Abstract Rationale Pulmonary arterial hypertension (PAH) is a progressive, fatal cardiovascular that develops as a result of elevated pressure and vascular remodelling within the pulmonary arteries. The pathobiology of PAH is driven by several factors, such as vasoconstriction, abnormal cellular proliferation, reduction of apoptosis, fibrosis, in situ thrombosis, and inflammation affecting small and muscular pulmonary arteries. Aberrant TGF-β and BMP signalling pathways serve as the primary mechanism contributing to the development and progression of PAH. Mutations in the type II receptor for bone morphogenetic protein (BMPR-II) account for approximately 80% of heritable cases, emphasising the critical role of BMP signalling. Despite these insights, the pathogenesis is incompletely understood. Current therapeutic strategies aim to manage symptoms and does not reverse the pathological changes and hence provide no cure. This highlights the need of developing novel therapeutic strategies that target the fundamental molecular mechanisms underlying PAH. The major objectives of this study are to investigate the underlying mechanisms of PAH and identify novel therapeutic interventions. Methods To achieve these aims, a series of cell-based assays including SMAD-responsive luciferase reporter assays were performed in HEK239T cells, while pulmonary arterial smooth muscle cells harbouring a pathogenic BMPR2 mutation were used for proliferation and apoptosis assays. Additionally, analyses of gene and protein expression were conducted using qPCR, RT-PCR, and Western blots. Results Initial screening using SMAD-responsive luciferase assays in HEK293T cells identified a panel of chemical agents that consistently inhibited TGF-β signalling, whilst a subset of analogues had no discernible effect on BMP signalling. In parallel, candidate genes were investigated for their regulatory roles on TGF-β and BMP signalling. Preliminary SMAD-responsive luciferase assays identified a number of genes which selectively inhibited either BMP or promoted TGF-β signalling pathway. These findings are currently being further validated using independent techniques including qPCR, RT-PCR, western blotting, and SEAP assays. Conclusion These findings reveal novel chemical agents and candidate genes, capable of modulating TGF- β and BMP signalling thereby restoring cellular defects such as excessive proliferation and reduction of apoptosis. Taken together, this study identifies promising therapeutic agents, clarifies the underlying molecular mechanisms and uncovers novel additional targets, which may be explored for developing novel diagnostics and therapeutics This abstract is funded by: None
Ahmed et al. (Fri,) studied this question.