OBJECTIVETo assess the association of transcobalamine II (TCN2) gene polymorphisms and serum levels of homocysteine (Hcy), vitamin Band folate with ulcerative colitis (UC) among Chinese patients.

METHODSFor 397 UC patients and 574 controls, two single nucleotide polymorphisms of the TCN2 gene (rs1801198, rs9606756) were tested with an improved multiple ligase detection reaction method. Serum Hcy, vitamin Band folate were measured with an enzymatic cycling assay and an chemiluminescence immunoassay, respectively.

RESULTSThe allelic and genotypic frequencies of rs1801198 and rs9606756 did not differ significantly between the two groups (all P> 0.05). Compared with those of the control group, the frequencies of G allele and CG+GG genotype of rs1801198 were greater in patients with moderate and severe UC (both P< 0.05). The same conclusion may also be drawn for the G allele and AG genotype of rs9606756 (both P< 0.05). Compared with the controls, average Hcy level was enhanced in UC patients (P< 0.01), whereas average vitamin Band folate levels were decreased in UC patients (both P< 0.01). In both groups, the average level of Hcy was lower in individuals carrying CC of (rs1801198) than in those with CG+GG (both P< 0.05). A similar conclusion was also drawn for individuals with AA of rs9606756 when compared with those carrying AG(both P< 0.05). Compared with patients with mild UC, average Hcy level was increased in those with moderate and severe UC (P< 0.01), while average vitamin Band folate levels were decreased in those with moderate and severe UC (both P< 0.01). The prevalence of hyperhomocysteinemia(HHcy), vitamin Bdeficiency and folate deficiency was greater in UC patients than in controls (all P< 0.01). In UC patients, the level of Hcy was negatively correlated with those of vitamin B(P< 0.01), albumin(P< 0.01), red blood cells(P< 0.01) and platelet (P< 0.05), but positively correlated with white blood cells(P< 0.01) and Mayo score (P< 0.01). Both HHcy and folate deficiency were independent risk factors for UC (OR=4.173, OR=5.206, both P< 0.01).

CONCLUSIONTCN2 (rs1801198, rs9606756) variations, as well as serum levels of Hcy, vitamin Band folate, are correlated with UC. Both HHcy and folate deficiency are independent risk factors for UC.

Adult ; Colitis, Ulcerative ; blood ; etiology ; genetics ; Female ; Folic Acid ; blood ; Genotype ; Homocysteine ; blood ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Transcobalamins ; genetics ; Vitamin B 12 ; blood

OBJECTIVETo assess the associations of death receptor DR4 and DR5 gene polymorphisms with Crohn's disease (CD).

METHODSA total of 295 CD patients and 490 healthy controls were recruited. Three single nucleotide polymorphisms (SNPs) of the DR4 (rs13278062, rs20575) and DR5 (rs1047266) genes were determined with a SNaPshot method. Unconditional logistic regression analysis was carried out for determining the allelic and genotypic differences of the three SNPs between CD patients and the controls, as well as the influence of the DR4 and DR5 gene polymorphisms on the clinical features of CD patients. Linkage disequilibrium and haplotype analysis were calculated by haplotype 4.2 and R language software. A gene-gene interaction model was established to analyze whether the three SNPs can exert a synergistic effect on the susceptibility to CD.

RESULTSThe mutant allele (T) and genotype (GT+TT) of DR4 (rs13278062) were increased among CD patients compared to the controls (37.12% vs. 32.04%, P = 0.040, 95%CI: 1.010-1.550; 62.71% vs. 54.90%, P = 0.032, 95%CI: 1.028-1.855, respectively). However, the allelic and genotypic frequencies of DR4 (rs20575) and DR5 (rs1047266) did not differ between the two groups (all P > 0.05). Based on the Montreal Classification Standards, the CD patients were stratified by locations and behaviors of the disease. After multiple comparison correction (P < 0.0125), compared to ileocolonic CD patients respectively, the mutant allele (T) and genotype (GT+TT) of the rs13278062 polymorphism were significantly increased in colonic CD patients (41.04% vs. 25.64%, P = 0.002, 95%CI: 0.315-0.778; 66.04% vs. 41.03%, P = 0.001, 95%CI: 0.196-0.655, respectively) and terminal ileum CD patients (41.44% vs. 25.64%, P = 0.002, 95%CI: 0.311-0.762; 74.77% vs. 41.03%, P < 0.001, 95%CI: 0.126-0.437, respectively). In comparison to penetrating CD patients, the mutant allele (T) and genotype (GT+TT) of DR4 (rs13278062) were significantly decreased in stricturing CD patients (32.29% vs. 48.91%, P = 0.007, 95%CI: 0.300-0.828; 57.29% vs. 86.96%, P = 0.001, 95%CI: 0.078-0.520, respectively). A similar conclusion was drawn for the mutant genotype (GT+TT) of DR4 (rs13278062) in non-stricturing, non-penetrating CD patients (58.82% vs. 86.96%, P = 0.001, 95%CI: 0.086-0.536). Haplotype analysis indicated that the CT haplotype formed by rs20575 and rs13278062 was increased in CD patients compared to the controls (37.1% vs. 31.8%, P = 0.029, OR=1.279, 95%CI: 1.022-1.600). The outcome of a gene-gene interaction model indicated that the mutant genotype (GT+TT) of DR4 (rs13278062) and mutant genotype (CT+TT) of DR5 (rs1047266) may play a negatively synergistic role in CD patients (B = - 0.483, OR = 0.617, P = 0.030).

