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Chalazan B, Palm D, Sridhar A, Lee C, Argos M, Daviglus M, Rehman J, Konda S, Darbar D. Common genetic variants associated with obesity in an African-American and Hispanic/Latino population. PLoS One 2021; 16:e0250697. [PMID: 33983957 PMCID: PMC8118531 DOI: 10.1371/journal.pone.0250697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 04/12/2021] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Over 35% of all adults in the world are currently obese and risk of obesity in racial or ethnic minority groups exist in the US, but the causes of these differences are not all known. As obesity is a leading cause of cardiovascular disease, an improved understanding of risk factors across racial and ethnic groups may improve outcomes. OBJECTIVE The objective of this study was to determine if susceptibility to obesity is associated with genetic variation in candidate single nucleotide polymorphisms (SNPs) in African Americans and Hispanic/Latinos. MATERIALS AND METHODS We examined data from 534 African Americans and 557 Hispanic/Latinos participants from the UIC Cohort of Patients, Family and Friends. Participants were genotyped for the top 26 obesity-associated SNPs within FTO, MC4R, TUB, APOA2, APOA5, ADIPOQ, ARL15, CDH13, KNG1, LEPR, leptin, and SCG3 genes. RESULTS The mean (SD) age of participants was 49±13 years, 55% were female, and mean body mass index (BMI) was 31±7.5 kg/m2. After adjusting for age and sex, we found that rs8050136 in FTO (odds ratio [OR] 1.40, 95% confidence interval [CI] 1.1-1.8; P = 0.01) among African Americans and rs2272383 in TUB (OR 1.34, 95% CI 1.04-1.71; P = 0.02) among Hispanic/Latinos were associated with obesity. However, none of the SNPs in multivariable analysis of either AA or H/L cohorts were significant when adjusted for multiple correction. CONCLUSIONS We show that candidate SNPs in the FTO and TUB genes are associated with obesity in African Americans and Hispanic/Latinos individuals respectively. While the underlying pathophysiological mechanisms by which common genetic variants cause obesity remain unclear, we have identified novel therapeutic targets across racial and ethnic groups.
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Affiliation(s)
- Brandon Chalazan
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Denada Palm
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Arvind Sridhar
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Christina Lee
- Broad Institute of MIT and Harvard, Boston, Massachusetts, United States of America
| | - Maria Argos
- Division of Epidemiology and Biostatics, School of Public Health, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Martha Daviglus
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Institute for Minority Health Research, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Jalees Rehman
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Sreenivas Konda
- Division of Epidemiology and Biostatics, School of Public Health, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Dawood Darbar
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Pharmacology, University of Illinois at Chicago, Chicago, Illinois, United States of America
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Tam V, Turcotte M, Meyre D. Established and emerging strategies to crack the genetic code of obesity. Obes Rev 2019; 20:212-240. [PMID: 30353704 DOI: 10.1111/obr.12770] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/11/2022]
Abstract
Tremendous progress has been made in the genetic elucidation of obesity over the past two decades, driven largely by technological, methodological and organizational innovations. Current strategies for identifying obesity-predisposing loci/genes, including cytogenetics, linkage analysis, homozygosity mapping, admixture mapping, candidate gene studies, genome-wide association studies, custom genotyping arrays, whole-exome sequencing and targeted exome sequencing, have achieved differing levels of success, and the identified loci in aggregate explain only a modest fraction of the estimated heritability of obesity. This review outlines the successes and limitations of these approaches and proposes novel strategies, including the use of exceptionally large sample sizes, the study of diverse ethnic groups and deep phenotypes and the application of innovative methods and study designs, to identify the remaining obesity-predisposing genes. The use of both established and emerging strategies has the potential to crack the genetic code of obesity in the not-too-distant future. The resulting knowledge is likely to yield improvements in obesity prediction, prevention and care.
