Cytokine and cytokine receptor gene polymorphisms and their functionality

Cytokines, signaling proteins produced by a variety of cell types, are essential for the development and functioning of both innate and adaptive immune response. Cytokine gene expression is tightly regulated, and aberrant expression from environmental and genetic polymorphism has been implicated in a range of diseases, susceptibility to infections, and responses to treatment. This review concentrates on the functionality of cytokine and cytokine receptor gene polymorphisms; it is through these variants that genuine disease-associations are based. Several mechanisms for single nucleotide polymorphism (SNP) functionality are present within cytokine genes including: amino acid changes (IL-6R, IL-13, IL-1α), exon skipping (IL-7Rα), proximal promoter variants (IL-1β, IL-Ra, IL-2, IL-6, IL-10, IL-12, IL-13, IL-16, TNF, IFN-γ, TGF-β), distal promoter variants (IL-6, IL-18) and intronic enhancer variants (IL-8).     

Inflammatory bowel disease: the role of inflammatory cytokine gene polymorphisms

The mechanisms responsible for development of inflammatory bowel disease (IBD) have not been fully elucidated, although the main cause of disease pathology is attributed to up-regulated inflammatory processes. The aim of this study was to investigate frequencies of polymorphisms in genes encoding pro-inflammatory and anti-inflammatory markers in IBD patients and controls. We determined genotypes of patients with IBD (n= 172) and healthy controls (n= 389) for polymorphisms in genes encoding various cytokines (interleukin (IL)-1beta, IL-6, tumour necrosis factor (TNF), IL-10, IL-1 receptor antagonist). Association of these genotypes to disease incidence and pathophysiology was investigated. No strong association was found with occurrence of IBD. Variation was observed between the ulcerative colitis study group and the control population for the TNF-alpha-308 polymorphism (p= 0.0135). There was also variation in the frequency of IL-6-174 and TNF-alpha-308 genotypes in the ulcerative colitis group compared with the Crohn's disease group (p= 0.01). We concluded that polymorphisms in inflammatory genes are associated with variations in IBD phenotype and disease susceptibility. Whether the polymorphisms are directly involved in regulating cytokine production, and consequently pathophysiology of IBD, or serve merely as markers in linkage disequilibrium with susceptibility genes remains unclear.     

Association of polymorphisms in the human IL-10 and IL-18 genes with rheumatoid arthritis

The decrease of anti-inflammatory cytokine and increase of pro-inflammatory cytokine was observed in rheumatoid arthritis (RA). Interleukin-10 (IL-10), a potent anti-inflammatory cytokine, has been demonstrated to suppress joint swelling and deformation in RA animal model. Interleukin-18 (IL-18), a widely distributed pro-inflammatory cytokine, induces the production of IFN-γ, activate NK cells, and promote inflammation. Recent studies demonstrated that the serum IL-10 and IL-18 levels may be influenced by genetics and related to susceptibility to several autoimmune diseases. In the present study, using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) and DNA sequencing techniques, we analyzed the genotype and allele distributions of two single nucleotide polymorphisms (SNP) loci in the promoter region of IL-10 and IL-18 genes (IL-10-592 A/C and IL-18-607 A/C loci, respectively). Our results indicated that IL-10-592 allelic and genotypic frequencies were significantly different between the RA patients and normal subjects (P < 0.05). In addition, significant differences of IL-10-592 allelic and genotypic frequencies were also detected between the patients with or without anti-cyclic citrullinated peptide antibody (anti-CCP) (P < 0.05). In contrast, allelic and genotypic frequencies of IL-18-607 did not show significant difference between RA patients and normal subjects (P > 0.05) or between anti-CCP-positive and anti-CCP-negative RA patients (P > 0.05). Furthermore, ELISA detection of IL-10 and IL-18 serum levels revealed that the genotype of IL-10-592 was associated with IL-10 serum level (P < 0.05), but the genotype and allele frequency of IL-18-607 was not associated with IL-18 serum level (P > 0.05). Taken together, our findings provide new insight for the polymorphism of IL-10 gene in the pathogenesis of RA.     

