A Novel Porcine Ex Vivo Retina Culture Model for Oxidative Stress Induced by H2O2

Oxidative stress is a key player in many ophthalmic diseases. However, the role of oxidative stress in most degenerative processes is not yet known. Therefore, accurate and practical models are required to efficiently screen for therapeutics. Porcine eyes are closely related to the human eye, and can be obtained from the abattoir as a by-product of the food industry. Therefore, they offer excellent opportunities for the development of culture models with which to pre-screen potential therapies, while reducing the use of laboratory animals. To induce oxidative stress, organotypic cultures of porcine retina were treated with different doses of hydrogen peroxide (H2O2; 100, 300 and 500 mu M) for three hours. On days 3 and 8, the retinas were conserved for histological and Western blotting analyses and for evaluation of gene expression, which determined the number of retinal ganglion cells (RGCs), the activation state of glial cells, and the expression levels of several oxidative stress markers. H2O2 treatment led to a reduction in the number of RGCs and to an increase in apoptotic RGCs. In addition, a dose-dependent increase of microglia and an elevation of CD11b expression was observed. On day 3, a reduction of IL-1 beta, and an increase of iNOS, as well as of HSP70 mRNA were found. On day 8, an increase in TNF-alpha and IL-1 beta mRNA expression was detected. In conclusion, this ex vivo model offers an opportunity to study the molecular mechanisms underlying certain eye disorders and to test new therapeutic approaches to diminish the effects of oxidative stress.