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Affiliation(s)
- V Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - M Turcotte
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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Han S, Miyoshi K, Shikada S, Amano G, Wang Y, Yoshimura T, Katayama T. TULP3 is required for localization of membrane-associated proteins ARL13B and INPP5E to primary cilia. Biochem Biophys Res Commun 2019; 509:227-234. [PMID: 30583862 DOI: 10.1016/j.bbrc.2018.12.109] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 12/14/2018] [Indexed: 01/24/2023]
Abstract
The primary cilia are known as biosensors that transduce signals through the ciliary membrane proteins in vertebrate cells. The ciliary membrane contains transmembrane proteins and membrane-associated proteins. Tubby-like protein 3 (TULP3), a member of the tubby family, has been shown to interact with the intraflagellar transport-A complex (IFT-A) and to be involved in the ciliary localization of transmembrane proteins, although its role in the ciliary entry of membrane-associated proteins has remained unclear. Here, to determine whether TULP3 is required for the localization of ciliary membrane-associated proteins, we generated and analyzed TULP3-knockout (KO) hTERT RPE-1 (RPE1) cells. Immunofluorescence analysis demonstrated that ciliary formation was downregulated in TULP3-KO cells and that membrane-associated proteins, ADP-ribosylation factor-like 13B (ARL13B) and inositol polyphosphate-5-phosphatase E (INPP5E), failed to localize to primary cilia in TULP3-KO cells. These defects in the localization of ARL13B and INPP5E in TULP3-KO cells were rescued by the exogenous expression of wild-type TULP3, but not that of mutant TULP3 lacking the ability to bind IFT-A. In addition, the expression of TUB protein, another member of the tubby family whose endogenous expression is absent in RPE1 cells, also rescued the defective ciliary localization of ARL13B and INPP5E in TULP3-KO cells, suggesting that there is functional redundancy between TULP3 and TUB. Our findings indicate that TULP3 participates in ciliogenesis, and targets membrane-associated proteins to primary cilia via binding to IFT-A.
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Affiliation(s)
- Sarina Han
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Ko Miyoshi
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan.
| | - Sho Shikada
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Genki Amano
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Yinshengzhuoma Wang
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Takeshi Yoshimura
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
| | - Taiichi Katayama
- Department of Child Development and Molecular Brain Science, United Graduate School of Child Development, Osaka University, Suita, Osaka, Japan
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4
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Regulation of Carbohydrate Energy Metabolism in Drosophila melanogaster. Genetics 2018; 207:1231-1253. [PMID: 29203701 DOI: 10.1534/genetics.117.199885] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/02/2017] [Indexed: 02/08/2023] Open
Abstract
Carbohydrate metabolism is essential for cellular energy balance as well as for the biosynthesis of new cellular building blocks. As animal nutrient intake displays temporal fluctuations and each cell type within the animal possesses specific metabolic needs, elaborate regulatory systems are needed to coordinate carbohydrate metabolism in time and space. Carbohydrate metabolism is regulated locally through gene regulatory networks and signaling pathways, which receive inputs from nutrient sensors as well as other pathways, such as developmental signals. Superimposed on cell-intrinsic control, hormonal signaling mediates intertissue information to maintain organismal homeostasis. Misregulation of carbohydrate metabolism is causative for many human diseases, such as diabetes and cancer. Recent work in Drosophila melanogaster has uncovered new regulators of carbohydrate metabolism and introduced novel physiological roles for previously known pathways. Moreover, genetically tractable Drosophila models to study carbohydrate metabolism-related human diseases have provided new insight into the mechanisms of pathogenesis. Due to the high degree of conservation of relevant regulatory pathways, as well as vast possibilities for the analysis of gene-nutrient interactions and tissue-specific gene function, Drosophila is emerging as an important model system for research on carbohydrate metabolism.
