Inhalable Carbonyl Sulfide Donor-Hybridized Selective Phosphodiesterase 10A Inhibitor for Treating Idiopathic Pulmonary Fibrosis by Inhibiting Tumor Growth Factor-beta Signaling and Activating the cAMP/Protein Kinase A/cAMP Response Element-Binding Protein (CREB)/p53 Axis.
Wang, Q., Liu, X., Yuan, H., Zhang, F., Wu, J., Yang, D., Qian, J., Huang, Y.Y., Chai, G., Luo, H.B., Guo, L.(2025) Acs Pharmacol Transl Sci 8: 256-269
- PubMed: 39816787 
- DOI: https://doi.org/10.1021/acsptsci.4c00671
- Primary Citation of Related Structures:  
9JA8 - PubMed Abstract: 
Idiopathic pulmonary fibrosis (IPF) is a debilitating, incurable, and life-threatening disease that lacks effective therapy. The overexpression of phosphodiesterase 10A (PDE10A) plays a vital role in pulmonary fibrosis (PF). However, the impact of selective PDE10A inhibitors on the tumor growth factor-β (TGF-β)/small mother against decapentaplegic (Smad) signaling pathway remains unclear. Herein, we have exploited a novel carbonyl sulfide (COS)/hydrogen sulfide (H 2 S)-donor hybrid PDE10A inhibitor called COS-2080 with a well-defined mechanism of H 2 S-releasing action. It exhibited highly potent inhibitory activity against PDE10A and excellent PDE subfamily selectivity. Moreover, COS-2080 demonstrated significant antifibrotic effects by inhibiting cell proliferation and mitigating fibroblast-to-myofibroblast transition (FMT). A dry powder inhalation formulation called COS-2080-DPI has been developed using the ultrasonic spray freeze drying (USFD) technique, demonstrating significant antifibrotic efficacy in mice with bleomycin-induced PF at a dosage approximately 600 times lower than pirfenidone. This remarkable antifibrotic efficacy of COS-2080 on TGF-β1-induced FMT could be primarily attributed to its inhibition of the Smad2/Smad3 phosphorylation. Moreover, COS-2080 effectively attenuated fibrosis in MRC-5 cells by activating the cAMP/protein kinase A (PKA)/CREB pathway and potentially increasing levels of p53 protein. Our findings suggest that effective inhibition of PDE10A potentially confers a protective effect on FMT in PF by impeding TGF-β signaling and activating the cAMP/PKA/CREB/p53 axis.
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510006, P. R. China.
Organizational Affiliation: