Fucosyltransferase 2 Gene Research Articles

The Human Milk Metabolome Reveals Diverse Oligosaccharide Profiles

Breast milk delivers nutrition and protection to the developing infant. There has been considerable research on the high-molecular-weight milk components; however, low-molecular-weight metabolites have received less attention. To determine the effect of maternal phenotype and diet on the human milk metabolome, milk collected at day 90 postpartum from 52 healthy women was analyzed by using proton nuclear magnetic resonance spectroscopy. Sixty-five milk metabolites were quantified (mono-, di-, and oligosaccharides; amino acids and derivatives; energy metabolites; fatty acids and associated metabolites; vitamins, nucleotides, and derivatives; and others). The biological variation, represented as the percentage CV of each metabolite, varied widely (4–120%), with several metabolites having low variation (<20%), including lactose, urea, glutamate, myo-inositol, and creatinine. Principal components analysis identified 2 clear groups of participants who were differentiable on the basis of milk oligosaccharide concentration and who were classified as secretors or nonsecretors of fucosyltransferase 2 (FUT2) gene products according to the concentration of 2′-fucosyllactose, lactodifucotetraose, and lacto-N-fucopentaose I. Exploration of the interrelations between the milk sugars by using Spearman rank correlations revealed significant positive and negative associations, including positive correlations between fucose and products of the FUT2 gene and negative correlations between fucose and products of the fucosyltransferase 3 (FUT3) gene. The total concentration of milk oligosaccharides was conserved among participants (%CV = 18%), suggesting tight regulation of total oligosaccharide production; however, concentrations of specific oligosaccharides varied widely between participants (%CV = 30.4–84.3%). The variability in certain milk metabolites suggests possible roles in infant or infant gut microbial development. This trial was registered at clinicaltrials.gov> as NCT01817127.

Preliminary study on the differences of fucosyltransferase 2 gene polymorphism between Uyghur and Han patients with ulcerative colitis

Objective To preliminarily evaluate the differences of fucosyltransferase 2 (FUT2) gene polymorphism between Han and Uyghur patients with ulcerative colitis (UC) in Xinjiang Uyghur Autonomous Region.Methods A total of 120 UC patients were enrolled,of whom 64 patients were Han and 56 patients were Uyghur.And there were another 320 healthy controls with matched age,gender and nationality.The DNA of subjects was extracted and the polymorphism of gene FUT2 at C357T,A385T,G428A,and G739A was detected by polymerase chain reaction (PCR) and gene sequencing.The chi-square test was performed to compare gene allele frequencies between Han,Uyghur UC patients and healthy controls.Results The gene frequencies of CC,CT,and TT in C357T mutation of Han UC patients were 0,11.3％ and 88.7％,respectively,while in the corresponding healthy controls were 5.5％,26.1 ％％ and 68.4％,respectively (x2 =9.091,P =0.011).The gene frequencies of AA,AT and TT in A385T mutation of Uyghur UC patients were 87.8％,8.2％ and 4.0％,respectively,while in the corresponding healthy controls were 59.7％,33.6％ and 6.7％,respectively (x2 =13.480,P=0.010).The gene frequencies of GG,AG and AA inG428A mutation of Han UC patients were 98.1％,1.9％ and 0,respectively,while in the corresponding healthy controls were 83.9％,14.3％ and 1.8％,respectively (x2=7.382,P=0.025).The gene frequencies of GG,AG and AA in G428A mutation of Uyghur UC patients were 69.4％,18.4％ and 12.2％,respectively,and in healthy controls were 35.6％,51.0％ and 13.4％,respectively (x2 18.790,P＜0.01).There were no significant differences in G739A mutation between Han and Uyghur UC patients and healthy controls (all P＞0.05).Conclusions The FUT2 gene polymorphisms are associated with UC.C357T and G428A are associated with UC in Han population.A385T and G428A are in the Uyghur population,which indicates gene FUT2 may play a potential role in the pathogenesis of UC in Xinjiang region. Key words: Colitis, ulcerative; Fucosyltransferases; Polymorphism, genetic; Xinjiang

Gastric intrinsic factor deficiency with combined GIF heterozygous mutations and FUT2 secretor variant

