Optimizing mechanical stretching protocols for hypertrophic and anti-apoptotic responses in cardiomyocyte-like H9C2 cells

• DOI: 10.1007/s11033-020-06112-z
• Publication Date: 2021-01-04T10:03:53Z
• Authors: Evangelos Zevolis; Anastassios Phili...; Athanasios Mousto...; Antonios Chatzige...; Michael Koutsilieris
• Keywords: Inflammation; 0303 health sciences; SKP Cullin F-Box Protein Ligases; Cell Death; Cell Survival; MAP Kinase Signaling System; Gene Expression Regulation, Developmental; Muscle Proteins; Apoptosis; Hypertrophy; Cellular Reprogramming; Mechanotransduction, Cellular; Cell Line; Rats; 03 medical and health sciences; Myogenic Regulatory Factors; Animals; Humans; Myocytes, Cardiac; Myogenin; Insulin-Like Growth Factor I; MyoD Protein

Cardiomyocytes possess the ability to respond to mechanical stimuli by reprogramming their gene expression. This study investigated the effects of different loading protocols on signaling and expression responses of myogenic, anabolic, inflammatory, atrophy and pro-apoptotic genes in cardiomyocyte-like H9C2 cells. Differentiated H9C2 cells underwent various stretching protocols by altering their elongation, frequency and duration, utilizing an in vitro cell tension system. The loading-induced expression changes of MyoD, Myogenin, MRF4, IGF-1 isoforms, Atrogin-1, Foxo1, Fuca and IL-6 were measured by Real Time-PCR. The stretching-induced activation of Akt and Erk 1/2 was also evaluated by Western blot analysis. Low strain (2.7% elongation), low frequency (0.25 Hz) and intermediate duration (12 h) stretching protocol was overall the most effective in inducing beneficial responses, i.e., protein synthesis along with the suppression of apoptosis, inflammation and atrophy, in the differentiated cardiomyocytes. These findings demonstrated that varying the characteristics of mechanical loading applied on H9C2 cells in vitro can regulate their anabolic/survival program.