1
|
Xiao HH, Zhang FR, Li S, Guo FF, Hou JL, Wang SC, Yu J, Li XY, Yang HJ. Xinshubao tablet rescues cognitive dysfunction in a mouse model of vascular dementia: Involvement of neurogenesis and neuroinflammation. Biomed Pharmacother 2024; 172:116219. [PMID: 38310654 DOI: 10.1016/j.biopha.2024.116219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/06/2024] Open
Abstract
Vascular dementia (VaD) represents a severe cognitive dysfunction syndrome closed linked to cardiovascular function. In the present study, we assessed the potential of Xinshubao tablet (XSB), a traditional Chinese prescription widely used for cardiovascular diseases, to mitigate neuropathological damage in a mouse model of VaD and elucidated the underlying mechanisms. Our findings revealed that oral administration of XSB rescued the cardiac dysfunction resulting from bilateral common carotid artery stenosis (BCAS), improved the cerebral blood flow (CBF) and cognitive function, reduced white matter injury, inhibited excessive microglial and astrocytic activation, stimulated hippocampal neurogenesis, and reduced neural apoptosis in the brains of BCAS mice. Mechanistically, RNA-seq analysis indicated that XSB treatment was significantly associated with neuroinflammation, vasculature development, and synaptic transmission, which were further confirmed by q-PCR assays. Western blot results revealed that XSB treatment hindered the nuclear translocation of nuclear factor-κB (NF-κB), thereby suppressing the NF-κB signaling pathway. These results collectively demonstrated that XSB could ameliorate cognitive dysfunction caused by BCAS through regulating CBF, reducing white matter lesions, suppressing glial activation, promoting neurogenesis, and mitigating neuroinflammation. Notably, the NF-κB signaling pathway emerged as a pivotal player in this mechanism.
Collapse
Affiliation(s)
- Hong-He Xiao
- Beijing Key Laboratory of Traditional Chinese Medicine Basic Research on Prevention and Treatment for Major Diseases, Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, China; School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China; Fujian Pien Tze Huang Enterprise Key Laboratory of Natural Medicine Research and Development, Zhangzhou Pien Tze Huang Pharmaceutical Co., Ltd., Zhangzhou, Fujian Province 363099, China
| | - Feng-Rong Zhang
- Beijing Key Laboratory of Traditional Chinese Medicine Basic Research on Prevention and Treatment for Major Diseases, Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, China; Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Sen Li
- Beijing Key Laboratory of Traditional Chinese Medicine Basic Research on Prevention and Treatment for Major Diseases, Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Fei-Fei Guo
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Jin-Li Hou
- Beijing Key Laboratory of Traditional Chinese Medicine Basic Research on Prevention and Treatment for Major Diseases, Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, China
| | - Shi-Cong Wang
- Fujian Pien Tze Huang Enterprise Key Laboratory of Natural Medicine Research and Development, Zhangzhou Pien Tze Huang Pharmaceutical Co., Ltd., Zhangzhou, Fujian Province 363099, China
| | - Juan Yu
- Fujian Pien Tze Huang Enterprise Key Laboratory of Natural Medicine Research and Development, Zhangzhou Pien Tze Huang Pharmaceutical Co., Ltd., Zhangzhou, Fujian Province 363099, China.
| | - Xian-Yu Li
- Beijing Key Laboratory of Traditional Chinese Medicine Basic Research on Prevention and Treatment for Major Diseases, Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, China.
| | - Hong-Jun Yang
- Beijing Key Laboratory of Traditional Chinese Medicine Basic Research on Prevention and Treatment for Major Diseases, Experimental Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, China; China Academy of Chinese Medical Sciences, Beijing 100700, China.
| |
Collapse
|
2
|
Kilbas PO, Can ND, Kizilboga T, Ezberci F, Doganay HL, Arisan ED, Dinler Doganay G. CRISPR/Cas9-mediated Bag-1 knockout increased mesenchymal characteristics of MCF-7 cells via Akt hyperactivation-mediated actin cytoskeleton remodeling. PLoS One 2022; 17:e0261062. [PMID: 34995286 PMCID: PMC8741009 DOI: 10.1371/journal.pone.0261062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 11/23/2021] [Indexed: 11/18/2022] Open
Abstract
Bag-1 protein is a crucial target in cancer to increase the survival and proliferation of cells. The Bag-1 expression is significantly upregulated in primary and metastatic cancer patients compared to normal breast tissue. Overexpression of Bag-1 decreases the efficiency of conventional chemotherapeutic drugs, whereas Bag-1 silencing enhances the apoptotic efficiency of therapeutics, mostly in hormone-positive breast cancer subtypes. In this study, we generated stable Bag-1 knockout (KO) MCF-7 breast cancer cells to monitor stress-mediated cellular alterations in comparison to wild type (wt) and Bag-1 overexpressing (Bag-1 OE) MCF-7 cells. Validation and characterization studies of Bag-1 KO cells showed different cellular morphology with hyperactive Akt signaling, which caused stress-mediated actin reorganization, focal adhesion decrease and led to mesenchymal characteristics in MCF-7 cells. A potent Akt inhibitor, MK-2206, suppressed mesenchymal transition in Bag-1 KO cells. Similar results were obtained following the recovery of Bag-1 isoforms (Bag-1S, M, or L) in Bag-1 KO cells. The findings of this study emphasized that Bag-1 is a mediator of actin-mediated cytoskeleton organization through regulating Akt activation.
Collapse
Affiliation(s)
- Pelin Ozfiliz Kilbas
- Department of Molecular Biology Genetics and Biotechnology, Istanbul Technical University, Istanbul, Turkey
- Department of Molecular Biology and Genetics, Istanbul Kultur University, Istanbul, Turkey
| | - Nisan Denizce Can
- Department of Molecular Biology Genetics and Biotechnology, Istanbul Technical University, Istanbul, Turkey
| | - Tugba Kizilboga
- Department of Molecular Biology Genetics and Biotechnology, Istanbul Technical University, Istanbul, Turkey
| | - Fikret Ezberci
- Department of General Surgery, Umraniye Teaching and Research Hospital, Istanbul, Turkey
| | - Hamdi Levent Doganay
- Genomic Laboratory (GLAB), Umraniye Teaching And Research Hospital, University of Health Sciences, Istanbul, Turkey
| | - Elif Damla Arisan
- Institute of Biotechnology, Gebze Technical University, Kocaeli, Turkey
- * E-mail: (EDA); (GDD)
| | - Gizem Dinler Doganay
- Department of Molecular Biology Genetics and Biotechnology, Istanbul Technical University, Istanbul, Turkey
- * E-mail: (EDA); (GDD)
| |
Collapse
|
3
|
Chen Y, Wang K, Di J, Guan C, Wang S, Li Q, Qu Y. Mutation of the BAG-1 domain decreases its protective effect against hypoxia/reoxygenation by regulating HSP70 and the PI3K/AKT signalling pathway in SY-SH5Y cells. Brain Res 2020; 1751:147192. [PMID: 33152339 DOI: 10.1016/j.brainres.2020.147192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 06/06/2020] [Revised: 09/30/2020] [Accepted: 10/28/2020] [Indexed: 10/23/2022]
Abstract
BCL-2-associated athanogene-1 (BAG-1) is a multifunctional protein that was first identified as a binding partner of BCL-2. Our previous results indicated that BAG-1 large (BAG-1L) overexpression significantly increases cell viability and decreases apoptosis by upregulating HSP70 and p-AKT in response to hypoxia/reoxygenation in SY-SH5Y cells. However, the functional domain of BAG-1L that exerts these protective effects against hypoxic damage has not been identified. In this study, we examined changes in HSP70 and p-AKT protein levels in SH-SY5Y cells with or without BAG-1L domain mutation after six hours of hypoxia/reoxygenation treatment. The BAG-1 domain mutant (BAG-1MUT) attenuated neuronal viability and proliferation while enhancing apoptosis after hypoxia/reoxygenation, which was achieved in part by inhibiting the HSP70 and p-AKT signalling pathways. This evidence illustrates that the BAG-1 domain plays a key role in protecting cells from hypoxia/reoxygenation injury.
Collapse
Affiliation(s)
- Ying Chen
- School of Nursing, Medical College of Qingdao University, Qingdao 26600, Shandong, China; Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao 266000, Shandong, China
| | - Keke Wang
- Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao 266000, Shandong, China
| | - Jie Di
- School of Nursing, Medical College of Qingdao University, Qingdao 26600, Shandong, China; Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao 266000, Shandong, China
| | - Chun Guan
- Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao 266000, Shandong, China
| | - Sumei Wang
- Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao 266000, Shandong, China
| | - Qingshu Li
- Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao 266000, Shandong, China.
| | - Yan Qu
- Affiliated Qingdao Municipal Hospital of Qingdao University, Qingdao 266000, Shandong, China
| |
Collapse
|
4
|
Abstract
The members of the BCL-2 associated athanogene (BAG) family participate in the regulation of a variety of interrelated physiological processes, such as autophagy, apoptosis, and protein homeostasis. Under normal circumstances, the six BAG members described in mammals (BAG1-6) principally assist the 70 kDa heat-shock protein (HSP70) in protein folding; however, their role as oncogenes is becoming increasingly evident. Deregulation of the BAG multigene family has been associated with cell transformation, tumor recurrence, and drug resistance. In addition to BAG overexpression, BAG members are also involved in many oncogenic protein-protein interactions (PPIs). As such, either the inhibition of overloading BAGs or of specific BAG-client protein interactions could have paramount therapeutic value. In this review, we will examine the role of each BAG family member in different malignancies, focusing on their modular structure, which enables interaction with a variety of proteins to exert their pro-tumorigenic role. Lastly, critical remarks on the unmet needs for proposing effective BAG inhibitors will be pointed out.
Collapse
Affiliation(s)
- Elena Mariotto
- Department of Woman's and Child's Health, University of Padova, Via Giustiniani 2, 35127 Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Corso Stati Uniti 4, 35128 Padova, Italy.
| | - Giampietro Viola
- Department of Woman's and Child's Health, University of Padova, Via Giustiniani 2, 35127 Padova, Italy; Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Corso Stati Uniti 4, 35128 Padova, Italy
| | - Carlo Zanon
- Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Corso Stati Uniti 4, 35128 Padova, Italy
| | - Sanja Aveic
- Neuroblastoma Laboratory, Fondazione Istituto di Ricerca Pediatrica Città della Speranza, Corso Stati Uniti 4, 35128 Padova, Italy
| |
Collapse
|
5
|
Wang Y, Jia C, Li QS, Xie CY, Zhang N, Qu Y. BAG-1L Protects SH-SY5Y Neuroblastoma Cells Against Hypoxia/Re-oxygenation Through Up-Regulating HSP70 and Activating PI3K/AKT Signaling Pathway. Neurochem Res 2017; 42:2861-8. [PMID: 28523530 DOI: 10.1007/s11064-017-2304-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Revised: 05/07/2017] [Accepted: 05/11/2017] [Indexed: 01/01/2023]
Abstract
BCL-2-associated athanogene-1(BAG-1) is a multifunctional and anti-apoptotic protein that was first identified as a binding partner of BCL-2. But the effects and mechanisms for BAG-1 against hypoxic damage is unclear up to now. Whether BAG-1 could protect the human brain against hypoxic damage through up-regulating 70 kDa heat shock proteins (HSP70) and PI3K/AKT pathway activation? In present study, we examined the changes of HSP70 and AKT and p-AKT protein level in SH-SY5Y cells with BAG-1L gene over-expression subjected to hypoxia/re-oxygenation injury. BAG-1L over-expression increased neuronal viability, and it reduced apoptosis of neurons after hypoxia/re-oxygenation for 8 h. BAG-1L over-expression enhanced the HSP70 protein levels and increased p-AKT/total AKT ratio after hypoxia/re-oxygenation for 8 h. These results suggest that BAG-1L over-expression protects against hypoxia/re-oxygenation injury, at least in part, by interacting with HSP70, and by accelerating the activation of PI3K/AKT pathways.
