Organotypic Retinal Explant Cultures from Macaque Monkey

Area of Science:

• Ophthalmology
• Neuroscience
• Genetics

Background:

• Hereditary retinal degeneration (RD) involves progressive photoreceptor cell death.
• Overactivation of the cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) pathway contributes to photoreceptor death, particularly in models with phosphodiesterase 6b (PDE6b) mutations.
• Murine models are common for RD research, but genetic and physiological differences necessitate more comparable models.

Purpose of the Study:

• To establish an in vitro primate retinal explant model for studying hereditary retinal degeneration (RD).
• To simulate RD pathogenesis by activating the cGMP-PKG pathway in primate retinal explants.
• To provide a more human-relevant model for understanding RD mechanisms and developing treatments.

Main Methods:

• In vitro culture of retinal explants from wild-type macaques (aged 1-3 years), including the retina-retinal pigment epithelium (RPE)-choroid complex.
• Treatment of explants with zaprinast, a phosphodiesterase 6 (PDE6) inhibitor, to induce cGMP accumulation and activate the cGMP-PKG pathway.
• Verification of cGMP accumulation and cell death using immunofluorescence and the TUNEL assay.

Main Results:

• Successful establishment of an in vitro primate retinal explant model.
• Demonstrated induction of the cGMP-PKG signaling pathway and subsequent photoreceptor cell death in primate retinal explants.
• Verified cGMP accumulation and cell death using established biological assays.

Conclusions:

• A novel primate retinal explant model effectively simulates cGMP-PKG-dependent hereditary retinal degeneration (RD).
• This model offers a valuable platform for studying RD mechanisms in a context more relevant to human physiology.
• The model holds potential for evaluating future therapeutic strategies for RD.