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GLI1, a novel target of the ER stress regulator p97/VCP, promotes ATF6f-mediated activation of XBP1. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194924. [PMID: 36842643 DOI: 10.1016/j.bbagrm.2023.194924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/31/2023] [Accepted: 02/19/2023] [Indexed: 02/28/2023]
Abstract
Upon accumulation of improperly folded proteins in the Endoplasmic Reticulum (ER), the Unfolded Protein Response (UPR) is triggered to restore ER homeostasis. The induction of stress genes is a sine qua non condition for effective adaptive UPR. Although this requirement has been extensively described, the mechanisms underlying this process remain in part uncharacterized. Here, we show that p97/VCP, an AAA+ ATPase known to contribute to ER stress-induced gene expression, regulates the transcription factor GLI1, a primary effector of Hedgehog (Hh) signaling. Under basal (non-ER stress) conditions, GLI1 is repressed by a p97/VCP-HDAC1 complex while upon ER stress GLI1 is induced through a mechanism requiring both USF2 binding and increase histone acetylation at its promoter. Interestingly, the induction of GLI1 was independent of ligand-regulated Hh signaling. Further analysis showed that GLI1 cooperates with ATF6f to induce promoter activity and expression of XBP1, a key transcription factor driving UPR. Overall, our work demonstrates a novel role for GLI1 in the regulation of ER stress gene expression and defines the interplay between p97/VCP, HDAC1 and USF2 as essential players in this process.
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2
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Unraveling the Molecular Nexus between GPCRs, ERS, and EMT. Mediators Inflamm 2021; 2021:6655417. [PMID: 33746610 PMCID: PMC7943314 DOI: 10.1155/2021/6655417] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 12/12/2022] Open
Abstract
G protein-coupled receptors (GPCRs) represent a large family of transmembrane proteins that transduce an external stimulus into a variety of cellular responses. They play a critical role in various pathological conditions in humans, including cancer, by regulating a number of key processes involved in tumor formation and progression. The epithelial-mesenchymal transition (EMT) is a fundamental process in promoting cancer cell invasion and tumor dissemination leading to metastasis, an often intractable state of the disease. Uncontrolled proliferation and persistent metabolism of cancer cells also induce oxidative stress, hypoxia, and depletion of growth factors and nutrients. These disturbances lead to the accumulation of misfolded proteins in the endoplasmic reticulum (ER) and induce a cellular condition called ER stress (ERS) which is counteracted by activation of the unfolded protein response (UPR). Many GPCRs modulate ERS and UPR signaling via ERS sensors, IRE1α, PERK, and ATF6, to support cancer cell survival and inhibit cell death. By regulating downstream signaling pathways such as NF-κB, MAPK/ERK, PI3K/AKT, TGF-β, and Wnt/β-catenin, GPCRs also upregulate mesenchymal transcription factors including Snail, ZEB, and Twist superfamilies which regulate cell polarity, cytoskeleton remodeling, migration, and invasion. Likewise, ERS-induced UPR upregulates gene transcription and expression of proteins related to EMT enhancing tumor aggressiveness. Though GPCRs are attractive therapeutic targets in cancer biology, much less is known about their roles in regulating ERS and EMT. Here, we will discuss the interplay in GPCR-ERS linked to the EMT process of cancer cells, with a particular focus on oncogenes and molecular signaling pathways.
