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Zhang X, Nickerson R, Burton L, Stueck A, Holbein B, Cheng Z, Zhou J, Lehmann C. The Hydroxypyridinone Iron Chelator DIBI Reduces Bacterial Load and Inflammation in Experimental Lung Infection. Biomedicines 2024; 12:1452. [PMID: 39062025 PMCID: PMC11274704 DOI: 10.3390/biomedicines12071452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 06/17/2024] [Accepted: 06/27/2024] [Indexed: 07/28/2024] Open
Abstract
Iron plays a critical role in lung infections due to its function in the inflammatory immune response but also as an important factor for bacterial growth. Iron chelation represents a potential therapeutic approach to inhibit bacterial growth and pathologically increased pro-inflammatory mediator production. The present study was designed to investigate the impact of the iron chelator DIBI in murine lung infection induced by intratracheal Pseudomonas aeruginosa (strain PA14) administration. DIBI is a polymer with a polyvinylpyrrolidone backbone containing nine 3-hydroxy-1-(methacrylamidoethyl)-2-methyl-4(1H) pyridinone (MAHMP) residues per molecule and was given by intraperitoneal injection either as a single dose (80 mg/kg) immediately after PA14 administration or a double dose (second dose 4 h after PA14 administration). The results showed that lung NF-κBp65 levels, as well as levels of various inflammatory cytokines (TNFα, IL-1β, IL-6) both in lung tissue and bronchoalveolar lavage fluid (BALF), were significantly increased 24 h after PA14 administration. Single-dose DIBI did not affect the bacterial load or inflammatory response in the lungs or BALF. However, two doses of DIBI significantly decreased bacterial load, attenuated NF-κBp65 upregulation, reduced inflammatory cytokines production, and relieved lung tissue damage. Our findings support the conclusion that the iron chelator, DIBI, can reduce lung injury induced by P. aeruginosa, via its anti-bacterial and anti-inflammatory effects.
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Affiliation(s)
- Xiyang Zhang
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada; (X.Z.); (J.Z.)
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
- Guangdong Provincial Key Laboratory of Precision Anaesthesia and Perioperative Organ Protection, Guangzhou 510515, China
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (R.N.); (L.B.); (B.H.); (Z.C.)
| | - Rhea Nickerson
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (R.N.); (L.B.); (B.H.); (Z.C.)
| | - Lauren Burton
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (R.N.); (L.B.); (B.H.); (Z.C.)
| | - Ashley Stueck
- Department of Pathology, Dalhousie University, Halifax, NS B3H 1X5, Canada;
| | - Bruce Holbein
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (R.N.); (L.B.); (B.H.); (Z.C.)
| | - Zhenyu Cheng
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (R.N.); (L.B.); (B.H.); (Z.C.)
| | - Juan Zhou
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada; (X.Z.); (J.Z.)
| | - Christian Lehmann
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada; (X.Z.); (J.Z.)
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (R.N.); (L.B.); (B.H.); (Z.C.)
- Department of Physiology & Biophysics, Dalhousie University, Halifax, NS B3H 1X5, Canada
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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Wang J, Guan P, Chen Y, Xu M, Wang N, Ji E. Cyclovirobuxine D pretreatment ameliorates septic heart injury through mitigation of ferroptosis. Exp Ther Med 2023; 26:407. [PMID: 37522059 PMCID: PMC10375449 DOI: 10.3892/etm.2023.12106] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/01/2023] [Indexed: 08/01/2023] Open
Abstract
Myocardial dysfunction is a frequent complication in patients with severe sepsis. However, effective drugs for the prevention of myocardial dysfunction and the molecular mechanisms of the disease remain elusive. The present study demonstrated that Cyclovirobuxine D (CVB-D) could improve cardiac dysfunction in a cecal ligation and puncture (CLP) model in rodents and in a lipopolysaccharide (LPS) model in vitro. Echocardiography and histopathological examination were used to detect changes in cardiac structure and function. Kits were used to detect indicators of cardiac injury, transmission electron microscopy to detect structural changes in mitochondria and reverse transcription-quantitative PCR to detect prostaglandin-endoperoxide synthase 2 and hamp expression levels. L-Glutathione and malondialdehyde levels and superoxide dismutase activity were measured using kits. Cell viability was measured with the Cell Counting Kit-8. Iron metabolism-related proteins, inflammatory factor levels and related pathway proteins were detected using western blot analysis. Changes in L-type calcium currents were detected by membrane clamp, and contractility of cardiomyocytes was measured by Ion Optix. CVB-D attenuated CLP-induced cardiac malfunction in septic rats, with changes observed in myocardial pathological structure, creatine kinase isoenzyme (CK-MB), lactate dehydrogenase (LDH) and cardiac troponin I (cTnI). CVB-D attenuated sepsis-induced lipid peroxidation and iron overload. In addition, CVB-D decreased the expression of CK-MB, LDH and cTnI, suppressed oxidative stress index levels and reduced the production of reactive oxygen species. CVB-D decreased LPS-induced cytoplasmic iron overload by increasing upregulation of iron uptake molecules. Conversely, CVB-D significantly increased the upregulation of ferroportin 1. CVB-D pretreatment significantly reduced the levels of hamp mRNA compared with the LPS-treated group. CVB-D pretreatment significantly reduced inflammatory factor levels and the ratio of phosphorylated vs. total signal transducer and activator of transcription 3. The expression of SLC7A11 and GPX4 was upregulated in septic cells pretreated with CVB-D, however treatment with ML385 largely decreased this upregulation. Of note, CVB-D inhibited the inward flow of calcium ions through the LTCC. In conclusion, these findings suggest that CVB-D alleviated sepsis-induced cardiac iron toxicity by alleviating iron metabolism.
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Affiliation(s)
- Jianxin Wang
- Department of Physiology, School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
| | - Peng Guan
- Department of Physiology, School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
- College of Life Science, Hebei Normal University, Shijiazhuang, Hebei 050024, P.R. China
| | - Yu Chen
- Department of Physiology, School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
| | - Meng Xu
- Department of Physiology, School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
| | - Na Wang
- Department of Physiology, School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
| | - Ensheng Ji
- Department of Physiology, School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei 050091, P.R. China
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Zhang X, Zhou J, Holbein BE, Lehmann C. Iron Chelation as a Potential Therapeutic Approach in Acute Lung Injury. Life (Basel) 2023; 13:1659. [PMID: 37629516 PMCID: PMC10455621 DOI: 10.3390/life13081659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/28/2023] [Accepted: 07/29/2023] [Indexed: 08/27/2023] Open
Abstract
Acute lung injury (ALI) has been challenging health care systems since before the COVID-19 pandemic due to its morbidity, mortality, and length of hospital stay. In view of the complex pathogenesis of ALI, effective strategies for its prevention and treatment are still lacking. A growing body of evidence suggests that iron dysregulation is a common characteristic in many subtypes of ALI. On the one hand, iron is needed to produce reactive oxygen species (ROS) as part of the immune response to an infection; on the other hand, iron can accelerate the occurrence of ferroptosis and extend host cell damage. Iron chelation represents a novel therapeutic strategy for alleviating lung injury and improving the survival of patients with ALI. This article reviews the current knowledge of iron homeostasis, the role of iron in ALI development, and potential therapeutic targets.
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Affiliation(s)
- Xiyang Zhang
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada; (X.Z.); (J.Z.)
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, 510515 Guangzhou, China
| | - Juan Zhou
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada; (X.Z.); (J.Z.)
| | - Bruce E. Holbein
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada;
| | - Christian Lehmann
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada; (X.Z.); (J.Z.)
