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Jujić A, Atabaki-Pasdar N, Nilsson PM, Almgren P, Hakaste L, Tuomi T, Berglund LM, Franks PW, Holst JJ, Prasad RB, Torekov SS, Ravassa S, Díez J, Persson M, Melander O, Gomez MF, Groop L, Ahlqvist E, Magnusson M. Glucose-dependent insulinotropic peptide and risk of cardiovascular events and mortality: a prospective study. Diabetologia 2020; 63:1043-1054. [PMID: 31974732 PMCID: PMC7145777 DOI: 10.1007/s00125-020-05093-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/18/2019] [Indexed: 12/17/2022]
Abstract
AIMS/HYPOTHESIS Evidence that glucose-dependent insulinotropic peptide (GIP) and/or the GIP receptor (GIPR) are involved in cardiovascular biology is emerging. We hypothesised that GIP has untoward effects on cardiovascular biology, in contrast to glucagon-like peptide 1 (GLP-1), and therefore investigated the effects of GIP and GLP-1 concentrations on cardiovascular disease (CVD) and mortality risk. METHODS GIP concentrations were successfully measured during OGTTs in two independent populations (Malmö Diet Cancer-Cardiovascular Cohort [MDC-CC] and Prevalence, Prediction and Prevention of Diabetes in Botnia [PPP-Botnia]) in a total of 8044 subjects. GLP-1 (n = 3625) was measured in MDC-CC. The incidence of CVD and mortality was assessed via national/regional registers or questionnaires. Further, a two-sample Mendelian randomisation (2SMR) analysis between the GIP pathway and outcomes (coronary artery disease [CAD] and myocardial infarction) was carried out using a GIP-associated genetic variant, rs1800437, as instrumental variable. An additional reverse 2SMR was performed with CAD as exposure variable and GIP as outcome variable, with the instrumental variables constructed from 114 known genetic risk variants for CAD. RESULTS In meta-analyses, higher fasting levels of GIP were associated with risk of higher total mortality (HR[95% CI] = 1.22 [1.11, 1.35]; p = 4.5 × 10-5) and death from CVD (HR[95% CI] 1.30 [1.11, 1.52]; p = 0.001). In accordance, 2SMR analysis revealed that increasing GIP concentrations were associated with CAD and myocardial infarction, and an additional reverse 2SMR revealed no significant effect of CAD on GIP levels, thus confirming a possible effect solely of GIP on CAD. CONCLUSIONS/INTERPRETATION In two prospective, community-based studies, elevated levels of GIP were associated with greater risk of all-cause and cardiovascular mortality within 5-9 years of follow-up, whereas GLP-1 levels were not associated with excess risk. Further studies are warranted to determine the cardiovascular effects of GIP per se.
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Affiliation(s)
- Amra Jujić
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Centre, Hämtställe HS 36, Box 50332, 202 13, Malmö, Sweden
- Department of Cardiology, Skåne University Hospital, Inga Marie Nilssons gata 49, 20502, Malmö, Sweden
| | | | - Peter M Nilsson
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Peter Almgren
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Liisa Hakaste
- Folkhälsan Research Centre, Biomedicum, Helsinki, Finland
- Research Program Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland
- Department of Endocrinology, Helsinki University Hospital, Helsinki, Finland
- Finnish Institute of Molecular Medicine, University of Helsinki, Helsinki, Finland
| | - Tiinamaija Tuomi
- Folkhälsan Research Centre, Biomedicum, Helsinki, Finland
- Research Program Unit, Diabetes and Obesity, University of Helsinki, Helsinki, Finland
- Department of Endocrinology, Helsinki University Hospital, Helsinki, Finland
- Finnish Institute of Molecular Medicine, University of Helsinki, Helsinki, Finland
| | - Lisa M Berglund
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Paul W Franks
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Department of Public Health & Clinical Medicine, Umeå University, Umeå, Sweden
- Department of Nutrition, Harvard School of Public Health, Boston, MA, USA
| | - Jens J Holst
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Rashmi B Prasad
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Signe S Torekov
- Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Copenhagen, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Susana Ravassa
- Program of Cardiovascular Diseases, CIMA, University of Navarra, Pamplona, Spain
- CIBERCV, Carlos III Institute of Health, Madrid, Spain
- Instituto de Investigación Sanitaria de Navarra (IdisNA), Pamplona, Spain
| | - Javier Díez
- Program of Cardiovascular Diseases, CIMA, University of Navarra, Pamplona, Spain
- CIBERCV, Carlos III Institute of Health, Madrid, Spain
- Instituto de Investigación Sanitaria de Navarra (IdisNA), Pamplona, Spain
- Department of Cardiology and Cardiac Surgery, University of Navarra Clinic, Pamplona, Spain
- Department of Nephrology, University of Navarra Clinic, Pamplona, Spain
| | | | - Olle Melander
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
| | - Maria F Gomez
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Leif Groop
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Lund University Diabetes Centre, Lund University, Malmö, Sweden
- Department of Endocrinology, Helsinki University Hospital, Helsinki, Finland
| | - Emma Ahlqvist
- Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden
- Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Martin Magnusson
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Centre, Hämtställe HS 36, Box 50332, 202 13, Malmö, Sweden.
