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Klevebro S, Hellgren G, Hansen-Pupp I, Wackernagel D, Hallberg B, Borg J, Pivodic A, Smith L, Ley D, Hellström A. Elevated levels of IL-6 and IGFBP-1 predict low serum IGF-1 levels during continuous infusion of rhIGF-1/rhIGFBP-3 in extremely preterm infants. Growth Horm IGF Res 2020; 50:1-8. [PMID: 31756675 PMCID: PMC7054155 DOI: 10.1016/j.ghir.2019.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/28/2019] [Accepted: 11/08/2019] [Indexed: 10/25/2022]
Abstract
OBJECTIVE Steady state insulin-like growth factor-1 (IGF-1) levels vary significantly during continuous intravenous infusion of recombinant human insulin-like growth factor-1/recombinant human insulin-like growth factor binding protein-3 (rhIGF-1/rhIGFBP-3) in the first weeks of life in extremely preterm infants. We evaluated interleukin-6 (IL-6) and insulin-like growth factor binding protein-1 (IGFBP-1) levels as predictors of low IGF-1 levels. METHODS Nineteen extremely preterm infants were enrolled in a trial, 9 received rhIGF-1/rhIGFBP-3 and 10 received standard neonatal care. Blood samples were analyzed daily for IGF-1, IL-6 and IGFBP-1 during intervention with rhIGF-1/rhIGFBP-3. RESULTS Thirty seven percent of IGF-1 values during active treatment were <20 μg/L. Among treated infants, higher levels of IL-6, one and two days before sampled IGF-1, were associated with IGF-1 < 20 μg/L, gestational age adjusted OR 1.30 (95% CI 1.03-1.63), p = .026, and 1.57 (95% CI 1.26-1.97), p < .001 respectively. Higher levels of IGFBP-1 one day before sampled IGF-1 was also associated with IGF-1 < 20 μg/L, gestational age adjusted OR 1.74 (95% CI 1.19-2.53), p = .004. CONCLUSION In preterm infants receiving continuous infusion of rhIGF-1/rhIGFBP-3, higher levels of IL-6 and IGFBP-1 preceded lower levels of circulating IGF-1. These findings demonstrate a need to further evaluate if inflammation and/or infection suppress serum IGF-1 levels. The trial is registered at ClinicalTrials.gov (NCT01096784).
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Affiliation(s)
- Susanna Klevebro
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
| | - Gunnel Hellgren
- Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden; Institute of Bioscience, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
| | - Ingrid Hansen-Pupp
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Pediatrics, Lund, Sweden
| | - Dirk Wackernagel
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Boubou Hallberg
- Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Jan Borg
- Former Premacure AB, Uppsala, Sweden
| | | | - Lois Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States of America
| | - David Ley
- Lund University, Skåne University Hospital, Department of Clinical Sciences Lund, Pediatrics, Lund, Sweden
| | - Ann Hellström
- Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden
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Chun JN, Cho M, Park S, So I, Jeon JH. The conflicting role of E2F1 in prostate cancer: A matter of cell context or interpretational flexibility? Biochim Biophys Acta Rev Cancer 2019; 1873:188336. [PMID: 31870703 DOI: 10.1016/j.bbcan.2019.188336] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/20/2019] [Indexed: 02/07/2023]
Abstract
The transcription factor E2F1 plays a crucial role in mediating multiple cancer hallmark capabilities that regulate cell cycle, survival, apoptosis, metabolism, and metastasis. Aberrant activation of E2F1 is closely associated with a poor clinical outcome in various human cancers. However, E2F1 has conflictingly been reported to exert tumor suppressive activity, raising a question as to the nature of its substantive role in the control of cell fate. In this review, we summarize deregulated E2F1 activity and its role in prostate cancer. We highlight the recent advances in understanding the molecular mechanism by which E2F1 regulates the development and progression of prostate cancer, providing insight into how cell context or data interpretation shapes the role of E2F1 in prostate cancer. This review will aid in translating biomedical knowledge into therapeutic strategies for prostate cancer.
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Affiliation(s)
- Jung Nyeo Chun
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Institute of Human-Environment Interface Biology, Seoul National University, Seoul 03080, Republic of Korea
| | - Minsoo Cho
- Undergraduate Research Program, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Soonbum Park
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Insuk So
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Institute of Human-Environment Interface Biology, Seoul National University, Seoul 03080, Republic of Korea
| | - Ju-Hong Jeon
- Department of Physiology and Biomedical Sciences, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; Institute of Human-Environment Interface Biology, Seoul National University, Seoul 03080, Republic of Korea.
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3
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Ertosun MG, Hapil FZ, Osman Nidai O. E2F1 transcription factor and its impact on growth factor and cytokine signaling. Cytokine Growth Factor Rev 2016; 31:17-25. [PMID: 26947516 DOI: 10.1016/j.cytogfr.2016.02.001] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 02/27/2016] [Indexed: 12/13/2022]
Abstract
E2F1 is a transcription factor involved in cell cycle regulation and apoptosis. The transactivation capacity of E2F1 is regulated by pRb. In its hypophosphorylated form, pRb binds and inactivates DNA binding and transactivating functions of E2F1. The growth factor stimulation of cells leads to activation of CDKs (cyclin dependent kinases), which in turn phosphorylate Rb and hyperphosphorylated Rb is released from E2F1 or E2F1/DP complex, and free E2F1 can induce transcription of several genes involved in cell cycle entry, induction or inhibition of apoptosis. Thus, growth factors and cytokines generally utilize E2F1 to direct cells to either fate. Furthermore, E2F1 regulates expressions of various cytokines and growth factor receptors, establishing positive or negative feedback mechanisms. This review focuses on the relationship between E2F1 transcription factor and cytokines (IL-1, IL-2, IL-3, IL-6, TGF-beta, G-CSF, LIF), growth factors (EGF, KGF, VEGF, IGF, FGF, PDGF, HGF, NGF), and interferons (IFN-α, IFN-β and IFN-γ).
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Affiliation(s)
- Mustafa Gokhan Ertosun
- Akdeniz University, Faculty of Medicine, Department of Medical Biology and Genetic, Kampus, Antalya 07070, Turkey
| | - Fatma Zehra Hapil
- Akdeniz University, Faculty of Medicine, Department of Medical Biology and Genetic, Kampus, Antalya 07070, Turkey
| | - Ozes Osman Nidai
- Akdeniz University, Faculty of Medicine, Department of Medical Biology and Genetic, Kampus, Antalya 07070, Turkey.
