Abstract
MicroRNAs (miRNAs) are a large class of non-coding RNAs that play important roles in the proliferation and differentiation of adipocytes. Our previous sequencing analysis revealed higher expression of miR-369-3p in the longissimus muscle of 2-month-old Aohan fine-wool sheep (AFWS) compared to 12-month-old sheep (P<0.05<math><mrow><mi>P</mi><mo><</mo><mn>0.05</mn></mrow></math>), suggesting that miR-369-3p may regulate fat deposition in AFWS. To test this, miR-369-3p mimics, inhibitors, and negative controls (NCs) were constructed and transfected into AFWS preadipocytes. After transfection with miR-369-3p mimics, we found a decrease (P<0.05<math><mrow><mi>P</mi><mo><</mo><mn>0.05</mn></mrow></math>) in the expression of genes and proteins related to cell proliferation and differentiation, detected by RT-qPCR (quantitative reverse transcription PCR) and western blot analyses. Moreover, EdU (5-ethynyl-2'<math><msup><mi></mi><mo>'</mo></msup></math>-deoxyuridine) detection and Oil Red O staining showed a decrease (P<0.05<math><mrow><mi>P</mi><mo><</mo><mn>0.05</mn></mrow></math>) in cell proliferation and lipid accumulation, respectively. The opposite trends (P<0.05<math><mrow><mi>P</mi><mo><</mo><mn>0.05</mn></mrow></math>) were obtained after transfection with miR-369-3p inhibitors. In conclusion, the results showed that miR-369-3p can inhibit the proliferation and differentiation of AFWS preadipocytes, providing a theoretical basis to further explore the molecular mechanism of fat deposition in sheep and other domestic animals.