Genetics – Page 5 – American ME and CFS Society

Glucocorticoid receptor DNA methylation and childhood trauma in chronic fatigue syndrome patient

Abstract:

OBJECTIVE: Although the precise mechanisms are not yet understood, previous studies have suggested that chronic fatigue syndrome(CFS) is associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation and trauma in early childhood. Consistent with findings suggesting that early life stress-induced DNA methylation changes may underlie dysregulation of the HPA axis, we previously found evidence for the involvement of glucocorticoid receptor (GR) gene (NR3C1) methylation in whole blood of CFS patients.

METHODS: In the current study, we assessed NR3C1-1F region DNA methylation status in peripheral blood from a new and independent sample of 80 female CFS patients and 91 female controls. In CFS patients, history of childhood trauma subtypes was evaluated using the Childhood Trauma Questionnaire short form (CTQ-SF).

RESULTS: Although absolute methylation differences were small, the present study confirms our previous findings of NR3C1-1F DNA hypomethylation at several CpG sites in CFS patients as compared to controls. Following multiple testing correction, only CpG_8 remained significant (DNA methylation difference: 1.3% versus 1.5%, p<0.001). In addition, we found associations between DNA methylation and severity of fatigue as well as with childhood emotional abuse in CFS patients, although these findings were not significant after correction for multiple testing.

CONCLUSIONS: In conclusion, we replicated findings of NR3C1-1F DNA hypomethylation in CFS patients versus controls. Our results support the hypothesis of HPA axis dysregulation and enhanced GR sensitivity in CFS.

Source: Vangeel EB, Kempke S, Bakusic J, Godderis L, Luyten P, Van Heddegem L, Compernolle V, Persoons P, Lambrechts D, Izzi B, Freson K, Claes S. Glucocorticoid receptor DNA methylation and childhood trauma in chronic fatigue syndrome patients. J Psychosom Res. 2018 Jan;104:55-60. doi: 10.1016/j.jpsychores.2017.11.011. Epub 2017 Nov 20. https://www.ncbi.nlm.nih.gov/pubmed/29275786

Genome-Epigenome Interactions Associated with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Abstract:

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is an example of a complex disease of unknown etiology. Multiple studies point to disruptions in immune functioning in ME/CFS patients as well as with specific genetic polymorphisms and alterations of the DNA methylome in lymphocytes. However, the association between DNA methylation and genetic background in relation to the ME/CFS is currently unknown.

In this study we explored this association by characterizing the genomic (~4.3 million SNPs) and epigenomic (~480 thousand CpG loci) variability between populations of ME/CFS patients and healthy controls. We found significant associations of methylation states in T-lymphocytes at several CpG loci and regions with ME/CFS phenotype. These methylation anomalies are in close proximity to genes involved with immune function and cellular metabolism.

Finally, we found significant correlations of genotypes with methylation phenotypes associated with ME/CFS. The findings from this study highlight the role of epigenetic and genetic interactions in complex diseases, and suggest several genetic and epigenetic elements potentially involved in the mechanisms of disease in ME/CFS.

Source: Santiago Herrera, Wilfred C. de Vega, David Ashbrook, Suzanne D. Vernon, Patrick O. McGowan. Genome-Epigenome Interactions Associated with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. bioRxiv preprint first posted online Dec. 22, 2017; doi: http://dx.doi.org/10.1101/237958. (Full article)

The epigenetic landscape of myalgic encephalomyelitis/chronic fatigue syndrome: deciphering complex phenotypes

By their very nature, complex disease phenotypes are characterized by the dysregulation of multiple physiological systems, polygenic origins and various environmental triggers that result in patient populations with heterogeneous symptom profiles. Less than 10% of the heritability of complex phenotypes and disease traits are due to genetic variation, indicating that other factors play major roles in disease onset and progression [1]. Epigenetic modifications may partly account for this ‘missing heritability’ [2] through mechanisms that regulate transcriptional potential. These mechanisms appear to be, at least to some extent, responsive to environmental exposures or treatments. An improved understanding of the pathophysiology underlying complex phenotypes and new diagnostic tools can help refine and update classification criteria reliant on nonspecific or self-reported symptoms. Consequently, unraveling complex phenotypes depends to a large extent upon an ability to discriminate what are likely many distinct conditions. We and others have argued that epigenetic investigations integrate multiple levels of information (genetic, stochastic and environmental) to enable a better understanding of the dimensions of illness underlying complex phenotypes [2,3]. Here, we turn to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) to illustrate progress and future directions in this regard.

