Effect of Thermal Stimulation on Gene Expression Related to Skeletal Muscle-derived Cell Density

Aims: Our previous study demonstrated favorable changes in plasma protein levels such as adiponectin by fomentation in healthy people. We also reported that the thermal stimulation caused changes of mRNA levels to prevent atherosclerosis in human skeletal muscle-derived cell (SMDC). However, cell number decreased to 74.6% by heat stimulation. In order to clarify this mechanism, we investigated whether the heat stimulation affects the levels of mRNA related to cell density or number of SMDC.

Study Design: Experimental study comparing transcriptome between cells cultured at higher temperature and control cells.

Place and Duration of Study: From September 2015 to March 2017, Division of Physiology and Metabolism, University of Hyogo.

Methodology: SMDC was cultured at 42°C and 37°C and its gene expression was analyzed by using microarray technique.

Results: Thermal stimulation of SMDC significantly altered the expression of 10 genes related to apoptosis, 1 gene related to cell division and 1 gene related to cell adhesion. mRNA expression of apoptosis promoting gene, such as THAP2 (THAP domain containing, apoptosis associated protein 2), PDCD6 (programmed cell death 6), BCL2L13 (BCL2-like 13), LOC728613 (programmed cell death 6 pseudogene), CASP4 (caspase 4), and FAS (Fas cell surface death, receptor) was up-regulated. On the other hand, PAWR (PRKC, apoptosis, WT1, regulator) was downregulated, and mRNA expression of anti-apoptotic genes, such as NOL3 (nucleolar protein 3), CIAPIN1 (cytokine-induced apoptosis inhibitor 1) and NAIF1 (nuclear apoptosis inducing factor1), was up-regulated, Gene Ontology analysis showed alterations in the expression of genes that promote apoptosis and cell growth inhibition. Pathway analysis demonstrated the pathways that promote apoptosis, stimulate cell growth and negatively or positively regulate cell adhesion.

Conclusion: The present study suggested that thermal stimulation of SMDC might predominantly promote apoptosis from consistent changes in related gene expression by any analysis.