1
|
Peixoto D, Carvalho I, Machado M, Aragão C, Costas B, Azeredo R. Dietary tryptophan intervention counteracts stress-induced transcriptional changes in a teleost fish HPI axis during inflammation. Sci Rep 2024; 14:7354. [PMID: 38548769 PMCID: PMC10978975 DOI: 10.1038/s41598-024-57761-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 03/21/2024] [Indexed: 04/01/2024] Open
Abstract
Immune nutrition is currently used to enhance fish health by incorporating functional ingredients into aquafeeds. This study aimed to investigate the connections between tryptophan nutrition and the network that regulates the communication pathways between neuroendocrine and immune systems in European seabass (Dicentrarchus labrax). When tryptophan was supplemented in the diet of unstressed fish, it induced changes in the hypothalamic-pituitary-interrenal axis response to stress. Tryptophan-mediated effects were observed in the expression of anti-inflammatory cytokines and glucocorticoid receptors. Tryptophan supplementation decreased pro-opiomelanocortin b-like levels, that are related with adrenocorticotropic hormone and cortisol secretion. When stressed fish fed a tryptophan-supplemented diet were subjected to an inflammatory stimulus, plasma cortisol levels decreased and the expression of genes involved in the neuroendocrine response was altered. Modulatory effects of tryptophan dietary intervention on molecular patterns seem to be mediated by altered patterns in serotonergic activity.
Collapse
Affiliation(s)
- Diogo Peixoto
- CIIMAR-Centro Interdisciplinar de Investigação Marinha e Ambiental, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
- Departamento de Biología Facultad de Ciencias del Mar y Ambientales, Instituto Universitario de Investigación Marina (INMAR), Campus de Excelencia Internacional del Mar (CEIMAR), Universidad de Cádiz, Puerto Real, Spain
| | - Inês Carvalho
- CIIMAR-Centro Interdisciplinar de Investigação Marinha e Ambiental, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Marina Machado
- CIIMAR-Centro Interdisciplinar de Investigação Marinha e Ambiental, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal
| | - Cláudia Aragão
- Centro de Ciências do Mar (CCMAR), Faro, Portugal
- Universidade do Algarve, Faro, Portugal
| | - Benjamín Costas
- CIIMAR-Centro Interdisciplinar de Investigação Marinha e Ambiental, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal.
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal.
| | - Rita Azeredo
- CIIMAR-Centro Interdisciplinar de Investigação Marinha e Ambiental, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal.
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal.
| |
Collapse
|
2
|
Falsetta ML, Maddipati KR, Honn KV. Inflammation, lipids, and pain in vulvar disease. Pharmacol Ther 2023; 248:108467. [PMID: 37285943 PMCID: PMC10527276 DOI: 10.1016/j.pharmthera.2023.108467] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/29/2023] [Accepted: 05/31/2023] [Indexed: 06/09/2023]
Abstract
Localized provoked vulvodynia (LPV) affects ∼14 million people in the US (9% of women), destroying lives and relationships. LPV is characterized by chronic pain (>3 months) upon touch to the vulvar vestibule, which surrounds the vaginal opening. Many patients go months or years without a diagnosis. Once diagnosed, the treatments available only manage the symptoms of disease and do not correct the underlying problem. We have focused on elucidating the underlying mechanisms of chronic vulvar pain to speed diagnosis and improve intervention and management. We determined the inflammatory response to microorganisms, even members of the resident microflora, sets off a chain of events that culminates in chronic pain. This agrees with findings from several other groups, which show inflammation is altered in the painful vestibule. The vestibule of patients is acutely sensitive to inflammatory stimuli to the point of being deleterious. Rather than protect against vaginal infection, it causes heightened inflammation that does not resolve, which coincides with alterations in lipid metabolism that favor production of proinflammatory lipids and not pro-resolving lipids. Lipid dysbiosis in turn triggers pain signaling through the transient receptor potential vanilloid subtype 4 receptor (TRPV4). Treatment with specialized pro-resolving mediators (SPMs) that foster resolution reduces inflammation in fibroblasts and mice and vulvar sensitivity in mice. SPMs, specifically maresin 1, act on more than one part of the vulvodynia mechanism by limiting inflammation and acutely inhibiting TRPV4 signaling. Therefore, SPMs or other agents that target inflammation and/or TRPV4 signaling could prove effective as new vulvodynia therapies.
Collapse
Affiliation(s)
- Megan L Falsetta
- University of Rochester, OB/GYN Research Division, Rochester, NY, United States of America; University of Rochester, Pharmacology and Physiology Department, Rochester, NY, United States of America.
| | - Krishna Rao Maddipati
- Wayne State University, Pathology Department, Detroit, MI, United States of America; Wayne State University, Lipidomics Core Facility and Bioactive Lipids Research Program, Detroit, MI, United States of America
| | - Kenneth V Honn
- Wayne State University, Pathology Department, Detroit, MI, United States of America; Wayne State University, Lipidomics Core Facility and Bioactive Lipids Research Program, Detroit, MI, United States of America
| |
Collapse
|
3
|
Blomqvist A. Prostaglandin E 2 Production by Brain Endothelial Cells and the Generation of Fever. DNA Cell Biol 2023; 42:107-112. [PMID: 36720071 PMCID: PMC10024267 DOI: 10.1089/dna.2022.0662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We recently demonstrated that prostaglandin production in brain endothelial cells is both necessary and sufficient for the generation of fever during systemic immune challenge. I here discuss this finding in light of the previous literature and point to some unresolved issues.
