Several microRNAs (miRNAs) have been identified to play roles in adipocyte differentiation. However, little is known about their involvement in the differentiation of ovine intramuscular adipocytes. Here, the role of one such miRNA, miR‐340‐5p, in ovine adipocyte differentiation was investigated. Stromal vascular (SV) cells were isolated from skeletal muscle tissues of 1‐month‐old lambs and induced to differentiate into mature adipocytes. miRNA mimics and inhibitors were used for miR‐340‐5p overexpression and knockdown assays. For overexpression and knockdown of activating transcription factor 7 (ATF7), lentivirus infection was performed. Luciferase reporter assay was performed to determine the relationship between miR‐340‐5p and ATF7. The expression of adipogenesis marker genes, PPARγ, C/EBPα, FABP4, ADIPOQ, and ACC, and formation of lipid droplets were detected after the overexpression and inhibition of miR‐340‐5p, or upon overexpression or knockdown of ATF7. miR‐340‐5p inhibited the expression of the marker genes and the formation of lipid droplets. ATF7 positively regulated the expression of the marker genes and the formation of lipids. Thus, ATF7 is the target of miR‐340‐5p in sheep. Overall, these findings indicate that miR‐340‐5p acts as an inhibitor of the differentiation of intramuscular adipocytes by targeting ATF7. Our study provides a new theoretical basis for improving sheep meat quality.

中文翻译：

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miR-340-5p通过靶向ATF7抑制绵羊脂肪细胞分化

已鉴定出几种 microRNA (miRNA) 在脂肪细胞分化中发挥作用。然而，人们对它们参与绵羊肌内脂肪细胞分化知之甚少。在这里，研究了一种这样的 miRNA，miR-340-5p，在绵羊脂肪细胞分化中的作用。从 1 个月大的羔羊的骨骼肌组织中分离出基质血管 (SV) 细胞，并诱导其分化为成熟的脂肪细胞。miRNA 模拟物和抑制剂用于 miR-340-5p 过表达和敲低分析。对于激活转录因子 7 ( ATF7 ) 的过表达和敲低，进行了慢病毒感染。进行荧光素酶报告基因测定以确定 miR-340-5p 和ATF7之间的关系。脂肪生成标记基因的表达，PPARγ、C/EBPα、FABP4、ADIPOQ和ACC，以及在 miR-340-5p 过表达和抑制后，或在ATF7过表达或敲低后检测到脂滴的形成。miR-340-5p 抑制标记基因的表达和脂滴的形成。ATF7积极调节标记基因的表达和脂质的形成。因此，ATF7是绵羊中 miR-340-5p 的靶标。总体而言，这些发现表明 miR-340-5p 通过靶向ATF7来抑制肌内脂肪细胞的分化. 本研究为提高羊肉品质提供了新的理论依据。