Inducible podocyte-specific deletion of CTCF drives progressive kidney disease and bone abnormalities

Area of Science:

• Nephrology
• Molecular Biology
• Genetics

Background:

• Chronic kidney diseases (CKDs) are increasing globally, but the mechanisms driving their progression are not fully understood.
• Existing animal models for CKD often involve systemic toxicity or invasive surgery, limiting their utility.
• Podocyte injury is a key factor in CKD development, but precise models are needed.

Purpose of the Study:

• To develop a novel, inducible mouse model for studying progressive chronic kidney disease (CKD).
• To investigate the direct consequences of podocyte-specific CTCF ablation on kidney function and systemic health.
• To elucidate the timeline of glomerular pathology and associated complications in CKD.

Main Methods:

• Generation of an inducible, podocyte-specific knockout mouse model by ablating the CCCTC-binding factor (CTCF).
• Induction of podocyte loss (iCTCFpod-/-) and monitoring of physiological and biochemical parameters.
• Analysis of renal function, serum markers, bone metabolism, and histological changes.

Main Results:

• Inducible podocyte-specific CTCF ablation (iCTCFpod-/-) led to rapid podocyte loss and severe, progressive CKD.
• Mice exhibited albuminuria, hyperlipidemia, hypoalbuminemia, renal dysfunction, and premature death (8-10 weeks).
• CKD progression was associated with hyperphosphatemia, elevated FGF23 and PTH, leading to bone mineralization defects and bone loss.

Conclusions:

• Podocyte ablation alone is sufficient to drive progressive CKD and osteodystrophy, even without interstitial fibrosis.
• This novel iCTCFpod-/- mouse model offers significant advantages for studying CKD progression.
• The findings underscore the importance of podocyte-protective strategies in developing future kidney therapeutics.