Huiying Yan,1,* Wei Wang,2,* Tingting Cui,1 Yanxin Shao,3 Mingquan Li,1 Limei Fang,1 Lina Feng1 

1Department of Neurology, The Third Affiliated Clinical Hospital of the Changchun University of Chinese Medicine, Changchun, People’s Republic of China; 2Department of Intensive Care Unit, The Affiliated Hospital to Changchun University of Chinese Medicine, Changchun, People’s Republic of China; 3Department of Neurology, The Second Affiliated Hospital of Shandong First Medical University, Taian, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Limei Fang; Lina Feng, Department of Neurology, The Third Affiliated Clinical Hospital of the Changchun University of Chinese Medicine, Changchun, People’s Republic of China, Email fanglm008@163.com; Fenglina0001@126.com

Abstract: Alzheimer’s disease (AD) is a fatal neurodegenerative disease with a subtle and progressive onset and is the most common type of dementia. However, its etiology and pathogenesis have not yet been fully elucidated. The common pathological manifestations of AD include extraneuronal β-amyloid deposition (Aβ), intraneuronal tau protein phosphorylation leading to the formation of ‘neurofibrillary tangles’ (NFTs), neuroinflammation, progressive loss of brain neurons/synapses, and glucose metabolism disorders. Current treatment approaches for AD primarily focus on the ‘Aβ cascade hypothesis and abnormal aggregation of hyperphosphorylation of tau proteins’, but have shown limited efficacy. Therefore, there is an ongoing need to identify more effective treatment targets for AD. The central nervous system (CNS) inflammatory response plays a key role in the occurrence and development of AD. Neuroinflammation is an immune response activated by glial cells in the CNS that usually occurs in response to stimuli such as nerve injury, infection and toxins or in response to autoimmunity. Neuroinflammation ranks as the third most prominent pathological feature in AD, following Aβ and NFTs. In recent years, the focus on the role of neuroinflammation and microglia in AD has increased due to the advancements in genome-wide association studies (GWAS) and sequencing technology. Furthermore, research has validated the pivotal role of microglia-mediated neuroinflammation in the progression of AD. Therefore, this article reviews the latest research progress on the role of neuroinflammation triggered by microglia in AD in recent years, aiming to provide a new theoretical basis for further exploring the role of neuroinflammation in the process of AD occurrence and development.

Keywords: neuroinflammation, microglia, Alzheimer’s disease, review, Trem2