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Source: de Vega WC, McGowan PO. The epigenetic landscape of myalgic encephalomyelitis/chronic fatigue syndrome: deciphering complex phenotypes. Epigenomics. 2017 Nov;9(11):1337-1340. doi: 10.2217/epi-2017-0106. Epub 2017 Oct 18. https://www.futuremedicine.com/doi/full/10.2217/epi-2017-0106 (Full article)

New light shed on cause of chronic fatigue syndrome

New research findings may shed new light on the potential cause of Chronic Fatigue Syndrome/Myalgic Encephalomyelitis (CFS/ME).

Researchers from Griffith University’s National Centre for Neuroimmunology and Emerging Diseases (NCNED) — part of the new Menzies Health Institute Queensland — have uncovered significant factors contributing to the pathology of this illness.

The results reveal genetic changes in important receptors associated with immunological and cellular function and contribute to the development of this complex illness.

“These findings have been achieved through a team effort involving researchers, patients, funding bodies, clinicians and the support of Griffith University and the Queensland Government,” say chief investigators Professor Sonya Marshall-Gradisnik and Professor Donald Staines.

Co-researcher and consultant immunologist Professor Pete Smith said that important signalling mechanisms are disrupted as a result of these genetic changes involving the detection and response to threats.

“These are primitive genes that are involved in many cellular signals in the brain, gut, cardiovascular and immune systems, as well as in the mediation of pain.”

These research findings coincide with International Neuroimmune Awareness week commencing Monday 11 May.

The Griffith Health Centre on the university’s Gold Coast campus is being lit up each evening from 10 -12 May to raise awareness of neurological conditions such as CFS/ME as well as other conditions such as Fibromyalgia and Gulf War Syndrome.

“The lighting up of the Griffith Health Centre signifies Griffith’s commitment to the CFS patient community and our team approach to this research,” says Pro-Vice Chancellor (Health) Professor Allan Cripps.

CFS/ME is a highly debilitating disorder characterized by profound fatigue, muscle and joint pain, cerebral symptoms of impaired memory and concentration, impaired cardiovascular function, gut disorder and sensory dysfunction such as noise intolerance and balance disturbance. Many cases can continue for months or years. It is believed to affect around 250,000 Australians.

The research findings are to be presented at an international conference in London later this month.

Journal Reference: Sonya Marshall-Gradisnik, Donald Staines, Pete Smith, Bernd Nilius, Ekua Brenu, Sandra Ramos. Examination of Single Nucleotide Polymorphisms (SNPs) in Transient Receptor Potential (TRP) Ion Channels in Chronic Fatigue Syndrome Patients. Immunology and Immunogenetics Insights, 2015; 1 DOI: 10.4137/III.S25147

Source: Griffith University. “New light shed on cause of chronic fatigue syndrome.” ScienceDaily. ScienceDaily, 11 May 2015. https://www.sciencedaily.com/releases/2015/05/150511172755.htm

Chronic Fatigue: Clues In The Blood

Press Release: University of New South Wales, July 8, 2007. Researchers at UNSW believe that blood may hold vital insights into what is happening in the brain of patients with chronic fatigue syndrome (CFS).

In a study unparalleled in its scope, a team led by UNSW Professor Andrew Lloyd of the Centre for Infection and Inflammation Research, has studied the differences in gene expression patterns in the blood of people who either recover promptly after acute glandular fever or develop the prolonged illness called post-infective syndrome.

