Nuclear YAP localization as a key regulator of podocyte function

Area of Science:

• Nephrology
• Cell Biology
• Molecular Biology

Background:

• Podocytes are vital for kidney filtration; their injury causes proteinuria and kidney disease.
• The Hippo pathway effector YAP (Yes-associated protein) is predominantly nuclear in podocytes and crucial for their survival.
• Dysregulation of podocyte YAP localization is implicated in kidney pathologies.

Purpose of the Study:

• To investigate the role of YAP localization in podocyte apoptosis and integrity.
• To explore the connection between Hippo pathway activity, podocyte function, and focal segmental glomerulopathy (FSGS).

Main Methods:

• Experimental manipulation of YAP localization in podocytes using substrate rigidity, dasatinib, and Hippo pathway component overexpression.
• RNA sequencing analysis of podocytes overexpressing large tumor suppressor kinase 2 (LATS2).
• Bioinformatic comparison of experimental data with human FSGS glomeruli transcriptomic data from the Nephroseq database.

Main Results:

• Sequestration of YAP into the cytoplasm induced apoptosis in podocytes.
• RNA sequencing revealed upregulation of apoptotic genes and downregulation of Hippo pathway components, suggesting feedback.
• Significant overlap was found between experimental findings and human FSGS transcriptomic data, particularly in genes regulating apoptosis, cell junctions, and migration.

Conclusions:

• Nuclear YAP is critical for podocyte survival; cytoplasmic sequestration triggers apoptosis.
• Hippo pathway activity influences podocyte integrity, affecting cell-cell junctions and migration.
• The observed link between Hippo pathway activation and altered gene expression in podocytes may underlie glomerular sclerosis and kidney function loss in FSGS.