Chicken intramuscular preadipocyte-derived exosome miR125b-5p promotes lipogenic differentiation of skeletal muscle satellite cells

Intramuscular fat (IMF) content critically determines chicken meat quality. Extracellular vesicles (EVs) are essential mediators of intercellular communication through bioactive molecule transfer. Although co-culture systems have demonstrated that intramuscular preadipocytes (IMPs) promote lipogenic differentiation of muscle satellite cells (MSCs), the involvement of EVs remained unclear. Here, we isolated IMP-derived exosomes and confirmed their ability to enhance lipid accumulation in MSCs. Through small RNA sequencing and functional validation, we identified miR-125b-5p as a key regulator that directly targets and suppresses NR5A2, a newly identified negative regulator of avian adipogenesis. Inhibition experiments confirmed the essential role of this axis, as miR-125b-5p inhibition attenuated exosomal pro-adipogenic effects. Collectively, we demonstrated that IMP-derived exosomes facilitate MSC lipogenic differentiation through miR-125b-5p delivery. Our findings provide the first evidence of exosome-mediated muscle-fat crosstalk in poultry, establishing the miR-125b-5p/NR5A2 axis as a potential target for IMF modulation.