101
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Niu J, Azfer A, Rogers LM, Wang X, Kolattukudy PE. Cardioprotective effects of cerium oxide nanoparticles in a transgenic murine model of cardiomyopathy. Cardiovasc Res 2006; 73:549-59. [PMID: 17207782 PMCID: PMC1855085 DOI: 10.1016/j.cardiores.2006.11.031] [Citation(s) in RCA: 294] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2006] [Revised: 11/20/2006] [Accepted: 11/21/2006] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE Cerium oxide (CeO2) nanoparticles have been shown to protect cells in culture from lethal stress, but no protection in vivo has been reported. Cardiac-specific expression of monocyte chemoattractant protein (MCP)-1 in mice causes ischemic cardiomyopathy associated with activation of endoplasmic reticulum (ER) stress. The aim of this study was to assess the effects of CeO2 nanoparticles on cardiac function and remodeling as well as ER stress response in this murine model of cardiomyopathy. METHODS MCP-1 transgenic mice (MCP mice) and wild-type controls were administered intravenously 15 nmol of CeO2 nanoparticles or vehicle only twice a week for 2 weeks. Cardiac function, myocardial histology, nitrotyrosine formation, expression of cytokines, and ER stress-associated genes were evaluated. RESULTS Treatment with CeO2 nanoparticles markedly inhibited progressive left ventricular dysfunction and dilatation in MCP mice and caused a significant decrease in serum levels of MCP-1, C-reactive protein, and total nitrated proteins. The infiltration of monocytes/macrophages, accumulation of 3-nitrotyrosine, apoptotic cell death, and expression of proinflammatory cytokines, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-6 in the myocardium were markedly inhibited by CeO2 nanoparticles. Expression of the key ER stress-associated genes, including glucose-regulated protein 78 (Grp78), protein disulfide isomerase (PDI), and heat shock proteins (HSP25, HSP40, HSP70), were also suppressed by CeO2 nanoparticles. CONCLUSIONS CeO2 nanoparticles protect against the progression of cardiac dysfunction and remodeling by attenuation of myocardial oxidative stress, ER stress, and inflammatory processes probably through their autoregenerative antioxidant properties.
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Affiliation(s)
- Jianli Niu
- Biomolecular Science Center, Burnett College of Biomedical Science, University of Central Florida, Orlando, FL 32816, USA
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102
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Woltjer RL, McMahan W, Milatovic D, Kjerulf JD, Shie FS, Rung LG, Montine KS, Montine TJ. Effects of chemical chaperones on oxidative stress and detergent-insoluble species formation following conditional expression of amyloid precursor protein carboxy-terminal fragment. Neurobiol Dis 2006; 25:427-37. [PMID: 17141508 DOI: 10.1016/j.nbd.2006.10.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2006] [Revised: 09/29/2006] [Accepted: 10/11/2006] [Indexed: 11/19/2022] Open
Abstract
Oxidative stress, protein misfolding, protein complex formation, and detergent insolubility are biochemical features of Alzheimer's disease (AD). We tested the cause-and-effect relationships among these using MC65 human neuroblastoma cells that exhibit toxicity upon conditional expression of carboxy-terminal fragments (CTFs) of the human amyloid precursor protein (APP). Treatments with three different antioxidants (alpha-tocopherol, N-acetyl cysteine, and alpha-lipoic acid) or three different compounds (glycerol, trimethylamine-N-oxide, and 4-phenylbutyric acid) that have been described to have a "chemical chaperone" function in promoting protein folding all had a protective effect on MC65 cells and decreased markers of oxidative damage and accumulation of high molecular weight amyloid (A) beta-immunoreactive (IR) species. However, chaperones partially reduced detergent insolubility of the remaining Abeta-IR species, while antioxidants did not. These results suggest that protein misfolding associated with overexpression of APP CTFs promotes oxidative stress and cytotoxicity and contributes to formation of detergent-insoluble species that appear unrelated to cytotoxicity.
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Affiliation(s)
- Randall L Woltjer
- Department of Pathology, University of Washington, Box 359645, Harborview Medical Center, 300 Ninth Avenue, Seattle, WA 98104, USA.
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103
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Lou LX, Geng B, Yu F, Zhang J, Pan CS, Chen L, Qi YF, Ke Y, Wang X, Tang CS. Endoplasmic reticulum stress response is involved in the pathogenesis of stress induced gastric lesions in rats. Life Sci 2006; 79:1856-64. [PMID: 16875701 DOI: 10.1016/j.lfs.2006.06.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Revised: 05/28/2006] [Accepted: 06/13/2006] [Indexed: 11/26/2022]
Abstract
Stress gastric ulcer is a serious complication, but the mechanism involved is not fully clarified. It is well known that mucosal cell apoptosis plays a crucial role in the pathogenesis of gastric ulceration. Recent studies have shown that endoplasmic reticulum (ER) stress is an important pathway leading to cellular apoptosis. To investigate the role of ER stress in the pathogenesis of stress gastric ulcer, we studied the alteration in the expression of ER stress markers GRP78 (glucose-regulated protein 78) and caspase-12 (an ER stress-specific proapoptotic molecule) and their relations with gastric mucosal apoptosis during development of stress gastric lesions in the water-immersion and restraint stress (WRS) model in rats. Rats developed severe gastric lesions after 6 h of WRS. Typical apoptosis was observed at the edge cells of WRS induced gastric lesions. Western blot analysis showed that GRP78 and activated caspase-12 were over-expressed in the gastric tissues of WRS rats. Immunohistochemical analysis demonstrated that increased GRP78 and caspase-12 were distributed only under the lesions. In addition, dithiothreitol and tunicamycin (ER stress inducers), which increased the expression of GRP78 and activated caspase-12, caused gastric mucosal injury and mucosal cell apoptosis in vitro. These findings suggest that ER stress might be involved in the development of stress gastric ulcer through an apoptotic mechanism.
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Affiliation(s)
- Li Xia Lou
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing, China
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104
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López-Antón N, Rudy A, Barth N, Schmitz ML, Schmitz LM, Pettit GR, Schulze-Osthoff K, Dirsch VM, Vollmar AM. The marine product cephalostatin 1 activates an endoplasmic reticulum stress-specific and apoptosome-independent apoptotic signaling pathway. J Biol Chem 2006; 281:33078-86. [PMID: 16945918 DOI: 10.1074/jbc.m607904200] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cephalostatin 1, a bis-steroidal marine natural product, has been reported to induce apoptosis without the requirement of an active caspase-8 or mitochondrial cytochrome c release and apoptosome formation. Here we show that despite the absence of these events, caspase-9 activation is essential for cephalostatin 1-induced apoptosis. Cephalostatin 1 initiates a rapid endoplasmic reticulum stress response characterized by phosphorylation of eukaryotic initiation factor-2 alpha-subunit and increased expression of the chaperone immunoglobulin heavy chain-binding protein GRP78 as well as the transcription factor C/EBP homologous protein (CHOP)/GADD153. Cephalostatin 1 activates apoptosis signal-regulating kinase 1 and c-Jun N-terminal kinase (JNK). However, this pathway does not play a major role in cephalostatin 1-induced apoptosis, as assessed by stable expression of a dominant negative apoptosis signal-regulating kinase 1. Importantly, the endoplasmic reticulum-associated caspase-4 is required and as shown by biochemical and genetic inhibition experiments, acts upstream of caspase-9 in cephalostatin-induced apoptosis.
