Missense Mutations in the MEFV Gene Are Associated with Fibromyalgia Syndrome and Correlate with Elevated IL-1β Plasma Levels

Background

Fibromyalgia syndrome (FMS), a common, chronic, widespread musculoskeletal pain disorder found in 2% of the general population and with a preponderance of 85% in females, has both genetic and environmental contributions. Patients and their parents have high plasma levels of the chemokines MCP-1 and eotaxin, providing evidence for both a genetic and an immunological/inflammatory origin for the syndrome (Zhang et al., 2008, Exp. Biol. Med. 233: 1171–1180).

Methods and Findings

In a search for a candidate gene affecting inflammatory pathways, among five screened in our patient samples (100 probands with FMS and their parents), we found 10 rare and one common alleles for MEFV, a gene in which various compound heterozygous mutations lead to Familial Mediterranean Fever (FMF). A total of 2.63 megabases of genomic sequence of the MEFV gene were scanned by direct sequencing. The collection of rare missense mutations (all heterozygotes and tested in the aggregate) had a significant elevated frequency of transmission to affecteds (p = 0.0085, one-sided, exact binomial test). Our data provide evidence that rare missense variants of the MEFV gene are, collectively, associated with risk of FMS and are present in a subset of 15% of FMS patients. This subset had, on average, high levels of plasma IL-1β (p = 0.019) compared to FMS patients without rare variants, unaffected family members with or without rare variants, and unrelated controls of unknown genotype. IL-1β is a cytokine associated with the function of the MEFV gene and thought to be responsible for its symptoms of fever and muscle aches.

Conclusions

Since misregulation of IL-1β expression has been predicted for patients with mutations in the MEFV gene, we conclude that patients heterozygous for rare missense variants of this gene may be predisposed to FMS, possibly triggered by environmental factors.     

The Effect of (-)-Epigallocatechin-3-Gallate on IL-1β Induced IL-8 Expression in Orbital Fibroblast from Patients with Thyroid-Associated Ophthalmopathy

Orbital fibroblasts have been reported to be an important effector cells for the development of thyroid-associated ophthalmopathy (TAO). Orbital fibroblasts secrete various inflammatory cytokines in response to an inflammatory stimulation, leading to TAO-related tissue swelling. It has also been reported that (-)-epigallocatechin-3-gallate (EGCG), a major polyphenolic constituent of green tea, has antioxidant and anti-inflammatory properties. In the current study, we investigated the issue of whether or how EGCG affects the interleukin (IL)-1β-induced secretion of IL-8 in human orbital fibroblasts from TAO patients. Treatment with EGCG significantly reduced the level of IL-1β-induced secretion of IL-8 and the expression of IL-8 mRNA. IL-1β-induced the degradation of IκBα, and the phosphorylation of p38 and ERK, and the IL-1β-induced expression of IL-8 mRNA was inhibited by specific inhibitors, such as BAY-117085 for NF-kB, SB203580 for p38, and PD98059 for ERK. In addition, treatment with EGCG inhibited the IL-1β-induced degradation of IκBα, and the phosphorylation of p38 and ERK. However, pre-treatment with antioxidants, NVN and NAC, which suppressed ROS generation, did not reduce IL-8 expression in IL-1β-treated orbital fibroblasts, suggesting that the IL-1β-induced IL-8 expression is not mediated by the generation of ROS. These results show that EGCG suppresses the IL-1β-induced expression of IL-8 through inhibition of the NF-κB, p38, and ERK pathways. These findings could contribute to the development of new types of EGCG-containing pharmacological agents for use in the treatment of TAO.     

Prion Protein Is Decreased in Alzheimer's Brain and Inversely Correlates with BACE1 Activity,Amyloid-β Levels and Braak Stage

