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Simbilyabo LZ, Yang L, Wen J, Liu Z. The unfolded protein response machinery in glioblastoma genesis, chemoresistance and as a druggable target. CNS Neurosci Ther 2024; 30:e14839. [PMID: 39021040 PMCID: PMC11255034 DOI: 10.1111/cns.14839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 06/22/2024] [Accepted: 06/24/2024] [Indexed: 07/20/2024] Open
Abstract
BACKGROUND The role of the unfolded protein response (UPR) has been progressively unveiled over the last decade and several studies have investigated its implication in glioblastoma (GB) development. The UPR restores cellular homeostasis by triggering the folding and clearance of accumulated misfolded proteins in the ER consecutive to endoplasmic reticulum stress. In case it is overwhelmed, it induces apoptotic cell death. Thus, holding a critical role in cell fate decisions. METHODS This article, reviews how the UPR is implicated in cell homeostasis maintenance, then surveils the evidence supporting the UPR involvement in GB genesis, progression, angiogenesis, GB stem cell biology, tumor microenvironment modulation, extracellular matrix remodeling, cell fate decision, invasiveness, and grading. Next, it concurs the evidence showing how the UPR mediates GB chemoresistance-related mechanisms. RESULTS The UPR stress sensors IRE1, PERK, and ATF6 with their regulator GRP78 are upregulated in GB compared to lower grade gliomas and normal brain tissue. They are activated in response to oncogenes and are implicated at different stages of GB progression, from its genesis to chemoresistance and relapse. The UPR arms can be effectors of apoptosis as mediators or targets. CONCLUSION Recent research has established the role of the UPR in GB pathophysiology and chemoresistance. Targeting its different sensors have shown promising in overcoming GB chomo- and radioresistance and inducing apoptosis.
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Affiliation(s)
- Lucette Z. Simbilyabo
- Department of Neurosurgery, Xiangya HospitalCentral South UniversityChangshaHunanChina
- Hypothalamic Pituitary Research Center, Xiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric Disorders, Xiangya HospitalCentral South UniversityChangshaHunanChina
| | - Liting Yang
- Department of Neurosurgery, Xiangya HospitalCentral South UniversityChangshaHunanChina
- Hypothalamic Pituitary Research Center, Xiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric Disorders, Xiangya HospitalCentral South UniversityChangshaHunanChina
| | - Jie Wen
- Department of Neurosurgery, Xiangya HospitalCentral South UniversityChangshaHunanChina
- Hypothalamic Pituitary Research Center, Xiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric Disorders, Xiangya HospitalCentral South UniversityChangshaHunanChina
| | - Zhixiong Liu
- Department of Neurosurgery, Xiangya HospitalCentral South UniversityChangshaHunanChina
- Hypothalamic Pituitary Research Center, Xiangya HospitalCentral South UniversityChangshaHunanChina
- National Clinical Research Center for Geriatric Disorders, Xiangya HospitalCentral South UniversityChangshaHunanChina
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Le Saux CJ, Ho TC, Brumwell AM, Kathiriya JJ, Wei Y, Hughes JWB, Garakani K, Atabai K, Auyeung VC, Papa FR, Chapman HA. BCL-2 Modulates IRE1α Activation to Attenuate Endoplasmic Reticulum Stress and Pulmonary Fibrosis. Am J Respir Cell Mol Biol 2024; 70:247-258. [PMID: 38117250 DOI: 10.1165/rcmb.2023-0109oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 12/19/2023] [Indexed: 12/21/2023] Open
Abstract
BCL-2 family members are known to be implicated in survival in numerous biological settings. Here, we provide evidence that in injury and repair processes in lungs, BCL-2 mainly acts to attenuate endoplasmic reticulum (ER) stress and limit extracellular matrix accumulation. Days after an intratracheal bleomycin challenge, mice lose a fraction of their alveolar type II epithelium from terminal ER stress driven by activation of the critical ER sensor and stress effector IRE1α. This fraction is dramatically increased by BCL-2 inhibition, because IRE1α activation is dependent on its physical association with the BCL-2-proapoptotic family member BAX, and we found BCL-2 to disrupt this association in vitro. In vivo, navitoclax (a BCL-2/BCL-xL inhibitor) given 15-21 days after bleomycin challenge evoked strong activation of IRE-1α in mesenchymal cells and markers of ER stress, but not apoptosis. Remarkably, after BCL-2 inhibition, bleomycin-exposed mice demonstrated persistent collagen accumulation at Day 42, compared with resolution in controls. Enhanced fibrosis proved to be due to the RNAase activity of IRE1α downregulating MRC2 mRNA and protein, a mediator of collagen turnover. The critical role of MRC2 was confirmed in precision-cut lung slice cultures of Day-42 lungs from bleomycin-exposed wild-type and MRC2 null mice. Soluble and tissue collagen accumulated in precision-cut lung slice cultures from navitoclax-treated, bleomycin-challenged mice compared with controls, in a manner nearly identical to that of challenged but untreated MRC2 null mice. Thus, apart from mitochondrial-based antiapoptosis, BCL-2 functions to attenuate ER stress responses, fostering tissue homeostasis and injury repair.
