Upstream Stimulatory Factor 2 Protects Cardiomyocytes by Regulating Mitochondrial Homeostasis

Area of Science:

• Cardiovascular Biology
• Mitochondrial Medicine
• Molecular Cardiology

Background:

• Myocardial ischemia and hypoxia are primary drivers of heart failure.
• Cardiomyocyte apoptosis from mitochondrial injury underlies adverse cardiac remodeling.
• The role of transcription factor USF2 in cardiovascular disease was previously unreported.

Purpose of the Study:

• To investigate the role of Upstream stimulatory factor 2 (USF2) in cardiomyocyte response to hypoxia.
• To elucidate the mechanisms by which USF2 influences mitochondrial function and apoptosis in the heart.

Main Methods:

• Investigated USF2 protein expression and degradation in cardiomyocytes under hypoxic conditions.
• Utilized USF2 deletion models to assess impact on mitochondrial function and apoptosis.
• Analyzed the involvement of the AMPK/mTOR signaling pathway in USF2-deficient cells.

Main Results:

• Hypoxia induces USF2 protein degradation in cardiomyocytes via the ubiquitin-proteasome pathway.
• USF2 deletion leads to mitochondrial dysfunction, increased damage, and enhanced apoptosis.
• USF2 deficiency promotes apoptosis by modulating the AMPK/mTOR signaling pathway.

Conclusions:

• USF2 plays a protective role against hypoxic cardiomyocyte injury.
• USF2 deficiency exacerbates mitochondrial damage and apoptosis in the heart.
• USF2 represents a potential therapeutic target for myocardial hypoxia and related heart failure.