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Lai WS, Hicks SN, Blackshear PJ. RNA-Binding Protein-Mediated mRNA Deadenylation in Mammalian Cell Extracts. Methods Mol Biol 2024; 2723:173-191. [PMID: 37824071 PMCID: PMC11025660 DOI: 10.1007/978-1-0716-3481-3_11] [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] [Indexed: 10/13/2023]
Abstract
Removal of the poly(A) tail, or deadenylation, is a crucial step in destabilizing mRNAs in eukaryotes. In this chapter, we describe a cell-free deadenylation assay that uses cytoplasmic cell extracts from human HEK293 cells transiently transfected with DNA encoding RNA-binding proteins (RBP), and in vitro-transcribed, radiolabeled, RNA probes. We include methods to evaluate the effects of RBPs or deadenylases on various in vitro-transcribed probes, with or without poly(A) tails. Finally, we also demonstrate the adaptability of these assays to test purified protein components in our cell-free deadenylation assay. In our experience, these methods are well suited for the initial assessment of the effects of RBPs on the deadenylation of mRNAs.
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Affiliation(s)
- Wi S Lai
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Stephanie N Hicks
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Perry J Blackshear
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA.
- Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC, USA.
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2
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Snyder BL, Blackshear PJ. Clinical implications of tristetraprolin (TTP) modulation in the treatment of inflammatory diseases. Pharmacol Ther 2022; 239:108198. [PMID: 35525391 PMCID: PMC9636069 DOI: 10.1016/j.pharmthera.2022.108198] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/19/2022] [Accepted: 04/25/2022] [Indexed: 11/24/2022]
Abstract
Abnormal regulation of pro-inflammatory cytokine and chemokine mediators can contribute to the excess inflammation characteristic of many autoimmune diseases, such as rheumatoid arthritis, psoriasis, Crohn's disease, type 1 diabetes, and many others. The tristetraprolin (TTP) family consists of a small group of related RNA-binding proteins that bind to preferred AU-rich binding sites within the 3'-untranslated regions of specific mRNAs to promote mRNA deadenylation and decay. TTP deficient mice develop a severe systemic inflammatory syndrome consisting of arthritis, myeloid hyperplasia, dermatitis, autoimmunity and cachexia, due at least in part to the excess accumulation of proinflammatory chemokine and cytokine mRNAs and their encoded proteins. To investigate the possibility that increased TTP expression or activity might have a beneficial effect on inflammatory diseases, at least two mouse models have been developed that provide proof of principle that increasing TTP activity can promote the decay of pro-inflammatory and other relevant transcripts, and decrease the severity of mouse models of inflammatory disease. Animal studies of this type are summarized here, and we briefly review the prospects for harnessing these insights for the development of TTP-based anti-inflammatory treatments in humans.
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Affiliation(s)
- Brittany L Snyder
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, United States of America; Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, United States of America
| | - Perry J Blackshear
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, United States of America; Department of Medicine, Duke University Medical Center, Durham, NC 27710, United States of America; Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, United States of America.
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3
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Suzuki T, Hoshina M, Nishijima S, Hoshina N, Kikuguchi C, Tomohiro T, Fukao A, Fujiwara T, Yamamoto T. Regulation of CCR4-NOT complex deadenylase activity and cellular responses by MK2-dependent phosphorylation of CNOT2. RNA Biol 2022; 19:234-246. [PMID: 35129087 PMCID: PMC8820811 DOI: 10.1080/15476286.2021.2021676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
CCR4-NOT complex-mediated mRNA deadenylation serves critical functions in multiple biological processes, yet how this activity is regulated is not fully understood. Here, we show that osmotic stress induces MAPKAPK-2 (MK2)-mediated phosphorylation of CNOT2. Programmed cell death is greatly enhanced by osmotic stress in CNOT2-depleted cells, indicating that CNOT2 is responsible for stress resistance of cells. Although wild-type (WT) and non-phosphorylatable CNOT2 mutants reverse this sensitivity, a phosphomimetic form of CNOT2, in which serine at the phosphorylation site is replaced with glutamate, does not have this function. We also show that mRNAs have elongated poly(A) tails in CNOT2-depleted cells and that introduction of CNOT2 WT or a non-phosphorylatable mutant, but not phosphomimetic CNOT2, renders their poly(A) tail lengths comparable to those in control HeLa cells. Consistent with this, the CCR4-NOT complex containing phosphomimetic CNOT2 exhibits less deadenylase activity than that containing CNOT2 WT. These data suggest that CCR4-NOT complex deadenylase activity is regulated by post-translational modification, yielding dynamic control of mRNA deadenylation.
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Affiliation(s)
- Toru Suzuki
- Laboratory for Immunogenetics, Center for Integrative Medical Sciences, Riken, Yokohama, Japan
| | - Miyuki Hoshina
- Cell Signal Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Saori Nishijima
- Cell Signal Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Naosuke Hoshina
- Cell Signal Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
| | - Chisato Kikuguchi
- Laboratory for Immunogenetics, Center for Integrative Medical Sciences, Riken, Yokohama, Japan
| | - Takumi Tomohiro
- Laboratory of Biochemistry, Kindai University, Higashi-Osaka, Japan
| | - Akira Fukao
- Laboratory of Biochemistry, Kindai University, Higashi-Osaka, Japan
| | | | - Tadashi Yamamoto
- Cell Signal Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Japan
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4
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Cottonseed extracts regulate gene expression in human colon cancer cells. Sci Rep 2022; 12:1039. [PMID: 35058516 PMCID: PMC8776848 DOI: 10.1038/s41598-022-05030-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 12/16/2021] [Indexed: 11/18/2022] Open
Abstract
Cotton plant provides economically important fiber and cottonseed, but cottonseed contributes 20% of the crop value. Cottonseed value could be increased by providing high value bioactive compounds and polyphenolic extracts aimed at improving nutrition and preventing diseases because plant polyphenol extracts have been used as medicinal remedy for various diseases. The objective of this study was to investigate the effects of cottonseed extracts on cell viability and gene expression in human colon cancer cells. COLO 225 cells were treated with ethanol extracts from glanded and glandless cottonseed followed by MTT and qPCR assays. Cottonseed extracts showed minor effects on cell viability. qPCR assay analyzed 55 mRNAs involved in several pathways including DGAT, GLUT, TTP, IL, gossypol-regulated and TTP-mediated pathways. Using BCL2 mRNA as the internal reference, qPCR analysis showed minor effects of ethanol extracts from glanded seed coat and kernel and glandless seed coat on mRNA levels in the cells. However, glandless seed kernel extract significantly reduced mRNA levels of many genes involved in glucose transport, lipid biosynthesis and inflammation. The inhibitory effects of glandless kernel extract on gene expression may provide a useful opportunity for improving nutrition and healthcare associated with colon cancer. This in turn may provide the potential of increasing cottonseed value by using ethanol extract as a nutrition/health intervention agent.
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Li T, Zhang H, Xu L, Chen X, Feng J, Wu W, Du Y. StMPK7 phosphorylates and stabilizes a potato RNA-binding protein StUBA2a/b to enhance plant defence responses. HORTICULTURE RESEARCH 2022; 9:uhac177. [PMID: 36324643 PMCID: PMC9614683 DOI: 10.1093/hr/uhac177] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/02/2022] [Indexed: 05/19/2023]
Abstract
Mitogen-activated protein kinase (MAPK) cascades play pivotal roles in regulating plant immunity. MAPKs usually transduce signals and regulate plant immunity by phosphorylating the downstream defence-related components. Our previous study indicates that StMPK7 positively regulates plant defence to Phytophthora pathogens via SA signalling pathway. However, the downstream component of StMPK7 remains unknown. In this study, we employed GFP-StMPK7 transgenic potato and performed immunoprecipitation-mass spectrometry (IP-MS) to identify the downstream component of StMPK7. We found that an RNA binding protein StUBA2a/b interacted with StMPK7, as revealed by luciferase complementation imaging (LCI) and coimmunoprecipitation (co-IP) assays. Transient expression of StUBA2a/b in Nicociana benthamiana enhanced plant resistance to Phytophthora pathogens, while silencing of UBA2a/b decreased the resistance, suggesting a positive regulator role of UBA2a/b in plant immunity. Similar to StMPK7, StUBA2a/b was also involved in SA signalling pathway and induced SGT1-dependent cell death as constitutively activated (CA)-StMPK7 did. Immune blotting indicated that StMPK7 phosphorylates StUBA2a/b at thr248 and thr408 (T248/408) sites and stabilizes StUBA2a/b. Silencing of MPK7 in N. benthamiana suppressed StUBA2a/b-induced cell death, while co-expression with StMPK7 enhanced the cell death. Besides, StUBA2a/bT248/408A mutant showed decreased ability to trigger cell death and elevate the expression of PR genes, indicating the phosphorylation by StMPK7 enhances the functions of StUBA2a/b. Moreover, CA-StMPK7-induced cell death was largely suppressed by silencing of NbUBA2a/b, genetically implying UBA2a/b acts as the downstream component of StMPK7. Collectively, our results reveal that StMPK7 phosphorylates and stabilizes its downstream substrate StUBA2a/b to enhance plant immunity via the SA signalling pathway.
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Affiliation(s)
| | | | - Liwen Xu
- College of Horticulture, Northwest A&F University and State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling 712100, China
| | - Xiaokang Chen
- College of Horticulture, Northwest A&F University and State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling 712100, China
| | - Jiashu Feng
- College of Horticulture, Northwest A&F University and State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling 712100, China
| | - Weijun Wu
- College of Horticulture, Northwest A&F University and State Key Laboratory of Crop Stress Biology for Arid Areas, Yangling 712100, China
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Tristetraprolin, Inflammation, and Metabolic Syndrome in Arab Adults: A Case Control Study. BIOLOGY 2021; 10:biology10060550. [PMID: 34207463 PMCID: PMC8235193 DOI: 10.3390/biology10060550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/13/2021] [Accepted: 06/16/2021] [Indexed: 01/06/2023]
Abstract
Simple Summary Metabolic syndrome (MetS) is a common disorder characterized as a low-grade chronic inflammatory state. The association of tristetraprolin (TTP), a novel anti-inflammatory protein, and MetS remains to be explored. We evaluated circulating TTP in a group of adult males and females with and without MetS. Serum levels of TTP were higher in the MetS group than in controls. In all subjects, serum TTP was also correlated with MetS components (e.g., glucose, lipids, and obesity indices). These findings suggest that TTP may be a promising biomarker for MetS. Abstract Tristetraprolin (TTP) is an mRNA binding protein suggested to have a substantial role in regulating the mRNA expression of numerous inflammatory factors, but data on TTP and its association with metabolic syndrome (MetS), a chronic low-grade inflammatory disorder, are scarce. We hypothesize that TTP may modulate MetS and its components. A total of 200 Saudi adults (aged 38.6 ± 8.3 years) were included in this cross-sectional study. Anthropometrics data were collected and fasting blood glucose taken for the assessment of glycemic, lipids and inflammatory markers using commercially available assays. The National Cholesterol Education Program Adult Treatment Panel (NCEP ATP III) criteria were used to define MetS. Results showed significantly higher levels of TTP in the MetS group than in controls [288.1 pg/mL vs. 150.9 pg/mL, p < 0.001]. Circulating TTP was significantly associated with tumor necrosis factor alpha [TNF-α, R = 0.30, p < 0.05], interleukin 1β [IL-1β, R = 0.41, p < 0.01] and C-reactive protein [CRP, R = 0.36, p < 0.01], adiponectin [R = 0.36, p < 0.05], insulin [R = 0.37, p < 0.05], and insulin resistance [HOMA-IR, R = 0.40, p < 0.05]. Receiver operating characteristics (ROC) suggest a potential use of TTP as diagnostic biomarker for MetS [AUC = 0.819, p < 0.001]. The findings suggest that TTP is associated with inflammation and glycemia, which may influence MetS. TTP is a promising diagnostic biomarker for MetS which can be confirmed in larger cohorts.
