易感基因多态性与支气管哮喘的相关性研究

目的:探讨白介素-4(Interleukin-4,IL-4)基因589位点、白介素-4受体(interleukin-4 receptor,IL-4R)基因576位点多态性与内蒙古地区汉族支气管哮喘患者是否存在遗传易感性,是否与血清总IgE浓度相关.方法:采用聚合酶链式反应-限制性片段长度多态性(PCR-RFLP)方法检测内蒙古地区62例支气管哮喘患者和30例汉族正常人群IL-4基因的589位点、IL-4R基因的576位点多态性,进行基因型和基因频率分析,同时采用Elisa法检测患者血清总IgE浓度.结果:哮喘组IL-4基因启动子区-589(C/T)位点多态性分布频率与对照组比较,两组间基因型频率分析(X2=3.437,P=0.179),无显著性统计学差异(P＞0.05);两组基因频率分析(X2=9.405,P=0.002),有显著性差异(P＜0.05).哮喘组IL-4R基因启动子区-576(Q/R)位点多态性分布频率与对照组比较,两组间基因型频率分析(X2=0.815,P=0.665),无显著性统计学差异(P＞0.05),两组基因频率分析(X2=0.245,P=0.621),无显著性差异(P＞0.05).哮喘组血清总IgE浓度高于对照组,有显著性差异(t=6.367,P=0.00,P＜0.05).结论:内蒙古地区汉族人群哮喘组中,IL-4基因启动子区-589(C/T)位点多态性与支气管哮喘的发病无显著性差异;IL-4R基因-576(Q/R)位点多态性与支气管哮喘的发病无显著性差异;患者组血清总IgE显著高于对照组,但是与IL-4基因启动子区-589(C/T)位点多态性和IL-4R基因-576(Q/R)位点多态性没有相关性.     

Cytokine gene polymorphisms and susceptibility to cutaneous leishmaniasis in Iranian patients

Cutaneous Leishmaniasis (CL) is one of the most prevalent clinical forms of leishmaniasis. Preliminary data suggest that cytokine gene polymorphisms can contribute to resistance or susceptibility to CL. Therefore, we investigated the association of functional polymorphisms in four cytokine genes with susceptibility to, and clinical outcome of CL. A total of 201 patients with self-healing cutaneous leishmaniasis (SCL) and 92 asymptomatic infected controls (AIC) from Fars province as well as 58 patients with chronic cutaneous leishmaniasis (CCL) and their 688 normal controls (normal Iranian population or NIP) who were collected from the different areas of Iran were included in the study. The allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) or PCR-RFLP (restriction fragment length polymorphism) methods were used for genotyping. The frequency of TNF-alpha -308 G-->A and TNF-beta +252 G-->A gene polymorphisms were not different between studied groups. Distribution of IFN-gamma +874 A-->T and IL-4 -590 C-->T polymorphism were also compared between SCl or CCL patients and their controls. IFN-gamma +874 A-->T polymorphism was less common in CCL patients compared to the NIP (chi(2)=12.53, p=0.0019). Significant differences in frequency of IL-4 -590 C -->T polymorphism were also found between the SCL and AIC (chi(2)=8.64, p=0.003). In conclusion, our results suggest that functional genetic variants in the IL-4 promoter could influence the risk of developing CL while the polymorphism in the first intron of the IFN-gamma gene might influence the progression of disease towards CCL.     

Cytokine genes and disease susceptibility

Complex networks of cytokines interact in a dynamic way to homeostatically regulate immune responses and other biological pathways. It is, therefore, not surprising that variation in cytokine level has been correlated with disease susceptibility and process. A fundamental issue is whether such variation is a primary cause for disease or reflects secondary inflammatory change. This can be unravelled by investigating cytokine gene polymorphism to determine whether a genetic basis for cytokine dysregulation is associated with disease. Thousands of disease association studies investigating cytokine gene polymorphisms have been reported although many have not been replicated. This is largely due to lack of statistical power, poor definition of clinical phenotype and lack of matching between cases and controls. An appropriate study design should include: Any genetic analysis of cytokine genes in disease studies should also take into account the fact that cytokines rarely manifest their effects in isolation but rather work in complex regulatory networks. Thus, gene-gene and gene-environment interactions may be at the centre of any disease association. Statistical methods are now being introduced to determine such relationships and this should ultimately allow a more accurate estimate of disease risk for individuals with particular cytokine gene profiles.     

