1
|
Pandey AK, Trivedi V. Hemin competitively inhibits HSPA8 ATPase activity mitigating its foldase function. Arch Biochem Biophys 2024; 752:109889. [PMID: 38215959 DOI: 10.1016/j.abb.2024.109889] [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: 10/17/2023] [Revised: 12/19/2023] [Accepted: 01/09/2024] [Indexed: 01/14/2024]
Abstract
Hemolysis in red blood cells followed by hemoglobin degradation results in high hemin levels in the systemic circulation. Such a level of hemin is disastrous for cells and tissues and is considerably responsible for the pathologies of diseases like severe malaria. Hemin's hydrophobic chemical nature and structure allow it to bind several proteins leading to their functional modification. Such modifications in physiologically relevant proteins can have a high impact on various cellular processes. HSPA8 is a chaperone that has a protective role in oxidative stress by aiding protein refolding. Through ATPase activity assays we found that hemin can competitively inhibit ATP hydrolysis by the chaperone HSPA8. Hemin as such does not affect the structural integrity of the protein which is inferred from CD spectroscopy and Gel filtration but it hinders the ATP-dependent foldase function of the chaperone. HSPA8 was not able to cause the refolding of the model protein lysozyme in the presence of hemin. The loss in HSPA8 function was due to competition between hemin and ATP as the chaperone was able to regain the foldase function when the concentration of ATP was gradually increased with hemin present at the inhibitory concentration. In-silico studies to establish the competition for the specific binding site revealed that ATP was unable to replace hemin from the ATP binding pocket of HSPA8 and was forced to form a non-specific and unstable complex. In-vitro isothermal calorimetry revealed that the affinity of ATP for binding to HSPA8 was reduced 22 folds in the presence of hemin. The prevention of HSPA8's cytoprotective function by hemin can be a major factor contributing to the overall cellular damage during hemin accumulation in the case of severe malaria and other hemolytic diseases.
Collapse
Affiliation(s)
- Alok Kumar Pandey
- Malaria Research Group, Department of Bioscience and Bioengineering, Indian Institute of Technology-Guwahati, Guwahati, 781039, Assam, India
| | - Vishal Trivedi
- Malaria Research Group, Department of Bioscience and Bioengineering, Indian Institute of Technology-Guwahati, Guwahati, 781039, Assam, India.
| |
Collapse
|
2
|
Hopp MT, Holze J, Lauber F, Holtkamp L, Rathod DC, Miteva MA, Prestes EB, Geyer M, Manoury B, Merle NS, Roumenina LT, Bozza MT, Weindl G, Imhof D. Insights into the molecular basis and mechanism of heme-triggered TLR4 signalling: The role of heme-binding motifs in TLR4 and MD2. Immunology 2024; 171:181-197. [PMID: 37885279 DOI: 10.1111/imm.13708] [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: 05/16/2023] [Accepted: 10/06/2023] [Indexed: 10/28/2023] Open
Abstract
Haemolytic disorders, such as sickle cell disease, are accompanied by the release of high amounts of labile heme into the intravascular compartment resulting in the induction of proinflammatory and prothrombotic complications in affected patients. In addition to the relevance of heme-regulated proteins from the complement and blood coagulation systems, activation of the TLR4 signalling pathway by heme was ascribed a crucial role in the progression of these pathological processes. Heme binding to the TLR4-MD2 complex has been proposed recently, however, essential mechanistic information of the processes at the molecular level, such as heme-binding kinetics, the heme-binding capacity and the respective heme-binding sites (HBMs) is still missing. We report the interaction of TLR4, MD2 and the TLR4-MD2 complex with heme and the consequences thereof by employing biochemical, spectroscopic, bioinformatic and physiologically relevant approaches. Heme binding occurs transiently through interaction with up to four HBMs in TLR4, two HBMs in MD2 and at least four HBMs in their complex. Functional studies highlight that mutations of individual HBMs in TLR4 preserve full receptor activation by heme, suggesting that heme interacts with TLR4 through different binding sites independently of MD2. Furthermore, we confirm and extend the major role of TLR4 for heme-mediated cytokine responses in human immune cells.
Collapse
Affiliation(s)
- Marie-T Hopp
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, Bonn, Germany
- Department of Chemistry, Institute of Integrated Natural Sciences, University of Koblenz, Koblenz, Germany
| | - Janine Holze
- Pharmacology and Toxicology, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Felicitas Lauber
- Pharmacology and Toxicology, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Laura Holtkamp
- Pharmacology and Toxicology, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Dhruv C Rathod
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Maria A Miteva
- CNRS UMR 8038 CiTCoM, Université de Paris, Faculté de Pharmacie de Paris, Paris, France
- INSERM U 1268 Medicinal Chemistry and Translational Research, Paris, France
| | - Elisa B Prestes
- Laboratório de Inflamação e Imunidade, Departamento de Imunologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, Bonn, Germany
| | - Bénédicte Manoury
- Institut Necker Enfants Malades, INSERM U1151-CNRS UMR8253, Université Paris Cité, Faculté de médecine Necker, Paris, France
| | - Nicolas S Merle
- Centre de Recherche des Cordeliers, UMR_S 1138, INSERM, Paris, France
- Centre de Recherche des Cordeliers, Sorbonne Universités, Paris, France
- Centre de Recherche des Cordeliers, Université Paris Descartes, Paris, France
| | - Lubka T Roumenina
- Centre de Recherche des Cordeliers, UMR_S 1138, INSERM, Paris, France
- Centre de Recherche des Cordeliers, Sorbonne Universités, Paris, France
- Centre de Recherche des Cordeliers, Université Paris Descartes, Paris, France
| | - Marcelo T Bozza
- Laboratório de Inflamação e Imunidade, Departamento de Imunologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Günther Weindl
- Pharmacology and Toxicology, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Diana Imhof
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| |
Collapse
|
3
|
DeVallance ER, Schmidt HM, Seman M, Lewis SE, Wood KC, Vickers SD, Hahn SA, Velayutham M, Hileman EA, Vitturi DA, Leonardi R, Straub AC, Kelley EE. Hemin and iron increase synthesis and trigger export of xanthine oxidoreductase from hepatocytes to the circulation. Redox Biol 2023; 67:102866. [PMID: 37703667 PMCID: PMC10506059 DOI: 10.1016/j.redox.2023.102866] [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: 07/28/2023] [Revised: 08/20/2023] [Accepted: 08/25/2023] [Indexed: 09/15/2023] Open
Abstract
We recently reported a previously unknown salutary role for xanthine oxidoreductase (XOR) in intravascular heme overload whereby hepatocellular export of XOR to the circulation was identified as a seminal step in affording protection. However, the cellular signaling and export mechanisms underpinning this process were not identified. Here, we present novel data showing hepatocytes upregulate XOR expression/protein abundance and actively release it to the extracellular compartment following exposure to hemopexin-bound hemin, hemin or free iron. For example, murine (AML-12 cells) hepatocytes treated with hemin (10 μM) exported XOR to the medium in the absence of cell death or loss of membrane integrity (2.0 ± 1.0 vs 16 ± 9 μU/mL p < 0.0001). The path of exocytosis was found to be noncanonical as pretreatment of the hepatocytes with Vaculin-1, a lysosomal trafficking inhibitor, and not Brefeldin A inhibited XOR release and promoted intracellular XOR accumulation (84 ± 17 vs 24 ± 8 hemin vs 5 ± 3 control μU/mg). Interestingly, free iron (Fe2+ and Fe3+) induced similar upregulation and release of XOR compared to hemin. Conversely, concomitant treatment with hemin and the classic transition metal chelator DTPA (20 μM) or uric acid completely blocked XOR release (p < 0.01). Our previously published time course showed XOR release from hepatocytes likely required transcriptional upregulation. As such, we determined that both Sp1 and NF-kB were acutely activated by hemin treatment (∼2-fold > controls for both, p < 0.05) and that silencing either or TLR4 with siRNA prevented hemin-induced XOR upregulation (p < 0.01). Finally, to confirm direct action of these transcription factors on the Xdh gene, chromatin immunoprecipitation was performed indicating that hemin significantly enriched (∼5-fold) both Sp1 and NF-kB near the transcription start site. In summary, our study identified a previously unknown pathway by which XOR is upregulated via SP1/NF-kB and subsequently exported to the extracellular environment. This is, to our knowledge, the very first study to demonstrate mechanistically that XOR can be specifically targeted for export as the seminal step in a compensatory response to heme/Fe overload.
