【作者】 忻菁；

【导师】 顾勇； 林善锬； 市川家国；

【作者基本信息】 复旦大学 ， 内科学， 2005， 博士

【摘要】 目的 转化生长因子β(TGF-β)在环孢霉素A(CsA)所致肾脏毒性的发病过程中可能发挥重要作用。转化生长因子βⅡ型受体—IgG Fc(TGF β RⅡ/IgGFc)是一将人类TGF β RⅡ细胞外区域与IgG1Fc段连接而成的可溶性嵌合蛋白,可在循环中阻断TGF β的活性。本研究旨在探讨TGF β RⅡ/IgG Fc基因转染对小鼠CsA肾毒性的作用。 方法 雌性ICR小鼠予低钠饮食,CsA用药组每日皮下注射CsA 25mg/Kg。在给药的第1天和第7天,对照组在布比卡因预处理的胫骨肌处注射50 μg质粒CAGGS—β半乳糖苷酶(lacZ)(pCAGGS-β galactosidase(lacZ)),治疗组注射等量质粒CAGGS-TGF β RⅡ/IgGFc(pCAGGS-TGF β RⅡ/IgGFc),均联合电穿孔,在CsA给药两周或三周后处死。肾组织中TGF β 1mRNA水平用Northern blot测定,肾组织和血浆中TGFβ1蛋白水平由免疫组化和ELISA法测得。利用石蜡切片PAS和Masson’s trichrom染色半定量评分评估肾小管损害和肾间质纤维化程度,免疫组化方法检测小管间质F4/80阳性的巨噬细胞的表达。 结果 CsA给药2周后,对照组血浆和肾脏TGFβ1表达最高,然后降至基线水平。而TGF β1的mRNA水平直到给药三周仍持续增高。小管间质病变在第二周逐渐显现,第三周病变明显加重。TGF β RⅡ/IgGFc干预组,2周时血浆TGFβ1水平与不用药的低钠饮食对照组相仿,肾组织TGFβ1表达较CsA对照组降低50%(P<0.01),对小管间质病变有保护作用(P<0.01)。第三周时,干预组的肾脏mRNA水平和蛋白水平较对照组没有明显改变,但小管间质病变持续减轻,呈现肾脏保护作用。 结论 TGF β RⅡ/IgG Fc基因转染有效抑制了CsA引起的小管间质病变。在第三周,尽管肾脏mRNA水平和蛋白水平与对照组比没有明显改变,但小管间质病变仍持续缓解。表明早期对TGFβ1的干预治疗对于延缓CsA肾毒性进展具有重要作用。更多还原

【Abstract】 Background. Transforming growth factor β (TGFβ) is implicated in the pathogenesis of cyclosprine A (CsA) nephrotoxicity. We examined the efficacy of TGFβ RII/IgG Fc, a soluble chimeric protein of the extracellular domain of human TGFβ type II receptor and IgGl Fc, on CsA nephrotoxicity in mice.Methods. Subcutaneous injection of CsA (25 mg/kg/day) was given daily to mice maintained on low sodium diet. On day 1 and 7, an expression vector carrying cDNA for either TGF RII/IgG Fc or β-galactosidase was transfected into the skeletal muscles by electroporation. At 2 or 3 weeks of CsA treatment, and plasma and renal TGF β1 levels, and tubulointerstitial injury and fibrosis were evaluated. Results. By 2 weeks of CsA administration, plasma and renal TGFβ1 levels increased to maximum and, thereafter, declined toward the baseline levels. Renal TGFP lmRNA remained elevated until 3 weeks. Tubulointerstitial alterations became appreciable in 2 weeks and intensified by 3 weeks. At 2 weeks, the TGFβ RII/IgG Fc intervention abolished the increase in plasma TGFβ 1, attenuated the increase in renal TGFβl by 50%, and markedly suppressed the histological alterations. At 3 weeks, the histological alterations remained markedly suppressed by the intervention, with no appreciable effects on the renal TGFβlmRNA and protein.Conclusion. Introduction of TGF β RII/IgG Fc by gene transfer effectively abrogated CsA-induced tubulointerstitial alterations. Suppression of tubulointerstitial changes was evident at 3 weeks when renal TGFP 1 mRNA and protein were comparable to those with CsA alone, suggesting that early更多还原