Apolipoprotein A-I gene polymorphism and susceptibility of non-insulin-dependent diabetes mellitus

A polymorphic DNA sequence of the apolipoprotein (apo) A-I gene region was studied in relation to non-insulin-dependent diabetes mellitus (NIDDM). We have examined 100 patients with NIDDM and 100 control subjects as well. The presence of a unique 2.5-kilobase (kb) EcoRI fragment was found in 13 diabetic patients and two control subjects with family history of diabetes. There were six homozygotes and nine heterozygotes among them. The analysis of clinical data did not confirm any linkage between the presence of a 2.5-kb fragment and atherosclerosis. These findings suggest that the observed defect in the apo A-I gene region may confer susceptibility to NIDDM.     

CYP17 gene polymorphism and prostate cancer susceptibility in a Tunisian population

Prostate cancer (PCa) formation has been reported to be associated with androgen. Two key steps in the sex steroid synthesis are mediated by the enzyme cytochrome P450c 17α which is encoded in the CYP17 gene. The A2 allele of the CYP17 gene has been thought to be associated with increased functional activity of this steroidogenic enzyme. Consequently, the A2 allele has been examined as a biomarker of individual susceptibility to hormone-related diseases among men. We prospectively assessed the association between the A2 allele of CYP17 and PCa risk among 125 cases and 125 controls in a case–control study. Our aim was to investigate whether a polymorphism of CYP17 gene could be used as a genetic marker for associating PCa. The result revealed a significant association between the CYP17 polymorphic genotypes and PCa. Therefore, CYP17 gene polymorphism is likely contributed to the pathogenesis of PCa but not to disease severity.     

BoLA-DRB3 gene polymorphism and FMD resistance or susceptibility in Wanbei cattle

For the further characterization of foot-and-mouth disease virus (FMDV)-induced foot-and-mouth disease, we investigated the association between polymorphism of BoLA-DRB3 gene and FMD resistance/susceptibility of Wanbei cattle challenged with FMDV. One hundred cattle were challenged with FMDV and exon 2 of BoLA-DRB3 genes was amplified by hemi-nested polymerase chain reaction from asymptomatic animals and from animals with FMD. PCR products were characterized by the RFLP technique using restriction enzymes Hae III. The results revealed extensive polymorphisms, 6 RFLP patterns were identified. By analyzing alleles and genotypic frequencies between healthy and infection with FMD cattle, we found that allele Hae III A was associated with susceptibility to FMD in Wanbei cattle (P < 0.05), whereas Hae III C was associated with resistance to FMD (P < 0.01) and may have a strong protective effect against FMD. Hae IIICC and Hae III BC genotype were associated with resistance to FMD (P < 0.01). By contrast, Hae III AA genotype was associated with susceptibility to FMD (P < 0.01). Sequence analysis show that 89 amino acids were translated in exon 2 of BoLA-DRB3 and 13.70 % of nucleotide mutated, which resulted in 14.61 % of amino acid change. One PKC, one Tyr and one CAMP phosphorylation were increased; the hydrophobicity and secondary structure of proteins produced change after amino acid substitution. These results revealed that Wanbei cattle had the ability of resistance to disease by mutation which result changes of the protein structure to perform the regulation of the cell using different signaling pathways in the long process of choice evolution.     

Cytokine gene polymorphism and graft-versus-host disease: a survey in Iranian bone marrow transplanted patients

Graft versus host disease (GVHD) is a major complication of bone marrow transplantation (BMT). Numerous studies have shown the potential role of cytokine genotypes in the occurrence of GVHD. In this retrospective, case–control study we aimed to investigate the association between 13 cytokine genes and acute GVHD (aGVHD) after HLA-identical sibling BMT in 91 Iranian subjects. Negative association was found between aGVHD and donor IL-10/GCC haplotype or donor IL-4Ra-A allele in the population study. When compared within the leukemia subgroup, we observed positive association between recipient IL-1α ?889/C allele and aGVHD. Also there were negative association between recipient IL-10/CAA haplotype and donor IL-4Ra/A allele and development of aGVHD. Among the different genotypes only donor IL-4Ra and donor IL-12 showed significant association. We conclude that several cytokine polymorphisms are positively and negatively associated with aGVHD in Iranian HLA matched siblings, of which IL-4Ra and IL-12 may play important roles.     

