Association of fucosyltransferase 2 gene variants with ulcerative colitis in Han and Uyghur patients in China

Intestinal Bacteremia After Liver Transplantation Is a Risk Factor for Recurrence of Primary Sclerosing Cholangitis

BACKGROUND

Primary sclerosing cholangitis (PSC) is a chronic progressive pathological process, related to inflammatory bowel disease and subsequent bacterial translocation. Liver transplantation (LT) is the only curative therapy, but outcomes are compromised by recurrence of PSC (rPSC). The aim of the study was to investigate a potential link between intestinal bacteremia, fucosyltransferase-2 (FUT2), and rPSC after LT.

METHODS

LT recipients with PSC (n = 81) or without PSC (n = 271) were analyzed for clinical outcomes and positive bacterial blood cultures. A link between bacteremia and the genetic variant of the FUT2 gene was investigated.

RESULTS

The incidence of inflammatory bowel disease was significantly higher in PSC recipients but not associated with rPSC. Bacteremia occurred in 31% of PSC recipients. The incidence of rPSC was 37% and was significantly more common in patients with intestinal bacteremia versus no bacteremia (82% versus 30%; P = 0.003). The nonsecretor polymorphism of the FUT2 gene was identified as a genetic risk factor for both intestinal bacteremia and rPSC. Combined FUT2 genotype and intestinal bacteremia in recipients resulted in the highest risk for rPSC (hazard ratio, 15.3; P < 0.001).

CONCLUSIONS

Thus, in this article, we showed that bacterial translocation is associated with rPSC after LT and related to the FUT2 nonsecretor status.

Fucosyltransferase 2: A Genetic Risk Factor for Intestinal Diseases

The fucosyltransferase 2 gene (FUT2) mediates the synthesis of histoblood group antigens (HBGA) that occur in vivo from multiple organs, particularly on the surface of intestinal epithelial cells and body fluids. To date, many studies have demonstrated that the interaction of HBGA with the host microbiota is the cause of pathogenesis of intestinal diseases, making FUT2 non-secretor a risk factor for inflammatory bowel disease (IBD) due to the lack of HBGA. As HBGA also acts as an attachment site for norovirus (NoV) and rotavirus (RV), the non-secretor becomes a protective factor for both viral infections. In addition, the interaction of norovirus and rotavirus with symbiotic bacteria has been found to play an important role in regulating enteroviral infection in IBD. Given the current incomplete understanding of the complex phenomenon and the underlying pathogenesis of intestinal diseases such as IBD, it has recently been hypothesized that the FUT2 gene regulates intestinal bacteria through attachment sites, may help to unravel the role of FUT2 and intestinal flora in the mechanism of intestinal diseases in the future, and provide new ideas for the prevention and treatment of intestinal diseases through more in-depth studies.

Altered gut microbiome in FUT2 loss-of-function mutants in support of personalized medicine for inflammatory bowel diseases

The FUT2 loss-of-function mutations are highly prevalent and are associated with inflammatory bowel disease (IBD). To investigate the impact of FUT2 loss-of-function mutation on the gut microbiota in patients with IBD, 81 endoscopically confirmed IBD patients were genotyped and divided into 3 groups: homozygous for functional FUT2 genes (SeSe), with one copy of non-functional FUT2 gene (Sese), or homozygous for non-functional FUT2 genes (sese). Escherichia, which attaches to fucosylated glycoconjugates, was the only abundant genus exhibiting decreased abundance in sese patients. Compared with SeSe or Sese patients, sese patients exhibited higher abundance in CD8+ inducing Alistipe and Phascolarctobacterium and Th17 inducing Erysipelotrichaceae UCG-003. Counter-intuitively, butyrate-producing bacteria were more abundant in sese patients. Consistently, metabolomics analysis found higher levels of butyrate in sese patients. Our data support the hypothesis that FUT2 loss-of-function mutation participates in the IBD pathogenesis by decreasing binding sites for adherent bacteria and thus altering the gut microbiota. Decreased abundances of adherent bacteria may allow the overgrowth of bacteria that induce inflammatory T cells, leading to intestinal inflammation. As FUT2 loss-of-function mutations are highly prevalent, the identification of T cell inducing bacteria in sese patients could be valuable for the development of personalized microbial intervention for IBD.

