101
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Yu M, Kang K, Bu P, Bell BA, Kaul C, Qiao JB, Sturgill-Short G, Yu X, Tarchick MJ, Beight C, Zhang SX, Peachey NS. Deficiency of CC chemokine ligand 2 and decay-accelerating factor causes retinal degeneration in mice. Exp Eye Res 2015; 138:126-33. [PMID: 26149093 DOI: 10.1016/j.exer.2015.05.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Revised: 05/22/2015] [Accepted: 05/25/2015] [Indexed: 12/15/2022]
Abstract
CC chemokine ligand 2 (CCL2) recruits macrophages to reduce inflammatory responses. Decay-accelerating factor (DAF) is a membrane regulator of the classical and alternative pathways of complement activation. In view of the link between complement genes and retinal diseases, we evaluated the retinal phenotype of C57BL/6J mice and mice lacking Ccl2 and/or Daf1 at 12 months of age, using scanning laser ophthalmoscopic imaging, electroretinography (ERG), histology, immunohistochemistry, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analysis. In comparison to C57BL/6J mice, mutant mice had an increased number of autofluorescent foci, with the greatest number in the Ccl2(-/-)/Daf1(-/-) retina. ERG amplitudes in Ccl2(-/-)/Daf1(-/-), Ccl2(-/-) and Daf1(-/-) mice were reduced, with the greatest reduction in Ccl2(-/-)/Daf1(-/-) mice. TUNEL-positive cells were not seen in C57BL/6J retina, but were prevalent in the outer and inner nuclear layers of Ccl2(-/-)Daf1(-/-) mice and were present at reduced density in Ccl2(-/-) or Daf1(-/-) mice. Cell loss was most pronounced in the outer and inner nuclear layers of Ccl2(-/-)/Daf1(-/-) mice. The levels of the endoplasmic reticulum chaperone GPR78 and transcription factor ATF4 were significantly increased in the Ccl2(-/-)/Daf1(-/-) retina. In comparison to the C57BL/6J retina, the phosphorylation of NF-κB p65, p38, ERK and JNK was significantly upregulated while SIRT1 was significantly downregulated in the Ccl2(-/-)/Daf1(-/-) retina. Our results suggest that loss of Ccl2 and Daf1 causes retinal neuronal death and degeneration which is related to increased endoplasmic reticulum stress, oxidative stress and inflammation.
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Affiliation(s)
- Minzhong Yu
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA; Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA.
| | - Kai Kang
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Ping Bu
- Department of Ophthalmology, Loyola University Chicago, Maywood, IL, USA
| | - Brent A Bell
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Charles Kaul
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - James B Qiao
- Department of Ophthalmology, Loyola University Chicago, Maywood, IL, USA
| | - Gwen Sturgill-Short
- Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Xiaoshan Yu
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Matthew J Tarchick
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, USA
| | - Craig Beight
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Sarah X Zhang
- Departments of Ophthalmology and Biochemistry, SUNY-Buffalo and SUNY Eye Institute, Buffalo, NY, USA
| | - Neal S Peachey
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA; Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA; Research Service, Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, OH, USA
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Wu Y, Wang F, Reece EA, Yang P. Curcumin ameliorates high glucose-induced neural tube defects by suppressing cellular stress and apoptosis. Am J Obstet Gynecol 2015; 212:802.e1-8. [PMID: 25595578 DOI: 10.1016/j.ajog.2015.01.017] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 12/20/2014] [Accepted: 01/08/2015] [Indexed: 02/07/2023]
Abstract
OBJECTIVE Curcumin is a naturally occurring polyphenol present in the roots of the Curcuma longa plant (turmeric), which possesses antioxidant, antitumorigenic, and antiinflammatory properties. Here, we test whether curcumin treatment reduces high glucose-induced neural tube defects (NTDs), and if this occurs via blocking cellular stress and caspase activation. STUDY DESIGN Embryonic day 8.5 mouse embryos were collected for use in whole-embryo culture under normal (100 mg/dL) or high (300 mg/dL) glucose conditions, with or without curcumin treatment. After 24 hours in culture, protein levels of oxidative stress makers, nitrosative stress makers, endoplasmic reticulum (ER) stress makers, cleaved caspase 3 and 8, and the level of lipid peroxides were determined in the embryos. After 36 hours in culture, embryos were examined for evidence of NTD formation. RESULTS Although 10 μmol/L of curcumin did not significantly reduce the rate of NTDs caused by high glucose, 20 μmol/L of curcumin significantly ameliorated high glucose-induced NTD formation. Curcumin suppressed oxidative stress in embryos cultured under high glucose conditions. Treatment reduced the levels of the lipid peroxidation marker, 4-hydroxynonenal, nitrotyrosine-modified protein, and lipid peroxides. Curcumin also blocked ER stress by inhibiting phosphorylated protein kinase RNA-like ER kinase, phosphorylated inositol-requiring protein-1α (p-IRE1α), phosphorylated eukaryotic initiation factor 2α (p-eIF2α), C/EBP-homologous protein, binding immunoglobulin protein, and x-box binding protein 1 messenger RNA splicing. Additionally, curcumin abolished caspase 3 and caspase 8 cleavage in embryos cultured under high glucose conditions. CONCLUSION Curcumin reduces high glucose-induced NTD formation by blocking cellular stress and caspase activation, suggesting that curcumin supplements could reduce the negative effects of diabetes on the embryo. Further investigation will be needed to determine if the experimental findings can translate into clinical settings.
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103
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Khan MJ, Jacometo CB, Vailati Riboni M, Trevisi E, Graugnard DE, Corrêa MN, Loor JJ. Stress and inflammatory gene networks in bovine liver are altered by plane of dietary energy during late pregnancy. Funct Integr Genomics 2015; 15:563-76. [DOI: 10.1007/s10142-015-0443-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 04/07/2015] [Accepted: 04/20/2015] [Indexed: 01/26/2023]
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104
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Boriushkin E, Wang JJ, Li J, Jing G, Seigel GM, Zhang SX. Identification of p58IPK as a novel neuroprotective factor for retinal neurons. Invest Ophthalmol Vis Sci 2015; 56:1374-86. [PMID: 25655802 DOI: 10.1167/iovs.14-15196] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
PURPOSE Endoplasmic reticulum (ER)-resident chaperone protein p58(IPK) plays a vital role in regulation of protein folding and biosynthesis. The goal of this study was to examine the role of p58(IPK) in retinal neuronal cells under normal and stressed conditions. METHODS Retinal expression of p58(IPK), retinal morphology, apoptosis, ER stress, and apoptotic gene expression were examined in p58(IPK) knockout (KO) and/or wild-type (WT) mice with or without intravitreal injection of N-methyl-D-aspartic acid (NMDA). In in vitro experiments, differentiated R28 retinal neuronal cells transduced with adenovirus encoding p58(IPK) (Ad-p58(IPK)) or control virus (Ad-LacZ) were exposed to tunicamycin (TM) or hydrogen peroxide (H2O2). Levels of ER stress, apoptosis, and cell survival were evaluated. RESULTS Chaperone protein p58(IPK) is expressed predominantly in retinal ganglion cells (RGC), inner retinal neurons, and the photoreceptor inner segments. Mice lacking p58(IPK) exhibited increased CHOP expression and loss of RGCs with aging (8-10 months). Intravitreal injection of NMDA induced retinal ER stress and increased p58(IPK) expression in WT mice; this resulted in greater ER stress and enhanced RGC apoptosis in p58(IPK) KO mice. In cultured R28 cells, overexpression of p58(IPK) significantly reduced eIF2α phosphorylation, decreased CHOP expression, and alleviated the activation of caspase-3 and PARP. Overexpression of p58(IPK) also protected against oxidative and ER stress-induced cell apoptosis. Furthermore, p58(IPK) downregulated the proapoptotic gene Bax and upregulated the antiapoptotic gene Bcl-2 expression in stressed R28 cells. CONCLUSIONS Our study has demonstrated a protective role of p58(IPK) in retinal neurons, which may act in part through a mechanism involving modulation of ER homeostasis and apoptosis, particularly under conditions of cellular stresses.
