2003 Fiscal Year Final Research Report Summary
INVESTIGATION OF NEW MAMBRANE MUCIN PRODUCED BY THE OCULAR SURFACE EPITHELIUM
| Project/Area Number |
13671838
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Ophthalmology
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| Research Institution | Osaka University |
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Principal Investigator |
WATANABE Hiroshi Osaka University, Graduate School of Medicine, Associate Professor, 医学系研究科, 助教授 (60252673)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIDA Kohji Osaka University, Graduate School of Medicine, Assistant Professor, 医学系研究科, 助手 (40244610)
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| Project Period (FY) |
2001 – 2003
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| Keywords | mucin / cornea / conjunctiva |
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| Research Abstract |
MUC 1, 4 and 5AC have been reported to express in the cornea and the conjunctiva. There exists some trans - membrane mucins capable of maintaining tear film over the ocular surface epithelium. However, based on knock out studies in mice, there are other mucins than MUC 1, and MUC4 having the function. Recently, MUC16 has been reported and this MUC16 may have the function to maintain tear film over the ocular surface. By real-time PCR on reverse transcription products from RNA isolated from human corneal and conjunctival tissues, MUC16 mucin gene was determined. Further studies by in situ hybridization and immunohistochemistry disclosed MUC16 mRNA was localized to the apical cell layers of the cornea. MUC16 protein was obsertved in apical cells of the corneal stratified cells. Whether MUC1 and MUC16 mucins carry the H185 carbohydrate epitope was performed by one- or two-step immunoprecipitation assays and immunodepletion experiments followed by Western blot analysis. Immunofluorescence microscopy demonstrated exact colocalization of the MUC16 mucin and the H185 carbohydrate epitope in the cornea. Immunoprecipitated products recognized by the H185 antibody mucin was recognized by the antibody recognizing MUC16 and Immunoprecipitated MUC16 mucin was recognized by the H185 antibody. These studies showed that MUC16 mucin carries the H185 epitope. Immunodepletion with H185 antibody has no reactivity to the antibodies by MUC16. No cross-reactivity between immunoprecipitated MUC1 and the H185 antibody was disclosed. This study demonstrates that the membrane-associated mucin MUC16 is expressed by the corneal epithelium. Moreover, MUC16 carries the H185 carbohydrate epitope.
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