Intestinal flora differences between patients with ulcerative colitis of different ethnic groups in China

To determine the differences in intestinal flora between Uygur and Han patients with ulcerative colitis (UC).Microbial diversity and structural composition of fecal bacteria from patients with UC and their matched healthy spouses or first-degree relatives were analyzed using high-throughput sequencing technology.The fecal microbial diversity and abundance index of Uygur patients with UC (UUC) were significantly lower compared with the Uygur normal control group, while there was no significant difference between the Han UC patients (HUC) and the Han normal control group (HN). Compared with their respective control groups, Uygur UC patients and Han UC patients had a different main composition of human intestinal flora (P < .05). The abundance of Burkholderia, Caballeronia, Paraburkholderia in the UUC group were higher compared with the HUC group, while Faecalibacterium, Bifidobacterium, and Blautia in the HUC group were higher than those in the UUC group (P < .05). Veillonella in the UUC group was higher than that in the Uygur normal control group group, while Subdoligranulum and Ruminococcaceae_UCG-002 were significantly lower (P < .05). Prevotella_9 in the HUC group was significantly higher than that in HN group, while Blautia, Anaerostipes, and [Eubacterium]_hallii_group were significantly lower. Moreover, the top 6 species in order of importance were Christensenellaceae_R_7_group, Ruminococcae_ucg_005, Ruminococcae_ucg_010, Ruminococcae_ucg_013, Haemophilus, and Ezakiella.The difference in intestinal microflora structure may be one of the reasons for the clinical heterogeneity between Uygur and Han patients with UC. Christensenellaceae_R_7_group, Ruminococcae_ucg_005, Ruminococcae_ucg_010, Ruminococcae_ucg_013, Haemophilus, and Ezakiella could be used as potential biomarkers for predicting UC.

Exogenous l-fucose protects the intestinal mucosal barrier depending on upregulation of FUT2-mediated fucosylation of intestinal epithelial cells

FUT2, a protein that uses l-fucose to mediate fucosylation of intestinal epithelial cells, is one of the detected gene variants in IBD patients. We aimed to investigate whether exogenous l-fucose could be an enteral nutritional supplement to protect intestinal barrier function. The effect of l-fucose on the restoration of epithelial barrier function in both the DSS-induced colitis mouse model and LPS-stimulated Caco-2 cells was investigated, and the impact on fucosylation of epithelial cells was examined. The severity of DSS-induced colitis was significantly reduced by l-fucose. Restoration of epithelial barrier function by l-fucose was detected. Direct l-fucose-mediated protection of tight junctions was observed in Caco-2 cells. Moreover, exogenous l-fucose promoted the exogenous metabolic pathway of l-fucose, and fucosylation of epithelial cells both in vivo and in vitro. Moreover, knockout of the FUT2 gene restrained fucosylation and the protective effect of l-fucose on barrier function. The severity of colitis was not improved by l-fucose in Fut2 knockout mice. Therefore we conclude that exogenous l-fucose protects intestinal barrier function and relieves intestinal inflammation via upregulation of FUT2-mediated fucosylation of intestinal epithelial cells.

Potential Biomarkers Associated with Differential Manifestations of Ulcerative Colitis (UC) in Uyghur and Han Population in China

BACKGROUND

Ulcerative colitis (UC) is one of the main subtypes of inflammatory bowel disease (IBD). The incidence of UC in the Xinjiang region is relatively high in China and the manifestations of UC in Uyghur and Han patients are usually differential. This study aimed to identify potential biomarkers of UC.

METHODS

All miRNA and mRNA were extracted from the tissue samples obtained from participants in Xinjiang. Differential expression analysis was performed on all mRNAs and miRNAs. The target genes of miRNAs were predicted via three databases. The clusterProfiler package was used for GO and KEGG pathway enrichment analysis.

RESULTS

Preliminarily, four miRNAs and 15 genes were associated with the differential manifestations of UC in Uyghur and Han patients. Through the co-expression network construction and further screening in more samples, two miRNAs (hsa-miR-141-5p and hsa-miR-378a-5p) and three genes (ARNTL2, CLDN1 and SLC6A14) were found to be more crucial. These 15 genes were enriched in tight junction, NF-κB, and several other pathways.

