Interstitial fibrosis is associated with increased COL1A2 transcription in AA-injured renal tubular epithelial cells in vivo
Interstitial fibrosis is associated with increased COL1A2 transcription in AA-injured renal tubular epithelial cells in vivo
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DOI：
10.1016/j.matbio.2011.07.004
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发表时间：
2011-09-01
期刊：
影响因子：
6.9
通讯作者：
Mason, Roger M.
中科院分区：
文献类型：
--
作者：
Fragiadaki, Maria;Witherden, Abigail S.;Mason, Roger M.
I型胶原的积聚是肾间质纤维化的关键事件。由于没有有效的治疗方法，了解胶原蛋白转录的部位以及体内驱动胶原蛋白对疾病做出反应的因素对于设计未来的治疗方法至关重要。本研究探讨了COL 1A 2基因在马兜铃酸诱导的小鼠进行性纤维化（马兜铃酸肾病，AAN）模型中的转录活性。为了实现这一点，我们对小鼠进行遗传修饰，使其在COL 1A 2启动子/增强子序列的转录控制下表达报告基因（LacZ）和CCN 2（结缔组织生长因子）。使用这些小鼠，我们询问胶原蛋白在哪里活跃转录，其次，CCN 2在AAN中的作用是什么。在这里，我们报告说，从头转录的COL 1A 2基因主要发生在受损的肾小管上皮细胞进行性间质纤维化在体内。通过激光捕获显微镜检测间质、肾小球、血管和肾小管上皮组织中报告基因LacZ和COL 1A 2 mRNA，研究COL 1A 2的激活。我们还证明了LacZ阳性细胞共表达E-钙粘蛋白，这是一种上皮来源的标志物，与损伤期间能够表达胶原蛋白的上皮表型一致。没有证据表明这些细胞从小管中分离成为肌成纤维细胞。此外，我们发现转基因小鼠表现出CCN 2表达的适度增强;然而，由M诱导的纤维化在转基因小鼠和对照小鼠中是相同的，这表明在该表达水平下，CCN 2不足以增强纤维形成。总的来说，我们的研究提供了一个更好的理解到两个主要的细胞外基质蛋白的表达模式和作用：I型胶原和CCN 2。(C)2011爱思唯尔有限公司版权所有。
Accumulation of type I collagen is a key event in renal interstitial fibrosis. As there is no effective treatment, understanding the site where collagen is transcribed and the factors driving it in response to disease in vivo is critical for designing future therapies. The present research investigated the transcriptional activity of the COL1A2 gene in a mouse model of progressive fibrosis induced by aristolochic acid (aristolochic acid nephropathy, AAN). To achieve this we genetically modified mice to express a reporter gene (LacZ) and CCN2 (connective tissue growth factor) under the transcriptional control of the COL1A2 promoter/enhancer sequences. Using these mice we asked where is collagen actively transcribed and secondly, what is the role of CCN2 in AAN. Here, we report that de-novo transcription of the COL1A2 gene occurred predominantly in damaged tubular epithelial cells during progressive interstitial fibrosis in vivo. The activation of COL1A2 was studied by detection of the reporter gene LacZ and COL1A2 mRNA in interstitial, glomerular, vascular, and tubular epithelial tissue from laser capture microscopy. We also demonstrated that LacZ-positive cells co-express E-Cadherin a marker of epithelial origin which is consistent with an epithelial phenotype which is capable of collagen expression during injury. There was no evidence of detachment of these cells from tubules to become myofibroblasts. Moreover, we showed that the transgenic mice show a modest enhancement of CCN2 expression; however fibrosis induced by M is the same in transgenics and controls suggesting that CCN2, at this level of expression, is not sufficient to enhance fibrogenesis. Overall our study provides a better understanding into the expression patterns and roles of two major extracellular matrix proteins: type I collagen and CCN2. (C) 2011 Elsevier B.V. All rights reserved.