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada;
- Department of Physiology & Biophysics, Dalhousie University, Halifax, NS B3H 1X5, Canada
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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Gal Y, Marcus H, Mamroud E, Aloni-Grinstein R. Mind the Gap-A Perspective on Strategies for Protecting against Bacterial Infections during the Period from Infection to Eradication. Microorganisms 2023; 11:1701. [PMID: 37512874 PMCID: PMC10386665 DOI: 10.3390/microorganisms11071701] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/06/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023] Open
Abstract
The emergence of antibiotic-resistant bacteria is a pressing public health concern, highlighting the need for alternative approaches to control bacterial infections. Promising approaches include the development of therapeutic vaccines and the utilization of innate immune activation techniques, which may prove useful in conjunction with antibiotics, as well as other antibacterial modalities. However, innate activation should be fast and self- or actively- contained to prevent detrimental consequences. TLR ligand adjuvants are effective at rapidly activating, within minutes to hours, the innate immune system by inducing cytokine production and other signaling molecules that bolster the host's immune response. Neutrophils serve as the first line of defense against invading pathogens by capturing and destroying them through various mechanisms, such as phagocytosis, intracellular degradation, and the formation of NETs. Nutritional immunity is another host defense mechanism that limits the availability of essential metals, such as iron, from invading bacterial pathogens. Thus, iron starvation has been proposed as a potential antibacterial strategy. In this review, we focus on approaches that have the potential to enhance rapid and precise antibacterial responses, bridging the gap between the onset of infection and the elimination of bacteria, hence limiting the infection by antibiotic-resistant bacteria.
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Affiliation(s)
- Yoav Gal
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Hadar Marcus
- Department of Biotechnology, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Emanuelle Mamroud
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona 74100, Israel
| | - Ronit Aloni-Grinstein
- Department of Biochemistry and Molecular Genetics, Israel Institute for Biological Research, Ness Ziona 74100, Israel
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Han J, Zeng S, Chen Y, Li H, Yoon J. Prospects of coupled iron-based nanostructures in preclinical antibacterial therapy. Adv Drug Deliv Rev 2023; 193:114672. [PMID: 36592895 DOI: 10.1016/j.addr.2022.114672] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 11/13/2022] [Accepted: 12/17/2022] [Indexed: 12/31/2022]
Abstract
Bacterial infections can threaten human health. Drug-resistant bacteria have become a challenge because of the excessive use of drugs. We summarize the current metallic antibacterial materials, especially Fe-based materials, for efficiently killing bacteria. The possible antibacterial mechanisms of metallic antibacterial agents are classified into interactions with bacterial proteins, iron metabolism, catalytic activity, and combinations of magnetic, photodynamic, and photothermal effects. This review will inspire the development of novel Fe-based antibacterial agents for clinical settings.
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Affiliation(s)
- Jingjing Han
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760 Republic of Korea; Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, CH-4058 Basel, Switzerland
| | - Shuang Zeng
- State Key Laboratory of Fine Chemicals, School of Bioengineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024 China
| | - Yahui Chen
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760 Republic of Korea; New and Renewable Energy Research Center, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Haidong Li
- State Key Laboratory of Fine Chemicals, School of Bioengineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024 China.
| | - Juyoung Yoon
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760 Republic of Korea.
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Zhang R, Di C, Gao H, Zhu Y, Li C, Zhu Z, Wang Q, Wang J, Zhou F, Wang S. Identification of iron metabolism-related genes in the circulation and myocardium of patients with sepsis via applied bioinformatics analysis. Front Cardiovasc Med 2023; 10:1018422. [PMID: 36937929 PMCID: PMC10017502 DOI: 10.3389/fcvm.2023.1018422] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Background Early diagnosis of septic cardiomyopathy is essential to reduce the mortality rate of sepsis. Previous studies indicated that iron metabolism plays a vital role in sepsis-induced cardiomyopathy. Here, we aimed to identify shared iron metabolism-related genes (IMRGs) in the myocardium and blood monocytes of patients with sepsis and to determine their prognostic signature. Methods First, an applied bioinformatics-based analysis was conducted to identify shared IMRGs differentially expressed in the myocardium and peripheral blood monocytes of patients with sepsis. Second, Cytoscape was used to construct a protein-protein interaction network, and immune infiltration of the septic myocardium was assessed using single-sample gene set enrichment analysis. In addition, a prognostic prediction model for IMRGs was established by Cox regression analysis. Finally, the expression of key mRNAs in the myocardium of mice with sepsis was verified using quantitative polymerase chain reaction analysis. Results We screened common differentially expressed genes in septic myocardium and blood monocytes and identified 14 that were related to iron metabolism. We found that HBB, SLC25A37, SLC11A1, and HMOX1 strongly correlated with monocytes and neutrophils, whereas HMOX1 and SLC11A1 strongly correlated with macrophages. We then established a prognostic model (HIF1A and SLC25A37) using the common differentially expressed IMRGs. The prognostic model we established was expected to better aid in diagnosing septic cardiomyopathy. Moreover, we verified these genes using datasets and experiments and found a significant difference between the sepsis and control groups. Conclusion Common differential expression of IMRGs was identified in blood monocytes and myocardium between sepsis and control groups, among which HIF1A and SLC25A37 might predict prognosis in septic cardiomyopathy. The study may help us deeply understand the molecular mechanisms of iron metabolism and aid in the diagnosis and treatment of septic cardiomyopathy.
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Affiliation(s)
| | | | | | | | | | | | | | - Junjie Wang
- *Correspondence: Junjie Wang, ; Feng Zhou, ; Sheng Wang,
| | - Feng Zhou
- *Correspondence: Junjie Wang, ; Feng Zhou, ; Sheng Wang,
| | - Sheng Wang
- *Correspondence: Junjie Wang, ; Feng Zhou, ; Sheng Wang,
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Lehmann C, Alizadeh-Tabrizi N, Hall S, Faridi S, Euodia I, Holbein B, Zhou J, Chappe V. Anti-Inflammatory Effects of the Iron Chelator, DIBI, in Experimental Acute Lung Injury. Molecules 2022; 27:molecules27134036. [PMID: 35807282 PMCID: PMC9268372 DOI: 10.3390/molecules27134036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 06/17/2022] [Accepted: 06/20/2022] [Indexed: 02/01/2023] Open
Abstract
Iron plays a critical role in the immune response to inflammation and infection due to its role in the catalysis of reactive oxygen species (ROS) through the Haber-Weiss and Fenton reactions. However, ROS overproduction can be harmful and damage healthy cells. Therefore, iron chelation represents an innovative pharmacological approach to limit excess ROS formation and the related pro-inflammatory mediator cascades. The present study was designed to investigate the impact of the iron chelator, DIBI, in an experimental model of LPS-induced acute lung injury (ALI). DIBI was administered intraperitoneally in the early and later stages of lung inflammation as determined by histopathological evaluation. We found that lung tissues showed significant injury, as well as increased NF-κB p65 activation and significantly elevated levels of various inflammatory mediators (LIX, CXCL2, CCL5, CXCL10, IL-1𝛽, IL-6) 4 h post ALI induction by LPS. Mice treated with DIBI (80 mg/kg) in the early stages (0 to 2 h) after LPS administration demonstrated a significant reduction of the histopathological damage score, reduced levels of NF-κB p65 activation, and reduced levels of inflammatory mediators. Intravital microscopy of the pulmonary microcirculation also showed a reduced number of adhering leukocytes and improved capillary perfusion with DIBI administration. Our findings support the conclusion that the iron chelator, DIBI, has beneficial anti-inflammatory effects in experimental ALI.
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Affiliation(s)
- Christian Lehmann
- Department of Physiology & Biophysics, Dalhousie University, Halifax, NS B3H 1X5, Canada; (N.A.-T.); (S.H.); (V.C.)
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (S.F.); (I.E.); (B.H.)