CONCLUSION

Two miRNAs (hsa-miR-141-5p and hsa-miR-378a-5p) and three genes (ARNTL2, CLDN1, and SLC6A14) associated with the differential manifestations of UC in Uyghur and Han population were identified, which were potential biomarkers.

Can the FUT2 Non-secretor Phenotype Associated With Gut Microbiota Increase the Children Susceptibility for Type 1 Diabetes? A Mini Review

The global toll of type 1 diabetes (T1D) has steadily increased over the last decades. It is now widely acknowledged that T1D pathophysiology is more complex than expected. Indeed, a multifaceted interplay between genetic, metabolic, inflammatory and environmental factors exists that leads to heterogeneous clinical manifestations across individuals. Children with non-secretor phenotype and those affected by T1D share low abundance of bifidobacteria, low content of short-chain fatty acids, intestinal phosphatase alkaline and a high incidence of inflammatory bowel diseases. In this context, host-gut microbiota dyad may represent a relevant contributor to T1D development and progression due to its crucial role in shaping host immunity and susceptibility to autoimmune conditions. The FUT2 gene is responsible for the composition and functional properties of glycans in mucosal tissues and bodily secretions, including human milk. FUT2 polymorphisms may profoundly influence gut microbiota composition and host susceptibility to viral infections and chronic inflammatory disease. In this minireview, the possible interplay between mothers' phenotype, host FUT2 genetic background and gut microbiota composition will be discussed in perspective of the T1D onset. The study of FUT2-gut microbiota interaction may add a new piece on the puzzling T1D etiology and unveil novel targets of intervention to contrast T1D development and progression. Dietary interventions, including the intake of α-(1, 2)-fucosyl oligosaccharides in formula milk and the use of specific prebiotics and probiotics, could be hypothesized.

Fucosylation in the intestinal mucosa and inflammatory bowel disease

Inflammatory bowel disease (IBD) is an unexplained, abnormal immune mediated chronic and recurrent inflammatory disorder of the intestine. Fucosylation in the intestinal mucosal is the process of transferring fucose to intestinal mucosal protein side chains under the control of fucosyltransferases to form fucosyl bonds. The mechanism of fucosylation in the intestinal mucosa in IBD has not been fully proved. In this paper, we will review the progress in understanding the relationship between fucosylation in the intestinal mucosa and IBD.

Fucosyltransferase Gene Polymorphisms and Lewisb-Negative Status Are Frequent in Swedish Newborns, With Implications for Infectious Disease Susceptibility and Personalized Medicine

BACKGROUND

Single-nucleotide polymorphisms (SNPs) in the fucosyltransferase genes FUT2 and FUT3 have been associated with susceptibility to various infectious and inflammatory disorders. FUT variations influence the expression of human histo-blood group antigens (HBGAs) (H-type 1 and Lewis), which are highly expressed in the gut and play an important role in microbial attachment, metabolism, colonization, and shaping of the microbiome. In particular, FUT polymorphisms confer susceptibility to specific rotavirus and norovirus genotypes, which has important global health implications.

METHODS

We designed a genotyping method using a nested polymerase chain reaction approach to determine the frequency of SNPs in FUT2 and FUT3, thereby inferring the prevalence of Lewisb-positive, Lewisb-negative, secretor, and nonsecretor phenotypes in 520 Swedish newborns.

RESULTS

There was an increased frequency of homozygotes for the minor allele for 1 SNP in FUT2 and 4 SNPs in FUT3. Overall, 37.3% of newborns were found to have Lewis b negative phenotypes (Le (a+b-) or Le (a-b-). Using our new, sensitive genotyping method, we were able to genetically define the Le (a-b-) individuals based on their secretor status and found that the frequency of Lewis b negative newborns in our cohort was 28%.

CONCLUSIONS

Given the high frequency of fucosyltransferase polymorphisms observed in our newborn cohort and the implications for disease susceptibility, FUT genotyping might play a future role in personalized health care, including recommendations for disease screening, therapy, and vaccination.

