Ras, Akt, and mechanotransduction in the cardiac myocyte

Area of Science:

• Molecular Biology
• Cell Signaling
• Cardiovascular Research

Background:

• Ras proteins (Ha-Ras, Ki-Ras, N-Ras) are critical regulators of intracellular signaling in mammalian cells, controlling growth, proliferation, differentiation, and survival.
• Ras isoforms act as molecular switches, transducing signals from cell surface receptors to downstream effectors, including ERK1/2 and Akt kinases.
• ERK1/2 activation is linked to cardiac myocyte hypertrophy and myofibrillogenesis, while Akt activation promotes protein accretion and cell survival during hypertrophy.

Purpose of the Study:

• To describe the regulation of Ras and Akt signaling pathways in cardiac cells.
• To discuss the mechanisms by which mechanical strain may activate Ras- and Akt-dependent signaling in the heart.
• To evaluate the potential involvement of Ras and Akt in cardiac mechanotransduction.

Main Methods:

• Review of existing literature on Ras and Akt signaling in mammalian cells and cardiac myocytes.
• Discussion of proposed mechanisms of mechanotransduction involving Ras, ERK1/2, and Akt.
• Analysis of studies investigating mechanical strain-induced cardiac hypertrophy.

Main Results:

• Mechanical strain induces cardiac hypertrophy through mechanotransduction, a process potentially involving Ras, ERK1/2, and Akt.
• ERK1/2 activation is associated with increased cell size and myofibrillogenesis, while Akt activation is linked to protein accretion in hypertrophy.
• Both ERK1/2 and Akt signaling pathways may contribute to myocyte survival.

Conclusions:

• Ras and Akt signaling are likely involved in cardiac mechanotransduction.
• Further investigation, particularly into mechanoreception, is required to unequivocally establish the roles of Ras and Akt in this process.
• Understanding these pathways could offer insights into cardiac remodeling and disease.