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Affiliation(s)
- Nancy López-Antón
- Department of Pharmacy, Center of Drug Research, University of Munich, 81377 Munich, Germany
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105
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Brouland JP, Valleur P, Papp B. Expression des pompes calciques de type SERCA au cours de la différenciation cellulaire et de la tumorigenèse: application à la carcinogenèse colique. Ann Pathol 2006; 26:159-72. [PMID: 17127848 DOI: 10.1016/s0242-6498(06)70701-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Calcium homeostasis of the endoplasmic reticulum (ER) is involved in intracellular signaling pathways and is implicated in major cell functions such as cell growth, differentiation, protein synthesis and apoptosis. The accumulation of calcium in the ER is performed by specific sarco/endoplasmic reticulum calcium transport ATPases (SERCA iso-enzymes). The expression of biochemically distinct SERCA isoforms is cell type dependent and developmentally regulated. This review summarizes pertinent data about the modulation of the expression of SERCA enzymes during the differentiation of normal and tumor cells. These data support the implication of SERCA pumps and especially SERCA3 in the differentiation program of cancer and leukemia cells. During the multi-step process of colon carcinogenesis, the decrease of SERCA3 expression seems to be linked to enhanced APC/ss-catenin/TCF4 signaling and deficient Sp1-like factor-dependent transcription.
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Affiliation(s)
- Jean-Philippe Brouland
- Service d'Anatomie et de Cytologie Pathologiques, Hôpital Lariboisière, 75475 Paris Cedex 10, France.
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106
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Rissanen A, Sivenius J, Jolkkonen J. Prolonged bihemispheric alterations in unfolded protein response related gene expression after experimental stroke. Brain Res 2006; 1087:60-6. [PMID: 16684512 DOI: 10.1016/j.brainres.2006.02.095] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2005] [Revised: 02/10/2006] [Accepted: 02/26/2006] [Indexed: 11/19/2022]
Abstract
After ischemia, endoplasmic reticulum (ER) stress pathways are activated that include unfolded protein response (UPR) and protein synthesis inhibition (PSI). Both of these mechanisms aim to restore ER functioning mainly by inhibition of translation and increased processing of excess proteins in ER. We were interested in the role of these pathways during spontaneous recovery after transient middle cerebral artery occlusion (MCAO) in rats. The spontaneous recovery of rats was assessed with a limb-placing test. The expression of ER-stress-related genes (IRE1, ATF6, GRP78, eif2alpha, ATF4, PERK) was studied by using in situ hybridization in different brain areas on post-operative days 2, 7, 14 and 28. Elevated signals were detected in striatum contralateral to the lesion on days 2 (PERK and IRE1) and 14 post-ischemia (IRE1). Gene expression was elevated on day 7 in the striatum ipsilateral to the lesion (ATF6 and GRP78) and on day 14 (GRP78) post-ischemia. Furthermore, elevated levels of GRP78 were detected on day 14 after ischemia in the ipsilateral sensorimotor cortex. These results suggest that altered gene expression related to unfolded protein response may be more long lasting than expected following focal cerebral ischemia. In addition, these results show that the response to ER stress differs ipsi- and contralaterally after MCAO in rats. Since these differences are detected in both hemispheres only in areas adjacent to the lesion, UPR may contribute to spontaneous recovery after MCAO in rats.
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Affiliation(s)
- Anna Rissanen
- Department of Neurology and Neuroscience, University of Kuopio, Kuopio, Finland.
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107
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Boyce M, Yuan J. Cellular response to endoplasmic reticulum stress: a matter of life or death. Cell Death Differ 2006; 13:363-73. [PMID: 16397583 DOI: 10.1038/sj.cdd.4401817] [Citation(s) in RCA: 539] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The proper functioning of the endoplasmic reticulum (ER) is critical for numerous aspects of cell physiology. Accordingly, all eukaryotes react rapidly to ER dysfunction through a set of adaptive pathways known collectively as the ER stress response (ESR). Normally, this suite of responses succeeds in restoring ER homeostasis. However, in metazoans, persistent or intense ER stress can also trigger programmed cell death, or apoptosis. ER stress and the apoptotic program coupled to it have been implicated in many important pathologies but the regulation and execution of ER stress-induced apoptosis in mammals remain incompletely understood. Here, we review what is known about the ESR in both yeast and mammals, and highlight recent findings on the mechanism and pathophysiological importance of ER stress-induced apoptosis.
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Affiliation(s)
- M Boyce
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
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108
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Azfer A, Niu J, Rogers LM, Adamski FM, Kolattukudy PE. Activation of endoplasmic reticulum stress response during the development of ischemic heart disease. Am J Physiol Heart Circ Physiol 2006; 291:H1411-20. [PMID: 16617122 PMCID: PMC1575464 DOI: 10.1152/ajpheart.01378.2005] [Citation(s) in RCA: 192] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Endoplasmic reticulum (ER) stress has been found to be associated with neurodegenerative diseases and diabetes mellitus. Whether ER stress is involved in the development of heart disease is not known. Cardiac-specific expression of monocyte chemoattractant protein-1 (MCP-1) in mice causes the development of ischemic heart disease. Here we report that microarray analysis of gene expression changes in the heart of these transgenic mice revealed that a cluster of ER stress-related genes was transcriptionally activated in the heart during the development of ischemic heart disease. The gene array results were verified by quantitative real-time PCR that showed highly elevated transcript levels of genes involved in unfolded protein response such as ER and cytoplasmic chaperones, oxidoreductases, protein disulfide isomerase (PDI) family, and ER-associated degradation system such as ubiquitin. Immunoblot analysis confirmed the expression of chaperones, PDI, and ubiquitin. Immunohistochemical analyses showed that ER stress proteins were associated mainly with the degenerating cardiomyocytes. A novel ubiquitin fold modifier (Ufm1) that has not been previously associated with ER stress and not found to be induced under any condition was also found to be upregulated in the hearts of MCP mice (transgenic mice that express MCP-1 specifically in the heart). The present results strongly suggest that activation of ER stress response is involved in the development of ischemic heart disease in this murine model.
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Affiliation(s)
| | | | | | | | - Pappachan E. Kolattukudy
- Address for reprint requests and other correspondence: P. E. Kolattukudy, Biomolecular Science Center, Burnett College of Biomedical Sciences, Univ. of Central Florida, Bldg. 20, Rm. 136, Orlando, FL 32816-2364 (e-mail: )
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109
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Scheper GC, Proud CG, van der Knaap MS. Defective translation initiation causes vanishing of cerebral white matter. Trends Mol Med 2006; 12:159-66. [PMID: 16545608 DOI: 10.1016/j.molmed.2006.02.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Revised: 02/06/2006] [Accepted: 02/28/2006] [Indexed: 01/19/2023]
Abstract
Leukoencephalopathy with vanishing white matter (VWM) is one of the most prevalent inherited white-matter disorders, especially in Caucasian populations. VWM is unusual because of its sensitivity to febrile infections and minor head trauma. The basic defect of this enigmatic brain disease resides in the regulation of initiation of protein synthesis. Recently, undue activation of the unfolded-protein response has emerged as an important factor in the pathophysiology of VWM. Here, we discuss the mechanisms that might be responsible for the selective involvement of the brain white matter in VWM. At present, VWM research is in need of an animal model to study disease mechanisms and therapeutic interventions.
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Affiliation(s)
- Gert C Scheper
- Department of Pediatrics, VU University Medical Center, 1081 HV Amsterdam, The Netherlands.
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110
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Usachev YM, Marsh AJ, Johanns TM, Lemke MM, Thayer SA. Activation of protein kinase C in sensory neurons accelerates Ca2+ uptake into the endoplasmic reticulum. J Neurosci 2006; 26:311-8. [PMID: 16399701 PMCID: PMC6674318 DOI: 10.1523/jneurosci.2920-05.2006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The rate of Ca2+ clearance from the neuronal cytoplasm affects the amplitude, duration, and localization of Ca2+ signals and influences a variety of Ca2+-dependent functions. We reported previously that activation of protein kinase C (PKC) accelerates Ca2+ efflux in rat sensory neurons mediated by the plasma membrane Ca2+-ATPase isoform 4 (PMCA4). Here we show that sarco-endoplasmic reticulum Ca2+-ATPase (SERCA)-mediated Ca2+ uptake into intracellular stores is also accelerated by PKC activation. The rate of intracellular Ca2+ concentration ([Ca2+]i) clearance was studied after small (<350 nM) action potential-induced Ca2+ loads in rat dorsal root ganglion neurons. Under these conditions, mitochondrial Ca2+ uptake and Na+/Ca2+ exchange do not significantly influence [Ca2+]i recovery. Phorbol dibutyrate (PDBu) increased the rate of [Ca2+]i clearance by 71% in a manner sensitive to the selective PKC inhibitors GF109203x (2-[1-(3-dimethylaminopropyl)-1H-indol-3-yl]-3-(1H-indol-3-yl)maleimide) and calphostin. PKC-dependent acceleration was still observed (approximately 39%) when the PKC-sensitive PMCA isoform was knocked down by expression of an antisense PMCA4 cDNA (AS4). Direct measurement of Ca2+ in the endoplasmic reticulum (ER) lumen revealed that PKC increased the rate of store refilling more than twofold after depletion by treatment with cyclopiazonic acid. ER refilling was less complete in PDBu-treated cells, although, in AS4-expressing cells, PDBu accelerated the rate without reducing the ER capacity, suggesting that PMCA and SERCA compete for Ca2+. Thus, activation of PKC accelerates the clearance of Ca2+ from the cytoplasm by the concerted stimulation of Ca2+ sequestration and Ca2+ efflux.
