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Stins MF, Mtaja A, Mulendele E, Mwimbe D, Pinilla-Monsalve GD, Mutengo M, Pardo CA, Chipeta J. Inflammation and Elevated Osteopontin in Plasma and CSF in Cerebral Malaria Compared to Plasmodium-Negative Neurological Infections. Int J Mol Sci 2024; 25:9620. [PMID: 39273566 PMCID: PMC11394774 DOI: 10.3390/ijms25179620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2024] [Revised: 08/26/2024] [Accepted: 09/01/2024] [Indexed: 09/15/2024] Open
Abstract
Cerebral malaria in young African children is associated with high mortality, and persisting neurological deficits often remain in survivors. Sequestered Plasmodium-infected red blood cells lead to cerebrovascular inflammation and subsequent neuroinflammation. Brain inflammation can play a role in the pathogenesis of neurologic sequelae. Therefore, we assessed a select set of proinflammatory analytes (IP10, IL23, MIP3α, GRO, MCP-1, and osteopontin in both the plasma and cerebrospinal fluid(CSF) of Zambian children with cerebral malaria and compared this with children with neurological symptoms that were negative for Plasmodium falciparum (non-cerebral malaria). Several similarities in plasma and CSF levels were found, as were some striking differences. We confirmed that IP10 levels were higher in the plasma of cerebral malaria patients, but this was not found in CSF. Levels of osteopontin were elevated in both the plasma and CSF of CM patients compared to the non-CM patients. These results show again a highly inflammatory environment in both groups but a different profile for CM when compared to non-cerebral malaria. Osteopontin may play an important role in neurological inflammation in CM and the resulting sequelae. Therefore, osteopontin could be a valid target for further biomarker research and potentially for therapeutic interventions in neuroinflammatory infections.
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Affiliation(s)
- Monique F Stins
- Malaria Research Institute, Johns Hopkins School of Public Health, 615N Wolfe Street, Baltimore, MD 21205, USA
- Biomedical Research Institute of Southern California, Oceanside, CA 92046, USA
| | - Agnes Mtaja
- University Teaching Hospital Malaria Research Unit (SMUTH-MRU), Department of Pediatrics and Child Health, University of Zambia School of Medicine, Lusaka P.O. Box 50110, Zambia
| | - Evans Mulendele
- University Teaching Hospital Malaria Research Unit (SMUTH-MRU), Department of Pediatrics and Child Health, University of Zambia School of Medicine, Lusaka P.O. Box 50110, Zambia
| | - Daniel Mwimbe
- University Teaching Hospital Malaria Research Unit (SMUTH-MRU), Department of Pediatrics and Child Health, University of Zambia School of Medicine, Lusaka P.O. Box 50110, Zambia
| | - Gabriel D Pinilla-Monsalve
- Division of Neuroimmunology and Neuroinfectious Diseases, Department of Neurology, Johns Hopkins School of Medicine, 600 N Wolfe Street, Baltimore, MD 21285, USA
- Department of Radiology, Faculty of Medicine, University of Montreal, 2900 Edouard Montpetit Blvd, Montreal, QC H3T 1J4, Canada
| | - Mable Mutengo
- University Teaching Hospital Malaria Research Unit (SMUTH-MRU), Department of Pediatrics and Child Health, University of Zambia School of Medicine, Lusaka P.O. Box 50110, Zambia
- Institute of Basic and Biomedical Sciences, Levy Mwanawasa Medical University, Lusaka P.O. Box 33991, Zambia
| | - Carlos A Pardo
- Division of Neuroimmunology and Neuroinfectious Diseases, Department of Neurology, Johns Hopkins School of Medicine, 600 N Wolfe Street, Baltimore, MD 21285, USA
| | - James Chipeta
- University Teaching Hospital Malaria Research Unit (SMUTH-MRU), Department of Pediatrics and Child Health, University of Zambia School of Medicine, Lusaka P.O. Box 50110, Zambia
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Bala Subramaniyan S, Karnan Singaravelu D, Raman T, Ameen F, Veerappan A. Antimicrobial lipids loaded on lectin display reduced MIC, curtail pathogenesis and protect zebrafish from reinfection by immunomodulation. Microb Pathog 2024; 193:106744. [PMID: 38876321 DOI: 10.1016/j.micpath.2024.106744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/27/2024] [Accepted: 06/11/2024] [Indexed: 06/16/2024]
Abstract
Antibiotic resistance and re-emergence of highly resistant pathogens is a grave concern everywhere and this has consequences for all kinds of human activities. Herein, we showed that N-palmitoylethanolamine-derived cationic lipid (cN16E) had a lower minimum inhibitory concentration (MIC) against both Gram-positive and Gram-negative bacteria when it was loaded with Butea monosperma seed lectin (BMSL). The analysis using lectin-FITC conjugate labelling indicated that the improved antibacterial activity of BMSL conjugation was due to bacterial cell surface glycan recognition. Live and dead staining experiments revealed that the BMSL-cN16E conjugate (BcN16E) exerts antibacterial activity by damaging the bacterial membrane. BcN16E antimicrobial activity was demonstrated using an infected zebrafish animal model because humans have 70 % genetic similarity to zebrafish. BcN16E therapeutic potential was established successfully by rescuing fish infected with uropathogenic Escherichia coli (UPEC). Remarkably, the rescued infected fish treated with BcN16E prevented reinfection without further therapy, indicating BcN16E immunomodulatory potential. Thus, the study examined the expression of immune-related genes, including tnfα, ifnγ, il-1β, il-4, il-10, tlr-2, etc. There was a significant elevation in the expression of all these genes compared to control and fish treated with BMSL or cN16E alone. Interestingly, when the rescued zebrafish were reinfected with the same pathogen, the levels of expression of these genes were many folds higher than seen earlier. Radial immune diffusion analyses (RIA) using zebrafish serum revealed antibody production during the initial infection and treatment. Interestingly, reinfected fish had significant immunoprecipitation in RIA, a feature absent in the groups treated with cN16E, BMSL, and control. These results clearly show that the BcN16E complex not only rescued infected zebrafish but also conferred long-lasting protection in terms of immunomodulation that protects against multiple reinfections. The findings support that BcN16E has immense potential as a novel immunostimulant for various biomedical applications.
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Affiliation(s)
- Siva Bala Subramaniyan
- Department of Chemistry, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, 613401, Tamil Nadu, India
| | - Dharshini Karnan Singaravelu
- Department of Chemistry, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, 613401, Tamil Nadu, India
| | - Thiagarajan Raman
- Department of Advanced Zoology and Biotechnology, Ramakrishna Mission Vivekananda College, Mylapore, Chennai, 600004, India.
| | - Fuad Ameen
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Anbazhagan Veerappan
- Department of Chemistry, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, 613401, Tamil Nadu, India.
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Park JH, Jeong E, Lin J, Ko R, Kim JH, Yi S, Choi Y, Kang IC, Lee D, Lee SY. RACK1 interaction with c-Src is essential for osteoclast function. Exp Mol Med 2019; 51:1-9. [PMID: 31358728 PMCID: PMC6802652 DOI: 10.1038/s12276-019-0285-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/28/2019] [Accepted: 04/29/2019] [Indexed: 12/30/2022] Open
Abstract
The scaffolding protein receptor for activated C-kinase 1 (RACK1) mediates receptor activator of nuclear factor κΒ ligand (RANKL)-dependent activation of p38 MAPK in osteoclast precursors; however, the role of RACK1 in mature osteoclasts is unclear. The aim of our study was to identify the interaction between RACK1 and c-Src that is critical for osteoclast function. A RACK1 mutant protein (mutations of tyrosine 228 and 246 residues to phenylalanine; RACK1 Y228F/Y246F) did not interact with c-Src. The mutant retained its ability to differentiate into osteoclasts; however, the integrity of the RANKL-mediated cytoskeleton, bone resorption activity, and phosphorylation of c-Src was significantly decreased. Importantly, lysine 152 (K152) within the Src homology 2 (SH2) domain of c-Src is involved in RACK1 binding. The c-Src K152R mutant (mutation of lysine 152 into arginine) impaired the resorption of bone by osteoclasts. These findings not only clarify the role of the RACK1-c-Src axis as a key regulator of osteoclast function but will also help to develop new antiresorption therapies to prevent bone loss-related diseases.
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Affiliation(s)
- Jin Hee Park
- Department of Life Science, Ewha Womans University, Seoul, 03760, Korea.,The Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Eutteum Jeong
- Department of Life Science, Ewha Womans University, Seoul, 03760, Korea.,The Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Jingjing Lin
- Department of Life Science, Ewha Womans University, Seoul, 03760, Korea.,The Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Ryeojin Ko
- Department of Life Science, Ewha Womans University, Seoul, 03760, Korea.,The Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea
| | - Ji Hee Kim
- Department of Life Science, Ewha Womans University, Seoul, 03760, Korea
| | - Sol Yi
- Department of Life Science, Ewha Womans University, Seoul, 03760, Korea
| | - Youngjin Choi
- Department of Food Science & Technology, Hoseo University, Asan, 31499, Korea
| | - In-Cheol Kang
- Department of Biological Science, College of Natural Science, BioChip Research Center, and Hoseo University, Asan, 31499, Korea
| | - Daekee Lee
- Department of Life Science, Ewha Womans University, Seoul, 03760, Korea
| | - Soo Young Lee
- Department of Life Science, Ewha Womans University, Seoul, 03760, Korea. .,The Research Center for Cellular Homeostasis, Ewha Womans University, Seoul, 03760, Korea.
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Zonis S, Breunig JJ, Mamelak A, Wawrowsky K, Bresee C, Ginzburg N, Chesnokova V. Inflammation-induced Gro1 triggers senescence in neuronal progenitors: effects of estradiol. J Neuroinflammation 2018; 15:260. [PMID: 30201019 PMCID: PMC6131894 DOI: 10.1186/s12974-018-1298-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 08/29/2018] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Inflammation has been proposed to contribute to the decline in adult hippocampal neurogenesis. Proinflammatory cytokines activate transcription of chemokine growth-regulated oncogene α (Gro1) in human and murine hippocampal neuronal progenitor cells (NPC). The goal of this study was to investigate the effects of Gro1 on hippocampal neurogenesis in the presence of inflammation. METHODS Human hippocampal NPC were transfected with lentivirus expressing Gro1, and murine NPC and hippocampal neuronal HT-22 cells were treated with Gro1 protein. A plasmid expressing mGro1 was electroporated in the hippocampus of newborn mice that were sacrificed 10 days later. Adult male and female mice were injected with lipopolysaccharide (LPS; 1 mg/kg, i.p in five daily injections) or normal saline. Adult male mice were implanted with pellets releasing 17-β estradiol (E2; 2.5 mg/pellet, 41.666 μg/day release) or placebo for 6 weeks and challenged with LPS or normal saline as above. In both experiments, mice were sacrificed 3 h after the last injection. Hippocampal markers of neurogenesis were assessed in vitro and in vivo by Western blot, real-time PCR, and immunohisto/cytochemistry. RESULTS Gro1 induced premature senescence in NPC and HT-22 cells, activating senescence-associated β-galactosidase and the cell cycle inhibitor p16 and suppressing neuroblast proliferation and expression of doublecortin (DCX) and neuron-specific class III beta-tubulin (Tuj-1), both neuroblast markers, while promoting proliferation of neural glial antigen 2 (Ng2)-positive oligodendrocytes. Gro1 overexpression in the hippocampus of newborn mice resulted in decreased neuroblast development, as evidenced by decreased DCX expression and increased expression of platelet-derived growth factor α receptor (PDGFαR), a marker of oligodendrocyte precursors. In adult mice, Gro1 was induced in response to LPS treatment in male but not in female hippocampus, with a subsequent decrease in neurogenesis and activation of oligodendrocyte progenitors. No changes in neurogenesis were observed in females. Treatment with E2 blunted LPS-induced Gro1 in the male hippocampus. CONCLUSIONS Inflammation-induced Gro1 triggers neuroblast senescence, thus suppressing new neuron development in the hippocampus. Sex-dependent differences in Gro1 response are attributed to estradiol, which blunts these changes, protecting the female hippocampus from the deleterious effects of inflammation-induced Gro1 on neurogenesis.
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Affiliation(s)
- Svetlana Zonis
- Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048 USA
| | - Joshua J. Breunig
- Department of Neurosurgery, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048 USA
| | - Adam Mamelak
- Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048 USA
- Department of Neurosurgery, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048 USA
| | - Kolja Wawrowsky
- Department of Biomedical Science, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048 USA
| | - Catherine Bresee
- Biostatistics and Bioinformatics Core, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048 USA
| | - Nadiya Ginzburg
- Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048 USA
| | - Vera Chesnokova
- Pituitary Center, Department of Medicine, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048 USA
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Lu D, Liu Y, Mai H, Zang J, Shen L, Zhang Y, Xu A. Rosuvastatin Reduces Neuroinflammation in the Hemorrhagic Transformation After rt-PA Treatment in a Mouse Model of Experimental Stroke. Front Cell Neurosci 2018; 12:225. [PMID: 30116175 PMCID: PMC6082938 DOI: 10.3389/fncel.2018.00225] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 07/11/2018] [Indexed: 12/31/2022] Open
Abstract
Hemorrhagic transformation (HT) is a serious complication that stimulates inflammation during reperfusion therapy after acute ischemic stroke. Rosuvastatin, a 3-hydroxymethyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, might improve the outcome of HT by inhibiting neuroinflammation. This study aimed to explore the protective effects of rosuvastatin against HT after recombinant tissue plasminogen activator (rt-PA) treatment in mice with experimental stroke via the attenuation of inflammation. A total of one hundred sixty-nine male BALB/c mice were used in the experiment. HT was successfully established in 70 mice that were subjected to 3 h of middle cerebral artery occlusion (MCAO) followed by a 10 mg/kg rt-PA injection over 10 min and reperfusion for 24 h. The mice were then administered rosuvastatin (1 mg/kg, 5 mg/kg) or saline (vehicle). The brain water content and neurological deficits (wire hang and adhesive removal somatosensory tests) were assessed at 24 h after rt-PA reperfusion following MCAO surgery. The morphology, blood-brain barrier (BBB) permeability and number of astrocytes and microglia were assessed by immunohistochemistry, electron microscopy and western blotting at 24 h after rt-PA reperfusion following MCAO surgery. Rosuvastatin protected against impaired neurological function and reversed the BBB leakage observed in the HT group. The increased activation of astrocytes and microglia and secretion of inflammatory factors caused by HT damage were significantly attenuated by high-dose rosuvastatin treatment vs. normal-dose rosuvastatin treatment. Related inflammatory pathways, such as the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways, were downregulated in the rosuvastatin-treated groups compared with the HT group. In conclusion, our results indicate that rosuvastatin is a promising therapeutic agent for HT after rt-PA reperfusion following MCAO surgery in mice, as it attenuates neuroinflammation. Additionally, high-dose rosuvastatin treatment could have a greater anti-inflammatory effect on HT than normal-dose rosuvastatin treatment.
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Affiliation(s)
- Dan Lu
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Jinan University, Guangzhou, China.,Clinical Neuroscience Institute of Jinan University, Guangzhou, China
| | - Yanfang Liu
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Jinan University, Guangzhou, China.,Clinical Neuroscience Institute of Jinan University, Guangzhou, China
| | - Hongcheng Mai
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Jinan University, Guangzhou, China.,Clinical Neuroscience Institute of Jinan University, Guangzhou, China
| | - Jiankun Zang
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Jinan University, Guangzhou, China.,Clinical Neuroscience Institute of Jinan University, Guangzhou, China
| | - Lingling Shen
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Jinan University, Guangzhou, China.,Clinical Neuroscience Institute of Jinan University, Guangzhou, China
| | - Yusheng Zhang
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Anding Xu
- Department of Neurology and Stroke Center, The First Affiliated Hospital, Jinan University, Guangzhou, China.,Clinical Neuroscience Institute of Jinan University, Guangzhou, China
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Lu C, Xia J, Bin W, Wu Y, Liu X, Zhang Y. Advances in diagnosis, treatments, and molecular mechanistic studies of traumatic brain injury. Biosci Trends 2016; 9:138-48. [PMID: 26166367 DOI: 10.5582/bst.2015.01066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Traumatic brain injury (TBI) is a main cause of death and disability around the world especially in soldiers, children, and young men. Since its clinical diagnosis and treatment cannot predict its prognosis, novel diagnostic techniques need to be developed, insight into its molecular mechanisms needs to be gleaned, and alternative and complementary medicine (ACM) approaches to its treatment need to be developed. This review summarizes the new diagnostic methods used in clinical practice, such as imaging of structural abnormalities after TBI and measurement of prognosis-related biomarkers. This review also describes the cellular mechanisms of traditional Chinese medicine in terms of intracellular signaling pathways, the extracellular microenvironment, and stem cells. This review concludes by describing experimental and clinical studies of the use of traditional Chinese medicine as a form of ACM to treat TBI. This review helps to understand advances in the field of TBI diagnosis and treatment.
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Affiliation(s)
- Chunyu Lu
- Department of Neurosurgery, The People's Hospital of Huaibei
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Wang Y, Hwaiz R, Luo L, Braun OÖ, Norström E, Thorlacius H. Rac1 regulates bacterial toxin-induced thrombin generation. Inflamm Res 2016; 65:405-13. [PMID: 26873877 DOI: 10.1007/s00011-016-0924-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE Systemic inflammatory response syndrome is associated with severe coagulopathy. The purpose of this study was to examine thrombin generation in systemic inflammation triggered by the endotoxin lipopolysaccharide (LPS) and the exotoxin streptococcal M1 protein. METHODS Thrombin generation, lung histology and myeloperoxidase (MPO) activity were determined 6 and 24 h after induction of systemic inflammation. Male C57BL/6 mice received the Rac1 inhibitor NSC23766 prior to challenge with bacterial toxins. RESULTS LPS and M1 protein challenge increased neutrophil infiltration and caused damage in the lung. Time to peak thrombin formation was increased and peak and total generation of thrombin were decreased in plasma from LPS- and M1 protein-treated mice. Coincubation of samples from mice exposed to bacterial toxins with platelet poor plasma from healthy mice completely reversed the inhibitory effect of LPS and M1 protein on thrombin generation, suggesting that bacterial toxins decreased levels of plasma factors explaining the reduction of thrombin generating capacity of plasma from septic animals. NSC23766 treatment not only decreased LPS- and M1 protein-induced neutrophil accumulation as well as levels of interleukin-6 and CXCL2 in the lung, but also abolished bacterial toxin-induced changes in thrombin generation. For example, NSC23766 increased peak formation by 57% and total thrombin generation by 48% in LPS-treated animals at 6 h. CONCLUSIONS Taken together, our novel findings show that bacterial toxins increase thrombin generation via consumption of plasma factors and that Rac1 signaling plays an important role in thrombin generation in response to bacterial toxins. Thus, targeting Rac1 activity might be a useful way not only to ameliorate pulmonary inflammation, but also inhibit pathological changes in coagulation in bacterial infections.
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Affiliation(s)
- Yongzhi Wang
- Department of Clinical Sciences, Malmö, Section for Surgery, Lund University, Skåne University Hospital, 205 02, Malmö, Sweden
| | - Rundk Hwaiz
- Department of Clinical Sciences, Malmö, Section for Surgery, Lund University, Skåne University Hospital, 205 02, Malmö, Sweden
| | - Lingtao Luo
- Department of Clinical Sciences, Malmö, Section for Surgery, Lund University, Skåne University Hospital, 205 02, Malmö, Sweden
| | - Oscar Ö Braun
- Department of Clinical Sciences, Lund, Section of Cardiology, Lund University, Lund, Sweden
| | - Eva Norström
- Department of Laboratory Medicine, Malmö, Section of Clinical Chemistry, Lund University, Lund, Sweden
| | - Henrik Thorlacius
- Department of Clinical Sciences, Malmö, Section for Surgery, Lund University, Skåne University Hospital, 205 02, Malmö, Sweden.
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Astrocytes Are Primed by Chronic Neurodegeneration to Produce Exaggerated Chemokine and Cell Infiltration Responses to Acute Stimulation with the Cytokines IL-1β and TNF-α. J Neurosci 2015; 35:8411-22. [PMID: 26041910 DOI: 10.1523/jneurosci.2745-14.2015] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Microgliosis and astrogliosis are standard pathological features of neurodegenerative disease. Microglia are primed by chronic neurodegeneration such that toll-like receptor agonists, such as LPS, drive exaggerated cytokine responses on this background. However, sterile inflammatory insults are more common than direct CNS infection in the degenerating brain and these insults drive robust IL-1β and TNF-α responses. It is unclear whether these pro-inflammatory cytokines can directly induce exaggerated responses in the degenerating brain. We hypothesized that glial cells in the hippocampus of animals with chronic neurodegenerative disease (ME7 prion disease) would display exaggerated responses to central cytokine challenges. TNF-α or IL-1β were administered intrahippocampally to ME7-inoculated mice and normal brain homogenate-injected (NBH) controls. Both IL-1β and TNF-α produced much more robust IL-1β synthesis in ME7 than in NBH animals and this occurred exclusively in microglia. However, there was strong nuclear localization of the NFκB subunit p65 in the astrocyte population, associated with marked astrocytic synthesis of the chemokines CXCL1 and CCL2 in response to both cytokine challenges in ME7 animals. Conversely, very limited expression of these chemokines was apparent in NBH animals similarly challenged. Thus, astrocytes are primed in the degenerating brain to produce exaggerated chemokine responses to acute stimulation with pro-inflammatory cytokines. Furthermore, this results in markedly increased neutrophil, T-cell, and monocyte infiltration in the diseased brain. These data have significant implications for acute sterile inflammatory insults such as stroke and traumatic brain injury occurring on a background of aging or neurodegeneration.
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9
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Rac1 regulates platelet shedding of CD40L in abdominal sepsis. J Transl Med 2014; 94:1054-63. [PMID: 25046439 DOI: 10.1038/labinvest.2014.92] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/20/2014] [Accepted: 05/29/2014] [Indexed: 01/25/2023] Open
Abstract
Matrix metalloproteinase-9 (MMP-9) regulates platelet shedding of CD40L in abdominal sepsis. However, the signaling mechanisms controlling sepsis-induced shedding of CD40L from activated platelets remain elusive. Rac1 has been reported to regulate diverse functions in platelets; we hypothesized herein that Rac1 might regulate platelet shedding of CD40L in sepsis. The specific Rac1 inhibitor NSC23766 (N6-[2-[[4-(diethylamino)-1-methylbutyl] amino]-6-methyl-4-pyrimidinyl]-2 methyl-4, 6-quinolinediamine trihydrochloride) was administered to mice undergoing cecal ligation and puncture (CLP). Levels of CD40L and MMP-9 in plasma, platelets, and neutrophils were determined by use of ELISA, western blot, and confocal microscopy. Platelet depletion abolished the CLP-induced increase in plasma levels of CD40L. Rac1 activity was significantly increased in platelets from septic animals. Administration of NSC23766 abolished the CLP-induced enhancement of soluble CD40L levels in the plasma. Moreover, Rac1 inhibition completely inhibited proteinase-activated receptor-4-induced surface mobilization and secretion of CD40L in isolated platelets. CLP significantly increased plasma levels of MMP-9 and Rac1 activity in neutrophils. Treatment with NSC23766 markedly attenuated MMP-9 levels in the plasma from septic mice. In addition, Rac1 inhibition abolished chemokine-induced secretion of MMP-9 from isolated neutrophils. Finally, platelet shedding of CD40L was significantly reduced in response to stimulation with supernatants from activated MMP-9-deficient neutrophils compared with supernatants from wild-type neutrophils, indicating a direct role of neutrophil-derived MMP-9 in regulating platelet shedding of CD40L. Our novel data suggest that sepsis-induced platelet shedding of CD40L is dependent on Rac1 signaling. Rac1 controls surface mobilization of CD40L on activated platelets and MMP-9 secretion from neutrophils. Thus, our findings indicate that targeting Rac1 signaling might be a useful way to control pathologic elevations of CD40L in the systemic circulation in abdominal sepsis.
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10
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Yu C, Zhang S, Song L, Wang Y, Hwaiz R, Luo L, Thorlacius H. Rac1 signaling regulates neutrophil-dependent tissue damage in experimental colitis. Eur J Pharmacol 2014; 741:90-6. [PMID: 25084221 DOI: 10.1016/j.ejphar.2014.07.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 12/13/2022]
Abstract
Excessive neutrophil recruitment in the colon is a major feature in acute colitis although the signaling mechanisms behind colonic recruitment of neutrophils remain elusive. Herein, we hypothesized that Rac1 activity might play an important role in neutrophil infiltration in the inflamed colon. Female Balb/c mice were treated with the Rac1 inhibitor NSC23766 (0.5 and 5mg/kg) before and daily after administration of 5% dextran sodium sulfate (DSS). Colonic tissue was collected for quantification of neutrophil recruitment, interleukin-6 (IL-6) and CXC chemokine formation as well as histological damage score five days after challenge with DSS. Rac1 activity was determined by western blot and Mac-1 expression by flow cytometry in neutrophils. Administration of NSC23766 decreased DSS-induced neutrophil recruitment and tissue damage in the colon. Rac1 inhibition decreased colonic formation of IL-6 and CXC chemokines in experimental colitis. Chemokine challenge increased Rac1 activity in neutrophils and NSC23766 markedly reduced this neutrophil activity of Rac1. Inhibition of Rac1 abolished CXC chemokine-induced neutrophil chemotaxis and up-regulation of Mac-1 in vitro. Taken together, Rac1 signaling plays a significant role in controlling accumulation of neutrophils and tissue injury in experimental colitis. Thus, our novel results suggest that targeting Rac1 signaling might be a useful way to protect against neutrophil-mediated tissue injury in acute colitis.
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Affiliation(s)
- Changhui Yu
- Department of Clinical Sciences, Section of Surgery, Malmö, Lund University, 20502 Malmö, Sweden; Department of Gastroenterology, Zhujiang Hospital of Southern Medical University, 510282 Guangzhou, China
| | - Su Zhang
- Department of Clinical Sciences, Section of Surgery, Malmö, Lund University, 20502 Malmö, Sweden
| | - Lei Song
- Department of Clinical Sciences, Section of Surgery, Malmö, Lund University, 20502 Malmö, Sweden
| | - Yusheng Wang
- Department of Clinical Sciences, Section of Surgery, Malmö, Lund University, 20502 Malmö, Sweden
| | - Rundk Hwaiz
- Department of Clinical Sciences, Section of Surgery, Malmö, Lund University, 20502 Malmö, Sweden
| | - Lingtao Luo
- Department of Clinical Sciences, Section of Surgery, Malmö, Lund University, 20502 Malmö, Sweden
| | - Henrik Thorlacius
- Department of Clinical Sciences, Section of Surgery, Malmö, Lund University, 20502 Malmö, Sweden.
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Mališová L, Kováčová Z, Koc M, Kračmerová J, Štich V, Rossmeislová L. Ursodeoxycholic acid but not tauroursodeoxycholic acid inhibits proliferation and differentiation of human subcutaneous adipocytes. PLoS One 2013; 8:e82086. [PMID: 24312631 PMCID: PMC3849437 DOI: 10.1371/journal.pone.0082086] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 10/30/2013] [Indexed: 12/21/2022] Open
Abstract
Stress of endoplasmic reticulum (ERS) is one of the molecular triggers of adipocyte dysfunction and chronic low inflammation accompanying obesity. ERS can be alleviated by chemical chaperones from the family of bile acids (BAs). Thus, two BAs currently used to treat cholestasis, ursodeoxycholic and tauroursodeoxycholic acid (UDCA and TUDCA), could potentially lessen adverse metabolic effects of obesity. Nevertheless, BAs effects on human adipose cells are mostly unknown. They could regulate gene expression through pathways different from their chaperone function, namely through activation of farnesoid X receptor (FXR) and TGR5, G-coupled receptor. Therefore, this study aimed to analyze effects of UDCA and TUDCA on human preadipocytes and differentiated adipocytes derived from paired samples of two distinct subcutaneous adipose tissue depots, abdominal and gluteal. While TUDCA did not alter proliferation of cells from either depot, UDCA exerted strong anti-proliferative effect. In differentiated adipocytes, acute exposition to neither TUDCA nor UDCA was able to reduce effect of ERS stressor tunicamycin. However, exposure of cells to UDCA during whole differentiation process decreased expression of ERS markers. At the same time however, UDCA profoundly inhibited adipogenic conversion of cells. UDCA abolished expression of PPARγ and lipogenic enzymes already in the early phases of adipogenesis. This anti-adipogenic effect of UDCA was not dependent on FXR or TGR5 activation, but could be related to ability of UDCA to sustain the activation of ERK1/2 previously linked with PPARγ inactivation. Finally, neither BAs did lower expression of chemokines inducible by TLR4 pathway, when UDCA enhanced their expression in gluteal adipocytes. Therefore while TUDCA has neutral effect on human preadipocytes and adipocytes, the therapeutic use of UDCA different from treating cholestatic diseases should be considered with caution because UDCA alters functions of human adipose cells.
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Affiliation(s)
- Lucia Mališová
- Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague, Czech Republic
- INSERM, Toulouse, France
| | - Zuzana Kováčová
- Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague, Czech Republic
- INSERM, Toulouse, France
| | - Michal Koc
- Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague, Czech Republic
- INSERM, Toulouse, France
| | - Jana Kračmerová
- Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague, Czech Republic
- INSERM, Toulouse, France
| | - Vladimír Štich
- Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague, Czech Republic
- INSERM, Toulouse, France
| | - Lenka Rossmeislová
- Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
- Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Prague, Czech Republic
- INSERM, Toulouse, France
- * E-mail:
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Enteric neural disruption in necrotizing enterocolitis occurs in association with myenteric glial cell CCL20 expression. J Pediatr Gastroenterol Nutr 2013; 57:788-93. [PMID: 24280992 DOI: 10.1097/mpg.0b013e3182a86fd4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVE The aetiology of necrotising enterocolitis (NEC) is unknown, but luminal factors and epithelial leakiness appear critical triggers of an inflammatory cascade. A separate finding has been suggested in mouse models, in which disruption of glial cells in the myenteric plexus induced a severe NEC-like lesion. We have thus looked for evidence of neuroglial abnormality in NEC. METHODS We studied full-thickness resected specimens from 20 preterm infants with acute NEC and from 13 control infants undergoing resection for other indications. Immunohistochemical analysis was performed for immunological (CD3, syndecan-1, human leucocyte antigen-DR), neural (glial fibrillary acidic protein [GFAP], nerve growth factor receptor, neurofilament protein, neuron-specific enolase), and functional markers (Ki67), and for potential inflammatory regulators (interleukin-12, transforming growth factor-β, CCL20, CCR6). RESULTS Expression of the chemokine CCL20 and its receptor CCR6 was significantly upregulated in myenteric plexus in NEC, with CCL20 strongly expressed by glial cells. In 9 of 20 cases with NEC, myenteric plexus architecture and GFAP+ glial cells were normal, with preserved submucosal and mucosal innervation; however, 11 cases showed disrupted myenteric plexus architecture, reduced GFAP expression, and loss of submucosal and mucosal innervation. Persistent abnormalities were identified in the 2 infants who had ongoing inflammation at ileostomy closure. CONCLUSIONS Our findings identified heterogeneity among patients with NEC. Approximately half showed evidence of marked neural abnormality extending from the deeper layers of the intestine, associated with glial activation and myenteric plexus disruption. The factors that may activate enteric glia in this manner, potentially including bacterial products or viruses, remain to be determined.
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Rho kinase regulates induction of T-cell immune dysfunction in abdominal sepsis. Infect Immun 2013; 81:2499-506. [PMID: 23630965 DOI: 10.1128/iai.00126-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
T-cell dysfunction increases susceptibility to infections in patients with sepsis. In the present study, we hypothesized that Rho kinase signaling might regulate induction of T-cell dysfunction in abdominal sepsis. Male C57BL/6 mice were treated with the specific Rho kinase inhibitor Y-27632 (5 mg/kg of body weight) prior to cecal ligation and puncture (CLP). Spleen CD4 T-cell apoptosis, proliferation, and percentage of regulatory T cells (CD4(+) CD25(+) Foxp3(+)) were determined by flow cytometry. Formation of gamma interferon (IFN-γ) and interleukin 4 (IL-4) in the spleen and plasma levels of HMBG1, IL-17, and IL-6 were quantified by use of enzyme-linked immunosorbent assay (ELISA). It was found that CLP evoked apoptosis and decreased proliferation in splenic CD4 T cells. Inhibition of Rho kinase activity decreased apoptosis and enhanced proliferation of CD4 T cells in septic animals. In addition, CLP-evoked induction of regulatory T cells in the spleen was abolished by Rho kinase inhibition. CLP reduced the levels of IFN-γ and IL-4 in the spleen. Pretreatment with Y-27632 inhibited the sepsis-induced decrease in IFN-γ but not IL-4 formation in the spleen. CLP increased plasma levels of high-mobility group box 1 (HMGB1) by 20-fold and IL-6 by 19-fold. Inhibition of Rho kinase decreased this CLP-evoked increase of HMGB1, IL-6, and IL-17 levels in the plasma by more than 60%, suggesting that Rho kinase regulates systemic inflammation in sepsis. Moreover, we observed that pretreatment with Y-27632 abolished CLP-induced bacteremia. Together, our novel findings indicate that Rho kinase is a powerful regulator of T-cell immune dysfunction in abdominal sepsis. Thus, targeting Rho kinase signaling might be a useful strategy to improve T-cell immunity in patients with abdominal sepsis.
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Li F, Nitteranon V, Tang X, Liang J, Zhang G, Parkin KL, Hu Q. In vitro antioxidant and anti-inflammatory activities of 1-dehydro-[6]-gingerdione, 6-shogaol, 6-dehydroshogaol and hexahydrocurcumin. Food Chem 2012; 135:332-7. [PMID: 22868095 DOI: 10.1016/j.foodchem.2012.04.145] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 04/14/2012] [Accepted: 04/30/2012] [Indexed: 12/21/2022]
Abstract
Hexahydrocurcumin, 1-dehydro-[6]-gingerdione, 6-dehydroshogaol and 6-shogaol were evaluated for their antioxidant and anti-inflammatory activities in the present study. The relative antioxidant potencies of ginger compounds decreased in similar order of 1-dehydro-[6]-gingerdione, hexahydrocurcumin>6-shogaol>6-dehydroshogaol in both 1,1-diphenyl-2-picyrlhydrazyl (DPPH) radical-scavenging and trolox equivalent antioxidant capacity (TEAC) assays. All tested compounds could attenuate lipopolysaccharide (LPS)-elicited increase of prostaglandin E2 (PGE(2)) in murine macrophages (RAW 264.7) in a concentration-dependent manner but hexahydrocurcumin of 7μM and 6-shogaol of 7μM. The strongest inhibitory effect was observed for 6-dehydroshogaol and 6-shogaol at 14μM with the inhibition of 53.3% and 48.9%, respectively. Furthermore, both 6-dehydroshogaol and 1-dehydro-[6]-gingerdione significantly suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in a concentration-dependent fashion. These results contribute to our theoretical understanding of the potential beneficial effects of consuming ginger as a food and/or dietary supplement.
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Affiliation(s)
- Feng Li
- College of Food Science and Engineering, Shandong Agricultural University, Taian 271018, PR China
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15
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Aravamudan B, Thompson M, Pabelick C, Prakash YS. Brain-derived neurotrophic factor induces proliferation of human airway smooth muscle cells. J Cell Mol Med 2012; 16:812-23. [PMID: 21651720 PMCID: PMC3175295 DOI: 10.1111/j.1582-4934.2011.01356.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Airway diseases such as asthma involve increased airway smooth muscle (ASM) contractility and remodelling via enhanced proliferation. Neurotrophins (NTs) such as brain-derived neurotrophic factor (BDNF), well-known in the nervous system, can regulate Ca2+ signalling, and interact with cytokines in contributing to airway hyperreactivity. In this study, we determined whether and how BDNF regulates human ASM cell proliferation in the presence of inflammation, thus testing its potential role in airway remodelling. Cells were treated with 10 nM BDNF, 25 ng/ml tumour necrosis factor (TNF-α) or interleukin-13 (IL-13), or 10 ng/ml platelet-derived growth factor (PDGF). Proliferation was measured using CyQuant dye, with immunoblotting of cell cycle proteins predicted to change with proliferation. Forty-eight hours of BDNF enhanced ASM proliferation to ∼50% of that by PDGF or cytokines. Transfection with small interfering RNAs (siRNAs) targeting high-affinity tropomyosin-related kinase B receptor abolished BDNF effects on proliferation, whereas low-affinity 75 kD neurotrophin receptor (p75NTR) siRNA had no effect. Systematic pharmacologic inhibition of different components of ERK1/2 and PI3K/Akt1 pathways blunted BDNF or TNF-α–induced proliferation. BDNF also induced IκB phosphorylation and nuclear translocation of p50 and p65 NF-κB subunits, with electron mobility shift assay confirmation of NF-κB binding to consensus DNA sequence. These results demonstrate that NTs such as BDNF can enhance human ASM cell proliferation by activating proliferation-specific signalling pathways and a versatile transcription factor such as NF-κB, which are common to cytokines and growth factors involved in asthma.
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Affiliation(s)
- Bharathi Aravamudan
- Department of Anesthesiology, College of Medicine, Mayo Clinic, Rochester, MN 55905, USA
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Tsai ML, Lai CS, Chang YH, Chen WJ, Ho CT, Pan MH. Pterostilbene, a natural analogue of resveratrol, potently inhibits 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse skin carcinogenesis. Food Funct 2012; 3:1185-94. [DOI: 10.1039/c2fo30105a] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Thair SA, Walley KR, Nakada TA, McConechy MK, Boyd JH, Wellman H, Russell JA. A single nucleotide polymorphism in NF-κB inducing kinase is associated with mortality in septic shock. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2011; 186:2321-8. [PMID: 21257964 DOI: 10.4049/jimmunol.1002864] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
We tested the hypothesis that single nucleotide polymorphisms (SNPs) within genes of the NF-κB pathway are associated with altered clinical outcome of septic shock patients. We genotyped 59 SNPs in the NF-κB pathway in a discovery cohort of septic shock patients (St. Paul's Hospital [SPH], N = 589), which identified the C allele of rs7222094 T/C within MAP3K14 (NF-κB inducing kinase; NIK) associated with increased 28-d mortality (uncorrected p = 0.00024, Bonferroni corrected p = 0.014). This result was replicated in a second cohort of septic shock patients (Vasopressin and Septic Shock Trial [VASST; N = 616]) in which the CC genotype of rs7222094 was associated with increased 28-d mortality (Cox regression: SPH cohort hazard ratio [HR], 1.35; 95% confidence interval [CI], 1.12-1.64; p = 0.002 Caucasian only; and VASST cohort HR, 1.24; 95% CI, 1.00-1.52; p = 0.048 Caucasian only). Patients having the CC genotype of rs7222094 in SPH experienced more renal and hematological dysfunction (p = 0.003 and p = 0.011), while patients of the VASST cohort with the rs7222094 CC genotype showed the same trend toward more renal dysfunction. In lymphoblastoid cell lines, we found the rs7222094 genotype most strongly associated with mRNA expression of CXCL10, a chemokine regulated by NF-κB. Accordingly, we measured CXCL10 protein levels and found that the CC genotype of rs7222094 was associated with significantly lower levels than those of the TT genotype in lymphoblastoid cell lines (p < 0.05) and in septic shock patients (p = 0.017). This suggests that the CC genotype of NIK rs7222094 is associated with increased mortality and organ dysfunction in septic shock patients, perhaps due to altered regulation of NF-κB pathway genes, including CXCL10.
