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Molecular Mechanisms of RSV and Air Pollution Interaction: A Scoping Review. Int J Mol Sci 2022; 23:ijms232012704. [PMID: 36293561 PMCID: PMC9604398 DOI: 10.3390/ijms232012704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/17/2022] [Accepted: 10/19/2022] [Indexed: 11/06/2022] Open
Abstract
RSV is one of the major infectious agents in paediatrics, and its relationship with air pollution is frequently observed. However, the molecular basis of this interaction is sparsely reported. We sought to systematically review the existing body of literature and identify the knowledge gaps to answer the question: which molecular mechanisms are implied in the air pollutants-RSV interaction? Online databases were searched for original studies published before August 2022 focusing on molecular mechanisms of the interaction. The studies were charted and a narrative synthesis was based upon three expected directions of influence: a facilitated viral entry, an altered viral replication, and an inappropriate host reaction. We identified 25 studies published between 1993 and 2020 (without a noticeable increase in the number of studies) that were performed in human (n = 12), animal (n = 10) or mixed (n = 3) models, and analysed mainly cigarette smoke (n = 11), particulate matter (n = 4), nanoparticles (n = 3), and carbon black (n = 2). The data on a damage to the epithelial barrier supports the hypothesis of facilitated viral entry; one study also reported accelerated viral entry upon an RSV conjugation to particulate matter. Air pollution may result in the predominance of necrosis over apoptosis, and, as an effect, an increased viral load was reported. Similarly, air pollution mitigates epithelium function with decreased IFN-γ and Clara cell secretory protein levels and decreased immune response. Immune response might also be diminished due to a decreased viral uptake by alveolar macrophages and a suppressed function of dendritic cells. On the other hand, an exuberant inflammatory response might be triggered by air pollution and provoke airway hyperresponsiveness (AHR), prolonged lung infiltration, and tissue remodeling, including a formation of emphysema. AHR is mediated mostly by increased IFN-γ and RANTES concentrations, while the risk of emphysema was related to the activation of the IL-17 → MCP-1 → MMP-9 → MMP-12 axis. There is a significant lack of evidence on the molecular basics of the RSV-air pollution interaction, which may present a serious problem with regards to future actions against air pollution effects. The major knowledge gaps concern air pollutants (mostly the influence of cigarette smoke was investigated), the mechanisms facilitating an acute infection or a worse disease course (since it might help plan short-term, especially non-pharmacological, interventions), and the mechanisms of an inadequate response to the infection (which may lead to a prolonged course of an acute infection and long-term sequelae). Thus far, the evidence is insufficient regarding the broadness and complexity of the interaction, and future studies should focus on common mechanisms stimulated by various air pollutants and a comparison of influence of the different contaminants at various concentrations.
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Olson B, Diba P, Korzun T, Marks DL. Neural Mechanisms of Cancer Cachexia. Cancers (Basel) 2021; 13:cancers13163990. [PMID: 34439145 PMCID: PMC8391721 DOI: 10.3390/cancers13163990] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 08/05/2021] [Indexed: 12/04/2022] Open
Abstract
Simple Summary Cancer cachexia is a devastating wasting syndrome that occurs in many illnesses, with signs and symptoms including anorexia, weight loss, cognitive impairment and fatigue. The brain is capable of exerting overarching homeostatic control of whole-body metabolism and is increasingly being recognized as an important mediator of cancer cachexia. Given the increased recognition and discovery of neural mechanisms of cancer cachexia, we sought to provide an in-depth review and update of mechanisms by which the brain initiates and propagates cancer cachexia programs. Furthermore, recent work has identified new molecular mediators of cachexia that exert their effects through their direct interaction with the brain. Therefore, this review will summarize neural mechanisms of cachexia and discuss recently identified neural mediators of cancer cachexia. Abstract Nearly half of cancer patients suffer from cachexia, a metabolic syndrome characterized by progressive atrophy of fat and lean body mass. This state of excess catabolism decreases quality of life, ability to tolerate treatment and eventual survival, yet no effective therapies exist. Although the central nervous system (CNS) orchestrates several manifestations of cachexia, the precise mechanisms of neural dysfunction during cachexia are still being unveiled. Herein, we summarize the cellular and molecular mechanisms of CNS dysfunction during cancer cachexia with a focus on inflammatory, autonomic and neuroendocrine processes and end with a discussion of recently identified CNS mediators of cachexia, including GDF15, LCN2 and INSL3.
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Affiliation(s)
- Brennan Olson
- Medical Scientist Training Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA; (B.O.); (P.D.); (T.K.)
- Papé Family Pediatric Research Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA
| | - Parham Diba
- Medical Scientist Training Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA; (B.O.); (P.D.); (T.K.)
- Papé Family Pediatric Research Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA
| | - Tetiana Korzun
- Medical Scientist Training Program, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA; (B.O.); (P.D.); (T.K.)
- Papé Family Pediatric Research Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA
| | - Daniel L. Marks
- Papé Family Pediatric Research Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA
- Brenden-Colson Center for Pancreatic Care, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd, Portland, OR 97239, USA
- Correspondence:
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Poon J, Campos M, Foronjy RF, Nath S, Gupta G, Railwah C, Dabo AJ, Baumlin N, Salathe M, Geraghty P. Cigarette smoke exposure reduces leukemia inhibitory factor levels during respiratory syncytial viral infection. Int J Chron Obstruct Pulmon Dis 2019; 14:1305-1315. [PMID: 31417248 PMCID: PMC6592033 DOI: 10.2147/copd.s196658] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Accepted: 04/12/2019] [Indexed: 12/12/2022] Open
Abstract
Background: Viral infections are considered a major driving factor of chronic obstructive pulmonary disease (COPD) exacerbations and thus contribute to disease morbidity and mortality. Respiratory syncytial virus (RSV) is a frequently detected pathogen in the respiratory tract of COPD patients during an exacerbation. We previously demonstrated in a murine model that leukemia inhibitory factor (LIF) expression was increased in the lungs during RSV infection. Subduing LIF signaling in this model enhanced lung injury and airway hypersensitivity. In this study, we investigated lung LIF levels in COPD patient samples to determine the impact of disease status and cigarette smoke exposure on LIF expression. Materials and methods: Bronchoalveolar lavage fluid (BALF) was obtained from healthy never smokers, smokers, and COPD patients, by written informed consent. Human bronchial epithelial (HBE) cells were isolated from healthy never smokers and COPD patients, grown at the air-liquid interface and infected with RSV or stimulated with polyinosinic:polycytidylic acid (poly (i:c)). Mice were exposed to cigarette smoke daily for 6 months and were subsequently infected with RSV. LIF expression was profiled in all samples. Results: In human BALF, LIF protein was significantly reduced in both smokers and COPD patients compared to healthy never smokers. HBE cells isolated from COPD patients produced less LIF compared to never smokers during RSV infection or poly (i:c) stimulation. Animals exposed to cigarette smoke had reduced lung levels of LIF and its corresponding receptor, LIFR. Smoke-exposed animals had reduced LIF expression during RSV infection. Two possible factors for reduced LIF levels were increased LIF mRNA instability in COPD epithelia and proteolytic degradation of LIF protein by serine proteases. Conclusions: Cigarette smoke is an important modulator for LIF expression in the lungs. Loss of LIF expression in COPD could contribute to a higher degree of lung injury during virus-associated exacerbations.
