Abstract
Idiopathic pulmonary fibrosis (IPF) is a life-threatening disease with a survival rate of <5 years. The TGF-β plays a significant role in the progression and severity of IPF. The TGF-β receptor type1 TGFBR1 antagonists inhibit the process of fibrosis and may have a role in the treatment of IPF. The main objective of the study was to identify promising drug candidates against IPF using In-silico and In-vitro evaluation methods. An in-silico screening was carried out of the marketed Coxibs to find their TGFBR1 inhibitory potential considering their structural resemblance with the JZO—a co-crystalized ligand of the crystal structure of the TGFBR1. The virtual screening yielded rofecoxib as a TGFBR1 ligand with a significant docking score. To further validate the outcome of molecular docking studies, MD simulation of 200 ns was carried out followed by the determination of conformational stability, binding free energy calculation using MMPBSA/MMGBSA, and Free Energy Landscape (FEL). The therapeutic efficacy of rofecoxib was compared with that of nintedanib (a therapeutic agent used in the treatment of IPF) at equimolar concentrations (5 µM). The model of TGF-β1 (1 ng/ml)-induced EMT of A549 was used to determine the effect of rofecoxib on the EMT markers like cellular morphology, cytokine expressions, fibrosis associated protein, E-cadherin, and α-smooth muscle actin. In vitro results indicated that rofecoxib significantly suppresses the TGF-β1-induced EMT of A549 cells and validates the possible preventive/protective role of rofecoxib in pulmonary fibrosis. In conclusion, rofecoxib may be considered for repositioning as an anti-fibrotic agent.
Communicated by Ramaswamy H. Sarma
Acknowledgements
The authors are thankful to AICTE for providing a fellowship to SK to pursue her post-graduation degree during which this work was conducted. She is also thankful to the Vice Chancellor DPSRU and Dean, Research and Development, KIIT Bhubaneswar for providing excellent infrastructure for this work.
Author contributions
KS, CP, CNK, and HP designed, directed, and coordinated this study; AK, HP, IA, and KS carried out the virtual screening, and SK carried out the in vitro testing; BD and SSA analyzed the experimental data; KS, CP, BD, SSA, and SK drafted the manuscript; CNK, AK, and HP corrected the proofs.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Notes
3 See note 1 above.
4 See note 2 above.
6 Ibid.