Imamura Minako, Inoguchi Toyoshi, Ikuyama Shoichiro, Taniguchi Susumu, Kobayashi Kunihisa, Nakashima Naoki, Nawata Hajime
Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
Am J Physiol Endocrinol Metab. 2002 Oct;283(4):E775-83. doi: 10.1152/ajpendo.00040.2002.
Adipose differentiation-related protein (ADRP) is a lipid droplet-associated protein that is expressed early during adipose differentiation. The present study was undertaken to reveal the role of ADRP in adipose differentiation. In murine fibroblasts infected with green fluorescent protein (GFP)-ADRP fusion protein expression adenovirus vector, confocal microscopic analysis showed the number and size of lipid droplets apparently increased comparing with those of control cells. Overexpressed GFP-ADRP were mainly located at the surface of lipid droplets and appeared to be "ring-shaped." Triacylglycerol content was also significantly (P < 0.001) increased in GFP-ADRP-overexpressed cells compared with control cells. ADRP-induced lipid accumulation did not depend on adipocyte-specific gene induction, such as peroxisome proliferator-activated receptor-gamma, lipoprotein lipase, or other lipogenic genes, including acyl-CoA synthetase, fatty acid-binding protein, and fatty acid transporter. In conclusion, ADRP stimulated lipid accumulation and lipid droplet formation without induction of other adipocyte-specific genes or other lipogenic genes in murine fibroblasts. The detailed molecular mechanisms of ADRP on lipid accumulation remain to be elucidated.
脂肪分化相关蛋白（ADRP）是一种与脂滴相关的蛋白质，在脂肪分化早期表达。本研究旨在揭示ADRP在脂肪分化中的作用。在感染绿色荧光蛋白（GFP）-ADRP融合蛋白表达腺病毒载体的小鼠成纤维细胞中，共聚焦显微镜分析显示，与对照细胞相比，脂滴的数量和大小明显增加。过表达的GFP-ADRP主要位于脂滴表面，呈“环形”。与对照细胞相比，GFP-ADRP过表达细胞中的三酰甘油含量也显著增加（P<0.001）。ADRP诱导的脂质积累不依赖于脂肪细胞特异性基因的诱导，如过氧化物酶体增殖物激活受体γ、脂蛋白脂肪酶或其他脂肪生成基因，包括酰基辅酶A合成酶、脂肪酸结合蛋白和脂肪酸转运蛋白。总之，ADRP在小鼠成纤维细胞中刺激脂质积累和脂滴形成，而不诱导其他脂肪细胞特异性基因或其他脂肪生成基因。ADRP促进脂质积累的详细分子机制仍有待阐明。
