title: A haplotype of angiotensin receptor type 1 associated with human hypertension increases blood pressure in transgenic mice.
abstract: The renin-angiotensin system plays an important role in the regulation of blood pressure via angiotensin II and the angiotensin II receptor type 1 (AT1R). Human AT1R gene promoter has four SNPs: T/A at -777, T/G at -680, A/C at -214, and A/G at -119, that are in linkage disequilibrium. Variants -777T, -680T, -214A, and -119A almost always occur together (named haplotype I), and variants -777A, -680G, -214C, and -119G almost always occur together (named haplotype II) in Caucasian subjects. Genomic DNA analyses, from 388 normotensive and 374 hypertensive subjects, link haplotype I of the human AT1R (hAT1R) gene with hypertension in Caucasians (p = 0.004, χ(2) = 8.46). Our results show increased basal promoter activity of the hAT1R gene in cells (H295R and A7r5) transfected with reporter construct containing haplotype I. We also show increased binding of the transcription factor, USF2, to oligonucleotide containing nucleoside -214A as opposed to -214C. Recombineering of a 166-kb bacterial artificial chromosome containing 68 kb of the 5'-flanking region, 45 kb of the coding sequence, and 53 kb of the 3'-flanking region of the hAT1R gene was employed to generate transgenic mice with either haplotype. We show that (a) hAT1R mRNA level is increased in the kidney and heart of transgenic mice containing haplotype I as compared with haplotype II; (b) USF2 binds more strongly to the chromatin obtained from the kidney of transgenic mice containing haplotype I as compared with haplotype II; and (c) blood pressure and oxidative stress are increased in transgenic mice containing haplotype I as compared with haplotype II.
authors.affiliation: From the Department of Physiology and Pharmacology, University of Toledo Health Science Campus, Toledo, Ohio 43614.
authors.forename: Sudhir
authors.initials: S
authors.lastname: Jain
authors.forename: Alicia
authors.initials: A
authors.lastname: Prater
authors.forename: Varunkumar
authors.initials: V
authors.lastname: Pandey
authors.forename: Anita
authors.initials: A
authors.lastname: Rana
authors.forename: Nitin
authors.initials: N
authors.lastname: Puri
authors.forename: Ashok
authors.initials: A
authors.lastname: Kumar
mesh_terms: D000368:Aged; D000818:Animals; D001794:Blood Pressure / Q000235:genetics; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics; D005260:Female; D006239:Haplotypes; D006801:Humans; D006973:Hypertension / Q000235:genetics / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D015810:Linkage Disequilibrium; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D018384:Oxidative Stress / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D044140:Receptor, Angiotensin, Type 1 / Q000096:biosynthesis / Q000235:genetics; D051720:Upstream Stimulatory Factors / Q000235:genetics / Q000378:metabolism; D044465:White People
chemical_list: D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; C497184:USF2 protein, human; D051720:Upstream Stimulatory Factors; C497186:Usf2 protein, mouse
keywords: Angiotensin II; G Protein-coupled receptors (GPCR); Gene Regulation; Genetic Polymorphism; Hypertension; Molecular Genetics; Transcription; Transgenic Mice