Fig. 5

Mitochondria transferring mechanisms and tracking methods: A Transferring mechanisms; TNTs, the tube-like structures that connect cells, are formed with the crucial involvement of F-actin, myosin, and tubulin. These components play a significant role in transferring cellular components such as RNAs, proteins, and mitochondria. Mitochondria, for instance, move through TNTs by interacting with F-actin and the cytoskeleton. GJCs, on the other hand, are large protein channels linked to the cytoplasm of adjacent cells and are made of connexins. Six connexins form a connexon, and two connexons create a channel, exchanging small molecules and nutrients. Cx43, a specific connexin, helps mitochondrial transfer through Ca2 + or ROS exchange. EVs, like exosomes and MVs, also facilitate intercellular communication. Mitochondrial extrusion occurs when cells expel mitochondria freely or in vesicles, usually due to stress or damage. This mechanism depends on intact actin filaments and microtubules, which are crucial in maintaining mitochondrial quality control. B Mitochondria tracking methods: Fluorescent-based labeling uses mitochondrial dyes such as MitoTracker deep red and green to observe mitochondria in live cells. Transgenic reporter systems use GFP to track mitochondria with targeting sequences. Quantifying mtDNA with qPCR or sequencing tracks specific mitochondria. A new tool, MERCI, analyzes single-cell sequencing data to trace mtDNA. C Mitochondrial transfer and quality control using a robot-aided micro-manipulation system; The innovative technique to control the quality and quantity of mitochondria injected into single live cells using a robotic microneedle and optical tweezers system. This method arranges Mitochondria and cells in a 1-D array within a microfluidic device. The robotic microneedle, aided by optical tweezers, collects a set number of functional mitochondria and injects them into live cells without causing damage. TNT; Tunneling nano tubes, GJC; Gap junction channel Cx43; Connexin-43, ROS; Reactive oxygen species, EV; Extracellular vesicle, MV; Micro vesicle, mtDNA; Mitochondrial DNA, GFP; Green fluorescent protein, qPCR; Quantitative polymerase chain reaction