Collapse
Affiliation(s)
- Anders Blomqvist
- Division of Neurobiology, Department of Biomedical and Clinical Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
| |
Collapse
|
4
|
Eskilsson A, Shionoya K, Engblom D, Blomqvist A. Fever During Localized Inflammation in Mice Is Elicited by a Humoral Pathway and Depends on Brain Endothelial Interleukin-1 and Interleukin-6 Signaling and Central EP 3 Receptors. J Neurosci 2021; 41:5206-5218. [PMID: 33941650 PMCID: PMC8211540 DOI: 10.1523/jneurosci.0313-21.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/01/2021] [Accepted: 04/26/2021] [Indexed: 02/02/2023] Open
Abstract
We examined the signaling route for fever during localized inflammation in male and female mice, elicited by casein injection into a preformed air pouch. The localized inflammation gave rise to high concentrations of prostaglandins of the E species (PGE2) and cytokines in the air pouch and elevated levels of these inflammatory mediators in plasma. There were also elevated levels of PGE2 in the cerebrospinal fluid, although there was little evidence for PGE2 synthesis in the brain. Global deletion of the PGE2 prostaglandin E receptor 3 (EP3) abolished the febrile response as did deletion of the EP3 receptor in neural cells, whereas its deletion on peripheral nerves had no effect, implying that PGE2 action on this receptor in the CNS elicited the fever. Global deletion of the interleukin-1 receptor type 1 (IL-1R1) also abolished the febrile response, whereas its deletion on neural cells or peripheral nerves had no effect. However, deletion of the IL-1R1 on brain endothelial cells, as well as deletion of the interleukin-6 receptor α on these cells, attenuated the febrile response. In contrast, deletion of the PGE2 synthesizing enzymes cyclooxygenase-2 and microsomal prostaglandin synthase-1 in brain endothelial cells, known to attenuate fever evoked by systemic inflammation, had no effect. We conclude that fever during localized inflammation is not mediated by neural signaling from the inflamed site, as previously suggested, but is dependent on humoral signaling that involves interleukin actions on brain endothelial cells, probably facilitating PGE2 entry into the brain from the circulation and hence representing a mechanism distinct from that at work during systemic inflammation.
Collapse
Affiliation(s)
- Anna Eskilsson
- Division of Neurobiology and Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, S-58185 Linköping, Sweden
| | - Kiseko Shionoya
- Division of Neurobiology and Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, S-58185 Linköping, Sweden
| | - David Engblom
- Division of Neurobiology and Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, S-58185 Linköping, Sweden
| | - Anders Blomqvist
- Division of Neurobiology and Center for Social and Affective Neuroscience, Department of Biomedical and Clinical Sciences, Linköping University, S-58185 Linköping, Sweden
| |
Collapse
|
5
|
Abstract
Fever is a common symptom of infectious and inflammatory disease. It is well-established that prostaglandin E2 is the final mediator of fever, which by binding to its EP3 receptor subtype in the preoptic hypothalamus initiates thermogenesis. Here, we review the different hypotheses on how the presence of peripherally released pyrogenic substances can be signaled to the brain to elicit fever. We conclude that there is unequivocal evidence for a humoral signaling pathway by which proinflammatory cytokines, through their binding to receptors on brain endothelial cells, evoke fever by eliciting prostaglandin E2 synthesis in these cells. The evidence for a role for other signaling routes for fever, such as signaling via circumventricular organs and peripheral nerves, as well as transfer into the brain of peripherally synthesized prostaglandin E2 are yet far from conclusive. We also review the efferent limb of the pyrogenic pathways. We conclude that it is well established that prostaglandin E2 binding in the preoptic hypothalamus produces fever by disinhibition of presympathetic neurons in the brain stem, but there is yet little understanding of the mechanisms by which factors such as nutritional status and ambient temperature shape the response to the peripheral immune challenge.
Collapse
Affiliation(s)
- Anders Blomqvist
- Department of Clinical and Experimental Medicine, Faculty of Medicine and Health, Linköping University, Linköping, Sweden
| | - David Engblom
- Department of Clinical and Experimental Medicine, Faculty of Medicine and Health, Linköping University, Linköping, Sweden
| |
Collapse
|
6
|
Doyle HH, Murphy AZ. Sex differences in innate immunity and its impact on opioid pharmacology. J Neurosci Res 2017; 95:487-499. [PMID: 27870418 DOI: 10.1002/jnr.23852] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 06/22/2016] [Accepted: 07/06/2016] [Indexed: 12/30/2022]
Abstract
Morphine has been and continues to be one of the most potent and widely used drugs for the treatment of pain. Clinical and animal models investigating sex differences in pain and analgesia demonstrate that morphine is a more potent analgesic in males than in females. In addition to binding to the neuronal μ-opioid receptor, morphine binds to the innate immune receptor toll-like receptor 4 (TLR4), located on glial cells. Activation of glial TLR4 initiates a neuroinflammatory response that directly opposes morphine analgesia. Females of many species have a more active immune system than males; however, few studies have investigated glial cells as a potential mechanism driving sexually dimorphic responses to morphine. This Mini-Review illustrates the involvement of glial cells in key processes underlying observed sex differences in morphine analgesia and suggests that targeting glia may improve current treatment strategies for pain. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Hillary H Doyle
- Neuroscience Institute, Georgia State University, Atlanta, Georgia
| | - Anne Z Murphy
- Neuroscience Institute, Georgia State University, Atlanta, Georgia
| |
Collapse
|
7
|
Zhao JL, Zhao YY, Zhu WJ. A high-fat, high-protein diet attenuates the negative impact of casein-induced chronic inflammation on testicular steroidogenesis and sperm parameters in adult mice. Gen Comp Endocrinol 2017; 252:48-59. [PMID: 28743557 DOI: 10.1016/j.ygcen.2017.07.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 06/30/2017] [Accepted: 07/16/2017] [Indexed: 12/16/2022]
Abstract
