Interleukin-6 in tear fluid after photorefractive keratectomy and its effects on keratocytes in culture.
OBJECTIVE
To investigate the participation of interleukin-6 (IL-6) after photorefractive keratectomy (PRK) and its possible roles and sources in corneal wound healing.


METHODS
IL-6, levels were measured in the tear fluids of patients before and after PRK and in conditioned media of human corneal epithelial cells and keratocytes. Its effects on total collagen and collagen-type synthesis by keratocytes were studied with a 3H-proline incorporation assay and Northern blot analysis. Zymography was used to evaluate the metalloproteinase content in the conditioned medium of IL-6-stimulated keratocytes.


RESULTS
IL-6 is present in the tear fluid samples after photorefractive keratectomy, possibly synthesized by epithelial cells and keratocytes.


CONCLUSIONS
IL-6 stimulates collagen synthesis in general and collagen type I in particular. Furthermore, it reduces the production of MMP-2, the latent form of the metalloproteinase, by cultured keratocytes. The results suggest that IL-6 might be regarded as a mediator involved in corneal healing after excimer laser.
Malecaze
F
F
Laboratoire d'Ophtalmologie, CJF INSERM 95-10, CHU Toulouse Rangueil, France.
Simorre
V
V
Chollet
P
P
Tack
J L
JL
Muraine
M
M
Le Guellec
D
D
Vita
N
N
Arne
J L
JL
Darbon
J M
JM
D000328:Adult; D015152:Blotting, Northern; D018929:Cell Culture Techniques; D003094:Collagen / Q000096:biosynthesis / Q000235:genetics; D003315:Cornea / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000601:surgery; D017077:Culture Media, Conditioned; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism / Q000601:surgery; D005260:Female; D018093:Gelatinases / Q000096:biosynthesis; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism* / Q000494:pharmacology; D054018:Lasers, Excimer; D008297:Male; D020778:Matrix Metalloproteinase 2; D008666:Metalloendopeptidases / Q000096:biosynthesis; D009216:Myopia / Q000601:surgery; D018903:Photorefractive Keratectomy; D012333:RNA, Messenger / Q000096:biosynthesis; D013666:Tears / Q000378:metabolism*
D017077:Culture Media, Conditioned; D015850:Interleukin-6; D012333:RNA, Messenger; D003094:Collagen; D018093:Gelatinases; D008666:Metalloendopeptidases; D020778:Matrix Metalloproteinase 2