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Yu Q, Lu ZK. Clinical significance of peripheral blood levels of insulin-like growth factor in patients with Crohn's disease. Shijie Huaren Xiaohua Zazhi 2011; 19:2790-2793. [DOI: 10.11569/wcjd.v19.i26.2790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To analyze the clinical significance of peripheral blood levels of insulin-like growth factor (IGF) in patients with Crohn's disease (CD).
METHODS: Fifty-four patients with CD were collected and divided into mild, moderate, and severe groups according to the severity of the disease. Enzyme-labeled chemiluminescent immunometric assay was used to detect peripheral blood levels of IGF-I and insulin-like growth factor-binding protein 3 (IGFBP3) in patients before and after standard treatment to assess their association with the severity of CD and therapeutic efficacy. Fifty healthy people were enrolled as controls.
RESULTS: The levels of IGF-I and IGFBP3 were significantly lower in the moderate and severe groups than in the control group (all P < 0.05) and decreased with the increase in clinical severity (P < 0.05). No significant difference was noted in the levels of IGF-I and IGFBP3 between the mild group and control group. However, the levels of IGF-I and IGFBP3 were significantly higher in patients with moderate or severe CD after treatment than before treatment (all P < 0.05). No significant difference was noted in the levels of IGF-I and IGFBP3 in patients with mild CD between before and after treatment.
CONCLUSION: Peripheral blood levels of IGF-I and IGFBP3 are useful to evaluate disease severity and therapeutic efficacy in patients with CD.
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Riboldi G, Nizzardo M, Simone C, Falcone M, Bresolin N, Comi GP, Corti S. ALS genetic modifiers that increase survival of SOD1 mice and are suitable for therapeutic development. Prog Neurobiol 2011; 95:133-48. [PMID: 21816207 DOI: 10.1016/j.pneurobio.2011.07.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 07/19/2011] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a frequently fatal motor neuron disease without any cure. To find molecular therapeutic targets, several studies crossed transgenic ALS murine models with animals transgenic for some ALS target genes. We aimed to revise the new discoveries and new works in this field. We selected the 10 most promising genes, according to their capability when down-regulated or up-regulated in ALS animal models, for increasing life span and mitigating disease progression: XBP-1, NogoA and NogoB, dynein, heavy and medium neurofilament, NOX1 and NOX2, MLC-mIGF-1, NSE-VEGF, and MMP-9. Interestingly, some crucial modifier genes have been described as being involved in common pathways, the most significant of which are inflammation and cytoskeletal activities. The endoplasmic reticulum also seems to play an important role in ALS pathogenesis, as it is involved in different selected gene pathways. In addition, these genes have evident links to each other, introducing the hypothesis of a single unknown, common pathway involving all of these identified genes and others to be discovered.
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Affiliation(s)
- Giulietta Riboldi
- Department of Neurological Sciences, Dino Ferrari Centre, University of Milan, IRCCS Fondazione Ca' Granda-Ospedale Maggiore Policlinico, Milan, Italy
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Insulin-like growth factor 1 activates methionine adenosyltransferase 2A transcription by multiple pathways in human colon cancer cells. Biochem J 2011; 436:507-16. [PMID: 21406062 DOI: 10.1042/bj20101754] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have previously reported that the expression of MAT2A (methionine adenosyltransferase 2A) is increased in human colon cancer and in colon cancer cells treated with IGF-1 (insulin-like growth factor-1), which was required for its mitogenic effect. The aim of the present study was to elucidate the molecular mechanisms of IGF-1-mediated MAT2A induction. Nuclear run-on analysis confirmed that the increase in MAT2A expression lies at the transcriptional level. DNase I footprinting of the MAT2A promoter region revealed a similar protein-binding pattern in colon cancer and IGF-1-treated RKO cells. IGF-1 induced MAT2A promoter activity and increased nuclear protein binding to USF (upstream stimulatory factor)/c-Myb, YY1 (Yin and Yang 1), E2F, AP-1 (activator protein 1) and NF-κB (nuclear factor κB) consensus elements. IGF-1 increased the expression of c-Jun, FosB, MafG, p65, c-Myb, E2F-1 and YY1 at the pre-translational level. Knockdown of p65, MafG, c-Myb or E2F-1 lowered basal MAT2A expression and blunted the inductive effect of IGF-1 on MAT2A, whereas knockdown of YY1 increased basal MAT2A expression and had no effect on IGF-1-mediated MAT2A induction. Consistently, mutation of AP-1, NF-κB, E2F and USF/c-Myb elements individually blunted the IGF-1-mediated increase in MAT2A promoter activity, and combined mutations completely prevented the increase. In conclusion, IGF-1 activates MAT2A transcription by both known and novel pathways. YY1 represses MAT2A expression.
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Thorn SR, Giesy SL, Myers MG, Boisclair YR. Mammary ductal growth is impaired in mice lacking leptin-dependent signal transducer and activator of transcription 3 signaling. Endocrinology 2010; 151:3985-95. [PMID: 20501669 PMCID: PMC3208358 DOI: 10.1210/en.2010-0029] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Mice lacking leptin (ob/ob) or its full-length receptor (db/db) are obese and reproductively incompetent. Fertility, pregnancy, and lactation are restored, respectively, in ob/ob mice treated with leptin through mating, d 6.5 post coitum, and pregnancy. Therefore, leptin signaling is needed for lactation, but the timing of its action and the affected mammary process remain unknown. To address this issue, we used s/s mice lacking only leptin-dependent signal transducer and activator of transcription (STAT)3 signaling. These mice share many features with db/db mice, including obesity, but differ by retaining sufficient activity of the hypothalamic-pituitary-ovarian axis to support reproduction. The s/s mammary epithelium was normal at 3 wk of age but failed to expand through the mammary fat pad (MFP) during the subsequent pubertal period. Ductal growth failure was not corrected by estrogen therapy and did not relate to inadequate IGF-I production by the MFP or to the need for epithelial or stromal leptin-STAT3 signaling. Ductal growth failure coincided with adipocyte hypertrophy and increased MFP production of leptin, TNFalpha, and IL6. These cytokines, however, were unable to inhibit the proliferation of a collection of mouse mammary epithelial cell lines. In conclusion, the very first step of postnatal mammary development fails in s/s mice despite sufficient estrogen IGF-I and an hypothalamic-pituitary-ovarian axis capable of supporting reproduction. This failure is not caused by mammary loss of leptin-dependent STAT3 signaling or by the development of inflammation. These data imply the existence of an unknown mechanism whereby leptin-dependent STAT3 signaling and obesity alter mammary ductal development.
