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Yung HW, Atkinson D, Campion-Smith T, Olovsson M, Charnock-Jones DS, Burton GJ. Differential activation of placental unfolded protein response pathways implies heterogeneity in causation of early- and late-onset pre-eclampsia. J Pathol 2014; 234:262-76. [PMID: 24931423 PMCID: PMC4277692 DOI: 10.1002/path.4394] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 05/22/2014] [Accepted: 06/10/2014] [Indexed: 12/12/2022]
Abstract
Based on gestational age at diagnosis and/or delivery, pre-eclampsia (PE) is commonly divided into early-onset (<34 weeks) and late-onset (≥34 weeks) forms. Recently, the distinction between ‘placental’ and ‘maternal’ causation has been proposed, with ‘placental’ cases being more frequently associated with early-onset and intrauterine growth restriction. To test whether molecular placental pathology varies according to clinical presentation, we investigated stress-signalling pathways, including unfolded protein response (UPR) pathways, MAPK stress pathways, heat-shock proteins and AMPKα in placentae delivered by caesarean section for clinical indications at different gestational ages. Controls included second-trimester, pre-term and normal-term placentae. BeWo cells were used to investigate how these pathways react to different severities of hypoxia–reoxygenation (H/R) and pro-inflammatory cytokines. Activation of placental UPR and stress-response pathways, including P-IRE1α, ATF6, XBP-1, GRP78 and GRP94, P-p38/p38 and HSP70, was higher in early-onset PE than in both late-onset PE and normotensive controls (NTCs), with a clear inflection around 34 weeks. Placentae from ≥ 34 weeks PE and NTC were indistinguishable. Levels of UPR signalling were similar between second-trimester and term controls, but were significantly higher in pre-term ‘controls’ delivered vaginally for chorioamnionitis and other conditions. Severe H/R (1/20% O2) induced equivalent activation of UPR pathways, including P-eIF2α, ATF6, P-IRE1α, GRP78 and GRP94, in BeWo cells. By contrast, the pro-inflammatory cytokines TNFα and IL-1β induced only mild activation of P-eIF2α and GRP78. AKT, a central regulator of cell proliferation, was reduced in the < 34 weeks PE placentae and severe H/R-treated cells, but not in other conditions. These findings provide the first molecular evidence that placental stress may contribute to the pathophysiology of early-onset pre-eclampsia, whereas that is unlikely to be the case in the late-onset form of the syndrome. © 2014 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Hong Wa Yung
- Centre for Trophoblast Research, University of CambridgeUK
| | | | - Tim Campion-Smith
- Department of Women's and Children's Health, Uppsala UniversitySweden
| | - Matts Olovsson
- Department of Women's and Children's Health, Uppsala UniversitySweden
| | - D Stephen Charnock-Jones
- Centre for Trophoblast Research, University of CambridgeUK
- Department of Obstetrics and Gynaecology, University of CambridgeUK
- National Institute for Health Research, Cambridge Comprehensive Biomedical Research CentreUK
| | - Graham J Burton
- Centre for Trophoblast Research, University of CambridgeUK
- National Institute for Health Research, Cambridge Comprehensive Biomedical Research CentreUK
- *Correspondence to: GJ Burton, Centre for Trophoblast Research, Physiological Laboratory, Downing Street, Cambridge CB2 3EG, UK. E-mail:
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52
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Robbins GR, Wen H, Ting JPY. Inflammasomes and metabolic disorders: old genes in modern diseases. Mol Cell 2014; 54:297-308. [PMID: 24766894 DOI: 10.1016/j.molcel.2014.03.029] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Modern medical and hygienic practices have greatly improved human health and longevity; however, increased human life span occurs concomitantly with the emergence of metabolic and age-related diseases. Studies over the past decade have strongly linked host inflammatory responses to the etiology of several metabolic diseases including atherosclerosis, type 2 diabetes (T2D), obesity, and gout. A common immunological factor to these diseases is the activation of the inflammasome and release of proinflammatory cytokines that promote disease progression. Here we review the molecular mechanism(s) of inflammasome activation in response to metabolic damage-associated molecular patterns (DAMPs) and discuss potential targets for therapeutic intervention.
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Affiliation(s)
- Gregory R Robbins
- The Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Haitao Wen
- The Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jenny P-Y Ting
- The Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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53
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Abe T, Kojima M, Akanuma S, Iwashita H, Yamazaki T, Okuyama R, Ichikawa K, Umemura M, Nakano H, Takahashi S, Takahashi Y. N-terminal hydrophobic amino acids of activating transcription factor 5 (ATF5) protein confer interleukin 1β (IL-1β)-induced stabilization. J Biol Chem 2013; 289:3888-900. [PMID: 24379400 DOI: 10.1074/jbc.m113.491217] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Activating transcription factor 5 (ATF5) is a stress-response transcription factor that responds to amino acid limitation and exposure to cadmium chloride (CdCl2) and sodium arsenite (NaAsO2). The N-terminal amino acids contribute to the destabilization of the ATF5 protein in steady-state conditions and serve as a stabilization domain in the stress response after CdCl2 or NaAsO2 exposure. In this study, we show that interleukin 1β (IL-1β), a proinflammatory cytokine, increases the expression of ATF5 protein in HepG2 hepatoma cells in part by stabilizing the ATF5 protein. The N-terminal domain rich in hydrophobic amino acids that is predicted to form a hydrophobic network was responsible for destabilization in steady-state conditions and served as an IL-1β response domain. Furthermore, IL-1β increased the translational efficiency of ATF5 mRNA via the 5' UTRα and phosphorylation of the eukaryotic translation initiation factor 2α (eIF2α). ATF5 knockdown in HepG2 cells up-regulated the IL-1β-induced expression of the serum amyloid A 1 (SAA1) and SAA2 genes. Our results show that the N-terminal hydrophobic amino acids play an important role in the regulation of ATF5 protein expression in IL-1β-mediated immune response and that ATF5 is a negative regulator for IL-1β-induced expression of SAA1 and SAA2 in HepG2 cells.
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Affiliation(s)
- Takanori Abe
- From the Laboratory of Environmental Molecular Physiology
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54
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Salim SY, Young PY, Lukowski CM, Madsen KL, Sis B, Churchill TA, Khadaroo RG. VSL#3 probiotics provide protection against acute intestinal ischaemia/reperfusion injury. Benef Microbes 2013; 4:357-365. [PMID: 24240573 DOI: 10.3920/bm2013.0026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Acute intestinal ischaemia/reperfusion injury (AII/R) is an adaptive physiologic response during critical illness, involving mesenteric vasoconstriction and hypoperfusion. Prevention of AII/R in high risk patient populations would have a significant impact on morbidity and mortality. The purpose of this study was to investigate the protective effects of VSL#3 probiotic treatment in a murine model of AII/R. Adult 129/SvEv mice were subjected to an experimental AII/R model using superior mesenteric artery occlusion. Animals were pre-treated with either three days or two weeks of VSL#3 probiotics. Local tissue injury markers were assessed by levels of myeloperoxidase and activation of nuclear factor kappa B (NFкB). Systemic and local cytokines, including interleukin (IL)-1β, IL- 10, TNFα, and interferon gamma were measured by ELISA and multiplex fluorescent detection. VSL#3 probiotics reduced local tissue inflammation and injury due to AII/R. A two-week course of VSL#3 was more effective than a shorter three-day course. The reduction in local inflammation from the two-week course of VSL#3 is correlated to a significant reduction in levels of active IL-1β, and tissue levels of myeloperoxidase. Levels of active NFкB were significantly elevated in the vehicle-fed AII/R mice, corroborating with tissue inflammation, which were attenuated by VSL#3 administrations. VSL#3 did not cause any systemic inflammation or lung injury. VSL#3 probiotics are effective in reducing local tissue injury from AII/R by down-regulating pro-inflammatory mediators and immune cell recruitment. This study highlights a potential role for VSL#3 in management of patients at high risk for AII/R.
