Corneal opacity is a source of blindness for millions worldwide. Penetrating keratoplasty (PK) using cadaveric corneas is highly successful, but donated tissue is in limited supply and over time PK grafts are subject to a significant rate of complications and failure. Developing better therapy for corneal opacity is world health-care need that has inspired this project. In the 10 years of this project we have identified stem cells from human corneal stroma (CSSC) and showed that these cells (a) differentiate to keratocytes, (b) produce corneal stromal tissue in vitro, and (c) prevent formation of corneal scars in mouse models in vivo. The long-term goal of the project is develop stem cell-based therapeutic applications that can treat or reverse corneal scarring reducing the need for PK. In the renewal of the project we will work toward this goal with three specific aims. CSSC but no other stromal cells express N-cadherin (NCad).
Aim 1 will test the hypothesis that NCad identifies a population of cells with keratocyte differentiation potential and provides a cell surface marker useful for isolating cells with high potential to effect corneal regeneration. We have found that CSSC can secrete connective tissue with aligned collagen and proteoglycans similar to corneal stroma.
Aim 2 will test the role of microstructure topology and stiffness of solid substrates in directing the composition and organization of this CSSC-secreted matrix.
The aim will also test the role of collagen crosslinking enzymes LOXL2 and TGM2 in increasing the strength and stiffness of the matrix elaborated by CSSC.
This aim will assemble multilamellar constructs by stacking of the engineered tissue sheets. These experiments will provide insights on how the 3D environment directs secretion and organization of transparent stromal tissue. We have recently shown that CSSC instilled in healing corneal wounds prevent scarring and reconstitute ablated tissue with matrix indistinguishable from native cornea.
Aim 3 will investigate how CSSC induce this tissue regeneration. CSSC reduce infiltration of neutrophils and induce the presence of TGF3, a cytokine attributed to induce scarless wound healing.
This aim will test the hypothesis that via secretion of TSG-6 protein, CSSC reduce neutrophil infiltration and influence macrophages to adopt an alternative activated (M2) phenotype stimulating tissue regeneration by secretion of TGF3. The impact of these studies will be identification of novel molecular mechanisms controlling corneal stromal tissue matrix synthesis and organization. Of particular potential significance is identification of a mechanism to induce regeneration of native mammalian tissue. There will also be progress toward the goal of clinical use of CSSC. Thicker, stronger, and more organized tissue constructs will be produced with increased potential for use in lamellar grafts. Identification of properties linked to immunosuppressive and regenerative potential for CSSC will improve potential for use of these cells in cell-based therapy.

Public Health Relevance

Millions of individuals around the world are blind due to corneal scarring, but have little hope of treatment due to the lack of transplant tissue. We have found that stem cells isolated from corneas can generate new corneal tissue for transplant and also can be used directly to reduce corneal scarring. This project will identify features of these stem cells responsible for their regenerative properties in order to develop consistent preparations of predictable potency in use as a cell-based treatment for corneal opacity, a simple procedure, which could reduce the need for donated corneas and improve treatment potential for many sufferers of corneal blindness.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
2R01EY016415-10A1
Application #
9025968
Study Section
Biology of the Visual System Study Section (BVS)
Program Officer
Mckie, George Ann
Project Start
2005-04-01
Project End
2019-01-31
Budget Start
2016-02-01
Budget End
2017-01-31
Support Year
10
Fiscal Year
2016
Total Cost
Indirect Cost
Name
University of Pittsburgh
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Hertsenberg, Andrew J; Shojaati, Golnar; Funderburgh, Martha L et al. (2017) Corneal stromal stem cells reduce corneal scarring by mediating neutrophil infiltration after wounding. PLoS One 12:e0171712
Wang, Siran; Ghezzi, Chiara E; Gomes, Rachel et al. (2017) In vitro 3D corneal tissue model with epithelium, stroma, and innervation. Biomaterials 112:1-9
Ghezzi, Chiara E; Marelli, Benedetto; Omenetto, Fiorenzo G et al. (2017) 3D Functional Corneal Stromal Tissue Equivalent Based on Corneal Stromal Stem Cells and Multi-Layered Silk Film Architecture. PLoS One 12:e0169504
Gosselin, Emily A; Torregrosa, Tess; Ghezzi, Chiara E et al. (2017) Multi-layered silk film coculture system for human corneal epithelial and stromal stem cells. J Tissue Eng Regen Med :
Romanowski, Eric G; Stella, Nicholas A; Brothers, Kimberly M et al. (2016) Predatory bacteria are nontoxic to the rabbit ocular surface. Sci Rep 6:30987
Funderburgh, James L; Funderburgh, Martha L; Du, Yiqin (2016) Stem Cells in the Limbal Stroma. Ocul Surf 14:113-20
Syed-Picard, Fatima N; Du, Yiqin; Hertsenberg, Andrew J et al. (2016) Scaffold-free tissue engineering of functional corneal stromal tissue. J Tissue Eng Regen Med :
Hertsenberg, Andrew J; Funderburgh, James L (2016) Generation of Corneal Keratocytes from Human Embryonic Stem Cells. Methods Mol Biol 1341:285-94
Palchesko, Rachelle N; Funderburgh, James L; Feinberg, Adam W (2016) Engineered Basement Membranes for Regenerating the Corneal Endothelium. Adv Healthc Mater 5:2942-2950
Morgan, Siân R; Dooley, Erin P; Kamma-Lorger, Christina et al. (2016) Early wound healing of laser in situ keratomileusis-like flaps after treatment with human corneal stromal stem cells. J Cataract Refract Surg 42:302-9

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