The association of −330 interleukin-2 gene polymorphism and HLA-DR15 allele in Iranian patients with multiple sclerosis

Distribution of 22 Single Nucleotide Polymorphisms in 13 Cytokine Genes in Malays, Chinese, and Indians in Peninsular Malaysia

Introduction: Cytokines are cell signaling glycoproteins that are particularly important in immunity and inflammatory responses. Therefore, variations, such as single nucleotide polymorphisms (SNPs), in genes encoding for cytokines may have important consequences for their roles in health. Materials and Methods: A total of 222 unrelated, healthy, and un-admixed Malays (n = 97), Chinese (n = 77), and Indians (n = 48) with a median age of 30 years old (range 21-50) were typed for 22 cytokine gene SNPs: IL-1α -889 T/C, IL-1β (-511 T/C, +3962 T/C), IL-1R pst1 1970 T/C, IL-1RA mspa1 11100 T/C, IL-4Rα +1902 G/A, IL-12 - 1188 C/A, IFN-γ +874 A/T, TGF-β (cdn 10 C/T, cdn 25 G/C), TNF-α (-308 A/G, -238 A/G) IL-2 (+166 G/T, -330 T/G), IL-4 (-1098 T/G, -590 T/C, -33 T/C), IL-6 (-174 C/G, nt565 G/A), and IL-10 (-1082 G/A, -819 C/T, -592 A/C). This involved using well-established polymerase chain reaction procedures with sequence-specific primers and restriction fragment length polymorphism methods. Results: The majority of the screened cytokine gene SNPs are polymorphic in all three ethnicities. Exceptions include TGF-β cdn 25 (G/C), IL-1β +3962 (T/C), and TNF-α -238 (A/G), which were all observed to be monomorphic in Malays, Chinese and Indians. Many of the analyzed cytokine gene SNP genotypes deviated from Hardy-Weinberg equilibrium and the three ethnic study groups were all well-separated from reference Asian, African and European populations in a principal component analysis plot. Conclusion: We successfully typed 22 SNPs in 13 cytokine genes from genetic material collected from unrelated and un-admixed Malay, Chinese and Indian individuals in Peninsular Malaysia. These new cytokine gene population datasets reveal interesting contrasts with other populations.

Correlation of -475 IL-2 Promoter Gene Polymorphisms and the Levels of Serum IL-2 on the Risk of Multiple Sclerosis

BACKGROUND

The aim of present study is to asset the IL-2 promoter gene (SNP -475) as a candidate gene for multiple sclerosis (MS) susceptibility.

METHODS

This study included 70 patients with relapsing - remitting multiple sclerosis (RRMS) and 50 healthy controls. Following the extraction of genomic DNA from peripheral blood, frequency of genotypes and alleles of SNP -475 was calculated using Restriction fragment length polymorphism-polymer chain reaction (RFLP-PCR) and then the results were analyzed statistically.

RESULTS

The results revealed the unusual ratio for the heterozygous (AT) was 1.6972 indicating that heterozygous patients were at higher risk of multiple sclerosis than wild homozygous (AA), and homomutant (TT). The results show protective role for - 475 IL-2 promoter among individuals with multiple sclerosis, (O.R: 0.4872; C.I. 95%: 0.1617- 1.4680) and (O.R: 0.9275; C.I. 95%: 0.2476 - 3.4745) for both AA and TT genotypes, respectively.

CONCLUSION

Our results showed that in this population of Iraqi patients, the AT genotype / A allele of -475 IL-2 promoter gene SNP may include attributed factors for MS predisposition.

