Mechanism Of Micro RNA-30d Abating Pulmonary Arterial Hypertension And Pulmonary Vascular Remodeling

Background: Pulmonary arterial hypertension is seriously harmful to human health,and may progress to right ventricular heart failure or even death.The commonly used drugs can not reverse the structural and functional disorders of pulmonary vasculatures,and there is still a lack of effective therapeutics at present.Micro RNAs play important roles in cardiopulmonary diseases.Studies have demonstrated that micro RNA-30d can improve the condition and prognosis of patients with heart failure,and micro RNA-30d can inhibit the abnormal proliferation of lung fibroblasts.However,it remains unclear whether micro RNA-30d is involved in the regulation of pulmonary hypertension and vascular remodeling.Objective: We aimed to clarify the function and mechanism of micro RNA-30d abating pulmonary arterial hypertension and pulmonary vascular remodeling.Methods: First,we used quantitative real-time PCR to determine the expression of micro RNA-30d in monocrotaline(MCT)-induced pulmonary arterial hypertension rat model and platelet derived growth factor-bb(PDGF-bb)-induced human pulmonary artery smooth muscle cell(PASMC)activation model.Then based on micro RNA-30d transgenic(TG)rats,micro RNA-30d knockout(KO)rats and cell-level micro RNA-30d interventions,the effects of micro RNA-30d on pulmonary hypertension and vascular remodeling were determined by right ventricular systolic pressure(RVSP)measurement,immunohistochemical detection,Ed U staining,cell scratching and other experimental methods.Furthermore,bioinformatics analysis,dual luciferase reporter assay system and function rescue experiments were used to identify whether micro RNA-30d was a downstream target gene of micro RNA-30d in the PASMC activation model.Meanwhile,bioinformatics analysis,quantitative real-time PCR and function rescue experiments were performed to clarify whether nuclear respiratory factor 1(NRF1)was an upstream regulator of micro RNA-30d.Finally,using micro RNA-30d knockout rats in the pulmonary arterial hypertension model treated with Sildenafil,we explored whether micro RNA-30d mediated the therapeutic effects of Sildenafil in pulmonary arterial hypertension.Results: Micro RNA-30d was downregulated in both animal model and cell model of pulmonary arterial hypertension.In the rat model of MCT-induced pulmonary hypertension,overexpression of micro RNA-30d reduced RVSP and right ventricular hypertrophy,and inhibited pulmonary vascular remodeling and proliferation of vascular wall cells,while micro RNA-30d KO did not aggravate pulmonary arterial hypertension and vascular remodeling.At the level of human PASMCs,micro RNA-30d mimics inhibited cell proliferation and migration,while micro RNA-30d inhibitors had no aggravating effects.Bioinformatics and dual luciferase reporter assay system identified MTDH as a target gene of micro RNA-30d.Overexpressing MTDH could reverse the protective effects of micro RNA-30d mimics on the proliferation and migration of PASMCs.NRF1 was found to be an upstream regulator factor of micro RNA-30d,which positively regulated the expression of micro RNA-30d.NRF1 via upregulating micro RNA-30d inhibited the proliferation and migration of PASMCs.Finally,animal experimental study showed that micro RNA-30d KO could partially abolish the therapeutic effects of Sildenafil on pulmonary arterial hypertension and vascular remodeling.Conclusions: Micro RNA-30d is downregulated in pulmonary arterial hypertension,while overexpression of micro RNA-30d abates pulmonary hypertension and vascular remodeling.MTDH mediates the inhibitory effects of micro RNA-30d on the proliferation and migration of PASMCs.NRF1 is an upstream transcription factor of micro RNA-30d,and micro RNA-30d plays a necessary role in the Sildenafil therapeutic effects in pulmonary arterial hypertension.Activating the NRF1/micro RNA-30d/MTDH axis may become potential novel targets for the treatment of pulmonary arterial hypertension and pulmonary vascular remodeling.