Strandjord T P, Clark J G, Madtes D K
Department of Pediatrics, University of Washington, Fred Hutchinson Cancer Research Center, Seattle 98195.
Am J Physiol. 1994 Oct;267(4 Pt 1):L384-9. doi: 10.1152/ajplung.1994.267.4.L384.
To define the distribution of transforming growth factor-alpha (TGF-alpha) and its relationship to epidermal growth factor (EGF) and EGF receptor in lung development and to determine whether epithelial cells produce TGF-alpha, we studied the expression of TGF-alpha, EGF, and their receptor in late-gestation fetal rat lung and in cultured fetal rat lung cells. TGF-alpha, EGF, and EGF receptor were colocalized in epithelial and smooth muscle cells of bronchioles and bronchi and in epithelial cells of saccules. Epithelial cells cultured from late-gestation fetal rat lung transcribe TGF-alpha and EGF receptor mRNA and produce TGF-alpha and EGF receptor proteins. Cultured fibroblasts contained EGF receptor mRNA, but no detectable TGF-alpha mRNA. These results demonstrate fetal lung epithelial cells are a source for TGF-alpha and suggest that TGF-alpha might act through an autocrine or paracrine mechanism with epithelial and mesenchymal cells. The colocalization of TGF-alpha and EGF suggests that these growth factors might act in parallel in lung development.
为了确定转化生长因子-α（TGF-α）的分布及其在肺发育过程中与表皮生长因子（EGF）和EGF受体的关系，并确定上皮细胞是否产生TGF-α，我们研究了TGF-α、EGF及其受体在妊娠晚期胎鼠肺组织以及培养的胎鼠肺细胞中的表达情况。TGF-α、EGF和EGF受体共定位于细支气管和支气管的上皮细胞和平滑肌细胞以及肺泡囊的上皮细胞中。从妊娠晚期胎鼠肺组织培养的上皮细胞可转录TGF-α和EGF受体mRNA，并产生TGF-α和EGF受体蛋白。培养的成纤维细胞含有EGF受体mRNA，但未检测到TGF-α mRNA。这些结果表明胎肺上皮细胞是TGF-α的来源之一，并提示TGF-α可能通过自分泌或旁分泌机制作用于上皮细胞和间充质细胞。TGF-α和EGF的共定位表明这些生长因子可能在肺发育过程中协同发挥作用。
