1
|
Hug S, Bernhard S, Stratmann AEP, Erber M, Wohlgemuth L, Knapp CL, Bauer JM, Vidoni L, Fauler M, Föhr KJ, Radermacher P, Hoffmann A, Huber-Lang M, Messerer DAC. Activation of Neutrophil Granulocytes by Platelet-Activating Factor Is Impaired During Experimental Sepsis. Front Immunol 2021; 12:642867. [PMID: 33796110 PMCID: PMC8007865 DOI: 10.3389/fimmu.2021.642867] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/15/2021] [Indexed: 11/13/2022] Open
Abstract
Platelet-activating factor (PAF) is an important mediator of the systemic inflammatory response. In the case of sepsis, proper activation and function of neutrophils as the first line of cellular defense are based on a well-balanced physiological response. However, little is known about the role of PAF in cellular changes of neutrophils during sepsis. Therefore, this study investigates the reaction patterns of neutrophils induced by PAF with a focus on membrane potential (MP), intracellular pH, and cellular swelling under physiological and pathophysiological conditions and hypothesizes that the PAF-mediated response of granulocytes is altered during sepsis. The cellular response of granulocytes including MP, intracellular pH, cellular swelling, and other activation markers were analyzed by multiparametric flow cytometry. In addition, the chemotactic activity and the formation of platelet-neutrophil complexes after exposure to PAF were investigated. The changes of the (electro-)physiological response features were translationally verified in a human ex vivo whole blood model of endotoxemia as well as during polymicrobial porcine sepsis. In neutrophils from healthy human donors, PAF elicited a rapid depolarization, an intracellular alkalization, and an increase in cell size in a time- and dose-dependent manner. Mechanistically, the alkalization was dependent on sodium-proton exchanger 1 (NHE1) activity, while the change in cellular shape was sodium flux- but only partially NHE1-dependent. In a pathophysiological altered environment, the PAF-induced response of neutrophils was modulated. Acidifying the extracellular pH in vitro enhanced PAF-mediated depolarization, whereas the increases in cell size and intracellular pH were largely unaffected. Ex vivo exposure of human whole blood to lipopolysaccharide diminished the PAF-induced intracellular alkalization and the change in neutrophil size. During experimental porcine sepsis, depolarization of the MP was significantly impaired. Additionally, there was a trend for increased cellular swelling, whereas intracellular alkalization remained stable. Overall, an impaired (electro-)physiological response of neutrophils to PAF stimulation represents a cellular hallmark of those cells challenged during systemic inflammation. Furthermore, this altered response may be indicative of and causative for the development of neutrophil dysfunction during sepsis.
Collapse
Affiliation(s)
- Stefan Hug
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Stefan Bernhard
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | | | - Maike Erber
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Lisa Wohlgemuth
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Christiane Leonie Knapp
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Jonas Martin Bauer
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Laura Vidoni
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - Michael Fauler
- Institute of General Physiology, University of Ulm, Ulm, Germany
| | - Karl Josef Föhr
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Ulm, Ulm, Germany
| | - Peter Radermacher
- Institute of Anesthesiological Pathophysiology and Process Development, University Hospital of Ulm, Ulm, Germany
| | - Andrea Hoffmann
- Institute of Anesthesiological Pathophysiology and Process Development, University Hospital of Ulm, Ulm, Germany
| | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany
| | - David Alexander Christian Messerer
- Institute of Clinical and Experimental Trauma Immunology, University Hospital of Ulm, Ulm, Germany.,Department of Anesthesiology and Intensive Care Medicine, University Hospital of Ulm, Ulm, Germany.,Institute of Anesthesiological Pathophysiology and Process Development, University Hospital of Ulm, Ulm, Germany
| |
Collapse
|
2
|
Klein M, Dao V, Khan F. A Review of Platelet-Activating Factor As a Potential Contributor to Morbidity and Mortality Associated with Severe COVID-19. Clin Appl Thromb Hemost 2021; 27:10760296211051764. [PMID: 34755565 PMCID: PMC8586171 DOI: 10.1177/10760296211051764] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 09/19/2021] [Accepted: 09/21/2021] [Indexed: 01/18/2023] Open
Abstract
The precise mechanisms of pathology in severe COVID-19 remains elusive. Current evidence suggests that inflammatory mediators are responsible for the manifestation of clinical symptoms that precedes a fatal response to infection. This review examines the nature of platelet activating factor and emphasizes the similarities between the physiological effects of platelet activating factor and the clinical complications of severe COVID-19.
