1. Academic Validation
  2. Protective effect of HINT2 on mitochondrial function via repressing MCU complex activation attenuates cardiac microvascular ischemia-reperfusion injury

Protective effect of HINT2 on mitochondrial function via repressing MCU complex activation attenuates cardiac microvascular ischemia-reperfusion injury

  • Basic Res Cardiol. 2021 Dec 16;116(1):65. doi: 10.1007/s00395-021-00905-4.
Su Li  # 1 Jinxiang Chen 1 Muyin Liu  # 1 Yuqiong Chen 2 Yuan Wu 3 Qiyu Li 1 Teng Ma 4 Jinfeng Gao 1 Yan Xia 1 5 Mengkang Fan 6 Ao Chen 1 5 Danbo Lu 1 5 Enyong Su 1 Fei Xu 1 Zhangwei Chen 7 8 Juying Qian 9 10 Junbo Ge 11 12
Affiliations

Affiliations

  • 1 Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
  • 2 Department of Cardiology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Gusu School, Nanjing Medical University, Suzhou, China.
  • 3 Department of Infectious Diseases, Zhongshan Hospital, Fudan University, Shanghai, China.
  • 4 Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
  • 5 National Clinical Research Center for Interventional Medicine, Shanghai, China.
  • 6 Department of Cardiology, Affiliated Hospital of Nantong University, Xisi Road 20, Nantong, Jiangsu, China.
  • 7 Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. [email protected].
  • 8 National Clinical Research Center for Interventional Medicine, Shanghai, China. [email protected].
  • 9 Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. [email protected].
  • 10 National Clinical Research Center for Interventional Medicine, Shanghai, China. [email protected].
  • 11 Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China. [email protected].
  • 12 National Clinical Research Center for Interventional Medicine, Shanghai, China. [email protected].
  • # Contributed equally.
Abstract

Current evidence indicates that coronary microcirculation is a key target for protecting against cardiac ischemia-reperfusion (I/R) injury. Mitochondrial calcium uniporter (MCU) complex activation and mitochondrial calcium ([Ca2+]m) overload are underlying mechanisms involved in Cardiovascular Disease. Histidine triad nucleotide-binding 2 (HINT2) has been reported to modulate [Ca2+]m via the MCU complex, and our previous work demonstrated that HINT2 improved cardiomyocyte survival and preserved heart function in mice with cardiac ischemia. This study aimed to explore the benefits of HINT2 on cardiac microcirculation in I/R injury with a focus on mitochondria, the MCU complex, and [Ca2+]m overload in endothelial cells. The present work demonstrated that HINT2 overexpression significantly reduced the no-reflow area and improved microvascular perfusion in I/R-injured mouse hearts, potentially by promoting endothelial nitric oxide synthase (eNOS) expression and phosphorylation. Microvascular barrier function was compromised by reperfusion injury, but was repaired by HINT2 overexpression via inhibiting VE-Cadherin phosphorylation at Tyr731 and enhancing the VE-Cadherin/β-catenin interaction. In addition, HINT2 overexpression inhibited the inflammatory response by suppressing vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1). Mitochondrial fission occurred in cardiac microvascular endothelial cells (CMECs) subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury and resulted in mitochondrial dysfunction and mitochondrion-dependent Apoptosis, the effects of which were largely relieved by HINT2 overexpression. Additional experiments confirmed that [Ca2+]m overload was an initiating factor for mitochondrial fission and that HINT2 suppressed [Ca2+]m overload via modulation of the MCU complex through directly interacting with MCU in CMECs. Regaining [Ca2+]m overload by spermine, an MCU agonist, abolished all the protective effects of HINT2 on OGD/R-injured CMECs and I/R-injured cardiac microcirculation. In conclusion, the present report demonstrated that HINT2 overexpression inhibited MCU complex-mitochondrial calcium overload-mitochondrial fission and Apoptosis pathway, and thereby attenuated cardiac microvascular ischemia-reperfusion injury.

Keywords

Cardiac ischemia–reperfusion injury; Cardiac microvascular injury; HINT2; MCU complex; Mitochondrial calcium overload; Mitochondrial fission.

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