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Affiliation(s)
- Justin Poon
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Michael Campos
- Division of Pulmonary, Critical Care, and Sleep Medicine, University of Miami, Miami, FL, USA
| | - Robert F Foronjy
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Sridesh Nath
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Gayatri Gupta
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Christopher Railwah
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Abdoulaye J Dabo
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Nathalie Baumlin
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Matthias Salathe
- Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Patrick Geraghty
- Division of Pulmonary & Critical Care Medicine, Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
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Keasey MP, Jia C, Pimentel LF, Sante RR, Lovins C, Hagg T. Blood vitronectin is a major activator of LIF and IL-6 in the brain through integrin-FAK and uPAR signaling. J Cell Sci 2018; 131:jcs.202580. [PMID: 29222114 DOI: 10.1242/jcs.202580] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 12/06/2017] [Indexed: 12/18/2022] Open
Abstract
We defined how blood-derived vitronectin (VTN) rapidly and potently activates leukemia inhibitory factor (LIF) and pro-inflammatory interleukin 6 (IL-6) in vitro and after vascular injury in the brain. Treatment with VTN (but not fibrinogen, fibronectin, laminin-111 or collagen-I) substantially increased LIF and IL-6 within 4 h in C6-astroglioma cells, while VTN-/- mouse plasma was less effective than that from wild-type mice. LIF and IL-6 were induced by intracerebral injection of recombinant human (rh)VTN in mice, but induction seen upon intracerebral hemorrhage was less in VTN-/- mice than in wild-type littermates. In vitro, VTN effects were inhibited by RGD, αvβ3 and αvβ5 integrin-blocking peptides and antibodies. VTN activated focal adhesion kinase (FAK; also known as PTK2), whereas pharmacological- or siRNA-mediated inhibition of FAK, but not PYK2, reduced the expression of LIF and IL-6 in C6 and endothelial cells and after traumatic cell injury. Dominant-negative FAK (Y397F) reduced the amount of injury-induced LIF and IL-6. Pharmacological inhibition or knockdown of uPAR (also known as PLAUR), which binds VTN, also reduced cytokine expression, possibly through a common target of uPAR and integrins. We propose that VTN leakage into tissues promotes inflammation. Integrin-FAK signaling is therefore a novel IL-6 and LIF regulation mechanism relevant to the inflammation and stem cell fields.
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Affiliation(s)
- Matthew P Keasey
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Cuihong Jia
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Lylyan F Pimentel
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA.,Keizo Asami Laboratory (LIKA), Universidade Federal de Pernambuco, Recife, PE, Brasil
| | - Richard R Sante
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Chiharu Lovins
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
| | - Theo Hagg
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN 37614, USA
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Burfeind KG, Michaelis KA, Marks DL. The central role of hypothalamic inflammation in the acute illness response and cachexia. Semin Cell Dev Biol 2015; 54:42-52. [PMID: 26541482 DOI: 10.1016/j.semcdb.2015.10.038] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 10/26/2015] [Indexed: 12/19/2022]
Abstract
When challenged with a variety of inflammatory threats, multiple systems across the body undergo physiological responses to promote defense and survival. The constellation of fever, anorexia, and fatigue is known as the acute illness response, and represents an adaptive behavioral and physiological reaction to stimuli such as infection. On the other end of the spectrum, cachexia is a deadly and clinically challenging syndrome involving anorexia, fatigue, and muscle wasting. Both of these processes are governed by inflammatory mediators including cytokines, chemokines, and immune cells. Though the effects of cachexia can be partially explained by direct effects of disease processes on wasting tissues, a growing body of evidence shows the central nervous system (CNS) also plays an essential mechanistic role in cachexia. In the context of inflammatory stress, the hypothalamus integrates signals from peripheral systems, which it translates into neuroendocrine perturbations, altered neuronal signaling, and global metabolic derangements. Therefore, we will discuss how hypothalamic inflammation is an essential driver of both the acute illness response and cachexia, and why this organ is uniquely equipped to generate and maintain chronic inflammation. First, we will focus on the role of the hypothalamus in acute responses to dietary and infectious stimuli. Next, we will discuss the role of cytokines in driving homeostatic disequilibrium, resulting in muscle wasting, anorexia, and weight loss. Finally, we will address mechanisms and mediators of chronic hypothalamic inflammation, including endothelial cells, chemokines, and peripheral leukocytes.
