The study about expression and role of latent TGF-beta binding protein (LTBP) in glomerulonephritis

TGF-β与肾纤维化密切相关，TGF-β有两种形式的活性和潜伏型。潜伏性TGF-β由大的潜伏性TGF-β结合蛋白（LTBP）复合物和小的潜伏性TGF-β结合蛋白（LTBP）复合物组成。1次注射抗胸腺细胞血清（ATS）诱导的急性自限性肾炎和2次注射抗胸腺细胞血清诱导的慢性进行性肾炎。胸腺细胞血清在正常肾脏中，TGF-β蛋白定位于肾小球内皮和远端小管，而LTBP蛋白和mRNA发现于肾小球上皮细胞和远端小管。在急性肾炎中，在肾小球内皮、系膜和上皮细胞中观察到TGF-β和LTBP表达增加，但在间质细胞中未观察到。在慢性进行性肾炎中，TGF-β LTBP蛋白和mRNA在肾小球和肾小管间质中表达增加。这些结果表明，在肾炎肾，大的潜伏性TGF-β复合物产生于肾小球和持续表达的大潜伏性TGF-β复合物在肾小管间质区可能有助于肾纤维化。

TGF-beta is deeply involved in renal fibrosis and there are two forms of active and latent types in TGF-beta. Latent TGF-beta is composed of large latent TGF-beta complex with latent TGF-beta binding protein (LTBP) and small latent TGF-beta complex without LTBP.In this study, we have examined the expression of TGF-beta protein, LTBP protein and mRNA in two forms of nephritis ; acute self-limiting nephritis induced by 1 injection of ainti-thymocyte serum (ATS) and chronic progressive nephritis induced by 2 shots of anti-thymocyte serum. In normal kidneys, TGF-beta protein is localized in glomerular endothelium and distal tubules, while LTBP protein and mRNA are found in glomerular epithelial cells and distal tubules. In acute nephritis, increased expression of TGF-beta and LTBP are observed in glomerular endothelium, mesangium, and epithelial cells but not in interstitial cells. In chronic progressive nephritis, Increased expression of TGF-beta LTBP protein and mRNA are demonstrated in glomeruli and tubulointerstitial area. These results suggest that in nephritic kidneys, large latent TGF-beta complexes are produced in glomeruli and sustained expression of large latent TGF-beta complex in tubulointerstitial area may contribute to renal fibrosis.