Oxidative and Nitrosative Stress and Immune-Inflammatory Pathways in Patients with Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS)

Abstract:

Myalgic Encephalomyelitis (ME) / Chronic Fatigue Syndrome (CFS) has been classified as a disease of the central nervous system by the WHO since 1969. Many patients carrying this diagnosis do demonstrate an almost bewildering array of biological abnormalities particularly the presence of oxidative and nitrosative stress (O&NS) and a chronically activated innate immune system.

The proposal made herein is that once generated chronically activated O&NS and immune-inflammatory pathways conspire to generate a multitude of self-sustaining and self-amplifying pathological processes which are associated with the onset of ME/CFS. Sources of continuous activation of O&NS and immune-inflammatory pathways in ME/CFS are chronic, intermittent and opportunistic infections, bacterial translocation, autoimmune responses, mitochondrial dysfunctions, activation of the Toll-Like Receptor Radical Cycle, and decreased antioxidant levels.

Consequences of chronically activated O&NS and immune-inflammatory pathways in ME/CFS are brain disorders, including neuroinflammation and brain hypometabolism / hypoperfusion, toxic effects of nitric oxide and peroxynitrite, lipid peroxidation and oxidative damage to DNA, secondary autoimmune responses directed against disrupted lipid membrane components and proteins, mitochondrial dysfunctions with a disruption of energy metabolism (e.g. compromised ATP production) and dysfunctional intracellular signaling pathways. The interplay between all of these factors leads to self-amplifying feed forward loops causing a chronic state of activated O&NS, immune-inflammatory and autoimmune pathways which may sustain the disease.

 

Source: Morris G, Maes M. Oxidative and Nitrosative Stress and Immune-Inflammatory Pathways in Patients with Myalgic Encephalomyelitis (ME)/Chronic Fatigue Syndrome (CFS). Curr Neuropharmacol. 2014 Mar;12(2):168-85. doi: 10.2174/1570159X11666131120224653. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3964747/ (Full article)

 

Increased nuclear factor-κB and loss of p53 are key mechanisms in Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS)

Abstract:

Fukuda’s criteria are adequate to make a distinction between Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS) and chronic fatigue (CF), but ME/CFS patients should be subdivided into those with (termed ME) and without (termed CFS) post exertional malaise [Maes et al. 2012].

ME/CFS is considered to be a neuro-immune disease. ME/CFS is characterized by activated immuno-inflammatory pathways, including increased levels of pro-inflammatory cytokines, nuclear factor κB (NF-κB) and aberrations in mitochondrial functions, including lowered ATP. These processes may explain typical symptoms of ME/CFS, e.g. fatigue, malaise, hyperalgesia, and neurologic and autonomic symptoms.

Here we hypothesize that increased NF-κB together with a loss of p53 are key phenomena in ME/CFS that further explain ME/CFS symptoms, such as fatigue and neurocognitive dysfunction, and explain ME symptoms, such as post-exertional malaise following mental and physical activities. Inactivation of p53 impairs aerobic mitochondrial functions and causes greater dependence on anaerobic glycolysis, elevates lactate levels, reduces mitochondrial density in skeletal muscle and reduces endurance during physical exercise. Lowered p53 and increased NF-κB are associated with elevated reactive oxygen species. Increased NF-κB induces the production of pro-inflammatory cytokines, which increase glycolysis and further compromise mitochondrial functions.

All these factors together may contribute to mitochondrial exhaustion and indicate that the demand for extra ATP upon the commencement of increased activity cannot be met. In conditions of chronic inflammation and oxidative stress, high NF-κB and low p53 may conspire to promote neuron and glial cell survival at a price of severely compromised metabolic brain function. Future research should examine p53 signaling in ME/CFS.

Copyright © 2012. Published by Elsevier Ltd.

 

Source: Morris G, Maes M. Increased nuclear factor-κB and loss of p53 are key mechanisms in Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS). Med Hypotheses. 2012 Nov;79(5):607-13. doi: 10.1016/j.mehy.2012.07.034. Epub 2012 Aug 27. https://www.ncbi.nlm.nih.gov/pubmed/22951418