Tag: fatigue

WASF3 disrupts mitochondrial respiration and may mediate exercise intolerance in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by various disabling symptoms including exercise intolerance and is diagnosed in the absence of a specific cause, making its clinical management challenging. A better understanding of the molecular mechanism underlying this apparent bioenergetic deficiency state may reveal insights for developing targeted treatment strategies.

We report that overexpression of Wiskott-Aldrich Syndrome Protein Family Member 3 (WASF3), here identified in a 38-y-old woman suffering from long-standing fatigue and exercise intolerance, can disrupt mitochondrial respiratory supercomplex formation and is associated with endoplasmic reticulum (ER) stress.

Increased expression of WASF3 in transgenic mice markedly decreased their treadmill running capacity with concomitantly impaired respiratory supercomplex assembly and reduced complex IV levels in skeletal muscle mitochondria. WASF3 induction by ER stress using endotoxin, well known to be associated with fatigue in humans, also decreased skeletal muscle complex IV levels in mice, while decreasing WASF3 levels by pharmacologic inhibition of ER stress improved mitochondrial function in the cells of the patient with chronic fatigue.

Expanding on our findings, skeletal muscle biopsy samples obtained from a cohort of patients with ME/CFS showed increased WASF3 protein levels and aberrant ER stress activation. In addition to revealing a potential mechanism for the bioenergetic deficiency in ME/CFS, our study may also provide insights into other disorders associated with fatigue such as rheumatic diseases and long COVID.

Source: Wang PY, Ma J, Kim YC, Son AY, Syed AM, Liu C, Mori MP, Huffstutler RD, Stolinski JL, Talagala SL, Kang JG, Walitt BT, Nath A, Hwang PM. WASF3 disrupts mitochondrial respiration and may mediate exercise intolerance in myalgic encephalomyelitis/chronic fatigue syndrome. Proc Natl Acad Sci U S A. 2023 Aug 22;120(34):e2302738120. doi: 10.1073/pnas.2302738120. Epub 2023 Aug 14. PMID: 37579159. https://pubmed.ncbi.nlm.nih.gov/37579159/

Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome

Abstract:

Symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are common in rheumatic diseases, but no studies report the frequency of these in early systemic sclerosis. There are no known biomarkers that can distinguish between patients with ME/CFS, although mitochondrial abnormalities are often demonstrated.

We sought to assess the prevalence of ME/CFS in limited cutaneous SSc (lcSSc) patients early in their disease (<5 years from the onset of non-Raynaud’s symptoms) and to determine if alterations in mitochondrial electron transport chain (ETC) transcripts and mitochondrial DNA (mtDNA) integrity could be used to distinguish between fatigued and non-fatigued patients.

All SSc patients met ACR/EULAR classification criteria. ME/CFS-related symptoms were assessed through validated questionnaires, and the expression of ETC transcripts and mtDNA integrity were quantified via qPCR.

SSc patients with ME/CFS could be distinguished from non-fatigued patients through ETC gene analysis; specifically, reduced expression of ND4 and CyB and increased expression of Cox7C. ND4 and CyB expression correlated with indicators of disease severity.

Further prospective and functional studies are needed to determine if this altered signature can be further utilized to better identify ME/CFS in SSc patients, and whether ME/CFS in early SSc disease could predict more severe disease outcomes.

Source: van Eeden C, Redmond D, Mohazab N, Larché MJ, Mason AL, Cohen Tervaert JW, Osman MS. Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome. International Journal of Molecular Sciences. 2023; 24(15):12057. https://doi.org/10.3390/ijms241512057 https://www.mdpi.com/1422-0067/24/15/12057 (Full text)

Characterizing Sjögren-Associated Fatigue: A Distinct Phenotype from ME/CFS

Abstract:

Fatigue is the most commonly reported and debilitating extraglandular symptom of primary Sjögren′s syndrome (pSS). Fatigue and exertional intolerance are hallmark symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). We aimed to characterize fatigue and further symptoms among pSS patients and to determine whether there is a symptom overlap in pSS and ME/CFS.
In 19 patients with pSS, we assessed pSS symptom severity and disease activity via questionnaires as well as the Canadian Consensus Criteria (CCC) for ME/CFS. Hand grip strength (HGS) and levels of α1-, α2-, β1-, β2-, M3- and M4-receptor-autoantibodies were measured. A subgroup of pSS patients exhibited severe fatigue and had higher severity of pain (p = 0.045), depression (p = 0.021) and sleep disturbances (p = 0.020) compared to those with less fatigue.
Four of eighteen pSS patients fulfilled the CCC. HGS parameters strongly correlated with fatigue severity (p < 0.05), but strength fully recovered one hour after exertion in contrast to ME/CFS. Levels of β1-, β2- and M4-receptor-autoantibodies were elevated and correlated significantly with disease activity assessed by the ESSDAI (p < 0.05), but not fatigue severity.
Only a minor subgroup of pSS patients fulfills the CCC, and post exertional malaise (PEM) is atypical, as it is primarily triggered by mental/emotional but not physical exertion. HGS assessment is an objective measure to assess overall fatigue severity.
Source: Kim L, Kedor C, Buttgereit F, Heidecke H, Schaumburg D, Scheibenbogen C. Characterizing Sjögren-Associated Fatigue: A Distinct Phenotype from ME/CFS. Journal of Clinical Medicine. 2023; 12(15):4994. https://doi.org/10.3390/jcm12154994 https://www.mdpi.com/2077-0383/12/15/4994 (Full text)

A Thesis on Immune Differences in Chronic Fatigue Syndrome, Fibromyalgia and Healthy Controls

Abstract:

Background: Chronic Fatigue Syndrome (CFS) and Fibromyalgia (FM) are debilitating disorders that significantly affect the daily lives of those suffering from them, as well as their loved ones. Both conditions have overlapping clinical features that resemble inflammatory disorders, and overlapping symptoms, such as depression, suggest central nervous system (CNS) involvement. The role of the immune system’s soluble messengers in the pathogenesis of CFS and FM has been under investigation, but so far the results are inconclusive. In addition, there is growing evidence that the kynurenine pathway is involved in the pathology of diseases related to the CNS, yet the role of each metabolite is not clear. The relationship between kynurenine metabolism and CFS and FM has not been extensively explored. Few studies have simultaneously examined the immunological status in both CFS and FM, making this thesis the first to comprehensively evaluate the potential distinct immunological differences between the two disorders.

Objective: The objective of this study was to compare the CFS and FM with healthy controls, regarding the levels of several soluble blood markers related to the immune system. The markers chosen were:

  • The inflammatory marker high-sensitive CRP (hsCRP)
  • The following cytokines and chemokines: Interferon (IFN)-γ, Interleukin (IL)-1β, IL1ra, IL-4, IL-6, IL-8, IL-10, IL-17, Interferon gamma-induced protein (IP)-10, Monocyte Chemoattractant Protein (MCP)-1, Transforming Growth Factor (TGF)-β1, TGF-β2, TGF-β3 and Tumour Necrosis Factor (TNF)-α
  • The metabolites and their ratios of the kynurenine pathway: Tryptophan (Try), kynurenine (Kyn), kynurenic acid (KA), 3-hydroxykykynurenine (HK), anthranilic acid (AA), xanthurenic acid (XA), 3-hydroxyanthranilic acid (HAA), quinolinic acid (QA) and picolinic acid (Pic).

Method: The population consisted of three groups: CFS patients (n = 49), FM patients (n = 58), and healthy controls (n = 54). All participants were females aged 18–60. Patients were recruited from a specialised university hospital clinic and controls were recruited by advertisement among the staff and students at the hospital and university.

Plasma levels of hsCRP were analysed at the hospital. The cytokines and chemokines IFN-γ, IL-1β, IL-1ra, xii IL-4, IL-6, IL-8, IL-10, IL-17, IP-10, MCP-1, TGF-β1, TGF-β2, TGF-β3, and TNF-α were analysed by multiplex. Kynurenine metabolites were analysed by LC-MS/MS.

Linear regression models of log-transformed data for hsCRP and the kynurenine metabolites were conducted for comparison of the three groups CFS, FM and controls. The Kruskal-Wallis test was used to analyse differences of cytokines between the three groups. Main findings were controlled for age, body mass index (BMI), and symptoms of anxiety and depression.

Results: hsCRP levels were significantly higher for both the CFS and FM groups compared to healthy controls when adjusting for age and BMI (p = .006). There was no difference between the two patient groups. Level of hsCRP was affected by BMI (p < .001) but not age.

MCP-1 was significantly increased in both patient groups compared to healthy controls (p < .001). IL-1β, Il-4, IL-6, TNF-α, TGF-β1, TGF-β2, TGF-β3 (all p < .001), IL-10 (p = .003) and IL17 (p = .002) all were significantly lower in the patient groups compared to healthy controls. IFN-γ was significantly lower in the FM group (p < .001). For IL-8, IP-10 and IL1ra there were no significant difference.