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Affiliation(s)
- Claude Jourdan Le Saux
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Tsung Che Ho
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Alexis M Brumwell
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Jaymin J Kathiriya
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Ying Wei
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | | | - Kiana Garakani
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Kamran Atabai
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Vincent C Auyeung
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Ferroz R Papa
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
| | - Harold A Chapman
- Division of Pulmonary, Critical Care, Allergy, and Sleep Medicine, Department of Medicine, University of California San Francisco, San Francisco, California; and
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Alvarez-Rivera E, Ortiz-Hernández EJ, Lugo E, Lozada-Reyes LM, Boukli NM. Oncogenic Proteomics Approaches for Translational Research and HIV-Associated Malignancy Mechanisms. Proteomes 2023; 11:22. [PMID: 37489388 PMCID: PMC10366845 DOI: 10.3390/proteomes11030022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/09/2023] [Accepted: 06/29/2023] [Indexed: 07/26/2023] Open
Abstract
Recent advances in the field of proteomics have allowed extensive insights into the molecular regulations of the cell proteome. Specifically, this allows researchers to dissect a multitude of signaling arrays while targeting for the discovery of novel protein signatures. These approaches based on data mining are becoming increasingly powerful for identifying both potential disease mechanisms as well as indicators for disease progression and overall survival predictive and prognostic molecular markers for cancer. Furthermore, mass spectrometry (MS) integrations satisfy the ongoing demand for in-depth biomarker validation. For the purpose of this review, we will highlight the current developments based on MS sensitivity, to place quantitative proteomics into clinical settings and provide a perspective to integrate proteomics data for future applications in cancer precision medicine. We will also discuss malignancies associated with oncogenic viruses such as Acquire Immunodeficiency Syndrome (AIDS) and suggest novel mechanisms behind this phenomenon. Human Immunodeficiency Virus type-1 (HIV-1) proteins are known to be oncogenic per se, to induce oxidative and endoplasmic reticulum stresses, and to be released from the infected or expressing cells. HIV-1 proteins can act alone or in collaboration with other known oncoproteins, which cause the bulk of malignancies in people living with HIV-1 on ART.
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Affiliation(s)
- Eduardo Alvarez-Rivera
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR 00960, USA
| | - Emanuel J. Ortiz-Hernández
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR 00960, USA
| | - Elyette Lugo
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR 00960, USA
| | | | - Nawal M. Boukli
- Biomedical Proteomics Facility, Department of Microbiology and Immunology, Universidad Central del Caribe, School of Medicine, Bayamón, PR 00960, USA
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Barua D, Sultana A, Islam MN, Cox F, Gupta A, Gupta S. RRM2 and CDC6 are novel effectors of XBP1-mediated endocrine resistance and predictive markers of tamoxifen sensitivity. BMC Cancer 2023; 23:288. [PMID: 36997866 PMCID: PMC10061897 DOI: 10.1186/s12885-023-10745-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 03/16/2023] [Indexed: 04/01/2023] Open
Abstract
BACKGROUND Endocrine-resistant breast cancers have elevated expression of XBP1, where it drives endocrine resistance by controlling the expression of its target genes. Despite the in-depth understanding of the biological functions of XBP1 in ER-positive breast cancer, effectors of endocrine resistance downstream of XBP1 are poorly understood. The aim of this study was to identify the XBP1-regulated genes contributing to endocrine resistance in breast cancer. METHODS XBP1 deficient sub-clones in MCF7 cells were generated using the CRISPR-Cas9 gene knockout strategy and were validated using western blot and RT-PCR. Cell viability and cell proliferation were evaluated using the MTS assay and colony formation assay, respectively. Cell death and cell cycle analysis were determined using flow cytometry. Transcriptomic data was analysed to identify XBP1-regulated targets and differential expression of target genes was evaluated using western blot and qRT-PCR. Lentivirus and retrovirus transfection were used to generate RRM2 and CDC6 overexpressing clones, respectively. The prognostic value of the XBP1-gene signature was analysed using Kaplan-Meier survival analysis. RESULTS Deletion of XBP1 compromised the upregulation of UPR-target genes during conditions of endoplasmic reticulum (EnR) stress and sensitized cells to EnR stress-induced cell death. Loss of XBP1 in MCF7 cells decreased cell growth, attenuated the induction of estrogen-responsive genes and sensitized them to anti-estrogen agents. The expression of cell cycle associated genes RRM2, CDC6, and TOP2A was significantly reduced upon XBP1 deletion/inhibition in several ER-positive breast cancer cells. Expression of RRM2, CDC6, and TOP2A was increased upon estrogen stimulation and in cells harbouring point-mutants (Y537S, D538G) of ESR1 in steroid free conditions. Ectopic expression of RRM2 and CDC6 increased cell growth and reversed the hypersensitivity of XBP1 KO cells towards tamoxifen conferring endocrine resistance. Importantly, increased expression of XBP1-gene signature was associated with poor outcome and reduced efficacy of tamoxifen treatment in ER-positive breast cancer. CONCLUSIONS Our results suggest that RRM2 and CDC6 downstream of XBP1 contribute to endocrine resistance in ER-positive breast cancer. XBP1-gene signature is associated with poor outcome and response to tamoxifen in ER-positive breast cancer.
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Affiliation(s)
- David Barua
- Discipline of Pathology, Cancer Progression and Treatment Research Group, Lambe Institute for Translational Research, School of Medicine, University of Galway, Galway, Ireland
| | - Afrin Sultana
- Discipline of Pathology, Cancer Progression and Treatment Research Group, Lambe Institute for Translational Research, School of Medicine, University of Galway, Galway, Ireland
| | - Md Nahidul Islam
- Discipline of Biochemistry, School of Medicine, University of Galway, Galway, Ireland
| | - Fergus Cox
- Discipline of Pathology, Cancer Progression and Treatment Research Group, Lambe Institute for Translational Research, School of Medicine, University of Galway, Galway, Ireland
| | - Ananya Gupta
- Discipline of Physiology, Human Biology Building, School of Medicine, University of Galway, Galway, Ireland
| | - Sanjeev Gupta
- Discipline of Pathology, Cancer Progression and Treatment Research Group, Lambe Institute for Translational Research, School of Medicine, University of Galway, Galway, Ireland.
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5
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Ibarra J, Elbanna YA, Kurylowicz K, Ciboddo M, Greenbaum HS, Arellano NS, Rodriguez D, Evers M, Bock-Hughes A, Liu C, Smith Q, Lutze J, Baumeister J, Kalmer M, Olschok K, Nicholson B, Silva D, Maxwell L, Dowgielewicz J, Rumi E, Pietra D, Casetti IC, Catricala S, Koschmieder S, Gurbuxani S, Schneider RK, Oakes SA, Elf SE. Type I but Not Type II Calreticulin Mutations Activate the IRE1α/XBP1 Pathway of the Unfolded Protein Response to Drive Myeloproliferative Neoplasms. Blood Cancer Discov 2022; 3:298-315. [PMID: 35405004 PMCID: PMC9338758 DOI: 10.1158/2643-3230.bcd-21-0144] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 01/21/2022] [Accepted: 04/08/2022] [Indexed: 01/09/2023] Open
Abstract
Approximately 20% of patients with myeloproliferative neoplasms (MPN) harbor mutations in the gene calreticulin (CALR), with 80% of those mutations classified as either type I or type II. While type II CALR-mutant proteins retain many of the Ca2+ binding sites present in the wild-type protein, type I CALR-mutant proteins lose these residues. The functional consequences of this differential loss of Ca2+ binding sites remain unexplored. Here, we show that the loss of Ca2+ binding residues in the type I mutant CALR protein directly impairs its Ca2+ binding ability, which in turn leads to depleted endoplasmic reticulum (ER) Ca2+ and subsequent activation of the IRE1α/XBP1 pathway of the unfolded protein response. Genetic or pharmacologic inhibition of IRE1α/XBP1 signaling induces cell death in type I mutant but not type II mutant or wild-type CALR-expressing cells, and abrogates type I mutant CALR-driven MPN disease progression in vivo. SIGNIFICANCE Current targeted therapies for CALR-mutated MPNs are not curative and fail to differentiate between type I- versus type II-driven disease. To improve treatment strategies, it is critical to identify CALR mutation type-specific vulnerabilities. Here we show that IRE1α/XBP1 represents a unique, targetable dependency specific to type I CALR-mutated MPNs. This article is highlighted in the In This Issue feature, p. 265.
