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Abstract #45714 Published in IGR 13-2
Elasticity-dependent modulation of TGF-(beta) responses in human trabecular meshwork cells
Han H; Wecker T; Grehn F; Schlunck GInvestigative Ophthalmology and Visual Science 2011; 52: 2889-2896
PURPOSE. To gain further insight into a possible role of biomechanical cues in glaucoma, the authors assessed the influence of extracellular matrix (ECM) elasticity on TGF-(beta)2-induced changes in trabecular meshwork (TM) cells. METHODS. Human TM cells derived from donor cornea rings were plated on rigid collagen-coated tissue culture plastic or polyacrylamide gels of different elasticity and treated with vehicle or TGF-(beta)2. Activation of Smad-2/3, ERK, and AKT signaling and expression of (alpha)-SMA and PAI-1 proteins were assessed by Western blot analysis. Subcellular localization of (alpha)-SMA was determined by confocal immunofluorescence microscopy. Transcription of collagen-I, -IV, and -VI, (alpha)-SMA, PAI-1, fibronectin, fibrillin-1, cochlin, and MGP-1 was studied by RT-qPCR. The contribution of non-Smad signaling pathways to TGF-(beta)-induced (alpha)-SMA and PAI-1 expression was assessed using the small molecule inhibitors U0126 and LY294002. RESULTS. TGF-(beta)2-induced activation of Smad-2/3, ERK, and AKT signaling as well as expression of collagen-1,(alpha)-SMA, fibulin, and MGP-1 were attenuated with increasing elasticity. In contrast, TGF-(beta)2-induced collagen-6, fibronectin, PAI-1, and cochlin expression were enhanced on elastic substrates. The MEK-inhibitor U0126 blocked TGF-_-induced PAI-1 expression, whereas (alpha)-SMA expression was enhanced. PI3K inhibition with LY294002 reduced (alpha)-SMA expression. CONCLUSIONS. ECM elasticity modulates TGF-(beta)-induced signaling and protein expression in human TM cells. Non-Smad signaling contributes to TGF-(beta)-induced alterations. Increasing ECM elasticity in vitro promotes protein expression patterns reminiscent of patterns reported in primary open-angle glaucoma. Therefore, changes in TM elasticity and mechanical load may have a significant role in primary open-angle glaucoma.
G. Schlunck. Department of Ophthalmology, Wurzburg University Hospital, Josef-Schneider-Strasse 11, 97080 Wurzburg, Germany. Email: schlunck_g@klinik.uni-wuerzburg.de
Classification:
2.5.1 Trabecular meshwork (Part of: 2 Anatomical structures in glaucoma > 2.5 Meshwork)
3.6 Cellular biology (Part of: 3 Laboratory methods)
