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Grunberg N, Pevsner-Fischer M, Goshen-Lago T, Diment J, Stein Y, Lavon H, Mayer S, Levi-Galibov O, Friedman G, Ofir-Birin Y, Syu LJ, Migliore C, Shimoni E, Stemmer SM, Brenner B, Dlugosz AA, Lyden D, Regev-Rudzki N, Ben-Aharon I, Scherz-Shouval R. Cancer-Associated Fibroblasts Promote Aggressive Gastric Cancer Phenotypes via Heat Shock Factor 1-Mediated Secretion of Extracellular Vesicles. Cancer Res 2021; 81:1639-1653. [PMID: 33547159 PMCID: PMC8337092 DOI: 10.1158/0008-5472.can-20-2756] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/22/2020] [Accepted: 02/01/2021] [Indexed: 12/11/2022]
Abstract
Gastric cancer is the third most lethal cancer worldwide, and evaluation of the genomic status of gastric cancer cells has not translated into effective prognostic or therapeutic strategies. We therefore hypothesize that outcomes may depend on the tumor microenvironment (TME), in particular, cancer-associated fibroblasts (CAF). However, very little is known about the role of CAFs in gastric cancer. To address this, we mapped the transcriptional landscape of human gastric cancer stroma by microdissection and RNA sequencing of CAFs from patients with gastric cancer. A stromal gene signature was associated with poor disease outcome, and the transcription factor heat shock factor 1 (HSF1) regulated the signature. HSF1 upregulated inhibin subunit beta A and thrombospondin 2, which were secreted in CAF-derived extracellular vesicles to the TME to promote cancer. Together, our work provides the first transcriptional map of human gastric cancer stroma and highlights HSF1 and its transcriptional targets as potential diagnostic and therapeutic targets in the genomically stable tumor microenvironment. SIGNIFICANCE: This study shows how HSF1 regulates a stromal transcriptional program associated with aggressive gastric cancer and identifies multiple proteins within this program as candidates for therapeutic intervention. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/7/1639/F1.large.jpg.
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Affiliation(s)
- Nil Grunberg
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | | | - Tal Goshen-Lago
- Division of Oncology, Rambam Health Care Campus, Haifa, Israel
| | - Judith Diment
- Department of Pathology, Kaplan Medical Center, Rehovot, Israel
| | - Yaniv Stein
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Hagar Lavon
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Shimrit Mayer
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Oshrat Levi-Galibov
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Gil Friedman
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Yifat Ofir-Birin
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Li-Jyun Syu
- Department of Dermatology, Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan
| | - Cristina Migliore
- University of Torino, Department of Oncology, Candiolo; Candiolo Cancer Institute, FPO-IRCCS, Candiolo, Italy
| | - Eyal Shimoni
- Department of Chemical Research Support, The Weizmann Institute of Science, Rehovot, Israel
| | - Salomon M Stemmer
- Institute of Oncology, Davidoff Cancer Center, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Baruch Brenner
- Institute of Oncology, Davidoff Cancer Center, Rabin Medical Center, Beilinson Hospital, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel
| | - Andrzej A Dlugosz
- Department of Dermatology, Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan
- Department of Cell & Developmental Biology, Rogel Cancer Center, University of Michigan, Ann Arbor, Michigan
| | - David Lyden
- Children's Cancer and Blood Foundation Laboratories, Departments of Pediatrics, and Cell and Developmental Biology, Drukier Institute for Children's Health, Meyer Cancer Center, Weill Cornell Medicine, New York, New York
| | - Neta Regev-Rudzki
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
| | - Irit Ben-Aharon
- Division of Oncology, Rambam Health Care Campus, Haifa, Israel
- Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Ruth Scherz-Shouval
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel.
