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Sollai G, Melis M, Pani D, Cosseddu P, Usai I, Crnjar R, Bonfiglio A, Tomassini Barbarossa I. First objective evaluation of taste sensitivity to 6-n-propylthiouracil (PROP), a paradigm gustatory stimulus in humans. Sci Rep 2017; 7:40353. [PMID: 28074885 PMCID: PMC5225483 DOI: 10.1038/srep40353] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/05/2016] [Indexed: 01/26/2023] Open
Abstract
Practical and reliable methods for the objective measure of taste function are critically important for studying eating behavior and taste function impairment. Here, we present direct measures of human gustatory response to a prototypical bitter compound, 6-n-propyltiouracil (PROP), obtained by electrophysiological recordings from the tongue of subjects who were classified for taster status and genotyped for the specific receptor gene (TAS2R38), and in which taste papilla density was determined. PROP stimulation evoked negative slow potentials that represent the summated depolarization of taste cells. Depolarization amplitude and rate were correlated with papilla density and perceived bitterness, and associated with taster status and TAS2R38. Our study provides a robust and generalizable research tool for the quantitative measure of peripheral taste function, which can greatly help to resolve controversial outcomes on the PROP phenotype role in taste perception and food preferences, and be potentially useful for evaluating nutritional status and health.
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Affiliation(s)
- Giorgia Sollai
- Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, I 09042, Italy
| | - Melania Melis
- Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, I 09042, Italy
| | - Danilo Pani
- Department of Electrical and Electronic Engineering, University of Cagliari, Piazza d’Armi, Cagliari, CA, I 09123, Italy
| | - Piero Cosseddu
- Department of Electrical and Electronic Engineering, University of Cagliari, Piazza d’Armi, Cagliari, CA, I 09123, Italy
| | - Ilenia Usai
- Department of Electrical and Electronic Engineering, University of Cagliari, Piazza d’Armi, Cagliari, CA, I 09123, Italy
| | - Roberto Crnjar
- Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, I 09042, Italy
| | - Annalisa Bonfiglio
- Department of Electrical and Electronic Engineering, University of Cagliari, Piazza d’Armi, Cagliari, CA, I 09123, Italy
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52
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Lu P, Zhang CH, Lifshitz LM, ZhuGe R. Extraoral bitter taste receptors in health and disease. J Gen Physiol 2017; 149:181-197. [PMID: 28053191 PMCID: PMC5299619 DOI: 10.1085/jgp.201611637] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 10/06/2016] [Accepted: 12/19/2016] [Indexed: 12/24/2022] Open
Abstract
Bitter taste receptors (TAS2Rs or T2Rs) belong to the superfamily of seven-transmembrane G protein-coupled receptors, which are the targets of >50% of drugs currently on the market. Canonically, T2Rs are located in taste buds of the tongue, where they initiate bitter taste perception. However, accumulating evidence indicates that T2Rs are widely expressed throughout the body and mediate diverse nontasting roles through various specialized mechanisms. It has also become apparent that T2Rs and their polymorphisms are associated with human disorders. In this review, we summarize the physiological and pathophysiological roles that extraoral T2Rs play in processes as diverse as innate immunity and reproduction, and the major challenges in this emerging field.
