Please use this identifier to cite or link to this item: http://dlib.scu.ac.ir/handle/2123/20951
Title: The effects of ultraviolet radiation on the repair and maintenance of the cornea
subject: cornea;UVR;keratoconus;LESC;cell biology
Publisher: University of Sydney
Faculty of Medicine and Health
Department of Dermatology
Description: Epidemiological studies have implicated UVR as a causative agent in a variety of ocular diseases. Keratoconus is the bulging of the cornea due to it becoming thinner, leading to poor vision. Although UVR has recently been identified as a likely contributing factor, the pathogenic mechanisms remain to be elucidated. This thesis aims to provide a model of keratoconus and subsequently study the components of corneal maintenance in response to UVR. The corneas of mice were chronically exposed to physiologically relevant doses of UVR, and studied in vivo using a slit lamp and ex vivo histopathologically to identify features of keratoconus. Acute cellular and molecular effects of UVR on the corneal epithelium was studied using genetically modified reported strains of mice to trace corneal epithelial cell linages and to measure their unique spoke-like pattern of growth as well as epithelial cell stratification. UVR-induced changes in the epithelium were studied using assays for proliferation, DNA damage and cell death. Keratoconus-like symptoms were induced after 20 weeks of chronic UVR including thinning of the stroma, loss of keratocytes, loss of epithelial cell layers, fragmentation of the basement membrane and stromal collagen disorganisation.Acute effects of low dose UVR included an increase in epithelial clonal growth rate and proliferation. UVR-induced photolesions were repaired quickly whereas apoptosis was not significantly increased, indicating that proliferation was not a response to cell death. Multiphoton imaging showed that delamination of epithelial cells was significantly increased after acute UVR exposure and was sustained for 3 days after irradiation. As a result of cell shedding and delamination, proliferation and centripetal migration are increased in the limbal stem cells and corneal epithelial cells. Potentially, corneal conditions from chronic UVR arise as a consequence of the compounding of these biological effects of acute UVR exposures.
Access is restricted to staff and students of the University of Sydney . UniKey credentials are required. Non university access may be obtained by visiting the University of Sydney Library.
URI: https://ses.library.usyd.edu.au/handle/2123/20951
More Information: http://hdl.handle.net/2123/20951
Appears in Collections:Postgraduate Theses

Files in This Item:
Click on the URI links for accessing contents.
Title: The effects of ultraviolet radiation on the repair and maintenance of the cornea
subject: cornea;UVR;keratoconus;LESC;cell biology
Publisher: University of Sydney
Faculty of Medicine and Health
Department of Dermatology
Description: Epidemiological studies have implicated UVR as a causative agent in a variety of ocular diseases. Keratoconus is the bulging of the cornea due to it becoming thinner, leading to poor vision. Although UVR has recently been identified as a likely contributing factor, the pathogenic mechanisms remain to be elucidated. This thesis aims to provide a model of keratoconus and subsequently study the components of corneal maintenance in response to UVR. The corneas of mice were chronically exposed to physiologically relevant doses of UVR, and studied in vivo using a slit lamp and ex vivo histopathologically to identify features of keratoconus. Acute cellular and molecular effects of UVR on the corneal epithelium was studied using genetically modified reported strains of mice to trace corneal epithelial cell linages and to measure their unique spoke-like pattern of growth as well as epithelial cell stratification. UVR-induced changes in the epithelium were studied using assays for proliferation, DNA damage and cell death. Keratoconus-like symptoms were induced after 20 weeks of chronic UVR including thinning of the stroma, loss of keratocytes, loss of epithelial cell layers, fragmentation of the basement membrane and stromal collagen disorganisation.Acute effects of low dose UVR included an increase in epithelial clonal growth rate and proliferation. UVR-induced photolesions were repaired quickly whereas apoptosis was not significantly increased, indicating that proliferation was not a response to cell death. Multiphoton imaging showed that delamination of epithelial cells was significantly increased after acute UVR exposure and was sustained for 3 days after irradiation. As a result of cell shedding and delamination, proliferation and centripetal migration are increased in the limbal stem cells and corneal epithelial cells. Potentially, corneal conditions from chronic UVR arise as a consequence of the compounding of these biological effects of acute UVR exposures.
Access is restricted to staff and students of the University of Sydney . UniKey credentials are required. Non university access may be obtained by visiting the University of Sydney Library.
URI: https://ses.library.usyd.edu.au/handle/2123/20951
More Information: http://hdl.handle.net/2123/20951
Appears in Collections:Postgraduate Theses

Files in This Item:
Click on the URI links for accessing contents.
Title: The effects of ultraviolet radiation on the repair and maintenance of the cornea
subject: cornea;UVR;keratoconus;LESC;cell biology
Publisher: University of Sydney
Faculty of Medicine and Health
Department of Dermatology
Description: Epidemiological studies have implicated UVR as a causative agent in a variety of ocular diseases. Keratoconus is the bulging of the cornea due to it becoming thinner, leading to poor vision. Although UVR has recently been identified as a likely contributing factor, the pathogenic mechanisms remain to be elucidated. This thesis aims to provide a model of keratoconus and subsequently study the components of corneal maintenance in response to UVR. The corneas of mice were chronically exposed to physiologically relevant doses of UVR, and studied in vivo using a slit lamp and ex vivo histopathologically to identify features of keratoconus. Acute cellular and molecular effects of UVR on the corneal epithelium was studied using genetically modified reported strains of mice to trace corneal epithelial cell linages and to measure their unique spoke-like pattern of growth as well as epithelial cell stratification. UVR-induced changes in the epithelium were studied using assays for proliferation, DNA damage and cell death. Keratoconus-like symptoms were induced after 20 weeks of chronic UVR including thinning of the stroma, loss of keratocytes, loss of epithelial cell layers, fragmentation of the basement membrane and stromal collagen disorganisation.Acute effects of low dose UVR included an increase in epithelial clonal growth rate and proliferation. UVR-induced photolesions were repaired quickly whereas apoptosis was not significantly increased, indicating that proliferation was not a response to cell death. Multiphoton imaging showed that delamination of epithelial cells was significantly increased after acute UVR exposure and was sustained for 3 days after irradiation. As a result of cell shedding and delamination, proliferation and centripetal migration are increased in the limbal stem cells and corneal epithelial cells. Potentially, corneal conditions from chronic UVR arise as a consequence of the compounding of these biological effects of acute UVR exposures.
Access is restricted to staff and students of the University of Sydney . UniKey credentials are required. Non university access may be obtained by visiting the University of Sydney Library.
URI: https://ses.library.usyd.edu.au/handle/2123/20951
More Information: http://hdl.handle.net/2123/20951
Appears in Collections:Postgraduate Theses

Files in This Item:
Click on the URI links for accessing contents.