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Rodríguez-Gómez G, Paredes-Villa A, Cervantes-Badillo MG, Gómez-Sonora JP, Jorge-Pérez JH, Cervantes-Roldán R, León-Del-Río A. Tristetraprolin: A cytosolic regulator of mRNA turnover moonlighting as transcriptional corepressor of gene expression. Mol Genet Metab 2021; 133:137-147. [PMID: 33795191 DOI: 10.1016/j.ymgme.2021.03.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 01/12/2023]
Abstract
Tristetraprolin (TTP) is a nucleocytoplasmic 326 amino acid protein whose sequence is characterized by possessing two CCCH-type zinc finger domains. In the cytoplasm TTP function is to promote the degradation of mRNAs that contain adenylate/uridylate-rich elements (AREs). Mechanistically, TTP promotes the recruitment of poly(A)-specific deadenylases and exoribonucleases. By reducing the half-life of about 10% of all the transcripts in the cell TTP has been shown to participate in multiple cell processes that include regulation of gene expression, cell proliferation, metabolic homeostasis and control of inflammation and immune responses. However, beyond its role in mRNA decay, in the cell nucleus TTP acts as a transcriptional coregulator by interacting with chromatin modifying enzymes. TTP has been shown to repress the transactivation of NF-κB and estrogen receptor suggesting the possibility that it participates in the transcriptional regulation of hundreds of genes in human cells and its possible involvement in breast cancer progression. In this review, we discuss the cytoplasmic and nuclear functions of TTP and the effect of the dysregulation of its protein levels in the development of human diseases. We suggest that TTP be classified as a moonlighting tumor supressor protein that regulates gene expression through two different mechanims; the decay of ARE-mRNAs and a transcriptional coregulatory function.
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Affiliation(s)
- Gabriel Rodríguez-Gómez
- Programa de Investigación en Cáncer de Mama, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Alejandro Paredes-Villa
- Programa de Investigación en Cáncer de Mama, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Mayte Guadalupe Cervantes-Badillo
- Programa de Investigación en Cáncer de Mama, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Jessica Paola Gómez-Sonora
- Programa de Investigación en Cáncer de Mama, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Jesús H Jorge-Pérez
- Programa de Investigación en Cáncer de Mama, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Rafael Cervantes-Roldán
- Programa de Investigación en Cáncer de Mama, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Alfonso León-Del-Río
- Programa de Investigación en Cáncer de Mama, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico.
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8
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Zhang Y, Zhou J, Wei Z, Dong H, Yang D, Deng Y, Li J, Shi S, Sun Y, Lu H, Yuan J, Ni B, Wu Y, Tian Y, Han C. TTP-mediated regulation of mRNA stability in immune cells contributes to adaptive immunity, immune tolerance and clinical applications. RNA Biol 2021; 18:2150-2156. [PMID: 33866923 DOI: 10.1080/15476286.2021.1917185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Dendritic cells (DCs) form a sentinel network to induce protective immunity against pathogens or self-tolerance. mRNA stability is an important part of the post-transcriptional regulation (PTR) that controls the maturation and function of DCs. In this review, we summarize the effects of TTP-mediated regulation of mRNA stability in DCs, focusing on DC maturation and antigen presentation, T cell activation and differentiation, immune tolerance and inflammation. We also discuss the potential DC-based immune treatment for HIV+ patients through regulation of mRNA stability. This review proposes the regulation of mRNA stability as a novel immune therapy for various inflammatory diseases, such as arthritis and dermatitis.
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Affiliation(s)
- Yiwei Zhang
- Institute of Immunology, PLA, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Jian Zhou
- Institute of Immunology, PLA, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Zhiyuan Wei
- Department of Orthopedics, The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Hui Dong
- Institute of Immunology, PLA, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Di Yang
- Institute of Immunology, PLA, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Yuanyu Deng
- School of Basic Medicine, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Jiahui Li
- School of Basic Medicine, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Saiyu Shi
- School of Basic Medicine, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Yi Sun
- The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Huimin Lu
- The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Jizhao Yuan
- Institute of Immunology, PLA, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Bing Ni
- Department of Pathophysiology, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Yuzhang Wu
- Institute of Immunology, PLA, Third Military Medical University (Army Medical University), Chongqing, PR China.,Department of Orthopedics, The First Affiliated Hospital of Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Yi Tian
- Institute of Immunology, PLA, Third Military Medical University (Army Medical University), Chongqing, PR China.,School of Basic Medicine, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Chao Han
- Institute of Immunology, PLA, Third Military Medical University (Army Medical University), Chongqing, PR China
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Cao H, Sethumadhavan K, Cao F, Wang TTY. Gossypol decreased cell viability and down-regulated the expression of a number of genes in human colon cancer cells. Sci Rep 2021; 11:5922. [PMID: 33723275 PMCID: PMC7961146 DOI: 10.1038/s41598-021-84970-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 02/22/2021] [Indexed: 02/06/2023] Open
Abstract
Plant polyphenol gossypol has anticancer activities. This may increase cottonseed value by using gossypol as a health intervention agent. It is necessary to understand its molecular mechanisms before human consumption. The aim was to uncover the effects of gossypol on cell viability and gene expression in cancer cells. In this study, human colon cancer cells (COLO 225) were treated with gossypol. MTT assay showed significant inhibitory effect under high concentration and longtime treatment. We analyzed the expression of 55 genes at the mRNA level in the cells; many of them are regulated by gossypol or ZFP36/TTP in cancer cells. BCL2 mRNA was the most stable among the 55 mRNAs analyzed in human colon cancer cells. GAPDH and RPL32 mRNAs were not good qPCR references for the colon cancer cells. Gossypol decreased the mRNA levels of DGAT, GLUT, TTP, IL families and a number of previously reported genes. In particular, gossypol suppressed the expression of genes coding for CLAUDIN1, ELK1, FAS, GAPDH, IL2, IL8 and ZFAND5 mRNAs, but enhanced the expression of the gene coding for GLUT3 mRNA. The results showed that gossypol inhibited cell survival with decreased expression of a number of genes in the colon cancer cells.
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Affiliation(s)
- Heping Cao
- grid.507314.40000 0001 0668 8000United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124 USA
| | - Kandan Sethumadhavan
- grid.507314.40000 0001 0668 8000United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124 USA
| | - Fangping Cao
- grid.66741.320000 0001 1456 856XBeijing Forestry University, No. 35 Tsinghua East Road, Haidian District, Beijing, 100083 China
| | - Thomas T. Y. Wang
- grid.508988.4United States Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, 10300 Baltimore Ave, Beltsville, MD 20705 USA
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Rezcallah MC, Al-Mazi T, Ammit AJ. Cataloguing the phosphorylation sites of tristetraprolin (TTP): Functional implications for inflammatory diseases. Cell Signal 2020; 78:109868. [PMID: 33276085 DOI: 10.1016/j.cellsig.2020.109868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/29/2020] [Accepted: 11/29/2020] [Indexed: 01/10/2023]
Abstract
Tristetraprolin (TTP) is a destabilizing mRNA binding protein known to regulate gene expression of a wide variety of targets, including those that control inflammation. TTP expression, regulation and function is controlled by phosphorylation. While the importance of key serine (S) sites (S52 and S178 in mice and S186 in humans) has been recognized, other sites on the hyperphosphorylated TTP protein have more recently emerged as playing an important role in regulating cellular signalling and downstream functions of TTP. In order to propel investigation of TTP and fully exploit its potential as a drug target in inflammatory disease, this review will catalogue TTP phosphorylation sites in both the murine and human TTP protein, the known and unknown roles and functions of these sites, the kinases and phosphatases that act upon TTP and overview methodological approaches to increase our knowledge of this important protein regulated by phosphorylation.
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Affiliation(s)
- Maria C Rezcallah
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, NSW, Australia; School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Trisha Al-Mazi
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, NSW, Australia; School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia
| | - Alaina J Ammit
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, NSW, Australia; School of Life Sciences, Faculty of Science, University of Technology Sydney, Sydney, NSW, Australia.
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11
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Ariana A, Alturki NA, Hajjar S, Stumpo DJ, Tiedje C, Alnemri ES, Gaestel M, Blackshear PJ, Sad S. Tristetraprolin regulates necroptosis during tonic Toll-like receptor 4 (TLR4) signaling in murine macrophages. J Biol Chem 2020; 295:4661-4672. [PMID: 32094226 DOI: 10.1074/jbc.ra119.011633] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/10/2020] [Indexed: 11/06/2022] Open
Abstract
The necrosome is a protein complex required for signaling in cells that results in necroptosis, which is also dependent on tumor necrosis factor receptor (TNF-R) signaling. TNFα promotes necroptosis, and its expression is facilitated by mitogen-activated protein (MAP) kinase-activated protein kinase 2 (MK2) but is inhibited by the RNA-binding protein tristetraprolin (TTP, encoded by the Zfp36 gene). We have stimulated murine macrophages from WT, MyD88 -/-, Trif -/-, MyD88 -/- Trif -/-, MK2 -/-, and Zfp36 -/- mice with graded doses of lipopolysaccharide (LPS) and various inhibitors to evaluate the role of various genes in Toll-like receptor 4 (TLR4)-induced necroptosis. Necrosome signaling, cytokine production, and cell death were evaluated by immunoblotting, ELISA, and cell death assays, respectively. We observed that during TLR4 signaling, necrosome activation is mediated through the adaptor proteins MyD88 and TRIF, and this is inhibited by MK2. In the absence of MK2-mediated necrosome activation, lipopolysaccharide-induced TNFα expression was drastically reduced, but MK2-deficient cells became highly sensitive to necroptosis even at low TNFα levels. In contrast, during tonic TLR4 signaling, WT cells did not undergo necroptosis, even when MK2 was disabled. Of note, necroptosis occurred only in the absence of TTP and was mediated by the expression of TNFα and activation of JUN N-terminal kinase (JNK). These results reveal that TTP plays an important role in inhibiting TNFα/JNK-induced necrosome signaling and resultant cytotoxicity.
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Affiliation(s)
- Ardeshir Ariana
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Norah A Alturki
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Stephanie Hajjar
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Deborah J Stumpo
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Christopher Tiedje
- Department of Cellular and Molecular Medicine, University of Copenhagen, The Maersk Tower, 7.3, Blegdamsvej 3B, Copenhagen DK-2200, Denmark.,Institute of Cell Biochemistry, Hannover Medical School, Germany, 30623
| | - Emad S Alnemri
- Thomas Jefferson University, Department of Biochemistry and Molecular Biology, Philadelphia, Pennsylvania 19107
| | - Matthias Gaestel
- Institute of Cell Biochemistry, Hannover Medical School, Germany, 30623
| | - Perry J Blackshear
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709
| | - Subash Sad
- Department of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada .,University of Ottawa, Ottawa Centre for Infection, Immunity and Inflammation, Ontario K1H 8M5, Canada
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12
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Ingawale DK, Mandlik SK. New insights into the novel anti-inflammatory mode of action of glucocorticoids. Immunopharmacol Immunotoxicol 2020; 42:59-73. [PMID: 32070175 DOI: 10.1080/08923973.2020.1728765] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Inflammation is a physiological intrinsic host response to injury meant for removal of noxious stimuli and maintenance of homeostasis. It is a defensive body mechanism that involves immune cells, blood vessels and molecular mediators of inflammation. Glucocorticoids (GCs) are steroidal hormones responsible for regulation of homeostatic and metabolic functions of body. Synthetic GCs are the most useful anti-inflammatory drugs used for the treatment of chronic inflammatory diseases such as asthma, chronic obstructive pulmonary disease (COPD), allergies, multiple sclerosis, tendinitis, lupus, atopic dermatitis, ulcerative colitis, rheumatoid arthritis and osteoarthritis whereas, the long term use of GCs are associated with many side effects. The anti-inflammatory and immunosuppressive (desired) effects of GCs are usually mediated by transrepression mechanism whereas; the metabolic and toxic (undesired) effects are usually manifested by transactivation mechanism. Though GCs are most potent anti-inflammatory and immunosuppressive drugs, the common problem associated with their use is GC resistance. Several research studies are rising to comprehend these mechanisms, which would be helpful in improving the GC resistance in asthma and COPD patients. This review aims to focus on identification of new drug targets in inflammation which will be helpful in the resolution of inflammation. The ample understanding of GC mechanisms of action helps in the development of novel anti-inflammatory drugs for the treatment of inflammatory and autoimmune disease with reduced side effects and minimal toxicity.
