Variation of interleukin 8 -251 A>T polymorphism in worldwide populations and intra-ethnic differences in Japanese populations

IL-8 (CXCL8) Correlations with Psychoneuroimmunological Processes and Neuropsychiatric Conditions

Interleukin-8 (IL-8/CXCL8), an essential CXC chemokine, significantly influences psychoneuroimmunological processes and affects neurological and psychiatric health. It exerts a profound effect on immune cell activation and brain function, suggesting potential roles in both neuroprotection and neuroinflammation. IL-8 production is stimulated by several factors, including reactive oxygen species (ROS) known to promote inflammation and disease progression. Additionally, CXCL8 gene polymorphisms can alter IL-8 production, leading to potential differences in disease susceptibility, progression, and severity across populations. IL-8 levels vary among neuropsychiatric conditions, demonstrating sensitivity to psychosocial stressors and disease severity. IL-8 can be detected in blood circulation, cerebrospinal fluid (CSF), and urine, making it a promising candidate for a broad-spectrum biomarker. This review highlights the need for further research on the diverse effects of IL-8 and the associated implications for personalized medicine. A thorough understanding of its complex role could lead to the development of more effective and personalized treatment strategies for neuropsychiatric conditions.

The IL-8 Gene Polymorphisms in Behçet's Disease Observed in Denizli Province of Turkey

Behçet's disease is a multisystemic inflammatory disorder as a triad of symptoms including recurrent oral and genital aphthous ulceration and uveitis with unknown pathogenesis. IL-8, a proinflammatory cytokine, has been found increased in the active stage of BD. DNA samples were obtained from 88 patients with BD and 112 healthy control subjects in Denizli province of Turkey. All genotyping experiments of SNPs in IL-8 gene were performed using polymerase chain reaction-restriction fragment polymorphism. We found that IL-8 -845 T > C and -738 T > A sites are non-polymorphic. There were no differences in the polymorphisms of IL-8 +396 G/T, +781 C/T, and +1633 C/T sites except IL-8 -251 T > A in between patients and healthy controls. Analysis of IL-8 polymorphisms indicates that the distribution of frequencies seems to be associated with -251 T > A and gender, -251 T > A and erythema nodosum, -251 T > A and ocular involvement, +781 C > T and erythema nodosum, +396 G > T and pathergy positivity, and +1633 C > T and papulopustular lesion. We demonstrated that the frequencies of IL-8 haplotypes were significantly different with BD patients than control group. We found that the distribution of IL-8 haplotypes was significantly different with genital ulcers, ocular involvement, positive pathergy test, erythema nodosum, papulopustular lesions, and arthritis with BD patients than healthy control individuals. Our study suggests that IL-8 gene polymorphisms may affect susceptibility to BD and increase the risk of developing disease. In order to confirm and assess the association of IL-8 and other cytokine gene polymorphisms in the pathophysiology of BD, large cohort studies are needed.

Association between TNF-α and IL-1β genotypes vs Helicobacter pylori infection in Indonesia

AIM: To investigate the correlation between the Helicobacter pylori (H. pylori) infection and host genetic background of healthy populations in Indonesia.

METHODS: In March 2007, epidemiological studies were undertaken on the general population of a city in Indonesia (Mataram, Lombok). The participants included 107 men and 187 women, whose ages ranged from 6 to 74 years old, with an average age of 34.0 (± 14.4) (± SD). The H. pylori of subject by UBT method determination, and through the polymerase chain reaction with confronting two-pair primers (PCR-CTPP) method parsing the single nucleotide polymorphism of interleukin (IL)-8, IL-4, IL-1β, CD14, tumor necrosis factor (TNF-α) and tyrosine-protein phosphates non-receptor type 11 (PTPN11) genotypes. The experimental data were analyzed by the statistical software SAS.