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Affiliation(s)
- Simone A Thair
- University of British Columbia Critical Care Research Laboratories, Heart and Lung Institute, St. Paul's Hospital, Vancouver, British Columbia V6Z 1Y6, Canada
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Kuo DH, Lai YS, Lo CY, Cheng AC, Wu H, Pan MH. Inhibitory effect of magnolol on TPA-induced skin inflammation and tumor promotion in mice. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:5777-5783. [PMID: 20218615 DOI: 10.1021/jf100601r] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Magnolol has been reported to have an anti-inflammatory and antitumor effect in vitro and in vivo. Herein, we report the investigation of the inhibitory effects of magnolol on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in mouse skin. We found that the topical application of magnolol effectively inhibited the transcriptional activation of iNOS and COX-2 mRNA and proteins in mouse skin stimulated by TPA. Pretreatment with magnolol resulted in the reduction of TPA-induced nuclear translocation of the nuclear factor-kappaB (NFkappaB) subunit and DNA binding by blocking the phosphorylation of IkappaBalpha and p65 and subsequent degradation of IkappaBalpha. In addition, magnolol can suppress TPA-induced activation of extracellular signal-regulated kinase (ERK)1/2, p38 mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3-kinase (PI3K)/Akt, which are upstream of NFkappaB. Moreover, magnolol significantly inhibited 7,12-dimethylbene[a]anthracene (DMBA)/TPA-induced skin tumor formation by reducing the tumor multiplicity, tumor incidence, and tumor size of papillomas at 20 weeks. All these results revealed that magnolol is an effective antitumor agent and that its inhibitory effect is through the down-regulation of inflammatory iNOS and COX-2 gene expression in mouse skin, suggesting that magnolol is a novel functional agent capable of preventing inflammation-associated tumorigenesis.
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Affiliation(s)
- Daih-Huang Kuo
- Department of Pharmacy and Graduate Institute of Pharmaceutical Technology, Tajen University, Pingtung, Taiwan.
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Wu H, Hsieh MC, Lo CY, Liu CB, Sang S, Ho CT, Pan MH. 6-Shogaol is more effective than 6-gingerol and curcumin in inhibiting 12-O
-tetradecanoylphorbol 13-acetate-induced tumor promotion in mice. Mol Nutr Food Res 2010; 54:1296-306. [DOI: 10.1002/mnfr.200900409] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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20
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Ronaldson PT, Ashraf T, Bendayan R. Regulation of Multidrug Resistance Protein 1 by Tumor Necrosis Factor α in Cultured Glial Cells: Involvement of Nuclear Factor-κB and c-Jun N-Terminal Kinase Signaling Pathways. Mol Pharmacol 2010; 77:644-59. [DOI: 10.1124/mol.109.059410] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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OmpA is the critical component for Escherichia coli invasion-induced astrocyte activation. J Neuropathol Exp Neurol 2009; 68:677-90. [PMID: 19458541 DOI: 10.1097/nen.0b013e3181a77d1e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Escherichia coli is the major Gram-negative bacterial pathogen in neonatal meningitis. Outer membrane protein A (OmpA) is a conserved major protein in the E. coli outer membrane and is involved in several host-cell interactions. To characterize the role of OmpA in the invasion of astrocytes by E. coli, we investigated OmpA-positive and OmpA-negative E. coli strains. Outer membrane protein A E44, E105, and E109 strains adhered to and invaded C6 glioma cells 10- to 15-fold more efficiently than OmpA-negative strains. Actin rearrangement, protein tyrosine kinase, and phosphoinositide 3-kinase activation were required for OmpA-mediated invasion by E. coli. In vitro infection of C6 cells and intracerebral injection into mice of the E44 strain induced expression of the astrocyte differentiation marker glial fibrillary acidic protein and the inflammatory mediators cyclooxygenase 2 and nitric oxide synthase 2. After intracerebral infection with E44, all C57BL/6 mice died within 36hours, whereas 80% of mice injected with E44 premixed with recombinant OmpA protein survived. Astrocyte activation and neutrophil infiltration were reduced in brain tissue sections in the mice given OmpA. Taken together, these data suggest that OmpA-mediated invasion plays an important role in the early stage of E.coli-induced brain damage, and that it may have therapeutic use in E. coli meningitis.
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Anti-inflammatory effect of Momordica grosvenori Swingle extract through suppressed LPS-induced upregulation of iNOS and COX-2 in murine macrophages. J Funct Foods 2009. [DOI: 10.1016/j.jff.2009.01.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Pan MH, Hsieh MC, Hsu PC, Ho SY, Lai CS, Wu H, Sang S, Ho CT. 6-Shogaol suppressed lipopolysaccharide-induced up-expression of iNOS and COX-2 in murine macrophages. Mol Nutr Food Res 2009; 52:1467-77. [PMID: 18683823 DOI: 10.1002/mnfr.200700515] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ginger, the rhizome of Zingiber officinale, is a traditional medicine with carminative effect, antinausea, anti-inflammatory, and anticarcinogenic properties. In this study, we investigated the inhibitory effects of 6-shogaol and a related compound, 6-gingerol, on the induction of nitric oxide synthase (NOS) and cyclooxygenase-2 (COX-2) in murine RAW 264.7 cells activated with LPS. Western blotting and reverse transcription-PCR analyses demonstrated that 6-shogaol significantly blocked protein and mRNA expression of inducible NOS (iNOS) and COX-2 in LPS-induced macrophages. The in vivo anti-inflammatory activity was evaluated by a topical 12-O-tetradecanoylphorbol 13-acetate (TPA) application to mouse skin. When applied topically onto the shaven backs of mice prior to TPA, 6-shogaol markedly inhibited the expression of iNOS and COX-2 proteins. Treatment with 6-shogaol resulted in the reduction of LPS-induced nuclear translocation of nuclear factor-kappaB (NF kappaB) subunit and the dependent transcriptional activity of NF kappaB by blocking phosphorylation of inhibitor kappaB (I kappaB)alpha and p65 and subsequent degradation of I kappaB alpha. Transient transfection experiments using NF kappaB reporter constructs indicated that 6-shogaol inhibits the transcriptional activity of NF kappaB in LPS-stimulated mouse macrophages. We found that 6-shogaol also inhibited LPS-induced activation of PI3K/Akt and extracellular signal-regulated kinase 1/2, but not p38 mitogen-activated protein kinase (MAPK). Taken together, these results show that 6-shogaol downregulates inflammatory iNOS and COX-2 gene expression in macrophages by inhibiting the activation of NF kappaB by interfering with the activation PI3K/Akt/I kappaB kinases IKK and MAPK.
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Affiliation(s)
- Min-Hsiung Pan
- Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung, Taiwan.
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El-Hage N, Bruce-Keller AJ, Yakovleva T, Bazov I, Bakalkin G, Knapp PE, Hauser KF. Morphine exacerbates HIV-1 Tat-induced cytokine production in astrocytes through convergent effects on [Ca(2+)](i), NF-kappaB trafficking and transcription. PLoS One 2008; 3:e4093. [PMID: 19116667 PMCID: PMC2605563 DOI: 10.1371/journal.pone.0004093] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Accepted: 11/26/2008] [Indexed: 12/26/2022] Open
Abstract
Astroglia are key cellular sites where opiate drug signals converge with the proinflammatory effects of HIV-1 Tat signals to exacerbate HIV encephalitis. Despite this understanding, the molecular sites of convergence driving opiate-accelerated neuropathogenesis have not been deciphered. We therefore explored potential points of interaction between the signaling pathways initiated by HIV-1 Tat and opioids in striatal astrocytes. Profiling studies screening 152 transcription factors indicated that the nuclear factor-kappa B (NF-κB) subunit, c-Rel, was a likely candidate for Tat or Tat plus opiate-induced increases in cytokine and chemokine production by astrocytes. Pretreatment with the NF-κB inhibitor parthenolide provided evidence that Tat±morphine-induced release of MCP-1, IL-6 and TNF-α by astrocytes is NF-κB dependent. The nuclear export inhibitor, leptomycin B, blocked the nucleocytoplasmic shuttling of NF-κB; causing p65 (RelA) accumulation in the nucleus, and significantly attenuated cytokine production in Tat±morphine exposed astrocytes. Similarly, chelating intracellular calcium ([Ca2+]i) blocked Tat±morphine-evoked MCP-1 and IL-6 release, while artificially increasing the concentration of extracellular Ca2+ reversed this effect. Taken together, these results demonstrate that: 1) exposure to Tat±morphine is sufficient to activate NF-κB and cytokine production, 2) the release of MCP-1 and IL-6 by Tat±morphine are highly Ca2+-dependent, while TNF-α appears to be less affected by the changes in [Ca2+]i, and 3) in the presence of Tat, exposure to opiates augments Tat-induced NF-κB activation and cytokine release through a Ca2+-dependent pathway.
