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Liwu Li, Jacinto R, Yoza B, McCall CE. Distinct post-receptor alterations generate gene- and signal-selective adaptation and cross-adaptation of TLR4 and TLR2 in human leukocytes. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/09680519030090010401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Gene- and signal-specific adaptation/tolerance of blood leukocytes to lipopolysaccharide endotoxin (LPS) occurs during human and animal septicemia. These phenotypes can be modeled in vitro. LPS-TLR4-adapted human THP-1 promonocytic cells cross-adapt to lipoteichoic acid (LTA)-TLR2-induced IL-1β/TNF-α production, suggesting disruption of a common intracellular signaling event(s). A plausible explanation for homologous adaptation of TLR4 with heterologous adaptation of TLR2 is a persistent inactivation and degradation of IRAK1 following TLR4 activation. LTA stimulation of TLR2 also produces homologous adaptation of TLR2 with inactivation of IRAK1, but there is no detectable degradation of IRAK1. Strikingly, such LTA-adapted cells still respond to LPS stimulation of TLR4 with rapid activation and degradation of IRAK1, and robust IL-1β/TNFα production. Moreover, cells adapted to either LTA- or LPS-production of IL-1β/TNF-α normally produce soluble interleukin 1 receptor antagonist (sIL-1Ra) anti-inflammatory protein when stimulated by either agonist. We conclude that: (i) disruption of a unique TLR2 signaling component upstream of IRAK1, but downstream of TLR2 sensing, induces homologous adaptation to LTA; (ii) disruption of IRAK1 may induce homologous adaptation of TLR4 to LPS and cross-adaptation of TLR2 to LTA; and (iii) TLR2/TLR4 signaling events that control sIL-1Ra translation do not adapt to LPS or LTA, indicating that TLR4 and TLR2 can still function. We present a hypothetical model of adaptation based on a signalsome, with IRAK1 evolving after IRAK4 to regulate TLR4 adaptation tightly.
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Affiliation(s)
- Liwu Li
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston Salem, North Carolina, USA
| | - Randy Jacinto
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston Salem, North Carolina, USA
| | - Barbara Yoza
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston Salem, North Carolina, USA
| | - Charles E. McCall
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston Salem, North Carolina, USA,
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Wang X, Buechler NL, Martin A, Wells J, Yoza B, McCall CE, Vachharajani V. Correction: Sirtuin-2 Regulates Sepsis Inflammation in ob/ob Mice. PLoS One 2016; 11:e0162560. [PMID: 27583522 PMCID: PMC5008694 DOI: 10.1371/journal.pone.0162560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Wang X, Buechler NL, Martin A, Wells J, Yoza B, McCall CE, Vachharajani V. Sirtuin-2 Regulates Sepsis Inflammation in ob/ob Mice. PLoS One 2016; 11:e0160431. [PMID: 27500833 PMCID: PMC4976857 DOI: 10.1371/journal.pone.0160431] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 07/19/2016] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE Obesity increases morbidity and resource utilization in sepsis patients. Sepsis transitions from early/hyper-inflammatory to late/hypo-inflammatory phase. Majority of sepsis-mortality occurs during the late sepsis; no therapies exist to treat late sepsis. In lean mice, we have shown that sirtuins (SIRTs) modulate this transition. Here, we investigated the role of sirtuins, especially the adipose-tissue abundant SIRT-2 on transition from early to late sepsis in obese with sepsis. METHODS Sepsis was induced using cecal ligation and puncture (CLP) in ob/ob mice. We measured microvascular inflammation in response to lipopolysaccharide/normal saline re-stimulation as a "second-hit" (marker of immune function) at different time points to track phases of sepsis in ob/ob mice. We determined SIRT-2 expression during different phases of sepsis. We studied the effect of SIRT-2 inhibition during the hypo-inflammatory phase on immune function and 7-day survival. We used a RAW264.7 (RAW) cell model of sepsis for mechanistic studies. We confirmed key findings in diet induced obese (DIO) mice with sepsis. RESULTS We observed that the ob/ob-septic mice showed an enhanced early inflammation and a persistent and prolonged hypo-inflammatory phase when compared to WT mice. Unlike WT mice that showed increased SIRT1 expression, we found that SIRT2 levels were increased in ob/ob mice during hypo-inflammation. SIRT-2 inhibition in ob/ob mice during the hypo-inflammatory phase of sepsis reversed the repressed microvascular inflammation in vivo via activation of endothelial cells and circulating leukocytes and significantly improved survival. We confirmed the key finding of the role of SIRT2 during hypo-inflammatory phase of sepsis in this project in DIO-sepsis mice. Mechanistically, in the sepsis cell model, SIRT-2 expression modulated inflammatory response by deacetylation of NFκBp65. CONCLUSION SIRT-2 regulates microvascular inflammation in obese mice with sepsis and may provide a novel treatment target for obesity with sepsis.
