IRF1-mediated downregulation of PGC1α contributes to cardiorenal syndrome type 4

Area of Science:

• Cardiology
• Nephrology
• Mitochondrial Biology
• Molecular Mechanisms

Background:

• Cardiorenal syndrome type 4 (CRS4) is a frequent complication of chronic kidney disease (CKD), with poorly understood underlying mechanisms.
• Morphological and functional mitochondrial abnormalities in the myocardium are characteristic of CKD.
• Key energy metabolism pathways, including oxidative phosphorylation and fatty acid metabolism, are impaired in the hearts of CKD patients.

Purpose of the Study:

• To elucidate the pathogenic mechanisms of CRS4 in the context of CKD.
• To investigate the role of high phosphate (HP) in myocardial energy metabolism dysfunction.
• To identify key molecular players involved in HP-induced cardiac alterations.

Main Methods:

• Utilized a mouse model of CKD to observe myocardial mitochondrial changes.
• Assessed oxidative phosphorylation and fatty acid metabolism in cardiac tissues.
• Investigated the effect of high phosphate (HP) on peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) expression.
• Identified interferon regulatory factor 1 (IRF1) as a key transcriptional factor regulated by HP via histone acetylation.
• Examined the direct binding of IRF1 to the PGC1α promoter region.
• Evaluated the therapeutic potential of restoring PGC1α or inhibiting IRF1 in vitro and in vivo.

Main Results:

• CKD mice exhibited myocardial mitochondrial dysfunction, with reduced oxidative phosphorylation and fatty acid metabolism.
• High phosphate (HP) significantly downregulated PGC1α, contributing to energy metabolism defects.
• HP upregulated IRF1 through histone H3K9 acetylation.
• IRF1 directly bound to the PGC1α promoter, inhibiting its transcription.
• Restoring PGC1α or knocking down IRF1 ameliorated HP-induced cardiac damage.

Conclusions:

• The IRF1-PGC1α axis is a critical mediator of myocardial energy metabolism remodeling in CRS4 pathogenesis.
• Targeting the IRF1-PGC1α pathway offers a potential therapeutic strategy for CRS4.