The researchers examined six million pieces of gene expression information for analysis in the project, known as the Dubbo Infection Outcomes Study. The study is named after the NSW town in which the work was conducted. The team studied the expression of 30,000 genes in the blood, testing each of the 15 individuals between four and five times over a 12-month period.

The team was able to narrow its findings to the expression of just 35 genes whose pattern of expression correlated closely with the key symptoms of the illness when examined from onset through to recovery. Gene expression is significant because it is the process by which a gene’s DNA sequence is converted into the proteins which ultimately determine the manifestations of disease.

Since 1999, the team has been tracking the long-term health of individuals infected with Ross River virus (RRV), Q fever infection and Epstein-Barr virus, which causes glandular fever.

“These [35] genes might point to the nature of the disease process that underlies CFS, which is currently unknown,” said Professor Lloyd, who is based in the School of Medical Sciences at UNSW. “None of them are ones that I would have predicted, except for those relating to neurotransmitters,” he concedes. “Some of them relate to transport of zinc and other metal ions within the cell, which may suggest a fundamental disturbance in cellular function.”

The researchers now hope to narrow the focus of research onto the expression of these 35 genes in the blood of a much larger group of subjects from the Dubbo Infection Outcomes Study, with varied patterns of illness and recovery.

“There are very few complex diseases which have been comprehensively analysed, with large scale and longitudinal studies, like this,” said Professor Lloyd. “It sets a standard for highly sophisticated, comprehensive gene expression studies in the blood of all sorts of human diseases from rheumatoid arthritis and multiple sclerosis through to schizophrenia.”

The research paper has been published in the Journal of Infectious Diseases.

Source: University of New South Wales. “Chronic Fatigue: Clues In The Blood.” ScienceDaily. ScienceDaily, 8 July 2007. https://www.sciencedaily.com/releases/2007/07/070706090020.htm

A systematic review of the association between fatigue and genetic polymorphisms

Abstract:

Fatigue is one of the most common and distressing symptoms, leading to markedly decreased quality of life among a large subset of patients with a variety of disorders. Susceptibility to fatigue may be influenced by genetic factors including single nucleotide polymorphisms (SNPs), especially in the regulatory regions, of relevant genes.

To further investigate the association of SNPs with fatigue in various patient populations, a systematic search was conducted on Pubmed, CINAHL, PsycINFO, and Sociological Abstracts Database for fatigue related-terms in combination with polymorphisms or genetic variation-related terms. Fifty papers in total met the inclusion and exclusion criteria for this analysis. These 50 papers were further classified into three subgroups for evaluation: chronic fatigue syndrome (CFS), cancer-related fatigue (CRF) and other disease-related fatigue.

SNPs in regulatory pathways of immune and neurotransmitter systems were found to play important roles in the etiologies of CFS, CRF and other disease-related fatigue. Evidence for associations between elevated fatigue and specific polymorphisms in TNFα, IL1b, IL4 and IL6 genes was revealed for all three subgroups of fatigue.

We also found CFS shared a series of polymorphisms in HLA, IFN-γ, 5-HT and NR3C1 genes with other disease-related fatigue, however these SNPs (excluding IFN-γ) were not found to be adequately investigated in CRF. Gaps in knowledge related to fatigue etiology and recommendations for future research are further discussed.

Source: Wang T, Yin J, Miller AH, Xiao C. A systematic review of the association between fatigue and genetic polymorphisms. Brain Behav Immun. 2017 Jan 12. pii: S0889-1591(17)30007-7. doi: 10.1016/j.bbi.2017.01.007. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/28089639

A targeted genome association study examining transient receptor potential ion channels, acetylcholine receptors, and adrenergic receptors in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Abstract:

BACKGROUND: Chronic Fatigue Syndrome, also known as Myalgic Encephalomyelitis (CFS/ME) is a debilitating condition of unknown aetiology. It is characterized by a range of physiological effects including neurological, sensory and motor disturbances. This study examined candidate genes for the above clinical manifestations to identify single nucleotide polymorphism (SNP) alleles associated with CFS/ME compared with healthy controls.

