Endocrinol Metab.  2017 Sep;32(3):360-369. 10.3803/EnM.2017.32.3.360.

Leu72Met and Other Intronic Polymorphisms in the GHRL and GHSR Genes Are Not Associated with Type 2 Diabetes Mellitus, Insulin Resistance, or Serum Ghrelin Levels in a Saudi Population

Affiliations
  • 1Department of Internal Medicine and Clinical Biochemistry Laboratory, King Abdulaziz Hospital, National Guard Health Affairs, Al-Ahsa, Saudi Arabia.
  • 2Department of Medical Biochemistry, Arabian Gulf University College of Medicine and Medical Sciences, Manama, Bahrain. gehaha2002@yahoo.com
  • 3Clinical Biochemistry Laboratory, Salmaniya Medical Complex, Manama, Bahrain.
  • 4Cell and Developmental Biology, Division of Biosciences, University College London, London, United Kingdom.

Abstract

BACKGROUND
Ghrelin (GHRL), a gastric peptide encoded by the GHRL gene, is known to be involved in energy homeostasis via its G protein receptor, encoded by the growth hormone secretagogue receptor (GHSR) gene. Some studies have shown associations between plasma GHRL levels and GHRL single-nucleotide polymorphisms (SNPs), namely the Leu72Met polymorphism (rs696217 TG), with type 2 diabetes mellitus (T2DM) and insulin resistance (IR), while others have not. The controversies in these associations raise the issue of "˜which SNPs in which populations.' The aim of this study was to investigate whether SNPs in GHRL and/or GHSR genes were associated with T2DM, IR, or plasma GHRL levels among Arab Saudis.
METHODS
Blood was collected from 208 Saudi subjects with (n=107) and without (n=101) T2DM. DNA samples from these subjects were analyzed by real-time polymerase chain reaction to genotype five intronic SNPs in the GHRL (rs696217 TG, rs27647 CT, rs2075356 CT, and rs4684677 AT) and GHSR (rs509030 GC) genes. In addition, plasma GHRL levels were measured by a radioimmunoassay.
RESULTS
None of the SNPs were associated with T2DM, IR, or plasma GHRL levels. The frequencies of the alleles, genotypes, and haplotypes of the five SNPs were comparable between the T2DM patients and the non-diabetic subjects. A large number of the GHRL haplotypes indicates the molecular heterogeneity of the preproghrelin gene in this region.
CONCLUSION
Neither the Leu72Met polymorphism nor the other intronic GHRL and GHSR SNPs were associated with T2DM, IR, or GHRL levels. Further investigations should be carried out to explain the molecular basis of the association of the GHRL peptide with T2DM and IR.

Keyword

Diabetes mellitus, type 2; Insulin resistance; Ghrelin; Receptors, ghrelin; Polymorphism

MeSH Terms

Alleles
Arabs
Diabetes Mellitus, Type 2*
DNA
Genotype
Ghrelin*
GTP-Binding Proteins
Haplotypes
Homeostasis
Humans
Insulin Resistance*
Insulin*
Introns*
Plasma
Polymorphism, Single Nucleotide
Population Characteristics
Radioimmunoassay
Real-Time Polymerase Chain Reaction
Receptors, Ghrelin
DNA
GTP-Binding Proteins
Ghrelin
Insulin
Receptors, Ghrelin

Figure

  • Fig. 1 Linkage disequilibrium analyses of ghrelin single-nucleotide polymorphisms (SNPs; rs2075356, rs696217, rs27647, rs3755777) and a growth hormone secretagogue receptor (GHSR) SNP (rs509030 GC). The strength of the linkage is indicated by the value of D′, and the maximum value (absolute linkage) is 100%. The GHSR SNP had the least linkage with the other ghrelin SNPs.