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Affiliation(s)
- S Y Salim
- Department of Surgery, University of Alberta, 2D WMC, 8440-112 St NW, Edmonton, AB T6G 2B7, Canada
- Department of Medicine, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - P Y Young
- Department of Surgery, University of Alberta, 2D WMC, 8440-112 St NW, Edmonton, AB T6G 2B7, Canada
| | - C M Lukowski
- Department of Surgery, University of Alberta, 2D WMC, 8440-112 St NW, Edmonton, AB T6G 2B7, Canada
| | - K L Madsen
- Department of Medicine, University of Alberta, Edmonton, AB T6G 2E1, Canada
| | - B Sis
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB T6G 2B7, Canada
| | - T A Churchill
- Department of Surgery, University of Alberta, 2D WMC, 8440-112 St NW, Edmonton, AB T6G 2B7, Canada
| | - R G Khadaroo
- Department of Surgery, University of Alberta, 2D WMC, 8440-112 St NW, Edmonton, AB T6G 2B7, Canada
- Division of Critical Care Medicine, University of Alberta, Edmonton, AB T6G 2B7, Canada
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55
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Digaleh H, Kiaei M, Khodagholi F. Nrf2 and Nrf1 signaling and ER stress crosstalk: implication for proteasomal degradation and autophagy. Cell Mol Life Sci 2013; 70:4681-94. [PMID: 23800989 PMCID: PMC11113484 DOI: 10.1007/s00018-013-1409-y] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Revised: 05/26/2013] [Accepted: 06/13/2013] [Indexed: 12/11/2022]
Abstract
The endoplasmic reticulum (ER) lumen is chemically complex and crowded with polypeptides in different stages of assembly. ER quality control monitors chaperone-assisted protein folding, stochastic errors and off-pathway intermediates. In acute conditions, potentially toxic polypeptides overflow the capacity of the chaperone system and lead to ER stress. Activation of the unfolded protein response (UPR) following ER stress buys time for non-native polypeptides to refold or be eliminated; otherwise cell death occurs. The clearance routes for deleterious proteins are endoplasmic reticulum-associated degradation (ERAD) and ER stress-activated autophagy. The ERAD pathway is a chaperone and proteasome-mediated polypeptide degradation, while autophagy applies to wider range of substances. ER stress signal transduction recruits diverse molecules and pathways upon UPR induction to compensate stress condition. NF-E2-related factor 1 (Nrf1) and Nrf2 are two transcription factors mostly known by their induction through an antioxidant response; they can also be activated by UPR machinery. Discovery of diverse molecules downstream of Nrf1 and Nrf2 has expanded our understanding of the biological impacts of these transcription factors beyond classic antioxidant activation. In this review, we summarize our current understanding of mutual relationships between Nrf1, Nrf2, and ER stress clearance mechanisms and highlight the crosstalk of specific molecules mediating these correlations.
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Affiliation(s)
- Hadi Digaleh
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahmoud Kiaei
- Department of Neurobiology and Developmental Sciences, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205 USA
| | - Fariba Khodagholi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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56
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Henderson B, Kaiser F. Do reciprocal interactions between cell stress proteins and cytokines create a new intra-/extra-cellular signalling nexus? Cell Stress Chaperones 2013; 18:685-701. [PMID: 23884786 PMCID: PMC3789882 DOI: 10.1007/s12192-013-0444-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 06/16/2013] [Accepted: 06/17/2013] [Indexed: 12/22/2022] Open
Abstract
Cytokine biology began in the 1950s, and by 1988, a large number of cytokines, with a myriad of biological actions, had been discovered. In 1988, the basis of the protein chaperoning function of the heat shock, or cell stress, proteins was identified, and it was assumed that this was their major activity. However, since this time, evidence has accumulated to show that cell stress proteins are secreted by cells and can stimulate cellular cytokine synthesis with the generation of pro- and/or anti-inflammatory cytokine networks. Cell stress can also control cytokine synthesis, and cytokines are able to induce, or even inhibit, the synthesis of selected cell stress proteins and may also promote their release. How cell stress proteins control the formation of cytokines is not understood and how cytokines control cell stress protein synthesis depends on the cellular compartment experiencing stress, with cytoplasmic heat shock factor 1 (HSF1) having a variety of actions on cytokine gene transcription. The endoplasmic reticulum unfolded protein response also exhibits a complex set of behaviours in terms of control of cytokine synthesis. In addition, individual intracellular cell stress proteins, such as Hsp27 and Hsp90, have major roles in controlling cellular responses to cytokines and in controlling cytokine synthesis in response to exogenous factors. While still confusing, the literature supports the hypothesis that cell stress proteins and cytokines may generate complex intra- and extra-cellular networks, which function in the control of cells to external and internal stressors and suggests the cell stress response as a key parameter in cytokine network generation and, as a consequence, in control of immunity.