The interaction between obesity and chronic inflammation has been studied. Diet-induced obesity or chronic inflammation could reduce the testicular functions of males. However, the mechanism underlying the reproductive effects of fattening foods in males with or without chronic inflammation still needs further discussion. This study was aimed to investigate the effects of high-fat, high-protein diet on testicular steroidogenesis and sperm parameters in adult mice under physiological and chronic inflammatory conditions. Because casein can trigger a non-infectious systemic inflammatory response, we used casein injection to induce chronic inflammation in male adult Kunming mice. Twenty-four mice were randomly and equally divided into four groups: (i) normal diet+saline (Control); (ii) normal diet+casein (ND+CS); (iii) high-fat, high-protein diet+saline (HFPD+SI); (iv) high-fat, high-protein diet+casein (HFPD+CS). After 8weeks, there was a significant increase in body weight for groups HFPD+SI and HFPD+CS and a decrease in group ND+CS compared with the control. The serum levels of tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10) and lipid profiles were increased markedly in groups ND+CS, HFPD+SI and HFPD+CS compared with the control. A remarkable reduction of serum adiponectin level occurred in group HFPD+CS compared with group ND+CS. Sperm parameters (sperm count, viability and abnormality) were also adversely affected in groups ND+CS and HFPD+SI. Groups ND+CS and HFPD+SI showed severe pathological changes in testicular tissues. Semiquantitative RT-PCR, Western blot and immunohistochemical staining also showed significant reductions in both testicular mRNA and protein levels of steroidogenic acute regulatory (StAR) and cytochrome P450scc (CYP11A1) in groups HFPD+SI and HFPD+CS compared with the control, whereas testicular mRNA and protein levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) in groups HFPD+SI and HFPD+CS significantly increased. The mRNA and protein levels of the StAR and 3β-HSD in group HFPD+CS were both higher than those of in group ND+CS. These results indicated that Kunming male mice with high-fat, high-protein diet and casein injection for 8weeks can be used to establish a diet-induced obesity and chronic systemic inflammation. The sperm parameters in groups ND+CS and HFPD+SI decreased accompanied by pathological changes of testicular tissue. This resultant effect of reduced serum testosterone levels was associated with the overproduction of TNF-α and IL-10 and down-regulation of StAR and CYP11A1. Under the same casein-induced chronic inflammation condition, the mice with high-fat, high-protein diet had better testicular steroidogenesis activity and sperm parameters compared with the mice in normal diet, indicating that the mice with casein-induced inflammatory injury consuming a high-fat, high-protein diet gained weight normally, reduced serum adiponectin level and increased testosterone production by an upregulation of 3β-HSD expression. High-fat, high-protein diet attenuated the negative impact of casein-induced chronic inflammation on testicular steroidogenesis and sperm parameters.
Collapse
Affiliation(s)
- Jing-Lu Zhao
- Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangdong, Guangzhou 510632, China
| | - Yu-Yun Zhao
- College of Chemical and Biological Engineering, Hunan University of Science and Engineering, Hunan, Yongzhou 425199, China
| | - Wei-Jie Zhu
- Department of Developmental and Regenerative Biology, College of Life Science and Technology, Jinan University, Guangdong, Guangzhou 510632, China.
| |
Collapse
|
8
|
Schieber AMP, Ayres JS. Thermoregulation as a disease tolerance defense strategy. Pathog Dis 2016; 74:ftw106. [PMID: 27815313 PMCID: PMC5975229 DOI: 10.1093/femspd/ftw106] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/03/2016] [Accepted: 11/02/2016] [Indexed: 12/28/2022] Open
Abstract
Physiological responses that occur during infection are most often thought of in terms of effectors of microbial destruction through the execution of resistance mechanisms, due to a direct action of the microbe, or are maladaptive consequences of host-pathogen interplay. However, an examination of the cellular and organ-level consequences of one such response, thermoregulation that leads to fever or hypothermia, reveals that these actions cannot be readily explained within the traditional paradigms of microbial killing or maladaptive consequences of host-pathogen interactions. In this review, the concept of disease tolerance is applied to thermoregulation during infection, inflammation and trauma, and we discuss the physiological consequences of thermoregulation during disease including tissue susceptibility to damage, inflammation, behavior and toxin neutralization.
Collapse
Affiliation(s)
- Alexandria M Palaferri Schieber
- The Salk Institute for Biological Studies, Immunobiology and Microbial Pathogenesis, 10010 North Torrey Pines Road, San DIego CA, USA
| | - Janelle S Ayres
- The Salk Institute for Biological Studies, Immunobiology and Microbial Pathogenesis, 10010 North Torrey Pines Road, San DIego CA, USA
| |
Collapse
|
9
|
Paradoxical effect of rapamycin on inflammatory stress-induced insulin resistance in vitro and in vivo. Sci Rep 2015; 5:14959. [PMID: 26449763 PMCID: PMC4598825 DOI: 10.1038/srep14959] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 09/11/2015] [Indexed: 12/16/2022] Open
Abstract
Insulin resistance is closely related to inflammatory stress and the mammalian target of rapamycin/S6 kinase (mTOR/S6K) pathway. The present study investigated whether rapamycin, a specific inhibitor of mTOR, ameliorates inflammatory stress-induced insulin resistance in vitro and in vivo. We used tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) stimulation in HepG2 hepatocytes, C2C12 myoblasts and 3T3-L1 adipocytes and casein injection in C57BL/6J mice to induce inflammatory stress. Our results showed that inflammatory stress impairs insulin signaling by reducing the expression of total IRS-1, p-IRS-1 (tyr632), and p-AKT (ser473); it also activates the mTOR/S6K signaling pathway both in vitro and in vivo. In vitro, rapamycin treatment reversed inflammatory cytokine-stimulated IRS-1 serine phosphorylation, increased insulin signaling to AKT and enhanced glucose utilization. In vivo, rapamycin treatment also ameliorated the impaired insulin signaling induced by inflammatory stress, but it induced pancreatic β-cell apoptosis, reduced pancreatic β-cell function and enhanced hepatic gluconeogenesis, thereby resulting in hyperglycemia and glucose intolerance in casein-injected mice. Our results indicate a paradoxical effect of rapamycin on insulin resistance between the in vitro and in vivo environments under inflammatory stress and provide additional insight into the clinical application of rapamycin.
Collapse
|
10
|
Sickness: From the focus on cytokines, prostaglandins, and complement factors to the perspectives of neurons. Neurosci Biobehav Rev 2015; 57:30-45. [PMID: 26363665 DOI: 10.1016/j.neubiorev.2015.07.015] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Revised: 07/06/2015] [Accepted: 07/31/2015] [Indexed: 12/29/2022]
Abstract
Systemic inflammation leads to a variety of physiological (e.g. fever) and behavioral (e.g. anorexia, immobility, social withdrawal, depressed mood, disturbed sleep) responses that are collectively known as sickness. While these phenomena have been studied for the past few decades, the neurobiological mechanisms by which sickness occurs remain unclear. In this review, we first revisit how the body senses and responds to infections and injuries by eliciting systemic inflammation. Next, we focus on how peripheral inflammatory molecules such as cytokines, prostaglandins, and activated complement factors communicate with the brain to trigger neuroinflammation and sickness. Since depression also involves inflammation, we further elaborate on the interrelationship between sickness and depression. Finally, we discuss how immune activation can modulate neurons in the brain, and suggest future perspectives to help unravel how changes in neuronal functions relate to sickness responses.
Collapse
|
11
|
Cellular and molecular mechanisms of chronic rhinosinusitis and potential therapeutic strategies: review on cytokines, nuclear factor kappa B and transforming growth factor beta. The Journal of Laryngology & Otology 2015; 129 Suppl 3:S2-7. [PMID: 26073199 DOI: 10.1017/s0022215115001322] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Chronic rhinosinusitis is characterised by persistent inflammation of the sinonasal mucosa. Multiple pathophysiological mechanisms are likely to exist. Previous research has focused predominantly on T-helper type cytokines to highlight the inflammatory mechanisms. However, proteins such as nuclear factor kappa B and transforming growth factor beta are increasingly recognised to have important roles in sinonasal inflammation and tissue remodelling. OBJECTIVE This review article explores the roles of T-helper type cytokines, nuclear factor kappa B and transforming growth factor beta in the pathophysiological mechanisms of chronic rhinosinusitis. An understanding of these mechanisms will allow for better identification and classification of chronic rhinosinusitis endotypes, and, ultimately, improved therapeutic strategies.
Collapse
|
12
|
Chronic inflammation aggravates metabolic disorders of hepatic fatty acids in high-fat diet-induced obese mice. Sci Rep 2015; 5:10222. [PMID: 25974206 PMCID: PMC4431481 DOI: 10.1038/srep10222] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 04/07/2015] [Indexed: 02/06/2023] Open
Abstract
The prevalence of nonalcoholic fatty liver disease (NAFLD) increases with increasing body mass index (BMI). However, approximately 40–50% of obese adults do not develop hepatic steatosis. The level of inflammatory biomarkers is higher in obese subjects with NAFLD compared to BMI-matched subjects without hepatic steatosis. We used a casein injection in high-fat diet (HFD)-fed C57BL/6J mice to induce inflammatory stress. Although mice on a HFD exhibited apparent phenotypes of obesity and hyperlipidemia regardless of exposure to casein injection, only the HFD+Casein mice showed increased hepatic vacuolar degeneration accompanied with elevated inflammatory cytokines in the liver and serum, compared to mice on a normal chow diet. The expression of genes related to hepatic fatty acid synthesis and oxidation were upregulated in the HFD-only mice. The casein injection further increased baseline levels of lipogenic genes and decreased the levels of oxidative genes in HFD-only mice. Inflammatory stress induced both oxidative stress and endoplasmic reticulum stress in HFD-fed mice livers. We conclude that chronic inflammation precedes hepatic steatosis by disrupting the balance between fatty acid synthesis and oxidation in the livers of HFD-fed obese mice. This mechanism may operate in obese individuals with chronic inflammation, thus making them more prone to NAFLD.
Collapse
|
13
|
Quan N. In-depth conversation: spectrum and kinetics of neuroimmune afferent pathways. Brain Behav Immun 2014; 40:1-8. [PMID: 24566385 PMCID: PMC6088807 DOI: 10.1016/j.bbi.2014.02.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/03/2014] [Accepted: 02/05/2014] [Indexed: 01/14/2023] Open
Abstract
Since my last review on neuroimmune communication afferents in 2008, this area has witnessed substantial growth. At a basic science level, numerous new and exciting phenomena have been described, adding both depth and complexity to the crosstalk between the immune system and the nervous system. At a translational level, accumulating evidence indicates neuroimmune interaction could be a contributing factor for many disease states, as well as an effective physiological mechanism that coordinates the activities of these two systems in healthy individuals or during tissue distress. Furthermore, new evidence suggests neuroimmune interactions are inherently dynamic: varying activities in either the nervous system or the immune system could impact interactions between them. In this review I will attempt to integrate multifarious, and sometimes disparate, findings into a modified conceptual framework that describes the concordance of neuroimmune communication through the cooperative connection between these two systems and the dysfunction that may arise when their inappropriate crosstalk occurs.