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2
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Fok JHL, Hedayat S, Zhang L, Aronson LI, Mirabella F, Pawlyn C, Bright MD, Wardell CP, Keats JJ, De Billy E, Rye CS, Chessum NEA, Jones K, Morgan GJ, Eccles SA, Workman P, Davies FE. HSF1 Is Essential for Myeloma Cell Survival and A Promising Therapeutic Target. Clin Cancer Res 2018; 24:2395-2407. [PMID: 29391353 PMCID: PMC6420136 DOI: 10.1158/1078-0432.ccr-17-1594] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 10/23/2017] [Accepted: 12/29/2017] [Indexed: 01/09/2023]
Abstract
Purpose: Myeloma is a plasma cell malignancy characterized by the overproduction of immunoglobulin, and is therefore susceptible to therapies targeting protein homeostasis. We hypothesized that heat shock factor 1 (HSF1) was an attractive therapeutic target for myeloma due to its direct regulation of transcriptional programs implicated in both protein homeostasis and the oncogenic phenotype. Here, we interrogate HSF1 as a therapeutic target in myeloma using bioinformatic, genetic, and pharmacologic means.Experimental Design: To assess the clinical relevance of HSF1, we analyzed publicly available patient myeloma gene expression datasets. Validation of this novel target was conducted in in vitro experiments using shRNA or inhibitors of the HSF1 pathway in human myeloma cell lines and primary cells as well as in in vivo human myeloma xenograft models.Results: Expression of HSF1 and its target genes were associated with poorer myeloma patient survival. ShRNA-mediated knockdown or pharmacologic inhibition of the HSF1 pathway with a novel chemical probe, CCT251236, or with KRIBB11, led to caspase-mediated cell death that was associated with an increase in EIF2α phosphorylation, CHOP expression and a decrease in overall protein synthesis. Importantly, both CCT251236 and KRIBB11 induced cytotoxicity in human myeloma cell lines and patient-derived primary myeloma cells with a therapeutic window over normal cells. Pharmacologic inhibition induced tumor growth inhibition and was well-tolerated in a human myeloma xenograft murine model with evidence of pharmacodynamic biomarker modulation.Conclusions: Taken together, our studies demonstrate the dependence of myeloma cells on HSF1 for survival and support the clinical evaluation of pharmacologic inhibitors of the HSF1 pathway in myeloma. Clin Cancer Res; 24(10); 2395-407. ©2018 AACRSee related commentary by Parekh, p. 2237.
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Affiliation(s)
- Jacqueline H L Fok
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Somaieh Hedayat
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Lei Zhang
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Lauren I Aronson
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Fabio Mirabella
- Division of Molecular Pathology, The Institute of Cancer Research, Sutton, London, United Kingdom
| | - Charlotte Pawlyn
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Michael D Bright
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Christopher P Wardell
- Division of Molecular Pathology, The Institute of Cancer Research, Sutton, London, United Kingdom
- Myeloma Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Jonathan J Keats
- Translational Genomics Research Institute (TGen), Phoenix, Arizona
| | - Emmanuel De Billy
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Carl S Rye
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Nicola E A Chessum
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Keith Jones
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Gareth J Morgan
- Myeloma Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Suzanne A Eccles
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Paul Workman
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom
| | - Faith E Davies
- Cancer Research UK Cancer Therapeutics Unit, Division of Cancer Therapeutics, The Institute of Cancer Research, London, United Kingdom.
- Myeloma Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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3
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Yang J, Hao X, Cao X, Liu B, Nyström T. Spatial sequestration and detoxification of Huntingtin by the ribosome quality control complex. eLife 2016; 5. [PMID: 27033550 PMCID: PMC4868537 DOI: 10.7554/elife.11792] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 03/02/2016] [Indexed: 11/13/2022] Open
Abstract
Huntington disease (HD) is a neurological disorder caused by polyglutamine expansions in mutated Huntingtin (mHtt) proteins, rendering them prone to form inclusion bodies (IB). We report that in yeast, such IB formation is a factor-dependent process subjected to age-related decline. A genome-wide, high-content imaging approach, identified the E3 ubiquitin ligase, Ltn1 of the ribosome quality control complex (RQC) as a key factor required for IB formation, ubiquitination, and detoxification of model mHtt. The failure of ltn1∆ cells to manage mHtt was traced to another RQC component, Tae2, and inappropriate control of heat shock transcription factor, Hsf1, activity. Moreover, super-resolution microscopy revealed that mHtt toxicity in RQC-deficient cells was accompanied by multiple mHtt aggregates altering actin cytoskeletal structures and retarding endocytosis. The data demonstrates that spatial sequestration of mHtt into IBs is policed by the RQC-Hsf1 regulatory system and that such compartmentalization, rather than ubiquitination, is key to mHtt detoxification. DOI:http://dx.doi.org/10.7554/eLife.11792.001 Huntington’s disease is a neurological disease that is caused by mutations in the gene that encodes a protein called Htt. Individuals with this mutation gradually lose neurons as they age, resulting in declines in muscle coordination and mental abilities. The mutant Htt proteins tend to form clumps inside cells, but it is not clear if these clumps are the cause of the disease symptoms or whether they have a protective effect. Yang et al. used yeast as a model to investigate whether the mutant Htt proteins need other molecules to allow them to form