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U18666A-mediated apoptosis in cultured murine cortical neurons: Role of caspases, calpains and kinases

Citation

Koh, CH and Qi, RZ and Qu, D and Melendez, A and Manikandan, J and Bay, BH and Duan, W and Cheung, NS, U18666A-mediated apoptosis in cultured murine cortical neurons: Role of caspases, calpains and kinases, Cellular Signalling, 18, (10) pp. 1572-1583. ISSN 0898-6568 (2006) [Refereed Article]

DOI: doi:10.1016/j.cellsig.2005.12.006

Abstract

Studies have suggested that cholesterol imbalance in the brain might be related to the development of neurological disorders such as Alzheimer's disease and Niemann-Pick disease type C. Previously, we have reported that U18666A, a cholesterol transport-inhibiting agent, leads to apoptosis and intracellular cholesterol accumulation in primary cortical neurons. In this study, we examined the effects of U18666A-mediated neuronal apoptosis, and found that chronic exposure to U18666A led to the activation of caspases and calpains and hyperphosphorylation of tau. Tau hyperphosphorylation is regulated by several kinases that phosphorylate specific sites of tau in vitro. Surprisingly, the kinase activity of cyclin-dependent kinase 5 decreased in U18666A-treated cortical neurons whereas its protein level remained unchanged. The amount of glycogen synthase kinase 3 and mitogen-activated protein kinases were found to decrease in their phosphorylated states by Western blot analysis. Gene transcription was further studied using microarray analysis. Genes encoding for kinases and phosphatases were differentially expressed with most up-regulated and some down-regulated in expression upon U18666A treatment. The activation of cysteine proteases and cholesterol accumulation with tauopathies may provide clues to the cellular mechanism of the inhibition of cholesterol transport-mediated cell death in neurodegenerative diseases.

Item Details

Item Type:Refereed Article
Research Division:Medical and Health Sciences
Research Group:Neurosciences
Research Field:Cellular Nervous System
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Nervous System and Disorders
Author:Cheung, NS (Dr Nam Cheung)
ID Code:61604
Year Published:2006
Web of Science® Times Cited:32
Deposited By:Menzies Institute for Medical Research
Deposited On:2010-03-04
Last Modified:2010-05-03
Downloads:0

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