Neuroprotective role of MMP-9 overexpression in the brain of Alzheimer's 5xFAD mice

Neurobiology of Disease - 2014-10-01Fragkouli A, Tsilibary EC, Tzinia A10.1016/j.nbd.2014.06.021
Alzheimer's disease (AD), the most prevalent age-related neurodegenerative disorder, is characterized by widespread synaptic loss, neuronal death and progressive cognitive decline. One of the hallmarks of AD is the abnormal deposition of aggregated amyloid-β peptide (Aβ) in extracellular plaques within the brain. Aβ, generated upon cleavage of the parent amyloid-β precursor protein (APP) by β- and γ-secretases, can form soluble oligomers, that were reported to be neurotoxic (Cheng et al., 2007, Dodart et al., 2002, Lacor et al., 2007, Mucke et al., 2000, Selkoe, 2002, Walsh and Selkoe, 2007, Walsh et al., 2002), as well as large insoluble aggregates, the major components of mature plaques, which do not appear linked with toxicity (Lee et al., 2007). Alternatively, APP can be cleaved within the Aβ sequence by enzymes with α-secretase activity, giving rise to the Ν-terminal fragment soluble APPα (sAPPα), a potent neurotrophic factor (Turner et al., 2003), that has been shown to play a critical role in neuronal plasticity and memory formation