Mechanobiology of Long-distance Mitochondria Transport in Neuronal Axon

As polar cells, neurons are composed of a cell body, dendritic networks, and long, branched axons. To maintain normal physiological functions throughout the lifespan of vertebrates, differentiated neurons require substantial energy to sustain resting potential and synaptic transmission. Neurons predominantly rely on ATP generated through mitochondrial oxidative phosphorylation for energy. They transport and accumulate healthy mitochondria to energy-demanding areas, such as the presynaptic terminals of axon branches, through long-distance transport and anchoring, while reversing the transport of aged or damaged mitochondria in the axon terminals back to the soma for degradation. This article, integrating authors' research, discusses from a mechanical perspective how mitochondria overcome resistance to achieve long-distance transport along axons under the influence of driving forces. The review covers topics such as microtubule polarity, microtubule motor proteins, mitochondrial docking protein complexes, interactions between mitochondria and anchoring proteins, intracellular resistance, interactions between mitochondria and the endoplasmic reticulum, and aspects of mitochondrial biogenesis, fission, fusion, division, and quality control. These novel perspectives will provide important insights for understanding neurological diseases caused by mitochondrial transport dysfunctions.