- Department of Cardiology, Skåne University Hospital, Inga Marie Nilssons gata 49, 20502, Malmö, Sweden.
- Wallenberg Center for Molecular Medicine, Lund University, Malmö, Sweden.
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Tai KY, Wong K, Aghakhanian F, Parhar IS, Dhaliwal J, Ayub Q. Selected neuropeptide genes show genetic differentiation between Africans and non-Africans. BMC Genet 2020; 21:31. [PMID: 32171244 PMCID: PMC7071772 DOI: 10.1186/s12863-020-0835-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 02/28/2020] [Indexed: 11/10/2022] Open
Abstract
Background Publicly available genome data provides valuable information on the genetic variation patterns across different modern human populations. Neuropeptide genes are crucial to the nervous, immune, endocrine system, and physiological homeostasis as they play an essential role in communicating information in neuronal functions. It remains unclear how evolutionary forces, such as natural selection and random genetic drift, have affected neuropeptide genes among human populations. To date, there are over 100 known human neuropeptides from the over 1000 predicted peptides encoded in the genome. The purpose of this study is to analyze and explore the genetic variation in continental human populations across all known neuropeptide genes by examining highly differentiated SNPs between African and non-African populations. Results We identified a total of 644,225 SNPs in 131 neuropeptide genes in 6 worldwide population groups from a public database. Of these, 5163 SNPs that had ΔDAF |(African - non-African)| ≥ 0.20 were identified and fully annotated. A total of 20 outlier SNPs that included 19 missense SNPs with a moderate impact and one stop lost SNP with high impact, were identified in 16 neuropeptide genes. Our results indicate that an overall strong population differentiation was observed in the non-African populations that had a higher derived allele frequency for 15/20 of those SNPs. Highly differentiated SNPs in four genes were particularly striking: NPPA (rs5065) with high impact stop lost variant; CHGB (rs6085324, rs236150, rs236152, rs742710 and rs742711) with multiple moderate impact missense variants; IGF2 (rs10770125) and INS (rs3842753) with moderate impact missense variants that are in linkage disequilibrium. Phenotype and disease associations of these differentiated SNPs indicated their association with hypertension and diabetes and highlighted the pleiotropic effects of these neuropeptides and their role in maintaining physiological homeostasis in humans. Conclusions We compiled a list of 131 human neuropeptide genes from multiple databases and literature survey. We detect significant population differentiation in the derived allele frequencies of variants in several neuropeptide genes in African and non-African populations. The results highlights SNPs in these genes that may also contribute to population disparities in prevalence of diseases such as hypertension and diabetes.
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Affiliation(s)
- Kah Yee Tai
- School of Information Technology, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - KokSheik Wong
- School of Information Technology, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Farhang Aghakhanian
- Monash University Malaysia Genomics Facility, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Ishwar S Parhar
- Jeffrey Cheah School of Medicine and Health Sciences, Brain Research Institute, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
| | - Jasbir Dhaliwal
- School of Information Technology, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia.
| | - Qasim Ayub
- Monash University Malaysia Genomics Facility, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia.,School of Science, Monash University Malaysia, 47500, Bandar Sunway, Selangor Darul Ehsan, Malaysia
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Cho YM. Incretin physiology and pathophysiology from an Asian perspective. J Diabetes Investig 2014; 6:495-507. [PMID: 26417406 PMCID: PMC4578486 DOI: 10.1111/jdi.12305] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 10/21/2014] [Indexed: 12/25/2022] Open
Abstract
Incretin hormones, such as glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1, are secreted on oral nutrient ingestion and regulate postprandial glucose homeostasis by conveying the signal of intestinal glucose flux. In East Asians, the secretion of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 is not reduced in type 2 diabetes relative to normal glucose tolerance. Although the incretin effect is blunted in European patients with type 2 diabetes, a few East Asian studies showed no difference in the incretin effect between type 2 diabetes and normal glucose tolerance. Interestingly, the glucose-lowering efficacy of dipeptidyl peptidase-4 inhibitors or glucagon-like peptide-1 receptor agonists was reported to be greater in Asians than in non-Asians. The difference in the treatment responses could be ascribed to a different pathophysiology of type 2 diabetes (lower insulin secretory function and less insulin resistance), lower body mass index, different genetic makeups, preserved incretin effect and different food compositions in East Asians compared with other ethnic groups. Based on the currently available data, incretin-based therapies appear to be safe and well tolerated in East Asians. Nevertheless, continuous pharmacovigilance is required. The characteristics of incretin biology and treatment responses to incretin-based therapies should be considered in developing ethnicity-specific treatment guidelines and making patient-centered decisions for patients with type 2 diabetes.
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Affiliation(s)
- Young Min Cho
- Department of Internal Medicine, Seoul National University College of Medicine Seoul, Korea
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Nakayama K, Watanabe K, Boonvisut S, Makishima S, Miyashita H, Iwamoto S. Common variants of GIP are associated with visceral fat accumulation in Japanese adults. Am J Physiol Gastrointest Liver Physiol 2014; 307:G1108-14. [PMID: 25324507 DOI: 10.1152/ajpgi.00282.2014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Animal studies have demonstrated that glucose-dependent insulinotropic polypeptide (GIP) and GIP receptor (GIPR) contribute to the etiology of obesity. In humans, genomewide association studies have identified single nucleotide polymorphisms (SNPs) in the GIPR gene that are strongly associated with body mass index (BMI); however, it is not clear whether genetic variations in the GIP gene are involved in the development of obesity. In the current study, we assessed the impact of GIP SNPs on obesity-related traits in Japanese adults. Six tag SNPs were tested for associations with obesity-related traits in 3,013 individuals. Multiple linear regression analyses showed that rs9904288, located at the 3'-end of GIP, was significantly associated with visceral fat area (VFA). Moreover, rs1390154 and rs4794008 showed significant associations with plasma triglyceride levels and hemoglobin A1c levels, respectively. Among the significant SNPs, rs9904288 and rs1390154 were independently linked with SNPs in active enhancers of the duodenum mucosa, the main GIP-secreting tissue. The haplotypes of these two SNPs exhibited stronger associations with VFA. Numbers of VFA-increasing alleles of rs9904288 and BMI-increasing alleles of previously identified GIPR SNPs showed a strong additive effect on VFA, waist circumference, and BMI in the subject population. These novel results support the notion that the GIP-GIPR axis plays a role in the etiology of central obesity in humans, which is characterized by the accumulation of visceral fat.