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Affiliation(s)
- Kevin G Burfeind
- Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, OR, USA
- MD/PhD Program, Oregon Health & Science University, Portland, OR, USA
| | - Katherine A Michaelis
- Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, OR, USA
- MD/PhD Program, Oregon Health & Science University, Portland, OR, USA
| | - Daniel L Marks
- Papé Family Pediatric Research Institute, Oregon Health & Science University, Portland, OR, USA
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Grossberg AJ, Scarlett JM, Marks DL. Hypothalamic mechanisms in cachexia. Physiol Behav 2010; 100:478-89. [PMID: 20346963 DOI: 10.1016/j.physbeh.2010.03.011] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 03/10/2010] [Accepted: 03/12/2010] [Indexed: 12/12/2022]
Abstract
The role of nutrition and balanced metabolism in normal growth, development, and health maintenance is well known. Patients affected with either acute or chronic diseases often show disorders of nutrient balance. In some cases, a devastating state of malnutrition known as cachexia arises, brought about by a synergistic combination of a dramatic decrease in appetite and an increase in metabolism of fat and lean body mass. Other common features that are not required for the diagnosis include decreases in voluntary movement, insulin resistance, and anhedonia. This combination is found in a number of disorders including cancer, cystic fibrosis, AIDS, rheumatoid arthritis, renal failure, and Alzheimer's disease. The severity of cachexia in these illnesses is often the primary determining factor in both quality of life, and in eventual mortality. Indeed, body mass retention in AIDS patients has a stronger association with survival than any other current measure of the disease. This has led to intense investigation of cachexia and the proposal of numerous hypotheses regarding its etiology. Most authors suggest that cytokines released during inflammation and malignancy act on the central nervous system to alter the release and function of a number of neurotransmitters, thereby altering both appetite and metabolic rate. This review will discuss the salient features of cachexia in human diseases, and review the mechanisms whereby inflammation alters the function of key brain regions to produce stereotypical illness behavior. The paper represents an invited review by a symposium, award winner or keynote speaker at the Society for the Study of Ingestive Behavior [SSIB] Annual Meeting in Portland, July 2009.
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Affiliation(s)
- Aaron J Grossberg
- Department of Pediatrics, Oregon Health & Science University, Portland, OR 97239, USA
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7
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Grossberg AJ, Scarlett JM, Zhu X, Bowe DD, Batra AK, Braun TP, Marks DL. Arcuate nucleus proopiomelanocortin neurons mediate the acute anorectic actions of leukemia inhibitory factor via gp130. Endocrinology 2010; 151:606-16. [PMID: 20016025 PMCID: PMC2817620 DOI: 10.1210/en.2009-1135] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The proinflammatory cytokine leukemia inhibitory factor (LIF) is induced in disease states and is known to inhibit food intake when administered centrally. However, the neural pathways underlying this effect are not well understood. We demonstrate that LIF acutely inhibits food intake by directly activating pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus. We show that arcuate POMC neurons express the LIF-R, and that LIF stimulates the release of the anorexigenic peptide, alpha-MSH from ex vivo hypothalami. Transgenic mice lacking gp130, the signal transducing subunit of the LIF-R complex, specifically in POMC neurons fail to respond to LIF. Furthermore, LIF does not stimulate the release of alpha-MSH from the transgenic hypothalamic explants. These findings indicate that POMC neurons mediate the acute anorectic actions of central LIF administration and provide a mechanistic link between inflammation and food intake.
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Affiliation(s)
- Aaron J Grossberg
- Department of Pediatrics, Oregon Health and Science University, Mail Code L-481, Portland, Oregon 97239, USA
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Evans J, Catalano RD, Brown P, Sherwin R, Critchley HOD, Fazleabas AT, Jabbour HN. Prokineticin 1 mediates fetal-maternal dialogue regulating endometrial leukemia inhibitory factor. FASEB J 2009; 23:2165-75. [PMID: 19255255 PMCID: PMC2704594 DOI: 10.1096/fj.08-124495] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Implantation requires communication between a receptive endometrium and a healthy blastocyst. This maternal-embryonic crosstalk involves local mediators within the uterine microenvironment. We demonstrate that a secreted protein, prokineticin 1 (PROK1), is expressed in the receptive endometrium and during early pregnancy. PROK1 induces expression of leukemia inhibitory factor (LIF) in endometrial epithelial cells and first trimester decidua via a Gq-Ca2+-cSrc-mitogen-activated protein kinase kinase-mediated pathway. We show that human embryonic chorionic gonadotropin (hCG) induces sequential mRNA expression of PROK1 and LIF in an in vivo baboon model, in human endometrial epithelial cells, and in first-trimester decidua. We have used micro RNA constructs targeted to PROK1 to demonstrate that hCG-mediated LIF expression in the endometrium is dependent on prior induction of PROK1. Dual immunohistochemical analysis colocalized expression of the luteinizing hormone/chorionic gonadotropin receptor, PROK1, PROKR1, and LIF to the glandular epithelial cells of the first trimester decidual tissue. PROK1 enhances adhesion of trophoblast cells to fibronectin and laminin matrices, which are mediated predominantly via LIF induction. These data describe a novel signaling pathway mediating maternal-embryonic crosstalk, in which embryonic hCG via endometrial PROK1 may play a pivotal role in enhancing receptivity and maintaining early pregnancy.—Evans, J., Catalano, R. D., Brown, P., Sherwin, R., Critchley, H. O. D., Fazleabas, A. T., Jabbour, H. N. Prokineticin 1 mediates fetal-maternal dialogue regulating endometrial leukemia inhibitory factor.
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Affiliation(s)
- Jemma Evans
- MRC Human Reproductive Sciences Unit, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK
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9
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Denervated Schwann cells attract macrophages by secretion of leukemia inhibitory factor (LIF) and monocyte chemoattractant protein-1 in a process regulated by interleukin-6 and LIF. J Neurosci 2002. [PMID: 12151548 DOI: 10.1523/jneurosci.22-15-06696.2002] [Citation(s) in RCA: 258] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Injury to peripheral nerves results in the infiltration of immune cells, which remove axonal- and myelin-derived material. Schwann cells could play a key role in this process by regulating macrophage infiltration. We show here that medium conditioned by primary denervated Schwann cells or the Schwannoma cell line RN22 produces chemotactic activity for macrophages. The presence of blocking antibodies to macrophage chemoattractant protein-1 (MCP-1) or leukemia inhibitory factor (LIF) reduced this activity to approximately 35 and 65% of control levels, respectively, and only 15% remained in the presence of both antibodies. The presence of chemotactic LIF in Schwann cell-conditioned medium was confirmed by using cells from lif-/- mice. Although interleukin-6 (IL-6) is not itself a chemotactic factor, we found that medium from il-6-/- nerves showed only 40% of the activity secreted by wild-type nerves. Furthermore, IL-6 rapidly induced LIF mRNA in primary Schwann cells, and LIF rapidly induced MCP-1 mRNA expression. Treatment of RN22 Schwannoma cells with IL-6 or LIF enhanced the secretion of the chemotactic activity of these cells. These observations show that Schwann cells attract macrophages by secreting MCP-1 and LIF. They also provide evidence for an autocrine-signaling cascade involving IL-6, LIF, and MCP-1, which amplifies the Schwann cell-derived chemotactic signals gradually, in agreement with the delayed entry of macrophages to injured nerves.
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Bakheet T, Frevel M, Williams BR, Greer W, Khabar KS. ARED: human AU-rich element-containing mRNA database reveals an unexpectedly diverse functional repertoire of encoded proteins. Nucleic Acids Res 2001; 29:246-54. [PMID: 11125104 PMCID: PMC29778 DOI: 10.1093/nar/29.1.246] [Citation(s) in RCA: 307] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2000] [Revised: 10/02/2000] [Accepted: 10/02/2000] [Indexed: 01/15/2023] Open
Abstract
The adenylate uridylate-rich elements (AREs) mediate the rapid turnover of mRNAs encoding proteins that regulate cellular growth and body response to exogenous agents such as microbes, inflammatory and environmental stimuli. However, the full repertoire of ARE-containing mRNAs is unknown. Here, we explore the distribution of AREs in human mRNA sequences. Computational derivation of a 13-bp ARE pattern was performed using multiple expectation maximization for motif elicitations (MEME) and consensus analyses. This pattern was statistically validated for the specificity towards the 3'-untranslated region and not coding region. The computationally derived ARE pattern is the basis of a database which contains non-redundant full-length ARE-mRNAs. The ARE-mRNA database (ARED; http://rc.kfshrc.edu.sa/ared) reveals that ARE-mRNAs encode a wide repertoire of functionally diverse proteins that belong to different biological processes and are important in several disease states. Cluster analysis was performed using the ARE sequences to demonstrate potential relationships between the type and number of ARE motifs, and the functional characteristics of the proteins.
