The VEGF receptor-2 (KDR) pathway in vascular endothelial cells (EC) promotes cell survival and migration, essential steps for vascular repair and remodeling. Culture of peripheral blood also results in an EC-like population of cells termed blood outgrowth endothelial cells (BOEC), which contribute to vascular remodeling through a poorly-defined mechanism of paracrine regulation of vascular EC. In our PRELIMINARY STUDIES, we have 1) identified the multifunctional cytokine, nitric oxide (NO) as a key paracrine factor released by BOEC, 2) elucidated an S-nitrosylation dependent mechanism by which NO activates dynamin GTPase, an important regulator of EC signaling and vesicle trafficking, and 3) identified a novel mechanism by which dynamin GTPase activity positively regulates the KDR pathway of EC migration and survival through both regulatory protein interaction and compartmentalization. These key observations will allow us to rigorously and mechanistically test our CENTRAL HYPOTHESIS that BOEC-derived NO stimulates KDR dependent migration and proliferation of native vascular EC through dynamin nitrosylation and GTPase activity regulation, thereby promoting vascular remodeling. Thus, in our SPECIFIC AIMS, we will: 1) examine the mechanism by which NO nitrosylates dynamin by mapping nitrosylation of individual cysteine residues in the dynamin GTPase domain and then establish the causative role of nitrosylation in the process of NO activation of dynamin function, 2) delineate the regulatory role of dynamin and its nitrosylation on KDR subcellular compartmentalization, activation, and function in vitro and in vivo, by studying dynamin-KDR protein interactions and dynamin dependent KDR internalization, 3) perform studies in BOEC and EC in coculture models and in an in vivo model of vascular remodeling, to directly test how BOEC-derived NO activates KDR- dependent EC migration, survival, endothelial reconstitution, and function. To address these aims, we will utilize a variety of feasible and state-of-the-art approaches including mechanistic recombinant protein studies, retroviral and siRNA based gain and loss of function in BOEC and vascular EC, and validated cell delivery approaches in in vivo models. Thus, these multidisciplinary studies will delineate novel paracrine signaling pathways between vascular EC and circulation-derived cells in the process of vascular remodeling.

Public Health Relevance

Vascular remodeling is an important physiologic process with therapeutic relevance in the setting of a broad number of vascular diseases. Thus, this work has physiologic, pathobiologic, and therapeutic importance.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL086990-02
Application #
7586103
Study Section
Vascular Cell and Molecular Biology Study Section (VCMB)
Program Officer
Gao, Yunling
Project Start
2008-04-01
Project End
2012-03-31
Budget Start
2009-04-01
Budget End
2010-03-31
Support Year
2
Fiscal Year
2009
Total Cost
$377,750
Indirect Cost
Name
Mayo Clinic, Rochester
Department
Type
DUNS #
006471700
City
Rochester
State
MN
Country
United States
Zip Code
55905
Zou, Li; Cao, Sheng; Kang, Ningling et al. (2012) Fibronectin induces endothelial cell migration through ?1 integrin and Src-dependent phosphorylation of fibroblast growth factor receptor-1 at tyrosines 653/654 and 766. J Biol Chem 287:7190-202
Yaqoob, Usman; Cao, Sheng; Shergill, Uday et al. (2012) Neuropilin-1 stimulates tumor growth by increasing fibronectin fibril assembly in the tumor microenvironment. Cancer Res 72:4047-59
Huebert, Robert C; Jagavelu, Kumaravelu; Hendrickson, Helen I et al. (2011) Aquaporin-1 promotes angiogenesis, fibrosis, and portal hypertension through mechanisms dependent on osmotically sensitive microRNAs. Am J Pathol 179:1851-60
Cao, Ying; Szabolcs, Annamaria; Dutta, Shamit K et al. (2010) Neuropilin-1 mediates divergent R-Smad signaling and the myofibroblast phenotype. J Biol Chem 285:31840-8
Huebert, Robert C; Vasdev, Meher M; Shergill, Uday et al. (2010) Aquaporin-1 facilitates angiogenic invasion in the pathological neovasculature that accompanies cirrhosis. Hepatology 52:238-48
Jagavelu, Kumaravelu; Routray, Chittaranjan; Shergill, Uday et al. (2010) Endothelial cell toll-like receptor 4 regulates fibrosis-associated angiogenesis in the liver. Hepatology 52:590-601
Das, Amitava; Shergill, Uday; Thakur, Lokendra et al. (2010) Ephrin B2/EphB4 pathway in hepatic stellate cells stimulates Erk-dependent VEGF production and sinusoidal endothelial cell recruitment. Am J Physiol Gastrointest Liver Physiol 298:G908-15
Shergill, U; Das, A; Langer, D et al. (2010) Inhibition of VEGF- and NO-dependent angiogenesis does not impair liver regeneration. Am J Physiol Regul Integr Comp Physiol 298:R1279-87
Cao, Sheng; Yaqoob, Usman; Das, Amitava et al. (2010) Neuropilin-1 promotes cirrhosis of the rodent and human liver by enhancing PDGF/TGF-beta signaling in hepatic stellate cells. J Clin Invest 120:2379-94
Abdelmoneim, Soha S; Talwalkar, Jayant; Sethi, Saurabh et al. (2010) A prospective pilot study of circulating endothelial cells as a potential new biomarker in portal hypertension. Liver Int 30:191-7

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