Genetic polymorphisms in adipokine genes and the risk of obesity: a systematic review and meta-analysis

Polymorphisms in adipokine genes, such as leptin (LEP), leptin receptor (LEPR), resistin (RETN), adiponectin (ADIPOQ), interleukin-1β (IL-1β), IL-6 (IL-6), and tumor necrosis factor-α (TNF-α) may be involved in the development of obesity. We conducted a systematic review of published evidence on the association between different adipokine genes and the risk of obesity. Librarian-designed searches of PubMed and HuGeNet, review of reference lists from published reviews and content expert advice identified potentially eligible studies. The genotyping information and polymorphisms of different adipokine genes, numbers of genotyped cases and controls and frequencies of genotypes were extracted from 48 eligible studies included in this review. Twenty-one polymorphisms each associated with obesity in at least one study were identified. Polymorphisms in the adipokine genes, LEP, LEPR, and RETN were not associated with obesity susceptibility, whereas ADIPOQ G276T (T vs. G: odds ratio (OR), 1.59; 95% confidence interval (CI), 1.39-1.81), IL-1β C3953T (CC vs. CT+TT: OR, 1.61; 95% CI, 1.18-2.20), and TNF-α G308A (GG vs. GA+AA: OR, 1.19; 95% CI, 1.02-1.39) polymorphisms were associated with an increased risk of obesity. The IL-6 G174C polymorphism was also associated obesity when using allelic comparisons, the recessive genetic model and the dominant genetic model with OR (95% CI) of 1.95 (1.37-2.77), 1.44 (1.15-1.80), and 1.36 (1.16-1.59), respectively. No significant evidence of publication bias was present. However, these "null" results were underpowered due to a small pooled sample size, and analysis of additional case-control studies with larger sample sizes should provide further clarifications.     

Differential effects of pro- and anti-inflammatory cytokines alone or in combinations on the metabolic profile of astrocytes

We have previously reported that the pro-inflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin-1β (IL-1β) induce profound modifications of the metabolic profile of astrocytes. The present study was undertaken to further characterize the effects of cytokines in astrocytes and to determine whether similar effects could also be observed in neurons. To do so, selected pro-inflammatory (IL-6 and interferon-γ, in addition to the above-mentioned TNFα and IL-1β) and anti-inflammatory cytokines (IL-4, IL-10, transforming growth factor-β1 and interferon-β) were applied to primary neuronal and astrocytic cultures, and key metabolic parameters were assessed. As a general pattern, we observed that pro-inflammatory cytokines increased glucose utilization in astrocytes while the anti-inflammatory cytokines IL-4 and IL-10 decreased astrocytic glucose utilization. In contrast, no significant change could be observed in neurons. When pairs of pro-inflammatory cytokines were co-applied in astrocytes, several additive or synergistic modifications could be observed. In contrast, IL-10 partially attenuated the effects of pro-inflammatory cytokines. Finally, the modifications of the astrocytic metabolism induced by TNFα?+?IL-1β and interferon-γ modulated neuronal susceptibility to an excitotoxic insult in neuron-astrocyte co-cultures. Together, these results suggest that pro- and anti-inflammatory cytokines differentially affect the metabolic profile of astrocytes, and that these changes have functional consequences for surrounding neurons.     

Cytokines genes polymorphisms in chronic hepatitis C: Impact on susceptibility to infection and response to therapy

