title: Differential Effects of Dexamethasone and Doxycycline on Inflammation and MMP Production in Murine Alkali-Burned Corneas Associated with Dry Eye.
abstract: Alkali burns to the cornea are among the most devastating injuries to the eye. The purpose of this study was to evaluate the effects of dexamethasone (Dex) or doxycycline (Doxy) on protease activity and corneal complications in a combined model (CM) of alkali burn and dry eye. C57BL/6 mice were subjected to the CM for 2 or 5 days (D). Mice were topically treated either with Dex (0.1%), Dox (0.025%) or vehicle QID and observed daily for appearance of corneal perforation. Quantitative real time PCR was performed to measure expression of inflammation cytokines and matrix metalloproteinases (MMPs) in whole cornea lysates. No perforations were observed in the Dex-treated corneas. All wounds in Doxy-treated corneas were closed 2D post-injury, and they had significantly lower corneal opacity scores at days 4 and 5 post-injury compared to BSS treatment. Dex-treated corneas had the lowest corneal opacity scores. Dex treatment significantly decreased expression of IL-1β, IL-6, MMPs -1, -9, -13, and TIMP-1 after 2 days but increased levels of MMP-8, while Doxy treatment significantly decreased IL-1β, IL-6, MMP-8, and -9, compared to vehicle. Decreased MMP-1, -9 and -13 immunoreactivity and gelatinolytic activity were seen in corneas treated with Doxy and Dex compared to vehicle. Increased neutrophil infiltration and myeloperoxidase activity was noted in the vehicle group compared to Dex 2 days post-injury. These findings demonstrate that early initiation of anti-inflammatory therapy is very efficacious in preserving corneal clarity and facilitating wound healing, while modulating MMP production and suppressing neutrophil infiltration.
authors.affiliation: Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Fang
authors.initials: F
authors.lastname: Bian
authors.affiliation: Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Flavia S A
authors.initials: FS
authors.lastname: Pelegrino
authors.affiliation: Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Johanna Tukler
authors.initials: JT
authors.lastname: Henriksson
authors.affiliation: Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Pflugfelder
authors.affiliation: Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Eugene A
authors.initials: EA
authors.lastname: Volpe
authors.affiliation: Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: De-Quan
authors.initials: DQ
authors.lastname: Li
authors.affiliation: Ocular Surface Center, Department of Ophthalmology, Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, USA. Electronic address: cintiadp@bcm.edu.
authors.forename: Cintia S
authors.initials: CS
authors.lastname: de Paiva
mesh_terms: D000468:Alkalies; D000818:Animals; D002057:Burns, Chemical; D003315:Cornea; D003907:Dexamethasone; D004195:Disease Models, Animal; D004318:Doxycycline; D015352:Dry Eye Syndromes; D005126:Eye Burns; D007249:Inflammation; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D000468:Alkalies; D003907:Dexamethasone; D004318:Doxycycline
keywords: MMPs; alkali injury; corticoid; dexamethasone; doxycycline; dry eye; neutrophils; ocular perforation