SPOP Is a Key Trigger of Pathological Cardiac Hypertrophy and Heart Failure.

Area of Science:

• Cardiovascular Biology
• Molecular Mechanisms of Disease
• Protein Degradation Pathways

Background:

• Protein synthesis and degradation are critical in biological and pathological processes.
• Speckle-type POZ protein (SPOP), an E3 ubiquitin ligase adaptor, is implicated in cancer progression.
• The role of SPOP in cardiac hypertrophy and heart failure requires investigation.

Purpose of the Study:

• To elucidate the biological function and underlying mechanisms of SPOP in cardiac hypertrophy and heart failure.
• To evaluate the therapeutic potential of targeting SPOP in heart conditions.

Main Methods:

• Generation of cardiac-specific transgenic and knockout mouse models.
• Induction of cardiac hypertrophy via transverse aortic constriction.
• Application of RNA-sequencing, proteomics, and molecular biology techniques.
• In vitro studies using neonatal mouse ventricular cardiomyocytes treated with Angiotensin II.

Main Results:

• SPOP is upregulated in human and mouse heart failure and promotes hypertrophic markers and cardiomyocyte size.
• Cardiac-specific SPOP overexpression induces hypertrophy and heart failure; SPOP deficiency attenuates these conditions.
• SPOP promotes TFEB degradation, inhibiting autophagy and mitophagy, leading to cardiac pathology.
• TFEB overexpression rescues SPOP-induced alterations, and SPOP inhibition prevents cardiac hypertrophy.

Conclusions:

• SPOP exacerbates pathological cardiac hypertrophy by degrading TFEB, a key regulator of the autophagy-lysosomal pathway.
• Targeting SPOP presents a promising therapeutic strategy for hypertrophy-related heart failure.