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5
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Nies VJM, Struik D, Wolfs MGM, Rensen SS, Szalowska E, Unmehopa UA, Fluiter K, van der Meer TP, Hajmousa G, Buurman WA, Greve JW, Rezaee F, Shiri-Sverdlov R, Vonk RJ, Swaab DF, Wolffenbuttel BHR, Jonker JW, van Vliet-Ostaptchouk JV. TUB gene expression in hypothalamus and adipose tissue and its association with obesity in humans. Int J Obes (Lond) 2017; 42:376-383. [PMID: 28852204 DOI: 10.1038/ijo.2017.214] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 07/21/2017] [Accepted: 07/30/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND/OBJECTIVES Mutations in the Tubby gene (TUB) cause late-onset obesity and insulin resistance in mice and syndromic obesity in humans. Although TUB gene function has not yet been fully elucidated, studies in rodents indicate that TUB is involved in the hypothalamic pathways regulating food intake and adiposity. Aside from the function in central nervous system, TUB has also been implicated in energy metabolism in adipose tissue in rodents. We aimed to determine the expression and distribution patterns of TUB in man as well as its potential association with obesity. SUBJECTS/METHODS In situ hybridization was used to localize the hypothalamic regions and cells expressing TUB mRNA. Using RT-PCR, we determined the mRNA expression level of the two TUB gene alternative splicing isoforms, the short and the long transcript variants, in the hypothalami of 12 obese and 12 normal-weight subjects, and in biopsies from visceral (VAT) and subcutaneous (SAT) adipose tissues from 53 severely obese and 24 non-obese control subjects, and correlated TUB expression with parameters of obesity and metabolic health. RESULTS Expression of both TUB transcripts was detected in the hypothalamus, whereas only the short TUB isoform was found in both VAT and SAT. TUB mRNA was detected in several hypothalamic regions involved in body weight regulation, including the nucleus basalis of Meynert and the paraventricular, supraoptic and tuberomammillary nuclei. We found no difference in the hypothalamic TUB expression between obese and control groups, whereas the level of TUB mRNA was significantly lower in adipose tissue of obese subjects as compared to controls. Also, TUB expression was negatively correlated with indices of body weight and obesity in a fat-depot-specific manner. CONCLUSIONS Our results indicate high expression of TUB in the hypothalamus, especially in areas involved in body weight regulation, and the correlation between TUB expression in adipose tissue and obesity. These findings suggest a role for TUB in human obesity.
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Affiliation(s)
- V J M Nies
- Section of Molecular Metabolism and Nutrition, Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - D Struik
- Section of Molecular Metabolism and Nutrition, Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - M G M Wolfs
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - S S Rensen
- Department of General Surgery, Maastricht University Medical Center, NUTRIM School for Nutrition and Translational Research in Metabolism, Maastricht, The Netherlands
| | - E Szalowska
- Centre for Medical Biomics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - U A Unmehopa
- Department of Endocrinology & Metabolism, Academic Medical Center, Amsterdam, The Netherlands
| | - K Fluiter
- Department of Genome Analysis, Academic Medical Center, Amsterdam, The Netherlands
| | - T P van der Meer
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - G Hajmousa
- Cardiovascular Regenerative Medicine, Department Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - W A Buurman
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - J W Greve
- Department of Surgery, Zuyderland Medical Center Heerlen; Dutch Obesity Clinic South, Heerlen, The Netherlands
| | - F Rezaee
- Centre for Medical Biomics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - R Shiri-Sverdlov
- Departments of Molecular Genetics, School of Nutrition & Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands
| | - R J Vonk
- Centre for Medical Biomics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - D F Swaab
- Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - B H R Wolffenbuttel
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - J W Jonker
- Section of Molecular Metabolism and Nutrition, Department of Pediatrics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - J V van Vliet-Ostaptchouk
- Department of Endocrinology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Department of Epidemiology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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6
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Wang Y, Wang A, Donovan SM, Teran-Garcia M. Individual genetic variations related to satiety and appetite control increase risk of obesity in preschool-age children in the STRONG kids program. Hum Hered 2013; 75:152-9. [PMID: 24081231 DOI: 10.1159/000353880] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The burden of the childhood obesity epidemic is well recognized; nevertheless, the genetic markers and gene-environment interactions associated with the development of common obesity are still unknown. In this study, candidate genes associated to satiety and appetite control pathways with obesity-related traits were tested in Caucasian preschoolers from the STRONG Kids project. METHODS Eight genetic variants in genes related to obesity (BDNF, LEPR, FTO, PCSK1, POMC, TUB, LEP, and MC4R) were genotyped in 128 children from the STRONG Kids project (mean age 39.7 months). Data were analyzed for individual associations and to test for genetic predisposition scores (GPSs) with body mass index (BMI) and anthropometric traits (Z-scores, e.g. height-for-age Z-score, HAZ). Covariates included age, sex, and breastfeeding (BF) duration. RESULTS Obesity and overweight prevalence was 6.3 and 19.5%, respectively, according to age- and sex-specific BMI percentiles. Individual genetic associations of MC4R and LEPR markers with HAZ were strengthened when BF duration was included as a covariate. Our GPSs show that, as the number of risk alleles increased, the risk of higher BMI and HAZ also increased. Overall, the GPSs assembled were able to explain 2-3% of the variability in BMI and HAZ phenotypes. CONCLUSION Genetic associations with common obesity-related phenotypes were found in the STRONG Kids project. GPSs assembled for specific candidate genes were associated with BMI and HAZ phenotypes.