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Affiliation(s)
- Deepa K Ingawale
- Department of Pharmacology, Poona College of Pharmacy, Bharati Vidyapeeth Deemed University, Pune, India
| | - Satish K Mandlik
- Department of Pharmacology, Sinhgad College of Pharmacy, Pune, India
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13
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Lee S, Micalizzi D, Truesdell SS, Bukhari SIA, Boukhali M, Lombardi-Story J, Kato Y, Choo MK, Dey-Guha I, Ji F, Nicholson BT, Myers DT, Lee D, Mazzola MA, Raheja R, Langenbucher A, Haradhvala NJ, Lawrence MS, Gandhi R, Tiedje C, Diaz-Muñoz MD, Sweetser DA, Sadreyev R, Sykes D, Haas W, Haber DA, Maheswaran S, Vasudevan S. A post-transcriptional program of chemoresistance by AU-rich elements and TTP in quiescent leukemic cells. Genome Biol 2020; 21:33. [PMID: 32039742 PMCID: PMC7011231 DOI: 10.1186/s13059-020-1936-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 01/15/2020] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Quiescence (G0) is a transient, cell cycle-arrested state. By entering G0, cancer cells survive unfavorable conditions such as chemotherapy and cause relapse. While G0 cells have been studied at the transcriptome level, how post-transcriptional regulation contributes to their chemoresistance remains unknown. RESULTS We induce chemoresistant and G0 leukemic cells by serum starvation or chemotherapy treatment. To study post-transcriptional regulation in G0 leukemic cells, we systematically analyzed their transcriptome, translatome, and proteome. We find that our resistant G0 cells recapitulate gene expression profiles of in vivo chemoresistant leukemic and G0 models. In G0 cells, canonical translation initiation is inhibited; yet we find that inflammatory genes are highly translated, indicating alternative post-transcriptional regulation. Importantly, AU-rich elements (AREs) are significantly enriched in the upregulated G0 translatome and transcriptome. Mechanistically, we find the stress-responsive p38 MAPK-MK2 signaling pathway stabilizes ARE mRNAs by phosphorylation and inactivation of mRNA decay factor, Tristetraprolin (TTP) in G0. This permits expression of ARE mRNAs that promote chemoresistance. Conversely, inhibition of TTP phosphorylation by p38 MAPK inhibitors and non-phosphorylatable TTP mutant decreases ARE-bearing TNFα and DUSP1 mRNAs and sensitizes leukemic cells to chemotherapy. Furthermore, co-inhibiting p38 MAPK and TNFα prior to or along with chemotherapy substantially reduces chemoresistance in primary leukemic cells ex vivo and in vivo. CONCLUSIONS These studies uncover post-transcriptional regulation underlying chemoresistance in leukemia. Our data reveal the p38 MAPK-MK2-TTP axis as a key regulator of expression of ARE-bearing mRNAs that promote chemoresistance. By disrupting this pathway, we develop an effective combination therapy against chemosurvival.
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Affiliation(s)
- Sooncheol Lee
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA, 02138, USA
| | - Douglas Micalizzi
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA
| | - Samuel S Truesdell
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA, 02138, USA
| | - Syed I A Bukhari
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA, 02138, USA
| | - Myriam Boukhali
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA
| | - Jennifer Lombardi-Story
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA
| | - Yasutaka Kato
- Laboratory of Oncology, Hokuto Hospital, Obihiro, Japan
| | - Min-Kyung Choo
- Cutaneous Biology Research Center, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Ipsita Dey-Guha
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA
| | - Fei Ji
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Benjamin T Nicholson
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
| | - David T Myers
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
| | - Dongjun Lee
- Department of Convergence Medical Science, Pusan National University School of Medicine, Yangsan, 50612, 1257-1258, South Korea
| | - Maria A Mazzola
- Center for Neurological Diseases, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Radhika Raheja
- Center for Neurological Diseases, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Adam Langenbucher
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - Nicholas J Haradhvala
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
- Broad Institute of Harvard & MIT, Cambridge, MA, 02142, USA
| | - Michael S Lawrence
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
- Broad Institute of Harvard & MIT, Cambridge, MA, 02142, USA
| | - Roopali Gandhi
- Center for Neurological Diseases, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Christopher Tiedje
- Department of Cellular and Molecular Medicine, Center for Healthy Aging, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Manuel D Diaz-Muñoz
- Centre de Physiopathologie Toulouse-Purpan, INSERM UMR1043/CNRS U5282, Toulouse, France
| | - David A Sweetser
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Pediatrics, Divisions of Pediatric Hematology/Oncology and Medical Genetics, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
| | - Ruslan Sadreyev
- Department of Molecular Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, 02129, USA
| | - David Sykes
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA
- Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA, 02138, USA
| | - Wilhelm Haas
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA
| | - Daniel A Haber
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, 20815, USA
| | - Shyamala Maheswaran
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA
- Department of Surgery, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, 02129, USA
| | - Shobha Vasudevan
- Massachusetts General Hospital Cancer Center, Harvard Medical School, 185 Cambridge St, CPZN4202, Boston, MA, 02114, USA.
- Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, Massachusetts, USA.
- Center for Regenerative Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA.
- Harvard Stem Cell Institute, Harvard University, Cambridge, MA, 02138, USA.
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14
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CXCL4 is a driver of cytokine mRNA stability in monocyte-derived dendritic cells. Mol Immunol 2019; 114:524-534. [DOI: 10.1016/j.molimm.2019.09.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 08/16/2019] [Accepted: 09/04/2019] [Indexed: 12/12/2022]
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15
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Yoshinaga M, Takeuchi O. RNA binding proteins in the control of autoimmune diseases. Immunol Med 2019; 42:53-64. [DOI: 10.1080/25785826.2019.1655192] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Masanori Yoshinaga
- Department of Medical Chemistry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Osamu Takeuchi
- Department of Medical Chemistry, Graduate School of Medicine, Kyoto University, Kyoto, Japan
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16
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Shin MK, Jeon YD, Jin JS. Apoptotic effect of enterodiol, the final metabolite of edible lignans, in colorectal cancer cells. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2019; 99:2411-2419. [PMID: 30357838 DOI: 10.1002/jsfa.9448] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Revised: 10/16/2018] [Accepted: 10/21/2018] [Indexed: 05/15/2023]
Abstract
BACKGROUND Enterodiol (END) is transformed by human intestinal bacteria from lignans contained in various whole-grain cereals, nuts, legumes, flaxseed, and vegetables. It is known to have several physiological effects, but its effects on mitogen-activated protein kinase (MAPK) signaling and apoptosis in colorectal cancer (CRC) cells have not yet been elucidated. We therefore investigated the effects of END on apoptosis in CRC cells and whether these effects are mediated via MAPK signaling. RESULTS Cell proliferation was decreased by END treatment in a time-dependent manner. In particular, END treatment resulted in an apoptosis rate of up to 40% in CT26 cells but showed no cytotoxicity toward RAW264.7 macrophages. Treatment with END also suppressed the migration of CRC cells in a concentration-dependent manner. The phosphorylation of extracellular signal-regulated kinase (ERK), jun N-terminal kinase (JNK), and p38 was down-regulated with END treatment. Furthermore, END decreased the expression levels of anti-apoptotic proteins in CRC cells. CONCLUSION Enterodiol inhibited the growth of CRC cells by controlling the MAPK signaling pathway involved in proliferation and apoptosis. These results demonstrate that END has an apoptotic effect in CRC cells. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Min-Kyoung Shin
- Department of Oriental Medicine Resources, Chonbuk National University, Iksan, South Korea
| | - Yong-Deok Jeon
- Department of Oriental Medicine Resources, Chonbuk National University, Iksan, South Korea
| | - Jong-Sik Jin
- Department of Oriental Medicine Resources, Chonbuk National University, Iksan, South Korea
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17
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Lai WS, Wells ML, Perera L, Blackshear PJ. The tandem zinc finger RNA binding domain of members of the tristetraprolin protein family. WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 10:e1531. [PMID: 30864256 DOI: 10.1002/wrna.1531] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 02/12/2019] [Accepted: 02/20/2019] [Indexed: 12/23/2022]
Abstract
Tristetraprolin (TTP), the prototype member of the protein family of the same name, was originally discovered as the product of a rapidly inducible gene in mouse cells. Development of a knockout (KO) mouse established that absence of the protein led to a severe inflammatory syndrome, due in part to elevated levels of tumor necrosis factor (TNF). TTP was found to bind directly and with high affinity to specific AU-rich sequences in the 3'-untranslated region of the TNF mRNA. This initial binding led to promotion of TNF mRNA decay and inhibition of its translation. Many additional TTP target mRNAs have since been identified, some of which are cytokines and chemokines involved in the inflammatory response. There are three other proteins in the mouse with similar activities and domain structures, but whose KO phenotypes are remarkably different. Moreover, proteins with similar domain structures and activities have been found throughout eukaryotes, demonstrating that this protein family arose from an ancient ancestor. The defining characteristic of this protein family is the tandem zinc finger (TZF) domain, a 64 amino acid sequence with many conserved residues that is responsible for the direct RNA binding. We discuss here many aspects of this protein domain that have been elucidated since the original discovery of TTP, including its sequence conservation throughout eukarya; its apparent continued evolution in some lineages; its functional dependence on many key conserved residues; its "interchangeability" among evolutionarily distant species; and the evidence that RNA binding is required for the physiological functions of the proteins. This article is categorized under: RNA Interactions with Proteins and Other Molecules > RNA-Protein Complexes RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Wi S Lai
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Durham, North Carolina
| | - Melissa L Wells
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Durham, North Carolina
| | - Lalith Perera
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, Durham, North Carolina
| | - Perry J Blackshear
- Signal Transduction Laboratory, National Institute of Environmental Health Sciences, Durham, North Carolina.,Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, North Carolina
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18
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Roles of Tristetraprolin in Tumorigenesis. Int J Mol Sci 2018; 19:ijms19113384. [PMID: 30380668 PMCID: PMC6274954 DOI: 10.3390/ijms19113384] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 10/25/2018] [Accepted: 10/26/2018] [Indexed: 12/13/2022] Open
Abstract
Genetic loss or mutations in tumor suppressor genes promote tumorigenesis. The prospective tumor suppressor tristetraprolin (TTP) has been shown to negatively regulate tumorigenesis through destabilizing the messenger RNAs of critical genes implicated in both tumor onset and tumor progression. Regulation of TTP has therefore emerged as an important issue in tumorigenesis. Similar to other tumor suppressors, TTP expression is frequently downregualted in various human cancers, and its low expression is correlated with poor prognosis. Additionally, disruption in the regulation of TTP by various mechanisms results in the inactivation of TTP protein or altered TTP expression. A recent study showing alleviation of Myc-driven lymphomagenesis by the forced expression of TTP has shed light on new therapeutic avenues for cancer prevention and treatment through the restoration of TTP expression. In this review, we summarize key oncogenes subjected to the TTP-mediated mRNA degradation, and discuss how dysregulation of TTP can contribute to tumorigenesis. In addition, the control mechanism underlying TTP expression at the posttranscriptional and posttranslational levels will be discussed.
