PI3K kinase and scaffold functions in heart

Area of Science:

• Cardiovascular Biology
• Molecular Signaling
• Biochemistry

Background:

• Signal transduction pathways regulate cellular functions, with phosphoinositide 3-kinases (PI3Ks) playing a significant role in the cardiovascular system.
• PI3Ks are enzymes that generate lipid second messengers through 3-phosphorylated phosphoinositides.
• Multiple PI3K isoforms are present in the heart, each potentially mediating distinct physiological and pathological processes.

Purpose of the Study:

• To review the multifaceted roles of PI3K signaling in cardiac hypertrophy and heart failure.
• To elucidate the distinct contributions of various PI3K isoforms (e.g., PI3Kalpha, PI3Kgamma) in cardiac adaptation and remodeling.
• To incorporate recent findings on PI3K involvement in protein-protein interactions and kinase-independent signaling in the heart.

Main Methods:

• Literature review of existing research on PI3K signaling in cardiovascular contexts.
• Analysis of studies investigating PI3K isoform-specific functions in cardiac hypertrophy and failure.
• Integration of findings related to both kinase-dependent and kinase-independent PI3K activities.

Main Results:

• PI3Kalpha, activated by tyrosine kinase receptors, is associated with adaptive cardiac hypertrophy.
• PI3Kgamma, activated by G protein-coupled receptors, is implicated in maladaptive heart remodeling.
• Emerging evidence highlights PI3K participation in protein-protein interactions, influencing signaling pathways independently of enzymatic activity.

Conclusions:

• PI3K signaling is a complex modulator of cardiac function, with distinct isoforms contributing to both beneficial and detrimental cardiac remodeling.
• Understanding the dual roles of PI3K activity and protein interactions is crucial for developing therapeutic strategies for cardiac hypertrophy and failure.
• Further research is warranted to fully delineate the intricate signaling networks involving PI3Ks in the cardiovascular system.