The octapeptide, angiotensin-ll (Ang II) is one of the most potent vasoactive substances known and regulates a variety of physiological responses, including fluid homeostasis, aldosterone production, renal function and contraction of vascular smooth muscle (VSM). Over-expression of the angiotensin receptor-1 (AT1R) gene produces hypertension especially in female transgenic mice. These studies have suggested that increased transcription of the hAT1 R gene may lead to hypertension. We have therefore analyzed the role of single nucleotide polymorphisms (SNPs) in the 5'flanking region of the hAT1R gene in hypertension. We have found that hAT1 R gene promoter has a haplotype block of at least five SNPs consisting of T/A at - 777, T/G at -680, A/C at -214, G/C at -213, and A/G at -119. Our studies have shown that variants -777T, - 680T, -214A, -213G, and -119A always occur together (creating haplotype-l containing TTAGA and haplotype-ll containing AGCCG respectively). Our studies have shown that haplotype-l of the hAT1R gene is associated with hypertension in Caucasian women and transient transfection of reporter construct containing haplotype-l of the hAT1R gene has increased promoter activity in adrenal cortical cells and VSMC as compared to haplotype-ll. Our gel shift assays have shown that: (a) transcription factor C/EBP binds more strongly to an oligonucleotide containing -119A (haplotype-l) as compared to -119G (haplotype- ll) and (b) transcription factor USF (which binds to an E-box motif CANNTG) binds strongly to an oligonucleotide containing nucleoside A and G at -214 and -213 (haplotype-l) as compared to the same oligonucleotide containing nucleoside C at -213 and -214 (haplotype-ll). We will therefore analyze the effect of haplotypes -I and II on transcriptional regulation of the hAT1R gene in an in-vitro system using adrenocortical and vascular smooth muscle cells, examine the effect of haplotypes-l and II on hAT1 R mRNA level and on blood pressure using male and female transgenic mice, and examine the effect of IL-6, glucocorticoids, and estrogens on hAT1R mRNA level in transgenic mice containing haplotype I and II of the hAT1 R gene, and to correlate potential changes in mRNA levels with blood pressure in transgenic mice.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL081752-04
Application #
7658752
Study Section
Special Emphasis Panel (ZRG1-CVS-B (92))
Program Officer
Tolunay, Eser
Project Start
2006-07-01
Project End
2011-06-30
Budget Start
2009-07-01
Budget End
2010-06-30
Support Year
4
Fiscal Year
2009
Total Cost
$383,545
Indirect Cost
Name
New York Medical College
Department
Pathology
Type
Schools of Medicine
DUNS #
041907486
City
Valhalla
State
NY
Country
United States
Zip Code
10595
Jain, Sudhir; Puri, Nitin; Rana, Anita et al. (2018) Metabolic Syndrome Induces Over Expression of the Human AT1R: A Haplotype-Dependent Effect With Implications on Cardio-Renal Function. Am J Hypertens 31:495-503
Jain, Sudhir; Tulsulkar, Jatin; Rana, Anita et al. (2016) Transgenic Mice Overexpressing Human Angiotensin I Receptor Gene Are Susceptible to Stroke Injury. Mol Neurobiol 53:1533-1539
Pandey, Varunkumar G; Jain, Sudhir; Rana, Anita et al. (2015) Dexamethasone promotes hypertension by allele-specific regulation of the human angiotensinogen gene. J Biol Chem 290:5749-58
Mopidevi, Brahmaraju; Kaw, Meenakshi K; Puri, Nitin et al. (2015) Variable transcriptional regulation of the human aldosterone synthase gene causes salt-dependent high blood pressure in transgenic mice. Circ Cardiovasc Genet 8:30-9
Maharjan, Shreekrishna; Mopidevi, Brahmaraju; Kaw, Meenakshi Kaul et al. (2014) Human aldosterone synthase gene polymorphism promotes miRNA binding and regulates gene expression. Physiol Genomics 46:860-5
Jain, Sudhir; Prater, Alicia; Pandey, Varunkumar et al. (2013) A haplotype of angiotensin receptor type 1 associated with human hypertension increases blood pressure in transgenic mice. J Biol Chem 288:37048-56
Mopidevi, Brahmaraju; Ponnala, Madhusudhan; Kumar, Ashok (2013) Human angiotensinogen +11525 C/A polymorphism modulates its gene expression through microRNA binding. Physiol Genomics 45:901-6
Jain, Sudhir; Tillinger, Andrej; Mopidevi, Brahmaraju et al. (2010) Transgenic mice with -6A haplotype of the human angiotensinogen gene have increased blood pressure compared with -6G haplotype. J Biol Chem 285:41172-86
Jain, Sudhir; Vinukonda, Govindaiah; Fiering, Steven N et al. (2008) A haplotype of human angiotensinogen gene containing -217A increases blood pressure in transgenic mice compared with -217G. Am J Physiol Regul Integr Comp Physiol 295:R1849-57