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Affiliation(s)
- T Bakheet
- Department of Biostatistics, Epidemiology and Scientific Computing (Bioinformatics Section), King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia
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Dowsing BJ, Morrison WA, Nicola NA, Starkey GP, Bucci T, Kilpatrick TJ. Leukemia inhibitory factor is an autocrine survival factor for Schwann cells. J Neurochem 1999; 73:96-104. [PMID: 10386959 DOI: 10.1046/j.1471-4159.1999.0730096.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Schwann cells play a major role in promoting nerve survival and regeneration after injury. Their activities include providing neurotrophic factors and increasing the production of extracellular matrix components and cell surface adhesion molecules to promote axon regeneration. Following nerve transection, leukemia inhibitory factor (LIF) is up-regulated by Schwann cells at the injury site. LIF receptors are also up-regulated at the nerve injury site, but their cellular localization and function have not been fully characterized. We demonstrate that Schwann cells express mRNAs for LIF and the LIF receptor components LIF receptor subunit beta and glycoprotein 130 in vitro. We also show that although LIF is not required for the genesis of Schwann cells, it can potentiate the survival of differentiated Schwann cells in the context of neuregulin support. Not only does exogenous LIF promote survival under these conditions, but addition of the soluble LIF receptor (LIF binding protein) and anti-LIF antibodies significantly reduced cell survival, suggesting that LIF exerts autocrine effects. These results suggest that Schwann cell survival following nerve injury is potentially modulated by LIF.
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Affiliation(s)
- B J Dowsing
- Bernard O'Brien Institute of Microsurgery, St. Vincent's Hospital, Melbourne, Victoria, Australia
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Nagamoto-Combs K, Vaccariello SA, Zigmond RE. The levels of leukemia inhibitory factor mRNA in a Schwann cell line are regulated by multiple second messenger pathways. J Neurochem 1999; 72:1871-81. [PMID: 10217263 DOI: 10.1046/j.1471-4159.1999.0721871.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Axotomy of sympathetic and sensory neurons leads to changes in their neuropeptide phenotypes. These changes are mediated in part by the induction of leukemia inhibitory factor (LIF) by nonneuronal cells. In the present study, we identified satellite/Schwann cells as a possible source of the injury-induced LIF. Using a Schwann cell line, SC-1 cells, we examined mechanisms of LIF induction. LIF mRNA levels increased rapidly when the cells were treated with 8-(4-chlorophenylthio)adenosine 3',5'-cyclic monophosphate, phorbol 12-myristate 13-acetate (PMA), or A23187. Among these reagents, PMA was the most efficacious. Inhibition of protein kinase C (PKC) by GF-1 09203X significantly reduced the PMA-induced LIF mRNA levels. As PKC is known to activate the extracellular signal-regulated kinase (ERK) signaling pathway, the involvement of this pathway in the PMA-stimulated induction of LIF mRNA was examined. Phosphorylation of ERKs was increased following PMA treatment in SC-1 cells. Moreover, inhibition of ERK kinase activity by PD98059 dramatically reduced PMA-stimulated phosphorylation of ERKs and induction of LIF mRNA. These results indicate that LIF mRNA levels can be regulated by ERK activation via stimulation of PKC in Schwann cells.
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Affiliation(s)
- K Nagamoto-Combs
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Knight DA, Lydell CP, Zhou D, Weir TD, Robert Schellenberg R, Bai TR. Leukemia inhibitory factor (LIF) and LIF receptor in human lung. Distribution and regulation of LIF release. Am J Respir Cell Mol Biol 1999; 20:834-41. [PMID: 10101017 DOI: 10.1165/ajrcmb.20.4.3429] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The distribution and regulation of leukemia inhibitory factor (LIF) and its receptor (LIFR) in human lung tissue is unknown. We recently found that LIF was immunolocalized to several cell types in human airways, and that exogenous LIF modulated neural and contractile responses of explanted airways. The present study aimed to determine the cellular distribution and regulation of gene transcripts for LIF and LIFR in human lung, and measured the release of LIF in response to anti-immunoglobulin (Ig)E, interleukin (IL)-1beta, and IL-6. Exposure of human lung to IL-1beta (100 pg/ml) resulted in the rapid induction of LIF messenger RNA (mRNA) (1 h) and subsequent protein release (6 h). Similar results were observed when lung tissue was exposed to anti-IgE (6 U/ml). Gene transcripts for LIF were observed in nine pulmonary cell types, with the greatest expression occurring in fibroblasts. LIFR transcripts were also widely expressed in these cell types. In cultures of nontransformed epithelial cells, lung fibroblasts, and airway smooth-muscle cells, IL-1beta (100 pg/ml) induced the rapid accumulation of LIF mRNA and protein release, with fibroblasts liberating the greatest amount. IL-6 also induced the expression of LIF mRNA and release of LIF in airway smooth-muscle cells, whereas exogenous LIF itself had no effect. Expression of LIFR mRNA was not influenced by exposure to IL-1beta or LIF in any of the cell lines used. These results highlight the widespread distribution and rapid release of LIF in human lung tissue and, in conjunction with our previous report, suggest that this cytokine may play an important role in lung inflammatory processes and neuroimmune interactions.
