Association of IL-12, IL-18 variants and serum IL-18 with bladder cancer susceptibility in North Indian population

IL-12 and IL-18 are immunomodulatory cytokines that play important roles in host immune response against cancers. Variation in DNA sequence in gene promoter may lead to altered IL-18 production and/or activity, and hence can modulate an individual's susceptibility to BC. To test this hypothesis, we investigated the relationship of IL-18 gene promoter −137 G/C and −607C/A polymorphisms and IL12 (− 16974) A/C with the risk of BC in North Indian population. Polymorphisms in IL-18 and IL-12 genes were analyzed in 200 BC patients and 200 age, ethnicity and sex-matched controls, using restriction fragment length polymorphism-polymerase chain reaction (PCR-RFLP) and amplification refractory mutation specific-polymerase chain reaction (ARMS) method. The concentrations of IL-18 in serum were determined by ELISA. Significant association was observed with IL18 (− 137) G/C heterozygous genotype (GC) with 1.96 folds risk of BC as well at C allele carrier and variant C allele having 2 fold and 1.6 fold risk for BC respectively. IL18 (− 607) C/A, heterozygous CA genotype also showed a high risk (OR = 1.59) for BC. While IL12 (− 16974) A/C heterozygote genotype and C allele carrier demonstrated reduced risk of BC. Hetero genotype of IL18 (− 137) G/C was associated with risk of recurrence (HR = 2.35) in superficial BC patients receiving BCG treatment thus showing least survival. The distributions of IL-18 gene haplotypes were not significantly different between patients and controls. Serum IL-18 levels were significantly higher in BC patients than in the healthy subjects (p = 0.025). Serum IL-18 levels was also significantly associated with IL18 (− 137) G/C in heterozygous genotype (GC) (p = 0.048). Our results suggest that IL-18 gene polymorphism contributes to bladder cancer risk whereas IL-12 is protective. A relation between IL18 (− 137) G/C in heterozygous genotype with elevated IL-18 serum level and bladder cancer risk has been registered in the present study.     

Interleukin-18 single nucleotide polymorphisms contribute to the susceptibility to brucellosis in Iranian patients

It seems that IL-18 has a crucial role in immunity against Brucella infection. Since the expression of IL-18 can be affected by polymorphisms in its gene, we decided to investigate any probable relationship between the six different IL-18 gene polymorphisms and brucellosis. A total of 193 patients with brucellosis and 83 healthy farmers who consumed contaminated raw milk and dairy products from the animals with brucellosis, were included in this study. All the individuals were genotyped for six IL-18 polymorphisms at positions -656, -607, -137, +113, +127 and codon 35/3, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The distributions of alleles for IL-18 polymorphisms at positions -137G/+113T/+127C/codon 35/3A (correlated with higher production of IL-18) were significantly higher in healthy controls than in patients (P=0.012, 0.012, 0.012 and 0.0018, respectively). It could be suggested that individuals who inherited the aforementioned genotypes/alleles are able to produce higher levels of IL-18 at the onset of infection, and it leads to more IFN-gamma production and control Brucella infection before the emerging brucellosis.     

Genetic polymorphisms of the interleukin-18 gene and risk of prostate cancer

Genetic factors are known to be important in the development of prostate cancer. Interleukin-18 (IL-18) is a multifunctional cytokine that induces interferon-gamma secretion and plays an important role in antitumor immunity. Variations in the DNA sequence in the IL-18 gene promoter may lead to altered IL-18 production and/or activity, and so this can modulate an individual's susceptibility to prostate cancer. To test this hypothesis, we investigated the relationship of IL-18 gene promoter -137 G/C and -607 C/A polymorphisms and their haplotypes with the risk of prostate cancer. We analyzed two single nucleotide polymorphisms of IL-18 gene promoter -137 G/C and -607 C/A in 265 patients with prostate cancer and 280 age- and sex-matched controls, using sequence-specific primers-polymerase chain reaction strategy. There were significant differences in the genotype and allele distribution of -137 G/C polymorphism of the IL-18 gene among cases and controls. The -137 GC and CC genotypes were associated with a significantly increased risk of prostate cancer as compared with the -137 GG genotypes [odds ratio (OR) = 1.721; 95% confidence interval (CI): 1.187-2.496; p = 0.004, and OR = 2.181; 95% CI: 1.034-4.603; p = 0.037, for GC and CC, respectively]. Consistent with the results of the genotyping analyses, the -137C/-607A haplotype was associated with a significantly increased risk of prostate cancer as compared with the -137G/-607C haplotype (OR = 1.544; 95% CI, 1.137-2.096; p = 0.005). This study shows for the first time an association between IL-18 gene promoter -137 G/C polymorphism and prostate cancer in a Chinese population.     

Interleukin-18 promoter polymorphism and asthma risk: a meta-analysis

Some studies have shown that IL-18 was associated with aetiology and progression of asthma. However, the association between single-nucleotide polymorphisms −607C/A (rs1946518) and −137G/C (rs187238) located in the IL-18 gene promoter and asthma risk was still controversial and ambiguous. To derive a more precise effect on the association between these polymorphisms and asthma risk, we performed a meta-analysis based on the currently available evidence of the literature. A total of 5 studies with 1411 cases and 1525 controls for −607C/A polymorphism and 5 studies with 1883 cases and 6645 controls for −137G/C polymorphism were identified to perform a meta-analysis, up to October 2010. Summary ORs and corresponding 95% CIs for IL-18 polymorphisms and asthma were estimated using fixed- and random-effects models when appropriate. Heterogeneity and publication bias were evaluated. We found that individuals carrying AC/CC genotype of −607C/A polymorphism were associated with an increased asthma risk in recessive model (OR = 1.278; 95% CI, 1.073–1.522). However, no significant association was observed between −137G/C polymorphism and asthma risk under different contrast models. There was no evidence of publication bias. The present meta-analysis suggested that IL-18 −607C/A polymorphism in promoter region was associated with asthma risk.     

Association between promoter variants of interleukin-18 and schizophrenia in a Han Chinese population

An increasing amount of evidence suggests that interleukin-18 (IL-18) plays a pivotal role in the pathophysiology of schizophrenia. However, association between single nucleotide polymorphism of IL-18 and the risk of schizophrenia has not been clarified. This study examined whether two promoter polymorphisms -137 G/C (rs187238) and -607 C/A (rs1946518) of IL-18 were associated with schizophrenia and six clinical symptoms (disorder of perception, thought disorder, disturbance of emotion, disorder of behavior and volition, suicide action, and aggressive action) to provide data for screening high-risk Han Chinese individuals. Three hundred seventy-two schizophrenic patients and 353 healthy controls from a Han Chinese population were examined to assess their genotype and allele frequencies of the two promoter polymorphisms of IL-18. The genotype distributions in both patients and controls were within Hardy-Weinberg equilibrium. No significant differences were observed in the genotype or the allele frequencies of the two single-nucleotide polymorphisms between patients and controls. However, genotype frequencies of -607 C/A showed significant differences between patients and controls in the appearance of perception disorder (χ2 = 6.153, p = 0.046). A significant difference was detected in -137 G/C between patients and controls in the appearance of aggressive action (χ2 = 3.909, p = 0.048). In conclusion, IL-18 gene promoter polymorphisms may not contribute to the susceptibility of schizophrenia in a Han Chinese population, but two single-nucleotide polymorphisms, -137 G/C and -607 C/A, may play a role in the development of perception disorder and aggressive action, respectively.     

Association of interleukin-18 gene variants with susceptibility to visceral leishmaniasis in Iranian population

Host resistance to Leishmania infection is mediated by cellular immune responses leading to macrophage activation and parasite killing. Interleukin-18 (IL-18) known as interferon-γ (IFN-γ) inducing factor, stimulates IFN-γ production by T cells. Taking into account the important role of IL-18 in the defense against visceral leishmaniasis (VL) and the known effect of IL-18 gene polymorphisms on its production, the aim of this study was to investigate the probable relationship between IL-18 gene polymorphisms and the susceptibility to VL. The study groups included 118 pediatric patients who suffered from VL and 156 non-relative healthy people as the controls from the same endemic area. IL-18 gene polymorphisms at the positions ?656 G/T, ?137 G/C and +105A/C (codon 35/3) were analyzed by polymerase chain reaction-restricted fragment length polymorphism (PCR–RFLP). The results showed that the frequency of T allele at the position -656 was significantly higher in the controls, compared with that in the patients (P = 0.047), but it couldn’t tolerate Bonferroni correction. Regarding the IL-18 genotypes, there was no significant difference between the patients and controls. Although the frequencies of ATG single haplotype and AGG/ATG double haplotype were significantly higher in the controls (P = 0.043) and the patients (P = 0.044), respectively, the two P values couldn’t tolerate Bonferroni correction. Furthermore, a strong linkage disequilibrium was observed among the ?656, ?137 and +105 single nucleotide polymorphisms of IL-18 gene (all Ps < 0.001). In conclusion, this study suggests that the inheritance of T allele at the position ?656 may be considered as a genetic factor for resistance to VL.     

