MicroRNA Profiling Reveals an Abundant ssc-miRNA-148a-3p that Promotes Proliferation and Differentiation during Intramuscular Adipogenesis in Chinese Guizhou Congjiang Pigs Breeds by targeting PPARGC1A

Abstract

BackgroundIntramuscular fat development is regulated by a series of complicated processes, and non-coding RNA (ncRNA) such as microRNA (miRNA) plays a critical role during intramuscular preadipocyte proliferation and differentiation development in pigs. In present research, we detected the expression profiles of miRNA during different differentiation stages, namely, day 0 (D0), day 4 (D4), and day 8 (D8), of intramuscular preadipocytes from the longissimus dorsi muscle of Chinese Guizhou Congjiang pigs to provide first insights into their potential involvement in intramuscular preadipocyte development. And we investigated the function of miR-148a-3p in adipocyte proliferation, apoptosis, and differentiation. ResultsA total of 67, 95, and 16 differentially expressed (DE) miRNAs were detected between D4 and D0, between D8 and D0, and between D8 and D4, respectively. We further characterized the role of miR-148a-3p which was differentially expressed and highest expressed abundance in D0, D4, and D8. To explore the role of miR-148a-3p in porcine intramuscular preadipocyte, miR-148a-3p mimics and inhibitors were used to perform miR-148a-3p overexpression and knockdown, respectively. Overexpression of miRNA-148a-3p increased the number of intramuscular preadipocytes in the S/G2 phase of the cell cycle and decreased the proportion of cells in the G0/G1 phase. Moreover, it promoted proliferation by regulation of cyclin B, cyclin G1, cyclin D1, CDK2, CDK3, and CDK4 and inhibited apoptosis of intramuscular preadipocyte by regulating the expression of Caspase-3, Bax, and Bcl-2. Meanwhile, the mimics of miR-148a-3p dramatically promoted intramuscular preadipocyte differentiation and upregulated the expression levels of adipogenic marker genes PPARγ, FASN, FABP4, HSL, APOE, LPL, and CEBPα. Furthermore, miR-148a-3p promoted intramuscular preadipocyte differentiation via restraining the AMPK/ACC/CPT1C signaling pathway. PPARGC1A was identified as a target gene of miR-148a-3p by luciferase activity and western blotting assays. ConclusionOur study provides novel insights into the regulatory mechanisms underlying intramuscular preadipocyte development and identified amount of miRNAs whose regulatory potential will need to be explored in the future. Our results establish that miR-148a-3p promoted adipocyte differentiation by targeting PPARGC1A.

Milk Exosomal microRNAs: Postnatal Promoters of β Cell Proliferation but Potential Inducers of β Cell De-Differentiation in Adult Life

“…Furthermore, peroxisome proliferator-activated receptor-γ coactivator 1α ( PPARGC1A ), which is a key coregulatory transcription factor of mitochondrial function [ 239 , 240 ], is a target of miR-148a [ 241 , 242 ]. Factors responsible for mitochondrial biogenesis and degradation play key roles in the balance of mitochondrial mass in β cells.…”

“…Of importance, ERRγ binds to its coactivator peroxisome proliferator-activated receptor-γ co-activator 1α (PGC-1α; PPARGC1A ), producing a stable transcription factor ERRγ/PGC-1α complex [ 256 , 257 ]. Intriguingly, both mRNAs of ESRRG and PPARGC1A exhibit highly conserved binding sites for miR-148a [ 242 , 258 ]. As previously mentioned, miR-148a also suppresses PRKAA1 [ 234 ], the catalytic subunit α1 of AMPK, and PRKAG2 [ 235 ], the regulatory subunit γ2 of AMPK.…”

Milk exosomal microRNAs: friend or foe?—a narrative review

“…Importantly, human and bovine milk fat as well as human and bovine MEX are a rich source of miR-148a (11,101,362,363), which targets key regulatory components of AMPK (225,226,364), thereby attenuating AMPK´s inhibitory function on mTORC1 via AMPK-mediated phosphorylation of TSC2 and Raptor (365,366). Milk fat and MEX miR-148a may stimulate β-cell mTORC1 activity promoting β-cell growth and mass expansion (367).…”

“…Ling et al (418) demonstrated that downregulation of PPARGC1A expression in human islets by siRNA, reduced insulin secretion. Remarkably, key signature miRs of milk and MEX including the let-7 family and miR-148a target PPARGC1A (364,419,420) and may thus restrain insulin secretion during the breastfeeding period. Increased plasma levels of miR-148a have been associated with T2DM progression, increased HbA1c, HOMA-IR, and hyperinsulinemia (421) (Table 6).…”