LKB1 Dysregulation in Duchenne Muscular Dystrophy Models: Disease Specificity and Epigenetic Control by HDAC...

Efficient skeletal muscle contraction requires tight mechano-metabolic coupling, a process regulated by AMP-activated protein kinase (AMPK). Duchenne muscular dystrophy (DMD) is characterized by aberrant AMPK activation and disrupted metabolic signaling. This study investigates the expression and regulation of the LKB1-STRADα-MO25 heterotrimeric complex, the primary upstream activator of AMPK, in DMD models. We analyzed muscles from dystrophic mice (BL10 mdx and D2 mdx) and patient-derived cells and found significant downregulation of the LKB1 complex across all disease stages in the DMD models, a defect not observed in an amyotrophic lateral sclerosis model. Treatment with the broad-spectrum HDAC inhibitor vorinostat effectively restored LKB1 expression at both transcript and protein levels in D2 mdx mice. This restoration was mechanistically linked to downregulation of miR-451, miR-195, and miR-17, which function as post-transcriptional repressors of LKB1. Conversely, the selective HDAC1/2 inhibitor Rodin-A increased Lkb1 mRNA but failed to rescue protein levels or alter miRNA expression. Our data identify the axis LKB1-STRADα-MO25 as a critical regulatory node that is disrupted in DMD, but remains responsive to epigenetic modulation. These findings suggest that restoring LKB1 activity via HDAC inhibition or miRNA targeting may represent a therapeutic avenue to address dystrophic muscle dysfunction.