Nitrosative Redox Homeostasis and Antioxidant Response Defense in Disused Vastus lateralis Muscle in Long-Term Bedrest (Toulouse Cocktail Study).

Dieter Blottner,Pompeo Volpe,Imre Vida,Katharina Block,Sandra Furlan,Michele Salanova,Enrica Torretta,Daniele Capitanio,Guido Gambara,Manuela Moriggi,Angèle Chopard,Gabor Trautmann,Cecilia Gelfi,Pietro Barbacini,Guillaume Py

doi:10.3390/antiox10030378

Abstract

Increased oxidative stress by reactive oxygen species (ROS) and reactive nitrogen species (RNS) is a major determinant of disuse-induced muscle atrophy. Muscle biopsies (thigh vastus lateralis, VL) obtained from healthy male subjects enrolled in the Toulouse Cocktail bedrest (BR) study were used to assess efficacy of an antioxidant cocktail (polyphenols, omega-3, vitamin E, and selenium) to counteract the increased redox homeostasis and enhance the antioxidant defense response by using label-free LC–MS/MS and NITRO-DIGE (nitrosated proteins), qPCR, and laser confocal microscopy. Label-free LC–MS/MS indicated that treatment prevented the redox homeostasis dysregulation and promoted structural remodeling (TPM3, MYH7, MYBPC, MYH1, MYL1, HRC, and LUM), increment of RyR1, myogenesis (CSRP3), and skeletal muscle development (MUSTN1, LMNA, AHNAK). These changes were absent in the Placebo group. Glycolysis, tricarboxylic acid cycle (TCA), oxidative phosphorylation, fatty acid beta-oxidation, and mitochondrial transmembrane transport were normalized in treated subjects. Proteins involved in protein folding were also normalized, whereas protein entailed in ion homeostasis decreased. NITRO-DIGE analysis showed significant protein nitrosylation changes for CAT, CA3, SDHA, and VDAC2 in Treatment vs. Placebo. Similarly, the nuclear factor erythroid 2-related factor 2 (Nrf-2) antioxidant response element (Nrf-2 ARE) signaling pathway showed an enhanced response in the Treatment group. Increased nitrosative redox homeostasis and decreased antioxidant defense response were found in post-BR control (Placebo, n = 10) vs. the antioxidant cocktail treated group (Treatment, n = 10). Taken together, increased nitrosative redox homeostasis and muscle deterioration during BR-driven physical inactivity were prevented, whereas decreased antioxidant nitrosative stress defense response was attenuated by Treatment suggesting positive effects of the nutritional intervention protocol in bedrest.

Highlights

A large body of evidence indicates that after extended periods of reduced physical activity, occurring in many clinical settings, in musculoskeletal disorders and during long-term bedrest immobilization or spaceflights, muscles undergo metabolic structural and functional adaptations resulting in skeletal muscle atrophy [1]
Comparing Placebo-Post and Placebo-R + 10 to Placebo-Pre, we found that 54 proteins were changed, whereas comparing TreatmentPost and Treatment-R + 10 to Treatment-Pre, 37 proteins were differentially abundant
Our findings were further supported by increase of the intracellular calcium release channel protein (RyR1), a positive regulator of myogenesis (CSRP3), and changes in a set of other proteins involved in skeletal muscle development (MUSTN1, LMNA, AHNAK) highlight the efficacy of the antioxidant cocktail as nutrition countermeasure intervention in our experimental model

Summary

Introduction

A large body of evidence indicates that after extended periods of reduced physical activity, occurring in many clinical settings, in musculoskeletal disorders and during long-term bedrest immobilization or spaceflights, muscles (especially those of the lower limb) undergo metabolic structural and functional adaptations resulting in skeletal muscle atrophy [1]. Several studies have proposed that increased production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in skeletal muscle plays a synergistic role as signaling mechanism contributing to disuse-induced muscle atrophy by enhancing protease activity and repressing protein synthesis [3,4]. In bedrest-induced muscle disuse (BR), the level of nitrosylated muscle proteins involved in the control of Ca2+ homeostasis is significantly increased [5]. In the mdx mouse model, the age-dependent RyR1 nitrosylation leads to channel remodeling resulting in “leaky” channels [7] with increased intracellular calcium release and increased calcium-dependent calpain protease activity [8]

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Discussion

Conclusion