Level of PICALM, a key component of clathrin-mediated endocytosis, is correlated with levels of phosphotau and autophagy-related proteins and is associated with tau inclusions in AD, PSP and Pick disease

• Published in: Neurobiology of disease Vol. 94; pp. 32 - 43
• Main Authors: Ando, Kunie, Tomimura, Karen, Sazdovitch, Véronique, Suain, Valérie, Yilmaz, Zehra, Authelet, Michèle, Ndjim, Marième, Vergara, Cristina, Belkouch, Mounir, Potier, Marie-Claude, Duyckaerts, Charles, Brion, Jean-Pierre
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2016; Elsevier
• Subjects: Alzheimer Disease - metabolism; Alzheimer's disease; Autophagy; Autophagy-Related Proteins - metabolism; Beclin-1; Brain - metabolism; Clathrin - metabolism; Corticobasal degeneration; Diffuse Lewy body disease; Endocytosis - physiology; Frontotemporal Lobar Degeneration - metabolism; FTLD-MAPT; FTLD-TDP; Humans; LC3; Life Sciences; Monomeric Clathrin Assembly Proteins - metabolism; Neurobiology; Neurofibrillary Tangles - metabolism; Neurology; Neurons - metabolism; Neurons and Cognition; NFTs; Phosphorylation; PICALM; Pick disease; Pick Disease of the Brain - metabolism; Pneumothorax - metabolism; Progressive supranuclear palsy; Supranuclear Palsy, Progressive - metabolism; Tau; tau Proteins - metabolism; Tauopathies - pathology; Beclin-1; FTLD-MAPT; Tau; Pick disease; Autophagy; NFTs; Progressive supranuclear palsy; FTLD-TDP; Alzheimer's disease; Corticobasal degeneration; LC3; PICALM; Diffuse Lewy body disease
• ISSN: 0969-9961; 1095-953X; 1095-953X
• DOI: 10.1016/j.nbd.2016.05.017

Single nucleotide polymorphisms in PICALM, a key component of clathrin-mediated endocytosis machinery, have been identified as genetic susceptibility loci for late onset Alzheimer's disease (LOAD). We previously reported that PICALM protein levels were decreased in AD brains and that PICALM was co-localised with neurofibrillary tangles in LOAD, familial AD with PSEN1 mutations and Down syndrome. In the present study, we analysed PICALM expression, cell localisation and association with pathological cellular inclusions in other tauopathies and in non-tau related neurodegenerative diseases. We observed that PICALM was associated with neuronal tau pathology in Pick disease and in progressive supranuclear palsy (PSP) and co-localised with both 3R and 4R tau positive inclusions unlike in corticobasal degeneration (CBD) or in frontotemporal lobar degeneration (FTLD)-MAPT P301L. PICALM immunoreactivities were not detected in tau-positive tufted astrocytes in PSP, astrocytic plaques in CBD, Lewy bodies in Lewy body disease, diffuse type (LBD) and in TDP-43-positive inclusions in FTLD. In the frontal cortex in tauopathies, the ratio of insoluble to soluble PICALM was increased while the level of soluble PICALM was decreased and was inversely correlated with the level of phosphotau. PICALM decrease was also significantly correlated with increased LC3-II and decreased Beclin-1 levels in tauopathies and in non-tau related neurodegenerative diseases. These results suggest that there is a close relationship between abnormal PICALM processing, tau pathology and impairment of autophagy in human neurodegenerative diseases. •PICALM and phospho-tau are co-localised in NFTs of AD, Pick disease and of PSP.•Level of PICALM is decreased in tauopathies and inversely correlated with phosphotau.•Level of PICALM is correlated with changes in autophagy markers in tauopathies.•Reduction of soluble PICALM may play a key role in tauopathies by affecting autophagy.