Collapse
|
6
|
Challagundla M, Koch JC, Ribas VT, Michel U, Kügler S, Ostendorf T, Bradke F, Müller HW, Bähr M, Lingor P. AAV-mediated expression of BAG1 and ROCK2-shRNA promote neuronal survival and axonal sprouting in a rat model of rubrospinal tract injury. J Neurochem 2015; 134:261-75. [DOI: 10.1111/jnc.13102] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 02/14/2015] [Accepted: 03/06/2015] [Indexed: 11/27/2022]
Affiliation(s)
| | - Jan Christoph Koch
- Department of Neurology; University Medicine Göttingen; Göttingen Germany
| | | | - Uwe Michel
- Department of Neurology; University Medicine Göttingen; Göttingen Germany
| | - Sebastian Kügler
- Department of Neurology; University Medicine Göttingen; Göttingen Germany
| | - Thomas Ostendorf
- Department of Neurology; University Medicine Göttingen; Göttingen Germany
| | - Frank Bradke
- German Center for Neurodegenerative Diseases (DZNE); Bonn Germany
| | - Hans Werner Müller
- Department of Neurology; Molecular Neurobiology Laboratory; Heinrich-Heine-University Medical Center Düsseldorf; Düsseldorf Germany
| | - Mathias Bähr
- Department of Neurology; University Medicine Göttingen; Göttingen Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB); Göttingen Germany
| | - Paul Lingor
- Department of Neurology; University Medicine Göttingen; Göttingen Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB); Göttingen Germany
| |
Collapse
|
7
|
Kermer P, Köhn A, Schnieder M, Lingor P, Bähr M, Liman J, Dohm CP. BAG1 is Neuroprotective in In Vivo and In Vitro Models of Parkinson’s Disease. J Mol Neurosci 2015; 55:587-95. [DOI: 10.1007/s12031-014-0396-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 07/29/2014] [Indexed: 11/27/2022]
|
8
|
Lee JW, Tapias V, Di Maio R, Greenamyre JT, Cannon JR. Behavioral, neurochemical, and pathologic alterations in bacterial artificial chromosome transgenic G2019S leucine-rich repeated kinase 2 rats. Neurobiol Aging 2014; 36:505-18. [PMID: 25174649 DOI: 10.1016/j.neurobiolaging.2014.07.011] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [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: 03/19/2014] [Revised: 06/19/2014] [Accepted: 07/08/2014] [Indexed: 12/16/2022]
Abstract
Mutations in leucine-rich repeated kinase 2 (LRRK2) cause autosomal dominant late-onset Parkinson's disease (PD), and the G2019S mutation in the kinase domain of LRRK2 is the most common genetic cause of familial PD. Enhanced kinase activity of G2019S LRRK2 is a suspected mechanism for carriers to develop PD but pathophysiological function of G2019S LRRK2 is not clear. The objective of the present study was to characterize a bacterial artificial chromosome rat expressing human G2019S LRRK2. Immunoblotting analysis showed that G2019S LRRK2 expression was approximately 5-8 times higher than wild-type rat LRRK2. At ages of 4, 8, and 12 months, our characterization showed that expression of G2019S LRRK2 induced oxidative stress in striatum and substantia nigra, increased inducible nitric oxide synthase expression in nigral dopamine neurons, and abnormal morphology of nigral dopaminergic neurons in transgenic rats compared with wild-type, without inducing overt neurodegeneration in nigrostriatal dopaminergic neurons. Thus, we conclude that although this model does not reproduce the key features of end-stage PD, important preclinical features of the disease are evident, which may be useful in studying the earliest stages of PD and for gene-environment interaction studies.
Collapse
Affiliation(s)
- Jang-Won Lee
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Victor Tapias
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
| | - Roberto Di Maio
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA; Ri.MED Foundation, Italy
| | - J Timothy Greenamyre
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN, USA.
| |
Collapse
|
9
|
Tapias V, Greenamyre JT. A rapid and sensitive automated image-based approach for in vitro and in vivo characterization of cell morphology and quantification of cell number and neurite architecture. Curr Protoc Cytom 2014; 68:12.33.1-12.33.22. [PMID: 24692056 DOI: 10.1002/0471142956.cy1233s68] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Stereological methods for tissue cell counting, specifically for neuron quantification, decrease systematic error and sampling bias; however, they are tedious, labor intensive, and time consuming. Approaches for cell (neuron) quantification in vitro are not accurate, sensitive, or subsequently reproducible. Neuronal phenotype is related to alterations in cell morphology and neurite pattern. The techniques currently available for quantification of these features present several limitations. In this unit, we provide validated automated procedures for in vivo and in vitro quantification of cell number, morphological cell changes, and neurite morphometry in a fast, simple, and reliable manner. Our method counts up to 8 times as many neurons in less than 5% to 10% of the time required for stereological analysis (optical fractionator). In summary, this technology offers an unparalleled opportunity to examine features of cells at high resolution in a complex three-dimensional environment. These techniques provide an exceptional in vivo and in vitro system for neurotoxicity studies, disease modeling, and drug discovery.
Collapse
Affiliation(s)
- Victor Tapias
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - J Timothy Greenamyre
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania.,Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania.,Pittsburgh VA Healthcare System, Pittsburgh, Pennsylvania
| |
Collapse
|
10
|
Weiss B, Haas S, Lessner G, Mikkat S, Kreutzer M, Glocker MO, Wree A, Schmitt O. The proteome of the differentiating mesencephalic progenitor cell line CSM14.1 in vitro. Biomed Res Int 2014; 2014:351821. [PMID: 24592386 DOI: 10.1155/2014/351821] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 12/16/2013] [Indexed: 11/23/2022]
Abstract
The treatment of Parkinson's disease by transplantation of dopaminergic (DA) neurons from human embryonic mesencephalic tissue is a promising approach. However, the origin of these cells causes major problems: availability and standardization of the graft. Therefore, the generation of unlimited numbers of DA neurons from various types of stem or progenitor cells has been brought into focus. A source for DA neurons might be conditionally immortalized progenitor cells. The temperature-sensitive immortalized cell line CSM14.1 derived from the mesencephalon of an embryonic rat has been used successfully for transplantation experiments. This cell line was analyzed by unbiased stereology of cell type specific marker proteins and 2D-gel electrophoresis followed by mass spectrometry to characterize the differentially expressed proteome. Undifferentiated CSM14.1 cells only expressed the stem cell marker nestin, whereas differentiated cells expressed GFAP or NeuN and tyrosine hydroxylase. An increase of the latter cells during differentiation could be shown. By using proteomics an explanation on the protein level was found for the observed changes in cell morphology during differentiation, when CSM14.1 cells possessed the morphology of multipolar neurons. The results obtained in this study confirm the suitability of CSM14.1 cells as an in vitro model for the study of neuronal and dopaminergic differentiation in rats.
Collapse
|
11
|
Kimura T, Okumura M, Kim E, Sasaki M, Orba Y, Sawa H. Characterization of Japanese encephalitis virus infection in an immortalized mesencephalic cell line, CSM14.1. Microbiol Immunol 2013; 57:723-31. [PMID: 23905906 DOI: 10.1111/1348-0421.12085] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 07/09/2013] [Accepted: 07/25/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Takashi Kimura
- Division of Molecular Pathobiology; Hokkaido University Research Center for Zoonosis Control; West 10 North 20; Kita-ku; Sapporo; 001-0020; Japan
| | - Megumi Okumura
- Division of Molecular Pathobiology; Hokkaido University Research Center for Zoonosis Control; West 10 North 20; Kita-ku; Sapporo; 001-0020; Japan
| | - Eunmi Kim
- Division of Molecular Pathobiology; Hokkaido University Research Center for Zoonosis Control; West 10 North 20; Kita-ku; Sapporo; 001-0020; Japan
| | - Michihito Sasaki
- Division of Molecular Pathobiology; Hokkaido University Research Center for Zoonosis Control; West 10 North 20; Kita-ku; Sapporo; 001-0020; Japan
| | - Yasuko Orba
- Division of Molecular Pathobiology; Hokkaido University Research Center for Zoonosis Control; West 10 North 20; Kita-ku; Sapporo; 001-0020; Japan
| | - Hirofumi Sawa
- Division of Molecular Pathobiology; Hokkaido University Research Center for Zoonosis Control; West 10 North 20; Kita-ku; Sapporo; 001-0020; Japan
| |
Collapse
|
12
|
Sillivan SE, Whittard JD, Jacobs MM, Ren Y, Mazloom AR, Caputi FF, Horvath M, Keller E, Ma’ayan A, Pan YX, Chiang LW, Hurd YL. ELK1 transcription factor linked to dysregulated striatal mu opioid receptor signaling network and OPRM1 polymorphism in human heroin abusers. Biol Psychiatry 2013; 74:511-9. [PMID: 23702428 PMCID: PMC4070524 DOI: 10.1016/j.biopsych.2013.04.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Revised: 04/12/2013] [Accepted: 04/12/2013] [Indexed: 12/21/2022]
Abstract
BACKGROUND Abuse of heroin and prescription opiate medications has grown to disturbing levels. Opioids mediate their effects through mu opioid receptors (MOR), but minimal information exists regarding MOR-related striatal signaling relevant to the human condition. The striatum is a structure central to reward and habitual behavior and neurobiological changes in this region are thought to underlie the pathophysiology of addiction disorders. METHODS We examined molecular mechanisms related to MOR in postmortem human brain striatal specimens from a homogenous European Caucasian population of heroin abusers and control subjects and in an animal model of heroin self-administration. Expression of ets-like kinase 1 (ELK1) was examined in relation to polymorphism of the MOR gene OPRM1 and drug history. RESULTS A characteristic feature of heroin abusers was decreased expression of MOR and extracellular regulated kinase signaling networks, concomitant with dysregulation of the downstream transcription factor ELK1. Striatal ELK1 in heroin abusers associated with the polymorphism rs2075572 in OPRM1 in a genotype dose-dependent manner and correlated with documented history of heroin use, an effect reproduced in an animal model that emphasizes a direct relationship between repeated heroin exposure and ELK1 dysregulation. A central role of ELK1 was evidenced by an unbiased whole transcriptome microarray that revealed ~20% of downregulated genes in human heroin abusers are ELK1 targets. Using chromatin immune precipitation, we confirmed decreased ELK1 promoter occupancy of the target gene Use1. CONCLUSIONS ELK1 is a potential key transcriptional regulatory factor in striatal disturbances associated with heroin abuse and relevant to genetic mutation of OPRM1.
Collapse
Affiliation(s)
- Stephanie E. Sillivan
- Department of Psychiatry and Neuroscience, Mount Sinai School of Medicine, New York, New York 10029,Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029
| | - John D. Whittard
- Department of Psychiatry and Neuroscience, Mount Sinai School of Medicine, New York, New York 10029
| | - Michelle M. Jacobs
- Department of Psychiatry and Neuroscience, Mount Sinai School of Medicine, New York, New York 10029,Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029
| | - Yanhua Ren
- Department of Psychiatry and Neuroscience, Mount Sinai School of Medicine, New York, New York 10029,Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029
| | - Amin R. Mazloom
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029
| | - Francesca F. Caputi
- Department of Psychiatry and Neuroscience, Mount Sinai School of Medicine, New York, New York 10029,Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029
| | - Monika Horvath
- Department of Forensic Medicine, Uppsala University, Uppsala, Sweden,Department of Forensic Medicine, Semmelweis University, Budapest, Hungary
| | - Eva Keller
- Department of Forensic Medicine, Semmelweis University, Budapest, Hungary
| | - Avi Ma’ayan
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029
| | - Ying-Xian Pan
- Department of Neurology and the Molecular Pharmacology and Chemistry Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10065
| | | | - Yasmin L. Hurd
- Department of Psychiatry and Neuroscience, Mount Sinai School of Medicine, New York, New York 10029,Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029,corresponding author: Departments of Psychiatry, Pharmacology and Systems Therapeutics and Neuroscience, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1603, New York, NY 10029, , Tel.: (212) 241-5007, Fax: (212) 996-7214
| |
Collapse
|
13
|
Wu H, Liu Y, Zhou Y, Long L, Cheng X, Ji L, Weng H, Ding T, Yang J, Wei H, Li M, Huan W, Deng X, Wang Y. Changes in the BAG1 expression of Schwann cells after sciatic nerve crush. J Mol Neurosci 2012; 49:512-22. [PMID: 23108487 DOI: 10.1007/s12031-012-9910-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 10/18/2012] [Indexed: 12/14/2022]
Abstract
Bcl-2-associated athanogene-1 (BAG1), a co-chaperone for Hsp70/Hsc70, is a multifunctional protein, which has been shown to suppress apoptosis and enhance neuronal differentiation. However, the expression and roles of BAG1 in peripheral system lesions and repair are still unknown. In this study, we investigated the dynamic changes in BAG1 expression in an acute sciatic nerve crush model in adult rats. Western blot analysis revealed that BAG1 was expressed in normal sciatic nerves. BAG1 expression increased progressively after sciatic nerve crush, reached a peak 2 weeks post-injury, and then returned to the normal level 4 weeks post-injury. Spatially, we observed that BAG1 was mainly expressed in Schwann cells and that BAG1 expression increased in Schwann cells after injury. In vitro, we found that BAG1 expression increased during the cyclic adenosine monophosphate (cAMP)-induced Schwann cell differentiation process. BAG1-specific siRNA inhibited cAMP-induced Schwann cell differentiation. In conclusion, we speculated that BAG1 was upregulated in the sciatic nerve after crush, which was associated with Schwann cell differentiation.
Collapse
Affiliation(s)
- Hao Wu
- Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong University, Nantong, 226001, Jiangsu, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Abstract
Part of the cellular and physiological functions of BAG-1 (Bcl-2-associated athanogene 1) has been ascribed to the ability of this hsp70 (heat-shock protein 70) co-chaperone to regulate steroid receptor activity. BAG-1 has been reported to inhibit the GR (glucocorticoid receptor) and stimulate the androgen receptor, but to leave the activity of the MR (mineralocorticoid receptor) unchanged. Given the high homology between the MR and GR, this disparity in the actions of BAG-1 is surprising. In the present study, we analysed the effect of BAG-1 on the activity of the closely related PR (progesterone receptor). Similarly to the GR, the transcriptional activity of the PR is inhibited by the long and middle isoforms of BAG-1, BAG-1L and BAG-1M, but not by the short isoform, BAG-1S. We found this inhibition to require the hsp70-binding domain of BAG-1. To shed light on the mechanisms that could explain BAG-1's differential actions on steroid receptors, we tested the binding of BAG-1M to the PR. Mutational analyses of the PR and BAG-1M revealed that the mode of interaction and BAG-1M-mediated inhibition of the PR differs from the reported scenario for the GR. Surprisingly, we also found binding of BAG-1M to the MR. In addition, BAG-1M was able to inhibit the transcriptional activity of the MR. These data entail a reappraisal of the physiological actions of BAG-1M on steroid receptor activity.
Collapse
|
15
|
Hinitt CA, Benn TM, Threadgold S, Wood J, Williams AC, Hague A. BAG-1L promotes keratinocyte differentiation in organotypic culture models and changes in relative BAG-1 isoform abundance may lead to defective stratification. Exp Cell Res 2011; 317:2159-70. [PMID: 21723279 DOI: 10.1016/j.yexcr.2011.06.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 05/31/2011] [Accepted: 06/16/2011] [Indexed: 01/23/2023]
Abstract
In keratinocytes the human Bag-1 gene produces three different protein isoforms from a single messenger RNA, BAG-1L, BAG-1M and BAG-1S. In this study we questioned whether BAG-1L or the shorter isoforms would promote keratinocyte differentiation in organotypic cultures of HaCaT. HaCaT parental and vector cells showed stratification, but terminal differentiation was not complete. Cultures overexpressing BAG-1L isoform-specifically were of increased thickness, demonstrated pronounced expression of basal cytokeratin 5 and β1-integrin, suprabasal involucrin, cytokeratin 1 and plasma membrane-localised filaggrin, and a marked keratinized layer of cells at the surface. We were unable to overexpress BAG-1S and BAG-1M isoform-specifically. Overexpression of BAG-1M gave rise to organotypic cultures intermediate in differentiation to controls and those overexpressing BAG-1L. Cells overexpressing BAG-1S also exhibited elevated endogenous BAG-1. These produced slow growing cultures with high levels of basal cytokeratin 5, but little involucrin or cytokeratin 1. Suprabasal β1-integrin and Ki67 positive cells indicated defective stratification. The results suggest that BAG-1L potentiates epidermal differentiation, but disruption in the relative balance of isoforms towards overexpression of BAG-1S can lead to defective tissue patterning. Hence, a delicate balance of BAG-1 isoforms may be required to regulate normal epidermal stratification and differentiation, with important implications for aberrant differentiation in cancer.
Collapse
|
16
|
Abstract
Huntington´s disease, one of the so-called poly-glutamine diseases, is a dominantly inherited movement disorder characterized by formation of cytosolic and nuclear inclusion bodies and progressive neurodegeneration. Recently, we have shown that Bcl-2-associated athanogene-1 (BAG1), a multifunctional co-chaperone, modulates toxicity, aggregation, degradation and subcellular distribution in vitro and in vivo of the disease-specific mutant huntingtin protein. Aiming at future small molecule-based therapeutical approaches, we further analysed structural demands for these effects employing the C-terminal deletion mutant BAGΔC. We show that disruption of the BAG domain known to eliminate intracellular heat shock protein 70 (Hsp70) binding and activation also precludes binding of Siah-1 thereby leaving nuclear huntingtin translocation unaffected. At the same time BAGΔC fails to induce increased proteasomal huntingtin turnover and does not inhibit intracellular huntingtin aggregation, a pre-requisite necessary for prevention of huntingtin toxicity.
Collapse
Affiliation(s)
- Jan Liman
- Deptment of Neurology, University of Göttingen, Robert-Koch Str. 40 37075 Göttingen, Germany
- DFG-Research Center for Molecular Physiology of the Brain (CMPB), Humboldtallee 23, 37075 Göttingen, Germany; E-Mails: (J.L.); (C.P.D.); (M.B.)
| | - Kamila Sroka
- Merz Pharmaceuticals, R&D CNS, In vitro Pharmacology, Eckenheimer Landstrasse 100, 60318 Frankfurt, Germany, E-Mail: (K.S.)
| | - Christoph P. Dohm
- Deptment of Neurology, University of Göttingen, Robert-Koch Str. 40 37075 Göttingen, Germany
- DFG-Research Center for Molecular Physiology of the Brain (CMPB), Humboldtallee 23, 37075 Göttingen, Germany; E-Mails: (J.L.); (C.P.D.); (M.B.)
| | - Sebastian Deeg
- Deptment of Neurology, University of Göttingen, Robert-Koch Str. 40 37075 Göttingen, Germany
- DFG-Research Center for Molecular Physiology of the Brain (CMPB), Humboldtallee 23, 37075 Göttingen, Germany; E-Mails: (J.L.); (C.P.D.); (M.B.)
| | - Mathias Bähr
- Deptment of Neurology, University of Göttingen, Robert-Koch Str. 40 37075 Göttingen, Germany
- DFG-Research Center for Molecular Physiology of the Brain (CMPB), Humboldtallee 23, 37075 Göttingen, Germany; E-Mails: (J.L.); (C.P.D.); (M.B.)
| | - Pawel Kermer
- Deptment of Neurology, University of Göttingen, Robert-Koch Str. 40 37075 Göttingen, Germany
- DFG-Research Center for Molecular Physiology of the Brain (CMPB), Humboldtallee 23, 37075 Göttingen, Germany; E-Mails: (J.L.); (C.P.D.); (M.B.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +49-551-396356; Fax: +1-111-111-112
| |
Collapse
|
17
|
Deeg S, Gralle M, Sroka K, Bähr M, Wouters FS, Kermer P. BAG1 restores formation of functional DJ-1 L166P dimers and DJ-1 chaperone activity. ACTA ACUST UNITED AC 2010; 188:505-13. [PMID: 20156966 PMCID: PMC2828921 DOI: 10.1083/jcb.200904103] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The L166P mutation in DJ-1 is associated with Parkinson’s disease. DJ-1–interacting protein BAG1 chaperones mutant DJ-1 and reverses its mutant phenotype. Mutations in the gene coding for DJ-1 protein lead to early-onset recessive forms of Parkinson’s disease. It is believed that loss of DJ-1 function is causative for disease, although the function of DJ-1 still remains a matter of controversy. We show that DJ-1 is localized in the cytosol and is associated with membranes and organelles in the form of homodimers. The disease-related mutation L166P shifts its subcellular distribution to the nucleus and decreases its ability to dimerize, impairing cell survival. Using an intracellular foldase biosensor, we found that wild-type DJ-1 possesses chaperone activity, which is abolished by the L166P mutation. We observed that this aberrant phenotype can be reversed by the expression of the cochaperone BAG1 (Bcl-2–associated athanogene 1), restoring DJ-1 subcellular distribution, dimer formation, and chaperone activity and ameliorating cell survival.
