Adipose-derived Mesenchymal Stem Cells and Retinal Pigment Epithelial Cells Interactions in Stress Environment via Tunneling Nanotubes

This study aims to demonstrate the formation of TNTs between AdMSCs and RPE-1 and their alterations in response to experimental stress conditions. Serum starvation was employed as a stress condition to induce TNTs between the AdMSC and RPE-1. The presence of TNTs was demonstrated through immunofluorescence microscopy while scanning electron microscopy was utilized to determine the average thickness. Cell viabilities were assessed after stress by CTG, and H2DCFH-DA probes evaluated the cells reactive oxygen species (ROS) levels. Further, JC-1 labeled mitochondrial exchange between cells via TNTs was supported by videos. A transmembrane culture system was employed to inhibit TNT formation. In this study, we investigated the role of TNTs in facilitating intercellular communication and mitochondrial transfer between AdMSCs and RPE-1 under stress. We found that TNT-mediated mitochondrial transfer from AdMSCs to RPE-1 helps to reduce ROS levels and improve cell viability. We demonstrated that direct interaction between AdMSCs and RPE-1 was crucial for stress recovery. Co-culture enhanced viability and sustained retinal epithelial cell function after stress-induced damage. Mechanical inhibition of TNT formation decreased cell viability and increased ROS levels, indicating the importance of TNTs in cellular protection. The findings can provide a new perspective on the therapeutic potential of stem cell-based therapy in protecting RPE against stress-induced damage and promoting tissue regeneration.