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Published on: December 9, 2022
CYP46A1 Activation Improves Retinal Neovascularization in a Mouse Model of Retinopathy of Prematurity
Insights
Activating CYP46A1 (cytochrome P450 46A1) with efavirenz reduced abnormal blood vessel growth and improved cell survival in developing mouse retinas with oxygen-induced retinopathy (OIR). This highlights a potential therapeutic target for retinal diseases.
Area of Science:
- Ophthalmology
- Neuroscience
- Biochemistry
Background:
- The role of CYP46A1 (cytochrome P450 46A1) in the developing retina remains uncharacterized, despite its known metabolic and regulatory functions in adult retinas.
- Oxygen-induced retinopathy (OIR) is a significant cause of vision loss, characterized by pathological neovascularization and retinal damage.
Purpose of the Study:
- To investigate CYP46A1 expression and the effects of its pharmacological activation in the developing mouse retina.
- To assess the therapeutic potential of CYP46A1 activation in mitigating OIR-induced retinal pathologies.
Main Methods:
- Developing C57BL/6J mice (P7-P17) were subjected to OIR and treated with efavirenz (EFV), a CYP46A1 activator.
- Retinal morphology, neovascularization, hypoxic areas, Müller cell and microglia activation, and retinal ganglion cell survival were analyzed.
Main Results:
- EFV treatment significantly reduced pathological neovascularization and hypoxic areas in OIR mouse retinas.
- EFV administration limited reactive gliosis, microglia activation, and enhanced retinal ganglion cell survival.
- CYP46A1 expression and its metabolite 24-hydroxycholesterol (24HC) levels were found to be dysregulated in OIR retinas.
Conclusions:
- CYP46A1 is developmentally regulated, and its activation shows promise in treating OIR.
- Pharmacological activation of CYP46A1 may offer a novel therapeutic strategy for pathological neovascularization in the developing retina.
Abstract:
Previous studies have shown the metabolic and regulatory significance of CYP46A1 in the adult retina; however, its role in the developing retina is unknown. Here, we evaluate CYP46A1 expression and the impact of its activation in the developing mouse retina under normal and pathological conditions. Seven-day-old (P7) C57BL/6J mice maintained in room air (controls) or subjected to oxygen-induced retinopathy (OIR) were treated with/without 20 mg/kg efavirenz (EFV), a CYP46A1 activator administered intraperitoneally from P7 to P17. Retinal cross sections and flat mounts were prepared to study retinal vasculature morphology, Müller and microglia activation, and ganglion cell viability. EFV treatment significantly reduced pathological neovascularization and the size of avascular and hypoxic areas in OIR mice retinas. EFV treatment additionally limited reactive gliosis and microglia activation and improved retinal ganglion cell survival in OIR mice. The current study demonstrates the developmental regulation of CYP46A1 and the dysregulated expression and levels of the downstream metabolite 24-Hydroxycholesterol (24HC) in OIR mice. The study further suggests that pharmacological CYP46A1 activation may improve key pathological features associated with pathological neovascularization in OIR mice.