Polymorphisms of interleukin-8 and -18 genes and diabetic retinopathy

We evaluated possible roles of interleukin-8 gene polymorphisms (1633T/C-rs2227543, 251A/T-rs4073) and interleukin-18 gene polymorphisms (-607C/A-rs1946518, -137G/C-rs187238) in the development of diabetic retinopathy (DR) in Caucasians with type 2 diabetes. 271 patients with DR and 113 without diabetic retinopathy were enrolled in this cross-sectional study. We did not observe an association between either interleukin-8 gene polymorphisms (1633T/C, 251A/T) or interleukin-18 gene polymorphisms (-607C/A, -137G/C) and diabetic retinopathy in Caucasians with type 2 diabetes. We did not find statistically significant differences in interleukin-8 serum levels between diabetics with the TT and AA genotype and those with other genotypes. The interleukin-18 serum levels between diabetics with the CC genotype of the -607C/A polymorphism and those with other genotypes (AA, AC) were not significantly different. Moreover, we did not observe a statistically significant effect of the tested polymorphisms of either interleukin-8 or interleukin-18 genes on serum levels in diabetics. In conclusion, our study indicates that the examined polymorphisms of interleukin-8 (1633T/C, 251A/T) and interleukin-18 (-607C/A or the -137G/C) genes are not genetic risk factors for diabetic retinopathy. Therefore, they may not be used as genetic markers for diabetic retinopathy in Caucasians with type 2 diabetes.     

Interleukin-18 gene polymorphism,but not interleukin-2 gene polymorphism,is associated with rheumatoid arthritis

To investigate whether polymorphisms of IL-2 and IL-18 genes are associated with rheumatoid arthritis (RA), polymorphisms of IL-2 and IL-18 genes were detected by polymerase-chain-reaction-based restriction analysis in the patients with RA and normal controls. The results for the IL-18 gene revealed a significant difference between the patients and the normal controls (p = 0.000003), but there was no significant difference for the IL-2 gene (p = 0.876). The IL-18 gene 105A allele was associated with RA in Chinese patients. Individuals possessing the 105A allele had a higher incidence of RA. A lack of association of IL-2 gene polymorphism between RA patients and healthy individuals was noted. The results of this study provide genetic evidence that IL-18-105A/C polymorphism may play an effective role in RA.     

Evaluation of Hs-CRP Levels and Interleukin 18 (-137G/C) Promoter Polymorphism in Risk Prediction of Coronary Artery Disease in First Degree Relatives

Background

Coronary Artery Disease (CAD) is clearly a multifactorial disease that develops from childhood and ultimately leads to death. Several reports revealed having a First Degree Relatives (FDRS) with premature CAD is a significant autonomous risk factor for CAD development. C - reactive protein (CRP) is a member of the pentraxin family and is the most widely studied proinflammatory biomarker. IL-18 is a pleiotrophic and proinflammatory cytokine which is produced mainly by macrophages and plays an important role in the inflammatory cascade.

Methods and Results

Hs-CRP levels were estimated by ELISA and Genotyping of IL-18 gene variant located on promoter -137 (G/C) by Allele specific PCR in blood samples of 300 CAD patients and 300 controls and 100 FDRS. Promoter Binding sites and Protein interacting partners were identified by Alibaba 2.1 and Genemania online tools respectively. Hs-CRP levels were significantly high in CAD patients followed by FDRS when compared to controls. In IL-18 -137 (G/C) polymorphism homozygous GG is significantly associated with occurrence of CAD and Hs-CRP levels were significantly higher in GG genotype subjects when compared to GC and CC. IL-18 was found to be interacting with 100 protein interactants.

Conclusion

Our results indicate that Hs-CRP levels and IL-18-137(G/C) polymorphism may help to identify risk of future events of CAD in asymptomatic healthy FDRS.     

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.     