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Affiliation(s)
- Yuriy M Usachev
- Department of Pharmacology, University of Iowa, Iowa City, Iowa 52242, USA
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111
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Zhao G, Zhou X, Wang L, Li G, Kisker C, Lennarz WJ, Schindelin H. Structure of the mouse peptide N-glycanase-HR23 complex suggests co-evolution of the endoplasmic reticulum-associated degradation and DNA repair pathways. J Biol Chem 2006; 281:13751-13761. [PMID: 16500903 DOI: 10.1074/jbc.m600137200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Peptide N-glycanase removes N-linked oligosaccharides from misfolded glycoproteins as part of the endoplasmic reticulum-associated degradation pathway. This process involves the formation of a tight complex of peptide N-glycanase with Rad23 in yeast and the orthologous HR23 proteins in mammals. In addition to its function in endoplasmic reticulum-associated degradation, HR23 is also involved in DNA repair, where it plays an important role in damage recognition in complex with the xeroderma pigmentosum group C protein. To characterize the dual role of HR23, we have determined the high resolution crystal structure of the mouse peptide N-glycanase catalytic core in complex with the xeroderma pigmentosum group C binding domain from HR23B. Peptide N-glycanase features a large cleft between its catalytic cysteine protease core and zinc binding domain. Opposite the zinc binding domain is the HR23B-interacting region, and surprisingly, the complex interface is fundamentally different from the orthologous yeast peptide N-glycanase-Rad23 complex. Different regions on both proteins are involved in complex formation, revealing an amazing degree of divergence in the interaction between two highly homologous proteins. Furthermore, the mouse peptide N-glycanase-HR23B complex mimics the interaction between xeroderma pigmentosum group C and HR23B, thereby providing a first structural model of how the two proteins interact within the nucleotide excision repair cascade in higher eukaryotes. The different interaction interfaces of the xeroderma pigmentosum group C binding domains in yeast and mammals suggest a co-evolution of the endoplasmic reticulum-associated degradation and DNA repair pathways.
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Affiliation(s)
- Gang Zhao
- Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794; Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794
| | - Xiaoke Zhou
- Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794; Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794
| | - Liqun Wang
- Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794; Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794
| | - Guangtao Li
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794
| | - Caroline Kisker
- Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794; Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York 11794; Rudolf Virchow Center for Experimental Biomedicine and Institute of Structural Biology, University of Würzburg, Versbacher Strasse 9, 97078 Würzburg, Germany
| | - William J Lennarz
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794
| | - Hermann Schindelin
- Center for Structural Biology, Stony Brook University, Stony Brook, New York 11794; Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794; Rudolf Virchow Center for Experimental Biomedicine and Institute of Structural Biology, University of Würzburg, Versbacher Strasse 9, 97078 Würzburg, Germany.
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112
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Toiber D, Soreq H. Cellular stress reactions as putative cholinergic links in Alzheimer's disease. Neurochem Res 2006; 30:909-19. [PMID: 16187225 DOI: 10.1007/s11064-005-6963-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/14/2005] [Indexed: 12/24/2022]
Abstract
Alzheimer's disease involves normal cellular aging and chronic cellular stress events, leading to interrelated changes in gene expression and subsequent neurodegeneration. Premature death of cholinergic neurons and the formation of amyloid fibrils separately initiated the cholinergic and amyloid hypotheses of Alzheimer's disease. Here, we present evidence to the fact that these two distinct phenomena both associate with specific changes in acetylcholinesterase (AChE) gene expression within cholinergic neurons. For example, calcium misregulation promotes aberrant transcription and pro-apoptotic events, as well as AChE-induced modifications in cellular signal cascades. These reciprocally intercept with AChE regulation at the Endoplasmic Reticulum, modifying AChE gene expression, folding and signaling. Altered AChE properties may reflect changes in the enzymatic and/or non-enzymatic features of the multiple AChE splice variants. Under chronic cellular stress, aberrant AChE regulation may thus facilitate apoptotic pathways, promoting plaque formation, cognitive impairments and degeneration of cholinergic nerve cells.
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Affiliation(s)
- Debra Toiber
- Department of Biological Chemistry, The Institute of Life Sciences and The Eric Roland Center for Neurodegenerative Diseases, The Hebrew University of Jerusalem, 91904, Jerusalem, Israel
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113
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Aufenberg C, Wenkel S, Mautes A, Paschen W. Spinal cord trauma activates processing of xbp1 mRNA indicative of endoplasmic reticulum dysfunction. J Neurotrauma 2006; 22:1018-24. [PMID: 16156717 DOI: 10.1089/neu.2005.22.1018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The contribution of the various subcellular compartments in the induction of cell injury triggered by spinal cord trauma has not been clearly elucidated yet. In the present study, we investigated changes in mRNA levels of processed xbp1, ho-1, and hsp70 induced in mice by hemisection or contusion of the spinal cord. The expression of these genes is upregulated under conditions associated with endoplasmic reticulum (ER; xbp1, ho-1) dysfunction or impairment of cytoplasmic function (hsp70) respectively. When the functioning of the ER or the cytoplasm is impaired, unfolded proteins accumulate in these compartments. This is the warning signal for activation of the unfolded protein response (ER) and heat-shock response (cytoplasm) respectively. Spinal cord trauma activated the expression of these genes starting at 3 h and peaking at 6 h of recovery (processed xbp1, 12-fold and fivefold increase; ho-1, fourfold and eightfold increase; hsp70, fourfold, no increase, after contusion and hemisection, respectively). After 6 h of recovery, the rise in hsp70 mRNA levels was confined to the traumatized segment (fourfold), whereas a significant increase in processed xbp1 and ho-1 mRNA levels was also observed in the adjacent segments. This suggests a spread of the pathological process from the site of the primary impact into the surrounding tissue. After induction of spinal cord trauma processed xbp1 mRNA levels rose in a delayed fashion. This implies that the pathological process that causes impairment of ER functioning, starts with a delay of a few hours after induction of trauma and may therefore be amenable to therapeutic intervention.
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Affiliation(s)
- Christoph Aufenberg
- Laboratory of Molecular Neurobiology, Max Planck Institute for Neurological Research, Cologne, Germany
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114
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Awai M, Koga T, Inomata Y, Oyadomari S, Gotoh T, Mori M, Tanihara H. NMDA-induced retinal injury is mediated by an endoplasmic reticulum stress-related protein, CHOP/GADD153. J Neurochem 2006; 96:43-52. [PMID: 16269013 DOI: 10.1111/j.1471-4159.2005.03502.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We investigated the role of an endoplasmic reticulum stress-associated protein, CHOP/GADD153, after NMDA-induced mouse retinal damage. After injection of NMDA into the vitreous, TUNEL-positive cells were detected in the retinal ganglion cell layer (GCL) and inner nuclear layer (INL) at 6 h after NMDA injection, and these gradually increased in number up to 24 h. Analysis by real-time RT-PCR revealed that CHOP mRNA was induced by about 3-fold, at 2 h after NMDA injection. Immunoreactivity for the CHOP protein was intense in cells of the GCL following NMDA treatment. Immunoblot analysis showed that NMDA injection increased the expression of CHOP protein in the retina. Compared with wild-type mice, CHOP/ mice were more resistant to NMDA-induced retinal cell death as determined by TUNEL assay. At 7 days after NMDA treatment, the thickness of the inner plexiform layer and INL were larger in CHOP/ mice than in wild-type mice. The number of residual cells in the GCL following NMDA treatment was significantly higher in CHOP/ mice than in wild-type mice. In conclusion, CHOP is induced in mouse retina by NMDA treatment, and CHOP/ mice are more resistant to NMDA-induced retinal damage, suggesting that CHOP plays an important role in NMDA-induced retinal cell death.