Collapse
Affiliation(s)
- Ning Quan
- Institute for Behavior Medicine Research, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
14
|
Chen Y, Varghese Z, Ruan XZ. The molecular pathogenic role of inflammatory stress in dysregulation of lipid homeostasis and hepatic steatosis. Genes Dis 2014; 1:106-112. [PMID: 30258859 PMCID: PMC6150078 DOI: 10.1016/j.gendis.2014.07.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 07/20/2014] [Indexed: 02/07/2023] Open
Abstract
Non-alcoholic Fatty Liver Disease (NAFLD) is becoming the leading cause of chronic liver injury in developed countries and China. Chronic systemic inflammation plays a decisive role and is fundamental in the progression of NAFLD from simple steatosis (SS) toward higher risk nonalcoholic steatohepatitis (NASH) states. However, the exact mechanisms by which inflammation leading to NASH are incompletely understood. In this review, we focus the role of the cross talk between inflammation and lipid homeostasis on the progression of NAFLD.
Collapse
Affiliation(s)
- Yaxi Chen
- Centre for Lipid Research, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Zac Varghese
- John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, London, UK
| | - Xiong Z Ruan
- Centre for Lipid Research, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China.,John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, London, UK
| |
Collapse
|
15
|
Wu Y, Wu T, Wu J, Zhao L, Li Q, Varghese Z, Moorhead JF, Powis SH, Chen Y, Ruan XZ. Chronic inflammation exacerbates glucose metabolism disorders in C57BL/6J mice fed with high-fat diet. J Endocrinol 2013; 219:195-204. [PMID: 24029730 DOI: 10.1530/joe-13-0160] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Inflammatory stress is closely related to metabolic disease and insulin resistance. The precise cellular mechanism linking obesity and diabetes is largely unknown, but about 14-20% of obese individuals develop diabetes. In this study, we investigated whether chronic inflammation exacerbated glucose metabolism disorder by impairing β cell function in high-fat diet (HFD)-fed C57BL/6J mice. We used s.c. casein injection to induce chronic inflammation in HFD-fed C57BL/6J mice; 14 weeks on a HFD resulted in weight gain, hyperlipidemia, and low insulin sensitivity in these mice which nevertheless had normal blood glucose and serum inflammatory cytokines levels. Casein injection in the background of HFD elevated serum tumor necrosis factor α (TNFα) and serum amyloid A levels and increased TNFα and MCP1 expression in the adipose tissue, liver, and muscle of HFD-fed mice. Chronic inflammation induced by casein injection further decreased insulin sensitivity and insulin signaling, resulting in insulin deficiency and hyperglycemia in these mice. Islet mass and insulin content were markedly increased in HFD mice. However, in contrast with HFD-fed alone, chronic inflammation in HFD-fed mice decreased both islet mass and insulin content, reduced the genetic expression of insulin synthesis and secretion, and increased β cell apoptosis. We conclude that chronic inflammation exacerbated glucose metabolism disorders by impairing β cell function in HFD-fed C57BL/6J mice, suggesting that this mechanism may operate in obese individuals with chronic inflammation, making them prone to hyperglycemia.
Collapse
Affiliation(s)
- Yu Wu
- Key Laboratory of Metabolism of Lipid and Glucose, Centre for Lipid Research, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China John Moorhead Research Laboratory, Centre for Nephrology, University College London (UCL) Medical School, Royal Free Campus, London, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Poon DCH, Ho YS, Chiu K, Chang RCC. Cytokines: how important are they in mediating sickness? Neurosci Biobehav Rev 2012; 37:1-10. [PMID: 23153795 DOI: 10.1016/j.neubiorev.2012.11.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 09/28/2012] [Accepted: 11/04/2012] [Indexed: 01/20/2023]
Abstract
Sickness refers to a set of coordinated physiological and behavioral changes in response to systemic inflammation. It is characterized by fever, malaise, social withdrawal, fatigue, and anorexia. While these responses collectively represent a protective mechanism against infection and injury, increasing lines of evidence indicate that over-exaggerated or persistent sickness can damage the brain, and could possibly raise the risk to developing delirium. Therefore, a clear understanding in sickness will be beneficial. It has long been believed that sickness results from increased systemic cytokines occurring during systemic inflammation. However, in recent years more and more conflicting data have suggested that development of sickness following peripheral immune challenge could be independent of cytokines. Hence, it is confusing as to whether cytokines really do act as primary mediators of sickness, or if they are secondary to alternative inducing factor(s). In this review, we will (1) introduce the relationships between systemic inflammation, cytokines, sickness, and delirium, and (2) attempt to interpret the recent controversies.
Collapse
Affiliation(s)
- David Chun-Hei Poon
- Laboratory of Neurodegenerative Diseases, Department of Anatomy, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | | | | | | |
Collapse
|
17
|
Tarr AJ, Chen Q, Wang Y, Sheridan JF, Quan N. Neural and behavioral responses to low-grade inflammation. Behav Brain Res 2012; 235:334-41. [PMID: 22898545 DOI: 10.1016/j.bbr.2012.07.038] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Revised: 06/26/2012] [Accepted: 07/26/2012] [Indexed: 12/23/2022]
Abstract
Neural and behavioral responses after peripheral immune challenge have been observed in numerous studies. The majority of these studies have utilized relatively high doses of lipopolysaccharide (LPS) as the immune stimulant. Little attention has been given to the effects of LPS dose ranges that simulate low grade-inflammation. The current studies were designed to characterize neural and behavioral responses following low-dose LPS stimulation. Results show burrowing and open field activity was significantly impaired following a single i.p. injection of 10, but not 1, μg/kg of LPS. In addition, following repeated 1 μg/kg LPS administration for 10 days, animals showed the progressive development of motor deficits over time. To correlate behavior with CNS activity, cFos activation was determined in the paraventricular nucleus, nucleus of the solitary tract, central amygdaloid nucleus, and ventrolateral medulla. Data revealed there was a dose-dependent activation in all brain areas examined, but only the PVN showed significant activation by low-dose LPS. Additionally, animals that received 1 μg/kg of LPS for 8 days had PVN cFos activation similar to animals that received a single 10 μg/kg LPS injection. These data demonstrate neural and behavior responses can be induced by low-grade inflammation and chronic exposure to sub-threshold levels of LPS can precipitate significantly heightened neural and behavioral responses.