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Affiliation(s)
- D A Knight
- University of British Columbia Pulmonary Research Laboratory, St. Paul's Hospital, Vancouver, British Columbia, Canada
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Abstract
Since recent work has identified an apoptotic pathway in sympathetic neurons that is mediated by autocrine interleukin-1 (IL-1), we investigated whether cultured sympathetic neurons possess functional IL-1 receptors. Cultured sympathetic neurons express levels of IL-1RI and IL-1RAcP mRNAs consistent with signal transduction. Neurons stimulated with IL-1 demonstrate enhanced p65 NF-kappaB nuclear translocation and enhanced NF-kappaB DNA binding activity, with at least p65 and p50 subunits participating in the DNA binding activity. RNA differential display identified several neuronal mRNAs regulated by IL-1, including a member of the reticulon family. We conclude that IL-1 stimulates a potential component of a neuronal secretory pathway.
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Affiliation(s)
- Y Bai
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102-1811, USA
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15
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Nagtegaal ID, Lakke EA, Marani E. Trophic and tropic factors in the development of the central nervous system. Arch Physiol Biochem 1998; 106:161-202. [PMID: 10099715 DOI: 10.1076/apab.106.3.161.4380] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- I D Nagtegaal
- Department of Physiology, University of Leiden, The Netherlands
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16
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Carlson CD, Bai Y, Ding M, Jonakait GM, Hart RP. Interleukin-1 involvement in the induction of leukemia inhibitory factor mRNA expression following axotomy of sympathetic ganglia. J Neuroimmunol 1996; 70:181-90. [PMID: 8898726 DOI: 10.1016/s0165-5728(96)00115-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Axotomy of superior cervical (sympathetic) ganglia (SCG) results in increased neuropeptide gene expression. In vitro, neuropeptide gene expression is similarly increased by exposure to the inflammatory cytokine interleukin-1 (IL-1). The effect of IL-1 in-vitro has been shown to be mediated by leukemia inhibitory factor (LIF). Since IL-1 regulates neuropeptide expression via LIF in vitro, we asked whether axotomy in vivo produces an increase in LIF mRNA, and whether that increase is regulated by IL-1 activity. Within 6 h following axotomy, ganglionic LIF mRNA is substantially elevated. Moreover, axotomy produces a rapid and transient increase in intraganglionic IL-1 beta mRNA, followed rapidly by an increase in ICAM-1 mRNA, thereby suggesting a local source of IL-1 activity. Pretreatment with the anti-inflammatory agent dexamethasone (DEX) reduces the increases of both IL-1 beta and LIF mRNAs following axotomy. mRNA encoding the specific signal-transducing Type I IL-1 receptor is present in unlesioned SCG in vivo, and increases following axotomy. Local application of IL-1 beta in vivo induces LIF mRNA even in uninjured ganglia, though not to the extent seen with axotomy. DEX treatment blocks this IL-1 beta-mediated increase in LIF mRNA. Therefore, DEX blocks the induction of LIF mRNA by inhibiting both the production of IL-1 and its action on LIF gene expression. Axotomy of a homozygous IL-1 receptor type I gene knockout mouse leads to a delayed and/or diminished induction of LIF mRNA in SCG, but does not prevent LIF mRNA expression. We conclude that while IL-1 is likely to be involved in the cascade of gene expression that follows axotomy, it alone is not sufficient to mediate the full induction of LIF mRNA by axotomy.
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Affiliation(s)
- C D Carlson
- Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
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