METHODS: DNA was extracted and whole genome genotyping was performed using the HumanOmniExpress BeadChip array. Gene families for transient receptor potential ion channels, acetylcholine receptors, and adrenergic receptors, and acetylcholinesterase were targeted. The frequency of each SNP and their association between CFS/ME and healthy controls was examined using Fisher’s exact test, and to adjust for multiple testing, False Detection Rate (FDR) and Bonferroni corrections were applied (p < 0.05).

RESULTS: The study included 172 participants, consisting of 95 Fukuda defined CFS/ME patients (45.8 ± 8.9; 69 % female) and 77 healthy controls (42.3 ± 10.3; 63 % female). A total of 950 SNPs were included for analysis. 60 significant SNPs were associated with CFS/ME compared with healthy controls. After applying FDR and Bonferroni corrections, SNP rs2322333 in adrenergic receptor α1 (ADRA1A) was higher in CFS/ME compared with healthy controls (45.3 % vs. 23.4 %; p = 0.059). The genotype class that was homozygous minor (AA) was substantially lower in CFS/ME compared with healthy controls (4.2 % vs. 24.7 %).

CONCLUSIONS: This study reports for the first time the identification of ADRA1A and a possible association between CFS/ME and genotype classes. Further examination of the functional role of this class of adrenergic receptors may elucidate the cause of particular clinical manifestations observed in CFS/ME

Source: Johnston S, Staines D, Klein A, Marshall-Gradisnik S. A targeted genome association study examining transient receptor potential ion channels, acetylcholine receptors, and adrenergic receptors in Chronic Fatigue Syndrome/Myalgic Encephalomyelitis. BMC Med Genet. 2016 Nov 11;17(1):79. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5105265/ (Full article)

Single nucleotide polymorphisms and genotypes of transient receptor potential ion channel and acetylcholine receptor genes from isolated B lymphocytes in myalgic encephalomyelitis/chronic fatigue syndrome patients

Abstract:

OBJECTIVE: The pathomechanism of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is unknown; however, a small subgroup of patients has shown muscarinic antibody positivity and reduced symptom presentation following anti-CD20 intervention. Given the important roles of calcium (Ca2+) and acetylcholine (ACh) signalling in B cell activation and potential antibody development, we aimed to identify relevant single nucleotide polymorphisms (SNPs) and genotypes in isolated B cells from CFS/ME patients.

METHODS: A total of 11 CFS/ME patients (aged 31.82 ± 5.50 years) and 11 non-fatigued controls (aged 33.91 ± 5.06 years) were included. Flow cytometric protocols were used to determine B cell purity, followed by SNP and genotype analysis for 21 mammalian TRP ion channel genes and nine mammalian ACh receptor genes. SNP association and genotyping analysis were performed using ANOVA and PLINK analysis software.

RESULTS: Seventy-eight SNPs were identified in nicotinic and muscarinic acetylcholine receptor genes in the CFS/ME group, of which 35 were in mAChM3. The remaining SNPs were identified in nAChR delta (n = 12), nAChR alpha 9 (n = 5), TRPV2 (n = 7), TRPM3 (n = 4), TRPM4 (n = 1) mAChRM3 2 (n = 2), and mAChRM5 (n = 3) genes. Nine genotypes were identified from SNPs in TRPM3 (n = 1), TRPC6 (n = 1), mAChRM3 (n = 2), nAChR alpha 4 (n = 1), and nAChR beta 1 (n = 4) genes, and were located in introns and 3′ untranslated regions. Odds ratios for these specific genotypes ranged between 7.11 and 26.67 for CFS/ME compared with the non-fatigued control group.

CONCLUSION: This preliminary investigation identified a number of SNPs and genotypes in genes encoding TRP ion channels and AChRs from B cells in patients with CFS/ME. These may be involved in B cell functional changes, and suggest a role for Ca2+ dysregulation in AChR and TRP ion channel signalling in the pathomechanism of CFS/ME.