TNF-308 gene polymorphism and tuberculosis susceptibility: a meta-analysis involving 18 studies

A number of studies have investigated the association between TNF-308 (rs1800629 G/A) polymorphisms and the susceptibility towards tuberculosis (TB) in different populations. However, many of these studies provided inconsistent results. In this study, a systematic review and meta-analysis of the published studies was performed to gain a clearer understanding of this association. The PubMed, Embase, Web of Science and CNKI databases were searched for case–control studies published up to Jan 2011, we used no lower date limit. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. A total of 18 publications from 2001 to 2010, involving 2584 TB cases and 3817 controls were included. Overall, for the A allele carriers (G/A + A/A) vs. homozygote GG, the pooled OR was 1.03 (95% CI = 0.89–1.19; P = 0.912 for heterogeneity). For the allele A vs. allele G, the pooled OR was 1.07 (95% CI = 0.93–1.22; P = 0.013 for heterogeneity). In the stratified analysis by ethnicity, among Asians significant risk was found for allele A vs. allele G (OR = 1.22, 95% CI = 1.02–1.47; P = 0.152 for heterogeneity), no significant risks were found among Caucasians. This meta-analysis indicated that the TNF-308 polymorphism was not associated with the risk of TB in the total population, however the significant risk for TNF-308 A allele was found among Asians not Caucasians.     

A major susceptibility gene for asthma maps to chromosome 14q24

Asthma is a complex genetic disorder with a heterogeneous phenotype, largely attributed to the interactions among many genes and between these genes and the environment. Numerous loci and candidate genes have been reported to show linkage and association to asthma and atopy. Although some studies reporting these observations are compelling, no gene has been mapped that confers a sufficiently high risk of asthma to meet the stringent criteria for genomewide significance. Using 175 extended Icelandic families that included 596 patients with asthma, we performed a genomewide scan with 976 microsatellite markers. The families were identified by cross-matching a list of patients with asthma from the Department of Allergy/Pulmonary Medicine of the National University Hospital of Iceland with a genealogy database of the entire Icelandic nation. We detected linkage of asthma to chromosome 14q24, with an allele-sharing LOD score of 2.66. After we increased the marker density within the locus to an average of one microsatellite every 0.2 cM, the LOD score rose to 4.00. We designate this locus "asthma locus one" (AS1). Taken together, these results provide evidence of a novel susceptibility gene for asthma on chromosome 14q24.     

Impact of glutathione-S-transferase gene polymorphisms on enzyme activity, lung function and bronchial asthma susceptibility in Egyptian children

Background

Asthma is a complex multifactorial disease with an obvious genetic predisposition. Polymorphisms of the glutathione-S-transferase (GST) genes are known risk factors for some environmentally-related diseases. The aim of the present study was to investigate the role of polymorphisms in the GSTT1, GSTM1 and GSTP1 genes and asthma susceptibility in Egyptian children, and to analyze their effect on GST activity and lung function.

Methods

GSTT1 and GSTM1 gene polymorphism was genotyped using the multiplex polymerase chain reaction (PCR) and GSTP1 ILe105Val polymorphism was determined using PCR-restriction fragment length polymorphism (PCR-RFLP) in 168 healthy and 126 asthmatic children (82 atopic and 44 nonatopic). Also GST enzyme activity and lung function were evaluated.

Results

Asthmatic children had a significant higher prevalence of the GSTM1 null (P = 0.003) and significant lower prevalence of GSTP1 Val/Val genotypes (P = 0.02) than control group. Lung function was significantly decreased in GSTM1 null genotype and GSTP1 Ile/Ile genotype. GSTP1 Val/Val genotypes and GSTM1 null genotype had a significant decrease in plasma GST activity.

Conclusions

GST genes polymorphisms may play an important role in pathogenesis and susceptibility to asthma in children.     

The gene encoding interleukin-13: a susceptibility locus for asthma and related traits

Respirable antisense oligonucleotides (RASONs), which attenuate specific disease-associated mRNAs, represent a new class of respiratory therapeutics with considerable potential. RASONs overcome previous obstacles that have impeded the development of antisense therapeutics targeting diseases in other organ systems. RASONs are delivered directly to the target tissue via inhalation; their uptake seems to be enhanced by cationic properties inherent in pulmonary surfactant, and, because of the markedly different target properties of mRNA and proteins, they can have very long durations of effect compared with traditional drugs targeting the protein of the same gene. RASONs contain chemical modifications that decrease their degradation by cellular nucleases. However, total insensitivity to nucleases is probably not an optimal design criterion for RASONs, because moderate nuclease sensitivity can prevent their systemic delivery, decreasing the potential for systemic toxicity. EPI-2010 is a 21-mer phosphorothioate RASON that attenuates bronchoconstriction, inflammation and surfactant depletion in preclinical models of human asthma, has a duration of effect of seven days, and seems to undergo minimal systemic delivery.     