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Affiliation(s)
- Brian Henderson
- />Department of Microbial Diseases, Eastman Dental Institute, University College London, London, UK
| | - Frank Kaiser
- />Department of Microbial Diseases, Eastman Dental Institute, University College London, London, UK
- />Division of Microbial Diseases, Eastman Dental Institute, University College London, 256 Gray’s Inn Road, London, WC1X 8LD UK
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57
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Down-regulation of voltage-gated Ca2+ channels in Ca2+ store-depleted rat insulinoma RINm5F cells. Biomedicine (Taipei) 2013. [DOI: 10.1016/j.biomed.2012.11.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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58
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Ding J, Kam WR, Dieckow J, Sullivan DA. The influence of 13-cis retinoic acid on human meibomian gland epithelial cells. Invest Ophthalmol Vis Sci 2013; 54:4341-50. [PMID: 23722388 DOI: 10.1167/iovs.13-11863] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE Meibomian gland dysfunction (MGD) is a primary cause of dry eye disease. One of the risk factors for MGD is exposure to 13-cis retinoic acid (13-cis RA), a metabolite of vitamin A. However, the mechanism is not well understood. We hypothesize that 13-cis RA inhibits cell proliferation, promotes cell death, alters gene and protein expressions, and attenuates cell survival pathways in human meibomian gland epithelial cells. METHODS To test our hypotheses, immortalized human meibomian gland epithelial cells were cultured with or without 13-cis RA for varying doses and time. Cell proliferation, cell death, gene expression, and proteins involved in proliferation/survival and inflammation were evaluated. RESULTS We found that 13-cis RA inhibited cell proliferation, induced cell death, and significantly altered the expression of 6726 genes, including those involved in cell proliferation, cell death, differentiation, keratinization, and inflammation, in human meibomian gland epithelial cells. Further, 13-cis RA also reduced the phosphorylation of Akt and increased the generation of interleukin-1β and matrix metallopeptidase 9. CONCLUSIONS Exposure to 13-cis RA inhibits cell proliferation, increases cell death, alters gene expression, changes signaling pathways, and promotes inflammatory mediator and protease expression in meibomian gland epithelial cells. These effects may be responsible, at least in part, for the 13-cis RA-related induction of MGD.
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Affiliation(s)
- Juan Ding
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
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59
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Verma G, Bhatia H, Datta M. JNK1/2 regulates ER-mitochondrial Ca2+ cross-talk during IL-1β-mediated cell death in RINm5F and human primary β-cells. Mol Biol Cell 2013; 24:2058-71. [PMID: 23615449 PMCID: PMC3681707 DOI: 10.1091/mbc.e12-12-0885] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Elevated interleukin-1β (IL-1β) induces apoptosis in pancreatic β-cells through endoplasmic reticulum (ER) stress induction and subsequent c-jun-N-terminal kinase 1/2 (JNK1/2) activation. In earlier work we showed that JNK1/2 activation is initiated before ER stress and apoptotic induction in response to IL-1β. However, the detailed regulatory mechanisms are not completely understood. Because the ER is the organelle responsible for Ca(2+) handling and storage, here we examine the effects of IL-1β on cellular Ca(2+) movement and mitochondrial dysfunction and evaluate the role of JNK1/2. Our results show that in RINm5F cells and human primary β-cells, IL-1β alters mitochondrial membrane potential, mitochondrial permeability transition pore opening, ATP content, and reactive oxygen species production and these alterations are preceded by ER Ca(2+) release via IP3R channels and mitochondrial Ca(2+) uptake. All these events are prevented by JNK1/2 small interfering RNA (siRNA), indicating the mediating role of JNK1/2 in IL-1β-induced cellular alteration. This is accompanied by IL-1β-induced apoptosis, which is prevented by JNK1/2 siRNA and the IP3R inhibitor xestospongin C. This suggests a regulatory role of JNK1/2 in modulating the ER-mitochondrial-Ca(2+) axis by IL-1β in apoptotic cell death.
