Abstract:
Tag: radiation
Commonalities in the Features of Cancer and Chronic Fatigue Syndrome (CFS): Evidence for Stress-Induced Phenotype Instability?
Abstract:
Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME) and Cancer-Related Fatigue (CRF) are syndromes with considerable overlap with respect to symptoms. There have been many studies that have compared the two conditions, and some of this research suggests that the etiologies of the conditions are linked in some cases. In this narrative review, CFS/ME and cancer are introduced, along with their known and putative mechanistic connections to multiple stressors including ionizing radiation.
Next, we summarize findings from the literature that suggest the involvement of HPA-axis dysfunction, the serotonergic system, cytokines and inflammation, metabolic insufficiency and mitochondrial dysfunction, and genetic changes in CRF and CFS/ME. We further suspect that the manifestation of fatigue in both diseases and its causes could indicate that CRF and CFS/ME lie on a continuum of potential biological effects which occur in response to stress. The response to this stress likely varies depending on predisposing factors such as genetic background.
Finally, future research ideas are suggested with a focus on determining if common biomarkers exist in CFS/ME patients and those afflicted with CRF. Both CFS/ME and CRF are relatively heterogenous syndromes, however, it is our hope that this review assists in future research attempting to elucidate the commonalities between CRF and CFS/ME.
Source: Rusin A, Seymour C, Cocchetto A, Mothersill C. Commonalities in the Features of Cancer and Chronic Fatigue Syndrome (CFS): Evidence for Stress-Induced Phenotype Instability? Int J Mol Sci. 2022 Jan 8;23(2):691. doi: 10.3390/ijms23020691. PMID: 35054876. https://pubmed.ncbi.nlm.nih.gov/35054876/
Inflammation plays a causal role in fatigue-like behavior induced by pelvic irradiation in mice
Abstract:
Fatigue is a persistent and debilitating symptom following radiation therapy for prostate cancer. However, it is not well-understood how radiation targeted to a small region of the body can lead to broad changes in behavior. In this study, we used targeted pelvic irradiation of healthy male mice to test whether inflammatory signaling mediates changes in voluntary physical activity levels.
First, we tested the relationship between radiation dose, blood cell counts, and fatigue-like behavior measured as voluntary wheel-running activity. Next, we used oral minocycline treatments to reduce inflammation and found that minocycline reduces, but does not eliminate, the fatigue-like behavioral changes induced by radiation. We also used a strain of mice lacking the MyD88 adaptor protein and found that these mice also showed less fatigue-like behavior than the wild-type controls. Finally, using serum and brain tissue samples, we determined changes in inflammatory signaling induced by irradiation in wild-type, minocycline treated, and MyD88 knockout mice.
We found that irradiation increased serum levels of IL-6, a change that was partially reversed in mice treated with minocycline or lacking MyD88. Overall, our results suggest that inflammation plays a causal role in radiation-induced fatigue and that IL-6 may be an important mediator.
Source: Wolff BS, Alshawi SA, Feng LR, Juneau PL, Saligan LN. Inflammation plays a causal role in fatigue-like behavior induced by pelvic irradiation in mice. Brain Behav Immun Health. 2021 May 19;15:100264. doi: 10.1016/j.bbih.2021.100264. PMID: 34589770; PMCID: PMC8474574. https://pubmed.ncbi.nlm.nih.gov/34589770/
Radiation exposure and mitochondrial insufficiency in chronic fatigue and immune dysfunction syndrome
Abstract:
Chronic fatigue and Immune Dysfunction Syndrome (CFIDS) is a heterogeneous disease that may be promoted by various environmental stressors, including viral infection, toxin uptake, and ionizing radiation exposure. Previous studies have identified mitochondrial dysfunction in CFIDS patients, including modulation of mitochondrial respiratory chain activity, deletions in the mitochondrial genome, and upregulation of reactive oxygen species (ROS). This paper focuses on radiation effects and hypothesizes that CFIDS is primarily caused by stressor-induced mitochondrial metabolic insufficiency, which results in decreased energy production and anabolic metabolites required for normal cellular metabolism. Furthermore, tissues neighbouring or distant from directly perturbed tissues compensate for this dysfunction, which causes symptoms associated with CFIDS.
