College of Life Science, Guizhou University, Guiyang, China.
Key Laboratory of Animal Genetics, Breeding and Reproduction in the Plateau Mountainous Region, Ministry of Education, Guizhou University, Guiyang, China.
Epigenetics. 2022 Dec;17(12):1800-1819. doi: 10.1080/15592294.2022.2086675. Epub 2022 Jun 12.
Intramuscular fat development is regulated by a series of complicated processes, with non-coding RNA (ncRNA) such as microRNA (miRNA) having a critical role during intramuscular preadipocyte proliferation and differentiation in pigs. In the present study, the miRNA expression profiles of intramuscular preadipocytes from the longissimus dorsi muscle of Chinese Guizhou Congjiang Xiang pigs were detected by RNA-seq during various differentiation stages, namely, day 0 (D0), day 4 (D4), and day 8 (D8). A total of 67, 95, and 16 differentially expressed (DE) miRNAs were detected between D4 and D0, D8 and D0, and D8 and D4, respectively. According to gene ontology and Kyoto Encyclopedia of Genes analysis, target genes of DE miRNAs were enriched in categories and pathways related to lipid metabolic process, lipid biosynthetic process, as well as the PI3K-Akt, AMPK, and MAPK signalling pathways. Notably, miR-148a-3p was differentially expressed, with highest expressed abundance in D0, D4, and D8. Overexpression of miR-148a-3p in intramuscular preadipocytes increased cell proliferation and differentiation, and decreased apoptosis, in comparison to the knockdown of miR-148a-3p in intramuscular preadipocytes. Luciferase activity assays, quantitative polymerase-chain reaction, and western blot analysis confirmed that miR-148a-3p regulated adipogenesis by repressing PPARGC1A expression. Accordingly, the effect of miR-148a-3p mimic was attenuated by overexpression of PPARGC1A intramuscular preadipocytes. Furthermore, miR-148a-3p promoted intramuscular preadipocyte differentiation by inhibiting the AMPK/ACC/CPT1C signalling pathway. Taken together, we identified expression profiles of miRNAs in intramuscular preadipocytes and determined that miR-148a-3p acted as a promoter of adipogenesis.
肌内脂肪的发育受一系列复杂过程的调节，非编码 RNA（ncRNA）如 microRNA（miRNA）在猪肌内前体脂肪细胞的增殖和分化过程中起着关键作用。本研究通过 RNA-seq 检测了中国贵州从江香猪背最长肌肌内前体脂肪细胞在不同分化阶段（即第 0 天（D0）、第 4 天（D4）和第 8 天（D8））的 miRNA 表达谱。在 D4 和 D0、D8 和 D0 以及 D8 和 D4 之间分别检测到 67、95 和 16 个差异表达（DE）miRNA。根据基因本体论和京都基因与基因组百科全书分析，DE miRNAs 的靶基因富集在与脂质代谢过程、脂质生物合成过程以及 PI3K-Akt、AMPK 和 MAPK 信号通路相关的类别和途径中。值得注意的是，miR-148a-3p 差异表达，在 D0、D4 和 D8 时表达丰度最高。与肌内前体脂肪细胞中的 miR-148a-3p 敲低相比，过表达 miR-148a-3p 可增加细胞增殖和分化，减少凋亡。荧光素酶活性测定、定量聚合酶链反应和 Western blot 分析证实，miR-148a-3p 通过抑制 PPARGC1A 的表达来调节脂肪生成。因此，PPARGC1A 肌内前体脂肪细胞过表达减弱了 miR-148a-3p 模拟物的作用。此外，miR-148a-3p 通过抑制 AMPK/ACC/CPT1C 信号通路促进肌内前体脂肪细胞分化。总之，我们鉴定了肌内前体脂肪细胞中 miRNA 的表达谱，并确定 miR-148a-3p 作为脂肪生成的促进因子。
