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.
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.
|Leung, Amy; Natarajan, Rama (2017) Long Noncoding RNAs in Diabetes and Diabetic Complications. Antioxid Redox Signal :|
|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|
|Chen, Zhuo; Miao, Feng; Paterson, Andrew D et al. (2016) Epigenomic profiling reveals an association between persistence of DNA methylation and metabolic memory in the DCCT/EDIC type 1 diabetes cohort. Proc Natl Acad Sci U S A 113:E3002-11|
|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|
|Yuan, Hang; Reddy, Marpadga A; Deshpande, Supriya et al. (2016) Epigenetic Histone Modifications Involved in Profibrotic Gene Regulation by 12/15-Lipoxygenase and Its Oxidized Lipid Products in Diabetic Nephropathy. Antioxid Redox Signal 24:361-75|
|Bhatt, Kirti; Lanting, Linda L; Jia, Ye et al. (2016) Anti-Inflammatory Role of MicroRNA-146a in the Pathogenesis of Diabetic Nephropathy. J Am Soc Nephrol 27:2277-88|
|Bhatt, Kirti; Kato, Mitsuo; Natarajan, Rama (2016) Mini-review: emerging roles of microRNAs in the pathophysiology of renal diseases. Am J Physiol Renal Physiol 310:F109-18|
|Reddy, Marpadga A; Natarajan, Rama (2016) Targeting miR-200c to Ameliorate Diabetes-Induced Endothelial Dysfunction. Diabetes 65:1152-4|
|Du, Juan; Leung, Amy; Trac, Candi et al. (2016) Chromatin variation associated with liver metabolism is mediated by transposable elements. Epigenetics Chromatin 9:28|
|Leung, Amy; Trac, Candi; Du, Juan et al. (2016) Persistent Chromatin Modifications Induced by High Fat Diet. J Biol Chem 291:10446-55|
Showing the most recent 10 out of 33 publications