Evidence map›Paper›PMID 42112684›Full record

ArticleInvestigative ophthalmology & visual science2026

Pigment Epithelium-Derived Factor From Müller Cells Is Involved in Angiopoietin-Mediated Survival Control of Retinal Neurons.

Ruaa Younis, Heidi Müller, Focke Ziemssen, Wolfram Eichler

Abstract read
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Article in Investigative ophthalmology & visual science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

4 authors.

Ruaa YounisDepartment of Ophthalmology and Eye Hospital, Leipzig University, Leipzig, Germany.
Heidi MüllerDepartment of Ophthalmology and Eye Hospital, Leipzig University, Leipzig, Germany.
Focke ZiemssenDepartment of Ophthalmology and Eye Hospital, Leipzig University, Leipzig, Germany.
Wolfram EichlerDepartment of Ophthalmology and Eye Hospital, Leipzig University, Leipzig, Germany.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Purpose: This study was performed to determine whether angiopoietin (Ang)-1 and Ang-2 influence the survival of retinal neurons via Müller cell-mediated mechanisms. Methods: Expression of Ang-1, Ang-2, and Tie-2 in retinal cells and their hypoxia-dependent regulation were investigated using (quantitative) reverse transcription (RT)-PCR (qPCR), immunofluorescence staining, and Western blotting. Survival of Ang-stimulated R28 cells was assessed in homotypic cultures and co-cultures with rat Müller cells (RMCs). Ang-1, Ang-2, PEDF in RMCs and PEDF receptor (PEDF-R) in R28 cells were knocked down by siRNA. Tie-2-PI3 kinase (PI3K)/Akt activation was demonstrated using signaling blockers and by detecting Tie-2-Akt phosphorylation. PEDF expression and secretion were determined by qPCR and ELISA. Results: Ang-1, Ang-2, and Tie-2 are expressed in primary retinal cells, in particular, RMCs and human Müller cells of gliosis tissue. Under hypoxia, Ang-1 and Ang-2 expression declined in RMCs and R28 cell viability was reduced. Although both angiopoietins did not significantly influence R28 cell survival in homotypic cultures, co-cultures with Ang-deficient RMCs revealed that Müller cell-derived Ang-1 promoted, whereas Ang-2 impaired, R28 cell survival. Ang-1 induced Tie-2 and PI3K/Akt activation in RMCs and prevented hypoxia-induced PEDF downregulation. Ang-2 suppressed Tie-2-Akt phosphorylation and PEDF expression. Impaired R28 cell survival under hypoxia or caused by Ang-1 knockdown in co-cultured RMCs was mitigated by Ang-2-deficient RMCs or rescued by supplemental Ang-1 in a PEDF-/PEDF-R-dependent fashion. Conclusions: Ang-regulated signaling and PEDF expression constitute a significant pathway in Müller cells to control retinal neuronal survival. This has implications for effector functions of the therapeutic antibody, Faricimab.

Indexed as

Angiopoietin-1Angiopoietin-2Ependymoglial CellsEye ProteinsGene Expression RegulationNerve Growth FactorsRetinal NeuronsSerpinsAnimalsBlotting, WesternCells, CulturedCell SurvivalCoculture TechniquesEnzyme-Linked Immunosorbent AssayPhosphatidylinositol 3-KinasesPigment Epithelium-Derived FactorAngiopoietin-1Angiopoietin-2Eye ProteinsNerve Growth FactorsPhosphatidylinositol 3-KinasesPigment Epithelium-Derived FactorProto-Oncogene Proteins c-aktReceptors, NeuropeptideReceptor, TIE-2Serpins

Identifiers

PMID42112684
PMCPMC13179589

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.