Guaragna R M, Trugo L, Borojevic R
Departamento de Bioquímica, Universidade Federal do Rio de Janeiro, Brazil.
Biochim Biophys Acta. 1992 Oct 30;1128(2-3):237-43. doi: 10.1016/0005-2760(92)90313-k.
Connective tissue cells of liver parenchyma (perisinusoidal myofibroblasts) can be induced to express the lipocyte (Ito cell) phenotype. We have studied phospholipid synthesis and phosphate incorporation during this in vitro conversion, induced by insulin and/or indomethacin, in the established murine cell line GRX. Phospholipid synthesis, measured by [14C]acetate incorporation, was increased after a full induction of the lipocyte phenotype. The 32Pi incorporation into phospholipids was increased from the beginning of induction. Phosphatidic acid and phosphatidylinositol synthesis were increased early in the induction, whilst the increase of major constitutive phospholipids was significant only after the full lipocyte phenotype induction. The presence of unsaturated fatty acids in phospholipids was increased in lipocytes. Linoleic acid was present only in diacylglycerols and in phosphatidylinositol. Since we have shown previously that linoleic acid was not present in triacylglycerols, this result indicates the importance of future studies on activation of phosphatidylinositol cycles in induction of lipocyte phenotype in liver connective tissue cells.
肝实质的结缔组织细胞（窦周肌成纤维细胞）可被诱导表达脂肪细胞（伊托细胞）表型。我们在已建立的小鼠细胞系GRX中研究了由胰岛素和/或吲哚美辛诱导的这种体外转化过程中的磷脂合成和磷酸盐掺入情况。通过[14C]乙酸掺入法测定的磷脂合成在脂肪细胞表型完全诱导后增加。从诱导开始，32Pi掺入磷脂的量就增加。在诱导早期，磷脂酸和磷脂酰肌醇的合成增加，而主要组成性磷脂的增加仅在脂肪细胞表型完全诱导后才显著。脂肪细胞中磷脂中不饱和脂肪酸的含量增加。亚油酸仅存在于二酰甘油和磷脂酰肌醇中。由于我们之前已表明三酰甘油中不存在亚油酸，这一结果表明未来研究磷脂酰肌醇循环的激活在肝结缔组织细胞脂肪细胞表型诱导中的重要性。
