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Updated: Dec 26, 2025
Monitoring Dynamic Growth of Retinal Vessels in Oxygen-Induced Retinopathy Mouse Model
Published on: April 2, 2021
Temporospatial distribution and transcriptional profile of retinal microglia in the oxygen-induced retinopathy mouse
Myriam Boeck1, Adrian Thien1, Julian Wolf1
1Eye Center, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany.
Abstract:
Myeloid cells such as resident retinal microglia (MG) or infiltrating blood-derived macrophages (Mϕ) accumulate in areas of retinal ischemia and neovascularization (RNV) and modulate neovascular eye disease. Their temporospatial distribution and biological function in this process, however, remain unclarified. Using state-of-the-art methods, including cell-specific reporter mice and high-throughput RNA sequencing (RNA Seq), this study determined the extent of MG proliferation and Mϕ infiltration in areas with retinal ischemia and RNV in Cx3cr1CreERT2 :Rosa26-tdTomato mice and examined the transcriptional profile of MG in the mouse model of oxygen-induced retinopathy (OIR). For RNA Seq, tdTomato-positive retinal MG were sorted by flow cytometry followed by Gene ontology (GO) cluster analysis. Furthermore, intraperitoneal injections of the cell proliferation marker 5-ethynyl-2'-deoxyuridine (EdU) were performed from postnatal day (p) 12 to p16. We found that MG is the predominant myeloid cell population while Mϕ rarely appears in areas of RNV. Thirty percent of retinal MG in areas of RNV were EdU-positive indicating a considerable local MG cell expansion. GO cluster analysis revealed an enrichment of clusters related to cell division, tubulin binding, ATPase activity, protein kinase regulatory activity, and chemokine receptor binding in MG in the OIR model compared to untreated controls. In conclusion, activated retinal MG alter their transcriptional profile, exhibit considerable proliferative ability and are by far the most frequent myeloid cell population in areas of ischemia and RNV in the OIR model thus presenting a potential target for future therapeutic approaches.
Insights
Resident retinal microglia (MG) are the main myeloid cells in retinal neovascularization (RNV), showing significant proliferation. These activated MG cells present a potential therapeutic target for neovascular eye diseases.
Area of Science:
- Ophthalmology
- Immunology
- Cell Biology
Background:
- Myeloid cells, including retinal microglia (MG) and blood-derived macrophages (Mϕ), accumulate in retinal ischemia and neovascularization (RNV).
- The precise roles and distribution of these myeloid cells in neovascular eye disease remain unclear.
Purpose of the Study:
- To investigate the temporospatial distribution and proliferation of retinal microglia (MG) and macrophages (Mϕ) in a mouse model of oxygen-induced retinopathy (OIR).
- To analyze the transcriptional profile of MG during retinal ischemia and RNV.
Main Methods:
- Utilized Cx3cr1CreERT2 :Rosa26-tdTomato reporter mice to track myeloid cells.
- Employed cell-specific sorting of tdTomato-positive MG via flow cytometry for high-throughput RNA sequencing (RNA Seq).
- Administered 5-ethynyl-2'-deoxyuridine (EdU) to assess cell proliferation in vivo.
Main Results:
- Retinal microglia (MG) were the predominant myeloid population in areas of RNV, with macrophages (Mϕ) infiltration being rare.
- Approximately 30% of MG in RNV areas were EdU-positive, indicating significant local MG proliferation.
- Gene ontology analysis revealed MG transcriptional changes related to cell division, tubulin binding, and signaling pathways.
Conclusions:
- Activated retinal MG exhibit substantial proliferative capacity and are the primary myeloid cells in ischemic and neovascular retinal areas in the OIR model.
- These findings highlight retinal MG as a potential therapeutic target for neovascular eye diseases.