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Affiliation(s)
- Ping Lu
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605
| | - Cheng-Hai Zhang
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605
| | - Lawrence M Lifshitz
- Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, MA 01605.,Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605
| | - Ronghua ZhuGe
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA 01605 .,Biomedical Imaging Group, University of Massachusetts Medical School, Worcester, MA 01605
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53
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Choi JH, Lee J, Choi IJ, Kim YW, Ryu KW, Kim J. Variations in TAS1R taste receptor gene family modify food intake and gastric cancer risk in a Korean population. Mol Nutr Food Res 2016; 60:2433-2445. [PMID: 27321875 DOI: 10.1002/mnfr.201600145] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 05/13/2016] [Accepted: 06/10/2016] [Indexed: 02/06/2023]
Abstract
SCOPE Human taste receptor type 1 (TAS1R, T1R) gene family mediates the perception of umami and sweet tastes and regulates metabolism. This study investigated whether variants in the TAS1R are associated with food intake and susceptibility to gastric cancer (GC). METHODS AND RESULTS A total of 1131 Koreans including 377 GC cases were analyzed to determine the dietary intake and genotype for 25 variants in TAS1R genes. Among the genotyped polymorphisms, six loci with a minor allele frequency >0.05 were tested for an association with dietary intake and GC risk. Findings suggest that TAS1R polymorphisms were associated with a variety of food intake that is beyond the known T1R-taste association. Furthermore, differential consumption for cigarettes and citrus fruits by TAS1R genetic variants may be linked to GC risk in males and females, respectively. Additionally, in males, TAS1R1 rs34160967 heterozygote showed an increased risk of GC (odds ratio: 1.52, 95% confidence interval: 1.10-2.09), independent of dietary intake. However, this GC-risk effect of TAS1R variants was not evident in females. CONCLUSIONS Genetic variants in TAS1R were associated with dietary consumption, which may be associated with GC risk. TAS1R1 rs34160967 may also modify the risk for GC independent of diet in Korean males.
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Affiliation(s)
- Jeong-Hwa Choi
- Molecular Epidemiology Branch, Division of Cancer Epidemiology and Prevention, National Cancer Center, Gyeonggi-do, Korea
| | - Jeonghee Lee
- Molecular Epidemiology Branch, Division of Cancer Epidemiology and Prevention, National Cancer Center, Gyeonggi-do, Korea
| | - Il Ju Choi
- Center for Gastric Cancer, National Cancer Center, Gyeonggi-do, Korea
| | - Young-Woo Kim
- Center for Gastric Cancer, National Cancer Center, Gyeonggi-do, Korea
| | - Keun Won Ryu
- Center for Gastric Cancer, National Cancer Center, Gyeonggi-do, Korea
| | - Jeongseon Kim
- Molecular Epidemiology Branch, Division of Cancer Epidemiology and Prevention, National Cancer Center, Gyeonggi-do, Korea
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Genetic Variation in the TAS2R38 Bitter Taste Receptor and Gastric Cancer Risk in Koreans. Sci Rep 2016; 6:26904. [PMID: 27245112 PMCID: PMC4887993 DOI: 10.1038/srep26904] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 05/10/2016] [Indexed: 12/21/2022] Open
Abstract
The human TAS2R38 gene encodes a bitter taste receptor that regulates the bitterness perception and differentiation of ingested nutritional/poisonous compounds in the oral cavity and gastrointestinal tract. TAS2R38 gene variants are associated with alterations in individual sensitivity to bitter taste and food intake; hence, these genetic variants may modify the risk for diet-related diseases, including cancer. However, little is known about the association between TAS2R38 polymorphisms and gastric cancer susceptibility. The present case-control study examined the influence of TAS2R38 polymorphisms on food intake and determined whether they predict gastric cancer risk in Koreans. A total of 1,580 subjects, including 449 gastric cancer cases, were genotyped for TAS2R38 A49P, V262A, I296V and diplotypes. Dietary data were analysed to determine the total consumption of energy, fibre, vegetables, fruits, sweets, fats, alcohol and cigarettes. TAS2R38 diplotype was not associated with food, alcohol or cigarette consumption, either independent or dependent of gastric cancer phenotype. However, the PAV/AVI diplotype significantly increased gastric cancer risk (adjusted odds ratio: 1.513; 95% confidence interval: 1.148–1.994) independent of dietary intake. Findings suggest that TAS2R38 may be associated with the risk for gastric cancer in Koreans, although the TAS2R38 diplotype did not influence dietary intake.