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Affiliation(s)
- Stephanie R Thorn
- Department of Animal Science, Cornell University, Ithaca, New York 14853, USA
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8
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Schayek H, Bentov I, Rotem I, Pasmanik-Chor M, Ginsberg D, Plymate SR, Werner H. Transcription factor E2F1 is a potent transactivator of the insulin-like growth factor-I receptor (IGF-IR) gene. Growth Horm IGF Res 2010; 20:68-72. [PMID: 19703789 DOI: 10.1016/j.ghir.2009.08.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2009] [Revised: 07/29/2009] [Accepted: 08/03/2009] [Indexed: 01/19/2023]
Abstract
OBJECTIVES The insulin-like growth factor-I receptor (IGF-IR) plays an important role in cancer development. The E2F1 transcription factor activates S-phase promoting genes and mediates apoptosis. Microarray analyses of E2F1-induced genes revealed that genes associated with proliferation as well as apoptosis are upregulated by E2F1. Among other candidate genes, DNA microarrays identified the IGF-IR gene as a putative E2F1 target. The aim of this study was to investigate the involvement of E2F1 in regulation of IGF-IR gene transcription. METHODS To examine the potential regulation of IGF-IR gene expression by E2F1, an E2F1 expression vector was transfected into P69 and M12 prostate cancer cell lines, after which IGF-IR levels were measured by Western blots. Transient transfections were used to evaluate IGF-IR promoter activity and chromatin immunoprecipitation (ChIP) assays were employed to assess E2F1-binding to the IGF-IR promoter. RESULTS Results obtained showed that E2F1 expression induced a significant increment in endogenous IGF-IR levels. ChIP assays showed enhanced E2F1-binding to the IGF-IR promoter in E2F1-expressing cells. Transient coexpression of an E2F1 vector along with an IGF-IR promoter-luciferase reporter resulted in a approximately 140-fold increase in IGF-IR promoter activity. Furthermore, deletion and bioinformatic analyses indicate that the ability of E2F1 to stimulate IGF-IR promoter activity was correlated with the number of E2F1 sites in the promoter region. CONCLUSIONS In summary, we provide evidence that E2F1 regulates IGF-IR gene transcription in prostate cancer cells via a mechanism that involves direct binding to specific elements in the proximal IGF-IR promoter.
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Affiliation(s)
- Hagit Schayek
- Department of Human Molecular Genetics and Biochemistry, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
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Fiaschi-Taesch N, Sicari B, Ubriani K, Cozar-Castellano I, Takane KK, Stewart AF. Mutant parathyroid hormone-related protein, devoid of the nuclear localization signal, markedly inhibits arterial smooth muscle cell cycle and neointima formation by coordinate up-regulation of p15Ink4b and p27kip1. Endocrinology 2009; 150:1429-39. [PMID: 18845646 DOI: 10.1210/en.2008-0737] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Arterial expression of PTH-related protein is markedly induced by angioplasty. PTH-related protein contains a nuclear localization signal (NLS). PTH-related protein mutants lacking the NLS (DeltaNLS-PTH-related protein) are potent inhibitors of arterial vascular smooth muscle cell (VSMC) proliferation in vitro. This is of clinical relevance because adenoviral delivery of DeltaNLS-PTH-related protein at angioplasty completely inhibits arterial restenosis in rats. In this study we explored the cellular mechanisms through which DeltaNLS-PTH-related protein arrests the cell cycle. In vivo, adenoviral delivery of DeltaNLS-PTH-related protein at angioplasty markedly inhibited VSMC proliferation as compared with angioplastied carotids infected with control adenovirus (Ad.LacZ). In vitro, DeltaNLS-PTH-related protein overexpression was associated with a decrease in phospho-pRb, and a G(0)/G(1) arrest. This pRb underphosphorylation was associated with stable levels of cdks 2, 4, and 6, the D and E cyclins, p16, p18, p19, and p21, but was associated with a dramatic decrease in cdk-2 and cdk4 kinase activities. Cyclin A was reduced, but restoring cyclin A adenovirally to normal did not promote cell cycle progression in DeltaNLS-PTH-related protein VSMC. More importantly, p15(INK4) and p27(kip1), two critical inhibitors of the G(1/S) progression, were markedly increased. Normalization of both p15(INK4b) and p27(kip1) by small interfering RNA knockdown normalized cell cycle progression. These data indicate that the changes in p15(INK4b) and p27(kip1) fully account for the marked cell cycle slowing induced by DeltaNLS-PTH-related protein in VSMCs. Finally, DeltaNLS-PTH-related protein is able to induce p15(INK4) and p27(kip1) expression when delivered adenovirally to primary murine VSMCs. These studies provide a mechanistic understanding of DeltaNLS-PTH-related protein actions, and suggest that DeltaNLS-PTH-related protein may have particular efficacy for the prevention of arterial restenosis.
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Affiliation(s)
- Nathalie Fiaschi-Taesch
- Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pennsylvania 15213, USA.
