Chemical Senses by Alexandros G. Sfakianakis


Publicado em 23 dezembro 2020

Por Alexandros G. Sfakianakis

Toll-Like Receptors, Associated Biochemical Signaling Networks, and S100 Ligands

Host cells recognize molecules that signal danger using pattern recognition receptors (PRRs). Toll-Like Receptors (TLRs) are the most studied class of PRRs and detect pathogen associated molecular patterns and danger associated molecular patterns. Cellular TLR activation and signal transduction can therefore contain, combat and clear danger by enabling appropriate gene transcription. Here we review the expression, regulation and function of different TLRs, with an emphasis on TLR-4, and how TLR adaptor protein binding directs intracellular signaling resulting in activation or termination of an innate immune response. Finally, we highlight the recent progress of research on the involvement of S100 proteins as ligands for TLR-4 in inflammatory disease. Address reprint requests to John C. Marshall, MD, St. Michael's Hospital, 4th Floor Bond Wing, Room 4-007, 30 Bond Street, Toronto, Ontario, M5B 1W8, Canada. E-mail: Received 25 October, 2020 Revised 12 November, 2020 Accepted 30 November, 2020 Conflicts of Interest: The authors have no conflicts of interest to declare. Grant Funding Source: Canadian Institutes of Health Research (MOP 129493) © 2020 by the Shock Society

Bone Marrow-Derived Mononuclear Cell Transplantation can Reduce Systemic Inflammation and Endothelial Glycocalyx Damage in Sepsis

Bone marrow-derived mononuclear cells (BMMNCs) secrete anti-inflammatory mediators that protect against acute inflammation. Current evidence suggests that BMMNC transplantation can reduce acute tissue injury caused by systemic inflammation and lung dysfunction. This study evaluated the role of BMMNCs in reducing systemic inflammatory responses to vascular endothelial injury in sepsis. Bone marrow cells were harvested from the tibias and femurs of twelve-week-old male Wistar rats; BMMNCs were separated by density centrifugation. Additional rats underwent cecal ligation and puncture (CLP) or similar sham surgery. BMMNCs were injected intravenously 30?min after CLP. The Sham and CLP Control groups were administered PBS. The seven-day survival rate improved markedly in the CLP-BMMNC group compared with that in the Control group. BMMNCs markedly suppressed the serum levels of pro-inflammatory mediators such as tumor necrosis factor-alpha, interleukin-6, and histone H3 at 3, 6, and 12?h after CLP. In the CLP-BMMNC group, the serum levels of syndecan-1, the main component of the vascular endothelial glycocalyx layer, were notably lower than those in the Control group 6?h after CLP. Histological analysis revealed improvement of morphological damages in the CLP-BMMNC group. Ultrastructural analysis revealed that the glycocalyx structure was maintained and the continuity of the vascular endothelial glycocalyx layer was preserved in the BMMNC group, compared to the case for the Control group at 6 and 12?h. Therefore, BMMNC transplantation may provide reduced systemic inflammation and endothelial glycocalyx damage, dramatically improving the survival of rats. These findings provide insights into formulating potential therapeutic strategies against sepsis. Address reprint requests to Tsunehiro Matsubara, MD, Osaka University Graduate School of Medicine Department of Traumatology and Acute Critical Care Center, 2-15 Yamadaoka, Suita-city, Osaka 565-0871, Japan. E-mail: Received 1 August, 2020 Revised 10 September, 2020 Accepted 9 December, 2020 Conflicts of Interest and Source of Funding: This study received a Grant-in-Aid for Young Scientists from The Ministry of Education, Culture, Sports, Science and Technology, Japan. The authors declare no conflicts of interest. © 2020 by the Shock Society

Neutrophil-To-Lymphocyte Ratio And Covid-19

No abstract available

Pharmacological and Genetic Inhibition of Translocator Protein 18 kDa Ameliorated Neuroinflammation in Murine Endotoxemia Model

