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Scott C, Neira Agonh D, White H, Sultana S, Lehmann C. Intravital Microscopy of Lipopolysaccharide-Induced Inflammatory Changes in Different Organ Systems-A Scoping Review. Int J Mol Sci 2023; 24:16345. [PMID: 38003533 PMCID: PMC10671110 DOI: 10.3390/ijms242216345] [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: 10/03/2023] [Revised: 11/02/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
Intravital microscopy (IVM) is a powerful imaging tool that captures biological processes in real-time. IVM facilitates the observation of complex cellular interactions in vivo, where ex vivo and in vitro experiments lack the physiological environment. IVM has been used in a multitude of studies under healthy and pathological conditions in different organ systems. IVM has become essential in the characterization of the immune response through visualization of leukocyte-endothelial interactions and subsequent changes within the microcirculation. Lipopolysaccharide (LPS), a common inflammatory trigger, has been used to induce inflammatory changes in various studies utilizing IVM. In this review, we provide an overview of IVM imaging of LPS-induced inflammation in different models, such as the brain, intestines, bladder, and lungs.
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Affiliation(s)
- Cassidy Scott
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H1X5, Canada;
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H1X5, Canada; (H.W.); (S.S.)
| | - Daniel Neira Agonh
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS B3H1X5, Canada;
| | - Hannah White
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H1X5, Canada; (H.W.); (S.S.)
| | - Saki Sultana
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H1X5, Canada; (H.W.); (S.S.)
| | - Christian Lehmann
- Department of Anesthesia, Pain Management and Perioperative Medicine, Dalhousie University, Halifax, NS B3H1X5, Canada;
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H1X5, Canada; (H.W.); (S.S.)
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS B3H1X5, Canada;
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Zhou S, Huang G, Chen G, Liu J. Synthesis, activity and mechanism for double-ring conjugated enones. Bioorg Med Chem Lett 2021; 49:128315. [PMID: 34390826 DOI: 10.1016/j.bmcl.2021.128315] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/22/2021] [Accepted: 08/08/2021] [Indexed: 02/07/2023]
Abstract
The relationship between TLR4 and inflammation-related diseases has been paid more and more attention. The studies have shown that TLR4/NF-κB signaling pathway plays an important role in the transmission of inflammatory signals. A large number of pro-inflammatory factors, chemokines, adhesion factors, TLR4 and its ligands interact with each other, and jointly promote the development of diseases. In this work, 8 target compounds were synthesized to screen the inhibitory activity of TLR4 in vitro. The results of TLR4 inhibition test in vitro showed that the double-ring conjugated enones had a good inhibitory activity, and the IC50 value of compound 4f was 0.56 ± 0.10 μM, and it was superior to the positive control methotrexate. To further study the anti-inflammatory effect and mechanism of double-ring conjugated enones by using LPS induced rat synovial cell inflammation model. The results of the mechanism test showed that compound 4f could effectively promote the apoptosis of rat synovial cells, and the mechanism might be related to the up-regulation of the expression of apoptosis-related protein Caspase-3. In addition, compound 4f could significantly inhibit the increase of inflammatory factors TNF-α, IL-1β and IL-6 in rat synovial cells induced by LPS, showing a good anti-inflammatory activity. In the TLR4/NF-κB signaling pathway test of rat synovial cells, compound 4f can effectively regulate the expression levels of TLR4, MyD88, NF-κB and IκB related proteins in TLR4/NF-κB signaling pathway, which may be due to its inhibition of LPS-induced inflammation in rat synovial cells. At the same time, it inhibits the abnormal proliferation of cells and its important mechanism promoted of apoptosis.
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Affiliation(s)
- Shiyang Zhou
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, Hainan Normal University, Haikou 571158, China; Chongqing Chemical Industry Vocational College, Chongqing 401228, China; Active Carbohydrate Research Institute, Chongqing Key Laboratory of Inorganic Functional Materials, College of Chemistry, Chongqing Normal University, Chongqing 401331, China
| | - Gangliang Huang
- Active Carbohydrate Research Institute, Chongqing Key Laboratory of Inorganic Functional Materials, College of Chemistry, Chongqing Normal University, Chongqing 401331, China.
| | - Guangying Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, Hainan Normal University, Haikou 571158, China.