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Chen HB, Pan K, Tang MK, Chui YL, Chen L, Su ZJ, Shen ZY, Li EM, Xie W, Lee KKH. Comparative proteomic analysis reveals differentially expressed proteins regulated by a potential tumor promoter, BRE, in human esophageal carcinoma cells. Biochem Cell Biol 2008; 86:302-11. [PMID: 18756325 DOI: 10.1139/o08-069] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Esophageal tumorigenesis is a complex and cascading process, involving the interaction of many genes and proteins. In this study, we have used the comparative proteomic approach to identify tumor-associated proteins and explore the carcinogenic mechanisms. Two-dimensional electrophoresis (2-DE) and MALDI-TOF MS analysis of esophageal carcinoma and control cells revealed 10 proteins that were upregulated. A further 10 proteins were downregulated. Among these 20 differentially expressed proteins, brain and reproductive organ-expressed (BRE) protein was identified as a potential tumor promoter. It was high expressed by the esophageal carcinoma cells, as confirmed by RT-PCR and immunoblotting. BRE has been reported to be a stress-responsive protein. To gain further insight into its function, BRE expression was silenced in esophageal carcinoma cells using BRE-specific small interference RNA. It was discovered that silencing BRE expression downregulated prohibitin expression, but upregulated tumor-suppressor p53 expression. Furthermore, cyclin A and CDK2 expressions were suppressed suggesting that BRE inhibited cell proliferation. These results implied that BRE plays a significant role in mediating antiapoptotic and proliferative responses in esophageal carcinoma cells.
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Affiliation(s)
- Hai Bin Chen
- Department of Histology and Embryology, Shantou University Medical College, Shantou, China
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O'Connor JC, McCusker RH, Strle K, Johnson RW, Dantzer R, Kelley KW. Regulation of IGF-I function by proinflammatory cytokines: at the interface of immunology and endocrinology. Cell Immunol 2008; 252:91-110. [PMID: 18325486 DOI: 10.1016/j.cellimm.2007.09.010] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 09/01/2007] [Indexed: 11/16/2022]
Abstract
During the past decade, the immune and endocrine systems have been discovered to interact in controlling physiologic processes as diverse as cell growth and differentiation, metabolism, and even human and animal behavior. The interaction between these two major physiological systems is a bi-directional process. While it has been well documented that hormones, including prolactin (PRL), growth hormone (GH), insulin-like growth factor-I (IGF-I), and thyroid-stimulating hormone (TSH), regulate a variety of immune events, a great deal of data have accumulated supporting the notion that cytokines from the innate immune system also affect the neuroendocrine system. Communication between these two systems coordinates processes that are necessary to maintain homeostasis. Proinflammatory cytokines often act as negative regulatory signals that temper the action of hormones and growth factors. This system of 'checks and balances' is an active, ongoing process, even in healthy individuals. Dysregulation of this process has been implicated as a potential pathogenic factor in the development of co-morbid conditions associated with several chronic inflammatory diseases, including type 2 diabetes, cardiovascular disease, cerebrovascular disease, inflammatory bowel disease, rheumatoid arthritis, major depression, and even normal aging. Over the past decade, research in our laboratory has focused on the ability of the major proinflammatory cytokines, tumor necrosis factor (TNF)alpha and interleukin (IL)-1beta, to induce a state of IGF resistance. This review will highlight these and other new findings by explaining how proinflammatory cytokines induce resistance to the major growth factor, insulin-like growth factor-I (IGF-I). We also highlight that IGF-I can induce resistance or reduce sensitivity to brain TNFalpha and discuss how TNFalpha, IL-1beta, and IGF-I interact to regulate several aspects of behavior and cognition.
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Affiliation(s)
- Jason C O'Connor
- Integrative Immunology and Behavior Program, Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Porter JF, Sharma S, Wilson DL, Kappil MA, Hart RP, Denhardt DT. Tissue inhibitor of metalloproteinases-1 stimulates gene expression in MDA-MB-435 human breast cancer cells by means of its ability to inhibit metalloproteinases. Breast Cancer Res Treat 2007; 94:185-93. [PMID: 16142437 DOI: 10.1007/s10549-005-7728-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a widely expressed, secreted protein that functions primarily to inhibit members of a large family of metalloproteinases (MPs). Because of the ability of TIMP-1 to inhibit MPs, it functions in many of the same pathophysiological processes as these enzymes, e.g. wound healing, ovulation, angiogenesis, and cancer cell metastasis. TIMP-1 can also stimulate proliferation ([3H]thymidine incorporation) and cellular anabolic processes (Alamar Blue reduction). This stimulation has been shown to be dependent on the MP-inhibitory ability of TIMP-1 in the human breast cancer cell line MDA-MB-435 (Porter et al., Br J Cancer 90: 463, 2004). To shed light on the mechanism by which TIMP-1 stimulates cellular anabolic processes, an oligonucleotide microarray analysis was performed over a time course of TIMP-1 treatment of MDA-MB-435 cells. Fifteen genes whose mRNAs were differentially regulated were identified. Six (Importin-7, MGC10471, FOXC1, subunit p20 of Arp2/3 complex, mitochondrial ribosomal protein L32, and the serine/threonine kinase-4 (MST1)) of these genes were confirmed by quantitative real time PCR. These same mRNAs were shown to be regulated by the synthetic hydroxamate MP-inhibitor GM6001 but not by its inactive derivative GM6001*, suggesting that the differential regulation occurs through the MP-inhibitory ability of TIMP-1. These results suggest a complex action of TIMP-1 on cancer cells mediated by constitutively active cell surface metalloproteinases that release factors regulating cell signaling pathways; they may account for the paradoxical observation that elevated levels of TIMP-1 in tumors can correlate with an adverse prognosis.
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Affiliation(s)
- Joseph F Porter
- The Graduate Program in Microbiology and Molecular Genetics, Nelson Laboratories, Rutgers University, Piscataway, NJ 08854, USA
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Wang J, Shen WH, Jin YJ, Brandt-Rauf PW, Yin Y. A Molecular Link between E2F-1 and the MAPK Cascade. J Biol Chem 2007; 282:18521-18531. [PMID: 17452331 DOI: 10.1074/jbc.m610538200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transcription factor E2F-1 mediates apoptosis and suppresses tumorigenesis. The mechanisms by which E2F-1 functions in these processes are largely unclear. We report here that E2F-1 acts as a transcriptional regulator of MKP-2 (MAPK phosphatase-2), a dual specificity protein phosphatase (DUSP4) with stringent substrate specificity for MAPKs. We show that E2F-1 is required for the cellular apoptotic response to oxidative damage. MKP-2 is greatly increased following oxidative stress, and E2F-1 is necessary for that induction. We found that E2F-1 is physically associated with the MKP-2 promoter and can transactivate the promoter of the MKP-2 gene. Specifically, E2F-1 binds to a perfect palindromic motif in the MKP-2 promoter. Finally, we show that this E2F-1/MKP-2 pathway mediates apoptosis under oxidative stress and that MKP-2 suppresses tumor formation in nude mice. Our findings demonstrate that E2F-1 is a transcriptional activator of MKP-2 and that MKP-2 is an essential cell death mediator in the E2F-1 pathway. Characterization of MKP-2 as a cell death mediator may lead to the development of new strategies for cancer treatment.
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Affiliation(s)
- Jianli Wang
- Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, New York 10032
| | - Wen Hong Shen
- Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, New York 10032
| | - Yan J Jin
- Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, New York 10032
| | - Paul W Brandt-Rauf
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032
| | - Yuxin Yin
- Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, New York 10032; Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, New York 10032.
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Kelley KW, Weigent DA, Kooijman R. Protein hormones and immunity. Brain Behav Immun 2007; 21:384-92. [PMID: 17198749 PMCID: PMC1894894 DOI: 10.1016/j.bbi.2006.11.010] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 11/03/2006] [Accepted: 11/09/2006] [Indexed: 01/22/2023] Open
Abstract
A number of observations and discoveries over the past 20 years support the concept of important physiological interactions between the endocrine and immune systems. The best known pathway for transmission of information from the immune system to the neuroendocrine system is humoral in the form of cytokines, although neural transmission via the afferent vagus is well documented also. In the other direction, efferent signals from the nervous system to the immune system are conveyed by both the neuroendocrine and autonomic nervous systems. Communication is possible because the nervous and immune systems share a common biochemical language involving shared ligands and receptors, including neurotransmitters, neuropeptides, growth factors, neuroendocrine hormones and cytokines. This means that the brain functions as an immune-regulating organ participating in immune responses. A great deal of evidence has accumulated and confirmed that hormones secreted by the neuroendocrine system play an important role in communication and regulation of the cells of the immune system. Among protein hormones, this has been most clearly documented for prolactin (PRL), growth hormone (GH), and insulin-like growth factor-1 (IGF-I), but significant influences on immunity by thyroid-stimulating hormone (TSH) have also been demonstrated. Here we review evidence obtained during the past 20 years to clearly demonstrate that neuroendocrine protein hormones influence immunity and that immune processes affect the neuroendocrine system. New findings highlight a previously undiscovered route of communication between the immune and endocrine systems that is now known to occur at the cellular level. This communication system is activated when inflammatory processes induced by proinflammatory cytokines antagonize the function of a variety of hormones, which then causes endocrine resistance in both the periphery and brain. Homeostasis during inflammation is achieved by a balance between cytokines and endocrine hormones.
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Affiliation(s)
- Keith W Kelley
- Laboratory of Integrative Immunophysiology, Integrative Immunology and Behavior Program, Department of Animal Sciences, College of ACES, 227 Edward R. Madigan Laboratory, 1201 West Gregory Drive, Urbana, IL 61801, USA.
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Wu J, Jin YJ, Calaf GM, Huang WL, Yin Y. PAC1 is a direct transcription target of E2F-1 in apoptotic signaling. Oncogene 2007; 26:6526-35. [PMID: 17471234 DOI: 10.1038/sj.onc.1210484] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
E2F-1 controls multiple cellular activities through transcriptional regulation of its target genes. As a mediator of cell death, E2F-1 can eliminate latent neoplastic cells through apoptosis. However, the mechanism by which E2F-1 mediates cancer cell killing is largely unknown. In this paper, we report that phosphatase of activated cells 1 (PAC1) phosphatase is a direct transcription target of E2F-1 in signaling apoptosis. We show that ectopic E2F-1 increases expression of PAC1 at both transcriptional and translational levels in breast cancer cells. E2F-1 physically interacts with the promoter of PAC1, binds to its consensus sequence in the promoter and transactivates the PAC1 promoter. E2F-1 suppresses extracellular signal-regulated kinase (ERK) phosphorylation through PAC1 and causes cancer cell death by apoptosis following treatment with a chemotherapeutic agent N-4-hydroxyphenylretinamide (4-HPR). Furthermore, ectopic PAC1 inhibits ERK phosphorylation and mediates cell killing. Moreover, endogenous E2F-1 upregulates PAC1 and suppresses ERK activity, leading to cell death in response to 4-HPR. These results reveal a crucial role of PAC1 in E2F-1-directed apoptosis. Our study demonstrates that E2F-1 mediates apoptosis through transcriptional regulation of PAC1 and subsequent suppression of the ERK signaling. Our findings establish a functional link between E2F-1 and mitogen-activated protein kinases. The E2F-1-PAC1 cascade in cancer cell killing may provide a molecular basis for cancer therapeutic intervention.
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Affiliation(s)
- J Wu
- Department of Radiation Oncology, Center for Radiological Research, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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16
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Zhang F, Rabinovici R. Adenosine deaminase acting on RNA 1 accelerates cell cycle through increased translation and activity of cyclin-dependent kinase 2. Shock 2007; 27:214-9. [PMID: 17224799 DOI: 10.1097/01.shk.0000238072.51653.f2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Adenosine-to-inosine RNA editing has been recently implicated in the pathogenesis of inflammation through the upregulation of the editase adenosine deaminase acting on RNA 1 (ADAR1). Because cell proliferation is a key feature of the inflammatory process, the present study tested the hypothesis that overexpression of ADAR1 accelerates cell cycle. To that end, human embryonic kidney 293 cells were transiently transfected with ADAR1 or vector, and cell cycle was evaluated by fluorescence-activated cell sorter. Overexpression of wild-type ADAR1 decreased the proportion of G0-G1 cells (-19%, P<0.01, n=3), increased the percentage of S phase cells (+19%, P<0.01, n=3), and did not change the ratio of cells residing in the G2-M phase (n=3). This finding was supported by three observations. First, there was a parallel production in ADAR1-transfected cells of cyclin-dependent kinase (Cdk) 2 and cyclin A, a pivotal protein complex upregulated at the G1-S phase checkpoint, and of [p]-Histone H1, a marker of Cdk2 activity (+102%, P<0.01, n=3). Second, ADAR1-transfected cells displayed higher activity of the proliferation marker, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide. Third, using anti-ADAR1 antibody, direct binding of ADAR1 to Cdk2 messenger RNA was demonstrated in ADAR1-transfected cells by protein-RNA cross-linking and immunoprecipitation (+974%, P<0.01, n=3). Finally, causal relationships between ADAR1 and Cdk2 were confirmed by a study with the Cdk2 inhibitor, kenpaullone, which prevented the ADAR1-induced shift from the G0-G1 to the S phase. Taken together, these data show that ADAR1 increases cell cycle by shifting cells from the G0-G1 to the S phase through the upregulation of Cdk2.
