In the previous funding period, we demonstrated that diabetic individuals and mice demonstrate dysfunctional endothelial progenitor cells. These bone marrow (BM) derived cells are released into the circulation in an abnormal manner due to diabetes-induced BM neuropathy. This BM neuropathy leads to dysregulation in the circadian release of these cells into the circulation. These BM changes precede development of diabetic retinopathy (DR) linking BM neuropathy for the first time to DR. Diabetic BM supernatants, but not control, contain high levels of monocyte/macrophage-colony stimulating factor (M-CSF) and diabetic mice exhibit an increase number of monocytes in the retina and circulation. Based on these findings, we hypothesize that: Diabetic BM denervation initiates HSC/progenitor dysfunction that leads to an increase in total monocytes generated, this, coupled with increased expression of CCL2 (monocyte chemoattractent protein-1) by retinal glia results in excessive levels of the pro-inflammatory (M1) monocytes in the diabetic retina. In addition, diminished levels of CX3CL1 (fractalkine) expression by dysfunctional neurons heightens the inflammatory response of resident microglia. This imbalance leads to a neural inflammation that accelerates DR pathogenesis. We will test this hypothesis both in vitro and in vivo through the simultaneous exploration of the following aims:
Aim 1 : To determine whether diabetes induced BM neuropathy is responsible for increased M-CSF production by BM stromal cells which shifts hematopoiesis towards generation of excessive numbers of monocytes, in particular pro-inflammatory Gr1+/CCR2+/CX3CR1lo monocytes, rather than the protective Gr1-/CCR2-/CX3CR1hi monocytes.
Aim 2 : To determine the roles of CCL2 and CX3CL1 in DR inflammation and to test whether restoration of the balance of CCR2+CX3CR1lo and CCR2-/CX3CR1hi monocytes and simultaneous restoration of levels of endothelial progenitors to retinal vasculature will prevent o reverse DR in T1D mice.
Aim 3 : Our hypothesis predicts that circulating pro- inflammatory Gr1+/CCR2+i/CX3CR1lo cells will cause endothelial cell activation, promote leukostasis and result in enhanced retinal permeability whereas Gr1-/CCR2-/CX3CR1hi cells will protect the BRB in diabetes. We will examine the effects of manipulating these subsets on the progression of DR. Targeting monocyte subtypes may represent an ideal strategy for DR prevention and treatment. CellMax?

Public Health Relevance

This proposal examines how loss of innervation (neuronal support) to the bone marrow in diabetes impacts the behavior of bone marrow derived cells, specifically the vascular reparative cells and the monocytes. We will examine why the diabetic bone marrow produces too few reparative cells and too many inflammatory cells that then enter the circulation, migrate into the retina and lead to histological and functional abnormalities associated with diabetic retinopathy.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY007739-24
Application #
8735950
Study Section
Special Emphasis Panel (DPVS)
Program Officer
Shen, Grace L
Project Start
2013-09-07
Project End
2016-08-31
Budget Start
2014-09-01
Budget End
2015-08-31
Support Year
24
Fiscal Year
2014
Total Cost
$452,378
Indirect Cost
$41,448
Name
Indiana University-Purdue University at Indianapolis
Department
Ophthalmology
Type
DUNS #
603007902
City
Indianapolis
State
IN
Country
United States
Zip Code
46202
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