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Affiliation(s)
- Kazuhiro Nakayama
- Division of Human Genetics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan; and
| | - Kazuhisa Watanabe
- Division of Human Genetics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan; and
| | - Supichaya Boonvisut
- Division of Human Genetics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan; and
| | - Saho Makishima
- Division of Human Genetics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan; and
| | | | - Sadahiko Iwamoto
- Division of Human Genetics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan; and
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Adaptive human CDKAL1 variants underlie hormonal response variations at the enteroinsular axis. PLoS One 2014; 9:e105410. [PMID: 25222615 PMCID: PMC4164438 DOI: 10.1371/journal.pone.0105410] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Accepted: 07/22/2014] [Indexed: 11/19/2022] Open
Abstract
Recent analyses have identified positively selected loci that explain differences in immune responses, body forms, and adaptations to extreme climates, but variants that describe adaptations in energy-balance regulation remain underexplored. To identify variants that confer adaptations in energy-balance regulation, we explored the evolutionary history and functional associations of candidate variants in 207 genes. We screened single nucleotide polymorphisms in genes that had been associated with energy-balance regulation for unusual genetic patterns in human populations, followed by studying associations among selected variants and serum levels of GIP, insulin, and C-peptide in pregnant women after an oral glucose tolerance test. Our analysis indicated that 5′ variants in CDKAL1, CYB5R4, GAD2, and PPARG are marked with statistically significant signals of gene–environment interactions. Importantly, studies of serum hormone levels showed that variants in CDKAL1 are associated with glucose-induced GIP and insulin responses (p<0.05). On the other hand, a GAD2 variant exhibited a significant association with glucose-induced C-peptide response. In addition, simulation analysis indicated that a type 2 diabetes risk variant in CDKAL1 (rs7754840) was selected in East Asians ∼6,900 years ago. Taken together, these data indicated that variants in CDKAL1 and GAD2 were targets of prior environmental selection. Because the selection of the CDKAL1 variant overlapped with the selection of a cluster of GIP variants in the same population ∼11,800 to 2,000 years ago, we speculate that these regulatory genes at the human enteroinsular axis could be highly responsive to environmental selection in recent human history.
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Oh TJ, Kim MY, Shin JY, Lee JC, Kim S, Park KS, Cho YM. The incretin effect in Korean subjects with normal glucose tolerance or type 2 diabetes. Clin Endocrinol (Oxf) 2014; 80:221-7. [PMID: 23405851 DOI: 10.1111/cen.12167] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 02/07/2013] [Accepted: 02/08/2013] [Indexed: 12/18/2022]
Abstract
BACKGROUND The incretin effect is known to be decreased in type 2 diabetes. However, there are limited data on the incretin effect in non-Caucasian subjects. Because Asian patients with type 2 diabetes are characterized by decreased insulin secretion, this study set out to examine the incretin effect in Korean subjects with normal glucose tolerance (NGT) or type 2 diabetes. METHODS We performed 75-g oral glucose tolerance tests (OGTTs) and corresponding isoglycaemic intravenous glucose infusion (IIGI) studies in Korean subjects with NGT (n = 14) or type 2 diabetes (n = 16). The incretin effect was calculated based on the incremental area under the curves (iAUCs) of the plasma levels of insulin, C-peptide or insulin secretion rate (ISR). The plasma levels of total glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) were measured by ELISA. RESULTS The incretin effect was not different between the subjects with NGT and type 2 diabetes (43 ± 6% vs 47 ± 4%, P = 0·575 by insulin; 29 ± 7% vs 38 ± 4%, P = 0·253 by C-peptide; 28 ± 7% vs 35 ± 5%, P = 0·372 by ISR, respectively). However, the gastrointestinally mediated glucose disposal (GIGD) was markedly decreased in type 2 diabetes (28·5 ± 4·2% vs 59·0 ± 4·3%, P < 0·001). The plasma levels of the total GLP-1 and GIP during the OGTTs were comparable between the two groups. CONCLUSION In Koreans, the secretion of GLP-1 or GIP during OGTTs and the incretin effect were comparable between subjects with NGT and type 2 diabetes, whereas the GIGD was significantly decreased in patients with type 2 diabetes.
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Affiliation(s)
- Tae Jung Oh
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
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A single-nucleotide polymorphism of human neuropeptide s gene originated from Europe shows decreased bioactivity. PLoS One 2013; 8:e83009. [PMID: 24386135 PMCID: PMC3873911 DOI: 10.1371/journal.pone.0083009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 11/07/2013] [Indexed: 11/19/2022] Open
Abstract
Using accumulating SNP (Single-Nucleotide Polymorphism) data, we performed a genome-wide search for polypeptide hormone ligands showing changes in the mature regions to elucidate genotype/phenotype diversity among various human populations. Neuropeptide S (NPS), a brain peptide hormone highly conserved in vertebrates, has diverse physiological effects on anxiety, fear, hyperactivity, food intake, and sleeping time through its cognate receptor-NPSR. Here, we report a SNP rs4751440 (L6-NPS) causing non-synonymous substitution on the 6th position (V to L) of the NPS mature peptide region. L6-NPS has a higher allele frequency in Europeans than other populations and probably originated from European ancestors ∼25,000 yrs ago based on haplotype analysis and Approximate Bayesian Computation. Functional analyses indicate that L6-NPS exhibits a significant lower bioactivity than the wild type NPS, with ∼20-fold higher EC50 values in the stimulation of NPSR. Additional evolutionary and mutagenesis studies further demonstrate the importance of the valine residue in the 6th position for NPS functions. Given the known physiological roles of NPS receptor in inflammatory bowel diseases, asthma pathogenesis, macrophage immune responses, and brain functions, our study provides the basis to elucidate NPS evolution and signaling diversity among human populations.
