Resolvin E1 normalizes contractility, Ca2+ sensitivity and smooth muscle cell migration rate in TNF-α- and IL-6-pretreated human pulmonary arteries

Pulmonary hypertension (PH) is a rare disease in which pathophysiology is characterized by an increase in proinflammatory mediators, chronic endothelial dysfunctions, and a high migration rate of smooth muscle cells (SMC). Over the course of the last decade, various treatments have been proposed to relax the pulmonary arteries, none of which have been effective in resolving PH. Our hypothesis is that artery-relaxing drugs are not the long-term solution, but rather the inhibition of tissue inflammation, which underlies human pulmonary artery (HPA) dysfunctions that lead to abnormal vasoconstriction. The goal of the present study was to assess the anti-inflammatory effects of resolvin E-1 (RvE(1)) with concomitant effects on SMC migration and on HPA reactivity. The role and mode of action of RvE(1) and its precursor, monoacylglyceride eicosapentaenoic acid were assessed on HPA under proinflammatory conditions, involving a combined pretreatment with 10 ng/ml TNF-alpha and 10 ng/ml IL-6. Our results show that TNF-alpha and IL-6 treatment induced hyperreactivity and Ca2+ hypersensitivity in response to pharmaco-mechanical stimuli, including 80 mM KCl, 1 mu M phorbol 12-13-dibutyrate, and 30 nM U-46619. Furthermore, the proinflammatory treatment increased the migration rate of SMC isolated from HPA. The phosphorylation level of regulatory contractile proteins (CPI-17, MYPT-1), and proinflammatory signaling pathways (c-Fos, c-Jun, NF-kappa B) were also significantly increased compared with control conditions. Conversely, 300 nM RvE(1) was able to normalize all of the above abnormal events triggered by proinflammation. In conclusion, RvE(1) can resolve human arterial hyperreactivity via the resolution of inflammatory markers.