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada;
- Correspondence:
| | - Nazli Alizadeh-Tabrizi
- Department of Physiology & Biophysics, Dalhousie University, Halifax, NS B3H 1X5, Canada; (N.A.-T.); (S.H.); (V.C.)
| | - Stefan Hall
- Department of Physiology & Biophysics, Dalhousie University, Halifax, NS B3H 1X5, Canada; (N.A.-T.); (S.H.); (V.C.)
| | - Sufyan Faridi
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (S.F.); (I.E.); (B.H.)
| | - Irene Euodia
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (S.F.); (I.E.); (B.H.)
| | - Bruce Holbein
- Department of Microbiology & Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (S.F.); (I.E.); (B.H.)
| | - Juan Zhou
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada;
| | - Valerie Chappe
- Department of Physiology & Biophysics, Dalhousie University, Halifax, NS B3H 1X5, Canada; (N.A.-T.); (S.H.); (V.C.)
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Abstract
Ferroptosis is a novel form of cell death characterized by the iron-dependent accumulation of lipid peroxides and is different from other types of cell death. The mechanisms of ferroptosis are discussed in the review, including System Xc-, Glutathione Peroxidase 4 pathway, Ferroptosis Suppressor Protein 1 and Dihydroorotate Dehydrogenase pathway. Ferroptosis is associated with the occurrence of various diseases, including sepsis. Research in recent years has displayed that ferroptosis is involved in sepsis occurrence and development. Iron chelators can inhibit the development of sepsis and improve the survival rate of septic mice. The ferroptotic cells can release damage-associated molecular patterns and lipid peroxidation, which further mediate inflammatory responses. Ferroptosis inhibitors can resist sepsis-induced multiple organ dysfunction and inflammation. Finally, we reviewed ferroptosis, an iron-dependent form of cell death that is different from other types of cell death in biochemistry, morphology, and major regulatory mechanisms, which is involved in multiple organ injuries caused by sepsis. Exploring the relationship between sepsis and ferroptosis may yield new treatment targets for sepsis.
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Affiliation(s)
- Yanting Liu
- Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, People's Republic of China.,Sepsis Translational Medicine Key Lab of Hunan Province, Changsha, People's Republic of China
| | - Sichuang Tan
- Department of Thoracic Surgery, Second Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Yongbin Wu
- Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, People's Republic of China.,Sepsis Translational Medicine Key Lab of Hunan Province, Changsha, People's Republic of China
| | - Sipin Tan
- Department of Pathophysiology, Xiangya School of Medicine, Central South University, Changsha, People's Republic of China.,Sepsis Translational Medicine Key Lab of Hunan Province, Changsha, People's Republic of China
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Hu Y, Cheng X, Mao H, Chen X, Cui Y, Qiu Z. Causal Effects of Genetically Predicted Iron Status on Sepsis: A Two-Sample Bidirectional Mendelian Randomization Study. Front Nutr 2021; 8:747547. [PMID: 34869523 PMCID: PMC8639868 DOI: 10.3389/fnut.2021.747547] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/19/2021] [Indexed: 12/16/2022] Open
Abstract
Background/Aim: Several observational studies showed a significant association between elevated iron status biomarkers levels and sepsis with the unclear direction of causality. A two-sample bidirectional mendelian randomization (MR) study was designed to identify the causal direction between seven iron status traits and sepsis. Methods: Seven iron status traits were studied, including serum iron, ferritin, transferrin saturation, transferrin, hemoglobin, erythrocyte count, and reticulocyte count. MR analysis was first performed to estimate the causal effect of iron status on the risk of sepsis and then performed in the opposite direction. The multiplicative random-effects and fixed-effects inverse-variance weighted, weighted median-based method and MR-Egger were applied. MR-Egger regression, MR pleiotropy residual sum and outlier (MR-PRESSO), and Cochran's Q statistic methods were used to assess heterogeneity and pleiotropy. Results: Genetically predicted high levels of serum iron (OR = 1.21, 95%CI = 1.13-1.29, p = 3.16 × 10-4), ferritin (OR = 1.32, 95%CI = 1.07-1.62, p =0.009) and transferrin saturation (OR = 1.14, 95%CI = 1.06-1.23, p = 5.43 × 10-4) were associated with an increased risk of sepsis. No significant causal relationships between sepsis and other four iron status biomarkers were observed. Conclusions: This present bidirectional MR analysis suggested the causal association of the high iron status with sepsis susceptibility, while the reverse causality hypothesis did not hold. The levels of transferrin, hemoglobin, erythrocytes, and reticulocytes were not significantly associated with sepsis. Further studies will be required to confirm the potential clinical value of such a prevention and treatment strategy.
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Affiliation(s)
- Yuanlong Hu
- First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, China.,Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xiaomeng Cheng
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China.,College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Huaiyu Mao
- Department of Emergency Medicine, The Second People's Hospital of Dongying, Dongying, China
| | - Xianhai Chen
- First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, China.,Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yue Cui
- Department of Dermatology, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Zhanjun Qiu
- First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, China.,Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
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Siraj MA, Islam Howlader MS, Islam MA, Irin T, Simal-Gandara J. Regulation of the redox signaling and inflammation by Terminalia myriocarpa leaves and the predictive interactions of it's major metabolites with iNOS and NF-ĸB. JOURNAL OF ETHNOPHARMACOLOGY 2021; 280:114459. [PMID: 34343646 DOI: 10.1016/j.jep.2021.114459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 07/06/2021] [Accepted: 07/24/2021] [Indexed: 06/13/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE The present study was designed to investigate the regulation of the redox signaling and inflammation by ethanolic leaf extract of Terminalia myriocarpaVan Heurck & Müller (ETM), inspired by the reported antioxidant potential of the plant bark and the anti-edema effect of the same genus. MATERIALS AND METHODS HPLC-DAD dereplication study was conducted to detect the major polyphenolic secondary metabolites. In-vitro DPPH free radical scavenging assay, nitric oxide (NO) scavenging assay, Fe2+ ion chelating ability assay and reducing power assay were conducted to evaluate the antioxidant capacity. The molecular mechanism of anti-inflammation was investigated via assessing the NO and NF-ĸB inhibiting properties in different cell lines. In-vivo carrageenan and histamine-induced edema tests were conducted using established animal models. Pro-inflammatory proteins iNOS and NF-κB were docked against the major metabolites of ETM in the in-silico study. RESULTS HPLC dereplication analysis revealed the presence of considerable amount of ellagic acid, where methyl-(S)-flavogallonate was previously reported in T. myriocarpa. Significant antioxidant activity was found in every in- vitro redox assay conducted. NO was reduced in RAW 264.7 cells, showing 83.67 ± 4.18% inhibitory activity at the highest tested concentration. TNF-α induced NF-κB was also observed to be reduced in 293/NF-кB-luc cells with an inhibitory activity of 66.23 ± 0.81% at the highest dose tested. In-vivo carrageenan-induced edema test demonstrated significant anti-inflammatory activity (p < 0.05; p < 0.01) at both doses of 250 and 500 mg/kg with 60.10% highest reduction in rat paw volume. Using same doses, histamine-induced edema test exhibited mentionable anti-inflammatory potential (p < 0.05; p < 0.01) with 67.91% highest reduction in rat paw volume. Moreover, ellagic acid and methyl-(S)-flavogallonate showed significant binding affinity with iNOS (-8.5 and -8.7 Kcal/moL, respectively) and NF-κB (-7.3 and -7.3 Kcal/moL, respectively). CONCLUSION Mentionable basis was found on behalf of the anti-inflammatory and antioxidant potentials of ETM which might be correlated with its NF-ĸB inhibiting properties.