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55
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Global diversity in the TAS2R38 bitter taste receptor: revisiting a classic evolutionary PROPosal. Sci Rep 2016; 6:25506. [PMID: 27138342 PMCID: PMC4853779 DOI: 10.1038/srep25506] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 04/18/2016] [Indexed: 02/07/2023] Open
Abstract
The ability to taste phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) is a polymorphic trait mediated by the TAS2R38 bitter taste receptor gene. It has long been hypothesized that global genetic diversity at this locus evolved under pervasive pressures from balancing natural selection. However, recent high-resolution population genetic studies of TAS2Rs suggest that demographic events have played a critical role in the evolution of these genes. We here utilized the largest TAS2R38 database yet analyzed, consisting of 5,589 individuals from 105 populations, to examine natural selection, haplotype frequencies and linkage disequilibrium to estimate the effects of both selection and demography on contemporary patterns of variation at this locus. We found signs of an ancient balancing selection acting on this gene but no post Out-Of-Africa departures from neutrality, implying that the current observed patterns of variation can be predominantly explained by demographic, rather than selective events. In addition, we found signatures of ancient selective forces acting on different African TAS2R38 haplotypes. Collectively our results provide evidence for a relaxation of recent selective forces acting on this gene and a revised hypothesis for the origins of the present-day worldwide distribution of TAS2R38 haplotypes.
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Hyland PL, Zhang H, Yang Q, Yang HH, Hu N, Lin SW, Su H, Wang L, Wang C, Ding T, Fan JH, Qiao YL, Sung H, Wheeler W, Giffen C, Burdett L, Wang Z, Lee MP, Chanock SJ, Dawsey SM, Freedman ND, Abnet CC, Goldstein AM, Yu K, Taylor PR. Pathway, in silico and tissue-specific expression quantitative analyses of oesophageal squamous cell carcinoma genome-wide association studies data. Int J Epidemiol 2016; 45:206-20. [PMID: 26635288 PMCID: PMC4881832 DOI: 10.1093/ije/dyv294] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2015] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Oesophageal cancer is the fourth leading cause of cancer death in China where essentially all cases are histologically oesophageal squamous cell carcinoma (ESCC). Agnostic pathway-based analyses of genome-wide association study (GWAS) data combined with tissue-specific expression quantitative trait loci (eQTL) analysis and publicly available functional data can identify biological pathways and/or genes enriched with functionally-relevant disease-associated variants. METHOD We used the adaptive multilocus joint test to analyse 1827 pathways containing 6060 genes using GWAS data from 1942 ESCC cases and 2111 controls with Chinese ancestry. We examined the function of risk alleles using in silico and eQTL analyses in oesophageal tissues. RESULTS Associations with ESCC risk were observed for 36 pathways predominantly involved in apoptosis, cell cycle regulation and DNA repair and containing known GWAS-associated genes. After excluding genes with previous GWAS signals, candidate pathways (and genes) for ESCC risk included taste transduction (KEGG_hsa04742; TAS2R13, TAS2R42, TAS2R14, TAS2R46,TAS2R50), long-patch base excision repair (Reactome_pid; POLD2) and the metabolics pathway (KEGG_hsa01100; MTAP, GAPDH, DCTD, POLD2, AMDHD1). We identified and validated CASP8 rs13016963 and IDH2 rs11630814 as eQTLs, and CASP8 rs3769823 and IDH2 rs4561444 as the potential functional variants in high-linkage disequilibrium with these single nucleotide polymorphisms (SNPs), respectively. Further, IDH2 mRNA levels were down-regulated in ESCC (tumour:normal-fold change = 0.69, P = .75E-14). CONCLUSION Agnostic pathway-based analyses and integration of multiple types of functional data provide new evidence for the contribution of genes in taste transduction and metabolism to ESCC susceptibility, and for the functionality of both established and new ESCC risk-related SNPs.