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3
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Brodskiy PA, Wu Q, Soundarrajan DK, Huizar FJ, Chen J, Liang P, Narciso C, Levis MK, Arredondo-Walsh N, Chen DZ, Zartman JJ. Decoding Calcium Signaling Dynamics during Drosophila Wing Disc Development. Biophys J 2019; 116:725-740. [PMID: 30704858 PMCID: PMC6382932 DOI: 10.1016/j.bpj.2019.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 12/04/2018] [Accepted: 01/04/2019] [Indexed: 01/07/2023] Open
Abstract
The robust specification of organ development depends on coordinated cell-cell communication. This process requires signal integration among multiple pathways, relying on second messengers such as calcium ions. Calcium signaling encodes a significant portion of the cellular state by regulating transcription factors, enzymes, and cytoskeletal proteins. However, the relationships between the inputs specifying cell and organ development, calcium signaling dynamics, and final organ morphology are poorly understood. Here, we have designed a quantitative image-analysis pipeline for decoding organ-level calcium signaling. With this pipeline, we extracted spatiotemporal features of calcium signaling dynamics during the development of the Drosophila larval wing disc, a genetic model for organogenesis. We identified specific classes of wing phenotypes that resulted from calcium signaling pathway perturbations, including defects in gross morphology, vein differentiation, and overall size. We found four qualitative classes of calcium signaling activity. These classes can be ordered based on agonist stimulation strength Gαq-mediated signaling. In vivo calcium signaling dynamics depend on both receptor tyrosine kinase/phospholipase C γ and G protein-coupled receptor/phospholipase C β activities. We found that spatially patterned calcium dynamics correlate with known differential growth rates between anterior and posterior compartments. Integrated calcium signaling activity decreases with increasing tissue size, and it responds to morphogenetic perturbations that impact organ growth. Together, these findings define how calcium signaling dynamics integrate upstream inputs to mediate multiple response outputs in developing epithelial organs.
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Affiliation(s)
- Pavel A Brodskiy
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Qinfeng Wu
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Dharsan K Soundarrajan
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Francisco J Huizar
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Jianxu Chen
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Peixian Liang
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Cody Narciso
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Megan K Levis
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana
| | | | - Danny Z Chen
- Department of Computer Science and Engineering, University of Notre Dame, Notre Dame, Indiana
| | - Jeremiah J Zartman
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana.
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4
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Wang J, Song Y, Zhang M, Wu Z, Xu YJ, Lin J, Ling D, Sheng Y, Lu Y, Wu Q. A liposomal curcumol nanocomposite for magnetic resonance imaging and endoplasmic reticulum stress-mediated chemotherapy of human primary ovarian cancer. J Mater Chem B 2019. [DOI: 10.1039/c8tb03123a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A liposomal curcumol nanocomposite has been successfully synthesized for the theranostics of human primary ovarian cancer cells from solid tumor tissue in patients.
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Affiliation(s)
- Jing Wang
- School of Basic Medical Sciences
- Anhui Medical University
- Hefei
- P. R. China
- Department of Obstetrics and Gynecology
| | - Yonghong Song
- School of Chemistry and Chemical Engineering
- Hefei University of Technology
- Hefei
- P. R. China
| | - Mingxun Zhang
- Department of Pathology
- Anhui Medical University
- Hefei
- P. R. China
| | - Zhensheng Wu
- Department of Pathology
- Anhui Medical University
- Hefei
- P. R. China
| | - Yun-Jun Xu
- University of Science and Technology of China
- Hefei
- P. R. China
| | - Jun Lin
- University of Science and Technology of China
- Hefei
- P. R. China
| | - Daishun Ling
- College of Pharmaceutical Sciences
- Zhejiang University
- Hangzhou 310058
- P. R. China
| | - Youjing Sheng
- Department of Pathology
- Anhui Medical University
- Hefei
- P. R. China
| | - Yang Lu
- School of Chemistry and Chemical Engineering
- Hefei University of Technology
- Hefei
- P. R. China
| | - Qiang Wu
- School of Basic Medical Sciences
- Anhui Medical University
- Hefei
- P. R. China
- Department of Pathology
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5
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Neohesperidin Prevents Aβ25–35-Induced Apoptosis in Primary Cultured Hippocampal Neurons by Blocking the S-Nitrosylation of Protein-Disulphide Isomerase. Neurochem Res 2018; 43:1736-1744. [DOI: 10.1007/s11064-018-2589-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 06/04/2018] [Accepted: 06/24/2018] [Indexed: 01/06/2023]
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6
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Stewart DP, Marada S, Bodeen WJ, Truong A, Sakurada SM, Pandit T, Pruett-Miller SM, Ogden SK. Cleavage activates dispatched for Sonic Hedgehog ligand release. eLife 2018; 7:31678. [PMID: 29359685 PMCID: PMC5811216 DOI: 10.7554/elife.31678] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/22/2018] [Indexed: 12/12/2022] Open
Abstract
Hedgehog ligands activate an evolutionarily conserved signaling pathway that provides instructional cues during tissue morphogenesis, and when corrupted, contributes to developmental disorders and cancer. The transmembrane protein Dispatched is an essential component of the machinery that deploys Hedgehog family ligands from producing cells, and is absolutely required for signaling to long-range targets. Despite this crucial role, regulatory mechanisms controlling Dispatched activity remain largely undefined. Herein, we reveal vertebrate Dispatched is activated by proprotein convertase-mediated cleavage at a conserved processing site in its first extracellular loop. Dispatched processing occurs at the cell surface to instruct its membrane re-localization in polarized epithelial cells. Cleavage site mutation alters Dispatched membrane trafficking and reduces ligand release, leading to compromised pathway activity in vivo. As such, convertase-mediated cleavage is required for Dispatched maturation and functional competency in Hedgehog ligand-producing cells.