IL-10基因启动子-627位点多态性与过敏性哮喘

目的：探讨白细胞介素-10（IL-10）启动子-627C／A基因多态性和等位基因频率与过敏性哮喘血清IgE、IL-10浓度以及病情严重程度的相互关系。方法：从哮喘病人DNA文库中选择青岛地区过敏性哮喘病人518例和健康志愿者501例,采用PCR—RFLP方法对IL．10基因启动子．627位点多态性进行观察,比较两组基因型和等位基因的分布频率,同时测定血清中总IgE、IL-10浓度和肺功能检查（FEV1、FVC、FEV1／FVC）。结果：轻度和中一重度哮喘组AA、CA和CC基因型所占比例分别为38．1％、46．0％、15．9％和45．6％、46．2％和8．2％（P=0．0168,X2=8．232,df=2）。A等位基因与哮喘病轻的严重程度有明显相关性（P〈0．05）。AA基因型哮喘病人血清的IgE浓度显著升高（P〈0．01）,但其血清IL-10浓度比CC基因型携带者明显降低（P〈0．01）。结论：IL-10基因启动子-627位点多态性与过敏性哮喘的发生有一定的相关性,等位基因A是哮喘患病的风险基因,而等位基因C则是哮喘病的保护基因。     

Association of common variants of vascular endothelial growth factor and interleukin-18 genes with allograft survival in renal transplant recipients of North India

Increased vascular endothelial growth factor (VEGF) production promotes enhanced endothelial permeability, enhanced leukocyte migration into the allograft, thereby leading to a clinically recognized rejection episode. Interleukin-18 (IL-18), a potent proinflammatory cytokine, may also be involved in mechanisms of kidney allograft rejection. The present study was, therefore, undertaken to investigate the association of functional polymorphisms in VEGF (2578C>A, 1154A>G) and IL-18 (607C>A, 137G>C) genes with risk of allograft rejection in renal transplant recipients of North India. Two hundred renal transplant recipients, 150 matched recipients-donors, and 200 unrelated healthy individuals were genotyped by amplification refractory mutation specific polymerase chain reaction and by polymerase chain reaction-restriction fragment length polymorphism. Variant allele VEGF 1154A>G (p?=?0.56; odds ratio [OR]?=?1.32) and variant allele (p?=?0.004, OR?=?1.54) and variant genotype (p?=?0.007, OR?=?3.26) of IL-18 607C>A, GC of IL-18 137G>C (p?=?0.043, OR?=?0.63) were significantly different in healthy individuals as compared with the patients with renal transplant. When 114 nonrejectors were compared with 36 rejectors (150 recipients) for association with allograft rejection, significant association was observed in heterozygous genotype of VEGF 2578C>A (p?=?0.033), VEGF 1154A>G (p?=?0.024). In IL-18 137G>C, CC genotype, C allele showed protective association with allograft rejection. Kaplan-Meier analysis indicated a higher mean time for first rejection episode in CA genotype carriers (31 months) as compared with AA (29 months) for VEGF 2578C>A (log p?=?0.035). In VEGF, the haplotypes A-A and A-G (2578-1154) were associated with reduced risk and in IL-18 607A-137G, they were associated with high risk for allograft rejection. This observation suggests these polymorphisms are an ideal marker for prediction of pretransplant allograft outcome.     

Calcium ionophore (A23187) increases interleukin 1 (IL-1) production by human peripheral blood monocytes and interacts synergistically with IL-1 to augment concanavalin A stimulated thymocyte proliferation

The effects of calcium ionophore, A23187, on production of interleukin 1 (IL-1) by human peripheral blood monocytes (PEMo) and on murine thymocyte proliferation were examined. A23187 induced IL-1 production by human PBMo. The optimal dose was 10(-6) M. Although IL-1 production induced by A23187 was less than that by lipopolysaccharide (LPS) or silica, A23187 together with LPS had a synergistic effect on induction of IL-1. A23187 also had a more marked synergistic effect in concert with Concanavalin A and/or IL-1 on murine thymocyte proliferation. The optimal dose was also 10(-6) M. This represents the first report suggesting that monocytes or the monocyte product, IL-1, may contribute to the mitogenic effect of A23187 for thymocytes.     

Association of TNF-alpha,IL-6 and IL-1beta gene polymorphisms with polycystic ovary syndrome: a meta-analysis

Background

Several studies on the association of TNF-alpha (−308 G/A), IL-6 (−174 G/C) and IL-1beta (−511 C/T) polymorphisms with polycystic ovary syndrome (PCOS) risk have reported conflicting results. The aim of the present study was to assess these associations by meta-analysis.