Collapse
Affiliation(s)
- Mark Klein
- Minneapolis Veterans Affairs Healthcare System, Minneapolis, MN, 55417, USA
- University of Minnesota, MN, USA
| | - Vinh Dao
- Minneapolis Veterans Affairs Healthcare System, Minneapolis, MN, 55417, USA
| | - Fatima Khan
- Minneapolis Veterans Affairs Healthcare System, Minneapolis, MN, 55417, USA
- University of Minnesota, MN, USA
| |
Collapse
|
3
|
Abstract
Acute kidney injury (AKI), a major public health problem associated with high mortality and increased risk of progression towards end-stage renal disease, is characterized by the activation of intra-renal haemostatic and inflammatory processes. Platelets, which are present in high numbers in the circulation and can rapidly release a broad spectrum of bioactive mediators, are important acute modulators of inflammation and haemostasis, as they are the first cells to arrive at sites of acute injury, where they interact with endothelial cells and leukocytes. Diminished control of platelet reactivity by endothelial cells and/or an increased release of platelet-activating mediators can lead to uncontrolled platelet activation in AKI. As increased platelet sequestration and increased expression levels of the markers P-selectin, thromboxane A2, CC-chemokine ligand 5 and platelet factor 4 on platelets have been reported in kidneys following AKI, platelet activation likely plays a part in AKI pathology. Results from animal models and some clinical studies highlight the potential of antiplatelet therapies in the preservation of renal function in the context of AKI, but as current strategies also affect other cell types and non-platelet-derived mediators, additional studies are required to further elucidate the extent of platelet contribution to the pathology of AKI and to determine the best therapeutic approach by which to specifically target related pathogenic pathways.
Collapse
Affiliation(s)
- Marcel P B Jansen
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Sandrine Florquin
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands
| | - Joris J T H Roelofs
- Department of Pathology, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.
| |
Collapse
|
4
|
Xia F, Li A, Chai Y, Xiao X, Wan J, Li P, Wang Y. UPLC/Q-TOFMS-Based Metabolomics Approach to Reveal the Protective Role of Other Herbs in An-Gong-Niu-Huang Wan Against the Hepatorenal Toxicity of Cinnabar and Realgar. Front Pharmacol 2018; 9:618. [PMID: 29950994 PMCID: PMC6008407 DOI: 10.3389/fphar.2018.00618] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 05/23/2018] [Indexed: 01/26/2023] Open
Abstract
An-Gong-Niu-Huang Wan (AGNH) is a well-known traditional Chinese medicine (TCM) recipe containing cinnabar (HgS) and realgar (As2S2). However, the application of AGNH is limited by the hepato- and nephrotoxicity of cinnabar and realgar. It should be noted that cinnabar and realgar in AGNH are not used alone, but rather combined with other herbs as formula to use. In this study, the protective effects and mechanisms of the other herbs in AGNH against the hepatorenal toxicity induced by cinnabar and realgar were investigated. The combination use of the other herbs in AGNH alleviated inflammatory cell infiltration and damage in the liver and kidney and restored the disturbed serum metabolic profile induced by cinnabar and realgar insults. By UPLC/Q-TOFMS combined with pattern recognition approaches, we identified 41 endogenous metabolites in the sera of mice that were related to the hepatorenal toxicity of cinnabar and realgar, 36 of which were restored to normal levels when various kinds of herbs were combined as compound recipe. These metabolites function as modulators in inflammation-associated glycerophospholipid, arachidonic acid, linoleic acid, sphingolipid, and ether lipid metabolic pathways. Notably, lysophosphatidylcholines (LysoPCs) were the most elevated among all of the metabolites detected after cinnabar and realgar treatment, while these LysoPCs did not show overt differences between the AGNH and saline control groups, which was associated with relatively unaffected or even up-regulated expression of lysophosphatidylcholine acyltransferase 1 (LPCAT1) and autotaxin (ATX). These findings indicated that other herbs in AGNH could have a protective effect against cinnabar- and realgar-induced hepatic and renal damage via modulating the disordered homeostasis of the glycerophospholipid, arachidonic acid, linoleic acid, ether lipid, and sphingolipid metabolism.
