Mitochondrial transplantation reverses the senescence phenotype of SH-SY5Y cells

Fusogenic plasma membrane vesicles (PMVs) were engineered as carriers for mitochondrial delivery into senescent SH-SY5Y cells, a human neuroblastoma cell line widely used as an in vitro model for neurodegenerative diseases. Mitochondrial transfer was achieved via cell fusion mediated by the fusogenic vesicular stomatitis virus glycoprotein G. After mitochondrial transplantation, senescent SH-SY5Y cells exhibited marked phenotypic reversal, accompanied by restoration of glucose metabolism, ATP production, lactate levels, and mitochondrial respiratory activity to near-normal levels. In addition, mitochondrial transplantation regulated the senescence-associated secretory phenotype and associated inflammatory signaling pathways, while significantly enhancing antiapoptotic activity. Single-nucleotide polymorphism tracing of mitochondrial DNA confirmed the stable persistence of transplanted mitochondria within recipient cells, which was associated with recovery of normal mitochondrial morphology, function, and biogenesis. Notably, autophagic activity decreased after mitochondrial transplantation. Finally, alpha-synuclein expression was reduced, whereas dopamine production and the activities of enzymes involved in dopamine synthesis were increased after mitochondrial transplantation. The results demonstrated that mitochondrial transplantation can effectively reverse the senescence phenotype of SH-SY5Y cells, suggesting that mitochondrial transplantation may represent a promising therapeutic strategy for neurodegenerative disorders such as Parkinson disease.