ABSTRACT
BACKGROUND: Microglia are resident immune cells of the central nervous system that normally perform sensing, housekeeping, and defense functions. In the context of neurodegenerative diseases, the dysfunction of microglia leads to or aggravates neuronal injury. OBJECTIVE: To investigate the mechanism of microglia-mediated neuronal injury in neurodegenerative diseases. METHODS: The first author searched for relevant articles published from January 2001 to January 2020 in PubMed, CNKI, Wanfang database, and VIP database with the key words of “microglia; neurodegenerative diseases; neuronal injury”. RESULTS AND CONCLUSION: In neurodegenerative diseases, microglia perform excessive sensing due to toxic substances during normal function, leading to increasing activation of microglia, accompanied with hyperfunction of housekeeping and intense neuroinflammation causing neuronal impairment. The dysregulation can also be manifested as dysfunction of sensing and housekeeping due to specific gene mutations, which bring about accumulation of toxic substances, aggravating the dysregulation of defense function and inducing apoptosis or necrosis of neurons as a result. Further exploration on the mechanism of microglia-mediated neuronal injury in neurodegenerative diseases may provide several targets for the treatment of neurodegenerative disease.