Increased soluble interleukin-6 receptor in vitreous fluid of proliferative vitreoretinopathy.
OBJECTIVE
To clarify the effect of the interaction between interleukin-6 (IL-6) and its soluble receptor (sIL-6R) on retinal pigment epithelial (RPE) cell proliferation in proliferative vitreoretinopathy (PVR).


METHODS
Concentrations of IL-6 and sIL-6R molecules in vitreous fluids were measured in eyes with PVR and idiopathic macular hole (MH), and the localization of IL-6 and IL-6R on the PVR fibrous membrane was studied. Production of IL-6 and sIL-6R by cultured RPE cells and the effect of the IL-6/sIL-6R complex on growth of cultured RPE cells were analyzed.


RESULTS
Positive staining of IL-6 and IL-6R was observed in proliferating membranes in all PVR cases. IL-6 and sIL-6R concentrations in vitreous fluid from eyes with PVR were significantly higher than in eyes with MH (p < 0.05). A time-dependent increase in IL-6 molecules was identified in the culture medium of RPE cells, although sIL-6R was not detected. Dose-dependent growth of RPE cells was observed in the three concentrations (50, 100, and 500 ng/ml) of sIL-6R used.


CONCLUSIONS
IL-6 derived from blood during the breakdown of the blood-retinal barrier (BRB) and produced by RPE cells and hematogenous sIL-6R cause RPE proliferation.
Yamamoto
Hideo
H
Department of Ophthalmology, Fukuoka University School of Medicine, Fukuoka, Nanakuma, Jyonan-ku, Japan. kenjio@fukuoka-u.ac.jp
Hayashi
Hideyuki
H
Uchida
Hiroko
H
Kato
Hitoshi
H
Oshima
Kenji
K
D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D003470:Culture Media / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D015850:Interleukin-6 / Q000378:metabolism; D009994:Osmolar Concentration; D010857:Pigment Epithelium of Eye / Q000378:metabolism / Q000473:pathology; D019947:Receptors, Interleukin-6 / Q000378:metabolism*; D012167:Retinal Perforations / Q000378:metabolism; D012995:Solubility; D013194:Staining and Labeling; D013997:Time Factors; D018630:Vitreoretinopathy, Proliferative / Q000378:metabolism* / Q000473:pathology; D014822:Vitreous Body / Q000378:metabolism*
D003470:Culture Media; D015850:Interleukin-6; D019947:Receptors, Interleukin-6