This hypothesis is justified by reviewing the links between radiation exposure and CFIDS, cancer, immune dysfunction, and induction of oxidative stress. Moreover, the relevance of mitochondria in cellular responses to radiation and metabolism are discussed and putative mitochondrial biomarkers for CFIDS are introduced. Implications for diagnosis are then described, including a potential urine assay and PCR test for mitochondrial genome mutations. Finally, future research needs are offered with an emphasis on where rapid progress may be made to assist the afflicted.
Source: Rusin A, Li M, Cocchetto A, Seymour C, Mothersill C. Radiation exposure and mitochondrial insufficiency in chronic fatigue and immune dysfunction syndrome. Med Hypotheses. 2021 Jul 27;154:110647. doi: 10.1016/j.mehy.2021.110647. Epub ahead of print. PMID: 34358921. https://pubmed.ncbi.nlm.nih.gov/34358921/
Chronic fatigue and immune deficiency syndrome (CFIDS), cellular metabolism, and ionizing radiation: a review of contemporary scientific literature and suggested directions for future research
Abstract:
PURPOSE: To investigate biochemical pathways known to be involved in radiation response and in CFIDS to determine if there might be common underlying mechanisms leading to symptoms experienced by those accidentally or deliberately exposed to radiation and those suffering from CFIDS. If such a link was established to suggest testable hypotheses to investigate the mechanisms with the aim of identifying new therapeutic targets.
CONCLUSIONS: Evidence for involvement of the alpha-synuclein, cytochrome c oxidase, αB-crystallin, RNase L, and lactate dehydrogenase/STAT1 pathways is strong and suggests a common underlying mechanism involving mitochondrial dysfunction mediated by ROS and disruption of ATP production. The downstream effect of this is compromised energy production. Testable hypotheses are suggested to investigate the involvement of these pathways further.
Source: Rusin A, Seymour C, Mothersill C. Chronic fatigue and immune deficiency syndrome (CFIDS), cellular metabolism, and ionizing radiation: a review of contemporary scientific literature and suggested directions for future research. Int J Radiat Biol. 2018 Jan 10:1-17. doi: 10.1080/09553002.2018.1422871. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/29297728
Post-radiation syndrome as a NO/ONOO- cycle, chronic fatigue syndrome-like disease
Abstract:
Post-radiation syndrome is proposed to be chronic fatigue syndrome (CFS) or a chronic fatigue syndrome-like illness, initiated by exposure to ionizing radiation. This view is supported by the nitric oxide/peroxynitrite (NO/ONOO-) cycle mechanism, the putative etiologic mechanism for CFS and related illnesses.
Ionizing radiation may initiate illness by increasing nitric oxide levels via increased activity of the transcription factor NF-kappaB and consequent increased synthesis of the inducible nitric oxide synthase. Two types of components of the nitric oxide/peroxynitrite cycle have been studied in post-radiation syndrome patients and shown to be elevated.
The symptoms and signs of post-radiation syndrome and its chronicity are similar or identical to those of chronic fatigue syndrome and can be explained as being a consequence of nitric oxide/peroxynitrite cycle etiology. While the data available to test this view are limited, it provides for the first time a comprehensive explanation for post-radiation syndrome.
Source: Pall ML. Post-radiation syndrome as a NO/ONOO- cycle, chronic fatigue syndrome-like disease. Med Hypotheses. 2008 Oct;71(4):537-41. doi: 10.1016/j.mehy.2008.05.023. Epub 2008 Jul 29. https://www.ncbi.nlm.nih.gov/pubmed/18667279