The Impact of N-Acetyl Cysteine and Coenzyme Q10 Supplementation on Skeletal Muscle Antioxidants and Proteome in Fit Thoroughbred Horses.

Marisa L Henry,Stephanie J Valberg,Joe D Pagan,Lorraine Sordillo,Deborah Velez-Irizarry,Jeff Gandy

doi:10.3390/antiox10111739

Marisa L Henry, Stephanie J Valberg + Show 4 more

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https://doi.org/10.3390/antiox10111739

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Abstract

Horses have one of the highest skeletal muscle oxidative capacities amongst mammals, which, combined with a high glycolytic capacity, could perturb redox status during maximal exercise. We determined the effect of 30 d of oral coenzyme Q10 and N-acetyl-cysteine supplementation (NACQ) on muscle glutathione (GSH), cysteine, ROS, and coenzyme Q10 concentrations, and the muscle proteome, in seven maximally exercising Thoroughbred horses using a placebo and randomized cross-over design. Gluteal muscle biopsies were obtained the day before and 1 h after maximal exercise. Concentrations of GSH, cysteine, coenzyme Q10, and ROS were measured, and citrate synthase, glutathione peroxidase, and superoxide dismutase activities analyzed. GSH increased significantly 1 h post-exercise in the NACQ group (p = 0.022), whereas other antioxidant concentrations/activities were unchanged. TMT proteomic analysis revealed 40 differentially expressed proteins with NACQ out of 387 identified, including upregulation of 13 mitochondrial proteins (TCA cycle and NADPH production), 4 Z-disc proteins, and down regulation of 9 glycolytic proteins. NACQ supplementation significantly impacted muscle redox capacity after intense exercise by enhancing muscle glutathione concentrations and increasing expression of proteins involved in the uptake of glutathione into mitochondria and the NAPDH-associated reduction of oxidized glutathione, without any evident detrimental effects on performance.

Highlights

Horses have one of the highest skeletal muscle oxidative capacities amongst mammals, with evolutionary adaptations in heart size and lung capacity maximizing aerobic metabolism [1]
The present study examined the impact of 30 d of supplementation of NAC and CoQ10 (NACQ) on nonenzymatic and enzymatic antioxidants in skeletal muscle as well as the effect on the muscle proteome in fit Thoroughbred horses
Results showed that NACQ supplementation significantly enhanced post-exercise glutathione concentrations, enhanced proteins involved in reduction of oxidized glutathione, and enhanced proteins involved in mitochondrial oxidative energy metabolism and the Z disc while decreasing glycolytic enzyme and fast-twitch type

Summary

Introduction

Horses have one of the highest skeletal muscle oxidative capacities amongst mammals, with evolutionary adaptations in heart size and lung capacity maximizing aerobic metabolism [1]. Physiological amounts of ROS generated in skeletal muscle serve important adaptive signaling functions to prevent muscle fatigue, excessive ROS can overwhelm antioxidant capacity, causing oxidative damage to proteins, lipids, and DNA, with detrimental effects on muscle function [2]. Both nonenzymatic and enzymatic cellular antioxidants reduce ROS. Glutathione (γ-l-glutamyl-l-cysteinylglycine) is the most abundant nonenzymatic antioxidant in mammalian cells [3] It maintains the thiol status of critical proteins via cysteine’s sulfhydryl group and defends against ROS via its reducing capacity [4]. Glutathione is synthesized endogenously from glutamate, cysteine, and glycine with cysteine availability being the rate-limiting step in synthesis [5]

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