Roles of Extracellular Vesicles in Cerebral Protection of Ischemic Stroke.

Stroke is the second-leading cause of death worldwide and exhibits a high disability rate. Ischemic stroke accounts for approximately 80% of all stroke cases. Inflammatory responses induced by innate immunity are involved in all stages of stroke-related injury, including early cerebral-infarction tissue repair and regeneration after ischemia. Toll-like receptors are the main receptors involved in innate immunity. Toll-like receptors specific antagonists inhibit neuroinflammation by reducing overproduction of inflammatory mediators. But there are still some limitations, such as affecting protein clearance and myelination. Extracellular vesicles are widespread and distributed in various body fluids, carry and transmit important signal molecules, affect the physiological state of cells and are closely related to the occurrence and progress of many diseases. In the present review, we summarize recent findings regarding the mechanisms by which extracellular vesicles act as signaling vectors to regulate cellular crosstalk between neurovascular units and further discuss the therapeutic effects of extracellular vesicles derived from mesenchymal stem cells on brain injury. Collectively, our review may provide novel insights into further elucidating pathogenesis and cerebral-protective measures of ischemic stroke.