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Affiliation(s)
- Daniel P Stewart
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Suresh Marada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - William J Bodeen
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States.,Integrated Program in Biomedical Sciences, University of Tennessee Health Sciences Center, Memphis, United States
| | - Ashley Truong
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Sadie Miki Sakurada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States.,Center for Advanced Genome Engineering, St. Jude Children's Research Hospital, Memphis, United States
| | - Tanushree Pandit
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
| | - Shondra M Pruett-Miller
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States.,Center for Advanced Genome Engineering, St. Jude Children's Research Hospital, Memphis, United States
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, United States
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7
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Bodeen WJ, Marada S, Truong A, Ogden SK. A fixation method to preserve cultured cell cytonemes facilitates mechanistic interrogation of morphogen transport. Development 2017; 144:3612-3624. [PMID: 28827391 PMCID: PMC5665483 DOI: 10.1242/dev.152736] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 08/14/2017] [Indexed: 12/11/2022]
Abstract
During development, extracellular cues guiding cell fate determination are provided by morphogens. One mechanism by which morphogens are proposed to traverse extracellular space is by traveling along specialized filopodia called cytonemes. These cellular highways extend between signal-producing and -receiving cells to enable direct morphogen delivery. Although genetic studies support cytoneme involvement in morphogen transport, mechanistic insight into how they are regulated is limited owing to technical challenges associated with performing cell biological analysis of the delicate filopodial structures. Here, we introduce a fixation method whereby cultured cell cytonemes can be preserved for imaging studies, allowing investigation of cytoneme regulation using standard cell biological techniques. Using this method, we examined Hedgehog-containing cytonemes and identified a role for the Hedgehog deployment protein Dispatched in cytoneme stabilization. We demonstrate that Hedgehog and Dispatched colocalize in cytonemes, and that cholesterol-modified Hedgehog acts through Dispatched to increase cytoneme occurrence. Live imaging suggests that this occurs through Dispatched-mediated slowing of cytoneme retraction rates. Dispatched-induced cytoneme modulation was recapitulated in wing imaginal discs of transgenic Drosophila, providing evidence that cultured cell cytoneme analysis is predictive of in vivo functionality. Summary: A new fixation method for preserving cultured cell cytonemes, used in combination with live cell imaging, reveals that the Hedgehog deployment protein Dispatched promotes cytoneme occurrence by slowing retraction rates.
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Affiliation(s)
- William J Bodeen
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.,Integrated Program in Biomedical Sciences, University of Tennessee Health Sciences Center, Memphis, TN, 38163, USA
| | - Suresh Marada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Ashley Truong
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
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8
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Cubillos-Ruiz JR, Bettigole SE, Glimcher LH. Tumorigenic and Immunosuppressive Effects of Endoplasmic Reticulum Stress in Cancer. Cell 2017; 168:692-706. [PMID: 28187289 DOI: 10.1016/j.cell.2016.12.004] [Citation(s) in RCA: 573] [Impact Index Per Article: 81.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 11/29/2016] [Accepted: 12/01/2016] [Indexed: 12/13/2022]
Abstract
Malignant cells utilize diverse strategies that enable them to thrive under adverse conditions while simultaneously inhibiting the development of anti-tumor immune responses. Hostile microenvironmental conditions within tumor masses, such as nutrient deprivation, oxygen limitation, high metabolic demand, and oxidative stress, disturb the protein-folding capacity of the endoplasmic reticulum (ER), thereby provoking a cellular state of "ER stress." Sustained activation of ER stress sensors endows malignant cells with greater tumorigenic, metastatic, and drug-resistant capacity. Additionally, recent studies have uncovered that ER stress responses further impede the development of protective anti-cancer immunity by manipulating the function of myeloid cells in the tumor microenvironment. Here, we discuss the tumorigenic and immunoregulatory effects of ER stress in cancer, and we explore the concept of targeting ER stress responses to enhance the efficacy of standard chemotherapies and evolving cancer immunotherapies in the clinic.