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Affiliation(s)
- Md Afjalus Siraj
- Department of Pharmaceutical Sciences, Daniel K. Inouye College of Pharmacy, University of Hawaii at Hilo, Hilo, 96720, HI, USA
| | - Md Sariful Islam Howlader
- Department of Pharmaceutical Sciences, Jerry H. Hodge School of Pharmacy, Texas Tech University Health Sciences Center, Amarillo, TX, 79106, USA; Department of Chemistry, Tennessee Technological University, Cookeville, TN, 38501, USA
| | - Md Arman Islam
- Pharmacy Discipline, Life Science School, Khulna University, Khulna, 9208, Bangladesh
| | - Tanzira Irin
- Pharmacy Discipline, Life Science School, Khulna University, Khulna, 9208, Bangladesh; Department of Pharmacy, ASA University Bangladesh, Dhaka, 1207, Bangladesh
| | - Jesus Simal-Gandara
- Nutrition and Bromatology Group, Department of Analytical and Food Chemistry, Faculty of Food Science and Technology, University of Vigo, Ourense Campus, E32004, Ourense, Spain.
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Yu Y, Yan Y, Niu F, Wang Y, Chen X, Su G, Liu Y, Zhao X, Qian L, Liu P, Xiong Y. Ferroptosis: a cell death connecting oxidative stress, inflammation and cardiovascular diseases. Cell Death Discov 2021; 7:193. [PMID: 34312370 PMCID: PMC8313570 DOI: 10.1038/s41420-021-00579-w] [Citation(s) in RCA: 255] [Impact Index Per Article: 85.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/06/2021] [Accepted: 07/11/2021] [Indexed: 12/12/2022] Open
Abstract
Ferroptosis, a recently identified and iron-dependent cell death, differs from other cell death such as apoptosis, necroptosis, pyroptosis, and autophagy-dependent cell death. This form of cell death does not exhibit typical morphological and biochemical characteristics, including cell shrinkage, mitochondrial fragmentation, nuclear condensation. The dysfunction of lipid peroxide clearance, the presence of redox-active iron as well as oxidation of polyunsaturated fatty acid (PUFA)-containing phospholipids are three essential features of ferroptosis. Iron metabolism and lipid peroxidation signaling are increasingly recognized as central mediators of ferroptosis. Ferroptosis plays an important role in the regulation of oxidative stress and inflammatory responses. Accumulating evidence suggests that ferroptosis is implicated in a variety of cardiovascular diseases such as atherosclerosis, stroke, ischemia-reperfusion injury, and heart failure, indicating that targeting ferroptosis will present a novel therapeutic approach against cardiovascular diseases. Here, we provide an overview of the features, process, function, and mechanisms of ferroptosis, and its increasingly connected relevance to oxidative stress, inflammation, and cardiovascular diseases.
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Affiliation(s)
- Yi Yu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Yuan Yan
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Fanglin Niu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Yajun Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Xueyi Chen
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Guodong Su
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Yuru Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Xiling Zhao
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, 710069, Shaanxi, China
| | - Lu Qian
- Department of Endocrinology, Xi'an No.3 Hospital, the Affiliated Hospital of Northwest University, Xi'an, Shaanxi, 710018, P. R. China.
| | - Ping Liu
- Department of Endocrinology, Xi'an No.3 Hospital, the Affiliated Hospital of Northwest University, Xi'an, Shaanxi, 710018, P. R. China.
| | - Yuyan Xiong
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, School of Medicine, Northwest University, Xi'an, 710069, Shaanxi, China.
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12
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Abbasi U, Abbina S, Gill A, Takuechi LE, Kizhakkedathu JN. Role of Iron in the Molecular Pathogenesis of Diseases and Therapeutic Opportunities. ACS Chem Biol 2021; 16:945-972. [PMID: 34102834 DOI: 10.1021/acschembio.1c00122] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Iron is an essential mineral that serves as a prosthetic group for a variety of proteins involved in vital cellular processes. The iron economy within humans is highly conserved in that there is no proper iron excretion pathway. Therefore, iron homeostasis is highly evolved to coordinate iron acquisition, storage, transport, and recycling efficiently. A disturbance in this state can result in excess iron burden in which an ensuing iron-mediated generation of reactive oxygen species imparts widespread oxidative damage to proteins, lipids, and DNA. On the contrary, problems in iron deficiency either due to genetic or nutritional causes can lead to a number of iron deficiency disorders. Iron chelation strategies have been in the works since the early 1900s, and they still remain the most viable therapeutic approach to mitigate the toxic side effects of excess iron. Intense investigations on improving the efficacy of chelation strategies while being well tolerated and accepted by patients have been a particular focus for many researchers over the past 30 years. Moreover, recent advances in our understanding on the role of iron in the pathogenesis of different diseases (both in iron overload and iron deficiency conditions) motivate the need to develop new therapeutics. We summarized recent investigations into the role of iron in health and disease conditions, iron chelation, and iron delivery strategies. Information regarding small molecule as well as macromolecular approaches and how they are employed within different disease pathogenesis such as primary and secondary iron overload diseases, cancer, diabetes, neurodegenerative diseases, infections, and in iron deficiency is provided.
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Affiliation(s)
- Usama Abbasi
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z7
| | - Srinivas Abbina
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z7
| | - Arshdeep Gill
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Lily E. Takuechi
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z7
| | - Jayachandran N. Kizhakkedathu
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z7
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
- The School of Biomedical Engineering, The University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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13
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Liu Q, Wu J, Zhang X, Wu X, Zhao Y, Ren J. Iron homeostasis and disorders revisited in the sepsis. Free Radic Biol Med 2021; 165:1-13. [PMID: 33486088 DOI: 10.1016/j.freeradbiomed.2021.01.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 12/31/2020] [Accepted: 01/11/2021] [Indexed: 12/26/2022]
Abstract
Sepsis is a life-threatening condition caused by a dysregulated host-response to inflammation, although it currently lacks a fully elucidated pathobiology. Iron is a crucial trace element that is essential for fundamental processes in both humans and bacteria. During sepsis, iron metabolism is altered, including increased iron transport and uptake into cells and decreased iron export. The intracellular sequestration of iron limits its availability to circulating pathogens, which serves as a conservative strategy against the pathogens. Although iron retention has been showed to have protective protect effects, an increase in labile iron may cause oxidative injury and cell death (e.g., pyroptosis, ferroptosis) as the condition progresses. Moreover, iron disorders are substantial and correlate with the severity of sepsis. This also suggests that iron may be useful as a diagnostic marker for evaluating the severity and predicting the outcome of the disease. Further knowledge about these disorders could help in evaluating how drugs targeting iron homeostasis can be optimally applied to improve the treatment of patients with sepsis. Here, we present a comprehensive review of recent advances in the understanding of iron metabolism, focusing on the regulatory mechanisms and iron-mediated injury in sepsis.
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Affiliation(s)
- Qinjie Liu
- Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, 210002, PR China.
| | - Jie Wu
- Department of General Surgery, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210002, PR China.
| | - Xufei Zhang
- Research Institute of General Surgery, Jinling Hospital, Nanjing Medical University, Nanjing, 210002, PR China.
| | - Xiuwen Wu
- Research Institute of General Surgery, Jinling Hospital, Nanjing, 210002, PR China.
| | - Yun Zhao
- Department of General Surgery, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210002, PR China.
| | - Jianan Ren
- Research Institute of General Surgery, Jinling Hospital, Medical School of Nanjing University, Nanjing, 210002, PR China; Department of General Surgery, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210002, PR China; Research Institute of General Surgery, Jinling Hospital, Nanjing Medical University, Nanjing, 210002, PR China.