Collapse
Affiliation(s)
- Evan R DeVallance
- Center for Inhalation Toxicology, West Virginia University School of Medicine, Morgantown, WV, USA; Department of Physiology and Pharmacology, Health Sciences Center, West Virginia University, Morgantown, WV, USA
| | - Heidi M Schmidt
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Madison Seman
- Department of Physiology and Pharmacology, Health Sciences Center, West Virginia University, Morgantown, WV, USA
| | - Sara E Lewis
- Department of Physiology and Pharmacology, Health Sciences Center, West Virginia University, Morgantown, WV, USA
| | - Katherine C Wood
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Schuyler D Vickers
- Department of Biochemistry, West Virginia University, Morgantown, WV, 26505, USA
| | - Scott A Hahn
- Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Murugesan Velayutham
- Department of Biochemistry, West Virginia University, Morgantown, WV, 26505, USA
| | - Emily A Hileman
- Department of Physiology and Pharmacology, Health Sciences Center, West Virginia University, Morgantown, WV, USA
| | - Dario A Vitturi
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Roberta Leonardi
- Department of Biochemistry, West Virginia University, Morgantown, WV, 26505, USA
| | - Adam C Straub
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA; Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Eric E Kelley
- Department of Physiology and Pharmacology, Health Sciences Center, West Virginia University, Morgantown, WV, USA.
| |
Collapse
|
4
|
Burnet AM, Brunetti T, Rochford R. Hemin treatment drives viral reactivation and plasma cell differentiation of EBV latently infected B cells. PLoS Pathog 2023; 19:e1011561. [PMID: 37639483 PMCID: PMC10491393 DOI: 10.1371/journal.ppat.1011561] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 09/08/2023] [Accepted: 07/16/2023] [Indexed: 08/31/2023] Open
Abstract
Epstein-Barr virus (EBV) and Plasmodium falciparum have a well described role in the development of endemic Burkitt lymphoma (BL), yet the mechanisms involved remain unknown. A major hallmark of malarial disease is hemolysis and bystander eryptosis of red blood cells, which causes release of free heme in large quantities into peripheral blood. We hypothesized that heme released during malaria infection drives differentiation of latently infected EBV-positive B cells, resulting in viral reactivation and release of infectious virus. To test this hypothesis, we used the EBV-positive Mutu I B-cell line and treated with hemin (the oxidized form of heme) and evaluated evidence of EBV reactivation. Hemin treatment resulted in the expression of EBV immediate early, early and late lytic gene transcripts. In addition, expression of CD138, a marker of plasma cells was co-expressed with the late lytic protein gp350 on hemin treated Mutu I cells. Finally, DNase-resistant EBV DNA indicative of virion production was detected in supernatant. To assess the transcriptional changes induced by hemin treatment, RNA sequencing was performed on mock- and hemin-treated Mutu I cells, and a shift from mature B cell transcripts to plasma cell transcripts was identified. To identify the mechanism of hemin-induced B cell differentiation, we measured levels of the plasma cell transcriptional repressor, BACH2, that contains specific heme binding sites. Hemin treatment caused significant degradation of BACH2 by 24 hours post-treatment in four BL cell lines (two EBV positive, two EBV negative). Knockdown of BACH2 in Mutu I cells using siRNAs significantly increased CD138+gp350+ cells to levels similar to treatment with hemin. This suggested that hemin induced BACH2 degradation was responsible for plasma cell differentiation and viral reactivation. Together, these data support a model where EBV reactivation can occur during malaria infection via heme modulation, providing a mechanistic link between malaria and EBV.
Collapse
Affiliation(s)
- Anna M. Burnet
- Department of Immunology and Microbiology, University of Colorado, School of Medicine, Aurora, Colorado, United States of America
| | - Tonya Brunetti
- Department of Immunology and Microbiology, University of Colorado, School of Medicine, Aurora, Colorado, United States of America
| | - Rosemary Rochford
- Department of Immunology and Microbiology, University of Colorado, School of Medicine, Aurora, Colorado, United States of America
| |
Collapse
|
5
|
Lolansen SD, Rostgaard N, Barbuskaite D, Capion T, Olsen MH, Norager NH, Vilhardt F, Andreassen SN, Toft-Bertelsen TL, Ye F, Juhler M, Keep RF, MacAulay N. Posthemorrhagic hydrocephalus associates with elevated inflammation and CSF hypersecretion via activation of choroidal transporters. Fluids Barriers CNS 2022; 19:62. [PMID: 35948938 PMCID: PMC9367104 DOI: 10.1186/s12987-022-00360-w] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/14/2022] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION Posthemorrhagic hydrocephalus (PHH) often develops following hemorrhagic events such as intraventricular hemorrhage (IVH) and subarachnoid hemorrhage (SAH). Treatment is limited to surgical diversion of the cerebrospinal fluid (CSF) since no efficient pharmacological therapies are available. This limitation follows from our incomplete knowledge of the molecular mechanisms underlying the ventriculomegaly characteristic of PHH. Here, we aimed to elucidate the molecular coupling between a hemorrhagic event and the subsequent PHH development, and reveal the inflammatory profile of the PHH pathogenesis. METHODS CSF obtained from patients with SAH was analyzed for inflammatory markers using the proximity extension assay (PEA) technique. We employed an in vivo rat model of IVH to determine ventricular size, brain water content, intracranial pressure, and CSF secretion rate, as well as for transcriptomic analysis. Ex vivo radio-isotope assays of choroid plexus transport were employed to determine the direct effect of choroidal exposure to blood and inflammatory markers, both with acutely isolated choroid plexus and after prolonged exposure obtained with viable choroid plexus kept in tissue culture conditions. RESULTS The rat model of IVH demonstrated PHH and associated CSF hypersecretion. The Na+/K+-ATPase activity was enhanced in choroid plexus isolated from IVH rats, but not directly stimulated by blood components. Inflammatory markers that were elevated in SAH patient CSF acted on immune receptors upregulated in IVH rat choroid plexus and caused Na+/K+/2Cl- cotransporter 1 (NKCC1) hyperactivity in ex vivo experimental conditions. CONCLUSIONS CSF hypersecretion may contribute to PHH development, likely due to hyperactivity of choroid plexus transporters. The hemorrhage-induced inflammation detected in CSF and in the choroid plexus tissue may represent the underlying pathology. Therapeutic targeting of such pathways may be employed in future treatment strategies towards PHH patients.