clumps. The experiments identified several new molecules that are required for mutated Htt to form clumps. Some of these are components of a system called the Ribosome Quality Control (RQC) complex, which monitors newly made proteins and labels abnormal ones for destruction. However, Yang et al.’s findings suggest that the RQC complex regulates the formation of Htt clumps through a different pathway involving a protein called heat shock factor 1. In this case, cells would need to fine-tune heat shock factor 1 activity to make mutant Htt proteins clump together to protect cells from damage. Future experiments should expand Yang et al.’s findings to animal models of Huntington’s disease and identify which other molecules contribute to the formation of Htt clumps. One challenge will be to find out why older neurons fail to form clumps of Htt proteins, and whether this can be overcome by drugs that boost the activity of the molecules that Yang et al. identified. DOI:http://dx.doi.org/10.7554/eLife.11792.002
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Affiliation(s)
- Junsheng Yang
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Xinxin Hao
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Xiuling Cao
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Beidong Liu
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Thomas Nyström
- Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden
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4
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Smith LM, Bhattacharya D, Williams DJ, Dixon I, Powell NR, Erkina TY, Erkine AM. High-throughput screening system for inhibitors of human Heat Shock Factor 2. Cell Stress Chaperones 2015; 20:833-41. [PMID: 26003133 PMCID: PMC4529873 DOI: 10.1007/s12192-015-0605-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 04/06/2015] [Accepted: 05/12/2015] [Indexed: 11/26/2022] Open
Abstract
Development of novel anti-cancer drug leads that target regulators of protein homeostasis is a formidable task in modern pharmacology. Finding specific inhibitors of human Heat Shock Factor 1 (hHSF1) has proven to be a challenging task, while screening for inhibitors of human Heat Shock Factor 2 (hHSF2) has never been described. We report the development of a novel system based on an in vivo cell growth restoration assay designed to identify specific inhibitors of human HSF2 in a high-throughput format. This system utilizes a humanized yeast strain in which the master regulator of molecular chaperone genes, yeast HSF, has been replaced with hHSF2 with no detrimental effect on cell growth. This replacement preserves the general regulatory patterns of genes encoding major molecular chaperones including Hsp70 and Hsp90. The controlled overexpression of hHSF2 creates a slow-growth phenotype, which is the basis of the growth restoration assay used for high-throughput screening. The phenotype is most robust when cells are cultured at 25 °C, while incubation at temperatures greater than 30 °C leads to compensation of the phenotype. Overexpression of hHSF2 causes overexpression of molecular chaperones which is a likely cause of the slowed growth. Our assay is characterized by two unique advantages. First, screening takes place in physiologically relevant, in vivo conditions. Second, hits in our screen will be of medically relevant potency, as compounds that completely inhibit hHSF2 function will further inhibit cell growth and therefore will not be scored as hits. This caveat biases our screening system for compounds capable of restoring hHSF2 activity to a physiologically normal level without completely inhibiting this essential system.
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Affiliation(s)
- Levi M. Smith
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Butler University, Indianapolis, IN 46208 USA
| | - Dwipayan Bhattacharya
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Butler University, Indianapolis, IN 46208 USA
| | - Daniel J. Williams
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Butler University, Indianapolis, IN 46208 USA
| | - Ivan Dixon
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Butler University, Indianapolis, IN 46208 USA
| | - Nicholas R. Powell
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Butler University, Indianapolis, IN 46208 USA
| | - Tamara Y. Erkina
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Butler University, Indianapolis, IN 46208 USA
| | - Alexandre M. Erkine
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Butler University, Indianapolis, IN 46208 USA
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5
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Tan J, Tan S, Zheng H, Liu M, Chen G, Zhang H, Wang K, Tan S, Zhou J, Xiao XZ. HSF1 functions as a transcription regulator for Dp71 expression. Cell Stress Chaperones 2015; 20:371-9. [PMID: 25430510 PMCID: PMC4326382 DOI: 10.1007/s12192-014-0558-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 11/13/2014] [Accepted: 11/17/2014] [Indexed: 11/25/2022] Open
Abstract
Heat shock factor 1 (HSF1) is one of the most important transcriptional molecules in the heat shock process; however, HSF1 can also regulate the expression of other proteins. Dystrophin Dp71 is one of the most widely expressed isoforms of the dystrophin gene family. In our experiments, we showed for the first time that HSF1 can function as a transcriptional factor for endogenous Dp71 expression in vivo and in vitro. We demonstrated that the messenger RNA (mRNA) and protein expression of Dp71 were significantly reduced in HSF1-knockout mice compared with wild-type mice in brain, lung, liver, spleen, and kidney. Overexpression of HSF1 significantly enhanced the mRNA and protein expression of Dp71 in HeLa cells. Inhibiting the expression of HSF1 in HeLa cells significantly reduced the expression of Dp71. By use of the EMSA technique, the chromatin immunoprecipitation assay, and the luciferase reporter system, we demonstrated that HSF1 can directly bind the HSE in the Dp71 promoter region. We concluded from our data that HSF1 functions as a transcriptional regulator of Dp71 expression.