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Affiliation(s)
- Gaurav Verma
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110 007, India
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60
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Sung HJ, Son SJ, Yang SJ, Rhee KJ, Kim YS. Increased expression of interleukin-1β in triglyceride-induced macrophage cell death is mediated by p38 MAP kinase. BMB Rep 2012; 45:414-8. [PMID: 22831977 DOI: 10.5483/bmbrep.2012.45.7.088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Triglycerides (TG) are implicated in the development of atherosclerosis through formation of foam cells and induction of macrophage cell death. In this study, we report that addition of exogenous TG induced cell death in phorbol 12-myristate 13-acetate-differentiated THP-1 human macrophages. TG treatment induced a dramatic decrease in interleukin-1β (IL-1β) mRNA expression in a dose- and time-dependent manner. The expression of granulocyte macrophage colony-stimulating factor and platelet endothelial cell adhesion molecule remained unchanged. To identify signaling pathways involved in TG-induced downregulation of IL-1β, we added p38 MAPK, protein kinase C (PKC) or c-Raf1 specific inhibitors. We found that inhibition of p38 MAPK alleviated the TG-induced downregulation of IL-1β, whereas inhibition of PKC and c-Raf1 had no effect. This is the first report showing decreased IL-1β expression during TG-induced cell death in a human macrophage line. Our results suggest that downregulation of IL-1β expression by TG-treated macrophages may play a role during atherogenesis.
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Affiliation(s)
- Ho Joong Sung
- Department of Biomedical Laboratory Science, College of Health Sciences, Eulji University, Gyeongi-Do, Korea
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61
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Gene expression profiling and pathway analysis identify the integrin signaling pathway to be altered by IL-1β in human pancreatic cancer cells: Role of JNK. Cancer Lett 2012; 320:86-95. [DOI: 10.1016/j.canlet.2012.01.036] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 01/18/2012] [Accepted: 01/25/2012] [Indexed: 11/23/2022]
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62
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Li B, Kim DS, Oh HW, Lim HD, Lee W, Rhew KY, Kim HR, Chae HJ. N-Nitrosodimethylamine induced lung fibroblast cell death is associated with JNK activation. Mol Cell Toxicol 2012. [DOI: 10.1007/s13273-012-0019-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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63
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Hydrogen sulfide (H2S) metabolism in mitochondria and its regulatory role in energy production. Proc Natl Acad Sci U S A 2012; 109:2943-8. [PMID: 22323590 DOI: 10.1073/pnas.1115634109] [Citation(s) in RCA: 334] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although many types of ancient bacteria and archea rely on hydrogen sulfide (H(2)S) for their energy production, eukaryotes generate ATP in an oxygen-dependent fashion. We hypothesize that endogenous H(2)S remains a regulator of energy production in mammalian cells under stress conditions, which enables the body to cope with energy demand when oxygen supply is insufficient. Cystathionine γ-lyase (CSE) is a major H(2)S-producing enzyme in the cardiovascular system that uses cysteine as the main substrate. Here we show that CSE is localized only in the cytosol, not in mitochondria, of vascular smooth-muscle cells (SMCs) under resting conditions, revealed by Western blot analysis and confocal microscopy of SMCs transfected with GFP-tagged CSE plasmid. After SMCs were exposed to A23187, thapsigargin, or tunicamycin, intracellular calcium level was increased, and CSE translocated from the cytosol to mitochondria. CSE was coimmunoprecipitated with translocase of the outer membrane 20 (Tom20) in mitochondrial membrane. Tom20 siRNA significantly inhibited mitochondrial translocation of CSE and mitochondrial H(2)S production. The cysteine level inside mitochondria is approximately three times that in the cytosol. Translocation of CSE to mitochondria metabolized cysteine, produced H(2)S inside mitochondria, and increased ATP production. Inhibition of CSE activity reversed A23187-stimulated mitochondrial ATP production. H(2)S improved mitochondrial ATP production in SMCs with hypoxia, which alone decreased ATP production. These results suggest that translocation of CSE to mitochondria on specific stress stimulations is a unique mechanism to promote H(2)S production inside mitochondria, which subsequently sustains mitochondrial ATP production under hypoxic conditions.