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14
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Lehmann C, Aali M, Zhou J, Holbein B. Comparison of Treatment Effects of Different Iron Chelators in Experimental Models of Sepsis. Life (Basel) 2021; 11:life11010057. [PMID: 33466819 PMCID: PMC7830599 DOI: 10.3390/life11010057] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/09/2021] [Accepted: 01/11/2021] [Indexed: 01/19/2023] Open
Abstract
Growing evidence indicates that dysregulated iron metabolism with altered and excess iron availability in some body compartments plays a significant role in the course of infection and sepsis in humans. Given that all bacterial pathogens require iron for growth, that iron withdrawal is a normal component of innate host defenses and that bacterial pathogens have acquired increasing levels of antibiotic resistance, targeting infection and sepsis through use of appropriate iron chelators has potential to provide new therapeutics. We have directly compared the effects of three Food and Drug Administration (FDA)-approved chelators (deferoxamine—DFO; deferiprone—DFP; and deferasirox—DFX), as were developed for treating hematological iron overload conditions, to DIBI, a novel purpose-designed, anti-infective and anti-inflammatory water-soluble hydroxypyridinone containing iron-selective copolymers. Two murine sepsis models, endotoxemia and polymicrobial abdominal sepsis, were utilized to help differentiate anti-inflammatory versus anti-infective activities of the chelators. Leukocyte adhesion, as measured by intravital microscopy, was observed in both models, with DIBI providing the most effective reduction and DFX the poorest. Inflammation in the abdominal sepsis model, assessed by cytokine measurements, indicated exacerbation by DFX and DFO for plasma Interleukin (IL)-6 and reductions to near-control levels for DIBI and DFP. Peritoneal infection burden was reduced 10-fold by DIBI while DFX and DFP provided no reductions. Overall, the results, together with those from other studies, revealed serious limitations for each of the three hematological chelators, i.e., as potentially repurposed for treating infection/sepsis. In contrast, DIBI provided therapeutic benefits, consistent with various in vitro and in vivo results from other studies, supporting the potential for its use in treating sepsis.
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Affiliation(s)
- Christian Lehmann
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 4R2, Canada;
- Correspondence:
| | - Maral Aali
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS B3H 4R2, Canada;
| | - Juan Zhou
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 4R2, Canada;
| | - Bruce Holbein
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada;
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15
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Holbein BE, Ang MTC, Allan DS, Chen W, Lehmann C. Iron-withdrawing anti-infectives for new host-directed therapies based on iron dependence, the Achilles' heel of antibiotic-resistant microbes. ENVIRONMENTAL CHEMISTRY LETTERS 2021; 19:2789-2808. [PMID: 33907538 PMCID: PMC8062846 DOI: 10.1007/s10311-021-01242-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 04/13/2021] [Indexed: 05/02/2023]
Abstract
The iron dependence of antibiotic-resistant microbes represents an Achilles' heel that can be exploited broadly. The growing global problem of antibiotic resistance of microbial pathogens wherein microbes become resistant to the very antibiotics used against them during infection is linked not only to our health uses but also to agribusiness practices and the changing environment. Here we review mechanisms of microbial iron acquisition and host iron withdrawal defense, and the influence of iron withdrawal on the antimicrobial activity of antibiotics. Antibiotic-resistant microbes are unaltered in their iron requirements, but iron withdrawal from microbes enhances the activities of various antibiotics and importantly suppresses outgrowth of antibiotic-exposed resistant microbial survivors. Of the three therapeutic approaches available to exploit microbial iron susceptibility, including (1) use of gallium as a non-functional iron analogue, (2) Trojan horse conjugates of microbial siderophores carrying antibiotics, and (3) new generation iron chelators, purposely designed as anti-microbials, the latter offers various advantages. For instance, these novel anti-microbial chelators overcome the limitations of conventional clinically-used hematological chelators which display host toxicity and are not useful antimicrobials. 3-Hydroxypyridin-4-one-containing polymeric chelators appear to have the highest potential. DIBI (developmental code name) is a well-developed lead candidate, being a low molecular weight, water-soluble copolymer with enhanced iron binding characteristics, strong anti-microbial and anti-inflammatory activities, low toxicity for animals and demonstrated freedom from microbial resistance development. DIBI has been shown to enhance antibiotic efficacy for antibiotic-resistant microbes during infection, and it also prevents recovery growth and resistance development during microbe exposure to various antibiotics. Because DIBI bolsters innate iron withdrawal defenses of the infected host, it has potential to provide a host-directed anti-infective therapy.
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Affiliation(s)
- Bruce E. Holbein
- Chelation Partners Inc., #58, The Labs at Innovacorp, Life Sciences Research Institute, 1344 Summer Street, Halifax, NS B3H OA8 Canada
- Department of Microbiology and Immunology, Dalhousie University, 5859 College St., Halifax, NS B3H 1X5 Canada
| | - M. Trisha C. Ang
- Chelation Partners Inc., #58, The Labs at Innovacorp, Life Sciences Research Institute, 1344 Summer Street, Halifax, NS B3H OA8 Canada
| | - David S. Allan
- Chelation Partners Inc., #58, The Labs at Innovacorp, Life Sciences Research Institute, 1344 Summer Street, Halifax, NS B3H OA8 Canada
| | - Wangxue Chen
- Human Health Therapeutics Research Center, National Research Council Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6 Canada
| | - Christian Lehmann
- Department of Microbiology and Immunology, Dalhousie University, 5859 College St., Halifax, NS B3H 1X5 Canada
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS Canada
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16
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Fokam D, Aali M, Dickson K, Scott C, Holbein B, Zhou J, Lehmann C. The novel iron chelator, DIBI, attenuates inflammation and improves outcome in colon ascendens stent peritonitis-induced experimental sepsis. Clin Hemorheol Microcirc 2020; 76:241-261. [PMID: 32925011 DOI: 10.3233/ch-209207] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Sepsis is the result of a dysregulated host immune response to an infection. An ideal therapy would target both the underlying infection and the dysregulated immune response. DIBI, a novel iron-binding polymer, was specifically developed as an antimicrobial agent and has also demonstrated in vivo anti-inflammatory properties. OBJECTIVE This study aimed to further investigate the effects of DIBI with and without the antibiotic imipenem (IMI) in colon ascendens stent peritonitis (CASP)-induced experimental sepsis. METHODS Vehicle, DIBI and/or IMI were administered in C57BL/6 mice after CASP surgery. Intestinal leukocyte activation and capillary perfusion was evaluated by intravital microscopy. Moreover, bacterial load in peritoneal lavage fluid and blood, and plasma cytokine levels were assessed. In a second series of experiments, surgery to repair the colon was performed at 5 hr and these mice were followed for long-term survival over 7 days. RESULTS DIBI reduced leukocyte adhesion, improved capillary blood flow, and decreased key plasma cytokines levels. DIBI also improved survival of infected mice and greatly improved IMI efficacy. Survivors treated with IMI and DIBI were found to be free of systemic infection. CONCLUSIONS DIBI has promising potential for sepsis treatment including its use as a sole or an adjunct therapeutic with antibiotics.
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Affiliation(s)
- Danielle Fokam
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Maral Aali
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Kayle Dickson
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - Cassidy Scott
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Bruce Holbein
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada.,Chelation Partners Inc., Halifax, NS, Canada
| | - Juan Zhou
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS, Canada
| | - Christian Lehmann
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada.,Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada.,Department of Pharmacology, Dalhousie University, Halifax, NS, Canada.,Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS, Canada
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17
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Dickson K, Malitan H, Lehmann C. Imaging of the Intestinal Microcirculation during Acute and Chronic Inflammation. BIOLOGY 2020; 9:E418. [PMID: 33255906 PMCID: PMC7760140 DOI: 10.3390/biology9120418] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 11/18/2020] [Indexed: 12/12/2022]
Abstract
Because of its unique microvascular anatomy, the intestine is particularly vulnerable to microcirculatory disturbances. During inflammation, pathological changes in blood flow, vessel integrity and capillary density result in impaired tissue oxygenation. In severe cases, these changes can progress to multiorgan failure and possibly death. Microcirculation may be evaluated in superficial tissues in patients using video microscopy devices, but these techniques do not allow the assessment of intestinal microcirculation. The gold standard for the experimental evaluation of intestinal microcirculation is intravital microscopy, a technique that allows for the in vivo examination of many pathophysiological processes including leukocyte-endothelial interactions and capillary blood flow. This review provides an overview of changes in the intestinal microcirculation in various acute and chronic inflammatory conditions. Acute conditions discussed include local infections, severe acute pancreatitis, necrotizing enterocolitis and sepsis. Inflammatory bowel disease and irritable bowel syndrome are included as examples of chronic conditions of the intestine.