Association of Fucosyltransferase 2 Gene Variant with Inflammatory Bowel Diseases: A Meta-Analysis

BACKGROUND Ulcerative colitis (UC) and Crohn's disease (CD) are the 2 main type of inflammatory bowel diseases (IBDs). Several studies have been conducted to investigate the association of fucosyltransferase 2 gene (rs601338) variant with UC and CD, but the results were inconsistent. Here, we performed a meta-analysis to clarify this issue based on a relatively larger sample size. MATERIAL AND METHODS A systematic literature search was conducted in PubMed, Embase, CNKI, and Chinese Wangfang databases up to 31 May 2018. Meta results were synthesized by using crude odds ratio with 95% confidence interval. Heterogeneity, sensitivity analysis, subgroup analysis, and publication bias were assessed using STATA 11.0 software. RESULTS A total of 8 relevant studies including 3874 IBDs patients (1872 UC cases, 2002 CD cases) and 5445 controls were included for meta-analysis. We found a significant association between rs601338 A allele and risk of IBDs in the Chinese population (OR=2.35, 95%CI=1.66~3.34, P=0.001), but not in whites. Stratified by disease type, we found a significant association between rs601338 polymorphism with CD and UC in the Chinese population, but not in the white population. In addition, funnel plot and Egger's linear regression test suggests no publication bias in all genetic models. CONCLUSIONS Fucosyltransferase 2 gene (rs601338) polymorphism is associated with susceptibility to IBD, UC, and CD in the Chinese population, but these results might not be generalizable to other ethnic populations. Further well-designed studies are needed to confirm these findings.

Association of Fucosyltransferase 2 Gene Polymorphisms with Inflammatory Bowel Disease in Patients from Southeast China

Aims. Fucosyltransferase 2 (FUT2) gene potentially affects the constituent of intestinal microbiota, which play a crucial role in the pathogenesis of inflammatory bowel disease (IBD). This study investigated the association of FUT2 gene polymorphisms with IBD in southeast China. Methods. We collected 671 IBD patients and 502 healthy controls. FUT2 gene polymorphisms (C357T, A385T, and G428A) were determined by SNaPshot. Frequencies of the FUT2 genotypes, alleles, and haplotype between groups were compared by χ² test. Results. The allele and genotype frequencies of FUT2 did not differ between ulcerative colitis patients and controls (all P > 0.05). However, mutant allele and genotype of FUT2 (A385T) were significantly increased in Crohn's disease (CD) patients (P = 0.024, OR = 1.271, and 95% CI = 1.031–1.565; P < 0.001, OR = 1.927, and 95% CI = 1.353–2.747, resp.). The same conclusion was drawn from FUT2 (G428A) (P = 0.023, OR = 3.324, and 95% CI = 1.108–9.968; P = 0.044, OR = 1.116–10.137, and 95% CI = 1.116–10.137, resp.). The haplotype TT formed with “C357T and A385T” was more prevalent in CD patients than in controls (P = 0.020, OR = 1.277, and 95% CI = 1.036–1.573). Besides, frequencies of mutant allele and genotype of FUT2 (A385T) were significantly lower in patients with ileocolonic CD than in those with colonic CD (P = 0.001 and 0.002, resp.) and ileal CD (P = 0.007 and 0.004, resp.). Conclusions. FUT2 gene polymorphisms and haplotypes were associated with the susceptibility to CD but not UC.

Associations of fucosyltransferase 2 gene polymorphism with susceptibility to inflammatory bowel disease: A meta-analysis

AIM

To explore the relationship between fucosyltransferase 2 (FUT2) A385T and G428A gene polymorphisms and susceptibility to inflammatory bowel disease(IBD).

METHODS

Databases including Embase, PubMed, EBM Reviews, Ovid, Springer, CNKI, and WanFang were searched for articles evaluating the relationship between FUT2 gene polymorphism and susceptibility to IBD. Available data were extracted and quality of the included studies was evaluated. Meta-analysis was conducted by using Review Manager 5.3 and Stata 12.0. Begg's funnel plot was used to assess the published bias of articles.

