IL23R and ATG16L1 variants in Moroccan patients with inflammatory bowel disease

Inflammatory bowel disease in Africa: what is the current state of knowledge?

Inflammatory bowel disease (IBD) is increasingly recognized as a global disease in the twenty-first century; however, little is known about its epidemiology in Africa. We conducted a literature review in order to assess what is currently known on this subject, the results of which are reported here. Based on available observational studies, it appears that the incidence of IBD in Africa is rising, although comprehensive epidemiological data are lacking. This is likely due to multiple factors, including shifting trends in diet and exposure to environmental pathogens. Many challenges relating to IBD exist for healthcare systems in Africa, including the need for improved access to diagnostic facilities such as endoscopy and histopathology, and the potential economic burden of treatment. Intestinal TB also represents a significant confounding factor in the diagnosis of IBD in Africa.

Harnessing the potential of gene editing technology using CRISPR in inflammatory bowel disease

The molecular scalpel of clustered regularly interspersed short palindromic repeats/CRISPR associated protein 9 (CRISPR/Cas9) technology may be sharp enough to begin cutting the genes implicated in inflammatory bowel disease (IBD) and consequently decrease the 6.3 billion dollar annual financial healthcare burden in the treatment of IBD. For the past few years CRISPR technology has drastically revolutionized DNA engineering and biomedical research field. We are beginning to see its application in gene manipulation of sickle cell disease, human immunodeficiency virus resistant embryologic twin gene modification and IBD genes such as Gatm (Glycine amidinotransferase, mitochondrial), nucleotide-binding oligomerization domain-containing protein 2, KRT12 and other genes implicated in adaptive immune convergence pathways have been subjected to gene editing, however there are very few publications. Furthermore, since Crohn's disease and ulcerative colitis have shared disease susceptibility and share genetic gene profile, it is paramount and is more advantageous to use CRISPR technology to maximize impact. Although, currently CRISPR does have its limitations due to limited number of specific Cas enzymes, off-target activity, protospacer adjacent motifs and crossfire between different target sites. However, these limitations have given researchers further insight on how to augment and manipulate enzymes to enable precise gene excision and limit crossfire between target sites.

Association between variants of the autophagy related gene ATG16L1 in inflammatory bowel diseases and clinical statues

AIM

In the present study, two main variants of ATG16L1 gene, rs2241880 T300A and rs2241879 C/T, were evaluated in IBD patients as well as in remission and flareup phase across an Iranian population for the first time.

BACKGROUND

Inflammatory bowel disease (IBD) has found increasing global incidence and prevalence in recent years especially among pediatrics. ATG16L1 is the major gene that regulates autophagy pathway. The autophagy pathway also affects dysbiosis.

METHODS

Genomic DNA was isolated from peripheral blood samples following salting out extraction method. The genotypes of ATG16L1 polymorphisms rs2241880 T300A and rs2241879 C/T were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

In this case control study, a total of 101 IBD patients (75 ulcerative colitis (UC) and 26 Crohn's disease (CD)) and 99 healthy controls were evaluated. In the present study, a significant association was found between rs2241879 single nucleotide polymorphism on ATG16L1 gene and increased risk of IBD among an Iranian population (P=0.01). There was no statistically significant relationship between rs2241880 and IBD risk (P= 0.42). The effect on these two variants was investigated in relapse and flareup phase which was not significant either, but in CD, rs2241879 and rs2241880 were difference in the relapse phase.

CONCLUSION

The results showed that ATG16L1 gene rs2241879 has a significant relationship with increased risk of IBD among an Iranian population. Individuals with C allele showed a significant relationship with 1.68-fold increased risk of IBD (P=0.01; adjusted OR=1.68; 95% CI=1.13-2.50).