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Affiliation(s)
- Evgenii Boriushkin
- Department of Ophthalmology and Biochemistry/Ross Eye Institute, University at Buffalo/SUNY, Buffalo, New York, United States SUNY Eye Institute, State University of New York, Buffalo, New York, United States
| | - Joshua J Wang
- Department of Ophthalmology and Biochemistry/Ross Eye Institute, University at Buffalo/SUNY, Buffalo, New York, United States
| | - Junhua Li
- Department of Ophthalmology and Biochemistry/Ross Eye Institute, University at Buffalo/SUNY, Buffalo, New York, United States SUNY Eye Institute, State University of New York, Buffalo, New York, United States
| | - Guangjun Jing
- Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States
| | - Gail M Seigel
- SUNY Eye Institute, State University of New York, Buffalo, New York, United States Center for Hearing & Deafness, University at Buffalo, Buffalo/SUNY, New York, United States
| | - Sarah X Zhang
- Department of Ophthalmology and Biochemistry/Ross Eye Institute, University at Buffalo/SUNY, Buffalo, New York, United States
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105
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Kim DY, Kim HR, Kim KK, Park JW, Lee BJ. NELL2 function in the protection of cells against endoplasmic reticulum stress. Mol Cells 2014; 38:145-50. [PMID: 25537860 PMCID: PMC4332037 DOI: 10.14348/molcells.2015.2216] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 11/10/2014] [Accepted: 11/12/2014] [Indexed: 01/21/2023] Open
Abstract
Continuous intra- and extracellular stresses induce disorder of Ca(2+) homeostasis and accumulation of unfolded protein in the endoplasmic reticulum (ER), which results in ER stress. Severe long-term ER stress triggers apoptosis signaling pathways, resulting in cell death. Neural epidermal growth factor-like like protein 2 (NELL2) has been reported to be important in protection of cells from cell death-inducing environments. In this study, we investigated the cytoprotective effect of NELL2 in the context of ER stress induced by thapsigargin, a strong ER stress inducer, in Cos7 cells. Overexpression of NELL2 prevented ER stress-mediated apoptosis by decreasing expression of ER stress-induced C/EBP homologous protein (CHOP) and increasing ER chaperones. In this context, expression of anti-apoptotic Bcl-xL was increased by NELL2, whereas NELL2 decreased expression of pro-apoptotic proteins, such as cleaved caspases 3 and 7. This anti-apoptotic effect of NELL2 is likely mediated by extracellular signal-regulated kinase (ERK) signaling, because its inhibitor, U0126, inhibited effects of NELL2 on the expression of anti- and pro-apoptotic proteins and on the protection from ER stress-induced cell death.
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Affiliation(s)
- Dong Yeol Kim
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 680-749, Korea
| | - Han Rae Kim
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 680-749, Korea
| | - Kwang Kon Kim
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 680-749, Korea
| | - Jeong Woo Park
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 680-749, Korea
| | - Byung Ju Lee
- Department of Biological Sciences, College of Natural Sciences, University of Ulsan, Ulsan 680-749, Korea
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106
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The unfolded protein response in retinal vascular diseases: implications and therapeutic potential beyond protein folding. Prog Retin Eye Res 2014; 45:111-31. [PMID: 25529848 DOI: 10.1016/j.preteyeres.2014.12.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 12/09/2014] [Accepted: 12/11/2014] [Indexed: 01/18/2023]
Abstract
Angiogenesis is a complex, step-wise process of new vessel formation that is involved in both normal embryonic development as well as postnatal pathological processes, such as cancer, cardiovascular disease, and diabetes. Aberrant blood vessel growth, also known as neovascularization, in the retina and the choroid is a major cause of vision loss in severe eye diseases, such as diabetic retinopathy, age-related macular degeneration, retinopathy of prematurity, and central and branch retinal vein occlusion. Yet, retinal neovascularization is causally and dynamically associated with vasodegeneration, ischemia, and vascular remodeling in retinal tissues. Understanding the mechanisms of retinal neovascularization is an urgent unmet need for developing new treatments for these devastating diseases. Accumulating evidence suggests a vital role for the unfolded protein response (UPR) in regulation of angiogenesis, in part through coordinating the secretion of pro-angiogenic growth factors, such as VEGF, and modulating endothelial cell survival and activity. Herein, we summarize current research in the context of endoplasmic reticulum (ER) stress and UPR signaling in retinal angiogenesis and vascular remodeling, highlighting potential implications of targeting these stress response pathways in the prevention and treatment of retinal vascular diseases that result in visual deficits and blindness.
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107
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Liu B, Zhu Y, Zhou J, Wei Y, Long C, Chen M, Ling Y, Ge J, Zhuo Y. Endoplasmic reticulum stress promotes amyloid-beta peptides production in RGC-5 cells. Cell Stress Chaperones 2014; 19:827-35. [PMID: 24643796 PMCID: PMC4389842 DOI: 10.1007/s12192-014-0506-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 02/19/2014] [Accepted: 02/21/2014] [Indexed: 01/05/2023] Open
Abstract
Endoplasmic reticulum (ER) stress has been implicated in various neurodegenerative diseases, including Alzheimer's disease. We have previously observed amyloid production in the retina of the Tg2576 transgenic mouse model of Alzheimer's disease. In this study, we used tunicamycin-induced ER stress in RGC-5 cells, a cell line identical to the photoreceptor cell line 661W, to investigate the effect of ER stress on production of amyloid-beta (Abeta) peptides. We found that the mRNA level of amyloid-beta precursor protein (APP) remained stable, while the protein level of amyloid-beta precursor protein (APP) was decreased, the amyloid-beta precursor protein cleaving enzymes beta-site APP-cleaving enzyme 1 and presenilin 1 were upregulated, Abeta1-40 and Abeta1-42 production were increased, and reactive oxygen species production and apoptosis markers were elevated following induction of ER stress. The protein level of Abeta degradation enzymes, neprilysin, endothelin-converting enzyme 1, and endothelin-converting enzyme 2 remained unchanged during the prolonged ER stress, showing that the generation of Abeta did not result from reduction of proteolysis by these enzymes. Inclusion of group II caspase inhibitor, Z-DEVD-FMK, increased the ER stress mediated Abeta production, suggesting that they are generated by a caspase-independent mechanism. Our findings provided evidence of a role of ER stress in Abeta peptide overproduction and apoptotic pathway activation in RGC-5 cells.
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Affiliation(s)
- Bingqian Liu
- />State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060 China
| | - Yingting Zhu
- />State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060 China
| | - Jiayi Zhou
- />New England College of Optometry, Boston, MA 02115 USA
| | - Yantao Wei
- />State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060 China
| | - Chongde Long
- />State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060 China
| | - Mengfei Chen
- />State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060 China
| | - Yunlan Ling
- />State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060 China
| | - Jian Ge
- />State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060 China
| | - Yehong Zhuo
- />State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong 510060 China
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108
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Wang F, Zhang Y, He C, Wang T, Piao Q, Liu Q. Silencing the gene encoding C/EBP homologous protein lessens acute brain injury following ischemia/reperfusion. Neural Regen Res 2014; 7:2432-8. [PMID: 25337093 PMCID: PMC4200717 DOI: 10.3969/j.issn.1673-5374.2012.31.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 10/31/2012] [Indexed: 11/18/2022] Open
Abstract
C/EBP homologous protein, an important transcription factor during endoplasmic reticulum stress, participates in cell apoptosis mediated by endoplasmic reticulum stress. Previous studies have shown that C/EBP homologous protein mediates nerve injury during Alzheimer’s disease, subarachnoid hemorrhage and spinal cord trauma. In this study, we introduced C/EBP homologous protein short hairpin RNA into the brains of ischemia/reperfusion rat models via injection of lentiviral vector through the left lateral ventricle. Silencing C/EBP homologous protein gene expression significantly reduced cerebral infarction volume, decreased water content and tumor necrosis factor-α and interleukin-1β mRNA expression in brain tissues following infarction, diminished the number of TUNEL-positive cells in the infarct region, decreased caspase-3 protein content and increased Bcl-2 protein content. These results suggest that silencing C/EBP homologous protein lessens cell apoptosis and inflammatory reactions, thereby protecting nerves.
