The contribution of circulating hematopoietic stem cells (HSCs) to vascular dysfunction remains controversial. Our data, however, support a critical role for these cells in proper retinal repair, their dependence on hypoxia regulated factors such as stromal derived factor (SDF-1) and VEGF for their recruitment to ischemic sites, and their marked dysfunction in diabetes. We propose to test the following hypothesis: In the nondiabetic state, CD34+ cells are the primary cells responding to any ischemia or injury in the retina and engage in effective revascularization and repair within the retina. Diabetes reduces the reparative potential of CD34+ cells favoring the participation of inflammatory CD14+ cells to the repair process. However, CD14+ cells form dysfunctional vessels resulting in persistent retinal ischemia and subsequent development of preretinal neovascularization. Thus, we suggest that in diabetes, the functional balance is upset by promotion of activity of one of these phenotypes (CD14+ cells) over the other (CD34+ cells). To test the above hypotheses, we will use a unique combination of experimental approaches to integrate findings on in vitro characterization of human CD34+ and CD14+ cells modulated by hypoxia with in vivo studies using rodent models of retinal ischemia and diabetes. We propose the following Specific Aims 1) To examine the effect of hypoxia-regulated factors, VEGF, SDF-1 and IGF binding protein-3, on CD34+ and CD14+ cell attachment to, differentiation on, and invasion into advance glycation endproduct(AGE)- modified matrix proteins. 2) In CD34+ and CD14+ cells, to compare the effect of hypoxia on a) expression of VEGF receptors, SDF-1 receptor, CXCR4 and IGF-1 receptor, b) migration and c) formation of capillary tubes in the presence retinal endothelial cells using a co-culture model. 3) To examine the recruitment and integration of nondiabetic and diabetic EPCs in vivo using two models of retinal ischemia in SCID mice and examine the potential of EPCs of diabetic and non-diabetic origin to repair acellular capillaries in diabetic mice and examine the effects of hypoxia pre-conditioning on these same cells. These studies will allow us to carefully examine the contribution of these two key endothelial precursor cell populations to the proper vs. aberrant repair of the retinal vasculature.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY007739-21
Application #
8007349
Study Section
Special Emphasis Panel (ZRG1-CB-G (90))
Program Officer
Shen, Grace L
Project Start
1989-08-01
Project End
2012-07-31
Budget Start
2011-01-01
Budget End
2012-07-31
Support Year
21
Fiscal Year
2011
Total Cost
$352,659
Indirect Cost
Name
University of Florida
Department
Pharmacology
Type
Schools of Medicine
DUNS #
969663814
City
Gainesville
State
FL
Country
United States
Zip Code
32611
Bhatwadekar, Ashay D; Duan, Yaqian; Chakravarthy, Harshini et al. (2016) Ataxia Telangiectasia Mutated Dysregulation Results in Diabetic Retinopathy. Stem Cells 34:405-17
Gonçalves, Andreia; Lin, Cheng-Mao; Muthusamy, Arivalagan et al. (2016) Protective Effect of a GLP-1 Analog on Ischemia-Reperfusion Induced Blood-Retinal Barrier Breakdown and Inflammation. Invest Ophthalmol Vis Sci 57:2584-92
Kong, Dejuan; Gong, Lijie; Arnold, Edith et al. (2016) Insulin-like growth factor 1 rescues R28 retinal neurons from apoptotic death through ERK-mediated BimEL phosphorylation independent of Akt. Exp Eye Res 151:82-95
Dominguez 2nd, James M; Hu, Ping; Caballero, Sergio et al. (2016) Adeno-Associated Virus Overexpression of Angiotensin-Converting Enzyme-2 Reverses Diabetic Retinopathy in Type 1 Diabetes in Mice. Am J Pathol 186:1688-700
Wang, Qi; Navitskaya, Svetlana; Chakravarthy, Harshini et al. (2016) Dual Anti-Inflammatory and Anti-Angiogenic Action of miR-15a in Diabetic Retinopathy. EBioMedicine 11:138-150
Beli, Eleni; Dominguez 2nd, James M; Hu, Ping et al. (2016) CX3CR1 deficiency accelerates the development of retinopathy in a rodent model of type 1 diabetes. J Mol Med (Berl) 94:1255-1265
Thinschmidt, Jeffrey S; Colon-Perez, Luis M; Febo, Marcelo et al. (2016) Depressed basal hypothalamic neuronal activity in type-1 diabetic mice is correlated with proinflammatory secretion of HMBG1. Neurosci Lett 615:21-7
Wert, Katherine J; Mahajan, Vinit B; Zhang, Lijuan et al. (2016) Neuroretinal hypoxic signaling in a new preclinical murine model for proliferative diabetic retinopathy. Signal Transduct Target Ther 1:
Chakravarthy, Harshini; Navitskaya, Svetlana; O'Reilly, Sandra et al. (2016) Role of Acid Sphingomyelinase in Shifting the Balance Between Proinflammatory and Reparative Bone Marrow Cells in Diabetic Retinopathy. Stem Cells 34:972-83
Chakravarthy, Harshini; Beli, Eleni; Navitskaya, Svetlana et al. (2016) Imbalances in Mobilization and Activation of Pro-Inflammatory and Vascular Reparative Bone Marrow-Derived Cells in Diabetic Retinopathy. PLoS One 11:e0146829

Showing the most recent 10 out of 73 publications