Falasca M, Marino M, Carvelli A, Iurisci C, Leoni S, Corda D
Istituto di Ricerche Farmacologiche Mario Negri, Consorzio Mario Negri Sud, Department of Cell Biology and Oncology, Santa Maria Imbaro, Italy.
Eur J Biochem. 1996 Oct 15;241(2):386-92. doi: 10.1111/j.1432-1033.1996.00386.x.
Glycerophosphoinositols are metabolites formed by a phosholipase A2 and a lysolipase specifically acting on membrane phosphoinositol lipids. High levels of these compounds characterize epithelial cells and fibroblasts transformed by ras and other cellular oncogenes. Here we have analyzed the glycerophosphoinositol levels in cells that are considered models of cell differentiation. Using rat hepatocytes at different stages of liver development we have shown that the glycerophosphoinositol basal levels of fetal cells were up to fourfold higher than in adult hepatocytes. No changes in glycerophosphoinositol were observed in regenerating rat liver, a model of differentiated cells proliferating in a synchronous manner, where only glycerophosphoinositol 4-phosphate increased by 80%. Similarly to fetal hepatocytes, a modest but significant increase (30%) in the levels of glycerophosphoinositols was observed in undifferentiated NG-108-15 cells as compared to the same cells induced to differentiate by cAMP. In a different neuronal cell line, PC12 cells, increased glycerophosphoinositol levels characterized the differentiated cells. Based on these observations we suggest that high glycerophosphoinositol levels characterize cellular phenomena associated with the activation of ras/mitogen-activated protein kinase pathways.
甘油磷酸肌醇是由磷脂酶A2和一种特异性作用于膜磷酸肌醇脂质的溶血磷脂酶形成的代谢产物。这些化合物的高水平是由ras和其他细胞癌基因转化的上皮细胞和成纤维细胞的特征。在这里，我们分析了被视为细胞分化模型的细胞中的甘油磷酸肌醇水平。使用处于肝脏发育不同阶段的大鼠肝细胞，我们发现胎儿细胞的甘油磷酸肌醇基础水平比成年肝细胞高多达四倍。在再生大鼠肝脏中未观察到甘油磷酸肌醇的变化，再生大鼠肝脏是分化细胞同步增殖的模型，其中只有甘油磷酸肌醇4-磷酸增加了80%。与胎儿肝细胞类似，与经cAMP诱导分化的相同细胞相比，未分化的NG-108-15细胞中甘油磷酸肌醇水平有适度但显著的增加（30%）。在另一种神经元细胞系PC12细胞中，甘油磷酸肌醇水平升高是分化细胞的特征。基于这些观察结果，我们认为高甘油磷酸肌醇水平是与ras/丝裂原活化蛋白激酶途径激活相关的细胞现象的特征。