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Affiliation(s)
| | - Han Zhang
- Division of Cancer Epidemiology and Genetics, and
| | - Qi Yang
- Division of Cancer Epidemiology and Genetics, and
| | | | - Nan Hu
- Division of Cancer Epidemiology and Genetics, and
| | - Shih-Wen Lin
- Division of Cancer Epidemiology and Genetics, and
| | - Hua Su
- Division of Cancer Epidemiology and Genetics, and
| | - Lemin Wang
- Division of Cancer Epidemiology and Genetics, and
| | - Chaoyu Wang
- Division of Cancer Epidemiology and Genetics, and
| | - Ti Ding
- Division of Cancer Epidemiology and Genetics, and
| | - Jin-Hu Fan
- Division of Cancer Epidemiology and Genetics, and
| | - You-Lin Qiao
- Division of Cancer Epidemiology and Genetics, and
| | - Hyuna Sung
- Division of Cancer Epidemiology and Genetics, and
| | | | - Carol Giffen
- Division of Cancer Epidemiology and Genetics, and
| | | | - Zhaoming Wang
- Division of Cancer Epidemiology and Genetics, and Division of Cancer Epidemiology and Genetics, and
| | | | | | | | | | | | | | - Kai Yu
- Division of Cancer Epidemiology and Genetics, and
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Boxer EE, Garneau NL. Rare haplotypes of the gene TAS2R38 confer bitter taste sensitivity in humans. SPRINGERPLUS 2015; 4:505. [PMID: 26405625 PMCID: PMC4574037 DOI: 10.1186/s40064-015-1277-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/25/2015] [Indexed: 11/12/2022]
Abstract
Background The TAS2R38 gene is widely responsible for the well-known bimodal response to a family of bitter chemicals which includes 6-n-propylthiouracial (PROP). There are two common haplotypes of this gene, the recessive AVI and the dominant PAV, both of which are well studied. Conversely, the role of rare TAS2R38 haplotypes on bitter taste sensitivity has been notoriously difficult to study due to small sample sizes. Here we present PROP sensitivity data of 97 individuals that have been observed to carry rare haplotypes (AAV, AAI, PAI, PVI) of the TAS2R38 gene. Results Participants rated their bitter taste perception to a PROP filter disc then provided a buccal DNA sample from which the TAS2R38 gene was sequenced and analyzed. We found the prevalence of the PAV haplotype to be 42.3 %, AVI 53.1 %, AAV 2.5 %, AAI 1.2 %, PAI 0.8 % and PVI 0.1 %. We found that the AAI, AAV, and PAI haplotypes present intermediate taste sensitivity. Conclusions These data are further evidence that bitter taste sensitivity to PROP exists as a broad range, and not exclusively as nontasters, medium tasters, and supertasters.
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Affiliation(s)
- Emma E Boxer
- Genetics of Taste Lab, Health Sciences Department, Denver Museum of Nature & Science, 2001 Colorado Blvd., Denver, CO 80205 USA ; University of Colorado Denver, 1201 Larimer St., Denver, CO 80204 USA
| | - Nicole L Garneau
- Genetics of Taste Lab, Health Sciences Department, Denver Museum of Nature & Science, 2001 Colorado Blvd., Denver, CO 80205 USA
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Beckett EL, Martin C, Yates Z, Veysey M, Duesing K, Lucock M. Bitter taste genetics--the relationship to tasting, liking, consumption and health. Food Funct 2015; 5:3040-54. [PMID: 25286017 DOI: 10.1039/c4fo00539b] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Bitter is the most complex of human tastes, and is arguably the most important. Aversion to bitter taste is important for detecting toxic compounds in food; however, many beneficial nutrients also taste bitter and these may therefore also be avoided as a consequence of bitter taste. While many polymorphisms in TAS2R genes may result in phenotypic differences that influence the range and sensitivity of bitter compounds detected, the full extent to which individuals differ in their abilities to detect bitter compounds remains unknown. Simple logic suggests that taste phenotypes influence food preferences, intake and consequently health status. However, it is becoming clear that genetics only plays a partial role in predicting preference, intake and health outcomes, and the complex, pleiotropic relationships involved are yet to be fully elucidated.
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Affiliation(s)
- Emma L Beckett
- School of Environmental and Life Sciences, University of Newcastle, Brush Rd, Ourimbah, NSW 2258, Australia.
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59
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LaBonte ML, Beers MA. An alternative laboratory designed to address ethical concerns associated with traditional TAS2R38 student genotyping. BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION : A BIMONTHLY PUBLICATION OF THE INTERNATIONAL UNION OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 43:100-109. [PMID: 25704857 DOI: 10.1002/bmb.20846] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 10/27/2014] [Accepted: 11/17/2014] [Indexed: 06/04/2023]
Abstract
The TAS2R38 alleles that code for the PAV/AVI T2R38 proteins have long been viewed as benign taste receptor variants. However, recent studies have demonstrated an expanding and medically relevant role for TAS2R38. The AVI variant of T2R38 is associated with an increased risk of both colorectal cancer and Pseudomonas aeruginosa-associated sinus infection and T2R38 variants have been implicated in off-target drug responses. To address ethical concerns associated with continued student TAS2R38 gene testing, we developed an alternative to the traditional laboratory genotyping exercise. Instead of determining their own genotype, introductory level students isolated plasmid DNA containing a section of the human TAS2R38 gene from Escherichia coli. Following PCR-mediated amplification of a section of the TAS2R38 gene spanning the SNP at position 785, students determined their assigned genotype by restriction enzyme digestion and agarose gel electrophoresis. Using the course wide genotype and phenotype data, students found that there was an association between TAS2R38 genotype and the age of persistent P. aeruginosa acquisition in cystic fibrosis "patients." Assessment data demonstrated that students taking part in this new TAS2R38 laboratory activity made clear learning gains.