RESULTS: The H. pylori infection rates in the healthy Indonesian population studied were 8.4% for men and 12.8% for women; no obvious differences were noted for H. pylori infection rates by sex or age. TC genotypes of IL-4, TC and CC genotypes of TNF-α, and GA genotypes of PTPN11, were higher in frequency. Both CC and TC genotype of TNF-α T-1031C loci featured higher expressions in the healthy Indonesian population Indonesia studied of (OR = 1.99; 95%CI: 0.67-5.89) and (OR = 1.66; 95%CI: 0.73-3.76), respectively. C allele of IL-1β T-31C gene locus was at a higher risk (OR = 1.11; 95%CI: 0.70-1.73) of H. pylori infection, but no statistical significance was found in our study.

CONCLUSION: We reveal that the association between the TNF-α and IL-1β genotypes may be the susceptibility of H. pylori in the studied population.

The association of IL-8-251T/A polymorphism with complicated malaria in Karbi Anglong district of Assam

Amongst host genetic factors, cytokine gene polymorphism can be anticipated to be an important factor as qualitative, quantitative and time of secretion play an important role in disease outcome. We have investigated association of cytokine promoter SNPs with risk of Plasmodium falciparum malaria and disease severity in a case control study in malaria endemic Karbi Anglong district of Assam, India. Frequency of IL-8-251T/A (p=0.03 and p=0.01) and TGF-β1-509C/T (p=0.02 and p=0.03) was higher in malaria in comparison to control participants and non-malarial fever controls. Interestingly, a higher frequency of mutant allele of IL-10-819T/C was observed in non-malarial fever controls compared to malaria thus suggesting its role as a distinguishing marker of the two disease groups. Higher IL-8 expression and increased frequency of IL-8-251T/A in complicated malaria (p=0.002) was reported indicating its role in susceptibility to complicated malaria. In conclusion, our study suggests the role of mutant genotype of IL-8-251T/A as a marker of complicated malaria in our population. Surprisingly, decreased expression of TGF-β1 in uncomplicated malaria even in presence of high expressing mutant genotype was observed and needs to be investigated in context of the pool of activated cells producing the cytokine.

Genetic and expression analysis of SNPs in the human deoxyribonuclease II: SNPs in the promoter region reduce its in vivo activity through decreased promoter activity

Five SNPs in the human DNase II gene have been reported to be associated with rheumatoid arthritis (RA). Genotype and haplotype analysis of 14 SNPs, nine SNPs of which reported in the NCBI dbSNP database in addition to these five SNPs, was performed in healthy subjects. The enzymatic activities of the amino acid substituted DNase II corresponding to each SNP and serum DNase II in healthy Japanese, and promoter activities derived from each haplotype of the RA-related SNPs were measured. Significant correlations between genotype in each RA-related SNP and enzymatic activity levels were found; alleles associated with RA exhibited a reduction in serum DNase II activity. Furthermore, the promoter activities of each reporter construct corresponding to predominant haplotypes in three SNPs in the promoter region of the gene exhibited significant correlation with levels of serum DNase II activity. These findings indicate these three SNPs could alter the promoter activity of DNASE2, leading to a decline in DNase II activity in the serum through gene expression. Since the three SNPs in the promoter region of the DNase II gene could affect in vivo DNase II activity through reduction of the promoter activity, it is feasible to identify these SNPs susceptible to RA.

Global genetic analysis of all single nucleotide polymorphisms in exons of the human deoxyribonuclease I-like 3 gene and their effect on its catalytic activity