Collapse
Affiliation(s)
- Sara Diana Lolansen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark
| | - Nina Rostgaard
- Department of Neurosurgery, The Neuroscience Centre, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Dagne Barbuskaite
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark
| | - Tenna Capion
- Department of Neurosurgery, The Neuroscience Centre, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Markus Harboe Olsen
- Department of Neuroanaesthesiology, The Neuroscience Centre, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Nicolas H Norager
- Department of Neurosurgery, The Neuroscience Centre, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Frederik Vilhardt
- Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Søren Norge Andreassen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark
| | - Trine L Toft-Bertelsen
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark
| | - Fenghui Ye
- Department of Neurosurgery, University of Michigan, Ann Arbor, USA
| | - Marianne Juhler
- Department of Neurosurgery, The Neuroscience Centre, Copenhagen University Hospital - Rigshospitalet, Copenhagen, Denmark
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, USA
| | - Nanna MacAulay
- Department of Neuroscience, University of Copenhagen, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark.
| |
Collapse
|
6
|
Hemin-Induced Endothelial Dysfunction and Endothelial to Mesenchymal Transition in the Pathogenesis of Pulmonary Hypertension Due to Chronic Hemolysis. Int J Mol Sci 2022; 23:ijms23094763. [PMID: 35563154 PMCID: PMC9104708 DOI: 10.3390/ijms23094763] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 01/08/2023] Open
Abstract
Pulmonary hypertension in sickle cell disease is an independent predictor of mortality, yet the pathogenesis of pulmonary vascular disease in chronic hemolytic disorders remains incompletely understood and treatment options are limited primarily to supportive care. The release of extracellular hemoglobin has been implicated in the development of pulmonary hypertension, and in this study we explored the direct effects of hemin, the oxidized moiety of heme, on the pulmonary artery endothelium. We found that low dose hemin exposure leads to significantly increased endothelial cell proliferation, migration, and cytokine release as markers of endothelial dysfunction. Protein expression changes in our pulmonary artery endothelial cells showed upregulation of mesenchymal markers after hemin treatment in conjunction with a decrease in endothelial markers. Endothelial to mesenchymal transition (EndoMT) resulting from hemin exposure was further confirmed by showing upregulation of the transcription factors SNAI1 and SLUG, known to regulate EndoMT. Lastly, given the endothelial dysfunction and phenotypic transition observed, the endothelial cytoskeleton was considered a potential novel target. Inhibiting myosin light chain kinase, to prevent phosphorylation of myosin light chain and cytoskeletal contraction, attenuated hemin-induced endothelial hyper-proliferation, migration, and cytokine release. The findings in this study implicate hemin as a key inducer of endothelial dysfunction through EndoMT, which may play an important role in pulmonary vascular remodeling during the development of pulmonary hypertension in chronic hemolytic states.
Collapse
|
7
|
Carbon Monoxide Therapy Using Hybrid Carbon Monoxide-Releasing/Nrf2-Inducing Molecules through a Neuroprotective Lens. CHEMISTRY 2021. [DOI: 10.3390/chemistry3030057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Carbon monoxide (CO) has long been known for its toxicity. However, in recent decades, new applications for CO as a therapeutic compound have been proposed, and multiple forms of CO therapy have since been developed and studied. Previous research has found that CO has a role as a gasotransmitter and promotes anti-inflammatory and antioxidant effects, making it an avenue of interest for medicine. Such effects are possible because of the Nrf2/HO1 pathway, which has become a target for therapy development because its activation also leads to CO release. Currently, different forms of treatment involving CO include inhaled CO (iCO), carbon monoxide-releasing molecules (CORMs), and hybrid carbon monoxide-releasing molecules (HYCOs). In this article, we review the progression of CO studies to develop possible therapies, the possible mechanisms involved in the effects of CO, and the current forms of therapy using CO.
Collapse
|
8
|
Gbotosho OT, Kapetanaki MG, Kato GJ. The Worst Things in Life are Free: The Role of Free Heme in Sickle Cell Disease. Front Immunol 2021; 11:561917. [PMID: 33584641 PMCID: PMC7873693 DOI: 10.3389/fimmu.2020.561917] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 12/04/2020] [Indexed: 12/15/2022] Open
Abstract
Hemolysis is a pathological feature of several diseases of diverse etiology such as hereditary anemias, malaria, and sepsis. A major complication of hemolysis involves the release of large quantities of hemoglobin into the blood circulation and the subsequent generation of harmful metabolites like labile heme. Protective mechanisms like haptoglobin-hemoglobin and hemopexin-heme binding, and heme oxygenase-1 enzymatic degradation of heme limit the toxicity of the hemolysis-related molecules. The capacity of these protective systems is exceeded in hemolytic diseases, resulting in high residual levels of hemolysis products in the circulation, which pose a great oxidative and proinflammatory risk. Sickle cell disease (SCD) features a prominent hemolytic anemia which impacts the phenotypic variability and disease severity. Not only is circulating heme a potent oxidative molecule, but it can act as an erythrocytic danger-associated molecular pattern (eDAMP) molecule which contributes to a proinflammatory state, promoting sickle complications such as vaso-occlusion and acute lung injury. Exposure to extracellular heme in SCD can also augment the expression of placental growth factor (PlGF) and interleukin-6 (IL-6), with important consequences to enthothelin-1 (ET-1) secretion and pulmonary hypertension, and potentially the development of renal and cardiac dysfunction. This review focuses on heme-induced mechanisms that are implicated in disease pathways, mainly in SCD. A special emphasis is given to heme-induced PlGF and IL-6 related mechanisms and their role in SCD disease progression.
Collapse
Affiliation(s)
- Oluwabukola T. Gbotosho
- Division of Hematology-Oncology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Maria G. Kapetanaki
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Gregory J. Kato
- Division of Hematology-Oncology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| |
Collapse
|
9
|
Janciauskiene S, Vijayan V, Immenschuh S. TLR4 Signaling by Heme and the Role of Heme-Binding Blood Proteins. Front Immunol 2020; 11:1964. [PMID: 32983129 PMCID: PMC7481328 DOI: 10.3389/fimmu.2020.01964] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/21/2020] [Indexed: 12/12/2022] Open
Abstract
Toll-like receptors (TLRs), also known as pattern recognition receptors, respond to exogenous pathogens and to intrinsic danger signals released from damaged cells and tissues. The tetrapyrrole heme has been suggested to be an agonist for TLR4, the receptor for the pro-inflammatory bacterial component lipopolysaccharide (LPS), synonymous with endotoxin. Heme is a double-edged sword with contradictory functions. On the one hand, it has vital cellular functions as the prosthetic group of hemoproteins including hemoglobin, myoglobin, and cytochromes. On the other hand, if released from destabilized hemoproteins, non-protein bound or “free” heme can have pro-oxidant and pro-inflammatory effects, the mechanisms of which are not fully understood. In this review, the complex interactions between heme and TLR4 are discussed with a particular focus on the role of heme-binding serum proteins in handling extracellular heme and its impact on TLR4 signaling. Moreover, the role of heme as a direct and indirect trigger of TLR4 activation and species-specific differences in the regulation of heme-dependent TLR4 signaling are highlighted.
Collapse
Affiliation(s)
- Sabina Janciauskiene
- Department of Pulmonology, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover Medical School, Hanover, Germany
| | - Vijith Vijayan
- Institute for Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hanover, Germany
| | - Stephan Immenschuh
- Institute for Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hanover, Germany
| |
Collapse
|
10
|
Oxidative Stress and Thrombosis during Aging: The Roles of Oxidative Stress in RBCs in Venous Thrombosis. Int J Mol Sci 2020; 21:ijms21124259. [PMID: 32549393 PMCID: PMC7352981 DOI: 10.3390/ijms21124259] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 01/17/2023] Open
Abstract
Mid-life stage adults are at higher risk of developing venous thrombosis (VT)/thromboembolism (VT/E). Aging is characterized by an overproduction of reactive oxygen species (ROS), which could evoke a series of physiological changes involved in thrombosis. Here, we focus on the critical role of ROS within the red blood cell (RBC) in initiating venous thrombosis during aging. Growing evidence has shifted our interest in the role of unjustifiably unvalued RBCs in blood coagulation. RBCs can be a major source of oxidative stress during aging, since RBC redox homeostasis is generally compromised due to the discrepancy between prooxidants and antioxidants. As a result, ROS accumulate within the RBC due to the constant endogenous hemoglobin (Hb) autoxidation and NADPH oxidase activation, and the uptake of extracellular ROS released by other cells in the circulation. The elevated RBC ROS level affects the RBC membrane structure and function, causing loss of membrane integrity, and decreased deformability. These changes impair RBC function in hemostasis and thrombosis, favoring a hypercoagulable state through enhanced RBC aggregation, RBC binding to endothelial cells affecting nitric oxide availability, RBC-induced platelet activation consequently modulating their activity, RBC interaction with and activation of coagulation factors, increased RBC phosphatidylserine exposure and release of microvesicles, accelerated aging and hemolysis. Thus, RBC oxidative stress during aging typifies an ultimate mechanism in system failure, which can affect major processes involved in the development of venous thrombosis in a variety of ways. The reevaluated concept of the critical role of RBC ROS in the activation of thrombotic events during aging will help identify potential targets for novel strategies to prevent/reduce the risk for VT/E or VT/E recurrences in mid-life stage adults.
