Margis R, Borojevic R
Departamento de Bioquimica, Universidade Federal do Rio de Janeiro, Brazil.
Biochim Biophys Acta. 1989 Mar 28;1011(1):1-5. doi: 10.1016/0167-4889(89)90069-4.
The GRX cell line is derived from murine liver connective tissue cells. It has myofibroblastic characteristics and can be induced to display a phenotype analogous to fat-storing (Ito) cells. Retinol-mediated induction of the fat-storing phenotype was studied in vitro. Based on the incorporation of radiolabelled acetate into cell lipids, cholesterol synthesis increased and phospholipid synthesis was modified shortly after the beginning of the induction, indicating an activation of pre-existing metabolic pathways. Triacylglycerol synthesis was increased only after a delay of 4 d, indicating the de novo induction of enzymes necessary for triacylglycerol metabolism. Retinol incorporation and conversion into retinyl esters were also considerably increased by previous incubation with retinoids. Retinoid-induced changes in GRX cells provide a model for studying in vitro the interconversion of liver connective tissue cells between the myofibroblastic and fat-storing phenotypes. This interconversion is considered to be one of the major control points of normal homeostasis and of pathological modifications of liver connective tissue.
GRX细胞系源自小鼠肝脏结缔组织细胞。它具有肌成纤维细胞特征，可被诱导表现出类似于储存脂肪（伊托）细胞的表型。在体外研究了视黄醇介导的储存脂肪表型的诱导过程。基于放射性标记的乙酸盐掺入细胞脂质中，诱导开始后不久胆固醇合成增加，磷脂合成发生改变，这表明预先存在的代谢途径被激活。三酰甘油合成仅在延迟4天后增加，这表明三酰甘油代谢所需酶的从头诱导。通过先前用类视黄醇孵育，视黄醇掺入和转化为视黄酯的量也显著增加。类视黄醇诱导的GRX细胞变化为体外研究肝脏结缔组织细胞在肌成纤维细胞和储存脂肪表型之间的相互转化提供了一个模型。这种相互转化被认为是正常稳态和肝脏结缔组织病理改变的主要控制点之一。