Deoxyribonucleases (DNases) have been suggested to be implicated in the pathophysiology of autoimmune diseases. In the DNASE1L3 gene encoding human DNase I-like 3 (DNase 1L3), a member of the DNase I family, only two non-synonymous (R178 H and R206C) single nucleotide polymorphisms (SNPs) have been examined [Ueki et al., Clin. Chim. Acta 2009, 407, 20-24]. Three other non-synonymous (G82R, K96N, and I243M) and four synonymous (S17S, T84T, R92R, and A181A) SNPs, in addition to R206C and R178H, have been identified in DNASE1L3. We investigated the distribution of all these SNPs in exons of the gene in eight Asian, three African, and three Caucasian populations worldwide using newly devised genotyping methods. SNP T84T showed polymorphism in all the populations, and R92R was polymorphic in the three African and three Caucasian populations; R206C was distributed only in Caucasian populations. In contrast, no minor allele was found in five SNPs (S17S, G82R, K96N, A181A, and I243M) in DNASE1L3. Generally, the DNase 1L3 gene shows relatively low genetic diversity with regard to exonic SNPs. When the effect of amino acid/nucleotide substitutions resulting from the SNPs on DNase 1L3 activity was examined, none of the synonymous SNPs had any effect on the DNase 1L3 activity, whereas among non-synonymous SNPs, SNP G82R diminished the activity of the enzyme, being similar to R206C. These findings permit us to assume that, although only R206 exhibits polymorphisms in a Caucasian-specific manner, at least SNPs G82R and R206C in DNASE1L3 might be potential risk factors for autoimmune disease.

Polymorphism of IL-8 in 251 allele and gastric cancer susceptibility: a meta-analysis

BACKGROUND

The relationship of gastric cancer to the presence of interleukin-8 (IL-8) 251 T/A has been reported with conflicting results.

AIM

To further explore the association of IL-8 251 allele polymorphism with gastric cancer susceptibility.

METHODS

We performed an extensive search of relevant studies and carried out a meta-analysis, including ten studies with 2,195 gastric cancer cases and 3,505 controls, to obtain a more precise estimate.

RESULTS

The combined results based on all studies showed that the IL-8 251 allele AA genotype was a risk factor for gastric cancer [AA versus TT: odds ratio (OR) = 1.363, 95% confidence interval (CI): 1.199-1.527]. In subgroup analysis, a clear effect of AA in IL-8 251 allele was shown in Asians (AA versus TT: OR = 1.593, 95% CI: 1.013-2.173) but not in Caucasians or Mexicans. When stratified by Lauren classification, we found that the IL-8 251 allele TA and AA polymorphism was significantly associated with the diffuse type of gastric cancer (TA versus TT: OR = 1.448, 95% CI: 1.177-1.720; AA versus TT: OR = 1.586, 95% CI: 1.128-2.044). The IL-8 251 AA genotype was found to be a risk factor for cardiac gastric cancer (AA versus TT: OR = 1.840, 95% CI: 1.112-2.568) but not for noncardiac gastric cancer.

CONCLUSIONS

This meta-analysis suggested that IL-8 251 allele A>T polymorphism might be a risk factor for gastric cancer.

Comparative study of atherosclerotic parameters in Mongolian and Japanese patients with hypertension and diabetes mellitus

AIM

Cardiovascular disease is becoming increasingly more problematic in Mongolia. The cardioankle vascular index (CAVI) and circulating C-reactive protein (CRP) are new atherosclerosis-related parameters, but no comparative studies of atherosclerotic parameters including CAVI and CRP are available between Mongolian and Japanese populations, such as disease populations of hypertension (HT) and diabetes mellitus (DM). Our study objective was to examine atherosclerotic profiles in HT and DM patients in both countries.

METHODS

From a hospital-based population, 156 Mongolian outpatients with HT and DM (men: 46%, mean age: 57.1 years) and 156 age- and sex-matched Japanese outpatients with HT and DM (men: 46%, age: 57.7) were recruited. Body mass index (BMI), heart rate (HR), blood pressure (BP), pulse pressure (PP), ankle-brachial index (ABI), ultrasonographic carotid intima-media thickness (IMT), blood total cholesterol (T-Cho), glucose, insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were measured, in addition to CAVI and CRP.

RESULTS

The levels of BMI, HR, BP, PP, insulin and IMT were significantly higher and T-Cho and glucose were significantly lower in the Mongolian patients in comparison to the Japanese patients. Particularly, the levels of CAVI (mean+/-SD) (8.1+/-1.1 vs. 8.8+/-1.2) and CRP(median[interquartile range])(0.05[0.03-0.12]vs. 0.19[0.09-0.42]mg/dL)were significantly higher in Mongolian than Japanese patients. These significant differences remained unchanged, even after taking into account multiple variables, including BP and HOMA-IR. In addition, except for CAVI in the subgroup of DM, generally similar trends regarding atherosclerotic parameters were seen in the subgroup by sex and disease (HT, DM and HT plus DM).

