Pressure-Induced Alterations in PEDF and PEDF-R Expression: Implications for Neuroprotective Signaling in Glaucoma.
INTRODUCTION: Alterations in neuron-glia signaling are implicated in glaucoma, a neurodegenerative disease characterized by retinal ganglion cell (RGC) death. Pigment epithelium derived factor (PEDF) is a secreted protein with potential neuroprotective qualities in retinal disease, including chronic ocular hypertension. Here we sought to determine whether moderate, short-term elevations in IOP alter PEDF signaling and whether pressure-induced PEDF signaling directly impacts RGC apoptosis.
METHODS: In retina from naïve mice and mice with unilateral, microbead-induced glaucoma, we examined expression and cell type-specific localization of PEDF and its receptor (PEDF-R), using quantitative PCR and immunohistochemistry. Using primary cultures of purified RGCs and Müller cells, we examined cell type-specific expression of PEDF in response to 48 hours of elevated hydrostatic pressure, using multiplex ELISA and immunocytochemistry. We also measured pressure-induced apoptosis of RGCs in the presence or absence of atglistatin, a potent and selective inhibitor of PEDF-R, and recombinant PEDF, using TUNEL assays.
RESULTS: PEDF and PEDF-R are constitutively expressed in naïve retina, primarily in the ganglion cell and nerve fiber layers. Elevated IOP increases PEDF and PEDF-R expression, particularly associated with RGCs and Müller cells. Elevated pressure
CONCLUSION: Our findings suggest that moderate, short-term elevations in IOP promote PEDF signaling via up-regulation of both PEDF and PEDF-R. Based on
Published In/Presented At
Lee, S. J., Duncan, D. S., Echevarria, F. D., McLaughlin, W. M., Hatcher, J. B., & Sappington, R. M. (2015). Pressure-Induced Alterations in PEDF and PEDF-R Expression: Implications for Neuroprotective Signaling in Glaucoma. Journal of clinical & experimental ophthalmology, 6(5), 491. https://doi.org/10.4172/2155-9570.1000491
Medicine and Health Sciences
Department of Medicine