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Affiliation(s)
- Maiko Awai
- Department of Ophthalmology and Visual Science, Kumamoto University Graduate School of Medical Sciences, Kumamoto, Japan
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115
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Paschen W, Mengesdorf T. Cellular abnormalities linked to endoplasmic reticulum dysfunction in cerebrovascular disease—therapeutic potential. Pharmacol Ther 2005; 108:362-75. [PMID: 16140387 DOI: 10.1016/j.pharmthera.2005.05.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 05/26/2005] [Indexed: 01/20/2023]
Abstract
Unfolded proteins accumulate in the lumen of the endoplasmic reticulum (ER) as part of the cellular response to cerebral hypoxia/ischemia and also to the overexpression of the mutant genes responsible for familial forms of degenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyothrophic lateral sclerosis, and Huntington's disease, as well as other disorders that are caused by an expanded CAG repeat. This accumulation arises from an imbalance between the load of proteins that need to be folded and processed in the ER lumen and the ER folding/processing capacity. To withstand such potentially lethal conditions, stress responses are activated that includes the shutdown of translation to reduce the ER work load and the activation of the expression of genes coding for proteins involved in the folding and processing reactions, to increase folding/processing capacity. In transient cerebral ischemia, ER stress-induced suppression of protein synthesis is believed to be too severe to permit sufficient activation of the genetic arm of the ER stress response. Mutations associated with Alzheimer's disease down-regulate the ER stress response and make cells more vulnerable to conditions associated with ER stress. When the functioning of the ER is severely impaired and affected cells can no longer withstand these stressful conditions, programmed cell death is induced, including a mitochondria-driven apoptotic pathway. Raising the resistance of cells to conditions that interfere with ER functions and activating the degradation and refolding of unfolded proteins accumulated in the ER lumen are possible strategies for blocking the pathological process leading to cell death at an early stage.
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Affiliation(s)
- Wulf Paschen
- Multidisciplinary Neuroprotection Laboratories, Duke University Medical Center, Department of Anesthesiology, 132 Sands Building, Research Drive, Durham, NC 27710, USA.
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116
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Abstract
Epilepsy is a common, chronic neurologic disorder characterized by recurrent unprovoked seizures. Experimental modeling and clinical neuroimaging of patients has shown that certain seizures are capable of causing neuronal death. Such brain injury may contribute to epileptogenesis, impairments in cognitive function or the epilepsy phenotype. Research into cell death after seizures has identified the induction of the molecular machinery of apoptosis. Here, the authors review the clinical and experimental evidence for apoptotic cell death pathway function in the wake of seizure activity. We summarize work showing intrinsic (mitochondrial) and extrinsic (death receptor) apoptotic pathway function after seizures, activation of the caspase and Bcl-2 families of cell death modulators and the acute and chronic neuropathologic impact of intervening in these molecular cascades. Finally, we describe evolving data on nonlethal roles for these proteins in neuronal restructuring and cell excitability that have implications for shaping the epilepsy phenotype. This review highlights the work to date on apoptosis pathway signaling during seizure-induced neuronal death and epileptogenesis, and speculates on how emerging roles in brain remodeling and excitability have enriched the number of therapeutic strategies for protection against seizure-damage and epileptogenesis.
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Affiliation(s)
- David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland.
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117
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Hu Q, Chang J, Tao L, Yan G, Xie M, Wang Z. Endoplasmic Reticulum Mediated Necrosis-like Apoptosis of HeLa Cells Induced by Ca2+ Oscillation. BMB Rep 2005; 38:709-16. [PMID: 16336787 DOI: 10.5483/bmbrep.2005.38.6.709] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Apoptosis and necrosis are distinguished by modality primarily. Here we show an apoptosis occurred instantly, induced by 300 muM W-7 ((N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride), inhibitor of calmodulin), which demonstrated necrotic modality. As early as 30 min after W-7 addition, apoptotic (sub-diploid) peak could be detected by fluorescence-activated cell sorter (FACS), "DNA ladders" began to emerge also at this time point, activity of caspase-3 elevated obviously within this period. Absence of mitochondrial membrane potential (MMP) reduction and cytochrome c, AIF (apoptosis inducing factor) release, verified that this rapid apoptosis did not proceed through mitochondria pathway. Activation of caspase-12 and changes of other endoplasmic reticulum (ER) located proteins ascertained that ER pathway mediated this necrosis-like apoptosis. Our findings suggest that it is not credible to judge apoptosis by modality. Elucidation of ER pathway is helpful to comprehend the pathology of diseases associated with ER stress, and may offer a new approach to the therapy of cancer and neurodegenerative diseases.
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Affiliation(s)
- Qingliu Hu
- Medical School, Tsinghua University, Beijing 100084, People's Republic of China
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118
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Larsen GA, Skjellegrind HK, Moe MC, Vinje ML, Berg-Johnsen J. Endoplasmic reticulum dysfunction and Ca2+ deregulation in isolated CA1 neurons during oxygen and glucose deprivation. Neurochem Res 2005; 30:651-9. [PMID: 16176069 DOI: 10.1007/s11064-005-2753-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Intracellular calcium ([Ca2+]i) plays a pivotal role in neuronal ischemia. The aim of the present study was to investigate the routes of Ca2+ entry during non-excitotoxic oxygen and glucose deprivation (OGD) in acutely dissociated rat CA1 neurons. During OGD the fluo-3/fura red ratio reflecting [Ca2+]i increased rapidly and irreversibly. [Ca2+]i increased to the same degree in Ca2 + depleted medium, and also when both the ryanodine receptors (RyR) and the inositol 1,4,5-trisphosphate (IP3) receptors were blocked. When the endoplasmic reticulum (ER) Ca2+ stores were emptied with thapsigargin no increase in [Ca2+]i was observed independent of extracellular Ca2+. The OGD induced Ca2+ deregulation in isolated CA1 neurons is not prevented by removing Ca2+, or by blocking the IP3- or RyR receptors. However, when SERCA was blocked, no increase in [Ca2+]i was observed suggesting that SERCA dysfunction represents an important mechanism for ischemic Ca2+ overload.
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Affiliation(s)
- Geir Arne Larsen
- Institute for Surgical Research, Department of Neurosurgery, National Hospital, Rikshospitalet, N-0027, Oslo, Norway.
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119
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Cullinan SB, Diehl JA. Coordination of ER and oxidative stress signaling: the PERK/Nrf2 signaling pathway. Int J Biochem Cell Biol 2005; 38:317-32. [PMID: 16290097 DOI: 10.1016/j.biocel.2005.09.018] [Citation(s) in RCA: 424] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2005] [Revised: 08/31/2005] [Accepted: 09/29/2005] [Indexed: 12/16/2022]
Abstract
In the broadest sense, cellular stress describes conditions wherein cells encounter and react to a 'non-normal' state. Perturbations may originate through both extracellular and intracellular means. Whereas transient levels of stress are expected to occur on a regular basis, a series of checks and balances ensures that cells are well equipped to maintain a homeostatic state. In the case of supra-physiological stress signaling, cellular challenges are more severe, and programmed cell death may be the best option for the organism. The ability of a cell, and by extension, an organism, to adequately manage cellular stress is fundamental--a question of life or death. The endoplasmic reticulum (ER) is exquisitely poised to sense and respond to cellular stresses including those that result from metabolic and/or protein folding imbalances. In response to stress originating from within the ER, the PERK and Ire1 protein kinases, along with other proximal signaling molecules, initiate a program of transcriptional and translational regulation termed the unfolded protein response. A consequence of ER stress is the accumulation of reactive oxygen species that promotes a state of oxidative stress. PERK signaling, via activation of the Nrf2 and ATF4 transcription factors, coordinates the convergence of ER stress with oxidative stress signaling. Here we discuss progress regarding the signaling pathways involved in these cellular stresses and the implications of the intersection between the two signaling pathways.