Collapse
|
11
|
Karimy JK, Reeves BC, Kahle KT. Targeting TLR4-dependent inflammation in post-hemorrhagic brain injury. Expert Opin Ther Targets 2020; 24:525-533. [PMID: 32249624 DOI: 10.1080/14728222.2020.1752182] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Recent data have implicated inflammation of the cerebrospinal fluid spaces after subarachnoid, intraventricular, and intracerebral hemorrhage to be a critical driver of multiple secondary brain injuries such as hydrocephalus, cerebral edema, and vasospasm. While TLR4-dependent reparative inflammation is an important protective response that can eliminate physical irritants and damaged cells, sustained or inappropriately triggered inflammation can initiate or propagate disease.Areas covered: We review recent advances in our understanding of how TLR4, including its upstream damage-associated molecular patterns and its downstream MyD88-dependent and independent signaling pathways, contributes to hemorrhage-induced inflammation in numerous brain diseases. We discuss prospects for the pharmacotherapeutic targeting of TLR4 in these disorders, including the use of repurposed FDA-approved agents.Expert opinion: TLR4 inhibitors with good blood-brain-barrier (BBB) penetration could be useful adjuncts in post-hemorrhagic hydrocephalus and multiple other diseases associated with brain hemorrhage and inflammation.
Collapse
Affiliation(s)
- Jason K Karimy
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA
| | - Benjamin C Reeves
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA
| | - Kristopher T Kahle
- Departments of Neurosurgery, Pediatrics, and Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT, USA.,Centers for Mendelian Genomics, Yale School of Medicine, New Haven, CT, USA
| |
Collapse
|
12
|
Humayun F, Domingo-Fernández D, Paul George AA, Hopp MT, Syllwasschy BF, Detzel MS, Hoyt CT, Hofmann-Apitius M, Imhof D. A Computational Approach for Mapping Heme Biology in the Context of Hemolytic Disorders. Front Bioeng Biotechnol 2020; 8:74. [PMID: 32211383 PMCID: PMC7069124 DOI: 10.3389/fbioe.2020.00074] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/28/2020] [Indexed: 01/07/2023] Open
Abstract
Heme is an iron ion-containing molecule found within hemoproteins such as hemoglobin and cytochromes that participates in diverse biological processes. Although excessive heme has been implicated in several diseases including malaria, sepsis, ischemia-reperfusion, and disseminated intravascular coagulation, little is known about its regulatory and signaling functions. Furthermore, the limited understanding of heme's role in regulatory and signaling functions is in part due to the lack of curated pathway resources for heme cell biology. Here, we present two resources aimed to exploit this unexplored information to model heme biology. The first resource is a terminology covering heme-specific terms not yet included in standard controlled vocabularies. Using this terminology, we curated and modeled the second resource, a mechanistic knowledge graph representing the heme's interactome based on a corpus of 46 scientific articles. Finally, we demonstrated the utility of these resources by investigating the role of heme in the Toll-like receptor signaling pathway. Our analysis proposed a series of crosstalk events that could explain the role of heme in activating the TLR4 signaling pathway. In summary, the presented work opens the door to the scientific community for exploring the published knowledge on heme biology.
Collapse
Affiliation(s)
- Farah Humayun
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, Bonn, Germany
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Sankt Augustin, Germany
| | - Daniel Domingo-Fernández
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Sankt Augustin, Germany
| | - Ajay Abisheck Paul George
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Marie-Thérèse Hopp
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Benjamin F. Syllwasschy
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Milena S. Detzel
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| | - Charles Tapley Hoyt
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Sankt Augustin, Germany
| | - Martin Hofmann-Apitius
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing (SCAI), Sankt Augustin, Germany
| | - Diana Imhof
- Pharmaceutical Biochemistry and Bioanalytics, Pharmaceutical Institute, University of Bonn, Bonn, Germany
| |
Collapse
|
13
|
Human Toll-Like Receptor 4 (hTLR4): Structural and functional dynamics in cancer. Int J Biol Macromol 2019; 122:425-451. [DOI: 10.1016/j.ijbiomac.2018.10.142] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 10/10/2018] [Accepted: 10/18/2018] [Indexed: 12/23/2022]
|
14
|
Role of Damage Associated Molecular Pattern Molecules (DAMPs) in Aneurysmal Subarachnoid Hemorrhage (aSAH). Int J Mol Sci 2018; 19:ijms19072035. [PMID: 30011792 PMCID: PMC6073937 DOI: 10.3390/ijms19072035] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 07/01/2018] [Accepted: 07/09/2018] [Indexed: 12/27/2022] Open
Abstract
Aneurysmal subarachnoid hemorrhage (aSAH) represents only a small portion of all strokes, but accounts for almost half of the deaths caused by stroke worldwide. Neurosurgical clipping and endovascular coiling can successfully obliterate the bleeding aneurysms, but ensuing complications such as cerebral vasospasm, acute and chronic hydrocephalus, seizures, cortical spreading depression, delayed ischemic neurological deficits, and delayed cerebral ischemia lead to poor clinical outcomes. The mechanisms leading to these complications are complex and poorly understood. Early brain injury resulting from transient global ischemia can release molecules that may be critical to initiate and sustain inflammatory response. Hence, the events during early brain injury can influence the occurrence of delayed brain injury. Since the damage associated molecular pattern molecules (DAMPs) might be the initiators of inflammation in the pathophysiology of aSAH, so the aim of this review is to highlight their role in the context of aSAH from diagnostic, prognostic, therapeutic, and drug therapy monitoring perspectives. DAMPs represent a diverse and a heterogenous group of molecules derived from different compartments of cells upon injury. Here, we have reviewed the most important DAMPs molecules including high mobility group box-1 (HMGB1), S100B, hemoglobin and its derivatives, extracellular matrix components, IL-1α, IL-33, and mitochondrial DNA in the context of aSAH and their role in post-aSAH complications and clinical outcome after aSAH.
