Dual-Functional MN-08 Attenuated Pulmonary Arterial Hypertension Through Vasodilation and Inhibition of Pulmonary Arterial Remodeling

Abstract

Pulmonary arterial hypertension (PAH) is a rare, progressive pulmonary vascular disease with limited therapeutic options. Pulmonary circulation resistance, pulmonary vascular remodeling, and over-activated NMDARs (N-methyl-d-aspartate receptors) play vital roles in the pathogenesis of PAH. In the present study, we aimed to evaluate the efficacy and molecular mechanism of MN-08, a dual-functional memantine nitrate derivative, in experimental animal models of PAH. MN-08 showed a high degree of accumulation in the lungs and dilated pulmonary arterial rings ex vivo by releasing nitric oxide. MN-08 did not lower systemic blood pressure. MN-08 attenuated right ventricular systolic pressure and right ventricular hypertrophy, inhibited pulmonary arterial remodeling, alleviated glutamate-NMDARs dysregulation, and improved survival rates in monocrotaline-induced PAH rats. More importantly, the therapeutic benefit of MN-08 for PAH was greater than that of sildenafil. Moreover, MN-08 can reduce right ventricular systolic pressure in U46619-induced acute PAH rats. Mechanistically, MN-08 suppressed proliferation of pulmonary arterial smooth muscle cells exposed to human platelet-derived growth factor-BB by regulating the cell cycle and expression of NMDAR1, AKT (serine/threonine kinase Akt), and ERK (extracellular signal-regulated kinase) 1/2. In conclusion, our studies demonstrated that MN-08 may be a promising therapeutic agent for PAH.