The Effect of Redox Potential on the Regulation of Satellite Cells and Skeletal Muscle Healing Following Exercise-Induced Muscle Damage
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 45
- 试验地点
- 2
- 主要终点
- Change in intracellular antioxidant enzymes in muscle
研究概览
简要总结
Skeletal muscle stem cells (Satellite cells) are indispensable for muscle growth and remodeling following myofibril damage. Skeletal muscle trauma is present in numerous catabolic conditions, characterized by elevated proteolysis and muscle wasting such as, cancer cachexia and muscular dystrophy, which result in physical capacity impairment and a deteriorated quality of life. Recent studies performed in animals and cell cultures indicate that the increased levels of inflammation and oxidative stress and the reduction of antioxidant defense may blunt the satellite cells response and myogenic programming during muscle healing. However, evidence regarding the effects of redox status on satellite cells and muscle myogenic potential in humans is lacking. Exercise-induced muscle damage bears striking similarities with the aforementioned conditions, which makes it a valuable tool to investigate the redox-dependent regulation of satellite cells during muscle healing. Thus, the objectives of the present study are to examine the effects of redox status perturbation (via N-acetylcysteine administration) on intracellular pathways responsible for satellite cells responses at rest and following aseptic muscle trauma induced by damaging exercise.
详细描述
A total number of 40-60 young males aged 18-30 will be initially enrolled in the study. Then, participants will be allocated to either a 1) Low glutathione (GSH-low) or a 2) High glutathione (GSH-high) group based on the basal glutathione levels of their vastus lateralis muscle. In a double-blind, crossover, repeated measures design, participants will consume either Placebo (PLA) or N-acetylcysteine (NAC) before (7-day loading phase), on exercise day and for 8 consecutive days following a single bout of intense exercise (300 eccentric contractions at 30 deg/sec in an isokinetic dynamometer). In both conditions, blood samples and muscle biopsies will be collected at baseline, before the exercise protocol and at 2- and 8-days post-exercise. Muscle performance and soreness will also be assessed at the same time points. Before each trial, participants' dietary intake will be analyzed via diet recalls. Physical activity will be analyzed only at baseline via accelerometry. A 4-week washout period will be implemented between trials. Blood samples will be analyzed for inflammation and oxidative stress markers. Muscle samples will be analyzed for satellite cell responses and myogenic potential, protein levels of intracellular signaling proteins, muscle thiols and antioxidant enzyme activity.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 30 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •No recent history of musculoskeletal injury
- •Non-smokers.
- •Abstain from any vigorous physical activity during the study
- •Abstain from consumption of caffeine, alcohol, performance-enhancing or antioxidant supplements, NSAIDs and medications before (at least 6 months) and during the study.
排除标准
- •A known NAC intolerance or allergy
- •A recent febrile illness
- •A recent history of muscle lesion and/or lower limb trauma
- •Presence of metabolic diseases
- •Use of anti-inflammatory medication.
- •Use of medication interacting with muscle metabolism.
结局指标
主要结局
Change in intracellular antioxidant enzymes in muscle
时间窗: At baseline, before the exercise protocol and at days 2 and 8 following exercise.
Protein levels of Glutathione peroxidase 3 (GPx3), Superoxide dismutase 1 (SOD1) and Thioredoxin (Trx1) will be measured using western blotting.
Change in muscle satellite cells number (i.e. Pax7+ cells) and activation status (i.e. Pax7+/MyoD+ cells)
时间窗: At baseline, before the exercise protocol and at days 2 and 8 following exercise.
Satellite cells number and activation status, will be assessed in muscle via immunohistochemistry.
Change in muscle inflammatory state
时间窗: At baseline, before the exercise protocol and at days 2 and 8 following exercise.
Pro-inflammatory (M1+) and anti-inflammatory (M2+) macrophages will be measured in muscle using immunohistochemistry.
Change in muscle thiol content
时间窗: At baseline, before the exercise protocol and at days 2 and 8 following exercise.
Concentration levels of reduced glutathione (GSH) and oxidized glutathione (GSSG) will be measured spectophotometrically.
Change in intracellular signaling proteins in muscle
时间窗: At baseline, before the exercise protocol and at days 2 and 8 following exercise.
Protein levels of IGF-1, Notch1 and Wnt3 will be measured using western blotting.
Change in skeletal muscle damage levels
时间窗: At baseline, before the exercise protocol and at days 2 and 8 following exercise.
Skeletal muscle damage will be quantified via histochemistry using H\&E staining.
Change in muscle myogenic mRNA expression
时间窗: At baseline, before the exercise protocol and at days 2 and 8 following exercise.
mRNA expression levels of Myogenic factor 5 (Myf5), myogenin and Myogenic factor 6 (Myf6/MRF4) and myostatin will be assessed in muscle using Real-Time Polymerase Chain Reaction (RT-PCR).
次要结局
- Body composition(At baseline)
- White blood cell count in blood(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Interleukin-8 (IL-8) in blood(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Resting metabolic rate (RMR)(At baseline)
- Change in delayed onset of muscle soreness (DOMS)(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Physical activity(At baseline.)
- Dietary intake(At baseline.)
- Maximal oxygen consumption (VO2max)(At baseline)
- Cortisol in blood(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Protein carbonyls (PC)(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Malondialdehyde (MDA)(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Isokinetic strength(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Interleukin-1β (IL-1β) in blood(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Interleukin-6 (IL-6) in blood(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Total antioxidant capacity (TAC)(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Interleukin-10 (IL-10) in blood(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Catalase(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
- Creatine Kinase (CK)(At baseline, before the exercise protocol and at days 2 and 8 following exercise.)
研究者
Ioannis G. Fatouros
Professor
University of Thessaly