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Affiliation(s)
- Fangming Zhang
- Section of Trauma, Surgical Critical Care, and Surgical Emergencies, Yale University School of Medicine, New Haven, CT 06520, USA
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17
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Ayllón V, O'connor R. PBK/TOPK promotes tumour cell proliferation through p38 MAPK activity and regulation of the DNA damage response. Oncogene 2006; 26:3451-61. [PMID: 17160018 DOI: 10.1038/sj.onc.1210142] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The contribution of the insulin-like growth-factor-I receptor (IGF-IR) to tumour progression is well documented. To identify new mediators of IGF-IR function in cancer, we recently isolated genes differentially expressed in cells overexpressing the IGF-IR. Among these was the serine/threonine kinase PBK/TOPK (PDZ-binding kinase/T-LAK cell-originated protein kinase), previously associated with highly proliferative cells and tissues. Here, we show that PBK is expressed at high levels in tumour cell lines compared with non-transformed cells. IGF-I could induce PBK expression only in transformed cells, whereas epidermal growth factor could induce PBK in non-transformed MCF-10A breast epithelial cells. Suppression of PBK expression using small interfering RNA did not prevent progression through the cell cycle, but caused decreased proliferation over time in culture, and reduced clonogenic growth in soft agarose. PBK knockdown impaired p38 activation after long-term stimulation with different growth factors and reduced DU145 cells motility. Suppressed PBK expression also resulted in an impaired response to DNA damage that was evident by the decreased generation of gamma-H2AX, increased DNA damage and decreased cell survival. Taken together, the data indicate that PBK is necessary for appropriate activation and function of the p38 pathway by growth factors. Thus, enhanced expression of PBK may facilitate tumour growth by mediating p38 activation and by helping cells to overcome DNA damage.
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Affiliation(s)
- V Ayllón
- Cell Biology Laboratory, Department of Biochemistry, Biosciences Institute, National University of Ireland, Cork, Ireland
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18
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Song J, Salek-Ardakani S, So T, Croft M. The kinases aurora B and mTOR regulate the G1-S cell cycle progression of T lymphocytes. Nat Immunol 2006; 8:64-73. [PMID: 17128276 DOI: 10.1038/ni1413] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2006] [Accepted: 10/23/2006] [Indexed: 12/13/2022]
Abstract
CD28-deficient T cells arrest at the G1-S transition of the cell cycle. Here we show that this is controlled by the kinase aurora B, which exists in a complex with survivin and mammalian target of rapamycin (mTOR). Expression of aurora B in Cd28-/- T cells augmented phosphorylation of mTOR substrates, expression of cyclin A, hyperphosphorylation of retinoblastoma protein and activation of cyclin-dependent kinases 1 and 2 and promoted cell cycle progression. Interleukin 2 enhanced aurora B activity, and inactive aurora B prevented interleukin 2-induced proliferation. Moreover, expression of aurora B restored Cd28-/- T cell proliferation and promoted inflammation in vivo. These data identify aurora B, along with survivin and mTOR, as a regulator of the G1-S checkpoint in T cells.
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Affiliation(s)
- Jianxun Song
- Division of Molecular Immunology, La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
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19
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Dorsey WC, Ford BD, Roane L, Haynie DT, Tchounwou PB. Induced mitogenic activity in AML-12 mouse hepatocytes exposed to low-dose ultra-wideband electromagnetic radiation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2006; 2:24-30. [PMID: 16705798 PMCID: PMC3814693 DOI: 10.3390/ijerph2005010024] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Ultra–wideband (UWB) technology has increased with the use of various civilian and military applications. In the present study, we hypothesized that low-dose UWB electromagnetic radiation (UWBR) could elicit a mitogenic effect in AML-12 mouse hepatocytes, in vitro. To test this hypothesis, we exposed AML-12 mouse hepatocytes, to UWBR in a specially constructed gigahertz transverse electromagnetic mode (GTEM) cell. Cells were exposed to UWBR for 2 h at a temperature of 23°C, a pulse width of 10 ns, a repetition rate of 1 kHz, and field strength of 5–20 kV/m. UWB pulses were triggered by an external pulse generator for UWBR exposure but were not triggered for the sham exposure. We performed an MTT Assay to assess cell viability for UWBR-treated and sham-exposed hepatocytes. Data from viability studies indicated a time-related increase in hepatocytes at time intervals from 8–24 h post exposure. UWBR exerted a statistically significant (p < 0.05) dose-dependent response in cell viability in both serum-treated and serum free medium (SFM) -treated hepatocytes. Western blot analysis of hepatocyte lysates demonstrated that cyclin A protein was induced in hepatocytes, suggesting that increased MTT activity after UWBR exposure was due to cell proliferation. This study indicates that UWBR has a mitogenic effect on AML-12 mouse hepatocytes and implicates a possible role for UWBR in hepatocarcinoma.
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Affiliation(s)
- W. C. Dorsey
- Wildlife Biology Unit, Grambling State University, Grambling, LA. USA
| | - B. D. Ford
- Department of Anatomy and Neurobiology, Morehouse School of Medicine, Atlanta, GA. USA
| | - L. Roane
- Wildlife Biology Unit, Grambling State University, Grambling, LA. USA
| | - D. T. Haynie
- Biomedical Engineering & Physics, Institute for Micromanufacturing, Louisiana Tech University, Ruston, LA. USA
| | - P. B. Tchounwou
- Molecular Toxicology Research Laboratory, NIH-Center for Environmental Health, College of Science, Engineering, and Technology, Jackson State University, Jackson, MS, USA
- Correspondence to Dr. Paul B. Tchounwou.