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Affiliation(s)
- Kayle Dickson
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada;
| | - Hajer Malitan
- Department of Anesthesia, Pain and Perioperative Management, Dalhousie University, Halifax, NS B3H 4R2, Canada;
| | - Christian Lehmann
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada;
- Department of Anesthesia, Pain and Perioperative Management, Dalhousie University, Halifax, NS B3H 4R2, Canada;
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H 4R2, Canada
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18
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Abbina S, Gill A, Mathew S, Abbasi U, Kizhakkedathu JN. Polyglycerol-Based Macromolecular Iron Chelator Adjuvants for Antibiotics To Treat Drug-Resistant Bacteria. ACS APPLIED MATERIALS & INTERFACES 2020; 12:37834-37844. [PMID: 32639137 DOI: 10.1021/acsami.0c06501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Iron is an essential micronutrient for life. Its redox activity is a key component in a plethora of vital enzymatic reactions that take place in processes such as drug metabolism, DNA synthesis, steroid synthesis, gene regulation, and cellular respiration (oxygen transport and the electron transport chain). Bacteria are highly dependent on iron for their survival and growth and have specific mechanisms to acquire iron. Limiting the availability of iron to bacteria, thereby preventing their growth, provides new opportunities to treat infection in the era of the persistent rise of antibiotic-resistant bacteria. In this work, we have developed macromolecular iron chelators, conjugates of a high-affinity iron chelator (HBEDS) with polyglycerol, in an attempt to sequester iron uptake by bacteria to limit their growth in order to enhance antibiotic activity. The new macromolecular chelators are successful in slowing the growth of Staphylococcus aureus and worked as an efficient bacteriostatic against S. aureus. Further, these cytocompatible macrochelators acted as effective adjuvants to prevent bacterial growth when used in conjunction with antibiotics. The adjuvant activity of the macrochelators depends on their molecular weight and the chelator density on these molecules. These selective macro iron(III) chelators are highly efficient in growth inhibition and killing of methicillin-resistant S. aureus in conjunction with a low concentration of rifampicin.
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Affiliation(s)
- Srinivas Abbina
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Arshdeep Gill
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Chemistry, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Snehamol Mathew
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Usama Abbasi
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
| | - Jayachandran N Kizhakkedathu
- Centre for Blood Research, Life Sciences Institute, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- Department of Chemistry, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
- School of Biomedical Engineering, The University of British Columbia, Vancouver V6T 1Z4, British Columbia, Canada
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19
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Fokam D, Dickson K, Kamali K, Holbein B, Colp P, Stueck A, Zhou J, Lehmann C. Iron Chelation in Murine Models of Systemic Inflammation Induced by Gram-Positive and Gram-Negative Toxins. Antibiotics (Basel) 2020; 9:antibiotics9060283. [PMID: 32466384 PMCID: PMC7345558 DOI: 10.3390/antibiotics9060283] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/08/2020] [Accepted: 05/22/2020] [Indexed: 12/28/2022] Open
Abstract
Iron is an essential element for various physiological processes, but its levels must remain tightly regulated to avoid cellular damage. Similarly, iron plays a dual role in systemic inflammation, such as with sepsis. Leukocytes utilize iron to produce reactive oxygen species (ROS) to kill bacteria, but pathologically increased iron-catalyzed ROS production in sepsis can lead to damage of host cells, multi-organ failure and death. Temporary reduction in bioavailable iron represents a potential therapeutic target in sepsis. This study investigates the effect of the novel iron chelator, DIBI, in murine models of systemic (hyper-)inflammation: C57BL/6 mice were challenged with toxins from Gram-positive (Staphylococcus aureus: lipoteichoic acid, peptidoglycan) and Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae: lipopolysaccharide). Intravital microscopy (IVM) was performed to assess immune cell activation and its impact on microvascular blood flow in vivo in the microcirculation of the gut. Plasma inflammatory mediators were measured via multiplex assay, and morphologic change in intestinal tissue was evaluated. DIBI treatment decreased leukocyte (hyper-)activation induced by Gram-positive and Gram-negative toxins. In some cases, it preserved capillary perfusion, reduced plasma inflammatory markers and attenuated tissue damage. These findings support the utility of DIBI as a novel treatment for systemic inflammation, e.g., sepsis.
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Affiliation(s)
- Danielle Fokam
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS B3H 1X5, Canada;
| | - Kayle Dickson
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (K.D.); (B.H.)
| | - Kiyana Kamali
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H 1X5, Canada;
| | - Bruce Holbein
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (K.D.); (B.H.)
| | - Patricia Colp
- Department of Pathology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (P.C.); (A.S.)
| | - Ashley Stueck
- Department of Pathology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (P.C.); (A.S.)
| | - Juan Zhou
- Department of Anesthesia, Pain and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada;
| | - Christian Lehmann
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS B3H 1X5, Canada;
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 1X5, Canada; (K.D.); (B.H.)
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H 1X5, Canada;
- Department of Anesthesia, Pain and Perioperative Medicine, Dalhousie University, Halifax, NS B3H 1X5, Canada;
- Correspondence: ; Tel.: +1-902-494-1287
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20
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Mylonakis ME, Harrus S, Breitschwerdt EB. An update on the treatment of canine monocytic ehrlichiosis (Ehrlichia canis). Vet J 2019; 246:45-53. [PMID: 30902188 DOI: 10.1016/j.tvjl.2019.01.015] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 01/26/2019] [Accepted: 01/30/2019] [Indexed: 12/14/2022]
Abstract
Canine monocytic ehrlichiosis (CME), caused by Ehrlichia canis, a gram-negative, obligate intracellular bacterium, is a tick-borne disease of worldwide distribution. Experimentally, the course of E. canis infection can be sequentially divided into acute, subclinical and chronic phases, although distinction of these phases is challenging in the clinical setting. Spontaneous clinical recovery of acutely infected dogs is common; however, dogs at this stage require medical treatment in order to hasten their clinical recovery, and to prevent clinical exacerbation or death. An unpredictable proportion of subclinically infected dogs will eventually develop the chronic, severe form of ehrlichiosis, characterized by aplastic pancytopenia and high mortality. The aims of antimicrobial treatment in CME include the achievement of clinical remission, resolution of the clinicopathologic abnormalities, and eradication of the infection, although the latter is not always feasible or diagnostically confirmable. Treatment of dogs with aplastic pancytopenia should be undertaken with the clear understanding that medical management will require long-term care, will be expensive, and may eventually prove ineffective. This manuscript reviews the current state of knowledge regarding treatment of ehrlichiosis, caused by E. canis infection in dogs, provides expert opinion guidelines for the management of the CME-associated aplastic pancytopenia, and outlines methods for evaluation of treatment outcomes.
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Affiliation(s)
- Mathios E Mylonakis
- Companion Animal Clinic, School of Veterinary Medicine, Aristotle University of Thessaloniki, 11 Stavrou Voutyra st., Thessaloniki 54627, Greece.
| | - Shimon Harrus
- Koret School of Veterinary Medicine, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
| | - Edward B Breitschwerdt
- Intracellular Pathogens Research Laboratory, Comparative Medicine Institute, College of Veterinary Medicine, North Carolina State University (NCSU-CVM),1060 William Moore Drive, Raleigh, NC 27607 USA
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Gomes AC, Moreira AC, Mesquita G, Gomes MS. Modulation of Iron Metabolism in Response to Infection: Twists for All Tastes. Pharmaceuticals (Basel) 2018; 11:ph11030084. [PMID: 30200471 PMCID: PMC6161156 DOI: 10.3390/ph11030084] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/21/2022] Open
Abstract
Iron is an essential nutrient for almost all living organisms, but is not easily made available. Hosts and pathogens engage in a fight for the metal during an infection, leading to major alterations in the host’s iron metabolism. Important pathological consequences can emerge from the mentioned interaction, including anemia. Several recent reports have highlighted the alterations in iron metabolism caused by different types of infection, and several possible therapeutic strategies emerge, based on the targeting of the host’s iron metabolism. Here, we review the most recent literature on iron metabolism alterations that are induced by infection, the consequent development of anemia, and the potential therapeutic approaches to modulate iron metabolism in order to correct iron-related pathologies and control the ongoing infection.