Collapse
Affiliation(s)
- Fangbo Xia
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Ao Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China.,College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China
| | - Yushuang Chai
- Guangzhou Baiyunshan Zhongyi Pharmaceutical Co., Ltd., Guangzhou, China
| | - Xiao Xiao
- College of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing, China
| | - Jianbo Wan
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Peng Li
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Yitao Wang
- State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macao, China
| |
Collapse
|
5
|
The importance of blood platelet lipid signaling in thrombosis and in sepsis. Adv Biol Regul 2017; 67:66-73. [PMID: 28993230 DOI: 10.1016/j.jbior.2017.09.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 12/11/2022]
Abstract
Blood platelets are the first line of defense against hemorrhages and are also strongly involved in the processes of arterial thrombosis, a leading cause of death worldwide. Besides their well-established roles in hemostasis, vascular wall repair and thrombosis, platelets are now recognized as important players in other processes such as inflammation, healing, lymphangiogenesis, neoangiogenesis or cancer. Evidence is accumulating they are key effector cells in immune and inflammatory responses to host infection. To perform their different functions platelets express a wide variety of membrane receptors triggering specific intracellular signaling pathways and largely use lipid signaling systems. Lipid metabolism is highly active in stimulated platelets including the phosphoinositide metabolism with the phospholipase C (PLC) and the phosphoinositide 3-kinase (PI3K) pathways but also other enzymatic systems producing phosphatidic acid, lysophosphatidic acid, platelet activating factor, sphingosine 1-phosphate and a number of eicosanoids. While several of these bioactive lipids regulate intracellular platelet signaling mechanisms others are released by activated platelets acting as autocrine and/or paracrine factors modulating neighboring cells such as endothelial and immune cells. These bioactive lipids have been shown to play important roles in hemostasis and thrombosis but also in vessel integrity and dynamics, inflammation, tissue remodeling and wound healing. In this review, we will discuss some important aspects of platelet lipid signaling in thrombosis and during sepsis that is an important cause of death in intensive care unit. We will particularly focus on the implication of the different isoforms of PI3Ks and on the generation of eicosanoids released by activated platelets.
Collapse
|
6
|
Correa-Costa M, Andrade-Oliveira V, Braga TT, Castoldi A, Aguiar CF, Origassa CST, Rodas ACD, Hiyane MI, Malheiros DMAC, Rios FJO, Jancar S, Câmara NOS. Activation of platelet-activating factor receptor exacerbates renal inflammation and promotes fibrosis. J Transl Med 2014; 94:455-66. [PMID: 24492283 DOI: 10.1038/labinvest.2013.155] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 11/20/2013] [Accepted: 12/19/2013] [Indexed: 12/13/2022] Open
Abstract
Platelet-activating factor (PAF) is a lipid mediator with important pro-inflammatory effects, being synthesized by several cell types including kidney cells. Although there is evidence of its involvement in acute renal dysfunction, its role in progressive kidney injury is not completely known. In the present study, we investigated the role of PAF receptor (PAFR) in an experimental model of chronic renal disease. Wild-type (WT) and PAFR knockout (KO) mice underwent unilateral ureter obstruction (UUO), and at kill time, urine and kidney tissue was collected. PAFR KO animals compared with WT mice present: (a) less renal dysfunction, evaluated by urine protein/creatinine ratio; (b) less fibrosis evaluated by collagen deposition, type I collagen, Lysyl Oxidase-1 (LOX-1) and transforming growth factor β (TGF-β) gene expression, and higher expression of bone morphogenetic protein 7 (BMP-7) (3.3-fold lower TGF-β/BMP-7 ratio); (c) downregulation of extracellular matrix (ECM) and adhesion molecule-related machinery genes; and (d) lower levels of pro-inflammatory cytokines. These indicate that PAFR engagement by PAF or PAF-like molecules generated during UUO potentiates renal dysfunction and fibrosis and might promote epithelial-to-mesenchymal transition (EMT). Also, early blockade of PAFR after UUO leads to a protective effect, with less fibrosis deposition. In conclusion, PAFR signaling contributes to a pro-inflammatory environment in the model of obstructive nephropathy, favoring the fibrotic process, which lately will generate renal dysfunction and progressive organ failure.
