YTHDF1 Regulates Pulmonary Hypertension through Translational Control of MAGED1

Rationale: Posttranscriptional modifications are implicated in vascular remodeling of pulmonary hypertension (PH). m(6)A (N-6 -methyladenosine) is an abundant RNA modification that is involved in various biological processes. Whether m(6)A RNA modification and m(6)A effector proteins play a role in pulmonary vascular remodeling and PH has not been demonstrated. Objectives: To determine whether m(6)A modification and m(6)A effectors contribute to the pathogenesis of PH. Methods: m(6)A modification and YTHDFI expression were measured in human and experimental PH samples. RNA immunoprecipitation analysis and m(6)A sequencing were employed to screen m(6)A -marked transcripts. Genetic approaches were employed to assess the respective roles of YTHDFI and MAGEDI in PH. Primary cell isolation and cultivation were used for function analysis of pulmonary artery smooth muscle cells (PASMCs). Measurements and Main Results: Elevated m(6)A levels and increased YTHDF1 protein expression were found in human and rodent PH samples as well as in hypoxic PASMCs. The deletion of YTHDFI ameliorated PASMC proliferation, phenotype switch, and PIT development both in vivo and in vitro. m(6)A RNA immunoprecipitation analysis identified MAGEDI as an m(6)A-regulated gene in PH, and genetic ablation of MAGEDI improved vascular remodeling and hemodynamic parameters in SU5416/hypoxia mice. YTHDFI recognized and promoted translation of MA GEDI in an m(6)A dependent manner that was absent in METTL3-deficient PASMCs. In addition, MAGEDI silencing inhibited hypoxia-induced proliferation of PASMCs through downregulating PCNA. Conclusions: YTHDF1 promotes PASMC proliferation and PH by enhancing MAGED1 translation. This study identifies the m(6)A RNA modification as a novel mediator of pathological changes in PASMCs and PH.

Automated summary

This study demonstrates the involvement of m(6)A RNA modification and m(6)A effector proteins in pulmonary hypertension (PH), with YTHDF1 promoting PASMC proliferation and PH by enhancing MAGED1 translation. The findings suggest a novel mechanism for pathological changes in PASMCs and PH mediated by m(6)A RNA modification.