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Role of potassium channels in Aβ 1–40 ‐activated apoptotic pathway in cultured cortical neurons
Author(s) -
Yu Haibo,
Li Zhengbin,
Zhang Haixia,
Wang Xiaoliang
Publication year - 2006
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.21054
Subject(s) - potassium channel , apoptosis , potassium channel blocker , tetraethylammonium , microbiology and biotechnology , potassium , programmed cell death , chemistry , cytochrome c , channel blocker , neuroscience , biology , biophysics , biochemistry , organic chemistry , calcium
Potassium channel dysfunction has been implicated in Alzheimer's disease (AD). In the present study, by using potassium channel blocker tetraethylammonium (TEA), we investigated the relationship between the enhancement of potassium currents and the alteration of apoptotic cascade in the neuronal apoptotic model induced by beta‐amyloid peptide 1‐40(Aβ 1–40 ). Cortical neurons exposed to Aβ 1–40 5 μM developed a specific increase in the delayed rectifier potassium current ( I K ), but not the transient outward potassium currents ( I A ), before the appearance of neuronal apoptosis. Aβ 1–40 induced various apoptotic features such as chromatin condensation, a decrease in the amount of Bcl‐2 protein, an increase in the amount of Bax protein, cytochrome c release from mitochondria, and caspase‐3 activation. Potassium channel blocker 5 mM TEA attenuated Aβ 1–40 ‐induced neuronal death and prevented the alterations of all above mentioned apoptotic indicators. The study indicates that I K enhancement might play an important role in certain form of programmed cell death induced by beta‐amyloid peptide (Aβ). Increased potassium channel activity might trigger the activation of apoptosis cascade in Aβ 1–40 ‐treated rat cortical neurons. © 2006 Wiley‐Liss, Inc.