The gene encoding interleukin-13: a susceptibility locus for asthma and related traits

Asthma is a complex inflammatory disorder controlled by both genetic and environmental influences. Multiple genetic analyses have identified the T helper type 2 (Th2) cytokine gene cluster on chromosome 5q as a susceptibility locus for asthma. Recently, the Th2 cytokine interleukin-13 has been shown to be a critical mediator of the asthma phenotype in murine models. In this commentary we discuss several recent studies that have identified polymorphisms in the gene encoding interleukin-13. The consistent genetic associations of interleukin-13 with asthma and related traits across diverse ethnic populations in these studies provides strong support for the candidacy of this cytokine as a susceptibility locus for asthma and atopy on chromosome 5q31.     

Glutathione S-transferase P1 gene polymorphism and bladder cancer susceptibility: an updated analysis

Studies investigating the association between glutathione S-transferase P1 (GSTP1) gene polymorphism and bladder cancer (BC) risk have reported conflicting results. In order to clarify the effect of GSTP1 polymorphism on the BC susceptibility, we conducted an updated system review of published epidemiology studies to provide more precise evidence. We performed a systematic search of PubMed, EMBASE, and China National Knowledge Infrastructure (CNKI). 20 studies with 4,428 BC cases and 5,457 controls were identified. The combined analyses based on all studies showed that there was a significant difference in the genotype distribution in GSTP1(A313G) polymorphism between BC cases and controls not only in Asians (GG vs. AA?+?AG, OR?=?1.59, 95?% CI?=?1.01?C2.51) but also in Caucasians (GG vs. AA?+?AG, OR?=?1.51, 95?% CI?=?1.11?C2.06). Upon stratification for smoking status, we observed no statistically significant difference in genotype distribution of GSTP1 in ever-smokers. Combination of the high-risk genotypes (GSTM1 null?+?GSTT1 null?+?GSTP1 313 A/G or G/G) demonstrated further increase in the BC risk (OR?=?6.64, 95?%CI?=?3.63?C12.16). This meta-analysis suggests that GSTP1 313 G/G polymorphism is a strong predisposing risk factor for BC.     

Cytokine profiles in asthma families depend on age and phenotype

Background

Circulating cytokine patterns may be relevant for the diagnosis of asthma, for the discrimination of certain phenotypes, and prognostic factors for exacerbation of disease.

Methodology/Principal Findings

In this study we investigated serum samples from 944 individuals of 218 asthma-affected families by a multiplex, microsphere based system detecting at high sensitivity eleven asthma associated mediators: eotaxin (CCL11), granulocyte macrophage stimulating factor (GM-CSF), interferon gamma (IFNγ), interleukin-4 (IL-4), IL-5, IL-8, IL-10, IL-12 (p40), IL-13, IL-17 and tumor necrosis factor alpha (TNFα). Single cytokine levels were largely similar between asthmatic and healthy individuals when analysing asthma as single disease entity. Regulatory differences between parental and pediatric asthma were reflected by six of the eleven mediators analyzed (eotaxin, IL-4, IL-5, IL-10, IL-12, TNFα). IL-12 (p40) and IL-5 were the best predictor for extrinsic asthma in children with an increased odds ratio of 2.85 and 1.96 per log pg/ml increase (IL-12 (p40): 1.2–6.8, p = 0.019, and IL-5: 1.2–2.5, p = 0.025). Frequent asthma attacks in children are associated with elevated IL-5 serum levels (p = 0.013). Cytokine patterns seem to be individually balanced in both, healthy and diseased adults and children, with various cytokines correlating among each other (IL-17 and IFNγ (r_s = 0.67), IL-4 and IL-5 (r_s = 0.55), IFNγ and GM-CSF (r_s = 0.54)).

Conclusion/Significance

Our data support mainly an age- but also an asthma phenotype-dependent systemic immune regulation.     

