Novel Small-Molecule ROCK2 Inhibitor GNS-3595 Attenuates Pulmonary Fibrosis in Preclinical Studies

• Published in: American journal of respiratory cell and molecular biology Vol. 71; no. 4; pp. 430 - 441
• Main Authors: Hwang, Soyoung, Lee, Wongil, Ravi, Dashnamoorthy, Devine, William, Yong, Miyong, Diebold, R Bruce, Seung, Sang-Ae, Ng, Nicholas W, Lee, Jaekyoo, Gupta, Anu, Koh, Jong Sung
• Format: Journal Article
• Language: English
• Published: United States American Thoracic Society 01.10.2024
• Subjects: Animals; Bleomycin; Body weight loss; Disease Models, Animal; Fibroblasts - drug effects; Fibroblasts - metabolism; Fibrosis; Gene expression; Humans; Idiopathic Pulmonary Fibrosis - chemically induced; Idiopathic Pulmonary Fibrosis - drug therapy; Idiopathic Pulmonary Fibrosis - metabolism; Idiopathic Pulmonary Fibrosis - pathology; Inhibitor drugs; Kinases; Lung - drug effects; Lung - metabolism; Lung - pathology; Lung diseases; Male; Medical treatment; Mice; Mice, Inbred C57BL; Myosin; Phosphorylation; Phosphorylation - drug effects; Protein Kinase Inhibitors - pharmacology; Pulmonary fibrosis; Pulmonary Fibrosis - chemically induced; Pulmonary Fibrosis - drug therapy; Pulmonary Fibrosis - metabolism; Pulmonary Fibrosis - pathology; rho-Associated Kinases - antagonists & inhibitors; rho-Associated Kinases - metabolism; Signal transduction; Signal Transduction - drug effects; Transcription factors; Transcriptomes; ROCK; idiopathic pulmonary fibrosis; bleomycin model; fibroblast-to-myofibroblast transition; extracellular matrix
• ISSN: 1044-1549; 1535-4989; 1535-4989
• DOI: 10.1165/rcmb.2023-0401OC

Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease that leads to respiratory decline caused by scarring and thickening of lung tissues. Multiple pathways contribute to the fibrotic process in this disease, such as inflammation, epithelial-to-mesenchymal transition, and oxidative stress. The Rho-associated coiled-coil forming protein kinase (ROCK) signaling pathway is a key regulator of profibrotic signaling, as it affects the organization of actin-myosin and the remodeling of the extracellular matrix. ROCK1/2, a downstream effector of RhoA, is overexpressed in patients with IPF and is a promising target for IPF therapy. However, because of the hypotensive side effects of ROCK1/2 inhibitors, selective ROCK2 compounds are being explored. In this study, we report the discovery of GNS-3595, a potent and selective ROCK2 inhibitor that has ∼80-fold selectivity over ROCK1 at physiological concentrations of ATP. GNS-3595 effectively inhibited ROCK2-mediated phosphorylation of myosin light chain and reduced the expression of fibrosis-related proteins (e.g., collagen, fibronectin, and α-smooth muscle actin) in various cellular models. GNS-3595 also prevented transforming growth factor β-induced fibroblast-to-myofibroblast transition. In addition, in a bleomycin-induced mouse model of pulmonary fibrosis, therapeutic exposure to GNS-3595, suppressed lung fibrosis, stabilized body weight loss, and prevented fibrosis-induced lung weight gain. Transcriptome and protein expression analysis from lung tissues showed that GNS-3595 can revert the fibrosis-related gene expression induced by bleomycin. These results indicate that GNS-3595 is a highly potent, selective, and orally active ROCK2 inhibitor with promising therapeutic efficacy against pulmonary fibrosis.