Berndt J, Kralisch S, Klöting N, Ruschke K, Kern M, Fasshauer M, Schön M R, Stumvoll M, Blüher M
Department of Medicine, University of Leipzig, Leipzig, Germany.
Exp Clin Endocrinol Diabetes. 2008 Apr;116(4):203-10. doi: 10.1055/s-2007-993148. Epub 2007 Dec 10.
In comparison to subcutaneous (SC) fat, visceral adipose tissue is more sensitive to catecholamine-induced lipolysis and less sensitive to the antilipolytic effects of insulin. Variation in the expression of lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) have been reported. We therefore hypothesized that expression of adipose triglyceride lipase (ATGL) is different in visceral and SC depot and investigated whether ATGL mRNA expression is related to obesity, fat distribution and insulin sensitivity. ATGL, LPL, and HSL mRNA expression was measured in 85 paired samples of omental and subcutaneous adipose tissue in normal glucose tolerant lean and obese individuals. In addition, we included a subgroup of obese (BMI >30 kg/m2) individuals with either impaired or preserved insulin sensitivity determined by euglycemic-hyperinsulinemic clamps. ATGL mRNA levels are significantly decreased in insulin resistant obese subjects. Independently of body fat mass, omental ATGL mRNA correlates with fasting insulin concentration, glucose uptake during the steady state of the clamp and HSL mRNA expression. In obese, but not in lean subjects, LPL and HSL mRNA expression was significantly higher in omental compared to SC fat. In both depots, HSL mRNA was significantly lower in obese individuals. Visceral HSL mRNA expression is closely related to adipocyte size and fasting plasma insulin concentrations, whereas visceral fat area significantly predicts visceral LPL mRNA expression. ATGL mRNA expression is not significantly different between omental and SC fat. HSL, but not ATGL mRNA expression is closely related to individual and regional differences in adipocyte size. Impaired insulin sensitivity was associated with decreased ATGL and HSL mRNA expression, independently of body fat mass and fat distribution.
与皮下（SC）脂肪相比，内脏脂肪组织对儿茶酚胺诱导的脂肪分解更敏感，而对胰岛素的抗脂解作用不太敏感。已有报道称脂蛋白脂肪酶（LPL）和激素敏感性脂肪酶（HSL）的表达存在差异。因此，我们推测内脏和皮下脂肪库中脂肪甘油三酯脂肪酶（ATGL）的表达不同，并研究了ATGL mRNA表达是否与肥胖、脂肪分布和胰岛素敏感性相关。在正常糖耐量的瘦人和肥胖个体的85对网膜和皮下脂肪组织样本中测量了ATGL、LPL和HSL mRNA的表达。此外，我们纳入了一组肥胖（BMI>30 kg/m²）个体，通过正常血糖-高胰岛素钳夹试验确定其胰岛素敏感性受损或保留。胰岛素抵抗的肥胖受试者中ATGL mRNA水平显著降低。独立于体脂量，网膜ATGL mRNA与空腹胰岛素浓度、钳夹稳态期间的葡萄糖摄取以及HSL mRNA表达相关。在肥胖个体而非瘦人中，网膜LPL和HSL mRNA表达显著高于皮下脂肪。在两个脂肪库中，肥胖个体的HSL mRNA均显著较低。内脏HSL mRNA表达与脂肪细胞大小和空腹血浆胰岛素浓度密切相关，而内脏脂肪面积显著预测内脏LPL mRNA表达。网膜和皮下脂肪之间的ATGL mRNA表达无显著差异。HSL而非ATGL mRNA表达与脂肪细胞大小的个体和区域差异密切相关。胰岛素敏感性受损与ATGL和HSL mRNA表达降低相关，独立于体脂量和脂肪分布。
