The MEF2A transcription factor interactome in cardiomyocytes

Area of Science:

• Cardiovascular Biology
• Molecular Cardiology
• Gene Regulation

Background:

• Myocyte Enhancer Factor 2 (MEF2) proteins are key regulators in cardiac development and function.
• MEF2A protein interactions are central to cardiomyocyte cellular processes.
• Understanding MEF2A's interactome is vital for elucidating its roles in cardiac gene expression.

Purpose of the Study:

• To systematically identify the protein interactome of MEF2A in primary cardiomyocytes.
• To investigate the functional significance of MEF2A protein-protein interactions in cardiac cells.
• To explore the interplay between MEF2A and STAT3 in regulating cardiomyocyte gene expression and survival.

Main Methods:

• Affinity purification coupled with quantitative mass spectrometry was used to screen the MEF2A interactome.
• Bioinformatic analysis identified protein networks associated with MEF2A.
• Biochemical and functional assays confirmed MEF2A-STAT3 interactions.
• Transcriptome analysis was performed on MEF2A and STAT3-depleted cardiomyocytes.

Main Results:

• The MEF2A interactome includes proteins involved in programmed cell death, inflammation, actin dynamics, and stress signaling.
• A dynamic interaction between MEF2A and STAT3 was confirmed.
• MEF2A and STAT3 co-regulate inflammatory responses and cardiomyocyte survival.
• MEF2A/STAT3 activity ameliorates phenylephrine-induced cardiomyocyte hypertrophy.
• Key co-regulated genes, including MMP9, were identified.

Conclusions:

• The cardiomyocyte MEF2A interactome provides insights into cardiac gene expression networks.
• The balance of MEF2A and STAT3 activity critically controls inflammatory responses and cell survival.
• Targeting MEF2A-STAT3 interactions may offer therapeutic strategies for cardiac hypertrophy and pathology.