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Affiliation(s)
- Fengzhang Wang
- Department of Neurology, Bethune First Hospital, Jilin University, Changchun 130021, Jilin Province, China
| | - Yuan Zhang
- Department of Neonatology, Bethune First Hospital, Jilin University, Changchun 130021, Jilin Province, China
| | - Chunke He
- Department of Orthopedics, Jilin Hospital of Integrated Traditional and Western Medicine, Changchun 130021, Jilin Province, China
| | - Tingting Wang
- Department of Infectious Diseases, Zibo First Hospital, Zibo 255200, Shandong Province, China
| | - Qiyan Piao
- Department of Cardiology, General Hospital of China National Petroleum Corporation in Jilin, Jilin 132021, Jilin Province, China
| | - Qun Liu
- Department of Neurology, Bethune First Hospital, Jilin University, Changchun 130021, Jilin Province, China
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Pérez CV, Theas MS, Jacobo PV, Jarazo-Dietrich S, Guazzone VA, Lustig L. Dual role of immune cells in the testis: Protective or pathogenic for germ cells? SPERMATOGENESIS 2014; 3:e23870. [PMID: 23687616 PMCID: PMC3644047 DOI: 10.4161/spmg.23870] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The purpose of this review is to describe how the immune cells present in the testis interact with the germinal epithelium contributing to survival or apoptosis of germ cells (GCs). Physiologically, the immunosuppressor testicular microenvironment protects GCs from immune attack, whereas in inflammatory conditions, tolerance is disrupted and immune cells and their mediators respond to GC self antigens, inducing damage of the germinal epithelium. Considering that experimental models of autoimmune orchitis have clarified the local immune mechanisms by which protection of the testis is compromised, we described the following topics in the testis of normal and orchitic rats: (1) cell adhesion molecule expression of seminiferous tubule specialized junctions and modulation of blood-testis barrier permeability by cytokines (2) phenotypic and functional characteristics of testicular dendritic cells, macrophages, effector and regulatory T cells and mast cells and (3) effects of pro-inflammatory cytokines (TNF-α, IL-6 and FasL) and the nitric oxide-nitric oxide synthase system on GC apoptosis.
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Affiliation(s)
- Cecilia V Pérez
- Instituto de Investigaciones Biomédicas; UBA/CONICET; Facultad de Medicina; Universidad de Buenos Aires; Buenos Aires, Argentina
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Chou ST, Lin HC, Chuang MY, Chiu TH. Treatment with C
aulerpa Microphysa
Pepsin-Digested Extract Induces Apoptosis in Murine Leukemia WEHI-3 Cells. J Food Biochem 2014. [DOI: 10.1111/jfbc.12079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Su-Tze Chou
- Department of Food and Nutrition; Providence University; Taichung Taiwan
| | - Hui-Chiu Lin
- Penghu Marine Biology Research Center; Fisheries Research Institute; Penghu County Taiwan
| | - Mei-Yu Chuang
- Department of Food and Nutrition; Providence University; Taichung Taiwan
| | - Tsai-Hsin Chiu
- Department of Food Science; National Penghu University of Science and Technology; 300 Liu-Ho Rd. Magong City, Penghu County 880 Taiwan
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111
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Progesterone production is affected by unfolded protein response (UPR) signaling during the luteal phase in mice. Life Sci 2014; 113:60-7. [PMID: 25108065 DOI: 10.1016/j.lfs.2014.07.033] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/23/2014] [Indexed: 12/29/2022]
Abstract
AIMS We examined whether the three unfolded protein response (UPR) signaling pathways, which are activated in response to endoplasmic reticulum (ER)-stress, are involved in progesterone production in the luteal cells of the corpus luteum (CL) during the mouse estrous cycle. MAIN METHODS The luteal phase of C57BL/6 female mice (8 weeks old) was divided into two stages: the functional stage (16, 24, and 48 h) and the regression stage (72 and 96 h). Western blotting and reverse transcription (RT)-PCR were performed to analyze UPR protein/gene expression levels in each stage. We investigated whether ER stress affects the progesterone production by using Tm (0.5 μg/g BW) or TUDCA (0.5 μg/g BW) through intra-peritoneal injection. KEY FINDINGS Our results indicate that expressions of Grp78/Bip, p-eIF2α/ATF4, p50ATF6, and p-IRE1/sXBP1 induced by UPR activation were predominantly maintained in functional and early regression stages of the CL. Furthermore, the expression of p-JNK, CHOP, and cleaved caspase3 as ER-stress mediated apoptotic factors increased during the regression stage. Cleaved caspase3 levels increased in the late-regression stage after p-JNK and CHOP expression in the early-regression stage. Additionally, although progesterone secretion and levels of steroidogenic enzymes decreased following intra-peritoneal injection of Tunicamycin, an ER stress inducer, the expression of Grp78/Bip, p50ATF6, and CHOP dramatically increased. SIGNIFICANCE These results suggest that the UPR signaling pathways activated in response to ER stress may play important roles in the regulation of the CL function. Furthermore, our findings enhance the understanding of the basic mechanisms affecting the CL life span.
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112
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Kucuksayan E, Konuk EK, Demir N, Mutus B, Aslan M. Neutral sphingomyelinase inhibition decreases ER stress-mediated apoptosis and inducible nitric oxide synthase in retinal pigment epithelial cells. Free Radic Biol Med 2014; 72:113-23. [PMID: 24742815 DOI: 10.1016/j.freeradbiomed.2014.04.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 03/17/2014] [Accepted: 04/09/2014] [Indexed: 01/06/2023]
Abstract
Endoplasmic reticulum (ER) stress and excessive nitric oxide production via the induction of inducible nitric oxide synthase (NOS2) have been implicated in the pathogenesis of ocular diseases characterized by retinal degeneration. Previous studies have revealed the sphingomyelinase/ceramide pathway in the regulation of NOS2 induction. Thus, the objective of this study was to determine the activity of the sphingomyelinase/ceramide pathway, assess nitric oxide production, and examine apoptosis in human retinal pigment epithelial (RPE) cells undergoing ER stress. Sphingomyelinase (SMase) activity; nuclear factor κB (NF-κB) activation; NOS2, nitrite/nitrate, and nitrotyrosine levels; and apoptosis were determined in cultured human RPE cell lines subjected to ER stress via exposure to tunicamycin. Induction of ER stress was confirmed by increased intracellular levels of ER stress markers including phosphorylated PKR-like ER kinase, C/EBP-homologous protein, and 78-kDa glucose-regulated protein. ER stress increased nuclear translocation of NF-κB, NOS2 expression, nitrite/nitrate levels, and nitrotyrosine formation and caused apoptosis in RPE cell lines. Inhibition of neutral SMase (N-SMase) activity via GW 4869 treatment caused a significant reduction in nuclear translocation of NF-κB, NOS2 expression, nitrite/nitrate levels, nitrotyrosine formation, and apoptosis in ER-stressed RPE cells. In conclusion, N-SMase inhibition reduced nitrative stress and apoptosis in RPE cells undergoing ER stress. Obtained data suggest that NOS2 can be regulated by N-SMase in RPE cells experiencing ER stress.
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Affiliation(s)
- Ertan Kucuksayan
- Department of Medical Biochemistry, Akdeniz University Medical School, 07070 Antalya, Turkey
| | | | - Nejdet Demir
- Department of Histology, Akdeniz University Medical School, 07070 Antalya, Turkey
| | - Bülent Mutus
- Department of Chemistry & Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Mutay Aslan
- Department of Medical Biochemistry, Akdeniz University Medical School, 07070 Antalya, Turkey.