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64
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Verma G, Datta M. The critical role of JNK in the ER-mitochondrial crosstalk during apoptotic cell death. J Cell Physiol 2012; 227:1791-5. [DOI: 10.1002/jcp.22903] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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65
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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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66
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ER stress and apoptosis: a new mechanism for retinal cell death. EXPERIMENTAL DIABETES RESEARCH 2011; 2012:589589. [PMID: 22216020 PMCID: PMC3246718 DOI: 10.1155/2012/589589] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 09/09/2011] [Indexed: 12/29/2022]
Abstract
The endoplasmic reticulum (ER) is the primary subcellular organelle where proteins are synthesized and folded. When the homeostasis of the ER is disturbed, unfolded or misfolded proteins accumulate in the ER lumen, resulting in ER stress. In response to ER stress, cells activate a set of tightly controlled regulatory programs, known as the unfolded protein response (UPR), to restore the normal function of the ER. However, if ER stress is sustained and the adaptive UPR fails to eliminate unfolded/misfolded proteins, apoptosis will occur to remove the stressed cells. In recent years, a large body of studies has shown that ER stress-induced apoptosis is implicated in numerous human diseases, such as diabetes and neurogenerative diseases. Moreover, emerging evidence supports a role of ER stress in retinal apoptosis and cell death in blinding disorders such as age-related macular degeneration and diabetic retinopathy. In the present review, we summarize recent progress on ER stress and apoptosis in retinal diseases, focusing on various proapoptotic and antiapoptotic pathways that are activated by the UPR, and discuss how these pathways contribute to ER stress-induced apoptosis in retinal cells.
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67
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Resveratrol mobilizes Ca2+ from intracellular stores and induces c-Jun N-terminal kinase activation in tumoral AR42J cells. Mol Cell Biochem 2011; 362:15-23. [DOI: 10.1007/s11010-011-1123-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 10/12/2011] [Indexed: 10/16/2022]
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68
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Li C, Xu J, Li F, Chaudhary SC, Weng Z, Wen J, Elmets CA, Ahsan H, Athar M. Unfolded protein response signaling and MAP kinase pathways underlie pathogenesis of arsenic-induced cutaneous inflammation. Cancer Prev Res (Phila) 2011; 4:2101-9. [PMID: 21911445 DOI: 10.1158/1940-6207.capr-11-0343] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Arsenic exposure through drinking water is a major global public health problem and is associated with an enhanced risk of various cancers including skin cancer. In human skin, arsenic induces precancerous melanosis and keratosis, which may progress to basal cell and squamous cell carcinoma. However, the mechanism by which these pathophysiologic alterations occur remains elusive. In this study, we showed that subchronic arsenic exposure to SKH-1 mice induced unfolded protein response (UPR) signaling regulated by proteins, inositol-requiring enzyme-1 (IRE1), PKR-like endoplasmic reticulum kinase (PERK) and activating transcription factor 6 (ATF6). Arsenic activated all three UPR regulatory proteins in the skin. Arsenic induced IRE1 phosphorylation which resulted in augmented splicing of X-box binding protein 1 (XBP-1) leading to its migration to the nucleus, and also enhanced transcriptional activation of downstream target proteins. Hyperphosphorylation of PERK which induces eukaryotic translation initial factor 2α (eIF2α) in a phosphorylation-dependent manner enhanced translation of ATF4, in addition to augmenting proteolytic activation of ATF6 in arsenic-treated skin. A similar increase in the expression of CHOP was observed. Enhanced XBP-1s, ATF4, and ATF6 regulated downstream chaperones GRP94 and GRP78. In addition, arsenic induced inflammation-related p38/MAPKAPK-2 MAPK signaling and alterations in Th-1/Th-2/Th-17 cytokines/chemokines and their receptors. Antioxidant N-acetyl cysteine blocked arsenic-induced reactive oxygen species, with a concomitant attenuation of UPR and mitogen-activated protein kinase (MAPK) signaling and proinflammatory cytokine/chemokine signatures. Our results identify novel pathways involved in the pathogenesis of arsenic-mediated cutaneous inflammation which may also be related to enhanced cancer risk in arsenic exposed cohorts.