Sepsis-associated encephalopathy (SAE) is a diffuse brain dysfunction associated with sepsis. The development of an effective strategy for early diagnosis and therapeutic intervention is essential for the prevention of poor prognosis of SAE. Translocator protein 18 kDa (TSPO) is a mitochondrial protein implicated in steroidogenesis and inflammatory responses. Despite accumulating evidence that implicates TSPO in the neuroinflammatory response of the central nervous system, the possible role of TSPO in SAE remains unclear. Aim of this study is to address a role of TSPO in neuroinflammation using mice 24?h after systemic injection of lipopolysaccharide (LPS), which consistently demonstrated microglial activation and behavioral inhibition. Quantitative polymerase chain reaction analysis revealed that hippocampal TSPO expression was induced following the systemic LPS injection, associated with an increase in pro-inflammatory cytokines such as tumor necrosis factor-a and interleukin-1ß. Interestingly, pretreatment with the TSPO antagonist, ONO-2952, or germ-line deletion of the TSPO gene exhibited an anti-inflammatory effect with significant suppression of LPS-induced production of those cytokines. These effects demonstrated by the ONO-2952 or TSPO knockout were associated with significant recovery from behavioral inhibition, as shown by improved locomotor activity in the open field analysis. Histological analysis revealed that ONO-2952 pretreatment suppressed the LPS-induced activation of TSPO-expressing microglia in the hippocampus of mice. Collectively, these results suggest that TSPO plays a critical role in the SAE mouse model. Based on this finding, monitoring TSPO activity, as well as the progress of endotoxemia and its sequelae in the animal model, would deepen our understanding of the underlying molecular mechanism of SAE. Address reprint requests to Hidenori Aizawa, MD, PhD, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8553 Japan. E-mail: Received 24 September, 2020 Revised 12 October, 2020 Accepted 23 November, 2020 Disclosure: The authors declare that they have no conflicts of interest. Funding: This research was supported by a Grant-in-Aid for Scientific Research on Innovative Areas (JP19H05723) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) to HA; a Grant-in-Aid for 'Integrated Research on Depression, Dementia and Development Disorders (20dm0107093)' carried out under the Strategic Research Program for Brain Sciences by AMED to SY and a Grant-in-Aid for Scientific Research C (18K08888) to KH. © 2020 by the Shock Society

HIF-1a and Hypoxia Responsive Genes are Differentially Expressed in Leukocytes from Survivors and Non-Survivors Patients during Clinical Sepsis

Hypoxia inducible factor 1 alpha (HIF-1a) is linked to the metabolic and immune alterations in septic patients. Stabilization of HIF-1a by hypoxia or inflammation promotes the expression of several genes related to glycolytic metabolism, angiogenesis, coagulation, cell proliferation and apoptosis. Here we analyzed public available blood transcriptome datasets from septic patients and evaluated by PCR array the expression of HIF-1a and other hypoxia responsive genes in peripheral blood mononuclear cells (PBMC) from patients with sepsis secondary to community acquired infections. Samples were collected at ICU admission (D0, n=29) and after 7 days follow-up (D7, n?=?18); healthy volunteers (n?=?10) were included as controls. Hypoxia and glycolysis were among the top scored molecular signatures in the transcriptome datasets. PCR array showed that 24 out of 78 analyzed genes were modulated in septic patients compared to healthy volunteers; most of them (23/24) were downregulated at admission. This same pattern was observed in surviving patients, while non-survivors presented more upregulated genes. EGLN1, EGLN2 and HIF1AN, inhibitors of HIF-1a activation were downregulated in patients, regardless of the outcome, while HIF-1a and other target genes, such as PDK1 and HMOX1, expression were higher in non-survivors than in survivors, mainly at D7. Non-survivor patients also presented a higher SOFA score and lower PaO2/FiO2 ratio. Our results indicate a differential modulation of hypoxia pathway in leukocytes between septic patients who survived and those who did not survive with an increased intensity at D7, which is possibly influenced by disease severity and may affect the immune response in sepsis. Address reprint requests to Reinaldo Salomao, MD, PhD, Division of Infectious Diseases, Escola Paulista de Medicina, Hospital São Paulo, Universidade Federal de São Paulo, Rua Pedro de Toledo, 669, 10th Floor, Sao Paulo, SP, 04039-032, Brazil. E-mail: Received 25 September, 2020 Revised 19 October, 2020 Accepted 6 November, 2020 Funding: This work was supported by FAPESP (Grant 2017/21052-0). RS is the recipient of a Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) fellowship. BLF has a scholarship from FAPESP (2016/13855-2). Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website ( © 2020 by the Shock Society

The Value of Extracellular Cold-Inducible RNA-Binding Protein (eCIRP) in Predicting the Severity and Prognosis of Patients after Cardiac Arrest: A Preliminary Observational Study

Background: Extracellular cold-inducible RNA-binding protein (eCIRP) acting as a novel damage-associated molecular pattern molecule promotes systemic inflammatory responses, including neuroinflammation in cerebral ischemia. We aimed to observe the changes of serum eCIRP and evaluate whether the increased serum eCIRP was associated with the severity and prognosis in patients with restoration of spontaneous circulation (ROSC). Methods: A total of 73 patients after ROSC were divided into non-survivor (n?=?48) and survivor (n?=?25) groups based on 28-day survival. Healthy volunteers (n?=?25) were enrolled as controls. Serum eCIRP, procalcitonin (PCT), the pro-inflammatory mediators tumor necrosis factor (TNF)-a, interleukin-6 (IL)-6 and high mobility group protein (HMGB1), the neurological damage biomarkers neuron-specific enolase (NSE) and soluble protein 100ß (S100ß) were measured on days 1, 3 and 7 after ROSC. Clinical data and laboratory findings were collected, and the Sequential Organ Failure Assessment (SOFA) score and Acute Physiology and Chronic Health Evaluation (APACHE II) were calculated concurrently. Cerebral performance category (CPC) scores on day 28 after ROSC were recorded. Results: Serum eCIRP, IL-6, TNF-a, PCT and HMGB1, NSE and S100ß were significantly increased within the first week after ROSC. The increased levels of eCIRP was positively correlated with IL-6, TNF-a, lactate, NSE, S100ß, CPR time, SOFA score, APACHE II score and HMGB1 after ROSC. Serum eCIRP on days 1, 3 and 7 after ROSC could predict 28-day mortality and neurological prognosis. Serum eCIRP on day 3 after ROSC had a biggest AUC [0.862 (95%CI: 0.741–0.941)] for 28-day mortality and a biggest AUC [0.807 (95%CI: 0.630–0.981)] for neurological prognosis. Conclusions: Systemic inflammatory response with increased serum eCIRP occurred in patients after ROSC. Increased eCIRP level was positively correlated with the aggravation of systemic inflammatory response and the severity after ROSC. Serum eCIRP serves as a potential predictor for 28-day mortality and poor neurological prognosis after ROSC. Address reprint requests to Ping Gong, Emergency Department, First Affiliated Hospital of Dalian Medical University, No. 222 Zhongshan Road, Dalian 116023, Liaoning Province, China. E-mail: Received 10 October, 2020 Revised 27 October, 2020 Accepted 20 November, 2020 LW and R-FL contributed equally to this study and should be considered co-first authors. The authors report no conflicts of interest. Funding: This study was supported by the National Natural Science Foundation of China (81571869). Competing interests: The authors declare that they have no competing interests. © 2020 by the Shock Society

Endothelial NOX2 Limits Systemic Inflammation and Hypotension in Endotoxemia by Controlling Expression of Toll-Like Receptor 4