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Affiliation(s)
- Juan R Cubillos-Ruiz
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, NY 10065, USA; Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA.
| | | | - Laurie H Glimcher
- Department of Medicine, Harvard Medical School and Brigham and Women's Hospital, Boston, MA 02215, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
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9
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Le Reste PJ, Avril T, Quillien V, Morandi X, Chevet E. Reprint of: Signaling the Unfolded Protein Response in primary brain cancers. Brain Res 2016; 1648:542-552. [PMID: 27362469 DOI: 10.1016/j.brainres.2016.06.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/16/2016] [Accepted: 03/17/2016] [Indexed: 11/15/2022]
Abstract
The Unfolded Protein Response (UPR) is an adaptive cellular program used by eukaryotic cells to cope with protein misfolding stress in the Endoplasmic Reticulum (ER). During tumor development, cancer cells are facing intrinsic (oncogene activation) and extrinsic (limiting nutrient or oxygen supply; exposure to chemotherapies) challenges, with which they must cope to survive. Primary brain tumors are relatively rare but deadly and present a significant challenge in the determination of risk factors in the population. These tumors are inherently difficult to cure because of their protected location in the brain. As such surgery, radiation and chemotherapy options carry potentially lasting patient morbidity and incomplete tumor cure. Some of these tumors, such as glioblastoma, were reported to present features of ER stress and to depend on UPR activation to sustain growth, but to date there is no clear general representation of the ER stress status in primary brain tumors. In this review, we describe the key molecular mechanisms controlling the UPR and their implication in cancers. Then we extensively review the literature reporting the status of ER stress in various primary brain tumors and discuss the potential impact of such observation on patient stratification and on the possibility of developing appropriate targeted therapies using the UPR as therapeutic target. This article is part of a Special Issue entitled SI:ER stress.
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Affiliation(s)
- Pierre-Jean Le Reste
- Department of Neurosurgery, University Hospital Pontchaillou, Rennes, France; Inserm ERL440 "Oncogenesis, Stress, Signaling", Université de Rennes 1, Rennes, France
| | - Tony Avril
- Inserm ERL440 "Oncogenesis, Stress, Signaling", Université de Rennes 1, Rennes, France; Centre de Lutte Contre le Cancer Eugène Marquis, Rennes, France
| | - Véronique Quillien
- Inserm ERL440 "Oncogenesis, Stress, Signaling", Université de Rennes 1, Rennes, France; Centre de Lutte Contre le Cancer Eugène Marquis, Rennes, France
| | - Xavier Morandi
- Department of Neurosurgery, University Hospital Pontchaillou, Rennes, France
| | - Eric Chevet
- Inserm ERL440 "Oncogenesis, Stress, Signaling", Université de Rennes 1, Rennes, France; Centre de Lutte Contre le Cancer Eugène Marquis, Rennes, France.
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10
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Le Reste PJ, Avril T, Quillien V, Morandi X, Chevet E. Signaling the Unfolded Protein Response in primary brain cancers. Brain Res 2016; 1642:59-69. [PMID: 27016056 DOI: 10.1016/j.brainres.2016.03.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 03/16/2016] [Accepted: 03/17/2016] [Indexed: 12/14/2022]
Abstract
The Unfolded Protein Response (UPR) is an adaptive cellular program used by eukaryotic cells to cope with protein misfolding stress in the Endoplasmic Reticulum (ER). During tumor development, cancer cells are facing intrinsic (oncogene activation) and extrinsic (limiting nutrient or oxygen supply; exposure to chemotherapies) challenges, with which they must cope to survive. Primary brain tumors are relatively rare but deadly and present a significant challenge in the determination of risk factors in the population. These tumors are inherently difficult to cure because of their protected location in the brain. As such surgery, radiation and chemotherapy options carry potentially lasting patient morbidity and incomplete tumor cure. Some of these tumors, such as glioblastoma, were reported to present features of ER stress and to depend on UPR activation to sustain growth, but to date there is no clear general representation of the ER stress status in primary brain tumors. In this review, we describe the key molecular mechanisms controlling the UPR and their implication in cancers. Then we extensively review the literature reporting the status of ER stress in various primary brain tumors and discuss the potential impact of such observation on patient stratification and on the possibility of developing appropriate targeted therapies using the UPR as therapeutic target.