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Hartman J, Müller P, Foster JS, Wimalasena J, Gustafsson JA, Ström A. HES-1 inhibits 17beta-estradiol and heregulin-beta1-mediated upregulation of E2F-1. Oncogene 2005; 23:8826-33. [PMID: 15467735 DOI: 10.1038/sj.onc.1208139] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have previously shown that expression of the transcription factor HES-1 is required for the growth-inhibitory effect of all-trans retinoic acid on MCF-7 cells. In this study, we have used T47D cells with tetracyclin-regulated expression of wild-type or a dominant-negative form of HES-1. Expression of HES-1 in T47D cells inhibited G1/S-phase transition and activation of Cdk2 elicited by estrogen. Estrogen treatment of T47D cells caused increased expression of E2F-1, and this expression was inhibited by cotreatment with all-trans retinoic acid. We show that the effect is mediated through HES-1, which directly downregulates E2F-1 expression through a CACGAG-site within the E2F-1 promoter. Furthermore, proliferation caused by heregulin-beta1 treatment of T47D cells was inhibited by all-trans retinoic acid and this effect was mediated by HES-1. Interestingly, heregulin-beta1-mediated upregulation of E2F-1 expression was directly inhibited by HES-1 through the same CACGAG-site as seen with estrogen-stimulated induction. In addition, we found that two important downstream target genes of estrogen and heregulin-beta1 that are regulated through E2F-1, cyclin E and NPAT, were both regulated in a similar fashion by all-trans retinoic acid, and these effects were antagonized by dominant-negative HES-1. These findings establish that HES-1 inhibits both estrogen- and heregulin-beta1-stimulated growth of breast cancer cells, and further suggest that growth inhibition induced in these cells by all-trans retinoic acid occurs via HES-1-mediated downregulation of E2F-1 expression.
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Affiliation(s)
- Johan Hartman
- Center for Biotechnology, Department of BioSciences, Karolinska Institutet, Novum, S-141 57 Huddinge Sweden
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Strle K, Broussard SR, McCusker RH, Shen WH, Johnson RW, Freund GG, Dantzer R, Kelley KW. Proinflammatory cytokine impairment of insulin-like growth factor I-induced protein synthesis in skeletal muscle myoblasts requires ceramide. Endocrinology 2004; 145:4592-602. [PMID: 15256490 DOI: 10.1210/en.2003-1749] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
GH and IGF-I control over 80% of postnatal growth. We recently established that TNFalpha impairs the ability of IGF-I to increase protein synthesis and promote expression of myogenin in myoblasts. Here we extend these results by showing that ceramide, a second messenger in both TNFalpha and IL-1beta receptor signaling pathways, is a key downstream sphingosine-based lipid that leads to IGF-I resistance. A cell-permeable ceramide analog, C2-ceramide, inhibits IGF-I-induced protein synthesis by 65% and blocks the ability of IGF-I to increase expression of two key myogenic factors, myogenin and MyoD. Identical results were obtained with both TNFalpha and IL-1beta (1 ng/ml). Consistent with these data, neutral sphingomyelinase (N-SMase), an enzyme that catalyzes formation of ceramide from sphingomyelin, blocks IGF-I-induced protein synthesis and expression of both myogenin and MyoD. The possibility that cytokine-induced ceramide production is required for disruption of IGF-I biologic activity was confirmed by treating C2C12 myoblasts with inhibitors of all three ceramide-generating pathways. A N-SMase inhibitor, glutathione, as well as an acidic sphingomyelinase (A-SMase) inhibitor, D609, reverse the cytokine inhibition of IGF-I-induced protein synthesis by 80% and 45%, respectively. Likewise, an inhibitor of de novo ceramide synthesis, FB1, causes a 50% inhibition. Similarly, all three inhibitors significantly impair the ability of both TNFalpha and IL-1beta to suppress IGF-I-driven expression of myogenin. These experiments establish that ceramide, derived both from sphingomyelin and de novo synthesis, is a key intermediate by which proinflammatory cytokines impair the ability of IGF-I to promote protein synthesis and expression of critical muscle-specific transcription factors.
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Affiliation(s)
- Klemen Strle
- University of Illinois, Laboratory of Immunophysiology, 207 Edward R. Madigan Laboratory, 1201 West Gregory Drive, Urbana, Illinois 61801, USA
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22
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Broussard SR, McCusker RH, Novakofski JE, Strle K, Shen WH, Johnson RW, Dantzer R, Kelley KW. IL-1beta impairs insulin-like growth factor i-induced differentiation and downstream activation signals of the insulin-like growth factor i receptor in myoblasts. THE JOURNAL OF IMMUNOLOGY 2004; 172:7713-20. [PMID: 15187154 DOI: 10.4049/jimmunol.172.12.7713] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Proinflammatory cytokines are elevated in disorders characterized by muscle wasting and weakness, such as inflammatory myopathies and AIDS wasting. We recently demonstrated that TNF-alpha impairs the ability of insulin-like growth factor (IGF)-I to promote protein synthesis in muscle precursor cells. In this study we extend these findings by showing that low concentrations of IL-1beta impair IGF-I-dependent differentiation of myoblasts, as assessed by expression of the muscle specific protein, myosin heavy chain. In the absence of exogenous IGF-I, IL-1beta (1 ng/ml) did not impair muscle cell development. However, in the presence of IGF-I, 100-fold lower concentrations of IL-1beta (0.01 ng/ml) significantly suppressed myoblast differentiation, protein synthesis, and myogenin expression. Increasing IL-1beta to 1 ng/ml completely blocked the anabolic actions of IGF-I in murine C(2)C(12) myoblasts. Similarly, IL-1beta inhibited IGF-I-stimulated protein synthesis in primary porcine myoblasts. IL-1beta impaired the actions of IGF-I at a point distal to the IGF receptor, and this was not due to IL-1beta-induced cell death. Instead, IL-1beta inhibited the ability of IGF-I to phosphorylate tyrosine residues on both of its downstream docking proteins, insulin receptor substrate 1 and insulin receptor substrate 2. These data establish that physiological concentrations of IL-1beta block the ability of IGF-I to promote protein synthesis, leading to reduced expression of the myogenic transcription factor, myogenin, and the subsequent development of more mature differentiated cells that express myosin heavy chain. Collectively, the results are consistent with the notion that very low concentrations of IL-1beta significantly impair myogenesis, but they are unable to do so in the absence of the growth factor IGF-I.
