Association between MDR1 gene polymorphisms and the risk of Crohn's disease in a cohort of Algerian pediatric patients

Multidrug resistance Gene-1 polymorphisms (C3435T and G2677T) and the risk of inflammatory bowel disease in Egyptian patients

BACKGROUND AND STUDY AIMS

The multidrug resistance 1 (MDR1) gene is a gene involved in the pathogenesis of inflammatory bowel disease (IBD).The aim of the study is to investigate the association of MDR-1 gene polymorphisms (C2345T and G2677T) and IBD incidence in Egyptian patients, and its relation with disease severity.

PATIENTS AND METHODS

This is a case-control study where genotyping of MDR-1 gene C3435T and G2677T single nucleotide polymorphisms (SNPs) were assayed.

RESULTS

Forty naïve IBD patients, who were composed of 25 UC and 15CD, were compared to 60 healthy controls. They were young aged with significant female predominance, particularly in CD (P = 0.004). UC was mainly (48 %) presented in moderate severity while CD was mainly (53.3 %) presented with mild severity. MDR-1 gene C3435T SNP was not statistically related to IBD, whether in terms of genotypes or alleles, yet its T allele was significantly related to moderate cases of UC (P = 0.014). However, GG genotype of G2677T SNP was significantly low in IBD (P = 0.013), while TT genotype and T allele were significantly related to CD (P = 0.011, and 0.012 respectively). Moreover, G allele proved to be associated significantly with moderate cases of UC (P = 0.001) and mild cases of CD (P = 0.002).

CONCLUSIONS

MDR-I gene G2677T SNP GG genotype proved to be protective against IBD, thus may be considered in diagnostic workup of IBD including its severity.

Clinical variables and ethnicity may influenced by polymorphism of CAT -262C/T and MnSOD 47C/T antioxidant enzymes in Algerian type1 diabetes without complications

The latest studies in Algeria show that the frequency of type 1 diabetes (T1D) without complications is lower than that with complications and represents a significant burden in terms of cost and treatment. For this reason, we are interested in uncomplicated type1 diabetes and risk factors that are related to polymorphisms of antioxidant enzymes in order to prevent its complications. A total of 260 blood samples of young Algerian adults were examined. The genotypic analysis of Catalase gene (CAT -262C/T, rs1001179) and the superoxide dismutase gene (MnSOD 47C/T, rs4880) was performed by real-time PCR using TaqMan technology. The genotypic distribution of the CAT -262C/T promoter gene's polymorphism showed a significant difference between control and T1D patients for the CC genotype (p = 0.009; OR = 0.30) and for the T allele (p = 0.002; OR = 2.82). In addition, the genotypic distribution of the MnSOD 47C/T gene showed an association with T1D for the CT genotype (p = 0.040; OR = 2.37). Our results revealed that polymorphisms of CAT and MnSOD may be associated with physiopathology causing the onset of T1D. Our data, suggest that the genotypic frequencies of these SNPs appear to be influenced by clinical variables and by the Arab-Berber ethnic origin of the Algerian population.

Activation of LANCL2 by BT-11 Ameliorates IBD by Supporting Regulatory T Cell Stability Through Immunometabolic Mechanisms

BACKGROUND

Inflammatory bowel disease (IBD) afflicts 5 million people and is increasing in prevalence. There is an unmet clinical need for safer and effective treatments for IBD. The BT-11 is a small molecule oral therapeutic that ameliorates IBD by targeting lanthionine synthetase C-like 2 (LANCL2) and has a benign safety profile in rats.

METHODS

Mdr1a-/-, dextran sodium sulphate , and adoptive transfer mouse models of colitis were employed to validate therapeutic efficacy and characterize the mechanisms of therapeutic efficacy of BT-11. In vitro cultures of CD4+ T cell differentiation and human peripheral blood mononuclear cells from Crohn's disease patients were used to determine its potential for human translation.

RESULTS

BT-11 reduces inflammation in multiple mouse models of IBD. Oral treatment with BT-11 increases the numbers of lamina propria regulatory T cells (Tregs) in a LANCL2-dependent manner. In vitro, BT-11 increases the differentiation in Treg phenotypes, the upregulation of genes implicated in Treg cell stability, and conditions Treg cells to elicit greater suppressive actions. These immunoregulatory effects are intertwined with the ability of BT-11 to regulate late stage glycolysis and tricarboxylic acid cycle. Immunometabolic mechanistic findings translate into human peripheral blood mononuclear cells from healthy individuals and Crohn's disease patients.