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Affiliation(s)
- Yingying Wang
- Division of Nutritional Sciences, University of Illinois, Urbana, Ill., USA
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7
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Rask-Andersen M, Moschonis G, Chrousos GP, Marcus C, Dedoussis GV, Fredriksson R, Schiöth HB. The STK33-linked SNP rs4929949 is associated with obesity and BMI in two independent cohorts of Swedish and Greek children. PLoS One 2013; 8:e71353. [PMID: 23967198 PMCID: PMC3744548 DOI: 10.1371/journal.pone.0071353] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 06/30/2013] [Indexed: 12/26/2022] Open
Abstract
Recent genome wide association studies (GWAS) have identified a locus on chromosome 11p15.5, closely associated with serine/threonine kinase 33 (STK33), to be associated with body mass. STK33, a relatively understudied protein, has been linked to KRAS mutation-driven cancers and explored as a potential antineoplastic drug target. The strongest association with body mass observed at this loci in GWAS was rs4929949, a single nucleotide polymorphism located within intron 1 of the gene encoding STK33. The functional implications of rs4929949 or related variants have not been explored as of yet. We have genotyped rs4929949 in two cohorts, an obesity case-control cohort of 991 Swedish children, and a cross-sectional cohort of 2308 Greek school children. We found that the minor allele of rs4929949 was associated with obesity in the cohort of Swedish children and adolescents (OR = 1.199 (95%CI: 1.002–1.434), p = 0.047), and with body mass in the cross-sectional cohort of Greek children (β = 0.08147 (95% CI: 0.1345–0.1618), p = 0.021). We observe the effects of rs4929949 on body mass to be detectable already at adolescence. Subsequent analysis did not detect any association of rs4929949 to phenotypic measurements describing body adiposity or to metabolic factors such as insulin levels, triglycerides and insulin resistance (HOMA).
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Affiliation(s)
- Mathias Rask-Andersen
- Department of Neuroscience, Functional Pharmacology, Uppsala University BMC, Uppsala, Sweden
| | - George Moschonis
- Department of Nutrition and Dietetics, Harokopio University of Athens, Athens, Greece
| | - George P. Chrousos
- First Department of Pediatrics, Athens University Medical School, Aghia Sophia Children’s Hospital, Athens, Greece
| | - Claude Marcus
- Department for Clinical Science Intervention and Technology (CLINTEC), Department of Pediatrics, Karolinska University Hospital Karolinska Institutet, Huddinge, Sweden
| | - George V. Dedoussis
- Department of Nutrition and Dietetics, Harokopio University of Athens, Athens, Greece
| | - Robert Fredriksson
- Department of Neuroscience, Functional Pharmacology, Uppsala University BMC, Uppsala, Sweden
| | - Helgi B. Schiöth
- Department of Neuroscience, Functional Pharmacology, Uppsala University BMC, Uppsala, Sweden
- * E-mail:
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8
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Musselman LP, Fink JL, Ramachandran PV, Patterson BW, Okunade AL, Maier E, Brent MR, Turk J, Baranski TJ. Role of fat body lipogenesis in protection against the effects of caloric overload in Drosophila. J Biol Chem 2013; 288:8028-8042. [PMID: 23355467 DOI: 10.1074/jbc.m112.371047] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The Drosophila fat body is a liver- and adipose-like tissue that stores fat and serves as a detoxifying and immune responsive organ. We have previously shown that a high sugar diet leads to elevated hemolymph glucose and systemic insulin resistance in developing larvae and adults. Here, we used stable isotope tracer feeding to demonstrate that rearing larvae on high sugar diets impaired the synthesis of esterified fatty acids from dietary glucose. Fat body lipid profiling revealed changes in both carbon chain length and degree of unsaturation of fatty acid substituents, particularly in stored triglycerides. We tested the role of the fat body in larval tolerance of caloric excess. Our experiments demonstrated that lipogenesis was necessary for animals to tolerate high sugar feeding as tissue-specific loss of orthologs of carbohydrate response element-binding protein or stearoyl-CoA desaturase 1 resulted in lethality on high sugar diets. By contrast, increasing the fat content of the fat body by knockdown of king-tubby was associated with reduced hyperglycemia and improved growth and tolerance of high sugar diets. Our work supports a critical role for the fat body and the Drosophila carbohydrate response element-binding protein ortholog in metabolic homeostasis in Drosophila.