Several genome-wide association studies (GWAS) have identified a strong association between serum vitamin B12 and fucosyltransferase 2 (FUT2), a gene associated with susceptibility to Helicobacter pylori infection. Hazra etal. conducted a meta-analysis of three GWAS and found three additional loci in MUT, CUBN and TCN1. Other GWAS conducted in Italy and China confirmed the association for FUT2 gene. Alpha-2-fucosyltransferase (FUT2) catalyzes fucose addition to form H-type antigens in exocrine secretions. FUT2 non-secretor variant produces no secretion of H-type antigens and is associated with high-plasma vitamin B12 levels. This association was explained by the influence of FUT2 on H. pylori, which is a risk factor of gastritis, a main cause of vitamin B12 impaired absorption. However, we recently showed that H. pylori serology had no influence on FUT2 association with vitamin B12, in a large sample population, suggesting the involvement of an alternative mechanism. GIF is another gene associated with plasma levels of vitamin B12 and gastric intrinsic factor (GIF) is a fucosylated protein needed for B12 absorption. Inherited GIF deficiency produces B12 deficiency unrelated with gastritis. We report 2 families with heterozygous GIF mutation, 290T>C, M97T, with decreased binding affinity of GIF for vitamin B12 and one family with heterozygous GIF mutation 435_437delGAA, K145_N146delinsN and no B12 binding activity of mutated GIF. All cases with vitamin B12 deficit carried the FUT2 rs601338 secretor variant. Ulex europeus binding to GIF was influenced by FUT2 genotypes and GIF concentration was lower, in gastric juice from control subjects with the secretor genotype. GIF290C allele was reported in 5 European cases and no Africans among 1282 ambulatory subjects and was associated with low plasma vitamin B12 and anaemia in the single case bearing the FUT2 secretor variant. We concluded that FUT2 secretor variant worsens B12 status in cases with heterozygous GIF mutations by impairing GIF secretion, independently from H. pylori-related gastritis.

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

To investigate the contribution of fucosyltransferase 2 (FUT2) variants to the genetic susceptibility and clinical heterogeneity of ulcerative colitis (UC) between Han and Uyghur patients in Xinjiang, China. A total of 102 UC patients (53 Han patients including 22 men and 31 women, and 49 Uyghur patients including 25 men and 24 women; aged 48 ± 16 years) and 310 age- and sex-matched healthy controls were enrolled from January 2010 to May 2011 in Xinjiang People's Hospital of China. UC was diagnosed based on the clinical, endoscopic and histological findings following Lennard-Jones criteria. Blood samples were collected and genomic DNA was extracted by the routine laboratory methods. Polymerase chain reaction-sequence-based typing method was used to identify FUT2 variants rs281377, rs1047781, rs601338 and rs602662. Genotypic and allelic frequencies were documented and compared between the UC patients and the healthy controls. Genotypic frequencies were also compared between Han and Uyghur patients. Potential association of genetic variation and UC between Han and Uyghur patients was examined. rs281377 was found significantly associated with UC in the Han population as compared with the controls (P = 0.011) while rs281377 was not associated with UC in the Uyghur population (P = 0.06). TT homozygous rs281377 frequencies were higher in the UC groups than in the controls (88.7% vs 68.7% and 55.1% vs 50.3%). rs1047781 was specifically associated with UC in the Uyghur population (P = 0.001), but not associated with UC in the Han population (P = 0.13). TT homozygous rs1047781 frequencies were lower in the UC groups than in the controls (9.5% vs 11.8% and 4.0% vs 6.7%). rs601338 was statistically related to UC in both populations (Han, P = 0.025; Uyghur, P = 8.33 × 10(-5)). AA homozygous rs601338 frequencies were lower in the UC groups than in the controls (0% vs 1.8% and 12.2% vs 13.4%). No association was found between rs602662 and UC in both Han and the Uyghur populations. Allelic analysis showed that rs281377 allele was significantly associated with UC in the Han population as compared with the controls [P = 0.001, odd ratio (OR) = 0.26], however, it was not associated with UC in the Uyghur population (P = 0.603, OR = 1.14), and rs1047781 allele was associated with UC in the Uyghur population (P = 0.001, OR = 0.029) while it was not associated with UC in the Han population (P = 0.074, OR = 0.62). Moreover, rs601338 was associated with UC in both Han (P = 0.005, OR = 0.1) and Uyghur populations (P = 0.002, OR = 0.43). Meta analysis showed that rs1047781 and rs601338 conferred risk of UC as compared with the controls [P = 0.005, OR = 0.47; P = 0.0003, OR = 0.35; 95% confidence interval (CI) = 0.31-0.72 and 0.21-0.58], but rs281377 and rs602662 showed no statistically significant differences between patients with UC and controls (P = 0.10, OR = 0.71; P = 0.68, OR = 0.09; 95% CI = 0.47-1.07 and 0.56-1.47). Functionally relevant FUT2 gene variants are associated with UC, suggesting that they play a potential role in the pathogenesis of UC and may contribute to the clinical heterogeneity of UC between Han and Uyghur patients.

