Zhang Yuchao, Yu Hongsheng, Gao Peng, Chen Jicui, Yu Cong, Zong Chen, Lu Sumei, Li Xia, Ma Xiaoli, Liu Yuantao, Wang Xiangdong
Department of Cell Biology, Shandong University School of Medicine, Jinan, China.
Cell Physiol Biochem. 2016;39(6):2135-2148. doi: 10.1159/000447909. Epub 2016 Nov 2.
Adipogenesis of adipocytes includes two stages: initiation and maturation. Growth hormone (GH) secretion is decreased in obese subjects and GH levels are inversely correlated with abdominal fat mass. The effects of growth hormone (GH) on lipids accumulation or maturation of adipocytes remains elusive.
In the present study, effect of GH on lipid accumulation in vitro and in vivo was examined. cDNA microarray, quantitative real time-PCR (qPCR) and western blotting was used to analyze the expression of genes related to adipocyte lipid accumulation or degradation in pre- or mature 3T3-F442A adipocytes treated with GH and in epididymal adipose tissue of C57BL/6 mice administrated with GH. Level of adiponectin in supernatants of cultured F442A adipocytes was determined by enzyme-linked immune-sorbent assay.
We found that in 3T3-F442A especially 6 days post initiation of adipogenesis, GH intervention resulted in decreased expression of adipocyte maturation regulators (C/EBPα, PPARγ) and prominent genes related to lipid synthesis such as FAS and FABP, while the expression of UCP1 was markedly enhanced. cDNA microarray analysis and qPCR showed that the expression of SOCS2 and Adipor2 was increased under GH-treatment in mature 3T3-F442A adipocytes. GH treatment increased the mRNA expression of adiponectin and UCP1 in mature adipocytes. The above results were confirmed by in vivo study.
GH potentially negatively modulates the maturation and accumulation of lipid in adipocytes.
脂肪细胞的脂肪生成包括两个阶段：起始和成熟。肥胖受试者的生长激素（GH）分泌减少，且GH水平与腹部脂肪量呈负相关。生长激素（GH）对脂肪细胞脂质积累或成熟的影响仍不明确。
在本研究中，检测了GH在体外和体内对脂质积累的影响。利用cDNA微阵列、定量实时PCR（qPCR）和蛋白质印迹法分析了用GH处理的前体或成熟3T3-F442A脂肪细胞以及给予GH的C57BL/6小鼠附睾脂肪组织中与脂肪细胞脂质积累或降解相关基因的表达。通过酶联免疫吸附测定法测定培养的F442A脂肪细胞上清液中脂联素的水平。
我们发现，在3T3-F442A细胞中，尤其是在脂肪生成起始后6天，GH干预导致脂肪细胞成熟调节因子（C/EBPα、PPARγ）以及与脂质合成相关的重要基因如FAS和FABP的表达降低，而UCP1的表达显著增强。cDNA微阵列分析和qPCR显示，在GH处理下，成熟3T3-F442A脂肪细胞中SOCS2和Adipor2的表达增加。GH处理增加了成熟脂肪细胞中脂联素和UCP1的mRNA表达。上述结果在体内研究中得到了证实。
GH可能对脂肪细胞中脂质的成熟和积累具有负调节作用。
