Pinheiro-Margis M, Margis R, Borojevic R
Departamento de Bioquimica, Universidade Federal do Rio de Janeiro, Brazil.
Exp Mol Pathol. 1992 Apr;56(2):108-18. doi: 10.1016/0014-4800(92)90028-a.
We have studied collagen synthesis and secretion in an established liver connective tissue cell line (GRX) that can be induced in vitro to express either the myofibroblastic or the fat-storing (lipocyte) phenotype. In lipocytes, collagen synthesis was reduced. Their intracellular collagen degradation corresponded to 15% of newly synthesized collagen. In myofibroblasts, collagen synthesis was high but its secretion was considerably altered by intracellular collagen degradation, which attained up to 60% of newly synthesized collagen. In this in vitro model, we have provided direct evidence that hepatic lipocytes, involved mainly in lipid and retinol metabolism, have a low basal level of collagen synthesis. Myofibroblastic phenotype correlates with increased collagen synthesis and may be directly related to increased collagen deposition in hepatic fibrosis. Modulation of the phenotype of liver connective tissue cells are possibly one of the major points of control in normal and pathological deposition of collagen in liver parenchyma.
我们研究了一种已建立的肝结缔组织细胞系（GRX）中的胶原蛋白合成与分泌，该细胞系在体外可被诱导表达肌成纤维细胞或脂肪储存（脂肪细胞）表型。在脂肪细胞中，胶原蛋白合成减少。它们细胞内的胶原蛋白降解量相当于新合成胶原蛋白的15%。在肌成纤维细胞中，胶原蛋白合成量高，但细胞内胶原蛋白降解对其分泌有显著影响，降解量高达新合成胶原蛋白的60%。在这个体外模型中，我们提供了直接证据，表明主要参与脂质和视黄醇代谢的肝脂肪细胞的胶原蛋白合成基础水平较低。肌成纤维细胞表型与胶原蛋白合成增加相关，可能与肝纤维化中胶原蛋白沉积增加直接相关。肝结缔组织细胞表型的调节可能是肝实质中胶原蛋白正常和病理沉积的主要控制点之一。