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113
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Zhang SX, Sanders E, Fliesler SJ, Wang JJ. Endoplasmic reticulum stress and the unfolded protein responses in retinal degeneration. Exp Eye Res 2014; 125:30-40. [PMID: 24792589 DOI: 10.1016/j.exer.2014.04.015] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 04/02/2014] [Accepted: 04/18/2014] [Indexed: 02/06/2023]
Abstract
The endoplasmic reticulum (ER) is the primary intracellular organelle responsible for protein and lipid biosynthesis, protein folding and trafficking, calcium homeostasis, and several other vital processes in cell physiology. Disturbance in ER function results in ER stress and subsequent activation of the unfolded protein response (UPR). The UPR up-regulates ER chaperones, reduces protein translation, and promotes clearance of cytotoxic misfolded proteins to restore ER homeostasis. If this vital process fails, the cell will be signaled to enter apoptosis, resulting in cell death. Sustained ER stress also can trigger an inflammatory response and exacerbate oxidative stress, both of which contribute synergistically to tissue damage. Studies performed over the past decade have implicated ER stress in a broad range of human diseases, including neurodegenerative diseases, cancer, diabetes, and vascular disorders. Several of these diseases also entail retinal dysfunction and degeneration caused by injury to retinal neurons and/or to the blood vessels that supply retinal cells with nutrients, trophic and homeostatic factors, oxygen, and other essential molecules, as well as serving as a conduit for removal of waste products and potentially toxic substances from the retina. Collectively, such injuries represent the leading cause of blindness world-wide in all age groups. Herein, we summarize recent progress on the study of ER stress and UPR signaling in retinal biology and discuss the molecular mechanisms and the potential clinical applications of targeting ER stress as a new therapeutic approach to prevent and treat neuronal degeneration in the retina.
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Affiliation(s)
- Sarah X Zhang
- Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA.
| | - Emily Sanders
- Department of Medicine, Endocrinology and Diabetes, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Steven J Fliesler
- Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA; Research Service, Veterans Administration Western New York Healthcare System, Buffalo, NY, USA
| | - Joshua J Wang
- Departments of Ophthalmology and Biochemistry, University at Buffalo, The State University of New York, Buffalo, NY, USA; SUNY Eye Institute, Buffalo, NY, USA
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Fu D, Yu JY, Wu M, Du M, Chen Y, Abdelsamie SA, Li Y, Chen J, Boulton ME, Ma JX, Lopes-Virella MF, Virella G, Lyons TJ. Immune complex formation in human diabetic retina enhances toxicity of oxidized LDL towards retinal capillary pericytes. J Lipid Res 2014; 55:860-9. [PMID: 24616481 DOI: 10.1194/jlr.m045401] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Recently it has been shown that levels of circulating oxidized LDL immune complexes (ox-LDL-ICs) predict the development of diabetic retinopathy (DR). This study aimed to investigate whether ox-LDL-ICs are actually present in the diabetic retina, and to define their effects on human retinal pericytes versus ox-LDL. In retinal sections from people with type 2 diabetes, costaining for ox-LDL and IgG was present, proportionate to DR severity, and detectable even in the absence of clinical DR. In contrast, no such staining was observed in retinas from nondiabetic subjects. In vitro, human retinal pericytes were treated with native LDL, ox-LDL, and ox-LDL-IC (0-200 mg protein/l), and measures of viability, receptor expression, apoptosis, endoplasmic reticulum (ER) and oxidative stresses, and cytokine secretion were evaluated. Ox-LDL-IC exhibited greater cytotoxicity than ox-LDL toward retinal pericytes. Acting through the scavenger (CD36) and IgG (CD64) receptors, low concentrations of ox-LDL-IC triggered apoptosis mediated by oxidative and ER stresses, and enhanced inflammatory cytokine secretion. The data suggest that IC formation in the diabetic retina enhances the injurious effects of ox-LDL. These findings offer new insights into pathogenic mechanisms of DR, and may lead to new preventive measures and treatments.
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Affiliation(s)
- Dongxu Fu
- Centre for Experimental Medicine, School of Medicine, Dentistry, and Biomedical Science, Queen's University Belfast, Northern Ireland, UK
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Davunetide (NAP) protects the retina against early diabetic injury by reducing apoptotic death. J Mol Neurosci 2014; 54:395-404. [PMID: 24488575 DOI: 10.1007/s12031-014-0244-4] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 01/20/2014] [Indexed: 01/18/2023]
Abstract
Davunetide (NAP) is an eight amino acid peptide that has been shown to provide potent neuroprotection. In the present study, we investigated the neuroprotective effect of NAP in diabetic retinopathy using an in vivo streptozotocin (STZ)-induced diabetic model. A single intraocular injection of NAP (100 μg/mL) or vehicle was administered 1 week after STZ injection. Three weeks after diabetes induction, we assessed the retinal expression and distribution of apoptosis markers, cleaved caspase-3, and Bcl2, by Western blot and immunofluorescent analysis. Furthermore, we evaluated the activation of mitogen-activated protein kinase/extracellular signal-regulated protein kinase (MAPK/ERK) and/or phosphatidylinositol-3 kinase/Akt pathways by measuring the protein levels of p-ERK and p-AKT with or without NAP treatment. Results demonstrated that NAP treatment reduced apoptotic event in diabetic retina, and it restored cleaved caspase-3 expression levels in the retina of STZ-injected rats as well as the decreased Bcl2. NAP treatment improved cellular survival through the activation of the MAPK/ERK pathway. Taken together, these findings suggested that NAP might be useful to treat retinal degenerative diseases.
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116
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Nezami BG, Mwangi SM, Lee JE, Jeppsson S, Anitha M, Yarandi SS, Farris AB, Srinivasan S. MicroRNA 375 mediates palmitate-induced enteric neuronal damage and high-fat diet-induced delayed intestinal transit in mice. Gastroenterology 2014; 146:473-83.e3. [PMID: 24507550 PMCID: PMC3920196 DOI: 10.1053/j.gastro.2013.10.053] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 10/02/2013] [Accepted: 10/22/2013] [Indexed: 01/01/2023]
Abstract
BACKGROUND & AIMS A high-fat diet (HFD) can cause serious health problems, including alteration of gastrointestinal transit, the exact mechanism of which is not clear. Several microRNAs (miRNAs) are involved in energy homeostasis, lipid metabolism, and HFD-induced weight gain. We investigated the role of miRNAs in HFD-induced damage to the enteric nervous system. METHODS Male mice were fed a HFD (60% calories from fat) or regular diets (18% calories from fat) for 11 weeks. Mice on regular diets and HFDs were given intraperitoneal injections of Mir375 inhibitor or a negative control. Body weights, food intake, stool indices, and gastrointestinal transit (following Evans blue gavage) were measured. An enteric neuronal cell line (immorto-fetal enteric neuronal) and primary enteric neurons were used for in vitro studies. RESULTS HFD delayed intestinal transit, which was associated with increased apoptosis and loss of colonic myenteric neurons. Mice fed a low-palmitate HFD did not develop a similar phenotype. Palmitate caused apoptosis of enteric neuronal cells associated with mitochondrial dysfunction and endoplasmic reticulum stress. Palmitate significantly increased the expression of Mir375 in vitro; transfection of cells with a Mir375 inhibitor prevented the palmitate-induced enteric neuronal cell apoptosis. Mir375 expression was increased in myenteric ganglia of mice fed HFD and associated with decreased levels of Mir375 target messenger RNAs, including Pdk1. Systemic injection of a Mir375 inhibitor for 5 weeks prevented HFD-induced delay in intestinal transit and morphologic changes. CONCLUSIONS HFDs delay colonic transit, partly by inducing apoptosis in enteric neuronal cells. This effect is mediated by Mir375 and is associated with reduced levels of Pdk1. Mir375 might be targeted to increase survival of enteric neurons and gastrointestinal motility.
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Affiliation(s)
- Behtash Ghazi Nezami
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta & Atlanta VA Medical Center, Decatur, GA, USA
| | - Simon M. Mwangi
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta & Atlanta VA Medical Center, Decatur, GA, USA
| | - Jai Eun Lee
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta & Atlanta VA Medical Center, Decatur, GA, USA
| | - Sabrina Jeppsson
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta & Atlanta VA Medical Center, Decatur, GA, USA
| | - Mallappa Anitha
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta & Atlanta VA Medical Center, Decatur, GA, USA
| | - Shadi S. Yarandi
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta & Atlanta VA Medical Center, Decatur, GA, USA
| | - Alton B Farris
- Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA
| | - Shanthi Srinivasan
- Department of Digestive Diseases, Emory University School of Medicine, Atlanta, Georgia; Atlanta VA Medical Center, Decatur, Georgia.
