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Rezayi S, Siri M, Rahmani-Kukia N, Zamani M, Dastghaib S, Mokarram P. The modulation of autophagy and unfolded protein response by ent-kaurenoid derivative CPUK02 in human colorectal cancer cells. Mol Biol Rep 2024; 51:599. [PMID: 38689181 DOI: 10.1007/s11033-024-09541-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/10/2024] [Indexed: 05/02/2024]
Abstract
BACKGROUND CPUK02 (15-Oxosteviol benzyl ester) is a semi-synthetic derivative of stevioside known for its anticancer effects. It has been reported that the natural compound of stevioside and its associated derivatives enhances the sensitivity of cancer cells to conventional anti-cancer agents by inducing endoplasmic reticulum (ER) stress. In response to ER stress, autophagy and unfolded protein responses (UPR) are activated to restore cellular homeostasis. Consequently, the primary aim of this study is to investigate the impact of CPUK02 treatment on UPR and autophagy markers in two colorectal cancer cell lines. METHODS HCT116 and SW480 cell lines were treated with various concentrations of CPUK02 for 72 h. The expression levels of several proteins and enzymes were evaluated to investigate the influence of CPUK02 on autophagy and UPR pathways. These include glucose-regulated protein 78 (GRP78), Inositol-requiring enzyme 1-α (IRE1-α), spliced X-box binding protein 1 (XBP-1 s), protein kinase R-like ER kinase (PERK), C/EBP homologous protein (CHOP), Beclin-1, P62 and Microtubule-associated protein 1 light chain 3 alpha (LC3βII). The evaluation was conducted using western blotting and quantitative real-time PCR techniques. RESULTS The results obtained indicate that the treatment with CPUK02 reduced the expression of UPR markers, including GRP78 and IRE1-α at protein levels and XBP-1 s, PERK, and CHOP at mRNA levels in both HCT116 and SW480 cell lines. Furthermore, CPUK02 also influenced autophagy by decreasing Beclin-1 and increasing P62 and LC3βII at mRNA levels in both HCT116 and SW480 treated cells. CONCLUSIONS The study findings suggest CPUK02 may exert its cytotoxic effects by inhibiting UPR and autophagy flux in colorectal cancer cells.
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Affiliation(s)
- Sedigheh Rezayi
- Department of Biochemistry, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Morvarid Siri
- Autophagy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Nasim Rahmani-Kukia
- Department of Biochemistry, School of Medicine, Autophagy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mozhdeh Zamani
- Autophagy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sanaz Dastghaib
- Endocrinology and Metabolism Research Center, Shiraz University of Medical Sciences, P.O. Box 71345-1744, Shiraz, Iran.
| | - Pooneh Mokarram
- Department of Biochemistry, School of Medicine, Autophagy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
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Mattam S, Thomas RH, Akansha EO, Jathanna JS, Poojary RR, Sarpangala S, Jose J, Theruveethi N. Influence of white-light-emitting diodes on primary visual cortex layer 5 pyramidal neurons (V1L5PNs) and remodeling by blue-light-blocking lenses. Int Ophthalmol 2024; 44:118. [PMID: 38416231 PMCID: PMC10901925 DOI: 10.1007/s10792-024-03036-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 01/12/2024] [Indexed: 02/29/2024]
Abstract
Studies have explored the consequences of excessive exposure to white-light-emitting diodes (LEDs) in the retina. Hence, we aimed to assess the implications of such exposure on structural alterations of the visual cortex, learning and memory, and amelioration by blue-light-blocking lenses (BBLs). Eight-week-old Wistar rats (n = 24) were used for the experiment and divided into four groups (n = 6 in each group) as control, white LED light exposure (LE), BBL Crizal Prevencia-1 (CP), and DuraVision Blue-2 (DB). Animals in the exposure group were exposed to white LED directly for 28 days (12:12-h light/dark cycle), whereas animals in the BBL groups were exposed to similar light with BBLs attached to the LEDs. Post-exposure, a Morris water maze was performed for memory retention, followed by structural analysis of layer 5 pyramidal neurons in the visual cortex. We observed a significant difference (P < 0.001) in the functional test on day 1 and day 2 of training in the LE group. Structural analysis of Golgi-Cox-stained visual cortex layer 5 pyramidal neurons showed significant alterations in the apical and basal branching points (p < 0.001) and basal intersection points (p < 0.001) in the LE group. Post hoc analysis revealed significant changes between (p < 0.001) LE and CP and (p < 0.001) CP and DB groups. Constant and cumulative exposure to white LEDs presented with structural and functional alterations in the visual cortex, which are partly remodeled by BBLs.
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Affiliation(s)
- Susmitha Mattam
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, 576104, India
- Sankara College of Optometry, Hyderabad, 500032, India
| | - R Huban Thomas
- Department of Anatomy, Kasturba Medical College Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Elizebeth O Akansha
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, 576104, India
- University of Houston College of Optometry, Houston, USA
| | - Judith S Jathanna
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Radhika R Poojary
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Shailaja Sarpangala
- Department of Ophthalmology, Kasturba Medical College Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Judy Jose
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, 576104, India
| | - Nagarajan Theruveethi
- Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, 576104, India.
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Liu XQ, Hu T, Wu GL, Qiao LJ, Cai YF, Wang Q, Zhang SJ. Tanshinone IIA, the key compound in Salvia miltiorrhiza, improves cognitive impairment by upregulating Aβ-degrading enzymes in APP/PS1 mice. Int J Biol Macromol 2024; 254:127923. [PMID: 37944734 DOI: 10.1016/j.ijbiomac.2023.127923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/04/2023] [Accepted: 11/04/2023] [Indexed: 11/12/2023]
Abstract
In Alzheimer's disease (AD), amyloid-beta (Aβ) plays a crucial role in pathogenesis. Clearing Aβ from the brain is considered as a key therapeutic strategy. Previous studies indicated that Salvia miltiorrhiza (Danshen) could protect against AD. However, the main anti-AD components in Danshen and their specific mechanisms are not clear. In this study, pharmacological network analysis indicated that Tanshinone IIA (Tan IIA) was identified as the key active compound in Danshen contributing to protect against AD. Then, APP/PS1 double transgenic mice were employed to examine the neuroprotective effect of Tan IIA. APP/PS1 mice (age, 6 months) were administered (10 and 20 mg/kg) for 8 weeks. Tan IIA improved learning and anxiety behaviors in APP/PS1 mice. Furthermore, Tan IIA reduced oxidative stress, inhibited neuronal apoptosis, improved cholinergic nervous system and decreased endoplasmic reticulum stress in the brain of APP/PS1 mice. Moreover, Tan IIA treatment reduced the level of Aβ. Molecular docking result showed that Tan IIA might block AD by upregulating Aβ-degrading enzymes. Western blot results confirmed that the expressions of insulin degrading enzymes (IDE) and neprilysin (NEP) were significantly increased after Tan IIA treatment, which demonstrated that Tan IIA improved AD by increasing Aβ-degrading enzymes.
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Affiliation(s)
- Xiao-Qi Liu
- State Key Laboratory of Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, China; Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510405, China; Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, China
| | - Tian Hu
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510405, China
| | - Guang-Liang Wu
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510405, China
| | - Li-Jun Qiao
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510405, China
| | - Ye-Feng Cai
- Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510405, China.
| | - Qi Wang
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou 510405, China.
| | - Shi-Jie Zhang
- State Key Laboratory of Traditional Chinese Medicine Syndrome, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, China; Department of Neurology, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510405, China; Department of Neurology, Guangdong Provincial Hospital of Chinese Medicine, Guangzhou 510405, China.
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Valcarce DG, Riesco MF, Cuesta-Martín L, Esteve-Codina A, Martínez-Vázquez JM, Robles V. Stress decreases spermatozoa quality and induces molecular alterations in zebrafish progeny. BMC Biol 2023; 21:70. [PMID: 37013516 PMCID: PMC10071778 DOI: 10.1186/s12915-023-01570-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
BACKGROUND Chronic stress can produce a severe negative impact on health not only in the exposed individuals but also in their offspring. Indeed, chronic stress may be contributing to the current worldwide scenario of increasing infertility and decreasing gamete quality in human populations. Here, we evaluate the effect of chronic stress on behavior and male reproductive parameters in zebrafish. Our goal is to provide information on the impact that chronic stress has at molecular, histological, and physiological level in a vertebrate model species. RESULTS We evaluated the effects of a 21-day chronic stress protocol covering around three full waves of spermatogenesis in Danio rerio adult males. The induction of chronic stress produced anxiety-like behavior in stressed males as assessed by a novel tank test. At a molecular level, the induction of chronic stress consistently resulted in the overexpression of two genes related to endoplasmic reticulum (ER) stress in the brain. Gene set enrichment analysis (GSEA) of testes suggested a dysregulation of the nonsense-mediated decay (NMD) pathway, which was also confirmed on qPCR analysis. Histological analysis of the testicle did not show significant differences in terms of the relative proportions of each germ-cell type; however, the quality of sperm from stressed males was compromised in terms of motility. RNA-seq analysis in stress-derived larval progenies revealed molecular alterations, including those predicted to affect translation initiation, DNA repair, cell cycle control, and response to stress. CONCLUSIONS Induction of chronic stress during a few cycles of spermatogenesis in the vertebrate zebrafish model affects behavior, gonadal gene expression, final gamete quality, and progeny. The NMD surveillance pathway (a key cellular mechanism that regulates the stability of both normal and mutant transcripts) is severely affected in the testes by chronic stress and therefore the control and regulation of RNAs during spermatogenesis may be affected altering the molecular status in the progeny.
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Affiliation(s)
- David G Valcarce
- Cell Biology Area, Molecular Biology Department, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain
- Instituto Español de Oceanografía, Centro Oceanográfico de Santander (COST-IEO), CSIC, Calle Severiano Ballesteros 16. 39004, Santander, Spain
| | - Marta F Riesco
- Cell Biology Area, Molecular Biology Department, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain
| | - Leyre Cuesta-Martín
- Cell Biology Area, Molecular Biology Department, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain
| | - Anna Esteve-Codina
- CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Juan Manuel Martínez-Vázquez
- Instituto Español de Oceanografía, Centro Oceanográfico de Santander (COST-IEO), CSIC, Calle Severiano Ballesteros 16. 39004, Santander, Spain
| | - Vanesa Robles
- Cell Biology Area, Molecular Biology Department, Universidad de León, Campus de Vegazana s/n, 24071, León, Spain.
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Sun W, Chang C, Long Q. Graph-guided Bayesian SVM with Adaptive Structured Shrinkage Prior for High-dimensional Data. PROCEEDINGS : ... IEEE INTERNATIONAL CONFERENCE ON BIG DATA. IEEE INTERNATIONAL CONFERENCE ON BIG DATA 2021; 2021:4472-4479. [PMID: 35187547 PMCID: PMC8855458 DOI: 10.1109/bigdata52589.2021.9671712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Support vector machine (SVM) is a popular classification method for the analysis of a wide range of data including big biomedical data. Many SVM methods with feature selection have been developed under the frequentist regularization or Bayesian shrinkage frameworks. On the other hand, the value of incorporating a priori known biological knowledge, such as those from functional genomics and functional proteomics, into statistical analysis of -omic data has been recognized in recent years. Such biological information is often represented by graphs. We propose a novel method that assigns Laplace priors to the regression coefficients and incorporates the underlying graph information via a hyper-prior for the shrinkage parameters in the Laplace priors. This enables smoothing of shrinkage parameters for connected variables in the graph and conditional independence between shrinkage parameters for disconnected variables. Extensive simulations demonstrate that our proposed methods achieve the best performance compared to the other existing SVM methods in terms of prediction accuracy. The proposed method are also illustrated in analysis of genomic data from cancer studies, demonstrating its advantage in generating biologically meaningful results and identifying potentially important features.
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Affiliation(s)
- Wenli Sun
- Dept of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, USA
| | - Changgee Chang
- Dept of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, USA
| | - Qi Long
- Dept of Biostatistics, Epidemiology, and Informatics, University of Pennsylvania, Philadelphia, USA
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Suliman M, Schmidtke MW, Greenberg ML. The Role of the UPR Pathway in the Pathophysiology and Treatment of Bipolar Disorder. Front Cell Neurosci 2021; 15:735622. [PMID: 34531727 PMCID: PMC8439382 DOI: 10.3389/fncel.2021.735622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/09/2021] [Indexed: 11/13/2022] Open
Abstract
Bipolar disorder (BD) is a mood disorder that affects millions worldwide and is associated with severe mood swings between mania and depression. The mood stabilizers valproate (VPA) and lithium (Li) are among the main drugs that are used to treat BD patients. However, these drugs are not effective for all patients and cause serious side effects. Therefore, better drugs are needed to treat BD patients. The main barrier to developing new drugs is the lack of knowledge about the therapeutic mechanism of currently available drugs. Several hypotheses have been proposed for the mechanism of action of mood stabilizers. However, it is still not known how they act to alleviate both mania and depression. The pathology of BD is characterized by mitochondrial dysfunction, oxidative stress, and abnormalities in calcium signaling. A deficiency in the unfolded protein response (UPR) pathway may be a shared mechanism that leads to these cellular dysfunctions. This is supported by reported abnormalities in the UPR pathway in lymphoblasts from BD patients. Additionally, studies have demonstrated that mood stabilizers alter the expression of several UPR target genes in mouse and human neuronal cells. In this review, we outline a new perspective wherein mood stabilizers exert their therapeutic mechanism by activating the UPR. Furthermore, we discuss UPR abnormalities in BD patients and suggest future research directions to resolve discrepancies in the literature.
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Affiliation(s)
- Mahmoud Suliman
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Michael W Schmidtke
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
| | - Miriam L Greenberg
- Department of Biological Sciences, Wayne State University, Detroit, MI, United States
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7
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ER Stress Responses: An Emerging Modulator for Innate Immunity. Cells 2020; 9:cells9030695. [PMID: 32178254 PMCID: PMC7140669 DOI: 10.3390/cells9030695] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 03/10/2020] [Indexed: 12/30/2022] Open
Abstract
The endoplasmic reticulum (ER) is a critical organelle, storing the majority of calcium and governing protein translation. Thus, it is crucial to keep the homeostasis in all ER components and machineries. The ER stress sensor pathways, including IRE1/sXBP1, PERK/EIf2 and ATF6, orchestrate the major regulatory circuits to ensure ER homeostasis. The embryonic or postnatal lethality that occurs upon genetic depletion of these sensors reveals the essential role of the ER stress pathway in cell biology. In contrast, the impairment or excessive activation of ER stress has been reported to cause or aggravate several diseases such as atherosclerosis, diabetes, NAFDL/NASH, obesity and cancer. Being part of innate immunity, myeloid cells are the first immune cells entering the inflammation site. Upon entry into a metabolically stressed disease environment, activation of ER stress occurs within the myeloid compartment, leading to the modulation of their phenotype and functions. In this review, we discuss causes and consequences of ER stress activation in the myeloid compartment with a special focus on the crosstalk between ER, innate signaling and metabolic environments.
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8
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Hiramatsu N, Chiang K, Aivati C, Rodvold JJ, Lee JM, Han J, Chea L, Zanetti M, Koo EH, Lin JH. PERK-mediated induction of microRNA-483 disrupts cellular ATP homeostasis during the unfolded protein response. J Biol Chem 2020; 295:237-249. [PMID: 31792031 PMCID: PMC6952592 DOI: 10.1074/jbc.ra119.008336] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 11/26/2019] [Indexed: 01/08/2023] Open
Abstract
Endoplasmic reticulum (ER) stress activates the unfolded protein response (UPR), which reduces levels of misfolded proteins. However, if ER homeostasis is not restored and the UPR remains chronically activated, cells undergo apoptosis. The UPR regulator, PKR-like endoplasmic reticulum kinase (PERK), plays an important role in promoting cell death when persistently activated; however, the underlying mechanisms are poorly understood. Here, we profiled the microRNA (miRNA) transcriptome in human cells exposed to ER stress and identified miRNAs that are selectively induced by PERK signaling. We found that expression of a PERK-induced miRNA, miR-483, promotes apoptosis in human cells. miR-483 induction was mediated by a transcription factor downstream of PERK, activating transcription factor 4 (ATF4), but not by the CHOP transcription factor. We identified the creatine kinase brain-type (CKB) gene, encoding an enzyme that maintains cellular ATP reserves through phosphocreatine production, as being repressed during the UPR and targeted by miR-483. We found that ER stress, selective PERK activation, and CKB knockdown all decrease cellular ATP levels, leading to increased vulnerability to ER stress-induced cell death. Our findings identify miR-483 as a downstream target of the PERK branch of the UPR. We propose that disruption of cellular ATP homeostasis through miR-483-mediated CKB silencing promotes ER stress-induced apoptosis.
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Affiliation(s)
- Nobuhiko Hiramatsu
- Department of Pathology, University of California San Diego, La Jolla, California 92093-0612
| | - Karen Chiang
- Department of Pathology, University of California San Diego, La Jolla, California 92093-0612; Department of Neurosciences, University of California San Diego, La Jolla, California 92093-0612
| | - Cathrine Aivati
- Department of Pathology, University of California San Diego, La Jolla, California 92093-0612
| | - Jeffrey J Rodvold
- Moores Cancer Center, University of California San Diego, La Jolla, California 92093-0612
| | - Ji-Min Lee
- Soonchunhyang Institute of Med-bio Science, Soonchunhyang University, Asan 31151, Korea
| | - Jaeseok Han
- Soonchunhyang Institute of Med-bio Science, Soonchunhyang University, Asan 31151, Korea
| | - Leon Chea
- Department of Pathology, Stanford University, Stanford, California 94304
| | - Maurizio Zanetti
- Moores Cancer Center, University of California San Diego, La Jolla, California 92093-0612
| | - Edward H Koo
- Department of Neurosciences, University of California San Diego, La Jolla, California 92093-0612; Departments of Medicine and Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 117549 Singapore
| | - Jonathan H Lin
- Department of Pathology, University of California San Diego, La Jolla, California 92093-0612; Department of Pathology, Stanford University, Stanford, California 94304; Veterans Affairs Palo Alto Healthcare System, Palo Alto, California 94304.
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Sun W, Chang C, Long Q. Bayesian Non-linear Support Vector Machine for High-Dimensional Data with Incorporation of Graph Information on Features. PROCEEDINGS : ... IEEE INTERNATIONAL CONFERENCE ON BIG DATA. IEEE INTERNATIONAL CONFERENCE ON BIG DATA 2019; 2019:4874-4882. [PMID: 32455423 PMCID: PMC7243270 DOI: 10.1109/bigdata47090.2019.9006473] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Support vector machine (SVM) is a popular classification method for analysis of high dimensional data such as genomics data. Recently a number of linear SVM methods have been developed to achieve feature selection through either frequentist regularization or Bayesian shrinkage, but the linear assumption may not be plausible for many real applications. In addition, recent work has demonstrated that incorporating known biological knowledge, such as those from functional genomics, into the statistical analysis of genomic data offers great promise of improved predictive accuracy and feature selection. Such biological knowledge can often be represented by graphs. In this article, we propose a novel knowledge-guided nonlinear Bayesian SVM approach for analysis of high-dimensional data. Our model uses graph information that represents the relationship among the features to guide feature selection. To achieve knowledge-guided feature selection, we assign an Ising prior to the indicators representing inclusion/exclusion of the features in the model. An efficient MCMC algorithm is developed for posterior inference. The performance of our method is evaluated and compared with several penalized linear SVM and the standard kernel SVM method in terms of prediction and feature selection in extensive simulation studies. Also, analyses of genomic data from a cancer study show that our method yields a more accurate prediction model for patient survival and reveals biologically more meaningful results than the existing methods.
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Affiliation(s)
- Wenli Sun
- Department of Biostatistics, Epidemiology and Informatics The University of Pennsylvania, Philadelphia, PA, 19104
| | - Changgee Chang
- Department of Biostatistics, Epidemiology and Informatics The University of Pennsylvania, Philadelphia, PA, 19104
| | - Qi Long
- Department of Biostatistics, Epidemiology and Informatics The University of Pennsylvania, Philadelphia, PA, 19104
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10
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Amodio G, Moltedo O, Fasano D, Zerillo L, Oliveti M, Di Pietro P, Faraonio R, Barone P, Pellecchia MT, De Rosa A, De Michele G, Polishchuk E, Polishchuk R, Bonifati V, Nitsch L, Pierantoni GM, Renna M, Criscuolo C, Paladino S, Remondelli P. PERK-Mediated Unfolded Protein Response Activation and Oxidative Stress in PARK20 Fibroblasts. Front Neurosci 2019; 13:673. [PMID: 31316342 PMCID: PMC6610533 DOI: 10.3389/fnins.2019.00673] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/12/2019] [Indexed: 12/20/2022] Open
Abstract
PARK20, an early onset autosomal recessive parkinsonism is due to mutations in the phosphatidylinositol-phosphatase Synaptojanin 1 (Synj1). We have recently shown that the early endosomal compartments are profoundly altered in PARK20 fibroblasts as well as the endosomal trafficking. Here, we report that PARK20 fibroblasts also display a drastic alteration of the architecture and function of the early secretory compartments. Our results show that the exit machinery from the Endoplasmic Reticulum (ER) and the ER-to-Golgi trafficking are markedly compromised in patient cells. As a consequence, PARK20 fibroblasts accumulate large amounts of cargo proteins within the ER, leading to the induction of ER stress. Interestingly, this stressful state is coupled to the activation of the PERK/eIF2α/ATF4/CHOP pathway of the Unfolded Protein Response (UPR). In addition, PARK20 fibroblasts reveal upregulation of oxidative stress markers and total ROS production with concomitant alteration of the morphology of the mitochondrial network. Interestingly, treatment of PARK20 cells with GSK2606414 (GSK), a specific inhibitor of PERK activity, restores the level of ROS, signaling a direct correlation between ER stress and the induction of oxidative stress in the PARK20 cells. All together, these findings suggest that dysfunction of early secretory pathway might contribute to the pathogenesis of the disease.
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Affiliation(s)
- Giuseppina Amodio
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| | - Ornella Moltedo
- Department of Pharmacy, University of Salerno, Salerno, Italy
| | - Dominga Fasano
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Lucrezia Zerillo
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Marco Oliveti
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| | - Paola Di Pietro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| | - Raffaella Faraonio
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Paolo Barone
- Section of Neuroscience, Department of Medicine, Surgery and Dentistry, University of Salerno, Salerno, Italy
| | - Maria Teresa Pellecchia
- Section of Neuroscience, Department of Medicine, Surgery and Dentistry, University of Salerno, Salerno, Italy
| | - Anna De Rosa
- Department of Neuroscience, Reproductive, and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | - Giuseppe De Michele
- Department of Neuroscience, Reproductive, and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | | | | | | | - Lucio Nitsch
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Giovanna Maria Pierantoni
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Maurizio Renna
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Chiara Criscuolo
- Department of Neuroscience, Reproductive, and Odontostomatological Sciences, University of Naples Federico II, Naples, Italy
| | - Simona Paladino
- Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Paolo Remondelli
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
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Hu Y, Wang Y, Yan T, Feng D, Ba Y, Zhang H, Zhu J, Cheng X, Cui L, Huang H. N-acetylcysteine alleviates fluoride-induced testicular apoptosis by modulating IRE1α/JNK signaling and nuclear Nrf2 activation. Reprod Toxicol 2019; 84:98-107. [PMID: 30633982 DOI: 10.1016/j.reprotox.2019.01.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 12/10/2018] [Accepted: 01/03/2019] [Indexed: 12/12/2022]
Abstract
We previously investigated excessive fluoride exposure elicited intracellular endoplasmic reticulum (ER) stress and led to Sertoli cells dysfunction in vitro. However, the mechanisms underlying fluoride-mediated male reproductive damage in vivo remain largely unknown. Considerable evidence has now revealed ER stress is closely linked with testicular oxidative damage. Hence, we aimed to explore whether ER stress signaling was involved in the testicular protective effects of antioxidant N-acetylcysteine (NAC) against testicular apoptosis induced by fluoride. Male SD rats were oral gavaged with sodium fluoride (NaF) for 7 weeks to induce fluorosis. The animals were pretreatment with or without NAC (150 mg/Bw•d). Our results demonstrated that sub-chronic NaF exposure triggered testicular apoptosis and sex hormonal disturbance in pituitary-testicular (PT) axis, promoted oxidative stress and the expression of ER stress mediators. Antioxidant NAC, however, prevented NaF-induced testicular apoptosis accompanied by activating Nrf2-mediated antioxidant potential. Simultaneously, NAC pretreatment downregulated XBP1 splicing, reduced JNK phosphorylation and further blocked cleavage of caspase-3, all these might contribute to the inhibition of testicular cell apoptosis. Collectively, the present results suggested that prolonged administration of NAC preserved testicular function and normalized sex hormonal disruption induced by NaF via the inhibition of Nrf2-associated oxidative damage and Ire1α-JNK-mediated apoptosis in rat testis.
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Affiliation(s)
- Yazhen Hu
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China
| | - Yawei Wang
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China
| | - Ting Yan
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China
| | - Demin Feng
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China
| | - Yue Ba
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China
| | - Huizhen Zhang
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China
| | - Jingyuan Zhu
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China
| | - Xuemin Cheng
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China
| | - Liuxin Cui
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China
| | - Hui Huang
- College of Public Health, Zhengzhou University, No. 100 Kexue Avenue, Zhengzhou, 450001, Henan, PR China.
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12
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Sun W, Chang C, Zhao Y, Long Q. Knowledge-Guided Bayesian Support Vector Machine for High-Dimensional Data with Application to Analysis of Genomics Data. PROCEEDINGS : ... IEEE INTERNATIONAL CONFERENCE ON BIG DATA. IEEE INTERNATIONAL CONFERENCE ON BIG DATA 2018; 2018:1484-1493. [PMID: 31041431 PMCID: PMC6486656 DOI: 10.1109/bigdata.2018.8622484] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Support vector machine (SVM) is a popular classification method for the analysis of wide range of data including big data. Many SVM methods with feature selection have been developed under frequentist regularization or Bayesian shrinkage frameworks. On the other hand, the importance of incorporating a priori known biological knowledge, such as gene pathway information which stems from the gene regulatory network, into the statistical analysis of genomic data has been recognized in recent years. In this article, we propose a new Bayesian SVM approach that enables the feature selection to be guided by the knowledge on the graphical structure among predictors. The proposed method uses the spike-and-slab prior for feature selection, combined with the Ising prior that encourages group-wise selection of the predictors adjacent to each other on the known graph. Gibbs sampling algorithm is used for Bayesian inference. The performance of our method is evaluated and compared with existing SVM methods in terms of prediction and feature selection in extensive simulation settings. In addition, our method is illustrated in the analysis of genomic data from a cancer study, demonstrating its advantage in generating biologically meaningful results and identifying potentially important features.
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Affiliation(s)
- Wenli Sun
- Department of Biostatistics, Epidemiology and Informatics The University of Pennsylvania, Philadelphia, PA, 19104
| | - Changgee Chang
- Department of Biostatistics, Epidemiology and Informatics The University of Pennsylvania, Philadelphia, PA, 19104
| | - Yize Zhao
- Department of Healthcare Policy and Research Weill Cornell Medicine, Cornell University, New York, NY, 10065
| | - Qi Long
- Department of Biostatistics, Epidemiology and Informatics The University of Pennsylvania, Philadelphia, PA, 19104
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13
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Sanchez-Pupo RE, Johnston D, Penuela S. N-Glycosylation Regulates Pannexin 2 Localization but Is Not Required for Interacting with Pannexin 1. Int J Mol Sci 2018; 19:ijms19071837. [PMID: 29932112 PMCID: PMC6073767 DOI: 10.3390/ijms19071837] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/16/2018] [Accepted: 06/20/2018] [Indexed: 02/07/2023] Open
Abstract
Pannexins (Panx1, 2, 3) are channel-forming glycoproteins expressed in mammalian tissues. We previously reported that N-glycosylation acts as a regulator of the localization and intermixing of Panx1 and Panx3, but its effects on Panx2 are currently unknown. Panx1 and Panx2 intermixing can regulate channel properties, and both pannexins have been implicated in neuronal cell death after ischemia. Our objectives were to validate the predicted N-glycosylation site of Panx2 and to study the effects of Panx2 glycosylation on localization and its capacity to interact with Panx1. We used site-directed mutagenesis, enzymatic de-glycosylation, cell-surface biotinylation, co-immunoprecipitation, and confocal microscopy. Our results showed that N86 is the only N-glycosylation site of Panx2. Panx2 and the N86Q mutant are predominantly localized to the endoplasmic reticulum (ER) and cis-Golgi matrix with limited cell surface localization was seen only in the presence of Panx1. The Panx2 N86Q mutant is glycosylation-deficient and tends to aggregate in the ER reducing its cell surface trafficking but it can still interact with Panx1. Our study indicates that N-glycosylation may be important for folding and trafficking of Panx2. We found that the un-glycosylated forms of Panx1 and 2 can readily interact, regulating their localization and potentially their channel function in cells where they are co-expressed.
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Affiliation(s)
- Rafael E Sanchez-Pupo
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6A5C1, Canada.
| | - Danielle Johnston
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6A5C1, Canada.
| | - Silvia Penuela
- Department of Anatomy and Cell Biology, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON N6A5C1, Canada.
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14
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Pitale PM, Gorbatyuk O, Gorbatyuk M. Neurodegeneration: Keeping ATF4 on a Tight Leash. Front Cell Neurosci 2017; 11:410. [PMID: 29326555 PMCID: PMC5736573 DOI: 10.3389/fncel.2017.00410] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 12/05/2017] [Indexed: 12/15/2022] Open
Abstract
Activation of the endoplasmic reticulum (ER) stress and ER stress response, also known as the unfolded protein response (UPR), is common to various degenerative disorders. Therefore, signaling components of the UPR are currently emerging as potential targets for intervention and treatment of human diseases. One UPR signaling member, activating transcription factor 4 (ATF4), has been found up-regulated in many pathological conditions, pointing to therapeutic potential in targeting its expression. In cells, ATF4 governs multiple signaling pathways, including autophagy, oxidative stress, inflammation, and translation, suggesting a multifaceted role of ATF4 in the progression of various pathologies. However, ATF4 has been shown to trigger both pro-survival and pro-death pathways, and this, perhaps, can explain the contradictory opinions in current literature regarding targeting ATF4 for clinical application. In this review, we summarized recent published studies from our labs and others that focus on the therapeutic potential of the strategy controlling ATF4 expression in different retinal and neurodegenerative disorders.
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Affiliation(s)
- Priyamvada M Pitale
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Oleg Gorbatyuk
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States.,Department of Neurology, Center for Neurodegeneration and Experimental Therapeutics, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Marina Gorbatyuk
- Department of Optometry and Vision Science, School of Optometry, University of Alabama at Birmingham, Birmingham, AL, United States
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15
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Hamieh A, Cartier D, Abid H, Calas A, Burel C, Bucharles C, Jehan C, Grumolato L, Landry M, Lerouge P, Anouar Y, Lihrmann I. Selenoprotein T is a novel OST subunit that regulates UPR signaling and hormone secretion. EMBO Rep 2017; 18:1935-1946. [PMID: 28928140 DOI: 10.15252/embr.201643504] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 08/04/2017] [Accepted: 08/09/2017] [Indexed: 12/12/2022] Open
Abstract
Selenoprotein T (SelT) is a recently characterized thioredoxin-like protein whose expression is very high during development, but is confined to endocrine tissues in adulthood where its function is unknown. We report here that SelT is required for adaptation to the stressful conditions of high hormone level production in endocrine cells. Using immunofluorescence and TEM immunogold approaches, we find that SelT is expressed at the endoplasmic reticulum membrane in all hormone-producing pituitary cell types. SelT knockdown in corticotrope cells promotes unfolded protein response (UPR) and ER stress and lowers endoplasmic reticulum-associated protein degradation (ERAD) and hormone production. Using a screen in yeast for SelT-membrane protein interactions, we sort keratinocyte-associated protein 2 (KCP2), a subunit of the protein complex oligosaccharyltransferase (OST). In fact, SelT interacts not only with KCP2 but also with other subunits of the A-type OST complex which are depleted after SelT knockdown leading to POMC N-glycosylation defects. This study identifies SelT as a novel subunit of the A-type OST complex, indispensable for its integrity and for ER homeostasis, and exerting a pivotal adaptive function that allows endocrine cells to properly achieve the maturation and secretion of hormones.
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Affiliation(s)
- Abdallah Hamieh
- Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Rouen-Normandie University UNIROUEN, Inserm, U1239, Mont-Saint-Aignan, France.,Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Dorthe Cartier
- Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Rouen-Normandie University UNIROUEN, Inserm, U1239, Mont-Saint-Aignan, France.,Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Houssni Abid
- Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Rouen-Normandie University UNIROUEN, Inserm, U1239, Mont-Saint-Aignan, France.,Institute for Research and Innovation in Biomedicine, Rouen, France
| | - André Calas
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, University of Bordeaux, Bordeaux, France
| | - Carole Burel
- Institute for Research and Innovation in Biomedicine, Rouen, France.,Glyco-MEV Laboratory, Rouen-Normandie University UNIROUEN, Mont-Saint-Aignan, France
| | - Christine Bucharles
- Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Rouen-Normandie University UNIROUEN, Inserm, U1239, Mont-Saint-Aignan, France.,Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Cedric Jehan
- Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Rouen-Normandie University UNIROUEN, Inserm, U1239, Mont-Saint-Aignan, France.,Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Luca Grumolato
- Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Rouen-Normandie University UNIROUEN, Inserm, U1239, Mont-Saint-Aignan, France.,Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Marc Landry
- Interdisciplinary Institute for Neuroscience, CNRS UMR 5297, University of Bordeaux, Bordeaux, France
| | - Patrice Lerouge
- Institute for Research and Innovation in Biomedicine, Rouen, France.,Glyco-MEV Laboratory, Rouen-Normandie University UNIROUEN, Mont-Saint-Aignan, France
| | - Youssef Anouar
- Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Rouen-Normandie University UNIROUEN, Inserm, U1239, Mont-Saint-Aignan, France.,Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Isabelle Lihrmann
- Neuronal and Neuroendocrine Differentiation and Communication Laboratory, Rouen-Normandie University UNIROUEN, Inserm, U1239, Mont-Saint-Aignan, France .,Institute for Research and Innovation in Biomedicine, Rouen, France
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16
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Jensen BC, Bultman SJ, Holley D, Tang W, de Ridder G, Pizzo S, Bowles D, Willis MS. Upregulation of autophagy genes and the unfolded protein response in human heart failure. Int J Clin Exp Med 2017; 10:1051-1058. [PMID: 28794819 PMCID: PMC5546743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The cellular environment of the mammalian heart constantly is challenged with environmental and intrinsic pathological insults, which affect the proper folding of proteins in heart failure. The effects of damaged or misfolded proteins on the cell can be profound and result in a process termed "proteotoxicity". While proteotoxicity is best known for its role in mediating the pathogenesis of neurodegenerative diseases such as Alzheimer's disease, its role in human heart failure also has been recognized. The UPR involves three branches, including PERK, ATF6, and IRE1. In the presence of a misfolded protein, the GRP78 molecular chaperone that normally interacts with the receptors PERK, ATF6, and IRE-1 in the endoplasmic reticulum detaches to attempt to stabilize the protein. Mouse models of cardiac hypertrophy, ischemia, and heart failure demonstrate increases in activity of all three branches after removing GRP78 from these internal receptors. Recent studies have linked elevated PERK and CHOP in vitro with regulation of ion channels linked with human systolic heart failure. With this in mind, we specifically investigated ventricular myocardium from 10 patients with a history of conduction system defects or arrhythmias for expression of UPR and autophagy genes compared to myocardium from non-failing controls. We identified elevated Chop, Atf3, and Grp78 mRNA, along with XBP-1-regulated Cebpa mRNA, indicative of activation of the UPR in human heart failure with arrhythmias.
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Affiliation(s)
- Brian C Jensen
- Division of Cardiology, Department of Internal Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Scott J Bultman
- Division of Cardiology, Department of Internal Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Darcy Holley
- Division of Cardiology, Department of Internal Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Wei Tang
- Department of Pathology & Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | - Salvatore Pizzo
- Department of Pathology, Duke University, Durham, NC 27710, USA
| | - Dawn Bowles
- Department of Duke University, Durham, NC 27710, USA
| | - Monte S Willis
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Pathology & Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA
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17
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Tan HK, Muhammad TST, Tan ML. 14-Deoxy-11,12-didehydroandrographolide induces DDIT3-dependent endoplasmic reticulum stress-mediated autophagy in T-47D breast carcinoma cells. Toxicol Appl Pharmacol 2016; 300:55-69. [DOI: 10.1016/j.taap.2016.03.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/18/2016] [Accepted: 03/30/2016] [Indexed: 12/11/2022]
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18
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Bultman SJ, Holley DW, G de Ridder G, Pizzo SV, Sidorova TN, Murray KT, Jensen BC, Wang Z, Bevilacqua A, Chen X, Quintana MT, Tannu M, Rosson GB, Pandya K, Willis MS. BRG1 and BRM SWI/SNF ATPases redundantly maintain cardiomyocyte homeostasis by regulating cardiomyocyte mitophagy and mitochondrial dynamics in vivo. Cardiovasc Pathol 2016; 25:258-269. [PMID: 27039070 DOI: 10.1016/j.carpath.2016.02.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/24/2016] [Accepted: 02/27/2016] [Indexed: 12/13/2022] Open
Abstract
There has been an increasing recognition that mitochondrial perturbations play a central role in human heart failure. Mitochondrial networks, whose function is to maintain the regulation of mitochondrial biogenesis, autophagy ('mitophagy') and mitochondrial fusion/fission, are new potential therapeutic targets. Yet our understanding of the molecular underpinning of these processes is just emerging. We recently identified a role of the SWI/SNF ATP-dependent chromatin remodeling complexes in the metabolic homeostasis of the adult cardiomyocyte using cardiomyocyte-specific and inducible deletion of the SWI/SNF ATPases BRG1 and BRM in adult mice (Brg1/Brm double mutant mice). To build upon these observations in early altered metabolism, the present study looks at the subsequent alterations in mitochondrial quality control mechanisms in the impaired adult cardiomyocyte. We identified that Brg1/Brm double-mutant mice exhibited increased mitochondrial biogenesis, increases in 'mitophagy', and alterations in mitochondrial fission and fusion that led to small, fragmented mitochondria. Mechanistically, increases in the autophagy and mitophagy-regulated proteins Beclin1 and Bnip3 were identified, paralleling changes seen in human heart failure. Evidence for perturbed cardiac mitochondrial dynamics included decreased mitochondria size, reduced numbers of mitochondria, and an altered expression of genes regulating fusion (Mfn1, Opa1) and fission (Drp1). We also identified cardiac protein amyloid accumulation (aggregated fibrils) during disease progression along with an increase in pre-amyloid oligomers and an upregulated unfolded protein response including increased GRP78, CHOP, and IRE-1 signaling. Together, these findings described a role for BRG1 and BRM in mitochondrial quality control, by regulating mitochondrial number, mitophagy, and mitochondrial dynamics not previously recognized in the adult cardiomyocyte. As critical to the pathogenesis of heart failure, epigenetic mechanisms like SWI/SNF chromatin remodeling seem more intimately linked to cardiac function and mitochondrial quality control mechanisms than previously realized.
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Affiliation(s)
- Scott J Bultman
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Darcy Wood Holley
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | | | - Tatiana N Sidorova
- Departments of Medicine and Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Katherine T Murray
- Departments of Medicine and Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Brian C Jensen
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Zhongjing Wang
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Ariana Bevilacqua
- Department of Pathology & Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Xin Chen
- Department of Neurosurgery, Shandong Provincial Hospital affiliated to Shandong University, 250021, Jinan, PR China
| | - Megan T Quintana
- Department of Surgery, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Manasi Tannu
- School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Gary B Rosson
- Department of Genetics, University of North Carolina, Chapel Hill, NC 27599, USA
| | | | - Monte S Willis
- McAllister Heart Institute, University of North Carolina, Chapel Hill, NC, USA; Department of Pathology & Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; Department of Pharmacology, University of North Carolina, Chapel Hill, NC 27599, USA.
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19
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Foufelle F, Fromenty B. Role of endoplasmic reticulum stress in drug-induced toxicity. Pharmacol Res Perspect 2016; 4:e00211. [PMID: 26977301 PMCID: PMC4777263 DOI: 10.1002/prp2.211] [Citation(s) in RCA: 163] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 12/14/2015] [Indexed: 12/13/2022] Open
Abstract
Drug‐induced toxicity is a key issue for public health because some side effects can be severe and life‐threatening. These adverse effects can also be a major concern for the pharmaceutical companies since significant toxicity can lead to the interruption of clinical trials, or the withdrawal of the incriminated drugs from the market. Recent studies suggested that endoplasmic reticulum (ER) stress could be an important event involved in drug liability, in addition to other key mechanisms such as mitochondrial dysfunction and oxidative stress. Indeed, drug‐induced ER stress could lead to several deleterious effects within cells and tissues including accumulation of lipids, cell death, cytolysis, and inflammation. After recalling important information regarding drug‐induced adverse reactions and ER stress in diverse pathophysiological situations, this review summarizes the main data pertaining to drug‐induced ER stress and its potential involvement in different adverse effects. Drugs presented in this review are for instance acetaminophen (APAP), arsenic trioxide and other anticancer drugs, diclofenac, and different antiretroviral compounds. We also included data on tunicamycin (an antibiotic not used in human medicine because of its toxicity) and thapsigargin (a toxic compound of the Mediterranean plant Thapsia garganica) since both molecules are commonly used as prototypical toxins to induce ER stress in cellular and animal models.
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20
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Chiang WC, Joseph V, Yasumura D, Matthes MT, Lewin AS, Gorbatyuk MS, Ahern K, LaVail MM, Lin JH. Ablation of Chop Transiently Enhances Photoreceptor Survival but Does Not Prevent Retinal Degeneration in Transgenic Mice Expressing Human P23H Rhodopsin. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:185-91. [PMID: 26427410 DOI: 10.1007/978-3-319-17121-0_25] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
RHO (Rod opsin) encodes a G-protein coupled receptor that is expressed exclusively by rod photoreceptors of the retina and forms the essential photopigment, rhodopsin, when coupled with 11-cis-retinal. Many rod opsin disease -mutations cause rod opsin protein misfolding and trigger endoplasmic reticulum (ER) stress, leading to activation of the Unfolded Protein Response (UPR) signal transduction network. Chop is a transcriptional activator that is induced by ER stress and promotes cell death in response to chronic ER stress. Here, we examined the role of Chop in transgenic mice expressing human P23H rhodopsin (hP23H Rho Tg) that undergo retinal degeneration. With the exception of one time point, we found no significant induction of Chop in these animals and no significant change in retinal degeneration by histology and electrophysiology when hP23H Rho Tg animals were bred into a Chop (-/-) background. Our results indicate that Chop does not play a significant causal role during retinal degeneration in these animals. We suggest that other modules of the ER stress-induced UPR signaling network may be involved photoreceptor disease induced by P23H rhodopsin.
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Affiliation(s)
- Wei-Chieh Chiang
- Department of Pathology, University of California, La Jolla, 92093, San Diego, CA, USA.
| | - Victory Joseph
- Department of Pathology, University of California, La Jolla, 92093, San Diego, CA, USA.
| | - Douglas Yasumura
- Department of Ophthalmology, University of California, 94143, San Francisco, CA, USA
| | - Michael T Matthes
- Department of Ophthalmology, University of California, 94143, San Francisco, CA, USA.
| | - Alfred S Lewin
- Department of Molecular Genetics and Microbiology, University of Florida, 32610, Gainesville, FL, USA.
| | - Marina S Gorbatyuk
- Department of Vision Sciences, University of Alabama at Birmingham, 35294, Birmingham, AL, USA.
| | - Kelly Ahern
- Department of Ophthalmology, University of California, 94143, San Francisco, CA, USA.
| | - Matthew M LaVail
- Departments of Anatomy and Ophthalmology, University of California, 94143, San Francisco, CA, USA.
| | - Jonathan H Lin
- Department of Pathology, University of California, La Jolla, 92093, San Diego, CA, USA. .,VA San Diego Healthcare System, 92161, San Diego, CA, USA.
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21
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Yan MM, Ni JD, Song D, Ding M, Huang J. Interplay between unfolded protein response and autophagy promotes tumor drug resistance. Oncol Lett 2015; 10:1959-1969. [PMID: 26622781 PMCID: PMC4579870 DOI: 10.3892/ol.2015.3508] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 06/23/2015] [Indexed: 02/07/2023] Open
Abstract
The endoplasmic reticulum (ER) is involved in the quality control of secreted protein via promoting the correct folding of nascent protein and mediating the degradation of unfolded or misfolded protein, namely ER-associated degradation. When the unfolded or misfolded proteins are abundant, the unfolded protein response (UPR) is elicited, an adaptive signaling cascade from the ER to the nucleus, which restores the homeostatic functions of the ER. Autophagy is a conserved catabolic process where cellular long-lived proteins and damaged organelles are engulfed and degraded for recycling to maintain homeostasis. The UPR and autophagy occur simultaneously and are involved in pathological processes, including tumorigenesis, chemoresistance of malignancies and neurodegeneration. Accumulative data has indicated that the UPR may induce autophagy and that autophagy is able to alleviate the UPR. However, the detailed mechanism of interplay between autophagy and UPR remains to be fully understood. The present review aimed to depict the core pathways of the two processes and to elucidate how autophagy and UPR are regulated. Moreover, the review also discusses the molecular mechanism of crosstalk between the UPR and autophagy and their roles in malignant survival and drug resistance.
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Affiliation(s)
- Ming-Ming Yan
- Department of Orthopedic Surgery, Second Xiangya Hospital of Central South University, Changsha, Hunan 410000, P.R. China
| | - Jiang-Dong Ni
- Department of Orthopedic Surgery, Second Xiangya Hospital of Central South University, Changsha, Hunan 410000, P.R. China
| | - Deye Song
- Department of Orthopedic Surgery, Second Xiangya Hospital of Central South University, Changsha, Hunan 410000, P.R. China
| | - Muliang Ding
- Department of Orthopedic Surgery, Second Xiangya Hospital of Central South University, Changsha, Hunan 410000, P.R. China
| | - Jun Huang
- Department of Orthopedic Surgery, Second Xiangya Hospital of Central South University, Changsha, Hunan 410000, P.R. China
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22
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Hiramatsu N, Chiang WC, Kurt TD, Sigurdson CJ, Lin JH. Multiple Mechanisms of Unfolded Protein Response-Induced Cell Death. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:1800-8. [PMID: 25956028 DOI: 10.1016/j.ajpath.2015.03.009] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 02/09/2015] [Accepted: 03/26/2015] [Indexed: 12/12/2022]
Abstract
Eukaryotic cells fold and assemble membrane and secreted proteins in the endoplasmic reticulum (ER), before delivery to other cellular compartments or the extracellular environment. Correctly folded proteins are released from the ER, and poorly folded proteins are retained until they achieve stable conformations; irreparably misfolded proteins are targeted for degradation. Diverse pathological insults, such as amino acid mutations, hypoxia, or infection, can overwhelm ER protein quality control, leading to misfolded protein buildup, causing ER stress. To cope with ER stress, eukaryotic cells activate the unfolded protein response (UPR) by increasing levels of ER protein-folding enzymes and chaperones, enhancing the degradation of misfolded proteins, and reducing protein translation. In mammalian cells, three ER transmembrane proteins, inositol-requiring enzyme-1 (IRE1; official name ERN1), PKR-like ER kinase (PERK; official name EIF2AK3), and activating transcription factor-6, control the UPR. The UPR signaling triggers a set of prodeath programs when the cells fail to successfully adapt to ER stress or restore homeostasis. ER stress and UPR signaling are implicated in the pathogenesis of diverse diseases, including neurodegeneration, cancer, diabetes, and inflammation. This review discusses the current understanding in both adaptive and apoptotic responses as well as the molecular mechanisms instigating apoptosis via IRE1 and PERK signaling. We also examine how IRE1 and PERK signaling may be differentially used during neurodegeneration arising in retinitis pigmentosa and prion infection.
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Affiliation(s)
- Nobuhiko Hiramatsu
- Department of Pathology, University of California-San Diego, La Jolla, California
| | - Wei-Chieh Chiang
- Department of Pathology, University of California-San Diego, La Jolla, California
| | - Timothy D Kurt
- Department of Pathology, University of California-San Diego, La Jolla, California
| | | | - Jonathan H Lin
- Department of Pathology, University of California-San Diego, La Jolla, California.
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Greenwood M, Greenwood MP, Paton JFR, Murphy D. Transcription Factor CREB3L1 Regulates Endoplasmic Reticulum Stress Response Genes in the Osmotically Challenged Rat Hypothalamus. PLoS One 2015; 10:e0124956. [PMID: 25915053 PMCID: PMC4411032 DOI: 10.1371/journal.pone.0124956] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 03/19/2015] [Indexed: 11/18/2022] Open
Abstract
Arginine vasopressin (AVP) is synthesised in magnocellular neurons (MCNs) of supraoptic nucleus (SON) and paraventricular nucleus (PVN) of the hypothalamus. In response to the hyperosmotic stressors of dehydration (complete fluid deprivation, DH) or salt loading (drinking 2% salt solution, SL), AVP synthesis increases in MCNs, which over-burdens the protein folding machinery in the endoplasmic reticulum (ER). ER stress and the unfolded protein response (UPR) are signaling pathways that improve ER function in response to the accumulation of misfold/unfold protein. We asked whether an ER stress response was activated in the SON and PVN of DH and SL rats. We observed increased mRNA expression for the immunoglobulin heavy chain binding protein (BiP), activating transcription factor 4 (Atf4), C/EBP-homologous protein (Chop), and cAMP responsive element binding protein 3 like 1 (Creb3l1) in both SON and PVN of DH and SL rats. Although we found no changes in the splicing pattern of X box-binding protein 1 (Xbp1), an increase in the level of the unspliced form of Xbp1 (Xbp1U) was observed in DH and SL rats. CREB3L1, a novel ER stress inducer, has been shown to be activated by ER stress to regulate the expression of target genes. We have previously shown that CREB3L1 is a transcriptional regulator of the AVP gene; however, a role for CREB3L1 in the response to ER stress has yet to be investigated in MCNs. Here, we used lentiviral vectors to introduce a dominant negative form of CREB3L1 (CREB3L1DN) in the rat SON. Expression of CREB3L1DN in the SON decreased Chop and Xbp1U mRNA levels, but not BiP and Atf4 transcript expression. CREB3L1 is thus implicated as a transcriptional mediator of the ER stress response in the osmotically stimulated SON.
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Affiliation(s)
- Mingkwan Greenwood
- School of Clinical Sciences, University of Bristol, Bristol, England
- * E-mail:
| | | | - Julian F. R. Paton
- School of Physiology and Pharmacology, University of Bristol, Bristol, England
| | - David Murphy
- School of Clinical Sciences, University of Bristol, Bristol, England
- Department of Physiology, University of Malaya, Kuala Lumpur, Malaysia
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The PERKs of damage-associated molecular patterns mediating cancer immunogenicity: From sensor to the plasma membrane and beyond. Semin Cancer Biol 2015; 33:74-85. [PMID: 25882379 DOI: 10.1016/j.semcancer.2015.03.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Revised: 03/17/2015] [Accepted: 03/19/2015] [Indexed: 12/20/2022]
Abstract
Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) are emerging as key adaptation mechanisms in response to loss of proteostasis, with major cell autonomous and non-autonomous functions impacting cancer progression and therapeutic responses. In recent years, vital physiological roles of the ER in maintenance of proteostasis, Ca(2+) signaling and trafficking through the secretory pathway have emerged. Some of these functions have been shown to be decisive for mobilizing certain signals from injured/dying cancer cells in response to certain anticancer treatments, toward the plasma membrane and ultimately emit them into the extracellular environment, where they may act as danger signals. The spatiotemporally defined emission of these signals, better known as damage-associated molecular patterns (DAMPs), distinguishes this type of cancer cell death from physiological apoptosis, which is tolerogenic in nature, thereby enabling these dying cancer cells to alert the immune system and "re-activate" antitumor immunity. The emission of DAMPs, decisive for immunogenic cell death (ICD) and which include the ER chaperone calreticulin and ATP, is reliant on a danger signaling module induced by certain assorted anticancer treatments through oxidative-ER stress. The main focus of this review is to discuss the emerging role of ER-stress regulated pathways and processes in danger signaling thereby regulating the cancer cell-immune cell interface by the extracellular emission of DAMPs. In particular, we discuss signaling contexts existing upstream and around PERK, a major ER-stress sensor in ICD context, which have not been emphatically discussed in the context of antitumor immunity and ICD up until now. Finally, we briefly discuss the pros and cons of targeting PERK in the context of ICD.
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Dzialo MC, Travaglini KJ, Shen S, Roy K, Chanfreau GF, Loo JA, Clarke SG. Translational roles of elongation factor 2 protein lysine methylation. J Biol Chem 2014; 289:30511-30524. [PMID: 25231983 DOI: 10.1074/jbc.m114.605527] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Methylation of various components of the translational machinery has been shown to globally affect protein synthesis. Little is currently known about the role of lysine methylation on elongation factors. Here we show that in Saccharomyces cerevisiae, the product of the EFM3/YJR129C gene is responsible for the trimethylation of lysine 509 on elongation factor 2. Deletion of EFM3 or of the previously described EFM2 increases sensitivity to antibiotics that target translation and decreases translational fidelity. Furthermore, the amino acid sequences of Efm3 and Efm2, as well as their respective methylation sites on EF2, are conserved in other eukaryotes. These results suggest the importance of lysine methylation modification of EF2 in fine tuning the translational apparatus.
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Affiliation(s)
- Maria C Dzialo
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Kyle J Travaglini
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Sean Shen
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Kevin Roy
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Guillaume F Chanfreau
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095
| | - Joseph A Loo
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095; Department of Biological Chemistry and UCLA/Department of Energy Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095
| | - Steven G Clarke
- Department of Chemistry and Biochemistry and the Molecular Biology Institute and UCLA, Los Angeles, California 90095.
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Unfolded protein response activation reduces secretion and extracellular aggregation of amyloidogenic immunoglobulin light chain. Proc Natl Acad Sci U S A 2014; 111:13046-51. [PMID: 25157167 DOI: 10.1073/pnas.1406050111] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Light-chain amyloidosis (AL) is a degenerative disease characterized by the extracellular aggregation of a destabilized amyloidogenic Ig light chain (LC) secreted from a clonally expanded plasma cell. Current treatments for AL revolve around ablating the cancer plasma cell population using chemotherapy regimens. Unfortunately, this approach is limited to the ∼ 70% of patients who do not exhibit significant organ proteotoxicity and can tolerate chemotherapy. Thus, identifying new therapeutic strategies to alleviate LC organ proteotoxicity should allow AL patients with significant cardiac and/or renal involvement to subsequently tolerate established chemotherapy treatments. Using a small-molecule screening approach, the unfolded protein response (UPR) was identified as a cellular signaling pathway whose activation selectively attenuates secretion of amyloidogenic LC, while not affecting secretion of a nonamyloidogenic LC. Activation of the UPR-associated transcription factors XBP1s and/or ATF6 in the absence of stress recapitulates the selective decrease in amyloidogenic LC secretion by remodeling the endoplasmic reticulum proteostasis network. Stress-independent activation of XBP1s, or especially ATF6, also attenuates extracellular aggregation of amyloidogenic LC into soluble aggregates. Collectively, our results show that stress-independent activation of these adaptive UPR transcription factors offers a therapeutic strategy to reduce proteotoxicity associated with LC aggregation.