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Affiliation(s)
- Laura Palanker Musselman
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Jill L Fink
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Prasanna Venkatesh Ramachandran
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Bruce W Patterson
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Adewole L Okunade
- Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Ezekiel Maier
- Department of Computer Science and Center for Genome Sciences and Systems Biology, Washington University, St. Louis, Missouri 63130
| | - Michael R Brent
- Department of Computer Science and Center for Genome Sciences and Systems Biology, Washington University, St. Louis, Missouri 63130
| | - John Turk
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Thomas J Baranski
- Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
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Murphy RA, Nalls MA, Keller M, Garcia M, Kritchevsky SB, Tylavsky FA, Newman AB, Tranah GJ, Eiriksdottir G, Gudnason V, Harris TB. Candidate gene association study of BMI-related loci, weight, and adiposity in old age. J Gerontol A Biol Sci Med Sci 2012; 68:661-6. [PMID: 23160366 DOI: 10.1093/gerona/gls227] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Most genome-wide association studies are confined to middle-aged populations. It is unclear whether associations between single nucleotide polymorphisms (SNPs) and obesity persist in old age. We aimed to relate 10 body mass index (BMI)-associated SNPs to weight, BMI, % fat, visceral and subcutaneous adipose tissue in Health ABC and AGES-Reykjavik comprising 4,846 individuals of European Ancestry, and 1,139 African Americans over age 65. SNPs were scaled using effect estimates from candidate SNPs. In Health ABC, a SNP near GNPDA2 was modestly associated with weight and SAT area (p = .008, p = .001). Risk score (sum of scaled SNPs) was associated with weight, BMI, and SAT area (p < .0001 for all), but neither GNPDA2 nor risk score was associated with weight, BMI, visceral adippose tissue, subcutaneous adipose tissue, or % fat in AGES-Reykjavik. In African Americans, a SNP near SEC16B was weakly associated with weight (p = .04). In this sample of older adults, no BMI-associated SNPs were associated with weight or adiposity.
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Affiliation(s)
- Rachel A Murphy
- Laboratory of Epidemiology, Demography, and Biometry, Intramural Research Program, National Institute on Aging, Bethesda, MD 20892, USA.
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10
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Koldemir M, Kahveci C, Bayer H, Cagatay P, Yildiz S, Bagriacik N, Susleyici-Duman B. Relationship of RIC-3 gene rs1528133 polymorphism with varying degrees of body weight and eating behavior. Diabetes Metab Syndr 2012; 6:90-95. [PMID: 23153976 DOI: 10.1016/j.dsx.2012.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
AIMS The aim of this study was to determine the allele frequencies of resistance to inhibitors of cholinesterase 3 homologue (RIC-3) gene rs1528133 polymorphism in overweight+obese+morbid obese and non-obese (non-OB) subjects. The effects of rs1528133 genotypes on anthropometric, diabetes and obesity related parameters, self-reported macronutrient intake and drugs were also evaluated. The study was performed on overweight+obese+morbid obese and non-obese subjects. METHODS RIC-3 gene rs1528133 genotypes were determined with qPCR. RESULTS The RIC-3 rs1528133 genotype frequencies were respectively as 89.4% for homozygous wild type (A/A), 10.6% for heterozygous (A/C) genotypes in overweight+obese+morbid obese patients and 92.7% for A/A, 7.3% for A/C genotypes in non-OB subjects. The homozygous mutant genotype (C/C) was not detected in our study population. Genotype frequencies were not significantly different among study groups. Heterozygous genotype carriers for the rs1528133 polymorphism were found to prefer higher glycemic load, fat and protein diet content compared to homozygous wild type genotype carriers (p=0.0001). The frequency of rs1528133 heterozygous individuals (16.7%) using antihypertensive drugs was lower (p=0.045) in comparison to wild type genotype carriers (46.9%) in the whole study population. CONCLUSIONS RIC-3 gene rs1528133 variation was not found to be effective over any analyzed obesity related parameter, but associated with higher glycemic load, protein and fat eating behavior and antihypertensive drug use.
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Affiliation(s)
- Meliha Koldemir
- Marmara University, Department of Biology, Goztepe-Istanbul, Turkey
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11
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Abstract
The tubby mouse shows a tripartite syndrome characterized by maturity-onset obesity, blindness and deafness. The causative gene Tub is the founding member of a family of related proteins present throughout the animal and plant kingdoms, each characterized by a signature carboxy-terminal tubby domain. This domain consists of a β barrel enclosing a central α helix and binds selectively to specific membrane phosphoinositides. The vertebrate family of tubby-like proteins (TULPs) includes the founding member TUB and the related TULPs, TULP1 to TULP4. Tulp1 is expressed in the retina and mutations in TULP1 cause retinitis pigmentosa in humans; Tulp3 is expressed ubiquitously in the mouse embryo and is important in sonic hedgehog (Shh)-mediated dorso-ventral patterning of the spinal cord. The amino terminus of these proteins is diverse and directs distinct functions. In the best-characterized example, the TULP3 amino terminus binds to the IFT-A complex, a complex important in intraflagellar transport in the primary cilia, through a short conserved domain. Thus, the tubby family proteins seem to serve as bipartite bridges through their phosphoinositide-binding tubby and unique amino-terminal functional domains, coordinating multiple signaling pathways, including ciliary G-protein-coupled receptor trafficking and Shh signaling. Molecular studies on this functionally diverse protein family are beginning to provide us with remarkable insights into the tubby-mouse syndrome and other related diseases.
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Affiliation(s)
- Saikat Mukhopadhyay
- Department of Cell Regulation, Genentech Inc., South San Francisco, CA 94080, USA.
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12
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Lemieux GA, Liu J, Mayer N, Bainton RJ, Ashrafi K, Werb Z. A whole-organism screen identifies new regulators of fat storage. Nat Chem Biol 2011; 7:206-13. [PMID: 21390037 PMCID: PMC3076723 DOI: 10.1038/nchembio.534] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Accepted: 01/24/2011] [Indexed: 01/08/2023]
Abstract
The regulation of energy homeostasis integrates diverse biological processes ranging from behavior to metabolism and is linked fundamentally to numerous disease states. To identify new molecules that can bypass homeostatic compensatory mechanisms of energy balance in intact animals, we screened for small-molecule modulators of Caenorhabditis elegans fat content. We report on several molecules that modulate fat storage without obvious deleterious effects on feeding, growth and reproduction. A subset of these compounds also altered fat storage in mammalian and insect cell culture. We found that one of the newly identified compounds exerts its effects in C. elegans through a pathway that requires previously undescribed functions of an AMP-activated kinase catalytic subunit and a transcription factor previously unassociated with fat regulation. Thus, our strategy identifies small molecules that are effective within the context of intact animals and reveals relationships between new pathways that operate across phyla to influence energy homeostasis.
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Affiliation(s)
- George A Lemieux
- Department of Anatomy, University of California, San Francisco, San Francisco, California, USA
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van Vliet-Ostaptchouk JV, Hofker MH, van der Schouw YT, Wijmenga C, Onland-Moret NC. Genetic variation in the hypothalamic pathways and its role on obesity. Obes Rev 2009; 10:593-609. [PMID: 19712437 DOI: 10.1111/j.1467-789x.2009.00597.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Over recent decades, the prevalence of obesity has increased dramatically worldwide. Although this epidemic is mainly attributable to modern (western) lifestyle, multiple twin and adoption studies indicate the significant role of genes in the individual's predisposition to becoming obese. As the hypothalamus plays a central role in controlling body weight, its regulatory circuits may represent a crucial system in the pathogenesis of the disorder. Genetic variations in genes in the hypothalamic pathways may therefore contribute to the susceptibility for obesity in humans and animals. We summarize current knowledge on the physiological role of the hypothalamus in body-weight regulation and review genetic studies on the hypothalamic candidate genes in relation to obesity. Together, data from functional and genetic studies as well as the new, common, obesity loci identified in genome-wide association scans support an important role for the hypothalamic genes in predisposing to obesity. However, findings are still inconclusive for many candidate genes. To improve our understanding of the genetic architecture of common obesity, we suggest that specific obesity phenotypes should be considered and different analytical approaches used. Such studies should consider multiple genes from the same physiological pathways, together with environmental risk factors.
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Affiliation(s)
- J V van Vliet-Ostaptchouk
- Molecular Genetics, Medical Biology Section, Department of Pathology and Medical Biology, University Medical Center and University of Groningen, Groningen, the Netherlands.