BackgroundCytokines play a key role in the regulation of immune responses. In hepatitis C virus infection, the production of abnormal cytokine levels appears to contribute in the progression of the disease, viral persistence, and affects response to therapy. Cytokine genes polymorphisms located within the coding/regulatory regions have been shown to affect the overall expression and secretion of cytokines. The aim of the study was to evaluate the association of of IL28B rs12979860, TGF-β1-509, TNF-α 308, and IL-10-1082 polymorphisms with the susceptibility to hepatitis C virus genotype 4 infection and response to pegylated interferon-α and ribavirin therapy.MethodsIL28B, TGF-β1 and TNF-α genes polymorphisms were genotyped using polymerase chain reaction (PCR)-based restriction fragment length polymorphism assay while IL-10 gene polymorphism was detected by sequence specific primer-PCR in 220 healthy individuals and 440 hepatitis C infected patients (220 sustained virological response and 220 non-responder to combination therapy).ResultsIL28 B CT and TT, TGF-β1 CT and TT and TNF-α AG and AA genotypes were significantly associated with susceptibility to hepatitis C infection and response to therapy. While no association was found between IL-10 gene polymorphism and susceptibility to HCV infection and response to treatment.ConclusionsThese results suggested that inheritance of IL28B CT and TT, TGF-β1 CT and TT and TNF-α AG and AA genotypes which appear to affect the cytokine production may be associated with susceptibility to HCV infection and resistance to combined antiviral therapy.     

IL-10 and IL-6 gene polymorphisms as potential host susceptibility factors in Brucellosis

Several genes encoding for different cytokines may play crucial roles in host susceptibility to Brucellosis, since the cytokine production capacity varies among individuals and depends on the cytokine gene polymorphism. The association of the cytokine gene polymorphisms with the development of Brucellosis was investigated in this study. DNA samples were obtained from a Turkish population of 40 patients with Brucellosis, and 50 healthy control subjects. All genotyping (IL-6, IL10, IFN-gamma, TGF-beta and TNF-alpha) experiments were performed using sequence-specific primers PCR (PCR-SSP). When compared to the healthy controls, the frequencies of high/intermediate producing genotypes of IL-10 and high producing genotype of IL-6 were significantly more common in the patient group. These results suggest that IL-10 and IL-6 gene polymorphisms may affect susceptibility to Brucellosis and increase risk of developing the disease. In order to confirm the biological significance of our results, further studies should be performed in larger population groups.     

Effect of acute sleep deprivation and recovery on Insulin-like Growth Factor-I responses and inflammatory gene expression in healthy men

Acute sleep deprivation in humans has been found to increase inflammatory markers and signaling pathways in the periphery through a possible Toll-like receptor 4 (TLR-4). In addition, short duration sleep has been associated with low circulating total Insulin-like Growth Factor-I (IGF-I) concentrations.We aimed to determine whether a total sleep deprivation (TSD) protocol with recovery altered whole-blood gene expression of the proinflammatory cytokines TNF-α and IL-6, as well as TLR-4 expression, and to examine the relationship with circulating concentrations of the IGF-I system. Twelve healthy men participated in a five-day TSD (two control nights followed by one night of sleep deprivation and one night of recovery). Blood was sampled at 0800, before and after sleep deprivation (D2 and D4), and after recovery (D5). It is shown that 25h of sleep deprivation (D4) induced significant increases in mRNA levels of TNF-α and its soluble receptor R1 (P<0.01 respectively), as well as TLR-4 (P<0.05), while IL-6 mRNA levels remained unchanged. Circulating concentrations of free IGF-I were decreased at D4 (P<0.001). One night of recovery was sufficient to restore basal expression levels for TNF-α, sTNF-R1, TLR-4 and circulating IGF-I. Changes in TLR-4 mRNA levels during the protocol correlated positively with those of TNF-α and sTNF-R1 (r = 0.393 and r = 0.490 respectively), and negatively with circulating free IGF-I (r = ?0.494). In conclusion, 25h of sleep deprivation in healthy subjects is sufficient to induce transient and reversible genomic expression of the pro-inflammatory cytokine TNF-α and its R1 receptor, and its mediator TLR-4, with a possible link to IGF-I axis inhibition.     