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Affiliation(s)
- Xianfeng Wang
- Departments of Anesthesiology Wake Forest School of Medicine, Winston-Salem, NC, United States of America
| | - Nancy L. Buechler
- Departments of Anesthesiology Wake Forest School of Medicine, Winston-Salem, NC, United States of America
| | - Ayana Martin
- Department of Medicine Wake Forest School of Medicine, Winston-Salem, NC, United States of America
| | - Jonathan Wells
- Department of Surgery Wake Forest School of Medicine, Winston-Salem, NC, United States of America
| | - Barbara Yoza
- Department of Medicine Wake Forest School of Medicine, Winston-Salem, NC, United States of America
- Department of Surgery Wake Forest School of Medicine, Winston-Salem, NC, United States of America
| | - Charles E. McCall
- Department of Medicine Wake Forest School of Medicine, Winston-Salem, NC, United States of America
| | - Vidula Vachharajani
- Departments of Anesthesiology Wake Forest School of Medicine, Winston-Salem, NC, United States of America
- Department of Medicine Wake Forest School of Medicine, Winston-Salem, NC, United States of America
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Millet P, Vachharajani V, McPhail L, Yoza B, McCall CE. GAPDH Binding to TNF-α mRNA Contributes to Posttranscriptional Repression in Monocytes: A Novel Mechanism of Communication between Inflammation and Metabolism. J Immunol 2016; 196:2541-51. [PMID: 26843329 DOI: 10.4049/jimmunol.1501345] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 01/03/2016] [Indexed: 12/14/2022]
Abstract
Expression of the inflammatory cytokine TNF is tightly controlled. During endotoxin tolerance, transcription of TNF mRNA is repressed, although not entirely eliminated. Production of TNF cytokine, however, is further controlled by posttranscriptional regulation. In this study, we detail a mechanism of posttranscriptional repression of TNF mRNA by GAPDH binding to the TNF 3' untranslated region. Using RNA immunoprecipitation, we demonstrate that GAPDH-TNF mRNA binding increases when THP-1 monocytes are in a low glycolysis state, and that this binding can be reversed by knocking down GAPDH expression or by increasing glycolysis. We show that reducing glycolysis decreases TNF mRNA association with polysomes. We demonstrate that GAPDH-TNF mRNA binding results in posttranscriptional repression of TNF and that the TNF mRNA 3' untranslated region is sufficient for repression. Finally, after exploring this model in THP-1 cells, we demonstrate this mechanism affects TNF expression in primary human monocytes and macrophages. We conclude that GAPDH-TNF mRNA binding regulates expression of TNF based on cellular metabolic state. We think this mechanism has potentially significant implications for treatment of various immunometabolic conditions, including immune paralysis during septic shock.
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Affiliation(s)
- Patrick Millet
- Molecular Genetics and Genomics Program, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Vidula Vachharajani
- Department of Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157; Department of Anesthesiology, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Linda McPhail
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, NC 27157; and
| | - Barbara Yoza
- Department of General Surgery, Wake Forest University School of Medicine, Winston-Salem, NC 27157
| | - Charles E McCall
- Department of Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem, NC 27157;
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Vachharajani V, Cunningham C, Yoza B, Carson J, Vachharajani TJ, McCall C. Adiponectin-deficiency exaggerates sepsis-induced microvascular dysfunction in the mouse brain. Obesity (Silver Spring) 2012; 20:498-504. [PMID: 21996662 PMCID: PMC3288614 DOI: 10.1038/oby.2011.316] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Obesity increases circulating cell-endothelial cell interactions; an early marker of inflammation in laboratory model of sepsis, but little is known about the effect of different adipokines. Adiponectin is an anti-inflammatory adipokine secreted by adipocytes. Adiponectin deficiency is implicated in exaggerated proinflammatory phenotype in both obesity and sepsis via increased proinflammatory cytokine expression. However the effect of adiponectin deficiency on circulating cell-endothelial cell interactions in polymicrobial sepsis is unknown. Furthermore although brain dysfunction in septic patients is a known predictor of death, the pathophysiology involved is unknown. In the current study, we examined the effects of adiponectin deficiency on leukocyte (LA) and platelet adhesion (PA) in cerebral microcirculation of septic mice. Adiponectin deficient (Adipoq(-/-): Adko) and background strain C57Bl/6 (wild type (WT)) mice were used. Sepsis was induced using cecal ligation and puncture (CLP). We studied LA and PA in the cerebral microcirculation using intravital fluorescent video microscopy (IVM), blood brain barrier (BBB) dysfunction using Evans Blue (EB) leakage method and E-selectin expression using dual radiolabeling technique in different WT and Adko mice with CLP. Adiponectin deficiency significantly exaggerated LA (WT-CLP:201 ± 17; Adko-CLP: ± 53 cells/mm(2); P < 0.05) and PA (WT-CLP:125 ± 17; Adko-CLP:188 ± 20 cells/mm(2); P < 0.05) in cerebral microcirculation, EB leakage (WT-CLP:10 ± 3.7; Adko-CLP:24 ± 4.3 ng/g × µl plasma; P < 0.05) and E-selectin expression (WT-CLP:0.06 ± 0.11; Adko-CLP:0.44 ± 0.053 ng/g; P < 0.05) in the brain tissue of the mice with CLP. Furthermore, E-selectin monoclonal antibody (mAb) treatment attenuated cell adhesion and BBB dysfunction of Adko-CLP mice. Adiponectin deficiency is associated with exaggerated leukocyte and PA in cerebral microcirculation of mice with CLP via modulation of E-selectin expression.
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Affiliation(s)
- Vidula Vachharajani
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
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McCall CE, El Gazzar M, Liu T, Vachharajani V, Yoza B. Epigenetics, bioenergetics, and microRNA coordinate gene-specific reprogramming during acute systemic inflammation. J Leukoc Biol 2011; 90:439-46. [PMID: 21610199 DOI: 10.1189/jlb.0211075] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Acute systemic inflammation from infectious and noninfectious etiologies has stereotypic features that progress through an initiation (proinflammatory) phase, an adaptive (anti-inflammatory) phase, and a resolution (restoration of homeostasis) phase. These phase-shifts are accompanied by profound and predictable changes in gene expression and metabolism. Here, we review the emerging concept that the temporal phases of acute systemic inflammation are controlled by an integrated bioenergy and epigenetic bridge that guides the timing of transcriptional and post-transcriptional processes of specific gene sets. This unifying connection depends, at least in part, on redox sensor NAD(+)-dependent deacetylase, Sirt1, and a NF-κB-dependent p65 and RelB feed-forward and gene-specific pathway that generates silent facultative heterochromatin and active euchromatin. An additional level of regulation for gene-specific reprogramming is generated by differential expression of miRNA that directly and indirectly disrupts translation of inflammatory genes. These molecular reprogramming circuits generate a dynamic chromatin landscape that temporally defines the course of acute inflammation.
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Affiliation(s)
- Charles E McCall
- Wake Forest University Medical Center, Winston Salem, NC 27157, USA.
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Abstract
OBJECTIVE Circulating cell-endothelial cell interaction in sepsis is a rate-determining factor in organ dysfunction, and interventions targeting this process have a potential therapeutic value. In this project, we examined whether curcumin, an active ingredient of turmeric and an anti-inflammatory agent, could disrupt interactions between circulating blood cells and endothelium and improve survival in a murine model of sepsis. METHODS Mice were subjected to cecal ligation and puncture (CLP) to induce sepsis vs. sham surgery. We studied leukocyte and platelet adhesion in cerebral microcirculation using intravital fluorescent video microscopy technique, blood-brain barrier (BBB) dysfunction using Evans Blue (EB) leakage method, P-selectin expression using dual radiolabeling technique, and survival in mice subjected to Sham, CLP, and CLP with curcumin pre-treatment (CLP + curcumin). RESULTS Curcumin significantly attenuated leukocyte and platelet adhesion in cerebral microcirculation, EB leakage in the brain tissue, and improved survival in mice with CLP. P-selectin expression in mice with CLP + curcumin was significantly attenuated compared with CLP in various microcirculatory beds, including brain. Reduction in platelet adhesion was predominantly via modulation of endothelium by curcumin. CONCLUSION Curcumin pre-treatment modulates leukocyte and platelet adhesion and BBB dysfunction in mice with CLP via P-selectin expression and improves survival in mice with CLP.
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Affiliation(s)
- Vidula Vachharajani
- Department of Anesthesiology/Section for Critical Care, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
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McCall CE, Yoza B, Liu T, El Gazzar M. Gene-specific epigenetic regulation in serious infections with systemic inflammation. J Innate Immun 2010; 2:395-405. [PMID: 20733328 DOI: 10.1159/000314077] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Accepted: 02/16/2010] [Indexed: 01/24/2023] Open
Abstract
Inflammation is a fundamental biologic process that is evolutionally conserved by a germ line code. The interplay between epigenetics and environment directs the code into temporally distinct inflammatory responses, which can be acute or chronic. Here, we discuss the epigenetic processes of innate immune cells during serious infections with systemic inflammation in four stages: homeostasis, incitement, evolution, and resolution. We describe feed-forward loops of serious infections with systemic inflammation that create gene-specific silent facultative heterochromatin and active euchromatin according to gene function, and speculate on the role of epigenetics in survival.
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Affiliation(s)
- Charles E McCall
- Translational Science Institute, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
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Li L, Jacinto R, Yoza B, McCall CE. Distinct post-receptor alterations generate gene- and signal-selective adaptation and cross-adaptation of TLR4 and TLR2 in human leukocytes. J Endotoxin Res 2003; 9:39-44. [PMID: 12691617 DOI: 10.1179/096805103125001324] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Gene- and signal-specific adaptation/tolerance of blood leukocytes to lipopolysaccharide endotoxin (LPS) occurs during human and animal septicemia. These phenotypes can be modeled in vitro. LPS-TLR4-adapted human THP-1 promonocytic cells cross-adapt to lipoteichoic acid (LTA)-TLR2-induced IL-1beta/TNF-alpha production, suggesting disruption of a common intracellular signaling event(s). A plausible explanation for homologous adaptation of TLR4 with heterologous adaptation of TLR2 is a persistent inactivation and degradation of IRAK1 following TLR4 activation. LTA stimulation of TLR2 also produces homologous adaptation of TLR2 with inactivation of IRAK1, but there is no detectable degradation of IRAK1. Strikingly, such LTA-adapted cells still respond to LPS stimulation of TLR4 with rapid activation and degradation of IRAK1, and robust IL-1beta/TNF-alpha production. Moreover, cells adapted to either LTA- or LPS-production of IL-1beta/TNF-alpha normally produce soluble interleukin 1 receptor antagonist (sIL-1Ra) anti-inflammatory protein when stimulated by either agonist. We conclude that: (i) disruption of a unique TLR2 signaling component upstream of IRAK1, but downstream of TLR2 sensing, induces homologous adaptation to LTA; (ii) disruption of IRAK1 may induce homologous adaptation of TLR4 to LPS and cross-adaptation of TLR2 to LTA; and (iii) TLR2/TLR4 signaling events that control sIL-1Ra translation do not adapt to LPS or LTA, indicating that TLR4 and TLR2 can still function. We present a hypothetical model of adaptation based on a signalsome, with IRAK1 evolving after IRAK4 to regulate TLR4 adaptation tightly.
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Affiliation(s)
- Liwu Li
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest University School of Medicine, Winston Salem, North Carolina 27104, USA
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Yoza B, LaRue K, McCall C. Molecular mechanisms responsible for endotoxin tolerance. Prog Clin Biol Res 1998; 397:209-15. [PMID: 9575561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Bacterial lipopolysaccharide endotoxin (LPS) is a potent activator of a number of inflammatory genes, including interleukin-1 (IL-1). IL-1 and other cytokines such as tumor necrosis factor alpha (TNF alpha) are essential mediators in inducing severe sepsis syndromes (SS). Major cellular targets of LPS are blood or tissue leukocytes, such as macrophages and neutrophils. These cells can respond and adapt to LPS, the latter phenomenon is known as LPS tolerance. In animals, LPS tolerance is a highly effective mechanism of protection against the lethal syndrome of severe sepsis. Two models are used to investigate the molecular basis of LPS tolerance. The first model employs blood leukocytes isolated from patients with SS. The second model employs the promonocytic cell line, THP-1 in vitro. In the SS model, LPS tolerance of involves repression at the level of IL-1 beta mRNA. Suppression of IL-1 beta mRNA is under the control of a labile repressor protein. In contrast to suppression of IL-1 beta, mRNA is under the control of a labile repressor protein. In contrast to suppression of IL-1 beta, there is increased expression of the Type 2 IL-1 receptor mRNA and protein in leukocytes from patients with SS. The THP-1 model of LPS tolerance also involves repression of LPS induction of IL-1 beta gene expression. The repression of THP-1 cell IL-1 beta expression is at the level of transcription, and like the SS model is under the control of a labile protein. LPS tolerance in both models is stimulus-specific. We further find that transcription factors such as NF kappa B and AP-1 may participate in regulating LPS tolerance.
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Affiliation(s)
- B Yoza
- Bowman Gray School of Medicine of Wake Forest University Winston-Salem, NC 27157-1042, USA
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