Collapse
Affiliation(s)
- Sebastian Deeg
- Department for Neurology, Georg-August University Göttingen, 37073 Göttingen, Germany
| | | | | | | | | | | |
Collapse
|
18
|
Sroka K, Voigt A, Deeg S, Reed JC, Schulz JB, Bähr M, Kermer P. BAG1 modulates huntingtin toxicity, aggregation, degradation, and subcellular distribution. J Neurochem 2009; 111:801-7. [DOI: 10.1111/j.1471-4159.2009.06363.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
19
|
Hunsberger JG, Austin DR, Chen G, Manji HK. Cellular mechanisms underlying affective resiliency: the role of glucocorticoid receptor- and mitochondrially-mediated plasticity. Brain Res 2009; 1293:76-84. [PMID: 19595676 DOI: 10.1016/j.brainres.2009.06.103] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Revised: 06/16/2009] [Accepted: 06/26/2009] [Indexed: 12/28/2022]
Abstract
Bipolar disorder (BPD) is a devastating psychiatric illness marked by recurrent episodes of mania and depression. While the underlying pathophysiology of BPD remains elusive, an abnormal hypothalamic-pituitary-adrenal (HPA) axis and dysfunctional glucocorticoid receptor (GR) signaling are considered hallmarks. This review will examine how targeting resiliency signaling cascades at the cellular level may serve as a mechanism to treat BPD. Here, cellular resiliency is defined as the ability of a cell to adapt to an insult or stressor. Such resiliency at the cellular level could confer resiliency at the systems level and, ultimately, help individuals to cope with stressors or recover from depressive or manic states. This review will focus on four molecular targets of mood stabilizers that are known to play integral roles in these cellular resiliency signaling pathways: (1) B-cell CLL/lymphoma 2 (Bcl-2), (2) Bcl-2-associated athanogene (BAG-1), (3) glucocorticoid receptors (GRs), and (4) 51 kDa FK506-binding protein (FKBP5). These targets have emerged from neurobiological and human genetic studies and employ mechanisms that modulate GR function or promote anti-apoptotic processes critical to affective resilience. Future research should focus on elucidating sustainable treatments that target resiliency factors-such as BAG-1 or FKBP5-which could ultimately be used to treat individuals suffering from BPD and prevent relapses in afflicted individuals. Further identification of resiliency and susceptibility factors will also be vital. Ultimately, these developments would allow for the treatment of susceptible individuals prior to the development of BPD.
Collapse
Affiliation(s)
- Joshua G Hunsberger
- Laboratory of Molecular Pathophysiology, Mood and Anxiety Disorders Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | | | | | | |
Collapse
|
20
|
Abstract
The closely related human and murine proteins Hap46/BAG-1M and BAG-1, respectively, were discovered more than a decade ago by molecular cloning techniques. These and the larger isoform Hap50/BAG-1L, as well as shorter isoforms, have the ability to interact with a seemingly unlimited array of proteins of completely unrelated structures. This problem was partially resolved when it was realized that molecular chaperones of the hsp70 heat shock protein family are major primary association partners, binding being mediated by the carboxy terminal BAG-domain and the ATP-binding domain of hsp70 chaperones. The latter, in turn, can associate with an almost unlimited variety of proteins through their substrate-binding domains, so that ternary complexes may result. The protein folding activity of hsp70 chaperones is affected by interactions with Hap46/BAG-1M or isoforms. However, there also exist several proteins which bind to Hap46/BAG-1M and isoforms independent of hsp70 mediation. Moreover, Hap46/BAG-1M and Hap50/BAG-1L, but not the shorter isoforms, can bind to DNA in a sequence-independent manner by making use of positively charged regions close to their amino terminal ends. This is the molecular basis for their effects on transcription which are of major physiological relevance, as discussed here in terms of a model. The related proteins Hap50/BAG-1L and Hap46/BAG-1M may thus serve as molecular links between such diverse bioactivities as regulation of gene expression and protein quality control. These activities are coordinated and synergize in helping cells to cope with conditions of external stress. Moreover, they recently became markers for the aggressiveness of several cancer types.
Collapse
Affiliation(s)
- Ulrich Gehring
- Biochemie-Zentrum der Universität Heidelberg, INF 328, D-69120 Heidelberg, Germany
| |
Collapse
|
21
|
Elliott E, Ginzburg I. BAG-1 is preferentially expressed in neuronal precursor cells of the adult mouse brain and regulates their proliferation in vitro. FEBS Lett 2009; 583:229-34. [DOI: 10.1016/j.febslet.2008.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2008] [Revised: 12/03/2008] [Accepted: 12/03/2008] [Indexed: 02/05/2023]
|
22
|
Millar EK, Anderson LR, McNeil CM, O'Toole SA, Pinese M, Crea P, Morey AL, Biankin AV, Henshall SM, Musgrove EA, Sutherland RL, Butt AJ. BAG-1 predicts patient outcome and tamoxifen responsiveness in ER-positive invasive ductal carcinoma of the breast. Br J Cancer 2009; 100:123-33. [PMID: 19066611 DOI: 10.1038/sj.bjc.6604809] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
BAG-1 (bcl-2-associated athanogene) enhances oestrogen receptor (ER) function and may influence outcome and response to endocrine therapy in breast cancer. We determined relationships between BAG-1 expression, molecular phenotype, response to tamoxifen therapy and outcome in a cohort of breast cancer patients and its influence on tamoxifen sensitivity in MCF-7 breast cancer cells in vitro. Publically available gene expression data sets were analysed to identify relationships between BAG-1 mRNA expression and patient outcome. BAG-1 protein expression was assessed using immunohistochemistry in 292 patients with invasive ductal carcinoma and correlated with clinicopathological variables, therapeutic response and disease outcome. BAG-1-overexpressing MCF-7 cells were treated with antioestrogens to assess its effects on cell proliferation. Gene expression data demonstrated a consistent association between high BAG-1 mRNA and improved survival. In ER+ cancer (n=189), a high nuclear BAG-1 expression independently predicted improved outcome for local recurrence (P=0.0464), distant metastases (P=0.0435), death from breast cancer (P=0.009, hazards ratio 0.29, 95% CI: 0.114-0.735) and improved outcome in tamoxifen-treated patients (n=107; P=0.0191). BAG-1 overexpression in MCF-7 cells augmented antioestrogen-induced growth arrest. A high BAG-1 expression predicts improved patient outcome in ER+ breast carcinoma. This may reflect both a better definition of the hormone-responsive phenotype and a concurrent increased sensitivity to tamoxifen.
Collapse
|
23
|
Rohde G, Kermer P, Reed JC, Bähr M, Weishaupt JH. Neuron-specific overexpression of the co-chaperone Bcl-2-associated athanogene-1 in superoxide dismutase 1(G93A)-transgenic mice. Neuroscience 2008; 157:844-9. [PMID: 18955116 DOI: 10.1016/j.neuroscience.2008.09.055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 09/02/2008] [Accepted: 09/23/2008] [Indexed: 11/29/2022]
Abstract
Bcl-2-associated athanogene-1 (BAG1) binds heat-shock protein 70 (Hsp70)/Hsc70, increases intracellular chaperone activity in neurons and proved to be protective in several models for neurodegeneration. Mutations in the superoxide dismutase 1 (SOD1) gene account for approximately 20% of familial amyotrophic lateral sclerosis (ALS) cases. A common property shared by all mutant SOD1 (mtSOD1) species is abnormal protein folding and the propensity to form aggregates. Toxicity and aggregate formation of mutant SOD1 can be overcome by enhanced chaperone function in vitro. Moreover, expression of mtSOD1 decreases BAG1 levels in a motoneuronal cell line. Thus, several lines of evidence suggested a protective role of BAG1 in mtSOD1-mediated motoneuron degeneration. To explore the therapeutic potential of BAG1 in a model for ALS, we generated SOD1G93A/BAG1 double transgenic mice expressing BAG1 in a neuron-specific pattern. Surprisingly, substantially increased BAG1 protein levels in spinal cord neurons did not significantly alter the phenotype of SOD1G93A-transgenic mice. Hence, expression of BAG1 is not sufficient to protect against mtSOD1-induced motor dysfunction in vivo. Our work shows that, in contrast to the in vitro situation, modulation of multiple cellular functions in addition to enhanced expression of a single chaperone is required to protect against SOD1 toxicity, highlighting the necessity of combined treatment strategies for ALS.
Collapse
Affiliation(s)
- G Rohde
- University of Göttingen, Department of Neurology, Robert-Koch-Str. 40, 37075 Göttingen, Germany
| | | | | | | | | |
Collapse
|
24
|
Abstract
Bag-1 is an anti-apoptotic protein that exhibits altered expression in many malignancies, including oral squamous cell carcinoma. The bag-1 gene gives rise to different protein products with different subcellular localisations through alternative translational initiation sites. In oral squamous cell carcinoma, cytoplasmic expression has been associated with metastasis to regional lymph nodes and poor prognosis. In contrast, the longest Bag-1 isoform is nuclear and may regulate differentiation in oral epithelium. In this review, the functions of the three isoforms of Bag-1 expressed in oral epithelial cells are discussed in relation to their contribution to oral carcinogenesis.
Collapse
Affiliation(s)
- Jemma Wood
- Department of Oral and Dental Science, University of Bristol, Lower Maudlin Street, Bristol, BS1 2LY, UK
| | | | | |
Collapse
|
25
|
Planchamp V, Bermel C, Tönges L, Ostendorf T, Kügler S, Reed JC, Kermer P, Bähr M, Lingor P. BAG1 promotes axonal outgrowth and regeneration in vivo via Raf-1 and reduction of ROCK activity. Brain 2008; 131:2606-19. [PMID: 18757464 DOI: 10.1093/brain/awn196] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Improved survival of injured neurons and the inhibition of repulsive environmental signalling are prerequisites for functional regeneration. BAG1 (Bcl-2-associated athanogene-1) is an Hsp70/Hsc70-binding protein, which has been shown to suppress apoptosis and enhance neuronal differentiation. We investigated BAG1 as a therapeutic molecule in the lesioned visual system in vivo. Using an adeno-associated viral vector, BAG1 (AAV.BAG1) was expressed in retinal ganglion cells (RGC) and then tested in models of optic nerve axotomy and optic nerve crush. BAG1 significantly increased RGC survival as compared to adeno-associated viral vector enhanced green fluorescent protein (AAV.EGFP) treated controls and this was independently confirmed in transgenic mice over-expressing BAG1 in neurons. The numbers and lengths of regenerating axons after optic nerve crush were also significantly increased in the AAV.BAG1 group. In pRGC cultures, BAG1-over-expression resulted in a approximately 3-fold increase in neurite length and growth cone surface. Interestingly, BAG1 induced an intracellular translocation of Raf-1 and ROCK2 and ROCK activity was decreased in a Raf-1-dependent manner by BAG1-over-expression. In summary, we show that BAG1 acts in a dual role by inhibition of lesion-induced apoptosis and interaction with the inhibitory ROCK signalling cascade. BAG1 is therefore a promising molecule to be further examined as a putative therapeutic tool in neurorestorative strategies.
Collapse
|
26
|
Maeng S, Hunsberger JG, Pearson B, Yuan P, Wang Y, Wei Y, McCammon J, Schloesser RJ, Zhou R, Du J, Chen G, McEwen B, Reed JC, Manji HK. BAG1 plays a critical role in regulating recovery from both manic-like and depression-like behavioral impairments. Proc Natl Acad Sci U S A 2008; 105:8766-71. [PMID: 18562287 DOI: 10.1073/pnas.0803736105] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Recent microarray studies with stringent validating criteria identified Bcl-2-associated athanogene (BAG1) as a target for the actions of medications that are mainstays in the treatment of bipolar disorder (BPD). BAG1 is a Hsp70/Hsc70-regulating cochaperone that also interacts with glucocorticoid receptors (GRs) and attenuates their nuclear trafficking and function. Notably, glucocorticoids are one of the few agents capable of triggering both depressive and manic episodes in patients with BPD. As a nexus for the actions of glucocorticoids and bipolar medications, we hypothesized that the level of BAG1 expression would play a pivotal role in regulating affective-like behaviors. This hypothesis was investigated in neuron-selective BAG1 transgenic (TG) mice and BAG1 heterozygous knockout (+/-) mice. On mania-related tests, BAG1 TG mice recovered much faster than wild-type (WT) mice in the amphetamine-induced hyperlocomotion test and displayed a clear resistance to cocaine-induced behavioral sensitization. In contrast, BAG1+/- mice displayed an enhanced response to cocaine-induced behavioral sensitization. The BAG1 TG mice showed less anxious-like behavior on the elevated plus maze test and had higher spontaneous recovery rates from helplessness behavior compared with WT mice. In contrast, fewer BAG1+/- mice recovered from helplessness behavior compared with their WT controls. BAG1 TG mice also exhibited specific alterations of hippocampal proteins known to regulate GR function, including Hsp70 and FKBP51. These data suggest that BAG1 plays a key role in affective resilience and in regulating recovery from both manic-like and depression-like behavioral impairments.
