Neurosteroids block the increase in intracellular calcium level induced by Alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons

Midori Kato-Negishi1, Masahiro Kawahara21Department of Developmental Morphology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu-shi, Tokyo 183- 8526, Japan; 2Department of Analytical Chemistry, School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, 1714-1 Y...

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Autores principales: Midori Kato-Negishi, Masahiro Kawahara
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spelling oai:doaj.org-article:24b8e4f0ec8d4d80b8a63da1034116292021-12-02T05:04:34ZNeurosteroids block the increase in intracellular calcium level induced by Alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons1176-63281178-2021https://doaj.org/article/24b8e4f0ec8d4d80b8a63da1034116292008-03-01T00:00:00Zhttp://www.dovepress.com/neurosteroids-block-the-increase-in-intracellular-calcium-level-induce-a988https://doaj.org/toc/1176-6328https://doaj.org/toc/1178-2021Midori Kato-Negishi1, Masahiro Kawahara21Department of Developmental Morphology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu-shi, Tokyo 183- 8526, Japan; 2Department of Analytical Chemistry, School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, 1714-1 Yoshino-cho, Nobeoka-shi, Miyazaki 882-8508, JapanAbstract: The neurotoxicity of β-amyloid protein (AβP) is implicated in the etiology of Alzheimer’s disease. We previously have demonstrated that AβP forms Ca2+-permeable pores on neuronal membranes, causes a marked increase in intracellular calcium level, and leads to neuronal death. Here, we investigated in detail the features of AβP-induced changes in intracellular Ca2+ level in primary cultured rat hippocampal neurons using a multisite Ca2+- imaging system with fura-2 as a fluorescent probe. Only a small fraction of short-term cultured hippocampal neurons (ca 1 week in vitro) exhibited changes in intracellular Ca2+ level after AβP exposure. However, AβP caused an acute increase in intracellular Ca2+ level in long-term cultured neurons (ca 1 month in vitro). The responses to AβP were highly heterogeneous, and immunohistochemical analysis using an antibody to AβP revealed that AβP is deposited on some but not all neurons. Considering that the disruption of Ca2+ homeostasis is the primary event in AβP neurotoxicity, substances that protect neurons from an AβP-induced intracellular Ca2+ level increase may be candidates as therapeutic drugs for Alzheimer’s disease. In line with the search for such protective substances, we found that the preadministration of neurosteroids including dehydroepiandrosterone, dehydroepiandrosterone sulfate, and pregnenolone significantly inhibits the increase in intracellular calcium level induced by AβP. Our results suggest the possible significance of neurosteroids, whose levels are reduced in the elderly, in preventing AβP neurotoxicity.Keywords: neurotoxicity, pore, calcium homeostasis, channel, aging Midori Kato-NegishiMasahiro KawaharaDove Medical PressarticleNeurosciences. Biological psychiatry. NeuropsychiatryRC321-571Neurology. Diseases of the nervous systemRC346-429ENNeuropsychiatric Disease and Treatment, Vol 2008, Iss Issue 1, Pp 209-218 (2008)
institution DOAJ
collection DOAJ
language EN
topic Neurosciences. Biological psychiatry. Neuropsychiatry
RC321-571
Neurology. Diseases of the nervous system
RC346-429
spellingShingle Neurosciences. Biological psychiatry. Neuropsychiatry
RC321-571
Neurology. Diseases of the nervous system
RC346-429
Midori Kato-Negishi
Masahiro Kawahara
Neurosteroids block the increase in intracellular calcium level induced by Alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons
description Midori Kato-Negishi1, Masahiro Kawahara21Department of Developmental Morphology, Tokyo Metropolitan Institute for Neuroscience, 2-6 Musashidai, Fuchu-shi, Tokyo 183- 8526, Japan; 2Department of Analytical Chemistry, School of Pharmaceutical Sciences, Kyushu University of Health and Welfare, 1714-1 Yoshino-cho, Nobeoka-shi, Miyazaki 882-8508, JapanAbstract: The neurotoxicity of β-amyloid protein (AβP) is implicated in the etiology of Alzheimer’s disease. We previously have demonstrated that AβP forms Ca2+-permeable pores on neuronal membranes, causes a marked increase in intracellular calcium level, and leads to neuronal death. Here, we investigated in detail the features of AβP-induced changes in intracellular Ca2+ level in primary cultured rat hippocampal neurons using a multisite Ca2+- imaging system with fura-2 as a fluorescent probe. Only a small fraction of short-term cultured hippocampal neurons (ca 1 week in vitro) exhibited changes in intracellular Ca2+ level after AβP exposure. However, AβP caused an acute increase in intracellular Ca2+ level in long-term cultured neurons (ca 1 month in vitro). The responses to AβP were highly heterogeneous, and immunohistochemical analysis using an antibody to AβP revealed that AβP is deposited on some but not all neurons. Considering that the disruption of Ca2+ homeostasis is the primary event in AβP neurotoxicity, substances that protect neurons from an AβP-induced intracellular Ca2+ level increase may be candidates as therapeutic drugs for Alzheimer’s disease. In line with the search for such protective substances, we found that the preadministration of neurosteroids including dehydroepiandrosterone, dehydroepiandrosterone sulfate, and pregnenolone significantly inhibits the increase in intracellular calcium level induced by AβP. Our results suggest the possible significance of neurosteroids, whose levels are reduced in the elderly, in preventing AβP neurotoxicity.Keywords: neurotoxicity, pore, calcium homeostasis, channel, aging
format article
author Midori Kato-Negishi
Masahiro Kawahara
author_facet Midori Kato-Negishi
Masahiro Kawahara
author_sort Midori Kato-Negishi
title Neurosteroids block the increase in intracellular calcium level induced by Alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons
title_short Neurosteroids block the increase in intracellular calcium level induced by Alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons
title_full Neurosteroids block the increase in intracellular calcium level induced by Alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons
title_fullStr Neurosteroids block the increase in intracellular calcium level induced by Alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons
title_full_unstemmed Neurosteroids block the increase in intracellular calcium level induced by Alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons
title_sort neurosteroids block the increase in intracellular calcium level induced by alzheimer’s β-amyloid protein in long-term cultured rat hippocampal neurons
publisher Dove Medical Press
publishDate 2008
url https://doaj.org/article/24b8e4f0ec8d4d80b8a63da103411629
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AT masahirokawahara neurosteroidsblocktheincreaseinintracellularcalciumlevelinducedbyalzheimeramprsquosampbetaamyloidproteininlongtermculturedrathippocampalneurons
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