Association analysis of interleukin gene polymorphisms in autoimmune thyroid diseases in the Tunisian population

Autoimmune thyroid diseases (AITDs), including Graves' disease (GD) and autoimmune hypothyroidism (AH), are inherited as complex traits. Among the genes contributing to AITDs susceptibility are genes of the IL-1 family. IL-1 regulates T and B lymphocyte maturation, including the induction of several cytokines and cytokine receptors. Therefore, disturbances of this balance may not only play a role in inflammation but also in the pathogenesis of autoimmunity. In order to investigate genetic association of IL-1 gene polymorphisms with AITDs, we performed both a familial study in a large Tunisian pedigree with high prevalence of AITDs (64 patients and 176 controls), and a case-control study (131 GD unrelated patients and 225 healthy controls). PCR and PCR-RFLP methods were used to analyse respectively a VNTR in the IL-1RN gene and three SNPs in both IL-1B genes (-511 C/T and +3954 C/T) and IL-1A (-889 C/T). The family-based association study showed an association of the IL-1B+3954 C/T polymorphism (p=0.02) and two haplotypes IL-1RN*3/C/T/T and IL-1RN*1/C/T/T (p=0.009 and p=0.047 respectively) with AITDs. The case-control study is the first study revealing a significant association of the IL-1A-889 C/T polymorphism (chi2=10.23; p=0.0014) with susceptibility to GD. Our data suggest that the IL-1 gene cluster may harbour susceptibility genes for AITDs and GD pathogenesis in the Tunisian population.     

Leptin and adiponectin, but not IL18, are related with insulin resistance in treated HIV-1-infected patients with lipodystrophy

Leptin, adiponectin and IL18 are adipokines related with obesity, insulin resistance and dyslipidemia in the general population. Treated HIV-1-infected patients with lipodystrophy may develop insulin resistance and proatherogenic dyslipidemia. We assessed the relationship between plasma adipokine levels, adipokine genetics, lipodystrophy and metabolic disturbances. Plasma leptin, adiponectin and IL18 levels were assessed in 446 individuals: 282 HIV-1-infected patients treated with antiretroviral drugs (132 with lipodystrophy and 150 without) and 164 uninfected controls (UC). The LEP2410A>G, LEPRQ223R, ADIPQ276G>T, ADIPOR2-Intron5A>G and IL18-607C>A polymorphisms were validated by sequencing. Leptin levels were higher in UC than in HIV-1-infected, either with or without lipodystrophy (p<0.001 for both comparisons) and were lower in patients with lipodystrophy compared with those without lipodystrophy (p=0.006). In patients with lipodystrophy, leptin had a positive correlation with insulin and with HOMA-IR. Adiponectin levels were non-significantly different in UC and HIV-1-infected patients. Patients with lipodystrophy had lower adiponectin levels than non-lipodystrophy subjects (p<0.001). In patients with lipodystrophy, adiponectin was negatively correlated with insulin, HOMA-IR and triglycerides. Plasma IL18 levels were higher in HIV-1-infected patients compared with UC (p<0.001), and no differences were found according to the presence of lipodystrophy. In patients with lipodystrophy there was a negative correlation between IL18 levels and LDLc. Genetic analyses indicated no significant associations with lipodystrophy nor with insulin resistance or with lipid abnormalities. In conclusion, HIV-1-infected patients have reduced plasma leptin levels. This reduction is magnified in patients with lipodystrophy whose adiponectin levels were lower than that of non-lipodystrophy subjects. Plasma IL18 levels are increased in infected patients irrespective of the presence of lipodystrophy. The polymorphisms assessed are not associated with lipodystrophy or metabolic disturbances in treated HIV-1-infected patients.     

Alteration in some pro and anti-inflammatory cytokines associated with complete and incomplete gestation cycle of cows

The maternal immune response during pregnancy is regulated by a complex array of pro and anti-inflammatory cytokines which provide optimum conditions for the embryo implantation and survival. The possible role of pro and anti-inflammatory cytokines during the complete gestation cycle of ruminants and the difference in their circadian rhythmicity between successful and unsuccessful pregnancies is still unknown. To study this, blood samples were collected from three groups of cows, pregnant (P), non-pregnant (NP) and aborted (ABORT) cows starting from the day of Artificial Insemination (AI) till calving in P cows and till stages of non pregnancy in other cows. Various pro and anti-inflammatory cytokines were estimated by bovine-specific ELISA test and compared. Successful pregnancies had lower levels of pro-inflammatory cytokines (IL-2, IL-6 and IL-8) but higher anti-inflammatory cytokine (IL-10) mainly during implantation. Significant (p < 0.05) increase in pro-inflammatory cytokines and low IL-10 levels was noticed at abortion and at calving. This study indicates that temporal and spatial aspects of reducing the release of various pro-inflammatory cytokines and maintaining high anti-inflammatory cytokines during pregnancy are essentially required for maintenance of pregnancy. Any disturbance in the cytokine equilibrium may lead to persistent inflammation and pregnancy failure.     

