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Rueli RHLH, Torres DJ, Dewing AST, Kiyohara AC, Barayuga SM, Bellinger MT, Uyehara-Lock JH, White LR, Moreira PI, Berry MJ, Perry G, Bellinger FP. Selenoprotein S Reduces Endoplasmic Reticulum Stress-Induced Phosphorylation of Tau: Potential Role in Selenate Mitigation of Tau Pathology. J Alzheimers Dis 2018; 55:749-762. [PMID: 27802219 DOI: 10.3233/jad-151208] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Previous studies demonstrated that selenium in the form of sodium selenate reduces neurofibrillary tangle formation in Alzheimer's disease models. Hyperphosphorylation of tau, which leads to formation of neurofibrillary tangles in Alzheimer's disease, is increased by endoplasmic reticulum (ER) stress. Selenoprotein S (SelS) is part of an ER membrane complex that removes misfolded proteins from the ER as a means to reduce ER stress. Selenate, as with other forms of selenium, will increase selenoprotein expression. We therefore proposed that increased SelS expression by selenate would contribute to the beneficial actions of selenate in Alzheimer's disease. SelS expression increased with ER stress and decreased under conditions of elevated glucose concentrations in the SH-SY5Y neuronal cell line. Reducing expression of SelS with siRNA promoted cell death in response to ER stress. Selenate increased SelS expression, which significantly correlated with decreased tau phosphorylation. Restricting SelS expression during ER stress conditions increased tau phosphorylation, and also promoted aggregation of phosphorylated tau in neurites and soma. In human postmortem brain, SelS expression coincided with neurofibrillary tangles, but not with amyloid-β plaques. These results indicate that selenate can alter phosphorylation of tau by increasing expression of SelS in Alzheimer's disease and potentially other neurodegenerative disorders.
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Affiliation(s)
- Rachel H L H Rueli
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - Daniel J Torres
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - Andrea S T Dewing
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - Arlene C Kiyohara
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - Stephanie M Barayuga
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - Miyoko T Bellinger
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - Jane H Uyehara-Lock
- Department of Pathology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - Lon R White
- Pacific Health Research and Education Institute, Honolulu, HI, USA
| | - Paula I Moreira
- Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra and Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - Marla J Berry
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA
| | - George Perry
- UTSA Neurosciences Institute and Department of Biology, University of Texas at San Antonio, San Antonio, TX, USA
| | - Frederick P Bellinger
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA
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Andres MA, Cooke IM, Bellinger FP, Berry MJ, Zaporteza MM, Rueli RH, Barayuga SM, Chang L. Methamphetamine acutely inhibits voltage-gated calcium channels but chronically up-regulates L-type channels. J Neurochem 2015; 134:56-65. [PMID: 25807982 DOI: 10.1111/jnc.13104] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 03/04/2015] [Accepted: 03/06/2015] [Indexed: 11/30/2022]
Abstract
In neurons, calcium (Ca(2+) ) channels regulate a wide variety of functions ranging from synaptic transmission to gene expression. They also induce neuroplastic changes that alter gene expression following psychostimulant administration. Ca(2+) channel blockers have been considered as potential therapeutic agents for the treatment of methamphetamine (METH) dependence because of their ability to reduce drug craving among METH users. Here, we studied the effects of METH exposure on voltage-gated Ca(2+) channels using SH-SY5Y cells as a model of dopaminergic neurons. We found that METH has different short- and long-term effects. A short-term effect involves immediate (< 5 min) direct inhibition of Ca(2+) ion movements through Ca(2+) channels. Longer exposure to METH (20 min or 48 h) selectively up-regulates the expression of only the CACNA1C gene, thus increasing the number of L-type Ca(2+) channels. This up-regulation of CACNA1C is associated with the expression of the cAMP-responsive element-binding protein (CREB), a known regulator of CACNA1C gene expression, and the MYC gene, which encodes a transcription factor that putatively binds to a site proximal to the CACNA1C gene transcription initiation site. The short-term inhibition of Ca(2+) ion movement and later, the up-regulation of Ca(2+) channel gene expression together suggest the operation of cAMP-responsive element-binding protein- and C-MYC-mediated mechanisms to compensate for Ca(2+) channel inhibition by METH. Increased Ca(2+) current density and subsequent increased intracellular Ca(2+) may contribute to the neurodegeneration accompanying chronic METH abuse. Methamphetamine (METH) exposure has both short- and long-term effects. Acutely, methamphetamine directly inhibits voltage-gated calcium channels. Chronically, neurons compensate by up-regulating the L-type Ca(2+) channel gene, CACNA1C. This compensatory mechanism is mediated by transcription factors C-MYC and CREB, in which CREB is linked to the dopamine D1 receptor signaling pathway. These findings suggest Ca(2+) -mediated neurotoxicity owing to over-expression of calcium channels.
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Affiliation(s)
- Marilou A Andres
- Bekesy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawaii, Honolulu, Hawaii, USA
| | - Ian M Cooke
- Bekesy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawaii, Honolulu, Hawaii, USA.,Department of Biology, University of Hawaii, Honolulu, Hawaii, USA
| | - Frederick P Bellinger
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Marla J Berry
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Maribel M Zaporteza
- Bekesy Laboratory of Neurobiology, Pacific Biosciences Research Center, University of Hawaii, Honolulu, Hawaii, USA
| | - Rachel H Rueli
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Stephanie M Barayuga
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
| | - Linda Chang
- Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA
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Barayuga SM, Pang X, Andres MA, Panee J, Bellinger FP. Methamphetamine decreases levels of glutathione peroxidases 1 and 4 in SH-SY5Y neuronal cells: protective effects of selenium. Neurotoxicology 2013; 37:240-6. [PMID: 23721877 PMCID: PMC3717519 DOI: 10.1016/j.neuro.2013.05.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 04/23/2013] [Accepted: 05/06/2013] [Indexed: 12/14/2022]
Abstract
Methamphetamine interferes with dopamine reuptake, and the resulting increased dopamine oxidation that creates oxidative stress can lead to degeneration of dopaminergic terminals. Previous studies have shown that the trace element selenium protects against methamphetamine toxicity. However, the specific selenoproteins responsible for protection have not been elucidated. Glutathione peroxidases 1 and 4 (GPx1 and GPx4) incorporate selenium into the amino acid selenocysteine, and their known antioxidant functions make them good candidates for protection from methamphetamine-induced oxidative damage. We differentiated SH-SY5Y neuronal cells in serum-free media with defined supplement containing 0, 10 and 100 nM selenium, and then challenged the cells with a 24-h exposure to methamphetamine. We found that 100 μM methamphetamine decreased GPx1 and GPx4 protein levels. However, both proteins were upregulated with increasing media selenium concentration. GPx enzymatic activity was also increased by selenium and decreased by methamphetamine and correlated with GPx protein levels. Total glutathione levels were reduced by methamphetamine at lower selenium conditions, while the oxidized fraction of GSH was increased at higher selenium levels. Additionally, we observed an increased generation of reactive oxygen species with methamphetamine exposure in media with 0 nM selenium, which was ameliorated by selenium supplementation. These results show that methamphetamine increases oxidative stress by reducing GPx levels, and this can be reversed with addition of selenium. These findings have important implications for treating patients with acute methamphetamine toxicity.
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Affiliation(s)
- Stephanie M Barayuga
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street, Honolulu, HI 96813, USA
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