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Affiliation(s)
- Michelle L LaBonte
- Department of the History of Science, Harvard University, Cambridge, Massachusetts, 02138
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Robino A, Mezzavilla M, Pirastu N, Dognini M, Tepper BJ, Gasparini P. A population-based approach to study the impact of PROP perception on food liking in populations along the Silk Road. PLoS One 2014; 9:e91716. [PMID: 24626196 PMCID: PMC3953580 DOI: 10.1371/journal.pone.0091716] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 02/14/2014] [Indexed: 12/15/2022] Open
Abstract
Taste is one of the main factors determining food choices. Differences in PROP bitter taste perception have been implicated in individual differences in food preferences and selection. The present study examined associations between, PROP phenotypes, self-reported food liking and TAS2R38 polymorphisms, the major gene implicated in PROP bitterness, in six different populations of the Caucasus and Central Asia, located along the ancient Silk Road. Differences in the distribution of PROP phenotypes across populations were detected, with a higher frequency of super tasters in Tajikistan (31.3%) and Armenia (39.0%) and a higher frequency of non tasters in Georgia (50.9%). While no relationships were observed between PROP phenotypes and food liking using standard statistical tests, we used an approach based on comparison of distance matrices derived from these data. The first matrix compared the food liking ratings of each population to all others pairwise using the Kruskal-Wallis test (at p<0.00063), and the second one compared the distribution of PROP phenotypes across all populations in a similar manner calculating the chi-square statistic as a distance measure. A strong correlation between the two matrices was found (Mantel test: r = 0.67, p-value = 0.03), suggesting that the pattern of food liking across populations was closely related to the distribution of PROP phenotypes. This same relationship was not observed when TAS2R38 genotypes were substituted for PROP phenotypes in this analysis. Our data suggest that a population-based approach utilizing distance matrices is a useful technique for detecting PROP-related differences in food liking and can be applied to other taste phenotypes.
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Affiliation(s)
- Antonietta Robino
- Institute for Maternal and Child Health - IRCCS “Burlo Garofolo”, Trieste, Italy
- University of Trieste, Trieste, Italy
- * E-mail:
| | - Massimo Mezzavilla
- Institute for Maternal and Child Health - IRCCS “Burlo Garofolo”, Trieste, Italy
- University of Trieste, Trieste, Italy
| | - Nicola Pirastu
- Institute for Maternal and Child Health - IRCCS “Burlo Garofolo”, Trieste, Italy
- University of Trieste, Trieste, Italy
| | | | - Beverly J. Tepper
- Department of Food Science, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Paolo Gasparini
- Institute for Maternal and Child Health - IRCCS “Burlo Garofolo”, Trieste, Italy
- University of Trieste, Trieste, Italy
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Schembre SM, Cheng I, Wilkens LR, Albright CL, Le Marchand L. Variations in bitter-taste receptor genes, dietary intake, and colorectal adenoma risk. Nutr Cancer 2013; 65:982-90. [PMID: 24083639 PMCID: PMC3836614 DOI: 10.1080/01635581.2013.807934] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Genetic variants in bitter-taste receptor genes have been hypothesized to negatively impact health outcomes and/or influence dietary intake and, consequently, could increase the risk of colorectal neoplasia. Using a case-control study of 914 colorectal adenoma cases/1188 controls, we explored associations among colorectal adenoma risk, dietary intake, and genetic variation in 3 bitter-taste receptor genes: TAS2R38 (rs713598, rs1726866, rs10246939), TAS2R16 (rs846672), and TAS2R50 (rs1376251). Analysis of covariance was conducted to detect trends in dietary intake across TAS2R genotypes/haplotypes. Odds ratios and 95% confidence intervals were estimated by logistic regression to test gene-adenoma risk associations. No significant associations were observed between the TAS2R38 PAV/PAV diplotype or the TAS2R16 (rs846672) polymorphism with the selected diet variables. We observed weak inverse associations between the TAS2R50 (rs1376251) C allele and dietary fiber and vegetable intake (Ps < 0.015). Odds ratios for adenoma risk were not significantly different from the null. Our findings do not support a link between these TAS2R genotypes/haplotypes and dietary intake that could impact colorectal adenoma risk. However, given the paucity of data, we cannot dismiss the possibility that these genes may influence colorectal adenoma risk in other ways, such as through impaired gastrointestinal function, particularly in subgroups of the population.
