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Pulmonary arterial hypertension (PAH) is commonly associated with chronic hypoxemia in disorders such as chronic obstructive pulmonary disease (COPD). Prostacyclin analogs are widely used in the management of PAH patients; however, clinical efficacy and long-term tolerability of some prostacyclin analogs may be compromised by concomitant activation of the E-prostanoid 3 (EP3) receptor. Here, we found that EP3 expression is upregulated in pulmonary arterial smooth muscle cells (PASMCs) and human distal pulmonary arteries (PAs) in response to hypoxia. Either pharmacological inhibition of EP3 or Ep3 deletion attenuated both hypoxia and monocrotaline-induced pulmonary hypertension and restrained extracellular matrix accumulation in PAs in rodent models. In a murine PAH model, Ep3 deletion in SMCs, but not endothelial cells, retarded PA medial thickness. Knockdown of EP3α and EP3β, but not EP3γ, isoforms diminished hypoxia-induced TGF-β1 activation. Expression of either EP3α or EP3β in EP3-deficient PASMCs restored TGF-β1 activation in response to hypoxia. EP3α/β activation in PASMCs increased RhoA-dependent membrane type 1 extracellular matrix metalloproteinase (MMP) translocation to the cell surface, subsequently activating pro-MMP-2 and promoting TGF-β1 signaling. Activation or disruption of EP3 did not influence PASMC proliferation. Together, our results indicate that EP3 activation facilitates hypoxia-induced vascular remodeling and pulmonary hypertension in mice and suggest EP3 inhibition as a potential therapeutic strategy for pulmonary hypertension., Introduction Pulmonary arterial hypertension (PAH), a rare but often fatal disease characterized by an average pulmonary arterial (PA) pressure of greater than 25 mmHg, contributes to unacceptably high morbidity and [...]

Mechanical insults, such as stent implantation, can induce endothelial injury, vascular inflammation, and ultimately lead to vascular neointimal hyperplasia. Resolvin E1 (RvE1), derived from the ω3 fatty acid eicosapentaenoic acid, can facilitate the resolution of inflammation in many settings. We therefore aimed to determine if there was a role for RvE1 in preventing neointimal formation after arterial injury and to understand the underlying mechanisms. Vascular inflammation and neointimal hyperplasia were induced by wire injury in the femoral arteries of mice. Administration of exogenous RvE1 and endogenously generated RvE1 via dietary supplementation with eicosapentaenoic acid and aspirin markedly reduced vascular neointima formation in this model. Mechanistically, RvE1 was found to inhibit vascular neutrophil infiltration, promote macrophage polarization toward an M2-like phenotype, suppress T-cell trafficking by reducing RANTES secretion from vascular smooth muscle cells, and inhibit vascular smooth muscle cell migration. In summary, RvE1 demonstrated a protective role against vascular inflammation and remodeling in response to mechanical injury, suggesting that it may serve as an adjuvant therapeutic agent for percutaneous coronary interventions, such as stent implantation.-Liu, G., Gong, Y., Zhang, R., Piao, L., Li, X., Liu, Q., Yan, S., Shen, Y., Guo, S., Zhu, M., Yin, H., Funk, C. D., Zhang, J., Yu, Y. Resolvin E1 attenuates injury-induced vascular neointimal formation by inhibition of inflammatory responses and vascular smooth muscle cell migration.