Seizure Susceptibility and Mortality in Mice That Over-express Amyloid Precursor Protein
Overview
Affiliations
Alzheimer's disease and Fragile X syndrome both display synaptic phenotypes, and based on recent studies, likely share dendritic over expression of amyloid precursor protein (APP) and beta-amyloid (Abeta). In order to create a mouse model to specifically study the effects of APP and Abeta at synapses, we crossed Tg2576, which over-express human APP with the Swedish mutation (hAPPsw), with fmr-1 KO mice. The progeny, named FRAXAD, displayed increased mortality (23% by 30 days of age) compared to Tg2576 (3%) and WT and fmr-1 KO littermate controls (0%) consistent with a developmental defect. By 60 days of age, both the Tg2576 and FRAXAD mice approached a 40% mortality rate compared to 0% for WT and fmr-1 KO littermates. To understand the mechanism underlying increased mortality in APP over-expressing mice, we assessed seizure thresholds in response to pentylenetetrazol (PTZ). Both the Tg2576 and FRAXAD mice had a lower threshold to PTZ-induced seizures (average seizure score of >/=4.0) in comparison to nontransgenic littermates (average seizure score 1.9-2.9). Seizures are a major phenotype of AD, FXS, Down syndrome, autism and epilepsy, and these data suggested that developmental over-expression of dendritic APP or Abeta increased seizure susceptibility.
Xiao L, Chen W, Guo W, Li H, Chen R, Chen Q Medicine (Baltimore). 2025; 104(7):e41414.
PMID: 39960946 PMC: 11835119. DOI: 10.1097/MD.0000000000041414.
Zou Y, Wang C, Li H, Zhong M, Lin J, Hu Y Front Pharmacol. 2024; 15:1500105.
PMID: 39545066 PMC: 11560768. DOI: 10.3389/fphar.2024.1500105.
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Barbour A, Gourmaud S, Lancaster E, Li X, Stewart D, Hoag K Brain. 2024; 147(6):2169-2184.
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C Sekhar V, Gulia K, Deepti A, Baby Chakrapani P, Baby S, Viswanathan G Mol Neurobiol. 2023; 61(6):3296-3313.
PMID: 37987958 DOI: 10.1007/s12035-023-03741-w.
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Yao A, Halloran P, Ge Y, Singh N, Zhou J, Galske J J Neurosci. 2023; 43(35):6197-6211.
PMID: 37536983 PMC: 10476643. DOI: 10.1523/JNEUROSCI.2124-22.2023.