| | - Jian Liu
- The First Hospital, Hunan University of Chinese Medicine, Changsha 410007, China
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Di Bella D, Ferreira JPS, Silva RDNO, Echem C, Milan A, Akamine EH, Carvalho MH, Rodrigues SF. Gold nanoparticles reduce inflammation in cerebral microvessels of mice with sepsis. J Nanobiotechnology 2021; 19:52. [PMID: 33608025 PMCID: PMC7893894 DOI: 10.1186/s12951-021-00796-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 02/08/2021] [Indexed: 12/17/2022] Open
Abstract
Background Sepsis is an emergency medical condition that can lead to death and it is defined as a life-threatening organ dysfunction caused by immune dysregulation in response to an infection. It is considered the main killer in intensive care units. Sepsis associated-encephalopathy (SAE) is mostly caused by a sepsis-induced systemic inflammatory response. Studies report SAE in 14–63% of septic patients. Main SAE symptoms are not specific and usually include acute impairment of consciousness, delirium and/or coma, along with electroencephalogram (EEG) changes. For those who recover from sepsis and SAE, impaired cognitive function, mobility and quality of life are often observed months to years after hospital discharge, and there is no treatment available today to prevent that. Inflammation and oxidative stress are key players for the SAE pathophysiology. Gold nanoparticles have been demonstrated to own important anti-inflammatory properties. It was also reported 20 nm citrate-covered gold nanoparticles (cit-AuNP) reduce oxidative stress. In this context, we tested whether 20 nm cit-AuNP could alleviate the acute changes caused by sepsis in brain of mice, with focus on inflammation. Sepsis was induced in female C57BL/6 mice by cecal ligation and puncture (CLP), 20 nm cit-AuNP or saline were intravenously (IV) injected 2 h after induction of sepsis and experiments performed 6 h after induction. Intravital microscopy was used for leukocyte and platelet adhesion study in brain, blood brain barrier (BBB) permeability carried out by Evans blue assay, cytokines measured by ELISA and real time PCR, cell adhesion molecules (CAMs) by flow cytometry and immunohistochemistry, and transcription factors, by western blotting. Results 20 nm cit-AuNP treatment reduced leukocyte and platelet adhesion to cerebral blood vessels, prevented BBB failure, reduced TNF- concentration in brain, and ICAM-1 expression both in circulating polymorphonuclear (PMN) leukocytes and cerebral blood vessels of mice with sepsis. Furthermore, 20 nm cit-AuNP did not interfere with the antibiotic effect on the survival rate of mice with sepsis. Conclusions Cit-AuNP showed important anti-inflammatory properties in the brain of mice with sepsis, being a potential candidate to be used as adjuvant drug along with antibiotics in the treatment of sepsis to avoid SAE ![]()
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Affiliation(s)
- Davide Di Bella
- Laboratory of Hypertension, Diabetes and Vascular Biology, Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes, 1524, ICB I, sala 205, 2º andar, Butanta, 05508-900, Sao Paulo, Brazil
| | - João P S Ferreira
- Laboratory of Hypertension, Diabetes and Vascular Biology, Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes, 1524, ICB I, sala 205, 2º andar, Butanta, 05508-900, Sao Paulo, Brazil
| | - Renee de Nazare O Silva
- Laboratory of Hypertension, Diabetes and Vascular Biology, Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes, 1524, ICB I, sala 205, 2º andar, Butanta, 05508-900, Sao Paulo, Brazil
| | - Cinthya Echem
- Laboratory of Hypertension, Diabetes and Vascular Biology, Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes, 1524, ICB I, sala 205, 2º andar, Butanta, 05508-900, Sao Paulo, Brazil
| | - Aline Milan
- Laboratory of Hypertension, Diabetes and Vascular Biology, Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes, 1524, ICB I, sala 205, 2º andar, Butanta, 05508-900, Sao Paulo, Brazil
| | - Eliana H Akamine
- Laboratory of Hypertension, Diabetes and Vascular Biology, Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes, 1524, ICB I, sala 205, 2º andar, Butanta, 05508-900, Sao Paulo, Brazil
| | - Maria H Carvalho
- Laboratory of Hypertension, Diabetes and Vascular Biology, Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes, 1524, ICB I, sala 205, 2º andar, Butanta, 05508-900, Sao Paulo, Brazil
| | - Stephen F Rodrigues
- Laboratory of Hypertension, Diabetes and Vascular Biology, Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes, 1524, ICB I, sala 205, 2º andar, Butanta, 05508-900, Sao Paulo, Brazil. .,Laboratory of Vascular Nanopharmacology, Department of Pharmacology, Institute of Biomedical Sciences, University of Sao Paulo, Av. Prof. Lineu Prestes, 1524, ICB I, sala 319, 3º andar, Butanta, 05508-900, Sao Paulo, Brazil.
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Ihler F, Freytag S, Kloos B, Spiegel JL, Haubner F, Canis M, Weiss BG, Bertlich M. Lipopolysaccharide decreases cochlear blood flow dose dependently in a guinea pig animal model via TNF signaling. Microcirculation 2021; 28:e12681. [PMID: 33501679 DOI: 10.1111/micc.12681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/15/2021] [Accepted: 01/20/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the effect of Lipopolysaccharide (LPS), a bacterial endotoxin on cochlear microcirculation, and its mode of action. METHODS Twenty-five Dunkin-Hartley guinea pigs were divided into five groups of five animals each. After surgical preparation, cochlear microcirculation was quantified by in vivo fluorescence microscopy. Placebo or LPS (1 mg, 10 µg, and 100 ng) was applied topically, and microcirculation was measured before and twice after application. A fifth group was pretreated with etanercept, a tumor necrosis factor (TNF) antagonist, and afterward the lowest LPS concentrations that yielded significant results (10 µg) were applied. RESULTS In the groups that had been treated with 1 mg and 10 µg LPS, a significant drop in cochlear microcirculation was observed after 30 (.791 ± .089 Arbitrary Units (AU), compared to baseline, and .888 ± .071AU) and 60 (.756 ± .101 AU and .817 ± .124 AU, respectively) minutes. The groups that had been treated with 100 ng LPS and that had been pretreated with etanercept showed no significant change in cochlear blood flow compared to placebo. CONCLUSION Lipopolysaccharide shows a dose-dependent effect on cochlear microcirculation; this effect can already be observed after 30 min. Pretreatment with etanercept can abrogate this effect, indicating that TNF mediates the effect of LPS on cochlear microcirculation.
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Affiliation(s)
- Friedrich Ihler
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
| | - Saskia Freytag
- Population Health and Immunity Division, Walter and Eliza Hall Institute, Parkville, Vic., Australia.,Department of Medical Biology, University of Melbourne, Melbourne, Vic., Australia
| | - Benedikt Kloos
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
| | - Jennifer Lee Spiegel
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Frank Haubner
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Martin Canis
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
| | - Bernhard G Weiss
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
| | - Mattis Bertlich
- Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig-Maximilians-University of Munich, Munich, Germany.,Walter Brendel Centre of Experimental Medicine, University of Munich Hospital, Munich, Germany
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Experimental TLR4 inhibition improves intestinal microcirculation in endotoxemic rats. Microvasc Res 2015; 101:33-7. [DOI: 10.1016/j.mvr.2015.06.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 06/19/2015] [Accepted: 06/22/2015] [Indexed: 12/14/2022]
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Iba T, Nagakari K. The effect of plasma-derived activated protein C on leukocyte cell-death and vascular endothelial damage. Thromb Res 2015; 135:963-9. [PMID: 25813362 DOI: 10.1016/j.thromres.2015.03.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 02/05/2015] [Accepted: 03/03/2015] [Indexed: 12/31/2022]
Abstract
INTRODUCTION The role of leukocyte and its death in the progression in inflammation attracts attention nowadays. The purpose of this study is to examine the effects of activated protein C (APC) on leucocyte cell death and vascular endothelial damage in sepsis. METHODS Wistar rats were infused with lipopolysaccharide (8.0mg/kg) concomitantly with either a low dose (0.5mg/kg), a high dose (5.0mg/kg) of plasma-derived APC or albumin. One and 3hours after the injections, the mesenteric microcirculation was observed by intravital microscopy. The serum levels of nucleosome and High Mobility Group Box 1 (HMGB1) were measured in each group. In another series, cultured leukocyte cell-death in the medium supplemented with serum obtained from each group was examined in vitro. RESULTS Microcirculatory disturbance was significantly suppressed in both the high-dose and low-dose groups compared to the control group (P<0.01, 0.05, respectively). The bleeding area was significantly increased in the control and high-dose groups (P<0.05, 0.01, respectively). Serum levels of cell death markers such as nucleosome and HMGB1 were significantly decreased in the treatment groups (P<0.01), and the protective effect was more pronounced in high-dose group. Cell death suppression was most prominent in high-dose group and the formation of neutrophil extracellular traps (NETs) was significantly suppressed in the treatment groups. CONCLUSION Low-dose plasma-derived APC exerted protective effects on the microcirculation without increasing the risk of bleeding. The protective effect against leukocyte cell death and the suppressive effect on NETs formation of APC might be related to its beneficial effects.
