Abstract
Purpose :
The use of mitochondrial transplantation from MSCs has emerged as a novel therapeutic approach to ameliorate mitochondrial dysfunction and mitigate cellular damage. There is a growing interest in utilizing external mitochondrial transplantation as a therapeutic strategy, given its proven efficacy in addressing diverse diseases associated with mitochondrial dysfunction. Hence, our hypothesis was that introducing mitochondria derived from BMMCs into RPE cells treated with oAβ would alleviate mitochondrial dysfunction and alleviate the disruption of tight junction protein.
Methods :
The mitochondria from BMMCs were isolated through differential centrifugation. Mitochondrial ROS, Mitochondrial membrane potential, intracellular ROS, and the timing of external mitochondrial transport were assessed via flow cytometry. Using a confocal microscope, we observed the internalization of external oAβ into cells and mitochondria, alteration in mitochondrial shape, and modifications in tight junction proteins. Quantitative analysis of changes in protein levels was conducted through western blotting. In the mouse model, external mitochondria were administered through IVT injection subsequent to the SR injection of FITC-oAβ. By employing human specific reactive mitochondrial antibodies on whole-mount retinal tissue, the delivery to the RPE layer and the impact of adapter proteins and FITC-oAβ on introduced mitochondria were scrutinized using confocal microscopy.
Results :
Extrinsic delivered amyloid-beta is taken up by cells and engages with mitochondria, leading to mitochondrial dysfunction. This dysfunction involves elevated mitochondrial ROS levels, mitochondrial fragmentation, imbalanced mitochondrial membrane potential, and intracellular damage, including increased intracellular ROS and the destruction of tight junction proteins. On the other hand, externally delivered mitochondria were verified to ameliorate mitochondrial dysfunction and prevent the disruption of tight junction proteins. Interestingly, we demonstrated an improvement in the clearance of internally accumulated oAβ. These findings were validated in an in vivo mouse model.
Conclusions :
The transfer of isolated mitochondria from MSCs externally holds promise as an innovate treatment for AMD, a condition characterized by oAβ-induced alteration in the RPE.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.