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Kim MJ, Park HK, Byun DW, Suh KI, Hur KY. Incretin levels 1 month after laparoscopic single anastomosis gastric bypass surgery in non-morbid obese type 2 diabetes patients. Asian J Surg 2013; 37:130-7. [PMID: 24210541 DOI: 10.1016/j.asjsur.2013.09.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 09/13/2013] [Accepted: 09/23/2013] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Bariatric surgery is an efficient procedure for the remission of type 2 diabetes (T2DM) from morbid obesity. However, in Asian countries, the mean body mass index (BMI) of T2DM patients is about 25 kg/m(2). Various data on patients undergoing gastric bypass surgery suggest that the control of T2DM after surgery occurs rapidly. We hypothesized that even in nonobese patients with T2DM, the levels of incretin and insulin changed along with the improvement of T2DM as a consequence of the gastric bypass. MATERIALS AND METHODS From March to December 2011, 12 nonobese patients (mean BMI; 26.2 kg/m(2)) with poorly-controlled [mean glycated hemoglobin (HbA1C); 9.5%] diabetes underwent gastric bypass surgery. Values related to diabetes, including incretin [gastric inhibitory peptide (GIP) and glucagon-like peptide-1 (GLP-1)] levels were measured before and 1 month after surgery. All values were measured in response to a 75 g oral glucose tolerance test (OGTT). RESULTS On average, the BMI decreased by 2.1 ± 0.7 kg/m(2). Mean HbA1C level decreased by 1.6 ± 2%. Oral glucose-stimulated insulin levels increased and GLP-1 levels also increased significantly. Oral glucose-stimulated GIP levels decreased sharply. CONCLUSION Soon after gastric bypass in nonobese T2DM patients, control of T2DM is achieved. The incretin release after oral glucose is improved. This could be a consequence of changes of the enteroinsular axis, particularly in the incretins.
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Affiliation(s)
- Myung Jin Kim
- Department of Surgery, Soonchunhyang University College of Medicine, Seoul, South Korea
| | - Hyeong Kyu Park
- Department of Endocrinology, Soonchunhyang University College of Medicine, Seoul, South Korea
| | - Dong Won Byun
- Department of Endocrinology, Soonchunhyang University College of Medicine, Seoul, South Korea
| | - Kyo Il Suh
- Department of Endocrinology, Soonchunhyang University College of Medicine, Seoul, South Korea
| | - Kyung Yul Hur
- Department of Surgery, Soonchunhyang University College of Medicine, Seoul, South Korea.
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Positive natural selection of TRIB2, a novel gene that influences visceral fat accumulation, in East Asia. Hum Genet 2012; 132:201-17. [PMID: 23108367 DOI: 10.1007/s00439-012-1240-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 10/16/2012] [Indexed: 10/27/2022]
Abstract
Accumulation of visceral fat increases cardiovascular mortality in industrialized societies. However, during the evolution of the modern human, visceral fat may have acted as energy storage facility to survive in times of famine. Therefore, past natural selection might contribute to shaping the variation of visceral fat accumulation in present populations. Here, we report that the gene encoding tribbles homolog 2 (TRIB2) influenced visceral fat accumulation and was operated by recent positive natural selection in East Asians. Our candidate gene association analysis on 11 metabolic traits of 5,810 East Asians revealed that rs1057001, a T/A transversion polymorphism in 3'untranslated region (UTR) of TRIB2, was strongly associated with visceral fat area (VFA) and waist circumference adjusted for body mass index (P = 2.7 × 10(-6) and P = 9.0 × 10(-6), respectively). rs1057001 was in absolute linkage disequilibrium with a conserved insertion-deletion polymorphism in the 3'UTR and was associated with allelic imbalance of TRIB2 transcript levels in adipose tissues. rs1057001 showed high degree of interpopulation variation of the allele frequency; the low-VFA-associated A allele was found with high frequencies in East Asians. Haplotypes containing the rs1057001 A allele exhibited a signature of a selective sweep, which may have occurred 16,546-27,827 years ago in East Asians. Given the predominance of the thrifty gene hypothesis, it is surprising that the apparently non-thrifty allele was selectively favored in the evolution of modern humans. Environmental/physiological factors other than famine would be needed to explain the non-neutral evolution of TRIB2 in East Asians.