Results

A total of 14 eligible articles (1665 cases/1687 controls) were included in this meta-analysis. The results suggested that there was no obvious association between the TNF-alpha (−308 G/A) polymorphism and PCOS in the overall population or subgroup analysis by ethnicity, Hardy–Weinberg equilibrium (HWE) in controls, genotyping method, PCOS diagnosis criteria, and study sample size. Also, no obvious association was found between the TNF-alpha (−308 G/A) polymorphism and obesity in patients with PCOS (body mass index [BMI] ≥ 25 kg/m² vs. BMI < 25 kg/m²). Regarding the IL-6 (−174 G/C) polymorphism, also no association was found in the overall population in heterozygote comparison, dominant model, and recessive model. Even though an allelic model (odds ratio [OR] = 0.63, 95% confidence interval [CI] = 0.41–0.96) and a homozygote comparison (OR = 0.52, 95% CI = 0.30–0.93) showed that the IL-6 (−174 G/C) polymorphism was marginally associated with PCOS. Further subgroup analysis suggested that the effect size was not significant among HWE in controls (sample size ≤ 200) and genotyping method of pyrosequencing under all genetic models. Similarly, there was no association between the IL-1beta (−511 C/T) polymorphism and PCOS in the overall population or subgroup analysis under all genetic models. Furthermore, no significant association was found between the IL-1beta (−511 C/T) polymorphism and several clinical and biochemical parameters in patients with PCOS.

Conclusions

The results of this meta-analysis suggest that the TNF-alpha (−308 G/A), IL-6 (−174 G/C), and IL-1beta (−511 C/T) polymorphisms may not be associated with PCOS risk. However, further case–control studies with larger sample sizes are needed to confirm our results.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-015-0165-4) contains supplementary material, which is available to authorized users.     

Interleukin-18 gene promoter and serum level in women with ovarian cancer

IL-18, initially defined as a potent inducer of IFN- γ production, is a systemic, multifunctional cytokine with both pro-cancerous and anti-cancer activities. The contribution of the IL-18 promoter polymorphisms at positions −607 (C/A) and −137 (G/C) to cancer development has been reported. We sought to examine IL-18 serum level and its polymorphisms in Iranian women with ovarian cancer. Single nucleotide polymorphisms (SNPs) at positions −607 (C/A) and −137 (G/C) were analyzed by allele-specific polymerase chain reaction in 85 women with ovarian cancer and 158 healthy controls. IL-18 serum level was determined using ELISA method. No significant association was found between the allele, genotype, and haplotype distributions of the SNPs and ovarian cancer. Mean IL-18 serum level was significantly higher in patients than in controls (P = 0.008). Comparing IL-18 serum levels with genotypes at positions −607 and −137 revealed no significant difference. No association was also found between IL-18 levels and the disease stage. In conclusion, our results indicate that IL-18 promoter polymorphisms at positions −607 (C/A) and −137 (G/C) appear not to confer susceptibility to ovarian cancer in Iranian population; however, IL-18 serum level increases in ovarian cancer patients.     

Virus infection activates IL-1 beta and IL-18 production in human macrophages by a caspase-1-dependent pathway.

Monocytes and macrophages play a significant role in host's defense system, since they produce a number of cytokines in response to microbial infections. We have studied IL-1 beta, IL-18, IFN-alpha/beta, and TNF-alpha gene expression and protein production in human primary monocytes and GM-CSF-differentiated macrophages during influenza A and Sendai virus infections. Virus-infected monocytes released only small amounts of IL-1 beta or IL-18 protein, whereas 7- and 14-day-old GM-CSF-differentiated macrophages readily produced these cytokines. Constitutive expression of proIL-18 was seen in monocytes and macrophages, and the expression of it was enhanced during monocyte/macrophage differentiation. Expression of IL-18 mRNA was clearly induced only by Sendai virus, whereas both influenza A and Sendai viruses induced IL-1 beta mRNA expression. Since caspase-1 is known to cleave proIL-1 beta and proIL-18 into their mature, active forms, we analyzed the effect of a specific caspase-1 inhibitor on virus-induced IL-1 beta and IL-18 production. The release of IL-1 beta and IL-18, but not that of IFN-alpha/beta or TNF-alpha, was clearly blocked by the inhibitor. Our results suggest that the cellular differentiation is a crucial factor that affects the capacity of monocytes/macrophages to produce IL-1 beta and IL-18 in response to virus infections. Furthermore, the virus-induced activation of caspase-1 is required for the efficient production of biologically active IL-1 beta and IL-18.     

