Highly-purified rapidly expanding clones, RECs, are superior for functional-mitochondrial transfer

• Published in: Stem cell research & therapy Vol. 14; no. 1; pp. 40 - 22
• Main Authors: Yang, Jiahao, Liu, Lu, Oda, Yasuaki, Wada, Keisuke, Ago, Mako, Matsuda, Shinichiro, Hattori, Miho, Goto, Tsukimi, Kawashima, Yuki, Matsuzaki, Yumi, Taketani, Takeshi
• Format: Journal Article
• Language: English
• Published: London BioMed Central 16.03.2023; BioMed Central Ltd; BMC
• Subjects: Adenosine Triphosphate - metabolism; Analysis; Biomedical and Life Sciences; Biomedical Engineering and Bioengineering; Bone marrow; Cell Biology; Cell culture; Cell lines; Clone Cells; Cloning; DNA, Mitochondrial - genetics; Endocytosis; Ethidium bromide; Flow cytometry; Gap junctions; Genetic aspects; Genetic disorders; HeLa Cells; Humans; Life Sciences; Medical research; Membrane potential; Mesenchymal stem cells; Mesenchymal stem cells (MSCs); Microscopy; Microtubules; Mitochondria; Mitochondria - metabolism; Mitochondrial DNA; Mitochondrial dysfunction; Mitochondrial transfer; Nanotubes; Oxygen consumption; Rapidly expanding clones (RECs); Reactive oxygen species; Regenerative Medicine/Tissue Engineering; Signal transduction; Stem Cells; Japan; United States > US; Rapidly expanding clones (RECs); Mitochondrial transfer; Mesenchymal stem cells (MSCs); Mitochondrial dysfunction
• ISSN: 1757-6512; 1757-6512
• DOI: 10.1186/s13287-023-03274-y

Background Mitochondrial dysfunction caused by mutations in mitochondrial DNA (mtDNA) or nuclear DNA, which codes for mitochondrial components, are known to be associated with various genetic and congenital disorders. These mitochondrial disorders not only impair energy production but also affect mitochondrial functions and have no effective treatment. Mesenchymal stem cells (MSCs) are known to migrate to damaged sites and carry out mitochondrial transfer. MSCs grown using conventional culture methods exhibit heterogeneous cellular characteristics. In contrast, highly purified MSCs, namely the rapidly expanding clones (RECs) isolated by single-cell sorting, display uniform MSCs functionality. Therefore, we examined the differences between RECs and MSCs to assess the efficacy of mitochondrial transfer. Methods We established mitochondria-deficient cell lines (ρ 0 A549 and ρ 0 HeLa cell lines) using ethidium bromide. Mitochondrial transfer from RECs/MSCs to ρ 0 cells was confirmed by PCR and flow cytometry analysis. We examined several mitochondrial functions including ATP, reactive oxygen species, mitochondrial membrane potential, and oxygen consumption rate (OCR). The route of mitochondrial transfer was identified using inhibition assays for microtubules/tunneling nanotubes, gap junctions, or microvesicles using transwell assay and molecular inhibitors. Results Co-culture of ρ 0 cells with MSCs or RECs led to restoration of the mtDNA content. RECs transferred more mitochondria to ρ 0 cells compared to that by MSCs. The recovery of mitochondrial function, including ATP, OCR, mitochondrial membrane potential, and mitochondrial swelling in ρ 0 cells co-cultured with RECs was superior than that in cells co-cultured with MSCs. Inhibition assays for each pathway revealed that RECs were sensitive to endocytosis inhibitor, dynasore. Conclusions RECs might serve as a potential therapeutic strategy for diseases linked to mitochondrial dysfunction by donating healthy mitochondria.