Collapse
|
27
|
Orr AL, Huang S, Roberts MA, Reed JC, Li S, Li XJ. Sex-dependent effect of BAG1 in ameliorating motor deficits of Huntington disease transgenic mice. J Biol Chem 2008; 283:16027-36. [PMID: 18400759 PMCID: PMC2414304 DOI: 10.1074/jbc.m710606200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2007] [Revised: 04/04/2008] [Indexed: 11/06/2022] Open
Abstract
The pathogenesis of Huntington disease (HD) is attributed to the misfolding of huntingtin (htt) caused by an expanded polyglutamine (polyQ) domain. Considerable effort has been devoted to identifying molecules that can prevent or reduce htt misfolding and the associated neuropathology. Although overexpression of chaperones is known to reduce htt cytotoxicity in cellular models, only modest protection is seen with Hsp70 overexpression in HD mouse models. Because the activity of Hsp70 is modulated by co-chaperones, an interesting issue is whether the in vivo effects of chaperones on polyQ protein toxicity are dependent on other modulators. In the present study, we focused on BAG1, a co-chaperone that interacts with Hsp70 and regulates its activity. Of htt mice expressing the N171-82Q mutant, we found that male N171-82Q mice show a greater deficit in rotarod performance than female N171-82Q mice. This sex-dependent motor deficit was improved by crossing N171-82Q mice with transgenic mice overexpressing BAG1 in neurons. Transgenic BAG1 also reduces the levels of mutant htt in synaptosomal fraction of male HD mice. Overexpression of BAG1 augmented the effects of Hsp70 by reducing aggregation of mutant htt in cultured cells and improving neurite outgrowth in htt-transfected PC12 cells. These findings suggest that the effects of chaperones on HD pathology are influenced by both their modulators and sex-dependent factors.
Collapse
Affiliation(s)
- Adam L. Orr
- Department of Human Genetics,
Emory University School of Medicine, Atlanta, Georgia 30322 and the
Burnham Institute for Medical
Research, La Jolla, California 92037
| | - Shanshan Huang
- Department of Human Genetics,
Emory University School of Medicine, Atlanta, Georgia 30322 and the
Burnham Institute for Medical
Research, La Jolla, California 92037
| | - Meredith A. Roberts
- Department of Human Genetics,
Emory University School of Medicine, Atlanta, Georgia 30322 and the
Burnham Institute for Medical
Research, La Jolla, California 92037
| | - John C. Reed
- Department of Human Genetics,
Emory University School of Medicine, Atlanta, Georgia 30322 and the
Burnham Institute for Medical
Research, La Jolla, California 92037
| | - Shihua Li
- Department of Human Genetics,
Emory University School of Medicine, Atlanta, Georgia 30322 and the
Burnham Institute for Medical
Research, La Jolla, California 92037
| | - Xiao-Jiang Li
- Department of Human Genetics,
Emory University School of Medicine, Atlanta, Georgia 30322 and the
Burnham Institute for Medical
Research, La Jolla, California 92037
| |
Collapse
|
28
|
Liman J, Faida L, Dohm CP, Reed JC, Bähr M, Kermer P. Subcellular distribution affects BAG1 function. Brain Res 2008; 1198:21-6. [DOI: 10.1016/j.brainres.2008.01.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 12/10/2007] [Accepted: 01/02/2008] [Indexed: 11/29/2022]
|
29
|
Lee SS, Crabb SJ, Janghra N, Carlberg C, Williams AC, Cutress RI, Packham G, Hague A. Subcellular localisation of BAG-1 and its regulation of vitamin D receptor-mediated transactivation and involucrin expression in oral keratinocytes: implications for oral carcinogenesis. Exp Cell Res 2007; 313:3222-38. [PMID: 17662274 DOI: 10.1016/j.yexcr.2007.06.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 06/11/2007] [Accepted: 06/25/2007] [Indexed: 11/20/2022]
Abstract
In oral cancers, cytoplasmic BAG-1 overexpression is a marker of poor prognosis. BAG-1 regulates cellular growth, differentiation and survival through interactions with diverse proteins, including the vitamin D receptor (VDR), a key regulator of keratinocyte growth and differentiation. BAG-1 is expressed ubiquitously in human cells as three major isoforms of 50 kDa (BAG-1L), 46 kDa (BAG-1M) and 36 kDa (BAG-1S) from a single mRNA. In oral keratinocytes BAG-1L, but not BAG-1M and BAG-1S, enhanced VDR transactivation in response to 1alpha,25-dihydroxyvitamin D3. BAG-1L was nucleoplasmic and nucleolar, whereas BAG-1S and BAG-1M were cytoplasmic and nucleoplasmic in localisation. Having identified the nucleolar localisation sequence in BAG-1L, we showed that mutation of this sequence did not prevent BAG-1L from potentiating VDR activity. BAG-1L also potentiated transactivation of known vitamin-D-responsive gene promoters, osteocalcin and 24-hydroxylase, and enhanced VDR-dependent transcription and protein expression of the keratinocyte differentiation marker, involucrin. These results demonstrate endogenous gene regulation by BAG-1L by potentiating nuclear hormone receptor function and suggest a role for BAG-1L in 24-hydroxylase regulation of vitamin D metabolism and the cellular response of oral keratinocytes to 1alpha,25-dihydroxyvitamin D3. By contrast to the cytoplasmic BAG-1 isoforms, BAG-1L may act to suppress tumorigenesis.
Collapse
Affiliation(s)
- San San Lee
- Department of Oral and Dental Science, University of Bristol, Lower Maudlin Street, Bristol BS1 2LY, UK
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Dohm CP, Siedenberg S, Liman J, Esposito A, Wouters FS, Reed JC, Bähr M, Kermer P. Bax inhibitor-1 protects neurons from oxygen-glucose deprivation. J Mol Neurosci 2007; 29:1-8. [PMID: 16757804 DOI: 10.1385/jmn:29:1:1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 11/30/1999] [Accepted: 10/14/2005] [Indexed: 12/29/2022]
Abstract
Bax ihibitor-1 (BI-1) has been characterized as an inhibitor of Bax-induced cell death in plants and various mammalian cell systems. To explore the function of BI-1 in neurons, we overexpressed BI-1 tagged to HA or GFP in rat nigral CSM14.1 and human SH-SY5Y neuroblastoma cells. Stable BI-1 expression proved marked protection from cell death induced by thapsigargine, a stress agent blocking the Ca2+-ATPase of the endoplasmic reticulum (ER) but failed to inhibit cell death induced by staurosporine, a kinase inhibitor initiating mitochondria-dependent apoptosis. Moreover, BI-1 was neuroprotective in a paradigm mimicking ischemia, namely oxygen-glucose as well as serum deprivation. Examination of the subcellular distribution revealed that BI-1 predominantly locates to the ER and nuclear envelope but not mitochondria. Taken together, BI-1 overexpression in the ER is protective in neurons, making BI-1 an interesting target for future studies aiming at the inhibition of neuronal cell death during neurodegenerative diseases and stroke.
Collapse
Affiliation(s)
- Christoph P Dohm
- Department of Neurology, University of Göttingen, 37075 Göttingen, Germany
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Curcio C, Asheld JJ, Chabla JM, Ayubcha D, Hallas BH, Horowitz JM, Torres G. Expression profile of Bag 1 in the postmortem brain. J Chem Neuroanat 2006; 32:191-5. [PMID: 17046197 PMCID: PMC1769523 DOI: 10.1016/j.jchemneu.2006.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 09/08/2006] [Accepted: 09/08/2006] [Indexed: 12/15/2022]
Abstract
Bag 1 is a protein intimately involved in signaling pathways that regulate cell survival. Here we examined the expression profile of Bag 1 in the brain to consider issues associated with the sampling of anti-apoptotic proteins in a rat model of the human postmortem process. Following a 4h postmortem interval, we analyzed the hippocampus of rats maintained at 24 or 4 degrees C storage temperatures using immunocytochemical and Western blotting techniques. Remarkably, postmortem tissue (up to 4h) showed a significant and prominent up-regulation of Bag 1 in CA1 and CA3 subfields of the hippocampal formation. Over-expression of Bag 1, however, could only be traced down to a storage temperature of 24 degrees C. These data suggest that storage temperatures, but not postmortem intervals, significantly affect the expression profile and cellular stability of Bag 1 proteins.
Collapse
Affiliation(s)
- Christine Curcio
- Department of Neuroscience, New York College of Osteopathic Medicine of New York Institute of Technology, Old Westbury New York, 11568 USA
| | - John J. Asheld
- Department of Neuroscience, New York College of Osteopathic Medicine of New York Institute of Technology, Old Westbury New York, 11568 USA
| | - Janet M. Chabla
- Department of Neuroscience, New York College of Osteopathic Medicine of New York Institute of Technology, Old Westbury New York, 11568 USA
| | - Diana Ayubcha
- Department of Neuroscience, New York College of Osteopathic Medicine of New York Institute of Technology, Old Westbury New York, 11568 USA
| | - Brian H. Hallas
- Department of Neuroscience, New York College of Osteopathic Medicine of New York Institute of Technology, Old Westbury New York, 11568 USA
| | - Judith M. Horowitz
- Clinical Neuroscience Laboratory, Medaille College, Buffalo, New York 14214 USA
| | - German Torres
- Department of Neuroscience, New York College of Osteopathic Medicine of New York Institute of Technology, Old Westbury New York, 11568 USA
| |
Collapse
|
32
|
Einat H, Manji HK. Cellular plasticity cascades: genes-to-behavior pathways in animal models of bipolar disorder. Biol Psychiatry 2006; 59:1160-71. [PMID: 16457783 DOI: 10.1016/j.biopsych.2005.11.004] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Revised: 11/11/2005] [Accepted: 11/17/2005] [Indexed: 11/28/2022]
Abstract
BACKGROUND Despite extensive research, the molecular/cellular underpinnings of bipolar disorder (BD) remain to be fully elucidated. Recent data has demonstrated that mood stabilizers exert major effects on signaling that regulate cellular plasticity; however, a direct extrapolation to mechanisms of disease demands proof that manipulation of candidate genes, proteins, or pathways result in relevant behavioral changes. METHODS We critique and evaluate the behavioral changes induced by manipulation of cellular plasticity cascades implicated in BD. RESULTS Not surprisingly, the behavioral data suggest that several important signaling molecules might play important roles in mediating facets of the complex symptomatology of BD. Notably, the protein kinase C and extracellular signal-regulated kinase cascades might play important roles in the antimanic effects of mood stabilizers, whereas glycogen synthase kinase (GSK)-3 might mediate facets of lithium's antimanic/antidepressant actions. Glucocorticoid receptor (GR) modulation also seems to be capable to inducing affective-like changes observed in mood disorders. And Bcl-2, amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors, and inositol homeostasis represent important pharmacological targets for mood stabilizers, but additional behavioral research is needed to more fully delineate their behavioral effects. CONCLUSIONS Behavioral data support the notion that regulation of cellular plasticity is involved in affective-like behavioral changes observed in BD. These findings are leading to the development of novel therapeutics for this devastating illness.