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19
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Kondo M, Noguchi A, Matsuura Y, Shimada M, Yokota N, Kawahara H. Novel phosphorelay-dependent control of ZFP36L1 protein during the cell cycle. Biochem Biophys Res Commun 2018; 501:387-393. [DOI: 10.1016/j.bbrc.2018.04.212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Accepted: 04/26/2018] [Indexed: 10/16/2022]
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20
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Qi MY, Song JW, Zhang Z, Huang S, Jing Q. P38 activation induces the dissociation of tristetraprolin from Argonaute 2 to increase ARE-mRNA stabilization. Mol Biol Cell 2018; 29:988-1002. [PMID: 29444957 PMCID: PMC5896936 DOI: 10.1091/mbc.e17-02-0105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
ARE-mRNAs are actively degraded with tristetraprolin (TTP) in resting cells while they turn into stable messengers in activated cells. P38 plays a crucial role in stabilizing ARE-mRNA. Here we reveal that P38 activation represses the interaction between TTP and Ago2, thus restraining TTP from being targeted into processing bodies and stabilizing ARE-mRNA.
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Affiliation(s)
- Mei-Yan Qi
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jing-Wen Song
- Department of Cardiology, Changhai Hospital, Shanghai 200433, China
| | - Zhuo Zhang
- Department of Cardiology, Changhai Hospital, Shanghai 200433, China.,Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, Shanghai 200237, China
| | - Shuang Huang
- Department of Cardiology, Changhai Hospital, Shanghai 200433, China
| | - Qing Jing
- Key Laboratory of Stem Cell Biology, Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.,Department of Cardiology, Changhai Hospital, Shanghai 200433, China
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21
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A Knock-In Tristetraprolin (TTP) Zinc Finger Point Mutation in Mice: Comparison with Complete TTP Deficiency. Mol Cell Biol 2018; 38:MCB.00488-17. [PMID: 29203639 DOI: 10.1128/mcb.00488-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 11/25/2017] [Indexed: 01/09/2023] Open
Abstract
Tristetraprolin (TTP) is a tandem CCCH zinc finger protein that can bind to AU-rich element-containing mRNAs and promote their decay. TTP knockout mice develop a severe inflammatory syndrome, largely due to excess tumor necrosis factor (TNF), whose mRNA is a direct target of TTP binding and destabilization. TTP's RNA binding activity and its ability to promote mRNA decay are lost when one of the zinc-coordinating residues of either zinc finger is mutated. To address several long-standing questions about TTP activity in intact animals, we developed a knock-in mouse with a cysteine-to-arginine mutation within the first zinc finger. Homozygous knock-in mice developed a severe inflammatory syndrome that was essentially identical to that of complete TTP deficiency, suggesting that TTP's critical anti-inflammatory role in mammalian physiology is secondary to its ability to bind RNA. In addition, there was no evidence for a "dominant-negative" effect of the mutant allele in heterozygotes, as suggested by previous experiments. Finally, mRNA decay experiments in mutant macrophages demonstrated that TTP can regulate the stability of its own mRNA, albeit to a minor extent. These studies suggest that RNA binding is an essential first step in the physiological activities of members of this protein family.
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22
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O'Neil JD, Ammit AJ, Clark AR. MAPK p38 regulates inflammatory gene expression via tristetraprolin: Doing good by stealth. Int J Biochem Cell Biol 2018; 94:6-9. [PMID: 29128684 PMCID: PMC6562201 DOI: 10.1016/j.biocel.2017.11.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 11/07/2017] [Indexed: 12/14/2022]
Abstract
Tristetraprolin (TTP) is an RNA-destabilizing protein that exerts profound anti-inflammatory effects by inhibiting the expression of tumour necrosis factor and many other inflammatory mediators. The mitogen-activated protein kinase (MAPK) p38 signaling pathway controls the strength and duration of inflammatory responses by regulating both the expression and function of TTP. The kinase MK2 (MAPK activated kinase 2) is activated by MAPK p38, and in turn phosphorylates TTP at two critical serine residues. One consequence of these phosphorylations is the protection of TTP from proteasome-mediated degradation. Another consequence is the loss of mRNA destabilizing activity. The control of TTP expression and function by the MAPK p38 pathway provides an elegant mechanism for coupling the on and off phases of inflammatory responses, and dictating the precise kinetics of expression of individual inflammatory mediators.
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Affiliation(s)
- J D O'Neil
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2WB, United Kingdom
| | - A J Ammit
- Woolcock Emphysema Centre, Woolcock Institute of Medical Research, University of Sydney, New South Wales, Australia; School of Life Sciences, Faculty of Science, University of Technology, Sydney, New South Wales, Australia
| | - A R Clark
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham B15 2WB, United Kingdom.
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23
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García-Mauriño SM, Rivero-Rodríguez F, Velázquez-Cruz A, Hernández-Vellisca M, Díaz-Quintana A, De la Rosa MA, Díaz-Moreno I. RNA Binding Protein Regulation and Cross-Talk in the Control of AU-rich mRNA Fate. Front Mol Biosci 2017; 4:71. [PMID: 29109951 PMCID: PMC5660096 DOI: 10.3389/fmolb.2017.00071] [Citation(s) in RCA: 120] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 10/04/2017] [Indexed: 02/06/2023] Open
Abstract
mRNA metabolism is tightly orchestrated by highly-regulated RNA Binding Proteins (RBPs) that determine mRNA fate, thereby influencing multiple cellular functions across biological contexts. Here, we review the interplay between six well-known RBPs (TTP, AUF-1, KSRP, HuR, TIA-1, and TIAR) that recognize AU-rich elements (AREs) at the 3' untranslated regions of mRNAs, namely ARE-RBPs. Examples of the links between their cross-regulations and modulation of their targets are analyzed during mRNA processing, turnover, localization, and translational control. Furthermore, ARE recognition can be self-regulated by several factors that lead to the prevalence of one RBP over another. Consequently, we examine the factors that modulate the dynamics of those protein-RNA transient interactions to better understand the final consequences of the regulation mediated by ARE-RBPs. For instance, factors controlling the RBP isoforms, their conformational state or their post-translational modifications (PTMs) can strongly determine the fate of the protein-RNA complexes. Moreover, mRNA specific sequence and secondary structure or subtle environmental changes are also key determinants to take into account. To sum up, the whole understanding of such a fine tuned regulation is a challenge for future research and requires the integration of all the available structural and functional data by in vivo, in vitro and in silico approaches.
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Affiliation(s)
| | | | | | | | | | | | - Irene Díaz-Moreno
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
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24
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The control of inflammation via the phosphorylation and dephosphorylation of tristetraprolin: a tale of two phosphatases. Biochem Soc Trans 2017; 44:1321-1337. [PMID: 27911715 PMCID: PMC5095909 DOI: 10.1042/bst20160166] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/25/2016] [Accepted: 07/28/2016] [Indexed: 12/14/2022]
Abstract
Twenty years ago, the first description of a tristetraprolin (TTP) knockout mouse highlighted the fundamental role of TTP in the restraint of inflammation. Since then, work from several groups has generated a detailed picture of the expression and function of TTP. It is a sequence-specific RNA-binding protein that orchestrates the deadenylation and degradation of several mRNAs encoding inflammatory mediators. It is very extensively post-translationally modified, with more than 30 phosphorylations that are supported by at least two independent lines of evidence. The phosphorylation of two particular residues, serines 52 and 178 of mouse TTP (serines 60 and 186 of the human orthologue), has profound effects on the expression, function and localisation of TTP. Here, we discuss the control of TTP biology via its phosphorylation and dephosphorylation, with a particular focus on recent advances and on questions that remain unanswered.
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25
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Gain-of-Function Mutation of Tristetraprolin Impairs Negative Feedback Control of Macrophages In Vitro yet Has Overwhelmingly Anti-Inflammatory Consequences In Vivo. Mol Cell Biol 2017; 37:MCB.00536-16. [PMID: 28265004 PMCID: PMC5440651 DOI: 10.1128/mcb.00536-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 02/25/2017] [Indexed: 12/20/2022] Open
Abstract
The mRNA-destabilizing factor tristetraprolin (TTP) binds in a sequence-specific manner to the 3' untranslated regions of many proinflammatory mRNAs and recruits complexes of nucleases to promote rapid mRNA turnover. Mice lacking TTP develop a severe, spontaneous inflammatory syndrome characterized by the overexpression of tumor necrosis factor and other inflammatory mediators. However, TTP also employs the same mechanism to inhibit the expression of the potent anti-inflammatory cytokine interleukin 10 (IL-10). Perturbation of TTP function may therefore have mixed effects on inflammatory responses, either increasing or decreasing the expression of proinflammatory factors via direct or indirect mechanisms. We recently described a knock-in mouse strain in which the substitution of 2 amino acids of the endogenous TTP protein renders it constitutively active as an mRNA-destabilizing factor. Here we investigate the impact on the IL-10-mediated anti-inflammatory response. It is shown that the gain-of-function mutation of TTP impairs IL-10-mediated negative feedback control of macrophage function in vitro However, the in vivo effects of TTP mutation are uniformly anti-inflammatory despite the decreased expression of IL-10.
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Ross EA, Naylor AJ, O'Neil JD, Crowley T, Ridley ML, Crowe J, Smallie T, Tang TJ, Turner JD, Norling LV, Dominguez S, Perlman H, Verrills NM, Kollias G, Vitek MP, Filer A, Buckley CD, Dean JL, Clark AR. Treatment of inflammatory arthritis via targeting of tristetraprolin, a master regulator of pro-inflammatory gene expression. Ann Rheum Dis 2016; 76:612-619. [PMID: 27597652 PMCID: PMC5446007 DOI: 10.1136/annrheumdis-2016-209424] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 08/10/2016] [Accepted: 08/11/2016] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Tristetraprolin (TTP), a negative regulator of many pro-inflammatory genes, is strongly expressed in rheumatoid synovial cells. The mitogen-activated protein kinase (MAPK) p38 pathway mediates the inactivation of TTP via phosphorylation of two serine residues. We wished to test the hypothesis that these phosphorylations contribute to the development of inflammatory arthritis, and that, conversely, joint inflammation may be inhibited by promoting the dephosphorylation and activation of TTP. METHODS The expression of TTP and its relationship with MAPK p38 activity were examined in non-inflamed and rheumatoid arthritis (RA) synovial tissue. Experimental arthritis was induced in a genetically modified mouse strain, in which endogenous TTP cannot be phosphorylated and inactivated. In vitro and in vivo experiments were performed to test anti-inflammatory effects of compounds that activate the protein phosphatase 2A (PP2A) and promote dephosphorylation of TTP. RESULTS TTP expression was significantly higher in RA than non-inflamed synovium, detected in macrophages, vascular endothelial cells and some fibroblasts and co-localised with MAPK p38 activation. Substitution of TTP phosphorylation sites conferred dramatic protection against inflammatory arthritis in mice. Two distinct PP2A agonists also reduced inflammation and prevented bone erosion. In vitro anti-inflammatory effects of PP2A agonism were mediated by TTP activation. CONCLUSIONS The phosphorylation state of TTP is a critical determinant of inflammatory responses, and a tractable target for novel anti-inflammatory treatments.