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Affiliation(s)
- Ana Cordeiro Gomes
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
| | - Ana C Moreira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
| | - Gonçalo Mesquita
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
| | - Maria Salomé Gomes
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal.
- Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4050-313 Porto, Portugal.
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22
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Dickson K, Liu S, Zhou J, Langille M, Holbein BE, Lehmann C. Selective sensitivity of the gut microbiome to iron chelators in polybacterial abdominal sepsis. Med Hypotheses 2018; 120:68-71. [PMID: 30220344 DOI: 10.1016/j.mehy.2018.08.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 07/16/2018] [Accepted: 08/23/2018] [Indexed: 01/09/2023]
Abstract
Iron chelation has been proposed as a potential therapy for polybacterial abdominal sepsis. Treatment with iron chelation is known to be able to attenuate bacterial growth. It is hypothesized that the different types of bacteria will exhibit variations in their sensitivity to iron chelation based on differences in their iron metabolism. Bacteria with weaker iron access systems might have their growth reduced initially, but stronger species may also be suppressed. Gram-positive and Gram-negative bacteria are known to possess different iron acquisition systems, which may affect their response to iron chelation. Bacteria which can produce siderophores are at a particular advantage for iron acquisition. Novel iron chelators, which do not act as xenosiderophores, may be effective in depriving these bacteria of iron. This has implications for the treatment of polybacterial sepsis, which might be enhanced if the sensitivity to iron chelation of the primary causative agents is known.
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Affiliation(s)
- Kayle Dickson
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, Canada
| | - Simo Liu
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, Canada
| | - Juan Zhou
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, Canada
| | - Morgan Langille
- Department of Pharmacology, Dalhousie University, Halifax, Canada
| | - Bruce E Holbein
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Canada
| | - Christian Lehmann
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, Canada; Department of Pharmacology, Dalhousie University, Halifax, Canada; Department of Microbiology and Immunology, Dalhousie University, Halifax, Canada.
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23
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Lan P, Pan KH, Wang SJ, Shi QC, Yu YX, Fu Y, Chen Y, Jiang Y, Hua XT, Zhou JC, Yu YS. High Serum Iron level is Associated with Increased Mortality in Patients with Sepsis. Sci Rep 2018; 8:11072. [PMID: 30038422 PMCID: PMC6056487 DOI: 10.1038/s41598-018-29353-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/03/2018] [Indexed: 12/26/2022] Open
Abstract
Iron is an essential nutrient for bacterial survival and thus higher iron levels may precipitate bacterial infections. We investigated the association between the serum iron level and prognosis in patients with sepsis by using the single-centre Medical Information Mart for Intensive Care III (MIMIC-III) database. Sepsis patients with iron parameters measured on ICU admission were included and stratified according to quartiles of serum iron levels. A total of 1,891 patients diagnosed with sepsis according to the Sepsis-3 criteria were included in this study, 324 of whom were septic shock. After adjusting for confounding variables, higher iron quartile was associated with an increase in 90-day mortality in the Cox regression analysis. Moreover, a stepwise increase in the risk of 90-day mortality was observed as the quartiles of serum iron levels increased in the patients with sepsis. In conclusion, higher serum iron levels were independently associated with increased 90-day mortality in this large cohort of patients with sepsis.
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Affiliation(s)
- Peng Lan
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Kong-Han Pan
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Shuo-Jia Wang
- Department of Epidemiology and Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Qiu-Cheng Shi
- Department of Infectious Disease, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yun-Xian Yu
- Department of Epidemiology and Health Statistics, School of Public Health, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Ying Fu
- Department of Clinical Laboratory, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yan Chen
- Department of Infectious Disease, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Yan Jiang
- Department of Infectious Disease, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiao-Ting Hua
- Department of Infectious Disease, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian-Cang Zhou
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
| | - Yun-Song Yu
- Department of Infectious Disease, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
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24
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Experimental Evidence of the Healing Properties of Lactobionic Acid for Ocular Surface Disease. Cornea 2018; 37:1058-1063. [PMID: 29634672 DOI: 10.1097/ico.0000000000001594] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
PURPOSE The aim of this study was to investigate the properties of lactobionic acid (LA) as a possible supplement in artificial tears in in vitro and in vivo experimental model systems. LA is a bionic derivative of a polyhydroxy acid, which consists of one galactose attached by an ether link to a gluconic acid. It is a molecule endowed with several properties that make it an ideal supplement in artificial tears: it is highly hygroscopic and a powerful antioxidant, it is an iron chelator and inhibits matrix metalloprotease activity; it favors wound healing (WH); and it inhibits bacterial growth. METHODS Promotion of WH by LA, alone or in combination with hyaluronic acid (HA), was investigated in vitro on monolayers of rabbit corneal cells (Statens Seruminstitut) and in vivo after epithelium debridement of rabbit corneas. TGF-β expression and MMP-9 activity in wounded corneas were detected in tears and cornea extracts by western blot or by Enzyme Linked ImmunoSorbent Assay (ELISA). Bacterial growth inhibition by LA was checked on Staphylococcus aureus isolates in liquid culture. RESULTS LA, with or without HA, favors WH in vitro and in vivo. The WH assay on the rabbit cornea showed that 4% LA in association with 0.15% HA also resulted in a blunted increase of MMP-9 and TGF-β in tears and corneal tissue. Finally, the presence of 4% LA resulted in slower growth of cultured bacterial isolates. CONCLUSIONS Our findings support the hypothesis that LA could be a useful supplement to artificial tears to treat ocular surface dysfunction such as dry eye.
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Ang MTC, Gumbau-Brisa R, Allan DS, McDonald R, Ferguson MJ, Holbein BE, Bierenstiel M. DIBI, a 3-hydroxypyridin-4-one chelator iron-binding polymer with enhanced antimicrobial activity. MEDCHEMCOMM 2018; 9:1206-1212. [PMID: 30109009 PMCID: PMC6071711 DOI: 10.1039/c8md00192h] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 06/12/2018] [Indexed: 12/21/2022]
Abstract
Depriving microorganisms of bioavailable iron is a promising strategy for new anti-infective agents. The new, highly water-soluble, low molecular weight co-polymer DIBI was developed to selectively bind iron(iii) ions as a tris chelate and acts as a standalone anti-infective. Minimum inhibitory concentration (MIC) studies show DIBI is effective against representative reference strains for Gram-positive and Gram-negative bacteria S. aureus and A. baumannii, and the fungus C. albicans. Compared to the small molecule iron chelators, deferiprone and deferoxamine, DIBI outclassed these by factors of 100 to 1000 for inhibition of initial growth. DIBI and a series of related co-polymers (Mw of 2-9 kDa) were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization of a chelating 3-hydroxypyridin-4-one (HPO) methacrylamide monomer and N-vinylpyrrolidone (NVP). Full incorporation of the HPO monomer into the co-polymers from the reaction solution was determined by 1H NMR spectroscopy and ranged from 4.6 to 25.6 mol%. UV-vis spectroscopy showed that all the HPO in DIBI binds readily to iron(iii) in a tris chelate mode to the maximum theoretical iron(iii) binding capacity of the co-polymer. Chemical characterization including single crystal X-ray diffraction analyses of the O-benzyl protected and the functional HPO monomer are discussed. By design, DIBI is highly water soluble; the highest mass fraction in water tested was 70% w/w, without the need of organic co-solvents.