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Affiliation(s)
- Toshiaki Iba
- Department of Emergency and Disaster Medicine, Juntendo University Graduate School of MedicineJapan.
| | - Kunihiko Nagakari
- Department of Emergency and Disaster Medicine, Juntendo University Graduate School of MedicineJapan.
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Epinephrine enhances the response of macrophages under LPS stimulation. BIOMED RESEARCH INTERNATIONAL 2014; 2014:254686. [PMID: 25243125 PMCID: PMC4160625 DOI: 10.1155/2014/254686] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Revised: 07/08/2014] [Accepted: 07/29/2014] [Indexed: 11/24/2022]
Abstract
Trauma associated with infection may directly trigger a neuroendocrine reaction in vivo while the hormone epinephrine is known to mediate immune responses to inflammation after injury. However, the role of epinephrine during the earliest stage of trauma still remains unclear. We therefore explored the role of epinephrine on activated macrophages under LPS stimulation in vitro as well as the mechanisms underlying its effect. Dose- and time-dependent effects of epinephrine on macrophage immune function were assessed after LPS activation. We also employed CD14 siRNA interference to investigate whether CD14 played a role in the mechanism underlying the effect of epinephrine on LPS-induced macrophage responses. Our results showed that epinephrine pretreatment (10 ng/mL) significantly promoted immune responses from LPS stimulated macrophages, including phagocytic rate, phagocytic index, TNFα/IL-1β/IL-10 secretion, and CD14 expression (P < 0.05). Moreover, TNFα/IL-1β/IL-10 levels attained their peak value 1 hour after incubation with 10 ng/mL epinephrine (P < 0.05), and CD14 siRNA transfection dramatically decreased phagocytosis and cytokine secretion by LPS-activated macrophages (P < 0.05). We therefore conclude that 10 ng/mL epinephrine enhances immune responses from macrophages under LPS stimulation and that the underlying mechanism may relate to CD14 upregulation on the surface of macrophages.
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Alabanza LM, Esmon NL, Esmon CT, Bynoe MS. Inhibition of endogenous activated protein C attenuates experimental autoimmune encephalomyelitis by inducing myeloid-derived suppressor cells. THE JOURNAL OF IMMUNOLOGY 2013; 191:3764-77. [PMID: 23997223 DOI: 10.4049/jimmunol.1202556] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Activated protein C (PC) is an anticoagulant involved in the interactions between the coagulation and immune systems. Activated PC has broad anti-inflammatory effects that are mediated through its ability to modulate leukocyte function and confer vascular barrier protection. We investigated the influence of activated PC on the pathogenesis of experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis. We modulated activated PC levels in the circulation during EAE induction through systemic administration of a mAb against PC/activated PC (anti-PC). We initially hypothesized that inhibition of activated PC may result in a heightened inflammatory environment, leading to increased EAE pathogenesis. Contrary to this hypothesis, mice treated with anti-PC Ab (anti-PC mice) exhibited attenuated EAE. Interestingly, despite reduced disease severity and minimal pathogenic conditions in the CNS, anti-PC mice exhibited considerable leukocyte infiltration in the brain, comparable to control mice with severe EAE. Furthermore, CD4(+) T cells were diminished in the periphery of anti-PC mice, whereas various CD11b(+) populations were increased, notably the myeloid-derived suppressor cells (MDSCs), a CD11b(+) subset characterized as potent T cell suppressors. MDSCs from anti-PC mice exhibited increased expression of T cell suppressive factors and effectively inhibited T cell proliferation. Overall, our findings show that activated PC inhibition affected EAE pathogenesis at multiple fronts, specifically increasing vascular barrier permeability, as evidenced by considerable leukocyte infiltration in the brain. Additionally, inhibition of activated PC modulated the functional responses of CD11b(+) cells, leading to the expansion and increased activation of MDSCs, which are suppressive to the CD4(+) T cells required for EAE progression, thereby resulting in attenuated EAE.
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Affiliation(s)
- Leah M Alabanza
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853
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