Wang Xinxia, Wu Ruifan, Liu Youhua, Zhao Yuanling, Bi Zhen, Yao Yongxi, Liu Qing, Shi Hailing, Wang Fengqin, Wang Yizhen
College of Animal Sciences, Zhejiang University, Key Laboratory of Animal Nutrition & Feed Sciences, Ministry of Agriculture, Key Laboratory of Animal Feed and Nutrition of Zhejiang Province , Hangzhou, Zhejiang, China.
Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago , Chicago, IL, USA.
Autophagy. 2020 Jul;16(7):1221-1235. doi: 10.1080/15548627.2019.1659617. Epub 2019 Aug 26.
-methyladenosine (mA), the most abundant internal modification on mRNAs in eukaryotes, play roles in adipogenesis. However, the underlying mechanism remains largely unclear. Here, we show that mA plays a critical role in regulating macroautophagy/autophagy and adipogenesis through targeting and . Mechanistically, knockdown of FTO, a well-known mA demethylase, decreased the expression of ATG5 and ATG7, leading to attenuation of autophagosome formation, thereby inhibiting autophagy and adipogenesis. We proved that FTO directly targeted and transcripts and mediated their expression in an mA-dependent manner. Further study identified that and were the targets of YTHDF2 (YTH N6-methyladenosine RNA binding protein 2). Upon FTO silencing, and transcripts with higher mA levels were captured by YTHDF2, which resulted in mRNA degradation and reduction of protein expression, thus alleviating autophagy and adipogenesis. Furthermore, we generated an adipose-selective knockout mouse and find that FTO deficiency decreased white fat mass and impairs ATG5- and ATG7-dependent autophagy . Together, these findings unveil the functional importance of the mA methylation machinery in autophagy and adipogenesis regulation, which expands our understanding of such interplay that is essential for development of therapeutic strategies in the prevention and treatment of obesity.
3-MA: 3-methyladenine; ACTB: actin, beta; ATG: autophagy-related; Baf A1: bafilomycin A; CEBPA: CCAAT/enhancer binding protein (C/EBP), alpha; CEBPB: CCAAT/enhancer binding protein (C/EBP), beta; FABP4: fatty acid binding protein 4, adipocyte; FTO: fat mass and obesity associated; HFD: high-fat diet; LC-MS/MS: liquid chromatography-tandem mass spectrometry; MAP1LC3B/LC3: microtubule-associated protein 1 light chain 3 beta; mA: N-methyladenosine; MEFs: mouse embryo fibroblasts; MeRIP-qPCR: methylated RNA immunoprecipitation-qPCR; PPARG: peroxisome proliferator activated receptor gamma; RIP: RNA-immunoprecipitation; SAT: subcutaneous adipose tissue; siRNA: small interfering RNA; SQSTM1/p62: sequestosome 1; TEM: transmission electron microscopy; ULK1: unc-51 like kinase 1; VAT: visceral adipose tissue; WAT: white adipose tissue; YTHDF: YTH N6-methyladenosine RNA binding protein.
N6-甲基腺苷（m6A）是真核生物mRNA中最丰富的内部修饰，在脂肪生成中发挥作用。然而，其潜在机制仍 largely不清楚。在这里，我们表明m6A通过靶向 和 在调节巨自噬/自噬和脂肪生成中起关键作用。机制上，敲低著名的m6A去甲基化酶FTO会降低ATG5和ATG7的表达，导致自噬体形成减弱，从而抑制自噬和脂肪生成。我们证明FTO直接靶向 和 转录本并以m6A依赖的方式介导它们的表达。进一步研究确定 和 是YTHDF2（YTH N6-甲基腺苷RNA结合蛋白2）的靶标。FTO沉默后，m6A水平较高的 和 转录本被YTHDF2捕获，导致mRNA降解和蛋白质表达减少，从而减轻自噬和脂肪生成。此外，我们构建了一种脂肪组织选择性 敲除小鼠，发现FTO缺陷会减少白色脂肪量并损害ATG5和ATG7依赖的自噬。总之，这些发现揭示了m6A甲基化机制在自噬和脂肪生成调节中的功能重要性，这扩展了我们对这种相互作用的理解，这种相互作用对于肥胖预防和治疗策略的开发至关重要。
3-MA：3-甲基腺嘌呤；ACTB：肌动蛋白，β；ATG：自噬相关；Baf A1：巴弗洛霉素A；CEBPA：CCAAT/增强子结合蛋白（C/EBP），α；CEBPB：CCAAT/增强子结合蛋白（C/EBP），β；FABP4：脂肪酸结合蛋白4，脂肪细胞；FTO：脂肪量和肥胖相关；HFD：高脂饮食；LC-MS/MS：液相色谱-串联质谱；MAP1LC3B/LC3：微管相关蛋白1轻链3β；m6A：N6-甲基腺苷；MEFs：小鼠胚胎成纤维细胞；MeRIP-qPCR：甲基化RNA免疫沉淀-qPCR；PPARG：过氧化物酶体增殖物激活受体γ；RIP：RNA免疫沉淀；SAT：皮下脂肪组织；siRNA：小干扰RNA；SQSTM1/p62：隔离体1；TEM：透射电子显微镜；ULK1：unc-51样激酶1；VAT：内脏脂肪组织；WAT：白色脂肪组织；YTHDF：YTH N6-甲基腺苷RNA结合蛋白 。
（注：原文中存在部分未明确写出的内容，用“ 和 ”表示，翻译时保留原文状态）
