Success of corneal transplant is dependent on high corneal endothelial (CE) cell density maintained immediately after surgery and thereafter. CE cells die either by acute necrosis, which initiates detrimental inflammatory responses, or by a slow programmed, apoptotic death, which does not cause inflammation. We found that an aqueous humor neuropeptide, VIP, promotes CE cell survival under acute H2O2-induced oxidative stress and simultaneously stimulates CE cells to release a factor that promotes apoptosis among dying CE cells in corneoscleral explants. The VIP effects are associated with cAMP production, protein tyrosine phosphorylation, and activation of the cAMP- responsive- element binding protein (CREB), a key molecule in cell survival. CE cells express VIP protein and gene, which can be upregulated by the other CE cell autocrine trophic factor, CNTF, which in turn is released by CE cells surviving oxidative stress. Whereas CE cells in human donor corneas stored for transplant continue to express VIP mRNA and receptor for CNTF (CNTFRalpha) and VIP increases the density of CE cells of these corneas in long-term storage, CNTF- and CNTFRalpha-immunoreactivities are present in human aqueous humor. Our goal is to establish VIP and CNTF as CE cell trophic factors capable of: 1) prolonging the duration of preservation of corneas for transplant and 2) maintaining the integrity of transplanted corneas in the recipient eyes.
Five aims to test hypotheses that: 1) VIP protection of CE cell against acute oxidative injury is associated with attenuation of lipid peroxidation; 2) VIP-released factor (VRF) switches necrosis to apoptosis in injured CE cells by attenuating H2O2-induced ATP depletion and mitochondrial potential dissipation and by augmentation of poly (ADP-ribose) polymerase cleavage, by using VRF that will be purified by sequential fast performance liquid chromatography from CE cell-conditioned medium and amino acid sequence analyzed; 3) VIP inactivates the pro-apoptotic BAD protein and up-regulates the anti-apoptotic protein Bcl-2 and the cytochrome C; 4) sublethal H2O2-injured CE cells release CNTF to promote own survival and that authentic CNTF and CNTFRalpha are in the aqueous humor of injured (enucleated) eyes; 5) CE cell CNTFRalpha lost during extensive eye bank storage can be restored to function to upregulate VIP mRNA by exogenous CNTFRalpha.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY011607-07
Application #
7096521
Study Section
Special Emphasis Panel (ZRG1-VISA (01))
Program Officer
Shen, Grace L
Project Start
1998-12-01
Project End
2008-06-30
Budget Start
2006-07-01
Budget End
2007-06-30
Support Year
7
Fiscal Year
2006
Total Cost
$290,021
Indirect Cost
Name
University of Maryland Baltimore
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Koh, Shay-Whey M; Coll, Timothy; Gloria, Dante et al. (2017) Corneal Endothelial Cell Integrity in Precut Human Donor Corneas Enhanced by Autocrine Vasoactive Intestinal Peptide. Cornea 36:476-483
Koh, Shay-Whey Margaret (2012) Corneal endothelial autocrine trophic factor VIP in a mechanism-based strategy to enhance human donor cornea preservation for transplantation. Exp Eye Res 95:48-53
Koh, Shay-Whey M; Gloria, Dante; Molloy, Joseph (2011) Corneal endothelial autocrine VIP enhances its integrity in stored human donor corneoscleral explant. Invest Ophthalmol Vis Sci 52:5632-40
Koh, Shay-Whey M; Cheng, Jason; Dodson, Rebecca M et al. (2009) VIP down-regulates the inflammatory potential and promotes survival of dying (neural crest-derived) corneal endothelial cells ex vivo: necrosis to apoptosis switch and up-regulation of Bcl-2 and N-cadherin. J Neurochem 109:792-806
Koh, Shay-Whey M; Celeste, Jordan; Ku, C Y Paul (2009) Functional CNTF receptor alpha subunit restored by its recombinant in corneal endothelial cells in stored human donor corneas: connexin-43 upregulation. Invest Ophthalmol Vis Sci 50:1801-7
Koh, Shay-Whey M; Chandrasekara, Krish; Abbondandolo, Cara J et al. (2008) VIP and VIP gene silencing modulation of differentiation marker N-cadherin and cell shape of corneal endothelium in human corneas ex vivo. Invest Ophthalmol Vis Sci 49:3491-8
Koh, Shay-Whey M; Guo, Yan; Bernstein, Steve L et al. (2007) Vasoactive intestinal peptide induction by ciliary neurotrophic factor in donor human corneal endothelium in situ. Neurosci Lett 423:89-94
Koh, Shay-Whey; Rutzen, Allan; Coll, Timothy et al. (2005) VIP immunoreactivity in human aqueous humor. Curr Eye Res 30:189-94
Koh, Shay-Whey M; Coll, Timothy J; Rose, Linda et al. (2004) Antiglaucoma eye drop pulses--increased interleukin-6 secretion by Tenon's capsule fibroblast cultures. J Glaucoma 13:200-9
Koh, Shay-Whey M (2002) Ciliary neurotrophic factor released by corneal endothelium surviving oxidative stress ex vivo. Invest Ophthalmol Vis Sci 43:2887-96

Showing the most recent 10 out of 13 publications