Powering Up the Brain: Intercellular Mitochondrial Quality Control and Its Implication in Stroke

Mitochondria are critical for neuronal survival and function, and their dysregulation is closely related to the incidence and prevalence of various neurological disorders, including stroke. Mitochondrial quality control (MQC) is vital for maintaining mitochondrial integrity, particularly in neurons. Under ischemic conditions, neurons evolve a range of adaptive strategies to preserve mitochondria function dynamically, either by generating functional mitochondria or by eliminating dysfunctional ones via autophagy, both of which play key roles in keeping neuronal survival under the conditions of stroke. Besides these intracellular strategies, the intercellular mechanisms underlying MQC have been observed in the nervous system. Functional mitochondria from healthy cells can be supplemented to ischemic neurons in distinct manners and thus restore the mitochondrial network of recipient cells. Conversely, injured neurons release dysfunctional mitochondria, which can be further degraded by adjacent glial cells. Alternatively, the discarded mitochondria act as a threat to surrounding cells and can disrupt the homeostasis of the nervous system. In this review, the key discoveries in intercellular MQC in the nervous system were summarized, and further discussed the implications of intercellular MQC strategies for stroke therapy.