Functional IL-18 promoter gene polymorphisms in Tunisian nasopharyngeal carcinoma patients

Objectives: There is growing evidence suggesting that IL-18 levels may affect individual to virus-associated neoplasia and that single nucleotide polymorphisms (SNPs) within the gene may influence its production. In this study we wanted to know whether IL-18 polymorphisms at positions −607 C/A and −137 G/A are associated with susceptibility and/or are markers of nasopharyngeal carcinoma (NPC) prognosis. Methods: Using the restriction fragment length polymerase chain reaction (RFLP-PCR), 163 Tunisian patients and 164 healthy controls were genotyped. Results: No significant association was found between each studied polymorphism and NPC. However, we noted that the −607 A allele, which is associated with lower IL-18 production, increased the risk of advanced tumor stages (OR = 3.59; P = 0.017) and that this risk was more pronounced among the older patient’s age at onset (OR = 3.85; P = 0.012). Moreover, the significant difference in CA/GG haplotype frequency distribution between young and older patients supported the idea that NPC disease has biologically different features between age sub-groups. Conclusion: Functional IL-18 gene polymorphisms do not influence the susceptibility to NPC in Tunisians but may contribute to disease onset and aggressiveness.     

Association of the IL-6 -174G/C gene polymorphism with knee osteoarthritis in a Thai population

Osteoarthritis is a chronic progressive degenerative joint disease characterized by age-related regressive change in articular cartilage. A single nucleotide polymorphism has been described at position -174 of the interleukin-6 (IL-6) promoter region, leading to three possible genotypes, GG, GC, and CC. We investigated a possible association of the IL-6 -174G/C gene polymorphism with knee osteoarthritis in a Thai population. Genotype distributions and allelic frequencies of the IL-6 -174G/C polymorphism were investigated in 115 knee osteoarthritis patients and 100 healthy controls. Genotyping was performed using PCR-RFLP. The genotype distribution of IL-6 was 79 GG, 36 GC, 0 CC in knee osteoarthritis patients and 88 GG, 12 GC, 0 CC in controls. The frequency of the GC genotype in subjects with knee osteoarthritis was higher than in controls (P< 0.001). Logistic regression analysis showed that the GC genotype was independently associated with increased risk of knee osteoarthritis (odds ratio = 3.3, 95% confidence interval = 1.6-6.9, P = 0.001). These findings suggest that the -174G/C polymorphism of the IL-6 gene promoter plays a role in the pathogenesis of knee osteoarthritis.     

Calcium ionophore A23187 does not stimulate lipopolysaccharide nonresponsive C3H/HeJ peritoneal macrophages to produce interleukin 1

C3H/HeJ mice are hyporesponsive to the biologic effects of bacterial lipopolysaccharide (LPS). The defect in the strain of mice is believed to be due to the expression of a mutant allele designated Lpsd at the chromosome four locus. The molecular basis of this hyporesponsiveness is not known, but it may result from some defective membrane signal transductions. To examine this possibility, we compared the abilities of interleukin 1 (IL-1) production by C3H/HeJ macrophages with those by C3H/He macrophages (LPS responsive) after stimulation with the calcium ionophore A23187 or phorbol myristate acetate (PMA). A23187 induced IL-1 production by C3H/He macrophages, but it did not induce IL-1 production by C3H/HeJ macrophages and neither did LPS. However, it had the ability to increase intracellular free Ca2+ in C3H/HeJ macrophages as well as in C3H/He macrophages, this being examined by the changes in cytosolic Ca2+ in the macrophages by using Quin 2. In contrast, PMA was able to induce IL-1 production by both C3H/He and C3H/HeJ macrophages without increasing intracellular Ca2+. Since polymyxin B did not inhibit A23187- or PMA-induced IL-1 production by C3H/He macrophages, these results are not due to the little amount of LPS in culture medium, but due to their own characteristics. A calmodulin antagonist W-7 effectively inhibited A23187-induced IL-1 production by C3H/He macrophages. However, it hardly inhibited LPS-induced IL-1 production except at high concentration, and it caused no inhibition of the PMA-stimulated one. These results suggest that the blocking sites expressed phenotypically by the Lpsd are shared by LPS- and A23187-stimulated cellular processes, although the actions of LPS and A23187 are different from each other. In addition to the direct study with LPS or lipid A, A23187 should provide another useful approach to clarify the molecular mechanisms of Lpsd defect in C3H/HeJ macrophages.