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.

A key role for the microglial NADPH oxidase in APP-dependent killing of neurons.

Qin B, Cartier L, Dubois-Dauphin M, Li B, Serrander L, Krause KH

Biology of Ageing Laboratory, Department of Geriatrics, Geneva University Hospitals, 2 chemin Petit Bel-Air, 1225 Chêne-Bourg, Geneva, Switzerland.

Reactive oxygen species (ROS) and deposition of cleaved products of amyloid precursor protein (APP) are thought to contribute to neuronal loss observed in Alzheimer's disease (AD). The relationship between these factors was studied in a neuroblastoma and microglia co-culture system. Overexpression of wild-type APP (APP-wt) or APP with three mutations typical of familial AD (APP-3m) in SH-SY5Y neuroblastoma cells did not directly alter their morphology, growth rate, cell cycle or H(2)O(2) sensitivity. In a co-culture of APP-wt neuroblastoma cells with microglia, microglial cells generated ROS and neuronal cells died. The cell death was more pronounced in APP-3m-expressing neurons. Neuroblastoma cell death was attenuated by ROS-scavengers and was dose-dependently inhibited by the NADPH oxidase inhibitor diphenyleneiodonium chloride (DPI). Macrophage cell lines behaved similarly to microglia in the co-culture model. However, a macrophage cell line deficient in the NADPH oxidase subunit, gp91phox, failed to kill neurons. These results suggest that APP-dependent microglia activation and subsequent ROS generation by the phagocyte NADPH oxidase play a crucial role in neuronal killing in a cellular model of AD.

Published 18 September 2006 in Neurobiol Aging, 27(11): 1577-87.
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