Association of Autophagy Gene ATG16L1 Polymorphism with Human Prostate Cancer and Bladder Cancer in Turkish Population

Background: Urological cancers (prostate cancer and bladder cancers) are the most common cancers in Western population and its rate is increasing in the Eastern World. Autophagy has appeared as a fundamental repair mechanism for degrading damaged organelles and proteins. It was clear that autophagy gene polymorphisms are correlated with development of inflammatory bowel disease and it can also be related with prostate cancer (PCa) or bladder cancer (BCa). In this study, we aimed to determine if ATG16L1 (Thr300Ala) polymorphism is associated with an increased risk of developing PCa and BCa and to establish correlations between ATG16L1 genotypes and morphological parameters. Methods: This study included 269 healthy controls and 131 patients (62 PCa and 69 BCa) with PCa and BCa. The ATG16L1 (rs2241880) gene regions were amplified using polymerase chain reaction (PCR), detected by restriction fragment length polymorphism (RFLP). Results: At the end of our research, we found out that the genotype AG was prevalent on patients and controls (34% vs 42%), followed by genotypes AA (35% vs 27%) and GG (31% vs 31%) in PCa. The prevalence of genotypes of AA (wild-type), AG (heterozygous mutant) and GG (homozygous mutant) profiles for the ATG16L1 Thr300Ala polymorphism were 35%, 40% and 25% respectively in BCa patients, and 32%, 40% and 28% respectively in healthy control groups. The G allele frequency was 0.53 for in BCa patients and the control groups. Conclusion: No association was found between ATG16L1 (Thr300Ala) polymorphism and patients with PCa and BCa in Turkish population we studied.

Association between ATG16L1 gene polymorphism and the risk of Crohn's disease

Objective

To perform a meta-analysis to evaluate studies investigating the association between ATG16L1 gene polymorphism and Crohn’s disease.

Methods

PubMed, Embase and Web of Science databases were searched for all studies focusing on the association of ATG16L1 and Crohn’s disease. Combined odds ratios with 95% confidence intervals were calculated for four genetic models (allelic model: G allele versus A allele; additive model: GG versus AA; dominant model: GA + GG versus AA; recessive model: GG versus GA + AA) using either a random effects or fixed effects model.

Results

A total of 47 case–control studies involving 18 638 cases and 30 181 controls were included in the final meta-analysis. There was a significant association between ATG16L1 and Crohn’s disease for all four genetic models. Significant associations were also shown in subgroup analyses when stratified by study design (population- or hospital-based).

Conclusion

In this meta-analysis, the ATG16L1 genotype was significantly associated with the risk of developing Crohn’s disease.

May autophagy be a novel biomarker and antitumor target in colorectal cancer?

Autophagy is a catabolic process associated with intracellular self-digestion of damaged organelles or redundant proteins enabling maintenance of cell homeostasis. It is accepted that impaired autophagy is closely linked to cancer development and has been extensively studied in a variety of malignancies including colorectal cancer (CRC) to elucidate its influence on carcinogenesis, metastasis and antitumor therapy response. CRC remains a great epidemiological problem because of poor 5-year survival and treatment resistance. Many studies concerning autophagy in CRC gave inconsistent and contradictory results, illustrating a multifaceted nature of this process. In this review, we focus on current knowledge of autophagy in CRC development to determinate its role as a potential prognostic and predictive biomarker as well as target in antitumor therapy.

Association of inflammatory cytokine gene polymorphisms with inflammatory bowel disease in a Moroccan cohort

The purpose of this study was to investigate whether common variants in inflammatory and immune response genes influence inflammatory bowel disease (IBD) risk among Moroccan patients. Using a candidate gene approach, 10 single-nucleotide polymorphisms mapping on six genes (MIF_rs755622, TNFA_rs1800629, IL6_rs2069840, IL6R_rs2228145, IL6ST_rs2228044, IL17A (rs2275913, rs4711998, rs7747909, rs8193036, rs3819024)) were assessed in 510 subjects grouped in 199 IBD and 311 healthy controls. Genotyping was performed with the TaqMan allelic discrimination technology. The results were analyzed using PLINK software. The frequency of allele A for TNFA rs1800629 was significantly higher in ulcerative colitis (UC) patients compared with controls (30.16 vs 16.72%; P=0.0005; odds ratio (OR)=2.15; 95% confidence interval (CI)=1.39-3.32). Statistically significant association to UC was also found under dominant AA+AG vs GG (OR=1.85, 95% CI=1.07-3.21; P=0.02) and recessive models (OR=8.38; 95% CI=2.86-24.53; P=0.0001). In the same way, an association of TNFA rs1800629 variant was observed with IBD under recessive model AA vs AG+GG (OR=4.10; 95% CI=1.56-10.76; P=0.004). No evidence of significant associations was found for the remaining investigated polymorphisms. Our data suggest that TNFA gene promoter polymorphism participates in determining IBD susceptibility in Moroccan patients.

