Association between fibromyalgia syndrome and polymorphism of the IL-4 gene in a Turkish population

The immunomodulatory effects of ethosuximide and sodium butyrate on experimentally induced fibromyalgia: The interaction between IL-4, synaptophysin, and TGF-β1/NF-κB signaling

BACKGROUND AND AIMS

Fibromyalgia is a widespread chronic pain syndrome associated with several comorbid conditions that affect the quality of patients' life. Its pathogenesis is complex, and the treatment strategies are limited by partial efficacy and potential adverse effects. So, our aim was to investigate the possible ameliorative effects of ethosuximide and sodium butyrate on fibromyalgia and compare their effects to pregabalin.

MATERIALS AND METHODS

In a mouse model of reserpine induced fibromyalgia, the effect of ethosuximide, sodium butyrate, and pregabalin was investigated. Evaluation of mechanical allodynia, cold hypersensitivity, anxiety, cognitive impairment, and depression was performed. Also, the brain and spinal cord tissue serotonin, dopamine and glutamate in addition to the serum levels of interleukin (IL)-4 and transforming growth factor beta 1 (TGF-β1) were assayed. Moreover, the expression of nuclear factor kappa B (NF-κB) synaptophysin was immunoassayed in the hippocampal tissues.

KEY FINDINGS

Ethosuximide and sodium butyrate restored the behavioral tests to the normal values except for the antidepressant effect which was evident only with ethosuximide. Both drugs elevated the levels of the anti-inflammatory cytokines IL-4 and TGF-β1, reduced the hippocampal NF-κB, and increased synaptophysin expression with superiority of sodium butyrate. Ethosuximide reduced only spinal cord and brain glutamate while improved brain dopamine while sodium butyrate elevated spinal cord dopamine and serotonin with no effect on glutamate. Also, sodium butyrate elevated brain serotonin and reduced glutamate with no effect on brain dopamine.

SIGNIFICANCE

Each of sodium butyrate and ethosuximide would serve as a promising therapeutic modality for management of fibromyalgia and its comorbid conditions.

A Comprehensive Review of the Genetic and Epigenetic Contributions to the Development of Fibromyalgia

This narrative review summarizes the current knowledge of the genetic and epigenetic contributions to the development of fibromyalgia (FM). Although there is no single gene that results in the development of FM, this study reveals that certain polymorphisms in genes involved in the catecholaminergic pathway, the serotonergic pathway, pain processing, oxidative stress, and inflammation may influence susceptibility to FM and the severity of its symptoms. Furthermore, epigenetic changes at the DNA level may lead to the development of FM. Likewise, microRNAs may impact the expression of certain proteins that lead to the worsening of FM-associated symptoms.

Fibromyalgia: A Review of Related Polymorphisms and Clinical Relevance

Fibromyalgia (FM) is a chronic pain syndrome that affects the central nervous system and generates disability, which is characterized by generalized pain, fatigue, and functional decline. In this review, we aimed to identify the polymorphisms related to the pathophysiology of FM and the clinical characteristics generated by genetic influence. Only original studies with genes related to FM were considered, totaling 27 articles. The genes found were: MTHFR, RGS4, MYT1L, TACR1, SCN9A, DRD3, ADRB2, IL-4, HLA-DRB1, EDN1, CNR1, TAAR1, OPRM1, ADRA1A, ADRB3, BDNF, GRIA4, HTR3A, HTR3B, HTR2A, SERPINA 1 or A1AT, NRXN3, GCH1, MEFV, TRPV3, SLC6A4, ACE I/D, TSPO, COMT, and MAOA. Several genes related to different pain syndromes and altered pain thresholds have been identified and some polymorphisms were related to susceptibility to FM. It was observed that 73.33% of the genes related to FM were also associated with some psychological disorders, such as anxiety, depression, schizophrenia, and obsessive and compulsive disorder, and 40.00% with pain sensitivity and/or migraine, besides other disorders associated (drug addiction, autoimmune disorders, circulatory problems, and metabolic alterations). This review demonstrated an association of FM and genetic polymorphisms that can expand our knowledge about the pathophysiology of this disease.

