Drying and cicatrizing ocular surface diseases can be debilitating and, in advanced disease states, cause blindness. Goblet cells, mucin-secreting cells that are intercalated within the stratified epithelium of the conjunctiva disappear in these diseases, as the epithelium becomes keratinized. Little is known regarding factors regulating goblet cell differentiation in the conjunctiva. With this application, we present evidence that mice null for SAM pointed domain Ets transcription factor, Spdef, lack conjunctival goblet cells. We further demonstrate by microarray comparison of fornicial conjunctiva of Spedf-null and wild type mice that, in addition to downregulation of goblet cell-specific genes, there is a significant downregulation of 4 genes in the Wnt signaling pathway. Of these, Sfrp3 (Frzb), an antagonist of canonical Wnt signaling, is downregulated 115 fold. Immunofluorescence microscopy indicates that the antagonist is expressed in the conjunctival goblet cell, raising the possibility that the goblet cell secretes the protein to effect epithelial homeostasis and/or goblet cell differentiation. Based on these findings, we propose the following specific aims to test hypotheses relevant to goblet cell function and differentiation at the ocular surface.
Aim 1. Determine the effect of lack of goblet cells on ocular surface health in the Spdef-null mice as indicated by comparison of tear volume, fluorescein staining, exposure to dry eye chamber conditions and susceptibility to infection to that of wild type mice.
Aim 2. Compare expression levels of genes down/upregulated in fornicial conjunctiva of Spdef-null mice (goblet cell mucin biosynthesis genes, Wnt signaling pathway genes and epithelial differentiation genes) to RNA from fornicial conjunctiva of mice with smoke induced goblet cell differentiation to verify genes in goblet cell differentiation/function as opposed to those involved in epithelial response to lack of goblet cells.
Aim 3. Examine the role of Wnt signaling in goblet cell/conjunctival cell differentiation by determining if the goblet cell is the source of the Wnt inhibitor Sfrp3 identified by microarray analysis as downregulated in Spdef null mice and by assaying the function of the soluble Wnt inhibitor in Sfrp3 (Frzb) null mice and in vitro.
Aim 4. Determine whether goblet cell differentiation can be induced by overexpression of SPDEF in conjunctival epithelial cell culture and whether downregulation of the Wnt pathway influences goblet cell differentiation in vitro.
Aim 5. Determine whether expression of Spdef, the Wnt pathway antagonist Sfrp3 identified as downregulated in the absence of Spdef, and the epithelial differentiation gene Sprr2h that is upregulated in Spdef-/- mice, are altered in human dry eye diseases where goblet cell numbers are reduced.

Public Health Relevance

Drying eye diseases often cause irritation and poor vision but in severe forms cause blindness. Research in this application seeks to learn the cellular and molecular changes that occur in the outer ocular surface cell layers that are associated with the diseases. With these insights future therapies may be developed.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
2R01EY003306-32A1
Application #
8235362
Study Section
Anterior Eye Disease Study Section (AED)
Program Officer
Mckie, George Ann
Project Start
1979-08-01
Project End
2015-11-30
Budget Start
2011-12-01
Budget End
2012-11-30
Support Year
32
Fiscal Year
2012
Total Cost
$485,000
Indirect Cost
$235,000
Name
Schepens Eye Research Institute
Department
Type
DUNS #
073826000
City
Boston
State
MA
Country
United States
Zip Code
02114
Marko, Christina Kaiser; Tisdale, Ann S; Spurr-Michaud, Sandra et al. (2014) The ocular surface phenotype of Muc5ac and Muc5b null mice. Invest Ophthalmol Vis Sci 55:291-300
Gipson, Ilene K; Spurr-Michaud, Sandra; Tisdale, Ann et al. (2014) Comparison of the transmembrane mucins MUC1 and MUC16 in epithelial barrier function. PLoS One 9:e100393
Arafat, Samer N; Suelves, Ana M; Spurr-Michaud, Sandra et al. (2014) Neutrophil collagenase, gelatinase, and myeloperoxidase in tears of patients with stevens-johnson syndrome and ocular cicatricial pemphigoid. Ophthalmology 121:79-87
Marko, Christina K; Menon, Balaraj B; Chen, Gang et al. (2013) Spdef null mice lack conjunctival goblet cells and provide a model of dry eye. Am J Pathol 183:35-48
Argueso, Pablo; Gipson, Ilene K (2012) Assessing mucin expression and function in human ocular surface epithelia in vivo and in vitro. Methods Mol Biol 842:313-25
Gipson, Ilene K; Spurr-Michaud, Sandra J; Senchyna, Michelle et al. (2011) Comparison of mucin levels at the ocular surface of postmenopausal women with and without a history of dry eye. Cornea 30:1346-52
Govindarajan, Bharathi; Gipson, Ilene K (2010) Membrane-tethered mucins have multiple functions on the ocular surface. Exp Eye Res 90:655-63
Albertsmeyer, Ann-Christin; Kakkassery, Vinodh; Spurr-Michaud, Sandra et al. (2010) Effect of pro-inflammatory mediators on membrane-associated mucins expressed by human ocular surface epithelial cells. Exp Eye Res 90:444-51
Saravanan, Chandrassegar; Liu, Fu-Tong; Gipson, Ilene K et al. (2009) Galectin-3 promotes lamellipodia formation in epithelial cells by interacting with complex N-glycans on alpha3beta1 integrin. J Cell Sci 122:3684-93
Sumiyoshi, Mika; Ricciuto, Jessica; Tisdale, Ann et al. (2008) Antiadhesive character of mucin O-glycans at the apical surface of corneal epithelial cells. Invest Ophthalmol Vis Sci 49:197-203

Showing the most recent 10 out of 47 publications