Leukocyte Nox2 is recognized to have a fundamental microbicidal function in sepsis but the specific role of Nox2 in endothelial cells (EC) remains poorly elucidated. Here, we tested the hypothesis that endothelial Nox2 participates in the pathogenesis of systemic inflammation and hypotension induced by lipopolysaccharide (LPS). LPS was injected intravenously in mice with Tie2-targeted deficiency or transgenic overexpression of Nox2. Mice with Tie2-targeted Nox2 deficiency had increased circulating levels of tumor necrosis factor alpha (TNF-a), enhanced numbers of neutrophils trapped in lungs and aggravated hypotension after LPS injection, as compared to control LPS-injected animals. In contrast, Tie2-driven Nox2 overexpression attenuated inflammation and prevented the hypotension induced by LPS. Because Tie2-Cre targets both EC and myeloid cells we generated bone marrow chimeric mice with Nox2 deletion restricted to leukocytes or ECs. Mice deficient in Nox2 either in leukocytes or ECs had reduced LPS-induced neutrophil trapping in the lungs and lower plasma TNF-a levels as compared to control LPS-injected mice. However, the pronounced hypotensive response to LPS was present only in mice with EC-specific Nox2 deletion. Experiments in vitro with human vein or aortic endothelial cells (HUVEC and HAEC, respectively) treated with LPS revealed that EC Nox2 controls NF-?B activation and the transcription of toll-like receptor 4 (TLR4), which is the recognition receptor for LPS. In conclusion, these results suggest that endothelial Nox2 limits NF-?B activation and TLR4 expression, which in turn attenuates the severity of hypotension and systemic inflammation induced by LPS. Address reprint requests to Prof. Ajay M. Shah, School of Cardiovascular Medicine and Sciences, James Black Centre, King's College London, 125 Coldharbour Lane SE5 9NU, London, United Kingdom. E-mail: Received 9 September, 2020 Revised 29 September, 2020 Accepted 2 December, 2020 Sources of support: This research was supported by Sao Paulo Research Foundation (FAPESP) under grant agreement no 2012/24677-7 (S.C.T. Fellowship) and 2013/08216-2 (Center for Research of Inflammatory Disease (CRID), 2013/07937-8 (LRL as member of CEPID Redoxoma), the European Society of Cardiology (ESC, Basic Research Fellowship), and the British Heart Foundation (BHF CH/1999001/11735). Disclosure: The authors declare no financial conflicts of interest. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website ( © 2020 by the Shock Society

Red Blood Cells Elicit Platelet-Dependent Neutrophil Recruitment into Lung Airspaces

Haemolysis that occurs in intravascular haemolytic disorders, such as sickle cell disease and malaria, is associated with inflammation and platelet activation. Alveolar haemorrhage, for example following primary blast lung injury (PBLI) or acute respiratory distress syndrome (ARDS), results in the escape of erythrocytes (RBCs) into alveolar spaces, where they subsequently lyse and release their intracellular contents. However, the inflammatory effects of RBCs in the airways are not fully understood. We hypothesized that RBCs in the airway induce an inflammatory response, associated with platelet activation. By instilling whole RBCs or lysed RBCs into the airways of mice, we have demonstrated that whole RBCs elicit macrophage accumulation in the lung. However, lysed RBCs induce significant inflammatory cell recruitment, particularly neutrophils and this was associated with a 50% increase in circulating platelet neutrophil complexes (PNCs). Platelet depletion prior to lysed RBC exposure in the lung resulted in reduced neutrophil recruitment, suggesting that the presence of intracellular RBC components in the airways can elicit inflammation that is platelet dependent. To identify specific platelet dependent signalling pathways involved in neutrophil recruitment, anti-P-selectin ligand and anti-PSGL1 blocking antibodies were tested, however neither affected neutrophil recruitment. These findings implicate an involvement for other, as yet unidentified platelet-dependent signalling and adhesion mechanisms. Further understanding of how platelets contribute to lung inflammation induced by the presence of RBCs could offer novel therapeutic approaches to attenuate inflammation that occurs in conditions associated with alveolar haemorrhage. Address reprint requests to Simon C. Pitchford, Sackler Institute of Pulmonary Pharmacology, Institute of Pharmaceutical Science, King's College London, London, UK. E-mail: Received 23 September, 2020 Revised 13 October, 2020 Accepted 2 December, 2020 Authorship: S.A. designed and performed the research, analyzed the data, and wrote the paper. S.A.S., S.J.C., B.G.O'S., R.T.A., and K.A contributed to assay development and performed in vivo procedures. S.C.P., and C.P.P proposed the project, designed research and wrote the paper. Conflicts of interest. No author has a conflicts of interest to disclose. © 2020 by the Shock Society

