Inhibition of pseudomonal ulceration in rabbit corneas by a synthetic matrix metalloproteinase inhibitor.
OBJECTIVE
To evaluate the effect of the synthetic matrix metalloproteinase inhibitor, Galardin, on proteases produced by Pseudomonas aeruginosa (PA) and on a rabbit model of Pseudomonas keratitis.


METHODS
Protease activities of culture broths from Pseudomonas strains PA-28 and W-186 were characterized in vitro by gelatin zymography and by digestion of Azocasein in the presence and absence of Galardin and the serine protease inhibitor, aprotinin. In a noninfectious in vivo experiment, sterile PA culture broth from W-186 was injected intrastromally into rabbit corneas that were treated topically with Galardin or vehicle, then evaluated clinically and histologically. In an infectious in vivo experiment, rabbit corneas were injected with washed PA-28, then treated topically with Galardin or vehicle and clinically scored.


RESULTS
Gelatin zymography of culture broth from W-186 and PA-28 detected two proteases that were both inhibited by Galardin. Galardin reduced the digestion of Azocasein by both PA culture broths by 99%, whereas aprotinin did not significantly reduce the protease activity of PA-28 conditioned broth. Intrastromal injection of sterile W-186 culture broth caused rapid corneal destruction that was prevented by topical treatment with Galardin. Intrastromal injection of washed PA-28 bacteria resulted in progressive corneal melting that was significantly (P < 0.005) delayed, but ultimately not prevented, by topical treatment with Galardin.


CONCLUSIONS
Pseudomonal protease activity in culture broth consisted predominantly of metalloproteinases and were effectively inhibited by Galardin in vitro. Topical treatment with Galardin prevented destruction of rabbit corneas by bacterial products present in culture broth, and it delayed corneal destruction after injection of PA bacteria. Galardin may be a useful adjuvant when corneal destruction proceeds despite prompt antibiotic treatment.
Department of Ophthalmology, University of Florida School of Medicine, Gainesville, USA.
J P
JP
Barletta
G
G
Angella
K C
KC
Balch
H G
HG
Dimova
G A
GA
Stern
M T
MT
Moser
G B
GB
van Setten
G S
GS
Schultz
D000287:Administration, Topical; D000818:Animals; D003315:Cornea / Q000187:drug effects / Q000382:microbiology / Q000473:pathology; D003320:Corneal Ulcer / Q000473:pathology / Q000517:prevention & control*; D003470:Culture Media; D004151:Dipeptides / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D015818:Eye Infections, Bacterial / Q000473:pathology / Q000517:prevention & control*; D005260:Female; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009883:Ophthalmic Solutions; D011480:Protease Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D011552:Pseudomonas Infections / Q000473:pathology / Q000517:prevention & control*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology; D011817:Rabbits
D003470:Culture Media; D004151:Dipeptides; C078131:N-(2(R)-2-(hydroxamidocarbonylmethyl)-4-methylpentanoyl)-L-tryptophan methylamide; D009883:Ophthalmic Solutions; D011480:Protease Inhibitors; D008666:Metalloendopeptidases