Purpose: The 27-kDa heat shock protein (HSP27) has been implicated in wound healing in multiple tissues. We investigated the expression and localization of phosphorylated HSP27 during epithelial wound healing in the murine cornea.
Methods: Corneas of 8- to 10-week-old C57BL6 mice were wounded by epithelial debridement (n = 40). Unwounded corneas served as controls (n = 3). After 3, 7, and 14 days, phosphorylated HSP27 localization in wounded corneas was observed by confocal immunohistochemistry and double immunogold labeling transmission immunoelectron microscopy. Western blot analysis was performed to determine expression levels of phosphorylated HSP27 in scraped epithelia. Phosphorylated HSP27 localization was also separately performed with confocal immunohistochemistry 8 hours after epithelial debridement to investigate the early epithelial wound-healing process.
Results: In unwounded corneas, phosphorylated HSP27 was localized only to the superficial epithelium. In contrast, phosphorylated HSP27 was localized in the basal and superficial epithelia 3 days after corneal epithelial wounding. After 7 and 14 days, HSP27 localization was similar to that in unwounded controls. Expression levels of phosphorylated HSP27 were greater in wounded corneal epithelia on day 3 than in unwounded controls and on day 14. After 8 hours, phosphorylated HSP27 expression was prominent in the leading edge of migrating corneal epithelium.
Conclusions: Constitutive expression of phosphorylated HSP27 is limited to the superficial corneal epithelium in unwounded murine corneas. Changes in HSP27 epithelial distribution and expression levels after corneal epithelial wounding suggest that phosphorylated HSP27 plays a role in early phase of corneal epithelial wound healing.
*Department of Ophthalmology and Visual Sciences, Illinois Eye Ear Infirmary, University of Illinois at Chicago, Chicago, IL
†Department of Ophthalmology
‡Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
Reprints: Jae Yong Kim, Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, 388-1 Pungnab-2dong, Songpa-gu, Seoul 138-736, Republic of Korea (e-mail: email@example.com).
Supported by Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (NRF-2008-331-E00209); a grant (2010-464) from the Asan Institute for Life Sciences, Seoul, Korea; and National Eye Institute grant K08EY018874 (S.J.).
The authors state that they have no proprietary interest in the products named in this article.
Received July 12, 2011
Accepted October 14, 2011