Collapse
|
15
|
Nath KA, Belcher JD, Nath MC, Grande JP, Croatt AJ, Ackerman AW, Katusic ZS, Vercellotti GM. Role of TLR4 signaling in the nephrotoxicity of heme and heme proteins. Am J Physiol Renal Physiol 2018; 314:F906-F914. [PMID: 28978536 PMCID: PMC6031913 DOI: 10.1152/ajprenal.00432.2017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 09/29/2017] [Accepted: 10/01/2017] [Indexed: 12/23/2022] Open
Abstract
Destabilized heme proteins release heme, and free heme is toxic. Heme is now recognized as an agonist for the Toll-like receptor-4 (TLR4) receptor. This study examined whether the TLR4 receptor mediates the nephrotoxicity of heme, specifically, the effects of heme on renal blood flow and inflammatory responses. We blocked TLR4 signaling by the specific antagonist TAK-242. Intravenous administration of heme to mice promptly reduced renal blood flow, an effect attenuated by TAK-242. In vitro, TAK-242 reduced heme-elicited activation of NF-κB and its downstream gene monocyte chemoattractant protein-1(MCP-1); in contrast, TAK-242 failed to reduce heme-induced activation of the anti-inflammatory transcription factor Nrf2 and its downstream gene heme oxygenase-1 (HO-1). TAK-242 did not reduce heme-induced renal MCP-1 upregulation in vivo. TAK-242 did not reduce dysfunction and histological injury in the glycerol model of heme protein-induced acute kidney injury (AKI), findings corroborated by studies in TLR4+/+ and TLR4-/- mice. We conclude that 1) acute heme-mediated renal vasoconstriction occurs through TLR4 signaling; 2) proinflammatory effects of heme in renal epithelial cells involve TLR4 signaling, whereas the anti-inflammatory effects of heme do not; 3) TLR4 signaling does not mediate the proinflammatory effects of heme in the kidney; and 4) major mechanisms underlying glycerol-induced, heme protein-mediated AKI do not involve TLR4 signaling. These findings in the glycerol model are in stark contrast with findings in virtually all other AKI models studied to date and emphasize the importance of TLR4-independent pathways of heme protein-mediated injury in this model. Finally, these studies urge caution when using observations derived in vitro to predict what occurs in vivo.
Collapse
Affiliation(s)
- Karl A Nath
- Division of Nephrology and Hypertension, Mayo Clinic , Rochester, Minnesota
| | - John D Belcher
- Division of Hematology, Oncology and Transplantation, University of Minnesota , Minneapolis, Minnesota
| | - Meryl C Nath
- Department of Pathology, Mayo Clinic , Rochester, Minnesota
| | | | - Anthony J Croatt
- Division of Nephrology and Hypertension, Mayo Clinic , Rochester, Minnesota
| | - Allan W Ackerman
- Division of Nephrology and Hypertension, Mayo Clinic , Rochester, Minnesota
| | | | - Gregory M Vercellotti
- Division of Hematology, Oncology and Transplantation, University of Minnesota , Minneapolis, Minnesota
| |
Collapse
|
16
|
Gao Z, Han Y, Hu Y, Wu X, Wang Y, Zhang X, Fu J, Zou X, Zhang J, Chen X, Jose PA, Lu X, Zeng C. Targeting HO-1 by Epigallocatechin-3-Gallate Reduces Contrast-Induced Renal Injury via Anti-Oxidative Stress and Anti-Inflammation Pathways. PLoS One 2016; 11:e0149032. [PMID: 26866373 PMCID: PMC4750900 DOI: 10.1371/journal.pone.0149032] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/25/2016] [Indexed: 12/12/2022] Open
Abstract
Both oxidative stress and inflammation are involved in the pathogenesis of contrast-induced nephropathy (CIN). Epigallocatechin-3-gallate (EGCG), a purified catechin from green tea, has antioxidant and anti-inflammatory effects. However, it is unknown whether or not EGCG is effective in treating CIN. Our present study found that intravenous administration of EGCG, either before or just after the establishment of CIN, had a protective effect, determined by normalization of serum creatinine and blood urea nitrogen levels, improvement in renal histopathological scoring and alleviation of apoptosis, accompanied by decreased oxidative stress and inflammation. Because EGCG is a potent inducer of the antioxidant heme oxygenase-1 (HO-1), we studied HO-1 signaling in CIN. HO-1 levels were increased in CIN; treatment with EGCG further increased HO-1 levels, accompanied by an increase in Nrf2, a regulator of antioxidant proteins. Interestingly, blockade of HO-1 with protoporphyrin IX zinc(II) (ZnPP) prevented the protective effect of EGCG on CIN. ZnPP also blocked the ability of EGCG to increase the activity of an antioxidant (superoxide dismutase), and decrease markers of oxidative stress (myeloperoxidase and malondialdehyde) and inflammation (myeloperoxidase and IL-1β), indicating that HO-1 is the upstream molecule that regulates the EGCG-mediated protection. To determine further the role of HO-1 on the EGCG-mediated inhibition of inflammation, we studied the effect of EGCG on the NLRP3 inflammasome, an upstream signaling of IL-1β. EGCG down-regulated NLRP3 expression, which was blocked by ZnPP, indicating that HO-1 links EGCG with NLRP3. Therefore, EGCG, via up-regulation of HO-1, protects against CIN by amelioration of oxidative stress and inflammation.
Collapse
Affiliation(s)
- Zhao Gao
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Yu Han
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Yunhui Hu
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Xiaoyan Wu
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Yongbin Wang
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Xiaoqun Zhang
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Jinjuan Fu
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Xue Zou
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Jun Zhang
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Xiongwen Chen
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
| | - Pedro A. Jose
- Department of Medicine, Division of Renal Disease and Hypertension, The George Washington University School of Medicine & Health Sciences, Washington, DC, United States of America
- Department of Physiology, The George Washington University School of Medicine & Health Sciences, Washington, DC, United States of America
| | - Xi Lu
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
- * E-mail: (CZ); (XL)
| | - Chunyu Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, P.R. China
- Chongqing Institute of Cardiology, Chongqing Key Laboratory for Hypertension Research, Chongqing, P.R. China
- * E-mail: (CZ); (XL)
| |
Collapse
|
17
|
Iqbal S, Hayman EG, Hong C, Stokum JA, Kurland DB, Gerzanich V, Simard JM. Inducible nitric oxide synthase (NOS-2) in subarachnoid hemorrhage: Regulatory mechanisms and therapeutic implications. Brain Circ 2016; 2:8-19. [PMID: 27774520 PMCID: PMC5074544 DOI: 10.4103/2394-8108.178541] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) typically carries a poor prognosis. Growing evidence indicates that overabundant production of nitric oxide (NO) may be responsible for a large part of the secondary injury that follows SAH. Although SAH modulates the activity of all three isoforms of nitric oxide synthase (NOS), the inducible isoform, NOS-2, accounts for a majority of NO-mediated secondary injuries after SAH. Here, we review the indispensable physiological roles of NO that must be preserved, even while attempting to downmodulate the pathophysiologic effects of NO that are induced by SAH. We examine the effects of SAH on the function of the various NOS isoforms, with a particular focus on the pathological effects of NOS-2 and on the mechanisms responsible for its transcriptional upregulation. Finally, we review interventions to block NOS-2 upregulation or to counteract its effects, with an emphasis on the potential therapeutic strategies to improve outcomes in patients afflicted with SAH. There is still much to be learned regarding the apparently maladaptive response of NOS-2 and its harmful product NO in SAH. However, the available evidence points to crucial effects that, on balance, are adverse, making the NOS-2/NO/peroxynitrite axis an attractive therapeutic target in SAH.
Collapse
Affiliation(s)
- Sana Iqbal
- Department of Neurosurgery, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Erik G Hayman
- Department of Neurosurgery, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Caron Hong
- Department of Anesthesiology, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Jesse A Stokum
- Department of Neurosurgery, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - David B Kurland
- Department of Neurosurgery, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - Volodymyr Gerzanich
- Department of Neurosurgery, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| | - J Marc Simard
- Department of Neurosurgery, School of Medicine, University of Maryland, Baltimore, Maryland, USA; Department of Pathology, School of Medicine, University of Maryland, Baltimore, Maryland, USA; Department of Physiology, School of Medicine, University of Maryland, Baltimore, Maryland, USA
| |
Collapse
|
18
|
Soares MP, Bozza MT. Red alert: labile heme is an alarmin. Curr Opin Immunol 2015; 38:94-100. [PMID: 26741528 DOI: 10.1016/j.coi.2015.11.006] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 11/24/2015] [Indexed: 01/03/2023]
Abstract
Alarmins are a heterogeneous group of endogenous molecules that signal cellular damage when sensed extracellularly. Heme is an endogenous molecule that acts as a prosthetic group of hemoproteins, such as hemoglobin and myoglobin. When released from damaged red blood cells or muscle cells, oxidized hemoglobin and myoglobin release their prosthetic heme groups, respectively. This generates labile heme, which is sensed by pattern recognition receptors (PRR) expressed by innate immune cells and possibly regulatory T cells (TREG). The ensuing adaptive response, which alerts for the occurrence of red blood cell or muscle cell damage, regulates the pathologic outcome of hemolysis or rhabdomyolysis, respectively. In conclusion, we propose that labile heme is an alarmin.