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Affiliation(s)
- Sara B Cullinan
- The Leonard and Madlyn Abramson Family Cancer Research Institute and Cancer Center, Philadelphia, PA 19104, USA
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120
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Kantor L, Harding HP, Ron D, Schiffmann R, Kaneski CR, Kimball SR, Elroy-Stein O. Heightened stress response in primary fibroblasts expressing mutant eIF2B genes from CACH/VWM leukodystrophy patients. Hum Genet 2005; 118:99-106. [PMID: 16041584 DOI: 10.1007/s00439-005-0024-x] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2005] [Accepted: 06/17/2005] [Indexed: 11/26/2022]
Abstract
Childhood ataxia with central nervous system hypomyelination (CACH), also called vanishing white matter (VWM) leukoencephalopathy, is a fatal genetic disease caused by mutations in eukaryotic initiation factor 2B (eIF2B) genes. The five subunits eIF2B factor is critical for translation initiation under normal conditions and regulates protein synthesis in response to cellular stresses. Primary fibroblasts from CACH/VWM patients and normal individuals were used to measure basal eIF2B activity as well as global protein synthesis and ATF4 induction in response to stress in the endoplasmic reticulum. We show that although the cells expressing mutant eIF2B genes respond normally to stress conditions by reduced global translation rates, they exhibit significantly greater increase in ATF4 induction compared to normal controls despite equal levels of stress and activity of the upstream eIF2alpha kinase. This heightened stress response observed in primary fibroblasts that suffer from minor loss of basal eIF2B activity may be employed as an initial screening tool for CACH/VWM leukodystrophy.
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Affiliation(s)
- Liraz Kantor
- Department of Cell Research & Immunology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 69978, Israel
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121
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Petersen OH, Michalak M, Verkhratsky A. Calcium signalling: Past, present and future. Cell Calcium 2005; 38:161-9. [PMID: 16076488 DOI: 10.1016/j.ceca.2005.06.023] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 01/25/2023]
Abstract
Ca2+ is a universal second messenger controlling a wide variety of cellular reactions and adaptive responses. The initial appreciation of Ca2+ as a universal signalling molecule was based on the work of Sydney Ringer and Lewis Heilbrunn. More recent developments in this field were critically influenced by the invention of the patch clamp technique and the generation of fluorescent Ca2+ indicators. Currently the molecular Ca2+ signalling mechanisms are being worked out and we are beginning to assemble a reasonably complete picture of overall Ca2+ homeostasis. Furthermore, investigations of organellar Ca2+ homeostasis have added complexity to our understanding of Ca2+ signalling. The future of the Ca2+ signalling field lies with detailed investigations of the integrative function in vivo and clarification of the pathology associated with malfunctions of Ca2+ signalling cascades.
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Affiliation(s)
- Ole H Petersen
- Physiological Laboratory, University of Liverpool, Crown Street, Liverpool L69 3BX, UK
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122
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Paschen W, Mengesdorf T. Endoplasmic reticulum stress response and neurodegeneration. Cell Calcium 2005; 38:409-15. [PMID: 16087231 DOI: 10.1016/j.ceca.2005.06.019] [Citation(s) in RCA: 202] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/28/2005] [Indexed: 11/18/2022]
Abstract
The endoplasmic reticulum (ER) is a subcellular compartment playing a central role in calcium storage and signaling. Disturbances of ER calcium homeostasis constitute a severe form of stress interfering with central functions of this structure including the folding and processing of newly synthesized membrane and secretory proteins. Blocking the folding and processing reactions results in the accumulation of unfolded proteins forming potentially toxic aggregates. To restore ER functioning, specific stress responses are activated one of which is the unfolded protein response (UPR). UPR is characterized by a shutdown of global protein synthesis and activation of expression of genes coding for ER-resident proteins that are involved in the folding and processing reactions. ER calcium homeostasis is therefore inevitably associated with major cellular functions, including gene transcription and translation. ER calcium homeostasis und ER functions are believed to be impaired in various degenerative diseases of the brain including Alzheimer's, Parkinson's and Huntington's disease, and amyotrophic lateral sclerosis. ER functioning has also been shown to be disturbed in acute pathological states of the brain such as ischemia and trauma, which have been identified as risk factors for the development of degenerative diseases. This implies that there are common underlying pathomechanisms. This review will summarize new observations suggesting that impairment of ER functioning may be a common denominator of pathological processes resulting in neuronal cell injury in acute disorders and degenerative diseases of the brain.
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Affiliation(s)
- Wulf Paschen
- Multidisciplinary Neuroprotection Research Laboratories, Department of Anesthesiology, Duke University Medical Center, 132 Sands Building, Research Drive, Durham, NC 27710, USA.
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123
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Kato C, Kakiuchi C, Umekage T, Tochigi M, Kato N, Kato T, Sasaki T. XBP1 gene polymorphism (-116C/G) and personality. Am J Med Genet B Neuropsychiatr Genet 2005; 136B:103-5. [PMID: 15892135 DOI: 10.1002/ajmg.b.30098] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recently, a polymorphism of the XBP1 gene (-116 C/G) was observed to play a significant role in the development of bipolar mood disorder from the Japanese population. The present study investigated a role of the polymorphism in the development of personality in healthy Japanese volunteers (n = 195). Personality traits were evaluated using NEO Personality Inventory-Revised (NEO PI-R). As a result, a statistical trend for association between the polymorphism (genotype) and the NEO PI-R scores of agreeableness and neuroticism was observed (ANOVA, P = 0.01 and 0.006, respectively). Subjects with the G allele, especially those with G-G genotype, tended to show lower neuroticism and higher agreeableness in the present study. The result is provisional and should be interpreted with caution, partly because the previous study suggested the allele as a risk allele for bipolar disorder. Further studies are required to confirm the results.
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Affiliation(s)
- Chieko Kato
- Department of Psychiatry, University of Tokyo, Bunkyo-ku, Japan
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124
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Seyfried FJ, Adachi N, Arai T. Suppression of energy requirement by lidocaine in the ischemic mouse brain. J Neurosurg Anesthesiol 2005; 17:75-81. [PMID: 15840992 DOI: 10.1097/01.ana.0000163201.56106.4e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Effects of lidocaine on parameters of membrane functional integrity were investigated in the mouse brain. Changes in the direct-current potential shift in the cerebral cortex provoked by decapitation ischemia were compared in animals given lidocaine (0.05, 0.25, or 1.0 micromol, intracerebroventricular) or saline 15 minutes before ischemia. The brain content of adenosine 5'-triphosphate (ATP) was measured in animals subjected to 0, 0.5, 1, and 2 minutes of decapitation ischemia, and the effect of preischemic administration of lidocaine (0.25 micromol, intracerebroventricular) was evaluated. Na+, K+-ATPase, and Ca2+-ATPase activity was evaluated in brains pretreated with lidocaine (0.25 micromol, intracerebroventricular) or saline 15 minutes before decapitation. Changes in the intracellular Ca concentration ([Ca2+]i) were evaluated in hippocampal slices and the effects of lidocaine (50, 100, or 400 microM) were assessed in the hippocampal CA1 field and dentate gyrus at pH 7.4 and pH 6.8 every 60s for a duration of 50 min. The preischemic administration of lidocaine (1.0 and 0.25 micromol) delayed the onset of anoxic depolarization to 49 seconds and 44 seconds, respectively, as compared with that in the saline group at 27 seconds. Lidocaine maintained ATP levels higher than those in corresponding saline groups, values being 165% after 1 minute of ischemia and 212% after 2 minutes, respectively. Lidocaine did not affect Na+, K+-ATPase, and Ca2+-ATPase activity. Lidocaine did not affect changes in the [Ca2+]i in either area at either pH. The findings may suggest that lidocaine maintains the energy level by delaying depolarization in neurons, which may contribute to removal of cytosolic Ca2+ in ischemic states.
