MicroRNA-125a-5p Affects Adipocytes Proliferation, Differentiation and Fatty Acid Composition of Porcine Intramuscular Fat

Abstract

Intramuscular fat (IMF) content and composition are considered crucial indicators of porcine meat quality. However, the molecular mechanism of porcine IMF development is still mostly unclear. Recently, new evidence suggested that microRNA (miRNAs) play important roles in porcine intramuscular adipogenesis. Previously, microRNA-125a-5p (miR-125a-5p) was identified as an important regulator of adipogenesis. In the present study, we found that the expression of miR-125a-5p is dynamically regulated during porcine intramuscular preadipocytes differentiation and that its expression levels in different porcine muscle tissues were negatively involved with IMF content. To investigate the potential function role of miR-125a-5p in IMF development, porcine intramuscular preadipocytes were collected and transfected with miR-125a-5p mimics, inhibitors, or a negative control (NC), respectively. The results showed that overexpression of miR-125a-5p promoted proliferation and inhibited differentiation of porcine intramuscular preadipocytes while inhibition of miR-125a-5p had the opposite effects. Furthermore, a luciferase reporter assay demonstrated that porcine kruppel like factor 3 (KLF13) is a target gene of miR-125a-5p during porcine intramuscular preadipocytes differentiation. Interestingly, porcine ELOVL fatty acid elongase 6 (ELOVL6), a regulator of fatty acid composition, was also identified as a target gene of miR-125a-5p during porcine intramuscular adipogenesis. Further studies show that miR-125a-5p overexpression reduced total saturated fatty acids (SFA) content and monounsaturated fatty acids (MUFA)/SFA ratios while having no significant impact on polyunsaturated fatty acids (PUFA)/SFA and n-6/n-3 ratios. Taken together, our results identified that miR-125a-5p may be a novel regulator of porcine intramuscular adipogenesis and the fatty acid composition of porcine IMF.

Functions of Circular RNAs in Regulating Adipogenesis of Mesenchymal Stem Cells

“…It can dramatically reduce the mRNA expression of adipogenic markers C/EBP α , PPAR γ , FABP4, fatty acid synthase (FASN), lipoprotein lipase (LPL), aP2, and estrogen-related receptor α (ERR α ) [ 118 ]. Furthermore, miR-125 can inhibit the differentiation of preadipocytes by directly targeting KLF13 and affect the fatty acid composition in adipocytes by regulating elongase of very-long-chain fatty acids 6 (ELOVL6) [ 119 ]. In summary, circPVT1 may be a potential regulatory factor of adipogenesis, which simultaneously upregulates PPAR α and PPAR γ by affecting miR-125.…”

Role of microRNAs in myogenesis and their effects on meat quality in pig — A review

“…Thus far, the molecular mechanisms underlying the deposition of IMF are not clear. In recent years, some progress has been made in exploring the role of miRNAs in intramuscular preadipocyte development [101]. IMF deposition is a complex process that could be diverse among different species, breeds, age, and depends upon the nutrition [102][103][104].…”

Differentially Expressed miRNA-Gene Targets Related to Intramuscular Fat in Musculus Longissimus Dorsi of Charolais × Holstein F2-Crossbred Bulls

“…MicroRNAs are involved in the fat deposition by regulating the expression of key genes in adipogenesis including PPARG , CEBPα , FABP7 , INSIG1 , RXR , RYR , FASN , SCD and IGF1R , among others. [ 14 , 15 , 16 , 17 ]. Intramuscular adipocyte proliferation and differentiation are influenced by miR-125-5p and miR-23a [ 15 , 18 ].…”

“…[ 14 , 15 , 16 , 17 ]. Intramuscular adipocyte proliferation and differentiation are influenced by miR-125-5p and miR-23a [ 15 , 18 ]. To date, most of the miRNA functional exploration findings are related to human and murine cell models, and reports of miRNA profiling in bovine fat accretion in general, and IMF in particular, are limited.…”