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Affiliation(s)
- Nazira El-Hage
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
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Khorooshi R, Babcock AA, Owens T. NF-kappaB-driven STAT2 and CCL2 expression in astrocytes in response to brain injury. THE JOURNAL OF IMMUNOLOGY 2008; 181:7284-91. [PMID: 18981150 DOI: 10.4049/jimmunol.181.10.7284] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tissue response to injury includes expression of genes encoding cytokines and chemokines. These regulate entry of immune cells to the injured tissue. The synthesis of many cytokines and chemokines involves NF-kappaB and signal transducers and activators of transcription (STAT). Injury to the CNS induces glial response. Astrocytes are the major glial population in the CNS. We examined expression of STATs and the chemokine CCL2 and their relationship to astroglial NF-kappaB signaling in the CNS following axonal transection. Double labeling with Mac-1/CD11b and glial fibrillary acidic protein revealed that STAT2 up-regulation and phosphorylation colocalized exclusively to astrocytes, suggesting the involvement of STAT2 activating signals selectively in astroglial response to injury. STAT1 was also up-regulated and phosphorylated but not exclusively in astrocytes. Both STAT2 up-regulation and phosphorylation were NF-kappaB -dependent since they did not occur in the lesion-reactive hippocampus of transgenic mice with specific inhibition of NF-kappaB activation in astrocytes. We further showed that lack of NF-kappaB signaling significantly reduced injury-induced CCL2 expression as well as leukocyte infiltration. Our results suggest that NF-kappaB signaling in astrocytes controls expression of both STAT2 and CCL2, and thus regulates infiltration of leukocytes into lesion-reactive hippocampus after axonal injury. Taken together, these findings indicate a central role for astrocytes in directing immune-glial interaction in the CNS injury response.
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Affiliation(s)
- Reza Khorooshi
- Medical Biotechnology Center, University of Southern Denmark, Odense, Denmark
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Pan MH, Chang YH, Tsai ML, Lai CS, Ho SY, Badmaev V, Ho CT. Pterostilbene suppressed lipopolysaccharide-induced up-expression of iNOS and COX-2 in murine macrophages. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:7502-7509. [PMID: 18656926 DOI: 10.1021/jf800820y] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Pterostilbene, an active constituent of blueberries, is known to possess anti-inflammatory activity and also to induce apoptosis in various types of cancer cells. Here, we investigated the inhibitory effects of pterostilbene on the induction of NO synthase (NOS) and cyclooxygenase-2 (COX-2) in murine RAW 264.7 cells activated with lipopolysaccharide (LPS). Western blotting and real-time polymerase chain reaction (PCR) analyses demonstrated that pterostilbene significantly blocked the protein and mRNA expression of iNOS and COX-2 in LPS-induced macrophages. Treatment with pterostilbene resulted in the reduction of LPS-induced nuclear translocation of the nuclear factor-kappaB (NFkappaB) subunit and the dependent transcriptional activity of NFkappaB by blocking phosphorylation of inhibitor kappaB (IkappaB)alpha and p65 and subsequent degradation of IkappaB alpha. Transient transfection experiments using NFkappaB reporter constructs indicated that pterostilbene inhibits the transcriptional activity of NFkappaB in LPS-stimulated mouse macrophages. We found that pterostilbene also inhibited LPS-induced activation of PI3K/Akt, extracellular signal-regulated kinase 1/2 and p38 MAPK. Taken together, these results show that pterostilbene down regulates inflammatory iNOS and COX-2 gene expression in macrophages by inhibiting the activation of NFkappaB by interfering with the activation of PI3K/Akt/IKK and MAPK. These results have an important implication for using pterostilbene toward the development of an effective anti-inflammatory agent.
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Affiliation(s)
- Min-Hsiung Pan
- Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung 811, Taiwan.
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Lai CS, Li S, Chai CY, Lo CY, Dushenkov S, Ho CT, Pan MH, Wang YJ. Anti-inflammatory and antitumor promotional effects of a novel urinary metabolite, 3',4'-didemethylnobiletin, derived from nobiletin. Carcinogenesis 2008; 29:2415-24. [DOI: 10.1093/carcin/bgn222] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Lectin-like domain of thrombomodulin binds to its specific ligand Lewis Y antigen and neutralizes lipopolysaccharide-induced inflammatory response. Blood 2008; 112:3661-70. [PMID: 18711002 DOI: 10.1182/blood-2008-03-142760] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Thrombomodulin (TM), a widely expressing glycoprotein originally identified in vascular endothelium, is an important cofactor in the protein C anticoagulant system. TM appears to exhibit anti-inflammatory ability through both protein C-dependent and -independent pathways. We presently have demonstrated that recombinant N-terminal lectinlike domain of TM (rTMD1) functions as a protective agent against sepsis caused by Gram-negative bacterial infections. rTMD1 caused agglutination of Escherichia coli and Klebsiella pneumoniae and enhanced the macrophage phagocytosis of these Gram-negative bacteria. Moreover, rTMD1 bound to the Klebsiella pneumoniae and lipopolysaccharide (LPS) by specifically interacting with Lewis Y antigen. rTMD1 inhibited LPS-induced inflammatory mediator production via interference with CD14 and LPS binding. Furthermore, rTMD1 modulated LPS-induced mitogen-activated protein kinase and nuclear factor-kappaB signaling pathway activations and inducible nitric oxide synthase expression in macrophages. Administration of rTMD1 protected the host by suppressing inflammatory responses induced by LPS and Gram-negative bacteria, and enhanced LPS and bacterial clearance in sepsis. Thus, rTMD1 can be used to defend against bacterial infection and inhibit LPS-induced inflammatory responses, suggesting that rTMD1 may be valuable in the treatment of severe inflammation in sepsis, especially in Gram-negative bacterial infections.
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Niederberger E, Geisslinger G. The IKK-NF-kappaB pathway: a source for novel molecular drug targets in pain therapy? FASEB J 2008; 22:3432-42. [PMID: 18559989 DOI: 10.1096/fj.08-109355] [Citation(s) in RCA: 144] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Several studies indicate that the nuclear factor-kappa B (NF-kappaB) -activation cascade plays a crucial role not only in immune responses, inflammation, and apoptosis but also in the development and processing of pathological pain. Accordingly, a pharmacological intervention into this pathway may have antinociceptive effects and could provide novel treatment strategies for pain and inflammation. In this review we summarize the role of NF-kappaB in the nervous system, its impact on nociception, and several approaches that investigated the effects of various modulators of the classical I-kappaB-kinase-NF-kappaB signal transduction pathway in inflammatory nociception and neuropathic pain. The results indicate that NF-kappaB has an impact on nociceptive transmission and processing and that a number of substances that inhibit the NF-kappaB-activating cascade are capable of reducing the nociceptive response in different animal models. Therefore, a modulation of specific participants in the NF-kappaB signal transduction might exert a useful approach for the development of new painkillers.
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Affiliation(s)
- Ellen Niederberger
- Pharmazentrum Frankfurt/ZAFES, Institut für Klinische Pharmakologie, Klinikum der Johann Wolfgang Goethe-Universität Frankfurt, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany.
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Conjugated linoleic acids produced by Lactobacillus dissociates IKK-gamma and Hsp90 complex in Helicobacter pylori-infected gastric epithelial cells. J Transl Med 2008; 88:541-52. [PMID: 18347582 DOI: 10.1038/labinvest.2008.16] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Although probiotics have been reported to reduce the gastric inflammatory response to Helicobacter pylori infection, little information is available regarding the molecular mechanisms behind this reduction. This study investigates the role of conjugated linoleic acids (CLA) produced by probiotics in interactions of IkappaB kinase (IKK) and heat shock protein 90 (Hsp90) to activate the nuclear factor-kappaB (NF-kappaB) signaling pathway in human gastric epithelial cells infected with H. pylori. Conditioned medium (CM) containing Lactobacillus acidophilus-producing CLA significantly inhibited the activated NF-kappaB signals and the upregulated expression of interleukin-8 (IL-8) in MKN-45 cells infected with H. pylori. Pretreatment with CM with CLA attenuated the increased IKK activity induced by H. pylori. Transfection of siRNA for IKK-beta dramatically reduced H. pylori-induced IkappaBalpha phosphorylation, but siRNA for IKK-alpha had little effect on IkappaBalpha phosphorylation, although the siRNA for IKK-alpha significantly decreased IL-8 production. Furthermore, Hsp90 was associated with IKK-alpha and IKK-gamma in H. pylori-infected cells, and CM with CLA dissociated the complex between Hsp90 and IKK-gamma. These results suggest that CLA produced by probiotics has anti-inflammatory activity in gastric epithelial cells infected with H. pylori via dissociation of the IKK-gamma and Hsp90 complex.