CONCLUSION

These findings suggest that Mongolian patients with HT and DM may be at higher risk for cardiovascular disease than Japanese patients.

Genetic and expression analysis of all 7 non-synonymous single nucleotide polymorphisms in the human deoxyribonuclease II gene, with potential relevance to autoimmunity

BACKGROUND

Several non-synonymous SNPs in the human DNase II gene, potentially relevant to autoimmunity, have been identified, but only limited population data are available. Also, the effects of these SNPs on the catalytic activity of the enzyme remain unknown.

METHODS

Genotyping of all the non-synonymous SNPs was performed in healthy subjects of 3 ethnic groups including 6 different populations using the PCR-RFLP technique. A series of mutants corresponding to each SNP was expressed in COS-7 cells and its activity was measured.

RESULTS

Five of the populations, including Japanese, Germans, Turks, Ghanaians and Ovambos, were typed as a single genotype at each SNP, but Koreans were not. Constructs derived from minor alleles at A58del, V284M, R298L and Q322Term exhibited drastically low or almost no activity.

CONCLUSION

The DNase II gene shows relatively low genetic diversity with regard to these non-synonymous SNPs, suggesting that the enzyme has been well conserved. A minor allele at V284M is distributed with a frequency of 0.013 in the database, and it seems plausible that levels of DNase II activity for the heterozygote are lower than those in individuals with the predominant homozygote. Our results may have clinical implications in relation to the prevalence of autoimmune diseases.

The interleukin-8-251 A allele is associated with increased risk of noncardia gastric adenocarcinoma in Helicobacter pylori-infected Koreans

BACKGROUND AND GOALS

Chronic inflammation associated with Helicobacter pylori infection is a risk factor of gastric adenocarcinoma. Interleukin-8 (IL-8) plays an important role in gastric mucosal inflammation induced by H. pylori infection. Recently, studies on the association of genetic polymorphisms of various proinflammatory cytokines with gastric carcinogenesis showed varying results on the basis of the ethnicity. We conducted this study to investigate the association of IL-8-251 A/T polymorphism with gastric carcinogenesis in H. pylori-infected Koreans.

STUDY

The IL-8-251 A/T polymorphism was identified by polymerase chain reaction-restriction fragment length polymorphism using DNA from a total of 605 H. pylori-infected subjects; 206 controls, 149 chronic atrophic gastritis and/or intestinal metaplasia, 97 gastric dysplasia, and 153 gastric adenocarcinoma. Degrees of gastric mucosal inflammation and mucosal IL-8 level were also assessed.

RESULTS

The IL-8-251 A carriers showed a higher risk of gastric adenocarcinoma (adjusted odds ratio 2.06, 95% confidence interval 1.16-3.68) than IL-8-251 T/T genotypes. The IL-8-251 A allele was also significantly associated with the degree of neutrophil infiltration, atrophy, and intestinal metaplasia in a younger age group. Among the chronic atrophic gastritis and/or intestinal metaplasia group, mucosal IL-8 level was significantly higher in subjects with IL-8-251 A allele than those with IL-8-251 T/T genotypes (P=0.011).

CONCLUSIONS

The IL-8-251 A allele is associated with higher IL-8 production, more severe inflammation, mucosal atrophy, and intestinal metaplasia than IL-8-251 T/T genotype in H. pylori-infected hosts. The IL-8-251 A allele may also increase the risk of gastric adenocarcinoma through an enhanced inflammatory process in H. pylori-infected Koreans.