Collapse
Affiliation(s)
- Andrew J Tarr
- Division of Oral Biology, The Ohio State University, 305 W. 12th Ave, Columbus, OH 43210, USA.
| | | | | | | | | |
Collapse
|
18
|
Damm J, Wiegand F, Harden LM, Gerstberger R, Rummel C, Roth J. Fever, sickness behavior, and expression of inflammatory genes in the hypothalamus after systemic and localized subcutaneous stimulation of rats with the Toll-like receptor 7 agonist imiquimod. Neuroscience 2011; 201:166-83. [PMID: 22116053 DOI: 10.1016/j.neuroscience.2011.11.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 11/03/2011] [Accepted: 11/04/2011] [Indexed: 11/19/2022]
Abstract
The Toll-like receptor 7 (TLR7) agonist imiquimod is used for topical treatment of skin cancers. We studied the consequences of injections of imiquimod into a subcutaneous (s.c.) air pouch or of intraperitoneal (i.p.) injections on the manifestation of fever, sickness behavior, and the peripheral and brain-intrinsic induction of a variety of inflammatory molecules. Rats were given imiqimod s.c. or i.p. (1 or 5 mg/kg). Body temperature, motor activity, and food and water intake were recorded by telemetric devices. Peripheral and brain-intrinsic induction of inflammatory mediators was analyzed by real-time polymerase chain reaction (RT-PCR), bioassays, enzyme-linked immunosorbent assays (ELISAs), and immunohistochemistry. Imiquimod is the first TLR-agonist to produce more potent effects with s.c. than i.p. administration. Peripheral induction of interferons (IFNs) and putative circulating pyrogens corresponded to the magnitude of the illness responses. In the brain, an expression of cytokines (TNFα, IL-1β, and IL-6) and inducible forms of enzymes for prostaglandin E2 synthesis (COX-2 and mPGES) occurred, which was accompanied by a moderate activation of the transcription factors NFκB and STAT3, and a strong activation of the transcription factor NF-IL6, in cells of specific areas with an open blood-brain barrier. These inflammatory responses noted within the brain were more marked after s.c. administration, than i.p. administration of imiquimod. At a dose of 5 mg/kg, imiquimod causes rather moderate brain-inflammatory responses, which are related to peripheral IFN-expression and possibly mediated by brain-intrinsic activation of NF-IL6 and induction of a proinflammatory cocktail. The lack of a septic-like state in imiquimod-treated rats reinforces the therapeutic use of this drug.
Collapse
Affiliation(s)
- J Damm
- Institut für Veterinär-Physiologie und -Biochemie, Justus-Liebig-Universität Giessen, Frankfurter Strasse 100, D-35392 Giessen, Germany
| | | | | | | | | | | |
Collapse
|
19
|
Mei M, Zhao L, Li Q, Chen Y, Huang A, Varghese Z, Moorhead JF, Zhang S, Powis SH, Li Q, Ruan XZ. Inflammatory stress exacerbates ectopic lipid deposition in C57BL/6J mice. Lipids Health Dis 2011; 10:110. [PMID: 21718499 PMCID: PMC3146847 DOI: 10.1186/1476-511x-10-110] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Accepted: 06/30/2011] [Indexed: 11/10/2022] Open
Abstract
Background Chronic systemic inflammation and abnormal free fatty acid metabolism are closely related to ectopic lipid deposition. In this study, we investigate if inflammation tissue-specifically disrupts lipogenesis and lipolysis in nonadipose tissues and adipose tissue, resulting in ectopic lipid deposition in C57BL/6J mice. Methods We used casein injection in C57BL/6J mice to induce a chronic systemic inflammatory stress in vivo. Serum was analyzed for free fatty acid and cytokines. Insulin sensitivities were evaluated by glucose and insulin tolerance tests. Liver, muscle, adipose tissues were taken for lipid analysis. Real-time polymerase chain reaction and western blotting were used to examine the gene and protein expression of molecules involved in adipogenesis and lipolysis in tissues. Results Casein injection elevated serum levels of IL-6 and SAA in mice, which are associated with increased lipid accumulation in liver and muscle, suggesting that chronic systemic inflammation induces ectopic lipid deposition in nonadipose tissues. The inflammatory stress upregulated mRNA and protein expression of sterol regulatory element binding protein 1, fatty acid synthase, and acetyl CoA carboxylase alpha, while inhibited these molecules expression in adipose. Interestingly, in the same experimental setting, inflammation increased triglyceride lipase and hormone-sensitive lipase expression in white adipose tissue. Inflammation also induced insulin resistance and increased serum free fatty acid levels in C57BL/6J mice. Conclusions Chronic systemic inflammation increased lipogenesis in nonadipose tissues and lipolysis in white adipose tissue, resulting in ectopic lipid deposition in nonadipose tissues. This disturbed free fatty acid homeostasis and caused insulin resistance in C57BL/6J mice.
