Collagen Deposition in Tuberous Sclerosis Complex Is Driven Through KDM6A-Mediated Activation of ERK/SNAI1 Signaling.

The mechanisms by which the autosomal dominant disorder tuberous sclerosis complex (TSC) results in liver fibrosis remain poorly understood. KDM6A, a histone demethylase, has been implicated in the pathogenesis of fibrosis in multiple tissues. This study aimed to elucidate the molecular mechanism by which KDM6A contributed to TSC-associated fibrosis. We observed fibrogenesis, epithelial-mesenchymal transition (EMT) induction and upregulation of Kdm6a in vivo and in vitro upon Tsc1 or Tsc2 deficiency. Knockdown of Kdm6a attenuated both fibrosis and EMT phenotypes. Mechanistically, Kdm6a depletion reduced phosphorylation of ERK1/2 and downregulated Snai1 expression. Activation of the MAPK/ERK pathway with PMA restored EMT-related protein expression, confirming the functional involvement of this signaling axis. Furthermore, Tsc1 or Tsc2 deficiency promoted Kdm6a expression via the mTORC1 pathway, while Kdm6a knockdown conversely suppressed mTORC1 activity by reducing mTOR protein expression, suggesting a positive feedback loop between Kdm6a expression and mTORC1. These findings indicate that Kdm6a promotes fibrosis in TSC through the activation of the MAPK/ERK/SNAI1 signaling pathway. Moreover, the combination of mTORC1 and KDM6A inhibitors results in marked regression of fibrosis and liver lesions in TSC models, unveiling a potential treatment for TSC patients with inadequate response to mTORC1 inhibitors.