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Affiliation(s)
- Pierre-Jean Le Reste
- Department of Neurosurgery, University Hospital Pontchaillou, Rennes, France; Inserm ERL440 "Oncogenesis, Stress, Signaling", Université de Rennes 1, Rennes, France
| | - Tony Avril
- Inserm ERL440 "Oncogenesis, Stress, Signaling", Université de Rennes 1, Rennes, France; Centre de Lutte Contre le Cancer Eugène Marquis, Rennes, France
| | - Véronique Quillien
- Inserm ERL440 "Oncogenesis, Stress, Signaling", Université de Rennes 1, Rennes, France; Centre de Lutte Contre le Cancer Eugène Marquis, Rennes, France
| | - Xavier Morandi
- Department of Neurosurgery, University Hospital Pontchaillou, Rennes, France
| | - Eric Chevet
- Inserm ERL440 "Oncogenesis, Stress, Signaling", Université de Rennes 1, Rennes, France; Centre de Lutte Contre le Cancer Eugène Marquis, Rennes, France.
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11
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Hormesis: Decoding Two Sides of the Same Coin. Pharmaceuticals (Basel) 2015; 8:865-83. [PMID: 26694419 PMCID: PMC4695814 DOI: 10.3390/ph8040865] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 12/09/2015] [Accepted: 12/11/2015] [Indexed: 12/13/2022] Open
Abstract
In the paradigm of drug administration, determining the correct dosage of a therapeutic is often a challenge. Several drugs have been noted to demonstrate contradictory effects per se at high and low doses. This duality in function of a drug at different concentrations is known as hormesis. Therefore, it becomes necessary to study these biphasic functions in order to understand the mechanistic basis of their effects. In this article, we focus on different molecules and pathways associated with diseases that possess a duality in their function and thus prove to be the seat of hormesis. In particular, we have highlighted the pathways and factors involved in the progression of cancer and how the biphasic behavior of the molecules involved can alter the manifestations of cancer. Because of the pragmatic role that it exhibits, the imminent need is to draw attention to the concept of hormesis. Herein, we also discuss different stressors that trigger hormesis and how stress-mediated responses increase the overall adaptive response of an individual to stress stimulus. We talk about common pathways through which cancer progresses (such as nuclear factor erythroid 2-related factor 2-Kelch-like ECH-associated protein 1 (Nrf2-Keap1), sirtuin-forkhead box O (SIRT-FOXO) and others), analyzing how diverse molecules associated with these pathways conform to hormesis.
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12
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Marada S, Truong A, Ogden SK. The small GTPase Rap1 is a modulator of Hedgehog signaling. Dev Biol 2015; 409:84-94. [PMID: 26481064 DOI: 10.1016/j.ydbio.2015.10.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 10/15/2015] [Accepted: 10/16/2015] [Indexed: 12/31/2022]
Abstract
During development, the evolutionarily conserved Hedgehog (Hh) morphogen provides instructional cues that influence cell fate, cell affinity and tissue morphogenesis. To do so, the Hh signaling cascade must coordinate its activity with other morphogenetic signals. This can occur through engagement of or response to effectors that do not typically function as core Hh pathway components. Given the ability of small G proteins of the Ras family to impact cell survival, differentiation, growth and adhesion, we wanted to determine whether Hh and Ras signaling might intersect during development. We performed genetic modifier tests in Drosophila to examine the ability of select Ras family members to influence Hh signal output, and identified Rap1 as a positive modulator of Hh pathway activity. Our results suggest that Rap1 is activated to its GTP-bound form in response to Hh ligand, and that the GTPase exchange factor C3G likely contributes to this activation. The Rap1 effector Canoe (Cno) also impacts Hh signal output, suggesting that a C3G-Rap1-Cno axis intersects the Hh pathway during tissue morphogenesis.