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Affiliation(s)
- Jin Tan
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Sichuang Tan
- />Department of Thoracic and Cardiovascular Surgery, Second Xiangya Hospital, 139# Ren Ming Road, Changsha, Hunan 410011 People’s Republic of China
| | - Hexin Zheng
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
- />Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning, Institute of Hunan Province, Changsha, 410126 China
| | - Meidong Liu
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Guangwen Chen
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Huali Zhang
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Kangkai Wang
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Sipin Tan
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
- />Molecular and Cell Experimental Center, Xiangya School of Medicine, Central South University, Changsha, Hunan 410013 People’s Republic of China
| | - Jiang Zhou
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
| | - Xian-zhong Xiao
- />Laboratory of Shock, Department of Pathophysiology, Xiangya School of Medicine, Central South University, 110# Xiangya Road, Changsha, Hunan 410008 People’s Republic of China
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6
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Ortner V, Ludwig A, Riegel E, Dunzinger S, Czerny T. An artificial HSE promoter for efficient and selective detection of heat shock pathway activity. Cell Stress Chaperones 2015; 20:277-88. [PMID: 25168173 PMCID: PMC4326385 DOI: 10.1007/s12192-014-0540-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 08/14/2014] [Accepted: 08/15/2014] [Indexed: 11/26/2022] Open
Abstract
Detection of cellular stress is of major importance for the survival of cells. During evolution, a network of stress pathways developed, with the heat shock (HS) response playing a major role. The key transcription factor mediating HS signalling activity in mammalian cells is the HS factor HSF1. When activated it binds to the heat shock elements (HSE) in the promoters of target genes like heat shock protein (HSP) genes. They are induced by HSF1 but in addition they integrate multiple signals from different stress pathways. Here, we developed an artificial promoter consisting only of HSEs and therefore selectively reacting to HSF-mediated pathway activation. The promoter is highly inducible but has an extreme low basal level. Direct comparison with the HSPA1A promoter activity indicates that heat-dependent expression can be fully recapitulated by isolated HSEs in human cells. Using this sensitive reporter, we measured the HS response for different temperatures and exposure times. In particular, long heat induction times of 1 or 2 h were compared with short heat durations down to 1 min, conditions typical for burn injuries. We found similar responses to both long and short heat durations but at completely different temperatures. Exposure times of 2 h result in pathway activation at 41 to 44 °C, whereas heat pulses of 1 min lead to a maximum HS response between 47 and 50 °C. The results suggest that the HS response is initiated by a combination of temperature and exposure time but not by a certain threshold temperature.
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Affiliation(s)
- Viktoria Ortner
- Department of Applied Life Sciences, University of Applied Sciences, FH Campus Wien, Helmut-Qualtinger-Gasse 2, A-1030, Vienna, Austria
| | - Alfred Ludwig
- Department of Agrarian Production, Genetics and Microbiology Research Group Public, University of Navarre, Pamplona, Navarre Spain
| | - Elisabeth Riegel
- Department of Applied Life Sciences, University of Applied Sciences, FH Campus Wien, Helmut-Qualtinger-Gasse 2, A-1030, Vienna, Austria
| | - Sarah Dunzinger
- Department of Applied Life Sciences, University of Applied Sciences, FH Campus Wien, Helmut-Qualtinger-Gasse 2, A-1030, Vienna, Austria
| | - Thomas Czerny
- Department of Applied Life Sciences, University of Applied Sciences, FH Campus Wien, Helmut-Qualtinger-Gasse 2, A-1030, Vienna, Austria
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7
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Place RF, Noonan EJ. Non-coding RNAs turn up the heat: an emerging layer of novel regulators in the mammalian heat shock response. Cell Stress Chaperones 2014; 19:159-72. [PMID: 24002685 PMCID: PMC3933615 DOI: 10.1007/s12192-013-0456-5] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 08/11/2013] [Accepted: 08/13/2013] [Indexed: 02/06/2023] Open
Abstract
The field of non-coding RNA (ncRNA) has expanded over the last decade following the discoveries of several new classes of regulatory ncRNA. A growing amount of evidence now indicates that ncRNAs are involved even in the most fundamental of cellular processes. The heat shock response is no exception as ncRNAs are being identified as integral components of this process. Although this area of research is only in its infancy, this article focuses on several classes of regulatory ncRNA (i.e., miRNA, lncRNA, and circRNA), while summarizing their activities in mammalian heat shock. We also present an updated model integrating the traditional heat shock response with the activities of regulatory ncRNA. Our model expands on the mechanisms for efficient execution of the stress response, while offering a more comprehensive summary of the major regulators and responders in heat shock signaling. It is our hope that much of what is discussed herein may help researchers in integrating the fields of heat shock and ncRNA in mammals.
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Affiliation(s)
- Robert F. Place
- />Anvil Biosciences, 3475 Edison Way, Ste J, Menlo Park, CA 94025 USA
| | - Emily J. Noonan
- />Division of Cancer Prevention, Cancer Prevention Fellowship Program, Rockville, MD USA
- />Laboratory of Human Carcinogenesis, Center for Cancer Research, 37 Convent Dr., Bldg. 37 Room 3060, Bethesda, MD 20892-4258 USA
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8
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Jing Z, Gangalum RK, Lee JZ, Mock D, Bhat SP. Cell-type-dependent access of HSF1 and HSF4 to αB-crystallin promoter during heat shock. Cell Stress Chaperones 2013; 18:377-87. [PMID: 23264262 PMCID: PMC3631099 DOI: 10.1007/s12192-012-0386-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Revised: 10/18/2012] [Accepted: 11/13/2012] [Indexed: 10/27/2022] Open
Abstract
Epithelial cells and fibroblasts both express heat shock transcription factors, HSF1 and HSF4, yet they respond to heat shock differentially. For example, while HSP70 is induced in both cell types, the small heat shock protein, αB-crystallin gene (CRYAB) that contains a canonical heat shock promoter, is only induced in fibroblasts. A canonical heat shock promoter contains three or more inverted repeats of the pentanucleotide 5'-nGAAn-3' that make the heat shock element. It is known that, in vitro, promoter architecture (the order and spacing of these repeats) impacts the interaction of various heat shock transcription factors (HSFs) with the heat shock promoter, but in vivo relevance of these binding preferences so far as the expression is concerned is poorly understood. In this report, we first establish cell-type-dependent differential expression of CRYAB in four established cell lines and then working with adult human retinal pigment epithelial cells and NIH3T3 fibroblasts and employing chromatin immunoprecipitation, attempt to relate expression to promoter occupancy by HSF1 and HSF4. We show that HSF4 occupies only CRYAB and not HSP70 promoter in epithelial cells, while HSF1 occupies only HSP70 promoter in both cell types, and cryab promoter, only in heat shocked fibroblasts; HSF4, on the other hand, is never seen on these two promoters in NIH3T3 fibroblasts. This comparative analysis with CRYAB and HSP70 demonstrates that differential heat shock response is controlled by cell-type-dependent access of HSFs (HSF1 and HSF4) to specific promoters, independent of the promoter architecture.
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Affiliation(s)
- Zhe Jing
- />Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Brain Research Institute and Molecular Biology Institute, University of California, Los Angeles, CA 90095 USA
| | - Rajendra K. Gangalum
- />Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Brain Research Institute and Molecular Biology Institute, University of California, Los Angeles, CA 90095 USA
| | - Josh Z. Lee
- />Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Brain Research Institute and Molecular Biology Institute, University of California, Los Angeles, CA 90095 USA
| | - Dennis Mock
- />Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Brain Research Institute and Molecular Biology Institute, University of California, Los Angeles, CA 90095 USA
| | - Suraj P. Bhat
- />Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Brain Research Institute and Molecular Biology Institute, University of California, Los Angeles, CA 90095 USA
- />Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA 90095 USA
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9
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Desai S, Liu Z, Yao J, Patel N, Chen J, Wu Y, Ahn EEY, Fodstad O, Tan M. Heat shock factor 1 ( HSF1) controls chemoresistance and autophagy through transcriptional regulation of autophagy-related protein 7 (ATG7). J Biol Chem 2013; 288:9165-76. [PMID: 23386620 PMCID: PMC3610989 DOI: 10.1074/jbc.m112.422071] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 02/04/2013] [Indexed: 01/07/2023] Open
Abstract
Heat shock factor 1 (HSF1), a master regulator of heat shock responses, plays an important role in tumorigenesis. In this study we demonstrated that HSF1 is required for chemotherapeutic agent-induced cytoprotective autophagy through transcriptional up-regulation of autophagy-related gene ATG7. Interestingly, this is independent of the HSF1 heat shock response function. Treatment of cancer cells with the FDA-approved chemotherapeutic agent carboplatin induced autophagy and growth inhibition, which were significantly increased upon knockdown of HSF1. Mechanistic studies revealed that HSF1 regulates autophagy by directly binding to ATG7 promoter and transcriptionally up-regulating its expression. Significantly, breast cancer patient sample study revealed that a higher ATG7 expression level is associated with poor patient survival. This novel finding was further confirmed by analysis of two independent patient databases, demonstrating a prognostic value of ATG7. Furthermore, a strong positive correlation was observed between levels of HSF1 and ATG7 in triple-negative breast cancer patient samples, thus validating our in vitro findings. This is the first study identifying a critical role for HSF1 in controlling cytoprotective autophagy through regulation of ATG7, which is distinct from the HSF1 function in the heat shock response. This is also the first study demonstrating a prognostic value of ATG7 in breast cancer patients. These findings strongly argue that combining chemotherapeutic agents with autophagy inhibition by repressing HSF1/ATG7 axis represents a promising strategy for future cancer treatment.
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Affiliation(s)
- Shruti Desai
- From the Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama 36604
| | - Zixing Liu
- From the Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama 36604
| | - Jun Yao
- the Department of Neuro-oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
| | - Nishant Patel
- the Department of Mathematics, Northwest Florida State College, Niceville, Florida 32578
| | - Jieqing Chen
- the Department of Pathology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
| | - Yun Wu
- the Department of Pathology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
| | - Erin Eun-Young Ahn
- From the Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama 36604
| | - Oystein Fodstad
- the Department of Tumor Biology, Norwegian Radium Hospital, University of Oslo, 0310 Oslo, Norway, and
| | - Ming Tan
- From the Mitchell Cancer Institute, University of South Alabama, Mobile, Alabama 36604
- the Department of Cell Biology and Neuroscience, University of South Alabama, Mobile, Alabama 36604
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10
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Sourbier C, Scroggins BT, Ratnayake R, Prince TL, Lee S, Lee MJ, Nagy PL, Lee YH, Trepel JB, Beutler JA, Linehan WM, Neckers L. Englerin A stimulates PKCθ to inhibit insulin signaling and to simultaneously activate HSF1: pharmacologically induced synthetic lethality. Cancer Cell 2013; 23:228-37. [PMID: 23352416 PMCID: PMC3574184 DOI: 10.1016/j.ccr.2012.12.007] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 10/19/2012] [Accepted: 12/18/2012] [Indexed: 12/31/2022]
Abstract
The natural product englerin A (EA) binds to and activates protein kinase C-θ (PKCθ). EA-dependent activation of PKCθ induces an insulin-resistant phenotype, limiting the access of tumor cells to glucose. At the same time, EA causes PKCθ-mediated phosphorylation and activation of the transcription factor heat shock factor 1, an inducer of glucose dependence. By promoting glucose addiction, while simultaneously starving cells of glucose, EA proves to be synthetically lethal to highly glycolytic tumors.
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Affiliation(s)
- Carole Sourbier
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892
| | - Bradley T. Scroggins
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892
| | - Ranjala Ratnayake
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702
| | - Thomas L. Prince
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892
| | - Sunmin Lee
- Medical Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892
| | - Min-Jung Lee
- Medical Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892
| | | | - Young H. Lee
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892
| | - Jane B. Trepel
- Medical Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892
| | - John A. Beutler
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702
| | - W. Marston Linehan
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892
| | - Len Neckers
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892
- corresponding author: Len Neckers, PhD, Urologic Oncology Branch, National Cancer Institute, Building 10 CRC 1-W5848, 9000 Rockville pike, Bethesda, Maryland 20892,
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11
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Reina CP, Nabet BY, Young PD, Pittman RN. Basal and stress-induced Hsp70 are modulated by ataxin-3. Cell Stress Chaperones 2012; 17:729-42. [PMID: 22777893 PMCID: PMC3468683 DOI: 10.1007/s12192-012-0346-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 05/11/2012] [Accepted: 06/07/2012] [Indexed: 12/24/2022] Open
Abstract
Regulation of basal and induced levels of hsp70 is critical for cellular homeostasis. Ataxin-3 is a deubiquitinase with several cellular functions including transcriptional regulation and maintenance of protein homeostasis. While investigating potential roles of ataxin-3 in response to cellular stress, it appeared that ataxin-3 regulated hsp70. Basal levels of hsp70 were lower in ataxin-3 knockout (KO) mouse brain from 2 to 63 weeks of age and hsp70 was also lower in fibroblasts from ataxin-3 KO mice. Transfecting KO cells with ataxin-3 rescued basal levels of hsp70 protein. Western blots of representative chaperones including hsp110, hsp90, hsp70, hsc70, hsp60, hsp40/hdj2, and hsp25 indicated that only hsp70 was appreciably altered in KO fibroblasts and KO mouse brain. Turnover of hsp70 protein was similar in wild-type (WT) and KO cells; however, basal hsp70 promoter reporter activity was decreased in ataxin-3 KO cells. Transfecting ataxin-3 restored hsp70 basal promoter activity in KO fibroblasts to levels of promoter activity in WT cells; however, mutations that inactivated deubiquitinase activity or the ubiquitin interacting motifs did not restore full activity to hsp70 basal promoter activity. Hsp70 protein and promoter activity were higher in WT compared to KO cells exposed to heat shock and azetidine-2-carboxylic acid, but WT and KO cells had similar levels in response to cadmium. Heat shock factor-1 had decreased levels and increased turnover in ataxin-3 KO fibroblasts. Data in this study are consistent with ataxin-3 regulating basal level of hsp70 as well as modulating hsp70 in response to a subset of cellular stresses.