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Affiliation(s)
- Juan Ibarra
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
- Committee on Cancer Biology, University of Chicago, Chicago, Illinois
| | - Yassmin A. Elbanna
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Katarzyna Kurylowicz
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Michele Ciboddo
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Harrison S. Greenbaum
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Nicole S. Arellano
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Deborah Rodriguez
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Maria Evers
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
- Committee on Cancer Biology, University of Chicago, Chicago, Illinois
| | - Althea Bock-Hughes
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Chenyu Liu
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Quinn Smith
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Julian Lutze
- Committee on Cancer Biology, University of Chicago, Chicago, Illinois
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois
| | - Julian Baumeister
- Department of Hematology, Oncology, Hemostaseology and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University and Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Milena Kalmer
- Department of Hematology, Oncology, Hemostaseology and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University and Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Kathrin Olschok
- Department of Hematology, Oncology, Hemostaseology and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University and Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | - Benjamin Nicholson
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
- Committee on Cancer Biology, University of Chicago, Chicago, Illinois
| | - Diane Silva
- Department of Pathology, University of Chicago, Chicago, Illinois
| | - Luke Maxwell
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
| | - Jonathan Dowgielewicz
- Committee on Molecular Metabolism and Nutrition, University of Chicago, Chicago, Illinois
| | - Elisa Rumi
- Department of Hematology Oncology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Daniela Pietra
- Department of Hematology Oncology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy
| | | | - Silvia Catricala
- Department of Hematology Oncology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico Policlinico San Matteo, Pavia, Italy
| | - Steffen Koschmieder
- Department of Hematology, Oncology, Hemostaseology and Stem Cell Transplantation, Faculty of Medicine, RWTH Aachen University and Center for Integrated Oncology Aachen Bonn Cologne Düsseldorf (CIO ABCD), Aachen, Germany
| | | | - Rebekka K. Schneider
- Department of Cell Biology, Institute for Biomedical Technologies, RWTH Aachen University, Aachen, Germany
- Department of Hematology, Erasmus MC Cancer Institute, Rotterdam, the Netherlands
| | - Scott A. Oakes
- Committee on Cancer Biology, University of Chicago, Chicago, Illinois
- Department of Pathology, University of Chicago, Chicago, Illinois
| | - Shannon E. Elf
- The Ben May Department for Cancer Research, University of Chicago, Chicago, Illinois
- Committee on Cancer Biology, University of Chicago, Chicago, Illinois
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Hunt EG, Andrews AM, Larsen SR, Thaxton JE. The ER-Mitochondria Interface as a Dynamic Hub for T Cell Efficacy in Solid Tumors. Front Cell Dev Biol 2022; 10:867341. [PMID: 35573704 PMCID: PMC9091306 DOI: 10.3389/fcell.2022.867341] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/28/2022] [Indexed: 01/09/2023] Open
Abstract
The endoplasmic reticulum (ER) is a large continuous membranous organelle that plays a central role as the hub of protein and lipid synthesis while the mitochondria is the principal location for energy production. T cells are an immune subset exhibiting robust dependence on ER and mitochondrial function based on the need for protein synthesis and secretion and metabolic dexterity associated with foreign antigen recognition and cytotoxic effector response. Intimate connections exist at mitochondrial-ER contact sites (MERCs) that serve as the structural and biochemical platforms for cellular metabolic homeostasis through regulation of fission and fusion as well as glucose, Ca2+, and lipid exchange. Work in the tumor immunotherapy field indicates that the complex interplay of nutrient deprivation and tumor antigen stimulation in the tumor microenvironment places stress on the ER and mitochondria, causing dysfunction in organellar structure and loss of metabolic homeostasis. Here, we assess prior literature that establishes how the structural interface of these two organelles is impacted by the stress of solid tumors along with recent advances in the manipulation of organelle homeostasis at MERCs in T cells. These findings provide strong evidence for increased tumor immunity using unique therapeutic avenues that recharge cellular metabolic homeostasis in T cells.
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Affiliation(s)
- Elizabeth G. Hunt
- Immunotherapy Program, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States,Department of Cell Biology and Physiology, School of Medicine, University of North Carolina, Chapel Hill, NC, United States
| | - Alex M. Andrews
- Hollings Cancer Center, Charleston, SC, United States,Department of Orthopedics and Physical Medicine, Medical University of South Carolina, Charleston, SC, United States
| | | | - Jessica E. Thaxton
- Immunotherapy Program, Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, United States,Department of Cell Biology and Physiology, School of Medicine, University of North Carolina, Chapel Hill, NC, United States,*Correspondence: Jessica E. Thaxton,
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Glab JA, Cao Z, Puthalakath H. Bcl-2 family proteins, beyond the veil. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 351:1-22. [PMID: 32247577 DOI: 10.1016/bs.ircmb.2019.12.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Apoptosis is an important part of both health and disease and is often regulated by the BCL-2 family of proteins. These proteins are either pro- or anti-apoptotic, existing in a delicate balance during homeostasis. They are best known for their role in regulating the activation of caspases and the execution of a cell in response to a variety of stimuli. However, it is often forgotten that these BCL-2 family proteins also have important roles to play in cell maintenance that are not associated with apoptosis. These include roles in regulating processes such as cell cycle progression, mitochondrial function, autophagy, intracellular calcium concentration, glucose and lipid metabolism, and the unfolded protein response. In addition to these established alternate functions, further discoveries are being made that have potential therapeutic benefits in diseases such as cancer. BOK, a BCL-2 family protein thought comparable to multidomain pro-apoptotic proteins BAX and BAK, has recently been identified as a key player in metabolism of and resistance to the commonly used chemotherapeutic 5-FU. As a result of such findings, which could see the potential use of BOK as a biomarker for 5-FU sensitivity or mimetic molecules as a resensitization strategy, new targets and mechanisms of pathology may arise from further investigation into the realm of alternate functions of BCL-2 family proteins.
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Affiliation(s)
- Jason Andrew Glab
- Department of Biochemistry and Genetics, La Trobe University, Bundoora, VIC, Australia
| | - Zhipeng Cao
- Department of Biochemistry and Genetics, La Trobe University, Bundoora, VIC, Australia
| | - Hamsa Puthalakath
- Department of Biochemistry and Genetics, La Trobe University, Bundoora, VIC, Australia.
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8
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Men L, Yu S, Yao J, Li Y, Ren D, Du J. Selenoprotein S protects against adipocyte death through mediation of the IRE1α-sXBP1 pathway. Biochem Biophys Res Commun 2018; 503:2866-2871. [PMID: 30146262 DOI: 10.1016/j.bbrc.2018.08.057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 08/06/2018] [Indexed: 10/28/2022]
Abstract
As the most conserved branch of the unfolded protein response (UPR), the inositol-requiring enzyme 1a (IRE1a)/X-box binding protein 1 (XBP1) pathway plays crucial roles in cell survival and cell death by upregulating UPR-associated genes involved in protein entry into the endoplasmic reticulum (ER) and ER-associated degradation (ERAD). Selenoprotein S (SelS) is localized to the ER membrane and involved in ERAD. Although SelS plays an important role in restoring ER stress, the SelS-dependent protective mechanisms against cell death remain unclear. Here, using an inducible SelS knockdown (KD) 3T3-L1 cell model, we showed that SelS KD resulted adipocyte death, which was associated with imbalance of the Bcl-2 family members. Furthermore, SelS KD decreased spliced XBP1 (sXBP1), increased IRE1α and p-JNK, suggesting a role of SelS in the modulation of the IRE1α-sXBP1 pathway. Moreover, adipocyte death induced by SelS suppression can be inhibited by overexpression of sXBP1. Thus, it is proposed that SelS promotes cell survival through the IRE1α-XBP1 signaling pathway.