QA differed between CFS and FM patients (p = .036) and was related to higher levels of BMI (p = .002). The KA/QA ratio was lower for CFS patients compared to healthy controls (p = .016). The KA/HK ratio was lower for FM patients compared to healthy controls, and this lower ratio was associated with increased symptoms of pain (p = .002). The kynurenine aminotransferase II (KAT II) enzymatic activity given by XA/HK was lower for FM patients compared to healthy controls (p = .013). In addition, BMI was negatively associated with enhanced KAT II enzymatic activity (p = .039).

Symptoms of anxiety and depression were not associated with any of the immune markers studied.

Conclusion: In our material hsCRP and MCP-1 are increased in patients both with CFS and with FM, while several other cytokines are either similar or significantly lower in patients than controls. Our study also indicates associations between kynurenine metabolism and CFS and FM. Kynurenine also is associated with single symptoms such as fatigue and pain. Forthcoming studies indicating interactions and causative effects, or restoration of the inflammatory status, may place cytokines and kynurenine metabolites as a target for treatment as well as prevention of these conditions in the future.

Source: Groven, Nina. A Thesis on Immune Differences in Chronic Fatigue Syndrome, Fibromyalgia and Healthy Controls. PhD Thesis [Norwegian University of Science and Technology] https://ntnuopen.ntnu.no/ntnu-xmlui/handle/11250/3072207 (Full text available as PDF file)

Modulation of Beta-Adrenergic Autoantibodies Over Time in Post-Viral ME/CFS is Related to Fatigue and Pain Symptoms

Abstract:

Background: Myalgic encephalomyelits/chronic fatigue syndrome (ME/CFS) is an acquired disease with symptoms of fatigue and pain. In pathogenesis, the induction of autoantibodies (AAB) against G-protein coupled receptors (GPCR), such as β-adrenergic receptors (β-AdR), has been suspected. GPCR-AAB correlate with symptom severity and autonomic dysfunction in ME/CFS.

Objectives: To describe symptoms and treatment of a patient presenting with infection-triggered ME/CFS demonstrating that levels of β-AdR-AAB underlie modulation over time, correlating with the severity of symptoms.

Methods: At T1 and T2, GPCR-AAB were measured and questionnaires assessing symptom severity were completed. TSHDS-IgM-AAB were tested, and SF density was analyzed via skin probe.

Results: At T2, elevated levels of β-AdR-AAB were found, corresponding with an aggravation of fatigue and pain symptoms. Elevated TSHDS-IgM-AAB were found, which corresponded with reduced fiber density from the skin probe.

Conclusions: The levels of β-AdR-AAB in post-infectious ME/CFS can be modulated. Future studies might target interventions to reduce these AAB.

Source: Busch L, Schriek C, Paul M, Heidecke H. Modulation of Beta-Adrenergic Autoantibodies Over Time in Post-Viral ME/CFS is Related to Fatigue and Pain Symptoms. Isr Med Assoc J. 2023 Apr;25(4):259-264. PMID: 37129123. https://pubmed.ncbi.nlm.nih.gov/37129123/

Ginsenoside Rg1 can reverse fatigue behavior in CFS rats by regulating EGFR and affecting Taurine and Mannose 6-phosphate metabolism

Abstract:

Background: Chronic fatigue syndrome (CFS) is characterized by significant and persistent fatigue. Ginseng is a traditional anti-fatigue Chinese medicine with a long history in Asia, as demonstrated by clinical and experimental studies. Ginsenoside Rg1 is mainly derived from ginseng, and its anti-fatigue metabolic mechanism has not been thoroughly explored.

Methods: We performed non-targeted metabolomics of rat serum using LC-MS and multivariate data analysis to identify potential biomarkers and metabolic pathways. In addition, we implemented network pharmacological analysis to reveal the potential target of ginsenoside Rg1 in CFS rats. The expression levels of target proteins were measured by PCR and Western blotting.

Results: Metabolomics analysis confirmed metabolic disorders in the serum of CFS rats. Ginsenoside Rg1 can regulate metabolic pathways to reverse metabolic biases in CFS rats. We found a total of 34 biomarkers, including key markers Taurine and Mannose 6-phosphate. AKT1, VEGFA and EGFR were identified as anti-fatigue targets of ginsenoside Rg1 using network pharmacological analysis. Finally, biological analysis showed that ginsenoside Rg1 was able to down-regulate the expression of EGFR.

Conclusion: Our results suggest ginsenoside Rg1 has an anti-fatigue effect, impacting the metabolism of Taurine and Mannose 6-phosphate through EGFR regulation. This demonstrates ginsenoside Rg1 is a promising alternative treatment for patients presenting with chronic fatigue syndrome.

