Lysosome‐associated membrane protein 1 (LAMP‐1) in Alzheimer's disease

M Barrachina, T Maes, C Buesa… - … and applied neurobiology, 2006 - Wiley Online Library
M Barrachina, T Maes, C Buesa, I Ferrer
Neuropathology and applied neurobiology, 2006Wiley Online Library
Lysosome‐associated membrane protein 1 (LAMP‐1) is a glycoprotein highly expressed in
lysosomal membranes. The present study was initiated to test LAMP‐1 mRNA and protein
levels in post mortem frontal cortex (area 8) of Alzheimer's disease (AD) stages I–IIA/B and
stages V–VIC of Braak and Braak, compared with age‐matched controls. TaqMan PCR
assays and Western blots demonstrated upregulation of LAMP‐1 mRNA and protein in the
cerebral cortex in ADVC. In addition, immunohistochemical studies have shown increased …
Lysosome‐associated membrane protein 1 (LAMP‐1) is a glycoprotein highly expressed in lysosomal membranes. The present study was initiated to test LAMP‐1 mRNA and protein levels in post mortem frontal cortex (area 8) of Alzheimer’s disease (AD) stages I–IIA/B and stages V–VIC of Braak and Braak, compared with age‐matched controls. TaqMan PCR assays and Western blots demonstrated upregulation of LAMP‐1 mRNA and protein in the cerebral cortex in ADVC. In addition, immunohistochemical studies have shown increased LAMP‐1 immunoreactivity in neurones, and in glial cells surrounding senile plaques, in AD cases. Interestingly, LAMP‐1 immunoreactivity has little correlation with phosphorylated tau deposition and neurofibrillary tangles (NFTs), as neurones with NFTs were rarely LAMP‐1 immunoreactive. In contrast, LAMP‐1 expression was enhanced in neurones with granulovacuolar degeneration. Finally, LAMP‐1 occurred in microglia and multinucleated giant cells in one AD case in whom amyloid burden was cleared following βA‐peptide immunization. These findings support the participation of lysosomes in βA‐amyloid and, probably, in hyperphosphorylated tau turnover in AD.
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