Recent Advances of Human Leukocyte Antigen (HLA) Typing Technology Based on High-Throughput Sequencing

The major histocompatibility complex (MHC) in humans is a genetic region consisting of cell surface proteins located on the short arm of chromosome 6. This is also known as the human leukocyte antigen (HLA) region. The HLA region consists of genes that exhibit complex genetic polymorphisms, and are extensively involved in immune responses. Each individual has a unique set of HLAs. Donor-recipient HLA allele matching is an important factor for organ transplantation. Therefore, an established rapid and accurate HLA typing technology is instrumental to preventing graft-verses-host disease (GVHD) in organ recipients. As of recent, high-throughput sequencing has allowed for an increase read length and higher accuracy and throughput, thus achieving complete and high-resolution full-length typing. With more advanced nanotechnology used in high-throughput sequencing, HLA typing is more widely used in third-generation single-molecule sequencing. This review article summarizes some of the most widely used sequencing typing platforms and evaluates the latest developments in HLA typing kits and their clinical applications.

Genetic and Molecular Biology of Multiple Sclerosis Among Iranian Patients: An Overview

Multiple sclerosis (MS) is one if the common types of autoimmune disorders in developed countries. Various environmental and genetic factors are associated with initiation and progression of MS. It is believed that the life style changes can be one of the main environmental risk factors. The environmental factors are widely studied and reported, whereas minority of reports have considered the role of genetic factors in biology of MS. Although Iran is a low-risk country in the case of MS prevalence, it has been shown that there was a dramatically rising trend of MS prevalence among Iranian population during recent decades. Therefore, it is required to assess the probable MS risk factors in Iran. In the present study, we summarized all of the reported genes until now which have been associated with MS susceptibility among Iranian patients. To clarify the probable molecular biology of MS progression, we categorized these reported genes based on their cellular functions. This review paves the way of introducing a specific population-based diagnostic panel of genetic markers among the Iranian population for the first time in the world.

HLA-DRB1 polymorphism and susceptibility to multiple sclerosis in the Middle East North Africa region: A systematic review and meta-analysis

This meta-analysis explores association of HLA-DRB1 alleles with MS risk in the Middle-east North Africa (MENA) countries. Divided into two groups of alleles (10 studies, 899 cases/1457 controls) and phenotypes (8 studies, 1,040 cases/1,256 controls), Odds ratios (ORs) of DRB1 distribution in MS subjects were assessed using Cochrane RevMan software. DRB1*15 demonstrated significant association with MS in both groups (OR=1.6 and OR=2.51, respectively). In phenotypes, DRB1*03 and DRB1*04 had predisposing role (OR=1.8 and OR=1.9), while DRB1*07 and DRB1*11 were protective (OR=0.56 and OR=0.67). Similar but non-significant trends were seen among alleles, which in sum coincides with a Caucasian-like pattern.

FOXP3 gene expression in the blood of Iranian multiple sclerosis patients

INTRODUCTION

Multiple sclerosis (MS) is a heterogeneous disease with an unknown etiology. Both genetic and environmental factors lead to MS disease. Recent studies have revealed the inhibitory role of T regulatory cells in the MS disease. Forkhead box P3 (FOXP3) gene is a transcript of the CD4+CD25+FOXP3 and T regulatory cells that is recently introduced as a factor in determining the lineage of immune cells. Based on these assumptions we investigate the expression of this gene in the peripheral blood of fifty MS patients in comparison to fifty controls.

MATERIAL AND METHODS

In this case-control study, we investigate the FOXP3 expression in fifty MS patients (30 females (60%) and 20 males (40%), mean age ± SD: 33.3 ± 5.4 years) in comparing to fifty healthy age and sex matched-controls (30 females (60%) and 20 males (40%), mean age ± SD: 34.2 ± 4.8) using real-time quantitative reverse transcription-PCR (qRT-PCR) in order to explore any association between FOXP3 expression level and MS.

RESULTS

The expression level of FOXP3 gene was not significantly different between MS patients and controls (p: 0.79). In addition the expression level of the gene was not significantly different between male and female (p: 0.8, p: 0.79, respectively).

CONCLUSION

Although, the FOXP3 gene is one of the most important genes in the regulation of the immune cells, according to no significant results of this study it may concluded that the expression of the gene is not different between MS patients and healthy controls at least at mRNA level. So it seems that investigating the protein level of FOXP3, related LNCs and microRNAs could be useful to investigate the relation between this gene and the disease. However, the clinical relevance of FOXP3 in patients with regard to their therapy needs to be further explored by evaluation of genetic background in relation to immune responses in MS patients.

