用抗转化生长因子-β抗体治疗可通过抑制Smad/转化生长因子-β信号传导来改善慢性进行性肾炎。

Treatment with anti-TGF-beta antibody ameliorates chronic progressive nephritis by inhibiting Smad/TGF-beta signaling.

作者信息

Fukasawa Hirotaka, Yamamoto Tatsuo, Suzuki Hiroyuki, Togawa Akashi, Ohashi Naro, Fujigaki Yoshihide, Uchida Chiharu, Aoki Michiko, Hosono Mareto, Kitagawa Masatoshi, Hishida Akira

机构信息

First Department of Medicine, Hamamatsu University School of Medicine, Hamamatsu, Shizuoka, Japan.

出版信息

Kidney Int. 2004 Jan;65(1):63-74. doi: 10.1111/j.1523-1755.2004.00393.x.

DOI:10.1111/j.1523-1755.2004.00393.x

PMID:14675037

Abstract

BACKGROUND

Although short-term treatment with anti-transforming growth factor-beta (TGF-beta) antibody (alphaT) has been shown to prevent early glomerular lesions, its long-term effects and molecular mechanisms, including intracellular signaling, remain poorly understood. We examined whether alphaT treatment induces prevention of renal insufficiency and fibrosis, and affects the TGF-beta/Smad signaling pathway in rats with chronic progressive anti-thymocyte serum (ATS) nephritis induced by repeated ATS injections on days 0 and 7.

METHODS

Nephritic and non-nephritic rats were treated with either alphaT or control immunoglobulin (Ig)G twice weekly for 4 weeks from days 7 to 35 (each group, N= 21). Renal lesions and cortical expression of TGF-beta1, TGF-beta2, TGF-beta3, type II TGF-beta receptor (TbetaRII), Smads, type I collagen, and plasminogen activator inhibitor-1 were examined by immunohistochemistry, Western blot, and/or real-time reverse transcription polymerase chain reaction (RT-PCR). The binding of Smad3 in renal cortical cell nuclei to the Smad-binding element (SBE) was investigated by the electrophoretic mobility shift assay.

RESULTS

Nephritic rats developed heavy proteinuria, renal insufficiency, and increased extracellular matrix deposition resulting in renal fibrosis. Cortical expression levels of TGF-beta1, TGF-beta2, TbetaRII, and Smad2, but not TGF-beta3, Smad3, and Smad4 were increased. Expression and preferential localization of phosphorylated Smad2/3 in the glomerular and tubular cell nuclei, and Smad3-SBE complex-forming activity were also increased. Four-week alphaT treatment resulted in marked amelioration of chronic progressive ATS nephritis at 8 weeks.

CONCLUSION

In chronic progressive ATS nephritis, the TGF-beta/Smad signaling was up-regulated. TGF-beta blockade by alphaT suppressed the progression of renal scarring, at least in part, via inhibition of activated TGF-beta/Smad signaling.

摘要

背景

尽管已证明用抗转化生长因子-β（TGF-β）抗体（αT）进行短期治疗可预防早期肾小球病变，但其长期效果及分子机制，包括细胞内信号传导，仍知之甚少。我们研究了αT治疗是否能预防大鼠慢性进行性抗胸腺细胞血清（ATS）肾炎的肾功能不全和纤维化，并影响TGF-β/Smad信号通路。该肾炎模型是通过在第0天和第7天重复注射ATS诱导而成。

方法

从第7天至第35天，每周两次给肾炎大鼠和非肾炎大鼠注射αT或对照免疫球蛋白（Ig）G，持续4周（每组n = 21）。通过免疫组织化学、蛋白质印迹和/或实时逆转录聚合酶链反应（RT-PCR）检测肾损伤以及肾皮质中TGF-β1、TGF-β2、TGF-β3、II型TGF-β受体（TβRII）、Smads、I型胶原和纤溶酶原激活物抑制剂-1的表达。通过电泳迁移率变动分析研究肾皮质细胞核中Smad3与Smad结合元件（SBE）的结合情况。

结果

肾炎大鼠出现大量蛋白尿、肾功能不全以及细胞外基质沉积增加，导致肾纤维化。TGF-β1、TGF-β2、TβRII和Smad2的皮质表达水平升高，但TGF-β3、Smad3和Smad4未升高。肾小球和肾小管细胞核中磷酸化Smad2/3的表达及优先定位以及Smad3-SBE复合物形成活性也增加。4周的αT治疗使8周时慢性进行性ATS肾炎得到显著改善。