Retinoic acid priming enhances myogenesis of bovine muscle stem cells for cultivated meat production by modulating mitochondrial function.

Large-scale production of cultivated meat will require robust myogenic differentiation of muscle stem cells (MuSCs) into muscle tissue using food-compatible cues. Retinoic acid (RA), a bioactive metabolite of dietary vitamin A, is an attractive candidate for this purpose. Here, we demonstrate that RA priming transitions fetal bovine MuSCs from a PAX7+ proliferative state to an activated pre-differentiation program. The pro-myogenic effect observed in two-dimensional (2D) culture was recapitulated in three-dimensional (3D) scaffolds, where RA priming accelerated and enhanced myotube formation in a setting that is more relevant to tissue. This response required canonical retinoic acid receptor (RAR) signaling. RA-RAR signaling increased the expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PPARGC1A) and nuclear respiratory factor 1 (NRF1), which is consistent with enhanced mitochondrial biogenesis and improved mitochondrial function. These findings are supported by elevated mitochondrial membrane potential and higher levels of respiratory chain components, together with modest changes in mitochondrial dynamics. In parallel, RA reduced the expression of PTEN-induced kinase 1 (PINK1), Parkin RBR E3 ubiquitin protein ligase (PRKN), and microtubule-associated protein 1 light chain 3 (LC3) and suppressed the transcriptional program associated with mitophagy. Taken together, these results suggest that the RA priming modulates mitochondrial function and quality-control pathways, reduces reliance on PINK1-PRKN-dependent mitophagy, and supports an activated, pro-myogenic primed state. This provides a food-compatible priming strategy with potential relevance for scalable cultivated beef production.