Cyclic strain alters the transcriptional and migratory response of scleral fibroblasts to TGF β

Exp Eye Res. 2024 Apr 30:109917. doi: 10.1016/j.exer.2024.109917. Online ahead of print.ABSTRACTIn glaucoma, scleral fibroblasts are exposed to IOP-associated mechanical strain and elevated TGFβ levels. These stimuli, in turn, lead to scleral remodeling. Here, we examine the scleral fibroblast migratory and transcriptional response to these stimuli to better understand mechanisms of glaucomatous scleral remodeling. Human peripapillary scleral (PPS) fibroblasts were cultured on parallel grooves, treated with TGFβ (2 ng/ml) in the presence of vehicle or TGFβ signaling inhibitors, and exposed to uniaxial strain (1 Hz, 5%, 12-24 hours). Axis of cellular orientation was determined at baseline, immediately following strain, and 24 hours after strain cessation with 0° being completely aligned with grooves and 90° being perpendicular. Fibroblasts migration in-line and across grooves was assessed using a scratch assay. Transcriptional profiling of TGFβ-treated fibroblasts with or without strain was performed by RT-qPCR and pERK, pSMAD2, and pSMAD3 levels were measured by immunoblot. Pre-strain alignment of TGFβ-treated cells with grooves (6.2±1.5°) was reduced immediately after strain (21.7±5.3°, p<0.0001) and restored 24 hours after strain cessation (9.5±2.6°). ERK, FAK, and ALK5 inhibition prevented this reduction; however, ROCK, YAP, or SMAD3 inhibition did not. TGFβ-induced myofibroblast markers were reduced by strain (αSMA, POSTN, ASPN, MLCK1). While TGFβ-induc...

Source: Experimental Eye Research - May 2, 2024 Category: Opthalmology Authors: Ann Mozzer Ian Pitha Source Type: research