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Hoover P, Naz RK. Do men with prostate abnormalities (prostatitis/benign prostatic hyperplasia/prostate cancer) develop immunity to spermatozoa or seminal plasma? ACTA ACUST UNITED AC 2012; 35:608-15. [DOI: 10.1111/j.1365-2605.2011.01246.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chang CL, Wang HS, Soong YK, Huang SY, Pai SY, Hsu SYT. Regulation of oocyte and cumulus cell interactions by intermedin/adrenomedullin 2. J Biol Chem 2011; 286:43193-203. [PMID: 22009752 DOI: 10.1074/jbc.m111.297358] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ovarian folliculogenesis has been studied as a model of hormonal regulation of development and differentiation, cell death, and cell-cell communication. In addition to gonadotropins from the pituitary and follicular paracrine factors, oocyte secreted factors have been shown to play critical roles in the regulation of follicular cell functions. Except for the well characterized BMP family proteins, including GDF9 and BMP15, oocytes are known to secrete oocyte secreted factors that are important for the regulation of cumulus cell survival and the maintenance of tertiary structure of cumulus cell-enclosed oocyte complexes (COCs). Based on genomic screening and studies of COCs cultured in vitro, we showed that intermedin (IMD)/adrenomedullin 2 (ADM2) is a novel oocyte-derived ligand important for the regulation of cell interactions in COCs that functions, in part, by suppressing cumulus cell apoptosis. Consistently, we showed that suppression of IMD/ADM2 signaling in growing rat ovaries in vivo leads to oocyte atresia and aberrant cell cycle progression in follicular cells. Together, our studies indicated that mammalian oocytes deploy a G protein-coupled receptor ligand to coordinate normal interactions of oocytes and cumulus cells and provided a better understanding of how the tertiary structure of a COC is maintained as follicles undergo exponential growth during the late stages of folliculogenesis.
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Affiliation(s)
- Chia Lin Chang
- Department of Obstetrics and Gynecology, Chang Gung University School of Medicine, Chang Gung Memorial Hospital Linkou Medical Center, Kweishan, Taoyuan 333, Taiwan.
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Lyssenko V, Eliasson L, Kotova O, Pilgaard K, Wierup N, Salehi A, Wendt A, Jonsson A, De Marinis YZ, Berglund LM, Taneera J, Balhuizen A, Hansson O, Osmark P, Dunér P, Brøns C, Stancáková A, Kuusisto J, Bugliani M, Saxena R, Ahlqvist E, Kieffer TJ, Tuomi T, Isomaa B, Melander O, Sonestedt E, Orho-Melander M, Nilsson P, Bonetti S, Bonadonna R, Miccoli R, Delprato S, Marchetti P, Madsbad S, Poulsen P, Vaag A, Laakso M, Gomez MF, Groop L. Pleiotropic effects of GIP on islet function involve osteopontin. Diabetes 2011; 60:2424-33. [PMID: 21810601 PMCID: PMC3161325 DOI: 10.2337/db10-1532] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The incretin hormone GIP (glucose-dependent insulinotropic polypeptide) promotes pancreatic β-cell function by potentiating insulin secretion and β-cell proliferation. Recently, a combined analysis of several genome-wide association studies (Meta-analysis of Glucose and Insulin-Related Traits Consortium [MAGIC]) showed association to postprandial insulin at the GIP receptor (GIPR) locus. Here we explored mechanisms that could explain the protective effects of GIP on islet function. RESEARCH DESIGN AND METHODS Associations of GIPR rs10423928 with metabolic and anthropometric phenotypes in both nondiabetic (N = 53,730) and type 2 diabetic individuals (N = 2,731) were explored by combining data from 11 studies. Insulin secretion was measured both in vivo in nondiabetic subjects and in vitro in islets from cadaver donors. Insulin secretion was also measured in response to exogenous GIP. The in vitro measurements included protein and gene expression as well as measurements of β-cell viability and proliferation. RESULTS The A allele of GIPR rs10423928 was associated with impaired glucose- and GIP-stimulated insulin secretion and a decrease in BMI, lean body mass, and waist circumference. The decrease in BMI almost completely neutralized the effect of impaired insulin secretion on risk of type 2 diabetes. Expression of GIPR mRNA was decreased in human islets from carriers of the A allele or patients with type 2 diabetes. GIP stimulated osteopontin (OPN) mRNA and protein expression. OPN expression was lower in carriers of the A allele. Both GIP and OPN prevented cytokine-induced reduction in cell viability (apoptosis). In addition, OPN stimulated cell proliferation in insulin-secreting cells. CONCLUSIONS These findings support β-cell proliferative and antiapoptotic roles for GIP in addition to its action as an incretin hormone. Identification of a link between GIP and OPN may shed new light on the role of GIP in preservation of functional β-cell mass in humans.