Comparative study of the cardio-ankle vascular index and ankle-brachial index between young Japanese and Mongolian subjects

Mongolian people have higher mortality and morbidity rates due to cardiovascular disease (CVD) than Japanese people. The cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI) are both atherosclerosis-related indexes. Presently, there is no comparative information on CAVI and ABI among young subjects between Mongolian and Japanese people. A total of one hundred Mongolian (men: 39%, mean age: 20.9+/-2.2 years) and 115 Japanese volunteers (men: 39%, mean age: 22.0+/-1.8 years) were recruited from among university students. The body mass index (BMI), heart rate (HR), blood pressure (BP), CAVI, ABI, carotid intima-media thickness, blood total cholesterol (TC), glucose and C reactive protein levels were measured. The levels of BMI, HR and diastolic BP were significantly higher, and TC and glucose were significantly lower in the Mongolian subjects than in the Japanese subjects. The CAVI values (median (interquartile range): 6.5 (5.8-7.0) vs. 5.6 (5.2-6.0)) and ABI (1.11 (1.05-1.17) vs. 1.09 (1.05-1.15)) were significantly higher in the Mongolian subjects than in the Japanese subjects. The patterns of correlation between CAVI, ABI and other atherosclerotic parameters were different: in age-, gender- and BMI-adjustment correlation tests for CAVI and ABI, HR (r=-0.25 for CAVI and ABI) showed a correlation in the Mongolian subjects, and for ABI systolic BP (r=-0.28) showed a correlation in the Japanese subjects. These results suggest that Mongolian subjects may be at higher risk of CVD, even among younger individuals, than Japanese subjects.

The chemokine network. II. On how polymorphisms and alternative splicing increase the number of molecular species and configure intricate patterns of disease susceptibility

In this second review on chemokines, we focus on the polymorphisms and alternative splicings and on their consequences in disease. Because chemokines are key mediators in the pathogenesis of inflammatory, autoimmune, vascular and neoplastic disorders, a large number of studies attempting to relate particular polymorphisms of chemokines to given diseases have already been conducted, sometimes with contradictory results. Reviewing the published data, it becomes evident that some chemokine genes that are polymorphic have alleles that are found repeatedly, associated with disease of different aetiologies but sharing some aspects of pathogenesis. Among CXC chemokines, single nucleotide polymorphisms (SNPs) in the CXCL8 and CXCL12 genes stand out, as they have alleles associated with many diseases such as asthma and human immunodeficiency virus (HIV), respectively. Of CC chemokines, the stronger associations occur among alleles from SNPs in CCL2 and CCL5 genes and a number of inflammatory conditions. To understand how chemokines contribute to disease it is also necessary to take into account all the isoforms resulting from differential splicing. The first part of this review deals with polymorphisms and the second with the diversity of molecular species derived from each chemokine gene due to alternative splicing phenomena. The number of molecular species and the level of expression of each of them for every chemokine and for each functionally related group of chemokines reaches a complexity that requires new modelling algorithms akin to those proposed in systems biology approaches.

Proteome of human T lymphocytes with treatment of cyclosporine and polysaccharopeptide: Analysis of significant proteins that manipulate T cells proliferation and immunosuppression

The aberrant activation of T lymphocyte proliferation is one of the key events in organ transplant recipients and autoimmune disorders. The present study adopted a gel-based proteomics approach to define the proteins representative of the T cell proliferation and to discover the molecules that play critical roles during the suppression of T cell proliferation. Human T lymphocytes were isolated from healthy donors and primed with phytohemagglutinin (PHA) to undergo proliferation. Two medical fungal products with specific T cell activation inhibitory properties, cyclosporine A (CsA) and polysaccharopeptide (PSP), were used to study the proteins that manipulate T cell proliferation. After demonstrating their similar effects on cell proliferation, cell survival and interleuklin-2 (IL-2) secretion, significant quantitative protein alterations were detected between the CsA- and PSP-treated T cell proteome. These altered proteins were identified by MALDI-TOF and classified into 3 categories: (i) proteins affected by both CsA and PSP, (ii) proteins affected by CsA alone, and (iii) proteins affected by PSP alone. Most of these altered proteins have functional significance in protein degradation, the antioxidant pathway, energy metabolism and immune cell regulation.