A complete understanding of signals that stimulate angiogenesis, or new blood vessel growth, is essential for promoting vascularization of wounded tissues. Although much evidence supports that growth factors are key in promoting angiogenic responses, much less is known about how other cues from the local environment convert quiescent endothelial cells to sprouting structures. These studies will provide significant new insights and answer as-yet unresolved fundamental issues of how angiogenic growth factors and lipids as well as changes in wall shear stress initiate endothelial sprouting responses in three dimensions. We hypothesize that pro-angiogenic factors stimulate phosphorylation and calpain-dependent cleavage of vimentin, which controls downstream activation of membrane-associated proteinases and initiates sprout formation. These studies will utilize discriminating, defined, quantifiable, three-dimensional systems where primary human endothelial cells invade and form multicellular, capillary-like sprouts. The studies proposed here are expected to demonstrate for the first time that pro-angiogenic factors and wall shear stress combine via calpain and intracellular kinases to disrupt vimentin networks and allow translocation of membrane- associated metalloproteinase to the membrane. These signals result in ensuing invasion and matrix alterations. We will utilize transgenic mice lacking vimentin to confirm the involvement of this intermediate filament in sprouting angiogenesis in the adult. These experiments represent a balanced, multidisciplinary approach to defining the intracellular signals that initiate angiogenic sprout formation in wounded tissue. Integration of defined in vitro and in vivo models of wound healing with intravital imaging will enhance our fundamental understanding of how biochemical and mechanical signals regulate angiogenic sprouting and cell-matrix communication events in 3D, providing a platform for future studies on signals that promote new blood vessel growth in living systems.

Public Health Relevance

Chronic wounds elicit significant social and economic burdens;therefore, a complete understanding of these events is warranted. This proposal will significantly advance our understanding of how various physiological forces and biochemical signals initiate new blood vessel growth, which is a required step in wound healing. Such knowledge will ultimately aid to decrease the socio-economic burdens associated with aberrations or deficiencies in the process.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL095786-05
Application #
8605544
Study Section
Vascular Cell and Molecular Biology Study Section (VCMB)
Program Officer
Reid, Diane M
Project Start
2010-02-01
Project End
2015-01-31
Budget Start
2014-02-01
Budget End
2015-01-31
Support Year
5
Fiscal Year
2014
Total Cost
$681,563
Indirect Cost
$211,563
Name
Texas A&M University
Department
Other Basic Sciences
Type
Schools of Medicine
DUNS #
835607441
City
College Station
State
TX
Country
United States
Zip Code
77845
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Dave, Jui M; Kang, Hojin; Abbey, Colette A et al. (2013) Proteomic profiling of endothelial invasion revealed receptor for activated C kinase 1 (RACK1) complexed with vimentin to regulate focal adhesion kinase (FAK). J Biol Chem 288:30720-33
Patterson, Jan L; Abbey, Colette A; Bayless, Kayla J et al. (2013) Materials composed of the Drosophila melanogaster protein ultrabithorax are cytocompatible. J Biomed Mater Res A :
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Kwak, Hyeong-Il; Kang, Hojin; Dave, Jui M et al. (2012) Calpain-mediated vimentin cleavage occurs upstream of MT1-MMP membrane translocation to facilitate endothelial sprout initiation. Angiogenesis 15:287-303
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Su, Shih-Chi; Maxwell, Steve A; Bayless, Kayla J (2010) Annexin 2 regulates endothelial morphogenesis by controlling AKT activation and junctional integrity. J Biol Chem 285:40624-34