Serum IL 4 and its gene polymorphism (rs79071878) in Egyptian children with familial Mediterranean fever

Familial Mediterranean fever (FMF) is an autoinflammatory disorder. It is caused by mutations in the MEFV gene encoding the pyrin protein, which regulates the innate inflammatory response. The aim of the current study was to investigate the relationship between serum Interleukin-4 (IL-4) and its gene polymorphism, namely rs79071878, and FMF occurrence, severity, and response to treatment in Egyptian children harboring the disease. Fifty Egyptian children diagnosed as having FMF were included in this study. They were divided equally into two groups according to disease activity. Forty controls, age- and gender-matched, were also included. Serum IL-4 levels were measured by enzyme-linked immunosorbent assay (ELISA). The IL-4 rs79071878 polymorphism was determined by polymerase chain reaction (PCR) analysis. There was no significant difference in genotype distribution of IL-4 gene rs79071878 between patients and controls (p = 0.286) and had no correlation with FMF severity or response to colchicine therapy. Serum IL-4 level had no significant difference between children with FMF attack and those in attack-free period compared to controls (p = 0. 794) and had no correlation with any of demographic, or clinical characteristics, disease severity, or response to colchicine therapy. Serum IL-4 level and its gene polymorphism were not found to have any increase risk of FMF occurrence, disease severity, or response to treatment in the Egyptian children. Further studies are needed to verify these results.

Ambroxol for the treatment of fibromyalgia: science or fiction?

Fibromyalgia appears to present in subgroups with regard to biological pain induction, with primarily inflammatory, neuropathic/neurodegenerative, sympathetic, oxidative, nitrosative, or muscular factors and/or central sensitization. Recent research has also discussed glial activation or interrupted dopaminergic neurotransmission, as well as increased skin mast cells and mitochondrial dysfunction. Therapy is difficult, and the treatment options used so far mostly just have the potential to address only one of these aspects. As ambroxol addresses all of them in a single substance and furthermore also reduces visceral hypersensitivity, in fibromyalgia existing as irritable bowel syndrome or chronic bladder pain, it should be systematically investigated for this purpose. Encouraged by first clinical observations of two working groups using topical or oral ambroxol for fibromyalgia treatments, the present paper outlines the scientific argument for this approach by looking at each of the aforementioned aspects of this complex disease and summarizes putative modes of action of ambroxol. Nevertheless, at this point the evidence basis for ambroxol is not strong enough for clinical recommendation.

The effect of IL-4 and MTHFR gene variants in ankylosing spondylitis

PURPOSE

Ankylosing Spondylitis (AS) is a chronic inflammatory rheumatic disease that characteristically affects the sacroiliac joints and the spine. The exact pathogenesis of AS remains poorly understood, but genetic factors play a key role in disease development. Several genes have been consistently associated with susceptibility to AS. This study was conducted in Turkish AS patients to determine the frequency of the methylenetetrahydrofolate reductase (MTHFR) gene C677T and interleukin-4 (IL-4) gene 70 bp variable number of tandem repeats (VNTR) variants, as well as their association with clinical characteristics.

METHODS

Genomic DNA obtained from 272 persons (122 AS patients and 150 healthy controls) was used in this study. Genomic DNA was isolated and genotyped using a polymerase chain reaction (PCR)-based restriction fragment length polymorphism (RFLP) assay for the MTHFR C677T and IL-4 70 bp VNTR gene variants, which were determined using specific PCR primers.

RESULTS

There was statistically significant difference between the groups with respect to MTHFR genotype distribution (p = 0.02) and allele frequencies (p < 0.001). When we examined MTHFR and IL-4 genotype frequencies according to clinical characteristics, we found an association between the homozygous MTHFR TT genotype and ocular involvement, although this did not reach statistical significance (p = 0.02). However, we did not find any difference between the groups with respect to IL-4 genotype distribution or allele frequencies and clinical characteristics (p > 0.05).

