Berger E, Héraud S, Mojallal A, Lequeux C, Weiss-Gayet M, Damour O, Géloën A
Lyon University; INSERM; UMR1060; INRA1397; CarMeN Laboratory; INSA; HCL ; Lyon, France.
Laboratoire des Substituts Cutanés; Hôpital Edouard Herriot ; Lyon, France.
Adipocyte. 2015 Jan 26;4(3):161-80. doi: 10.4161/21623945.2014.987578. eCollection 2015 Jul-Sep.
Obesity is linked to adipose tissue hypertrophy (increased adipocyte cell size) and hyperplasia (increased cell number). Comparative analyses of gene datasets allowed us to identify 1426 genes which may represent common adipose phenotype in humans and mice. Among them we identified several adipocyte-specific genes dysregulated in obese adipose tissue, involved in either fatty acid storage (acyl CoA synthase ACSL1, hormone-sensitive lipase LIPE, aquaporin 7 AQP7, perilipin PLIN) or cell adhesion (fibronectin FN1, collagens COL1A1, COL1A3, metalloprotein MMP9, or both (scavenger receptor FAT/CD36). Using real-time analysis of cell surface occupancy on xCELLigence system we developed a new method to study lipid uptake and differentiation of mouse 3T3L1 fibroblasts and human adipose stem cells. Both processes are regulated by insulin and fatty acids such as oleic acid. We showed that fatty acid addition to culture media increased the differentiation rate and was required for full differentiation into unilocular adipocytes. Significant activation of lipogenesis, i.e. lipid accumulation, by either insulin or oleic acid was monitored in times ranging from 1 to 24 h, depending on differentiation state, whereas significant effects on adipogenesis, i.e., surperimposed lipid accumulation and gene transcriptional regulations were measured after 3 to 4 d. Combination of selected times for analysis of lipid contents, cell counts, size fractionations, and gene transcriptional regulations showed that FAT/CD36 specific inhibitor AP5258 significantly increased cell survival of oleic acid-treated mouse and human adipocytes, and partially restored the transcriptional response to oleic acid in the presence of insulin through JNK pathway. Taken together, these data open new perspectives to study the molecular mechanisms commonly dysregulated in mouse and human obesity at the level of lipogenesis linked to hypertrophy and adipogenesis linked to hyperplasia.
肥胖与脂肪组织肥大（脂肪细胞大小增加）和增生（细胞数量增加）有关。对基因数据集的比较分析使我们能够鉴定出1426个可能代表人类和小鼠常见脂肪表型的基因。其中，我们鉴定出几个在肥胖脂肪组织中失调的脂肪细胞特异性基因，它们参与脂肪酸储存（酰基辅酶A合成酶ACSL1、激素敏感性脂肪酶LIPE、水通道蛋白7 AQP7、围脂滴蛋白PLIN）或细胞黏附（纤连蛋白FN1、胶原蛋白COL1A1、COL1A3、金属蛋白酶MMP9），或两者皆有（清道夫受体FAT/CD36）。通过在xCELLigence系统上对细胞表面占有率进行实时分析，我们开发了一种新方法来研究小鼠3T3L1成纤维细胞和人脂肪干细胞的脂质摄取和分化。这两个过程均受胰岛素和油酸等脂肪酸的调节。我们发现，向培养基中添加脂肪酸可提高分化率，并且是完全分化为单泡脂肪细胞所必需的。根据分化状态，在1至24小时内监测到胰岛素或油酸对脂肪生成（即脂质积累）有显著激活作用，而在3至4天后测量到对脂肪形成（即叠加的脂质积累和基因转录调控）有显著影响。对脂质含量、细胞计数、大小分级和基因转录调控进行分析的选定时间组合显示，FAT/CD36特异性抑制剂AP5258显著提高了油酸处理的小鼠和人脂肪细胞的存活率，并在存在胰岛素的情况下通过JNK途径部分恢复了对油酸的转录反应。综上所述，这些数据为研究在小鼠和人类肥胖中通常在与肥大相关的脂肪生成和与增生相关的脂肪形成水平上失调的分子机制开辟了新的视角。