Cytokine gene polymorphisms and cytokine levels in pulmonary tuberculosis

Polymorphisms in the cytokine genes are known to influence cytokine levels and may be associated with outcome of infections. We investigated the polymorphisms in the cytokine genes namely IFN-gamma (+874 and +5644), IL-2 (-330 and +160), IL-4 (VNTR), IL-6 (-174), IL-10 (-1082 and -819) and IL-12B (+1188) in 188 normal healthy subjects (NHS) and 166 pulmonary tuberculosis patients (PTB) using polymerase chain reaction-based methods. To study the influence of cytokine gene polymorphisms on cytokine levels, phytohaemagglutinin and culture filtrate antigen of Mycobacterium tuberculosis-induced cytokine levels were measured by ELISA from 72-h-old peripheral blood mononuclear cell culture supernatants. Significantly decreased frequency of TT genotype of IL-2 -330 polymorphism (p=0.024, odds ratio (OR) 0.53, 95% CI 0.31-0.92) was observed in patients compared to NHS. The genotype frequencies of other polymorphisms were not different between patients and NHS. IL-12p40 levels were significantly decreased among NHS with AA genotype of IL-12B gene polymorphism compared to NHS with AC genotype (p<0.05). Increased levels of IL-12p40 were observed among patients with CC genotype of IL-12B gene compared to patients with other genotypes (p<0.01). The present study suggests that the TT genotype of IL-2 -330 polymorphism may be associated with the protection to PTB in south India. Further, +1188 polymorphism of IL-12B gene either alone or in combination with closely linked genes may regulate IL-12p40 production and may play a major role on acquired immunity to tuberculosis.     

Interleukin-10 (IL-10) gene polymorphism as a potential host susceptibility factor in tuberculosis

Several genes encoding for different cytokines may play crucial roles in host susceptibility to tuberculosis (TB), since the cytokine production capacity varies among individuals and depends on the cytokine gene polymorphism. The association of the cytokine gene polymorphisms with the development of TB was investigated in this study. DNA samples were obtained from a Turkish population of 81 patients with the different clinical forms of TB, and 50 healthy control subjects. All genotyping (IL-6, IL-10, IFN-gamma, TGF-beta and TNF-alpha) experiments were performed using sequence-specific primers PCR (PCR-SSP). Analysis of allele frequencies showed that IL-10 -1082 G allele frequency was significantly more common in TB patients than healthy controls (37.7% vs 23.0%, p: 0.014). No statistically significant differences were observed between the different clinical forms of the disease. These results suggest that the polymorphisms in IL-10 gene may affect susceptibility to TB and increase risk of developing the disease. To confirm the biological significance of our results, further studies should be performed on other population groups.     

Interleukin-32 induced thymic stromal lymphopoietin plays a critical role in the inflammatory response in human corneal epithelium