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Affiliation(s)
- Christopher P. Reina
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104 USA
- Present Address: Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ 08854 USA
| | - Barzin Y. Nabet
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104 USA
- Present Address: Department of Cancer Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104 USA
| | - Peter D. Young
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104 USA
| | - Randall N. Pittman
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104 USA
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12
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Ambade A, Catalano D, Lim A, Mandrekar P. Inhibition of heat shock protein (molecular weight 90 kDa) attenuates proinflammatory cytokines and prevents lipopolysaccharide-induced liver injury in mice. Hepatology 2012; 55:1585-95. [PMID: 22105779 PMCID: PMC3342823 DOI: 10.1002/hep.24802] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 11/02/2011] [Indexed: 01/18/2023]
Abstract
UNLABELLED Endotoxin-mediated proinflammatory cytokines play a significant role in the pathogenesis of acute and chronic liver diseases. Heat shock protein 90 (molecular weight, 90 kDa) (hsp90) functions as an important chaperone of lipopolysaccharide (LPS) signaling and is required for the production of proinflammatory cytokines. We hypothesized that inhibition of hsp90 would prevent LPS-induced liver injury by decreasing proinflammatory cytokines. C57BL/6 mice were injected intraperitoneally with an hsp90 inhibitor, 17-dimethylamino-ethylamino-17-demethoxygeldanamycin (17-DMAG), and LPS. Parameters of liver injury, proinflammatory cytokines, and associated mechanisms were studied by in vivo and in vitro experiments. Inhibition of hsp90 by 17-DMAG prevented LPS-induced increases in serum alanine aminotransferase activity and significantly reduced serum tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) protein as well as messenger RNA (mRNA) in liver. Enhanced DNA-binding activity of heat shock transcription factor 1 (HSF1) and induction of target gene heat shock protein 70 (molecular weight, 70 kDa) confirmed hsp90 inhibition in liver. 17-DMAG treatment decreased cluster of differentiation 14 mRNA and LPS-induced nuclear factor kappa light-chain enhancer of activated B cells (NFκB) DNA binding without affecting Toll-like receptor 4 mRNA in liver. Mechanistic studies revealed that 17-DMAG-mediated inhibition of TNFα showed no effect on LPS-induced NFκB promoter-driven reporter activity, but significantly decreased TNFα promoter-driven reporter activity. Chromatin immunoprecipitation assays showed that 17-DMAG enhanced HSF1 binding to the TNFα promoter, but not the IL-6 promoter, suggesting HSF1 mediated direct inhibition of TNFα, but not IL-6. We show that HSF1 indirectly regulates IL-6 by the induction of another transcription factor, activating transcription factor 3. Inhibition of HSF1, using small interfering RNA, prevented 17-DMAG-mediated down-regulation of NFκB-binding activity, TNFα, and IL-6 induction, supporting a repressive role for HSF1 on proinflammatory cytokine genes during hsp90 inhibition. CONCLUSION Hsp90 inhibition in vivo reduces proinflammatory cytokines and prevents LPS-induced liver injury likely through repressive action of HSF1. Our results suggest a novel application for 17-DMAG in alleviating LPS-induced liver injury.
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13
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Chang Z, Lu M, Park SM, Park HK, Kang HS, Pak Y, Park JS. Functional HSF1 requires aromatic-participant interactions in protecting mouse embryonic fibroblasts against apoptosis via G2 cell cycle arrest. Mol Cells 2012; 33:465-70. [PMID: 22526392 PMCID: PMC3887730 DOI: 10.1007/s10059-012-2246-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 03/01/2012] [Accepted: 03/02/2012] [Indexed: 11/28/2022] Open
Abstract
The present study highlighted the aromatic-participant interactions in in vivo trimerization of HSF1 and got an insight into the process of HSF1 protecting against apoptosis. In mouse embryonic fibroblasts (MEFs), mutations of mouse HSF1 (W37A, Y60A and F104A) resulted in a loss of trimerization activity, impaired binding of the heat shock element (HSE) and lack of heat shock protein 70 (HSP70) expression after a heat shock. Under UV irradiation, wild-type mouse HSF1 protected the MEFs from UV-induced apoptosis, but none of the mutants offered protection. We found that normal expression of HSF1 was essential to the cell arrest in G2 phase, assisting with the cell cycle checkpoint. The cells that lack normal HSF1 failed to arrest in the G2 phase, resulting in the process of cell apoptosis. We conclude that the treatment with UV or heat shock stresses appears to induce the approach of HSF1 monomers directly via aromatic-participant interactions, followed by the formation of a HSF1 trimer. HSF1 protects the MEFs from the stresses through the expression of HSPs and a G2 cell cycle arrest.
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Affiliation(s)
- Ziwei Chang
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 609-735,
Korea
| | - Ming Lu
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 609-735,
Korea
| | - Sung-Min Park
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 609-735,
Korea
| | - Hyun-Kyung Park
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 609-735,
Korea
| | - Ho Sung Kang
- Department of Molecular Biology, College of Natural Sciences, and Research Institute of Genetic Engineering, Pusan National University, Busan 609-735,
Korea
| | - Youngshang Pak
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 609-735,
Korea
| | - Jang-Su Park
- Department of Chemistry and Chemistry Institute of Functional Materials, Pusan National University, Busan 609-735,
Korea
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14
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Abstract
Heat-shock transcription factors (Hsfs) regulate transcription of heat-shock proteins as well as other genes whose promoters contain heat-shock elements. There are at least five Hsfs in mammalian cells, Hsf1, Hsf2, Hsf3, Hsf4, and Hsfy. To understand the physiological roles of Hsf1, Hsf2, and Hsf4 in vivo, we generated knockout mouse lines for these factors. In this chapter, we describe the design of the targeting vectors, the plasmids used, and the successful generation of mice lacking the individual genes. We also briefly describe what we have learned about the physiological functions of these genes in vivo.
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Affiliation(s)
- Xiongjie Jin
- Center for Molecular Chaperone/Radiobiology and Cancer Virology, Medical College of Georgia, Augusta, GA, USA
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15
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Abstract
Small ubiquitin-related modifier (SUMO) is an ubiquitin-like protein that is covalently attached to a variety of target proteins. Unlike ubiquitination, sumoylation does not target proteins for proteolytic breakdown, but is involved in regulation of protein function, nuclear targeting, and the formation of subcellular structures. Because SUMO is involved in such a plethora of functions and modifies numerous proteins it is important to identify proteins that are sumoylated in order to increase our understanding of how this modification affects protein function and localization. This overview describes techniques utilized for the detection of sumoylated proteins. The techniques covered include immunoprecipitation, an in vitro sumoylation assay, and gel shift mobility assays that have been used to identify SUMO-modified proteins.
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Affiliation(s)
| | - Kevin D. Sarge
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536
- To whom correspondence should be addressed: , Phone: (859) 323-5777
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16
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Batulan Z, Shinder GA, Minotti S, He BP, Doroudchi MM, Nalbantoglu J, Strong MJ, Durham HD. High threshold for induction of the stress response in motor neurons is associated with failure to activate HSF1. J Neurosci 2003; 23:5789-98. [PMID: 12843283 PMCID: PMC6741252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023] Open
Abstract
Heat shock protein 70 (Hsp70) protects cultured motor neurons from the toxic effects of mutations in Cu/Zn-superoxide dismutase (SOD-1), which is responsible for a familial form of the disease, amyotrophic lateral sclerosis (ALS). Here, the endogenous heat shock response of motor neurons was investigated to determine whether a high threshold for activating this protective mechanism contributes to their vulnerability to stresses associated with ALS. When heat shocked, cultured motor neurons failed to express Hsp70 or transactivate a green fluorescent protein reporter gene driven by the Hsp70 promoter, although Hsp70 was induced in glial cells. No increase in Hsp70 occurred in motor neurons after exposure to excitotoxic glutamate or expression of mutant SOD-1 with a glycine--> alanine substitution at residue 93 (G93A), nor was Hsp70 increased in spinal cords of G93A SOD-1 transgenic mice or sporadic or familial ALS patients. In contrast, strong Hsp70 induction occurred in motor neurons with expression of a constitutively active form of heat shock transcription factor (HSF)-1 or when proteasome activity was sufficiently inhibited to induce accumulation of an alternative transcription factor HSF2. These results indicate that the high threshold for induction of the stress response in motor neurons stems from an impaired ability to activate the main heat shock-stress sensor, HSF1.
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Affiliation(s)
- Zarah Batulan
- Montreal Neurological Institute and Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada H3A 2B4
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Satyal SH, Chen D, Fox SG, Kramer JM, Morimoto RI. Negative regulation of the heat shock transcriptional response by HSBP1. Genes Dev 1998; 12:1962-74. [PMID: 9649501 PMCID: PMC316975 DOI: 10.1101/gad.12.13.1962] [Citation(s) in RCA: 171] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/1998] [Accepted: 04/28/1998] [Indexed: 11/24/2022]
Abstract
In response to stress, heat shock factor 1 (HSF1) acquires rapid DNA binding and transient transcriptional activity while undergoing conformational transition from an inert non-DNA-binding monomer to active functional trimers. Attenuation of the inducible transcriptional response occurs during heat shock or upon recovery at non-stress conditions and involves dissociation of the HSF1 trimer and loss of activity. We have used the hydrophobic repeats of the HSF1 trimerization domain in the yeast two-hybrid protein interaction assay to identify heat shock factor binding protein 1 (HSBP1), a novel, conserved, 76-amino-acid protein that contains two extended arrays of hydrophobic repeats that interact with the HSF1 heptad repeats. HSBP1 is nuclear-localized and interacts in vivo with the active trimeric state of HSF1 that appears during heat shock. During attenuation of HSF1 to the inert monomer, HSBP1 associates with Hsp70. HSBP1 negatively affects HSF1 DNA-binding activity, and overexpression of HSBP1 in mammalian cells represses the transactivation activity of HSF1. To establish a biological role for HSBP1, the homologous Caenorhabditis elegans protein was overexpressed in body wall muscle cells and was shown to block activation of the heat shock response from a heat shock promoter-reporter construct. Alteration in the level of HSBP1 expression in C. elegans has severe effects on survival of the animals after thermal and chemical stress, consistent with a role for HSBP1 as a negative regulator of the heat shock response.
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Affiliation(s)
- S H Satyal
- Department of Biochemistry, Molecular Biology and Cell Biology, Rice Institute for Biomedical Research, Northwestern University, Evanston, Illinois 60208 USA
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