title: The regulation of connective tissue growth factor expression influences the viability of human trabecular meshwork cells.
abstract: Connective tissue growth factor (CTGF) induces extracellular matrix (ECM) synthesis and contractility in human trabecular meshwork (HTM) cells. Both processes are involved in the pathogenesis of primary open-angle glaucoma. To date, little is known about regulation and function of CTGF expression in the trabecular meshwork (TM). Therefore, we analysed the effects of different aqueous humour proteins and stressors on CTGF expression in HTM cells. HTM cells from three different donors were treated with endothelin-1, insulin-like growth factor (IGF)-1, angiotensin-II, H2 O2 and heat shock and were analysed by immunohistochemistry, real-time RT-PCR and Western blotting. Viability after H2 O2 treatment was measured in CTGF silenced HTM-N cells and their controls. Latrunculin A reduced expression of CTGF by about 50% compared to untreated HTM cells, whereas endothelin-1, IGF-1, angiotensin-II, heat shock and oxidative stress led to a significant increase. Silencing of CTGF resulted in a delayed expression of αB-crystallin and in reduced cell viability in comparison to the controls after oxidative stress. Conversely, CTGF treatment led to a higher cell viability rate after H2 O2 treatment. CTGF expression is induced by factors that have been linked to glaucoma. An increased level of CTGF appears to protect TM cells against damage induced by stress. The beneficial effect of CTGF for viability of TM cells is likely associated with the effects on increased ECM synthesis and higher contractility of the TM, thereby contributing to reduced aqueous humour outflow facility causing increased intraocular pressure.
authors.affiliation: Institute of Human Anatomy and Embryology, University of Regensburg, Regensburg, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Kuespert
authors.forename: Benjamin
authors.initials: B
authors.lastname: Junglas
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Braunger
authors.forename: Ernst R
authors.initials: ER
authors.lastname: Tamm
authors.forename: Rudolf
authors.initials: R
authors.lastname: Fuchshofer
mesh_terms: D000328:Adult; D000368:Aged; D000804:Angiotensin II / Q000494:pharmacology; D015153:Blotting, Western; D002470:Cell Survival / Q000235:genetics; D002478:Cells, Cultured; D055513:Connective Tissue Growth Factor / Q000235:genetics* / Q000378:metabolism; D003459:Crystallins / Q000235:genetics / Q000378:metabolism; D019332:Endothelin-1 / Q000494:pharmacology; D005109:Extracellular Matrix / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics*; D006358:Hot Temperature; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D016877:Oxidants / Q000494:pharmacology; D034622:RNA Interference; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014129:Trabecular Meshwork / Q000166:cytology / Q000378:metabolism*
chemical_list: C526317:CCN2 protein, human; D003459:Crystallins; D019332:Endothelin-1; D008869:Microtubule-Associated Proteins; D016877:Oxidants; C530883:cryaB protein, rat; D000804:Angiotensin II; D055513:Connective Tissue Growth Factor; D007334:Insulin-Like Growth Factor I; D006861:Hydrogen Peroxide
keywords: CTGF; IGF-1; angiotensin-II; cell viability; endothelin-1; glaucoma; heat shock; oxidative stress; trabecular meshwork; αB-crystallin