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Affiliation(s)
- Suresh Marada
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States
| | - Ashley Truong
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States; Rhodes College Summer Plus Program, Rhodes College, Memphis, TN 38112, United States
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, United States.
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13
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Arensdorf AM, Marada S, Ogden SK. Smoothened Regulation: A Tale of Two Signals. Trends Pharmacol Sci 2015; 37:62-72. [PMID: 26432668 DOI: 10.1016/j.tips.2015.09.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/31/2015] [Accepted: 09/01/2015] [Indexed: 02/09/2023]
Abstract
The G protein-coupled receptor (GPCR) Smoothened (Smo) is the signal transducer of the developmentally and therapeutically relevant Hedgehog (Hh) pathway. Although recent structural analyses have advanced our understanding of Smo biology, several questions remain. Chief among them are the identity of its natural ligand, the regulatory processes controlling its activation, and the mechanisms by which it signals to downstream effectors. In this review, we discuss recent discoveries from multiple model systems that have set the stage for solving these mysteries. We focus on the roles of distinct Smo functional domains, post-translational modifications, and trafficking, and conclude by discussing their contributions to signal output.
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Affiliation(s)
- Angela M Arensdorf
- Department of Cell and Molecular Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place MS#340, Memphis, TN 38105, USA
| | - Suresh Marada
- Department of Cell and Molecular Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place MS#340, Memphis, TN 38105, USA
| | - Stacey K Ogden
- Department of Cell and Molecular Biology, St Jude Children's Research Hospital, 262 Danny Thomas Place MS#340, Memphis, TN 38105, USA.
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14
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Marada S, Navarro G, Truong A, Stewart DP, Arensdorf AM, Nachtergaele S, Angelats E, Opferman JT, Rohatgi R, McCormick PJ, Ogden SK. Functional Divergence in the Role of N-Linked Glycosylation in Smoothened Signaling. PLoS Genet 2015; 11:e1005473. [PMID: 26291458 PMCID: PMC4546403 DOI: 10.1371/journal.pgen.1005473] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 07/28/2015] [Indexed: 01/06/2023] Open
Abstract
The G protein-coupled receptor (GPCR) Smoothened (Smo) is the requisite signal transducer of the evolutionarily conserved Hedgehog (Hh) pathway. Although aspects of Smo signaling are conserved from Drosophila to vertebrates, significant differences have evolved. These include changes in its active sub-cellular localization, and the ability of vertebrate Smo to induce distinct G protein-dependent and independent signals in response to ligand. Whereas the canonical Smo signal to Gli transcriptional effectors occurs in a G protein-independent manner, its non-canonical signal employs Gαi. Whether vertebrate Smo can selectively bias its signal between these routes is not yet known. N-linked glycosylation is a post-translational modification that can influence GPCR trafficking, ligand responsiveness and signal output. Smo proteins in Drosophila and vertebrate systems harbor N-linked glycans, but their role in Smo signaling has not been established. Herein, we present a comprehensive analysis of Drosophila and murine Smo glycosylation that supports a functional divergence in the contribution of N-linked glycans to signaling. Of the seven predicted glycan acceptor sites in Drosophila Smo, one is essential. Loss of N-glycosylation at this site disrupted Smo trafficking and attenuated its signaling capability. In stark contrast, we found that all four predicted N-glycosylation sites on murine Smo were dispensable for proper trafficking, agonist binding and canonical signal induction. However, the under-glycosylated protein was compromised in its ability to induce a non-canonical signal through Gαi, providing for the first time evidence that Smo can bias its signal and that a post-translational modification can impact this process. As such, we postulate a profound shift in N-glycan function from affecting Smo ER exit in flies to influencing its signal output in mice. N-linked glycosylation is a post-translational modification occurring on membrane proteins such as G protein-coupled receptors (GPCR). Smoothened (Smo) is a GPCR that functions as the signal transducer of the Hedgehog (Hh) pathway. We used a mutagenesis approach to assess the role of N-glycans in Smo signaling in two genetic models for Hh pathway activity, Drosophila and mouse. In doing so, we discovered a divergence in glycan function between them. We mapped an essential N-glycan acceptor site that when lost in Drosophila, triggered ER retention, altered Smo protein stability and blunted its signaling capacity. Conversely, ER exit of the murine protein was unaffected by glycan loss, as was its ability to traffic and induce a G protein-independent signal to activate Hh target genes. However, the ability of vertebrate Smo to induce a distinct G protein-dependent signal was lost. This suggests that N-linked glycosylation may influence signal bias of vertebrate Smo to favor one signal output over the other. We therefore propose that the role of this conserved post-translational modification may have been repurposed from governing Smo ER exit in the fly to influencing effector route selection in vertebrates.