Collapse
Affiliation(s)
- Haim Einat
- College of Pharmacy, Duluth, University of Minnesota, 55812, USA.
| | | |
Collapse
|
33
|
Choi JS, Lee JH, Kim HY, Chun MH, Chung JW, Lee MY. Developmental expression of Bis protein in the cerebral cortex and hippocampus of rats. Brain Res 2006; 1092:69-78. [PMID: 16690035 DOI: 10.1016/j.brainres.2006.02.137] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2005] [Revised: 02/09/2006] [Accepted: 02/09/2006] [Indexed: 11/29/2022]
Abstract
Bis (Bcl-2 interacting death suppressor), identified as a Bcl-2-binding protein, has been suggested to have diverse functions in addition to binding to Bcl-2, thereby regulating cell death. To investigate the potential role of Bis in the developing brain, the spatiotemporal expression of Bis protein was studied in the rat forebrain during prenatal and early postnatal development using immunohistochemistry. Initial expression of Bis was detected in the medial telencephalic wall of the lateral ventricle, the area most likely corresponded to the cortical hem from the earliest age examined (E13). There was an abrupt increase of immunoreactive neurons in the cortex and hippocampus during the first postnatal week, which declined thereafter. Two populations of Bis-immunoreactive neurons can be clearly distinguished in the developing forebrain: a population of differentiating and postmitotic neurons coexpressing Bis and microtubule-associated protein-2 (MAP-2), and a population of neurons with the characteristic morphology of Cajal-Retzius cells located exclusively in the marginal zone/layer I of the cortex and in the hippocampal equivalents of the marginal zone. The latter neurons were colabeled with reelin, a marker for Cajal-Retzius cells. While Bis expression in the cerebral cortex and hippocampus exists only transiently by P14, considerable expression was found to be maintained in the rostral migratory stream and the subventricular zone of the lateral ventricle, where Bis-immunoreactive cells were glutamine synthetase-positive glial cells. Our results suggest that Bis may contribute to the developmental processes, including the differentiation and maturation of specific neuronal populations in relation to Bcl-2 in the developing rat forebrain.
Collapse
Affiliation(s)
- Jeong-Sun Choi
- Department of Anatomy, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Socho-gu, 137-701 Seoul, Republic of Korea
| | | | | | | | | | | |
Collapse
|
34
|
Zhou R, Gray NA, Yuan P, Li X, Chen J, Chen G, Damschroder-Williams P, Du J, Zhang L, Manji HK. The anti-apoptotic, glucocorticoid receptor cochaperone protein BAG-1 is a long-term target for the actions of mood stabilizers. J Neurosci 2006; 25:4493-502. [PMID: 15872096 PMCID: PMC6725025 DOI: 10.1523/jneurosci.4530-04.2005] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Increasing data suggest that impairments of cellular plasticity/resilience underlie the pathophysiology of bipolar disorder. A series of microarray studies with validating criteria have recently revealed a common, novel target for the long-term actions of the structurally highly dissimilar mood stabilizers lithium and valproate: BAG-1 [BCL-2 (B-cell CLL/lymphoma 2)-associated athanogene]. Because BAG-1 attenuates glucocorticoid receptor (GR) nuclear translocation, activates ERK (extracellular signal-regulated kinase) MAP (mitogen-activated protein) kinases, and potentiates anti-apoptotic functions of BCL-2, extensive additional studies were undertaken. Chronic administration of both agents at therapeutic doses increased the expression of BAG-1 in rat hippocampus. Furthermore, these findings were validated at the protein level, and the effects were seen in a time frame consistent with therapeutic effects and were specific for mood stabilizers. Functional studies showed that either lithium or valproate, at therapeutically relevant levels, inhibited dexamethasone-induced GR nuclear translocation and inhibited GR transcriptional activity. Furthermore, small interfering RNA studies showed that these inhibitory effects on GR activity were mediated, at least in part, through BAG-1. The observation that BAG-1 inhibits glucocorticoid activation suggests that mood stabilizers may counteract the deleterious effects of hypercortisolemia seen in bipolar disorder by upregulating BAG-1. Additionally, these studies suggest that regulation of GR-mediated plasticity may play a role in the treatment of bipolar disorder and raise the possibility that agents affecting BAG-1 more directly may represent novel therapies for this devastating illness.
Collapse
Affiliation(s)
- Rulun Zhou
- Laboratory of Molecular Pathophysiology, National Institute of Mental Health, Bethesda, Maryland 20852, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
Heat shock protein Hsp70 is implicated in the mechanism of cell reaction to a variety of cytotoxic factors. The protective function of Hsp70 is related to its ability to promote folding of nascent polypeptides and to remove denatured proteins. Many types of cancer cells contain high amounts of Hsp70, whose protective capacity may pose a problem for therapy in oncology. Hsp70 was shown to be expressed on the surface of cancer cells and to participate in the presentation of tumor antigens to immune cells. Therefore, the chaperone activity of Hsp70 is an important factor that should be taken into consideration in cancer therapy. The protective role of Hsp70 is also evident in neuropathology. Many neurodegenerative processes are associated with the accumulation of insoluble aggregates of misfolded proteins in neural cells. These aggregates hamper intracellular transport, inhibit metabolism, and activate apoptosis through diverse pathways. The increase of Hsp70 content results in the reduction of aggregate size and number and ultimately enhances cell viability.
Collapse
Affiliation(s)
- Irina Guzhova
- Laboratory of Cell Protection Mechanisms, Institute of Cytology, Russian Academy of Science, St Petersburg, Russia
| | | |
Collapse
|
36
|
Barnes JD, Arhel NJ, Lee SS, Sharp A, Al-Okail M, Packham G, Hague A, Paraskeva C, Williams AC. Nuclear BAG-1 expression inhibits apoptosis in colorectal adenoma-derived epithelial cells. Apoptosis 2005; 10:301-11. [PMID: 15843891 DOI: 10.1007/s10495-005-0804-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
BAG-1 is an anti-apoptotic protein that is frequently deregulated in a variety of malignancies including colorectal cancer. There are three isoforms: BAG-1L is located in the nucleus, BAG-1M and BAG-1S are located both in the nucleus and the cytoplasm. In colon cancer, the expression of nuclear BAG-1 is associated with poorer prognosis and is potentially a useful predictive factor for distant metastasis. However, the function of BAG-1 in colonic epithelial cells has not been studied. Having previously shown a predominant nuclear localisation of BAG-1 in adenoma-derived cell lines, we wanted to determine the function of nuclear BAG-1 in these non-tumourigenic cells, to identify whether nuclear BAG-1 was implicated in tumour progression in the colon. In the current report we established that nuclear BAG-1 inhibits apoptosis in a colorectal adenoma-derived cell line. We demonstrate that apoptosis induced by gamma-radiation or the vitamin D analogue EB1089 in the non-tumourigenic human colorectal adenoma-derived S/RG/C2 cell line, was preceded by a decrease in nuclear and an increase in cytoplasmic BAG-1 expression. This change in subcellular localisation of BAG-1 was due to the redistribution of the BAG-1M isoform. In addition, we have shown that the maintenance of high nuclear BAG-1 through enforced expression of the nuclear localised BAG-1L isoform enhanced cellular survival after gamma-radiation or exposure to EB1089. Furthermore the expression of cytoplasmic BAG-1S isoform fused with a nuclear localisation signal protected against gamma-radiation induced apoptosis. This demonstrates that nuclear localisation of the BAG-1 protein confers a survival advantage in colorectal adenoma-derived cells and that nuclear BAG-1 could potentially be an important survival factor in colorectal carcinogenesis.
Collapse
Affiliation(s)
- J D Barnes
- Cancer Research UK Colorectal Tumour Biology Research Group, Department of Pathology and Microbiology, School of Medical Sciences, University of Bristol, Bristol, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Batistatou A, Kyzas PA, Goussia A, Arkoumani E, Voulgaris S, Polyzoidis K, Agnantis NJ, Stefanou D. Estrogen receptor beta (ERbeta) protein expression correlates with BAG-1 and prognosis in brain glial tumours. J Neurooncol 2005; 77:17-23. [PMID: 16292491 DOI: 10.1007/s11060-005-9005-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Indexed: 02/06/2023]
Abstract
Estrogen receptor beta (ERbeta) is an important mediator of estrogen function in a variety of tissues. Its expression declines in breast, ovarian, prostatic and colon carcinomas as well as in astrocytic tumours. BAG-1 is a multifunctional protein with an important role in neoplasia and is possibly regulated by estrogen receptors. One of the direct targets of BAG-1 is HSP70. The purpose of this study was to analyse the expression pattern of these proteins in two distinct types of glial neoplasms, to investigate their possible correlation and probe their impact on prognosis. ERbeta, BAG-1 and HSP70 protein expression was monitored immunohistochemically in 66 cases of astrocytomas and 20 oligodendrogliomas. In astrocytic tumours low ERbeta expression correlated significantly with high grade (P < 0.001), higher expression of cytoplasmic BAG-1 (P < 0.001) and worse survival (log rank P = 0.02). Multivariate analysis revealed that ERbeta expression had a prognostic value for overall survival in these patients (Cox P = 0.03), which was not dependent on grade. There was also statistically significant association of BAG-1 nuclear expression with HSP70 cytoplasmic expression. Our results strengthen the hypothesis that ERbeta, BAG-1 and HSP70 play an important role in the pathogenesis and progression of glial neoplasms. Moreover, ERbeta expression in astrocytic tumors might be an important prognostic factor for survival.
Collapse
Affiliation(s)
- Anna Batistatou
- Department of Pathology, University of Ioannina, Medical School, 451 10, Ioannina, Greece.
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Götz R, Wiese S, Takayama S, Camarero GC, Rossoll W, Schweizer U, Troppmair J, Jablonka S, Holtmann B, Reed JC, Rapp UR, Sendtner M. Bag1 is essential for differentiation and survival of hematopoietic and neuronal cells. Nat Neurosci 2005; 8:1169-78. [PMID: 16116448 PMCID: PMC1361767 DOI: 10.1038/nn1524] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2005] [Accepted: 07/22/2005] [Indexed: 11/08/2022]
Abstract
Bag1 is a cochaperone for the heat-shock protein Hsp70 that interacts with C-Raf, B-Raf, Akt, Bcl-2, steroid hormone receptors and other proteins. Here we use targeted gene disruption in mice to show that Bag1 has an essential role in the survival of differentiating neurons and hematopoietic cells. Cells of the fetal liver and developing nervous system in Bag1-/- mice underwent massive apoptosis. Lack of Bag1 did not disturb the primary function of Akt or Raf, as phosphorylation of the forkhead transcription factor FKHR and activation of extracellular signal-regulated kinase (Erk)-1/2 were not affected. However, the defect was associated with the disturbance of a tripartite complex formed by Akt, B-Raf and Bag1, in addition to the absence of Bad phosphorylation at Ser136. We also observed reduced expression of members of the inhibitor of apoptosis (IAP) family. Our data show that Bag1 is a physiological mediator of extracellular survival signals linked to the cellular mechanisms that prevent apoptosis in hematopoietic and neuronal progenitor cells.