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Affiliation(s)
- E A Ross
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - A J Naylor
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - J D O'Neil
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - T Crowley
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - M L Ridley
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - J Crowe
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK
| | - T Smallie
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - T J Tang
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - J D Turner
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - L V Norling
- William Harvey Research Institute, QMUL, London, UK
| | - S Dominguez
- Division of Rheumatology, Northwestern University, Chicago, Illinois, USA
| | - H Perlman
- Division of Rheumatology, Northwestern University, Chicago, Illinois, USA
| | - N M Verrills
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, New South Wales, Australia
| | - G Kollias
- Division of Immunology, Biomedical Sciences Research Center 'Alexander Fleming', Vari, Greece
| | - M P Vitek
- Cognosci Inc., Research Triangle Park, North Carolina, USA
| | - A Filer
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - C D Buckley
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
| | - J L Dean
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK
| | - A R Clark
- Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
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Schwerk J, Savan R. Translating the Untranslated Region. THE JOURNAL OF IMMUNOLOGY 2016; 195:2963-71. [PMID: 26386038 DOI: 10.4049/jimmunol.1500756] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Gene expression programs undergo constant regulation to quickly adjust to environmental stimuli that alter the physiological status of the cell, like cellular stress or infection. Gene expression is tightly regulated by multilayered regulatory elements acting in both cis and trans. Posttranscriptional regulation of the 3' untranslated region (UTR) is a powerful regulatory process that determines the rate of protein translation from mRNA. Regulatory elements targeting the 3' UTR include microRNAs, RNA-binding proteins, and long noncoding RNAs, which dramatically alter the immune response. We provide an overview of our current understanding of posttranscriptional regulation of immune gene expression. The focus of this review is on regulatory elements that target the 3' UTR. We delineate how the synergistic or antagonistic interactions of posttranscriptional regulators determine gene expression levels and how dysregulation of 3' UTR-mediated posttranscriptional control associates with human diseases.
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Affiliation(s)
- Johannes Schwerk
- Department of Immunology, University of Washington, Seattle, WA 98109
| | - Ram Savan
- Department of Immunology, University of Washington, Seattle, WA 98109
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Inoue Y, Abe K, Onozaki K, Hayashi H. TGF-β decreases the stability of IL-18-induced IFN-γ mRNA through the expression of TGF-β-induced tristetraprolin in KG-1 cells. Biol Pharm Bull 2016; 38:536-44. [PMID: 25832634 DOI: 10.1248/bpb.b14-00673] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have previously reported that transforming growth factor-β (TGF-β) down-regulates interferon-γ (IFN-γ) production in an interleukin-18 (IL-18) treated mouse natural killer (NK) cell line, LNK5E6. In LNK5E6 cells, TGF-β exhibited no inhibition of the IL-18-induced transcription of IFN-γ, but did stimulate the degradation of IFN-γ mRNA induced by IL-18. In the present study, we investigated the mechanism of the down-regulatory effects of TGF-β on IFN-γ mRNA expression in a human myelomonocytic cell line, KG-1, which produces IFN-γ in response to IL-18 alone. Interestingly, IL-18 induced the production of the IFN-γ through the stabilization of IFN-γ mRNA, but not the enhanced transcription of IFN-γ gene. The stability of IFN-γ mRNA was regulated by mRNA destabilizing elements in the 3'untranslated region (UTR) of IFN-γ mRNA, especially adenylate-uridylate (AU)-rich elements (AREs) in the 5' half of 3'UTR. Tristetraprolin (TTP), one of the ARE-binding proteins, destabilizes IFN-γ mRNA, and IL-18 repressed the expression of TTP mRNA. Moreover, TGF-β repressed the IL-18-induced expression of IFN-γ mRNA through the induction of TTP mRNA to destabilize IFN-γ mRNA. Our data is the first to reveal that the crosstalk between IL-18 and TGF-β through the expression of TTP regulates the production of IFN-γ.
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Affiliation(s)
- Yasumichi Inoue
- Department of Drug Metabolism and Disposition, Graduate School of Pharmaceutical Sciences, Nagoya City University
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29
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Ross EA, Smallie T, Ding Q, O'Neil JD, Cunliffe HE, Tang T, Rosner DR, Klevernic I, Morrice NA, Monaco C, Cunningham AF, Buckley CD, Saklatvala J, Dean JL, Clark AR. Dominant Suppression of Inflammation via Targeted Mutation of the mRNA Destabilizing Protein Tristetraprolin. THE JOURNAL OF IMMUNOLOGY 2015; 195:265-76. [PMID: 26002976 PMCID: PMC4472942 DOI: 10.4049/jimmunol.1402826] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 04/27/2015] [Indexed: 02/07/2023]
Abstract
In myeloid cells, the mRNA-destabilizing protein tristetraprolin (TTP) is induced and extensively phosphorylated in response to LPS. To investigate the role of two specific phosphorylations, at serines 52 and 178, we created a mouse strain in which those residues were replaced by nonphosphorylatable alanine residues. The mutant form of TTP was constitutively degraded by the proteasome and therefore expressed at low levels, yet it functioned as a potent mRNA destabilizing factor and inhibitor of the expression of many inflammatory mediators. Mice expressing only the mutant form of TTP were healthy and fertile, and their systemic inflammatory responses to LPS were strongly attenuated. Adaptive immune responses and protection against infection by Salmonella typhimurium were spared. A single allele encoding the mutant form of TTP was sufficient for enhanced mRNA degradation and underexpression of inflammatory mediators. Therefore, the equilibrium between unphosphorylated and phosphorylated TTP is a critical determinant of the inflammatory response, and manipulation of this equilibrium may be a means of treating inflammatory pathologies.
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Affiliation(s)
- Ewan A Ross
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Tim Smallie
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Qize Ding
- Imperial College London, Hammersmith Hospital, London W12 0NN, United Kingdom
| | - John D O'Neil
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Helen E Cunliffe
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Tina Tang
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Dalya R Rosner
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Iva Klevernic
- Unit of Signal Transduction, Interdisciplinary Cluster for Applied Genoproteomics, University of Liege, University Hospital, 4000 Liege, Belgium
| | - Nicholas A Morrice
- Beatson Institute for Cancer Research, Bearsden, Glasgow G61 1BD, United Kingdom; and
| | - Claudia Monaco
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7FY, United Kingdom
| | - Adam F Cunningham
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Christopher D Buckley
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Jeremy Saklatvala
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7FY, United Kingdom
| | - Jonathan L Dean
- Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford OX3 7FY, United Kingdom
| | - Andrew R Clark
- School of Immunity and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham B15 2TT, United Kingdom;
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Hausburg MA, Doles JD, Clement SL, Cadwallader AB, Hall MN, Blackshear PJ, Lykke-Andersen J, Olwin BB. Post-transcriptional regulation of satellite cell quiescence by TTP-mediated mRNA decay. eLife 2015; 4:e03390. [PMID: 25815583 PMCID: PMC4415119 DOI: 10.7554/elife.03390] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 03/26/2015] [Indexed: 12/20/2022] Open
Abstract
Skeletal muscle satellite cells in their niche are quiescent and upon muscle injury, exit quiescence, proliferate to repair muscle tissue, and self-renew to replenish the satellite cell population. To understand the mechanisms involved in maintaining satellite cell quiescence, we identified gene transcripts that were differentially expressed during satellite cell activation following muscle injury. Transcripts encoding RNA binding proteins were among the most significantly changed and included the mRNA decay factor Tristetraprolin. Tristetraprolin promotes the decay of MyoD mRNA, which encodes a transcriptional regulator of myogenic commitment, via binding to the MyoD mRNA 3′ untranslated region. Upon satellite cell activation, p38α/β MAPK phosphorylates MAPKAP2 and inactivates Tristetraprolin, stabilizing MyoD mRNA. Satellite cell specific knockdown of Tristetraprolin precociously activates satellite cells in vivo, enabling MyoD accumulation, differentiation and cell fusion into myofibers. Regulation of mRNAs by Tristetraprolin appears to function as one of several critical post-transcriptional regulatory mechanisms controlling satellite cell homeostasis. DOI:http://dx.doi.org/10.7554/eLife.03390.001 When muscles are damaged, they can repair themselves to some extent by making new muscle cells. These develop from groups of cells called satellite cells, which are found near the surface of muscle fibers. Once the muscle is injured, the satellite cells are activated and can divide to form two cells with different properties. One remains a satellite cell, while the other forms a ‘myoblast’ that eventually fuses into a mature muscle fiber. Under normal conditions the satellite cells remain in a dormant state and do not divide, but it is not clear how they maintain this dormant state. To create a protein, the gene that encodes it is first ‘transcribed’ to produce a molecule called mRNA, which is then used as a template to build the protein. A protein called Tristetraprolin (TTP) can bind to mRNA molecules and cause them to break down or decay, and so TTP can prevent the mRNA from being used to make a protein. Hausburg, Doles et al. analyzed satellite cells from uninjured muscle and compared them with those from injured tissue. This revealed that when injured, the satellite cells reduced the abundance of several mRNAs, including TTP. Further investigation found that in satellite cells from uninjured tissue, TTP causes the decay of mRNA molecules that are used to produce a protein called MyoD. As MyoD helps the satellite cells to specialize, this decay therefore prevents the formation of myoblasts and keeps the satellite cells in a dormant state. In contrast, damage to the muscle tissue activates a signaling pathway that ultimately inactivates TTP. This enables more of the MyoD protein to be made and the myoblast population to expand. When Hausburg, Doles et al. experimentally reduced the levels of TTP inside satellite cells, the cells developed into myoblasts even when the tissue was uninjured. Thus, TTP is an important regulator that allows satellite cells to remain in a dormant state. In dormant adult stem cells, regulation of protein availability by RNA binding proteins, such as TTP, may co-ordinate rapid changes in metabolic state to promptly repair injured tissue. A major challenge will be to identify the group of proteins involved and determine the precise mechanisms involved in regulating their availability. DOI:http://dx.doi.org/10.7554/eLife.03390.002
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Affiliation(s)
- Melissa A Hausburg
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Jason D Doles
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Sandra L Clement
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Adam B Cadwallader
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Monica N Hall
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Perry J Blackshear
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Jens Lykke-Andersen
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
| | - Bradley B Olwin
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado Boulder, Boulder, United States
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31
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Miná VAL, Lacerda-Pinheiro SF, Maia LC, Pinheiro RFF, Meireles CB, de Souza SIR, Reis AOA, Bianco B, Rolim MLN. The influence of inflammatory cytokines in physiopathology of suicidal behavior. J Affect Disord 2015; 172:219-30. [PMID: 25451421 DOI: 10.1016/j.jad.2014.09.057] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Accepted: 09/30/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND Based on the urgent need for reliable biomarkers in relation to suicide risk both for more accurate prediction as well as for new therapeutic opportunities, several researchers have been studied evidences of the potential participation of inflammatory processes in the brain, in particular cytokines, in suicide. The purpose of this review was to analyze the associations between inflammation markers and suicide. METHODS To achieve this goal, a systematic review of literature was conducted via electronic database Scopus using the Medical Subject Headings (MeSH) terms: "cytokines", "suicide" and "inflammation". Through this search it was found 54 articles. After analyzing them 15 met the eligibility criteria and were included in the final sample. RESULTS One of the most mentioned inflammatory markers was Interferon-α (IFN-α), a pro-inflammatory cytokine which has been shown to increase serum concentrations of pro-inflammatory cytokines such as interleukin (IL)-1, IL-6, tumor necrosis factor-a (TNF- α) and IFN-ϒ, which are factors increased suicide victims and attempters. In this line, IL-6 is not only found to be elevated in the cerebrospinal fluid of suicide attempters, even its levels in the peripheral blood have been proposed as a biological suicide marker. Another study stated that increased levels of IL-4 and IL-13 transcription in the orbitofrontal cortex of suicides suggest that these cytokines may affect neurobehavioral processes relevant to suicide. LIMITATIONS A lack of studies and great amount of cross-sectional studies. CONCLUSION Inflammation may play an important role in the pathophysiology of suicide, especially, levels of some specific inflammatory cytokines.