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117
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Ma JH, Wang JJ, Zhang SX. The unfolded protein response and diabetic retinopathy. J Diabetes Res 2014; 2014:160140. [PMID: 25530974 PMCID: PMC4229964 DOI: 10.1155/2014/160140] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Revised: 09/27/2014] [Accepted: 09/28/2014] [Indexed: 12/11/2022] Open
Abstract
Diabetic retinopathy, a common complication of diabetes, is the leading cause of blindness in adults. Diabetes chronically damages retinal blood vessels and neurons likely through multiple pathogenic pathways such as oxidative stress, inflammation, and endoplasmic reticulum (ER) stress. To relieve ER stress, the cell activates an adaptive mechanism known as the unfolded protein response (UPR). The UPR coordinates the processes of protein synthesis, protein folding, and degradation to ensure proteostasis, which is vital for cell survival and activity. Emerging evidence suggests that diabetes can activate all three UPR branches in retinal cells, among which the PERK/ATF4 pathway is the most extensively studied in the development of diabetic retinopathy. X-box binding protein 1 (XBP1) is a major transcription factor in the core UPR pathway and also regulates a variety of genes involved in cellular metabolism, redox state, autophagy, inflammation, cell survival, and vascular function. The exact function and implication of XBP1 in the pathogenesis of diabetic retinopathy remain elusive. Focusing on this less studied pathway, we summarize recent progress in studies of the UPR pertaining to diabetic changes in retinal vasculature and neurons, highlighting the perspective of XBP1 as a potential therapeutic target in diabetic retinopathy.
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Affiliation(s)
- Jacey Hongjie Ma
- Departments of Ophthalmology and Biochemistry (Ira G. Ross Eye Institute), School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, 308 Farber Hall, Buffalo, NY 14214, USA
- SUNY Eye Institute, Buffalo, NY 14214, USA
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Josh J. Wang
- Departments of Ophthalmology and Biochemistry (Ira G. Ross Eye Institute), School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, 308 Farber Hall, Buffalo, NY 14214, USA
- SUNY Eye Institute, Buffalo, NY 14214, USA
| | - Sarah X. Zhang
- Departments of Ophthalmology and Biochemistry (Ira G. Ross Eye Institute), School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, 308 Farber Hall, Buffalo, NY 14214, USA
- SUNY Eye Institute, Buffalo, NY 14214, USA
- *Sarah X. Zhang:
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Unfolding protein response signaling is involved in development, maintenance, and regression of the corpus luteum during the bovine estrous cycle. Biochem Biophys Res Commun 2013; 441:344-50. [DOI: 10.1016/j.bbrc.2013.10.056] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 10/11/2013] [Indexed: 12/15/2022]
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119
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Ardeljan D, Chan CC. Aging is not a disease: distinguishing age-related macular degeneration from aging. Prog Retin Eye Res 2013; 37:68-89. [PMID: 23933169 PMCID: PMC3830684 DOI: 10.1016/j.preteyeres.2013.07.003] [Citation(s) in RCA: 168] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 07/29/2013] [Accepted: 07/30/2013] [Indexed: 12/18/2022]
Abstract
Age-related macular degeneration (AMD) is a disease of the outer retina, characterized most significantly by atrophy of photoreceptors and retinal pigment epithelium accompanied with or without choroidal neovascularization. Development of AMD has been recognized as contingent on environmental and genetic risk factors, the strongest being advanced age. In this review, we highlight pathogenic changes that destabilize ocular homeostasis and promote AMD development. With normal aging, photoreceptors are steadily lost, Bruch's membrane thickens, the choroid thins, and hard drusen may form in the periphery. In AMD, many of these changes are exacerbated in addition to the development of disease-specific factors such as soft macular drusen. Para-inflammation, which can be thought of as an intermediate between basal and robust levels of inflammation, develops within the retina in an attempt to maintain ocular homeostasis, reflected by increased expression of the anti-inflammatory cytokine IL-10 coupled with shifts in macrophage plasticity from the pro-inflammatory M1 to the anti-inflammatory M2 polarization. In AMD, imbalances in the M1 and M2 populations together with activation of retinal microglia are observed and potentially contribute to tissue degeneration. Nonetheless, the retina persists in a state of chronic inflammation and increased expression of certain cytokines and inflammasomes is observed. Since not everyone develops AMD, the vital question to ask is how the body establishes a balance between normal age-related changes and the pathological phenotypes in AMD.
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Affiliation(s)
- Daniel Ardeljan
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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120
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A peptide derived from phage display library exhibits anti-tumor activity by targeting GRP78 in gastric cancer multidrug resistance cells. Cancer Lett 2013; 339:247-59. [PMID: 23792224 DOI: 10.1016/j.canlet.2013.06.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2013] [Revised: 06/09/2013] [Accepted: 06/13/2013] [Indexed: 11/23/2022]
Abstract
Multidrug resistance (MDR) remains a significant challenge to the clinical treatment of gastric cancer (GC). In the present study, using a phage display approach combined with MTT assays, we screened a specific peptide GMBP1 (Gastric cancer MDR cell-specific binding peptide), ETAPLSTMLSPY, which could bind to the surface of GC MDR cells specifically and reverse their MDR phenotypes. Immunocytochemical staining showed that the potential receptor of GMBP1 was located at the membrane and cytoplasm of MDR cells. In vitro and in vivo drug sensitivity assays, FACS analysis and Western blotting confirmed that GMBP1 was able to re-sensitize MDR cells to chemical drugs. Western blotting and proteomic approaches were used to screen the receptor of GMBP1, and GRP78, a MDR-related protein, was identified as a receptor of GMBP1. This result was further supported by immunofluoresence microscopy and Western blot. Additionally, Western blotting demonstrated that pre-incubation of GMBP1 in MDR cells greatly diminished MDR1, Bcl-2 and GRP78 expression but increased the expression of Bax, whereas downregulation of GRP78, function as a receptor and directly target for GMBP1, only inhibited MDR1 expression. Our findings suggest that GMBP1 could re-sensitize GC MDR cells to a variety of chemotherapeutic agents and this role might be mediated partly through down-regulating GRP78 expression and then inhibiting MDR1 expression. These findings indicate that peptide GMBP1 likely recognizes a novel GRP78 receptor and mediates cellular activities associated with the MDR phenotype, which provides new insight into research on the management of MDR in gastric cancer cells.
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121
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Tang S, Yuan G, Yu Z, Yin L, Jiang H. The flavonoid casticin enhances TRAIL-induced apoptosis of colon cancer cells through endoplasmic reticulum stress-mediated up-regulation of DR5. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s10330-013-1180-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Montalbano R, Waldegger P, Quint K, Jabari S, Neureiter D, Illig R, Ocker M, Di Fazio P. Endoplasmic reticulum stress plays a pivotal role in cell death mediated by the pan-deacetylase inhibitor panobinostat in human hepatocellular cancer cells. Transl Oncol 2013; 6:143-57. [PMID: 23544167 PMCID: PMC3610545 DOI: 10.1593/tlo.12271] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 02/01/2013] [Accepted: 02/04/2013] [Indexed: 02/07/2023] Open
Abstract
Panobinostat, a pan-deacetylase inhibitor, represents a novel therapeutic option for cancer diseases. Besides its ability to block histone deacetylases (HDACs) by promoting histone hyperacetylation, panobinostat interferes with several cell death pathways providing a potential efficacy against tumors. We have previously demonstrated that panobinostat has a potent apoptotic activity in vitro and causes a significant growth delay of hepatocellular carcinoma (HCC) tumor xenografts in nude mice models. Here, we show that treatment with panobinostat is able to induce noncanonical apoptotic cell death in HepG2 and in Hep3B cells, involving the endoplasmic reticulum (ER) stress by up-regulation of the molecular chaperone binding immunoglobulin protein/glucose-regulated protein 78, activation of eukaryotic initiation factor 2α-activating transcription factor 4 (tax-responsive enhancer element B67) and inositol requiring 1α-X-box binding protein 1 factors, strong increase and nuclear translocation of the transcription factor C/EBP homologous protein/growth arrest and DNA damage-inducible gene 153, and involvement of c-Jun N-terminal kinase. These signaling cascades culminate into the activation of the ER-located caspase-4/12 and of executioner caspases, which finally lead to cell demise. Our results clearly show that panobinostat induces an alternative ER stress-mediated cell death pathway in HCC cells, independent of the p53 status.
