Meng, Jie; Yang, Xiu Mei; Scheer, Oliver; Lange, Johannes; Müller, Heidi; Bürger, Susanne; Rothemund, Sven; Younis, Ruaa; Unterlauft, Jan D; Eichler, Wolfram (2024). Pigment Epithelium-Derived Factor Binding to VEGFR-1 (Flt-1) Increases the Survival of Retinal Neurons. Investigative ophthalmology & visual science, 65(10) Association for Research in Vision and Ophthalmology 10.1167/iovs.65.10.27
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PURPOSE
The purpose of this study was to examine possible involvement of vascular endothelial growth factor (VEGF) receptor (VEGFR)-1/Flt-1 in pigment epithelium-derived factor (PEDF)-promoted survival of retinal neurons.
METHODS
Survival of growth factor-deprived retinal ganglion cells (RGCs) and R28 cells and activation of ERK-1/-2 MAP kinases were assessed in the presence of PEDF, placental growth factor (PlGF), and VEGF using cell cultures, viability assays and quantitation of ERK-1/-2 phosphorylation. VEGFR-1/Flt-1 expression was determined using quantitative PCR (qPCR) and Western blotting. VEGFR-1/Flt-1 was knocked down in R28 cells by small interfering RNA (siRNA). Binding of a PEDF-IgG Fc fusion protein (PEDF-Fc) to retinal neurons, immobilized VEGFR-1/Flt-1 and VEGFR-1/Flt-1-derived peptides was studied using binding assays and peptide scanning.
RESULTS
PEDF in combination with PlGF stimulated increased cell survival and ERK-1/-2 MAP kinase activation compared to effects of either factor alone. VEGFR-1/Flt-1 expression in RGCs and R28 cells was significantly upregulated by hypoxia, VEGF, and PEDF. VEGFR-1/Flt-1 ligands (VEGF and PlGF) or soluble VEGFR-1 (sflt-1) competed with PEDF-Fc for binding to R28 cells. Depleting R28 cells of VEGFR-1/Flt-1 resulted in reduced PEDF-Fc binding when comparing VEGFR-1/Flt-1 siRNA- and control siRNA-treated cells. PEDF-Fc interacted with immobilized sflt-1, which was specifically blocked by VEGF and PlGF. PEDF-Fc binding sites were mapped to VEGFR-1/Flt-1 extracellular domains D3 and D4. Peptides corresponding to D3 and D4 specifically inhibited PEDF-Fc binding to R28 cells. These peptides and sflt-1 significantly inhibited PEDF-promoted survival of R28 cells.
CONCLUSIONS
These results suggest that PEDF can target VEGFR-1/Flt-1 and this interaction plays a significant role in PEDF-mediated neuroprotection in the retina.
Item Type: |
Journal Article (Original Article) |
|---|---|
Division/Institute: |
04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Ophthalmology |
UniBE Contributor: |
Unterlauft, Jan Darius |
Subjects: |
600 Technology > 610 Medicine & health |
ISSN: |
0146-0404 |
Publisher: |
Association for Research in Vision and Ophthalmology |
Language: |
English |
Submitter: |
Pubmed Import |
Date Deposited: |
22 Aug 2024 10:45 |
Last Modified: |
22 Aug 2024 11:17 |
Publisher DOI: |
10.1167/iovs.65.10.27 |
PubMed ID: |
39167401 |
BORIS DOI: |
10.48350/199902 |
URI: |
https://boris.unibe.ch/id/eprint/199902 |
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