Pujades C, Forsberg E, Enrich C, Johansson S
Departamento de Biología Celular, Facultad de Medicina, Universidad de Barcelona, Spain.
J Cell Sci. 1992 Aug;102 ( Pt 4):815-20. doi: 10.1242/jcs.102.4.815.
The surface expression of fibronectin and its major integrin receptor in liver, integrin alpha 5 beta 1, was studied during liver regeneration after partial hepatectomy. Using immunoblotting, plasma membranes isolated from livers at different regeneration stages were found to contain 6- to 8-fold elevated levels of fibronectin, alpha 5 and beta 1 at 12-24 h after the operation. Normal levels were gradually restored during the following 8-9 days. The membrane-associated fibronectin lacked the ED-A domain, suggesting that it consisted of plasma fibronectin. A prominent fibronectin fragment (180 kDa) was present at 12-24 h after surgery, possibly reflecting turnover of the pericellular matrix during cell division. Indirect immunohistochemical staining of liver sections revealed beta 1 and fibronectin mainly in the sinusoidal region of the hepatocyte plasma membrane. The distribution was not markedly altered during liver regeneration. The results suggest that the fibronectin-mediated contacts between the cells and the extracellular matrix increase during the pre-replicative and proliferative phases of liver regeneration. The significance of these results for the growth and for the structure of the liver during regeneration and development is discussed.
在部分肝切除术后肝脏再生过程中，研究了纤连蛋白及其在肝脏中的主要整合素受体整合素α5β1的表面表达。采用免疫印迹法，发现在术后12 - 24小时，从处于不同再生阶段的肝脏分离的质膜中纤连蛋白、α5和β1的水平升高了6至8倍。在接下来的8 - 9天中逐渐恢复到正常水平。膜相关纤连蛋白缺乏ED - A结构域，表明它由血浆纤连蛋白组成。术后12 - 24小时出现一个显著的纤连蛋白片段（180 kDa），这可能反映了细胞分裂期间细胞周围基质的更新。肝脏切片的间接免疫组织化学染色显示β1和纤连蛋白主要位于肝细胞质膜的窦状区域。在肝脏再生过程中分布没有明显改变。结果表明，在肝脏再生的复制前期和增殖期，细胞与细胞外基质之间由纤连蛋白介导的接触增加。讨论了这些结果对肝脏再生和发育过程中生长及结构的意义。
