Mitochondrial Transfer by Photothermal Nanoblade Restores Metabolite Profile in Mammalian Cells.

Mitochondrial DNA (mtDNA) sequence alterations are challenging to generate but desirable for basic studies and potential correction of mtDNA diseases. Here, we report a new method for transferring isolated mitochondria into somatic mammalian cells using a photothermal nanoblade, which bypasses endocytosis and cell fusion. The nanoblade rescued the pyrimidine auxotroph phenotype and respiration of rho0 cells that lack mtDNA. Three stable isogenic nanoblade-rescued clones grown in uridine-free medium showed distinct bioenergetics profiles. Rescue lines 1 and 3 reestablished nucleus-encoded anapleurotic and catapleurotic enzyme gene expression patterns and had metabolite profiles similar to the parent cells from which the rho0 recipient cells were derived. By contrast, rescue line 2 retained a rho0 cell metabolic phenotype despite growth in uridine-free selection. The known influence of metabolite levels on cellular processes, including epigenome modifications and gene expression, suggests metabolite profiling can help assess the quality and function of mtDNA-modified cells. Thus, this apparatus allows the transfer of mitochondria from a host cell to a recipient cell, bypassing the typical and tedious approach of cell fusion assays.