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Affiliation(s)
- M Trisha C Ang
- Chelation Partners Inc. , 1411 Oxford St. Suite 369 , Halifax , Nova Scotia B3H 3Z1 , Canada
- Department of Chemistry , Cape Breton University , 1250 Grand Lake Rd , Sydney , Nova Scotia B1P 6L2 , Canada . ; Tel: +1 (902) 563 1391
| | - Roger Gumbau-Brisa
- Chelation Partners Inc. , 1411 Oxford St. Suite 369 , Halifax , Nova Scotia B3H 3Z1 , Canada
- Department of Chemistry , Cape Breton University , 1250 Grand Lake Rd , Sydney , Nova Scotia B1P 6L2 , Canada . ; Tel: +1 (902) 563 1391
| | - David S Allan
- Chelation Partners Inc. , 1411 Oxford St. Suite 369 , Halifax , Nova Scotia B3H 3Z1 , Canada
| | - Robert McDonald
- X-Ray Crystallography Laboratory , Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Michael J Ferguson
- X-Ray Crystallography Laboratory , Department of Chemistry , University of Alberta , Edmonton , Alberta T6G 2G2 , Canada
| | - Bruce E Holbein
- Chelation Partners Inc. , 1411 Oxford St. Suite 369 , Halifax , Nova Scotia B3H 3Z1 , Canada
- Department of Microbiology and Immunology , Dalhousie University , 5859 College St. , Halifax , Nova Scotia B3H 1X5 , Canada
| | - Matthias Bierenstiel
- Department of Chemistry , Cape Breton University , 1250 Grand Lake Rd , Sydney , Nova Scotia B1P 6L2 , Canada . ; Tel: +1 (902) 563 1391
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26
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Iron Loading Exaggerates the Inflammatory Response to the Toll-like Receptor 4 Ligand Lipopolysaccharide by Altering Mitochondrial Homeostasis. Anesthesiology 2017; 127:121-135. [PMID: 28430694 DOI: 10.1097/aln.0000000000001653] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Perioperative and critically ill patients are often exposed to iron (in the form of parenteral-iron administration or blood transfusion) and inflammatory stimuli, but the effects of iron loading on the inflammatory response are unclear. Recent data suggest that mitochondrial reactive oxygen species have an important role in the innate immune response and that increased mitochondrial reactive oxygen species production is a result of dysfunctional mitochondria. We tested the hypothesis that increased intracellular iron potentiates lipopolysaccharide-induced inflammation by increasing mitochondrial reactive oxygen species levels. METHODS Murine macrophage cells were incubated with iron and then stimulated with lipopolysaccharide. C57BL/6 wild-type mice were intraperitoneally injected with iron and then with lipopolysaccharide. Markers of inflammation and mitochondrial superoxide production were examined. Mitochondrial homeostasis (the balance between mitochondrial biogenesis and destruction) was assessed, as were mitochondrial mass and the proportion of nonfunctional to total mitochondria. RESULTS Iron loading of mice and cells potentiated the inflammatory response to lipopolysaccharide. Iron loading increased mitochondrial superoxide production. Treatment with MitoTEMPO, a mitochondria-specific antioxidant, blunted the proinflammatory effects of iron loading. Iron loading increased mitochondrial mass in cells treated with lipopolysaccharide and increased the proportion of nonfunctional mitochondria. Iron loading also altered mitochondrial homeostasis to favor increased production of mitochondria. CONCLUSIONS Acute iron loading potentiates the inflammatory response to lipopolysaccharide, at least in part by disrupting mitochondrial homeostasis and increasing the production of mitochondrial superoxide. Improved understanding of iron homeostasis in the context of acute inflammation may yield innovative therapeutic approaches in perioperative and critically ill patients.
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27
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Xia Y, Farah N, Maxan A, Zhou J, Lehmann C. Therapeutic iron restriction in sepsis. Med Hypotheses 2016; 89:37-9. [PMID: 26968906 DOI: 10.1016/j.mehy.2016.01.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 01/18/2016] [Accepted: 01/30/2016] [Indexed: 01/27/2023]
Abstract
Sepsis represents the systemic immune response to an infection. Mortality of sepsis slightly decreased over the past years, but due to the growing incidence, the absolute number of deaths still increases and belongs to the three most frequent causes of death worldwide. To date, there is no specific treatment for sepsis available yet. Iron is essential to both human beings and microbes and of great significance in many physiological and biochemical processes. Since iron is involved in the bacterial proliferation and immune dysregulation, we hypothesize that restricting host iron levels by application of iron chelators attenuates bacterial growth and improves the detrimental dysregulation of the systemic immune response in sepsis.
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Affiliation(s)
- Yanfang Xia
- School of Basic Medical Sciences, Zhejiang University, Zhejiang, China
| | - Nizam Farah
- Department of Pharmacology, Dalhousie University, Halifax, Canada
| | - Alexander Maxan
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Canada
| | - Juan Zhou
- Department of Microbiology and Immunology, Dalhousie University, Halifax, Canada; Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, Canada
| | - Christian Lehmann
- Department of Pharmacology, Dalhousie University, Halifax, Canada; Department of Microbiology and Immunology, Dalhousie University, Halifax, Canada; Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, Canada; Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada
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28
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Kell DB, Kenny LC. A Dormant Microbial Component in the Development of Preeclampsia. Front Med (Lausanne) 2016; 3:60. [PMID: 27965958 PMCID: PMC5126693 DOI: 10.3389/fmed.2016.00060] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 11/04/2016] [Indexed: 12/12/2022] Open
Abstract
Preeclampsia (PE) is a complex, multisystem disorder that remains a leading cause of morbidity and mortality in pregnancy. Four main classes of dysregulation accompany PE and are widely considered to contribute to its severity. These are abnormal trophoblast invasion of the placenta, anti-angiogenic responses, oxidative stress, and inflammation. What is lacking, however, is an explanation of how these themselves are caused. We here develop the unifying idea, and the considerable evidence for it, that the originating cause of PE (and of the four classes of dysregulation) is, in fact, microbial infection, that most such microbes are dormant and hence resist detection by conventional (replication-dependent) microbiology, and that by occasional resuscitation and growth it is they that are responsible for all the observable sequelae, including the continuing, chronic inflammation. In particular, bacterial products such as lipopolysaccharide (LPS), also known as endotoxin, are well known as highly inflammagenic and stimulate an innate (and possibly trained) immune response that exacerbates the inflammation further. The known need of microbes for free iron can explain the iron dysregulation that accompanies PE. We describe the main routes of infection (gut, oral, and urinary tract infection) and the regularly observed presence of microbes in placental and other tissues in PE. Every known proteomic biomarker of "preeclampsia" that we assessed has, in fact, also been shown to be raised in response to infection. An infectious component to PE fulfills the Bradford Hill criteria for ascribing a disease to an environmental cause and suggests a number of treatments, some of which have, in fact, been shown to be successful. PE was classically referred to as endotoxemia or toxemia of pregnancy, and it is ironic that it seems that LPS and other microbial endotoxins really are involved. Overall, the recognition of an infectious component in the etiology of PE mirrors that for ulcers and other diseases that were previously considered to lack one.
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Affiliation(s)
- Douglas B. Kell
- School of Chemistry, The University of Manchester, Manchester, UK
- The Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
- Centre for Synthetic Biology of Fine and Speciality Chemicals, The University of Manchester, Manchester, UK
- *Correspondence: Douglas B. Kell,
| | - Louise C. Kenny
- The Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland
- Department of Obstetrics and Gynecology, University College Cork, Cork, Ireland
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