CH6824025, Potent and Selective Discoidin Domain Receptor 1 Inhibitor, Reduces Kidney Fibrosis in Unilateral Ureteral Obstruction Mice.

Discoidin domain receptor 1 (DDR1) is a collagen receptor with tyrosine kinase activity, and its expression is enhanced in various disease conditions. Although previous research suggests that DDR1 contributes to renal disease progression, DDR1 inhibitors for renal fibrosis have yet to be developed. In this study, we used unilateral ureteral obstruction (UUO) mice to investigate whether CH6824025, a strong and selective DDR1 phosphorylation inhibitor, can improve renal fibrosis. Furthermore, we performed 10x Visium spatial transcriptomics (ST) analysis on the kidney. CH6824025 suppressed the phosphorylation of DDR1 in the kidney, and the amount of hydroxyproline, the Sirius red- and the F4/80-positive area, and the mRNA expression of fibrosis and inflammation-related genes in the kidney were significantly decreased. 10x Visium ST analysis suggested that DDR1 is mainly expressed in distal nephrons under normal conditions but its expression appears to increase in the injured proximal tubules in UUO mice. Comparing mRNA expression in DDR1-positive spots in the Vehicle and the CH6824025 group, oxidative phosphorylation and mitochondrial dysfunction might be improved, and pathways involved in fibrosis tended to be inhibited in the CH6824025 administration group. Downstream analysis would suggest that mRNA expression changes in the CH6824025 group contribute to the inhibition of cell movement. Taken together, our findings suggest that CH6824025 inhibited kidney fibrosis in UUO mice, which might be due to the inhibition of the migration of inflammatory cells to the injury site and the reduction of inflammation. DDR1 inhibitors are expected to be a promising treatment of renal fibrosis. SIGNIFICANCE STATEMENT: The novel discoidin domain receptor 1 inhibitor CH6824025 could ameliorate fibrosis and inflammation in unilateral ureteral obstruction (UUO) mice. CH6824025 would inhibit cell motility (e.g., migration) that prevents the progression of fibrosis and improves mitochondrial function in UUO mice. CH6824025 could provide a significant benefit to patients with kidney fibrosis.