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Affiliation(s)
- Susan M. Schembre
- Department of Behavioral Science, The University of Texas MD Anderson Cancer Center, Houston, Texas, 77030, USA
| | - Iona Cheng
- Epidemiology Program, University of Hawaii Cancer Center, Honolulu, Hawaii 96813, USA
| | - Lynne R. Wilkens
- Epidemiology Program, University of Hawaii Cancer Center, Honolulu, Hawaii 96813, USA
| | - Cheryl L. Albright
- School of Nursing and Dental Hygiene, University of Hawaii at Manoa, Honolulu, Hawaii 96813
| | - Loïc Le Marchand
- Epidemiology Program, University of Hawaii Cancer Center, Honolulu, Hawaii 96813, USA
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Melis M, Atzori E, Cabras S, Zonza A, Calò C, Muroni P, Nieddu M, Padiglia A, Sogos V, Tepper BJ, Tomassini Barbarossa I. The gustin (CA6) gene polymorphism, rs2274333 (A/G), as a mechanistic link between PROP tasting and fungiform taste papilla density and maintenance. PLoS One 2013; 8:e74151. [PMID: 24040192 PMCID: PMC3767652 DOI: 10.1371/journal.pone.0074151] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 07/29/2013] [Indexed: 01/29/2023] Open
Abstract
Taste sensitivity to PROP varies greatly among individuals and is associated with polymorphisms in the bitter receptor gene TAS2R38, and with differences in fungiform papilla density on the anterior tongue surface. Recently we showed that the PROP non-taster phenotype is strongly associated with the G variant of polymorphism rs2274333 (A/G) of the gene that controls the salivary trophic factor, gustin. The aims of this study were 1) to investigate the role of gustin gene polymorphism rs2274333 (A/G), in PROP sensitivity and fungiform papilla density and morphology, and 2) to investigate the effect of this gustin gene polymorphism on cell proliferation and metabolic activity. Sixty-four subjects were genotyped for both genes by PCR techniques, their PROP sensitivity was assessed by scaling and threshold methods, and their fungiform papilla density, diameter and morphology were determined. In vitro experiments examined cell proliferation and metabolic activity, following treatment with saliva of individuals with and without the gustin gene mutation, and with isolated protein, in the two iso-forms. Gustin and TAS2R38 genotypes were associated with PROP threshold (p=0.0001 and p=0.0042), but bitterness intensity was mostly determined by TAS2R38 genotypes (p<0.000001). Fungiform papillae densities were associated with both genotypes (p<0.014) (with a stronger effect for gustin; p=0.0006), but papilla morphology was a function of gustin alone (p<0.0012). Treatment of isolated cells with saliva from individuals with the AA form of gustin or direct application of the active iso-form of gustin protein increased cell proliferation and metabolic activity (p<0.0135). These novel findings suggest that the rs2274333 polymorphism of the gustin gene affects PROP sensitivity by acting on fungiform papilla development and maintenance, and could provide the first mechanistic explanation for why PROP super-tasters are more responsive to a broad range of oral stimuli.
