Mayer D C, Leinwand L A
Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Colorado 80309, USA.
J Cell Biol. 1997 Dec 15;139(6):1477-84. doi: 10.1083/jcb.139.6.1477.
Myofibroblasts are unusual cells that share morphological and functional features of muscle and nonmuscle cells. Such cells are thought to control liver blood flow and kidney glomerular filtration rate by having unique contractile properties. To determine how these cells achieve their contractile properties and their resemblance to muscle cells, we have characterized two myofibroblast cell lines. Here, we demonstrate that myofibroblast cell lines from kidney mesangial cells (BHK) and liver stellate cells activate extensive programs of muscle gene expression including a wide variety of muscle structural proteins. In BHK cells, six different striated myosin heavy chain isoforms and many thin filament proteins, including troponin T and tropomyosin are expressed. Liver stellate cells express a limited subset of the muscle thick filament proteins expressed in BHK cells. Although these cells are mitotically active and do not morphologically differentiate into myotubes, we show that MyoD and myogenin are expressed and functional in both cell types. Finally, these cells contract in response to endothelin-1 (ET-1); and we show that ET-1 treatment increases the expression of sarcomeric myosin.
肌成纤维细胞是一种特殊的细胞，兼具肌肉细胞和非肌肉细胞的形态及功能特征。人们认为这类细胞凭借其独特的收缩特性来控制肝脏血流和肾小球滤过率。为了确定这些细胞如何获得其收缩特性以及它们与肌肉细胞的相似之处，我们对两种肌成纤维细胞系进行了特性分析。在此，我们证明来自肾系膜细胞（BHK）和肝星状细胞的肌成纤维细胞系激活了广泛的肌肉基因表达程序，包括多种肌肉结构蛋白。在BHK细胞中，表达了六种不同的横纹肌肌球蛋白重链异构体以及许多细肌丝蛋白，包括肌钙蛋白T和原肌球蛋白。肝星状细胞表达的肌肉粗肌丝蛋白是BHK细胞中所表达蛋白的一个有限子集。尽管这些细胞具有有丝分裂活性且在形态上不会分化为肌管，但我们表明MyoD和肌细胞生成素在这两种细胞类型中均有表达且具有功能。最后，这些细胞会对内皮素 -1（ET -1）产生收缩反应；并且我们表明ET -1处理会增加肌节肌球蛋白的表达。