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Affiliation(s)
- Valeriya Lyssenko
- Diabetes and Endocrinology, Department of Clinical Sciences, University Hospital Malmö, Lund University, Malmö, Sweden.
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Chang CL, Cai JJ, Cheng PJ, Chueh HY, Hsu SYT. Identification of metabolic modifiers that underlie phenotypic variations in energy-balance regulation. Diabetes 2011; 60:726-34. [PMID: 21300845 PMCID: PMC3046833 DOI: 10.2337/db10-1331] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Although recent studies have shown that human genomes contain hundreds of loci that exhibit signatures of positive selection, variants that are associated with adaptation in energy-balance regulation remain elusive. We reasoned that the difficulty in identifying such variants could be due to heterogeneity in selection pressure and that an integrative approach that incorporated experiment-based evidence and population genetics-based statistical judgments would be needed to reveal important metabolic modifiers in humans. RESEARCH DESIGN AND METHODS To identify common metabolic modifiers that underlie phenotypic variation in diabetes-associated or obesity-associated traits in humans, or both, we screened 207 candidate loci for regulatory single nucleotide polymorphisms (SNPs) that exhibited evidence of gene-environmental interactions. RESULTS Three SNPs (rs3895874, rs3848460, and rs937301) at the 5' gene region of human GIP were identified as prime metabolic-modifier candidates at the enteroinsular axis. Functional studies have shown that GIP promoter reporters carrying derived alleles of these three SNPs (haplotype GIP(-1920A)) have significantly lower transcriptional activities than those with ancestral alleles at corresponding positions (haplotype GIP(-1920G)). Consistently, studies of pregnant women who have undergone a screening test for gestational diabetes have shown that patients with a homozygous GIP(-1920A/A) genotype have significantly lower serum concentrations of glucose-dependent insulinotropic polypeptide (GIP) than those carrying an ancestral GIP(-1920G) haplotype. After controlling for a GIPR variation, we showed that serum glucose concentrations of patients carrying GIP(-1920A/A) homozygotes are significantly higher than that of those carrying an ancestral GIP(-1920G) haplotype (odds ratio 3.53). CONCLUSIONS Our proof-of-concept study indicates that common regulatory GIP variants impart a difference in GIP and glucose metabolism. The study also provides a rare example that identified the common variant-common phenotypic variation pattern based on evidence of moderate gene-environmental interactions.
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Affiliation(s)
- Chia Lin Chang
- Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital Linkou Medical Center, Chang Gung University, Kweishan, Taoyuan, Taiwan
| | - James J. Cai
- Department of Biology, Stanford University, Stanford, California
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas
| | - Po Jen Cheng
- Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital Linkou Medical Center, Chang Gung University, Kweishan, Taoyuan, Taiwan
| | - Ho Yen Chueh
- Department of Obstetrics and Gynecology, Chang Gung Memorial Hospital Linkou Medical Center, Chang Gung University, Kweishan, Taoyuan, Taiwan
| | - Sheau Yu Teddy Hsu
- Reproductive Biology and Stem Cell Research Program, Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California
- Corresponding author: Sheau Yu Teddy Hsu,
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