Induction of IL-6 expression by mechanical stress in the trabecular meshwork.
The trabecular meshwork (TM)/Schlemm's canal (SC) outflow pathway is the tissue responsible for maintaining normal levels of intraocular pressure. In the present study, we investigate the effects of mechanical stress on the expression of IL-6 in the TM meshwork, as well as the effects of this cytokine on outflow pathway function. Application of cyclic mechanical stress to human TM primary cultures resulted in a statistically significant increase in both secretion and transcription of IL-6, compared to nonstressed controls. Addition of TGF-beta1, which has been reported to be upregulated in TM cells under mechanical stress, also induced a significant activation of both the transcription and secretion of IL-6. Moreover, anti-TGF-b1 antibodies partially blocked the stretch-induced IL-6 production. Injection of IL-6 into perfused porcine anterior segments resulted in a 30% increase in outflow facility, as well as increased permeability through SC cell monolayers. These results suggest a role for IL-6 in the homeostatic modulation of aqueous humor outflow resistance.
Liton
Paloma B
PB
Department of Ophthalmology, Duke University, Erwin Road, Box 3802, Durham, NC 27710, USA.
Luna
Coralia
C
Bodman
Marc
M
Hong
Anna
A
Epstein
David L
DL
Gonzalez
Pedro
P
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D013314:Stress, Mechanical; D013552:Swine; D014129:Trabecular Meshwork / Q000187:drug effects / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053773:Transforming Growth Factor beta1
D015850:Interleukin-6; C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1