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Affiliation(s)
- Lili Men
- Department of Endocrinology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Shanshan Yu
- Department of Endocrinology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Junjie Yao
- Department of Endocrinology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Yu Li
- Department of Endocrinology, The First Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Decheng Ren
- Department of Medicine, The University of Chicago, Chicago, IL, USA.
| | - Jianling Du
- Department of Endocrinology, The First Affiliated Hospital of Dalian Medical University, Dalian, China.
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9
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Wu L, Liu H, Li L, Xu D, Gao Y, Guan Y, Chen Q. 5,7,3',4'-Tetramethoxyflavone protects chondrocytes from ER stress-induced apoptosis through regulation of the IRE1α pathway. Connect Tissue Res 2018; 59:157-166. [PMID: 28436754 PMCID: PMC6104397 DOI: 10.1080/03008207.2017.1321639] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
AIM OF THE STUDY To investigate the roles of endoplasmic reticulum (ER) transmembrane sensor inositol-requiring enzyme-1 (IRE1)α signaling in ER stress-induced chondrocyte apoptosis, and to determine the molecular mechanisms underlying chondroprotective activity of 5,7,3',4'-tetramethoxyflavone (TMF) from Murraya exotica. MATERIALS AND METHODS IRE1α was knocked down by siRNA transfection in chondrocytes, which were harvested from rats' knee cartilages. Chondrocytes with IRE1α deficiency were administrated with tunicamycin (TM) and TMF. Chondrocyte apoptosis was quantified by flow cytometry and DAPI/TUNEL staining. Expression of mRNA and proteins was quantified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western-blot, respectively. RESULTS IRE1α deficiency significantly increased the rate of TM-induced chondrocyte apoptosis, down-regulated the expression of pro-survival factors XBP1S and Bcl-2, and up-regulated pro-apoptotic factors CHOP, p-JNK, and caspase-3. TMF suppressed TM-induced chondrocyte apoptosis by activating the expression of IRE1α, which reversed the expression patterns of downstream pro-survival and pro-apoptotic factors due to IRE1α deficiency. CONCLUSION The mechanism of TMF in protecting chondrocytes against ER stress-induced apoptosis might be associated with regulating the activity of ER sensor IRE1α and its downstream pathway.
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Affiliation(s)
- Longhuo Wu
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA;,College of Pharmacy, Gannan Medical University, Ganzhou, China
| | - Haiqing Liu
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA;,College of Pharmacy, Gannan Medical University, Ganzhou, China
| | - Linfu Li
- College of Pharmacy, Gannan Medical University, Ganzhou, China
| | - Daohua Xu
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA;,Department of Pharmacology, Guangdong Medical University, Dongguan, China
| | - Yun Gao
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA
| | - Yingjie Guan
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA
| | - Qian Chen
- Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA
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10
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Gross A, Katz SG. Non-apoptotic functions of BCL-2 family proteins. Cell Death Differ 2017; 24:1348-1358. [PMID: 28234359 PMCID: PMC5520452 DOI: 10.1038/cdd.2017.22] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 01/26/2017] [Accepted: 01/30/2017] [Indexed: 02/06/2023] Open
Abstract
The BCL-2 family proteins are major regulators of the apoptosis process, but the mechanisms by which they regulate this process are only partially understood. It is now well documented that these proteins play additional non-apoptotic roles that are likely to be related to their apoptotic roles and to provide important clues to cracking their mechanisms of action. It seems that these non-apoptotic roles are largely related to the activation of cellular survival pathways designated to maintain or regain cellular survival, but, if unsuccessful, will switch over into a pro-apoptotic mode. These non-apoptotic roles span a wide range of processes that include the regulation of mitochondrial physiology (metabolism, electron transport chain, morphology, permeability transition), endoplasmic reticulum physiology (calcium homeostasis, unfolded protein response (UPR)), nuclear processes (cell cycle, DNA damage response (DDR)), whole-cell metabolism (glucose and lipid), and autophagy. Here we review all these different non-apoptotic roles, make an attempt to link them to the apoptotic roles, and present many open questions for future research directions in this fascinating field.