Source: Lei C, Chen J, Huang Z, Men Y, Qian Y, Yu M, Xu X, Li L, Zhao X, Jiang Y, Liu Y. Ginsenoside Rg1 can reverse fatigue behavior in CFS rats by regulating EGFR and affecting Taurine and Mannose 6-phosphate metabolism. Front Pharmacol. 2023 Apr 10;14:1163638. doi: 10.3389/fphar.2023.1163638. PMID: 37101547; PMCID: PMC10123289. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10123289/ (Full text)

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia: PR3-versus MPO-ANCA-associated vasculitis, an exploratory cross-sectional study

Summary:

Background: Persistent fatigue is a common complaint in ANCA-vasculitis (AAV) patients and has a profound impact on patient’s quality of life. The symptoms associated with this fatigue mirror those found in patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia. Etiologic and pathophysiologic differences exist between PR3- and MPO-ANCA disease, yet differences in their fatigue manifestations have not been well researched. We compared fatigue and its associations in healthy controls, AAV patients and fibromyalgia controls.

Methods: The Canadian consensus criteria were used for ME/CFS diagnosis, and American College of Rheumatology criteria for fibromyalgia diagnosis. Factors such as cognitive failure, depression, anxiety, and sleep disturbances were assessed by patient reported questionnaires. Clinical factors such as BVAS, vasculitis damage index, CRP and BMI were also collected.

Findings: Our AAV cohort comprised 52 patients, with a mean age of 44.7 (20–79), 57% (30/52) of the patients were female. We found 51.9% (27/52) of patients fulfilled the diagnostic criteria for ME/CFS, with 37% (10/27) of those having comorbid fibromyalgia. Rates of fatigue were higher in MPO-ANCA patients, than in PR3-ANCA patients, and their symptoms were more similar to the fibromyalgia controls. Fatigue in PR3-ANCA patients was related to inflammatory markers. These differences may be due to the varied pathophysiology of the PR3- and MPO-ANCA serotypes.

Interpretation: A large proportion of AAV patients suffer from debilitating fatigue consequential enough to meet the diagnostic criteria for ME/CFS. Fatigue associations were not the same between PR3- and MPO-ANCA patients, suggesting that the underlying mechanisms may be different. Future studies should consider ANCA serotype, as further research may inform different clinical treatment strategies for AAV patients suffering from ME/CFS.

Source: Charmaine van Eeden, Naima Mohazab, Desiree Redmond, Elaine Yacyshyn, Alison Clifford, Anthony S. Russell, Mohammed S. Osman, and Jan Willem Cohen Tervaer. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and fibromyalgia: PR3-versus MPO-ANCA-associated vasculitis, an exploratory cross-sectional study. The Lancet Regional Health – Americas 2023;20: 100460.  https://www.thelancet.com/journals/lanam/article/PIIS2667-193X(23)00034-0/fulltext# (Full text)

Characteristics associated with physical functioning and fatigue in patients with chronic fatigue syndrome (CFS): secondary analyses of a randomized controlled trial

Abstract

Objective: This study aimed to explore associations at the group level between patient characteristics at baseline and the outcomes of physical functioning and fatigue in patients with chronic fatigue syndrome (CFS) participating in a randomized controlled trial on cognitive behavioural therapy (CBT).

Methods/design: Consecutively, 236 adult participants fulfilling the Centres for Disease Control and Prevention (CDC) 1994 criteria for CFS were randomly allocated to either 16 weeks of standard CBT, 8 weeks of Interpersonal CBT or a treatment as usual control group. In secondary analyses we investigated how gender, age, pain, anxiety, depression, memory and VO2max at baseline were associated with physical function and fatigue before and after treatment, controlling for the CBT-interventions and the baseline levels of the outcome measures.

For the two groups receiving CBT, a 1-year follow-up analysis was also done. Bivariate and multivariable linear regression was used to explore the targeted associations.

Results: At baseline, less pain (p < .001) and higher VO2max (p = 0.014) were associated with better physical function, while better memory (p = 0.001) and fewer depressive symptoms (p = 0.017) were associated with less fatigue. Better memory and physical function at baseline (p = 0.015 and p < .001, respectively) and male gender (p = 0.003) were associated with higher physical function post-intervention.

Male gender (p = 0.010) was associated with higher physical function at 1-year follow-up. Fatigue severity at baseline was the only variable associated with follow up scores for fatigue (p < .001).

Conclusion: Our findings show that fatigue and physical function were associated with different types of characteristics at baseline, indicating a heterogeneity among CFS patients.

