Growth Factor Midkine Aggravates Pulmonary Arterial Hypertension via Surface Nucleolin

Daisuke Kinoshita,Tetsuya Takahashi,Takayuki Sugai,Takanori Arimoto,Isao Kubota,Harutoshi Tamura,Masafumi Watanabe,Kenji Kadomatsu,Satoshi Kishida,Tsuneo Konta,Jun-Ichi Abe,Tetsuro Shishido,Miyuki Yokoyama,Satoshi Nishiyama,Ken Watanabe,Tetsu Watanabe,Hiroki Takahashi,Yasuchika Takeishi,Takuya Miyamoto

doi:10.1038/s41598-020-67217-w

Abstract

Pulmonary arterial hypertension (PAH) is a progressive fatal disease caused by pulmonary arterial remodeling. Midkine regulates cell proliferation and migration, and it is induced by hypoxia, but its roles in pulmonary arterial remodeling remain unclear. Serum midkine levels were significantly increased in PAH patients compared with control patients. Midkine expression was increased in lungs and sera of hypoxia-induced PAH mice. Hypoxia-induced pulmonary arterial remodeling and right ventricular hypertrophy were attenuated in midkine-knockout mice. Midkine-induced proliferation and migration of pulmonary arterial smooth muscle cells (PASMC) and epidermal growth factor receptor (EGFR) signaling were significantly increased under hypoxia, which also induced cell-surface translocation of nucleolin. Nucleolin siRNA treatment suppressed midkine-induced EGFR activation in vitro, and nucleolin inhibitor AS1411 suppressed proliferation and migration of PASMC induced by midkine. Furthermore, AS1411 significantly prevented the development of PAH in Sugen hypoxia rat model. Midkine plays a crucial role in PAH development through interaction with surface nucleolin. These data define a role for midkine in PAH development and suggest midkine-nucleolin-EGFR axis as a novel therapeutic target for PAH.

Highlights

Pulmonary arterial hypertension (PAH) is a progressive fatal disease caused by pulmonary arterial remodeling
Hypoxia induced the translocation of nucleolin to the cell surface, and enhanced midkine-induced activation of epidermal growth factor receptor (EGFR) signaling
Silencing of nucleolin expression by small interfering RNA (siRNA) and AS1411 suppressed midkine-induced EGFR signaling and pulmonary arterial smooth muscle cells (PASMC) proliferation, and this inhibitor was shown to attenuate the development of PAH by suppressing pulmonary arterial remodeling

Summary

Introduction

Pulmonary arterial hypertension (PAH) is a progressive fatal disease caused by pulmonary arterial remodeling. Midkine regulates cell proliferation and migration, and it is induced by hypoxia, but its roles in pulmonary arterial remodeling remain unclear. Midkine-induced proliferation and migration of pulmonary arterial smooth muscle cells (PASMC) and epidermal growth factor receptor (EGFR) signaling were significantly increased under hypoxia, which induced cell-surface translocation of nucleolin. Endothelial dysfunction and ischemia induce the upregulation of midkine expression in the renal tubular cells of chronic kidney disease mouse model and its release to systemic circulation, which results in the activation of angiotensin converting enzyme (ACE) in lungs[14] and epidermal growth factor receptor (EGFR) in the hearts[15]. We hypothesized that hypoxia induces the upregulation of surface nucleolin, which facilitates midkine binding to surface nucleolin and EGFR activation, leading to the development of PAH

Methods

Results

Conclusion