Potential role of Rho-associated protein kinase inhibitor Y-27632 in glaucoma filtration surgery.
OBJECTIVE
To investigate the role of Y-27632, a specific inhibitor of Rho-associated protein kinase (ROCK) in regulating human Tenon fibroblast (HTF) activities including proliferation, adhesion, contraction, migratory response, and myofibroblast transdifferentiation. Effects of Y-27632 on prevention of postoperative scar formation were also examined in a rabbit model of glaucoma filtration surgery.


METHODS
After treatment of HTFs with Y-27632, cell toxicity, proliferation, migration, adhesion, and contraction were studied. The cytoskeleton and alpha-smooth muscle actin (alpha-SMA) expression were examined via immunohistochemistry. In vivo studies in Japanese white rabbits consisted of a full-thickness sclerostomy followed in the 7-day postoperative period by topical application of Y-27632. Intraocular pressure, morphologic changes in bleb features, and histology of surgical sites were evaluated.


RESULTS
Y-27632 had no direct toxicity or significant effects on cell proliferation of HTF. The cell adhesion assay showed that Y-27632 promoted adhesiveness to both fibronectin and collagen type I. Use of Y-27632 significantly inhibited collagen gel contraction and alpha-SMA expression in HTFs. Y-27632 also increased HTF motility. In vivo, Y-27632 inhibited wound healing and fibroproliferation after filtration surgery and significantly improved surgical outcome compared with the vehicle. Histologic examination revealed that blebs in the Y-27632-treated group differed from those in the vehicle-treated group in that they lacked significant collagen deposition in the sclerostomy area.


CONCLUSIONS
Y-27632 had profound effects on activities of HTFs and was effective in preventing fibroproliferation and scar formation in a rabbit model of glaucoma surgery. A ROCK inhibitor may be an effective anti-scarring agent after glaucoma filtering surgery.
Honjo
Megumi
M
Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Sakyo, Kyoto, Japan. m_honjo@kuhp.kyoto-u.ac.jp
Tanihara
Hidenobu
H
Kameda
Takanori
T
Kawaji
Takahiro
T
Yoshimura
Nagahisa
N
Araie
Makoto
M
D000199:Actins / Q000378:metabolism; D000577:Amides / Q000494:pharmacology* / Q000633:toxicity; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002921:Cicatrix / Q000517:prevention & control*; D024042:Collagen Type I / Q000378:metabolism; D003239:Connective Tissue Cells / Q000187:drug effects; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000633:toxicity; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005353:Fibronectins / Q000378:metabolism; D018463:Filtering Surgery; D005901:Glaucoma / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure; D011183:Postoperative Complications / Q000517:prevention & control; D011725:Pyridines / Q000494:pharmacology* / Q000633:toxicity; D011817:Rabbits; D012599:Sclerostomy; D014945:Wound Healing / Q000187:drug effects; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors*
D000199:Actins; D000577:Amides; D024042:Collagen Type I; D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D005353:Fibronectins; D011725:Pyridines; C108830:Y 27632; D054460:rho-Associated Kinases