Moderate Exercise Increases Expression for Sensory, Adrenergic, and Immune Genes in CFS

J Pain. 2009 Jul 30. [Epub ahead of print]

Moderate Exercise Increases Expression for Sensory, Adrenergic, and Immune Genes in Chronic Fatigue Syndrome Patients But Not in Normal Subjects.

Light AR, White AT, Hughen RW, Light KC. Department of Anesthesiology, University of Utah Salt Lake City, Utah, University of Utah Salt Lake City, Utah; Department of Neurobiology and Anatomy, University of Utah Salt Lake City, Utah, University of Utah Salt Lake City, Utah.

Chronic fatigue syndrome (CFS) is characterized by debilitating fatigue, often accompanied by widespread muscle pain that meets criteria for fibromyalgia syndrome (FMS). Symptoms become markedly worse after exercise. Previous studies implicated dysregulation of the sympathetic nervous system (SNS), and immune system (IS) in CFS and FMS. We recently demonstrated that acid sensing ion channel (probably ASIC3), purinergic type 2X receptors (probably P2X4 and P2X5) and the transient receptor potential vanilloid type 1 (TRPV1) are molecular receptors in mouse sensory neurons detecting metabolites that cause acute muscle pain and possibly muscle fatigue. These molecular receptors are found on human leukocytes along with SNS and IS genes. Real-time, quantitative PCR showed that 19 CFS patients had lower expression of beta-2 adrenergic receptors but otherwise did not differ from 16 control subjects before exercise. After a sustained moderate exercise test, CFS patients showed greater increases than control subjects in gene expression for metabolite detecting receptors ASIC3, P2X4, and P2X5, for SNS receptors alpha-2A, beta-1, beta-2, and COMT and IS genes for IL10 and TLR4 lasting from 0.5 to 48 hours (P < .05). These increases were also seen in the CFS subgroup with comorbid FMS and were highly correlated with symptoms of physical fatigue, mental fatigue, and pain. These new findings suggest dysregulation of metabolite detecting receptors as well as SNS and IS in CFS and CFS-FMS.

PERSPECTIVE: Muscle fatigue and pain are major symptoms of CFS. After moderate exercise, CFS and CFS-FMS patients show enhanced gene expression for receptors detecting muscle metabolites and for SNS and IS, which correlate with these symptoms. These findings suggest possible new causes, points for intervention, and objective biomarkers for these disorders.

PMID: 19647494 [PubMed - as supplied by publisher]

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written by Maff, August 10, 2009

This is an interesting an important study that not only provides evidence of what is going on after exercise in ME/CFS patients and how this relates to symptoms but also points to possible diagnostic tests based on post-exercise biomarkers to confirm ME/CFS diagnosis. As the authors conclude their work could also provide targets for new treatments.

N.B. The SNS receptors alpha-2A, beta-1, beta-2 mentioned in the article are all receptors for catacholamine neurotransmitters/hormones including adrenaline. Great gene expression after exercise in ME/CFS patients suggests they would feel greater adrenline type effects/symptoms. IL-10 (interleukin 10) is an immune system signalling chemical called a cytokine. IL-10 suppresses the Th1 immune response and activates the Th2 response which is associated with increased antibody production, histamine release, and allergic reactions. A Th2 biased immune system has commonly been seen in ME/CFS patients in previous research.