rats with adriamycin nephropathy.Its mechanism may be related to the inhibition of PERK/eIF2α/CHOP signaling pathway.