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Affiliation(s)
- Frank-Joachim Seyfried
- Department of Anesthesiology and Resuscitology, Ehime University School of Medicine, Touon-shi, Ehime, Japan
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125
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Li F, Hayashi T, Jin G, Deguchi K, Nagotani S, Nagano I, Shoji M, Chan PH, Abe K. The protective effect of dantrolene on ischemic neuronal cell death is associated with reduced expression of endoplasmic reticulum stress markers. Brain Res 2005; 1048:59-68. [PMID: 15921666 DOI: 10.1016/j.brainres.2005.04.058] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2005] [Revised: 04/11/2005] [Accepted: 04/15/2005] [Indexed: 01/21/2023]
Abstract
The endoplasmic reticulum (ER) plays an important role in ischemic neuronal cell death. In order to determine the effect of dantrolene, a ryanodine receptor antagonist, on ER stress response and ischemic brain injury, we investigated changes in ER stress-related molecules, that is phosphorylated form of double-stranded RNA-activated protein kinase (PKR)-like ER kinase (p-PERK), phosphorylated form of eukaryotic initiation factor 2alpha (p-eIF2alpha), activating transcription factor-4 (ATF-4), and C/EBP-homologous protein (CHOP), as well as terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) in the peri-ischemic area and ischemic core region of rat brain after transient middle cerebral artery occlusion (MCAO). In contrast to the cases treated with vehicle, the infarct volume and TUNEL-positive cells were significantly reduced at 24 h of reperfusion by treatment with dantrolene. The immunoreactivities for p-PERK, p-eIF2alpha, ATF-4, and CHOP were increased at the ischemic peripheral region after MCAO, which were partially inhibited by dantrolene treatment. The present results suggest that dantrolene significantly decreased infarct volume and provided neuroprotective effect on rats after transient MCAO by reducing ER stress-mediated apoptotic signal pathway activation in the ischemic area.
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Affiliation(s)
- Feng Li
- Department of Neurology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8558, Japan
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126
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Aoyama K, Burns DM, Suh SW, Garnier P, Matsumori Y, Shiina H, Swanson RA. Acidosis causes endoplasmic reticulum stress and caspase-12-mediated astrocyte death. J Cereb Blood Flow Metab 2005; 25:358-70. [PMID: 15689959 DOI: 10.1038/sj.jcbfm.9600043] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Endoplasmic reticulum (ER) stress leads to activation of caspase-12, which in turn can lead to activation of caspase-3 and cell death. Here we report that transient acidosis induces ER stress and caspase-12-mediated cell death in mouse astrocytes. After a 3-hour incubation at pH 6.0, astrocytes exhibited delayed cell death associated with nuclear condensation and fragmentation. Cell death was reduced by the protein synthesis inhibitor cycloheximide, further suggesting an active cell death program. Acidosis increased the expression of the ER chaperone protein GRP-78, indicative of ER stress. Acidosis also increased caspase-12 mRNA expression, caspase-12 protein expression, cleavage of caspase-12 to its active form, and activation of caspase-3. Each of these effects was suppressed in astrocytes pretreated with caspase-12 antisense phosphorodiamidate morpholino oligodeoxynucleotides (PMOs). Caspase-12 antisense PMOs also reduced the cell death induced by acidosis. Immunoprecipitation studies showed dissociation of both caspase-12 and Ire1-alpha from GRP-78, thereby suggesting a mechanism by which acidosis can initiate the ER stress response. To evaluate caspase-12 activation in vivo, rats were subjected to middle cerebral artery ischemia-reperfusion. Immunostaining of brain sections harvested 24 hours later showed increased caspase-12 expression and nuclear condensation in astrocytes of the periinfarct region exposed to acidosis during ischemia. These findings suggest that acidosis induces ER stress and caspase-12 activation, and that these changes may contribute to delayed cell death after ischemia.
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Affiliation(s)
- Koji Aoyama
- Department of Neurology, University of California at San Francisco and Veterans Affairs Medical Center, San Francisco, California, USA
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127
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LIU C, HU B. Alterations of N-ethylmaleimide-sensitive atpase following transient cerebral ischemia. Neuroscience 2005; 128:767-74. [PMID: 15464284 PMCID: PMC3518270 DOI: 10.1016/j.neuroscience.2004.07.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/07/2004] [Indexed: 10/26/2022]
Abstract
Neuronal repair following injury requires recruitment of large amounts of membranous proteins into synaptic and other cell membranes, which is carried out by the fusion of transport vesicles to their target membranes. A critical molecule responsible for assemblage of membranous proteins is N-ethylmaleimide-sensitive factor (NSF) which is an ATPase. To study whether NSF is involved in ischemic neurological deficits and delayed neuronal death, we investigated alterations of NSF after transient cerebral ischemia by means of biochemical methods, as well as confocal and electron microscopy. We found that transient cerebral ischemia induced depletion of free NSF and concomitantly relocalization of NSF into the Triton X-100-insoluble fraction including postsynaptic densities in CA1 neurons during the postischemic period. The NSF alterations are accompanied by accumulation of large quantities of intracellular vesicles in CA1 neurons that are undergoing delayed neuronal death after transient cerebral ischemia. Therefore, permanent depletion of free NSF and relocalization of NSF into the Triton X-100-insoluble fraction may disable the vesicle fusion machinery necessary for repair of synaptic injury, and ultimately leads to synaptic dysfunction and delayed neuronal death in CA1 neurons after transient cerebral ischemia.
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Affiliation(s)
| | - B. HU
- Corresponding author. Tel: +1-305-243-4854; fax: +1-305-243-7183.
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128
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Martínez-Sánchez M, Striggow F, Schröder UH, Kahlert S, Reymann KG, Reiser G. Na(+) and Ca(2+) homeostasis pathways, cell death and protection after oxygen-glucose-deprivation in organotypic hippocampal slice cultures. Neuroscience 2005; 128:729-40. [PMID: 15464281 DOI: 10.1016/j.neuroscience.2004.06.074] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/28/2004] [Indexed: 11/25/2022]
Abstract
Intracellular ATP supply and ion homeostasis determine neuronal survival and degeneration after ischemic stroke. The present study provides a systematic investigation in organotypic hippocampal slice cultures of the influence of experimental ischemia, induced by oxygen-glucose-deprivation (OGD). The pathways controlling intracellular Na(+) and Ca(2+) concentration ([Na(+)](i) and [Ca(2+)](i)) and their inhibition were correlated with delayed cell death or protection. OGD induced a marked decrease in the ATP level and a transient elevation of [Ca(2+)](i) and [Na(+)](i) in cell soma of pyramidal neurons. ATP level, [Na(+)](i) and [Ca(2+)](i) rapidly recovered after reintroduction of oxygen and glucose. Pharmacological analysis showed that the OGD-induced [Ca(2+)](i) elevation in neuronal cell soma resulted from activation of both N-methyl-d-aspartate (NMDA)-glutamate receptors and Na(+)/Ca(2+) exchangers, while the abnormal [Na(+)](i) elevation during OGD was due to Na(+) influx through voltage-dependent Na(+) channels. In hippocampal slices, cellular degeneration occurring 24 h after OGD, selectively affected the pyramidal cell population through apoptotic and non-apoptotic cell death. OGD-induced cell loss was mediated by activation of ionotropic glutamate receptors, voltage-dependent Na(+) channels, and both plasma membrane and mitochondrial Na(+)/Ca(2+) exchangers. Thus, we show that neuroprotection induced by blockade of NMDA receptors and plasma membrane Na(+)/Ca(2+) exchangers is mediated by reduction of Ca(2+) entry into neuronal soma, whereas neuroprotection induced by blockade of AMPA/kainate receptors and mitochondrial Na(+)/Ca(2+) exchangers might result from reduced Na(+) entry at dendrites level.