Ectopic expression of blood type antigens in inflamed mucosa with higher incidence of FUT2 secretor status in colonic Crohn’s disease

Host-intestinal microbial interaction plays an important role in the pathogenesis of inflammatory bowel diseases (IBDs). The surface molecules of the intestinal epithelium act as receptors for bacterial adhesion and regulate the intestinal bacteria. Some known receptors are the mucosal blood type antigens, which are regulated by the fucosyltransferase2 (FUT2) gene, and individuals who express these antigens in the gastrointestinal tract are called secretors. Recent research has revealed that the FUT2 gene is associated with Crohn's disease (CD) in western populations. To clarify the contribution of mucosal blood type antigens in IBD, we determined the incidence of five previously reported single-nucleotide polymorphisms of the FUT2 gene in Japanese patients. We also used immunohistochemistry to investigate the antigen expression in mucosal specimens from IBD patients and animal models. Genetic analysis revealed that all of the patients with colonic CD were secretors, whereas the incidence of secretors was 80, 80, 67, and 80%, respectively, for the control, ileocolonic CD, ileal CD, and ulcerative colitis groups (P = 0.036). Abnormal expression of blood type antigens was observed only in colonic CD. Interleukin-10⁻/⁻ mice, but not dextran sulfate sodium colitis mice, had enhanced colonic expression of blood type antigens, and the expression of these antigens preceded the development of colitis in the interleukin-10⁻/⁻ mice. FUT2 secretor status was associated with colonic-type CD. This finding, taken together with the immunohistochemistry data, suggests that the abnormal expression of blood type antigens in the colon may be a unique and essential factor for colonic CD.

Infection-associated FUT2 (Fucosyltransferase 2) genetic variation and impact on functionality assessed by in vivo studies

The secretor (Se)/nonsecretor (se) histo-blood group variation depends on the action of the FUT2 enzyme and has major implications for human susceptibility to infections. To characterize the functionality of FUT2 variants, we assessed the correlation between saliva phenotypes and sequence variation at the FUT2 gene in sixty seven individuals from northern Portugal. While most non-secretor haplotypes were found to carry the 428G > A nonsense mutation in association with a 739G > A missense substitution, we have also identified a recombinant haplotype carrying the 739*A allele together with the efficient 428*G variant in individuals with the Se phenotype. This finding suggested, in contrast to previous results, that the 739*A allele encodes an efficient Se allele. To test this hypothesis we evaluated the in vivo enzyme activity of full coding expression constructs in transient transfection of CHO-K1 cells using FACS (fluorescence-activated cell sorting) analysis and expression of type 2 and type 3 chain H structures as read out. We detected FUT2 activity for the 739*A expression construct, demonstrating that the 739G > A substitution is indeed not inactivating. In accordance with the hypothesis that FUT2 is under long standing balancing selection, we estimated that the time depth of FUT2 global genetic variation is as old as 3 million years. Age estimates of specific variants suggest that the 428G > A mutation occurred at least 1.87 million years ago while the 739G > A substitution is about 816,000 years old. The 385A > T missense mutation underlying the non-secretor phenotype in East Asians appears to be more recent and is likely to have occurred about 256,000 years ago.