Enhanced myofibroblastic differentiation and survival in Thy-1(-) lung fibroblasts
Enhanced myofibroblastic differentiation and survival in Thy-1(-) lung fibroblasts
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DOI：
10.1165/rcmb.2006-0178oc
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发表时间：
2007-02-01
影响因子：
6.4
通讯作者：
Hagood, James S.
中科院分区：
文献类型：
--
作者：
Sanders, Yan Y.;Kumbla, Pallavi;Hagood, James S.
Thy-1是一种糖基磷脂酰肌醇连接的细胞表面糖蛋白，其确切的生物学作用尚不清楚。Thy-1的差异表达影响成纤维细胞增殖和纤维化信号传导。在特发性肺纤维化中，成纤维细胞病灶内增殖的肌成纤维细胞为Thy-1（-），而正常肺成纤维细胞主要为Thy-1（+）。在这项研究中，我们使用大鼠肺成纤维细胞分选的Thy-1的表达，以检查肌纤维母细胞分化的纤维化刺激。我们研究了转化生长因子-β，血管内皮素-1，结缔组织生长因子对肌成纤维细胞蛋白和生肌调节因子的表达的影响，通过实时RTPCR和免疫印迹。Thy-1（-）细胞与Thy-1（+）细胞相比具有显著更高的肌成纤维细胞和肌生成调节因子基因和蛋白表达，通过免疫荧光证实。我们还使用漂浮胶原基质收缩测定来评估成纤维细胞的功能分化。在基线和用转化生长因子-β和内皮素-1刺激后，Thy-1（-）细胞比Thy-1（+）细胞引起显著更大的胶原收缩，支持Thy-1（-）细胞是更完全分化的肌成纤维细胞的假设。由于细胞凋亡与肌成纤维细胞的消退有关，我们检查了基线时和用纤维化剂刺激后收缩的胶原基质中凋亡细胞的百分比。与Thy-1（-）成纤维细胞相比，在所有条件下，Thy-1（+）细胞发生凋亡的比例显著更大。Thy-1转染Thy-1（-）细胞抑制胶原基质收缩并降低细胞存活。我们的数据表明，Thy-1调节成肌基因的表达，成肌纤维细胞分化，并在肺成纤维细胞的生存。
Thy-1 is a glycosyl phosphaticlyl-inositol-linked cell surface glycoprotein whose exact biological role remains unclear. Differential expression of Thy-1 affects fibroblast proliferation and fibrogenic signaling. In idiopathic pulmonary fibrosis, the proliferating myofibroblasts within the fibroblastic foci are Thy-1 (-), whereas normal lung fibroblasts are predominantly Thy-1 (+). In this study, we used rat lung fibroblasts sorted for Thy-1 expression to examine myofibroblastic differentiation in response to fibrogenic stimuli. We examined the effects of transforming growth factor-beta, enclothelin-1, and connective tissue growth factor on the expression of myofibroblast proteins and myogenic regulatory factors by real-time RTPCR and immunoblotting. Thy-1 (-) cells have significantly higher myofibroblast and myogenic regulatory factor gene and protein expression compared with Thy-1 (+) cells, confirmed by immunofluorescence. We also used floating Collagen matrix contraction assays to assess the functional differentiation of the fibroblasts. At baseline and after stimulation with transforming growth factor-beta and enclothelin-1, Thy-1(-) cells caused significantly greater Collagen contraction than did Thy-1 (+) cells, supporting the hypothesis that Thy-1(-) cells are more fully differentiated myofibroblasts. Because apoptosis has been implicated in the regression of myofibroblasts, we examined the percentage of apoptotic cells in the contracted Collagen matrices at baseline and after stimulation with fibrogenic agents. A significantly greater proportion of Thy-1(+) cells underwent apoptosis in all conditions compared with Thy-1(-) fibroblasts. Transfection of Thy-1 into Thy-1(-) cells inhibits Collagen matrix contraction and reduces cell survival. Our data indicate that Thy-1 regulates myogenic gene expression, myofibroblastic differentiation, and survival in lung fibroblasts.