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Affiliation(s)
- M Martínez-Sánchez
- Project Group Neuropharmacology, Leibniz Institute for Neurobiology, Brenneckestrasse 6, D-39118 Magdeburg, Germany
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129
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Niederer KE, Morrow DK, Gettings JL, Irick M, Krawiecki A, Brewster JL. Cypermethrin blocks a mitochondria-dependent apoptotic signal initiated by deficient N-linked glycosylation within the endoplasmic reticulum. Cell Signal 2005; 17:177-86. [PMID: 15494209 DOI: 10.1016/j.cellsig.2004.06.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2004] [Accepted: 06/30/2004] [Indexed: 11/28/2022]
Abstract
The endoplasmic reticulum (ER) serves as a critical site of protein synthesis and processing. The temperature-sensitive hamster fibroblast cell line (tsBN7) displays deficient N-linked glycosylation activity at the restrictive temperature and activates cellular apoptosis. Temperature-shifted tsBN7 cells display induction of Grp78 and Gadd153, genes known to be induced by ER stress, and activate apoptosis via the release of cytochrome c from the mitochondria. Cyclosporin A (CsA), a potent blocker of the mitochondrial permeability transition pore (PTP), was sufficient to block cytochrome c release and to rescue tsBN7 cells from apoptosis. CsA-treated cells displayed Grp78 induction at the restrictive temperature, consistent with an ER stress signal being carried to the nucleus, while the apoptosis-associated transcription factor, Gadd153, displayed only a mild induction. Cypermethrin, a type II pyrethroid known to perturb Ca(2+) signaling in neuronal cells, was sufficient to arrest apoptosis under these conditions. This work identifies type II pyrethroids as a valuable new tool in the characterization of cellular stress signaling pathways.
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Affiliation(s)
- Katherine E Niederer
- Natural Science Division, Pepperdine University, 24255 Pacific Coast Highway, Malibu, CA 90263, USA
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130
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Affiliation(s)
- Emil C Toescu
- Department of Physiology, Division of Medical Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
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131
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Toescu EC. Hypoxia sensing and pathways of cytosolic Ca2+ increases. Cell Calcium 2005; 36:187-99. [PMID: 15261475 DOI: 10.1016/j.ceca.2004.02.019] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2004] [Accepted: 02/18/2004] [Indexed: 10/26/2022]
Abstract
Oxygen-sensing and reactivity to changes in the concentration of oxygen is a fundamental property of cellular physiology. This central role is determined, mainly, by, to the fact that oxygen represents the final acceptor of electrons, derived from the normal cellular metabolism, at the end of the mitochondrial respiratory chain. Despite significant advances in molecular characterization of various oxygen-sensitive processes, the nature of the oxygen-sensor molecules and the mechanisms that link sensors to effects remains unclear. One such controversy is about the role and nature of reactive oxygen species (ROS) changes during hypoxia. Irrespective of the mechanisms of oxygen sensing, one of the constant early responses to hypoxia in almost all cell types is an increase in intracellular Ca2+ ([Ca2+]i). In many instances, this increase is mediated by the activation of various plasma membrane Ca2+ conductances. Some of these channels have specific Ca2+ permeability (e.g. voltage-operated Ca2+ channels), whereas others have non-specific cation conductances and are activated by a variety of ligands (ligand-operated channels). In the last decade, a large superfamily of channels with significant Ca2+ permeability has been progressively identified and characterised: the TRP channels. Through their properties, some groups of the TRP channels provide a link to the other hypoxia-activated mechanism of [Ca2+]i increase: the release of Ca2+ from intracellular Ca2+ stores. Since the [Ca2+]i signals, depending on their localization and intensity, are important regulators of the subsequent cellular responses to hypoxia, a deeper understanding of the mechanisms through which hypoxia regulate the activity of these pathways that increase intracellular Ca2+ could point the way towards the development of new therapeutic approaches to reduce or suppress the pathological effects of cellular hypoxia, such as those seen in stroke or myocardial ischemia.
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Affiliation(s)
- Emil C Toescu
- Department of Physiology, Division of Medical Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
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132
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Hiroi T, Wei H, Hough C, Leeds P, Chuang DM. Protracted lithium treatment protects against the ER stress elicited by thapsigargin in rat PC12 cells: roles of intracellular calcium, GRP78 and Bcl-2. THE PHARMACOGENOMICS JOURNAL 2005; 5:102-11. [PMID: 15668729 DOI: 10.1038/sj.tpj.6500296] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We investigated the cytoprotective effects of lithium, the mood-stabilizer, on thapsigargin-induced stress on the endoplasmic reticulum (ER) in rat PC12 cells. Protracted lithium pretreatment of PC12 cells elicited cytoprotection against thapsigargin-induced cytotoxicity. Lithium protection was concurrent with inhibition of thapsigargin-induced intracellular calcium increase and with elevated expression of the molecular chaperone GRP78. Moreover, lithium pretreatment upregulated the antiapoptotic protein Bcl-2, and blocked Bcl-2 downregulation elicited by thapsigargin. Prior to the induction of GRP78, lithium treatment alone increased the expression of c-Fos whose induction by ER stress is necessary for GRP78 induction. Curcumin, an inhibitor of transcription factor AP-1, blocked lithium cytoprotection against thapsigargin cytotoxicity. Thus, the induction of GRP78 and Bcl-2, and activation of AP-1 likely contribute to lithium-induced protection against cytotoxicity resulting from ER stress. Additionally, thapsigargin-induced cytotoxicity was suppressed by pretreatment with another mood-stabilizer, valproate, indicating that cytoprotection against ER stress is a common action of mood-stabilizing drugs.
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Affiliation(s)
- T Hiroi
- Molecular Neurobiology Section, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892-1363, USA
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133
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Verkhratsky A. Physiology and Pathophysiology of the Calcium Store in the Endoplasmic Reticulum of Neurons. Physiol Rev 2005; 85:201-79. [PMID: 15618481 DOI: 10.1152/physrev.00004.2004] [Citation(s) in RCA: 560] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The endoplasmic reticulum (ER) is the largest single intracellular organelle, which is present in all types of nerve cells. The ER is an interconnected, internally continuous system of tubules and cisterns, which extends from the nuclear envelope to axons and presynaptic terminals, as well as to dendrites and dendritic spines. Ca2+release channels and Ca2+pumps residing in the ER membrane provide for its excitability. Regulated ER Ca2+release controls many neuronal functions, from plasmalemmal excitability to synaptic plasticity. Enzymatic cascades dependent on the Ca2+concentration in the ER lumen integrate rapid Ca2+signaling with long-lasting adaptive responses through modifications in protein synthesis and processing. Disruptions of ER Ca2+homeostasis are critically involved in various forms of neuropathology.
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Affiliation(s)
- Alexei Verkhratsky
- The University of Manchester, Faculty of Biological Sciences, United Kingdom.
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Abstract
Understanding the cellular mechanisms that characterize the functional changes of the aged brain is an ongoing and formidable challenge for the neuroscience community. Evidence now links changes in Ca(2+) influx and homeostasis with perturbations induced by the aging process in the function of the main intracellular organelles involved in Ca(2+) regulation: the endoplasmic reticulum and mitochondria. New perspectives are also offered by recent gene microarray studies, illustrating the multifactorial nature of the aging process.