Reference

1. Kojima M, Hosoda H, Date Y, Nakazato M, Matsuo H, Kangawa K. Ghrelin is a growth-hormone-releasing acylated peptide from stomach. Nature. 1999; 402:656–660. PMID: 10604470.
Article
2. Tschop M, Smiley DL, Heiman ML. Ghrelin induces adiposity in rodents. Nature. 2000; 407:908–913. PMID: 11057670.
Article
3. Lopez M, Lage R, Saha AK, Perez-Tilve D, Vazquez MJ, Varela L, et al. Hypothalamic fatty acid metabolism mediates the orexigenic action of ghrelin. Cell Metab. 2008; 7:389–399. PMID: 18460330.
4. Poykko SM, Kellokoski E, Horkko S, Kauma H, Kesaniemi YA, Ukkola O. Low plasma ghrelin is associated with insulin resistance, hypertension, and the prevalence of type 2 diabetes. Diabetes. 2003; 52:2546–2553. PMID: 14514639.
5. Leite-Moreira AF, Soares JB. Physiological, pathological and potential therapeutic roles of ghrelin. Drug Discov Today. 2007; 12:276–288. PMID: 17395087.
Article
6. Grundy SM. Atherogenic dyslipidemia associated with metabolic syndrome and insulin resistance. Clin Cornerstone. 2006; 8(Suppl 1):S21–S27. PMID: 16903166.
Article
7. Grundy SM. Metabolic syndrome: connecting and reconciling cardiovascular and diabetes worlds. J Am Coll Cardiol. 2006; 47:1093–1100. PMID: 16545636.
Article
8. Wajnrajch MP, Ten IS, Gertner JM, Leibel RL. Genomic organization of the human GHRELIN gene. J Endocr Genet. 2000; 1:231–233.
Article
9. Davenport AP, Bonner TI, Foord SM, Harmar AJ, Neubig RR, Pin JP, et al. International Union of Pharmacology. LVI. Ghrelin receptor nomenclature, distribution, and function. Pharmacol Rev. 2005; 57:541–546. PMID: 16382107.
Article
10. Al Qarni AA, Joatar FE, Das N, Awad M, Eltayeb M, Al-Zubair AG, et al. Association of plasma ghrelin levels with insulin resistance in type 2 diabetes mellitus among Saudi subjects. Endocrinol Metab (Seoul). 2017; 32:230–240. PMID: 28555463.
Article
11. Dezaki K, Sone H, Yada T. Ghrelin is a physiological regulator of insulin release in pancreatic islets and glucose homeostasis. Pharmacol Ther. 2008; 118:239–249. PMID: 18433874.
Article
12. Yada T, Dezaki K, Sone H, Koizumi M, Damdindorj B, Nakata M, et al. Ghrelin regulates insulin release and glycemia: physiological role and therapeutic potential. Curr Diabetes Rev. 2008; 4:18–23. PMID: 18220691.
Article
13. Pacifico L, Poggiogalle E, Costantino F, Anania C, Ferraro F, Chiarelli F, et al. Acylated and nonacylated ghrelin levels and their associations with insulin resistance in obese and normal weight children with metabolic syndrome. Eur J Endocrinol. 2009; 161:861–870. PMID: 19773372.
Article
14. Mager U, Kolehmainen M, Lindstrom J, Eriksson JG, Valle TT, Hamalainen H, et al. Association between ghrelin gene variations and blood pressure in subjects with impaired glucose tolerance. Am J Hypertens. 2006; 19:920–926. PMID: 16942934.
Article
15. Takezawa J, Yamada K, Morita A, Aiba N, Watanabe S. Preproghrelin gene polymorphisms in obese Japanese: association with diabetes mellitus in men and with metabolic syndrome parameters in women. Obes Res Clin Pract. 2009; 3:179–191. PMID: 24973147.
Article
16. Zavarella S, Petrone A, Zampetti S, Gueorguiev M, Spoletini M, Mein CA, et al. A new variation in the promoter region, the -604 C>T, and the Leu72Met polymorphism of the ghrelin gene are associated with protection to insulin resistance. Int J Obes (Lond). 2008; 32:663–668. PMID: 18071345.
17. Liu J, Liu J, Tian LM, Liu JX, Bing YJ, Zhang JP, et al. Association of ghrelin Leu72Met polymorphism with type 2 diabetes mellitus in Chinese population. Gene. 2012; 504:309–312. PMID: 22441120.
Article
18. Hedayatizadeh-Omran A, Rafiei A, Khajavi R, Alizadeh-Navaei R, Mokhberi V, Moradzadeh K. Association between ghrelin gene (Leu72Met) polymorphism and ghrelin serum level with coronary artery diseases. DNA Cell Biol. 2014; 33:95–101. PMID: 24341728.
Article
19. Alberti KG, Zimmet PZ. Definition, diagnosis and classification of diabetes mellitus and its complications. Part 1: diagnosis and classification of diabetes mellitus provisional report of a WHO consultation. Diabet Med. 1998; 15:539–553. PMID: 9686693.
Article
20. Matthews DR, Hosker JP, Rudenski AS, Naylor BA, Treacher DF, Turner RC. Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia. 1985; 28:412–419. PMID: 3899825.
21. Prudom C, Liu J, Patrie J, Gaylinn BD, Foster-Schubert KE, Cummings DE, et al. Comparison of competitive radioimmunoassays and two-site sandwich assays for the measurement and interpretation of plasma ghrelin levels. J Clin Endocrinol Metab. 2010; 95:2351–2358. PMID: 20194708.
