Asengeprast, a Novel G-Protein Coupled Receptor 68 Antagonist, Reverses Clinically Relevant Inflammatory and Fibrotic Pathways in Chronic Kidney Disease

Limiting progressive fibrosis in chronic kidney disease (CKD) is an ongoing therapeutic challenge that requires effective and safe inhibition of a broad inflammatory cell milieu that leads to irreversible organ damage. Asengeprast, an anti-fibrotic and anti-inflammatory small molecule, has shown promising efficacy in animal models of kidney disease, however its target and mechanism of action was unknown. Using in vitro assays, we showed that asengeprast modulates inflammatory and fibrotic responses through selective inhibition of G protein-coupled receptor 68 (GPR68), a proton sensor, expressed in tissue-resident and immune-infiltrating cells of the kidney. Transcriptomic analysis of kidney tissue from animal models of diabetic kidney disease (DKD) and CKD demonstrated that fibrotic and inflammatory pathways dysregulated in disease were reversed by asengeprast treatment. Differential expression analysis of upstream regulators showed that the major, distinct signaling networks reversed were centered on a key driver of fibroblast activation, transforming growth factor β1, and associated signaling molecules. An asengeprast response gene signature derived from the CKD animal model when mapped onto gene expression profiles obtained from human kidney biopsies confirmed that the molecular pathways modulated by asengeprast were also dysregulated in human DKD and CKD. Further, this asengeprast response signature correlated with clinical markers of disease progression and tissue pathology. Overall, these findings provide evidence for targeted inhibition of GPR68 by asengeprast as a promising therapeutic strategy for treatment of CKD and potentially other fibrotic and inflammatory conditions.