Collapse
Affiliation(s)
- Mei Mei
- Centre for Lipid Research, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, The Second Affiliated Hospital, Chongqing Medical University, P.R. China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Zhao L, Chen Y, Tang R, Chen Y, Li Q, Gong J, Huang A, Varghese Z, Moorhead JF, Ruan XZ. Inflammatory stress exacerbates hepatic cholesterol accumulation via increasing cholesterol uptake and de novo synthesis. J Gastroenterol Hepatol 2011; 26:875-83. [PMID: 21488946 DOI: 10.1111/j.1440-1746.2010.06560.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND AIM Cholesterol accumulation plays an important role in the progression of non-alcoholic fatty liver disease. We have demonstrated that inflammation aggravated cholesterol accumulation, causing tissue injury in the vessel and kidney. This study was undertaken to investigate whether inflammatory stress exacerbates hepatic cholesterol accumulation and we explored the underlying mechanisms. METHODS We used casein injection in C57BL/6J mice, interleukin-1β and interleukin-6 stimulation in human hepatoblastoma cell line (HepG2) cells to induce inflammatory stress. Oil Red O staining and intracellular cholesterol assay were used to quantify cellular cholesterol levels. Real-time reverse transcription polymerase chain reaction and Western blot were used to measure messenger RNA (mRNA) and protein expression of target genes. HMGCoA reductase (HMGCoA-r) enzymatic activity and cellular cholesterol synthesis were measured by radioactive methods. RESULTS We demonstrated that inflammatory stress increased hepatic cholesterol accumulation and enhanced sterol regulatory element binding protein 2 (SREBP2), low-density lipoprotein receptor (LDLr) and HMGCoA-r mRNA and protein expression in livers of C57BL/6J mice and in HepG2 cells. A high-fat diet in mice or LDL loading in HepG2 cells inhibited mRNA and protein expression of these genes. However, the suppressive effect was overridden by inflammatory stress both in vivo and in vitro. Inflammatory stress increased HMGCoA-r enzymatic activity and cellular cholesterol synthesis in HepG2 cells in the absence or presence of LDL loading. CONCLUSION Inflammatory stress disrupted hepatic SREBP2-mediated low-density lipoprotein receptor and HMGCoA-r feedback regulation resulting in exacerbated cholesterol accumulation in livers of C57BL/6J mice and HepG2 cells.
Collapse
Affiliation(s)
- Lei Zhao
- Centre for Lipid Research, Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Ballou MA, Cobb CJ, Hulbert LE, Carroll JA. Effects of intravenous Escherichia coli dose on the pathophysiological response of colostrum-fed Jersey calves. Vet Immunol Immunopathol 2011; 141:76-83. [PMID: 21420179 PMCID: PMC7112639 DOI: 10.1016/j.vetimm.2011.02.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 02/03/2011] [Accepted: 02/14/2011] [Indexed: 12/02/2022]
Abstract
Objectives of the present study were to characterize the dose dependency of an intravenous Escherichia coli O111:H8 challenge in colostrum-fed Jersey calves and to identify any biochemical markers indicative of septicemia. Eighteen 3-week old colostrum-fed Jersey calves were completely randomized to 1 of 6 doses of E. coli O111:H8. The challenge doses included 0, 1.5 × 105, 1.5 × 106, 1.5 × 107, 1.5 × 108, and 1.5 × 109 colony-forming units (CFU) given intravenously as a bolus in 5 mL of sterile isotonic saline. Peripheral blood samples were collected at 0, 2, 4, 8, 12, 24, and 48 h relative to the challenge for biochemical, total leukocyte count, and differential analyses. Rectal temperatures were collected via indwelling rectal temperature probes at 5-min intervals, and hourly averages calculated from 2 d prior to the challenge till 2 d after the challenge. All calves survived the 48 h observation period following the challenge. Calves given 1.5 × 108 and 1.5 × 109 CFU displayed sickness behaviors (P < 0.01) beginning 0.5 h after the challenge and returned to that of the control calves by 6 and 32 h for calves challenged with 1.5 × 108 and 1.5 × 109 CFU, respectively. There were treatment × time interactions (P < 0.01) on total leukocyte counts and plasma glucose and zinc concentrations. Calves administered 1.5 × 108 and 1.5 × 109 CFU had leucopenia beginning 2 h after the challenge and returning to counts similar to the control calves within 24 h. Additionally, those calves were hypoglycemic from 4 to 12 h after the challenge with the degree of hypoglycemia inversely related to the dose of the E. coli. All calves challenged with E. coli had decreased plasma zinc concentrations, and the magnitude was inversely proportional to the challenge dose. There were treatment × time interactions (P < 0.001) on rectal temperatures following the challenge. All calves challenged with E. coli developed a febrile response, but the intensity and duration of the response were dependent on the challenge dose. These data indicate that calves intravenously challenged with 1.5 × 108 and 1.5 × 109 CFU of the E. coli O111:H8 showed immediate clinical and biochemical signs indicative of septicemia. However, calves administered 1.5 × 107 or less of the E. coli had febrile responses, but did not develop septicemia. Blood glucose and zinc concentrations may be dose responsive indicators that could potentially differentiate between a septicemic versus non-septicemic calf.