Source: Merethe Eide Gotaas, Tormod Landmark, Anne S. Helvik & Egil A. Fors (2023) Characteristics associated with physical functioning and fatigue in patients with chronic fatigue syndrome (CFS): secondary analyses of a randomized controlled trial, Fatigue: Biomedicine, Health & Behavior, DOI: 10.1080/21641846.2023.2175521 https://www.tandfonline.com/doi/full/10.1080/21641846.2023.2175521 (Full text)

Myopathy as a cause of Long COVID fatigue: Evidence from quantitative and single fiber EMG and muscle histopathology

Highlights:

• Myopathic changes in qEMG and/or increased jitter in sfEMG were seen in 63% of 84 patients with Long COVID neuromuscular symptoms.

• Low quality of life score correlated with higher mean jitter values in sfEMG but not with qEMG measures.

• Electron microscopy showed damage of terminal nerves and motor endplate.Abstract:

Objective: To describe neurophysiological abnormalities in Long COVID and correlate quantitative electromyography (qEMG) and single fiber EMG (sfEMG) results to clinical scores and histopathology.

Methods: 84 patients with non-improving musculoskeletal Long COVID symptoms were examined with qEMG and sfEMG. Muscle biopsies were taken in a subgroup.

Results: Mean motor unit potential (MUP) duration was decreased in ≥1 muscles in 52% of the patients. Mean jitter was increased in 17% of the patients in tibialis anterior and 25% in extensor digitorum communis. Increased jitter was seen with or without myopathic qEMG. Low quality of life score correlated with higher jitter values but not with qEMG measures. In addition to our previously published mitochondrial changes, inflammation, and capillary injury, we show now in muscle biopsies damage of terminal nerves and motor endplate with abundant basal lamina material. At the endplate, axons were present but no vesicle containing terminals. The post-synaptic cleft in areas appeared atrophic with short clefts and coarse crests.

Conclusions: Myopathic changes are common in Long COVID. sfEMG abnormality is less common but may correlate with clinical scores. sfEMG changes may be due to motor endplate pathology.

Significance: These findings may indicate a muscle pathophysiology behind fatigue in Long COVID.

Source: Jane Agergaard, Benjamin Yamin Ali Khan, Thomas Engell-Sørensen, Berit Schiøttz-Christensen, Lars Østergaard, Eva K. Hejbøl, Henrik D. Schrøder, Henning Andersen, Jakob Blicher, Thomas Holm Pedersen, Thomas Harbo, Hatice Tankisi,
Myopathy as a cause of Long COVID fatigue: Evidence from quantitative and single fiber EMG and muscle histopathology,
Clinical Neurophysiology, 2023, ISSN 1388-2457, https://doi.org/10.1016/j.clinph.2023.01.010.
https://www.sciencedirect.com/science/article/pii/S1388245723000196 (Full text)

Different risk factors distinguish myalgic encephalomyelitis/chronic fatigue syndrome from severe fatigue

Abstract:

Fatigue is a common reason that patients seek medical care. Only a fraction of these patients meet criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). To determine if ME/CFS is just a more extreme form of fatigue, or a qualitatively different condition, we assessed whether risk factors for ME/CFS and for Severe Fatigue were similar.

An email questionnaire that inquired about symptoms of Severe Fatigue and ME/CFS was completed by 41,802 US female nurses from whom detailed medical and lifestyle information had been collected since 1989: 102 met criteria for ME/CFS, 522 had Severe Fatigue, and 41,178 individuals were without significant chronic fatigue.

We used Cox proportional hazards regression to estimate the Hazard Ratio (HR) of Severe Fatigue and of ME/CFS with each of several potential risk factors, according to the level of exposure to each risk factor. The risk of Severe Fatigue was significantly increased among participants who were older, had a higher BMI in adulthood, used hormone therapy, had increased alcohol intake and decreased caffeine intake.

In contrast, these risk factor associations were not seen in people with ME/CFS. A self-reported past history of acute infectious mononucleosis was associated with a non-significantly increased Hazard Ratio of later ME/CFS (HR 1.77, 0.87–3.61) and, to a lesser extent, of Severe Fatigue (HR 1.28, 0.98–1.66). The different contribution of various risk factors to Severe Fatigue and ME/CFS suggests that ME/CFS has a qualitatively different underlying biology from the more common state of Severe Fatigue.

Source: Palacios, N., Molsberry, S., Fitzgerald, K.C. et al. Different risk factors distinguish myalgic encephalomyelitis/chronic fatigue syndrome from severe fatigue. Sci Rep 13, 2469 (2023). https://doi.org/10.1038/s41598-023-29329-x https://www.nature.com/articles/s41598-023-29329-x (Full text)