CONCLUSIONS

BT-11 is a safe, efficacious oral therapeutic for IBD with a human translatable mechanism of action that involves activation of LANCL2, immunometabolic modulation of CD4+ T cell subsets leading to stable regulatory phenotypes in the colonic LP.

T300A variant of AT16L1 gene in a cohort of Algerian Crohn disease patients

The T300A variant is among the most Crohn's disease (CD) associated genetic variants. The aim of our study is to bring a first insight about the contribution of the T300A variant in a cohort of Algerian CD. In a case/control design, 118 Algerian CD patients and 161 unrelated healthy subjects were genotyped for the T300A variant using the allelic discrimination test by Applied Biosystems Taqman^® genotyping technology. A serological analysis was carried out using Biosystems™ ELISA kit for the assessment of the anti-Saccharomyces cerevisiae antibodies and immunofluorimetry via Luminex^® technology for the evaluation of cytokine levels (TNFα, IFNγ, IL-6 and IL-17). The comparison between allelic and genotypic frequencies was performed using the χ² test and the exact Fischer test. The odds ratio (OR) was noted adopting confidence interval of 95%. The comparison between the averages was carried out by the Mann-Whitney and Kruskal-Wallis tests. A factorial discriminant analysis and a binary logistic regression were performed as further analyses. The T300A variant showed an increased risk of CD within homozygous variant carriers (P=0.027). Moreover, the carriage of the G allele was associated with the early onset of CD (P=0.01) and a severe CD impairment (P=0.045). We were not able to comfort the association of the T300A variant and ASCA IgA, ASCA IgG and IFNγ levels detected at the univariate analysis. Our results suggest a possible association between the T300A variant and CD in this cohort of Algerian CD patients. Moreover, this variant might be incriminated in the early onset of CD and a severe disease impairment. At the serological study, the univariate and the multivariate analyses yielded contradictory results. Further investigations of larger cohorts of Algerian CD are needed to better assess the suggested associations at the present study.

Genetic association and epistatic interaction of the interleukin-10 signaling pathway in pediatric inflammatory bowel disease

AIM

To study the genetic association and epistatic interaction of the interleukin (IL)-10 and IL-10/STAT3 pathways in pediatric inflammatory bowel disease (IBD).

METHODS

A total of 159 pediatric inflammatory IBD patients (Crohn’s disease, n = 136; ulcerative colitis, n = 23) and 129 matched controls were studied for genetic association of selected single nucleotide polymorphisms (SNPs) of the IL-10 gene and the genes IL10RA, IL10RB, STAT3, and HO1, from the IL-10/STAT3 signaling pathway. As interactions between SNPs from different loci may significantly affect the associated risk for disease, additive (a) and dominant (d) modeling of SNP interactions was also performed to examine high-order epistasis between combinations of the individual SNPs.

RESULTS

The results showed that IL-10 rs304496 was associated with pediatric IBD (P = 0.022), but no association was found for two other IL-10 SNPs, rs1800872 and rs2034498, or for SNPs in genes IL10RA, IL10RB, STAT3, and HO1. However, analysis of epistatic interaction among these genes showed significant interactions: (1) between two IL-10 SNPs rs1800872 and rs3024496 (additive-additive P = 0.00015, Bonferroni P value (Bp) = 0.003); (2) between IL-10RB rs2834167 and HO1 rs2071746 (dominant-additive, P = 0.0018, Bp = 0.039); and (3) among IL-10 rs1800872, IL10RB rs2834167, and HO1 rs2071746 (additive-dominant-additive, P = 0.00015, Bp = 0.005), as well as weak interactions among IL-10 rs1800872, IL-10 rs3024496, and IL-10RA (additive-additive-additive, P = 0.003; Bp = 0.099), and among IL10RA, IL10RB, and HO1 genes (additive-dominant-additive, P = 0.008, Bp = 0.287).

CONCLUSION

These results indicate that both the IL-10 gene itself, and through epistatic interaction with genes within the IL-10/STAT3 signaling pathway, contribute to the risk of pediatric IBD.