Collapse
Affiliation(s)
- Miguel P Soares
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande, 6, 2780-156 Oeiras, Portugal.
| | - Marcelo T Bozza
- Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Cidade Universitária, 21941-902 Rio de Janeiro, Brazil.
| |
Collapse
|
19
|
Irwin DC, Baek JH, Hassell K, Nuss R, Eigenberger P, Lisk C, Loomis Z, Maltzahn J, Stenmark KR, Nozik-Grayck E, Buehler PW. Hemoglobin-induced lung vascular oxidation, inflammation, and remodeling contribute to the progression of hypoxic pulmonary hypertension and is attenuated in rats with repeated-dose haptoglobin administration. Free Radic Biol Med 2015; 82:50-62. [PMID: 25656991 PMCID: PMC4387123 DOI: 10.1016/j.freeradbiomed.2015.01.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/11/2014] [Accepted: 01/20/2015] [Indexed: 12/28/2022]
Abstract
Haptoglobin (Hp) is an approved treatment in Japan for trauma, burns, and massive transfusion-related hemolysis. Additional case reports suggest uses in other acute hemolytic events that lead to acute kidney injury. However, Hp's protective effects on the pulmonary vasculature have not been evaluated within the context of mitigating the consequences of chronic hemoglobin (Hb) exposure in the progression of pulmonary hypertension (PH) secondary to hemolytic diseases. This study was performed to assess the utility of chronic Hp therapy in a preclinical model of Hb and hypoxia-mediated PH. Rats were simultaneously exposed to chronic Hb infusion (35 mg per day) and hypobaric hypoxia for 5 weeks in the presence or absence of Hp treatment (90 mg/kg twice a week). Hp inhibited the Hb plus hypoxia-mediated nonheme iron accumulation in lung and heart tissue, pulmonary vascular inflammation and resistance, and right-ventricular hypertrophy, which suggests a positive impact on impeding the progression of PH. In addition, Hp therapy was associated with a reduction in critical mediators of PH, including lung adventitial macrophage population and endothelial ICAM-1 expression. By preventing Hb-mediated pathology, Hp infusions: (1) demonstrate a critical role for Hb in vascular remodeling associated with hypoxia and (2) suggest a novel therapy for chronic hemolysis-associated PH.
Collapse
Affiliation(s)
- David C. Irwin
- Cardiovascular Pulmonary Research Group, Division of Cardiology, School of Medicine, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado
- Corresponding Author: David C. Irwin, Ph.D., Assistant Professor, 12700 East 19th Avenue, Research Building 2, Room 8121, Aurora, CO 80045, Phone: 303 724-3684, Fax: 303 724-3693,
| | - Jin Hyen Baek
- Laboratory of Biochemistry and Vascular Biology, Office of Blood Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Bethesda, Maryland
| | - Kathryn Hassell
- Colorado Sickle Cell Treatment and Research Center, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado
| | - Rachelle Nuss
- Colorado Sickle Cell Treatment and Research Center, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado
| | - Paul Eigenberger
- Cardiovascular Pulmonary Research Group, Division of Cardiology, School of Medicine, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado
| | - Christina Lisk
- Cardiovascular Pulmonary Research Group, Division of Cardiology, School of Medicine, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado
| | - Zoe Loomis
- Colorado Sickle Cell Treatment and Research Center, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado
| | - Joanne Maltzahn
- Cardiovascular Pulmonary Research Group, Division of Cardiology, School of Medicine, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado
| | - Kurt R Stenmark
- Cardiovascular Pulmonary Research Group, Pediatrics, School of Medicine, University of Colorado Denver | Anschutz Medical Campus, Aurora Colorado
| | - Eva Nozik-Grayck
- Cardiovascular Pulmonary Research Group, Pediatrics, School of Medicine, University of Colorado Denver | Anschutz Medical Campus, Aurora Colorado
| | - Paul W. Buehler
- Cardiovascular Pulmonary Research Group, Division of Cardiology, School of Medicine, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado
- Laboratory of Biochemistry and Vascular Biology, Office of Blood Research and Review, Center for Biologics Evaluation and Research, U.S. Food and Drug Administration, Bethesda, Maryland
| |
Collapse
|
20
|
Methemoglobin is an endogenous toll-like receptor 4 ligand-relevance to subarachnoid hemorrhage. Int J Mol Sci 2015; 16:5028-46. [PMID: 25751721 PMCID: PMC4394463 DOI: 10.3390/ijms16035028] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 03/01/2015] [Accepted: 03/03/2015] [Indexed: 12/21/2022] Open
Abstract
Neuroinflammation is a well-recognized consequence of subarachnoid hemorrhage (SAH), and may be responsible for important complications of SAH. Signaling by Toll-like receptor 4 (TLR4)-mediated nuclear factor κB (NFκB) in microglia plays a critical role in neuronal damage after SAH. Three molecules derived from erythrocyte breakdown have been postulated to be endogenous TLR4 ligands: methemoglobin (metHgb), heme and hemin. However, poor water solubility of heme and hemin, and lipopolysaccharide (LPS) contamination have confounded our understanding of these molecules as endogenous TLR4 ligands. We used a 5-step process to obtain highly purified LPS-free metHgb, as confirmed by Fourier Transform Ion Cyclotron Resonance mass spectrometry and by the Limulus amebocyte lysate assay. Using this preparation, we show that metHgb is a TLR4 ligand at physiologically relevant concentrations. metHgb caused time- and dose-dependent secretion of the proinflammatory cytokine, tumor necrosis factor α (TNFα), from microglial and macrophage cell lines, with secretion inhibited by siRNA directed against TLR4, by the TLR4-specific inhibitors, Rs-LPS and TAK-242, and by anti-CD14 antibodies. Injection of purified LPS-free metHgb into the rat subarachnoid space induced microglial activation and TNFα upregulation. Together, our findings support the hypothesis that, following SAH, metHgb in the subarachnoid space can promote widespread TLR4-mediated neuroinflammation.
Collapse
|
21
|
Zimring JC, Spitalnik SL. Pathobiology of Transfusion Reactions. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2015; 10:83-110. [DOI: 10.1146/annurev-pathol-012414-040318] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- James C. Zimring
- Puget Sound Blood Center Research Institute, Seattle, Washington 98102;
- Departments of Laboratory Medicine and Internal Medicine, Division of Hematology, University of Washington, Seattle, Washington 98195
| | - Steven L. Spitalnik
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY 10032
| |
Collapse
|
22
|
Gómez R, Villalvilla A, Largo R, Gualillo O, Herrero-Beaumont G. TLR4 signalling in osteoarthritis—finding targets for candidate DMOADs. Nat Rev Rheumatol 2014; 11:159-70. [DOI: 10.1038/nrrheum.2014.209] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
23
|
Zhong H, Bao W, Friedman D, Yazdanbakhsh K. Hemin controls T cell polarization in sickle cell alloimmunization. THE JOURNAL OF IMMUNOLOGY 2014; 193:102-10. [PMID: 24879794 DOI: 10.4049/jimmunol.1400105] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Patients with sickle cell disease (SCD) often require transfusions to treat and prevent worsening anemia and other SCD complications. However, transfusions can trigger alloimmunization against transfused RBCs with serious clinical sequelae. Risk factors for alloimmunization in SCD remain poorly understood. We recently reported altered regulatory T cell (Treg) and Th responses with higher circulating Th1 (IFN-γ(+)) cytokines in chronically transfused SCD patients with alloantibodies as compared with those without alloantibodies. Because monocytes play a critical role in polarization of T cell subsets and participate in clearance of transfused RBCs, we tested the hypothesis that in response to the RBC breakdown product hemin, monocyte control of T cell polarization will differ between alloimmunized and non-alloimmunized SCD patients. Exogenous hemin induced Treg polarization in purified T cell/monocyte cocultures from healthy volunteers through the monocyte anti-inflammatory heme-degrading enzyme heme oxygenase-1. Importantly, hemin primarily through its effect on CD16+ monocytes induced an anti-inflammatory (higher Treg/lower Th1) polarization state in the non-alloimmunized SCD group, whereas it had little effect in the alloimmunized group. Non-alloimmunized SCD CD16+ monocytes expressed higher basal levels of heme oxygenase-1. Furthermore, IL-12, which contributed to a proinflammatory polarization state (low Treg/high Th1) in SCD, was dampened in hemin-treated stimulated monocytes from non-alloimmunized SCD patients, but not in the alloimmunized group. These data suggest that unlike alloimmunized patients, non-alloimmunized SCD CD16+ monocytes in response to transfused RBC breakdown products promote an anti-inflammatory state that is less conducive to alloimmunization.
