MyoGene: Effects of Acute Exercise on (Myokine) Gene Expression in Human Skeletal Muscle
Rationale: Proteins released from muscle during and shortly after exercise, often referred to as myokines, may be central to our understanding of the cross-talk during and after exercise between skeletal muscles and other organs, in particular the liver. So far only a few myokines are identified (e.g. IL-6, IL-8, IL-15, TNF-alpha). Taking into account the role of these several known myokines in developing insulin resistance, revealing new putative myokines might provide valuable information and a direction for future research on the pathogenesis and treatment of type 2 diabetes mellitus.
Objective: The objective of the present study is to identify novel myokines, expression of which is altered in skeletal muscle after a single bout of exercise.
Study design: experimental study. Study population: Ten healthy, male subjects between 40 and 60 years of age and BMI < 30 kg/m2, will participate in this study.
Intervention: A single exercise bout that consists of one hour one-legged cycling on a adapted recumbent cycle ergometer at a submaximal rate. The non-exercising leg will serve as control for the exercising leg.
Main study outcomes: Main study outcomes include upregulation of genes in skeletal muscle after exercise (with a focus on genes encoding myokines) and changes of blood plasma levels of selected proteins after exercise.
|Study Design:||Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Basic Science
|Official Title:||Effects of Acute Exercise on (Myokine) Gene Expression in Human Skeletal Muscle|
- Gene expression changes in skeletal muscle from baseline to after exercise [ Time Frame: T = 0 and T =1 ] [ Designated as safety issue: No ]Gene expression is measured using whole genome Affymatrix microarrays Muscle tissue will be collected at time points T = 0 (before exercise) and T = 1 (directly after exercise). Special focus is on the changes in genes coding for myokines. Up to 5 genes will be selected for follow-up analysis.
- Changes in plasma levels of selected proteins [ Time Frame: T = 0, T =1 and T = 3 ] [ Designated as safety issue: No ]Selected proteins will be analyzed by ELISA assays or western blot analysis, depending on ELISA availability at T = 0, T = 1 and T = 3 (2 hours post-exercise). The selection of the proteins is based on significance, the robustness of induction (>80% of subjects showing induction) and the magnitude of the induction ( mean fold change > 2)
- PBMC gene expression changes before and after exercise [ Time Frame: T = 0, T = 1 and T =3 ] [ Designated as safety issue: No ]Gene expression changes in the blood will be assessed using whole genome Affymetrix microarrays for the samples at T = 0, 1 and 3.
- Routine plasma level changes before and after exercise [ Time Frame: T = 0, 1 and 3 ] [ Designated as safety issue: No ]At all three time point (T = 0, 1 and 3) plasma levels of glucose, insulin, fatty acids, triglycerides, cortisol, adrenalin and lactate will be determined.
- Heart rate changes, baseline compared with exercise [ Time Frame: During the intervention ] [ Designated as safety issue: No ]Heart rate will be measured during the maximum work load test and the experimental exercise period.
|Study Start Date:||February 2011|
|Study Completion Date:||June 2011|
|Primary Completion Date:||June 2011 (Final data collection date for primary outcome measure)|
Other: Single legged exercise
A single exercise bout that consists of one hour one-legged cycling on a adapted recumbent cycle ergometer at a submaximal rate. The non-exercising leg will serve as control for the exercising leg.