Genomes and Genes
Control of Conjuctival Goblet Cell Mucin Production
Principal Investigator: Darlene Dartt
Abstract: Mucins synthesized and secreted by conjunctival goblet cells provide a critical line of defense for the ocular surface by protecting it from the external environment. A decrease in conjunctival goblet cell mucin production is devastating to the ocular surface and results in a spectrum of ocular surface diseases. Mucin production depends upon two processes, the percentage of goblet cells secreting mucins in response to a given stimulus (rapid response) and the total number of goblet cells present in the conjunctiva (long-term response). Thus the long-term goal of this project is to treat diseases of ocular surface mucin deficiency by stimulating goblet cell secretion and proliferation thus increasing mucin production and replenishing the mucous layer of the tear film. The focus of the present proposal is to determine: (1) if sensory nerves in the cornea stimulate epidermal growth factor (EGF) release from the conjunctiva, perhaps from the goblet cells, to stimulate goblet cell proliferation and (2) the signaling pathways used by EGF to stimulate this proliferation. Goblet cell proliferation will be stimulated in vivo by a corneal sensory nerve stimulus and proliferating goblet cells measured by immuno-fluorescence microscopy to determine if activation of the EGF receptor is used. Pieces of conjunctiva will be used to determine if activation of nerves releases EGF and cultured goblet cells used to determine if these cells release EGF. Passaged rat and human conjunctival goblet cells will be used to determined if EGF stimulates proliferation by activating 1) p44/p42 mitogen-activated protein kinase, (2) phosphatidylinositol-3 kinase, or (3) PKC isoforms, Proliferation will be measured by a biochemical and an immunohistochemical assay. Pharmacological inhibitors and neutralizing antibodies, as well as dominant negative and constitutively active adenovirus will be used to inhibit or stimulate specific signaling pathways. Individual signaling components will be measured by immunoprecipitation, western blotting, and immunofluorescence microscopy techniques. In diseases of mucin deficiency such as anesthetic cornea, herpetic keratitis, and neurotrophic keratitis, as well as in aging and LASIK surgery, activation of neural and growth factor regulation of goblet cell proliferation is impaired. Study of the signaling pathways that stimulate conjunctival goblet cell proliferation will lead to the development of treatments to replenish the mucin layer in these diseases.
Funding Period: 1991-05-01 - 2010-05-31
more information: NIH RePORT
- Biopsy harvesting site and distance from the explant affect conjunctival epithelial phenotype ex vivoI G Fostad
Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
Exp Eye Res 104:15-25. 2012..These cells could be important during conjunctival migration as they are mostly located close to the leading edge and their density does not decrease with increasing outgrowth size...
- Effect of biopsy location and size on proliferative capacity of ex vivo expanded conjunctival tissueJon R Eidet
Schepens Eye Research Institute, Harvard Medical School, Boston, MA 02114, USA
Invest Ophthalmol Vis Sci 53:2897-903. 2012..To evaluate the effect of location and size of biopsy on phenotype and proliferative capacity of cultured rat conjunctival epithelial cells...
- Role of neurotrophins and neurotrophin receptors in rat conjunctival goblet cell secretion and proliferationJ David Rios
Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
Invest Ophthalmol Vis Sci 48:1543-51. 2007....
- Effect of protein kinase C and Ca(2+) on p42/p44 MAPK, Pyk2, and Src activation in rat conjunctival goblet cellsRobin R Hodges
Department of Ophthalmology, Harvard Medical School, 20 Staniford Street, Boston, MA 02114, USA
Exp Eye Res 85:836-44. 2007..We conclude that PKC and intracellular Ca(2+) activate Pyk2 and Src and phosphorylate the EGF receptor leading to stimulation of MAPK in conjunctival goblet cells...
- Presence of EGF growth factor ligands and their effects on cultured rat conjunctival goblet cell proliferationJian Gu
Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
Exp Eye Res 86:322-34. 2008..EGF, TGF-alpha and HB-EGF all stimulated the activation of signaling intermediates and caused goblet cell proliferation...
- ERK/p44p42 mitogen-activated protein kinase mediates EGF-stimulated proliferation of conjunctival goblet cells in cultureMarie A Shatos
Department of Ophthalmology, Shepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114, USA
Invest Ophthalmol Vis Sci 49:3351-9. 2008..To determine whether activation of the ERK pathway by EGF leads to rat and human goblet cell proliferation...
- Role of cPKCalpha and nPKCepsilon in EGF-stimulated goblet cell proliferationMarie A Shatos
Schepens Eye Research Institute and Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114, USA
Invest Ophthalmol Vis Sci 50:614-20. 2009..The authors determined the role of the protein kinase C (PKC) isoforms cPKCalpha and nPKCepsilon in EGF-stimulated proliferation of cultured rat and human conjunctival goblet cells...
- Stimulatory role of PKCalpha in extracellular regulated kinase 1/2 pathway in conjunctival goblet cell proliferationMarie A Shatos
Schepens Eye Research Institute, Boston, Massachusetts 02114, USA
Invest Ophthalmol Vis Sci 50:1619-25. 2009..To determine whether a constitutively active protein kinase C (PKC)-alpha stimulates rat and human conjunctival goblet cell proliferation through activation of ERK 1/2...