Acetyl-CoA metabolism in skeletal biology and bone disorders: From mechanisms to therapeutic implications.

Acetyl-CoA is a central metabolite that links energy status to transcriptional regulation through protein acetylation, yet its functions in skeletal biology depend strongly on subcellular compartmentalization. Because acetyl-CoA does not freely traverse biological membranes, its mitochondrial, cytosolic, and nuclear pools are maintained through compartment-specific synthesis and exchange routes, including the citrate-SLC25A1-ACLY axis, acetylcarnitine/carnitine cycling, acetate-dependent ACSS2 activity, and local nuclear enzyme activity. This review synthesizes current evidence that three conserved modules, including glycolytic/PDC-driven mitochondrial production, CIC/ACLY-mediated citrate export, and HAT-dependent acetylation, connect carbon flux with skeletal cell fate. However, lineage-specific outcomes are shaped by local acetyl-CoA availability, acetyltransferase context, and the transcription-factor landscape, including RUNX2 (osteogenesis), SOX9 (chondrogenesis) and NFATc1 (osteoclastogenesis). Critically, compartmentalized acetyl-CoA dysregulation can contribute to different pathological states: excess acetyl-CoA supply is linked to ACLY/FAO-driven cartilage catabolism and osteoclast resorption, whereas insufficient nucleocytosolic supply is associated with impaired regenerative programs in aged or inflamed bone. This duality argues for context-specific therapeutic strategies that either restrain excess acetyl-CoA flux or restore deficient pools. We propose that the translational bottleneck is not target identification but delivery precision, advocating for localized metabolite supplementation, cell-selective ACLY/FAO inhibitors, and spatial acetylome mapping to deconvolute cell-type-specific fluxes. Moving beyond broad HDAC/HAT modulation toward compartment-resolved strategies will be essential for translating acetyl-CoA biology into effective skeletal therapies.