Collapse
Affiliation(s)
- Hui Zhong
- Laboratory of Complement Biology, New York Blood Center, New York, NY 10065
| | - Weili Bao
- Laboratory of Complement Biology, New York Blood Center, New York, NY 10065
| | - David Friedman
- Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104; and Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104
| | - Karina Yazdanbakhsh
- Laboratory of Complement Biology, New York Blood Center, New York, NY 10065;
| |
Collapse
|
24
|
Dutra FF, Bozza MT. Heme on innate immunity and inflammation. Front Pharmacol 2014; 5:115. [PMID: 24904418 PMCID: PMC4035012 DOI: 10.3389/fphar.2014.00115] [Citation(s) in RCA: 225] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 04/29/2014] [Indexed: 12/30/2022] Open
Abstract
Heme is an essential molecule expressed ubiquitously all through our tissues. Heme plays major functions in cellular physiology and metabolism as the prosthetic group of diverse proteins. Once released from cells and from hemeproteins free heme causes oxidative damage and inflammation, thus acting as a prototypic damage-associated molecular pattern. In this context, free heme is a critical component of the pathological process of sterile and infectious hemolytic conditions including malaria, hemolytic anemias, ischemia-reperfusion, and hemorrhage. The plasma scavenger proteins hemopexin and albumin reduce heme toxicity and are responsible for transporting free heme to intracellular compartments where it is catabolized by heme-oxygenase enzymes. Upon hemolysis or severe cellular damage the serum capacity to scavenge heme may saturate and increase free heme to sufficient amounts to cause tissue damage in various organs. The mechanism by which heme causes reactive oxygen generation, activation of cells of the innate immune system and cell death are not fully understood. Although heme can directly promote lipid peroxidation by its iron atom, heme can also induce reactive oxygen species generation and production of inflammatory mediators through the activation of selective signaling pathways. Heme activates innate immune cells such as macrophages and neutrophils through activation of innate immune receptors. The importance of these events has been demonstrated in infectious and non-infectious diseases models. In this review, we will discuss the mechanisms behind heme-induced cytotoxicity and inflammation and the consequences of these events on different tissues and diseases.
Collapse
Affiliation(s)
- Fabianno F. Dutra
- Laboratório de Inflamação e Imunidade, Departamento de Imunologia, Instituto de Microbiologia, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| | - Marcelo T. Bozza
- Laboratório de Inflamação e Imunidade, Departamento de Imunologia, Instituto de Microbiologia, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil
| |
Collapse
|
25
|
Lisk C, Kominsky D, Ehrentraut S, Bonaventura J, Nuss R, Hassell K, Nozik-Grayck E, Irwin DC. Hemoglobin-induced endothelial cell permeability is controlled, in part, via a myeloid differentiation primary response gene-88-dependent signaling mechanism. Am J Respir Cell Mol Biol 2014; 49:619-26. [PMID: 23713977 DOI: 10.1165/rcmb.2012-0440oc] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The release of hemoglobin (Hb) with hemolysis causes vascular dysfunction. New evidence implicates Hb-induced NF-κB and hypoxia inducible factor (HIF) activation, which may be under the control of a Toll-like receptor (TLR)-signaling pathway. Nearly all TLR-signaling pathways activate the myeloid differentiation primary response gene-88 (MyD88) that regulates NF-κB. We hypothesized that the differing transition states of Hb influence endothelial cell permeability via NF-κB activation and HIF regulation through a MyD88-dependent pathway. In cultured human dermal microvascular endothelial cells (HMECs-1), we examined the effects of Hb in the ferrous (HbFe(2+)), ferric (HbFe(3+)), and ferryl (HbFe(4+)) transition states on NF-κB and HIF activity, HIF-1α and HIF-2α mRNA up-regulation, and monolayer permeability, in the presence or absence of TLR4, MyD88, NF-κB, or HIF inhibition, as well as superoxide dismutase (SOD) and catalase. Our data showed that cell-free Hb, in each transition state, induced NF-κB and HIF activity, up-regulated HIF-1α and HIF-2α mRNA, and increased HMEC-1 permeability. The blockade of either MyD88 or NF-κB, but not TLR4, attenuated Hb-induced HIF activity, the up-regulation HIF-1 and HIF-2α mRNA, and HMEC-1 permeability. The inhibition of HIF activity exerted less of an effect on Hb-induced monolayer permeability. Moreover, SOD and catalase attenuated NF-κB, HIF activity, and monolayer permeability. Our results demonstrate that Hb-induced NF-κB and HIF are regulated by two mechanisms, either MyD88 activation or Hb transition state-induced ROS formation, that influence HMEC-1 permeability.
Collapse
Affiliation(s)
- Christina Lisk
- 1 Cardiovascular Pulmonary Research Group, Division of Cardiology, Department of Medicine
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Teghanemt A, Weiss JP, Gioannini TL. Radioiodination of an endotoxin·MD-2 complex generates a novel sensitive, high-affinity ligand for TLR4. Innate Immun 2013; 19:545-60. [PMID: 23439691 DOI: 10.1177/1753425913475688] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A purified complex of metabolically labeled [(3)H]lipooligosaccharide (LOS) and recombinant human myeloid differentiation factor 2 (MD-2), [(3)H]LOS·MD-2, has been used to demonstrate pM affinity binding interactions with soluble TLR4 ectodomain (TLR4ecd). For measurement of the binding parameters of membrane-bound TLR4, we took advantage of the stability of endotoxin·MD-2 and tyrosine(s) present on the surface of MD-2 to radioiodinate LOS·MD-2. Radioiodinated LOS·MD-2 generated a reagent with an estimated 1:1 molar ratio of [(125)I] to sMD-2 with 20-fold higher specific radioactivity and TLR4-activating properties comparable to metabolically-labeled LOS·MD-2. LOS·MD-2[(125)I] and [(3)H]LOS·MD-2 have similar affinities for soluble (FLAG) TLR4ecd and for membrane-bound TLR4 in HEK293T/TLR4 cells. In a similar dose-dependent manner, sMD-2 and LOS·MD-2 inhibit LOS·MD-2[(125)I] binding to TLR4 indicating the pM affinity binding of LOS·MD-2[(125)I] is agonist-independent. LOS·MD-2[(125)I] allowed measurement of low levels of cell-surface human or murine TLR4 expressed by stable cell lines (2000-3000 sites/cell) and quantitatively measures low levels of 'MD-2-free' TLR4 (est. 250 molecules/cell) in cells co-expressing TLR4 and MD-2. Occupation of 50-100 TLR4/cell by LOS·MD-2 is sufficient to trigger measurable TLR4-dependent cell activation. LOS·MD-2[(125)I] provides a powerful reagent to measure quantitatively functional human and murine cell-surface TLR4, including in cells where surface TLR4 is potentially functionally significant but not detectable by other methods.
Collapse
Affiliation(s)
- Athmane Teghanemt
- 1Inflammation Program, Department of Internal Medicine, Roy A. and Lucille J. Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | | | | |
Collapse
|
27
|
Neal MD, Raval JS, Triulzi DJ, Simmons RL. Innate immune activation after transfusion of stored red blood cells. Transfus Med Rev 2013; 27:113-8. [PMID: 23434246 DOI: 10.1016/j.tmrv.2013.01.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 11/26/2012] [Accepted: 01/02/2013] [Indexed: 01/28/2023]
Abstract
The transfusion of red blood cells (RBCs), although necessary for treatment of anemia and blood loss, has also been linked to increased morbidity and mortality. RBCs stored for longer durations and transfused in larger volumes are often cited as contributory to adverse outcomes. The potential mechanisms underlying deleterious effects of RBC transfusion are just beginning to be elucidated. In this narrative review, we explore the hypothesis that prolonged RBC storage results in elaboration of substances which may function as danger associated molecular pattern molecules that activate the innate immune system with consequences unfavorable to healthy homeostasis. The nature of these chemical mediators and the biological responses to them offers insight into the mechanisms of these pathological responses. Three major areas of activation of the innate immune apparatus by stored RBCs have been tentatively identified: RBC hemolysis, recipient neutrophil priming, and reactive oxygen species production. The possible mechanisms by which each might perturb the innate immune response are reviewed in a search for potential novel pathways through which transfusion can lead to an altered inflammatory response.
Collapse
Affiliation(s)
- Matthew D Neal
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | | | | | | |
Collapse
|
28
|
Yang D, Postnikov YV, Li Y, Tewary P, de la Rosa G, Wei F, Klinman D, Gioannini T, Weiss JP, Furusawa T, Bustin M, Oppenheim JJ. High-mobility group nucleosome-binding protein 1 acts as an alarmin and is critical for lipopolysaccharide-induced immune responses. J Exp Med 2012; 209:157-71. [PMID: 22184635 PMCID: PMC3260868 DOI: 10.1084/jem.20101354] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2010] [Accepted: 11/15/2011] [Indexed: 01/08/2023] Open
Abstract
Alarmins are endogenous mediators capable of promoting the recruitment and activation of antigen-presenting cells (APCs), including dendritic cells (DCs), that can potentially alert host defense against danger signals. However, the relevance of alarmins to the induction of adaptive immune responses remains to be demonstrated. In this study, we report the identification of HMGN1 (high-mobility group nucleosome-binding protein 1) as a novel alarmin and demonstrate that it contributes to the induction of antigen-specific immune responses. HMGN1 induced DC maturation via TLR4 (Toll-like receptor 4), recruitment of APCs at sites of injection, and activation of NF-κB and multiple mitogen-activated protein kinases in DCs. HMGN1 promoted antigen-specific immune response upon co-administration with antigens, and Hmgn1(-/-) mice developed greatly reduced antigen-specific antibody and T cell responses when immunized with antigens in the presence of lipopolysaccharide (LPS). The impaired ability of Hmgn1(-/-) mice to mount antigen-specific immune responses was accompanied by both deficient DC recruitment at sites of immunization and reduced production of inflammatory cytokines. Bone marrow chimera experiments revealed that HMGN1 derived from nonleukocytes was critical for the induction of antigen-specific antibody and T cell responses. Thus, extracellular HMGN1 acts as a novel alarmin critical for LPS-induced development of innate and adaptive immune responses.
Collapse
Affiliation(s)
- De Yang
- Basic Research Program, Scientific Application and International Corporation–Frederick, Inc.; and Laboratory of Molecular Immunoregulation and Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer Research; National Cancer Institute at Frederick, Frederick, MD 21702
| | - Yuri V. Postnikov
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Yana Li
- Basic Research Program, Scientific Application and International Corporation–Frederick, Inc.; and Laboratory of Molecular Immunoregulation and Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer Research; National Cancer Institute at Frederick, Frederick, MD 21702
| | - Poonam Tewary
- Basic Research Program, Scientific Application and International Corporation–Frederick, Inc.; and Laboratory of Molecular Immunoregulation and Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer Research; National Cancer Institute at Frederick, Frederick, MD 21702
| | - Gonzalo de la Rosa
- Basic Research Program, Scientific Application and International Corporation–Frederick, Inc.; and Laboratory of Molecular Immunoregulation and Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer Research; National Cancer Institute at Frederick, Frederick, MD 21702
| | - Feng Wei
- Basic Research Program, Scientific Application and International Corporation–Frederick, Inc.; and Laboratory of Molecular Immunoregulation and Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer Research; National Cancer Institute at Frederick, Frederick, MD 21702
| | - Dennis Klinman
- Basic Research Program, Scientific Application and International Corporation–Frederick, Inc.; and Laboratory of Molecular Immunoregulation and Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer Research; National Cancer Institute at Frederick, Frederick, MD 21702
| | - Theresa Gioannini
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242
| | - Jerrold P. Weiss
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242
| | - Takashi Furusawa
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Michael Bustin
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892
| | - Joost J. Oppenheim
- Basic Research Program, Scientific Application and International Corporation–Frederick, Inc.; and Laboratory of Molecular Immunoregulation and Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer Research; National Cancer Institute at Frederick, Frederick, MD 21702
| |
Collapse
|
29
|
Piazza M, Calabrese V, Damore G, Cighetti R, Gioannini T, Weiss J, Peri F. A synthetic lipid A mimetic modulates human TLR4 activity. ChemMedChem 2011; 7:213-7. [PMID: 22140087 DOI: 10.1002/cmdc.201100494] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Indexed: 02/06/2023]
Affiliation(s)
- Matteo Piazza
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
| | | | | | | | | | | | | |
Collapse
|
30
|
Opal SM. Endotoxemia before and after surgical repair for congenital heart disease. Am J Respir Crit Care Med 2011; 184:1223-4. [PMID: 22162881 DOI: 10.1164/rccm.201108-1432ed] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
31
|
Peri F, Piazza M. Therapeutic targeting of innate immunity with Toll-like receptor 4 (TLR4) antagonists. Biotechnol Adv 2011; 30:251-60. [PMID: 21664961 DOI: 10.1016/j.biotechadv.2011.05.014] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 04/27/2011] [Accepted: 05/18/2011] [Indexed: 01/04/2023]
Abstract
Early recognition of invading bacteria by the innate immune system has a crucial function in antibacterial defense by triggering inflammatory responses that prevent the spread of infection and suppress bacterial growth. Toll-like receptor 4 (TLR4), the innate immunity receptor of bacterial endotoxins, plays a pivotal role in the induction of inflammatory responses. TLR4 activation by bacterial lipopolysaccharide (LPS) is achieved by the coordinate and sequential action of three other proteins, LBP, CD14 and MD-2 receptors, that bind lipopolysaccharide (LPS) and present it to TLR4 by forming the activated (TLR4-MD-2-LPS)(2) complex. Small molecules active in modulating the TLR4 activation process have great pharmacological interest as vaccine adjuvants, immunotherapeutics or antisepsis and anti-inflammatory agents. In this review we present natural and synthetic molecules active in inhibiting TLR4-mediated LPS signalling in humans and their therapeutic potential. New pharmacological applications of TLR4 antagonists will be also presented related to the recently discovered role of TLR4 in the insurgence and progression of neuropathic pain and sterile inflammations.
Collapse
Affiliation(s)
- Francesco Peri
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy.
| | | |
Collapse
|