CONCLUSION

Our findings suggest that there is an association of the MTHFR gene C677T polymorphism with the susceptibility of a person for development of AS. However, the IL-4 gene is not associated with AS within the same population.

Angiotensin converting enzyme and methylenetetrahydrofolate reductase gene variations in fibromyalgia syndrome

OBJECTIVE

Fibromyalgia syndrome (FM) is a common disease characterized by generalized body pain, sensitivity in certain physical areas (sensitive points), lowered pain threshold, sleep disorder, and fatigue. The study aimed to determine the effects ACE I/D and MTHFR C677T gene polymorphisms in Turkish patients with FM and evaluate if there was an association with clinical features.

METHODS

This study included 200 FM patients and 190 healthy controls recruited from the department of Physical Medicine and Rehabilitation at Gaziosmanpasa University in Tokat, Turkey. ACE I/D polymorphism genotypes were determined by using polymerase chain reaction (PCR) by specific primers. The MTHFR C677T mutation was analyzed by PCR-based restriction fragment length polymorphism (RFLP) methods.

RESULTS

We found a statistically significant relation between ACE polymorphism and FM (p<0.001, OR: 1.71, 95% CI: 1.28-2.27). However, this was not the case for ACE polymorphism and the clinical characteristics of the disease. There was also no statistically significant relation between MTHFR C677T mutation and FMS (p>0.05, OR: 1.20, 95% CI: 0.82-1.78), but dry eye and feeling of stiffness which are among the clinical characteristics of FMS were significantly related with MTHFR C677T mutation (p<0.05).

CONCLUSION

Our findings showed that there are associations of ACE I/D polymorphism with susceptibility of a person for development of fibromyalgia syndrome. Also, it is determined an association between MTHFR C677T polymorphism and feeling of stiffness and dry eye which are among the clinical characteristics of FM. Our study is the first report of ACE I/D and MTHFR C677T polymorphisms in fibromyalgia syndrome.

Juvenile fibromyalgia: current status of research and future developments

Juvenile-onset fibromyalgia (JFM) is a poorly understood chronic pain condition most commonly affecting adolescent girls. The condition is characterized by widespread musculoskeletal pain and other associated symptoms, including fatigue, nonrestorative sleep, headaches, irritable bowel symptoms, dysautonomia and mood disorders such as anxiety and/or depression. In the past few years, there has been a greater focus on understanding JFM in adolescents. Research studies have provided insight into the clinical characteristics of this condition and its effect on both short-term and long-term psychosocial and physical functioning. The importance of early and effective intervention is being recognized, as research has shown that symptoms of JFM tend to persist and do not resolve over time as was previously believed. Efforts to improve treatments for JFM are underway, and new evidence strongly points to the potential benefits of cognitive-behavioural therapy on improving mood and daily functioning. Research into pharmacotherapy and other nonpharmacological options is in progress. Advancements in the understanding of adult fibromyalgia have paved the way for future studies on diagnosis, assessment and management of JFM. This Review focuses on our current knowledge of the condition, provides an update of the latest research advances, and highlights areas for further study.

Fibromyalgia and cytokines

Fibromyalgia is a common chronic pain syndrome characterized by widespread pains and characteristic somatic symptoms. Current evidence suggests that cytokines and especially chemokines may have a role in the pathogenesis of this syndrome. Cytokines are small soluble factors that work as immune system messengers. They can be classified as pro-inflammatory and anti-inflammatory cytokines. Chemokines are a special kind of pro-inflammatory cytokines that guide the movement of circulating mononuclear cells to the injured side. Some pro-inflammatory cytokine levels (i.e. IL-1RA, IL-6, and IL-8) and, recently, some chemokines' levels have been found to be increased in patients with fibromyalgia. Thus, herein we review the current knowledge regarding the role of cytokines in fibromyalgia patients and their possible clinical relevance.