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Hiramatsu N, Messah C, Han J, LaVail MM, Kaufman RJ, Lin JH. Translational and posttranslational regulation of XIAP by eIF2α and ATF4 promotes ER stress-induced cell death during the unfolded protein response. Mol Biol Cell 2014; 25:1411-20. [PMID: 24623724 PMCID: PMC4004591 DOI: 10.1091/mbc.e13-11-0664] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Chronic ER stress down-regulates XIAP by activating the PERK branch of the UPR. PERK attenuates Xiap translation via eIF2α phosphorylation. PERK promotes XIAP degradation via ATF4. CHOP induction and XIAP suppression act in parallel to sensitize cells to ER stress–induced apoptosis. Endoplasmic reticulum (ER) protein misfolding activates the unfolded protein response (UPR) to help cells cope with ER stress. If ER homeostasis is not restored, UPR promotes cell death. The mechanisms of UPR-mediated cell death are poorly understood. The PKR-like endoplasmic reticulum kinase (PERK) arm of the UPR is implicated in ER stress–induced cell death, in part through up-regulation of proapoptotic CCAAT/enhancer binding protein homologous protein (CHOP). Chop−/− cells are partially resistant to ER stress–induced cell death, and CHOP overexpression alone does not induce cell death. These findings suggest that additional mechanisms regulate cell death downstream of PERK. Here we find dramatic suppression of antiapoptosis XIAP proteins in response to chronic ER stress. We find that PERK down-regulates XIAP synthesis through eIF2α and promotes XIAP degradation through ATF4. Of interest, PERK's down-regulation of XIAP occurs independently of CHOP activity. Loss of XIAP leads to increased cell death, whereas XIAP overexpression significantly enhances resistance to ER stress–induced cell death, even in the absence of CHOP. Our findings define a novel signaling circuit between PERK and XIAP that operates in parallel with PERK to CHOP induction to influence cell survival during ER stress. We propose a “two-hit” model of ER stress–induced cell death involving concomitant CHOP up-regulation and XIAP down-regulation both induced by PERK.
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Affiliation(s)
- Nobuhiko Hiramatsu
- Department of Pathology, University of California at San Diego, La Jolla, CA 92093 Center for Neuroscience, Aging, and Stem Cell Research, Sanford Burnham Medical Research Institute, La Jolla, CA 92037 Departments of Anatomy and Ophthalmology, University of California at San Francisco, San Francisco, CA 94143
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Jerry Chiang WC, Lin JH. The effects of IRE1, ATF6, and PERK signaling on adRP-linked rhodopsins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 801:661-7. [PMID: 24664756 DOI: 10.1007/978-1-4614-3209-8_83] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Many mutations in rhodopsin gene linked to retinitis pigmentosa (RP) cause rhodopsin misfolding. Rod photoreceptor cells expressing misfolded rhodopsin eventually die. Identifying mechanisms to prevent rhodopsin misfolding or to remove irreparably misfolded rhodopsin could provide new therapeutic strategies. IRE1, ATF6, and PERK signaling pathways, collectively called the unfolded protein response (UPR), regulate the functions of endoplasmic reticulum, responsible for accurate folding of membrane proteins such as rhodopsin. We used chemical and genetic approaches to selectively activate IRE1, ATF6, or PERK signaling pathways one at a time and analyzed their effects on mutant rhodopsin linked to RP. We found that both artificial IRE1 and ATF6 signaling promoted the degradation of mutant rhodopsin with lesser effects on wild-type rhodopsin. Furthermore, IRE1 and ATF6 signaling preferentially reduced levels of aggregated rhodopsins. By contrast, PERK signaling reduced levels of wild-type and mutant rhodopsin. These studies indicate that activation of either IRE1, ATF6, or PERK prevents mutant rhodopsin from accumulating in the cells. In addition, activation of IRE1 or ATF6 can selectively remove aggregated or mutant rhodopsin from the cells and may be useful in treating RP associated with rhodopsin protein misfolding.
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Affiliation(s)
- Wei-Chieh Jerry Chiang
- Department of Pathology, University of California at San Diego, 9500 Gilman Dr., 92093-0612, La Jolla, CA, USA,
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29
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IRE1: ER stress sensor and cell fate executor. Trends Cell Biol 2013; 23:547-55. [PMID: 23880584 DOI: 10.1016/j.tcb.2013.06.005] [Citation(s) in RCA: 387] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/31/2013] [Accepted: 06/19/2013] [Indexed: 12/20/2022]
Abstract
Cells operate a signaling network termed the unfolded protein response (UPR) to monitor protein-folding capacity in the endoplasmic reticulum (ER). Inositol-requiring enzyme 1 (IRE1) is an ER transmembrane sensor that activates the UPR to maintain the ER and cellular function. Although mammalian IRE1 promotes cell survival, it can initiate apoptosis via decay of antiapoptotic miRNAs. Convergent and divergent IRE1 characteristics between plants and animals underscore its significance in cellular homeostasis. This review provides an updated scenario of the IRE1 signaling model, discusses emerging IRE1 sensing mechanisms, compares IRE1 features among species, and outlines exciting future directions in UPR research.
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Balakrishnan B, Sen D, Hareendran S, Roshini V, David S, Srivastava A, Jayandharan GR. Activation of the cellular unfolded protein response by recombinant adeno-associated virus vectors. PLoS One 2013; 8:e53845. [PMID: 23320106 PMCID: PMC3540029 DOI: 10.1371/journal.pone.0053845] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 12/05/2012] [Indexed: 12/11/2022] Open
Abstract
The unfolded protein response (UPR) is a stress-induced cyto-protective mechanism elicited towards an influx of large amount of proteins in the endoplasmic reticulum (ER). In the present study, we evaluated if AAV manipulates the UPR pathways during its infection. We first examined the role of the three major UPR axes, namely, endoribonuclease inositol-requiring enzyme-1 (IRE1α), activating transcription factor 6 (ATF6) and PKR-like ER kinase (PERK) in AAV infected cells. Total RNA from mock or AAV infected HeLa cells were used to determine the levels of 8 different ER-stress responsive transcripts from these pathways. We observed a significant up-regulation of IRE1α (up to 11 fold) and PERK (up to 8 fold) genes 12–48 hours after infection with self-complementary (sc)AAV2 but less prominent with single-stranded (ss)AAV2 vectors. Further studies demonstrated that scAAV1 and scAAV6 also induce cellular UPR in vitro, with AAV1 vectors activating the PERK pathway (3 fold) while AAV6 vectors induced a significant increase on all the three major UPR pathways [6–16 fold]. These data suggest that the type and strength of UPR activation is dependent on the viral capsid. We then examined if transient inhibition of UPR pathways by RNA interference has an effect on AAV transduction. siRNA mediated silencing of PERK and IRE1α had a modest effect on AAV2 and AAV6 mediated gene expression (∼1.5–2 fold) in vitro. Furthermore, hepatic gene transfer of scAAV2 vectors in vivo, strongly elevated IRE1α and PERK pathways (2 and 3.5 fold, respectively). However, when animals were pre-treated with a pharmacological UPR inhibitor (metformin) during scAAV2 gene transfer, the UPR signalling and its subsequent inflammatory response was attenuated concomitant to a modest 2.8 fold increase in transgene expression. Collectively, these data suggest that AAV vectors activate the cellular UPR pathways and their selective inhibition may be beneficial during AAV mediated gene transfer.
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Affiliation(s)
- Balaji Balakrishnan
- Department of Hematology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Dwaipayan Sen
- Department of Hematology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Sangeetha Hareendran
- Centre for Stem Cell Research, Christian Medical College, Vellore, Tamil Nadu, India
| | - Vaani Roshini
- Department of Hematology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Sachin David
- Department of Hematology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Alok Srivastava
- Department of Hematology, Christian Medical College, Vellore, Tamil Nadu, India
- Centre for Stem Cell Research, Christian Medical College, Vellore, Tamil Nadu, India
| | - Giridhara R. Jayandharan
- Department of Hematology, Christian Medical College, Vellore, Tamil Nadu, India
- Centre for Stem Cell Research, Christian Medical College, Vellore, Tamil Nadu, India
- * E-mail:
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Kroeger H, Messah C, Ahern K, Gee J, Joseph V, Matthes MT, Yasumura D, Gorbatyuk MS, Chiang WC, LaVail MM, Lin JH. Induction of endoplasmic reticulum stress genes, BiP and chop, in genetic and environmental models of retinal degeneration. Invest Ophthalmol Vis Sci 2012; 53:7590-9. [PMID: 23074209 DOI: 10.1167/iovs.12-10221] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
PURPOSE Endoplasmic reticulum (ER) stress has been observed in animal models of retinitis pigmentosa expressing P23H rhodopsin. We compared levels of tightly induced ER stress genes, Binding of immunoglobulin protein (BiP) and CCAAT/enhancer-binding protein homologous protein (Chop), in seven additional models of retinal degeneration arising from genetic or environmental causes. METHODS Retinas from transgenic S334ter rhodopsin (lines 3, 4, and 5) and Royal College of Surgeons (RCS and RCS-p+) rats from postnatal (P) days 10 to 120 were analyzed. In a constant light (CL) model of retinal degeneration, BALB/c mice were exposed to 15,000 lux of CL for 0 to 8 hours. Retinal tissues from three to eight animals per experimental condition were collected for histologic and molecular analyses. RESULTS S334ter animals revealed significant increases in BiP, S334ter-3 (3.3× at P15), S334ter-4 (4× at P60), and S334ter-5 (2.2× at P90), and Chop, S334ter-3 (1.3× at P15), S334ter-4 (1.5× at P30), and S334ter-5 (no change), compared with controls. P23H-3 rats showed significant increase of BiP at P60 (2.3×) and Chop (1.6×). RCS and RCS-p+ rats showed significant increases in BiP at P60 (2.4×) and P20 (1.8×), respectively, but no statistically significant changes in Chop. BALB/c mice showed increases in BiP (1.5×) and Chop (1.3×) after 4 hours of CL. Increased levels of these ER stress markers correlated with photoreceptor cell loss. CONCLUSIONS Our study reveals surprising increases in BiP and to a lesser degree Chop in retinal degenerations arising from diverse causes. We propose that manipulation of ER stress responses may be helpful in treating many environmental and heritable forms of retinal degeneration.
