VCAM-1/Ezrin axis antagonizes myocardial damage in ischemia-reperfusion injury

Area of Science:

• Cardiovascular Biology
• Molecular Medicine
• Cellular Physiology

Background:

• Vascular cell adhesion molecule 1 (VCAM-1) is a target of Forkhead box O (FoxO) transcription factors.
• VCAM-1 has known roles in development, cell interactions, and survival.
• The precise function of VCAM-1 in cardiomyocyte homeostasis during ischemic heart disease is unclear.

Purpose of the Study:

• To investigate the role and mechanisms of VCAM-1 in protecting cardiomyocytes during ischemic heart disease.
• To elucidate the FoxO1/VCAM-1 axis in myocardial ischemia/reperfusion (I/R) injury.

Main Methods:

• Utilized wild-type (WT) and cardiomyocyte-specific Vcam1-deficient mice.
• Induced ischemia/reperfusion (I/R) injury.
• Assessed myocardial damage, apoptosis, contractile function, and cardiac remodeling.
• Examined pro-survival signaling pathways (Ezrin, Akt, ERK1/2) and gene expression (TNFα, Sod2) in cardiomyocytes in vivo and in vitro.

Main Results:

• I/R injury reduced FoxO1 and Vcam1 mRNA levels in WT mice.
• Loss of Vcam1 in cardiomyocytes exacerbated I/R-induced damage, apoptosis, dysfunction, and remodeling.
• Vcam1-deficient cardiomyocytes showed reduced pro-survival cues, including impaired Ezrin induction and downstream Akt/ERK1/2 phosphorylation.
• Expression of TNFα and Sod2 genes was decreased in Vcam1-deficient cardiomyocytes.

Conclusions:

• The FoxO1/VCAM-1 axis plays a protective role against I/R injury in the heart.
• VCAM-1 is essential for maintaining cardiomyocyte homeostasis during ischemic events.
• A VCAM-1/Ezrin axis is identified as a critical, previously unrecognized mediator of cardiomyocyte protection in ischemic myocardium.