All ETDs from UAB

Advisory Committee Chair

Jennifer S Pollock

Advisory Committee Members

Kelly A Hyndman

Timmy Lee

David M Pollack

Thomas M Ryan

Document Type


Date of Award


Degree Name by School

Doctor of Philosophy (PhD) Heersink School of Medicine


In the vasculature, nitric oxide is produced by nitric oxide synthase 3 (NOS3) and protects against the development of cardiovascular disease (CVD). The histone deacetylases (HDACs) are a family of enzymes responsible for lysine deacetylation of both histone and non-histone proteins. Understanding how NO signaling is regulated by HDACs will allow us to better understand how HDAC inhibitors may be of use in treating CVD. This dissertation seeks to provide novel insight into the regulation of NOS3 by this family of enzymes. Endothelial NO production is impaired in human subjects and rodents fed a high salt diet (HS). We have previously shown HS increases HDAC1 in the kidney and represses NO signaling in cultured endothelial cells. We therefore hypothesized that HS represses endothelial NO signaling in an HDAC1-dependent manner. Male rats fed HS demonstrated impaired NO signaling in the afferent arteriole compared to rats fed normal salt diet (NS). This was restored by ex vivo inhibition of HDAC1 with MS-275. HS increased HDAC1 activity but not abundance in isolated renal endothelial cells. We also found plasma from HS fed rats impaired NO signaling in the afferent arterioles from NS fed rats in an HDAC1-dependent manner. Additional studies were carried out to determine whether novel lysine acetylation sites on NOS3 regulate NO signaling. Seven lysines on NOS3 were mutated to arginine. We found NOS3 containing arginine substitution at K610 (K610R) to be more active iv than WT. In order to better understand how acetylation of this lysine would impact NOS3 activity, we substituted K610 for glutamine (K610Q) mimicking acetylation of this site. We found K610Q to have higher activity than both WT and K610R. Additional studies found both K610R and K610Q to have increased phosphorylation at S1177 and decreased phosphorylation at T495. Additionally, K610R demonstrated increased phosphorylation at S615. From these studies, we conclude that HS changes the composition of the plasma such that it activates HDAC1 in endothelial cells leading to decreased NO signaling. We further conclude K610 is a potential lysine acetylation site on NOS3. These studies provide novel insights into the contexts and mechanisms by which HDACs regulate NOS3.



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