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Affiliation(s)
- Changzhao Li
- Department of Dermatology and Skin Diseases Research Center, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Shen C, Yan J, Jiang LS, Dai LY. Autophagy in rat annulus fibrosus cells: evidence and possible implications. Arthritis Res Ther 2011; 13:R132. [PMID: 21846367 PMCID: PMC3239374 DOI: 10.1186/ar3443] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Revised: 04/13/2011] [Accepted: 08/16/2011] [Indexed: 01/24/2023] Open
Abstract
INTRODUCTION Programmed cell death of intervertebral disc (IVD) cells plays an important role in IVD degeneration, but the role of autophagy, a closely related cell death event, in IVD cells has not been documented. The current study was designed to investigate the effect of interleukin (IL)-1β on the occurrence of autophagy of rat annulus fibrosus (AF) cells and the interrelationship between autophagy and apoptosis. METHODS Rat AF cells were isolated and exposed, in tissue cultures with or without serum, to IL-1β in different concentrations for 24 hours. Ultrastructural analysis, flow cytometry and lysosomal activity assessment were performed after the in vitro treatment to determine the presence and levels of autophagy. The mRNA expression of autophagy-related proteins (Beclin-1, Bcl-2 and microtubule associated protein 1 light chain 3 (LC3)) were evaluated using real-time PCR. 3-methyladenine (3-MA), a PI3K inhibitor, was used to determine the interaction between autophagy and apoptosis via the suppression of autophagy. RESULTS Autophagy was detected in rat AF cells under serum starvation condition by transmission electron microscopy. PCR and flow cytometry results showed that IL-1β enhanced the autophagy-induction effect of serum deprivation in a dose-dependent manner. However, IL-1β alone failed to induce autophagy in AF cells cultured without serum starvation. When autophagy was suppressed by 3-MA, the apoptosis incidence was increased. Serum supplement also partly reversed the autophagy incidence without affecting the apoptosis incidence in the same cells. CONCLUSIONS IL-1β up-regulates serum deprivation-induced autophagy of AF cells in a dose-dependent manner. Autophagy may represent a protective mechanism against apoptosis in AF cells and IVD degeneration.
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Affiliation(s)
- Chao Shen
- Department of Orthopedic Surgery, Xinhua Hospital, 1665 Kongjiang Road, 200092, Shanghai, China
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Calvatia lilacina protein extract induces apoptosis through endoplasmic reticulum stress in human colon carcinoma cells. Process Biochem 2011. [DOI: 10.1016/j.procbio.2011.04.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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71
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Sun C, Li F, Meng Q. WITHDRAWN: Activation of p38 MAPK attenuates endoplasmic reticulum stress by up-regulating XBP1s. Cell Signal 2011:S0898-6568(11)00201-4. [PMID: 21767637 DOI: 10.1016/j.cellsig.2011.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 07/04/2011] [Accepted: 07/04/2011] [Indexed: 10/18/2022]
Abstract
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Cheng Sun
- MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center of Nanjing University, Nanjing, China
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Lipke AB, Matute-Bello G, Herrero R, Wong VA, Mongovin SM, Martin TR. Death receptors mediate the adverse effects of febrile-range hyperthermia on the outcome of lipopolysaccharide-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2011; 301:L60-70. [PMID: 21515659 DOI: 10.1152/ajplung.00314.2010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We have shown that febrile-range hyperthermia enhances lung injury and mortality in mice exposed to inhaled LPS and is associated with increased TNF-α receptor activity, suppression of NF-κB activity in vitro, and increased apoptosis of alveolar epithelial cells in vivo. We hypothesized that hyperthermia enhances lung injury and mortality in vivo by a mechanism dependent on TNF receptor signaling. To test this, we exposed mice lacking the TNF-receptor family members TNFR1/R2 or Fas (TNFR1/R2(-/-) and lpr) to inhaled LPS with or without febrile-range hyperthermia. For comparison, we studied mice lacking IL-1 receptor activity (IL-1R(-/-)) to determine the role of inflammation on the effect of hyperthermia in vivo. TNFR1/R2(-/-) and lpr mice were protected from augmented alveolar permeability and mortality associated with hyperthermia, whereas IL-1R(-/-) mice were susceptible to augmented alveolar permeability but protected from mortality associated with hyperthermia. Hyperthermia decreased pulmonary concentrations of TNF-α and keratinocyte-derived chemokine after LPS in C57BL/6 mice and did not affect pulmonary inflammation but enhanced circulating markers of oxidative injury and nitric oxide metabolites. The data suggest that hyperthermia enhances lung injury by a mechanism that requires death receptor activity and is not directly associated with changes in inflammation mediated by hyperthermia. In addition, hyperthermia appears to enhance mortality by generating a systemic inflammatory response and not by a mechanism directly associated with respiratory failure. Finally, we observed that exposure to febrile-range hyperthermia converts a modest, survivable model of lung injury into a fatal syndrome associated with oxidative and nitrosative stress, similar to the systemic inflammatory response syndrome.
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Affiliation(s)
- Anne B Lipke
- Division of Pulmonary and Critical Care Medicine, Puget Sound Medical Center, University of Washington, Seattle, Washington 98108, USA.
