The role of conjunctival epithelial cell xanthine oxidoreductase/xanthine oxidase in oxidative reactions on the ocular surface of dry eye patients with Sjögren’s syndrome
J. Cejková1, T. Ardan1, K. Jirsová2, G. Jechová2, J. Malec3, Z. Simonová1, C. Cejka1,3, M. Filipec2, D. Dotrelová3 and B. Brunová3
1Department of Eye Histochemistry and Pharmacology, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic, 2Laboratory of the Biology and Pathology of the Eye, Institute of Inherited Metabolic Disorders, General Teaching Hospital and Charles University, Prague, Czech Republic, and 3Department of Ophthalmology for Children and Adults, Motol Hospital, Charles University, 2nd Medical School, Prague, Czech Republic
Offprint requests to: Prof. Jitka Cejková, MD, Ph, D,D, DSc, Head, Department of Eye Histochemistry, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Videnska 1083, 14220, Prague 4, Czech Republic. e-mail: cejkova@biomed.cas.cz
Summary. Previous papers examined lipid peroxidase levels and myeloperoxidase activity as products of oxidative and inflammatory reactions in the tear fluid of patients suffering from dry eye. The aim of the present paper was to investigate whether the enzymes xanthine oxidoreductase/xanthine oxidase known to generate reactive oxygen species contribute to oxidative reactions on the ocular surface. Xanthine oxidoreductase/xanthine oxidase were examined immunohistochemically as well as histochemically in conjunctival epithelial cells of patients suffering from dry eye. Patients with verified autoimmune dry eye (Sjögren’s syndrome) participated in our study; normal eyes served as controls. Conjunctival epithelial cells were obtained by the method of impression cytology using Millicell membranes. The results revealed a pronounced expression, as well as activity of xanthine oxidoreductase/xanthine oxidase in the conjunctival epithelium of dry eye. It is suggested that reactive oxygen species which are generated by this enzymatic system, contribute to oxidative reactions on the eye surface of patients with ocular manifestations of autoimmune disease (Sjögren’s syndrome). Histol Histopathol 22, 997-1003 (2007)
Key words: Dry eye, Impression cytology, Oxidative reactions
DOI: 10.14670/HH-22.997