Tanaka Y, Nouchi T, Yamane M, Irie T, Miyakawa H, Sato C, Marumo F
Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan.
J Pathol. 1991 Jul;164(3):273-8. doi: 10.1002/path.1711640314.
The presence of a-smooth muscle actin (smA)-positive cells has recently been reported in the fibrotic liver. Lipocytes have been considered to play important roles in hepatic fibrosis. However, the relation of the a-smA-positive cells and lipocytes has not been determined. The biological implication of a-smA expression remains unknown. To study these questions, we carried out double immunofluorescent staining of a-smA and desmin (a marker for lipocytes), or a-smA and collagen, and double immunohistochemical staining of a-smA and 5-bromo-2'-deoxyuridine (BrdUrd) in carbon tetrachloride-induced fibrotic rat livers. In normal and control livers, a-smA-positive cells were not seen in the lobules, whereas scattered desmin-positive cells were present. With the development of hepatic fibrosis, a-smA was expressed only in a portion of desmin-positive cells located predominantly around collagen bundles. A number of a-smA-positive cells in the lobules were labelled with BrdUrd. These results suggest phenotypic modulation in lipocytes and differentiation of lipocytes towards myofibroblast-like cells, since a-smA is expressed with desmin in myofibroblasts in scar tissue. The expression of a-smA may be related to events of the fibrotic process, such as tissue contraction or fibrogenesis per se.
最近有报道称，在纤维化肝脏中存在α-平滑肌肌动蛋白（α-smA）阳性细胞。脂肪细胞被认为在肝纤维化中起重要作用。然而，α-smA阳性细胞与脂肪细胞之间的关系尚未确定。α-smA表达的生物学意义仍然未知。为了研究这些问题，我们对四氯化碳诱导的纤维化大鼠肝脏进行了α-smA与结蛋白（脂肪细胞的标志物）或α-smA与胶原蛋白的双重免疫荧光染色，以及α-smA与5-溴-2'-脱氧尿苷（BrdUrd）的双重免疫组织化学染色。在正常和对照肝脏中，小叶内未见α-smA阳性细胞，而存在散在的结蛋白阳性细胞。随着肝纤维化的发展，α-smA仅在主要位于胶原束周围的一部分结蛋白阳性细胞中表达。小叶内许多α-smA阳性细胞被BrdUrd标记。这些结果表明脂肪细胞存在表型调节，且脂肪细胞向肌成纤维细胞样细胞分化，因为在瘢痕组织的肌成纤维细胞中α-smA与结蛋白共同表达。α-smA的表达可能与纤维化过程中的事件有关，如组织收缩或纤维化本身。