西藏登山队员谷胱甘肽硫转移酶基因多态性与低氧反应敏感性关系的研究

目的：考察西藏登山队员谷胱甘肽硫转移酶（GSTs）基因多态性与高原低氧反应敏感性之间的关系。方法：采用高原-平原对照法,通过多重PCR和PCR—RFLP技术检测西藏登山队员和平原汉族人群体内谷胱甘肽硫转移酶基因多态性。结果：GSTT1缺失基因型频率在西藏登山队员和平原汉族人群中有显著性差异（P〈0．05）,OR=1．86（95％CI=101～3．39）;GSTP1-105变异基因型频率差异非常显蓍（P〈0．01）,OR=2．19（95％CI=1．16～4．13）．其等位基因A和G在两组人群中有显著性差异（P〈0．01）。而GSTM1缺失基因型无显著性差异（P〉0．05）,OR=0．78（95％CI=0．43～1．42）。结论：GSTT1和GSTP1-105基因型可能与高原低氧反应敏感性有关。     

Ala45Thr polymorphism of the NEUROD1 gene and diabetes susceptibility: a meta-analysis

A meta-analysis assessed whether the Ala45Thr polymorphism of the neurogenic differentiation 1 (NEUROD1) gene is associated with increased risk of diabetes mellitus type 1 (T1D) or type 2 (T2D). Fourteen case-control studies were analyzed, including genotype data on 3,057 patients with diabetes (T1D n=1,213, T2D n=1,844) and 2,446 controls. Overall and race-specific summary odds ratios (ORs) were obtained with fixed and random effects models. The Thr allele did not significantly increase the overall risk for T1D (OR 1.27 [0.94–1.71], P=0.12) or T2D (OR 1.07 [0.90–1.28], P=0.46). The Thr allele conferred increased susceptibility in subjects of Asian racial descent to T1D (OR 1.88 [1.10–3.21], P=0.020), but not to T2D (OR 1.08 [0.74–1.56], P=0.70). There was no association in subjects of European descent (OR 0.97 [0.76–1.23], P=0.80 for T1D; OR 1.03 [0.88–1.21], P=0.68 for T2D). Larger studies seemed to show more conservative estimates for the association with T1D (P=0.083). The Ala45Thr polymorphism of the NEUROD1 gene has no effect on susceptibility to T2D. It may however be a risk factor for susceptibility to T1D, in particular for subjects of Asian descent, although bias cannot be totally excluded.     

Lack of association between methylenetetrahydrofolate reductase gene A1298C polymorphism and breast cancer susceptibility

Published data on the association between methylenetetrahydrofolate reductase gene (MTHFR) A1298C polymorphism and breast cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Medline, PubMed, Embase, and Web of Science were searched. Crude ORs with 95% CIs were used to assess the strength of association between the MTHFR A1298C polymorphism and breast cancer risk. The pooled ORs were performed for co-dominant model (AC vs. AA, CC vs. AA), dominant model (CC+AC vs. AA), and recessive model (CC vs. AC+AA), respectively. A total of 26 studies including 12,244 cases and 15,873 controls were involved in this meta-analysis. Overall, no significant associations were found between MTHFR A1298C polymorphism and breast cancer risk when all studies pooled into the meta-analysis (AC vs. AA: OR=0.99, 95% CI 0.94-1.05; CC vs. AA: OR 0.99, 95% CI 0.90-1.09; dominant model: OR=0.99, 95% CI 0.95-1.04; and recessive model: OR=0.98, 95% CI 0.90-1.08). In the subgroup analysis by ethnicity or study design, still no significant associations were found for all comparison models. In conclusion, this meta-analysis suggests that the MTHFR A1298C polymorphism may be not associated with breast cancer development. However, large sample and representative population-based studies with homogeneous breast cancer patients and well matched controls are warranted to confirm this finding.     

Discovering susceptibility genes for asthma and allergy

Asthma and asthma-related traits are complex diseases with strong genetic and environmental components. Rapid progress in asthma genetics has led to the identification of several candidate genes that are associated with asthma-related traits. Typically the phenotypic impact of each of these genes, including the ones most often replicated in association studies, is mild, but larger effects may occur when multiple variants synergize within a permissive environmental context. Despite the achievements made in asthma genetics formidable challenges remain. The development of novel, powerful tools for gene discovery, and a closer integration of genetics and biology, should help to overcome these challenges.