Impairment of thrombospondin-1 expression during epithelial wound healing in corneas of vitamin A-deficient mice
K. Uno1, M. Kuroki2, H. Hayashi1, H. Uchida1, M. Kuroki2 and K. Oshima1
Departments of 1Ophthalmology and 2Biochemistry, Fukuoka University School of Medicine, Fukuoka, Japan
Offprint requests to: Koichi Uno, MD, Ph. D, Department of Ophthalmology, Fukuoka University School of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan. e-mail: uno6@mac.com
Summary. The purpose of this study is to investigate the expression of thrombospondin-1 (TSP-1), a multifunctional extracellular matrix protein, during re-epithelialization in wounded corneas of vitamin A-deficient mice. Epithelial defects were created in the corneas of normal and Vitamin A-deficient mice with a microgrinder. Wounded corneas were stained with fluorescein and photographed for evaluation of re-epithelialization. Histological examination and immunohistochemical analysis of TSP-1 expression were also performed on the specimens from wounded corneas. In vitamin A-deficient mice, re-epithelialization of the wounded corneal epithelium was significantly delayed compared with that in normal mice. TSP-1 was detectable neither in the unwounded corneal epithelium of normal mice nor in that of vitamin A-deficient mice. In normal mice, linear staining of TSP-1 was observed on the wounded corneal surface and stroma at 30 min and 8 h to 16 h, respectively, after abrasion, and this TSP-1 expression disappeared at 36 to 48 h, when re-epithelialization was completed. In contrast, no TSP-1 staining was observed in the wounded corneas of vitamin A-deficient mice, except for the endothelial cells, throughout the wound healing process. Histological examination revealed a progressive increase in polymorphonuclear neutrophil infiltration in the stroma of the corneas of vitamin A-deficient mice during the healing process. These findings suggest that vitamin A may modulate the expression of TSP-1 in the corneas to accelerate the re-epithelialization of wounded corneas. Histol Histopathol 20, 493-499 (2005).
Key words: Thrombospondin-1, Vitamin A deficiency, Cornea, Wound healing, Extracellular matrix
DOI: 10.14670/HH-20.493