BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) expression is increased in adipose tissue of both rodent models of obesity and obese humans. It has therefore been considered as a candidate gene for obesity. Several studies have indeed shown statistical evidence of linkage between obesity and the chromosomal region encompassing the TNF-alpha gene, suggesting that TNF-alpha and/or a nearby gene (eg hsp70 gene) is involved in the onset and progression of weight gain. We designed a case-controlled study to investigate the potential association of polymorphism of the TNF-alpha and that of a stress protein (hsp70-2) with obesity. METHODS: We used the polymerase chain reaction and restriction enzyme digestion to characterize the variation of the TNF-alpha promoter region and that of the hsp70-2 gene in 343 unrelated Tunisian patients with obesity and 174 healthy control subjects. RESULTS: Analysis of the -308 TNF-alpha polymorphism in patients with obesity and in control subjects did not reveal an association between TNF-alpha alleles and obesity. In contrast, polymorphism analysis of the hsp70-2 gene in patients with obesity demonstrated highly significant differences in genotypic distribution of this bi-allelic locus compared to the control subject group. Homozygosity for one hsp70-2 allele was highly associated with obesity (r2=7.12; P<10(-6)). CONCLUSION: Tunisian persons carrying the P2/P2 genotype of the hsp70-2 gene may have an increased risk of obesity.
BACKGROUND:Tumor necrosis factor-alpha (TNF-alpha) expression is increased in adipose tissue of both rodent models of obesity and obesehumans. It has therefore been considered as a candidate gene for obesity. Several studies have indeed shown statistical evidence of linkage between obesity and the chromosomal region encompassing the TNF-alpha gene, suggesting that TNF-alpha and/or a nearby gene (eg hsp70 gene) is involved in the onset and progression of weight gain. We designed a case-controlled study to investigate the potential association of polymorphism of the TNF-alpha and that of a stress protein (hsp70-2) with obesity. METHODS: We used the polymerase chain reaction and restriction enzyme digestion to characterize the variation of the TNF-alpha promoter region and that of the hsp70-2 gene in 343 unrelated Tunisian patients with obesity and 174 healthy control subjects. RESULTS: Analysis of the -308 TNF-alpha polymorphism in patients with obesity and in control subjects did not reveal an association between TNF-alpha alleles and obesity. In contrast, polymorphism analysis of the hsp70-2 gene in patients with obesity demonstrated highly significant differences in genotypic distribution of this bi-allelic locus compared to the control subject group. Homozygosity for one hsp70-2 allele was highly associated with obesity (r2=7.12; P<10(-6)). CONCLUSION: Tunisian persons carrying the P2/P2 genotype of the hsp70-2 gene may have an increased risk of obesity.
Authors: Gudmar Thorleifsson; G Bragi Walters; Daniel F Gudbjartsson; Valgerdur Steinthorsdottir; Patrick Sulem; Anna Helgadottir; Unnur Styrkarsdottir; Solveig Gretarsdottir; Steinunn Thorlacius; Ingileif Jonsdottir; Thorbjorg Jonsdottir; Elinborg J Olafsdottir; Gudridur H Olafsdottir; Thorvaldur Jonsson; Frosti Jonsson; Knut Borch-Johnsen; Torben Hansen; Gitte Andersen; Torben Jorgensen; Torsten Lauritzen; Katja K Aben; André L M Verbeek; Nel Roeleveld; Ellen Kampman; Lisa R Yanek; Lewis C Becker; Laufey Tryggvadottir; Thorunn Rafnar; Diane M Becker; Jeffrey Gulcher; Lambertus A Kiemeney; Oluf Pedersen; Augustine Kong; Unnur Thorsteinsdottir; Kari Stefansson Journal: Nat Genet Date: 2008-12-14 Impact factor: 38.330
Authors: Amina Nadeem; Sadaf Mumtaz; Abdul Khaliq Naveed; Muhammad Aslam; Arif Siddiqui; Ghulam Mustafa Lodhi; Tausif Ahmad Journal: World J Diabetes Date: 2015-05-15