101
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Gillard BK, Bassett GR, Gotto AM, Rosales C, Pownall HJ. Scavenger receptor B1 (SR-B1) profoundly excludes high density lipoprotein (HDL) apolipoprotein AII as it nibbles HDL-cholesteryl ester. J Biol Chem 2017; 292:8864-8873. [PMID: 28373285 DOI: 10.1074/jbc.m117.781963] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 03/24/2017] [Indexed: 01/12/2023] Open
Abstract
Reverse cholesterol transport (transfer of macrophage-cholesterol in the subendothelial space of the arterial wall to the liver) is terminated by selective high density lipoprotein (HDL)-cholesteryl ester (CE) uptake, mediated by scavenger receptor class B, type 1 (SR-B1). We tested the validity of two models for this process: "gobbling," i.e. one-step transfer of all HDL-CE to the cell and "nibbling," multiple successive cycles of SR-B1-HDL association during which a few CEs transfer to the cell. Concurrently, we compared cellular uptake of apoAI with that of apoAII, which is more lipophilic than apoAI, using HDL-[3H]CE labeled with [125I]apoAI or [125I]apoAII. The studies were conducted in CHO-K1 and CHO-ldlA7 cells (LDLR-/-) with (CHO-SR-B1) and without SR-B1 overexpression and in human Huh7 hepatocytes. Relative to CE, both apoAI and apoAII were excluded from uptake by all cells. However, apoAII was more highly excluded from uptake (2-4×) than apoAI. To distinguish gobbling versus nibbling mechanisms, media from incubations of HDL with CHO-SR-B1 cells were analyzed by non-denaturing PAGE, size-exclusion chromatography, and the distribution of apoAI, apoAII, cholesterol, and phospholipid among HDL species as a function of incubation time. HDL size gradually decreased, i.e. nibbling, with the concurrent release of lipid-free apoAI; apoAII was retained in an HDL remnant. Our data support an SR-B1 nibbling mechanism that is similar to that of streptococcal serum opacity factor, which also selectively removes CE and releases apoAI, leaving an apoAII-rich remnant.
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Affiliation(s)
- Baiba K Gillard
- From the Houston Methodist Research Institute, Houston Texas 77030, .,Weill Cornell Medicine, New York, New York 10065, and
| | | | - Antonio M Gotto
- From the Houston Methodist Research Institute, Houston Texas 77030.,Weill Cornell Medicine, New York, New York 10065, and
| | - Corina Rosales
- From the Houston Methodist Research Institute, Houston Texas 77030.,Weill Cornell Medicine, New York, New York 10065, and
| | - Henry J Pownall
- From the Houston Methodist Research Institute, Houston Texas 77030.,Weill Cornell Medicine, New York, New York 10065, and
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102
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Fan Y, Zhang J, Xiao W, Lee K, Li Z, Wen J, He L, Gui D, Xue R, Jian G, Sheng X, He JC, Wang N. Rtn1a-Mediated Endoplasmic Reticulum Stress in Podocyte Injury and Diabetic Nephropathy. Sci Rep 2017; 7:323. [PMID: 28336924 PMCID: PMC5428279 DOI: 10.1038/s41598-017-00305-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 02/20/2017] [Indexed: 11/10/2022] Open
Abstract
We previously reported a critical role of reticulon (RTN) 1A in mediating endoplasmic reticulum (ER) stress in kidney tubular cells and the expression of RTN1A correlates with the renal function and the severity of kidney injury in patients with diabetic nephropathy (DN). Here, we determined the roles of RTN1A and ER stress in podocyte injury and DN. We used db/db mice with early unilateral nephrectomy (Unx) as a murine model of progressive DN and treated mice with tauroursodeoxycholic acid (TUDCA), a specific inhibitor of ER stress. We found increased expression of RTN1A and ER stress markers in the kidney of db/db-Unx mice. Treatment of TUDCA not only attenuated proteinuria and kidney histological changes, but also ameliorated podocyte and glomeruli injury in diabetic mice, which were associated with reduction of RTN1A and ER stress marker expression in the podocytes of TUDCA-treated mice. In vitro, we showed RTN1A mediates albumin-induced ER stress and apoptosis in human podocytes. A positive feedback loop between RTN1A and CHOP was found leading to an enhanced ER stress in podocytes. Our data suggest that ER stress plays a major role in podocyte injury in DN and RTN1A might be a key regulator of ER stress in podocytes.
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Affiliation(s)
- Ying Fan
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Jing Zhang
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Wenzhen Xiao
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, NY, United States
| | - Kyung Lee
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, NY, United States
| | - Zhengzhe Li
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, NY, United States
| | - Jiejun Wen
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Li He
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Dingkun Gui
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Rui Xue
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Guihua Jian
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - Xiaohua Sheng
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China
| | - John Cijiang He
- Department of Medicine, Division of Nephrology, Icahn School of Medicine at Mount Sinai, NY, United States. .,Renal Section, James J Peter Veterans Administration Medical Center, Bronx, NY, United States.
| | - Niansong Wang
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, China.
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103
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Ocaña GJ, Pérez L, Guindon L, Deffit SN, Evans-Molina C, Thurmond DC, Blum JS. Inflammatory stress of pancreatic beta cells drives release of extracellular heat-shock protein 90α. Immunology 2017; 151:198-210. [PMID: 28190264 DOI: 10.1111/imm.12723] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 01/19/2017] [Accepted: 02/05/2017] [Indexed: 12/26/2022] Open
Abstract
A major obstacle in predicting and preventing the development of autoimmune type 1 diabetes (T1D) in at-risk individuals is the lack of well-established early biomarkers indicative of ongoing beta cell stress during the pre-clinical phase of disease. Recently, serum levels of the α cytoplasmic isoform of heat-shock protein 90 (hsp90) were shown to be elevated in individuals with new-onset T1D. We therefore hypothesized that hsp90α could be released from beta cells in response to cellular stress and inflammation associated with the earliest stages of T1D. Here, human beta cell lines and cadaveric islets released hsp90α in response to stress induced by treatment with a combination of pro-inflammatory cytokines including interleukin-1β, tumour necrosis factor-α and interferon-γ. Mechanistically, hsp90α release was found to be driven by cytokine-induced endoplasmic reticulum stress mediated by c-Jun N-terminal kinase (JNK), a pathway that can eventually lead to beta cell apoptosis. Cytokine-induced beta cell hsp90α release and JNK activation were significantly reduced by pre-treating cells with the endoplasmic reticulum stress-mitigating chemical chaperone tauroursodeoxycholic acid. The hsp90α release by cells may therefore be a sensitive indicator of stress during inflammation and a useful tool in assessing therapeutic mitigation of cytokine-induced cell damage linked to autoimmunity.
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Affiliation(s)
- Gail J Ocaña
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Liliana Pérez
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Lynette Guindon
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Sarah N Deffit
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Carmella Evans-Molina
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA.,Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Debbie C Thurmond
- Department of Molecular and Cellular Endocrinology, Beckman Research Institute of City of Hope, Duarte, CA, USA
| | - Janice S Blum
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN, USA
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104
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Mesbah Moosavi ZS, Hood DA. The unfolded protein response in relation to mitochondrial biogenesis in skeletal muscle cells. Am J Physiol Cell Physiol 2017; 312:C583-C594. [PMID: 28274921 DOI: 10.1152/ajpcell.00320.2016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 02/27/2017] [Accepted: 03/01/2017] [Indexed: 12/20/2022]
Abstract
Mitochondria comprise both nuclear and mitochondrially encoded proteins requiring precise stoichiometry for their integration into functional complexes. The augmented protein synthesis associated with mitochondrial biogenesis results in the accumulation of unfolded proteins, thus triggering cellular stress. As such, the unfolded protein responses emanating from the endoplasmic reticulum (UPRER) or the mitochondrion (UPRMT) are triggered to ensure correct protein handling. Whether this response is necessary for mitochondrial adaptations is unknown. Two models of mitochondrial biogenesis were used: muscle differentiation and chronic contractile activity (CCA) in murine muscle cells. After 4 days of differentiation, our findings depict selective activation of the UPRMT in which chaperones decreased; however, Sirt3 and UPRER markers were elevated. To delineate the role of ER stress in mitochondrial adaptations, the ER stress inhibitor TUDCA was administered. Surprisingly, mitochondrial markers COX-I, COX-IV, and PGC-1α protein levels were augmented up to 1.5-fold above that of vehicle-treated cells. Similar results were obtained in myotubes undergoing CCA, in which biogenesis was enhanced by ~2-3-fold, along with elevated UPRMT markers Sirt3 and CPN10. To verify whether the findings were attributable to the terminal UPRER branch directed by the transcription factor CHOP, cells were transfected with CHOP siRNA. Basally, COX-I levels increased (~20%) and COX-IV decreased (~30%), suggesting that CHOP influences mitochondrial composition. This effect was fully restored by CCA. Therefore, our results suggest that mitochondrial biogenesis is independent of the terminal UPRER Under basal conditions, CHOP is required for the maintenance of mitochondrial composition, but not for differentiation- or CCA-induced mitochondrial biogenesis.
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Affiliation(s)
- Zahra S Mesbah Moosavi
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - David A Hood
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
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105
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Sarvani C, Sireesh D, Ramkumar KM. Unraveling the role of ER stress inhibitors in the context of metabolic diseases. Pharmacol Res 2017; 119:412-421. [PMID: 28237513 DOI: 10.1016/j.phrs.2017.02.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 02/16/2017] [Accepted: 02/20/2017] [Indexed: 02/05/2023]
Abstract
ER stress is provoked by the accumulation of unfolded and misfolded proteins in the ER lumen leading to perturbations in ER homeostasis. ER stress activates a signaling cascade called the Unfolded Protein Response (UPR) which triggers a set of transcriptional and translational events that restore ER homeostasis, promoting cell survival and adaptation. If this adaptive response fails, a terminal UPR program commits such cells to apoptosis. Existing preclinical and clinical evidence testify that prolonged ER stress escalates the risk of several metabolic disorders including diabetes, obesity and dyslipidemia. There have been considerable efforts to develop small molecules that are capable of ameliorating ER stress. Few naturally occurring and synthetic molecules have already been demonstrated for their efficacy in abrogating ER stress in both in vitro and in vivo models of metabolic disorders. This review provides a broad overview of the molecular mechanisms of inhibition of ER stress and its association with various metabolic diseases.
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Affiliation(s)
- Chodisetty Sarvani
- SRM Research Institute, SRM University, Kattankulathur 603 203, Tamilnadu, India
| | - Dornadula Sireesh
- SRM Research Institute, SRM University, Kattankulathur 603 203, Tamilnadu, India
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106
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Ariyasu D, Yoshida H, Hasegawa Y. Endoplasmic Reticulum (ER) Stress and Endocrine Disorders. Int J Mol Sci 2017; 18:ijms18020382. [PMID: 28208663 PMCID: PMC5343917 DOI: 10.3390/ijms18020382] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/24/2017] [Accepted: 02/03/2017] [Indexed: 12/15/2022] Open
Abstract
The endoplasmic reticulum (ER) is the organelle where secretory and membrane proteins are synthesized and folded. Unfolded proteins that are retained within the ER can cause ER stress. Eukaryotic cells have a defense system called the “unfolded protein response” (UPR), which protects cells from ER stress. Cells undergo apoptosis when ER stress exceeds the capacity of the UPR, which has been revealed to cause human diseases. Although neurodegenerative diseases are well-known ER stress-related diseases, it has been discovered that endocrine diseases are also related to ER stress. In this review, we focus on ER stress-related human endocrine disorders. In addition to diabetes mellitus, which is well characterized, several relatively rare genetic disorders such as familial neurohypophyseal diabetes insipidus (FNDI), Wolfram syndrome, and isolated growth hormone deficiency type II (IGHD2) are discussed in this article.
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Affiliation(s)
- Daisuke Ariyasu
- Division of Developmental Genetics, Institute of Resource Development and Analysis, Kumamoto University, Kumamoto 860-0811, Japan.
| | - Hiderou Yoshida
- Department of Biochemistry and Molecular Biology, Graduate School of Life Science, University of Hyogo, Hyogo 678-1297, Japan.
| | - Yukihiro Hasegawa
- Division of Endocrinology and Metabolism, Tokyo Metropolitan Children's Medical Center, Tokyo 183-8561, Japan.
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107
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Modulation of the Unfolded Protein Response by Tauroursodeoxycholic Acid Counteracts Apoptotic Cell Death and Fibrosis in a Mouse Model for Secondary Biliary Liver Fibrosis. Int J Mol Sci 2017; 18:ijms18010214. [PMID: 28117681 PMCID: PMC5297843 DOI: 10.3390/ijms18010214] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 01/09/2017] [Accepted: 01/13/2017] [Indexed: 12/12/2022] Open
Abstract
The role of endoplasmic reticulum stress and the unfolded protein response (UPR) in cholestatic liver disease and fibrosis is not fully unraveled. Tauroursodeoxycholic acid (TUDCA), a hydrophilic bile acid, has been shown to reduce endoplasmic reticulum (ER) stress and counteract apoptosis in different pathologies. We aimed to investigate the therapeutic potential of TUDCA in experimental secondary biliary liver fibrosis in mice, induced by common bile duct ligation. The kinetics of the hepatic UPR and apoptosis during the development of biliary fibrosis was studied by measuring markers at six different timepoints post-surgery by qPCR and Western blot. Next, we investigated the therapeutic potential of TUDCA, 10 mg/kg/day in drinking water, on liver damage (AST/ALT levels) and fibrosis (Sirius red-staining), in both a preventive and therapeutic setting. Common bile duct ligation resulted in the increased protein expression of CCAAT/enhancer-binding protein homologous protein (CHOP) at all timepoints, along with upregulation of pro-apoptotic caspase 3 and 12, tumor necrosis factor receptor superfamily, member 1A (TNFRsf1a) and Fas-Associated protein with Death Domain (FADD) expression. Treatment with TUDCA led to a significant reduction of liver fibrosis, accompanied by a slight reduction of liver damage, decreased hepatic protein expression of CHOP and reduced gene and protein expression of pro-apoptotic markers. These data indicate that TUDCA exerts a beneficial effect on liver fibrosis in a model of cholestatic liver disease, and suggest that this effect might, at least in part, be attributed to decreased hepatic UPR signaling and apoptotic cell death.
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108
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Chen J, Wu X, Yao L, Yan L, Zhang L, Qiu J, Liu X, Jia S, Meng A. Impairment of Cargo Transportation Caused by gbf1 Mutation Disrupts Vascular Integrity and Causes Hemorrhage in Zebrafish Embryos. J Biol Chem 2016; 292:2315-2327. [PMID: 28003365 DOI: 10.1074/jbc.m116.767608] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/19/2016] [Indexed: 12/11/2022] Open
Abstract
ADP-ribosylation factor GTPases are activated by guanine nucleotide exchange factors including Gbf1 (Golgi brefeldin A-resistant factor 1) and play important roles in regulating organelle structure and cargo-selective vesicle trafficking. However, the developmental role of Gbf1 in vertebrates remains elusive. In this study, we report the zebrafish mutant line tsu3994 that arises from N-ethyl-N-nitrosourea (ENU)-mediated mutagenesis and is characterized by prominent intracerebral and trunk hemorrhage. The mutant embryos develop hemorrhage accompanied by fewer pigments and shorter caudal fin at day 2 of development. The hemorrhage phenotype is caused by vascular breakage in a cell autonomous fashion. Positional cloning identifies a T → G nucleotide substitution in the 23rd exon of the gbf1 locus, resulting in a leucine → arginine substitution (L1246R) in the HDS2 domain. The mutant phenotype is mimicked by gbf1 knockouts and morphants, suggesting a nature of loss of function. Experimental results in mammalian cells show that the mutant form Gbf1(L1246R) is unable to be recruited to the Golgi apparatus and fails to activate Arf1 for recruiting COPI complex. The hemorrhage in tsu3994 mutants can be prevented partially and temporally by treating with the endoplasmic reticulum stress/apoptosis inhibitor tauroursodeoxycholic acid or by knocking down the proapoptotic gene baxb Therefore, endothelial endoplasmic reticulum stress and subsequent apoptosis induced by gbf1 deficiency may account for the vascular collapse and hemorrhage.
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Affiliation(s)
- Jing Chen
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xiaotong Wu
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Likun Yao
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lu Yan
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Lin Zhang
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Juhui Qiu
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xingfeng Liu
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Shunji Jia
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Anming Meng
- From the Laboratory of Molecular Developmental Biology, State Key Laboratory of Membrane Biology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
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109
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Li H, Guo W, Ma XJ, Li JS, Song X. In Vitro and in Vivo Anticancer Activity of Sophorolipids to Human Cervical Cancer. Appl Biochem Biotechnol 2016; 181:1372-1387. [DOI: 10.1007/s12010-016-2290-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 10/10/2016] [Indexed: 01/05/2023]
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110
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Gu XW, Yan JQ, Dou HT, Liu J, Liu L, Zhao ML, Liang XH, Yang ZM. Endoplasmic reticulum stress in mouse decidua during early pregnancy. Mol Cell Endocrinol 2016; 434:48-56. [PMID: 27283502 DOI: 10.1016/j.mce.2016.06.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/10/2016] [Accepted: 06/05/2016] [Indexed: 02/07/2023]
Abstract
Unfolded or misfolded protein accumulation in the endoplasmic reticulum lumen leads to endoplasmic reticulum stress (ER stress). Although it is known that ER stress is crucial for mammalian reproduction, little is known about its physiological significance and underlying mechanism during decidualization. Here we show that Ire-Xbp1 signal transduction pathway of unfolded protein response (UPR) is activated in decidual cells. The process of decidualization is compromised by ER stress inhibitor tauroursodeoxycholic acid sodium (TUDCA) and Ire specific inhibitor STF-083010 both in vivo and in vitro. A high concentration of ER stress inducer tunicamycin (TM) suppresses stromal cells proliferation and decidualization, while a lower concentration is beneficial. We further show that ER stress induces DNA damage and polyploidization in stromal cells. In conclusion, our data suggest that the GRP78/Ire1/Xbp1 signaling pathway of ER stress-UPR is activated and involved in mouse decidualization.
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Affiliation(s)
- Xiao-Wei Gu
- Department of Biology, Shantou University, Shantou 515063, China; College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Jia-Qi Yan
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Hai-Ting Dou
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Jie Liu
- Department of Biology, Shantou University, Shantou 515063, China
| | - Li Liu
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Meng-Long Zhao
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Xiao-Huan Liang
- College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China
| | - Zeng-Ming Yang
- Department of Biology, Shantou University, Shantou 515063, China; College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China.
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111
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Imbernon M, Sanchez‐Rebordelo E, Romero‐Picó A, Kalló I, Chee MJ, Porteiro B, Al‐Massadi O, Contreras C, Fernø J, Senra A, Gallego R, Folgueira C, Seoane LM, van Gestel M, Adan RA, Liposits Z, Dieguez C, López M, Nogueiras R. Hypothalamic kappa opioid receptor mediates both diet-induced and melanin concentrating hormone-induced liver damage through inflammation and endoplasmic reticulum stress. Hepatology 2016; 64:1086-104. [PMID: 27387967 PMCID: PMC5129461 DOI: 10.1002/hep.28716] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 07/05/2016] [Indexed: 12/14/2022]
Abstract
UNLABELLED The opioid system is widely known to modulate the brain reward system and thus affect the behavior of humans and other animals, including feeding. We hypothesized that the hypothalamic opioid system might also control energy metabolism in peripheral tissues. Mice lacking the kappa opioid receptor (κOR) and adenoviral vectors overexpressing or silencing κOR were stereotaxically delivered in the lateral hypothalamic area (LHA) of rats. Vagal denervation was performed to assess its effect on liver metabolism. Endoplasmic reticulum (ER) stress was inhibited by pharmacological (tauroursodeoxycholic acid) and genetic (overexpression of the chaperone glucose-regulated protein 78 kDa) approaches. The peripheral effects on lipid metabolism were assessed by histological techniques and western blot. We show that in the LHA κOR directly controls hepatic lipid metabolism through the parasympathetic nervous system, independent of changes in food intake and body weight. κOR colocalizes with melanin concentrating hormone receptor 1 (MCH-R1) in the LHA, and genetic disruption of κOR reduced melanin concentrating hormone-induced liver steatosis. The functional relevance of these findings was given by the fact that silencing of κOR in the LHA attenuated both methionine choline-deficient, diet-induced and choline-deficient, high-fat diet-induced ER stress, inflammation, steatohepatitis, and fibrosis, whereas overexpression of κOR in this area promoted liver steatosis. Overexpression of glucose-regulated protein 78 kDa in the liver abolished hypothalamic κOR-induced steatosis by reducing hepatic ER stress. CONCLUSIONS This study reveals a novel hypothalamic-parasympathetic circuit modulating hepatic function through inflammation and ER stress independent of changes in food intake or body weight; these findings might have implications for the clinical use of opioid receptor antagonists. (Hepatology 2016;64:1086-1104).
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Affiliation(s)
- Monica Imbernon
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain
| | - Estrella Sanchez‐Rebordelo
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain
| | - Amparo Romero‐Picó
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain
| | - Imre Kalló
- Laboratory of Endocrine NeurobiologyInstitute of Experimental Medicine, Hungarian Academy of SciencesBudapestHungary
| | - Melissa J. Chee
- Division of Endocrinology, Department of MedicineBeth Israel Deaconess Medical Center, Harvard Medical SchoolBostonMA
| | - Begoña Porteiro
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain
| | - Omar Al‐Massadi
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain
| | - Cristina Contreras
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain
| | - Johan Fernø
- Department of Clinical ScienceKG Jebsen Center for Diabetes Research, University of BergenBergenNorway
| | - Ana Senra
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain
| | - Rosalia Gallego
- Department of Morphological Sciences, School of MedicineUniversity of Santiago de Compostela‐Instituto de Investigación Sanitaria
| | - Cintia Folgueira
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain,Grupo Fisiopatología Endocrina, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo, Hospitalario Universitario de Santiago (CHUS/SERGAS)Santiago de CompostelaSpain
| | - Luisa M. Seoane
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain,Grupo Fisiopatología Endocrina, Instituto de Investigación Sanitaria de Santiago de Compostela, Complexo, Hospitalario Universitario de Santiago (CHUS/SERGAS)Santiago de CompostelaSpain
| | - Margriet van Gestel
- Department of Neuroscience and PharmacologyRudolf Magnus Institute of Neuroscience, University Medical Center UtrechtUtrechtThe Netherlands
| | - Roger A. Adan
- Department of Neuroscience and PharmacologyRudolf Magnus Institute of Neuroscience, University Medical Center UtrechtUtrechtThe Netherlands
| | - Zsolt Liposits
- Laboratory of Endocrine NeurobiologyInstitute of Experimental Medicine, Hungarian Academy of SciencesBudapestHungary
| | - Carlos Dieguez
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain
| | - Miguel López
- Department of PhysiologyCIMUS, University of Santiago de Compostela‐Instituto de Investigación Sanitaria,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn)Santiago de CompostelaSpain
| | - Ruben Nogueiras
- Department of Physiology, CIMUS, University of Santiago de Compostela-Instituto de Investigación Sanitaria. .,CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Santiago de Compostela, Spain.
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Yin JJ, Xie G, Zhang N, Li Y. Inhibiting autophagy promotes endoplasmic reticulum stress and the ROS‑induced nod‑like receptor 3‑dependent proinflammatory response in HepG2 cells. Mol Med Rep 2016; 14:3999-4007. [PMID: 27600251 DOI: 10.3892/mmr.2016.5708] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 08/09/2016] [Indexed: 11/06/2022] Open
Abstract
Inflammation and endoplasmic reticulum (ER) stress are key contributors to insulin resistance and metabolic disease, and interleukin (IL)‑1β is involved in insulin resistance. The present study aimed to investigated the role of autophagy in LPS‑induced ER stress and inflammation, which may provide evidence for controlling metabolic disease associated with inflammation. Lipopolysaccharide (LPS) induced the activation of ER stress and the nod‑like receptor 3‑dependent expression of IL‑1β and caspase‑1, as shown by western blotting, which contributed to HepG2 cell death. This also involved the generation of mitochondrial reactive oxygen species and the autophagy signaling response, which are derived from the ER stress pathway. The percentage of apoptotic cells was measured by flow cytometry with fluorescein isothiocyanate/propidium iodide staining. Reactive oxygen species formation was detected by flow cytometry using the peroxide sensitive fluorescent probe 2',7'‑dichlorofluorescin diacetate. Autophagy activation was measured by western blotting and confirmed using transmission electron microscopy. Furthermore, inhibiting autophagy promoted ER stress and the proinflammatory response in addition to cell death. These findings provide insights into the protective role of autophagy in LPS‑induced cell death and ER stress, and further identified the association of autophagy, ER stress and inflammation in HepG2 cells.
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Affiliation(s)
- Jia-Jing Yin
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Guangying Xie
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Ning Zhang
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
| | - Yanbo Li
- Department of Endocrinology, First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China
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113
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Pagliassotti MJ, Kim PY, Estrada AL, Stewart CM, Gentile CL. Endoplasmic reticulum stress in obesity and obesity-related disorders: An expanded view. Metabolism 2016; 65:1238-46. [PMID: 27506731 PMCID: PMC4980576 DOI: 10.1016/j.metabol.2016.05.002] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 04/01/2016] [Accepted: 05/06/2016] [Indexed: 02/07/2023]
Abstract
The endoplasmic reticulum (ER) is most notable for its central roles in calcium ion storage, lipid biosynthesis, and protein sorting and processing. By virtue of its extensive membrane contact sites that connect the ER to most other organelles and to the plasma membrane, the ER can also regulate diverse cellular processes including inflammatory and insulin signaling, nutrient metabolism, and cell proliferation and death via a signaling pathway called the unfolded protein response (UPR). Chronic UPR activation has been observed in liver and/or adipose tissue of dietary and genetic murine models of obesity, and in human obesity and non-alcoholic fatty liver disease (NAFLD). Activation of the UPR in obesity and obesity-related disorders likely has two origins. One linked to classic ER stress involving the ER lumen and one linked to alterations to the ER membrane environment. This review discusses both of these origins and also considers the role of post-translational protein modifications, such as acetylation and palmitoylation, and ER-mitochondrial interactions to obesity-mediated impairments in the ER and activation of the UPR.
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Affiliation(s)
| | - Paul Y Kim
- Department of Biological Sciences, Grambling State University
| | - Andrea L Estrada
- Department of Food Science and Human Nutrition, Colorado State University
| | - Claire M Stewart
- Department of Food Science and Human Nutrition, Colorado State University
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114
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Tauroursodeoxycholic acid dampens oncogenic apoptosis induced by endoplasmic reticulum stress during hepatocarcinogen exposure. Oncotarget 2016; 6:28011-25. [PMID: 26293671 PMCID: PMC4695041 DOI: 10.18632/oncotarget.4377] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 07/10/2015] [Indexed: 12/18/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is characterized by the accumulation of unfolded proteins in the endoplasmic reticulum (ER), which activates the unfolded protein response (UPR). However, the role of ER stress in tumor initiation and progression is controversial. To determine the impact of ER stress, we applied tauroursodeoxycholic acid (TUDCA), a bile acid with chaperone properties. The effects of TUDCA were assessed using a diethylnitrosamine-induced mouse HCC model in preventive and therapeutic settings. Cell metabolic activity, proliferation and invasion were investigated in vitro. Tumor progression was assessed in the HepG2 xenograft model. Administration of TUDCA in the preventive setting reduced carcinogen-induced elevation of alanine and aspartate aminotransferase levels, apoptosis of hepatocytes and tumor burden. TUDCA also reduced eukaryotic initiation factor 2α (eIf2α) phosphorylation, C/EBP homologous protein expression and caspase-12 processing. Thus, TUDCA suppresses carcinogen-induced pro-apoptotic UPR. TUDCA alleviated hepatic inflammation by increasing NF-κB inhibitor IκBα. Furthermore, TUDCA altered the invasive phenotype and enhanced metabolic activity but not proliferation in HCC cells. TUDCA administration after tumor development did not alter orthotopic tumor or xenograft growth. Taken together, TUDCA attenuates hepatocarcinogenesis by suppressing carcinogen-induced ER stress-mediated cell death and inflammation without stimulating tumor progression. Therefore, this chemical chaperone could represent a novel chemopreventive agent.
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115
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Choy KW, Mustafa MR, Lau YS, Liu J, Murugan D, Lau CW, Wang L, Zhao L, Huang Y. Paeonol protects against endoplasmic reticulum stress-induced endothelial dysfunction via AMPK/PPARδ signaling pathway. Biochem Pharmacol 2016; 116:51-62. [PMID: 27449753 DOI: 10.1016/j.bcp.2016.07.013] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 07/18/2016] [Indexed: 12/31/2022]
Abstract
Endoplasmic reticulum (ER) stress in endothelial cells often leads to endothelial dysfunction which underlies the pathogenesis of cardiovascular diseases. Paeonol, a major phenolic component extracted from Moutan Cortex, possesses various medicinal benefits which have been used extensively in traditional Chinese medicine. The present study investigated the protective mechanism of paeonol against tunicamycin-induced ER stress in isolated mouse aortas and human umbilical vein endothelial cells (HUVECs). Vascular reactivity in aorta was measured using a wire myograph. The effects of paeonol on protein expression of ER stress markers, reactive oxygen species (ROS) production, nitric oxide (NO) bioavailability and peroxisome proliferator-activated receptor δ (PPARδ) activity in the vascular wall were assessed by Western blot, dihydroethidium fluorescence (DHE) or lucigenin enhanced-chemiluminescence, 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM DA) and dual luciferase reporter assay, respectively. Ex vivo treatment with paeonol (0.1μM) for 16h reversed the impaired endothelium-dependent relaxations in C57BJ/6J and PPARδ wild type (WT) mouse aortas following incubation with tunicamycin (0.5μg/mL). Elevated ER stress markers, oxidative stress and reduction of NO bioavailability induced by tunicamycin in HUVECs, C57BJ/6J and PPARδ WT mouse aortas were reversed by paeonol treatment. These beneficial effects of paeonol were diminished in PPARδ knockout (KO) mouse aortas. Paeonol increased the expression of 5' adenosine monophosphate-activated protein kinase (AMPK) and PPARδ expression and activity while restoring the decreased phosphorylation of eNOS. The present study delineates that paeonol protects against tunicamycin-induced vascular endothelial dysfunction by inhibition of ER stress and oxidative stress, thus elevating NO bioavailability via the AMPK/PPARδ signaling pathway.
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Affiliation(s)
- Ker-Woon Choy
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Mohd Rais Mustafa
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
| | - Yeh Siang Lau
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Jian Liu
- Institute of Vascular Medicine and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Dharmani Murugan
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Chi Wai Lau
- Institute of Vascular Medicine and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Li Wang
- Institute of Vascular Medicine and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Lei Zhao
- Institute of Vascular Medicine and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Yu Huang
- Institute of Vascular Medicine and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China.
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116
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Munshi S, Dahl R. Cytoprotective small molecule modulators of endoplasmic reticulum stress. Bioorg Med Chem 2016; 24:2382-2388. [PMID: 27091069 DOI: 10.1016/j.bmc.2016.03.045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Revised: 03/21/2016] [Accepted: 03/27/2016] [Indexed: 01/03/2023]
Abstract
Cellular health depends on the normal function of the endoplasmic reticulum (ER) to fold, assemble, and modify critical proteins to maintain viability. When the ER cannot process proteins effectively, a condition known as ER stress ensues. When this stress is excessive or prolonged, cell death via apoptotic pathways is triggered. Interestingly, most major diseases have been shown to be intimately linked to ER stress, including diabetes, stroke, neurodegeneration, and many cancers. Thus, controlling ER stress presents a significant strategy for drug development for these diseases. The goal of this review is to present various small molecules that alleviate ER stress with the intention that they may serve as useful starting points for therapeutic agent development.
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Affiliation(s)
- Soumyabrata Munshi
- Department of Neuroscience, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Russell Dahl
- Neurodon LLC, 5700 Tanager St., Schererville, IN 46375, USA.
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117
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Siddesha JM, Nakada EM, Mihavics BR, Hoffman SM, Rattu GK, Chamberlain N, Cahoon JM, Lahue KG, Daphtary N, Aliyeva M, Chapman DG, Desai DH, Poynter ME, Anathy V. Effect of a chemical chaperone, tauroursodeoxycholic acid, on HDM-induced allergic airway disease. Am J Physiol Lung Cell Mol Physiol 2016; 310:L1243-59. [PMID: 27154200 DOI: 10.1152/ajplung.00396.2015] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 04/27/2016] [Indexed: 12/14/2022] Open
Abstract
Endoplasmic reticulum (ER) stress-induced unfolded protein response plays a critical role in inflammatory diseases, including allergic airway disease. However, the benefits of inhibiting ER stress in the treatment of allergic airway disease are not well known. Herein, we tested the therapeutic potential of a chemical chaperone, tauroursodeoxycholic acid (TUDCA), in combating allergic asthma, using a mouse model of house dust mite (HDM)-induced allergic airway disease. TUDCA was administered during the HDM-challenge phase (preventive regimen), after the HDM-challenge phase (therapeutic regimen), or therapeutically during a subsequent HDM rechallenge (rechallenge regimen). In the preventive regimen, TUDCA significantly decreased HDM-induced inflammation, markers of ER stress, airway hyperresponsiveness (AHR), and fibrosis. Similarly, in the therapeutic regimen, TUDCA administration efficiently decreased HDM-induced airway inflammation, mucus metaplasia, ER stress markers, and AHR, but not airway remodeling. Interestingly, TUDCA administered therapeutically in the HDM rechallenge regimen markedly attenuated HDM-induced airway inflammation, mucus metaplasia, ER stress markers, methacholine-induced AHR, and airway fibrotic remodeling. These results indicate that the inhibition of ER stress in the lungs through the administration of chemical chaperones could be a valuable strategy in the treatment of allergic airway diseases.
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Affiliation(s)
- Jalahalli M Siddesha
- Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | - Emily M Nakada
- Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | - Bethany R Mihavics
- Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | - Sidra M Hoffman
- Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | | | - Nicolas Chamberlain
- Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | - Jonathon M Cahoon
- Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | - Karolyn G Lahue
- Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | - Nirav Daphtary
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | - Minara Aliyeva
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | - David G Chapman
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont; Woolcock Institute of Medical Research, Sydney Medical School, University of Sydney, Sydney, Australia; and
| | - Dhimant H Desai
- Department of Pharmacology, Penn State Hershey College of Medicine, Hershey, Pensylvania
| | - Matthew E Poynter
- Department of Medicine, University of Vermont College of Medicine, Burlington, Vermont
| | - Vikas Anathy
- Department of Pathology and Laboratory Medicine, University of Vermont College of Medicine, Burlington, Vermont;
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118
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Memme JM, Oliveira AN, Hood DA. Chronology of UPR activation in skeletal muscle adaptations to chronic contractile activity. Am J Physiol Cell Physiol 2016; 310:C1024-36. [PMID: 27122157 DOI: 10.1152/ajpcell.00009.2016] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 04/27/2016] [Indexed: 12/29/2022]
Abstract
The mitochondrial and endoplasmic reticulum unfolded protein responses (UPR(mt) and UPR(ER)) are important for cellular homeostasis during stimulus-induced increases in protein synthesis. Exercise triggers the synthesis of mitochondrial proteins, regulated in part by peroxisome proliferator activator receptor-γ coactivator 1α (PGC-1α). To investigate the role of the UPR in exercise-induced adaptations, we subjected rats to 3 h of chronic contractile activity (CCA) for 1, 2, 3, 5, or 7 days followed by 3 h of recovery. Mitochondrial biogenesis signaling, through PGC-1α mRNA, increased 14-fold after 1 day of CCA. This resulted in 10-32% increases in cytochrome c oxidase activity, indicative of mitochondrial content, between days 3 and 7, as well as increases in the autophagic degradation of p62 and microtubule-associated proteins 1A/1B light chain 3A (LC3)-II protein. Before these adaptations, the UPR(ER) transcripts activating transcription factor-4, spliced X-box-binding protein 1, and binding immunoglobulin protein were elevated (1.3- to 3.8-fold) at days 1-3, while CCAAT/enhancer-binding protein homologous protein (CHOP) and chaperones binding immunoglobulin protein and heat shock protein (HSP) 70 were elevated at mRNA and protein levels (1.5- to 3.9-fold) at days 1-7 of CCA. The mitochondrial chaperones 10-kDa chaperonin, HSP60, and 75-kDa mitochondrial HSP, the protease ATP-dependent Clp protease proteolytic subunit, and the regulatory protein sirtuin-3 of the UPR(mt) were concurrently induced 10-80% between days 1 and 7 To test the role of the UPR in CCA-induced remodeling, we treated animals with the endoplasmic reticulum stress suppressor tauroursodeoxycholic acid and subjected them to 2 or 7 days of CCA. Tauroursodeoxycholic acid attenuated CHOP and HSP70 protein induction; however, this failed to impact mitochondrial remodeling. Our data indicate that signaling to the UPR is rapidly activated following acute contractile activity, that this is attenuated with repeated bouts, and that the UPR is involved in chronic adaptations to CCA; however, this appears to be independent of CHOP signaling.
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Affiliation(s)
- Jonathan M Memme
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - Ashley N Oliveira
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
| | - David A Hood
- Muscle Health Research Centre, School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada
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119
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Jalan R, De Chiara F, Balasubramaniyan V, Andreola F, Khetan V, Malago M, Pinzani M, Mookerjee RP, Rombouts K. Ammonia produces pathological changes in human hepatic stellate cells and is a target for therapy of portal hypertension. J Hepatol 2016; 64:823-33. [PMID: 26654994 DOI: 10.1016/j.jhep.2015.11.019] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 11/09/2015] [Accepted: 11/11/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND & AIMS Hepatic stellate cells (HSCs) are vital to hepatocellular function and the liver response to injury. They share a phenotypic homology with astrocytes that are central in the pathogenesis of hepatic encephalopathy, a condition in which hyperammonemia plays a pathogenic role. This study tested the hypothesis that ammonia modulates human HSC activation in vitro and in vivo, and evaluated whether ammonia lowering, by using l-ornithine phenylacetate (OP), modifies HSC activation in vivo and reduces portal pressure in a bile duct ligation (BDL) model. METHODS Primary human HSCs were isolated and cultured. Proliferation (BrdU), metabolic activity (MTS), morphology (transmission electron, light and immunofluorescence microscopy), HSC activation markers, ability to contract, changes in oxidative status (ROS) and endoplasmic reticulum (ER) were evaluated to identify effects of ammonia challenge (50 μM, 100 μM, 300 μM) over 24-72 h. Changes in plasma ammonia levels, markers of HSC activation, portal pressure and hepatic eNOS activity were quantified in hyperammonemic BDL animals, and after OP treatment. RESULTS Pathophysiological ammonia concentrations caused significant and reversible changes in cell proliferation, metabolic activity and activation markers of hHSC in vitro. Ammonia also induced significant alterations in cellular morphology, characterised by cytoplasmic vacuolisation, ER enlargement, ROS production, hHSC contraction and changes in pro-inflammatory gene expression together with HSC-related activation markers such as α-SMA, myosin IIa, IIb, and PDGF-Rβ. Treatment with OP significantly reduced plasma ammonia (BDL 199.1 μmol/L±43.65 vs. BDL+OP 149.27 μmol/L±51.1, p<0.05) and portal pressure (BDL 14±0.6 vs. BDL+OP 11±0.3 mmHg, p<0.01), which was associated with increased eNOS activity and abrogation of HSC activation markers. CONCLUSIONS The results show for the first time that ammonia produces deleterious morphological and functional effects on HSCs in vitro. Targeting ammonia with the ammonia lowering drug OP reduces portal pressure and deactivates hHSC in vivo, highlighting the opportunity for evaluating ammonia lowering as a potential therapy in cirrhotic patients with portal hypertension.
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Affiliation(s)
- Rajiv Jalan
- Liver Failure Group, Institute for Liver & Digestive Health, University College of London, Royal Free, London, UK
| | - Francesco De Chiara
- Liver Failure Group, Institute for Liver & Digestive Health, University College of London, Royal Free, London, UK
| | - Vairappan Balasubramaniyan
- Liver Failure Group, Institute for Liver & Digestive Health, University College of London, Royal Free, London, UK
| | - Fausto Andreola
- Liver Failure Group, Institute for Liver & Digestive Health, University College of London, Royal Free, London, UK
| | - Varun Khetan
- Liver Failure Group, Institute for Liver & Digestive Health, University College of London, Royal Free, London, UK
| | - Massimo Malago
- Division of Surgery, University College London, Royal Free, London, UK
| | - Massimo Pinzani
- Regenerative Medicine & Fibrosis Group, Institute for Liver & Digestive Health, University College London, Royal Free, London, UK
| | - Rajeshwar P Mookerjee
- Liver Failure Group, Institute for Liver & Digestive Health, University College of London, Royal Free, London, UK.
| | - Krista Rombouts
- Regenerative Medicine & Fibrosis Group, Institute for Liver & Digestive Health, University College London, Royal Free, London, UK.
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120
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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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121
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Jung TW, Choi KM. Pharmacological Modulators of Endoplasmic Reticulum Stress in Metabolic Diseases. Int J Mol Sci 2016; 17:ijms17020192. [PMID: 26840310 PMCID: PMC4783926 DOI: 10.3390/ijms17020192] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 01/20/2016] [Accepted: 01/27/2016] [Indexed: 01/23/2023] Open
Abstract
The endoplasmic reticulum (ER) is the principal organelle responsible for correct protein folding, a step in protein synthesis that is critical for the functional conformation of proteins. ER stress is a primary feature of secretory cells and is involved in the pathogenesis of numerous human diseases, such as certain neurodegenerative and cardiometabolic disorders. The unfolded protein response (UPR) is a defense mechanism to attenuate ER stress and maintain the homeostasis of the organism. Two major degradation systems, including the proteasome and autophagy, are involved in this defense system. If ER stress overwhelms the capacity of the cell's defense mechanisms, apoptotic death may result. This review is focused on the various pharmacological modulators that can protect cells from damage induced by ER stress. The possible mechanisms for cytoprotection are also discussed.
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Affiliation(s)
- Tae Woo Jung
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul 152-703, Korea.
| | - Kyung Mook Choi
- Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, Korea University, Seoul 152-703, Korea.
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122
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Cha BH, Jung MJ, Moon BK, Kim JS, Ma Y, Arai Y, Noh M, Shin JY, Kim BS, Lee SH. Administration of tauroursodeoxycholic acid enhances osteogenic differentiation of bone marrow-derived mesenchymal stem cells and bone regeneration. Bone 2016; 83:73-81. [PMID: 26499839 DOI: 10.1016/j.bone.2015.10.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 08/24/2015] [Accepted: 10/20/2015] [Indexed: 01/06/2023]
Abstract
It is known that osteogenic differentiation of mesenchymal stem cells (MSCs) can be promoted by suppression of adipogenesis of MSCs. We have recently found that the chemical chaperone tauroursodeoxycholic acid (TUDCA) significantly reduces adipogenesis of MSCs. In the present study, we examined whether TUDCA can promote osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMMSCs) by regulating Integrin 5 (ITGA5) associated with activation of ERK1/2 signal pathway and thereby enhance bone tissue regeneration by reducing apoptosis and the inflammatory response. TUDCA treatment promoted in vitro osteogenic differentiation of BMMSCs and in vivo bone tissue regeneration in a calvarial defect model, as confirmed by micro-computed tomography, histological staining, and immunohistochemistry for osteocalcin. In addition, TUDCA treatment significantly decreased apoptosis and the inflammatory response in vivo and in vitro, which is important to enhance bone tissue regeneration. These results indicate that TUDCA plays a critical role in enhancing osteogenesis of BMMSCs, and is therefore a potential alternative drug for bone tissue regeneration.
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Affiliation(s)
- Byung-Hyun Cha
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si, Republic of Korea
| | - Moon-Joo Jung
- Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Bo-Kyung Moon
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si, Republic of Korea
| | - Jin-Su Kim
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si, Republic of Korea
| | - Yoonji Ma
- Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Yoshie Arai
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si, Republic of Korea
| | - Myungkyung Noh
- Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Jung-Youn Shin
- Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Byung-Soo Kim
- Interdisciplinary Program for Bioengineering, Seoul National University, Seoul 151-744, Republic of Korea; School of Chemical and Biological Engineering, Seoul National University, Seoul 151-744, Republic of Korea; Bio-MAX Institute, Institute for Chemical Processes, Seoul National University, Seoul 151-744, Republic of Korea.
| | - Soo-Hong Lee
- Department of Biomedical Science, College of Life Science, CHA University, Seongnam-si, Republic of Korea.
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Wong MK, Holloway AC, Hardy DB. Nicotine Directly Induces Endoplasmic Reticulum Stress Response in Rat Placental Trophoblast Giant Cells. Toxicol Sci 2016; 151:23-34. [PMID: 26803847 DOI: 10.1093/toxsci/kfw019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Nicotine exposure during pregnancy leads to placental insufficiency impairing both fetal and neonatal development. Previous studies from our laboratory have demonstrated that in rats, nicotine augmented endoplasmic reticulum (ER) stress in association with placental insufficiency; however, the underlying mechanisms remain elusive. Therefore, we sought to investigate the possible direct effect of nicotine on ER stress in Rcho-1 rat placental trophoblast giant (TG) cells during differentiation. Protein and/or mRNA expression of markers involved in ER stress (eg, phosphorylated PERK, eIF2α, CHOP, and BiP/GRP78) and TG cell differentiation and function (eg, Pl-1, placental growth factor [Pgf], Hsd11b1, and Hsd11b2) were quantified via Western blot or real-time polymerase chain reaction. Nicotine treatment led to dose-dependent increases in the phosphorylation of PERK[Thr981] and eIF2α[Ser51], whereas pretreatment with a nicotinic acetylcholine receptor (nAChR) antagonist (mecamylamine hydrochloride) blocked the induction of PERK phosphorylation, verifying the direct involvement of nicotine and nAChR binding. We next investigated select target genes known to play essential roles in placental TG cell differentiation and function (Pl-1, Pgf, Hsd11b1, and Hsd11b2), and found that nicotine significantly augmented the mRNA levels of Hsd11b1 in a dose-dependent manner. Furthermore, using tauroursodeoxycholic acid, a safe bile acid known to improve protein chaperoning and folding, we were able to prevent nicotine-induced increases in both PERK phosphorylation and Hsd11b1 mRNA levels, revealing a potential novel therapeutic approach to reverse the deleterious effects of nicotine exposure in pregnancy. Collectively, these results implicate that nicotine, acting through its receptor, can directly augment ER stress and impair placental function.
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Affiliation(s)
- Michael K Wong
- *Department of Physiology and Pharmacology, Western University, London, Ontario, Canada N6A 5C1
| | - Alison C Holloway
- Department of Obstetrics and Gynecology, McMaster University, Hamilton, Ontario, Canada L8S 4K1
| | - Daniel B Hardy
- *Department of Physiology and Pharmacology, Western University, London, Ontario, Canada N6A 5C1 Departments of Obstetrics and Gynecology, Children's Health Research Institute, Lawson, Health Research Institute, Western University, London, Ontario, Canada N6A 5C1
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Cho JG, Lee JH, Hong SH, Lee HN, Kim CM, Kim SY, Yoon KJ, Oh BJ, Kim JH, Jung SY, Asahara T, Kwon SM, Park SG. Tauroursodeoxycholic acid, a bile acid, promotes blood vessel repair by recruiting vasculogenic progenitor cells. Stem Cells 2015; 33:792-805. [PMID: 25407160 DOI: 10.1002/stem.1901] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 09/22/2014] [Accepted: 10/26/2014] [Indexed: 01/19/2023]
Abstract
Although serum bile acid concentrations are approximately 10 µM in healthy subjects, the crosstalk between the biliary system and vascular repair has never been investigated. In this study, tauroursodeoxycholic acid (TUDCA) induced dissociation of CD34(+) hematopoietic stem cells (HSCs) from stromal cells by reducing adhesion molecule expression. TUDCA increased CD34(+) /Sca1(+) progenitors in mice peripheral blood (PB), and CD34(+) , CD31(+) , and c-kit(+) progenitors in human PB. In addition, TUDCA increased differentiation of CD34(+) HSCs into EPC lineage cells via Akt activation. EPC invasion was increased by TUDCA, which was mediated by fibroblast activating protein via Akt activation. Interestingly, TUDCA induced integration of EPCs into human aortic endothelial cells (HAECs) by increasing adhesion molecule expression. In the mouse hind limb ischemia model, TUDCA promoted blood perfusion by enhancing angiogenesis through recruitment of Flk-1(+) /CD34(+) and Sca-1(+) /c-kit(+) progenitors into damaged tissue. In GFP(+) bone marrow-transplanted hind limb ischemia, TUDCA induced recruitment of GFP(+) /c-kit(+) progenitors to the ischemic area, resulting in an increased blood perfusion ratio. Histological analysis suggested that GFP(+) progenitors mobilized from bone marrow, integrated into blood vessels, and differentiated into VEGFR(+) cells. In addition, TUDCA decreased cellular senescence by reducing levels of p53, p21, and reactive oxygen species and increased nitric oxide. Transplantation of TUDCA-primed senescent EPCs in hind limb ischemia significantly improved blood vessel regeneration, as compared with senescent EPCs. Our results suggested that TUDCA promoted neovascularization by enhancing the mobilization of stem/progenitor cells from bone marrow, their differentiation into EPCs, and their integration with preexisting endothelial cells.
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Affiliation(s)
- Jin Gu Cho
- Department of Biomedical Science, CHA University, Sungnamsi, Gyunggido, Korea
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Cai F, Liu J, Li C, Wang J. Critical Role of Endoplasmic Reticulum Stress in Cognitive Impairment Induced by Microcystin-LR. Int J Mol Sci 2015; 16:28077-86. [PMID: 26602924 PMCID: PMC4691030 DOI: 10.3390/ijms161226083] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 01/11/2023] Open
Abstract
Recent studies showed that cyanobacteria-derived microcystin-leucine-arginine (MCLR) can cause hippocampal pathological damage and trigger cognitive impairment; but the underlying mechanisms have not been well understood. The objective of the present study was to investigate the mechanism of MCLR-induced cognitive deficit; with a focus on endoplasmic reticulum (ER) stress. The Morris water maze test and electrophysiological study demonstrated that MCLR caused spatial memory injury in male Wistar rats; which could be inhibited by ER stress blocker; tauroursodeoxycholic acid (TUDCA). Meanwhile; real-time polymerase chain reaction (real-time PCR) and immunohistochemistry demonstrated that the expression level of the 78-kDa glucose-regulated protein (GRP78); C/EBP homologous protein (CHOP) and caspase 12 were significantly up-regulated. These effects were rescued by co-administration of TUDCA. In agreement with this; we also observed that treatment of rats with TUDCA blocked the alterations in ER ultrastructure and apoptotic cell death in CA1 neurons from rats exposed to MCLR. Taken together; the present results suggested that ER stress plays an important role in potential memory impairments in rats treated with MCLR; and amelioration of ER stress may serve as a novel strategy to alleviate damaged cognitive function triggered by MCLR.
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Affiliation(s)
- Fei Cai
- Department of Pharmacology, Hubei University of Science and Technology, Xianning 437100, China.
| | - Jue Liu
- Department of Pharmacy, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430014, China.
| | - Cairong Li
- Hubei Province Key Laboratory on Cardiovascular, Cerebrovascular, and Metabolic Disorders, Hubei University of Science and Technology, Xianning 437100, China.
| | - Jianghua Wang
- Fisheries College, Huazhong Agricultural University, Wuhan 430070, China.
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Jang MK, Han YR, Nam JS, Han CW, Kim BJ, Jeong HS, Ha KT, Jung MH. Protective Effects of Alisma orientale Extract against Hepatic Steatosis via Inhibition of Endoplasmic Reticulum Stress. Int J Mol Sci 2015; 16:26151-65. [PMID: 26540043 PMCID: PMC4661803 DOI: 10.3390/ijms161125944] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 10/09/2015] [Accepted: 10/21/2015] [Indexed: 01/27/2023] Open
Abstract
Endoplasmic reticulum (ER) stress is associated with the pathogenesis of hepatic steatosis. Alisma orientale Juzepzuk is a traditional medicinal herb for diuretics, diabetes, hepatitis, and inflammation. In this study, we investigated the protective effects of methanol extract of the tuber of Alisma orientale (MEAO) against ER stress-induced hepatic steatosis in vitro and in vivo. MEAO inhibited the tunicamycin-induced increase in luciferase activity of ER stress-reporter constructs containing ER stress response element and ATF6 response element. MEAO significantly inhibited tunicamycin-induced ER stress marker expression including GRP78, CHOP, and XBP-1 in tunicamycin-treated Human hepatocellular carcinoma (HepG2) cells and the livers of tunicamycin-injected mice. It also inhibited tunicamycin-induced accumulation of cellular triglyceride. Similar observations were made under physiological ER stress conditions such as in palmitate (PA)-treated HepG2 cells and the livers of high-fat diet (HFD)-induced obese mice. MEAO repressed hepatic lipogenic gene expression in PA-treated HepG2 cells and the livers of HFD obese mice. Furthermore, MEAO repressed very low-density lipoprotein receptor (VLDLR) expression and improved ApoB secretion in the livers of tunicamycin-injected mice or HFD obese mice as well as in tunicamycin or PA-treated HepG2 cells. Alismol, a guaiane-type sesquiterpenes in Alisma orientale, inhibited GRP78 expression in tunicamycin-treated HepG2 cells. In conclusion, MEAO attenuates ER stress and prevents hepatic steatosis pathogenesis via inhibition of expression of the hepatic lipogenic genes and VLDLR, and enhancement of ApoB secretion.
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Affiliation(s)
- Min-Kyung Jang
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (M.-K.J.); (Y.-R.H.); (J.S.N.); (B.J.K.)
- Healthy Aging Korean Medical Research Center, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (C.W.H.); (H.-S.J.); (G.-T.H.)
| | - Yu-Ran Han
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (M.-K.J.); (Y.-R.H.); (J.S.N.); (B.J.K.)
- Healthy Aging Korean Medical Research Center, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (C.W.H.); (H.-S.J.); (G.-T.H.)
| | - Jeong Soo Nam
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (M.-K.J.); (Y.-R.H.); (J.S.N.); (B.J.K.)
- Healthy Aging Korean Medical Research Center, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (C.W.H.); (H.-S.J.); (G.-T.H.)
| | - Chang Woo Han
- Healthy Aging Korean Medical Research Center, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (C.W.H.); (H.-S.J.); (G.-T.H.)
| | - Byung Joo Kim
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (M.-K.J.); (Y.-R.H.); (J.S.N.); (B.J.K.)
- Healthy Aging Korean Medical Research Center, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (C.W.H.); (H.-S.J.); (G.-T.H.)
| | - Han-Sol Jeong
- Healthy Aging Korean Medical Research Center, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (C.W.H.); (H.-S.J.); (G.-T.H.)
| | - Ki-Tae Ha
- Healthy Aging Korean Medical Research Center, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (C.W.H.); (H.-S.J.); (G.-T.H.)
| | - Myeong Ho Jung
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (M.-K.J.); (Y.-R.H.); (J.S.N.); (B.J.K.)
- Healthy Aging Korean Medical Research Center, School of Korean Medicine, Pusan National University, Yangsan-si 626-870, Korea; (C.W.H.); (H.-S.J.); (G.-T.H.)
- Correspondence: ; Tel.: +82-51-510-8468; Fax: +82-51-510-8437
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Wang Y, Su K, Sabeva NS, Ji A, van der Westhuyzen DR, Foufelle F, Gao X, Graf GA. GRP78 rescues the ABCG5 ABCG8 sterol transporter in db/db mice. Metabolism 2015; 64:1435-43. [PMID: 26365598 PMCID: PMC4609626 DOI: 10.1016/j.metabol.2015.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 07/31/2015] [Accepted: 08/10/2015] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Mice lacking leptin (ob/ob) or its receptor (db/db) are obese, insulin resistant, and have reduced levels of biliary cholesterol due, in part, to reduced levels of hepatic G5G8. Chronic leptin replacement restores G5G8 abundance and increases biliary cholesterol concentrations, but the molecular mechanisms responsible for G5G8 regulation remain unclear. In the current study, we used a series of mouse models to address potential mechanisms for leptin-mediated regulation of G5G8. METHODS AND RESULTS We acutely replaced leptin in ob/ob mice and deleted hepatic leptin receptors in lean mice. Neither manipulation altered G5G8 abundance or biliary cholesterol. Similarly, hepatic vagotomy had no effect on G5G8. Alternatively, G5G8 may be decreased in ob/ob and db/db mice due to ER dysfunction, the site of G5G8 complex assembly. Overexpression of the ER chaperone GRP78 using an adenoviral vector restores ER function and reduces steatosis in ob/ob mice. Therefore, we determined if AdGRP78 could rescue G5G8 in db/db mice. As in ob/ob mice, AdGRP78 reduced expression of lipogenic genes and plasma triglycerides in the db/db strain. Both G5 and G8 protein levels increased as did total biliary cholesterol, but in the absence of changes in G5 or G8 mRNAs. The increase in G5G8 was associated with increases in a number of proteins, including the ER lectin chaperone, calnexin, a key regulator of G5G8 complex assembly. CONCLUSIONS Leptin signaling does not directly regulate G5G8 abundance. The loss of G5G8 in mice harboring defects in the leptin axis is likely associated with compromised ER function.
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Affiliation(s)
- Yuhuan Wang
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, USA
| | - Kai Su
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, USA
| | - Nadezhda S Sabeva
- Department of Neuroscience, Universidad Central del Caribe, Bayamón, PR, USA
| | - Ailing Ji
- Department of Internal Medicine and Molecular, University of Kentucky, Lexington, KY, USA; Department of Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Deneys R van der Westhuyzen
- Graduate Center for Nutritional Sciences, Saha Cardiovascular Research Center and Barnstable Brown Kentucky Diabetes and Obesity Center, Lexington, KY, USA; Department of Internal Medicine and Molecular, University of Kentucky, Lexington, KY, USA; Department of Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Fabienne Foufelle
- INSERM, UMR-S 872, Centre de Recherches des Cordeliers, 15 rue de L'école de Médecine, Paris, France
| | - Xia Gao
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Gregory A Graf
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, USA; Graduate Center for Nutritional Sciences, Saha Cardiovascular Research Center and Barnstable Brown Kentucky Diabetes and Obesity Center, Lexington, KY, USA.
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Xu LH, Xie H, Shi ZH, Du LD, Wing YK, Li AM, Ke Y, Yung WH. Critical Role of Endoplasmic Reticulum Stress in Chronic Intermittent Hypoxia-Induced Deficits in Synaptic Plasticity and Long-Term Memory. Antioxid Redox Signal 2015; 23:695-710. [PMID: 25843188 PMCID: PMC4580307 DOI: 10.1089/ars.2014.6122] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
AIMS This study examined the role of endoplasmic reticulum (ER) stress in mediating chronic intermittent hypoxia (IH)-induced neurocognitive deficits. We designed experiments to demonstrate that ER stress is initiated in the hippocampus under chronic IH and determined its role in apoptotic cell death, impaired synaptic structure and plasticity, and memory deficits. RESULTS Two weeks of IH disrupted ER fine structure and upregulated ER stress markers, glucose-regulated protein 78, caspase-12, and C/EBP homologous protein, in the hippocampus, which could be suppressed by ER stress inhibitors, tauroursodeoxycholic acid (TUDCA) and 4-phenylbutyric acid. Meanwhile, ER stress induced apoptosis via decreased Bcl-2, promoted reactive oxygen species production, and increased malondialdehyde formation and protein carbonyl, as well as suppressed mitochondrial function. These effects were largely prevented by ER stress inhibitors. On the other hand, suppression of oxidative stress could reduce ER stress. In addition, the length of the synaptic active zone and number of mature spines were reduced by IH. Long-term recognition memory and spatial memory were also impaired, which was accompanied by reduced long-term potentiation in the Schaffer collateral pathway. These effects were prevented by coadministration of the TUDCA. INNOVATION AND CONCLUSION These results show that ER stress plays a critical role in underlying memory deficits in obstructive sleep apnea (OSA)-associated IH. Attenuators of ER stress may serve as novel adjunct therapeutic agents for ameliorating OSA-induced neurocognitive impairment.
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Affiliation(s)
- Lin-Hao Xu
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Hui Xie
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Zhi-Hui Shi
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Li-Da Du
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Yun-Kwok Wing
- 2 Department of Psychiatry, Prince of Wales Hospital , Shatin, Hong Kong, China
| | - Albert M Li
- 3 Department of Pediatrics, Prince of Wales Hospital , Shatin, Hong Kong, China
| | - Ya Ke
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
| | - Wing-Ho Yung
- 1 Faculty of Medicine, School of Biomedical Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong, China
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Gómez-Vicente V, Lax P, Fernández-Sánchez L, Rondón N, Esquiva G, Germain F, de la Villa P, Cuenca N. Neuroprotective Effect of Tauroursodeoxycholic Acid on N-Methyl-D-Aspartate-Induced Retinal Ganglion Cell Degeneration. PLoS One 2015; 10:e0137826. [PMID: 26379056 PMCID: PMC4574963 DOI: 10.1371/journal.pone.0137826] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 08/24/2015] [Indexed: 01/01/2023] Open
Abstract
Retinal ganglion cell degeneration underlies the pathophysiology of diseases affecting the retina and optic nerve. Several studies have previously evidenced the anti-apoptotic properties of the bile constituent, tauroursodeoxycholic acid, in diverse models of photoreceptor degeneration. The aim of this study was to investigate the effects of systemic administration of tauroursodeoxycholic acid on N-methyl-D-aspartate (NMDA)-induced damage in the rat retina using a functional and morphological approach. Tauroursodeoxycholic acid was administered intraperitoneally before and after intravitreal injection of NMDA. Three days after insult, full-field electroretinograms showed reductions in the amplitudes of the positive and negative-scotopic threshold responses, scotopic a- and b-waves and oscillatory potentials. Quantitative morphological evaluation of whole-mount retinas demonstrated a reduction in the density of retinal ganglion cells. Systemic administration of tauroursodeoxycholic acid attenuated the functional impairment induced by NMDA, which correlated with a higher retinal ganglion cell density. Our findings sustain the efficacy of tauroursodeoxycholic acid administration in vivo, suggesting it would be a good candidate for the pharmacological treatment of degenerative diseases coursing with retinal ganglion cell loss.
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Affiliation(s)
- Violeta Gómez-Vicente
- Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain
| | - Pedro Lax
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Laura Fernández-Sánchez
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Netxibeth Rondón
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Gema Esquiva
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Francisco Germain
- Departamento de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Pedro de la Villa
- Departamento de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Nicolás Cuenca
- Departamento de Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
- * E-mail:
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130
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Zheng XY, Xu J, Chen XI, Li W, Wang TY. Attenuation of oxygen fluctuation-induced endoplasmic reticulum stress in human lens epithelial cells. Exp Ther Med 2015; 10:1883-1887. [PMID: 26640566 DOI: 10.3892/etm.2015.2725] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 05/28/2015] [Indexed: 12/31/2022] Open
Abstract
Cataractogenic stresses are associated with the induction of endoplasmic reticulum (ER) stress. However, little is known about oxygen (O2)-induced ER stress in the lens. Cataract research has focused on elevated levels of O2 in lens epithelial cells (LECs). Excessive levels or a lack of O2 are known to induce ER stress whereas chronic ER stress activates the unfolded protein response (UPR). The present study investigated the hypothesis that the fluctuation of O2 levels induces a UPR, and may be controlled by maintaining human LECs (hLECs) in a specific concentration of O2. Human LECs were cultured in different atmospheric levels of O2. Hypoxic conditions were determined by the level of hypoxia-inducible factor (HIF)-1α. 2',7'-Dichlorodihydrofluorescein diacetate and ethidium homodimer-1 staining were conducted to detect reactive oxygen species (ROS) and cell death, respectively. Protein blot analyses were performed with antibodies specific to antioxidant and UPR-specific proteins. Reverse transcription-quantitatative polymerase chain reaction assays were performed to quantify the mRNA levels of activated NF-E2-related factor 2 (Nrf2) and kelch-like ECH-associated protein 1 (Keap1). The treatment of human LECs with 0 and 20% atmospheric O2 activated Nrf2/Keap1. The LECs shifted to 1% atmospheric O2 from 0, 4 or 20% for 24 h showed decreased levels of Keap1. By contrast, hLECs cultured in 1% atmospheric O2 for 24 h and then shifted to 0, 4 or 20% O2 exhibited a significant upregulation of Nrf2. These results suggest that oxidative stress proteins were not expressed in a 1% O2 environment. The O2 levels in the culture medium were equilibrated within 2 h in the cell culture plates. These results showed that an appropriate oxygen environment for the culture of LECs is ~1 % atmospheric O2. Either 0 or 20% of atmospheric O2 activated the UPR and the Nrf2/Keap1-mediated antioxidant system in LECs and chronic exposure to O2 fluctuation led to ROS production and cell death. This study revealed that O2 fluctuation-induced UPR/ER stress could be prevented by maintaining the cells in a 1% O2 environment.
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Affiliation(s)
- Xiao-Yu Zheng
- Department of Ophthalmology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, P.R. China
| | - Jia Xu
- Department of Ophthalmology, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, P.R. China
| | - X I Chen
- The Central Laboratory, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, P.R. China
| | - Wei Li
- The Central Laboratory, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, P.R. China
| | - Ting-Yan Wang
- Department of Ophthalmology, The Children's Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang 310003, P.R. China
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Fernández-Sánchez L, Lax P, Noailles A, Angulo A, Maneu V, Cuenca N. Natural Compounds from Saffron and Bear Bile Prevent Vision Loss and Retinal Degeneration. Molecules 2015; 20:13875-93. [PMID: 26263962 PMCID: PMC6332441 DOI: 10.3390/molecules200813875] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 07/23/2015] [Accepted: 07/28/2015] [Indexed: 12/13/2022] Open
Abstract
All retinal disorders, regardless of their aetiology, involve the activation of oxidative stress and apoptosis pathways. The administration of neuroprotective factors is crucial in all phases of the pathology, even when vision has been completely lost. The retina is one of the most susceptible tissues to reactive oxygen species damage. On the other hand, proper development and functioning of the retina requires a precise balance between the processes of proliferation, differentiation and programmed cell death. The life-or-death decision seems to be the result of a complex balance between pro- and anti-apoptotic signals. It has been recently shown the efficacy of natural products to slow retinal degenerative process through different pathways. In this review, we assess the neuroprotective effect of two compounds used in the ancient pharmacopoeia. On one hand, it has been demonstrated that administration of the saffron constituent safranal to P23H rats, an animal model of retinitis pigmentosa, preserves photoreceptor morphology and number, the capillary network and the visual response. On the other hand, it has been shown that systemic administration of tauroursodeoxycholic acid (TUDCA), the major component of bear bile, to P23H rats preserves cone and rod structure and function, together with their contact with postsynaptic neurons. The neuroprotective effects of safranal and TUDCA make these compounds potentially useful for therapeutic applications in retinal degenerative diseases.
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Affiliation(s)
- Laura Fernández-Sánchez
- Departament of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain.
| | - Pedro Lax
- Departament of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain.
| | - Agustina Noailles
- Departament of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain.
| | - Antonia Angulo
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain.
| | - Victoria Maneu
- Department of Optics, Pharmacology and Anatomy, University of Alicante, 03690 Alicante, Spain.
| | - Nicolás Cuenca
- Departament of Physiology, Genetics and Microbiology, University of Alicante, 03690 Alicante, Spain.
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Liu C, Cao Y, Yang X, Shan P, Liu H. Tauroursodeoxycholic acid suppresses endoplasmic reticulum stress in the chondrocytes of patients with osteoarthritis. Int J Mol Med 2015; 36:1081-7. [PMID: 26238983 DOI: 10.3892/ijmm.2015.2295] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 06/26/2015] [Indexed: 11/06/2022] Open
Abstract
The main pathogenic events in osteoarthritis (OA) include loss and abnormal remodeling of cartilage extracellular matrix. The present study aimed to evaluate the protective effect of tauroursodeoxycholic acid on chondrocyte apoptosis induced by endoplasmic reticulum (ER) stress. Articular cartilage tissues were collected from 18 patients who underwent total knee arthroplasty and were analyzed histologically. Subsequently, chondrocyte apoptosis was assessed by TUNEL. Quantitative polymerase chain reaction and western blot analysis were employed to evaluate gene and protein expression, respectively, of ER stress markers, including glucose‑regulated protein 78 (GRP78), growth arrest and DNA‑damage‑inducible gene 153 (GADD153) and caspase‑12 along with type II collagen. Chondrocytes obtained from osteoarthritis patients at different stages were cultured in three conditions including: No treatment (CON group), tunicamycin treatment to induce ER stress (ERS group) and tauroursodeoxycholic acid treatment after 4 h of tunicamycin (TDA group); and cell proliferation, apoptosis, function and ER stress level were assessed. Degradation of cartilage resulted in histological damage with more apoptotic cartilage cells observed. Of note, GRP78, GADD153 and caspase‑12 mRNA and protein expression increased gradually from grade I to III cartilage tissue, while type II collagen expression decreased. Tunicamycin induced ER stress, as shown by a high expression of ER stress markers, reduced cell proliferation, increased apoptosis and decreased synthesis of type II collagen. Notably, tauroursodeoxycholic acid treatment resulted in the improvement of tunicamycin‑induced ER stress. These results indicated that ER stress is highly involved in the tunicamycin‑induced apoptosis in chondrocytes, which can be prevented by tauroursodeoxycholic acid.
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Affiliation(s)
- Chao Liu
- Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, P.R. China
| | - Yongping Cao
- Department of Orthopedics, Peking University First Hospital, Beijing 100034, P.R. China
| | - Xin Yang
- Department of Orthopedics, Peking University First Hospital, Beijing 100034, P.R. China
| | - Pengcheng Shan
- Department of Orthopedics, Peking University First Hospital, Beijing 100034, P.R. China
| | - Heng Liu
- Department of Orthopedics, Peking University First Hospital, Beijing 100034, P.R. China
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Zhu D, Deng Y, Pan Y, Wang Z, Yuan X, Guo X, Wang Y, Liu H. N-acetylcysteine Ameliorates the Erectile Dysfunction Caused by Chronic Intermittent Hypoxia in Rats: Partly Involvement of Endoplasmic Reticulum Stress. Urology 2015. [PMID: 26206453 DOI: 10.1016/j.urology.2015.07.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE To conduct a study using a rodent model of chronic intermittent hypoxia (CIH) to define whether endoplasmic reticulum stress (ERS) is involved in the CIH-induced apoptosis of penile tissue and erectile dysfunction (ED), and whether treatment with N-acetylcysteine (NAC) alleviates pathological variations in corpus cavernosa. Previous work has prompted that CIH acted as the major trigger linking obstructive sleep apnea syndrome and ED. MATERIALS AND METHODS Five-month-old Sprague-Dawley male rats were subjected to 8 hours of intermittent hypoxia per day, with or without NAC for 5 weeks. Erectile function, apoptosis of penile tissue, levels of ERS-associated proapoptotic effectors, and nitric oxide (NO) and nitric oxide synthase (NOS) activity were determined. RESULTS Treatment with NAC inhibited apoptosis of penile tissue, the expressions of ERS-related products: BIP, CHOP, caspase12, and Bax, NO, and endothelial NOS. Administration of NAC before CIH significantly improved the CIH-induced impaired erectile function. CONCLUSION Our results show that pre-CIH NAC administration ameliorates the ED following CIH partly by alleviating CIH-induced ERS and cell apoptosis via regulating the expressions of BIP, CHOP, caspase12, and Bax.
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Affiliation(s)
- Die Zhu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Deng
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yueying Pan
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhihua Wang
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao Yuan
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xueling Guo
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Wang
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huiguo Liu
- Department of Respiratory and Critical Care Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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Kim SK, Oh E, Yun M, Lee SB, Chae GT. Palmitate induces cisternal ER expansion via the activation of XBP-1/CCTα-mediated phospholipid accumulation in RAW 264.7 cells. Lipids Health Dis 2015; 14:73. [PMID: 26174230 PMCID: PMC4502558 DOI: 10.1186/s12944-015-0077-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 07/09/2015] [Indexed: 01/08/2023] Open
Abstract
Background Endoplasmic reticulum (ER) stress induces ER expansion. The expansion of the intracisternal space of the ER was found in macrophages associated with human atherosclerotic lesions. We also previously reported that palmitate induces cisternal ER expansion and necrosis in RAW 264.7 cells. In this study, we report on an investigation of the likely mechanism responsible for this palmitate-induced cisternal ER expansion in a mouse macrophage cell line, RAW 264.7 cells. Methods RAW 264.7 cells were pre-treated with the designated inhibitor or siRNA, followed by treatment with palmitate. Changes in the ER structure were examined by transmission electron microscopy. The induction of ER stress was confirmed by an increase in the extent of phosphorylation of PERK, the expression of BiP and CHOP, and the splicing of XBP-1 mRNA. Phospholipid staining was performed with the LipidTOX Red phospholipidosis detection reagent. Related gene expressions were detected by quantitative real time-RT-PCR or RT-PCR. Results Palmitate was found to induce ER stress and cisternal ER expansion. In addition, palmitate-induced cisternal ER expansion was attenuated by ER stress inhibitors, such as 4-phenylbutyric acid (4-PBA) and tauroursodeoxycholic acid (TUDCA). The findings also show that palmitate induced-mRNA expression of CCTα, which increases phospholipid synthesis, was attenuated by the down-regulation of XBP-1, a part of ER stress. Furthermore, palmitate-induced phospholipid accumulation and cisternal ER expansion were attenuated by the down-regulation of XBP-1 or CCTα. Conclusions The findings reported herein indicate that palmitate-induced cisternal ER expansion is dependent on the activation of XBP-1/CCTα-mediated phospholipid accumulation in RAW 264.7 cells.
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Affiliation(s)
- Seong Keun Kim
- Institute of Hansen's Disease, Department of Pathology, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea
| | - Eunhye Oh
- Institute of Hansen's Disease, Department of Pathology, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea
| | - Mihee Yun
- Institute of Hansen's Disease, Department of Pathology, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea
| | - Seong-Beom Lee
- Institute of Hansen's Disease, Department of Pathology, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea.
| | - Gue Tae Chae
- Institute of Hansen's Disease, Department of Pathology, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul, 137-701, Republic of Korea.
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135
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Passos E, Ascensão A, Martins MJ, Magalhães J. Endoplasmic Reticulum Stress Response in Non-alcoholic Steatohepatitis: The Possible Role of Physical Exercise. Metabolism 2015; 64:780-92. [PMID: 25838034 DOI: 10.1016/j.metabol.2015.02.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 02/11/2015] [Accepted: 02/17/2015] [Indexed: 02/06/2023]
Abstract
Sedentary lifestyle coupled with excessive consumption of high caloric food has been related to the epidemic increase of non-alcoholic fatty liver disease, which can progress from simple steatosis to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis and, eventually, may culminate in hepatocellular carcinoma. Although the precise mechanisms underlying the progression of NASH are not completely understood, endoplasmic reticulum (ER) dysfunction seems to play a key role in the process. Hepatic ER stress has been associated to hepatic steatosis, insulin resistance, inflammation, oxidative stress and hepatocyte death, contributing to liver dysfunction. Physical exercise seems to be the most effective preventive and therapeutic non-pharmacological strategy to mitigate several features related to NASH, possibly targeting most of the referred mechanisms associated with the pathophysiology of ER-related NASH. Nevertheless, little is known about the impact of physical exercise on NASH-related ER stress. In this review, we will discuss the ER stress associated to NASH conditions and highlight the possible benefits of physical exercise in the attenuation and/or reversion of NASH-related ER stress.
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Affiliation(s)
- Emanuel Passos
- Department of Biochemistry, Faculty of Medicine and Instituto de Investigação e Inovação em Saúde, University of Porto, Porto, Portugal; Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - António Ascensão
- Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - Maria João Martins
- Department of Biochemistry, Faculty of Medicine and Instituto de Investigação e Inovação em Saúde, University of Porto, Porto, Portugal
| | - José Magalhães
- Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal.
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136
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Kowal JM, Haanes KA, Christensen NM, Novak I. Bile acid effects are mediated by ATP release and purinergic signalling in exocrine pancreatic cells. Cell Commun Signal 2015; 13:28. [PMID: 26050734 PMCID: PMC4459444 DOI: 10.1186/s12964-015-0107-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/26/2015] [Indexed: 02/06/2023] Open
Abstract
Background In many cells, bile acids (BAs) have a multitude of effects, some of which may be mediated by specific receptors such the TGR5 or FXR receptors. In pancreas systemic BAs, as well as intra-ductal BAs from bile reflux, can affect pancreatic secretion. Extracellular ATP and purinergic signalling are other important regulators of similar secretory mechanisms in pancreas. The aim of our study was to elucidate whether there is interplay between ATP and BA signalling. Results Here we show that CDCA (chenodeoxycholic acid) caused fast and concentration-dependent ATP release from acini (AR42J) and duct cells (Capan-1). Taurine and glycine conjugated forms of CDCA had smaller effects on ATP release in Capan-1 cells. In duct monolayers, CDCA stimulated ATP release mainly from the luminal membrane; the releasing mechanisms involved both vesicular and non-vesicular secretion pathways. Duct cells were not depleted of intracellular ATP with CDCA, but acinar cells lost some ATP, as detected by several methods including ATP sensor AT1.03YEMK. In duct cells, CDCA caused reversible increase in the intracellular Ca2+ concentration [Ca2 +]i, which could be significantly inhibited by antagonists of purinergic receptors. The TGR5 receptor, expressed on the luminal side of pancreatic ducts, was not involved in ATP release and Ca2+ signals, but could stimulate Na+/Ca2+ exchange in some conditions. Conclusions CDCA evokes significant ATP release that can stimulate purinergic receptors, which in turn increase [Ca2+]i. The TGR5 receptor is not involved in these processes but can play a protective role at high intracellular Ca2+ conditions. We propose that purinergic signalling could be taken into consideration in other cells/organs, and thereby potentially explain some of the multifaceted effects of BAs. Electronic supplementary material The online version of this article (doi:10.1186/s12964-015-0107-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Justyna M Kowal
- Department of Biology, Section for Cell Biology and Physiology, August Krogh Building, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
| | - Kristian A Haanes
- Department of Biology, Section for Cell Biology and Physiology, August Krogh Building, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark. .,Present address: Department of Clinical Experimental Research, Glostrup Research Institute, Copenhagen University Hospital, Glostrup, Denmark.
| | - Nynne M Christensen
- Department of Biology, Section for Cell Biology and Physiology, August Krogh Building, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
| | - Ivana Novak
- Department of Biology, Section for Cell Biology and Physiology, August Krogh Building, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
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137
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Gomez-Cavazos JS, Hetzer MW. The nucleoporin gp210/Nup210 controls muscle differentiation by regulating nuclear envelope/ER homeostasis. ACTA ACUST UNITED AC 2015; 208:671-81. [PMID: 25778917 PMCID: PMC4362455 DOI: 10.1083/jcb.201410047] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The luminal domain of Nup210 that lacks NPC sorting signals is sufficient for myogenesis, which suggests that Nup210 may operate within the nuclear envelope/ER lumen during differentiation. Previously, we identified the nucleoporin gp210/Nup210 as a critical regulator of muscle and neuronal differentiation, but how this nucleoporin exerts its function and whether it modulates nuclear pore complex (NPC) activity remain unknown. Here, we show that gp210/Nup210 mediates muscle cell differentiation in vitro via its conserved N-terminal domain that extends into the perinuclear space. Removal of the C-terminal domain, which partially mislocalizes gp210/Nup210 away from NPCs, efficiently rescues the differentiation defect caused by the knockdown of endogenous gp210/Nup210. Unexpectedly, a gp210/Nup210 mutant lacking the NPC-targeting transmembrane and C-terminal domains is sufficient for C2C12 myoblast differentiation. We demonstrate that the endoplasmic reticulum (ER) stress-specific caspase cascade is exacerbated during Nup210 depletion and that blocking ER stress-mediated apoptosis rescues differentiation of Nup210-deficient cells. Our results suggest that the role of gp210/Nup210 in cell differentiation is mediated by its large luminal domain, which can act independently of NPC association and appears to play a pivotal role in the maintenance of nuclear envelope/ER homeostasis.
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Affiliation(s)
- J Sebastian Gomez-Cavazos
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037 Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Martin W Hetzer
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA 92037
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138
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Cheng S, Swanson K, Eliaz I, McClintick JN, Sandusky GE, Sliva D. Pachymic acid inhibits growth and induces apoptosis of pancreatic cancer in vitro and in vivo by targeting ER stress. PLoS One 2015; 10:e0122270. [PMID: 25915041 PMCID: PMC4411097 DOI: 10.1371/journal.pone.0122270] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 02/12/2015] [Indexed: 12/17/2022] Open
Abstract
Pachymic acid (PA) is a purified triterpene extracted from medicinal fungus Poria cocos. In this paper, we investigated the anticancer effect of PA on human chemotherapy resistant pancreatic cancer. PA triggered apoptosis in gemcitabine-resistant pancreatic cancer cells PANC-1 and MIA PaCa-2. Comparative gene expression array analysis demonstrated that endoplasmic reticulum (ER) stress was induced by PA through activation of heat shock response and unfolded protein response related genes. Induced ER stress was confirmed by increasing expression of XBP-1s, ATF4, Hsp70, CHOP and phospho-eIF2α. Moreover, ER stress inhibitor tauroursodeoxycholic acid (TUDCA) blocked PA induced apoptosis. In addition, 25 mg kg-1 of PA significantly suppressed MIA PaCa-2 tumor growth in vivo without toxicity, which correlated with induction of apoptosis and expression of ER stress related proteins in tumor tissues. Taken together, growth inhibition and induction of apoptosis by PA in gemcitabine-resistant pancreatic cancer cells were associated with ER stress activation both in vitro and in vivo. PA may be potentially exploited for the use in treatment of chemotherapy resistant pancreatic cancer.