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Coyle CA, Strand SC, Good DJ. Reduced activity without hyperphagia contributes to obesity in Tubby mutant mice. Physiol Behav 2008; 95:168-75. [PMID: 18619628 DOI: 10.1016/j.physbeh.2008.05.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 05/22/2008] [Accepted: 05/23/2008] [Indexed: 10/22/2022]
Abstract
The Tub gene was originally identified as a spontaneous mutation in C57Bl/6J mice, and associated with adult-onset obesity (Tub MUT mice). Although the original Tub MUT mouse was identified over 15 years ago, there have been few reports on the animal's food intake, body fat percentage or energy expenditure. In this study, we report food intake, body weight from 5-20 weeks, body fat, body temperature and three different measures of physical activity behavior. Tub MUT mice display reduced food intake, uncharacteristic of many obese mouse models, and reduced voluntary wheel running with normal home cage ambulatory behavior. We conclude that motivation for food and exercise is an underlying defect in TUB MUT mice.
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Affiliation(s)
- Christopher A Coyle
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, United States
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Polymorphisms of the TUB gene are associated with body composition and eating behavior in middle-aged women. PLoS One 2008; 3:e1405. [PMID: 18183286 PMCID: PMC2157487 DOI: 10.1371/journal.pone.0001405] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Accepted: 10/01/2007] [Indexed: 11/23/2022] Open
Abstract
Background The TUB gene, encoding an evolutionary conserved protein, is highly expressed in the hypothalamus and might act as a transcription factor. Mutations in TUB cause late-onset obesity, insulin-resistance and neurosensory deficits in mice. An association of common variants in the TUB gene with body weight in humans has been reported. Methods/Findings The aim was to investigate the relationship of single nucleotide polymorphisms (SNPs) of the TUB gene (rs2272382, rs2272383 and rs1528133) with both anthropometry and self-reported macronutrient intake from a validated food frequency questionnaire. These associations were studied in a population-based, cross-sectional study of 1680 middle-aged Dutch women, using linear regression analysis. The minor allele C of the rs1528133 SNP was significantly associated with increased weight (+1.88 kg, P = 0.022) and BMI (+0.56 units, P = 0.05). Compared with non-carriers, both AG heterozygotes and AA homozygotes of the rs2272382 SNP derived less energy from fat (AG: −0.55±0.28%, P = 0.05, AA: −0.95±0.48%, P = 0.047). However, both genotypes were associated with an increased energy intake from carbohydrates (0.69±0.33%, P = 0.04 and 1.68±0.56%, P = 0.003, respectively), mainly because of a higher consumption of mono- and disaccharides. Both these SNPs, rs2272382 and rs1528133, were also associated with a higher glycemic load in the diet. The glycemic load was higher among those with AG and AA genotypes for the variant rs2272382 than among the wild types (+1.49 (95% CI: −0.27–3.24) and +3.89 (95% CI: 0.94–6.85) units, respectively). Carriers of the minor allele C of rs1528133 were associated with an increased glycemic load of 1.85 units compared with non-carriers. Conclusions Genetic variation of the TUB gene was associated with both body composition and macronutrient intake, suggesting that TUB might influence eating behavior.
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Snieder H, Wang X, Shiri-Sverdlov R, van Vliet-Ostaptchouk JV, Hofker MH, Perks U, Spector TD, O'Dell SD. TUB is a candidate gene for late-onset obesity in women. Diabetologia 2008; 51:54-61. [PMID: 17955208 DOI: 10.1007/s00125-007-0851-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2007] [Accepted: 09/24/2007] [Indexed: 10/22/2022]
Abstract
AIMS/HYPOTHESES We recently reported significant associations between BMI and three TUB single nucleotide polymorphisms (SNPs) in two Dutch cohorts enriched for type 2 diabetes. Here, we attempted a replication of these associations in a large population-based cohort of female twins comprehensively phenotyped for measures of general and central obesity. METHODS Two TUB SNPs (rs2272382, rs2272383) and a third (rs1528133), 22 kb distal to RIC3, were genotyped in 2694 Europid women from the St Thomas' UK Adult Twin Registry (Twins UK) (mean age +/- SD: 47.6 +/- 12.7 years; 42.8% postmenopausal). We explored the hypothesis that TUB is a candidate gene for late-onset obesity in humans through testing the interaction of the SNPs by menopausal status. RESULTS In the whole cohort, none of the three SNPs showed a significant main effect on measures of general or central obesity. However, for central obesity the rs2272382 SNP showed a significant interaction with menopausal status (p = 0.036). Postmenopausal women homozygous for the minor allele of rs2272382 showed significantly more general obesity (p = 0.022) and central obesity (p = 0.009) than carriers of the major allele. Differences (beta [95% CI]) between the two genotype groups were 0.92 kg/m2 (0.03-1.81) for BMI (p = 0.036), 2.73 cm (0.62-4.84) for waist circumference (p = 0.013) and 2.43% (0.27-4.60) for per cent central fat (p = 0.027). These associations were confirmed by a sibling transmission disequilibrium test for central obesity, waist circumference and per cent central fat. CONCLUSIONS/INTERPRETATION We have replicated associations of TUB SNP rs2272382 with measures of general and central obesity in normal postmenopausal women. These findings confirm TUB as a candidate gene for late-onset obesity in humans.