Burn Injury Impairs Neutrophil Chemotaxis through Increased Ceramide

Infection is a common and often deadly complication after burn injury. A major underlying factor is burn-induced immune dysfunction, particularly with respect to neutrophils as the primary responders to infection. Temporally after murine scald injury, we demonstrate impaired bone marrow neutrophil chemotaxis towards CXCL1 ex vivo. Additionally, we observed a reduced recruitment of neutrophils to the peritoneal after elicitation seven days after injury. We demonstrate that neutrophil ceramide levels increase after burn injury, and this is associated with decreased expression of CXCR2 and blunted chemotaxis. A major signaling event upon CXCR2 activation is Akt phosphorylation and this was reduced when ceramide was elevated. In contrast, PTEN levels were elevated and PTEN-inhibition elevated phospho-Akt levels and mitigated the burn-induced neutrophil chemotaxis defect. Altogether, this study identifies a newly described pathway of ceramide-mediated suppression of neutrophil chemotaxis after burn injury and introduces potential targets to mitigate this defect and reduce infection-related morbidity and mortality after burn. Address reprint requests to Charles C. Caldwell, Department of Surgery, University of Cincinnati College of Medicine, MSB SRU G479, 231 Albert Sabin Way, Cincinnati, OH 45267-0558. E-mail: Received 17 September, 2020 Revised 7 October, 2020 Accepted 5 November, 2020 Conflict of Interest: None Authorship: NB, VN, CCC: Conception and study design. NB, FS: Data acquisition and analysis, drafting of the article. NB, FS, BK, EG, VN, CCC: Data interpretation, revision of the article, final approval of the version to be submitted. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website ( © 2020 by the Shock Society

Findings and Prognostic Value of Lung Ultrasonography in Coronal Virus Disease 2019(COVID-19) Pneumonia

Purpose: We used lung ultrasonography to identify features of COVID-19 pneumonia and to evaluate the prognostic value. Materials and Methods: We performed lung ultrasonography on 48 COVID-19 patients in an ICU (Wuhan, China) using a 12-zone method. The associations between lung ultrasonography score, PaO2/FiO2, APACHE II, SOFA, and PaCO2 with 28-day mortality were analyzed and the receiver operator characteristic curve was plotted. Results: 25.9% areas in all scanning zones presented with B7 lines and 23.5% with B3 lines(B-pattern) on lung ultrasonography; 13% areas with confluent B lines(B-pattern), 24.9% in areas with consolidations, and 9.9% in areas with A lines. Pleural effusion was observed in 2.8% of areas. Lung ultrasonography score was negatively correlated with PaO2/FiO2 (n?=?48, r?=?-0.498, P?, Received 12 September, 2020 Revised 1 October, 2020 Accepted 18 November, 2020 Lu Li and Aihua Qin: Authors contributed equally to this study and therefore shared the first authorship. Declaration of Conflicting Interests' statement: The authors have no conflicts of interest to declare relevant to this publication. Funding: This work was supported by the National Natural Science Fund (grants 81772046 and 81971816 to Dr Peng) and the Special Project for Significant New Drug Research and Development in the Major National Science and Technology Projects of China (2020ZX09201007 to Dr Peng). Ethics approval and consent to participate: This study was approved by the institutional ethics board of Zhongnan Hospital of Wuhan University (No. 2020088K). Informed consent was waived as it was a retrospective study. Consent for publication: Not applicable. Availability of data and materials: The datasets analyzed during the current study are available from the corresponding author on reasonable request. Authors' contributions: LL and AQ collected the data and wrote the manuscript. XY did the statistical analysis. SZ, YL, and FZ collected the data. JL, BH, and SC revised the manuscript. ZP designed and finalized the manuscript.{Citation} © 2020 by the Shock Society


Medicine by Alexandros G. Sfakianakis,Anapafseos 5 Agios Nikolaos 72100 Crete Greece,00302841026182,00306932607174,,

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