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Affiliation(s)
- Suzanne R Broussard
- Laboratories of Immunophysiology,207 Edward R. Madigan Laboratory, University of Illinois at Urbana-Champaign, 1201 West Gregory Drive, Urbana, IL 61801, USA.
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23
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N/A. N/A. Shijie Huaren Xiaohua Zazhi 2004; 12:1962-1964. [DOI: 10.11569/wcjd.v12.i8.1962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/26/2023] Open
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Shen WH, Zhou JH, Broussard SR, Johnson RW, Dantzer R, Kelley KW. Tumor necrosis factor alpha inhibits insulin-like growth factor I-induced hematopoietic cell survival and proliferation. Endocrinology 2004; 145:3101-5. [PMID: 15087433 DOI: 10.1210/en.2004-0246] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Proinflammatory cytokines, such as TNFalpha and IL-1beta, are both cytostatic and cytotoxic. In contrast, IGF-I promotes proliferation and survival of hematopoietic progenitor cells. In this report, we establish that both the cytostatic and cytotoxic activity of TNFalpha on murine myeloid progenitor cells is only evident in the presence of IGF-I. We first confirmed that IGF-I (100 ng/ml) increases DNA synthesis and reduces apoptosis in murine myeloid progenitor cells induced to die by growth factor withdrawal. TNFalpha inhibits, in a dose-dependent fashion from 0.1 to 10 ng/ml, both activities of IGF-I. TNFalpha activity was not detected in the absence of IGF-I. Another proinflammatory cytokine, IL-1beta, did not inhibit IGF-I-induced activity in murine factor-dependent cell progenitor-1/Mac-1 cells. However, the ability of TNFalpha to impair IGF-I-induced DNA synthesis in human promyeloid cells extends to IL-1beta. Statistically significant inhibition of all these events occurs at very low concentrations of 1 ng/ml or less. These results support the general concept that proinflammatory cytokines impair the actions of hormones on hematopoietic cells, leading to IGF-I receptor resistance.
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Affiliation(s)
- Wen Hong Shen
- University of Illinois, Laboratory of Immunophysiology, Department of Animal Sciences, 207 Edward R. Madigan Laboratory, 1201 West Gregory Drive, Urbana, Illinois 61801, USA
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Shen WH, Jackson ST, Broussard SR, McCusker RH, Strle K, Freund GG, Johnson RW, Dantzer R, Kelley KW. IL-1β Suppresses Prolonged Akt Activation and Expression of E2F-1 and Cyclin A in Breast Cancer Cells. THE JOURNAL OF IMMUNOLOGY 2004; 172:7272-81. [PMID: 15187102 DOI: 10.4049/jimmunol.172.12.7272] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cell cycle aberrations occurring at the G(1)/S checkpoint often lead to uncontrolled cell proliferation and tumor growth. We recently demonstrated that IL-1beta inhibits insulin-like growth factor (IGF)-I-induced cell proliferation by preventing cells from entering the S phase of the cell cycle, leading to G(0)/G(1) arrest. Notably, IL-1beta suppresses the ability of the IGF-I receptor tyrosine kinase to phosphorylate its major docking protein, insulin receptor substrate-1, in MCF-7 breast carcinoma cells. In this study, we extend this juxtamembrane cross-talk between cytokine and growth factor receptors to downstream cell cycle machinery. IL-1beta reduces the ability of IGF-I to activate Cdk2 and to induce E2F-1, cyclin A, and cyclin A-dependent phosphorylation of a retinoblastoma tumor suppressor substrate. Long-term activation of the phosphatidylinositol 3-kinase/Akt signaling pathway, but not the mammalian target of rapamycin or mitogen-activated protein kinase pathways, is required for IGF-I to hyperphosphorylate retinoblastoma and to cause accumulation of E2F-1 and cyclin A. In the absence of IGF-I to induce Akt activation and cell cycle progression, IL-1beta has no effect. IL-1beta induces p21(Cip1/Waf1), which may contribute to its inhibition of IGF-I-activated Cdk2. Collectively, these data establish a novel mechanism by which prolonged Akt phosphorylation serves as a convergent target for both IGF-I and IL-1beta; stimulation by growth factors such as IGF-I promotes G(1)-S phase progression, whereas IL-1beta antagonizes IGF-I-induced Akt phosphorylation to induce cytostasis. In this manner, Akt serves as a critical bridge that links proximal receptor signaling events to more distal cell cycle machinery.
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Affiliation(s)
- Wen Hong Shen
- Laboratory of Immunophysiology, University of Illinois, Urbana, IL 61801, USA
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Kelley KW. From hormones to immunity: the physiology of immunology. Brain Behav Immun 2004; 18:95-113. [PMID: 14759588 DOI: 10.1016/j.bbi.2003.10.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2003] [Revised: 10/13/2003] [Accepted: 10/13/2003] [Indexed: 10/26/2022] Open
Abstract
Discoveries in the physiology of immunology have increased at an increasing rate during the past two decades. It is now recognized that the immune system is just another physiological system that regulates, and is regulated by, other physiological systems such as the brain. These advances make it clear that recent findings in genomic biology must be interpreted in the context of the environment in which animals and humans live. Lack of a strong genetic basis for significant human mental health disorders, such as major depression, points to the critical importance of interactions. Several examples of environmental x genetic x disease interactions are presented. Regulation of cells of the hematopoietic lineage by two genes that control over 80% of postnatal growth, growth hormone and IGF-I, are then highlighted. The reciprocal relationship of how proinflammatory cytokines from the immune system regulate the growth hormone/IGF-I axis is also summarized. Particular emphasis is placed upon TNFalpha-induced IGF-I resistance in neurons, muscle cells and epithelial cells. This cytokine regulation of hormone action may ultimately be more important for human and animal health than direct effects of growth hormone and IGF-I on hematopoietic cells. Wasting of AIDS patients is given as an important clinical example of how TNFalpha from an activated immune system reduces IGF-I sensitivity in multiple physiologic systems, including muscle, nervous and hematopoietic tissues.
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Affiliation(s)
- Keith W Kelley
- Laboratory of Immunophysiology, Department of Animal Sciences, University of Illinois, Urbana, IL 61801, USA.
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