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Affiliation(s)
- Melania Melis
- Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
| | - Elena Atzori
- Department of Life and Environment Sciences, University of Cagliari, Monserrato, Italy
| | - Stefano Cabras
- Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
| | - Andrea Zonza
- Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
| | - Carla Calò
- Department of Life and Environment Sciences, University of Cagliari, Monserrato, Italy
| | - Patrizia Muroni
- Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
| | - Mariella Nieddu
- Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
| | - Alessandra Padiglia
- Department of Life and Environment Sciences, University of Cagliari, Monserrato, Italy
| | - Valeria Sogos
- Department of Biomedical Sciences, University of Cagliari, Monserrato, Italy
| | - Beverly J. Tepper
- Department of Food Science, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, New Jersey, United States of America
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Campa D, De Rango F, Carrai M, Crocco P, Montesanto A, Canzian F, Rose G, Rizzato C, Passarino G, Barale R. Bitter taste receptor polymorphisms and human aging. PLoS One 2012; 7:e45232. [PMID: 23133589 PMCID: PMC3487725 DOI: 10.1371/journal.pone.0045232] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 08/17/2012] [Indexed: 01/10/2023] Open
Abstract
Several studies have shown that genetic factors account for 25% of the variation in human life span. On the basis of published molecular, genetic and epidemiological data, we hypothesized that genetic polymorphisms of taste receptors, which modulate food preferences but are also expressed in a number of organs and regulate food absorption processing and metabolism, could modulate the aging process. Using a tagging approach, we investigated the possible associations between longevity and the common genetic variation at the three bitter taste receptor gene clusters on chromosomes 5, 7 and 12 in a population of 941 individuals ranging in age from 20 to 106 years from the South of Italy. We found that one polymorphism, rs978739, situated 212 bp upstream of the TAS2R16 gene, shows a statistically significant association (p = 0.001) with longevity. In particular, the frequency of A/A homozygotes increases gradually from 35% in subjects aged 20 to 70 up to 55% in centenarians. These data provide suggestive evidence on the possible correlation between human longevity and taste genetics.
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Affiliation(s)
- Daniele Campa
- Genomic Epidemiology Group, German Cancer Research Center (DKFZ), Heidelberg, Germany.
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Wooding SP, Atanasova S, Gunn HC, Staneva R, Dimova I, Toncheva D. Association of a bitter taste receptor mutation with Balkan Endemic Nephropathy (BEN). BMC MEDICAL GENETICS 2012; 13:96. [PMID: 23050764 PMCID: PMC3495054 DOI: 10.1186/1471-2350-13-96] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Accepted: 09/28/2012] [Indexed: 11/10/2022]
Abstract
Background Balkan Endemic Nephropathy (BEN) is late-onset kidney disease thought to arise from chronic exposure to aristolochic acid, a phytotoxin that contaminates wheat supplies in rural areas of Eastern Europe. It has recently been demonstrated that humans are capable of perceiving aristolochic acid at concentrations below 40 nM as the result of high-affinity interactions with the TAS2R43 bitter taste receptor. Further, TAS2R43 harbors high-frequency loss-of-function mutations resulting in 50-fold variability in perception. This suggests that genetic variation in TAS2R43 might affect susceptibility to BEN, with individuals carrying functional forms of the receptor being protected by an ability to detect tainted foods. Methods To determine whether genetic variation in TAS2R43 predicts BEN susceptibility, we examined genotype-phenotype associations in a case–control study. A cohort of 88 affected and 99 control subjects from western Bulgaria were genotyped with respect to two key missense variants and a polymorphic whole-gene deletion of TAS2R43 (W35S, H212R, and wt/Δ), which are known to affect taste sensitivity to aristolochic acid. Tests for association between haplotypes and BEN status were then performed. Results Three major TAS2R43 haplotypes observed in previous studies (TAS2R43-W35/H212, -S35/R212 and –Δ) were present at high frequencies (0.17, 0.36, and 0.47 respectively) in our sample, and a significant association between genotype and BEN status was present (P = 0.020; odds ratio 1.18). However, contrary to expectation, BEN was positively associated with TAS2R43-W35/H212, a highly responsive allele previously shown to confer elevated bitter sensitivity to aristolochic acid, which should drive aversion but might also affect absorption, altering toxin activation. Conclusions Our findings are at strong odds with the prediction that carriers of functional alleles of TAS2R43 are protected from BEN by an ability to detect and avoid aristolochic acid exposure. Evidence for a positive association between high-sensitivity alleles and BEN status suggests instead that possession of toxin-responsive receptor variants may paradoxically increase vulnerability, possibly by shifting attractive responses associated with low-intensity bitter sensations. The broad-spectrum tuning of the ~25-member TAS2R family as a whole toward xenobiotics points to a potentially far-reaching relevance of bitter responses to exposure-related disease in both individuals and populations.
