van Harmelen Vanessa, Rydén Mikael, Sjölin Eva, Hoffstedt Johan
Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
J Lipid Res. 2007 Jan;48(1):201-6. doi: 10.1194/jlr.M600272-JLR200. Epub 2006 Oct 11.
The mouse lipin gene, Lpin1, is important for adipose tissue development and is a candidate gene for insulin resistance. Here, we investigate the adipose tissue expression levels of the human LPIN1 gene in relation to various clinical variables as well as adipocyte function. LPIN1 gene expression was induced at an early step in human preadipocyte differentiation in parallel with peroxisome proliferator-activated receptor gamma. Lipin mRNA levels were higher in fat cells than in adipose tissue segments but showed no difference between subcutaneous and omental depots. Moreover, LPIN1 expression levels were reduced in obesity, improved following weight reduction in obese subjects, and were downregulated in women with the metabolic syndrome. With respect to adipocyte function, adipose LPIN1 gene expression was strongly associated with both basal and insulin-mediated subcutaneous adipocyte glucose transport as well as mRNA levels of glucose transporter 4 (GLUT4). We show that body fat accumulation is a major regulator of human adipose LPIN1 expression and suggest a role of LPIN1 in human preadipocyte as well as mature adipocyte function.
小鼠脂联素基因Lpin1对脂肪组织发育很重要，是胰岛素抵抗的候选基因。在此，我们研究了人类LPIN1基因在脂肪组织中的表达水平与各种临床变量以及脂肪细胞功能的关系。LPIN1基因表达在人类前脂肪细胞分化的早期阶段与过氧化物酶体增殖物激活受体γ同时被诱导。脂联素mRNA水平在脂肪细胞中高于脂肪组织切片，但在皮下和网膜脂肪库之间没有差异。此外，LPIN1表达水平在肥胖时降低，肥胖受试者体重减轻后改善，并且在患有代谢综合征的女性中下调。关于脂肪细胞功能，脂肪组织中LPIN1基因表达与基础和胰岛素介导的皮下脂肪细胞葡萄糖转运以及葡萄糖转运蛋白4（GLUT4）的mRNA水平密切相关。我们表明，体脂积累是人类脂肪组织中LPIN1表达的主要调节因子，并提示LPIN1在人类前脂肪细胞以及成熟脂肪细胞功能中发挥作用。