Collapse
Affiliation(s)
- Rudolf Götz
- Institut für Klinische Neurobiologie, University of Wuerzburg, Josef Schneider Str. 11, D-97080 Wuerzburg, Germany
| | - Stefan Wiese
- Institut für Klinische Neurobiologie, University of Wuerzburg, Josef Schneider Str. 11, D-97080 Wuerzburg, Germany
| | | | - Guadalupe C. Camarero
- Institut für Medizinische Strahlenkunde und Zellforschung (MSZ), University of Wuerzburg, Versbacher Str. 5, D-97078 Wuerzburg, Germany
| | - Wilfried Rossoll
- Institut für Klinische Neurobiologie, University of Wuerzburg, Josef Schneider Str. 11, D-97080 Wuerzburg, Germany
| | - Ulrich Schweizer
- Institut für Klinische Neurobiologie, University of Wuerzburg, Josef Schneider Str. 11, D-97080 Wuerzburg, Germany
| | - Jakob Troppmair
- Institut für Medizinische Strahlenkunde und Zellforschung (MSZ), University of Wuerzburg, Versbacher Str. 5, D-97078 Wuerzburg, Germany
| | - Sibylle Jablonka
- Institut für Klinische Neurobiologie, University of Wuerzburg, Josef Schneider Str. 11, D-97080 Wuerzburg, Germany
| | - Bettina Holtmann
- Institut für Klinische Neurobiologie, University of Wuerzburg, Josef Schneider Str. 11, D-97080 Wuerzburg, Germany
| | - John C. Reed
- The Burnham Institute, La Jolla, California 92037, USA
| | - Ulf R. Rapp
- Institut für Medizinische Strahlenkunde und Zellforschung (MSZ), University of Wuerzburg, Versbacher Str. 5, D-97078 Wuerzburg, Germany
| | - Michael Sendtner
- Institut für Klinische Neurobiologie, University of Wuerzburg, Josef Schneider Str. 11, D-97080 Wuerzburg, Germany
- Corresponding author: Dr. Michael Sendtner, University of Wuerzburg, Institute for Clinical Neurobiology, Josef-Schneider-Str. 11, D-97080 Wuerzburg, Germany, Tel.: 0049-(0)931-201-49771, Fax: 0049-(0)931-201-49788,
| |
Collapse
|
39
|
Liman J, Ganesan S, Dohm CP, Krajewski S, Reed JC, Bähr M, Wouters FS, Kermer P. Interaction of BAG1 and Hsp70 mediates neuroprotectivity and increases chaperone activity. Mol Cell Biol 2005; 25:3715-25. [PMID: 15831476 PMCID: PMC1084317 DOI: 10.1128/mcb.25.9.3715-3725.2005] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It was recently shown that Bcl-2-associated athanogene 1 (BAG1) is a potent neuroprotectant as well as a marker of neuronal differentiation. Since there appears to exist an equilibrium within the cell between BAG1 binding to heat shock protein 70 (Hsp70) and BAG1 binding to Raf-1 kinase, we hypothesized that changing BAG1 binding characteristics might significantly alter BAG1 function. To this end, we compared rat CSM14.1 cells and human SHSY-5Y cells stably overexpressing full-length BAG1 or a deletion mutant (BAGDeltaC) no longer capable of binding to Hsp70. Using a novel yellow fluorescent protein-based foldase biosensor, we demonstrated an upregulation of chaperone in situ activity in cells overexpressing full-length BAG1 but not in cells overexpressing BAGDeltaC compared to wild-type cells. Interestingly, in contrast to the nuclear and cytosolic localizations of full-length BAG1, BAGDeltaC was expressed exclusively in the cytosol. Furthermore, cells expressing BAGDeltaC were no longer protected against cell death. However, they still showed accelerated neuronal differentiation. Together, these results suggest that BAG1-induced activation of Hsp70 is important for neuroprotectivity, while BAG1-dependent modulation of neuronal differentiation in vitro is not.
Collapse
Affiliation(s)
- Jan Liman
- Neurologische Klinik, Universität Göttingen, Cell Biophysics Group, European Neuroscience Institute Göttingen, Göttingen, Germany, The Burnham Institute, La Jolla, California
| | - Sundar Ganesan
- Neurologische Klinik, Universität Göttingen, Cell Biophysics Group, European Neuroscience Institute Göttingen, Göttingen, Germany, The Burnham Institute, La Jolla, California
| | - Christoph P. Dohm
- Neurologische Klinik, Universität Göttingen, Cell Biophysics Group, European Neuroscience Institute Göttingen, Göttingen, Germany, The Burnham Institute, La Jolla, California
| | - Stan Krajewski
- Neurologische Klinik, Universität Göttingen, Cell Biophysics Group, European Neuroscience Institute Göttingen, Göttingen, Germany, The Burnham Institute, La Jolla, California
| | - John C. Reed
- Neurologische Klinik, Universität Göttingen, Cell Biophysics Group, European Neuroscience Institute Göttingen, Göttingen, Germany, The Burnham Institute, La Jolla, California
| | - Mathias Bähr
- Neurologische Klinik, Universität Göttingen, Cell Biophysics Group, European Neuroscience Institute Göttingen, Göttingen, Germany, The Burnham Institute, La Jolla, California
| | - Fred S. Wouters
- Neurologische Klinik, Universität Göttingen, Cell Biophysics Group, European Neuroscience Institute Göttingen, Göttingen, Germany, The Burnham Institute, La Jolla, California
- Corresponding author. Mailing address for Fred S. Wouters: Cell Biophysics Group, European Neuroscience Institute Göttingen, Waldweg 33, 37075 Göttingen, Germany. Phone: 0049-551-3912368. Fax: 0049-551-3912346. E-mail:
| | - Pawel Kermer
- Neurologische Klinik, Universität Göttingen, Cell Biophysics Group, European Neuroscience Institute Göttingen, Göttingen, Germany, The Burnham Institute, La Jolla, California
- Corresponding author. Mailing address for Pawel Kermer: Neurologische Klinik, Universität Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany. Phone: 49-551-394927. Fax: 49-551-3914302. E-mail:
| |
Collapse
|
40
|
Abstract
Terminally differentiated, mature neurons are essential cells that are not easily regenerated. Neurotropic viruses, such as Sindbis virus (SV), cause encephalomyelitis through their ability to replicate in neurons. SV causes the death of immature neurons, while mature neurons can often survive infection. The lack of a reproducible and convenient neuronal cell culture system has hindered a detailed study of the differences in levels of virus replication between immature and mature neurons and the molecular events involved in virus clearance from mature neurons. We have characterized SV replication in immortalized CSM14.1 rat neuronal cells that can be differentiated into neurons. During differentiation, CSM14.1 cells ceased dividing, developed neuronal morphology, and expressed neuron-specific cell markers. SV infection of undifferentiated CSM14.1 cells was efficient and resulted in high levels of virus replication and cell death. SV infection of differentiated CSM14.1 cells was less efficient and resulted in the production of 10- to 100-fold less virus and cell survival. In undifferentiated cells, SV induced a rapid shutdown of cellular protein synthesis and pE2 was efficiently processed to E2 (ratio of E2 to pE2, 2.14). In differentiated cells, the SV-induced shutdown of cellular protein synthesis was transient and pE2 was the primary form of E2 in cells (ratio of E2 to pE2, 0.0426). We conclude that age-dependent restriction of virus replication is an intrinsic property of maturing neurons and that the CSM14.1 cell line is a convenient model system for investigating the interactions of alphaviruses with neurons at various stages of differentiation.
Collapse
Affiliation(s)
- Patty S Vernon
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA
| | | |
Collapse
|
41
|
Abstract
BAG-1 (Bcl-2-associated athanogene) is a multifaceted protein implicated in the modulation of a large variety of cellular processes. Elucidating the molecular mechanisms that underlie the cellular functions of BAG-1 becomes an increasingly important task, particularly in light of the growing evidence connecting aberrant BAG-1 expression to certain human cancers. A common element of the remarkable functional diversity of BAG-1 appears to be the interaction with molecular chaperones of the Hsp70 family. In fact, BAG-1 functions as a nucleotide exchange factor of mammalian cytosolic Hsc70, thereby triggering substrate unloading from the chaperone. In addition, recent findings reveal an association of BAG-1 with the proteasome, which suggests a role in coordinating chaperone and degradation pathways.
Collapse
Affiliation(s)
- Simon Alberti
- Institut für Zellbiologie und Bonner Forum Biomedizin, Rheinische Friedrich-Wilhelms-Universität Bonn, Ulrich-Haberland-Str. 61a, D-53121 Bonn, Germany
| | | | | |
Collapse
|
42
|
Chae HJ, Kim HR, Xu C, Bailly-Maitre B, Krajewska M, Krajewski S, Banares S, Cui J, Digicaylioglu M, Ke N, Kitada S, Monosov E, Thomas M, Kress CL, Babendure JR, Tsien RY, Lipton SA, Reed JC. BI-1 Regulates an Apoptosis Pathway Linked to Endoplasmic Reticulum Stress. Mol Cell 2004; 15:355-66. [PMID: 15304216 DOI: 10.1016/j.molcel.2004.06.038] [Citation(s) in RCA: 231] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Revised: 05/26/2004] [Accepted: 05/28/2004] [Indexed: 12/25/2022]
Abstract
Bax inhibitor-1 (BI-1) is an evolutionarily conserved endoplasmic reticulum (ER) protein that suppresses cell death in both animal and plant cells. We characterized mice in which the bi-1 gene was ablated. Cells from BI-1-deficient mice, including fibroblasts, hepatocytes, and neurons, display selective hypersensitivity to apoptosis induced by ER stress agents (thapsigargin, tunicamycin, brefeldin A), but not to stimulators of mitochondrial or TNF/Fas-death receptor apoptosis pathways. Conversely, BI-1 overexpression protects against apoptosis induced by ER stress. BI-1-mediated protection from apoptosis induced by ER stress correlated with inhibition of Bax activation and translocation to mitochondria, preservation of mitochondrial membrane potential, and suppression of caspase activation. BI-1 overexpression also reduces releasable Ca(2+) from the ER. In vivo, bi-1(-/-) mice exhibit increased sensitivity to tissue damage induced by stimuli that trigger ER stress, including stroke and tunicamycin injection. Thus, BI-1 regulates a cell death pathway important for cytopreservation during ER stress.
Collapse
Affiliation(s)
- Han-Jung Chae
- The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Roth W, Kermer P, Krajewska M, Welsh K, Davis S, Krajewski S, Reed JC. Bifunctional apoptosis inhibitor (BAR) protects neurons from diverse cell death pathways. Cell Death Differ 2004; 10:1178-87. [PMID: 14502241 DOI: 10.1038/sj.cdd.4401287] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The bifunctional apoptosis regulator (BAR) is a multidomain protein that was originally identified as an inhibitor of Bax-induced apoptosis. Immunoblot analysis of normal human tissues demonstrated high BAR expression in the brain, compared to low or absent expression in other organs. Immunohistochemical staining of human adult tissues revealed that the BAR protein is predominantly expressed by neurons in the central nervous system. Immunofluorescence microscopy indicated that BAR localizes mainly to the endoplasmic reticulum (ER) of cells. Overexpression of BAR in CSM 14.1 neuronal cells resulted in significant protection from a broad range of cell death stimuli, including agents that activate apoptotic pathways involving mitochondria, TNF-family death receptors, and ER stress. Downregulation of BAR by antisense oligonucleotides sensitized neuronal cells to induction of apoptosis. Moreover, the search for novel interaction partners of BAR identified several candidate proteins that might contribute to the regulation of neuronal apoptosis (HIP1, Hippi, and Bap31). Taken together, the expression pattern and functional data suggest that the BAR protein is involved in the regulation of neuronal survival.