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Affiliation(s)
- Roberta Montalbano
- Institute for Surgical Research, Philipps University of Marburg, Marburg, Germany
| | - Petra Waldegger
- Institute for Surgical Research, Philipps University of Marburg, Marburg, Germany
| | - Karl Quint
- Institute for Surgical Research, Philipps University of Marburg, Marburg, Germany
| | - Samir Jabari
- Institute for Anatomy I, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Daniel Neureiter
- Institute of Pathology, Paracelsus Private Medical University, Salzburg, Austria
| | - Romana Illig
- Institute of Pathology, Paracelsus Private Medical University, Salzburg, Austria
| | - Matthias Ocker
- Institute for Surgical Research, Philipps University of Marburg, Marburg, Germany
| | - Pietro Di Fazio
- Institute for Surgical Research, Philipps University of Marburg, Marburg, Germany
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Ragusa M, Caltabiano R, Russo A, Puzzo L, Avitabile T, Longo A, Toro MD, Di Pietro C, Purrello M, Reibaldi M. MicroRNAs in vitreus humor from patients with ocular diseases. Mol Vis 2013; 19:430-40. [PMID: 23441115 PMCID: PMC3580974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 02/18/2013] [Indexed: 11/02/2022] Open
Abstract
PURPOSE Based on evidence that microRNAs (miRNAs) are found in many biologic fluids (e.g., urine, saliva, pleural fluid), we sought to detect the presence of miRNAs and analyze their profile in vitreous humor (VH) from patients affected by various ocular diseases. METHODS MiRNAs were purified from VH samples taken during vitrectomy, by using the Qiagen miRNeasy Mini Kit. The expression profile on 745 miRNAs was performed by using TaqMan Low Density Array. Single TaqMan expression assays were performed on 18 VH samples (six each from patients with choroidal melanomas, retinal detachment, or macular hole) for miRNAs commonly expressed in serum or retinal cells: let-7b, miR-21, miR-26a, miR-146a, miR-199-3p, miR-210, miR-374a*, miR-532-5p. RNA extracted from serum of six healthy donors or from formalin-fixed, paraffin-embedded samples of choroidal melanocytes from four uveal melanomas (epithelioid cells) and from three unaffected eyes were used as controls. RESULTS We identified the presence of 94 circulating small RNAs in the vitreous, some of which (miR-9, miR-9*, miR-125a-3p, miR-184, miR-211, miR-214, miR-302c, miR-452, miR-628, miR-639) are particularly abundant in the VH but downrepresented or not detectable in serum. MiR-146a and miR-26a were overexpressed more than threefold in VH from patients with uveal melanomas compared to the other pathological groups (Wilcoxon signed-rank test, p value < 0.05). CONCLUSIONS Our experimental data suggest that a specific set of circulating miRNAs is secreted in the vitreous, which is quite different from the miRNA pattern in serum, and that the quantity of vitreal miRNAs could change, depending on the pathologies of the eye.
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Affiliation(s)
- Marco Ragusa
- Department Gian Filippo Ingrassia, Unità di BioMedicina Molecolare Genomica e dei Sistemi Complessi, Genetica, Biologia Computazionale, Università di Catania, Catania, Italy
| | - Rosario Caltabiano
- Department Gian Filippo Ingrassia, Unità di Anatomia Patologica, Università di Catania, Catania, Italy
| | - Andrea Russo
- Department of Ophthalmology, University of Catania, Catania, Italy
| | - Lidia Puzzo
- Department Gian Filippo Ingrassia, Unità di Anatomia Patologica, Università di Catania, Catania, Italy
| | | | - Antonio Longo
- Department of Ophthalmology, University of Catania, Catania, Italy
| | - Mario D. Toro
- Department of Ophthalmology, University of Catania, Catania, Italy
| | - Cinzia Di Pietro
- Department Gian Filippo Ingrassia, Unità di BioMedicina Molecolare Genomica e dei Sistemi Complessi, Genetica, Biologia Computazionale, Università di Catania, Catania, Italy
| | - Michele Purrello
- Department Gian Filippo Ingrassia, Unità di BioMedicina Molecolare Genomica e dei Sistemi Complessi, Genetica, Biologia Computazionale, Università di Catania, Catania, Italy
| | - Michele Reibaldi
- Department of Ophthalmology, University of Catania, Catania, Italy
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The unfolded protein response to endoplasmic reticulum stress in cultured astrocytes and rat brain during experimental diabetes. Neurochem Int 2013; 62:784-95. [PMID: 23411409 DOI: 10.1016/j.neuint.2013.02.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 01/29/2013] [Accepted: 02/04/2013] [Indexed: 12/21/2022]
Abstract
Oxidative-nitrosative stress and inflammatory responses are associated with endoplasmic reticulum (ER) stress in diabetic retinopathy, raising the possibility that disturbances in ER protein processing may contribute to CNS dysfunction in diabetics. Upregulation of the unfolded protein response (UPR) is a homeostatic response to accumulation of abnormal proteins in the ER, and the present study tested the hypothesis that the UPR is upregulated in two models for diabetes, cultured astrocytes grown in 25mmol/L glucose for up to 4weeks and brain of streptozotocin (STZ)-treated rats with diabetes for 1-7months. Markers associated with translational blockade (phospho-eIF2α and apoptosis (CHOP), inflammatory response (inducible nitric oxide synthase, iNOS), and nitrosative stress (nuclear translocation of glyceraldehyde-3-phosphate dehydrogenase, GAPDH) were not detected in either model. Nrf2 was present in nuclei of low- and high-glucose cultures, consistent with oxidative stress. Astrocytic ATF4 expression was not altered by culture glucose concentration, whereas phospho-IRE and ATF6 levels were higher in low- compared with high-glucose cultures. The glucose-regulated chaperones, GRP78 and GRP94, were also expressed at higher levels in low- than high-glucose cultures, probably due to recurrent glucose depletion between feeding cycles. In STZ-rat cerebral cortex, ATF4 level was transiently reduced at 4months, and p-IRE levels were transiently elevated at 3months. However, GRP78 and GRP94 expression was not upregulated, and iNOS, amyloid-β, and nuclear accumulation of GAPDH were not evident in STZ-diabetic brain. High-glucose cultured astrocytes and STZ-diabetic brain are relatively resistant to diabetes-induced ER stress, in sharp contrast with cultured retinal Müller cells and diabetic rodent retina.
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125
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Brg1 governs distinct pathways to direct multiple aspects of mammalian neural crest cell development. Proc Natl Acad Sci U S A 2013; 110:1738-43. [PMID: 23319608 DOI: 10.1073/pnas.1218072110] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Development of the cerebral vessels, pharyngeal arch arteries (PAAs). and cardiac outflow tract (OFT) requires multipotent neural crest cells (NCCs) that migrate from the neural tube to target tissue destinations. Little is known about how mammalian NCC development is orchestrated by gene programming at the chromatin level, however. Here we show that Brahma-related gene 1 (Brg1), an ATPase subunit of the Brg1/Brahma-associated factor (BAF) chromatin-remodeling complex, is required in NCCs to direct cardiovascular development. Mouse embryos lacking Brg1 in NCCs display immature cerebral vessels, aberrant PAA patterning, and shortened OFT. Brg1 suppresses an apoptosis factor, Apoptosis signal-regulating kinase 1 (Ask1), and a cell cycle inhibitor, p21(cip1), to inhibit apoptosis and promote proliferation of NCCs, thereby maintaining a multipotent cell reservoir at the neural crest. Brg1 also supports Myosin heavy chain 11 (Myh11) expression to allow NCCs to develop into mature vascular smooth muscle cells of cerebral vessels. Within NCCs, Brg1 partners with chromatin remodeler Chromodomain-helicase-DNA-binding protein 7 (Chd7) on the PlexinA2 promoter to activate PlexinA2, which encodes a receptor for semaphorin to guide NCCs into the OFT. Our findings reveal an important role for Brg1 and its downstream pathways in the survival, differentiation, and migration of the multipotent NCCs critical for mammalian cardiovascular development.