Collapse
Affiliation(s)
- Matheus Correa-Costa
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Vinicius Andrade-Oliveira
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Tarcio T Braga
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Angela Castoldi
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Cristhiane F Aguiar
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | | | - Andrea C D Rodas
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Meire I Hiyane
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | | | - Francisco J O Rios
- 1] Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil [2] British Heart Foundation, Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - Sonia Jancar
- Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil
| | - Niels O S Câmara
- 1] Department of Immunology, Institute of Biomedical Sciences IV, University of São Paulo, São Paulo, Brazil [2] Nephrology Division, Federal University of São Paulo, São Paulo, Brazil
| |
Collapse
|
7
|
Zheng CM, Liao MT, Lin MY, Lo L, Wu CC, Hsu YH, Lin YF, Lu KC. Biomarkers in Acute Kidney Injury. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/ojneph.2013.31009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
8
|
|
9
|
Ronco C, Ratanarat R, Bellomo R, Salvatori G, Petras D, Cal MD, Nalasso F, Bonello M, Brendolan A. Multiple organ support therapy for the critically ill patient in intensive care. ACTA ACUST UNITED AC 2009. [DOI: 10.1080/17471060500233109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
10
|
Granfeldt A, Ebdrup L, Tønnesen E, Wogensen L. Renal cytokine profile in an endotoxemic porcine model. Acta Anaesthesiol Scand 2008; 52:614-20. [PMID: 18419714 DOI: 10.1111/j.1399-6576.2008.01625.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION In animals exposed to acute endotoxemia with lipopolysaccharide (LPS), high levels of cytokines are found in the kidney. The objective of this study is to determine whether the high renal content of TNF-alpha, IL-1beta, IL-10 and IL-1 receptor antagonist (IL-1ra) is due to glomerular filtration and reabsorption, or whether the cytokines are produced locally in the kidney. METHODS Eighteen anesthetized and mechanically ventilated pigs (35-43 kg) were randomized into two groups: Group 1 (n=12) LPS infusion for 360 min and Group 2 (n=6) control pigs, no treatment. At 360 min, the pigs were euthanized and tissue samples from the kidneys were obtained. Localization of the cytokines was determined by immunohistochemistry and double immunofluorescence (dIF). RESULTS Pigs exposed to endotoxemia showed increased accumulation of leukocytes and increased protein expression of TNF-alpha and IL-1beta when compared with controls. dIF showed that TNF-alpha-positive cells co-localized with both endothelial and mesangial cells in the glomeruli. Furthermore, the endothelial cells of the cortical arterioles were positive for IL-1beta. TNF-alpha and IL-1beta staining were absent in renal tubular cells. A positive signal for IL-10 was detected at the tubular brush border while IL-1ra was detected in the glomerulus and in the tubular cells. CONCLUSION LPS-induced endotoxemia increased TNF-alpha and IL-1beta protein expression and leukocyte accumulation in the kidneys. The results indicate that the increased levels of the pro-inflammatory cytokines TNF-alpha and IL-1beta are caused by a local production in the kidneys while the anti-inflammatory cytokines IL-10 and IL-1ra are filtrated and reabsorbed in the tubuli.
Collapse
Affiliation(s)
- A Granfeldt
- Department of Anesthesiology and Intensive Care Medicine, Aarhus University Hospital, Aarhus, Denmark.
