Microglia play important roles in maintenance of brain homeostasis, while due to some pathological stimuli in aging-related neurodegenerative diseases including Alzheimer's disease, they are malfunctioning. Here, we demonstrated that amyloid- (A) accelerated cell senescence characterized by the upregulation of p21 and PAI-1 as well as senescence-associated beta-galactosidase (SA--gal) in human microglial cells. Consistently, A induced the senescence-associated mitochondrial dysfunctions such as repression of ATP production, oxygen consumption rate (OCR), and mitochondrial membrane potential and enhancement of ROS production. Furthermore, A was found to significantly suppress mRNA expression and protein level of Sirtuin-1 (SIRT1), a key regulator of senescence, and inhibit mRNA expression and translocation of NRF2, a critical transcription factor in inflammatory responses, leading to impairment of phagocytosis. Rescue of SIRT1, as expected, could counteract the pathological effects of A. In summary, our findings revealed that A accelerates human microglial senescence mainly through its suppression of the SIRT1/NRF2 pathway and suggested that genetic and pharmaceutical rescue of SIRT1 may provide a potential alternative treatment.
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http://dx.doi.org/10.1155/2022/3086010 | DOI Listing |
Biomaterials
December 2024
Department of Nuclear Medicine and PET Center, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China; Institute of Nuclear Medicine and Molecular Imaging of Zhejiang University, Hangzhou, China; Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou, China; Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, China. Electronic address:
Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder globally, with no effective treatment available yet. A crucial pathological hallmark of AD is the accumulation of hyperphosphorylated tau protein, which is deteriorated by reactive oxygen species (ROS) and neuroinflammation in AD progression. Thus, alleviation of ROS and inflammation has become a potential therapeutic strategy in many studies.
View Article and Find Full Text PDFThe role of immune cells in neurodegeneration remains incompletely understood. Our recent study revealed the presence of mucosal-associated invariant T (MAIT) cells in the meninges, where they express antioxidant molecules to maintain meningeal barrier integrity. Accumulation of misfolded tau proteins are a hallmark of neurodegenerative diseases.
View Article and Find Full Text PDFMicroglia modulate their cell state in response to various stimuli. Changes to cellular lipids often accompany shifts in microglial cell state, but the functional significance of these metabolic changes remains poorly understood. In human induced pluripotent stem cell-derived microglia, we observed that both extrinsic activation (by lipopolysaccharide treatment) and intrinsic triggers (the Alzheimer's disease-associated genotype) result in accumulation of triglyceride-rich lipid droplets.
View Article and Find Full Text PDFJ Prev Alzheimers Dis
January 2025
School of Health and Biomedical Sciences, RMIT University, 220 3-5 Plenty Road, Bundoora VIC 3082, Australia. Electronic address:
Alzheimer's Disease (AD) is a chronic neurodegenerative disorder characterized by the accumulation of toxic amyloid-beta (Aβ) plaques and neurofibrillary tangles (NFTs) of tau protein in the brain. Microglia, key immune cells of the central nervous system, play an important role in AD development and progression, primarily through their responses to Aβ and NFTs. Initially, microglia can clear Aβ, but in AD, chronic activation overwhelms protective mechanisms, leading to sustained neuroinflammation that enhances plaque toxicity, setting off a damaging cycle that affects neurons, astrocytes, cerebral vasculature, and other microglia.
View Article and Find Full Text PDFNutrients
December 2024
Department of Environmental and Prevention Sciences, University of Ferrara, 44121 Ferrara, Italy.
Background: A neuroinflammatory disease such as Alzheimer's disease, presents a significant challenge in neurotherapeutics, particularly due to the complex etiology and allostatic factors, referred to as CNS stressors, that accelerate the development and progression of the disease. These CNS stressors include cerebral hypo-glucose metabolism, hyperinsulinemia, mitochondrial dysfunction, oxidative stress, impairment of neuronal autophagy, hypoxic insults and neuroinflammation. This study aims to explore the efficacy and safety of DAG-MAG-ΒHB, a novel ketone diester, in mitigating these risk factors by sustaining therapeutic ketosis, independent of conventional metabolic pathways.
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