RESULTS

Totally 10 articles were included, including 3682 cases and 5470 controls. Each genetic model in ulcerative colitis (UC) was as follows: dominant model [(AA + AT) vs TT: OR = 0.60 (95%CI: 0.43-0.85); (GG + GA) vs AA: OR = 0.51 (95%CI: 0.38-0.70)]; recessive model [(AT + TT) vs AA: OR = 0.96 (95%CI: 0.73-1.25); (GA + AA) vs GG: OR = 0.70 (95%CI: 0.36-1.36)]; codominant model [AA vs TT: OR = 1.02 (95%CI: 0.82-1.27); GG vs AA: OR = 1.23 (95%CI: 0.93-1.63)]; allele genetic model [A vs T: OR = 1.06 (95%CI: 0.95-1.17); G vs A: OR = 1.18 (95%CI: 0.68-2.04)]. Each genetic model in Crohn's disease (CD) was as follows: dominant model [(AA + AT) vs TT: OR = 0.60 (95%CI: 0.43-0.85); (GG + GA) vs AA: OR = 0.51 (95%CI: 0.38-0.70)]; recessive model [(AT + TT) vs AA]: OR = 0.99 (95%CI: 0.73-1.35); (GA + AA) vs GG: OR = 1.49 (95%CI: 1.17-1.91)]; codominant model [AA vs TT: OR = 1.37 (95%CI: 0.95-1.98); GG vs AA: OR = 0.46 (95%CI: 0.33-0.65)]; allele genetic model [G vs A: OR = 0.67 (95%CI: 0.57-0.79); G vs A: OR = 0.67 (95%CI: 0.57-0.79)].

CONCLUSION

FUT2 A385T and G428A polymorphisms are not significantly related with IBD. In Asians, the TT on A385T confers a significant risk for developing CD. FUT2 G428A polymorphism is related with CD, and the allele gene A confers a risk for developing CD.

Association of Ulcerative Colitis with FUT2 and FUT3 Polymorphisms in Patients from Southeast China

OBJECTIVES

Dysbiosis of intestinal microbiota has been implicated in ulcerative colitis (UC). Fucosyltransferase (FUT) 2 and FUT3 determine expression of histo-blood group antigens in the gut and may affect the intestinal microbiota. We investigated the association between FUT2 and FUT3 polymorphisms and UC in Chinese patients.

METHODS

We genotyped FUT2 (rs281377, rs1047781 and rs601338) and FUT3 (rs28362459, rs3745635 and rs3894326) in 485 UC patients and 580 healthy controls using SNaPshot. We also evaluated expression of Lewis a and b antigens in the sigmoid colon of 7 UC patients and 7 patients with benign colonic polyps.

RESULTS

The frequencies of mutant allele (A) and genotype (GA+AA) in FUT3 (rs3745635) were higher in UC patients than controls (P = 0.016, 95%CI: 1.339-1.699; P = 0.038, 95%CI: 1.330-1.742, respectively). Stratified analyses revealed that the frequencies of mutant allele (G) and genotype (TG+GG) of FUT3 (rs28362459) were significantly lower in patients with extensive colitis than those with distal colitis (P<0.001, 95%CI: 0.503-0.742; P = 0.001, 95%CI: 0.567-0.786, respectively). Similar conclusions were drawn for the mutant allele (A) and genotype (GA+AA) of FUT3 (rs3745635) in patients with extensive colitis compared to those with distal colitis (P = 0.006, 95%CI: 0.553-0.845; P = 0.011, 95%CI: 0.621-0.900, respectively). Although expression of Lewis b antigen in the sigmoid colon did not differ between UC patients and controls, Lewis a antigen expression was higher in the cryptic epithelium of both inflammatory and non-inflammatory sigmoid colon of UC patients than controls (P = 0.028).

CONCLUSIONS

Our findings indicated that polymorphisms in FUT3 and its intestinal expression might be associated with UC pathogenesis.

Fucosyltransferase 2: a genetic risk factor for primary sclerosing cholangitis and Crohn's disease--a comprehensive review