Interleukin (IL)-32, a novel cytokine, participates in a variety of inflammatory disorders. Thymic stromal lymphopoietin (TSLP) plays important roles in mucosal epithelial cells, especially in allergy-induced inflammation, through the TSLP-TSLPR (thymic stromal lymphopoietin receptor) signalling pathway. However, the association of IL-32 with TSLP on the ocular surface remains unclear. The present work aimed to assess the functional association of IL-32 with TSLP in the control of pro-inflammatory cytokine levels in the corneal epithelium. Human corneal tissue specimens and human corneal epithelial cells (HCECs) were administered different concentrations of IL-32 in the presence or absence of various inhibitors to assess TSLP levels and localization, as well as the molecular pathways that control pro-inflammatory cytokine production. TSLP mRNA levels were determined by real time RT- PCR, while protein levels were quantitated by ELISA and immunohistochemical staining. TSLP protein expression was examined in donor corneal epithelium samples. IL-32 significantly upregulated TSLP and pro-inflammatory cytokines (TNFα and IL-6) in HCECs at the gene and protein levels. The production of pro-inflammatory molecules by IL-32 was increased by recombinant TSLP. Interestingly, both NF-κB (quinazoline) and caspase-1 (VX-765) inhibitors suppressed the IL-32-related upregulation of pro-inflammatory cytokines (TNFα and IL-6). These findings demonstrate that IL-32 and IL-32-induced-TSLP are critical cytokines that participate in inflammatory responses through the caspase-1 and NF-κB signalling pathways in the corneal epithelium, suggesting new molecular targets for inflammatory diseases of the ocular surface. The effects of IL-32 on cell proliferation and apoptosis were investigated by MTT assays and RT-PCR,respectively. The results demonstrated that IL-32 inhibits cells apoptosis in HCECs.     

Modeling of the effects of IL-17 and TNF-α on endothelial cells and thrombus growth

Rheumatoid and psoriatic arthritis are chronic inflammatory diseases, with massive increase of cardiovascular events (CVE), and contribution of the cytokines TNF-α and IL-17. Chronic inflammation inside the joint membrane or synovium results from the activation of fibroblasts/synoviocytes, and leads to the release of cytokines from monocytes (Tumor Necrosis Factor or TNF) and from T lymphocytes (Interleukin-17 or IL-17). At the systemic level, the very same cytokines affect endothelial cells and vessel wall. We have previously shown [1], [2] that IL-17 and TNF-α, specifically when combined, increase procoagulation, decrease anticoagulation and increase platelet aggregation, leading to thrombosis. These results are the basis for the models of interactions between IL-17 and TNF, and genes expressed by activated endothelial cells. This work is devoted to mathematical modeling and numerical simulations of blood coagulation and clot growth under the influence of IL-17 and TNF-α. We show that they can provoke thrombosis, leading to the complete or partial occlusion of blood vessels. The regimes of blood coagulation and conditions of occlusion are investigated in numerical simulations and in approximate analytical models. The results of mathematical modeling allow us to predict thrombosis development for an individual patient.     

Cytokine single nucleotide polymorphisms in patients’ with gallstone: dose TGF-β gene variants affect gallstone formation?

Gallstone is a common biliary disorder with several risk factors. Immune responses and inflammatory cytokines are important in this disease; as a result, some cytokines can be detected in bile fluid. In this research, cytokine gene polymorphisms were studied, and their effects on gallstone formation were evaluated. On 158 gallstone patients and 254 normal subjects, by PCR- RFLP method, IL-4-C590T polymorphism and by ARMS-PCR method, IFN-γ T+874A, TNF-α-A308G, IL-6 G-174C and TGF-β T+869C variants were studied. Pathologic evaluations were done on surgical specimens. There were no significant differences in distribution of evaluated polymorphisms between patient group and normal control group (P > 0.05), except TGF-β +869T allele (P = 0.04, OR = 1.23, 95 % CI = 1–1.79) which was higher in patients with gallstone. Although the pro-inflammatory cytokines such as TNF-α and IL-6 may promote gallstone formation, in this study no significant correlation between TNF-α and IL-6 polymorphisms and gallstone formation was seen. It is taught that TGF-β may affect gallbladder cells to promote gallstone formation and higher producer TGF-β +869T allele can be a risk factor of gallstone disease, so further studies would be more elucidative.     

