匹多莫德对紫癜性肾炎模型大鼠蛋白尿和肾组织的影响及其机制

Effect of pidotimod on proteinuria and renal tissue in rats with purpura nephritis and its action of mode

目的 探讨匹多莫德对紫癜性肾炎(HSPN)模型大鼠蛋白尿和肾组织的影响及其机制。方法 40只SD大鼠选取10只为对照组,剩余30只采用牛血清白蛋白(BSA)+脂多糖(LPS)+四氯化碳(CCl)法建立HSPN模型,建模成功的28只大鼠均分为模型组和匹多莫德组;匹多莫德组腹腔注射10 mg/kg的匹多莫德,模型组和对照组腹腔注射等量生理盐水(1次/d),连续28 d;给药第7、14及28天时检测各组大鼠的24 h尿蛋白水平,末次给药后取各组大鼠肾脏、切片,采用常规苏木精-伊红(HE)和过碘酸雪夫(PAS)染色法观察各组大鼠肾脏的组织学变化,酶联免疫吸附法检测肾组织中白细胞介素4(IL-4)、IL-1β水平,Western blot法检测肾组织中转化生长因子β1(TGF-β1)、Smad同源物4(Smad4)、Smad7蛋白表达水平。结果 第7、14、28天时,大鼠24 h尿蛋白含量比较,模型组>匹多莫德组>对照组,差异有统计学意义(P<0.05);HE染色显示,匹多莫德组肾组织病理改变较模型组减轻,但仍伴少量炎性细胞浸润,模型组和匹多莫德组大鼠肾组织PAS染色阳性面积灰度值、IL-4、IL-1β水平及TGF-β1、Smad4蛋白表达水平比较,模型组>匹多莫德组>对照组,差异有统计学意义(P<0.05);Smad7蛋白表达水平比较,模型组<匹多莫德组<对照组,差异有统计学意义(P<0.05)。结论 匹多莫德可有效抑制HSPN大鼠蛋白尿,减轻肾组织病理损伤,其作用机制可能与抑制炎症反应、调节TGF-β1/Smad信号通路有关。

Objective To investigate the effect of pidotimod on proteinuria and renal tissues in rats with Henoch-Schonlein purpura nephritis(HSPN).Methods Of 40 Sprague Dawley(SD) rats, 10rats were selected as control group, and the remaining 30 rats were treated with bovine serum albumin(BSA) + lipopolysaccharide( LPS) + carbon tetrachloride( CCl) to establish rat with HSPN model. Twenty-eight rats with HSPN were divided into model group and pidotimod group. Pidotimod group was intraperitoneally injected with 10 mg/kg of pidotimod, while model and control groups were intraperitoneally injected with the same amount of normal saline(once/d). The treatment lasted for 28 consecutive days. On the 7, 14, and 28days of administration, the levels of 24-hour proteinuria were measured in each group. After the last administration, conventional hematoxylin-eosin( HE)staining and periodic acid Schiff(PAS) staining were performed to observe the histological alterations of the kidneys in each group. Enzyme-linked immunosorbent assay(ELISA) was applied to detect the levels of interleukin-4(IL-4) and IL-1β in renal tissues. Western blot was used to detect the protein expression levels of transforming growth factor β1(TGF-β1), Smad homolog 4(Smad4) and Smad7 in renal tissues.Results On the 7, 14, and 28days, the level of 24-hour proteinuria was in model group > pidotimod group > control group(P< 0. 05). HE staining showed that the pathological alterations of renal tissues in pidotimod group were less than those in the model group, but still accompanied by a small amount of inflammatory cell infiltration. The gray value of PAS staining positive area, the protein expression levels of IL-4, IL-1β, TGF-β1, and Smad4 were model group >pidotimod group > control group(P< 0. 05). Smad7 expression level was model group < pidotimod group < control group(P< 0. 05).Conclusion Pidotimod can effectively inhibit proteinuria in rats with HSPN and reduce the pathological damage of kidney tissue. Its action of mode may be related to the inhibition of inflammation and regulation of TGF-β1/Smad signaling pathway.