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Affiliation(s)
| | | | - L C Maia
- Federal University of Cariri, Brazil
| | | | | | - S I R de Souza
- Pos-graduation Program in Health Sciences, Faculty of Medicine of ABC, Brazil
| | - A O A Reis
- Pos-graduation Program in Public Health, University of São Paulo, Brazil
| | - B Bianco
- Pos-graduation Program in Health Sciences, Faculty of Medicine of ABC, Brazil
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Prabhala P, Ammit AJ. Tristetraprolin and its role in regulation of airway inflammation. Mol Pharmacol 2014; 87:629-38. [PMID: 25429052 DOI: 10.1124/mol.114.095984] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Chronic inflammatory diseases, such as asthma and chronic obstructive pulmonary disease (COPD), are clinically and socioeconomically important diseases globally. Currently the mainstay of anti-inflammatory therapy in respiratory diseases is corticosteroids. Although corticosteroids have proven clinical efficacy in asthma, many asthmatic inflammatory conditions (e.g., infection, exacerbation, and severe asthma) are not responsive to corticosteroids. Moreover, despite an understanding that COPD progression is driven by inflammation, we currently do not have effective anti-inflammatory strategies to combat this disease. Hence, alternative anti-inflammatory strategies are required. p38 mitogen-activated protein kinase (MAPK) has emerged as an important signaling molecule driving airway inflammation, and pharmacological inhibitors against p38 MAPK may provide potential therapies for chronic respiratory disease. In this review, we discuss some of the recent in vitro and in vivo studies targeting p38 MAPK, but suggest that p38 MAPK inhibitors may prove less effective than originally considered because they may block anti-inflammatory molecules along with proinflammatory responses. We propose that an alternative strategy may be to target an anti-inflammatory molecule farther downstream of p38 MAPK, i.e., tristetraprolin (TTP). TTP is an mRNA-destabilizing, RNA-binding protein that enhances the decay of mRNAs, including those encoding proteins implicated in chronic respiratory diseases. We suggest that understanding the molecular mechanism of TTP expression and its temporal regulation will guide future development of novel anti-inflammatory pharmacotherapeutic approaches to combat respiratory disease.
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Affiliation(s)
- Pavan Prabhala
- Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia
| | - Alaina J Ammit
- Faculty of Pharmacy, University of Sydney, Sydney, New South Wales, Australia
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Abstract
Our laboratory has contributed to the areas of B cell receptor (BCR) and pre-BCR gene identification and transcription and has focused on the problem of the aged immune system in mice and humans for the last 15 years. We have found biomarkers for the decrease in B cell function in aged mice and humans. These include decreases in immunoglobulin (Ig) class switch (e.g., IgM to IgG), decreases in the enzyme AID (activation-induced cytidine deaminase) and decreases in the transcription factor E47. The E47 mRNA stability is decreased in old B cells due to decreased phospho-MAPKinase and phospho-TTP (tristetraprolin). Inflammation, e.g., TNF-α, which increases with age, impacts B cells directly by increasing their TNF-α and NF-κB and leads to the above decreased pathway. Both class switch and affinity maturation are decreased in elderly responses to the influenza vaccine and biomarkers we have found (numbers and percentages of switched memory B cells and AID in stimulated B cells in culture) can predict a beneficial or decreased immune response to the vaccine. Current and future avenues to improve the humoral immune response in the elderly are discussed.
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Affiliation(s)
- Bonnie B Blomberg
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, RMSB #3146A, P.O. Box 016960 (R-138), Miami, FL, 33101, USA,
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Resch U, Cuapio A, Sturtzel C, Hofer E, de Martin R, Holper-Schichl YM. Polyubiquitinated tristetraprolin protects from TNF-induced, caspase-mediated apoptosis. J Biol Chem 2014; 289:25088-100. [PMID: 25056949 DOI: 10.1074/jbc.m114.563312] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Binding of TNF to its receptor (TNFR1) elicits the spatiotemporal assembly of two signaling complexes that coordinate the balance between cell survival and cell death. We have shown previously that, following TNF treatment, the mRNA decay protein tristetraprolin (TTP) is Lys-63-polyubiquitinated by TNF receptor-associated factor 2 (TRAF2), suggesting a regulatory role in TNFR signaling. Here we demonstrate that TTP interacts with TNFR1 in a TRAF2-dependent manner, thereby initiating the MEKK1/MKK4-dependent activation of JNK activities. This regulatory function toward JNK activation but not NF-κB activation depends on lysine 105 of TTP, which we identified as the corresponding TRAF2 ubiquitination site. Disabling TTP polyubiquitination results in enhanced TNF-induced apoptosis in cervical cancer cells. Together, we uncover a novel aspect of TNFR1 signaling where TTP, in alliance with TRAF2, acts as a balancer of JNK-mediated cell survival versus death.
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Affiliation(s)
- Ulrike Resch
- From the Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
| | - Angélica Cuapio
- From the Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
| | - Caterina Sturtzel
- From the Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
| | - Erhard Hofer
- From the Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
| | - Rainer de Martin
- From the Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
| | - Yvonne M Holper-Schichl
- From the Department of Vascular Biology and Thrombosis Research, Medical University of Vienna, Schwarzspanierstraße 17, 1090 Vienna, Austria
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Cao H, Deterding LJ, Blackshear PJ. Identification of a major phosphopeptide in human tristetraprolin by phosphopeptide mapping and mass spectrometry. PLoS One 2014; 9:e100977. [PMID: 25010646 PMCID: PMC4091943 DOI: 10.1371/journal.pone.0100977] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 06/02/2014] [Indexed: 11/18/2022] Open
Abstract
Tristetraprolin/zinc finger protein 36 (TTP/ZFP36) binds and destabilizes some pro-inflammatory cytokine mRNAs. TTP-deficient mice develop a profound inflammatory syndrome due to excessive production of pro-inflammatory cytokines. TTP expression is induced by various factors including insulin and extracts from cinnamon and green tea. TTP is highly phosphorylated in vivo and is a substrate for several protein kinases. Multiple phosphorylation sites are identified in human TTP, but it is difficult to assign major vs. minor phosphorylation sites. This study aimed to generate additional information on TTP phosphorylation using phosphopeptide mapping and mass spectrometry (MS). Wild-type and site-directed mutant TTP proteins were expressed in transfected human cells followed by in vivo radiolabeling with [32P]-orthophosphate. Histidine-tagged TTP proteins were purified with Ni-NTA affinity beads and digested with trypsin and lysyl endopeptidase. The digested peptides were separated by C18 column with high performance liquid chromatography. Wild-type and all mutant TTP proteins were localized in the cytosol, phosphorylated extensively in vivo and capable of binding to ARE-containing RNA probes. Mutant TTP with S90 and S93 mutations resulted in the disappearance of a major phosphopeptide peak. Mutant TTP with an S197 mutation resulted in another major phosphopeptide peak being eluted earlier than the wild-type. Additional mutations at S186, S296 and T271 exhibited little effect on phosphopeptide profiles. MS analysis identified the peptide that was missing in the S90 and S93 mutant protein as LGPELSPSPTSPTATSTTPSR (corresponding to amino acid residues 83–103 of human TTP). MS also identified a major phosphopeptide associated with the first zinc-finger region. These analyses suggest that the tryptic peptide containing S90 and S93 is a major phosphopeptide in human TTP.
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Affiliation(s)
- Heping Cao
- U. S. Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, Louisiana, United States of America
- * E-mail:
| | - Leesa J. Deterding
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America
| | - Perry J. Blackshear
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America and Departments of Biochemistry and Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
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Xiao J, Gao H, Jin Y, Zhao Z, Guo J, Liu Z, Zhao Z. The abnormal expressions of tristetraprolin and the VEGF family in uraemic rats with peritoneal dialysis. Mol Cell Biochem 2014; 392:229-38. [PMID: 24696420 DOI: 10.1007/s11010-014-2033-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 03/14/2014] [Indexed: 01/01/2023]
Abstract
The effect of peritoneal dialysis (PD) with high-glucose dialysis fluid on the VEGF family, tristetraprolin (TTP), angiogenesis and lymphangiogenesis was investigated. Forty male SD rats were randomised into five groups: normal group, sham operation group, uraemia group, PD 2-week group and PD4-week group. After 4 weeks of PD, microvessel density (MVD) and lymphatic vessel density (LVD) were measured. The expressions of both the VEGF family and TTP were detected. Compared with the normal group, the mRNA expression levels of the VEGF family were significantly increased in the uraemia group (P < 0.05), and also in the PD 2-week group and PD4-week group (P < 0.05) compared with uraemia group. The mRNAs of VEGF-A and VEGF-C in 4-week PD group likewise were significantly increased compared with the 2-week PD group. However, the mRNA expression of TTP was significantly decreased in the uraemia group compared with the normal group (P < 0.05), and also in the PD group compared with the uraemia group (P < 0.05). Compared with the normal group, the protein expressions of TTP were significantly decreased in the uraemia group (P < 0.05), and also in the PD group compared with the uraemia group (P < 0.05). Compared with the normal group, the MVD and LVD counts were gradually increased in the PD group, which was associated with PD time. In addition, the expression of TTP gradually decreased over PD time. High-glucose PD fluid and uraemic circumstance resulted in the abnormal expression of TTP and the VEGF family in a PD time-dependent manner; this may lead to UFF through angiogenesis and lymphangiogenesis.
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Affiliation(s)
- Jing Xiao
- Department of Nephrology, The First Affiliated Hospital of Zhengzhou University, No.1 Eastern Jianshe Road, Zhengzhou, 450052, Henan, China
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Trained immunity or tolerance: opposing functional programs induced in human monocytes after engagement of various pattern recognition receptors. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2014; 21:534-45. [PMID: 24521784 PMCID: PMC3993125 DOI: 10.1128/cvi.00688-13] [Citation(s) in RCA: 218] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Upon priming with Candida albicans or with the fungal cell wall component β-glucan, monocytes respond with an increased cytokine production upon restimulation, a phenomenon termed "trained immunity." In contrast, the prestimulation of monocytes with lipopolysaccharide has long been known to induce tolerance. Because the vast majority of commensal microorganisms belong to bacterial or viral phyla, we sought to systematically investigate the functional reprogramming of monocytes induced by the stimulation of pattern recognition receptors (PRRs) with various bacterial or viral ligands. Monocytes were functionally programmed for either enhanced (training) or decreased (tolerance) cytokine production, depending on the type and concentration of ligand they encountered. The functional reprogramming of monocytes was also associated with cell shape, granulocity, and cell surface marker modifications. The training effect required p38- and Jun N-terminal protein kinase (JNK)-mediated mitogen-activated protein kinase (MAPK) signaling, with specific signaling patterns directing the functional fate of the cell. The long-term effects on the function of monocytes were mediated by epigenetic events, with both histone methylation and acetylation inhibitors blocking the training effects. In conclusion, our experiments identify the ability of monocytes to acquire adaptive characteristics after prior activation with a wide variety of ligands. Trained immunity and tolerance are two distinct and opposing functional programs induced by the specific microbial ligands engaging the monocytes.
