Phytic acid (InsP₆) activates HDAC3 epigenetic axis to maintain intestinal barrier function

Area of Science:

• Epigenetics
• Molecular Biology
• Gastroenterology

Background:

• Histone deacetylase (HDAC) inhibition is a promising cancer therapy but limited by gastrointestinal side effects.
• Understanding HDAC activation is key for broader therapeutic applications.
• The role of inositol polyphosphates in epigenetic regulation is an emerging area.

Purpose of the Study:

• To elucidate the mechanism by which inositol polyphosphate multikinase (IPMK) and inositol hexakisphosphate (InsP6) activate HDAC3.
• To investigate the role of the IPMK-HDAC3 pathway in maintaining intestinal barrier integrity.
• To explore the therapeutic potential of InsP6 in inflammatory conditions.

Main Methods:

• Biochemical assays to study IPMK-HDAC3 interaction and InsP6 synthesis.
• Cellular models of IPMK deletion and InsP6 treatment.
• Analysis of histone acetylation and matrix metalloproteinase (MMP) gene expression.
• In vivo studies using inflammatory bowel disease models.

Main Results:

• IPMK directly binds to HDAC3 and promotes InsP6 synthesis.
• InsP6 selectively activates HDAC3 at nanomolar concentrations by recruiting its corepressor.
• IPMK deletion compromises intestinal barrier integrity via histone hyperacetylation and MMP upregulation.
• InsP6 treatment rescues these defects.
• Diminished IPMK exacerbates intestinal permeability in IBD models; oral InsP6 mitigates 'leaky gut'.

Conclusions:

• The IPMK-HDAC3 pathway is essential for maintaining intestinal barrier function.
• InsP6 is a selective activator of HDAC3 and a potential therapeutic agent for gut barrier disorders.
• Dietary phytic acid (InsP6) may play a significant role in gut health through epigenetic mechanisms.