Foxc1 and Foxc2 are necessary to maintain glomerular podocytes

Area of Science:

• Nephrology
• Molecular Biology
• Genetics

Background:

• Foxc1 and Foxc2 (Foxc1/2) are transcription factors vital for numerous biological processes.
• In adult kidneys, Foxc1/2 expression is restricted to podocytes, the key filtering cells in glomeruli.

Purpose of the Study:

• To investigate the role of Foxc1/2 in maintaining adult podocyte function and kidney integrity.
• To determine the dose-dependent and differential roles of Foxc1 and Foxc2 in podocyte biology.

Main Methods:

• Generated conditional knockout mouse models using inducible Cre (ROSA26-CreER^T2) and podocyte-specific Cre (Nephrin-Cre) systems crossed with floxed Foxc1 and Foxc2 alleles.
• Activated Cre-mediated recombination via tamoxifen administration in adult mice.
• Analyzed kidney histology, urinary protein levels (microalbuminuria), and gene expression profiles.

Main Results:

• Conditional deletion of Foxc1/2 in adult mice led to microalbuminuria, proteinuria, and severe podocyte injury, characterized by casts, reabsorption droplets, and podocyte vacuoles.
• Gene expression analysis revealed that Foxc1/2 maintain essential podocyte genes like podocin and Cxcl12.
• Podocyte-specific deletion using Nephrin-Cre recapitulated similar injury, confirming the critical role of Foxc1/2 in podocytes.

Conclusions:

• Foxc1/2 transcription factors are essential for maintaining podocyte structure and function in adult kidneys.
• Foxc2 plays a more critical role than Foxc1 in preserving podocyte integrity.
• Foxc1/2 regulate key genes necessary for maintaining the integrity of the podocyte filtration barrier.