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Dai XY, Cai Y, Sun W, Ding Y, Wang W, Kong W, Tang C, Zhu Y, Xu MJ, Wang X. Intermedin inhibits macrophage foam-cell formation via tristetraprolin-mediated decay of CD36 mRNA. Cardiovasc Res 2013; 101:297-305. [PMID: 24253523 DOI: 10.1093/cvr/cvt254] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS CD36-mediated uptake of oxidized low-density lipoprotein (oxLDL) plays a pivotal role in macrophage foam-cell formation and atherogenesis. Previously we reported on intermedin (IMD), a novel member of the calcitonin gene-related peptide family, in atherosclerotic plaque reducing atherogenesis in apolipoprotein E-deficient (apoE(-/-)) mice. Here, we studied the role of IMD in CD36-mediated macrophage foam-cell formation. METHODS AND RESULTS In apoE(-/-) mice, 6-week IMD infusion reduced oxLDL uptake, intracellular cholesterol content, and foam-cell formation in peritoneal macrophages and reduced protein and mRNA levels of CD36. These in vivo results agreed with in vitro observations in primary peritoneal macrophages. Reduced CD36 protein and mRNA levels were due to an IMD-accelerated decay of CD36 mRNA. Tristetraprolin (TTP), which binds to AU-rich elements in the 3' untranslated regions (UTRs) of mRNA and promotes its degradation, mediated CD36 mRNA destabilization. TTP knockdown by short-hairpin RNA increased and TTP overexpression reduced CD36 expression, and TTP knockdown rescued IMD-reduced CD36 expression. Moreover, IMD repressed TTP phosphorylation, thereby activating TTP, for increased TTP binding to the 3'-UTR of CD36 mRNA. CONCLUSION Thus, IMD attenuates macrophage foam-cell formation via TTP-mediated degradation of CD36 mRNA. Our findings reveal a new mechanism of the anti-atherogenic role of IMD and a novel pattern for regulation of CD36 expression in macrophages.
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Affiliation(s)
- Xiao-Yan Dai
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Peking University Health Science Center, Key Laboratory of Molecular Cardiovascular Science, Ministry of Education, Beijing 100191, P. R. China
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Molle C, Zhang T, Ysebrant de Lendonck L, Gueydan C, Andrianne M, Sherer F, Van Simaeys G, Blackshear PJ, Leo O, Goriely S. Tristetraprolin regulation of interleukin 23 mRNA stability prevents a spontaneous inflammatory disease. J Exp Med 2013; 210:1675-84. [PMID: 23940256 PMCID: PMC3754859 DOI: 10.1084/jem.20120707] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 07/23/2013] [Indexed: 12/13/2022] Open
Abstract
Interleukin (IL) 12 and IL23 are two related heterodimeric cytokines produced by antigen-presenting cells. The balance between these two cytokines plays a crucial role in the control of Th1/Th17 responses and autoimmune inflammation. Most studies focused on their transcriptional regulation. Herein, we explored the role of the adenine and uridine-rich element (ARE)-binding protein tristetraprolin (TTP) in influencing mRNA stability of IL12p35, IL12/23p40, and IL23p19 subunits. LPS-stimulated bone marrow-derived dendritic cells (BMDCs) from TTP(-/-) mice produced normal levels of IL12/23p40. Production of IL12p70 was modestly increased in these conditions. In contrast, we observed a strong impact of TTP on IL23 production and IL23p19 mRNA stability through several AREs in the 3' untranslated region. TTP(-/-) mice spontaneously develop an inflammatory syndrome characterized by cachexia, myeloid hyperplasia, dermatitis, and erosive arthritis. We observed IL23p19 expression within skin lesions associated with exacerbated IL17A and IL22 production by infiltrating γδ T cells and draining lymph node CD4 T cells. We demonstrate that the clinical and immunological parameters associated with TTP deficiency were completely dependent on the IL23-IL17A axis. We conclude that tight control of IL23 mRNA stability by TTP is critical to avoid severe inflammation.
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Affiliation(s)
- Céline Molle
- Institute for Medical Immunology (IMI), Laboratoire de Biologie Moléculaire du Gène, and Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
| | - Tong Zhang
- Institute for Medical Immunology (IMI), Laboratoire de Biologie Moléculaire du Gène, and Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
| | - Laure Ysebrant de Lendonck
- Institute for Medical Immunology (IMI), Laboratoire de Biologie Moléculaire du Gène, and Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
| | - Cyril Gueydan
- Institute for Medical Immunology (IMI), Laboratoire de Biologie Moléculaire du Gène, and Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
| | - Mathieu Andrianne
- Institute for Medical Immunology (IMI), Laboratoire de Biologie Moléculaire du Gène, and Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
| | - Félicie Sherer
- Institute for Medical Immunology (IMI), Laboratoire de Biologie Moléculaire du Gène, and Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
- Department of Nuclear Medicine, Hôpital Erasme, Université Libre de Bruxelles, B-1070 Brussels, Belgium
| | - Gaetan Van Simaeys
- Institute for Medical Immunology (IMI), Laboratoire de Biologie Moléculaire du Gène, and Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
- Department of Nuclear Medicine, Hôpital Erasme, Université Libre de Bruxelles, B-1070 Brussels, Belgium
| | - Perry J. Blackshear
- The Laboratory of Signal Transduction, National Institute of Environmental Health, National Institutes of Health Sciences, Research Triangle Park, NC 27709
- Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, NC 27710
| | - Oberdan Leo
- Institute for Medical Immunology (IMI), Laboratoire de Biologie Moléculaire du Gène, and Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
| | - Stanislas Goriely
- Institute for Medical Immunology (IMI), Laboratoire de Biologie Moléculaire du Gène, and Center for Microscopy and Molecular Imaging (CMMI), Université Libre de Bruxelles, B-6041 Charleroi-Gosselies, Belgium
- WELBIO, B-6041 Charleroi-Gosselies, Belgium
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Lai WS, Stumpo DJ, Kennington EA, Burkholder AB, Ward JM, Fargo DL, Blackshear PJ. Life without TTP: apparent absence of an important anti-inflammatory protein in birds. Am J Physiol Regul Integr Comp Physiol 2013; 305:R689-700. [PMID: 23904106 DOI: 10.1152/ajpregu.00310.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Both innate and adaptive immunity in birds are different from their mammalian counterparts. Understanding bird immunity is important because of the enormous potential impact of avian infectious diseases, both in their role as food animals and as potential carriers of zoonotic diseases in man. The anti-inflammatory protein tristetraprolin (TTP) is an important component of the mammalian innate immune response, in that it binds to and destabilizes key cytokine mRNAs. TTP knockout mice exhibit a severe systemic inflammatory syndrome, and they are abnormally sensitive to innate immune stimuli such as LPS. TTP orthologs have been found in most vertebrates studied, including frogs. Here, we attempted to identify TTP orthologs in chicken and other birds, using database searches and deep mRNA sequencing. Although sequences encoding the two other widely expressed TTP family members, ZFP36L1 and ZFP36L2, were identified, we did not find sequences corresponding to TTP in any bird species. Sequences corresponding to TTP were identified in both lizards and alligators, close evolutionary relatives of birds. The induction kinetics of Zfp36l1 and Zfp36l2 mRNAs in LPS-stimulated chicken macrophages or serum-stimulated chick embryo fibroblasts did not resemble the normal mammalian TTP response to these stimuli, suggesting that the other two family members might not compensate for the TTP deficiency in regulating rapidly induced mRNA targets. Several mammalian TTP target transcripts have chicken counterparts that contain one or more potential TTP binding sites, raising the possibility that birds express other proteins that subsume TTP's function as a rapidly inducible regulator of AU-rich element (ARE)-dependent mRNA turnover.
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Affiliation(s)
- Wi S Lai
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina
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41
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Ciais D, Cherradi N, Feige JJ. Multiple functions of tristetraprolin/TIS11 RNA-binding proteins in the regulation of mRNA biogenesis and degradation. Cell Mol Life Sci 2013; 70:2031-44. [PMID: 22968342 PMCID: PMC11113850 DOI: 10.1007/s00018-012-1150-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 08/27/2012] [Accepted: 08/28/2012] [Indexed: 02/06/2023]
Abstract
Members of the tristetraprolin (TTP/TIS11) family are important RNA-binding proteins initially characterized as mediators of mRNA degradation. They act via their interaction with AU-rich elements present in the 3'UTR of regulated transcripts. However, it is progressively appearing that the different steps of mRNA processing and fate including transcription, splicing, polyadenylation, translation, and degradation are coordinately regulated by multifunctional integrator proteins that possess a larger panel of functions than originally anticipated. Tristetraprolin and related proteins are very good examples of such integrators. This review gathers the present knowledge on the functions of this family of RNA-binding proteins, including their role in AU-rich element-mediated mRNA decay and focuses on recent advances that support the concept of their broader involvement in distinct steps of mRNA biogenesis and degradation.
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Affiliation(s)
- Delphine Ciais
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1036, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV)/Biologie du Cancer et de l’Infection (BCI), 38054 Grenoble, France
- Université Joseph Fourier-Grenoble 1, 38041 Grenoble, France
| | - Nadia Cherradi
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1036, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV)/Biologie du Cancer et de l’Infection (BCI), 38054 Grenoble, France
- Université Joseph Fourier-Grenoble 1, 38041 Grenoble, France
| | - Jean-Jacques Feige
- Institut National de la Santé et de la Recherche Médicale (INSERM) U1036, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
- Commissariat à l’Energie Atomique et aux Energies Alternatives (CEA), Institut de Recherches en Technologies et Sciences pour le Vivant (iRTSV)/Biologie du Cancer et de l’Infection (BCI), 38054 Grenoble, France
- Université Joseph Fourier-Grenoble 1, 38041 Grenoble, France
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Brooks SA, Blackshear PJ. Tristetraprolin (TTP): interactions with mRNA and proteins, and current thoughts on mechanisms of action. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1829:666-79. [PMID: 23428348 PMCID: PMC3752887 DOI: 10.1016/j.bbagrm.2013.02.003] [Citation(s) in RCA: 296] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 01/25/2013] [Accepted: 02/04/2013] [Indexed: 12/14/2022]
Abstract
Changes in mRNA stability and translation are critical control points in the regulation of gene expression, particularly genes encoding growth factors, inflammatory mediators, and proto-oncogenes. Adenosine and uridine (AU)-rich elements (ARE), often located in the 3' untranslated regions (3'UTR) of mRNAs, are known to target transcripts for rapid decay. They are also involved in the regulation of mRNA stability and translation in response to extracellular cues. This review focuses on one of the best characterized ARE binding proteins, tristetraprolin (TTP), the founding member of a small family of CCCH tandem zinc finger proteins. In this survey, we have reviewed the current status of TTP interactions with mRNA and proteins, and discussed current thinking about TTP's mechanism of action to promote mRNA decay. We also review the proposed regulation of TTP's functions by phosphorylation. Finally, we have discussed emerging evidence for TTP operating as a translational regulator. This article is part of a Special Issue entitled: RNA Decay mechanisms.
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Affiliation(s)
- Seth A. Brooks
- Veterans Affairs Medical Center, White River Junction, Vermont, USA
- Department of Medicine, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
| | - Perry J. Blackshear
- The Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
- Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, North Carolina USA
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Suswam EA, Shacka JJ, Walker K, Lu L, Li X, Si Y, Zhang X, Zheng L, Nabors LB, Cao H, King PH. Mutant tristetraprolin: a potent inhibitor of malignant glioma cell growth. J Neurooncol 2013; 113:195-205. [PMID: 23525947 DOI: 10.1007/s11060-013-1112-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 03/12/2013] [Indexed: 02/02/2023]
Abstract
Malignant gliomas rely on the production of certain critical growth factors including VEGF, interleukin (IL)-6 and IL-8, to fuel rapid tumor growth, angiogenesis, and treatment resistance. Post-transcriptional regulation through adenine and uridine-rich elements of the 3' untranslated region is one mechanism for upregulating these and other growth factors. In glioma cells, we have shown that the post-transcriptional machinery is optimized for growth factor upregulation secondary to overexpression of the mRNA stabilizer, HuR. The negative regulator, tristetraprolin (TTP), on the other hand, may be suppressed because of extensive phosphorylation. Here we test that possibility by analyzing the phenotypic effects of a mutated form of TTP (mt-TTP) in which 8 phosphoserine residues were converted to alanines. We observed a significantly enhanced negative effect on growth factor expression in glioma cells at the post-transcriptional and transcriptional levels. The protein became stabilized and displayed significantly increased antiproliferative effects compared to wild-type TTP. Macroautophagy was induced with both forms of TTP, but inhibition of autophagy did not affect cell viability. We conclude that glioma cells suppress TTP function through phosphorylation of critical serine residues which in turn contributes to growth factor upregulation and tumor progression.
