Abstract | PURPOSE: The purpose of this study was to correlate the temporal expression of alpha-smooth muscle specific actin (alpha-SM actin), a molecular marker for myofibroblast transformation, with corneal wound contraction. METHODS: After full-thickness, central corneal injury in rabbit eyes, the anterior width of the wound ( wound gape) was measured in the same animals using in vivo confocal microscopy. In addition, animals were sacrificed at various times after injury for the determination of alpha-SM actin expression by immunofluorescent microscopy using a mouse monoclonal antibody specific for human alpha-actin. Antibody specificity was confirmed by Western blot analysis of normal and wound fibroblasts. Expression of alpha-SM actin also was related spatially to f-actin and the wound margin by co-localization with phalloidin and DTAF (5([4,6-dichlorotriazin-2yl]amino) fluorescein), a fluorescent marker bound to the wound margin. RESULTS:
Wound contraction was most evident from days 7 to 42, when wound gape progressively decreased from 574 +/- 120 microns to 250 +/- 61 microns. Thereafter, the wound remained stable to day 84 (304 +/- 58 microns). Expression of alpha-SM actin directly correlated with wound contraction--appearing across the wound at day 7, the full thickness of the wound at day 14, and the posterior wound at day 28. alpha-SM actin was localized exclusively to phalloidin-stained, f-actin microfilament bundles or stress fibers within wound healing fibroblasts, and the disappearance of alpha-SM actin correlated with the concomitant disappearance of stress fibers at days 28 to 42. Staining of the wound margin with DTAF confirmed that the expression of alpha-SM actin was limited to fibroblasts within the wound. CONCLUSIONS: The expression of alpha-SM actin was directly correlated to corneal wound contraction, appearing at the initiation of and disappearing at the completion of the contraction process. Furthermore, the exclusive expression of alpha-SM actin by fibroblasts present only within the wound suggests that local environmental factors unique to the wound may play an important role in myofibroblast transformation.
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Authors | J V Jester, W M Petroll, P A Barry, H D Cavanagh |
Journal | Investigative ophthalmology & visual science
(Invest Ophthalmol Vis Sci)
Vol. 36
Issue 5
Pg. 809-19
(Apr 1995)
ISSN: 0146-0404 [Print] United States |
PMID | 7706029
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Actins
- Antibodies, Monoclonal
- Fluoresceins
- Phalloidine
- 5-((4,6-dichloro-1,3,5-triazin-2-yl)amino)fluorescein
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Topics |
- Actins
(biosynthesis)
- Animals
- Antibodies, Monoclonal
- Corneal Injuries
- Corneal Stroma
(metabolism, pathology)
- Electrophoresis, Polyacrylamide Gel
- Eye Injuries
(metabolism, pathology)
- Fibroblasts
(metabolism, ultrastructure)
- Fluoresceins
- Fluorescent Antibody Technique
- Microscopy, Confocal
- Muscle, Smooth
(metabolism)
- Phalloidine
- Rabbits
- Wound Healing
(physiology)
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