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Li S, Wang L, Berman MA, Zhang Y, Dorf ME. RNAi screen in mouse astrocytes identifies phosphatases that regulate NF-kappaB signaling. Mol Cell 2007; 24:497-509. [PMID: 17188031 PMCID: PMC2572259 DOI: 10.1016/j.molcel.2006.10.015] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Revised: 08/11/2006] [Accepted: 10/11/2006] [Indexed: 11/28/2022]
Abstract
Regulation of NF-kappaB activation is controlled by a series of kinases; however, the roles of phosphatases in regulating this pathway are poorly understood. We report a systematic RNAi screen of phosphatases that modulate NF-kappaB activity. Nineteen of 250 phosphatase genes were identified as regulators of NF-kappaB signaling in astrocytes. RNAi selectively regulates endogenous chemokine and cytokine expression. Coimmunoprecipitation identified associations of distinct protein phosphatase 2A core or holoenzymes with the IKK, NF-kappaB, and TRAF2 complexes. Dephosphorylation of these complexes leads to modulation of NF-kappaB transcriptional activity. In contrast to IKK and NF-kappaB, TRAF2 phosphorylation has not been well elucidated. We show that the Thr117 residue in TRAF2 is phosphorylated following TNFalpha stimulation. This phosphorylation process is modulated by PP2A and is required for TRAF2 functional activity. These results provide direct evidence for TNF-induced TRAF2 phosphorylation and demonstrate that phosphorylation is regulated at multiple levels in the NF-kappaB pathway.
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Affiliation(s)
- Shitao Li
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Lingyan Wang
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | | | - Ye Zhang
- Department of Pathology, Harvard Medical School, Boston, MA 02115
| | - Martin E. Dorf
- Department of Pathology, Harvard Medical School, Boston, MA 02115
- Contact: ; phone 617-432-1978; FAX 617-432-2789
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ESEN NILUFER, SHUFFIELD DEBBIE, MOHSIN MDSYED, KIELIAN TAMMY. Modulation of connexin expression and gap junction communication in astrocytes by the gram-positive bacterium S. aureus. Glia 2007; 55:104-17. [PMID: 17029244 PMCID: PMC2440499 DOI: 10.1002/glia.20438] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Gap junctions establish direct intercellular conduits between adjacent cells and are formed by the hexameric organization of protein subunits called connexins (Cx). It is unknown whether the proinflammatory milieu that ensues during CNS infection with S. aureus, one of the main etiologic agents of brain abscess in humans, is capable of eliciting regional changes in astrocyte homocellular gap junction communication (GJC) and, by extension, influencing neuron homeostasis at sites distant from the primary focus of infection. Here we investigated the effects of S. aureus and its cell wall product peptidoglycan (PGN) on Cx43, Cx30, and Cx26 expression, the main Cx isoforms found in astrocytes. Both bacterial stimuli led to a time-dependent decrease in Cx43 and Cx30 expression; however, Cx26 levels were elevated following bacterial exposure. Functional examination of dye coupling, as revealed by single-cell microinjections of Lucifer yellow, demonstrated that both S. aureus and PGN inhibited astrocyte GJC. Inhibition of protein synthesis with cyclohexamide (CHX) revealed that S. aureus directly modulates, in part, Cx43 and Cx30 expression, whereas Cx26 levels appear to be regulated by a factor(s) that requires de novo protein production; however, CHX did not alter the inhibitory effects of S. aureus on astrocyte GJC. The p38 MAPK inhibitor SB202190 was capable of partially restoring the S. aureus-mediated decrease in astrocyte GJC to that of unstimulated cells, suggesting the involvement of p38 MAPK-dependent pathway(s). These findings could have important implications for limiting the long-term detrimental effects of abscess formation in the brain which may include seizures and cognitive deficits.
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Affiliation(s)
| | | | | | - TAMMY KIELIAN
- *Correspondence to: Tammy Kielian, University of Arkansas for Medical Sciences, Department of Neurobiology and Developmental Sciences, 4301 W. Markham St., Slot 846, Little Rock, AR 72205, USA. E-mail:
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Pan MH, Lai CS, Wang YJ, Ho CT. Acacetin suppressed LPS-induced up-expression of iNOS and COX-2 in murine macrophages and TPA-induced tumor promotion in mice. Biochem Pharmacol 2006; 72:1293-303. [PMID: 16949556 DOI: 10.1016/j.bcp.2006.07.039] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 07/07/2006] [Accepted: 07/26/2006] [Indexed: 11/26/2022]
Abstract
Acacetin (5,7-dihydroxy-4'-methoxyflavone), a flavonoid compound, has anti-peroxidative and anti-inflammatory effects. In this study, we investigated the inhibitory effects of acacetin and a related compound, wogonin, on the induction of NO synthase (NOS) and COX-2 in RAW 264.7 cells activated with lipopolysaccharide (LPS). Acacetin markedly and actively inhibited the transcriptional activation of iNOS and COX-2. Western blotting, reverse transcription-polymerase chain reaction (PCR), and real-time PCR analyses demonstrated that acacetin significantly blocked protein and mRNA expression of iNOS and COX-2 in LPS-inducted macrophages. Treatment with acacetin reduced translocation of nuclear factor-kappa B (NF kappa B) subunit and the dependent transcriptional activity of NF kappa B. The activation of NF kappa B was inhibited by prevention of the degradation of inhibitor kappa B (I kappa B). Furthermore, acacetin inhibited LPS-induced phosphorylation as well as degradation of I kappa B alpha. We further investigated the roles of tyrosine kinase, phosphatidylinositiol 3-kinase (PI3K)/Akt and mitogen-activated protein kinase (MAPK) in LPS-induced macrophages. We found that acacetin also inhibited LPS-induced activation of PI3K/Akt and p44/42, but not p38 MAPK. After initiation of 7,12-dimethlybene[a]anthracene (DMBA), applying acacentin topically before each 12-O-tetradecanoylphorbol 13-acetat (TPA) treatment was found to reduce the number of papillomas at 20 weeks. Taken together, these results show that acacetin down regulates inflammatory iNOS and COX-2 gene expression in macrophages by inhibiting the activation of NF kappa B by interfering with the activation PI3K/Akt/IKK and MAPK, suggesting that acacetin is a functionally novel agent capable of preventing inflammation-associated tumorigenesis.
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Affiliation(s)
- Min-Hsiung Pan
- Department of Seafood Science, National Kaohsiung Marine University, Nan-Tzu, Kaohsiung , Taiwan.
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Zhao J, Brooks DM, Lurie DI. Lipopolysaccharide-activated SHP-1-deficient motheaten microglia release increased nitric oxide, TNF-alpha, and IL-1beta. Glia 2006; 53:304-12. [PMID: 16265671 DOI: 10.1002/glia.20283] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Accumulating evidence suggests a deleterious role for activated microglia in facilitating neuronal death by producing neurocytotoxic substances during injury, infection, or neurodegenerative diseases. After cochlear ablation, abnormal microglial activation accompanied by increased neuronal loss within the auditory brainstem occurs in motheaten (me/me) mice deficient in the protein tyrosine phosphatase SHP-1. To determine whether abnormally activated microglia contribute to neuronal death in me/me mice, primary microglial cultures from me/me and wild-type mouse cortices were stimulated by the bacterial endotoxin lipopolysaccharide (LPS) to evaluate the secretion of the neurotoxic mediators nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta). Me/me microglia release significantly greater amounts of all three mediators compared with wild-type microglia. However, the increased release of these compounds in microglia lacking SHP-1 does not appear to occur through activation of extracellular signal-regulated kinase (ERK), p38 kinase subgroups of mitogen-activated protein (MAP) kinases, or increases in NF-kappaB-inducing kinase (NIK). These results suggest that abnormal microglial activation and release of neurotoxic compounds may potentiate neuronal death in deafferented cells and can thus potentiate neurodegeneration in the me/me brainstem. Our data also indicate that SHP-1 is engaged in signaling pathways in LPS-activated microglia, but not through regulation of the ERK and p38 MAP kinases.
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Affiliation(s)
- Jie Zhao
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy and Allied Health Sciences, University of Montana, Missoula, MT 59812, USA
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