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Affiliation(s)
- Esther A Suswam
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294-3300, USA.
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44
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Liu WH, Chou WM, Chang LS. p38 MAPK/PP2Acα/TTP pathway on the connection of TNF-α and caspases activation on hydroquinone-induced apoptosis. Carcinogenesis 2013; 34:818-27. [PMID: 23288922 DOI: 10.1093/carcin/bgs409] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
This study investigated tumor necrosis factor-α (TNF-α)-mediated death pathway contribution to hydroquinone (HQ) cytotoxicity in human leukemia U937 cells. HQ-induced apoptosis of human leukemia U937 cells was characterized by the increase in mitochondrial membrane depolarization, procaspase-8 degradation and tBid production. Downregulation of Fas-associated death domain protein (FADD) blocked HQ-induced procaspase-8 degradation and rescued the viability of HQ-treated cells, suggesting the involvement of a death receptor-mediated pathway in HQ-induced cell death. HQ induced increased TNF-α mRNA stability led to TNF-α protein expression upregulation, whereas HQ suppressed TNF-α-mediated NFκB pathway activation. HQ elicited protein phosphatase 2A catalytic subunit α (PP2Acα) upregulation via p38 mitogen-activated protein kinase (MAPK)-mediated CREB/c-Jun/ATF-2 phosphorylation, and PP2Acα upregulation was found to promote tristetraprolin (TTP) degradation. Suppression of p38 MAPK activation and protein phosphatase 2A (PP2A) activity abrogated TNF-α upregulation and procaspase degradation in HQ-treated cells. Overexpression of TTP suppressed HQ-induced TNF-α upregulation and restored the viability of HQ-treated cells. Moreover, TTP overexpression increased TNF-α mRNA decay in HQ-treated cells. Taken together, our data indicate that HQ elicits TNF-α upregulation via p38 MAPK/PP2A-mediated TTP downregulation, and suggest that the TNF-α-mediated death pathway is involved in HQ-induced U937 cell death. The same pathway was also proven to be involved in the HQ-induced death of human leukemia HL-60 and Jurkat cells.
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Affiliation(s)
- Wen-Hsin Liu
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
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45
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Damgaard CK, Lykke-Andersen J. Regulation of ARE-mRNA Stability by Cellular Signaling: Implications for Human Cancer. Cancer Treat Res 2013; 158:153-80. [PMID: 24222358 DOI: 10.1007/978-3-642-31659-3_7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
During recent years, it has become clear that regulation of mRNA stability is an important event in the control of gene expression. The stability of a large class of mammalian mRNAs is regulated by AU-rich elements (AREs) located in the mRNA 3' UTRs. mRNAs with AREs are inherently labile but as a response to different cellular cues they can become either stabilized, allowing expression of a given gene, or further destabilized to silence their expression. These tightly regulated mRNAs include many that encode growth factors, proto-oncogenes, cytokines, and cell cycle regulators. Failure to properly regulate their stability can therefore lead to uncontrolled expression of factors associated with cell proliferation and has been implicated in several human cancers. A number of transfactors that recognize AREs and regulate the translation and degradation of ARE-mRNAs have been identified. These transfactors are regulated by signal transduction pathways, which are often misregulated in cancers. This chapter focuses on the function of ARE-binding proteins with an emphasis on their regulation by signaling pathways and the implications for human cancer.
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46
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Venigalla RKC, Turner M. RNA-binding proteins as a point of convergence of the PI3K and p38 MAPK pathways. Front Immunol 2012; 3:398. [PMID: 23272005 PMCID: PMC3530045 DOI: 10.3389/fimmu.2012.00398] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 12/10/2012] [Indexed: 12/26/2022] Open
Abstract
Understanding the mechanisms by which signal transduction pathways mediate changes in RNA abundance requires the examination of the fate of RNA from its transcription to its degradation. Evidence suggests that RNA abundance is partly regulated by post-transcriptional mechanisms affecting RNA decay and this in turn is modulated by some of the same signaling pathways that control transcription. Furthermore, the translation of mRNA is a key regulatory step that is influenced by signal transduction. These processes are regulated, in part, by RNA-binding proteins (RBPs) which bind to sequence-specific RNA elements. The function of RBPs is controlled and co-ordinated by phosphorylation. Based on the current literature we hypothesize that RBPs may be a point of convergence for the activity of different kinases such as phosphoinositide-3-kinase and mitogen-activated protein kinase which regulate RBP localization and function.
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Affiliation(s)
- Ram K C Venigalla
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute Babraham, UK
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Fähling M, Persson AB, Klinger B, Benko E, Steege A, Kasim M, Patzak A, Persson PB, Wolf G, Blüthgen N, Mrowka R. Multilevel regulation of HIF-1 signaling by TTP. Mol Biol Cell 2012; 23:4129-41. [PMID: 22918951 PMCID: PMC3469526 DOI: 10.1091/mbc.e11-11-0949] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Phosphorylation of the RNA-binding protein tristetraprolin (TTP) by p38 MAPK/MK2 does not prevent its RNA interaction and switches the mode of TTP action from destabilization to stabilization of the HIF-1α mRNA and subsequent activation of HIF-1 signaling. Hypoxia-inducible factor-1 (HIF-1) is a well-studied transcription factor mediating cellular adaptation to hypoxia. It also plays a crucial role under normoxic conditions, such as in inflammation, where its regulation is less well understood. The 3′-untranslated region (UTR) of HIF-1α mRNA is among the most conserved UTRs in the genome, hinting toward posttranscriptional regulation. To identify potential trans factors, we analyzed a large compilation of expression data. In contrast to its known function of being a negative regulator, we found that tristetraprolin (TTP) positively correlates with HIF-1 target genes. Mathematical modeling predicts that an additional level of posttranslational regulation of TTP can explain the observed positive correlation between TTP and HIF-1 signaling. Mechanistic studies revealed that TTP indeed changes its mode of regulation from destabilizing to stabilizing HIF-1α mRNA upon phosphorylation by p38 mitogen-activated protein kinase (MAPK)/MAPK-activated protein kinase 2. Using a model of monocyte-to-macrophage differentiation, we show that TTP-driven HIF-1α mRNA stabilization is crucial for cell migration. This demonstrates the physiological importance of a hitherto-unknown mechanism for multilevel regulation of HIF-1α in normoxia.
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Affiliation(s)
- Michael Fähling
- Institut für Vegetative Physiologie, Charité-Universitätsmedizin Berlin, D-10115 Berlin, Germany.
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Selmi T, Martello A, Vignudelli T, Ferrari E, Grande A, Gemelli C, Salomoni P, Ferrari S, Zanocco-Marani T. ZFP36 expression impairs glioblastoma cell lines viability and invasiveness by targeting multiple signal transduction pathways. Cell Cycle 2012; 11:1977-87. [PMID: 22544323 DOI: 10.4161/cc.20309] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
RNA binding proteins belonging to the TIS11/TTP gene family regulate the stability of multiple targets. Their inactivation or deregulated expression has recently been related to cancer, and it has been suggested that they are capable of displaying tumor suppressor activities. Here we describe three new targets of ZFP36 (PIM-1, PIM-3 and XIAP) and show by different approaches that its ectopic expression is capable of impairing glioblastoma cell lines viability and invasiveness by interfering with different transduction pathways. Moreover, we provide evidence that compounds capable of inducing the expression of TIS11/TTP genes determine a comparable biological effect on the same cell contexts.
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Affiliation(s)
- Tommaso Selmi
- Dipartimento di Scienze Biomediche, Sezione di Chimica Biologica, Università di Modena e Reggio Emilia, Modena, Italy
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Sanduja S, Blanco FF, Dixon DA. The roles of TTP and BRF proteins in regulated mRNA decay. WILEY INTERDISCIPLINARY REVIEWS-RNA 2012; 2:42-57. [PMID: 21278925 DOI: 10.1002/wrna.28] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Adenylate- and uridylate-rich element (ARE) motifs are cis-acting elements present in the 3′ untranslated region of mRNA transcripts that encode many inflammation- and cancer-associated genes. The TIS11 family of RNA-binding proteins, composed of tristetraprolin (TTP) and butyrate response factors 1 and 2 (BRF-1 and -2), plays a critical role in regulating the expression of ARE-containing mRNAs. Through their ability to bind and target ARE-containing mRNAs for rapid degradation, this class of RNA-binding proteins serves a fundamental role in limiting the expression of a number of critical genes, thereby exerting anti-inflammatory and anti-cancer effects. Regulation of TIS11 family members occurs on a number of levels through cellular signaling events to control their transcription, mRNA turnover, phosphorylation status, cellular localization, association with other proteins, and proteosomal degradation, all of which impact TIS11 members' ability to promote ARE-mediated mRNA decay along with decay-independent functions. This review summarizes our current understanding of posttranscriptional regulation of ARE-containing gene expression by TIS11 family members and discusses their role in maintaining normal physiological processes and the pathological consequences in their absence.
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Affiliation(s)
- Sandhya Sanduja
- Department of Biological Sciences and Cancer Research Center, University of South Carolina, Columbia, SC, USA
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50
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Bode JG, Ehlting C, Häussinger D. The macrophage response towards LPS and its control through the p38(MAPK)-STAT3 axis. Cell Signal 2012; 24:1185-94. [PMID: 22330073 DOI: 10.1016/j.cellsig.2012.01.018] [Citation(s) in RCA: 302] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Accepted: 01/27/2012] [Indexed: 12/19/2022]
Abstract
In macrophages detection of gram-negative bacteria particularly involves binding of the outer-wall component lipopolysaccharide (LPS) to its cognate receptor complex, comprising Toll like receptor 4 (TLR4), CD14 and MD2. LPS-induced formation of the LPS receptor complex elicits a signaling network, including intra-cellular signal-transduction directly activated by the TLR4 receptor complex as well as successional induction of indirect autocrine and paracrine signaling events. All these different pathways are integrated into the macrophage response towards an inflammatory stimulus by a highly complex cross-talk of the pathways engaged. This also includes a tight control by several intra- and inter-cellular feedback loops warranting an inflammatory response sufficient to battle invading pathogens and to avoid non-essential tissue damage caused by an overwhelming inflammatory response. Several evidences indicate that the reciprocal cross-talk between the p38(MAPK)-pathway and signal transducer and activator of transcription (STAT)3-mediated signal-transduction forms a critical axis successively activated by LPS. The balanced activation of this axis is essential for both induction and propagation of the inflammatory macrophage response as well as for the control of the resolution phase, which is largely driven by IL-10 and sustained STAT3 activation. In this context regulation of suppressor of cytokine signaling (SOCS)3 expression and the recently described divergent regulatory roles of the two p38(MAPK)-activated protein kinases MK2 and MK3 for the regulation of LPS-induced NF-κB- and IRF3-mediated signal-transduction and gene expression, which includes the regulation of IFNβ, IL-10 and DUSP1, appears to play an important role.
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Affiliation(s)
- Johannes G Bode
- Department of Gastroenterology, Hepatology and Infectious Disease, University Hospital, Heinrich Heine University of Düsseldorf, Moorenstrasse 5, 40225 Düsseldorf, Germany.
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