Abstract: TH-PO067

Loss of Robo2 Rescues Podocyte Number and Ultrastructure Defects in Adult Ilk Knockout Mice

Session Information

Category: Glomerular

  • 1002 Glomerular: Basic/Experimental Pathology

Authors

  • Sharma, Richa, Boston University Medical Center, Boston, Massachusetts, United States
  • Milo Rasouly, Hila, Boston University Medical Center, Boston, Massachusetts, United States
  • Fan, Xueping, Boston University Medical Center, Boston, Massachusetts, United States
  • Kumar, Sudhir, Boston University Medical Center, Boston, Massachusetts, United States
  • Strzelewicz, Arielle Rhianna, Boston University Medical Center, Boston, Massachusetts, United States
  • Belghasem, Mostafa, Boston University Medical Center, Boston, Massachusetts, United States
  • Henderson, Joel M., Boston University Medical Center, Boston, Massachusetts, United States
  • Salant, David J., Boston University Medical Center, Boston, Massachusetts, United States
  • Lu, Weining, Boston University Medical Center, Boston, Massachusetts, United States
Background

Previous studies showed that ROBO2 signaling functions as a negative regulator on podocyte actin polymerization and podocyte adhesion. Our data shows that ROBO2 forms a complex with integrin-linked kinase (ILK) and loss of Robo2 improves the survival of Ilk podocyte-specific knockout (cKO) mice. However, the mechanism of this renoprotective role of Robo2 loss in Ilk cKO is not clear.

Methods

Robo2 and Ilk single cKO were crossed to generate Robo2-Ilk podocyte specific double knockout mice (dKO). Glomerular histology, podocyte number, and podocyte ultrastructure of single cKO and double dKO mice were analyzed at 4 weeks and 16 weeks of age. Glomerular histology was evaluated by PAS staining. Podocyte numbers were quantified using WT1 staining. Podocyte ultrastructure was analyzed and quantified by transmission electron microscopy (TEM). Quantitative data were analyzed using SPSS statistics software.

Results

Results: At 4 weeks old, the podocyte number and glomerular sclerotic index are almost the same in both Ilk single cKO and Robo2-Ilk dKO mice. However, analyses of podocyte number, glomerular histology, and TEM in 16 weeks old mice showed a significant improvement in podocyte number (p=0.02), sclerotic index (p=0.006), glomerular basement membrane width (p=0.03), podocyte foot process width (p=0.002), and slit diaphragm density (p=0.04) in Robo2-Ilk dKO as compared to Ilk single cKO mice.

Conclusion

Loss of Robo2 improves the survival of Ilk podocyte-specific knockout mice by rescuing podocyte number and podocyte ultrastructure defects in adult mice. Our findings suggest that inhibition of ROBO2 signaling could be beneficial for glomerular disease associated with podocyte loss and be a potential therapeutic target.

Funding

  • NIDDK Support