Cross-talk between TRPC-1, mTOR, PGC-1α and PPARδ in the dystrophic muscle cells treated with tempol

Abstract

Background Ca2+ dysregulation and oxidative damage appear to have a central role in Duchenne muscular dystrophy (DMD) progression. The current study provides muscle cell-specific insights into the effect of Tempol on the TRPC 1 channel; on the positive and negative regulators of muscle cell differentiation; on the antioxidant enzymatic system; on the activators of mitochondrial biogenesis; and on the inflammatory process in the dystrophic primary muscle cells in culture. Methods: Mdx myotubes were treated with Tempol (5 mM) for 24 h. Untreated mdx myotubes and C57BL/10 myotubes were used as controls. Results: The Trypan Blue, MTT and Live/Dead Cell assays showed that Tempol (5 mM) presented no cytotoxic effect on the dystrophic muscle cells. The Tempol treated-mdx muscle cells showed significantly lower levels in the fluorescence intensity of intracellular calcium; TRPC-1 channel; MyoD; H₂O₂ and O₂^•− production; 4-HNE levels; SOD2, CAT and GPx levels; and TNF levels. On the other hand, SOD, CAT and GR mRNA relative expression were significantly higher in Tempol treated-mdx muscle cells. In addition, higher levels of Myogenin, MHC-Slow, mTOR, PGC-1α and PPARδ were also observed in Tempol treated-mdx muscle cells. Conclusion: Our findings demonstrated that Tempol decreased intracellular calcium and oxidative stress in primary dystrophic muscle cells, promoting a cross-talk between TRPC-1, mTOR, PGC-1α and PPARδ.

Keywords:

• Dystrophic muscle cells
• tempol
• calcium channels
• mitochondrial biogenesis
• muscle cell differentiation

Acknowledgments

The authors thank Mrs. Deirdre Jane Donovan Giraldo for the English revision of the manuscript.

Author contributions

The authors contributed substantially to conception and design, acquisition of data, analysis, and interpretation of data. All authors participated in drafting the article, revised it critically for important intellectual content and gave final approval of the version to be submitted.

Disclosure statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Additional information

Funding

This research was funded by Fundação de Amparo à Pesquisa do Estado de São Paulo [FAPESP; #2017/01638-0], Coordenação de Pessoal de Nível Superior-Brasil (CAPES) – Finance Code 001, CNPq and FAEPEX. I.F.R. was the recipient of a FAPESP [#2014/25010-1] and CNPq fellowship. T.A.H., D.S.M and C.C.L were the recipient of a CAPES fellowship. G.L.R is the recipient of a CAPES fellowship. H.N.M.S and C.C. are the recipients of a CNPq fellowship. H.N.A was the recipient of a CNPq fellowship.