虫草菌粉对慢性马兜铃酸肾病大鼠模型肾间质纤维化的保护作用

目的研究虫草菌粉对慢性马兜铃酸肾病（CAAN）模型大鼠肾间质纤维化的拮抗作用。方法雄性sD大鼠随机分为对照组、模型组和虫草组;每组6只。于0、1、4,8及12周末分别检测大鼠体重、尿糖、尿蛋白定量和血清肌酐（SCr）;并于第12周末处死大鼠留取肾组织,行Masson染色观察肾间质纤维化程度,逆转录实时聚合酶链反应和免疫组织化学方法检测肾组织中转化生长因子-β1（TGF-β1）、结缔组织生长因子（CTGF）、纤溶酶原激活物抑制物-1（PAI-1）、金属蛋白酶组织抑制物-1（TIMP-1）和Ⅰ型胶原（ColⅠ）mRNA及蛋白质表达。结果模型组大鼠尿蛋白定量及SCr显著高于对照组（P〈0．01及P〈0．05）;12周时肾间质纤维化面积显著增加（P〈0．01）;肾组织内上述指标的mRNA及蛋白质表达显著上调（P〈0．01）。与对照组相比,模型组大鼠肾组织TGF-β1、CTGF、PAI-1、TIMP-1和ColⅠ的mRNA表达分别上调4．19、2．66、6．12、3．09和7．03倍;蛋白质表达分别上调2．31、3．53、3．17、3．18和6．87倍。虫草组大鼠第12周时尿蛋白定量、SCr及肾间质纤维化面积均显著低于模型组（P〈0．05）,上述高表达的mRNA及蛋白质指标均被显著抑制（P〈0．05）,与模型组相比,虫草组大鼠肾组织TGF-β1、CTGF、PAI-1、TIMP-1和ColⅠ的mRNA表达分别下调45％、41％、47％、48％和67％;蛋白质表达分别下调38％、39％、49％、46％和61％。结论虫草菌粉可通过抑制肾组织促细胞外基质（ECM）合成因子（TGF-β1、CTGF）及抗ECM降解因子（TIMP-1、PAI-1）生成,而改善CAAN的肾间质纤维化及肾功能。

Protective effects of Hirsutella sinensis on renal interstitial fibrosis: experiment with rat model of chronic aristolochic acid nephropathy

OBJECTIVE: To study the protective effects of Hirsutella sinensis on renal interstitial fibrosis in chronic aristolochic acid nephropathy (CAAN). METHODS: Eighteen male SD rats were divided into 3 equal groups: model group, given the extract of Aristolochia manshuriensis Kom (AmK) by gavage in the morning everyday for 12 weeks, intervention group, given the extract of Amk in the morning and suspension of Hirsutella sinensis in the afternoon by gavage once a day for 12 weeks, and control group, receiving tap water only by gavage. Bodyweight, urinary glucose, 24 h urinary protein excretion, and serum creatinine (SCr) were measured at the ends of the 1st, 4th, 8th, and 12th weeks respectively. At the end of the 12th week, all the rats were sacrificed with their kidneys taken out to undergo pathological examination. RT-PCR and immunohistochemistry were used to detect the mRNA and protein expression of transforming growth factor-beta1 (TGF-beta1), connective tissue growth factor (CTGF), plasminogen activator inhibitor-1 (PAI-1), tissue inhibitor of metalloproteinase-1 (TIMP-1), and type I collagen (ColI) in the kidney tissues. RESULTS: Since the 1st week, the urinary protein excretion and SCr levels in the model group were significantly higher than those in the control group (P < 0.01 or 0.05). At the end of the 12th week, the relative area of interstitial fibrosis of the model group was significantly enlarged (P < 0.01). The mRNA expression levels of TGF-beta1, CTGF, PAI-1, TIMP-1, and ColI in the model group were up-regulated by 4.19, 2.66, 6.12, 3.09, and 7.03 times respectively, and their protein expression levels were up-regulated by 2.31, 3.53, 3.17, 3.18, and 6.87 times respectively (all P < 0.01). By the end of the 12th week, the urinary protein excretion, SCr level and the relative area of interstitial fibrosis in the intervention group were all significantly lower than those in the model group (all P < 0.05). The mRNA expression levels of TGF-beta, CTGF, PAI-1, TIMP-1, and ColIof the intervention group were all significantly lower than those of the model group (all P < 0.05) with the inhibition rates of 45%, 41%, 47%, 48%, and the protein expression levels of TGF-beta, CTGF, PAI-1, TIMP-1, and ColI of the intervention group were all significantly lower than those of the model group (all P < 0.05) with the inhibition rates of 38%, 39%, 49%, 46%, and 61% respectively. CONCLUSION: Hirsutella sinensis can inhibit the production of TGF-beta1 and CTGF, factors that promote the extracellular matrix (ECM) synthesis and TIMP-1 and PAI-1, factors that antagonize ECM degradation in kidney tissues, thus alleviating renal interstitial fibrosis and improving renal function in CAAN.