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Su J, Zhou L, Kong X, Yang X, Xiang X, Zhang Y, Li X, Sun L. Endoplasmic reticulum is at the crossroads of autophagy, inflammation, and apoptosis signaling pathways and participates in the pathogenesis of diabetes mellitus. J Diabetes Res 2013; 2013:193461. [PMID: 23762873 PMCID: PMC3673337 DOI: 10.1155/2013/193461] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 05/08/2013] [Indexed: 12/22/2022] Open
Abstract
Diabetes mellitus (DM) is a chronic metabolic disease, and its incidence is growing worldwide. The endoplasmic reticulum (ER) is a central component of cellular functions and is involved in protein folding and trafficking, lipid synthesis, and maintenance of calcium homeostasis. The ER is also a sensor of both intra- and extracellular stress and thus participates in monitoring and maintaining cellular homeostasis. Therefore, the ER is one site of interaction between environmental signals and a cell's biological function. The ER is tightly linked to autophagy, inflammation, and apoptosis, and recent evidence suggests that these processes are related to the pathogenesis of DM and its complications. Thus, the ER has been considered an intersection integrating multiple stress responses and playing an important role in metabolism-related diseases including DM. Here, we review the relationship between the ER and autophagy, inflammation, and apoptosis in DM to better understand the molecular mechanisms of this disease.
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Affiliation(s)
- Jing Su
- Department of Pathophysiology, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China
| | - Lei Zhou
- Department of Pathology, Affiliated Hospital to Changchun University of Chinese Medicine, Changchun 130021, China
| | - Xiaoxia Kong
- Institute of Hypoxia Research, School of Basic Medical Sciences, Wenzhou Medical College, Wenzhou, Zhejiang 325035, China
| | - Xiaochun Yang
- Department of Pathophysiology, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China
| | - Xiyan Xiang
- Department of Pathophysiology, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China
| | - Yu Zhang
- Department of Pathophysiology, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China
| | - Xiaoning Li
- Department of Pathophysiology, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China
| | - Liankun Sun
- Department of Pathophysiology, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China
- *Liankun Sun:
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Abstract
Clinical epidemiological studies have revealed relatively weak, yet statistically significant, associations between dyslipidemia/dyslipoproteinemia and diabetic retinopathy (DR). Recent large interventional studies, however, demonstrated an unexpectedly robust efficacy of fenofibrate on the development of DR, possibly independent of plasma lipids. To unify the apparent discrepancies, we hypothesize that plasma lipoproteins play an indirect but important role in DR, contingent on the integrity of the blood-retina-barrier (BRB). In retinas with an intact BRB, plasma lipoproteins may be largely irrelevant; however, important effects become operative after the BRB is impaired in diabetes, leading to lipoprotein extravasation and subsequent modification, hence toxicity to the neighbouring retinal cells. In this hypothesis, BRB leakage is the key, plasma lipoprotein concentrations mainly modulate its consequences, and fenofibrate has intra-retinal actions. This review summarizes our current knowledge of the direct effects and mechanisms of modified lipoproteins on retinal cells and their potential contribution to the pathogenesis of DR.
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Affiliation(s)
- Jeremy Y Yu
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Northern Ireland, UK
| | - Timothy J Lyons
- Centre for Experimental Medicine, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Northern Ireland, UK ; Harold Hamm Diabetes Center and Section of Endocrinology and Diabetes, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Zhang HY, Zhang X, Wang ZG, Shi HX, Wu FZ, Lin BB, Xu XL, Wang XJ, Fu XB, Li ZY, Shen CJ, Li XK, Xiao J. Exogenous basic fibroblast growth factor inhibits ER stress-induced apoptosis and improves recovery from spinal cord injury. CNS Neurosci Ther 2012; 19:20-9. [PMID: 23082997 DOI: 10.1111/cns.12013] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Revised: 08/26/2012] [Accepted: 08/27/2012] [Indexed: 01/13/2023] Open
Abstract
AIM To investigate the mechanism of endoplasmic reticulum (ER) stress-induced apoptosis as well as the protective action of basic fibroblast growth factor (bFGF) both in vivo and in vitro. METHODS AND RESULTS ER stress-induced apoptosis was involved in the injuries of spinal cord injury (SCI) model rat. bFGF administration improved the recovery and increased the survival of neurons in spinal cord lesions in model rat. The protective effect of bFGF is related to the inhibition of CHOP, GRP78 and caspase-12, which are ER stress-induced apoptosis response proteins. bFGF administration also increased the survival of neurons and the expression of growth-associated protein 43 (GAP43), which is related to neural regeneration. The protective effect of bFGF is related to the activation of downstream signals, PI3K/Akt/GSK-3β and ERK1/2, especially in the ER stress cell model. CONCLUSIONS This is the first study to illustrate that the role of bFGF in SCI recovery is related to the inhibition of ER stress-induced cell death via the activation of downstream signals. Our work also suggested a new trend for bFGF drug development in central neural system injuries, which are involved in chronic ER stress-induced apoptosis.
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Affiliation(s)
- Hong-Yu Zhang
- School of Pharmacy, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical College, China
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129
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Fiandalo M, Kyprianou N. Caspase control: protagonists of cancer cell apoptosis. Exp Oncol 2012; 34:165-175. [PMID: 23070001 PMCID: PMC3721730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Emergence of castration-resistant metastatic prostate cancer is due to activation of survival pathways, including apoptosis suppression and anoikis resistance, and increased neovascularization. Thus targeting of apoptotic players is of critical significance in prostate cancer therapy since loss of apoptosis and resistance to anoikis are critical in aberrant malignant growth, metastasis and conferring therapeutic failure. The majority of therapeutic agents act through intrinsic mitochondrial, extrinsic death receptor pathways or endoplasmic reticulum stress pathways to induce apoptosis. Current therapeutic strategies target restoring regulatory molecules that govern the pro-survival pathways such as PTEN which regulates AKT activity. Other strategies focus on reactivating the apoptotic pathways either by down-regulating anti-apoptotic players such as BCL-2 or by up-regulating pro-apoptotic protein families, most notably, the caspases. Caspases are a family of cystine proteases which serve critical roles in apoptotic and inflammatory signaling pathways. During tumorigenesis, significant loss or inactivation of lead members in the caspase family leads to impairing apoptosis induction, causing a dramatic imbalance in the growth dynamics, ultimately resulting in aberrant growth of human cancers. Recent exploitation of apoptosis pathways towards re-instating apoptosis induction via caspase re-activation has provided new molecular platforms for the development of therapeutic strategies effective against advanced prostate cancer as well as other solid tumors. This review will discuss the current cellular landscape featuring the caspase family in tumor cells and their activation via pharmacologic intervention towards optimized anti-cancer therapeutic modalities. This article is part of a Special Issue entitled "Apoptosis: Four Decades Later".
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130
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Abstract
The large conductance calcium- and voltage-activated potassium channel (BK(Ca)) is widely expressed at the plasma membrane. This channel is involved in a variety of fundamental cellular functions including excitability, smooth muscle contractility, and Ca(2+) homeostasis, as well as in pathological situations like proinflammatory responses in rheumatoid arthritis, and cancer cell proliferation. Immunochemical, biochemical and pharmacological studies from over a decade have intermittently shown the presence of BK(Ca) in intracellular organelles. To date, intracellular BK(Ca) (iBK(Ca)) has been localized in the mitochondria, endoplasmic reticulum, nucleus and Golgi apparatus but its functional role remains largely unknown except for the mitochondrial BK(Ca) whose opening is thought to play a role in protecting the heart from ischaemic injury. In the nucleus, pharmacology suggests a role in regulating nuclear Ca(2+), membrane potential and eNOS expression. Establishing the molecular correlates of iBK(Ca), the mechanisms defining iBK(Ca) organelle-specific targeting, and their modulation are challenging questions. This review summarizes iBK(Ca) channels, their possible functions, and efforts to identify their molecular correlates.