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A new Phaseolus vulgaris lectin induces selective toxicity on human liver carcinoma Hep G2 cells. Arch Toxicol 2011; 85:1551-63. [PMID: 21445585 DOI: 10.1007/s00204-011-0698-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 03/14/2011] [Indexed: 01/10/2023]
Abstract
We describe here the purification and characterization of a new Phaseolus vulgaris lectin that exhibits selective toxicity to human hepatoma Hep G2 cells and lacks significant toxicity on normal liver WRL 68 cells. This polygalacturonic acid-specific lectin (termed BTKL) was purified from seeds of P. vulgaris cv. Blue tiger king by liquid chromatography techniques. The 60-kDa dimeric lectin showed strong and broad-spectrum hemagglutinating activity toward human, rabbit, rat, and mouse erythrocytes. Bioinformatic analysis unveils substantial N-terminal sequence similarity of BTKL to other Phaseolus lectins. Among a number of tumor cells tested, BTKL exhibits potent anti-Hep G2 activity which is associated with (1) induction of DNA fragmentation, (2) production of apoptotic bodies and chromatin condensation, (3) triggering of cell apoptosis and necrosis, and (4) depolarization of mitochondrial membrane (low ΔΨm). Furthermore, BTKL could induce inducible nitric oxide synthase (iNOS) expression and subsequent nitric oxide production in vitro in mouse macrophages, which may contribute to its antitumor activity. In addition, BTKL could bring about a significant dose-dependent increase in the production of mRNAs of proinflammatory cytokines including interleukin-1 beta, interleukin-2, tumor necrosis factor alpha, and interferon-gamma. In sum, the antitumor activity and mechanism of BTKL provided here suggest that it has potential therapeutic value for human liver cancer.
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Choudhury M, Qadri I, Rahman SM, Schroeder-Gloeckler J, Janssen RC, Friedman JE. C/EBPβ is AMP kinase sensitive and up-regulates PEPCK in response to ER stress in hepatoma cells. Mol Cell Endocrinol 2011; 331:102-8. [PMID: 20797423 PMCID: PMC2981635 DOI: 10.1016/j.mce.2010.08.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/12/2010] [Accepted: 08/17/2010] [Indexed: 01/11/2023]
Abstract
Diabetes and obesity are associated with activation of endoplasmic reticulum (ER) stress; however a direct link between ER stress and increased hepatic gluconeogenesis remains unclear. Here we show that ER stress triggers a significant increase in expression of CCAAT/enhancer-binding protein (C/EBPβ) and phosphorylated CREB together with reduced phospho-AMP-activated protein kinase (pAMPK) in hepatoma cells. ER stress contributed to transcriptional activation of the gluconeogenic phosphoenolpyruvate carboxykinase (PEPCK) promoter in Huh7 and HepG2 cells via cAMP binding motif (CRE site). Chromatin immunoprecipitation assays demonstrate that C/EBPβ is recruited to the PEPCK promoter during ER stress and is reversed by pre-treatment with a JNK inhibitor that relieves ER stress. C/EBPβ but not pCREB was suppressed by the AMPK-activator AICAR or constitutively active AMPK, while dominant negative AMPK increased C/EBPβ expression. These data suggest that ER stress triggers suppression of AMPK while increasing C/EBPβ and pCREB expression which activates PEPCK gene transcription. Understanding how ER stress suppresses AMPK activation and increases C/EBPβ expression could lead to a potentially novel pathway for treatment of diabetes.
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Affiliation(s)
- Mahua Choudhury
- Department of Pediatrics, University of Colorado Denver, Aurora, CO 80045, USA
| | - Ishtiaq Qadri
- Department of Pediatrics, University of Colorado Denver, Aurora, CO 80045, USA
| | | | | | - Rachel C. Janssen
- Department of Pediatrics, University of Colorado Denver, Aurora, CO 80045, USA
| | - Jacob E. Friedman
- Department of Pediatrics, University of Colorado Denver, Aurora, CO 80045, USA
- Biochemistry and Molecular Genetics, University of Colorado Denver, Aurora, CO 80045, USA
- Corresponding author: University of Colorado Denver, Department of Pediatrics, P.O. Box 6511, MS 8106, Aurora, CO 80045, USA. Tel.: +1 303 724 3983; fax: +1 303 724 3920.
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