Inositol Hexaphosphate (InsP6) Activates the HDAC1/3 Epigenetic Axis to Maintain Intestinal Barrier Function

HDACs (histone deacetylase) play a crucial role in regulating gene expression, and the inhibition of these enzymes is gaining attention as a promising therapeutic approach for cancer treatment. Despite their significant physiological and clinical importance, the mechanisms of HDAC activation remain poorly understood. This study reveals that inositol polyphosphate multikinase (IPMK) is essential for activating HDAC1 and HDAC3 in cell lines and mice. IPMK deletion or inactivation of its kinase activity selectively impairs HDAC1/3's deacetylase activity, significantly influencing gene expression. Disruption of the IPMK-HDAC1/3 epigenetic axis results in transcriptional upregulation of matrix metalloproteinase (MMP) genes, exacerbating cell and intestinal permeability. Remarkably, treatment of IPMK KO cells with cell-permeable inositol hexaphosphate (InsP6) rescues these defects. This study elucidates the role of IPMK's kinase activity in HDAC1/3 activation and its implications for intestinal barrier function.