Background: The ex vivo model represented by mouse retinal explants in culture is a useful experimental model to investigate the molecular mechanism involved in neurovascular diseases such as diabetic retinopathy (DR). It ensures an experimental overview with more complete respect to isolate cells and reduce problems in terms of accessibility and management with respect to in vivo model. In particular, it allows the evaluation of the relationship between retinal cells in response to the typical stressors involved in DR pathogenesis.
Methods: Ex vivo retinal fragments derived from 3- to 5-week-old C57BL/6J mice. In particular, after dissection, the retina is cut into 4 separate fragments and transferred onto inserts placed with ganglion cells up. Once in culture, the explants could be treated in stress conditions typical of DR. In particular, this study protocol describes the procedure for the preparation and the culture of retinal explants with specific metabolic stressors such as high glucose (HG), advanced glycation end product (AGE), and oxidative stress (OS). In the end, this paper provides the protocols to perform molecular analyses in order to evaluate the response of retinal explants to stress and/or neuroprotective treatments.
Discussion: The cultured retinal explants represent an ex vivo experimental model to investigate the molecular mechanisms involved in neurovascular diseases such as DR. Moreover, they could be useful to test the effect of neuroprotective compounds in response to metabolic stressors in a fewer time respect to an in vivo model. In conclusion, retinal explants in culture represent a valuable experimental model to conduct further studies to better understand the pathophysiology of DR.
Background: Retinopathy of prematurity (ROP) is considered as the most common reason for blindness in children, particularly in preterm infants. The disease is characterized by the dysregulation of angiogenic mechanisms due to preterm birth, leading ultimately to vascular abnormalities and pathological neovascularization (NV). Retinal detachment and vision loss could represent a concrete risk connected to the most severe forms of ROP, also characterized by inflammation and retinal cell death.
Methods: During the last decades, many animal models of oxygen-induced retinopathy (OIR) have been recognized as useful tools to study the mechanisms of disease, since they reproduce the hallmarks typical of human ROP. Indeed, modulation of retinal vascular development by exposure to different oxygen protocols is possible in these animals, reproducing the main pathological phenotypes of the disease. The easy quantification of abnormal NV and the possibility to perform electrophysiologic, histological and molecular analyses on these models, make OIR animals a fundamental instrument in studying the pathophysiology of ROP and the effects of novel treatments against the disease.
Discussion: Here, the most commonly used OIR protocols in rodents, such as mice and rats, are described as well as the main pathological outcomes typical of these models. Despite their limitations and variables which should be considered whilst using these models, OIR models display several characteristics which have also been confirmed in human patients, validating the usefulness of such animals in the pre-clinical research of ROP.