Collapse
Affiliation(s)
- M A Ballou
- Department of Animal and Food Sciences, Texas Tech University, Lubbock, TX, USA.
| | | | | | | |
Collapse
|
22
|
Vollmar P, Kullmann JS, Thilo B, Claussen MC, Rothhammer V, Jacobi H, Sellner J, Nessler S, Korn T, Hemmer B. Active Immunization with Amyloid-β 1–42 Impairs Memory Performance through TLR2/4-Dependent Activation of the Innate Immune System. THE JOURNAL OF IMMUNOLOGY 2010; 185:6338-47. [DOI: 10.4049/jimmunol.1001765] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
23
|
Belevych N, Buchanan K, Chen Q, Bailey M, Quan N. Location-specific activation of the paraventricular nucleus of the hypothalamus by localized inflammation. Brain Behav Immun 2010; 24:1137-47. [PMID: 20570615 PMCID: PMC2939270 DOI: 10.1016/j.bbi.2010.05.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 05/25/2010] [Accepted: 05/26/2010] [Indexed: 02/06/2023] Open
Abstract
The existence of an immunological homunculus has been proposed, but evidence for location-specific response of the central nervous system to immunological stimulation is lacking. In this study, we show that inflammation induced by injection of casein into one of the causes c-fos expression in the paraventricular nucleus of the hypothalamus (PVN) in an asymmetrical manner: much stronger activation is always induced in the contralateral PVN. Unilateral sciatic nerve transection abolished the casein-induced PVN activation if casein was injected into the hindlimb with the nerve transection, but had no effect if casein was injected into the hindlimb with intact nerve innervation. Injection of casein into one the forelimbs also caused contralateral PNV activation. Further, stronger PVN activation was found in the anterior PVN after the forelimb injection, but in the posterior PVN after the hindlimb injection. Casein-induced PVN activation is absent in IL-1R1 KO, IL-6 KO, TNFα KO, and in C3H/HeJ (TLR4 mutant) animals. In comparison, injection of LPS, a systemic inflammagen, into one hindlimb induced bilateral PVN activation but injection of live Escherichia coli into one hindlimb induced contralateral PVN activation. These results support the notion that local inflammation may activate the PVN by neural routes in a location-specific manner.
Collapse
|
24
|
Involvement of mitogen-activated protein kinases and nuclear factor kappa B pathways in signaling COX-2 expression in chronic rhinosinusitis. Inflamm Res 2009; 58:649-58. [PMID: 19319478 DOI: 10.1007/s00011-009-0030-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2009] [Revised: 02/22/2009] [Accepted: 03/06/2009] [Indexed: 10/21/2022] Open
Abstract
OBJECTIVE To investigate the signal pathways involved in cyclooxygenase-2 (COX-2) expression in chronic rhinosinusitis (CRS). METHODS The expressions of COX-2, p38 mitogen-activated protein kinase (p38MAPK), extracellular signal-regulated kinase (ERK), and nuclear factor kappa B (NF-kappaB) in nasal mucosa were detected by immunohistological stain and polymerase chain reaction (PCR). Their expressions and prostaglandin E2 (PGE(2)) release were determined by PCR, Western blot and enzyme immunoassay (EIA) in human nasal epithelia (HNE) cells after lipopolysaccharide (LPS) induction, and/or small interfering RNA (siRNA) transfection. RESULTS Positive protein expressions of COX-2, p38MAPK, ERK, NF-kappaB subunits were detected in epithelial and inflammatory cells. Their mRNA levels were significantly higher in CRS than controls (P < 0.05). The expressions varied in time and concentration-dependent manner in LPS-induced HNE cells. COX-2 expression was suppressed by siRNAs of P38MAPK, ERK, and NF-kappaB; however, COX-2-specific siRNA had no blocking effect on them. SiRNAs of P38MAPK or ERK could block NF-kappaB, but NF-kappaB-specific siRNA had no blocking effect on the former. SiRNA of p38MAPK, or ERK did not inhibit each other. CONCLUSION Upregulation of COX-2 expression suggested its role as a mediator in CRS. ERK and p38MAPK pathways were involved in signaling COX-2 through NF-kappaB pathway.
Collapse
|
25
|
Chen Q, Zhang H, Li Q, An Y, Herkenham M, Lai W, Popovich P, Agarwal S, Quan N. Three Promoters Regulate Tissue- and Cell Type-specific Expression of Murine Interleukin-1 Receptor Type I. J Biol Chem 2009; 284:8703-13. [PMID: 19196714 DOI: 10.1074/jbc.m808261200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The type 1 interleukin-1 receptor (IL-1R1) mediates diverse functions of interleukin-1 (IL-1) in the nervous, immune, and neuroendocrine systems. It has been suggested previously that the versatile functions of IL-1 may in part be conferred by the multiple promoters of IL-1R1 that have been identified for the human IL-1R1 gene. Promoters for murine IL-1R1 (mIL-1R1) gene have not been studied in detail. We performed 5'-rapid amplification of cDNA ends to determine the transcription start sites (TSS) in mIL-1R1, using mRNAs derived from 24 different tissues. The results revealed three putative TSSs of mIL-1R1. Three full-length cDNAs containing these distinct TSSs were recovered in screens of cloned cDNA libraries. Translation of these cDNAs produced IL-1R1 proteins that were verified by Western blot analysis. IL-1 stimulation of the individual IL-1R1 proteins resulted in the activation of NF-kappaB. Promoter-reporter assay for genomic DNA sequences immediately upstream of the three TSSs validated that the sequences possess promoter activity in a cell type-specific manner. These promoters are termed P1, P2, and P3 of the mIL-1R1, in 5' to 3' order. Quantitative PCR analysis of P1-, P2-, and P3-specific mIL-1R1 mRNAs showed that there is tissue-specific distribution of these mRNAs in vivo, and there are distinct patterns of P1, P2, and P3 mRNA expression in different cell lines. In the brain, P3 mRNA is expressed preferentially in the dentate gyrus. Further, glucocorticoids differentially regulate these promoters in a cell type-specific manner. Together, these results suggest that the different IL-1R1 promoters contribute to the discrete and diverse actions of IL-1.
Collapse
Affiliation(s)
- Qun Chen
- Department of Oral Biology, Ohio State University, Columbus, Ohio 43210, USA
| | | | | | | | | | | | | | | | | |
Collapse
|