Hydrogen sulfide increases glutathione biosynthesis, and glucose uptake and utilisation in C₂C₁₂ mouse myotubes

Abstract

Diabetic patients have lower blood concentrations of hydrogen sulfide (H₂S), L-cysteine (LC), and glutathione (GSH). Using C₂C₁₂ mouse myotubes as a model, this study investigates the hypothesis that the beneficial effects of LC supplementation are mediated by upregulation of the H₂S status under diabetic conditions. Results show that exogenous administration of sodium hydrosulfide (NaHS, 10 or 20 µM; 6 hours), a H₂S donor, significantly (p < .05) upregulates the gene expression of cystathionine-γ-lyase (CSE), LC transporter (Slc7a11/xCT), and the genes involved in GSH biosynthesis. Additionally, it reduces homocysteine (HCys), reactive oxygen species (ROS) production, and enhances cellular LC, H₂S, and glucose uptake and utilisation in myoblasts. The use of CSE siRNA to induce deficient endogenous H₂S production causes an increase in H₂O₂, ROS, HCys levels, and downregulation of GSH biosynthesis pathway enzymes. In additional, CSE knockdown downregulates glucose transporter type 4 (GLUT4) and gene expression of its key transcription factors, and reduces glucose uptake in C₂C₁₂ myotubes. CSE knockdown cells showed specific increases in the protein S-glutathionylation of LC transporter and GLUT4 along with increased total protein S-glutathionylation. Taken together, evidence from this study provides molecular insights into the importance of the CSE/H₂S system in maintaining the cellular glutathione and glucose homeostasis in C₂C₁₂ myotubes.

Keywords:

• C₂C₁₂
• cystathionine-γ-lyase (CSE)
• glucose homeostasis
• GLUT4
• glutathione
• hydrogen sulfide (H₂S)
• Slc7a11/xCT

Acknowledgements

The authors acknowledge Ms. Morgan for critical proof reading and excellent editing of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by grants from the National Institutes of Health/National Center for Complementary and Integrative Health [RO1 AT007442, 2013–2016], and the Malcolm W. Feist Cardiovascular Research Fellowship and Endowed Chair in Diabetes, Center for Cardiovascular Diseases and Sciences (CCDS) from LSUHSC, Shreveport.