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Affiliation(s)
- H Snieder
- Unit of Genetic Epidemiology and Bioinformatics, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands.
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Mukhopadhyay A, Pan X, Lambright DG, Tissenbaum HA. An endocytic pathway as a target of tubby for regulation of fat storage. EMBO Rep 2007; 8:931-8. [PMID: 17762880 PMCID: PMC2002550 DOI: 10.1038/sj.embor.7401055] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Revised: 07/05/2007] [Accepted: 07/26/2007] [Indexed: 01/17/2023] Open
Abstract
The tubby loci provide a unique opportunity to study adult-onset obesity. Mutation in either mammalian tubby or its homologue in Caenorhabditis elegans, tub-1, results in increased fat storage. Previously, we have shown that TUB-1 interacts with a new Rab GTPase-activating protein, RBG-3, for the regulation of fat storage. To understand further the molecular mechanism of TUB-1, we identified the Rab GTPase downstream of RBG-3. We found that RBG-3 preferentially stimulates the intrinsic GTPase activity of RAB-7 in both human and C. elegans. Importantly, either mutation or RNA interference knockdown in rab-7 reduces stored fat in wild type and tub-1 mutants. In addition, the small GTPase rab-5 and genes that regulate Rab membrane localization and nucleotide recycling are required for the regulation of fat storage, thereby defining a role for endocytic recycling in this process. We propose that TUB-1 controls receptor or sensory molecule degradation in neurons by regulating a RAB-7-mediated endocytic pathway.
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Affiliation(s)
- Arnab Mukhopadhyay
- Program in Gene Function and Expression, University of Massachusetts Medical School, 364 Plantation Street, Worcester, Massachusetts 01605, USA
| | - Xiaojing Pan
- Program in Molecular Medicine, University of Massachusetts Medical School, Two Biotech, 373 Plantation Street, Worcester, Massachusetts 01605, USA
| | - David G Lambright
- Program in Molecular Medicine, University of Massachusetts Medical School, Two Biotech, 373 Plantation Street, Worcester, Massachusetts 01605, USA
| | - Heidi A Tissenbaum
- Program in Gene Function and Expression, University of Massachusetts Medical School, 364 Plantation Street, Worcester, Massachusetts 01605, USA
- Program in Molecular Medicine, University of Massachusetts Medical School, Two Biotech, 373 Plantation Street, Worcester, Massachusetts 01605, USA
- Tel: +1 508 854 5840; Fax: +1 508 856 5460; E-mail:
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Giannaccini G, Giusti L, Santini F, Marsili A, Betti L, Mascia G, Pelosini C, Baroni S, Ciregia F, Fabbrini L, Lucacchini A, Vitti P, Pinchera A. Tubby protein in human lymphocytes from normal weight and obese subjects. Clin Biochem 2007; 40:806-9. [PMID: 17498679 DOI: 10.1016/j.clinbiochem.2007.03.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2007] [Accepted: 03/27/2007] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The presence of tubby protein in human lymphocytes was investigated and their electrophoretic mobility property between normal weight and obese subjects was compared. DESIGN AND METHODS 2-DE proteome map of lymphocytes has been generated and western blot analysis was conducted using anti-tub polyclonal antibody. RESULTS AND CONCLUSIONS We found the presence of tubby protein both in normal weight and in obese subjects; however in the latter an isoelectric point shift toward the acidic end was observed.
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Affiliation(s)
- Gino Giannaccini
- Department of Psychiatry, Neurobiology, Pharmacology and Biotechnology, Environment and Endocrine and Nervous Systems High Technology Center for the Study of the Effects of Harmful Agents, University of Pisa, Via Bonanno 6, Pisa, Italy.
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