Article
22. Finan RR, Mustafa FE, Al-Zaman I, Madan S, Issa AA, Almawi WY. STAT3 polymorphisms linked with idiopathic recurrent miscarriages. Am J Reprod Immunol. 2010; 63:22–27. PMID: 20059466.
23. Weyer C, Bogardus C, Mott DM, Pratley RE. The natural history of insulin secretory dysfunction and insulin resistance in the pathogenesis of type 2 diabetes mellitus. J Clin Invest. 1999; 104:787–794. PMID: 10491414.
Article
24. Ma ZA, Zhao Z, Turk J. Mitochondrial dysfunction and β-cell failure in type 2 diabetes mellitus. Exp Diabetes Res. 2012; 2012:703538. PMID: 22110477.
25. Steinle NI, Pollin TI, O’Connell JR, Mitchell BD, Shuldiner AR. Variants in the ghrelin gene are associated with metabolic syndrome in the Old Order Amish. J Clin Endocrinol Metab. 2005; 90:6672–6677. PMID: 16204371.
Article
26. Takezawa J, Yamada K, Miyachi M, Morita A, Aiba N, Sasaki S, et al. Preproghrelin gene polymorphisms in obese Japanese women. Minor homozygotes are light eaters, do not prefer protein or fat, and apparently have a poor appetite. Appetite. 2013; 63:105–111. PMID: 23257630.
Article
27. Zhuang L, Li M, Yu C, Li C, Zhao M, Lu M, et al. The Leu72Met polymorphism of the GHRL gene prevents the development of diabetic nephropathy in Chinese patients with type 2 diabetes mellitus. Mol Cell Biochem. 2014; 387:19–25. PMID: 24132517.
Article
28. Wu IC, Zhao Y, Zhai R, Liu G, Ter-Minassian M, Asomaning K, et al. Association between polymorphisms in cancer-related genes and early onset of esophageal adenocarcinoma. Neoplasia. 2011; 13:386–392. PMID: 21472143.
Article
29. Ando T, Komaki G, Naruo T, Okabe K, Takii M, Kawai K, et al. Possible role of preproghrelin gene polymorphisms in susceptibility to bulimia nervosa. Am J Med Genet B Neuropsychiatr Genet. 2006; 141B:929–934. PMID: 16921495.
Article
30. Larsen LH, Gjesing AP, Sorensen TI, Hamid YH, Echwald SM, Toubro S, et al. Mutation analysis of the preproghrelin gene: no association with obesity and type 2 diabetes. Clin Biochem. 2005; 38:420–424. PMID: 15820771.
Article
31. Kim SY, Jo DS, Hwang PH, Park JH, Park SK, Yi HK, et al. Preproghrelin Leu72Met polymorphism is not associated with type 2 diabetes mellitus. Metabolism. 2006; 55:366–370. PMID: 16483881.
Article
32. Garcia EA, King P, Sidhu K, Ohgusu H, Walley A, Lecoeur C, et al. The role of ghrelin and ghrelin-receptor gene variants and promoter activity in type 2 diabetes. Eur J Endocrinol. 2009; 161:307–315. PMID: 19460888.
Article
33. Zou CC, Huang K, Liang L, Zhao ZY. Polymorphisms of the ghrelin/obestatin gene and ghrelin levels in Chinese children with short stature. Clin Endocrinol (Oxf). 2008; 69:99–104. PMID: 18182091.
Article
34. Gueorguiev M, Lecoeur C, Meyre D, Benzinou M, Mein CA, Hinney A, et al. Association studies on ghrelin and ghrelin receptor gene polymorphisms with obesity. Obesity (Silver Spring). 2009; 17:745–754. PMID: 19165163.
Article
35. Berthold HK, Giannakidou E, Krone W, Tregouet DA, Gouni-Berthold I. Influence of ghrelin gene polymorphisms on hypertension and atherosclerotic disease. Hypertens Res. 2010; 33:155–160. PMID: 20010782.
Article
36. Campa D, Pardini B, Naccarati A, Vodickova L, Novotny J, Steinke V, et al. Polymorphisms of genes coding for ghrelin and its receptor in relation to colorectal cancer risk: a two-step gene-wide case-control study. BMC Gastroenterol. 2010; 10:112. PMID: 20920174.
Article
37. Pabalan NA, Seim I, Jarjanazi H, Chopin LK. Associations between ghrelin and ghrelin receptor polymorphisms and cancer in Caucasian populations: a meta-analysis. BMC Genet. 2014; 15:118. PMID: 25376984.
Article
38. Choi HJ, Cho YM, Moon MK, Choi HH, Shin HD, Jang HC, et al. Polymorphisms in the ghrelin gene are associated with serum high-density lipoprotein cholesterol level and not with type 2 diabetes mellitus in Koreans. J Clin Endocrinol Metab. 2006; 91:4657–4663. PMID: 16954159.
Article
39. Li WJ, Zhen YS, Sun K, Xue H, Song XD, Wang YB, et al. Ghrelin receptor gene polymorphisms are associated with female metabolic syndrome in Chinese population. Chin Med J (Engl). 2008; 121:1666–1669. PMID: 19024096.
Article
40. Liao N, Xie ZK, Huang J, Xie ZF. Association between the ghrelin Leu72Met polymorphism and type 2 diabetes risk: a meta-analysis. Gene. 2013; 517:179–183. PMID: 23321590.
Article
Full Text Links
  • ENM
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2024 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr