|
|
||||||||
From the University of Houston, College of Optometry, Houston, Texas.
PURPOSE. The goals of this study were to examine the expression of the antimicrobial peptide LL-37 in the corneal epithelium during wound healing and to investigate whether LL-37 stimulates human corneal epithelial cell (HCEC) migration, proliferation, and cytokine production.
METHODS. Expression of LL-37 was determined by RT-PCR and immunostaining in tissue sections and HCECs scraped from corneas before (original) and after (regrown) re-epithelialization. The antimicrobial activity of LL-37 against Pseudomonas aeruginosa (PA) was determined in the presence of NaCl and tears. Blind-well chamber assays were performed to study the effect of LL-37 on migration. Proliferation was determined using calcein-AM, and cytotoxicity was evaluated by MTT assay. ELISA was performed to assess the ability of LL-37 to stimulate HCEC cytokine secretion.
RESULTS. LL-37 peptide was present throughout the corneal epithelium (n = 4). All original corneal epithelial samples expressed a low level of LL-37 (n = 10). Regrown epithelial samples collected 24 (n = 3 of 5) or 48 (n = 4 of 5) hours after wounding showed upregulated expression of LL-37. LL-37 killed PA in the presence of NaCl (EC50= 10.3 ± 2.5 µg/mL) and retained its activity in tears (n = 3). LL-37 induced HCEC migration (n = 5) and secretion of IL-8, IL-6, IL-1ß, and TNF-
(2- to 23-fold, n = 47). Inhibitor studies indicated that LL-37s effects are mediated through multiple pathways involving a G protein-coupled receptor (formyl peptide receptorlike 1 in migration) and the epidermal growth factor receptor (n = 2 to 5). LL-37 did not stimulate HCEC proliferation (n = 3) and high concentrations (>10 µg/mL) were cytotoxic (n = 3).
CONCLUSIONS. LL-37 expression is upregulated in regenerating human corneal epithelium, has antibacterial activity against ocular pathogens under physiologically relevant conditions, and stimulates HCEC migration and cytokine production. These findings suggest that LL-37 acts as a multifunctional mediator that helps protect the cornea from infection and modulates wound healing.
This article has been cited by other articles:
![]() |
A. Abedin, I. Mohammed, A. Hopkinson, and H. S. Dua A Novel Antimicrobial Peptide on the Ocular Surface Shows Decreased Expression in Inflammation and Infection Invest. Ophthalmol. Vis. Sci., January 1, 2008; 49(1): 28 - 33. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. C. Huang, R. L. Redfern, S. Narayanan, R. Y. Reins, and A. M. McDermott In Vitro Activity of Human {beta}-Defensin 2 against Pseudomonas aeruginosa in the Presence of Tear Fluid Antimicrob. Agents Chemother., November 1, 2007; 51(11): 3853 - 3860. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. C. Huang, R. Y. Reins, R. L. Gallo, and A. M. McDermott Cathelicidin-Deficient (Cnlp / ) Mice Show Increased Susceptibility to Pseudomonas aeruginosa Keratitis Invest. Ophthalmol. Vis. Sci., October 1, 2007; 48(10): 4498 - 4508. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Kumar, J. Yin, J. Zhang, and F.-S. X. Yu Modulation of Corneal Epithelial Innate Immune Response to Pseudomonas Infection by Flagellin Pretreatment Invest. Ophthalmol. Vis. Sci., October 1, 2007; 48(10): 4664 - 4670. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |