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Rastgar S, Movahedinia A, Salamat N, Salati AP, Zabihi E. Interruption of immune responses in primary macrophages exposed to nonylphenol provides insights into the role of ER and NF-KB in immunotoxicity of Persian sturgeon. FISH & SHELLFISH IMMUNOLOGY 2019; 86:125-134. [PMID: 30453043 DOI: 10.1016/j.fsi.2018.11.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 11/13/2018] [Accepted: 11/15/2018] [Indexed: 05/02/2023]
Abstract
The severe decline in population of sturgeons due to pollution highlighted poor understanding about the immunotoxicological responses of sturgeons. This study was designed in three experiments to find out how nonylphenol (NP) interrupts some pro-inflammatory immune parameters in macrophages from Persian sturgeon (Acipencer persicous) as the oldest vertebrate model conserving intact innate immune system. After determination of IC50 values of NP (200 μM), some pro-inflammatory immune parameters and induced apoptosis in macrophages at low dose (10 nM) and high dose (100 nM) of NP and of 17β estradiol (E2) (positive control) were determined after 6, 24 and 48 h of the exposure (as the first experiment). The two doses of NP induced pro-inflammatory reaction and apoptosis with strong correlations, whereas this result was observed more obviously in high dose of E2. In the second experiments, the macrophages were exposed to the two doses of NP along with estrogen receptor alpha (ERα) antagonist, which consequently decreased the induction of pro-inflammatory reactions. Similarly, in the third experiment, NF-KB and ERα antagonists were used and pro-inflammatory reactions decreased compared to the control group (P < 0.05). Decreasing correlation between immune parameters following the second and third experiments verified interaction between ERα and NF-KB pathways. Thus, NP could be immune disrupter and apoptosis inducer in sturgeon macrophages in vitro, even in low dose. For the first time, this study revealed that NP can induce pro-inflammatory reactions in macrophages derived from sturgeons.
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Affiliation(s)
- Sara Rastgar
- Department of Marine Biology, Faculty of Marine Sciences, Khorramshahr University of Marine Science and Technology, P.O. Box 669, Khorramshahr, Iran
| | - Abdolali Movahedinia
- Department of Marine Biology, Faculty of Marine Sciences, University of Mazandaran, Babolsar, Iran.
| | - Negin Salamat
- Department of Marine Biology, Faculty of Marine Sciences, Khorramshahr University of Marine Science and Technology, P.O. Box 669, Khorramshahr, Iran
| | - Amir Parviz Salati
- Department of Fisheries, Faculty of Marine Natural Resources, Khoramshahr University of Marine, Iran
| | - Ebrahim Zabihi
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
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Lin HY, Chang YY, Kao MC, Huang CJ. Naloxone inhibits nod-like receptor protein 3 inflammasome. J Surg Res 2017; 219:72-77. [PMID: 29078913 DOI: 10.1016/j.jss.2017.05.119] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/14/2017] [Accepted: 05/25/2017] [Indexed: 12/23/2022]
Abstract
BACKGROUND Naloxone, an opioid receptor antagonist, possesses potent anti-inflammation effects. We previously confirmed the effects of naloxone on inhibiting upregulation of inflammatory cytokine interleukin-1β (IL-1β). Production of mature form IL-1β is mediated by the nod-like receptor protein 3 (NLRP3) inflammasome, a multiprotein complex composed of NLRP3, and the adaptor protein apoptosis-associated speck-like protein contains a caspase recruitment domain (ASC). We elucidated whether naloxone could inhibit the activation of NLRP3 inflammasome. MATERIAL AND METHODS To induce IL-1β production and NLRP3 inflammasome activation, the human monocytic leukemia cell line THP-1 cells were first primed with lipopolysaccharide (LPS, 1 μg/mL) and then activated with adenosine triphosphate (ATP, 1 mM). For NLRP3 transcription, THP-1 cells were only treated with LPS priming. RESULTS Enzyme-link immunosorbent assay data revealed that the concentration of IL-1β in THP-1 cells treated with LPS plus ATP was significantly higher than that in THP-1 cells treated with LPS plus ATP plus naloxone (0.1 μM) (P < 0.001). Real-time quantitative reverse transcription and polymerase chain reaction data also revealed that NLRP3 mRNA concentration in THP-1 cells treated with LPS was significantly higher than that in THP-1 cells treated with LPS plus naloxone (P = 0.001). ASC speck formation, that is, ASC assembles into a large protein complex, is an indicator for NLRP3 inflammasome activation. Our data revealed that the percentage of cells containing ASC specks in THP-1 cells treated with LPS plus ATP was also significantly higher than that in THP-1 cells treated with LPS plus ATP plus naloxone (P < 0.001). CONCLUSIONS Naloxone inhibits NLRP3 inflammasome activation.
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Affiliation(s)
- Han-Yu Lin
- Department of Anesthesiology, Taipei Tzu Chi Hospital, Taipei, Taiwan
| | - Ya-Ying Chang
- Department of Anesthesiology, Taipei Tzu Chi Hospital, Taipei, Taiwan
| | - Ming-Chang Kao
- Department of Anesthesiology, Taipei Tzu Chi Hospital, Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Chun-Jen Huang
- Department of Anesthesiology, Taipei Tzu Chi Hospital, Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan.
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Hanski L, Vuorela P. Lead Discovery Strategies for Identification of Chlamydia pneumoniae Inhibitors. Microorganisms 2016; 4:E43. [PMID: 27916800 PMCID: PMC5192526 DOI: 10.3390/microorganisms4040043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/28/2016] [Accepted: 11/04/2016] [Indexed: 12/18/2022] Open
Abstract
Throughout its known history, the gram-negative bacterium Chlamydia pneumoniae has remained a challenging target for antibacterial chemotherapy and drug discovery. Owing to its well-known propensity for persistence and recent reports on antimicrobial resistence within closely related species, new approaches for targeting this ubiquitous human pathogen are urgently needed. In this review, we describe the strategies that have been successfully applied for the identification of nonconventional antichlamydial agents, including target-based and ligand-based virtual screening, ethnopharmacological approach and pharmacophore-based design of antimicrobial peptide-mimicking compounds. Among the antichlamydial agents identified via these strategies, most translational work has been carried out with plant phenolics. Thus, currently available data on their properties as antichlamydial agents are described, highlighting their potential mechanisms of action. In this context, the role of mitogen-activated protein kinase activation in the intracellular growth and survival of C. pneumoniae is discussed. Owing to the complex and often complementary pathways applied by C. pneumoniae in the different stages of its life cycle, multitargeted therapy approaches are expected to provide better tools for antichlamydial therapy than agents with a single molecular target.
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Affiliation(s)
- Leena Hanski
- Pharmaceutical Biology, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki FI-00014, Finland.
| | - Pia Vuorela
- Pharmaceutical Biology, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki FI-00014, Finland.
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Demaurex N, Nunes P. The role of STIM and ORAI proteins in phagocytic immune cells. Am J Physiol Cell Physiol 2016; 310:C496-508. [PMID: 26764049 PMCID: PMC4824159 DOI: 10.1152/ajpcell.00360.2015] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Phagocytic cells, such as neutrophils, macrophages, and dendritic cells, migrate to sites of infection or damage and are integral to innate immunity through two main mechanisms. The first is to directly neutralize foreign agents and damaged or infected cells by secreting toxic substances or ingesting them through phagocytosis. The second is to alert the adaptive immune system through the secretion of cytokines and the presentation of the ingested materials as antigens, inducing T cell maturation into helper, cytotoxic, or regulatory phenotypes. While calcium signaling has been implicated in numerous phagocyte functions, including differentiation, maturation, migration, secretion, and phagocytosis, the molecular components that mediate these Ca(2+) signals have been elusive. The discovery of the STIM and ORAI proteins has allowed researchers to begin clarifying the mechanisms and physiological impact of store-operated Ca(2+) entry, the major pathway for generating calcium signals in innate immune cells. Here, we review evidence from cell lines and mouse models linking STIM and ORAI proteins to the control of specific innate immune functions of neutrophils, macrophages, and dendritic cells.
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Affiliation(s)
- Nicolas Demaurex
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Paula Nunes
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
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Hakala E, Hanski L, Uvell H, Yrjönen T, Vuorela H, Elofsson M, Vuorela PM. Dibenzocyclooctadiene lignans from Schisandra spp. selectively inhibit the growth of the intracellular bacteria Chlamydia pneumoniae and Chlamydia trachomatis. J Antibiot (Tokyo) 2015; 68:609-14. [PMID: 25944533 DOI: 10.1038/ja.2015.48] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 03/01/2015] [Accepted: 03/23/2015] [Indexed: 01/20/2023]
Abstract
Lignans from Schisandra chinensis berries show various pharmacological activities, of which their antioxidative and cytoprotective properties are among the most studied ones. Here, the first report on antibacterial properties of six dibenzocyclooctadiene lignans found in Schisandra spp. is presented. The activity was shown on two related intracellular Gram-negative bacteria Chlamydia pneumoniae and Chlamydia trachomatis upon their infection in human epithelial cells. All six lignans inhibited C. pneumoniae inclusion formation and infectious progeny production. Schisandrin B inhibited C. pneumoniae inclusion formation even when administered 8 h post infection, indicating a target that occurs relatively late within the infection cycle. Upon infection, lignan-pretreated C. pneumoniae elementary bodies had impaired inclusion formation capacity. The presence and substitution pattern of methylenedioxy, methoxy and hydroxyl groups of the lignans had a profound impact on the antichlamydial activity. In addition our data suggest that the antichlamydial activity is not caused only by the antioxidative properties of the lignans. None of the compounds showed inhibition on seven other bacteria, suggesting a degree of selectivity of the antibacterial effect. Taken together, the data presented support a role of the studied lignans as interesting antichlamydial lead compounds.
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Affiliation(s)
- Elina Hakala
- Pharmaceutical Biology, CDR, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Leena Hanski
- Pharmaceutical Biology, CDR, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Hanna Uvell
- Laboratories for Chemical Biology Umeå, Department of Chemistry, Umeå University, Umeå, Sweden
| | - Teijo Yrjönen
- Pharmaceutical Biology, CDR, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Heikki Vuorela
- Pharmaceutical Biology, CDR, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Mikael Elofsson
- Laboratories for Chemical Biology Umeå, Department of Chemistry, Umeå University, Umeå, Sweden
| | - Pia Maarit Vuorela
- Pharmaceutical Biology, CDR, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
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Antony C, Mehto S, Tiwari BK, Singh Y, Natarajan K. Regulation of L-type Voltage Gated Calcium Channel CACNA1S in Macrophages upon Mycobacterium tuberculosis Infection. PLoS One 2015; 10:e0124263. [PMID: 25915405 PMCID: PMC4411123 DOI: 10.1371/journal.pone.0124263] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 03/11/2015] [Indexed: 01/17/2023] Open
Abstract
We demonstrated earlier the inhibitory role played by Voltage Gated Calcium Channels (VGCCs) in regulating Mycobacterium tuberculosis (M. tb) survival and pathogenesis. In this report, we investigated mechanisms and key players that regulate the surface expression of VGCC-CACNA1S by Rv2463 and M. tb infection in macrophages. Our earlier work identified Rv2463 to be expressed at early times post infection in macrophages that induced suppressor responses to dendritic cells and macrophages. Our results in this study demonstrate a role of MyD88 independent TLR pathway in mediating CACNA1S expression. Dissecting the role for second messengers, we show that calcium homeostasis plays a key role in CACNA1S expression during M. tb infection. Using siRNAs against molecular sensors of calcium regulation, we show an involvement of ER associated Stromal Interaction Molecules 1 and 2 (STIM1 and STIM2), and transcription factor pCREB, towards CACNA1S expression that also involved the MyD88 independent pathway. Interestingly, reactive oxygen species played a negative role in M. tb mediated CACNA1S expression. Further, a cross-regulation of ROS and pCREB was noted that governed CACNA1S expression. Characterizing the mechanisms governing CACNA1S expression would improve our understanding of the regulation of VGCC expression and its role in M. tb pathogenesis during M. tb infection.
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Affiliation(s)
- Cecil Antony
- Infectious Disease Immunology Lab, Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India
- * E-mail: (CA); (KN)
| | - Subhash Mehto
- Infectious Disease Immunology Lab, Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India
| | - Brijendra K. Tiwari
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, 110007, India
| | - Yogendra Singh
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi, 110007, India
| | - Krishnamurthy Natarajan
- Infectious Disease Immunology Lab, Dr. B. R. Ambedkar Centre for Biomedical Research, University of Delhi, Delhi, 110007, India
- * E-mail: (CA); (KN)
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El-Tanbouly DM, Abdelsalam RM, Attia AS, Abdel-Aziz MT. Pretreatment with magnesium ameliorates lipopolysaccharide-induced liver injury in mice. Pharmacol Rep 2015; 67:914-20. [PMID: 26398385 DOI: 10.1016/j.pharep.2015.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 02/11/2015] [Accepted: 02/12/2015] [Indexed: 12/18/2022]
Abstract
BACKGROUND Lipopolysaccharide (LPS), a component of the outer membrane of Gram-negative bacteria, is involved in the pathogenesis of sepsis. LPS administration induces systemic inflammation that mimics many of the initial clinical features of sepsis and has deleterious effects on several organs including the liver and eventually leading to septic shock and death. The present study aimed to investigate the protective effect of magnesium (Mg), a well known cofactor in many enzymatic reactions and a critical component of the antioxidant system, on hepatic damage associated with LPS-induced endotoxima in mice. METHODS Mg (20 and 40mg/kg, po) was administered for 7 consecutive days. Systemic inflammation was induced 1h after the last dose of Mg by a single dose of LPS (2mg/kg, ip) and 3h thereafter plasma was separated, animals were sacrificed and their livers were isolated. RESULTS LPS-treated mice suffered from hepatic dysfunction revealed by histological observation, elevation in plasma transaminases activities, C-reactive protein content and caspase-3, a critical marker of apoptosis. Liver inflammation was evident by elevation in liver cytokines contents (TNF-α and IL-10) and MPO activity. Additionally, oxidative stress was manifested by increased liver lipoperoxidation, glutathione depletion, elevated total nitrate/nitrite (NOx) content and glutathione peroxidase (GPx) activity. Pretreatment with Mg largely mitigated these alternations. CONCLUSION Pretreatment with Mg protects the liver from the acute injury which occurs shortly after septicemia.
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Affiliation(s)
- Dalia M El-Tanbouly
- Pharmacology & Toxicology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
| | - Rania M Abdelsalam
- Pharmacology & Toxicology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Amina S Attia
- Pharmacology & Toxicology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Mohamed T Abdel-Aziz
- Pharmacology & Toxicology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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8
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Marangoni A, Bergamini C, Fato R, Cavallini C, Donati M, Nardini P, Foschi C, Cevenini R. Infection of human monocytes by Chlamydia pneumoniae and Chlamydia trachomatis: an in vitro comparative study. BMC Res Notes 2014; 7:230. [PMID: 24721461 PMCID: PMC3984436 DOI: 10.1186/1756-0500-7-230] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 04/03/2014] [Indexed: 12/24/2022] Open
Abstract
Background An increasing number of studies suggest that chlamydiae can infect immune cells. The altered immune cell function could contribute to the progression of several chronic inflammatory diseases. The aim of this study was to comparatively evaluate Chlamydia pneumoniae (CP) and Chlamydia trachomatis (CT) interactions with in vitro infected human blood monocytes. Results Fresh isolated monocytes were infected with viable CP and CT elementary bodies and infectivity was evaluated by recultivating disrupted monocytes in permissive epithelial cells. The production of reactive oxygen and nitrogen species was studied in the presence of specific fluorescent probes. Moreover, TNF-α, INF-α, INF-β and INF-γ gene expression was determined. CT clearance from monocytes was complete at any time points after infection, while CP was able to survive up to 48 hours after infection. When NADPH oxydase or nitric oxide synthase inhibitors were used, CT infectivity in monocytes was restored, even if at low level, and CT recovery’s rate was comparable to CP one. CT-infected monocytes produced significantly higher levels of reactive species compared with CP-infected monocytes, at very early time points after infection. In the same meanwhile, TNF-α and INF-γ gene expression was significantly increased in CT-infected monocytes. Conclusions Our data confirm that CP, but not CT, is able to survive in infected monocytes up to 48 hours post-infection. The delay in reactive species and cytokines production by CP-infected monocytes seems to be crucial for CP survival.
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Affiliation(s)
- Antonella Marangoni
- Microbiology, DIMES, University of Bologna, S,Orsola Hospital, via Massarenti 9, 40138 Bologna, Italy.
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Magnesium sulfate provides neuroprotection in lipopolysaccharide-activated primary microglia by inhibiting NF-κB pathway. J Surg Res 2013; 184:944-50. [DOI: 10.1016/j.jss.2013.03.034] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 03/04/2013] [Accepted: 03/12/2013] [Indexed: 11/20/2022]
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Abstract
Given the manifold ways that depression impairs Darwinian fitness, the persistence in the human genome of risk alleles for the disorder remains a much debated mystery. Evolutionary theories that view depressive symptoms as adaptive fail to provide parsimonious explanations for why even mild depressive symptoms impair fitness-relevant social functioning, whereas theories that suggest that depression is maladaptive fail to account for the high prevalence of depression risk alleles in human populations. These limitations warrant novel explanations for the origin and persistence of depression risk alleles. Accordingly, studies on risk alleles for depression were identified using PubMed and Ovid MEDLINE to examine data supporting the hypothesis that risk alleles for depression originated and have been retained in the human genome because these alleles promote pathogen host defense, which includes an integrated suite of immunological and behavioral responses to infection. Depression risk alleles identified by both candidate gene and genome-wide association study (GWAS) methodologies were found to be regularly associated with immune responses to infection that were likely to enhance survival in the ancestral environment. Moreover, data support the role of specific depressive symptoms in pathogen host defense including hyperthermia, reduced bodily iron stores, conservation/withdrawal behavior, hypervigilance and anorexia. By shifting the adaptive context of depression risk alleles from relations with conspecifics to relations with the microbial world, the Pathogen Host Defense (PATHOS-D) hypothesis provides a novel explanation for how depression can be nonadaptive in the social realm, whereas its risk alleles are nonetheless represented at prevalence rates that bespeak an adaptive function.
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Affiliation(s)
- C L Raison
- Department of Psychiatry, College of Medicine, University of Arizona, Tucson, AZ 85724-5137, USA.
| | - A H Miller
- grid.189967.80000 0001 0941 6502Department of Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA USA
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Kim DH, Lim JJ, Lee JJ, Kim DG, Lee HJ, Min W, Kim KD, Chang HH, Endale M, Rhee MH, Watarai M, Kim S. RGS2-Mediated Intracellular Ca2+ Level Plays a Key Role in the Intracellular Replication of Brucella abortus Within Phagocytes. J Infect Dis 2011; 205:445-52. [DOI: 10.1093/infdis/jir765] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Salin OP, Pohjala LL, Saikku P, Vuorela HJ, Leinonen M, Vuorela PM. Effects of coadministration of natural polyphenols with doxycycline or calcium modulators on acute Chlamydia pneumoniae infection in vitro. J Antibiot (Tokyo) 2011; 64:747-52. [DOI: 10.1038/ja.2011.79] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Magnesium sulfate mitigates acute lung injury in endotoxemia rats. ACTA ACUST UNITED AC 2011; 70:1177-85; discussion 1185. [PMID: 21610432 DOI: 10.1097/ta.0b013e31820ca695] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Magnesium sulfate (MgSO4) possesses potent anti-inflammation capacity. We sought to elucidate the effects of MgSO4 on mitigating acute lung injury induced by endotoxemia. MgSO4 is an antagonist of the L-type calcium channels and the N-methyl-D-aspartate (NMDA) receptor. The roles of the L-type calcium channels and NMDA receptor in this regard were also elucidated. METHODS Ninety-six adult male rats were randomized to receive normal saline, MgSO4 (100 mg/kg), lipopolysaccharide (LPS), LPS plus MgSO4 (10, 50, or 100 mg/kg), LPS plus MgSO4 (100 mg/kg) plus the L-type calcium channel activator BAY-K8644, or LPS plus MgSO4 (100 mg/kg) plus exogenous NMDA (n=12 in each group). Between-group differences in lung injury were evaluated. RESULTS Histologic findings, in concert with assays of leukocyte infiltration (polymorphonuclear leukocytes/alveoli ratio and myeloperoxidase activity) and lung water content (wet/dry weight ratio), confirmed that LPS induced acute lung injury. LPS also caused significant inflammatory response (increases in chemokine, cytokine, and prostaglandin E2 concentrations) and imposed significant oxidative stress (increases in nitric oxide and malondialdehyde concentrations) in rat lungs. MgSO4 at the dosages of 50 mg/kg and 100 mg/kg, but not at 10 mg/kg, significantly mitigated the acute lung injury, lung inflammatory response, and oxidative stress caused by endotoxemia. Moreover, the protective effects of MgSO4 were counteracted by BAY-K8644 and exogenous NMDA. CONCLUSIONS MgSO4 mitigates lung inflammatory response, oxidative stress, and acute lung injury in endotoxemia rats in a dose-dependent manner. The mechanisms may involve antagonizing the L-type calcium channels and the NMDA receptor.
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Azenabor AA, Cintrón-Cuevas J, Schmitt H, Bumah V. Chlamydia trachomatis induces anti-inflammatory effect in human macrophages by attenuation of immune mediators in Jurkat T-cells. Immunobiology 2011; 216:1248-55. [PMID: 21802168 DOI: 10.1016/j.imbio.2011.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Accepted: 07/03/2011] [Indexed: 11/30/2022]
Abstract
The chronic course of Chlamydia trachomatis infection is subtle with no obvious unusual inflammatory change. The reason for this is not clear. The data reported here explain how macrophage usual inflammatory response switches to anti-inflammatory response during C. trachomatis infection of mixed culture of macrophages and Jurkat T-cells. We assessed the establishment of productive infection in individual or mixed cell culture models, determined the status of C. trachomatis in the cells by monitoring HSP-60:MOMP or the proportions of the estimated IFUs that shed HSP-60 or MOMP. Also, the specific time-course expression of IL-12, IL-10 and IFN-γ or IL-12R, IL-10R, and IFN-γ-R during infection of cell models was assessed. Finally, the early events in cytokine elaboration in circumstances of varying intracellular Ca²⁺ levels were determined. There was evidence of productive infection in all individual and mixed cell culture models. The shedding of HSP-60 was highest in THP-1/Jurkat mixed cell culture model. The proportions of IFU that shed HSP-60 was heightened in infected THP-1/Jurkat mixed culture model, while the proportion of IFU that shed MOMP was higher in infected macrophage/Jurkat mixed culture and infected macrophages only. There was profound early elaboration of IL-10, varying significantly from IL-12 and IFN-γ in all infected individual or mixed cell culture models except in the case of Jurkat; where all cytokine elaboration was downregulated. The receptor to IL-10 was upregulated in infected macrophage/Jurkat cells and THP-1/Jurkat cells compared with other models in which IL-12 and IFN-γ receptors were more expressed. There was no observed significant change in cytokine in any model following the impairment of intracellular Ca²⁺ except in the case of macrophage/Jurkat cell model in which IL-12 and IL-10 were upregulated in 1h or 3 h, respectively. The implication of these findings is that C. trachomatis mediates a switch from inflammatory to anti-inflammatory function in macrophages due to downregulation of the regulatory cytokine, IFN-γ in Jurkat cells, culminating in C. trachomatis chronic course.
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Affiliation(s)
- Anthony A Azenabor
- Department of Health Sciences, University of Wisconsin, Milwaukee, WI 53211, USA.
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Jan WC, Chen CH, Hsu K, Tsai PS, Huang CJ. L-Type Calcium Channels and μ-Opioid Receptors are Involved in Mediating the Anti-Inflammatory Effects of Naloxone. J Surg Res 2011; 167:e263-72. [DOI: 10.1016/j.jss.2010.03.039] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 02/13/2010] [Accepted: 03/16/2010] [Indexed: 11/24/2022]
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16
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Kao MC, Jan WC, Tsai PS, Wang TY, Huang CJ. Magnesium sulfate mitigates lung injury induced by bilateral lower limb ischemia-reperfusion in rats. J Surg Res 2011; 171:e97-106. [PMID: 21514604 DOI: 10.1016/j.jss.2011.03.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 03/06/2011] [Accepted: 03/10/2011] [Indexed: 12/20/2022]
Abstract
BACKGROUND Lower limb ischemia-reperfusion (I/R) elicits oxidative stress and causes inflammation in lung tissues that may lead to lung injury. Magnesium sulfate (MgSO(4)) possesses potent anti-oxidation and anti-inflammation capacity. We sought to elucidate whether MgSO(4) could mitigate I/R-induced lung injury. As MgSO(4) is an L-type calcium channel inhibitor, the role of the L-type calcium channels was elucidated. MATERIALS AND METHODS Adult male rats were allocated to receive I/R, I/R plus MgSO(4) (10, 50, or 100 mg/kg), or I/R plus MgSO(4) (100 mg/kg) plus the L-type calcium channels activator BAY-K8644 (20 μg/kg) (n = 12 in each group). Control groups were run simultaneously. I/R was induced by applying rubber band tourniquets high around each thigh for 3 h followed by reperfusion for 3 h. After euthanization, degrees of lung injury, oxidative stress, and inflammation were determined. RESULTS Arterial blood gas and histologic assays, including histopathology, leukocyte infiltration (polymorphonuclear leukocytes/alveoli ratio and myeloperoxidase activity), and lung water content, confirmed that I/R caused significant lung injury. Significant increases in inflammatory molecules (chemokine, cytokine, and prostaglandin E(2) concentrations) and lipid peroxidation (malondialdehyde concentration) confirmed that I/R caused significant inflammation and oxidative stress in rat lungs. MgSO(4), at the dosages of 50 and 100 mg/kg but not 10 mg/kg, attenuated the oxidative stress, inflammation, and lung injury induced by I/R. Moreover, BAY-K8644 reversed the protective effects of MgSO(4). CONCLUSIONS MgSO(4) mitigates lung injury induced by bilateral lower limb I/R in rats. The mechanisms may involve inhibiting the L-type calcium channels.
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Affiliation(s)
- Ming-Chang Kao
- Department of Anesthesiology, Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan
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17
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Magnesium Sulfate Inhibits Activator Protein-1 Upregulation in Endotoxin-activated Murine Macrophages. Tzu Chi Med J 2010. [DOI: 10.1016/s1016-3190(10)60068-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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18
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Lin C, Tsai P, Hung Y, Huang C. L-type calcium channels are involved in mediating the anti-inflammatory effects of magnesium sulphate. Br J Anaesth 2010; 104:44-51. [DOI: 10.1093/bja/aep336] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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19
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Azenabor AA, York J. Chlamydia trachomatis evokes a relative anti-inflammatory response in a free Ca2+ dependent manner in human macrophages. Comp Immunol Microbiol Infect Dis 2009; 33:513-28. [PMID: 19782401 DOI: 10.1016/j.cimid.2009.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2009] [Revised: 08/19/2009] [Accepted: 09/04/2009] [Indexed: 01/08/2023]
Abstract
Chlamydia trachomatis infections manifest as unique, chronic inflammatory diseases, indicating a relative compromise in the capacity of early immune responders such as macrophages to resolve the infection. We decided to investigate whether or not the chronic inflammatory manifestations are influenced by a disturbance in the pattern of inflammatory:anti-inflammatory cytokine elaboration early in the infection cycle in macrophages and assess the possible modulatory role of Ca(2+) signals in the process. Although the basal and functional levels of IL-12 and IL-10 are not identical in concentration, chlamydia initiated a significant decline in IL-12. This led to a difference in the ratio of time-course decline in IL-12 compared with IL-10 in a Ca(2+)-poor medium, while there was significant increase in IL-10 in a Ca(2+)-rich medium. Also, when macrophages were infected after treatment with drugs that either facilitated Ca(2+) influx into cells or inhibited efflux from intracellular stores into cytosol, there was a significant enhancement of the elaboration of IL-10 compared with IL-12. The immobilization of cytosolic Ca(2+) by BAPTA-AM resulted in the decline of macrophage IL-12 and IL-10 in both infected and uninfected cases. There was evidence that infectivity and status of chlamydial elementary bodies harvested from macrophages during these experiments were consistent with chronic forms as assessed by HSP-60:MOMP ratio. The implication of these findings is that chlamydia infection of macrophages, together with its capacity to moderate macrophage intracellular Ca(2+) levels, may evoke a net anti-inflammatory response that presumably favors chronic chlamydia infections.
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Affiliation(s)
- Anthony A Azenabor
- Department of Health Sciences, University of Wisconsin, Milwaukee, WI 53211, USA.
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20
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Free intracellular Ca2+ regulates bacterial lipopolysaccharide induction of iNOS in human macrophages. Immunobiology 2009; 214:143-52. [DOI: 10.1016/j.imbio.2008.06.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 05/15/2008] [Accepted: 06/06/2008] [Indexed: 11/23/2022]
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21
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Wang C, Zhang D, Li G, Liu J, Tian J, Fu F, Liu K. Neuroprotective effects of safflor yellow B on brain ischemic injury. Exp Brain Res 2006; 177:533-9. [PMID: 17006684 DOI: 10.1007/s00221-006-0705-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Accepted: 08/30/2006] [Indexed: 10/24/2022]
Abstract
The present study was conducted to investigate whether safflor yellow B (SYB) had a protective effect on cerebral ischemic injury and to determine the possible mechanisms in vivo and in vitro. In vivo, Male Wistar-Kyoto (WKY) rats were used to make the model of middle cerebral artery occlusion (MCAO). The behavioral test was used to measure neurological deficit scores for evaluation of the ischemic damage of brain. The infarction area of brain was assessed in brain slices stained with 2% solution of 2,3,5-triphenyl tetrazolium chloride (TTC). Spectrophotometric assay was used to determine the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), contents of malondialdehyde (MDA) and adenosine triphosphate (ATP) of the brain. Furthermore, the respiratory control ratio (RCR = state 3/state 4) was assessed in the brain mitochondria. In vitro, the effect of SYB was tested in cultured fetal cortical cells exposed to glutamate to identify its neuroprotection against neurons damage. The results in vivo showed that SYB at doses of 3.0 and 6.0 mg kg(-1) markedly decreased the neurological deficit scores and the infarction area in MCAO rats. At the same time, SYB significantly improved mitochondrial energy metabolism, decreased MDA content, and increased SOD and GPx activities in ischemic brain. The results in vitro showed that SYB remarkably inhibited neuron damage induced by glutamate in cultured fetal cortical cells. These suggest that SYB might act as a potential neuroprotective agent against the cerebral ischemia-induced injury in rat brain through reducing lipid peroxides, scavenging free radicals, and improving the energy metabolism.
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Affiliation(s)
- Chaoyun Wang
- Department of Pharmacology, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi 710061, People's Republic of China
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22
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Azenabor AA, Muili K, Akoachere JF, Chaudhry A. Macrophage antioxidant enzymes regulate Chlamydia pneumoniae chronicity: evidence of the effect of redox balance on host-pathogen relationship. Immunobiology 2006; 211:325-39. [PMID: 16716802 DOI: 10.1016/j.imbio.2005.12.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Accepted: 12/14/2005] [Indexed: 10/24/2022]
Abstract
Latency, chronicity and recurrent nature are the features of Chlamydia pneumoniae biology which play a central role in the course and outcome of C. pneumoniae-host interaction. Since redox status is directly an indicator of inflammatory response via molecular signaling mechanisms, we decided to study the regulatory role of macrophage cellular redox balance on the molecular indices of C. pneumoniae chronicity. We examined GSH-GSSG status, the activities of antioxidant enzymes (SOD, GPx and gamma-GCS), along with their protein and gene expression, the MOMP and cHSP-60 protein and gene expression, and the consequence of redox balance on the establishment of productive infection in macrophages. Results showed that C. pneumoniae caused changes in GSH-GSSG levels, antioxidant enzymes activity, mRNA gene and protein expression in macrophages. The relevance of this to the state and status of C. pneumoniae in macrophages was assessed by inhibitor induced attenuation of antioxidant enzymes and there was evidence that, while SOD attenuation did not significantly affect MOMP and cHSP-60 gene and protein expression, gamma-GCS attenuation increased cHSP-60 gene and protein expression. The increase in molecular evidence of chronic forms of C. pneumoniae (cHSP-60) was consistent with decrease in normal forms of C. pneumoniae. These findings reflect the importance of redox balance modulation on the outcome of C. pneumoniae infection in macrophages, a significant process in the pathogenesis of chlamydial diseases.
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Affiliation(s)
- Anthony A Azenabor
- Department of Health Sciences, University of Wisconsin, Enderis Hall, Room 469, 2400 E. Hartford Avenue, Milwaukee, WI 53211, USA.
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23
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Azenabor AA, Job G, Adedokun OO. Chlamydia pneumoniae infected macrophages exhibit enhanced plasma membrane fluidity and show increased adherence to endothelial cells. Mol Cell Biochem 2005; 269:69-84. [PMID: 15786718 DOI: 10.1007/s11010-005-2537-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Chlamydia pneumoniae, an intracellular prokaryote, is known to have requirement for some lipids which it is incapable of synthesizing, and these lipids have important fluidizing roles in plasma membrane. We decided to examine if the trafficking of these lipids to C. pneumoniae alters the physicochemical properties of macrophage plasma membrane, affects the expression of genes and proteins of enzymes associated with metabolism of some of these lipids and assess if Ca2+ signaling usually induced in macrophages infected with C. pneumoniae modulates the genes of these selected enzymes. Chlamydia pneumoniae induced the depletion of macrophage membrane cholesterol, phosphatidylinositol and cardiolipin but caused an increase in phosphotidylcholine resulting in a relative increase in total phospholipids. There was increased membrane fluidity, enhanced macrophage fragility and heightened adherence of macrophages to endothelial cells despite the application of inhibitor of adhesion molecules. Also, there was impairment of macrophage 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase gene and protein expression independent of Ca2+ signaling, while phospholipase C gene and protein were up-regulated in a manner minimally dependent on Ca2+ signaling. The implications of these findings are that macrophages infected with C. pneumoniae have altered membrane physicochemical characteristics which may render them atherogenic.
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Affiliation(s)
- Anthony A Azenabor
- Department of Health Sciences, University of Wisconsin, Milwaukee, WI 53211, USA
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24
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Azenabor AA, Yang S, Job G, Adedokun OO. Elicitation of reactive oxygen species in Chlamydia pneumoniae-stimulated macrophages: a Ca2+-dependent process involving simultaneous activation of NADPH oxidase and cytochrome oxidase genes. Med Microbiol Immunol 2005; 194:91-103. [PMID: 15197588 DOI: 10.1007/s00430-004-0223-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chlamydia pneumoniae, a respiratory pathogen implicated in the development and progress of atherosclerosis, is known to infect and survive in macrophages, despite macrophage producing reactive oxygen species (ROS). To gain insight into ROS generation in macrophages infected with C. pneumoniae and to explore factors accounting for their final levels and effect, we investigated the role of NADPH oxidase and cytochrome oxidase pathways in the production and modulation of ROS. We also determined the operational role of Ca2+ signaling in the process. Macrophages stimulated with C. pneumoniae exhibit early release of ROS via up-regulation of NADPH oxidase and cytochrome c oxidase activities. Increasing the dose of C. pneumoniae led to an increase in the expression of these enzymes gene production, which was accompanied by a significant up-regulation of their gene products, implying a probable activation of transcriptional and translational processes, respectively. The change in levels of free Ca2+, influx across plasma membrane and efflux from intracellular store into cytosol all exhibited a significant regulatory role on the ROS generation pathways in macrophages. The observed events were shown to be dependent on binding of C. pneumoniae to CD14 receptors of macrophages. The data reported here imply that macrophages infected with C. pneumoniae produce ROS through membrane-associated NADPH oxidase with oxidative phosphorylation levels depending on Ca2+ influx signals.
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Affiliation(s)
- Anthony A Azenabor
- Department of Health Sciences, Enderis Hall, University of Wisconsin, Milwaukee, WI 53211, USA.
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Yaraei K, Campbell LA, Zhu X, Liles WC, Kuo CC, Rosenfeld ME. Chlamydia pneumoniae augments the oxidized low-density lipoprotein-induced death of mouse macrophages by a caspase-independent pathway. Infect Immun 2005; 73:4315-22. [PMID: 15972525 PMCID: PMC1168605 DOI: 10.1128/iai.73.7.4315-4322.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2004] [Revised: 02/03/2005] [Accepted: 02/28/2005] [Indexed: 11/20/2022] Open
Abstract
Chlamydia pneumoniae is a common respiratory pathogen that is associated with an increased risk of cardiovascular disease. However, the mechanisms by which C. pneumoniae contributes to cardiovascular disease have not been determined yet. C. pneumoniae infection may accelerate the death of cells within atherosclerotic lesions and contribute to the formation of unstable lesions. To test this hypothesis, the impact of C. pneumoniae infection on the death of lipid-loaded mouse macrophages was investigated. It was observed that RAW 264.7 cells are highly susceptible to the toxic effects of oxidized low-density lipoprotein (LDL) and exhibit markers of cell death within 24 h of treatment with as little as 5 microg/ml oxidized LDL. Subsequent infection with either live C. pneumoniae or heat-killed or UV-inactivated C. pneumoniae at a low multiplicity of infection for 24 to 72 h stimulated both additional binding of annexin V and the uptake of propidium iodide. Thus, C. pneumoniae augments the effects of oxidized LDL on cell death independent of a sustained infection. However, unlike oxidized LDL, C. pneumoniae infection does not activate caspase 3 or induce formation of the mitochondrial transition pore or the fragmentation of DNA, all of which are classical markers of apoptosis. Furthermore, primary bone marrow macrophages isolated from mice deficient in Toll-like receptor 2 (TLR-2) but not TLR-4 are resistant to C. pneumoniae-induced death. These data suggest that C. pneumoniae kills cells by a caspase-independent pathway and that the process is potentially mediated by activation of TLR-2.
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Affiliation(s)
- Kambiz Yaraei
- Department of Pathobiology, Box 353410, University of Washington, Seattle, Washington 98195, USA
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26
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Azenabor AA, Job G, Yang S. Induction of lipoprotein lipase gene expression in Chlamydia pneumoniae-infected macrophages is dependent on Ca2+ signaling events. Biol Chem 2004; 385:67-74. [PMID: 14977048 DOI: 10.1515/bc.2004.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Unregulated uptake of low density lipoprotein (LDL) in macrophages is the hallmark of early atherogenic lesions, and Chlamydia pneumoniae infection of macrophages induces this process by an unknown mechanism. It was therefore aimed in this study to investigate (i) the role of C. pneumoniae in macrophage expression of the lipoprotein lipase (LpL) gene, (ii) the probable role of Ca2+ influx signals and (iii) the effect of the process on LDL uptake. Lipoprotein lipase mRNA expression and LpL activity in infected RAW-264.7 cells were significantly upregulated. A biphasic Ca2+ influx signal was observed in infected cells with a moderate influx (303 nM Ca2+) favoring optimal LpL gene expression. Also, the antagonists of L-type Ca2+ channel in macrophages significantly down-regulated LpL gene expression and the biomolecular content of C. pneumoniae responsible for the observed events was in part found to be Chlamydia lipopolysaccharide (cLPS). Investigations aimed at determining the specific relevance of Ca(2+)-dependent lipoprotein lipase gene expression in C. pneumoniae-infected macrophages showed that the condition caused enhanced uptake of LDL which was abrogated by Calphostin-C-mediated down-regulation of LpL. This discovery of a specialized Ca2+ influx signal-mediated LpL upregulation in C. pneumoniae-infected macrophages provides a mechanistic insight into early events involving C. pneumoniae in macrophage foam cell formation resulting from LDL uptake.
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Affiliation(s)
- Anthony A Azenabor
- Department of Health Sciences, University of Wisconsin, 2400 E. Hartford Avenue, Milwaukee, WI 53211, USA.
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27
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Azenabor AA, Yang S, Job G, Adedokun OO. Expression of iNOS gene in macrophages stimulated with 17β-estradiol is regulated by free intracellular Ca2+. Biochem Cell Biol 2004; 82:381-90. [PMID: 15181472 DOI: 10.1139/o04-032] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
17β-Estradiol has potent Ca2+ ionophore capability and its signaling in macrophages is mediated through binding to surface and genomic receptors, resulting in transient nitric oxide (NO) elaboration. We decided to examine if the transient release of NO is due to Ca2+ influx pattern or the quenching effect of superoxide (·O2–) through peroxynitrite formation. Differential chelation of intracellular Ca2+ ([Ca2+]i) showed that NO generation was favored by [Ca2+]i concentration of 237 nM. Application of an estrogen receptor antagonist ICI 182 780 resulted in attenuation of estradiol mediated NO release. Studies directed at identifying the possible role of ·O2– in the attenuation of NO showed no supportive evidence. Inhibition of extracellular Ca2+ channel or extracellular and intracellular Ca2+ channels showed data consistent with a case for optimum Ca2+ influx signal favoring iNOS gene expression, accompanied by an elevation in iNOS protein. These data show that Ca2+ influx pattern determines macrophage NO elaboration.Key words: optimum Ca2+ signals, activation of iNOS gene, estradiol signaling.
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Affiliation(s)
- A A Azenabor
- Department of Health Sciences, Univesrity of Wisconsin, Enderis Hall, Room 469, 2400 E. Hartford Avenue, Milwaukee, WI 53211, USA.
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28
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Azenabor AA, Chaudhry AU, Yang S. Macrophage L-type Ca2+ channel antagonists alter Chlamydia pneumoniae MOMP and HSP-60 mRNA gene expression, and improve antibiotic susceptibility. Immunobiology 2004; 207:237-45. [PMID: 12952346 DOI: 10.1078/0171-2985-00238] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Recent data have shown a unique relationship between Ca2+ signaling in macrophages through L-type channels and the outcome of C. pneumoniae infection of such cells. The present investigation seeks to provide insights into the manner in which macrophage L-type Ca2+ channel operation affects major outer membrane protein (MOMP) and heat shock protein-60 (HSP-60) mRNA gene expression (factors associated with Chlamydia chronicity), and the possible effect of this on antibiotic susceptibility. Intracellular calcium ([Ca2+]i) chelation using varying doses of 1,2-bis (o-aminophenoxy) ethane-N,N,N'N'--tetra acetic acid (acetoxymethyl) ester (BAPTA-AM) induced an increase in MOMP and a decrease in HSP-60 mRNA gene expression. L-type Ca2+ channel antagonists produced an identical but enhanced effect. Since these findings associate specialized Ca2+ channels to Chlamydia chronicity, it was important to determine Ca2+ channel effect on the usual antibiotic refractory form of C. pneumoniae in macrophages. Inhibition of macrophage L-type Ca2+ channel operation improved C. pneumoniae antibiotic susceptibility assessed by decreased inclusion counts or down-regulated MOMP and HSP-60 mRNA gene expression. These findings provide molecular insights into how specialized Ca2+ channels influence Chlamydia chronic course in macrophages and demonstrates a role for L-type Ca2+ channel inhibitors in enhanced C. pneumoniae susceptibility to antibiotic therapy.
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Affiliation(s)
- Anthony A Azenabor
- Department of Health Sciences, University of Wisconsin, Milwaukee, WI 53211, USA.
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