VDR and CYP24A1 Expression Analysis in Iranian Relapsing-Remitting Multiple Sclerosis Patients

OBJECTIVES

Multiple sclerosis (MS) is a common disease of the central nervous system.This disease may be initiated by either vitamin deficiency or triggered by abnormality in CYP24A1 and vitamin D receptor.

MATERIALS AND METHODS

In this case-control study, the expression of genes encoding vitamin D receptor (VDR) and CYP24A1 in relapsing-remitting MS (RR-MS) patients was compared with normal individuals in the Iranian population. RNA from whole blood of 50 RR-MS patients (HLA-DRB1*15-negative and responders to interferonbeta with a normal vitamin D level) and 50 normal controls was extracted. The levels of CYP24A1 and VDR expression were measured using real-time quantitative polymerase chain reaction.

RESULTS

The RR-MS group had a significantly more than 2 times higher expression level of VDR than the normal group (P=0.04). On the other hand, there was a 0.89 times decrease in the expression level of CYP24A1 in RR-MS patients which was not statistically significant. There was no linear correlation between the risk of expanded disability status scale of Kurtzke (EDSS) and the expression level of either CYP24A1 or VDR. In addition, the expression level of CYP24A1 or VDR was not correlated with the duration of the disease.

CONCLUSIONS

Up-regulation of VDR is likely to happen in RR-MS patients in the Iranian population. We did not observe a gene expression-phenotype correlation for CYP24A1 which may be due to limited statistical power as a result of the small sample size. Although the individuals taking part in this study had normal levels of vitamin D, the increase in VDR expression levels may perhaps be a response to a defect in vitamin D processing. Another possibility is that despite an increase in VDR expression level, factors such as micro-RNAs may result in their deactivation while an increase in VDR expression level can be seen as a compensatory response. Of course, further studies are required to identify the mechanism of action of vitamin D by analyzing genes involved in its signaling pathway, particularly VDR and CYP24A1.

Down-regulation of CYP27B1 gene expression in Iranian patients with relapsing-remitting multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) as a complex neurological disease can be due to vitamin D deficiency. CYP27B1 is referred to as a vitamin D metabolizing enzyme.

MATERIALS AND METHODS

This study compared the expression level of CYP27B1 in Relapsing-Remitting MS (RRMS) patients with normal individuals in Iran. The RNA was extracted from 50 RRMS patients and 50 normal controls. Quantitative RT-PCR was adopted to measure the expression level of CYP27B1 gene.

RESULTS

The expression level of CYP27B1gene was significantly lower in the RRMS patients than their normal counterparts (P value = 0.04). Also, the RRMS females participating had a significant reduction in CYP27B1 gene expression compared to normal females (P-Value = 0.01). In addition, the correlation between CYP27B1 expression level, and the risk of Expanded Disability Status Scale of Kurtzke (EDSS) was not linear. Additionally, there was no significant correlation between expression status of CYP27B1gene and duration of the disease.

CONCLUSION

A significant decrease in the expression level of CYP27A1 in female patients could indicate their greater vulnerability to MS than the male patients.

TRAIL gene expression analysis in multiple sclerosis patients

BACKGROUND

Multiple sclerosis (MS) as an autoimmune disorder in which the insulating covers of neurons in the Central Nervous System are destructed. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an immunomodulatory molecule to protect against T cells hyper activation.

METHODS

In this Case-control study, we compare TRAIL gene expression in peripheral blood between 50 relapse remitting MS patients and 50 healthy controls by TaqMan Real time PCR. All the patients were negative for HLA-DRB1*15 susceptible allele, normal serum vitamin D, responder to Interferon beta. All the health individuals were matched to patients. Also, we tried to find correlation between TRAIL gene expression and clinical characteristics of patients.

