Induced pluripotent stem cells as suitable sensors for fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Background: Fibromyalgia (FM) and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are devastating metabolic neuroimmune diseases that are difficult to diagnose because of the presence of numerous symptoms and a lack of specific biomarkers. Despite patient heterogeneity linked to patient subgroups and variation in disease severity, anomalies are found in the blood and plasma of these patients when compared with healthy control groups. The seeming specificity of these “plasma factors”, as recently reported by Ron Davis and his group at Stanford University, CA, United States, and observations by our group, have led to the proposal that induced pluripotent stem cells (iPSCs) may be used as metabolic sensors for FM and ME/CFS, a hypothesis that is the basis for this in-depth review.

Aim: To identify metabolic signatures in FM and/or ME/CFS supporting the existence of disease-associated plasma factors to be sensed by iPSCs.

Methods: A PRISMA (Preferred Reported Items for Systematic Reviews and Meta-analysis)-based systematic review of the literature was used to select original studies evaluating the metabolite profiles of FM and ME/CFS body fluids. The MeSH terms “metabolomic” or “metabolites” in combination with FM and ME/CFS disease terms were screened against the PubMed database. Only original studies applying omics technologies, published in English, were included. The data obtained were tabulated according to the disease and type of body fluid analyzed. Coincidences across studies were searched and P-values reported by the original studies were gathered to document significant differences found in the disease groups.

Results: Eighteen previous studies show that some metabolites are commonly altered in ME/CFS and FM body fluids. In vitro cell-based assays have the potential to be developed as screening platforms, providing evidence for the existence of factors in patient body fluids capable of altering morphology, differentiation state and/or growth patterns. Moreover, they can be further developed using approaches aimed at blocking or reversing the effects of specific plasma/serum factors seen in patients. The documented high sensitivity and effective responses of iPSCs to environmental cues suggests that these pluripotent cells could form robust, reproducible reporter systems of metabolic diseases, including ME/CFS and FM. Furthermore, culturing iPSCs, or their mesenchymal stem cell counterparts, in patient-conditioned medium may provide valuable information to predict individual outcomes to stem-cell therapy in the context of precision medicine studies.

Conclusion: This opinion review explains our hypothesis that iPSCs could be developed as a screening platform to provide evidence of a metabolic imbalance in FM and ME/CFS.

Source: Monzón-Nomdedeu MB, Morten KJ, Oltra E. Induced pluripotent stem cells as suitable sensors for fibromyalgia and myalgic encephalomyelitis/chronic fatigue syndrome. World J Stem Cells. 2021 Aug 26;13(8):1134-1150. doi: 10.4252/wjsc.v13.i8.1134. PMID: 34567431; PMCID: PMC8422931. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8422931/ (Full article)

A map of metabolic phenotypes in patients with myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating disease usually presenting after infection. Emerging evidence supports that energy metabolism is affected in ME/CFS, but a unifying metabolic phenotype has not been firmly established. We performed global metabolomics, lipidomics, and hormone measurements, and we used exploratory data analyses to compare serum from 83 patients with ME/CFS and 35 healthy controls.

Some changes were common in the patient group, and these were compatible with effects of elevated energy strain and altered utilization of fatty acids and amino acids as catabolic fuels. In addition, a set of heterogeneous effects reflected specific changes in 3 subsets of patients, and 2 of these expressed characteristic contexts of deregulated energy metabolism. The biological relevance of these metabolic phenotypes (metabotypes) was supported by clinical data and independent blood analyses.

In summary, we report a map of common and context-dependent metabolic changes in ME/CFS, and some of them presented possible associations with clinical patient profiles. We suggest that elevated energy strain may result from exertion-triggered tissue hypoxia and lead to systemic metabolic adaptation and compensation. Through various mechanisms, such metabolic dysfunction represents a likely mediator of key symptoms in ME/CFS and possibly a target for supportive intervention.

Source: Hoel F, Hoel A, Pettersen IK, Rekeland IG, Risa K, Alme K, Sørland K, Fosså A, Lien K, Herder I, Thürmer HL, Gotaas ME, Schäfer C, Berge RK, Sommerfelt K, Marti HP, Dahl O, Mella O, Fluge Ø, Tronstad KJ. A map of metabolic phenotypes in patients with myalgic encephalomyelitis/chronic fatigue syndrome. JCI Insight. 2021 Aug 23;6(16):149217. doi: 10.1172/jci.insight.149217. PMID: 34423789. https://pubmed.ncbi.nlm.nih.gov/34423789/

Insights into Metabolite Diagnostic Biomarkers for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a persistent and unexplained pathological state characterized by exertional and severely debilitating fatigue, with/without infectious or neuropsychiatric symptoms, and with a minimum duration of 6 consecutive months. Its pathogenesis is not fully understood. There are no firmly established diagnostic biomarkers or treatment, due to incomplete understanding of the etiology of ME/CFS and diagnostic uncertainty. Establishing a biomarker for the objective diagnosis is urgently needed to treat a lot of patients. Recently, research on ME/CFS using metabolome analysis methods has been increasing. Here, we overview recent findings concerning the metabolic features in patients with ME/CFS and the animal models which contribute to the development of diagnostic biomarkers for ME/CFS and its treatment. In addition, we discuss future perspectives of studies on ME/CFS.