| | | | | | | |
Collapse
|
11
|
Mariano F, Cantaluppi V, Stella M, Romanazzi GM, Assenzio B, Cairo M, Biancone L, Triolo G, Ranieri VM, Camussi G. Circulating plasma factors induce tubular and glomerular alterations in septic burns patients. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2008; 12:R42. [PMID: 18364044 PMCID: PMC2447585 DOI: 10.1186/cc6848] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2007] [Revised: 02/08/2008] [Accepted: 03/25/2008] [Indexed: 01/20/2023]
Abstract
Background Severe burn is a systemic illness often complicated by sepsis. Kidney is one of the organs invariably affected, and proteinuria is a constant clinical finding. We studied the relationships between proteinuria and patient outcome, severity of renal dysfunction and systemic inflammatory state in burns patients who developed sepsis-associated acute renal failure (ARF). We then tested the hypothesis that plasma in these patients induces apoptosis and functional alterations that could account for proteinuria and severity of renal dysfunction in tubular cells and podocytes. Methods We studied the correlation between proteinuria and indexes of systemic inflammation or renal function prospectively in 19 severe burns patients with septic shock and ARF, and we evaluated the effect of plasma on apoptosis, polarity and functional alterations in cultured human tubular cells and podocytes. As controls, we collected plasma from 10 burns patients with septic shock but without ARF, 10 burns patients with septic shock and ARF, 10 non-burns patients with septic shock without ARF, 10 chronic uremic patients and 10 healthy volunteers. Results Septic burns patients with ARF presented a severe proteinuria that correlated to outcome, glomerular (creatinine/urea clearance) and tubular (fractional excretion of sodium and potassium) functional impairment and systemic inflammation (white blood cell (WBC) and platelet counts). Plasma from these patients induced a pro-apoptotic effect in tubular cells and podocytes that correlated with the extent of proteinuria. Plasma-induced apoptosis was significantly higher in septic severe burns patients with ARF with respect to those without ARF or with septic shock without burns. Moreover, plasma from septic burns patients induced an alteration of polarity in tubular cells, as well as reduced expression of the tight junction protein ZO-1 and of the endocytic receptor megalin. In podocytes, plasma from septic burns patients increased permeability to albumin and decreased the expression of the slit diaphragm protein nephrin. Conclusion Plasma from burns patients with sepsis-associated ARF contains factors that affect the function and survival of tubular cells and podocytes. These factors are likely to be involved in the pathogenesis of acute tubular injury and proteinuria, which is a negative prognostic factor and an index of renal involvement in the systemic inflammatory reaction.
Collapse
Affiliation(s)
- Filippo Mariano
- Dipartimento di Area Medica, Unita' di Nefrologia e Dialisi, Ospedale CTO, Via G, Zuretti 29, Torino, 10126, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
|
13
|
Bagshaw SM, Langenberg C, Haase M, Wan L, May CN, Bellomo R. Urinary biomarkers in septic acute kidney injury. Intensive Care Med 2007; 33:1285-1296. [PMID: 17487471 DOI: 10.1007/s00134-007-0656-5] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2007] [Accepted: 04/06/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To appraise the literature on the value of urinary biomarkers in septic acute kidney injury (AKI). DESIGN Systematic review. SETTING Academic medical centre. PATIENTS AND PARTICIPANTS Human studies of urinary biomarkers. INTERVENTIONS None. MEASUREMENTS AND RESULTS Fourteen articles fulfilled inclusion criteria. Most studies were small, single-centre, and included mixed medical/surgical adult populations. Few focused solely on septic AKI and all had notable limitations. Retrieved articles included data on low-molecular-weight proteins (beta2-microglobulin, alpha1-microglobulin, adenosine deaminase binding protein, retinol binding protein, cystatin C, renal tubular epithelial antigen-1), enzymes (N-acetyl-beta-glucosaminidase, alanine-aminopeptidase, alkaline phosphatase; lactate dehydrogenase, alpha/pi-glutathione-S-transferase, gamma-glutamyl transpeptidase), cytokines [platelet activating factor (PAF), interleukin-18 (IL-18)] and other biomarkers [kidney injury molecule-1, Na/H exchanger isoform-3 (NHE3)]. Increased PAF, IL-18, and NHE3 were detected early in septic AKI and preceded overt kidney failure. Several additional biomarkers were evident early in AKI; however, their diagnostic value in sepsis remains unknown. In one study, IL-18 excretion was higher in septic than in non-septic AKI. IL-18 also predicted deterioration in kidney function, with increased values preceding clinically significant kidney failure by 24-48 h. Detection of cystatin C, alpha1-microglobulin, and IL-18 predicted need for renal replacement therapy (RRT). CONCLUSIONS Few clinical studies of urinary biomarkers in AKI have included septic patients. However, there is promising evidence that selected biomarkers may aid in the early detection of AKI in sepsis and may have value for predicting subsequent deterioration in kidney function. Additional prospective studies are needed to accurately describe their diagnostic and prognostic value in septic AKI.
Collapse
Affiliation(s)
- Sean M Bagshaw
- Division of Critical Care Medicine, University of Alberta Hospital, 3C1.16 Walter C. Mackenzie Centre, 8440-112 Street, T6G 2B7, Edmonton, Alberta, Canada.