RESULTS

No statistically significant difference was found in TRAIL mRNA expression between MS patients and controls (p> 0.05). There was no correlation in the TRAIL expression and age of onset, disease duration and Expanded Disability Status Scale of Kurtzke (EDSS). As IFN-b may have stimulatory effects on immunoregulatory function of TRAIL and all of our patients were treated with interferon beta and were responder, it lead to no significant change in TRAIL expression. We suggest comparing between responders and non-responders should be investigated.

Increased expression ratio of matrix metalloproteinase-9 (MMP9) and tissue inhibitor of matrix metalloproteinase (TIMP-1) RNA levels in Iranian multiple sclerosis patients

OBJECTIVES

Multiple sclerosis (MS) is an autoimmune disease involving the central nervous system (CNS) with unknown immunopathogenic mechanisms. Matrix metalloproteinase-9 (MMP-9) facilitates T-cell migration into the CNS while the tissue inhibitor matrix metalloproteinase-1 (TIMP-1) inhibits MMP-9 actions. The aim of this study was to evaluate the expression of TIMP-1 RNA and MMP-9/TIMP-1 RNA ratio in blood cells of Iranian patients with relapsing-remitting multiple sclerosis (RRMS) treated with IFNb.

MATERIAL AND METHODS

The study compared the expression level of TIMP-1 gene in RRMS samples with normal individuals in Iran and the results were compared using a ratio of MMP-9 to TIMP-1. All patients were HLA-DRB1*15 negative and were responders to interferon-beta with a normal vitamin D level.

RESULTS

The RRMS patients manifested a lower expression level of TIMP-1 RNA than their normal counterparts although the result was not significant (P= 0.06). Also, the ratio of MMP-9 to TIMP-1 RNA increased significantly (P= 0.009). There was no linear correlation between TIMP-1 expression level and risk of Expanded Disability Status Scale of Kurtzke (EDSS); nor was there any significant correlation between expression status of TIMP-1 and duration of the disease. Although there was no significant decrease in TIMP-1 expression level, the MMP-9/TIMP-1 RNA ratio in RRMS was significantly higher than normal subjects.

CONCLUSION

Further studies are recommended to compare MMP-9/TIMP-1 RNA ratio in patients before and after taking IFN-beta in order to find out if MMP-9/TIMP-1 RNA ratio can function as a proper marker of the bio efficacy of IFN-beta treatment of MS.

A single-nucleotide polymorphism in serine-threonine kinase 11, the gene encoding liver kinase B1, is a risk factor for multiple sclerosis

We identified a family in which five siblings were diagnosed with multiple sclerosis (MS) or clinically isolated syndrome. Several women in the maternal lineage have comorbidities typically associated with Peutz Jeghers Syndrome, a rare autosomal-dominant disease caused by mutations in the serine-threonine-kinase 11 (STK11) gene, which encodes liver kinase B1. Sequence analysis of DNA from one sibling identified a single-nucleotide polymorphism (SNP) within STK11 intron 5. This SNP (dbSNP ID: rs9282860) was identified by TaqMan polymerase chain reaction (PCR) assays in DNA samples available from two other siblings. Further screening was carried out in samples from 654 relapsing-remitting MS patients, 100 primary progressive MS patients, and 661 controls. The STK11-SNP has increased frequency in all female patients versus controls (odds ratio = 1.66, 95% CI = 1.05, 2.64, p = .032). The STK11-SNP was not associated with disease duration or onset; however, it was significantly associated with reduced severity (assessed by MS severity scores), with the lowest scores in patients who also harbored the HLA-DRB1*1501 allele. In vitro studies showed that peripheral blood mononuclear cells from members of the family were more sensitive to the mitochondrial inhibitor metformin than cells from MS patients with the major STK11 allele. The increased association of SNP rs9282860 in women with MS defines this variant as a genetic risk factor. The lower disease severity observed in the context of HLA-DRB1*1501 combined with limited in vitro studies raises the provocative possibility that cells harboring the STK11-SNP could be targeted by drugs which increase metabolic stress.