Microvascular endothelial dysfunction precedes the development of vascular disease and portends future adverse vascular events. Endothelial dysfunction is readily identified by a characteristic loss of nitric oxide (NO) bioavailability, whch results from the dysregulation of a wide variety of proteins and molecular pathways. However, we lack important knowledge of how these proteins and molecules are coordinately regulated. MicroRNAs have been demonstrated to act as master regulators of physiological or disease processes by coordinately targeting multiple genes involved in the process. However, the role of microRNAs in endothelial dysfunction, especially in the context of diabetes, remains largely unexplored. We have obtained preliminary data suggesting a homeostatic level of vascular miR-29b is critical for the maintenance of normal microvascular NO bioavailability and endothelium-dependent vasodilation in humans and animal models. Conversely, in type 2 diabetes mellitus, a disease typified by reduced microvascular NO bioavailability and microvascular morbidity, miR-29b could restore NO bioavailability and endothelium- dependent vasodilation. MiR-29b's impact on NO bioavailability appears to arise from its coordinated effects on several genes that alter NO bioavailability at multiple levels of regulation. We propose in this application to investigate the novel role of miR-29b in microvascular endothelium- dependent vasodilation and NO bioavailability in health and in type 2 diabetes and identify the mechanisms mediating these effects of miR-29b. The proposed project will employ a highly translational approach that combines functional studies of a newly developed knockout rat model with studies of intact human vessels obtained from well-phenotyped volunteers. We will also employ newly developed methods for identifying target genes and molecular pathways involved in the effect of miR-29b. Specifically, we will test the hypothesis that endogenous miR-29b is critical to maintaining normal endothelium-dependent vasodilation and NO bioavailability in resistance vessels in healthy humans and animals in Aim 1.
Aim 2 studies will test the hypothesis that miR-29b can restore endothelium-dependent vasodilation and NO bioavailability in resistance vessels from T2DM patients and db/db mice. The molecular mechanisms underlying the role of miR-29b in endothelium-dependent vasodilation and NO bioavailability will be examined in Aim 3. The study will be carried out by a team of experienced researchers led by a physician scientist and a basic scientist who possess complementary expertise ideally suited for the proposed project. Successful completion of the project will reveal novel mechanisms regulating endothelial function and demonstrate their clinical relevance.

Public Health Relevance

The world-wide prevalence of diabetes mellitus surpassed 380 million individuals in 2013, and is expected to rise to nearly 600 million by 2035. Microvascular disease is particularly prevalent in diabetic patients and portends future adverse vascular events. The proposed project will investigate a novel mechanism underlying endothelial function in humans and animal models and examine a new approach to reverse endothelial dysfunction in diabetes.

National Institute of Health (NIH)
National Heart, Lung, and Blood Institute (NHLBI)
Research Project (R01)
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Hypertension and Microcirculation Study Section (HM)
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Galis, Zorina S
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Medical College of Wisconsin
Internal Medicine/Medicine
Schools of Medicine
United States
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Widlansky, Michael E; Puppala, Venkata K; Suboc, Tisha M et al. (2017) Impact of DPP-4 inhibition on acute and chronic endothelial function in humans with type 2 diabetes on background metformin therapy. Vasc Med 22:189-196
Mattson, David L; Liang, Mingyu (2017) Hypertension: From GWAS to functional genomics-based precision medicine. Nat Rev Nephrol 13:195-196
Kieu, Andrew; Shaikh, Armaan; Kaeppler, Mark et al. (2017) Patients with hypertensive responses to exercise or dobutamine stress testing differ in resting hypertensive phenotype. J Am Soc Hypertens :
Baker, Maria Angeles; Davis, Seth J; Liu, Pengyuan et al. (2017) Tissue-Specific MicroRNA Expression Patterns in Four Types of Kidney Disease. J Am Soc Nephrol 28:2985-2992
Touyz, Rhian M; Montezano, Augusto C; Rios, Francisco et al. (2017) Redox Stress Defines the Small Artery Vasculopathy of Hypertension: How Do We Bridge the Bench-to-Bedside Gap? Circ Res 120:1721-1723
Fetterman, Jessica L; Holbrook, Monica; Westbrook, David G et al. (2016) Mitochondrial DNA damage and vascular function in patients with diabetes mellitus and atherosclerotic cardiovascular disease. Cardiovasc Diabetol 15:53
Collini, Paul; Morris, Alison (2016) Maintaining lung health with longstanding HIV. Curr Opin Infect Dis 29:31-8
Mohandas, Appesh; Suboc, Tisha B; Wang, Jingli et al. (2015) Mineralocorticoid exposure and receptor activity modulate microvascular endothelial function in African Americans with and without hypertension. Vasc Med 20:401-8