Regulation of Satellite Cells and Myogenesis in Response to Eccentric Resistance Exercise in Hypoxia

Regulation of Satellite Cells and Myogenesis in Response to Eccentric Resistance Exercise in Hypoxic Conditions in Healthy Young Men

Satellite cells (SC) are muscle stem cells that once activated, proliferate, and differentiate into myocytes that finally fuse with an existing myofiber to regenerate or increase its mass. This process is called 'myogenesis'. Satellite cell activation can be modulated by exercise and by hypoxia. Hypoxia is a state of lower availability of oxygen that can be reached either by going at high altitude (hypobaric hypoxia) or by lowering the percentage of oxygen in hypoxic rooms at sea level. In opposition to the previously described systemic hypoxia, local hypoxia can be reached placing a cuff around a limb, which will induce a partial vascular occlusion. The latter is termed as blood flow restriction (BFR). In addition, in response to physical exercise, a local intramuscular hypoxia can be found back in the skeletal muscle. Myogenesis has been shown to be modulated by hypoxia in different ways, depending on the level of hypoxia: in conditions of mild hypoxia, satellite cell proliferation appears to be favorized, whereas SC differentiation is decreased in those conditions. In conditions of severe hypoxia, SC quiescence is promoted. SC activation increases in response to resistance training, with and without BFR. Some recent data also suggest that resistance exercise in hypoxic rooms may modulate SC activation, but this area is less well understood. Eccentric exercise may enhance SC activation in comparison to concentric contraction. Up to now, no study has analyzed SC activation and myogenesis in response to an eccentric exercise in hypoxia. Whereas macroscopic differences such as higher muscle force gains or hypertrophy, have been observed between normoxic and hypoxic resistance training, but could not be explained by the classical protein balance and growth factors, there is a need for a better understanding of the muscle response in hypoxia and several studies suggest a role of satellite cells and myogenesis in that difference. The purpose of this study is to elucidate whether or not satellite cells are regulated in a different way in response to an eccentric exercise in hypoxia comparing to normoxia. In addition, differences in SC activation between environmental normobaric hypoxia and BFR, two methods used to reach hypoxia at sea level, are not well understood yet. Finally, most of the studies evaluating myogenic response following a resistance exercise have only taken samples at two time-points, before and 24h after exercise in most of the cases. As the different steps of the myogenic process evolves over the days and may be enhanced or inhibited by hypoxic conditions, multiple time-points would be interesting to observe the evolution of the myogenic process. In that purpose, blood and skeletal muscle samples will be taken at different time-points to evaluate the progress of myogenesis following an acute eccentric exercise. Myogenic regulatory factors will be analyzed by RT-qPCR (mRNA), Western-Blot (protein) and immunofluorescence (localization). In addition, factors able to regulate myogenesis such as muscle damage, inflammation, growth factors, early-regulated genes, MAPK… will also be analyzed in order to understand if they play a role in response to hypoxic conditions.

Study Overview

• Status: Completed
• Conditions: Hypoxia; Exercise; Satellite Cells; Myogenesis
• Intervention / Treatment: Device: Resistance exercise on an isokinetic dynamometer; Procedure: Vastus lateralis biopsy; Procedure: Blood samples; Device: Normoxia; Device: Hypoxia; Device: Blood flow restriction

• Study Type: Interventional
• Enrollment (Actual): 38
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Belgium
  • Louvain-la-Neuve, Belgium, 1348
    • Faculté des Sciences de la Motricité

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy man
• Aged between 20 and 49 years
• Physically active
• Not involved in resistance training,
• No exposed to high altitude (>1500m) 1 month before experiment

Exclusion Criteria:

• Intake of AINS,
• Illness with altered inflammatory status,
• Condition that prohibits resistance exercise (muscle injury) or the sampling of tissue biopsies (aspirin, anticoagulants, allergy to lidocaine)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Resistance exercise in normoxia; Group that performed the resistance exercise in normoxia (FiO2=0.21)	Device: Resistance exercise on an isokinetic dynamometer; Leg flexion/extension: 5 series of 15 repetitions at 60°/sec for the knee extension and 30°/sec for the knee flexion; Procedure: Vastus lateralis biopsy; Biopsy taken in the vastus lateralis; Procedure: Blood samples; Blood samples taken from the antecubital vein; Device: Normoxia; Environmental condition for exercise: in a pressurized chamber with a inspired oxygen fraction of 0.21 (sea level)
Experimental: Resistance exercise in hypoxia; Group that performed the resistance exercise in hypoxia (FiO2=0.14)	Device: Resistance exercise on an isokinetic dynamometer; Leg flexion/extension: 5 series of 15 repetitions at 60°/sec for the knee extension and 30°/sec for the knee flexion; Procedure: Vastus lateralis biopsy; Biopsy taken in the vastus lateralis; Procedure: Blood samples; Blood samples taken from the antecubital vein; Device: Hypoxia; Environmental hypoxia: in a chamber where oxygen is extracted and replaced by nitrogen to reach an inspired oxygen fraction of 0.135 (equivalent to 2500m altitude)
Experimental: Resistance exercise with blood flow restriction; Group that performed the resistance exercise with blood flow restriction (60%AOP)	Device: Resistance exercise on an isokinetic dynamometer; Leg flexion/extension: 5 series of 15 repetitions at 60°/sec for the knee extension and 30°/sec for the knee flexion; Procedure: Vastus lateralis biopsy; Biopsy taken in the vastus lateralis; Procedure: Blood samples; Blood samples taken from the antecubital vein; Device: Blood flow restriction; Tourniquet placed around the proximal extremity of the lower limb and inflated at 60% of arterial occlusion pressure to induce local hypoxia

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Analysis of markers of satellite cells and myogenesis	Throughout the entire study, approximately during 30 months

Secondary Outcome Measures

Outcome Measure	Time Frame
Comparison of the differences between exercise in environmental and local hypoxia	Throughout the entire study, approximately during 30 months

Collaborators and Investigators

• Sponsor: Université Catholique de Louvain

Study record dates

Study Major Dates

• Study Start (Actual): April 4, 2023
• Primary Completion (Actual): May 8, 2023
• Study Completion (Actual): September 5, 2025

Study Registration Dates

• First Submitted: December 19, 2025
• First Submitted That Met QC Criteria: January 6, 2026
• First Posted (Actual): January 14, 2026

Study Record Updates

• Last Update Posted (Actual): January 14, 2026
• Last Update Submitted That Met QC Criteria: January 6, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Signs and Symptoms, Respiratory; Pathological Conditions, Signs and Symptoms; Behavior; Signs and Symptoms; Hypoxia; Motor Activity; Investigative Techniques; Therapeutics; Specimen Handling; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Punctures; Surgical Procedures, Operative; Physical Therapy Modalities; Patient Care; Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Blood Flow Restriction Therapy; Blood Specimen Collection
• Other Study ID Numbers: SCHYPECC

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No