Gene-chip studies of adipogenesis-regulatedmicroRNAs in mouse primary adipocytes andhuman obesity
基因芯片方法分析脂肪形成相关microRNAs
James A Timmons
2011 BMC Endocrine Disorders
Abstractabstract：Background: Adipose tissue abundance relies partly on the factors that regulate adipogenesis, i.e. proliferation a differentiation of adipocytes. While components of the transcriptional program that initiates adipogenesis is well-known, the importance of microRNAs in adipogenesis is less well studied. We thus set out to investigate whether miRNAs would be actively modulated during adipogenesis and obesity.Methods: Several models exist to study adipogenesis in vitro, ofwhich the cell line 3T3-L1 is the most well know albeit not the most physiologicaly appropriate.Thus, as an alternative, we produced EXIQON microarray of browl and white primary murine adipocytes(prior to and following differentiation) to yield global profiles of miRNAs.Results: We found 65 miRNAs regulated during in vitro adipogenesis in primary adipocytes. We evaluated the similarity of our responses to those found in non-primary cell models, through literature data-mining. When comparing primary adipocyte profiles, with those of cell lines reported in the literature, we found a high degree difference in ‘adipogenesis’regulated miRNAs suggesting that the model systems may not be accurately representing adipogenesis. The expression of 10 adipogenesis-regulated miRNAs were studied using real-time qP and then we selected 5 miRNAs, that showed robust expression, were profiled in subcutaneous adipose tissue obtained from 20 humans with a range of body mass indices (BMI, range = 21-48, and all samples have U133+2 Affymetrix profiles provided). Of the miRNAs tested, mir-21 was robustly expressed in human adipose tissue and positively correlated with BMI (R2 = 0.49, p < 0.001).Conclusion: In conclusion, we provide a preliminary analysis of miRNAs associated with primary cell in vitro adipogenesis and demonstrate that the inflammation-associated miRNA, mir-21 is up-regulated in subcutaneous adipose tissue in human obesity. Further, we provide a novel transcriptomics database of EXIQON and Affymetrix adipocyte profiles to facilitate data mining.
摘要：脂肪组织丰满与否，部分取决于脂肪形成过程中脂肪母细胞的增殖和分化。尽管关于脂肪形成相关的转录调控通路已经有较深入的了解，但关于转录后的miRNA调控机制却不甚清楚。本研究诣在探索miRNA在脂肪形成中的相关作用。ST3-L1是一种常用的在体外对脂肪形成进行研究的细胞模型，但该类细胞的生理学进程却不能完全模拟体内。所以，我们利用基因芯片方法对啮齿类动物的棕色和白色初级脂肪母细胞与成熟脂肪细胞间的miRNA的表达差异进行研究。我们发现，有65种miRNA对脂肪形成进行调控，这个数据与之前的利用其它模型对脂肪形成进行研究的数据有很大差异，这说明前人利用非脂肪母细胞进行研究并不能完全模拟体内的分化环境。利用实时定量RT-PCR方法，我们对其中10个miRNA的表达进行了验证，并选取其中5个高表达量的miRNA在20名肥胖患者的皮下脂肪组织中进行检测。我们发现，mir-21在人类皮下脂肪中高表达，与其他miRNAs表达差异具有统计学意义。