Collapse
MESH Headings
- Adaptor Proteins, Signal Transducing
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal/pharmacology
- Apoptosis/drug effects
- Apoptosis/physiology
- Apoptosis Regulatory Proteins
- Arabidopsis Proteins/genetics
- Arabidopsis Proteins/metabolism
- Blotting, Western
- Brain Chemistry
- COS Cells
- Carrier Proteins/genetics
- Carrier Proteins/metabolism
- Carrier Proteins/physiology
- Caspase 8
- Caspases/genetics
- Caspases/metabolism
- Cell Line
- Cell Line, Tumor/drug effects
- Cell Line, Tumor/metabolism
- Cell Survival/drug effects
- Cell Survival/physiology
- Chlorocebus aethiops
- Culture Media, Serum-Free/pharmacology
- DNA-Binding Proteins
- Down-Regulation
- Endoplasmic Reticulum/chemistry
- Fatty Acid Desaturases/genetics
- Fatty Acid Desaturases/metabolism
- Gene Expression Regulation
- Green Fluorescent Proteins
- Humans
- Immunohistochemistry
- Luminescent Proteins/genetics
- Luminescent Proteins/metabolism
- Male
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Membrane Proteins/physiology
- Microscopy, Fluorescence
- Molecular Sequence Data
- Nervous System/chemistry
- Neurons/physiology
- Oligodeoxyribonucleotides, Antisense/genetics
- Oligodeoxyribonucleotides, Antisense/metabolism
- Protein Binding
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins/physiology
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Rats
- Sequence Homology, Amino Acid
- Signal Transduction/physiology
- Staurosporine/pharmacology
- Thapsigargin/pharmacology
- Transfection
- Tumor Necrosis Factor-alpha/pharmacology
- fas Receptor/immunology
Collapse
Affiliation(s)
- W Roth
- The Burnham Institute, 10901 N Torrey Pines Road, La Jolla, CA 92037, USA
| | | | | | | | | | | | | |
Collapse
|
44
|
Kermer P, Liman J, Weishaupt JH, Bähr M. Neuronal Apoptosis in Neurodegenerative Diseases: From Basic Research to Clinical Application. NEURODEGENER DIS 2004; 1:9-19. [PMID: 16908969 DOI: 10.1159/000076665] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2003] [Accepted: 10/09/2003] [Indexed: 12/16/2022] Open
Abstract
In recent years, the investigation of erroneous regulation of apoptotic mechanisms during acute and chronic injury of neuronal cells has gained increasing attention. Besides acute neuronal trauma and ischemia, chronic neurodegenerative diseases like Alzheimer's, Huntington's, Parkinson's and Lou-Gehrig's disease (amyotrophic lateral sclerosis) are of particular interest. The present article will provide an overview of basic apoptotic mechanisms, the contribution of neuronal apoptosis to the above-mentioned disorders, potential clinical applications and their limitations and the possible implications for future studies regarding these neurodegenerative diseases.
Collapse
Affiliation(s)
- Pawel Kermer
- Department of Neurology, University of Göttingen, Göttingen, Germany.
| | | | | | | |
Collapse
|
45
|
Kermer P, Digicaylioglu MH, Kaul M, Zapata JM, Krajewska M, Stenner-Liewen F, Takayama S, Krajewski S, Lipton SA, Reed JC. BAG1 over-expression in brain protects against stroke. Brain Pathol 2004; 13:495-506. [PMID: 14655755 PMCID: PMC8096046 DOI: 10.1111/j.1750-3639.2003.tb00480.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The co-chaperone BAG1 binds and regulates 70 kDa heat shock proteins (Hsp70/Hsc70) and exhibits cytoprotective activity in cell culture models. Recently, we observed that BAG1 expression is induced during neuronal differentiation in the developing brain. However, the in vivo effects of BAG1 during development and after maturation of the central nervous system have never been examined. We generated transgenic mice over-expressing BAG1 in neurons. While brain development was essentially normal, cultured cortical neurons from transgenic animals exhibited resistance to glutamate-induced, apoptotic neuronal death. Moreover, in an in vivo stroke model involving transient middle cerebral artery occlusion, BAG1 transgenic mice demonstrated decreased mortality and substantially reduced infarct volumes compared to wild-type littermates. Interestingly, brain tissue from BAG1 transgenic mice contained higher levels of neuroprotective Hsp70/Hsc70 protein but not mRNA, suggesting a potential mechanism whereby BAG1 exerts its anti-apoptotic effects. In summary, BAG1 displays potent neuroprotective activity in vivo against stroke, and therefore represents an interesting target for developing new therapeutic strategies including gene therapy and small-molecule drugs for reducing brain injury during cerebral ischemia and neurodegenerative diseases.
Collapse
MESH Headings
- Animals
- Animals, Newborn
- Blotting, Northern
- Blotting, Western
- Brain/anatomy & histology
- Brain/metabolism
- Brain/pathology
- Brain Chemistry
- Cell Death
- Cells, Cultured
- DNA-Binding Proteins
- Disease Models, Animal
- Heat-Shock Proteins/metabolism
- Immunohistochemistry
- Infarction, Middle Cerebral Artery/metabolism
- Infarction, Middle Cerebral Artery/pathology
- Infarction, Middle Cerebral Artery/physiopathology
- Male
- Membrane Proteins
- Mice
- Mice, Transgenic
- Microtubule-Associated Proteins/metabolism
- Neurons/metabolism
- Polymerase Chain Reaction/methods
- Proteins/metabolism
- RNA, Messenger/biosynthesis
- Regional Blood Flow
- Staining and Labeling
- Stroke/metabolism
- Stroke/pathology
- Time Factors
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transfection
Collapse
Affiliation(s)
- Pawel Kermer
- Department of Neurology, University of Goettingen, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Guo B, Zhai D, Cabezas E, Welsh K, Nouraini S, Satterthwait AC, Reed JC. Humanin peptide suppresses apoptosis by interfering with Bax activation. Nature 2003; 423:456-61. [PMID: 12732850 DOI: 10.1038/nature01627] [Citation(s) in RCA: 457] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2003] [Accepted: 03/31/2003] [Indexed: 12/20/2022]
Abstract
Bax (Bcl2-associated X protein) is an apoptosis-inducing protein that participates in cell death during normal development and in various diseases. Bax resides in an inactive state in the cytosol of many cells. In response to death stimuli, Bax protein undergoes conformational changes that expose membrane-targeting domains, resulting in its translocation to mitochondrial membranes, where Bax inserts and causes release of cytochrome c and other apoptogenic proteins. It is unknown what controls conversion of Bax from the inactive to active conformation. Here we show that Bax interacts with humanin (HN), an anti-apoptotic peptide of 24 amino acids encoded in mammalian genomes. HN prevents the translocation of Bax from cytosol to mitochondria. Conversely, reducing HN expression by small interfering RNAs sensitizes cells to Bax and increases Bax translocation to membranes. HN peptides also block Bax association with isolated mitochondria, and suppress cytochrome c release in vitro. Notably, the mitochondrial genome contains an identical open reading frame, and the mitochondrial version of HN can also bind and suppress Bax. We speculate therefore that HN arose from mitochondria and transferred to the nuclear genome, providing a mechanism for protecting these organelles from Bax.
Collapse
Affiliation(s)
- Bin Guo
- The Burnham Institute, 10901 North Torrey Pines Road, La Jolla, California 92037, USA
| | | | | | | | | | | | | |
Collapse
|
47
|
Abstract
BAG-1 is multifunctional protein which interacts with a wide range of cellular targets to regulate growth control pathways important for normal and malignant cells, including apoptosis, signaling, proliferation, transcription and cell motility. Of particular relevance to tumour cells, BAG-1 interacts with the anti-apoptotic BCL-2 protein, various nuclear hormone receptors and the 70 kDa heat shock proteins, Hsc70 and Hsp70. Interaction with chaperones may account for many of the pleiotropic effects associated with BAG-1 overexpression. Recent studies have shown that BAG-1 expression is frequently altered in malignant cells, and BAG-1 expression may have clinical value as a prognostic/predictive marker. This review summarises current understanding of molecular mechanisms of BAG-1 expression and function.
Collapse
Affiliation(s)
- Paul A Townsend
- Cancer Research UK Oncology Unit, Cancer Sciences Division, School of Medicine, University of Southampton, Southampton SO16 6YD, UK
| | | | | | | | | |
Collapse
|
48
|
Schmidt U, Wochnik GM, Rosenhagen MC, Young JC, Hartl FU, Holsboer F, Rein T. Essential role of the unusual DNA-binding motif of BAG-1 for inhibition of the glucocorticoid receptor. J Biol Chem 2003; 278:4926-31. [PMID: 12482863 DOI: 10.1074/jbc.m212000200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The co-chaperone BAG-1 is involved in the regulation of steroid hormone receptors, including the glucocorticoid receptor (GR). More recently, BAG-1 was found in the nucleus where it decreases GR transactivation. Moreover, nonspecific DNA binding of BAG-1 has been reported. We discovered that of the N-terminal part of BAG-1M, the first 8 amino acids are sufficient for DNA binding, containing a stretch of three lysines and a stretch of three arginines. Changing the spacing between these stretches had no effect on DNA binding. Surprisingly, this small, nonsequence-specific DNA binding domain was nonetheless necessary for the inhibitory function of BAG-1 for GR-dependent transcription, whereas the following serine- and threonine-rich E(2)X(4) repeat domain was not. Mutational analysis of these two domains revealed that only mutants retaining DNA binding capability were able to down-regulate GR-mediated transactivation. Intriguingly, lack of DNA binding could not be functionally rescued by BAG-1M harboring a point mutation abolishing interaction with hsp70. Thus, DNA binding and hsp70 interaction are required in cis. We propose that the nonsequence-specific DNA-binding protein BAG-1 acts at specific chromosomal loci by interacting with other proteins.
Collapse
Affiliation(s)
- Ulrike Schmidt
- Max Planck Institute of Psychiatry, Kraepelinstrasse 10, D-80804 Munich, Germany
| | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
BAG-1 (Bcl-2-associated athanogene) is a multifaceted protein implicated in the modulation of a large variety of cellular processes. Elucidating the molecular mechanisms that underlie the cellular functions of BAG-1 becomes an increasingly important task, particularly in light of the growing evidence connecting aberrant BAG-1 expression to certain human cancers. A common element of the remarkable functional diversity of BAG-1 appears to be the interaction with molecular chaperones of the Hsp70 family. In fact, BAG-1 functions as a nucleotide exchange factor of mammalian cytosolic Hsc70, thereby triggering substrate unloading from the chaperone. In addition, recent findings reveal an association of BAG-1 with the proteasome, which suggests a role in coordinating chaperone and degradation pathways.
Collapse
Affiliation(s)
- Simon Alberti
- Institut für Zellbiologie und Bonner Forum Biomedizin, Rheinische Friedrich-Wilhelms-Universität Bonn, Ulrich-Haberland-Str. 61a, D-53121 Bonn, Germany
| | | | | |
Collapse
|