2. Academic Validation
  3. CRB2 Depletion Induces YAP Signaling and Disrupts Mechanosensing in Podocytes

CRB2 Depletion Induces YAP Signaling and Disrupts Mechanosensing in Podocytes

  • bioRxiv. 2024 Oct 26:2024.10.22.619513. doi: 10.1101/2024.10.22.619513.
Yingyu Sun 1,  Nils M Kronenberg 1,  Sidharth K Sethi 2,  Surjya N Dash 3 4,  Maria E Kovalik 4,  Benjamin Sempowski 4,  Shelby Strickland 4,  Rupresh Raina 5 6,  C John Sperati 7,  Xuefei Tian 5,  Shuta Ishibe 5,  Gentzon Hall 3 4,  Malte C Gather 1 8 9
Affiliations

Affiliations

  • 1 Humboldt Centre for Nano- and Biophotonics, Department of Chemistry, University of Cologne, Cologne, Germany.
  • 2 Pediatric Nephrology and Pediatric Kidney Transplantation, Medanta Kidney and Urology Institute, The Medicity Hospital, Gurgaon, Haryana, India.
  • 3 Division of Nephrology, Department of Medicine, Duke University, Durham, North Carolina, U.S.A.
  • 4 Duke Molecular Physiology Institute, Duke University, Durham, North Carolina, U.S.A.
  • 5 Cleveland Clinic Akron General Medical Center, Akron Nephrology Associates, Akron, Ohio, USA.
  • 6 Division of Nephrology, Department of Medicine, Yale University, New Haven, Connecticut, U.S.A.
  • 7 Division of Nephrology, Department of Medicine, Johns Hopkins University, Baltimore, Maryland, U.S.A.
  • 8 Centre of Biophotonics, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, U.K.
  • 9 Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Disease (CECAD), University of Cologne, Cologne, Germany.
PMID: 39484460 DOI: 10.1101/2024.10.22.619513
Abstract

Focal Segmental Glomerulosclerosis (FSGS) is a histologic lesion caused by a variety of injurious stimuli that lead to dysfunction/loss of glomerular visceral epithelial cells (i.e. podocytes). Pathogenic mutations in CRB2, encoding the type 1 transmembrane protein Crumb 2 Homolog Protein, have been shown to cause early-onset corticosteroid-resistant nephrotic syndrome (SRNS)/FSGS. Here, we identified a 2-generation East Asian kindred (DUK40595) with biopsy-proven SRNS/FSGS caused by a compound heterozygous mutation in CRB2 comprised of the previously described truncating mutation p.Gly1036_Alafs*43 and a rare 9-bp deletion mutation p.Leu1074_Asp1076del. Because compound heterozygous mutations involving the truncating p.Gly1036_Alafs*43 variant have been associated with reduced CRB2 expression in podocytes and autosomal recessive SRNS/FSGS, we sought to define the pathogenic effects of CRB2 deficiency in podocytes. We show that CRB2 knockdown induces YAP activity and target gene expression in podocytes. It upregulates YAP-mediated mechanosignaling and increases the density of focal adhesion and F-actin. Using Elastic Resonator Interference Stress Microscopy (ERISM), we demonstrate that CRB2 knockdown also enhances podocyte contractility in a substrate stiffness-dependent manner. The knockdown effect decreases with increasing substrate stiffness, indicating impaired mechanosensing in CRB2 knockdown cells at low substrate stiffness. While the mechanical activation of CRB2 knockdown cells is associated with increased YAP activity, the enhanced cell contractility is not significantly reduced by the selective YAP inhibitors K-975 and verteporfin, suggesting that multiple pathways may be involved in mechanosignaling downstream of CRB2. Taken together, these studies provide the first evidence that CRB2 deficiency may impair podocyte mechanotransduction via disruption of YAP signaling in podocytes.

Keywords

CRB2; Cell mechanics; FSGS; YAP signaling; podocytes.

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