Lymphatic research represents an explosive field of new discovery in recent years. The cornea provides an ideal tissue for lymphatic studies due to its accessible location, transparent nature, and lymphatic-free and - inducible features. Additionally, corneal transplantation offers an excellent model for lymphatic research because it allows for (i) functional lymphatic cell trafficking studies;and (ii) the identification of cellulr contributions (donor or recipient source) to the process of lymphangiogenesis (LG). Studies on corneal LG bears direct implication to high-risk (HR) transplantation where grafting is performed on lymphatic-rich host beds and the rejection rate can be as high as 90%. Many patients who are blind from corneal diseases fall into this category after inflammatory, infectious, traumatic, r chemical insults. To date, there is no effective management for this situation. Our long-term goal is to elucidate the molecular and cellular mechanisms of LG using both in vitro cell culture and in vivo corneal models, a necessary prerequisite to the development of new therapeutic protocols. Our hypothesis is that corneal LG can be manipulated through specific lymphatic factors or cell populations. Molecular blockade of the lymphatic factors promotes HR graft survival. This proposal is based on the most recent advances in technology and lymphatic research, and a large amount of preliminary data we have generated during the past few years.
The specific aims are: 1) define the role of integrin alpha 9 (Itga-9) in corneal lymphatic valve formation and function using neutralizing antibodies and knockout mice;2) determine the role of Angiopoietin-2 (Ang-2) in lymphatic endothelial cell functions in vitro, and LG and transplant rejection in vivo using small interference RNAs, neutralizing antibodies, and knockout mice;and 3) investigate the cell origins of lymphatic vessels using cell type-specific gene-manipulated mice and live imaging techniques. Research on corneal LG will have broader clinical implications beyond the treatment of ocular diseases alone since lymphatic dysfunction is associated with a diverse array of diseases and conditions, which include but are not limited to cancer metastasis, inflammation, infections, diabetes, obesity, hypertension and lymphedema.

Public Health Relevance

Lymphatic vessel formation accompanies many corneal diseases after an inflammatory, infectious, traumatic, or chemical insult. It is also a primary mediator of transplant rejection, which can be as high as 90%, irrespective of current treatment modalities. This project will provide novel insights into the mechanisms of lymphatic growth and offer new therapeutic strategies for corneal transplant rejection, and potentially other lymphatic disorders in the body ranging from cancer metastasis to diabetes and lymphedema.

Agency
National Institute of Health (NIH)
Type
Research Project (R01)
Project #
5R01EY017392-07
Application #
8713996
Study Section
Anterior Eye Disease Study Section (AED)
Program Officer
Mckie, George Ann
Project Start
Project End
Budget Start
Budget End
Support Year
7
Fiscal Year
2014
Total Cost
Indirect Cost
Name
University of California Berkeley
Department
Ophthalmology
Type
Schools of Optometry/Opht Tech
DUNS #
City
Berkeley
State
CA
Country
United States
Zip Code
94704
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Truong, Tan; Huang, Eric; Yuen, Don et al. (2014) Corneal lymphatic valve formation in relation to lymphangiogenesis. Invest Ophthalmol Vis Sci 55:1876-83
Truong, Tan N; Li, Hannah; Hong, Young-Kwon et al. (2014) Novel characterization and live imaging of Schlemm's canal expressing Prox-1. PLoS One 9:e98245
Iolyeva, Maria; Aebischer, David; Proulx, Steven T et al. (2013) Interleukin-7 is produced by afferent lymphatic vessels and supports lymphatic drainage. Blood 122:2271-81
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Cueni, Leah N; Chen, Lu; Zhang, Hui et al. (2010) Podoplanin-Fc reduces lymphatic vessel formation in vitro and in vivo and causes disseminated intravascular coagulation when transgenically expressed in the skin. Blood 116:4376-84