Atherosclerotic and hypertensive cardiovascular diseases (CVDs) are major causes of morbidity and mortality and a severe strain on our healthcare system. The peptide hormone Angiotensin II (Ang II) plays a major role in these pathologies due to its vasoconstrictive, pro-oxidant, -growth and -inflammatory properties in target cells such as vascular smooth muscle cells (VSMC). Several studies have documented the biochemical and signaling mechanisms of Ang II actions via the type 1 receptor (AT1R) in VSMC. However, the precise nuclear epigenetic mechanisms involved in AngII induced transcriptional regulation of pathological genes are not clear. It is increasingly recognized that profound alterations in chromatin structure, including changes in epigenetic posttranslational modifications (PTMs) of histones, such as Histone H3 -lysine methylation (H3Kme) can regulate the """"""""active"""""""" or """"""""inactive"""""""" state of genes. Recent evidence has also demonstrated the key roles of microRNAs (miRs) in gene regulation by posttranscriptional mechanisms. Our goal is to evaluate such epigenetic and miR mechanisms in Ang II actions in order to unravel new therapeutic targets. We hypothesize that the dysregulation of histone H3Kme and aberrant expression of key miRs contribute to Ang II induced VSMC dysfunction associated with various CVDs. This will be tested via 3 Specific Aims using state-of-the-art genome-wide profiling and bioinformatics approaches in cell culture along with relevant mouse models.
Specific Aim 1 is to perform epigenome profiling of key chromatin histone H3Kme marks in VSMC treated with and without Ang II, evaluate the chromatin enzymes regulating these marks, and then their functional roles in VSMC.
Specific Aim 2 is to profile the miR signatures in VSMC in response to Ang II and then determine the functional relevance of key differentially expressed miRs.
Specific Aim 3 is to evaluate specific mouse models of increased Ang II action in order to determine the in vivo relevance of the epigenetic marks and miRs uncovered in Aims 1 and 2. When completed, the proposed work will yield novel new data describing the epigenetic and miR profiles of VSMC under Ang II treated conditions, and also bring in new next generation genome sequencing technologies to the field of vascular biology. The results can increase our understanding of Ang II actions, and identify new targets that might be developed as clinical therapies for CVDs such as hypertension and atherosclerosis.

Public Health Relevance

Despite the availability of several therapies, the rates of cardiovascular diseases such as atherosclerosis and hypertension are soaring. Furthermore, these vascular complications are significantly higher in the diabetic population. Together, they are a severe drain on our healthcare resources. Since Angiotensin II is a major player in these pathologies, we propose to identify novel new epigenetic and micro-RNA based mechanisms responsible for Angiotensin II- induced expression of pathologic genes in vascular smooth muscle cells. We will use state-of- the-art profiling technologies to achieve our Specific Aims and thereby advance our long-term goal to identify new mechanisms and drug targets for cardiovascular diseases.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL106089-03
Application #
8399013
Study Section
Vascular Cell and Molecular Biology Study Section (VCMB)
Program Officer
OH, Youngsuk
Project Start
2011-01-01
Project End
2015-12-31
Budget Start
2013-01-01
Budget End
2013-12-31
Support Year
3
Fiscal Year
2013
Total Cost
$395,080
Indirect Cost
$157,080
Name
City of Hope/Beckman Research Institute
Department
Type
DUNS #
027176833
City
Duarte
State
CA
Country
United States
Zip Code
91010
Das, Sadhan; Reddy, Marpadga A; Senapati, Parijat et al. (2018) Diabetes Mellitus-Induced Long Noncoding RNA Dnm3os Regulates Macrophage Functions and Inflammation via Nuclear Mechanisms. Arterioscler Thromb Vasc Biol 38:1806-1820
Leung, Amy; Natarajan, Rama (2018) Long Noncoding RNAs in Diabetes and Diabetic Complications. Antioxid Redox Signal 29:1064-1073
Das, Sadhan; Zhang, Erli; Senapati, Parijat et al. (2018) A Novel Angiotensin II-Induced Long Noncoding RNA Giver Regulates Oxidative Stress, Inflammation, and Proliferation in Vascular Smooth Muscle Cells. Circ Res 123:1298-1312
Deshpande, Supriya; Abdollahi, Maryam; Wang, Mei et al. (2018) Reduced Autophagy by a microRNA-mediated Signaling Cascade in Diabetes-induced Renal Glomerular Hypertrophy. Sci Rep 8:6954
Leung, Amy; Amaram, Vishnu; Natarajan, Rama (2018) Linking diabetic vascular complications with LncRNAs. Vascul Pharmacol :
Gangwar, Roopesh S; Rajagopalan, Sanjay; Natarajan, Rama et al. (2018) Noncoding RNAs in Cardiovascular Disease: Pathological Relevance and Emerging Role as Biomarkers and Therapeutics. Am J Hypertens 31:150-165
Rosen, Evan D; Kaestner, Klaus H; Natarajan, Rama et al. (2018) Epigenetics and Epigenomics: Implications for Diabetes and Obesity. Diabetes 67:1923-1931
Das, Sadhan; Senapati, Parijat; Chen, Zhuo et al. (2017) Regulation of angiotensin II actions by enhancers and super-enhancers in vascular smooth muscle cells. Nat Commun 8:1467
Reddy, Marpadga A; Das, Sadhan; Zhuo, Chen et al. (2016) Regulation of Vascular Smooth Muscle Cell Dysfunction Under Diabetic Conditions by miR-504. Arterioscler Thromb Vasc Biol 36:864-73
Kato, Mitsuo; Wang, Mei; Chen, Zhuo et al. (2016) An endoplasmic reticulum stress-regulated lncRNA hosting a microRNA megacluster induces early features of diabetic nephropathy. Nat Commun 7:12864

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