The cellular prion protein (PrP^C) has been implicated in the development of Alzheimer''s disease (AD). PrP^C decreases amyloid-β (Aβ) production, which is involved in AD pathogenesis, by inhibiting β-secretase (BACE1) activity. Contactin 5 (CNTN5) has also been implicated in the development of AD by a genome-wide association study. Here we measured PrP^C and CNTN5 in frontal cortex samples from 24 sporadic AD and 24 age-matched control brains and correlated the expression of these proteins with markers of AD. PrP^C was decreased in sporadic AD compared to controls (by 49%, p = 0.014) but there was no difference in CNTN5 between sporadic AD and controls (p = 0.217). PrP^C significantly inversely correlated with BACE1 activity (r_s = −0.358, p = 0.006), Aβ load (r_s = −0.456, p = 0.001), soluble Aβ (r_s = −0.283, p = 0.026) and insoluble Aβ (r_s = −0.353, p = 0.007) and PrP^C also significantly inversely correlated with the stage of disease, as indicated by Braak tangle stage (r_s = −0.377, p = 0.007). CNTN5 did not correlate with Aβ load (r_s = 0.040, p = 0.393), soluble Aβ (r_s = 0.113, p = 0.223) or insoluble Aβ (r_s = 0.169, p = 0.125). PrP^C was also measured in frontal cortex samples from 9 Down''s syndrome (DS) and 8 age-matched control brains. In contrast to sporadic AD, there was no difference in PrP^C in the DS brains compared to controls (p = 0.625). These data are consistent with a role for PrP^C in regulating Aβ production and indicate that brain PrP^C level may be important in influencing the onset and progression of sporadic AD.     

Effect of Interleukin-1β on Gene Expression Signatures in Schwann Cells Associated with Neuropathic Pain

Neurochemical Research - Interleukin-1β (IL-1β) plays a critical role in the development of neuropathic pain through activation of Schwann cells (SCs) after nerve injury. Here, we applied...     

Chronic Exposure to High Levels of Zinc or Copper has Little Effect on Brain Metal Homeostasis or Aβ Accumulation in Transgenic APP-C100 Mice

Aberrant metal homeostasis may enhance the formation of reactive oxygen species and Aβ oligomerization and may therefore be a contributing factor in Alzheimer’s disease. This study investigated the effect of chronic high intake of dietary Zn or Cu on brain metal levels and the accumulation and solubility of Aβ in vivo, using a transgenic mouse model that over expresses the C-terminal containing Aβ fragment of human amyloid precursor protein but does not develop amyloid deposits. Exposure to chronic high Zn or Cu in the drinking water resulted in only slight elevations of the respective metals in the brain. Total Aβ levels were unchanged although soluble Aβ levels were slightly decreased, without visible plaque formation, enhanced gliosis, antioxidant upregulation or neuronal loss. This study indicates that brain metal levels are only marginally altered by long term oral exposure to extremely high Cu or Zn levels, and that this does not induce Aβ-amyloid formation in human Aβ expressing, amyloid-free mice, although this is sufficient to modulate Aβ solubility in vivo.     

Effect of honey on mRNA expression of TNF-α, IL-1β and IL-6 following acute toxoplasmosis in mice

This study analyzed the mRNA expression of tumor necrosis factor (TNF-α), interleukin 1 beta (IL-1β) and interleukin 6 (IL-6) in mice experimentally infected with T. gondii undergoing honey treatment. Thirty male mice were divided in groups: pre-treatment/infected (1), infected/non-treated (2), infected/treated (3), non-infected/treated (4) and control (5). Honey was applied for groups 1, 3, 4 by gavage and the mice in group 1–3 were infected by T. gondii tissue cysts. The parasite load and the level of mRNA expression of the aforementioned cytokines in the brains of mice were assessed by qPCR. The mean number of T. gondii tachyzoite in 1 mg brain tissue was 32, 73 and 59 in groups one, two and three, respectively. The mRNA expression of TNF-α increased in group 1, 2 and 3, about 49.1%, 307.3% and 63.2%, respectively but it was down-regulated by 53% in group 4. The mRNA expression of IL-1β and IL-6 was also up-regulated in all groups except group 2. The mRNA level of TNF-α was reduced by 2.7-fold and 1.18-fold in pre-treated/infected (group 1) and infected/treated (group 3) compared with infected/non-treated (group 2). The mRNA level of IL-1β and IL-6 were increased in these groups. The current study demonstrated that honey can stimulate or suppress the mRNA expression of some pro-inflammatory cytokines in mice brains. Furthermore, honey suppresses the TNF-α mRNA expression in the presence of T. gondii infection but it stimulates the IL-1β and IL-6 mRNA expression. Treatment of the mice with honey reduces parasite multiplication in the brain.     

Erratum to: Endogenous TGFβ1 Plays a Crucial Role in Functional Recovery After Traumatic Brain Injury Associated with Smad3 Signal in Rats

Neurochemical Research -     

An Increase in Cerebral γ-Amino Butyric Acid Concentration in Children with Mild Traumatic Brain Injury in the Acute Phase: 1H MRS Study

Biophysics - In this study, the concentrations of major inhibitory (γ-amino butyric acid) and excitatory (glutamate) neurotransmitters have been estimated for the first time in the norman...     

Neurodegeneration Induced by PVC-211 Murine Leukemia Virus Is Associated with Increased Levels of Vascular Endothelial Growth Factor and Macrophage Inflammatory Protein 1α and Is Inhibited by Blocking Activation of Microglia

PVC-211 murine leukemia virus (MuLV) is a neuropathogenic retrovirus that has undergone genetic changes from its nonneuropathogenic parent, Friend MuLV, that allow it to efficiently infect rat brain capillary endothelial cells (BCEC). To clarify the mechanism by which PVC-211 MuLV expression in BCEC induces neurological disease, we examined virus-infected rats at various times during neurological disease progression for vascular and inflammatory changes. As early as 2 weeks after virus infection and before any marked appearance of spongiform neurodegeneration, we detected vessel leakage and an increase in size and number of vessels in the areas of the brain that eventually become diseased. Consistent with these findings, the amount of vascular endothelial growth factor (VEGF) increased in the brain as early as 1 to 2 weeks postinfection. Also detected at this early disease stage was an increased level of macrophage inflammatory protein 1α (MIP-1α), a cytokine involved in recruitment of microglia to the brain. This was followed at 3 weeks postinfection by a marked accumulation of activated microglia in the spongiform areas of the brain accompanied by an increase in tissue plasminogen activator, a product of microglia implicated in neurodegeneration. Pathological observations at the end stage of the disease included loss of neurons, decreased myelination, and mild muscle atrophy. Treatment of PVC-211 MuLV-infected rats with clodronate-containing liposomes, which specifically kill microglia, significantly blocked neurodegeneration. Together, these results suggest that PVC-211 MuLV infection of BCEC results in the production of VEGF and MIP-1α, leading to the vascular changes and microglial activation necessary to cause neurodegeneration.PVC-211 murine leukemia virus (MuLV), a highly neuropathogenic variant of the leukemia-inducing virus Friend MuLV (F-MuLV), induces a rapid, age-dependent spongiform neurodegenerative disease in rodents, resulting in paralysis (24, 33). The primary target of PVC-211 MuLV infection within the rat central nervous system (CNS) is brain capillary endothelial cells (BCEC), which are resistant to F-MuLV infection (19). Previous studies using chimeras between PVC-211 MuLV and F-MuLV demonstrated that infection of BCEC is a prerequisite for neurodegeneration induced by PVC-211 MuLV (32). Further studies attributed the ability of PVC-211 MuLV to efficiently infect BCEC to two amino acid changes in the receptor binding domain of its envelope protein (31), which creates a unique heparin binding domain that may allow the virus to bind to proteoglycans on the surface of BCEC (22), aiding infection of this difficult-to-infect cell type. These results suggested that neurodegeneration caused by PVC-211 MuLV is an indirect result of virus infection of blood vessels within the CNS.The spongiform vacuolation observed in PVC-211 MuLV-infected brains is associated with oxidative damage (47), and BCEC isolated from PVC-211 MuLV-infected rats produce inducible nitric oxide synthase (iNOS) (23). However, iNOS was not induced after in vitro infection of primary BCEC, suggesting that expression of the virus in BCEC is insufficient to activate iNOS. Activated microglia, which can be detected in the brains of PVC-211 MuLV-infected rats (47), release inflammatory molecules that are known mediators of iNOS induction, and these molecules may stimulate BCEC to express iNOS and other factors. Microglial activation is thought to play a role in neuron death in a number of diseases (6, 26). Unlike BCEC, microglia in PVC-211 MuLV-infected brains are not infected with the virus, so the mechanism by which microglia are activated is unclear. Since vascular damage has been shown to lead to microglial activation (11), it is possible that PVC-211 MuLV infection of BCEC results in damaged vessels, causing the activation of microglia. Although an earlier study failed to detect enough vessel damage in the brains of PVC-211 MuLV-infected rats to allow entry of horseradish peroxidase across the blood-brain barrier (19), one cannot rule out the possibility that the virus causes more subtle vessel damage that is still sufficient to activate microglia.In this study, we examined the brains of rats at various times after infection with PVC-211 MuLV and found that vascular and inflammatory changes, associated with elevation of the endothelial cell growth factor VEGF and the inflammatory chemokine MIP-1α, occur early in the course of the disease. After spongiform neurodegeneration occurred, we detected loss of neurons, demyelination, axonal degeneration, and muscle atrophy as well as high levels of tissue plasminogen activator (tPA). Treatment of rats with clodronate-containing liposomes, which specifically kill macrophages and microglia, blocked the development of PVC-211 MuLV-induced neurodegeneration.     

Effect of TNF-α and IL-1β genetic variants on the development of myocardial infarction in Turkish population

Tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL-1β) genetic variants which resulting in TNF-α and IL-1 overproduction may increase susceptibility to autoimmune diseases such as atherosclerosis. We have studied the association of TNF-α G308A and IL-1β (+3953) C/T polymorphism with myocardial infarction in Turkish population. 143 patients with myocardial infarction and 213 age-matched healthy controls were included in the study. In univariant analysis, the frequencies of IL-1β, TNF-α genotype or allele, and haplotype of C:A and T:A were significantly elevated in patients when compared with those of controls. GA genotype of TNF-α, T allele of IL-1β and A of TNF-α allele seem to be risk factors for myocardial infarction. In contrast, CC genotype of IL-1β and GG genotype of TNF-α have protective effect against myocardial infarction. In multivariate logistic regression analysis, TNF-α A allele, gender and smoking were associated with myocardial infarction. In conclusion, we can state that TNF-α A allele might be associated with myocardial infarction.     

Effect of interleukin-1β on spinal cord nociceptive transmission of normal and monoarthritic rats after disruption of glial function

Introduction  

Cytokines produced by spinal cord glia after peripheral injuries have a relevant role in the maintenance of pain states. Thus, while IL-1β is overexpressed in the spinal cords of animals submitted to experimental arthritis and other chronic pain models, intrathecal administration of IL-1β to healthy animals induces hyperalgesia and allodynia and enhances wind-up activity in dorsal horn neurons.     

High Pulmonary Levels of IL-6 and IL-1β in Children with Chronic Suppurative Lung Disease Are Associated with Low Systemic IFN-γ Production in Response to Non-Typeable Haemophilus influenzae

Non-typeable Haemophilus influenzae (NTHi) is commonly associated with chronic suppurative lung disease in children. We have previously shown that children with chronic suppurative lung disease have a reduced capacity to produce IFN-γ in response to NTHi compared with healthy control children. The aim of this study was to determine if deficient NTHi-specific IFN-γ production is associated with heightened systemic or airway inflammation. We measured a panel of cytokines (IFN-γ, IL-1β, IL-6, IL-8, IL-12 p70), antimicrobial proteins (LL-37, IP-10) as well as cellular and clinical factors associated with airway and systemic inflammation in 70 children with chronic suppurative lung disease. IFN-γ was measured in peripheral blood mononuclear cells challenged in vitro with live NTHi. Regression analysis was used to assess the association between the systemic and airway inflammation and the capacity to produce IFN-γ. On multivariate regression, NTHi-specific IFN-γ production was significantly negatively associated with the BAL concentrations of the inflammatory cytokines IL-6 (β=-0.316; 95%CI -0.49, -0.14; p=0.001) and IL-1β (β=-0.023; 95%CI -0.04, -0.01; p=0.001). This association was independent of bacterial or viral infection, BAL cellularity and the severity of bronchiectasis (using modified Bhalla score on chest CT scans). We found limited evidence of systemic inflammation in children with chronic suppurative lung disease. In summary, increased local airway inflammation is associated with a poorer systemic cell-mediated immune response to NTHi in children with chronic suppurative lung disease. These data support the emerging body of evidence that impaired cell-mediated immune responses and dysregulated airway inflammation may be linked and contribute to the pathobiology of chronic suppurative lung disease.     

Effect of the CALHM1 G330D and R154H Human Variants on the Control of Cytosolic Ca2+ and Aβ Levels

CALHM1 is a plasma membrane voltage-gated Ca²⁺-permeable ion channel that controls amyloid-β (Aβ) metabolism and is potentially involved in the onset of Alzheimer''s disease (AD). Recently, Rubio-Moscardo et al. (PLoS One (2013) 8: e74203) reported the identification of two CALHM1 variants, G330D and R154H, in early-onset AD (EOAD) patients. The authors provided evidence that these two human variants were rare and resulted in a complete loss of CALHM1 function. Recent publicly available large-scale exome sequencing data confirmed that R154H is a rare CALHM1 variant (minor allele frequency (MAF)  = 0.015%), but that G330D is not (MAF  = 3.5% in an African American cohort). Here, we show that both CALHM1 variants exhibited gating and permeation properties indistinguishable from wild-type CALHM1 when expressed in Xenopus oocytes. While there was also no effect of the G330D mutation on Ca²⁺ uptake by CALHM1 in transfected mammalian cells, the R154H mutation was associated with defects in the control by CALHM1 of both Ca²⁺ uptake and Aβ levels in this cell system. Together, our data show that the frequent CALHM1 G330D variant has no obvious functional consequences and is therefore unlikely to contribute to EOAD. Our data also demonstrate that the rare R154H variant interferes with CALHM1 control of cytosolic Ca²⁺ and Aβ accumulation. While these results strengthen the notion that CALHM1 influences Aβ metabolism, further investigation will be required to determine whether CALHM1 R154H, or other natural variants in CALHM1, is/are associated with EOAD.     

Effect of Astragalus polysaccharides on expression of TNF-α, IL-1β and NFATc4 in a rat model of experimental colitis

AimAstragalus membranaceus is a Chinese medicinal herb and has been shown to improve hapten-induced experimental colitis. One of its major components is polysaccharides. We investigated the effect of Astragalus polysaccharides (APS) on expression of TNF-α, IL-1β and NFATc4 in a rat model of experimental colitis.MethodsThe experimental colitis model was induced by TNBS. Forty five rats were divided into five groups (n = 9): Normal control group, receiving ethanol vehicle with no TNBS during induction and IP saline injection during treatment; TNBS colitis model group (TNBS + IP saline), receiving only IP saline vehicle treatment; APS low dose group (TNBS + L-APS), receiving APS 100 mg/kg; APS high dose group (TNBS + H-APS), receiving APS 200 mg/kg; and positive control group (TNBS + Dexm), receiving dexamethasone 0.3 mg/kg. The clinical features, macroscopic and microscopic scores were assessed. The expressions of TNF-α, IL-1β and NFATc4 were measured by real-time PCR and ELISA assays.ResultsCompared to normal control rats, TNBS + IP saline had significant weight loss, increased macroscopic and microscopic scores, higher disease activity index (DAI) up-regulation of TNF-α, IL-1β and NFATc4 mRNA expression and up-regulation of TNF-α and IL-1β protein expression. Compared to TNBS + IP saline, treatment with APS or dexamethasone significantly reduced DAI, partially but significantly prevented TNBS colitis-induced weight loss and improved both macroscopic and microscopic scores; high dose APS or dexamethasone significantly down-regulated TNF-α and IL-1β expressions (both mRNA and protein) and up-regulated NFATc4 mRNA and protein expression. The effect of high dose APS and dexamethasone is comparable.ConclusionsAPS significantly improved experimental TNBS-induced colitis in rats through regulation of TNF-α, IL-1β and NFATc4 expression.     

Production of Anti-LPS IgM by B1a B Cells Depends on IL-1β and Is Protective against Lung Infection with Francisella tularensis LVS

The role of IL-1β and IL-18 during lung infection with the gram-negative bacterium Francisella tularensis LVS has not been characterized in detail. Here, using a mouse model of pneumonic tularemia, we show that both cytokines are protective, but through different mechanisms. Il-18^-/- mice quickly succumb to the infection and showed higher bacterial burden in organs and lower level of IFNγ in BALF and serum compared to wild type C57BL/6J mice. Administration of IFNγ rescued the survival of Il-18^-/- mice, suggesting that their decreased resistance to tularemia is due to inability to produce IFNγ. In contrast, mice lacking IL-1 receptor or IL-1β, but not IL-1α, appeared to control the infection in its early stages, but eventually succumbed. IFNγ administration had no effect on Il-1r1^-/- mice survival. Rather, Il-1r1^-/- mice were found to have significantly reduced titer of Ft LPS-specific IgM. The anti-Ft LPS IgM was generated in a IL-1β-, TLR2-, and ASC-dependent fashion, promoted bacteria agglutination and phagocytosis, and was protective in passive immunization experiments. B1a B cells produced the anti-Ft LPS IgM and these cells were significantly decreased in the spleen and peritoneal cavity of infected Il-1b^-/- mice, compared to C57BL/6J mice. Collectively, our results show that IL-1β and IL-18 activate non-redundant protective responses against tularemia and identify an essential role for IL-1β in the rapid generation of pathogen-specific IgM by B1a B cells.     

Bioprotective and Functional Effect of Carnosine on Sepsis Induced Renal Damage in Male Albino Rat Model through Targeting IL-1β and TNF-α Production

Doklady Biochemistry and Biophysics - Acute kidney injury (AKI), one of the frequently diagnosed and serious sepsis induced complication has high morbidity and mortality. The present study...