Unveiling the potential of the long-term organotypic culture of the postmortem adult human retina

Abstract

Purpose : There is an increasing demand in research for 3D human retina models. Here, we present an organotypic culture model that allows the postmortem adult human neural retina to survive in its full complexity for over 35 weeks.

Methods : Eyes of adult multi-organ donors without known ocular diseases were enucleated prior to cardiac arrest. Eyes from more than 150 donors, ranging in age from 18 to 74 years, were used. After dissection, organotypic cultures were prepared and placed on a polycarbonate membrane. The cultures were maintained for up to 245 days using a chemically defined serum-free medium. Light sensitivity of the cultures and spontaneous ganglion cell activity were evaluated using a multi-electrode array system. To demonstrate a significant application of the method, a subset of cultures was transduced with different viral vectors. Following fixation, the quality of the cultures was analyzed by immunohistochemistry and TUNEL assay.

Results : The morphology of the cultures was remarkably well preserved, with low variability between samples. All major cell types survived, and the integrity of retinal layers was conserved even after 35 weeks. No direct correlation was found between donor age or sex regarding tissue survival. While cones exhibited a gradual loss of outer segments, they did not undergo severe apoptosis. In the inner retina, subpopulations of bipolar, horizontal, and amacrine cells showed morphology closely resembling the normal state. Additionally, synaptophysin staining unveiled synaptic structures with a similar normal-like morphology. Despite a reduction in the number of ganglion cells, the presence of surviving ganglion cells was confirmed by immunohistochemistry and electrophysiology. The applied viral vectors led to an effective and consistent transduction, demonstrating reproducibility across cultures from diverse donors.

Conclusions : Our results show that it is possible to maintain adult human retinas in a suitable culture system for at least 8 months. The long survival time and low inter-sample variability provide a cost- and time-efficient platform for evaluating pharmacological compounds on the human retina. In addition, long-term culture enables the delivery of viral vectors and opens up new and efficient strategies for the development and testing of gene therapeutics in the preclinical phase, which can significantly increase the success rate of clinical trials.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.