Insights into IL-23 biology: From structure to function

Interleukin (IL-)23 is a central cytokine controlling TH17 development. Overshooting IL-23 signaling contribute to autoimmune diseases. Moreover, GWAS studies have identified several SNPs within the IL-23 receptor, which are associated with autoimmune diseases. IL-23 is a member of the IL-12-type cytokine family and consists of IL-23p19 and p40. Within the IL-12 family, IL-12 and IL-23 share the p40 cytokine subunit and the IL-12Rβ1 as one chain of the receptor complex. For signaling, IL-23 triggers heterodimerization of IL-12Rβ1 and the IL-23R. Subsequently, signal transduction pathways including JAK/STAT, MAPK and PI3K are activated. Most studies have investigated the biological relevance of IL-23 in the development of TH17 cells and autoimmunity, whereas less is known about the molecular context of IL-23 biology. Therefore, we focused on IL-23 receptor complex assembly, signal transduction and functional relevance of IL-23R SNPs in the context of IL-23-inhibitory principles.

CNTNAP3 associated ATG16L1 expression and Crohn's disease

Autophagy is a common physiological process in cell homeostasis and regulation. Autophagy-related gene mutations and autophagy disorders are important in Crohn's disease (CD). The nucleotide oligomerization domain 2–autophagy genes autophagy 16-like 1 (NOD2–ATG16L1) signaling axis disorder contributes to the dysfunction of autophagy. This paper is focused on the relationship between contactin associated protein-like 3 (CNTNAP3) and ATG16L1 expression in Crohn's disease. The results indicated that the expression of ATG16L1 is higher in some CD patients compared to normal controls. ATG16L1 was well correlated with the C-reactive protein (CRP) in some CD patients. In vitro study revealed that CNTNAP3 could upregulate the expression of ATG16L1 and increase autophagy vacuoles.

Toll-like receptor 4 Asp299Gly and Thr399Ile polymorphisms: New data and a meta-analysis

Background

The pathogenesis of inflammatory bowel disease (IBD) involves interactions between the host genetic susceptibility, intestinal microflora and mucosal immune responses through the pattern recognition receptor. Polymorphisms in toll-like receptor 4 (TLR4) induce an aberrant immune response to indigenous intestinal flora, which might favor IBD development. In this study, we aimed to determine whether TLR4 gene was associated with Crohn’s disease (CD) and ulcerative colitis (UC) among Moroccan patients, and evaluated its correlation with clinical manifestation of the disease.

Methods

The study population comprised 117 patients with IBD and 112 healthy unrelated blood donors. TLR4 polymorphisms: Asp299Gly and Thr399Ile were genotyped by polymerase chain reaction-restriction fragment length polymorphism. PCR products were cleaved with Nco I for the Asp299Gly polymorphism and Hinf I for the Thr399Ile polymorphism. Meta-analysis was performed to test the association of 299Gly and 399Ileu carriage with CD, UC and the overall IBD risk.

Results

Our study revealed that the frequency of Asp299Gly and Thr399Ile did not differ significantly between patients and controls in the Moroccan population. However, meta-analysis demonstrated significantly higher frequencies of both Asp299Gly and Thr399Ile SNPs in IBD and CD and for 399Ileu carriage in UC patients.

Conclusion

The meta-analysis provides evidence that TLR4 polymorphisms confer a significant increased risk for the overall IBD development.