Matsumoto Ken-Ichi, Sato Takashige, Oka Seiko, Inokuchi Jin-Ichi, Ariga Hiroyoshi
Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita 12, Nishi 6, Kita-ku, Sapporo 060-0812, Japan.
Biol Pharm Bull. 2004 Sep;27(9):1447-50. doi: 10.1248/bpb.27.1447.
Tenascin-X (TNX) is a member of the tenascin family of glycoproteins of the extracellular matrix. We previously showed that TNX regulates the synthesis of triglyceride and the composition of triglyceride-associated fatty acids. The aim of the present study was to determine whether TNX controls the synthesis of phospholipids and the composition of phospholipid-associated fatty acids by using TNX-deficient (TNX-/-) mice and TNX-overexpressing fibroblast cell lines. Thin-layer chromatography of total lipids of the skin and sciatic nerves from wild-type and TNX-/- mice revealed that the amounts of major phospholipids, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), in wild-type and TNX-/- mice are not different. Gas chromatography-mass spectrometry showed that the major fatty acid compositions of PC and PE in wild-type and TNX-/- mice are almost the same. Fibroblast cells stably overexpressing TNX also showed almost the same amounts of PC and PE and almost the same fatty acid compositions of PC and PE as those in mock-transfected cells. These results suggest that TNX regulates the amount of triglyceride and the composition of triglyceride-associated fatty acids but not the amount and species of phospholipids or the composition of phospholipid-associated fatty acids.
腱生蛋白-X（TNX）是细胞外基质中腱生蛋白家族糖蛋白的成员之一。我们之前发现TNX可调节甘油三酯的合成以及与甘油三酯相关的脂肪酸组成。本研究的目的是通过使用TNX基因敲除（TNX-/-）小鼠和过表达TNX的成纤维细胞系，来确定TNX是否控制磷脂的合成以及与磷脂相关的脂肪酸组成。对野生型和TNX-/-小鼠的皮肤和坐骨神经总脂质进行薄层色谱分析，结果显示野生型和TNX-/-小鼠中主要磷脂（磷脂酰胆碱（PC）和磷脂酰乙醇胺（PE））的含量并无差异。气相色谱-质谱分析表明，野生型和TNX-/-小鼠中PC和PE的主要脂肪酸组成几乎相同。稳定过表达TNX的成纤维细胞系所显示的PC和PE含量以及PC和PE的脂肪酸组成，也与mock转染细胞几乎相同。这些结果表明，TNX调节甘油三酯的量以及与甘油三酯相关的脂肪酸组成，但不调节磷脂的量和种类或与磷脂相关脂肪酸的组成。