Source: Yamano E, Watanabe Y, Kataoka Y. Insights into Metabolite Diagnostic Biomarkers for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Int J Mol Sci. 2021 Mar 26;22(7):3423. doi: 10.3390/ijms22073423. PMID: 33810365. https://pubmed.ncbi.nlm.nih.gov/33810365/

Metabolic abnormalities in chronic fatigue syndrome/myalgic encephalomyelitis: a mini-review

Abstract:

Chronic fatigue syndrome (CFS), commonly known as myalgic encephalomyelitis (ME), is a debilitating disease of unknown etiology. CFS/ME is a heterogeneous disease associated with a myriad of symptoms but with severe, prolonged fatigue as the core symptom associated with the disease. There are currently no known biomarkers for the disease, largely due to the lack of knowledge surrounding the eitopathogenesis of CFS/ME. Numerous studies have been conducted in an attempt to identify potential biomarkers for the disease.

This mini-review offers a brief summary of current research into the identification of metabolic abnormalities in CFS/ME which may represent potential biomarkers for the disease. The progress of research into key areas including immune dysregulation, mitochondrial dysfunction, 5′-adenosine monophosphate-activated protein kinase activation, skeletal muscle cell acidosis, and metabolomics are presented here. Studies outlined in this mini-review show many potential causes for the pathogenesis of CFS/ME and identify many potential metabolic biomarkers for the disease from the aforementioned research areas.

The future of CFS/ME research should focus on building on the potential biomarkers for the disease using multi-disciplinary techniques at multiple research sites in order to produce robust data sets. Whether the metabolic changes identified in this mini-review occur as a cause or a consequence of the disease must also be established.

Source: Cara Tomas; Julia Newton. Metabolic abnormalities in chronic fatigue syndrome/myalgic encephalomyelitis: a mini-review. Biochemical Society Transactions Apr 17, 2018; DOI: https://doi.org/10.1042/BST20170503. http://www.biochemsoctrans.org/content/early/2018/04/16/BST20170503

Characteristic chemical signature for chronic fatigue syndrome identified

Chronic fatigue syndrome (CFS) is a mysterious and maddening condition, with no cure or known cause. But researchers at the University of California San Diego School of Medicine, using a variety of techniques to identify and assess targeted metabolites in blood plasma, have identified a characteristic chemical signature for the debilitating ailment and an unexpected underlying biology: It is similar to the state of dauer, and other hypometabolic syndromes like caloric restriction, diapause and hibernation.

Dauer is the German word for persistence or long-lived. It is a type of stasis in the development in some invertebrates that is prompted by harsh environmental conditions. The findings are published online in the August 29 issue of PNAS.

“CFS is a very challenging disease,” said first author Robert K. Naviaux, MD, PhD, professor of medicine, pediatrics and pathology and director of the Mitochondrial and Metabolic Disease Center at UC San Diego School of Medicine. “It affects multiple systems of the body. Symptoms vary and are common to many other diseases. There is no diagnostic laboratory test. Patients may spend tens of thousands of dollars and years trying to get a correct diagnosis.”

As many as 2.5 million Americans are believed to have CFS. It most often afflicts women in their 30s to 50s, though both genders and all ages can be affected. The primary symptom is severe fatigue lasting at least six months, with corollary symptoms ranging from muscle pain and headaches to sleep and memory problems.

Naviaux and colleagues studied 84 subjects: 45 men and women who met the diagnostic criteria for CFS and 39 matched controls. The researchers targeted 612 metabolites (substances produced by the processes of metabolism) from 63 biochemical pathways in blood plasma. They found that individuals with CFS showed abnormalities in 20 metabolic pathways. Eighty percent of the diagnostic metabolites measured were decreased, consistent with hypometabolic syndrome or reduced metabolism. The diagnostic accuracy rate exceeded 90 percent.

“Despite the heterogeneity of CFS, the diversity of factors that lead to this condition, our findings show that the cellular metabolic response is the same in patients,” said Naviaux. “And interestingly, it’s chemically similar to the dauer state you see in some organisms, which kicks in when environmental stresses trigger a slow-down in metabolism to permit survival under conditions that might otherwise cause cell death. In CFS, this slow-down comes at the cost of long-term pain and disability.”

Naviaux said the findings show that CFS possesses an objectively identifiable chemical signature in both men and women and that targeted metabolomics, which provide direct small molecule information, can provide actionable treatment information. Only 25 percent of the metabolite disturbances found in each person were needed for the diagnosis of CFS. Roughly 75 percent of abnormalities were unique to each individual, which Naviaux said is useful in guiding personalized treatment.

“This work opens a fresh path to both understanding the biology of CFS and, more importantly to patients, a robust, rational way to develop new therapeutics for a disease sorely in need of them.”

The study authors noted additional research using larger groups of participants from diverse geographical areas is needed to validate both the universality and specificity of the findings.

 

Journal Reference: Robert K. Naviaux, Jane C. Naviaux, Kefeng Li, A. Taylor Bright, William A. Alaynick, Lin Wang, Asha Baxter, Neil Nathan, Wayne Anderson, Eric Gordon. Metabolic features of chronic fatigue syndrome. Proceedings of the National Academy of Sciences, 2016; 201607571 DOI: 10.1073/pnas.1607571113

 

Source: University of California – San Diego. “Characteristic chemical signature for chronic fatigue syndrome identified: Discovery, along with revealed underlying biology, could lead to faster, more accurate diagnoses and more effective, personalized therapies.” ScienceDaily. ScienceDaily, 29 August 2016. https://www.sciencedaily.com/releases/2016/08/160829163253.htm