Alzheimer's Disease Research Today is a free monthly online journal that collates and summarizes the latest research about Alzheimer's Disease, including details on diagnosis, memory loss, heredity, treatment, medication.

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

Barrachina M, Maes T, Buesa C, Ferrer I

Institut de Neuropatologia, Servei Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, L'Hospitalet de Llobregat, Spain.

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 betaA-peptide immunization. These findings support the participation of lysosomes in betaA-amyloid and, probably, in hyperphosphorylated tau turnover in AD.

Published 15 September 2006 in Neuropathol Appl Neurobiol, 32(5): 505-16.
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