CONCLUSIONThe rs13278062 polymorphism of the DR4 gene not only can confer an increased risk for CD, but may also influence the location of the lesions and the disease behaviors. The CT haplotype formed by rs20575 and rs13278062 may be an independent risk factor for CD. Furthermore, the mutant genotype (GT+TT) of DR4 (rs13278062) and mutant genotype (CT+TT) of DR5 (rs1047266) may exert a negative synergistic effect on CD.

Adult ; Crohn Disease ; genetics ; Epistasis, Genetic ; Female ; Genetic Predisposition to Disease ; Genotype ; Haplotypes ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide ; Receptors, TNF-Related Apoptosis-Inducing Ligand ; genetics

Objective: To investigate the influence of tumor necrosis factor-related apoptosis-inducing ligant (TRAIL) deficiency on mice colitis and the gut microbiota composition by inclding the expermental colitis model in tumor necrosis factor-related apoptosis-inducing ligand gene knockout (TRAIL^-/-) mice. Methods: C57BL/6 TRAIL^-/- mice and wild type (WT) mice were selected and assigned into TRAIL^-/- control group (eight mice), TRAIL^-/- colitis group (16 mice), WT control group (eight mice) and WT colitis group (16 mice). The mice of two colitis groups were oral administrated with 3.5% dextran sulphate sodium (DSS) in drinking water for seven consecutive days to induce experimental colitis model. The severity of colitis was evaluated by clinical appearance and histopathological examination. The colonic tissue samples of mice were collected and microbiota profile was analyzed by 16S rDNA sequencing method. USEARCH software and R language were used to analyze the difference of gut microbiota among TRAIL^-/- control group, TRAIL^-/- colitis group, WT control group and WT colitis group. T test and Mann-Whitney U test were used for statistical analysis. Results: After modeling, the disease activity index (DAI) of WT colitis mice and TRAIL^-/- colitis mice both gradually increased over time. Furthermore, compared with colitis mice, TRAIL^-/- colitis mice developed body weight loss, diarrhea and hemafecia earlier. On the seventh day after modeling, the percentage of body weight loss of TRAIL^-/- colitis mice and WT colitis mice was (28.98±2.84)% and (17.87±3.70)%, respectively; and the difference was statistically significant (t=9.53, P<0.01). The length of colon of TRAIL^-/- colitis mice was shorter than that of WT colitis mice ((4.63±0.28) cm vs. (6.02±0.41) cm), and the difference was statistically significant (t=11.20, P<0.01). The DAI of TRAIL^-/- colitis mice was higher than that of WT colitis mice (3.00±0.00 vs. 2.32±0.05), and the difference was statistically significant (t=54.40, P<0.01). The histological score of TRAIL^-/- colitis mice was higher than that of WT colitis mice (6.19±0.25 vs. 3.87±0.22), and the difference was statistically significant (t=27.87, P<0.01). Under the microscope, colonic mucosal epithelial injury, crypt structure destruction and inflammatory cell infiltration were more obvious in TRAIL^-/- colitis mice than in WT colitis mice. The alpha diversity of colonic flora was more significant in TRAIL^-/- colitis group compared with that of WT colitis group. At the family level, the relative richness of Deferribacteraceae, Ruminococcaceae, Rikenellaceae, F16 and Paraprevotellaceae significantly increased in TRAIL^-/- colitis group, but the relative richness of Enterococcaceae obviously reduced ((19.839±19.991)% vs. (7.224±11.241)%, (3.564±2.543)% vs.(2.861±3.821)%, (0.123±0.066)% vs. (0.068±0.049)%, (0.032±0.033)% vs. (0.006±0.011)%, (0.153±0.098)% vs. (0.062±0.054)% and (0.013±0.027)% vs. (0.054±0.121)%, respectively; U=51, 69, 53, 35, 49 and 69, respectively; P<0.01 and 0.05, respectively). In addition, at the genus level the relative richness of Oscillospira, Mucispirillum and Cytophaga in TRAIL^-/- colitis group remarkably elevated, and the relative richness of Enterococcus significantly decreased ((2.363±2.147)% vs. (1.813±2.847)%, (19.839±19.991)% vs. (7.223±11.241)%, (0.104±0.153)% vs. (0.046±0.069)% and (0.076±0.049)% vs. (0.135±0.074)%, respectively; U=70, 51, 66 and 65, respectively; P <0.05 and 0.01, respectively). Conclusion TRAIL deficiency aggravate DSS-induced colitis, and increase the alpha diversity of colonic microbiota in colitis mice.