LUNG FIBROSIS--MECHANISMS OF COLLAGEN GENE EXPRESSION

这项建议的长期目标是获得更好的 对导致增长的机制的理解 胶原蛋白在肺内积聚。两处牙槽的损伤 上皮或毛细血管内皮导致复杂的相互作用 炎性细胞和效应器分子。间隙 成纤维细胞在这个过程中被激活，导致产生 大量的细胞外基质材料，包括I型 和III型胶原。 几种炎症因子对成纤维细胞胶原的影响 我们的实验室已经对产品进行了检验。我们的数据和 其他人的研究表明转化生长因子β (转化生长因子-β)刺激成纤维细胞产生大量 胶原蛋白。此外，我们的结果表明，转化生长因子-β 刺激肺成纤维细胞增加胶原生成 而不会增加扩散。稳定状态下的基因表达水平 α1(I)和αI(III)胶原链在 用转化生长因子-β刺激。α2(I)基因的表达增加 稳态水平因细胞类型而异。根本没有 人肺成纤维细胞在体外培养过程中α2(I)mRNA的表达 用转化生长因子-β刺激。 在转化生长因子-β的情况下，胶原可能通过增加 通过转录和/或转录后机制。这个 这项提案的具体目标是：1)确定 转化生长因子-β对肺成纤维细胞I型和型胶原表达的影响 通过检测丰度、转录和稳定性来检测III基因 2)鉴定和表征顺式作用 I型胶原基因的调节或稳定元件，3) 鉴定和比较转化生长因子-β中的DNA结合蛋白 刺激和未刺激的成纤维细胞，以及4)确定 胶原蛋白堆积的调节是否发生改变 博莱霉素处理的大鼠肺成纤维细胞。

The long term goal of this proposal is to gain a better understanding of the mechanisms responsible for increased collagen accumulation in the lung. Injury to either the alveolar epithelium or capillary endothelium leads to a complex interaction of inflammatory cells and effector molecules. Interstitial fibroblasts are activated during this process leading to production of large amounts of extracellular matrix material, including type I and type III collagen. The effect of several inflammatory factors on fibroblast collagen production have been examined in our laboratories. Our data and that of others indicate that transforming growth factor beta (TGF-beta) stimulates fibroblasts to produce significant amounts of collagen. In addition, our results demonstrate that TGF-beta stimulates lung fibroblasts to increase collagen production without increasing proliferation. Steady state mRNA levels of alpha 1(I) and alpha I(III) collagen chains increase during stimulation with TGF-beta. The increase in alpha 2(I) mRNA steady state levels varied depending on cell type. There was no increase in alpha 2(I) mRNA when human lung fibroblasts were stimulated with TGF-beta. In the case of TGF-beta, collagen may be stimulated by increased by a transcriptional and/or a post-transcriptional mechanism. The specific aims of this proposal are to 1) determine the effects of TGF-beta on lung fibroblast expression of collagen type I and type III genes by examining the abundance, transcription, and stability of collagen mRNA, 2) identify and characterize the cis acting regulatory or stabilizing elements of the collagen type I genes, 3) identify and compare DNA binding proteins, in TGF-beta stimulated versus unstimulated fibroblast, and 4) determine whether the regulation of collagen accumlation is altered in fibroblasts derived from bleomycin-treated rat lungs.