gms | German Medical Science

Background: The age-related macular degeneration (AMD) is a multifactorial disease, where good research models are limited. Hence, an established porcine degeneration model (Kuehn et al., 2017) was modified to enable improved photoreceptor cultivation and make it applicable for AMD research.

Methods: Two Methods, namely “filter” and “tweezers”, were tested to gain porcine neuroretina explants, with the ganglion cell layer facing down. Retinas were cultivated for 4 and 8 days and compared to explants obtained with the established method, photoreceptors facing down. To characterize the explants optical coherence tomography (OCT; n=6/group), H&E staining, immunohistochemistry, and qRT-PCR (n=4/group) were performed. More specifically, cones, rods, amacrine, bipolar, and retinal ganglion cells were investigated, followed by group comparisons.

Results: OCT analyses revealed a decrease of retinal thickness to a lower extent in tweezers explants compared to filter (p<0.001) and established method (p=0.04). Moreover, measurements of retinal thickness, via H&E staining, showed for both new Methods a significantly improved photoreceptor structure compared to the established method (p<0.05). Additionally, the rhodopsin+ area was increased in the filter (p<0.05) and tweezers group (p=0.048) in contrast to the established one. On mRNA level, we revealed an upregulation of Rhodopsin and Opsin in both new Methods compared to the established one. The amount of amacrine, bipolar and retinal ganglion cells was unaltered.

Conclusion: This project aimed to develop a more suitable organ culture photoreceptor degeneration model. The cultivation using the tweezer method led to a significantly improved morphology. Subsequently, to establish a reliable AMD model a co-cultivation of neuroretina and RPE-cells will follow.