Source: Marshall-Gradisnik S, Johnston S, Chacko A, Nguyen T, Smith P, Staines D. Single nucleotide polymorphisms and genotypes of transient receptor potential ion channel and acetylcholine receptor genes from isolated B lymphocytes in myalgic encephalomyelitis/chronic fatigue syndrome patients. J Int Med Res. 2016 Nov 10. pii: 0300060516671622. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/27834303

Gene Expression in Response to Exercise in Patients with Chronic Fatigue Syndrome: A Pilot Study

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating disorder of unknown pathogenesis, characterized by fatigue, which is exacerbated after minimal exercise. We examined the effect of a single bout of aerobic exercise on leucocyte mRNA expression of genes putatively linked to exaggerated afferent signaling as an under-pinning of the fatigue state.

A carefully-characterized sample of patients with CFS (N = 10) and healthy matched control participants (N = 12) were included. Participant ratings of fatigue and other symptoms, as well as blood samples, were obtained at baseline, and five other time-points up to 72 h after 25 min of moderate-intensity cycling exercise. Leucocyte mRNA of 19 metabolite-sensing, adrenergic, immune, and neurotransmission genes was examined using quantitative polymerase chain reaction.

Patients with CFS reported substantial fatigue, functional impairment, and poor sleep at baseline (all p < 0.02), and exercise immediately induced worsened patients’ fatigue (effect size, ES = 1.17).

There were no significant changes in gene expression after exercise and patients did not differ from control participants at any time point. Higher levels of expression of ficolin (FCN1) and a purinergic receptor (P2RX4) in patients with CFS were found when all time points were combined. Patients with CFS did not show significant exercise-induced changes in leucocyte mRNA of 19 metabolite-sensing, adrenergic, immune and neurotransmission genes despite a prominent exacerbation of fatigue.

Source: Keech A, Vollmer-Conna U, Barry BK, Lloyd AR. Gene Expression in Response to Exercise in Patients with Chronic Fatigue Syndrome: A Pilot Study. Front Physiol. 2016 Sep 22;7:421. eCollection 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5031769/ (Full article)

Dysregulation of Protein Kinase Gene Expression in NK Cells from Chronic Fatigue Syndrome/Myalgic Encephalomyelitis Patients

Abstract:

BACKGROUND: The etiology and pathomechanism of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) are unknown. However, natural killer (NK) cell dysfunction, in particular reduced NK cytotoxic activity, is a consistent finding in CFS/ME patients. Previous research has reported significant changes in intracellular mitogen-activated protein kinase pathways from isolated NK cells. The purpose of this present investigation was to examine whether protein kinase genes have a role in abnormal NK cell intracellular signaling in CFS/ME.

METHOD: Messenger RNA (mRNA) expression of 528 protein kinase genes in isolated NK cells was analyzed (nCounter GX Human Kinase Kit v2 (XT); NanoString Technologies) from moderate (n = 11; age, 54.9 ± 10.3 years) and severe (n = 12; age, 47.5 ± 8.0 years) CFS/ME patients (classified by the 2011 International Consensus Criteria) and nonfatigued controls (n = 11; age, 50.0 ± 12.3 years).

RESULTS: The expression of 92 protein kinase genes was significantly different in the severe CFS/ME group compared with nonfatigued controls. Among these, 37 genes were significantly upregulated and 55 genes were significantly downregulated in severe CFS/ME patients compared with nonfatigued controls.

CONCLUSIONS: In severe CFS/ME patients, dysfunction in protein kinase genes may contribute to impairments in NK cell intracellular signaling and effector function. Similar changes in protein kinase genes may be present in other cells, potentially contributing to the pathomechanism of this illness.

Source: Chacko A, Staines DR, Johnston SC, Marshall-Gradisnik SM. Dysregulation of Protein Kinase Gene Expression in NK Cells from Chronic Fatigue Syndrome/Myalgic Encephalomyelitis Patients. Gene Regul Syst Bio. 2016 Aug 28;10:85-93. doi: 10.4137/GRSB.S40036. ECollection 2016. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5003121/ (Full article)