Resistance training regulates cardiac function through modulation of miRNA-214

Area of Science:

• Cardiovascular Physiology
• Molecular Biology
• Exercise Science

Background:

• Resistance training (RT) impacts cardiac function.
• MicroRNAs (miRNAs) play regulatory roles in cellular processes.
• SERCA2a is crucial for cardiac muscle relaxation and contraction.

Purpose of the Study:

• To investigate the effect of RT on miRNA-214 expression and its target SERCA2a in rat ventricular myocytes.
• To assess RT's influence on the morphological and mechanical properties of isolated left ventricular myocytes.

Main Methods:

• Male Wistar rats underwent an 8-week RT program (4x12 bouts/week, 80% 1RM).
• Control and trained groups were compared for myocyte dimensions and mechanical function.
• miRNA-214 and SERCA2a expression levels were quantified.

Main Results:

• RT significantly increased left ventricular myocyte width (15%) and volume (12%).
• Myocyte contraction and relaxation times were reduced post-RT.
• RT led to decreased miRNA-214 levels and increased SERCA2a expression.

Conclusions:

• RT improves cardiac myocyte dimensions and mechanical function, promoting faster contraction and relaxation.
• Enhanced SERCA2a expression, possibly due to reduced miRNA-214, underlies these adaptations.
• Epigenetic modifications via miRNA regulation may mediate RT's beneficial effects on cardiac myocytes.