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Affiliation(s)
- Shujie Cheng
- Cancer Research Laboratory, Methodist Research Institute, Indiana University Health, Indianapolis, Indiana, United States of America
| | - Kristen Swanson
- Cancer Research Laboratory, Methodist Research Institute, Indiana University Health, Indianapolis, Indiana, United States of America
| | - Isaac Eliaz
- Amitabha Medical Clinic and Healing Center, Santa Rosa, California, United States of America
| | - Jeanette N. McClintick
- Departments of Biochemistry and Molecular Biology, School of Medicine, Indiana University, Indianapolis, Indiana, United States of America
| | - George E. Sandusky
- Departments of Pathology, School of Medicine, Indiana University, Indianapolis, Indiana, United States of America
| | - Daniel Sliva
- Cancer Research Laboratory, Methodist Research Institute, Indiana University Health, Indianapolis, Indiana, United States of America
- Departments of Medicine, School of Medicine, Indiana University, Indianapolis, Indiana, United States of America
- DSTest Laboratories, Purdue Research Park, Indianapolis, Indiana, United States of America
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139
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Peng P, Ma Q, Wang L, Zhang O, Han H, Liu X, Zhou Y, Zhao Y. Preconditioning With Tauroursodeoxycholic Acid Protects Against Contrast-Induced HK-2 Cell Apoptosis by Inhibiting Endoplasmic Reticulum Stress. Angiology 2015; 66:941-9. [DOI: 10.1177/0003319715575965] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To investigate whether tauroursodeoxycholic acid (TUDCA) could attenuate contrast media (CM)-induced renal tubular cell apoptosis by inhibiting endoplasmic reticulum stress (ERS), we exposed HK-2 cells to increasing doses of meglumine diatrizoate (20, 40, and 80 mg I/mL) for 2 to 16 hours, with/without TUDCA preconditioning for 24 hours. Cell viability test, Hoechst 33258 staining, and flow cytometry were used to detect meglumine diatrizoate-induced cell apoptosis, while real-time polymerase chain reaction and Western blot analysis were used to measure the expressions of ERS markers of glucose-regulated protein 78 (GRP78), activating transcription factor 4 (ATF4), and the apoptosis-related marker of caspase 12. Cell apoptosis and messenger RNA (mRNA) expression of GRP78 ( P = .005), ATF4 ( P = .01), and caspase 12 ( P = .001) were significantly higher in the CM 4 hours group than the control as well as the protein expressions. The TUDCA preconditioning reduced the mRNA expression of GRP78, ATF4, and caspase 12 in the CM 4 hours groups ( P = .009, .019, and .003, respectively) as well as the protein expression. In conclusion, TUDCA could protect renal tubular cells from meglumine diatrizoate-induced apoptosis by inhibiting ERS.
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Affiliation(s)
- Pingan Peng
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, The Key Laboratory of Remodeling-related Cardiovascular Disease, Ministry of Education, Beijing, China
| | - Qian Ma
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, The Key Laboratory of Remodeling-related Cardiovascular Disease, Ministry of Education, Beijing, China
| | - Le Wang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, The Key Laboratory of Remodeling-related Cardiovascular Disease, Ministry of Education, Beijing, China
| | - Ou Zhang
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, The Key Laboratory of Remodeling-related Cardiovascular Disease, Ministry of Education, Beijing, China
| | - Hongya Han
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, The Key Laboratory of Remodeling-related Cardiovascular Disease, Ministry of Education, Beijing, China
| | - Xiaoli Liu
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, The Key Laboratory of Remodeling-related Cardiovascular Disease, Ministry of Education, Beijing, China
| | - Yujie Zhou
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, The Key Laboratory of Remodeling-related Cardiovascular Disease, Ministry of Education, Beijing, China
| | - Yingxin Zhao
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing Institute of Heart Lung and Blood Vessel Disease, The Key Laboratory of Remodeling-related Cardiovascular Disease, Ministry of Education, Beijing, China
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Chiu HW, Xia T, Lee YH, Chen CW, Tsai JC, Wang YJ. Cationic polystyrene nanospheres induce autophagic cell death through the induction of endoplasmic reticulum stress. NANOSCALE 2015; 7:736-46. [PMID: 25429417 DOI: 10.1039/c4nr05509h] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Nanoparticles (NPs) have been used to produce a wide range of products that have applications in imaging and drug delivery in medicine. Due to their chemical stability, well-controlled sizes and surface charges, polystyrene (PS) NPs have been developed as biosensors and drug delivery carriers. However, the possible adverse biological effects and underlying mechanisms are still unclear. Recently, autophagy has been implicated in the regulation of cell death. In this study, we evaluated a library of PS NPs with different surface charges. We found that NH2-labeled polystyrene (NH2-PS) nanospheres were highly toxic with enhanced uptake in macrophage (RAW 264.7) and lung epithelial (BEAS-2B) cells. Furthermore, NH2-PS could induce autophagic cell death. NH2-PS increased autophagic flux due to reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress caused by misfolded protein aggregation. The inhibition of ER stress decreased cytotoxicity and autophagy in the NH2-PS-treated cells. In addition, the Akt/mTOR and AMPK signaling pathways were involved in the regulation of NH2-PS-triggered autophagic cell death. These results suggest an important role of autophagy in cationic NP-induced cell death and provide mechanistic insights into the inhibition of the toxicity and safe material design.
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Affiliation(s)
- Hui-Wen Chiu
- Department of Environmental and Occupational Health, National Cheng Kung University, Tainan, Taiwan.
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141
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Guo Q, Shi Q, Li H, Liu J, Wu S, Sun H, Zhou B. Glycolipid Metabolism Disorder in the Liver of Obese Mice Is Improved by TUDCA via the Restoration of Defective Hepatic Autophagy. Int J Endocrinol 2015; 2015:687938. [PMID: 26681941 PMCID: PMC4668323 DOI: 10.1155/2015/687938] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 10/24/2015] [Accepted: 11/01/2015] [Indexed: 12/16/2022] Open
Abstract
Objective. Tauroursodeoxycholic acid (TUDCA) has been considered an important regulator of energy metabolism in obesity. However, the mechanism underlying how TUDCA is involved in insulin resistance is not fully understood. We tested the effects of TUDCA on autophagic dysfunction in obese mice. Material and Methods. 500 mg/kg of TUDCA was injected into obese mice, and metabolic parameters, autophagy markers, and insulin signaling molecular were assessed by Western blotting and real-time PCR. Results. The TUDCA injections in the obese mice resulted in a reduced body weight gain, lower blood glucose, and improved insulin sensitivity compared with obese mice that were injected with vehicle. Meanwhile, TUDCA treatment not only reversed autophagic dysfunction and endoplasmic reticulum stress, but also improved the impaired insulin signaling in the liver of obese mice. Additionally, the same results obtained with TUDCA were evident in obese mice treated with the adenoviral Atg7. Conclusions. We found that TUDCA reversed abnormal autophagy, reduced ER stress, and restored insulin sensitivity in the liver of obese mice and that glycolipid metabolism disorder was also improved via the restoration of defective hepatic autophagy.
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Affiliation(s)
- Qinyue Guo
- Critical Care Medicine, The First Affiliated Hospital of Medical School of Xi'an Jiaotong University, 277 Yanta West Street, Xi'an, Shaanxi 710061, China
| | - Qindong Shi
- Critical Care Medicine, The First Affiliated Hospital of Medical School of Xi'an Jiaotong University, 277 Yanta West Street, Xi'an, Shaanxi 710061, China
| | - Huixia Li
- Key Laboratory of Environment and Genes Related to Diseases, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Jiali Liu
- Key Laboratory of Environment and Genes Related to Diseases, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Shufang Wu
- Center for Translational Medicine, The First Affiliated Hospital of Medical School of Xi'an Jiaotong University, 277 Yanta West Street, Xi'an, Shaanxi 710061, China
| | - Hongzhi Sun
- Key Laboratory of Environment and Genes Related to Diseases, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
- *Hongzhi Sun: and
| | - Bo Zhou
- Department of Respiratory, The First Affiliated Hospital of Medical School of Xi'an Jiaotong University, 277 Yanta West Street, Xi'an, Shaanxi 710061, China
- *Bo Zhou:
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142
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Liu Z, Xia Y, Li B, Xu H, Wang C, Liu Y, Li Y, Li C, Gao N, Li L. Induction of ER stress-mediated apoptosis by ceramide via disruption of ER Ca(2+) homeostasis in human adenoid cystic carcinoma cells. Cell Biosci 2014; 4:71. [PMID: 25937892 PMCID: PMC4417540 DOI: 10.1186/2045-3701-4-71] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 11/15/2014] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Ceramides are a class of sphingolipids that form the structural component of the cell membrane and also act as second messengers in cell signaling pathways. Emerging results suggest that ceramide induces growth arrest and apoptosis in various human cancer cells. However, the mechanisms underlying its antitumor activity are yet to be identified. Endoplasmic reticulum stress (ER stress), a cellular adaptive response, is believed to initially compensate for damage but can eventually trigger cell death if the stimulus is severe or prolonged. In this study, we investigated whether ceramide induces cell death in human salivary adenoid cystic carcinoma (ACCs) through activation of the apoptotic ER stress. RESULTS RT-PCR, real-time PCR and western blot demonstrated that exogenous ceramide treatment up-regulated GRP78 and p-eIF2α expression and XBP1 splicing. Moreover, the ceramide synthase inhibitor FB1 abolished ceramide-induced ER stress. Up-regulation of the ER stress-associated apoptosis promoting transcription factor CHOP and p-JNK suggested that the antitumor activity of ceramide is owing to activation of apoptotic ER stress. Mechanistically, [Ca(2+)]ER depletion and SERCA inhibition by ceramide treatment suggested that it induces ER stress by disrupting [Ca(2+)]ER homeostasis. The chemical chaperone TUDCA inhibited ceramide-induced ER stress and cell death. In addition, the downstream metabolite of ceramide, S1P, cannot activate ER stress. CONCLUSIONS These results demonstrated that exogenous ceramide induces cancer cell death through a mechanism involving severe ER stress triggered by the disruption of ER Ca(2+) homeostasis.
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Affiliation(s)
- Zhe Liu
- Department of Head and Neck Oncology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China ; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Yichao Xia
- Department of Head and Neck Oncology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China ; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Bo Li
- Department of Head and Neck Oncology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China ; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Hui Xu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Chenxing Wang
- Department of Head and Neck Oncology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China ; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Ying Liu
- Department of Head and Neck Oncology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China ; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Yi Li
- Department of Head and Neck Oncology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China ; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Chunjie Li
- Department of Head and Neck Oncology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China ; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Ning Gao
- Department of Head and Neck Oncology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China ; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Longjiang Li
- Department of Head and Neck Oncology, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China ; State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
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143
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Li X, Wang Y, Wang H, Huang C, Huang Y, Li J. Endoplasmic reticulum stress is the crossroads of autophagy, inflammation, and apoptosis signaling pathways and participates in liver fibrosis. Inflamm Res 2014; 64:1-7. [PMID: 25286903 DOI: 10.1007/s00011-014-0772-y] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 09/17/2014] [Accepted: 09/18/2014] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVE The objective of the review is to examine the crossroads of autophagy, inflammation, and apoptosis signaling pathways and their participation in liver fibrosis. INTRODUCTION Endoplasmic reticulum (ER) stress was emerged as a common feature relevant to the pathogenesis of diseases associated with organ fibrosis. However, the functional consequences of these alterations on ER stress and the possible involvement in liver fibrosis were currently largely unexplored. Here, we will survey the recent literature in the field and discuss recent insights focusing on some cellular models expressing mutant proteins involved in liver fibrosis. METHODS A computer-based online search with PubMed, Scopus and Web of Science databases was performed for articles published, concerning ER stress, adaptation, inflammation and apoptosis with relevance to liver fibrosis. RESULTS AND CONCLUSIONS Progression of liver fibrosis requires sustained inflammation leading to hepatocytes apoptosis through ER stress, whereas associated with activation of hepatic stellate cells (HSCs) into a fibrogenic and proliferative cell type. Faced with persistent and massive ER stress, HSCs adaptation starts to fail and apoptosis occurs in reversal of liver fibrosis, possibly mediated through calcium perturbations, unfolded protein response, and the pro-apoptotic transcription factor CHOP. Although limited in scope, current studies underscored that ER stress is tightly linked to adaptation, inflammation and apoptosis, and recent evidences suggested that these processes are related to the pathogenesis of liver fibrosis and its recovery.
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Affiliation(s)
- Xiaohui Li
- Department of Pharmacy, The People's Hospital of Bozhou, Bozhou, 236800, China
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144
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van der Harg JM, Nölle A, Zwart R, Boerema AS, van Haastert ES, Strijkstra AM, Hoozemans JJ, Scheper W. The unfolded protein response mediates reversible tau phosphorylation induced by metabolic stress. Cell Death Dis 2014; 5:e1393. [PMID: 25165879 PMCID: PMC4454326 DOI: 10.1038/cddis.2014.354] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/11/2014] [Accepted: 07/23/2014] [Indexed: 01/01/2023]
Abstract
The unfolded protein response (UPR) is activated in neurodegenerative tauopathies such as Alzheimer's disease (AD) in close connection with early stages of tau pathology. Metabolic disturbances are strongly associated with increased risk for AD and are a potent inducer of the UPR. Here, we demonstrate that metabolic stress induces the phosphorylation of endogenous tau via activation of the UPR. Strikingly, upon restoration of the metabolic homeostasis, not only the levels of the UPR markers pPERK, pIRE1α and BiP, but also tau phosphorylation are reversed both in cell models as well as in torpor, a physiological hypometabolic model in vivo. Intervention in the UPR using the global UPR inhibitor TUDCA or a specific small-molecule inhibitor of the PERK signaling pathway, inhibits the metabolic stress-induced phosphorylation of tau. These data support a role for UPR-mediated tau phosphorylation as part of an adaptive response to metabolic stress. Failure to restore the metabolic homeostasis will lead to prolonged UPR activation and tau phosphorylation, and may thus contribute to AD pathogenesis. We demonstrate that the UPR is functionally involved in the early stages of tau pathology. Our data indicate that targeting of the UPR may be employed for early intervention in tau-related neurodegenerative diseases.
