Endothelial-derived nitric oxide (NO) is an important regulator of blood flow and systemic blood pressure. However, little is known about the mechanisms by which NO acts to control endothelial cell (EC) function or how interference with the NO pathway may affect microvascular structure and function. The applicant's preliminary studies show that blockade of nitric oxide synthase (NOS) profoundly attenuates angiogenesis and in the face of NOS blockade, exogenous NO donors and cGMP analogues stimulate capillary tube formation. Thus, activation of soluble guanlyate cyclase and the attendant rise in cGMP are required for the pro-angiogenic actions of NO. To elucidate the mechanisms by which NO influences EC growth and blood flow, the following Specific Aims are proposed.
Aim 1. Elucidate the role of NO as a determinant of capillary organization in vitro and of microvascular structure in vivo. The applicant hypothesizes that (i) EC-derived NO regulates aspects of vasculogenesis, angiogenesis, microvascular structure and network remodeling; and (ii) Selective inhibition of NOS will impair vasculogenesis, angiogenesis and contribute to microvascular rarefaction. To test these hypotheses, embryos from ENOS and inducible NOS (iNOS) knockout mice and three dimensional (3D) cultures of capillary EC will be used to examine the NO dependency of capillary organization and remodeling in vitro, and the role of NO in vessel remodeling will be determined in the microcirculation of the cremaster muscle of eNOS knockout mice.
Aim 2. Define the NO dependent signal transduction pathways of angiogenesis, network modeling and microvascular hemodynamics. The applicant hypothesizes that (iii) Activation of cGMP-dependent pathway(s) will trigger pro-angiogenic pathways in EC; and (iv) Selective inhibition of NOS will reduce tissue blood flow and impair microvascular flow control thereby promoting network rarefaction. In 3D cultures of ECs, TGF-beta1 modulation of NOS, NO production and activation of the cGMP pathway will be studied in light of capillary morphogenesis. The influence of NO and cGMP on the expression and regulation of well described pro-angiogenic pathways will be determined. Short and long term roles for NO in control of pressure and flow will be investigated in the microcirculation of the cremaster muscle in eNOS knockout mice in vivo. The applicant's long term goals are to understand the interrelationships between NO as a molecular signal necessary for angiogenesis and vessel growth, and as a key determinant of pressure and flow control. Results derived from these studies will uniquely define the physiological role(s) of NO as a vasodilator that influences migration and organization of ECs; thereby defining microvascular geometry and tissue perfusion, in vivo.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL057665-04
Application #
6056397
Study Section
Special Emphasis Panel (ZHL1-CSR-N (S1))
Project Start
1996-09-30
Project End
2001-06-30
Budget Start
1999-09-01
Budget End
2001-06-30
Support Year
4
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Yale University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
082359691
City
New Haven
State
CT
Country
United States
Zip Code
06520
Kraehling, Jan R; Hao, Zhengrong; Lee, Monica Y et al. (2016) Uncoupling Caveolae From Intracellular Signaling In Vivo. Circ Res 118:48-55
Kraehling, Jan R; Sessa, William C (2015) Enhanced eNOS Activation as the Fountain of Youth for Vascular Disease: Is BPIFB4 What Ponce de León Was Looking For? Circ Res 117:309-10
Chidlow Jr, John H; Sessa, William C (2010) Caveolae, caveolins, and cavins: complex control of cellular signalling and inflammation. Cardiovasc Res 86:219-25
Fernández-Hernando, Carlos; József, Levente; Jenkins, Deborah et al. (2009) Absence of Akt1 reduces vascular smooth muscle cell migration and survival and induces features of plaque vulnerability and cardiac dysfunction during atherosclerosis. Arterioscler Thromb Vasc Biol 29:2033-40
Chidlow Jr, John H; Greer, Joshua J M; Anthoni, Christoph et al. (2009) Endothelial caveolin-1 regulates pathologic angiogenesis in a mouse model of colitis. Gastroenterology 136:575-84.e2
Suárez, Yajaira; Sessa, William C (2009) MicroRNAs as novel regulators of angiogenesis. Circ Res 104:442-54
Fernández-Hernando, Carlos; Yu, Jun; Suárez, Yajaira et al. (2009) Genetic evidence supporting a critical role of endothelial caveolin-1 during the progression of atherosclerosis. Cell Metab 10:48-54
Dobrucki, Lawrence W; Dione, Donald P; Kalinowski, Leszek et al. (2009) Serial noninvasive targeted imaging of peripheral angiogenesis: validation and application of a semiautomated quantitative approach. J Nucl Med 50:1356-63
Sessa, W C (2009) Molecular control of blood flow and angiogenesis: role of nitric oxide. J Thromb Haemost 7 Suppl 1:35-7
Di Lorenzo, Annarita; Fernández-Hernando, Carlos; Cirino, Giuseppe et al. (2009) Akt1 is critical for acute inflammation and histamine-mediated vascular leakage. Proc Natl Acad Sci U S A 106:14552-7

Showing the most recent 10 out of 77 publications