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Corna, A.

Publications and source records attributed to Corna, A..

3 recordsLinked to original sources

IDENTIFICATION OF HUMAN PHOTORECEPTORS SUITABLE FOR CELL REPLACEMENT STUDIES IN A PRECLINICAL ACHROMATOPSIA MODEL

Cell replacement represents a potential treatment modality for retinal disorders characterized by photoreceptor loss. However, photoreceptor replacement approaches have not been clinically established. To take this forward, the main goal of this study was to systematically compare human photoreceptors of different ages and identify those that enable functional integration into the degenerative retina. Donor cells were isolated from iPSC-derived retinal organoids generated by a GMP-compliant protocol at differentiation days 120, 150, or 200 and transplanted subretinally into cone photoreceptor function loss 1 (Cpfl1) recipients, an inherited mouse model of cone degeneration. While younger photoreceptors showed slightly improved transplantation outcomes, donor photoreceptors of all culture stages displayed long-term survival, cone identity, structural integration into the host retina, and tight interactions with host Muller glia, including formation of a continuous outer limiting membrane. Transplanted photoreceptors showed signs of advanced maturation, including correct polarization with generation of apical inner- and outer segments, while basal synapses were formed with host bipolar cells. Electrophysiological assessment of host retinal ganglion cells revealed light-evoked responses in transplant-containing regions, providing evidence for functional incorporation of human photoreceptors into the mouse neuro-retinal circuitry. Thus, GMP-compliant human iPSC-derived photoreceptors are stable over a wide range of differentiation stages and constitute a robust cell source for retinal transplantation and functional repair. The findings provide important prerequisites for the development of standardized procedures towards clinical translation of photoreceptor replacement in the retina. Significant statementCell transplantation represents a potential therapy for retinal dystrophies. However, conditions allowing stable functional integration and maturation of donor photoreceptors have not been defined. We systematically compared GMP-compliant iPSC-derived photoreceptors of different culture times after transplantation into a retinal degeneration mouse model. Photoreceptors of all ages showed structural integration and advanced maturation in close interaction with host Muller glia and bipolar cells, allowing restoration of light-driven responses. Thus human photoreceptors isolated from retinal organoids represent a robust source for clinical development of cell replacement in the diseased retina.

neuroscience↗

HDAC inhibition ameliorates cone survival in retinitis pigmentosa mice

Cone photoreceptor cell death in inherited retinal diseases, such as Retinitis Pigmentosa (RP), leads to the loss of high acuity and color vision and ultimately to blindness. In RP, a vast number of mutations perturb the structure and function of rod photoreceptors while cones remain initially unaffected. Cone death follows rod death secondarily due to increased oxidative stress, inflammation, and loss of structural and nutritional support provided by rods. Here, we show that secondary cone cell death in animal models for RP was associated with an increased activity of histone deacetylates (HDACs). A single intravitreal injection of an HDAC inhibitor at a late stage of the disease, when majority of rods have already degenerated, was sufficient to delay cone death and support long-term cone survival. Moreover, the surviving cones remained light sensitive and initiated light-driven ganglion cell responses. RNA-seq analysis of protected cones demonstrated that HDAC inhibition led to multi-level protection via regulation of different pro-survival pathways, including MAPK, PI3K-Akt, and autophagy. This study suggests a unique possibility for a targeted pharmacological protection of both primary degenerating rods and secondary dying cones by HDAC inhibition and creates hope to maintain vision in RP patients independent of the disease stage.

neuroscience↗

Human cerebrospinal fluid induce neuronal excitability changes in resected human neocortical and hippocampal brain slices

Human cerebrospinal fluid (hCSF) have proven advantageous over conventional medium when culturing both rodent and human brain tissue. Increased excitability and synchronicity, similar to the active state exclusively recorded in vivo, reported in rodent slice and cell-cultures with hCSF as recording medium, indicates properties of the hCSF not matched by the artificial cerebrospinal fluid (aCSF) commonly used for electrophysiological recording. To evaluate the possible importance of using hCSF as electrophysiological recording medium of human brain tissue, we compared the general excitability in ex vivo human brain tissue slice cultures during perfusion with hCSF and aCSF. For measuring the general activity from a majority of neurons within neocortical and hippocampal human ex vivo slices we used a microelectrode array (MEA) recording technique with 252 electrodes covering an area of 3.2 x 3.2 mm2 and a second CMOS-based MEA with 4225 electrodes on a 2 x 2 mm2 area for detailed mapping of action potential waveforms. We found that hCSF increase the number of active neurons and the firing rate of the neurons in the slices as well as increasing the numbers of bursts while leaving the duration of the bursts unchanged. Interestingly, not only an increase in the overall activity in the slices was observed, but a reconfiguration of the network functionality could be detected with specific activation and inactivation of subpopulations of neuronal ensembles. In conclusion, hCSF is an important component to consider for future human tissue studies, especially for experiments designed to mimic the in vivo situation.

neuroscience↗