Fucosyltransferase 2 (FUT2) mediates the inclusion of fucose in sugar moieties of glycoproteins and glycolipids. ABO blood group antigens and host-microbe interactions are influenced by FUT2 activity. About 20 % of the population has a "non-secretor" status caused by inactivating variants of FUT2 on both alleles. The non-sense mutation G428A and the missense mutation A385T are responsible for the vast majority of the non-secretor status in Caucasians, Africans, and Asians, respectively. Non-secretor individuals do not secrete fucose-positive antigens and lack fucosylation in epithelia. They also appear to be protected against a number of infectious diseases, such as Norovirus and Rotavirus infections. In recent years, genome-wide association studies (GWAS) identified inactivating variants at the FUT2 locus to be associated with primary sclerosing cholangitis (PSC), Crohn's disease (CD), and biochemical markers of biliary damage. These associations are intriguing given the important roles of fucosylated glycans in host-microbe interactions and membrane stability. Non-secretors have a reduced fecal content of Bifidobacteria. The intestinal bacterial composition of CD patients resembles the one of non-secretors, with an increase in Firmicutes and decreases in Proteobacteria and Actinobacteria. Non-secretor individuals lack fucosylated glycans at the surface of biliary epithelium and display a different bacterial composition of bile compared to secretors. Notably, an intact biliary epithelial glycocalix is relevant for a stable 'biliary HCO3 (-) umbrella' to protect against toxic effects of hydrophobic bile salt monomers. Here, the biology of FUT2 will be discussed as well as hypotheses to explain the role of FUT2 in the pathophysiology of PSC and Crohn's disease.

Associations of FUT2 and FUT3 gene polymorphisms with Crohn's disease in Chinese patients

BACKGROUND AND AIM

FUT2 and FUT3 genes are responsible for the formation of histo-blood group antigens, which act as binding sites for some intestinal microbes. Several studies suggested that FUT2 gene might affect the intestinal microbiota composition and modulate innate immune responses. However, the effect of FUT2 polymorphisms on Crohn's disease (CD) is uncertain. Our study aimed to analyze associations of CD with FUT2 and FUT3 polymorphisms in Chinese population.

METHODS

A total of 273 CD patients and 479 controls were recruited. The genotypes of FUT2 (rs281377, rs1047781, and rs601338) and FUT3 (rs28362459, rs3745635, and rs3894326) were detected by SNaPshot analysis.

RESULTS

Compared with controls, homozygote TT of FUT2 (rs1047781) was significantly increased in CD patients (TT vs others; P = 0.002, odds ratio [OR] = 1.767, 95% confidence interval [CI] = 1.235-2.528). The haplotype TT formed with FUT2 (rs281377) and (rs1047781) was more prevalent in CD patients than in controls (48.9% vs 43.5%, P = 0.046). Mutant T allele and homozygote TT of FUT2 (rs1047781) were increased in colonic CD patients compared with controls (P < 0.001, OR = 1.843, 95% CI = 1.353-2.512; P < 0.001, OR = 2.607, 95% CI = 1.622-4.191, respectively). Although allele and genotypic distributions of FUT3 were not statistically different between CD patients and controls, mutant allele and genotype of FUT3 (rs28362459) and (rs3745635) were significantly discrepant in three subgroups of CD patients according to lesion locations (all P < 0.05).

CONCLUSIONS

Our study strongly implicates the polymorphic locus of FUT2 (rs1047781) in CD susceptibility in Chinese population. Mutations of FUT3 (rs28362459) and (rs3745635) might influence the lesion locations in CD patients.

Variation in urinary stone composition between adult Uyghur and Han patients with urolithiasis in Xinjiang, China

OBJECTIVE

To analyze variations in urinary stone composition between Uyghur and Han patients with urolithiasis in Xinjiang, China, and to explore the possible factors associated with urinary stone composition in Uyghur and Han patients.

MATERIALS AND METHODS

We analyzed the components of urinary stones in 317 adults (152 Uyghur and 165 Han) with urolithiasis admitted to our hospital from March 2009 to June 2011. Urinary stones were collected by endoscopic or open surgical procedures and analyzed by infrared spectroscopy. Also analyzed were clinical data, including patient's age, sex, geographic distribution, blood tests, and urine tests. Logistic regression was performed to analyze the association between stone components and the clinical characteristics of the patients.

RESULTS

There were significant differences between Uyghur and Han patients in age, geographic distribution, serum concentrations of uric acid, potassium, and phosphorus, urine magnesium concentrations, 24-hour volumes of urine, and in stone components of calcium oxalate monohydrate, calcium oxalate dihydrate plus carbapatite, and uric acid. Differences in sex, family history, complications, sites of calculi, or other blood and urine test results were not significant. Logistic regression analysis revealed that geographic location, ethnicity, blood potassium concentration, and urine volume were significantly correlated with the calcium oxalate dihydrate plus carbapatite component of urinary stones.

CONCLUSION

Urinary stone composition differs between Uyghur and Han patients with urolithiasis, possibly as a result of geographic distribution.