Salusin-α attenuates inflammatory responses in vascular endothelial cells

Atherosclerosis accounts for numerous cardiovascular diseases, and cytokines have a critical role in acceleration or suppression of disease. Salusin-α presents a new class of bioactive peptides that can have anti-atherogenic properties. Therefore, the effects of salusin-α on the expression of some pro- and anti-inflammatory cytokines and on TNF-α-induced inflammatory responses in human umbilical vein endothelial cells (HUVECs) were examined. The involvement of the NF-κB pathway in effects of salusin-α in HUVECs was checked using Bay 11-7082 as an NF-κB inhibitor. The mRNA expression of pro-inflammatory cytokines including IL-6, IL-8, and IL-18 and anti-inflammatory cytokine IL-1Ra was assessed by real-time PCR. The protein levels of cytokines were measured by the ELISA method. Salusin-α suppressed both mRNA and protein expression of pro-inflammatory cytokines and induced mRNA and protein expression of IL-1Ra in HUVECs. Salusin-α suppressed TNF-α-induced inflammatory responses in HUVECs. The down-regulatory or up-regulatory effects of salusin-α on expression of cytokines could not be influenced by Bay 11-7082 pretreatment. Our findings indicate anti-inflammatory effects of salusin-α and suggest a novel peptide-based therapeutic strategy for atherosclerosis.     

Inflammatory cytokines in vitro production are associated with Ala16Val superoxide dismutase gene polymorphism of peripheral blood mononuclear cells

Obesity is considered a chronic low-grade inflammatory state associated with a chronic oxidative stress caused by superoxide production (O(2)(-)). The superoxide dismutase manganese dependent (SOD2) catalyzes O(2)(-) in H(2)O(2) into mitochondria and is encoded by a single gene that presents a common polymorphism that results in the replacement of alanine (A) with a valine (V) in the 16 codon. This polymorphism has been implicated in a decreased efficiency of SOD2 transport into targeted mitochondria in V allele carriers. Previous studies described an association between VV genotype and metabolic diseases, including obesity and diabetes. However, the causal mechanisms to explain this association need to be more elucidated. We postulated that the polymorphism could influence the inflammatory response. To test our hypothesis, we evaluated the in vitro cytokines production by human peripheral blood mononuclear cells (PBMCs) carrier's different Ala16Val-SOD2 genotypes (IL-1, IL-6, IL-10, TNF-α, IFN-γ). Additionally, we evaluated if the culture medium glucose, enriched insulin, could influence the cytokine production. Higher levels of proinflammatory cytokines were observed in VV-PBMCs when compared to AA-PBMCs. However, the culture medium glucose and enriched insulin did not affect cytokine production. The results suggest that Ala16Val-SOD2 gene polymorphism could trigger the PBMCs proinflammatory cytokines level. However, discerning if a similar mechanism occurs in fat cells is an open question.     

Association of PARP-1, NF-κB,NF-κBIA and IL-6, IL-1β and TNF-α with Graves Disease and Graves Ophthalmopathy

Background

Graves Disease (GD) is an autoimmune disorder affected by an interaction of multiple genes such as Nuclear Factor-κB (NF-κB), Nuclear Factor-κB Inhibitor (NF-κBIA), Poly (ADP-ribose) polymerase-1 (PARP-1) and cytokines like Interleukin-1β (IL-1β), Interleukin-6 (IL-6) and Tumor Necrosis Factor-α (TNF-α) and mostly accompanied by an ocular disorder, Graves Ophthalmopathy (GO). We hypothesize that there is a relationship between GD, GO, polymorphisms of inflammatory related genes and their association with cytokines, which may play important roles in autoimmune and inflammatory processes.

Subjects and methods

To confirm our hypothesis, we studied the polymorphisms and cytokine levels of 120 patients with GD and GO using PCR-RFLP and ELISA methods, respectively.

Results

We found that patients with GG genotype and carriers of G allele of PARP-1 G1672A polymorphism are at risk in the group having GD (p = 0.0007) while having GA genotype may be protective against the disease. PARP-1 C410T polymorphism was found to be associated with GO by increasing the risk by 1.7 times (p = 0.004). Another risk factor for development of GO was the polymorphism of del/ins of NFkB1 gene (p = 0.032) that increases the risk by 39%. Levels of cytokines were also elevated in patients with GD, but no association was found between levels of cytokines and the development of GO as there was no change in levels of cytokines.

Conclusions

We suggest that, PARP-1 and NFkB1 gene polymorphisms may be risk factors for developing Graves Disease and Ophthalmopathy.