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135
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Wray S, Ravens U, Verkhratsky A, Eisner D. Two centuries of excitation-contraction coupling. Cell Calcium 2004; 35:485-9. [PMID: 15110138 DOI: 10.1016/j.ceca.2004.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Accepted: 01/12/2004] [Indexed: 11/25/2022]
Affiliation(s)
- Susan Wray
- Physiological Laboratory, Liverpool University, Crown Street, P.O. Box 147, Liverpool L69 3BX, UK
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136
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Papp B, Brouland JP, Gélébart P, Kovàcs T, Chomienne C. Endoplasmic reticulum calcium transport ATPase expression during differentiation of colon cancer and leukaemia cells. Biochem Biophys Res Commun 2004; 322:1223-36. [PMID: 15336970 DOI: 10.1016/j.bbrc.2004.08.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2004] [Indexed: 11/19/2022]
Abstract
The calcium homeostasis of the endoplasmic reticulum (ER) is connected to a multitude of cell functions involved in intracellular signal transduction, control of proliferation, programmed cell death, or the synthesis of mature proteins. Calcium is accumulated in the ER by various biochemically distinct sarco/endoplasmic reticulum calcium transport ATPase isoenzymes (SERCA isoforms). Experimental data indicate that the SERCA composition of some carcinoma and leukaemia cell types undergoes significant changes during differentiation, and that this is accompanied by modifications of SERCA-dependent calcium accumulation in the ER. Because ER calcium homeostasis can also influence cell differentiation, we propose that the modulation of the expression of various SERCA isoforms, and in particular, the induction of the expression of SERCA3-type proteins, is an integral part of the differentiation program of some cancer and leukaemia cell types. The SERCA content of the ER may constitute a new parameter by which the calcium homeostatic characteristics of the organelle are adjusted. The cross-talk between ER calcium homeostasis and cell differentiation may have some implications for the better understanding of the signalling defects involved in the acquisition and maintenance of the malignant phenotype.
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Affiliation(s)
- Béla Papp
- INSERM EMI-00-03 Laboratoire de Biologie Cellulaire Hématopoïétique, Institut Universitaire d'Hématologie, Hôpital Saint-Louis, 1, Avenue Claude Vellefaux, 75010 Paris, France.
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137
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Oono K, Yoneda T, Manabe T, Yamagishi S, Matsuda S, Hitomi J, Miyata S, Mizuno T, Imaizumi K, Katayama T, Tohyama M. JAB1 participates in unfolded protein responses by association and dissociation with IRE1. Neurochem Int 2004; 45:765-72. [PMID: 15234121 DOI: 10.1016/j.neuint.2004.01.003] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2003] [Revised: 01/05/2004] [Accepted: 01/05/2004] [Indexed: 11/20/2022]
Abstract
Recent papers have reported that neuronal death in patients with Alzheimer's disease, Parkinson's disease, and cerebral ischemia has its origin in the endoplasmic reticulum (ER). IRE1alpha is one of the ER stress transducers that detect the accumulation of unfolded proteins in the ER. IRE1alpha mediates two major cellular responses, which are the unfolded protein response (UPR), a defensive response, and apoptosis that leads to cell death. However, little is known about the regulatory mechanisms that select between the UPR and apoptosis. We identified Jun activation domain-binding protein-1 (JAB1) as a molecule that interacts with IRE1alpha using a yeast two-hybrid system. We demonstrated that JAB1 binds to IRE1alpha in the absence of stress, but that binding is decreased by ER stress inducers. Moreover, mutant JAB1 down-regulates the UPR signaling pathway through tight binding with IRE1alpha. These results suggested that JAB1 may act as a key molecule in selecting the UPR or cell death by association and dissociation with IRE1alpha.
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Affiliation(s)
- Kayoko Oono
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
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138
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Tessitore A, del P Martin M, Sano R, Ma Y, Mann L, Ingrassia A, Laywell ED, Steindler DA, Hendershot LM, d'Azzo A. GM1-ganglioside-mediated activation of the unfolded protein response causes neuronal death in a neurodegenerative gangliosidosis. Mol Cell 2004; 15:753-66. [PMID: 15350219 DOI: 10.1016/j.molcel.2004.08.029] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2004] [Revised: 06/25/2004] [Accepted: 07/07/2004] [Indexed: 10/26/2022]
Abstract
GM1-ganglioside (GM1) is a major sialoglycolipid of neuronal membranes that, among other functions, modulates calcium homeostasis. Excessive accumulation of GM1 due to deficiency of lysosomal beta-galactosidase (beta-gal) characterizes the neurodegenerative disease GM1-gangliosidosis, but whether the accumulation of GM1 is directly responsible for CNS pathogenesis was unknown. Here we demonstrate that activation of an unfolded protein response (UPR) associated with the upregulation of BiP and CHOP and the activation of JNK2 and caspase-12 leads to neuronal apoptosis in the mouse model of GM1-gangliosidosis. GM1 loading of wild-type neurospheres recapitulated the phenotype of beta-gal-/- cells and activated this pathway by depleting ER calcium stores, which ultimately culminated in apoptosis. Activation of UPR pathways did not occur in mice double deficient for beta-gal and ganglioside synthase, beta-gal-/-/GalNAcT-/-, which do not accumulate GM1. These findings suggest that the UPR can be induced by accumulation of the sialoglycolipid GM1 and this causes a novel mechanism of neuronal apoptosis.
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Affiliation(s)
- Alessandra Tessitore
- Department of Genetics and Tumor Cell Biology, St. Jude Children's Research Hospital, 332 N. Lauderdale, Memphis, TN 38105, USA
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139
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Matarazzo V, Ronnett GV. Temporal and regional differences in the olfactory proteome as a consequence of MeCP2 deficiency. Proc Natl Acad Sci U S A 2004; 101:7763-8. [PMID: 15128950 PMCID: PMC419680 DOI: 10.1073/pnas.0307083101] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the gene encoding MeCP2. By binding to methylated CpG dinucleotide promoter regions, MeCP2 acts as a transcriptional repressor, predicting that its absence might result in widespread aberrant gene transcription, leading to the RTT phenotype. Considering this potentially broad action of MeCP2 on expression and the complexity of the brain, especially during development, we approached the consequences of MeCP2 deficiency in a mouse model by using a temporal and regional proteomic strategy. We used the olfactory system (olfactory epithelium and bulb) because its attributes make it an excellent developmental model system. We find evidence of temporal and regional proteomic pattern differences between WT and MeCP2-deficient mice. It was possible to segregate these changes in protein expression into five biological function groups: cytoskeleton arrangement, chromatin modeling, energy metabolism, cell signaling, and neuroprotection. By combining the proteomic results with the RNA levels of the identified proteins, we show that protein expression changes are the consequence of differences in mRNA level or posttranslational modifications. We conclude that brain regions and ages must be carefully considered when investigating MeCP2 deficiency, and that not only transcription should be taken into account as a source for these changes, but posttranslational protein modifications as well.
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Affiliation(s)
- Valéry Matarazzo
- Department of Neuroscience, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA
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140
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Abstract
The endoplasmic reticulum (ER) is a universal signalling organelle, which regulates a wide range of neuronal functional responses. Calcium release from the ER underlies various forms of intracellular Ca(2+) signalling by either amplifying Ca(2+) entry through voltage-gated Ca(2+) channels by Ca(2+)-induced Ca(2+) release (CICR) or by producing local or global cytosolic calcium fluctuations following stimulation of metabotropic receptors through inositol-1,4,5-trisphosphate-induced Ca(2+) release (IICR). The ER Ca(2+) store emerges as a single interconnected pool, thus allowing for a long-range Ca(2+) signalling via intra-ER tunnels. The fluctuations of intra-ER free Ca(2+) concentration regulate the activity of numerous ER resident proteins responsible for post-translational protein folding and modification. Disruption of ER Ca(2+) homeostasis results in the developing of ER stress response, which in turn controls neuronal survival. Altered ER Ca(2+) handling may be involved in pathogenesis of various neurodegenerative diseases including brain ischemia and Alzheimer dementia.
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Affiliation(s)
- A Verkhratsky
- The University of Manchester, School of Biological Sciences, Manchester, United Kingdom.
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141
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Paschen W. Mechanisms of neuronal cell death: diverse roles of calcium in the various subcellular compartments. Cell Calcium 2003; 34:305-10. [PMID: 12909077 DOI: 10.1016/s0143-4160(03)00138-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Wulf Paschen
- Department of Experimental Neurology, Max-Planck-Institute for Neurological Research, Cologne, Germany.
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