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Affiliation(s)
- Harpreet Singh
- Department of Anesthesiology, University of California, Los Angeles, CA 90095, USA
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131
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Li C, Harada A, Oh Y. IGFBP-3 sensitizes antiestrogen-resistant breast cancer cells through interaction with GRP78. Cancer Lett 2012; 325:200-6. [PMID: 22801219 DOI: 10.1016/j.canlet.2012.07.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Accepted: 07/02/2012] [Indexed: 01/01/2023]
Abstract
IGFBP-3 is known to possess intrinsic biological activities such as anti-tumor property in addition to its IGF/IGF-R axis-dependent actions in a variety of human cancers including breast cancer. To investigate the molecular mechanisms underlying the intrinsic biological actions of IGFBP-3 on breast cancer cells, we performed yeast two-hybrid screening and found GRP78, known to cause drug-resistance, as a binding partner of IGFBP-3. Overexpression of IGFBP-3 in antiestrogen-resistant LCC9 cells showed that IGFBP-3 interacted with GRP78, resulting in disruption of the GRP78-caspase-7 complex, thereby activating caspase-7, and further inducing apoptosis. Combination of overexpression of IGFBP-3 and application of siRNAs against GRP78 led to decrease in cell viability upon ICI 182,780 treatment. These data suggest that IGFBP-3 could sensitize antiestrogen-resistant breast cancer cells to ICI 182,780 by preventing the anti-apoptotic function of GRP78.
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Affiliation(s)
- Chao Li
- Department of Pathology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, 23298, USA
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132
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Wu M, Yang S, Elliott MH, Fu D, Wilson K, Zhang J, Du M, Chen J, Lyons T. Oxidative and endoplasmic reticulum stresses mediate apoptosis induced by modified LDL in human retinal Müller cells. Invest Ophthalmol Vis Sci 2012; 53:4595-604. [PMID: 22678501 DOI: 10.1167/iovs.12-9910] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
PURPOSE We previously showed that extravasated, modified LDL is implicated in pericyte loss in diabetic retinopathy (DR). Here, we investigate whether modified LDL induces apoptosis in retinal Müller glial cells. METHODS Cultured human retinal Müller cells (MIO-M1) were treated with highly oxidized glycated LDL (HOG-LDL, 200 mg protein/L) or native LDL (N-LDL, 200 mg protein/L) for up to 24 hours with or without pretreatment with N-acetyl-cysteine (NAC, a blocker of oxidative stress) and 4-phenylbutyrate (4-PBA, a blocker of endoplasmic reticulum [ER] stress). Effects of HOG-LDL on cell viability, apoptosis, oxidative stress, and ER stress were assessed by cell viability, TUNEL, and Western blot assays. In separate experiments, Müller cells were treated with 7-ketocholesterol (7-KC, 5-20 μM) or 4-hydroxynonenal (4-HNE, 5-40 μM) for up to 24 hours. The same markers were measured. RESULTS HOG-LDL induced apoptosis (decreased cell viability, increased TUNEL staining, increased expression of cleaved PARP, cleaved caspase-3, and BAX; decreased Bcl-2), oxidative stress (increased NOX4 and antioxidant enzymes, catalase, and superoxide dismutase 2), and ER stress (increased phospho-eIF2α, KDEL, ATF6, and CHOP). Pretreatment with NAC or 4-PBA partially attenuated apoptosis. In addition. NAC attenuated activation of ER stress. Similar to HOG-LDL, 7KC, and 4HNE also induced apoptosis, oxidative stress, and ER stress. CONCLUSIONS Our data suggest that extravasated, modified lipoproteins may be implicated in apoptotic Müller cell death, acting at least partially via enhanced levels of oxidative and ER stresses. They support our main hypothesis that, in addition to hyperglycemia, extravasated and oxidized LDL is an important insult to the diabetic retina.
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Affiliation(s)
- Mingyuan Wu
- Harold Hamm Diabetes Center, Oklahoma City, Oklahoma, USA
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133
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Zhong Y, Li J, Chen Y, Wang JJ, Ratan R, Zhang SX. Activation of endoplasmic reticulum stress by hyperglycemia is essential for Müller cell-derived inflammatory cytokine production in diabetes. Diabetes 2012; 61:492-504. [PMID: 22228718 PMCID: PMC3266398 DOI: 10.2337/db11-0315] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Inflammation plays an important role in diabetes-induced retinal vascular leakage. The purpose of this study is to examine the role of endoplasmic reticulum (ER) stress and the signaling pathway of ER stress-induced activating transcription factor 4 (ATF4) in the regulation of Müller cell-derived inflammatory mediators in diabetic retinopathy. In diabetic animals, elevated ER stress markers, ATF4, and vascular endothelial growth factor (VEGF) expression were partially localized to Müller cells in the retina. In cultured Müller cells, high glucose induced a time-dependent increase of ER stress, ATF4 expression, and inflammatory factor production. Inducing ER stress or overexpressing ATF4 resulted in elevated intracellular adhesion molecule 1 and VEGF proteins in Müller cells. In contrast, alleviation of ER stress or blockade of ATF4 activity attenuated inflammatory gene expression induced by high glucose or hypoxia. Furthermore, we found that ATF4 regulated the c-Jun NH2-terminal kinase pathway resulting in VEGF upregulation. ATF4 was also required for ER stress-induced and hypoxia-inducible factor-1α activation. Finally, we showed that administration of chemical chaperone 4-phenylbutyrate or genetic inhibition of ATF4 successfully attenuated retinal VEGF expression and reduced vascular leakage in mice with STZ-induced diabetes. Taken together, our data indicate that ER stress and ATF4 play a critical role in retinal inflammatory signaling and Müller cell-derived inflammatory cytokine production in diabetes.
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Affiliation(s)
- Yimin Zhong
- Department of Medicine, Endocrinology, and Diabetes, Harold Hamm Oklahoma Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jingming Li
- Department of Medicine, Endocrinology, and Diabetes, Harold Hamm Oklahoma Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Yanming Chen
- Department of Medicine, Endocrinology, and Diabetes, Harold Hamm Oklahoma Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Medicine, Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Joshua J. Wang
- Department of Medicine, Endocrinology, and Diabetes, Harold Hamm Oklahoma Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Rajiv Ratan
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, Burke Medical Research Institute, White Plains, New York
| | - Sarah X. Zhang
- Department of Medicine, Endocrinology, and Diabetes, Harold Hamm Oklahoma Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Corresponding author: Sarah X. Zhang,
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Zhang SX, Sanders E, Wang JJ. Endoplasmic reticulum stress and inflammation: mechanisms and implications in diabetic retinopathy. J Ocul Biol Dis Infor 2012; 4:51-61. [PMID: 23330021 DOI: 10.1007/s12177-011-9075-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 12/29/2011] [Indexed: 12/21/2022] Open
Abstract
The endoplasmic reticulum (ER) is the primary cellular compartment where proteins are synthesized and modified before they can be transported to their destination. Dysfunction of the ER impairs protein homeostasis and leads to the accumulation of misfolded/unfolded proteins in the ER, or ER stress. While it has long been recognized that ER stress is a major cause of conformational disorders, such as Alzheimer's disease, Huntington's disease, certain types of cancer, and type 2 diabetes, recent evidence suggests that ER stress is also implicated in many chronic inflammatory diseases. These diseases include irritable bowel syndrome, atherosclerosis, diabetic complications, and many others. Diabetic retinopathy is a common microvascular complication of diabetes, characterized by chronic inflammation, progressive damage to retinal vascular and neuronal cells, vascular leakage, and abnormal blood vessel growth (neovascularization). In this review, we discuss the role and mechanisms of ER stress in retinal inflammation and vascular damage in diabetic retinopathy.
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Affiliation(s)
- Sarah X Zhang
- Department of Medicine, Endocrinology and Diabetes, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA ; Harold Hamm Diabetes Center at University of Oklahoma, University of Oklahoma Health Sciences Center, Oklahoma City, OK USA ; Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, 941 Stanton L. Young Blvd, Oklahoma City, OK USA
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