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Affiliation(s)
- Suresh Marada
- Department of Cell & Molecular Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Gemma Navarro
- Department of Biochemistry and Molecular Biology, Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)University of Barcelona, Barcelona, Spain
| | - Ashley Truong
- Department of Cell & Molecular Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
- Summer Plus Program, Rhodes College, Memphis, Tennessee, United States of America
| | - Daniel P. Stewart
- Department of Cell & Molecular Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Angela M. Arensdorf
- Department of Cell & Molecular Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Sigrid Nachtergaele
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
| | - Edgar Angelats
- Department of Biochemistry and Molecular Biology, Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)University of Barcelona, Barcelona, Spain
| | - Joseph T. Opferman
- Department of Cell & Molecular Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Rajat Rohatgi
- Departments of Medicine and Biochemistry, Stanford University School of Medicine, Stanford, California, United States of America
| | - Peter J. McCormick
- Department of Biochemistry and Molecular Biology, Centro de Investigacion Biomedica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)University of Barcelona, Barcelona, Spain
- School of Pharmacy, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Stacey K. Ogden
- Department of Cell & Molecular Biology, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
- * E-mail:
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Mollereau B, Manié S, Napoletano F. Getting the better of ER stress. J Cell Commun Signal 2014; 8:311-21. [PMID: 25354560 DOI: 10.1007/s12079-014-0251-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 10/15/2014] [Indexed: 12/11/2022] Open
Abstract
Research over the past few years has highlighted the ability of the unfolded protein response (UPR) to minimize the deleterious effects of accumulated misfolded proteins under both physiological and pathological conditions. The endoplasmic reticulum (ER) adapts to endogenous and exogenous stressors by expanding its protein-folding capacity and by stimulating protective processes such as autophagy and antioxidant responses. Although it is clear that severe ER stress can elicit cell death, several recent studies have shown that low levels of ER stress may actually be beneficial to cells by eliciting an adaptive UPR that 'preconditions' the cell to a subsequent lethal insult; this process is called ER hormesis. The findings have important implications for the treatment of a wide variety of diseases associated with defective proteostasis, including neurodegenerative diseases, diabetes, and cancer. Here, we review the physiological and pathological functions of the ER, with a particular focus on the molecular mechanisms that lead to ER hormesis and cellular protection, and discuss the implications for disease treatment.
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Affiliation(s)
- Bertrand Mollereau
- Laboratory of Molecular Biology of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, UMS 3444 Biosciences Lyon Gerland, University of Lyon, Lyon, France,
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16
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Wang M, Kaufman RJ. The impact of the endoplasmic reticulum protein-folding environment on cancer development. Nat Rev Cancer 2014; 14:581-97. [PMID: 25145482 DOI: 10.1038/nrc3800] [Citation(s) in RCA: 776] [Impact Index Per Article: 77.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The endoplasmic reticulum (ER) is an essential organelle in eukaryotic cells for the storage and regulated release of calcium and as the entrance to the secretory pathway. Protein misfolding in the ER causes accumulation of misfolded proteins (ER stress) and activation of the unfolded protein response (UPR), which has evolved to maintain a productive ER protein-folding environment. Both ER stress and UPR activation are documented in many different human cancers. In this Review, we summarize the impact of ER stress and UPR activation on every aspect of cancer and discuss outstanding questions for which answers will pave the way for therapeutics.
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Affiliation(s)
- Miao Wang
- Degenerative Diseases Program, Center for Cancer Research, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd, La Jolla, California 92037, USA
| | - Randal J Kaufman
- Degenerative Diseases Program, Center for Cancer Research, Sanford-Burnham Medical Research Institute, 10901 N. Torrey Pines Rd, La Jolla, California 92037, USA
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17
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Establishing links between endoplasmic reticulum-mediated hormesis and cancer. Mol Cell Biol 2013; 33:2372-4. [PMID: 23572563 DOI: 10.1128/mcb.00315-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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