Distribution of receptors to collagen and globular domains of Clq in human lung fibroblasts
Distribution of receptors to collagen and globular domains of Clq in human lung fibroblasts
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DOI：
10.1165/ajrcmb.17.1.2732
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发表时间：
1997-07-01
影响因子：
6.4
通讯作者：
Raghu, G
中科院分区：
文献类型：
--
作者：
Narayanan, AS;Lurton, J;Raghu, G
成纤维细胞是正常和纤维化肺中负责合成胶原和其他基质元素的主要细胞类型。我们以前曾报道，人肺成纤维细胞在C1q结合上是异质性的，可以分离和传代C1q结合不同的亚群。我们研究了C1q-胶原区受体(cC1q-R)和球状区受体(gC1q-R)在成人肺成纤维细胞中的分布。在含有新鲜或加热的血浆来源的人血清的培养液中，从成人肺外植体的培养物中分离成纤维细胞，并通过FAGS细胞分选将其分离成与C1q结合的具有高(HF)和低(LF)荧光的群体。通过抗cC1q-R抗体柱亲和层析，从成纤维细胞膜制剂中获得cC1q-R，并通过Western分析确定其分布。用抗gC1q-R抗体的免疫印迹法检测gC1q-R的存在。结果表明，LF细胞能产生与抗cC1q-R抗体发生交叉反应的54kD蛋白，而在HF细胞中几乎检测不到该蛋白。抗cC1q-R抗体免疫染色显示，LF培养的细胞多数为阳性，而HF细胞为阴性。肺成纤维细胞产生一种可被抗gC1q-R抗体识别的38kD蛋白，但其在LF和HF培养中的分布无明显差异。结合到C1q-球状片段亲和柱上的膜蛋白的SDS-聚丙烯酰胺凝胶电泳法表明，HF培养物含有与51kD相似的蛋白质，这是LF膜中的一个次要成分。这些数据表明，cC1q-R主要由一组人肺成纤维细胞表达，而38kD的gC1q-R则由所有细胞产生。另一种51kD的蛋白似乎是由不表达cC1q-R的成纤维细胞产生的。我们的结果表明，肺成纤维细胞的两种亚型可以根据54kD可能的cC1q-R和另一种与C1q球状结构域结合的51kD蛋白的产生来区分。
Fibroblasts are the predominant cell type responsible for the synthesis of collagen and other matrix elements in normal and fibrotic lungs. We have previously reported that human lung fibroblasts are heterogeneous in C1q binding and that subpopulations differing in C1q binding can be isolated and subcultured. We have investigated the distribution of receptors for C1q-collagen domain (cC1q-R) and globular domain (gC1q-R) in adult human lung fibroblasts. Fibroblasts were isolated from cultures of adult human lung explants in medium containing fresh- or heated plasma-derived human sera and separated by FAGS-cell sorting into populations binding to C1q with high-(HF) and low-(LF) fluorescence. The cC1q-R was obtained from fibroblast membrane preparations by affinity chromatography through an anti-cC1q-R antibody column and its distribution was determined by Western analysis. The presence of gC1q-R was determined by immunoblots using an anti-gC1q-R antibody raised against a synthetic peptide. The results showed that a 54 kD protein crossreacting with anti-cC1q-R antibody was produced by LF cells, but it was barely detectable in HF cultures. Immunostaining with anti-cC1q-R antibody revealed that most of the cells in LF cultures were positive while the HF cells were negative. A 38 kD protein recognized by anti-gC1q-R antibody was produced by lung fibroblasts; however, no differences were detected in its distribution between LF and HF cultures. SDS-polyacrylamide gel electrophoresis of membrane proteins binding to an affinity column of C1q-globular fragment showed that the HF cultures contain a similar to 51 kD protein, which was a minor component in LF membranes. These data show that cC1q-R is expressed predominantly by a population of human lung fibroblasts, while the 38 kD gC1q-R is produced by all cells. Another 51 kD protein appears to be produced by a separate population of fibroblasts which does not express cC1q-R. Our results indicate that two lung fibroblast subtypes may be distinguished based on production of the 54 kD putative cC1q-R and another 51 kD protein which binds to C1q-globular domain.