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Affiliation(s)
- Heike Kroeger
- Department of Pathology, University of California, San Diego, La Jolla, California, USA
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Chiang WC, Hiramatsu N, Messah C, Kroeger H, Lin JH. Selective activation of ATF6 and PERK endoplasmic reticulum stress signaling pathways prevent mutant rhodopsin accumulation. Invest Ophthalmol Vis Sci 2012; 53:7159-66. [PMID: 22956602 DOI: 10.1167/iovs.12-10222] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
PURPOSE Many rhodopsin mutations that cause retinitis pigmentosa produce misfolded rhodopsin proteins that are retained within the endoplasmic reticulum (ER) and cause photoreceptor cell death. Activating transcription factor 6 (ATF6) and protein kinase RNA-like endoplasmic reticulum kinase (PERK) control intracellular signaling pathways that maintain ER homeostasis. The aim of this study was to investigate how ATF6 and PERK signaling affected misfolded rhodopsin in cells, which could identify new molecular therapies to treat retinal diseases associated with ER protein misfolding. METHODS To examine the effect of ATF6 on rhodopsin, wild-type (WT) or mutant rhodopsins were expressed in cells expressing inducible human ATF6f, the transcriptional activator domain of ATF6. Induction of ATF6f synthesis rapidly activated downstream genes. To examine PERK's effect on rhodopsin, WT or mutant rhodopsins were expressed in cells expressing a genetically altered PERK protein, Fv2E-PERK. Addition of the dimerizing molecule (AP20187) rapidly activated Fv2E-PERK and downstream genes. By use of these strategies, it was examined how selective ATF6 or PERK signaling affected the fate of WT and mutant rhodopsins. RESULTS ATF6 significantly reduced T17M, P23H, Y178C, C185R, D190G, K296E, and S334ter rhodopsin protein levels in the cells with minimal effects on monomeric WT rhodopsin protein levels. By contrast, the PERK pathway reduced both levels of WT, mutant rhodopsins, and many other proteins in the cell. CONCLUSIONS This study indicates that selectively activating ATF6 or PERK prevents mutant rhodopsin from accumulating in cells. ATF6 signaling may be especially useful in treating retinal degenerative diseases arising from rhodopsin misfolding by preferentially clearing mutant rhodopsin and abnormal rhodopsin aggregates.
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Affiliation(s)
- Wei-Chieh Chiang
- Department of Pathology, University of California at San Diego, La Jolla, California, USA
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Antiviral activity of a small molecule deubiquitinase inhibitor occurs via induction of the unfolded protein response. PLoS Pathog 2012; 8:e1002783. [PMID: 22792064 PMCID: PMC3390402 DOI: 10.1371/journal.ppat.1002783] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 05/16/2012] [Indexed: 12/11/2022] Open
Abstract
Ubiquitin (Ub) is a vital regulatory component in various cellular processes, including cellular responses to viral infection. As obligate intracellular pathogens, viruses have the capacity to manipulate the ubiquitin (Ub) cycle to their advantage by encoding Ub-modifying proteins including deubiquitinases (DUBs). However, how cellular DUBs modulate specific viral infections, such as norovirus, is poorly understood. To examine the role of DUBs during norovirus infection, we used WP1130, a small molecule inhibitor of a subset of cellular DUBs. Replication of murine norovirus in murine macrophages and the human norovirus Norwalk virus in a replicon system were significantly inhibited by WP1130. Chemical proteomics identified the cellular DUB USP14 as a target of WP1130 in murine macrophages, and pharmacologic inhibition or siRNA-mediated knockdown of USP14 inhibited murine norovirus infection. USP14 is a proteasome-associated DUB that also binds to inositol-requiring enzyme 1 (IRE1), a critical mediator of the unfolded protein response (UPR). WP1130 treatment of murine macrophages did not alter proteasome activity but activated the X-box binding protein-1 (XBP-1) through an IRE1-dependent mechanism. In addition, WP1130 treatment or induction of the UPR also reduced infection of other RNA viruses including encephalomyocarditis virus, Sindbis virus, and La Crosse virus but not vesicular stomatitis virus. Pharmacologic inhibition of the IRE1 endonuclease activity partially rescued the antiviral effect of WP1130. Taken together, our studies support a model whereby induction of the UPR through cellular DUB inhibition blocks specific viral infections, and suggest that cellular DUBs and the UPR represent novel targets for future development of broad spectrum antiviral therapies. Deubiquitinases (DUBs) are enzymes, which are implicated in many cellular processes but their functions during virus infection are not well understood. We used WP1130, a small molecule inhibitor of a subset of DUBs, as a probe to unravel the functions of DUBs during norovirus infections. We identified USP14 as a cellular DUB target of WP1130 that is required for optimal norovirus infection. Furthermore, we demonstrated that chemical induction of the unfolded protein response can significantly inhibit viral progeny production of several RNA viruses, including noroviruses. These results suggest that chemical inhibition of cellular DUBs and/or modulation of the unfolded protein response could represent novel targets for therapy against a variety of viral pathogens.
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Shinde VM, Sizova OS, Lin JH, LaVail MM, Gorbatyuk MS. ER stress in retinal degeneration in S334ter Rho rats. PLoS One 2012; 7:e33266. [PMID: 22432009 PMCID: PMC3303830 DOI: 10.1371/journal.pone.0033266] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 02/06/2012] [Indexed: 11/18/2022] Open
Abstract
The S334ter rhodopsin (Rho) rat (line 4) bears the rhodopsin gene with an early termination codon at residue 334 that is a model for several such mutations found in human patients with autosomal dominant retinitis pigmentosa (ADRP). The Unfolded Protein Response (UPR) is implicated in the pathophysiology of several retinal disorders including ADRP in P23H Rho rats. The aim of this study was to examine the onset of UPR gene expression in S334ter Rho retinas to determine if UPR is activated in ADRP animal models and to investigate how the activation of UPR molecules leads to the final demise of S334ter Rho photoreceptors. RT-PCR was performed to evaluate the gene expression profiles for the P10, P12, P15, and P21 stages of the development and progression of ADRP in S334ter Rho photoreceptors. We determined that during the P12–P15 period, ER stress-related genes are strongly upregulated in transgenic retinas, resulting in the activation of the UPR that was confirmed using western blot analysis and RT-PCR. The activation of UPR was associated with the increased expression of JNK, Bik, Bim, Bid, Noxa, and Puma genes and cleavage of caspase-12 that together with activated calpains presumably compromise the integrity of the mitochondrial MPTP, leading to the release of pro-apoptotic AIF1 into the cytosol of S334ter Rho photoreceptor cells. Therefore, two major cross-talking pathways, the UPR and mitochondrial MPTP occur in S334ter-4 Rho retina concomitantly and eventually promote the death of the photoreceptor cells.
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Affiliation(s)
- Vishal M Shinde
- Department of Cell Biology and Anatomy, University of North Texas Health Science Center, North Texas Eye Research Institute, Fort Worth, Texas, United States of America
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Hong DY, Kwon K, Lee KR, Choi YJ, Goo TW, Yu K, Kim SW, Kwon OY. Lidocaine induces endoplasmic reticulum stress-associated apoptosis in vitro and in vivo. Int J Mol Sci 2011; 12:7652-61. [PMID: 22174623 PMCID: PMC3233429 DOI: 10.3390/ijms12117652] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 10/25/2011] [Accepted: 10/26/2011] [Indexed: 01/22/2023] Open
Abstract
We demonstrated that upregulation of both gene expression of endoplasmic reticulum (ER) stress chaperones (BiP, calnexin, calreticulin, and PDI) and ER stress sensors (ATF6, IRE1 and PERK) was induced by lidocaine, a local anesthetic, in PC12 cells. In addition to gene regulation, lidocaine also induced typical ER stress phenomena such as ART6 proteolytic cleavage, eIF2 alpha phosphorylation, and XBP1 mRNA splicing. In in vivo experiments, while lidocaine downregulated gene expression of antiapoptotic factors (Bcl-2 and Bcl-xl), pro-apoptotic factor (Bak and Bax) gene expression was upregulated. Furthermore, lidocaine induced apoptosis, as measured histochemically, and upregulated PARP1, a DNA damage repair enzyme. These results are the first to show that lidocaine induces apoptosis through ER stress in vitro and in vivo.
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Affiliation(s)
- Dae Young Hong
- Department of Emergency Medicine, Konkuk University Medical Center, Seoul 143-729, Korea; E-Mails: (D.Y.H.); (K.R.L.)
| | - Kisang Kwon
- Department of Anatomy, Chungnam National University, Taejon 301-747, Korea; E-Mails: (K.K.); (Y.J.C.)
| | - Kyeong Ryong Lee
- Department of Emergency Medicine, Konkuk University Medical Center, Seoul 143-729, Korea; E-Mails: (D.Y.H.); (K.R.L.)
| | - Young Jin Choi
- Department of Anatomy, Chungnam National University, Taejon 301-747, Korea; E-Mails: (K.K.); (Y.J.C.)
| | - Tae-Won Goo
- Department of Agricultural Biology, National Academy of Agricultural Science, RDA, Suwon 441-100, Korea; E-Mail:
| | - Kweon Yu
- Korea Research Institute of Bioscience and Biotechnology, Taejon 305-806, Korea; E-Mail:
| | - Seung-Whan Kim
- Department of Emergency Medicine, Chungnam National University Hospital, Taejon 301-721, Korea
- Authors to whom correspondence should be addressed: E-Mails: (S.-W.K.); (O.-Y.K.); Tel.: +81-42-580-8206; Fax: +81-42-586-4800
| | - O-Yu Kwon
- Department of Anatomy, Chungnam National University, Taejon 301-747, Korea; E-Mails: (K.K.); (Y.J.C.)
- Authors to whom correspondence should be addressed: E-Mails: (S.-W.K.); (O.-Y.K.); Tel.: +81-42-580-8206; Fax: +81-42-586-4800
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