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Affiliation(s)
- Atan Gross
- Department of Biological Regulation, Weizmann Institute of Science, 100 Herzel Street, Rehovot, Israel,Department of Biological Regulation, Weizmann Institute of Science, 100 Herzel Street, Rehovot 76100, Israel. Tel: +972 8 9343656; Fax: +972 8 934 4116; E-mail:
| | - Samuel G Katz
- Department of Pathology, Yale University School of Medicine, 310 Cedar Street, Brady Memorial Laboratory 127A, New Haven, CT 06520, USA,Department of Pathology, Yale University School of Medicine, 310 Cedar Street, Brady Memorial Laboratory 127A, New Haven CT 06520, USA. Tel: +203 785 2757; E-mail:
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Pihán P, Carreras-Sureda A, Hetz C. BCL-2 family: integrating stress responses at the ER to control cell demise. Cell Death Differ 2017. [PMID: 28622296 DOI: 10.1038/cdd.2017.82] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the last decade, the endoplasmic reticulum (ER) has emerged as a central organelle regulating the core mitochondrial apoptosis pathway. At the ER membrane, a variety of stress signals are integrated toward determining cell fate, involving a complex cross talk between key homeostatic pathways including the unfolded protein response, autophagy, calcium signaling and mitochondrial bioenergetics. In this context, key regulators of cell death of the BCL-2 and TMBIM/BI-1 family of proteins have relevant functions as stress rheostats mediated by the formation of distinct protein complexes that regulate the switch between adaptive and proapoptotic phases under stress. Here, we overview recent advances on our molecular understanding of how the apoptotic machinery integrates stress signals toward cell fate decisions upstream of the mitochondrial gateway of death.
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Affiliation(s)
- Philippe Pihán
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.,Faculty of Medicine, Center for Geroscience, Brain Health and Metabolism, University of Chile, Santiago, Chile
| | - Amado Carreras-Sureda
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.,Faculty of Medicine, Center for Geroscience, Brain Health and Metabolism, University of Chile, Santiago, Chile
| | - Claudio Hetz
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.,Faculty of Medicine, Center for Geroscience, Brain Health and Metabolism, University of Chile, Santiago, Chile.,Buck Institute for Research on Aging, Novato, CA 94945, USA.,Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston MA 02115, USA
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Lee JK, Wang B, Reyes M, Armstrong JS, Kulikowicz E, Santos PT, Lee JH, Koehler RC, Martin LJ. Hypothermia and Rewarming Activate a Macroglial Unfolded Protein Response Independent of Hypoxic-Ischemic Brain Injury in Neonatal Piglets. Dev Neurosci 2016; 38:277-294. [PMID: 27622292 DOI: 10.1159/000448585] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 07/20/2016] [Indexed: 12/22/2022] Open
Abstract
Therapeutic hypothermia provides incomplete neuroprotection after hypoxia-ischemia (HI)-induced brain injury in neonates. We previously showed that cortical neuron and white matter apoptosis are promoted by hypothermia and early rewarming in a piglet model of HI. The unfolded protein response (UPR) may be one of the potential mediators of this cell death. Here, neonatal piglets underwent HI or sham surgery followed by 29 h of normothermia, 2 h of normothermia + 27 h of hypothermia or 18 h of hypothermia + rewarming. Piglets recovered for 29 h. Immunohistochemistry for endoplasmic reticulum to nucleus signaling-1 protein (ERN1), a marker of UPR activation, was used to determine the ratios of ERN1+ macroglia and neurons in the motor subcortical white matter and cerebral cortex. The ERN1+ macroglia were immunophenotyped as oligodendrocytes and astrocytes by immunofluorescent colabeling. Temperature (p = 0.046) and HI (p < 0.001) independently affected the ratio of ERN1+ macroglia. In sham piglets, sustained hypothermia (p = 0.011) and rewarming (p = 0.004) increased the ERN1+ macroglia ratio above that in normothermia. HI prior to hypothermia diminished the UPR. Ratios of ERN1+ macroglia correlated with white matter apoptotic profile counts in shams (r = 0.472; p = 0.026), thereby associating UPR activation with white matter apoptosis during hypothermia and rewarming. Accordingly, macroglial cell counts decreased in shams that received sustained hypothermia (p = 0.009) or rewarming (p = 0.007) compared to those in normothermic shams. HI prior to hypothermia neutralized the macroglial cell loss. Neither HI nor temperature affected ERN1+ neuron ratios. In summary, delayed hypothermia and rewarming activate the macroglial UPR, which is associated with white matter apoptosis. HI may decrease the macroglial endoplasmic reticulum stress response after hypothermia and rewarming.
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Affiliation(s)
- Jennifer K Lee
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, Md., USA
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