Abstract: SA-PO199

DDR1 Inhibition Preserves Renal Function in a Mouse Model of Alport Syndrome

Session Information

  • Glomerular: Cell Biology
    November 04, 2017 | Location: Hall H, Morial Convention Center
    Abstract Time: 10:00 AM - 10:00 AM

Category: Glomerular

  • 1003 Glomerular: Cell Biology

Authors

  • Molina David, Judith T., University of Miami Miller School of Medicine, Miami, Florida, United States
  • Kim, Jin Ju, University of Miami Miller School of Medicine, Miami, Florida, United States
  • Varona Santos, Javier T., University of Miami Miller School of Medicine, Miami, Florida, United States
  • Harmeier, Anja, Hoffmann-La Roche, AG , Basel, Switzerland
  • Richter, Hans, Hoffmann-La Roche, AG , Basel, Switzerland
  • Gasser, Rodolfo, Hoffmann-La Roche, AG , Basel, Switzerland
  • Faul, Christian, University of Miami Miller School of Medicine, Miami, Florida, United States
  • Prunotto, Marco, Hoffmann-La Roche, AG , Basel, Switzerland
  • Fornoni, Alessia, University of Miami Miller School of Medicine, Miami, Florida, United States
Background

Alport Syndrome (AS) is a hereditary disease condition caused by mutations in the type IV collagen genes, leading to progressive renal fibrosis, hearing loss and ocular changes. Discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase that is activated by collagen and that promotes fibrosis, whereas genetic deletion of DDR1 in mice protects from renal failure in AS. Our study was aimed at identifying a selective DDR1 inhibitor to prevent kidney disease in Col4a3 knockout (KO) mice.

Methods

Approximately 56.000 compounds were screened in in vitro binding assay and a fraction of those (circa 1000) were further evaluated in a cell based assay aimed at evaluating DDR1 phosphorylation in dose response. Five compounds were finally selected based on their selectivity, potency and pharmacokinetic and pharmacodynamics profile for further in vivo testing and a unique lead compound (cpd) was identified for further in depth in vivo analysis. Four-week-old Col4a3 KO and wildtype (WT) mice were injected intraperitoneally with cpd (90 mg/kg) or vehicle on a daily basis. Experimental groups included: WT+vehicle (n=10), WT+cpd (n=11), KO+vehicle (n=11), and KO+cpd (n=14). At 8-weeks of age, mice were sacrificed and kidney tissue, blood and urine were collected for further analysis. Histological analysis was performed by H&E, PAS, Picrosirius Red and immunofluorescence staining (IF). Serum and urine samples were used to determine BUN, albumin, creatinine. Total and pDDR1 levels were measured in kidney cortex by immunoprecipitation.

Results

Fibrosis was assessed by IF for smooth muscle actin (αSMA), Collagen type 1 and laminin. Cpd treatment significantly improved serum BUN, urine albumin/creatinine ratio and fibrosis in KO mice in association with reduced levels of total and phosphorylated DDR1.

Conclusion

These results indicate that drugs targeting DDR1 may represent a novel strategy to treat kidney disease in patients with AS.

Funding

  • Commercial Support