Mild Hyperthermia‐Induced Myogenic Differentiation in Skeletal Muscle Cells: Implications for Local Hyperthermic Therapy for Skeletal Muscle Injury

Abstract

The percutaneous application of controlled temperature on damaged muscle is regarded as a prevalent remedy. However, specific mechanisms are not completely understood. Therefore, cellular behaviors of myoblasts were investigated under a physiological hyperthermic temperature. The myoblasts were cultured under no treatment (NT, 37°C, 24 h/day), intermittent heat treatment (IHT, 39°C, 2 h/day), and continuous heat treatment (CHT, 39°C, 24 h/day) during proliferation, migration, or myogenic differentiation. Although the effects of mild heat on migration were not observed, the proliferation was promoted by both IHT and CHT. The myogenic differentiation was also enhanced in a treatment time-dependent manner, as evidenced by an increase in myotube size and fusion index. The gene expressions of mitochondrial biogenesis (Pgc-1α, Nrf1, and Tfam), a subset of mitochondrial dynamics (Mfn1 and Drp1), and a myogenic regulatory factor (myogenin) were increased in a heat treatment time-dependent manner. Interestingly, the mild heat-induced myogenic differentiation and myogenin expression were retarded significantly in PGC-1α-targeted siRNA-transfected cells, suggesting that mild hyperthermia promotes myogenic differentiation via the modulation of PGC-1α. This study provides cellular evidence supporting that local hyperthermic treatment at 39°C is regarded as an effective therapeutic strategy to promote satellite cell activities in regenerating myofibers.

Mechanobiology-based physical therapy and rehabilitation after orthobiologic interventions: a narrative review

“…The introduction of heat during healing was proposed to have a counter effect on healing and inflammation [41]. However, recent research has shown that mild hyperthermia actually supports the differentiation of satellite cells and stem cells, a crucial step in the late proliferation and early remodeling phases of healing [42,43]. Although the optimal Hong Z et al 12 9 Llion et al 38 6 Barakat AS et al 15 5 Ellefsen et al 53 7 Aydogdu et al 31 6 Gilsanz et al 56 5 Anandkumare et al 32 9 Lohman et al 58 6 Mutlu et al 34 9 Simão et al 59 7 D'Souza et al 36 6 Wang et al 60 9 procedure (i.e., time, duration, temperature, and intervals) for controlled hyperthermia has not been confirmed, research by Guo et al demonstrated pilot results in which the observed moderate hyperthermia at the late inflammatory phase upregulated the production of myofibril proteins through the late stages of myogenesis.…”

Large scale and integrated platform for digital mass culture of anchorage dependent cells

“…Thermal stimulation induces mitochondrial biogenesis and enhance AMP-activated protein kinase activity 32 . Both electrical and thermal stimulations (ES and TS, respectively) are applied to C2C12 myoblast culture on a single-layer CCP according to the timetable and parameters 31–34 shown in Supplementary Fig. 21a.…”

Mitochondrial stress response and myogenic differentiation

“…In addition, some important transcription factors, such as NRF1/2 and TFAM, have been found to show a trend of transcriptional upregulation during differentiation (Kraft et al, 2006;Remels et al, 2010), and NRF1 has been shown to mediate PGC-1β-induced mitochondrial biogenesis and activation of cellular respiration in conjunction with ERR alpha (Shao et al, 2010). So far, a number of studies have shown that activation of mitochondrial biogenesis-related signaling pathways can promote myogenic differentiation (Li et al, 2007;Barbieri et al, 2016;Lee and Choi, 2018;Niu et al, 2021;You et al, 2023). Thus, mitochondrial biogenesis plays an important role in myogenic differentiation.…”