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Affiliation(s)
- Stephen P Wooding
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX 75244, USA.
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Campa D, Sainz J, Pardini B, Vodickova L, Naccarati A, Rudolph A, Novotny J, Försti A, Buch S, von Schönfels W, Schafmayer C, Völzke H, Hoffmeister M, Frank B, Barale R, Hemminki K, Hampe J, Chang-Claude J, Brenner H, Vodicka P, Canzian F. A comprehensive investigation on common polymorphisms in the MDR1/ABCB1 transporter gene and susceptibility to colorectal cancer. PLoS One 2012; 7:e32784. [PMID: 22396794 PMCID: PMC3292569 DOI: 10.1371/journal.pone.0032784] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Accepted: 02/02/2012] [Indexed: 02/07/2023] Open
Abstract
ATP Binding Cassette B1 (ABCB1) is a transporter with a broad substrate specificity involved in the elimination of several carcinogens from the gut. Several polymorphic variants within the ABCB1 gene have been reported as modulators of ABCB1-mediated transport. We investigated the impact of ABCB1 genetic variants on colorectal cancer (CRC) risk. A hybrid tagging/functional approach was performed to select 28 single nucleotide polymorphisms (SNPs) that were genotyped in 1,321 Czech subjects, 699 CRC cases and 622 controls. In addition, six potentially functional SNPs were genotyped in 3,662 German subjects, 1,809 cases and 1,853 controls from the DACHS study. We found that three functional SNPs (rs1202168, rs1045642 and rs868755) were associated with CRC risk in the German population. Carriers of the rs1202168_T and rs868755_T alleles had an increased risk for CRC (P(trend) = 0.016 and 0.029, respectively), while individuals bearing the rs1045642_C allele showed a decreased risk of CRC (P(trend) = 0.022). We sought to replicate the most significant results in an independent case-control study of 3,803 subjects, 2,169 cases and 1,634 controls carried out in the North of Germany. None of the SNPs tested were significantly associated with CRC risk in the replication study. In conclusion, in this study of about 8,800 individuals we show that ABCB1 gene polymorphisms play at best a minor role in the susceptibility to CRC.
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Affiliation(s)
- Daniele Campa
- Genomic Epidemiology Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Biology, University of Pisa, Pisa, Italy
| | - Juan Sainz
- Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Barbara Pardini
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Ludmila Vodickova
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Alessio Naccarati
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Anja Rudolph
- Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Jan Novotny
- Department of Oncology, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Asta Försti
- Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Center for Primary Health Care Research, Clinical Research Center, SUS Malmö, Malmö, Sweden
| | - Stephan Buch
- Department of General Internal Medicine, University Hospital Schleswig-Holstein, Kiel, Germany
- POPGEN Biobank Project, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Witigo von Schönfels
- Department of General and Thoracic Surgery, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Clemens Schafmayer
- POPGEN Biobank Project, University Hospital Schleswig-Holstein, Kiel, Germany
- Department of General and Thoracic Surgery, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Henry Völzke
- Institute for Community Medicine, University Hospital of the Ernst Moritz Arndt University, Greifswald, Greifswald, Germany
| | - Michael Hoffmeister
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Bernd Frank
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Kari Hemminki
- Division of Molecular Genetic Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Center for Primary Health Care Research, Clinical Research Center, SUS Malmö, Malmö, Sweden
| | - Jochen Hampe
- Department of General Internal Medicine, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Jenny Chang-Claude
- Division of Cancer Epidemiology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Hermann Brenner
- Division of Clinical Epidemiology and Aging Research, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Pavel Vodicka
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Federico Canzian
- Genomic Epidemiology Group, German Cancer Research Center (DKFZ), Heidelberg, Germany
- * E-mail:
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