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Affiliation(s)
- J M van der Harg
- Department of Genome Analysis, Academic Medical Center, Amsterdam, The Netherlands
| | - A Nölle
- Department of Genome Analysis, Academic Medical Center, Amsterdam, The Netherlands
| | - R Zwart
- Department of Genome Analysis, Academic Medical Center, Amsterdam, The Netherlands
| | - A S Boerema
- Units of Chronobiology and Molecular Neurobiology, Center for Behaviour and Neurosciences, University of Groningen, Groningen, The Netherlands
| | - E S van Haastert
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - A M Strijkstra
- Units of Chronobiology and Molecular Neurobiology, Center for Behaviour and Neurosciences, University of Groningen, Groningen, The Netherlands
| | - J Jm Hoozemans
- Department of Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
| | - W Scheper
- 1] Department of Genome Analysis, Academic Medical Center, Amsterdam, The Netherlands [2] Department of Clinical Genetics and Alzheimer Center, VU University Medical Center, Amsterdam, The Netherlands [3] Departments of Functional Genomics and Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, Amsterdam, The Netherlands
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145
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Cho EJ, Yoon JH, Kwak MS, Jang ES, Lee JH, Yu SJ, Kim YJ, Kim CY, Lee HS. Tauroursodeoxycholic acid attenuates progression of steatohepatitis in mice fed a methionine-choline-deficient diet. Dig Dis Sci 2014; 59:1461-74. [PMID: 24865256 DOI: 10.1007/s10620-014-3217-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 05/13/2014] [Indexed: 12/30/2022]
Abstract
BACKGROUND AND AIM Endoplasmic reticulum (ER) stress has been implicated in the development of nonalcoholic steatohepatitis. A methionine-choline-deficient (MCD) diet induces robust ER stress response and steatohepatitis, but the effects of ER stress modulation on the course of steatohepatitis remain uncertain. The present study evaluated whether reducing ER stress using the chemical chaperone tauroursodeoxycholic acid (TUDCA) could limit hepatocyte lipoapoptosis and progression of MCD diet-induced steatohepatitis. METHODS HuH7 cells stably transfected with sodium taurocholate cotransporting polypeptide (HuH-Ntcp cells) and palmitate (PA) were used. Experimental steatohepatitis was induced in male C57BL/6 mice using an MCD diet, and three different doses of TUDCA (500, or 1,000 mg/kg, once daily; or 500 mg/kg twice daily) were administered by gavage from the start of the MCD diet regimen or after 4 weeks. RESULTS TUDCA reduced PA-induced ER stress as manifested by decreased eIF2α phosphorylation, XBP1 splicing and expression of BiP, ATF4, and CHOP in HuH-Ntcp cells. TUDCA also decreased PA-induced JNK phosphorylation, Puma up-regulation and Bax activation, which in turn suppressed caspase-dependent hepatocyte lipoapoptosis. Mice given TUDCA did not show a significant decrease in the intrahepatic triglyceride contents and steatosis. However, TUDCA treatment significantly reduced hepatic damage compared to controls for both early and late treatment groups. TUDCA treatment reduced the expression of ER stress markers and pro-apoptotic proteins, leading to decreased apoptosis and oxidative stress. Finally, TUDCA reduced histological fibrosis along with the down-regulation of pro-fibrotic gene expression in both early and late treatment groups. CONCLUSIONS These results show that TUDCA attenuates the progression of MCD diet-induced steatohepatitis by reducing ER stress.
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Affiliation(s)
- Eun-Ju Cho
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, Korea
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146
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Palsamy P, Bidasee KR, Ayaki M, Augusteyn RC, Chan JY, Shinohara T. Methylglyoxal induces endoplasmic reticulum stress and DNA demethylation in the Keap1 promoter of human lens epithelial cells and age-related cataracts. Free Radic Biol Med 2014; 72:134-48. [PMID: 24746615 PMCID: PMC4410980 DOI: 10.1016/j.freeradbiomed.2014.04.010] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 04/03/2014] [Accepted: 04/08/2014] [Indexed: 01/03/2023]
Abstract
Age-related cataracts are a leading cause of blindness. Previously, we have demonstrated the association of the unfolded protein response with various cataractogenic stressors. However, DNA methylation alterations leading to suppression of lenticular antioxidant protection remains unclear. Here, we report the methylglyoxal-mediated sequential events responsible for Keap1 promoter DNA demethylation in human lens epithelial cells, because Keap1 is a negative regulatory protein that regulates the Nrf2 antioxidant protein. Methylglyoxal induces endoplasmic reticulum stress and activates the unfolded protein response leading to overproduction of reactive oxygen species before human lens epithelial cell death. Methylglyoxal also suppresses Nrf2 and DNA methyltransferases but activates the DNA demethylation pathway enzyme TET1. Bisulfite genomic DNA sequencing confirms the methylglyoxal-mediated Keap1 promoter DNA demethylation leading to overexpression of Keap1 mRNA and protein. Similarly, bisulfite genomic DNA sequencing shows that human clear lenses (n = 15) slowly lose 5-methylcytosine in the Keap1 promoter throughout life, at a rate of 1% per year. By contrast, diabetic cataractous lenses (n = 21) lose an average of 90% of the 5-methylcytosine regardless of age. Overexpressed Keap1 protein is responsible for decreasing Nrf2 by proteasomal degradation, thereby suppressing Nrf2-dependent stress protection. This study demonstrates for the first time the associations of unfolded protein response activation, Nrf2-dependent antioxidant system failure, and loss of Keap1 promoter methylation because of altered active and passive DNA demethylation pathway enzymes in human lens epithelial cells by methylglyoxal. As an outcome, the cellular redox balance is altered toward lens oxidation and cataract formation.
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Affiliation(s)
- Periyasamy Palsamy
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Keshore R Bidasee
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Masahiko Ayaki
- Department of Ophthalmology, Keio University, Tokyo 1698582, Japan
| | - Robert C Augusteyn
- Vision Cooperative Research Centre, Brien Holden Vision Institute, Sydney 2052, Australia; Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Jefferson Y Chan
- Department of Laboratory Medicine and Pathology, University of California at Irvine, Irvine, CA 92697, USA
| | - Toshimichi Shinohara
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA.
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147
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Chen C, Cano M, Wang JJ, Li J, Huang C, Yu Q, Herbert TP, Handa JT, Zhang SX. Role of unfolded protein response dysregulation in oxidative injury of retinal pigment epithelial cells. Antioxid Redox Signal 2014; 20:2091-106. [PMID: 24053669 PMCID: PMC3995121 DOI: 10.1089/ars.2013.5240] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
AIMS Age-related macular degeneration (AMD), a major cause of legal blindness in the elderly, is associated with genetic and environmental risk factors, such as cigarette smoking. Recent evidence shows that cigarette smoke (CS) that contains high levels of potent oxidants preferably targets retinal pigment epithelium (RPE) leading to oxidative damage and apoptosis; however, the mechanisms are poorly understood. The present study aimed to investigate the role of endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) in CS-related RPE apoptosis. RESULTS ER stress and proapoptotic gene C/EBP homologous protein (CHOP) were induced in the RPE/choroid complex from mice exposed to CS for 2 weeks and in human RPE cells treated with hydroquinone, a potent oxidant found at high concentrations in CS. Suppressing ER stress or inhibiting CHOP activation by pharmacological chaperones or genetic approaches attenuated hydroquinone-induced RPE cell apoptosis. In contrast to enhanced CHOP activation, protein level of active X-box binding protein 1 (XBP1), a major regulator of the adaptive UPR, was reduced in hydroquinone-treated cells. Conditional knockout of XBP1 gene in the RPE resulted in caspase-12 activation, increased CHOP expression, and decreased antiapoptotic gene Bcl-2. Furthermore, XBP1-deficient RPE cells are more sensitive to oxidative damage induced by hydroquinone or NaIO3, a CS-unrelated chemical oxidant. Conversely, overexpressing XBP1 protected RPE cells and attenuated oxidative stress-induced RPE apoptosis. INNOVATION AND CONCLUSION These findings provide strong evidence suggesting an important role of ER stress and the UPR in CS-related oxidative injury of RPE cells. Thus, the modulation of the UPR signaling may provide a promising target for the treatment of AMD.
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Affiliation(s)
- Chen Chen
- 1 Department of Ophthalmology/Ross Eye Institute, University at Buffalo, The State University of New York , Buffalo, New York
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148
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Mitzel DN, Lowry V, Shirali AC, Liu Y, Stout-Delgado HW. Age-enhanced endoplasmic reticulum stress contributes to increased Atg9A inhibition of STING-mediated IFN-β production during Streptococcus pneumoniae infection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2014; 192:4273-83. [PMID: 24670807 PMCID: PMC4007355 DOI: 10.4049/jimmunol.1303090] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Pneumococcal infections remain a leading cause of death in persons ≥ 65 y of age. Recent reports have illustrated detrimental changes in the endoplasmic reticulum stress response or unfolded protein response in aging and age-related diseases; however, the relationship between aging, the unfolded protein response, and innate immune responses to Streptococcus pneumoniae has not been fully elucidated. Our results illustrate that stimulator of IFN genes-mediated production of IFN-β during S. pneumoniae infection is decreased in aged hosts. Enhanced endoplasmic reticulum stress in response to S. pneumoniae augmented inositol-requiring protein 1/X-box binding protein 1-mediated production of autophagy-related gene 9 (Atg9a). Knockdown of Atg9a or treatment with gemcitabine HCl resulted in enhanced stimulator of IFN genes-mediated production of IFN-β by aged macrophages. Consecutive treatments with gemcitabine during in vivo S. pneumoniae infection decreased morbidity and mortality in aged hosts, which was associated with decreased Atg9a expression, increased IFN-β production, and improved bacterial clearance from lung tissue. Taken together, data presented in this study provide new evidence as to why older persons are more susceptible to S. pneumoniae, and provide a possible mechanism to enhance these responses, thereby decreasing morbidity and mortality in this population.
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Affiliation(s)
- Dana N Mitzel
- Animal Biosafety Level 3 Management Support, Lovelace Respiratory Research Institute, Albuquerque, NM 87108
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149
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Chao CC, Chan P, Kuo CS, Gong CL, Cheng TH, Liu ZM, Shen PC, Huang CC, Leung YM. Protection of differentiated neuronal NG108-15 cells from P2X7 receptor-mediated toxicity by taurine. Pharmacol Rep 2014; 66:576-84. [PMID: 24948057 DOI: 10.1016/j.pharep.2014.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 01/07/2014] [Accepted: 01/13/2014] [Indexed: 01/23/2023]
Abstract
BACKGROUND Strong P2X7 receptor (P2X7R) activation causes Ca(2+) overload and consequent cell death. We previously showed that depletion of Ca(2+) stores and endoplasmic reticulum (ER) stress in differentiated NG108-15 neuronal cells contributed to P2X7R-mediated cytotoxicity. In this work, we assessed whether taurine (2-aminoethanesulfonic acid) could prevent this P2X7R-mediated cytotoxicity in this neuronal cell line. METHODS Cytotoxicity markers were assessed by MTT assay and Western blotting. Cytosolic Ca(2+) and mitochondrial Ca(2+) concentrations were measured microfluorimetrically using fura-2 and rhod-2, respectively. Intracellular reactive oxygen species (ROS) production was assayed by the indicator 2',7'-dichlorodihydrofluorescein diacetate. RESULTS Selective P2X7R agonist BzATP treatment causes neuronal cell death by causing cytosolic Ca(2+) overload, depletion of Ca(2+) stores, endoplasmic reticulum (ER) stress, and caspase-3 activation (cleaved caspase 3). Remarkably, taurine (10mM) pretreatment could prevent P2X7R-mediated neuronal cell death by blocking BzATP-mediated ER stress as determined by phosphorylated eukaryotic translation initiation factor 2α (peIF2α) and C/EBP-homologous protein (CHOP). However, taurine did not block BzATP-induced Ca(2+) overload and depletion of ER Ca(2+) stores. Interestingly, P2X7R activation did not result in mitochondrial Ca(2+) overload, nor did it affect mitochondrial membrane potential. BzATP-induced generation of intracellular reactive oxygen species (ROS) was prevented by taurine. CONCLUSIONS The neuroprotective effect by taurine is attributed to the suppression of P2X7R-mediated ER stress and ROS formation.
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Affiliation(s)
- Chia-Chia Chao
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang Hospital, Taipei, Taiwan
| | - Chang-Shin Kuo
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan
| | - Chi-Li Gong
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Tzu-Hurng Cheng
- Department of Biological Sciences and Technology, China Medical University, Taichung, Taiwan
| | - Zhong-Min Liu
- Department of Cardiovascular Surgery, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Pei-Chen Shen
- Department of Cardiology, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.
| | - Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan.
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150
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Reduced IRE1α mediates apoptotic cell death by disrupting calcium homeostasis via the InsP3 receptor. Cell Death Dis 2014; 5:e1188. [PMID: 24743743 PMCID: PMC4001297 DOI: 10.1038/cddis.2014.129] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 01/28/2014] [Accepted: 02/27/2014] [Indexed: 02/07/2023]
Abstract
The endoplasmic reticulum (ER) is not only a home for folding and posttranslational modifications of secretory proteins but also a reservoir for intracellular Ca(2+). Perturbation of ER homeostasis contributes to the pathogenesis of various neurodegenerative diseases, such as Alzheimer's and Parkinson diseases. One key regulator that underlies cell survival and Ca(2+) homeostasis during ER stress responses is inositol-requiring enzyme 1α (IRE1α). Despite extensive studies on this ER membrane-associated protein, little is known about the molecular mechanisms by which excessive ER stress triggers cell death and Ca(2+) dysregulation via the IRE1α-dependent signaling pathway. In this study, we show that inactivation of IRE1α by RNA interference increases cytosolic Ca(2+) concentration in SH-SY5Y cells, leading to cell death. This dysregulation is caused by an accelerated ER-to-cytosolic efflux of Ca(2+) through the InsP3 receptor (InsP3R). The Ca(2+) efflux in IRE1α-deficient cells correlates with dissociation of the Ca(2+)-binding InsP3R inhibitor CIB1 and increased complex formation of CIB1 with the pro-apoptotic kinase ASK1, which otherwise remains inactivated in the IRE1α-TRAF2-ASK1 complex. The increased cytosolic concentration of Ca(2+) induces mitochondrial production of reactive oxygen species (ROS), in particular superoxide, resulting in severe mitochondrial abnormalities, such as fragmentation and depolarization of membrane potential. These Ca(2+) dysregulation-induced mitochondrial abnormalities and cell death in IRE1α-deficient cells can be blocked by depleting ROS or inhibiting Ca(2+) influx into the mitochondria. These results demonstrate the importance of IRE1α in Ca(2+) homeostasis and cell survival during ER stress and reveal a previously unknown Ca(2+)-mediated cell death signaling between the IRE1α-InsP3R pathway in the ER and the redox-dependent apoptotic pathway in the mitochondrion.
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