Amyloid-beta precursor protein (APP) was identified on expression cloning from a human placenta cDNA library as a gene product that modulates the activity of membrane-type matrix metalloproteinase-1 (MT1-MMP). Co-expression of MT1-MMP with APP in HEK293T cells induced cleavage and shedding of the APP ectodomain when co-expressed with APP adaptor protein Fe65. Among the MT-MMPs tested, MT3-MMP and MT5-MMP also caused efficient APP shedding. The recombinant APP protein was cleaved by MT3-MMP in vitro at the A463-M464, N579-M580, H622-S623, and H685-Q686 peptide bonds, which included a cleavage site within the amyloid beta peptide region known to produce a C-terminal fragment. The Swedish-type mutant of APP, which produces a high level of amyloid beta peptide, was more effectively cleaved by MT3-MMP than wild-type APP in both the presence and absence of Fe65; however, amyloid beta peptide production was not affected by MT3-MMP expression. Expression of MT3-MMP enhanced Fe65-dependent transactivation by APP fused to the Gal4 DNA-binding and transactivation domains. These results suggest that MT1-MMP, MT3-MMP and MT5-MMP should play an important role in the regulation of APP functions in tissues including the central nervous system.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/jb/mvj054 | DOI Listing |
PLoS One
January 2025
Center for Innovation in Brain Science, University of Arizona Health Sciences, Tucson, Arizona, United States of America.
Translational validity of mouse models of Alzheimer's disease (AD) is variable. Because change in weight is a well-documented precursor of AD, we investigated whether diversity of human AD risk weight phenotypes was evident in a longitudinally characterized cohort of 1,196 female and male humanized APOE (hAPOE) mice, monitored up to 28 months of age which is equivalent to 81 human years. Autoregressive Hidden Markov Model (AHMM) incorporating age, sex, and APOE genotype was employed to identify emergent weight trajectories and phenotypes.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Yusuf Hamied Department of Chemistry, Centre for Misfolding Diseases, University of Cambridge, Cambridge CB2 1EW, United Kingdom.
The onset and development of Alzheimer's disease is linked to the accumulation of pathological aggregates formed from the normally monomeric amyloid-β peptide within the central nervous system. These Aβ aggregates are increasingly successfully targeted with clinical therapies at later stages of the disease, but the fundamental molecular steps in early stage disease that trigger the initial nucleation event leading to the conversion of monomeric Aβ peptide into pathological aggregates remain unknown. Here, we show that the Aβ peptide can form biomolecular condensates on lipid bilayers both in molecular assays and in living cells.
View Article and Find Full Text PDFAlzheimers Dement
January 2025
Institute of Neurological and Psychiatric Disorders, Shenzhen Bay Laboratory, Shenzhen, China.
Introduction: Alzheimer's disease (AD) patients with higher educational attainment (EA) often exhibit better cognitive function. However, the relationship among EA status, AD pathology, structural brain reserve, and cognitive decline requires further investigation.
Methods: We compared cognitive performance across different amyloid beta (Aβ) positron emission tomography (A ±) statuses and EA levels (High EA/Low EA).
Alzheimers Dement
January 2025
Department of Psychiatry, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, UK.
Introduction: Lewy body dementia (LBD) shares genetic risk factors with Alzheimer's disease (AD), including apolipoprotein E (APOE), but is distinguishable at the genome-wide level. Polygenic risk scores (PRS) may therefore improve diagnostic classification.
Methods: We assessed diagnostic classification using AD-PRS excluding APOE (AD-PRS ), APOE risk score (APOE-RS), and plasma phosphorylated tau 181 (p-tau181), in 83 participants with LBD, 27 with positron emission tomography amyloid beta (Aβ)positive mild cognitive impairment or AD (MCI+/AD), and 57 controls.
J Biochem Mol Toxicol
February 2025
Department of Histology and Embryology, Faculty of Basic Medical Sciences, Hubei University of Medicine, Shiyan, People's Republic of China.
The coexistence of Alzheimer's disease (AD) and chronic pain (CP) in the elderly population has been extensively documented, and a growing body of evidence supports the potential interconnections between these two conditions. This comprehensive review explores the mechanisms by which CP may contribute to the development and progression of AD, with a particular focus on neuroinflammatory pathways and the role of microglia, as well as the activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome. The review proposes that prolonged pain processing in critical brain regions can dysregulate the activity of the NLRP3 inflammasome within microglia, leading to the overproduction of pro-inflammatory cytokines and excessive oxidative stress in these regions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!