- Department of Intensive Care Medicine, Austin Hospital, Studley Road, 3084, Heidelberg, VIC, Australia.
| | - Christoph Langenberg
- Department of Intensive Care Medicine, Austin Hospital, Studley Road, 3084, Heidelberg, VIC, Australia
- Howard Florey Institute, University of Melbourne, 161 Barry Street, 3053, South Carlton, VIC, Australia
| | - Michael Haase
- Department of Intensive Care Medicine, Austin Hospital, Studley Road, 3084, Heidelberg, VIC, Australia
| | - Li Wan
- Department of Intensive Care Medicine, Austin Hospital, Studley Road, 3084, Heidelberg, VIC, Australia
- Howard Florey Institute, University of Melbourne, 161 Barry Street, 3053, South Carlton, VIC, Australia
| | - Clive N May
- Howard Florey Institute, University of Melbourne, 161 Barry Street, 3053, South Carlton, VIC, Australia
| | - Rinaldo Bellomo
- Department of Intensive Care Medicine, Austin Hospital, Studley Road, 3084, Heidelberg, VIC, Australia
- Department of Medicine, Melbourne University, Melbourne, Australia
| |
Collapse
|
14
|
Osborn TM, Dahlgren C, Hartwig JH, Stossel TP. Modifications of cellular responses to lysophosphatidic acid and platelet-activating factor by plasma gelsolin. Am J Physiol Cell Physiol 2006; 292:C1323-30. [PMID: 17135294 DOI: 10.1152/ajpcell.00510.2006] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Gelsolin is a highly conserved intracellular actin-binding protein with an extracellular isoform, plasma gelsolin (pGSN). Blood concentrations of pGSN decrease in response to diverse tissue injuries. Depletion of pGSN to critical levels precedes and often predicts complications of injuries such as lung permeability changes and death. Administration of recombinant pGSN ameliorates such complications and reduces mortality in animal models. One proposed mechanism for pGSN's protective effects is that it inhibits inflammatory mediators generated during primary injuries, since pGSN binds bioactive mediators, including lysophospatidic acid (LPA) and endotoxin in vitro. However, no direct evidence in support of this hypothesis has been available. Here we show that recombinant pGSN modestly inhibited LPA-induced P-selectin upregulation by human platelets in the presence of albumin (P < 0.0001). However, physiologically relevant pGSN concentrations inhibit platelet-activating factor (PAF)-mediated P-selectin expression by up to 77% (P < 0.0001). pGSN also markedly inhibited PAF-induced superoxide anion (O(2)(-)) production of human peripheral neutrophils (PMN) in a concentration-dependent manner (P < 0.0001). A phospholipid-binding peptide derived from pGSN (QRLFQVKGRR) also inhibited PAF-mediated O(2)(-) generation (P = 0.024). Therefore, pGSN interferes with PAF- and LPA-induced cellular activation in vitro, suggesting a mechanism for the protective role of pGSN in vivo.
Collapse
Affiliation(s)
- Teresia M Osborn
- Translational Medicine Division/ Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA.
| | | | | | | |
Collapse
|
15
|
Moreno SE, Alves-Filho JC, Rios-Santos F, Silva JS, Ferreira SH, Cunha FQ, Teixeira MM. Signaling via platelet-activating factor receptors accounts for the impairment of neutrophil migration in polymicrobial sepsis. THE JOURNAL OF IMMUNOLOGY 2006; 177:1264-71. [PMID: 16818786 DOI: 10.4049/jimmunol.177.2.1264] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Sepsis is a systemic inflammatory response that results from the inability of the immune system to limit bacterial spread during an ongoing infection. Recently, we have documented an impaired neutrophil migration toward the infectious focus in severe sepsis. This impairment seems to be mediated by circulating cytokines, chemokines, and NO. Platelet-activating factor (PAF) plays an important role in the orchestration of different inflammatory reactions, including the release of cytokines, chemokines, and free radicals. Using a PAFR antagonist, PCA-4248, and PAFR-deficient mice, we investigated whether signaling via PAFR was relevant for the failure of neutrophils to migrate to the site of infection after lethal sepsis caused by cecum ligation and puncture in mice. In PAFR-deficient mice or mice pretreated with PCA-4248 (5 mg/kg) and subjected to lethal sepsis, neutrophil migration failure was prevented, and bacterial clearance was more efficient. There was also reduced systemic inflammation (low serum cytokine levels), lower nitrate levels in plasma, and higher survival rate. Altogether, the results firmly establish a role for PAFR in mediating the early impairment of neutrophil migration toward the infectious focus. Blockade of PAFR may prevent the establishment of severe sepsis.
Collapse
Affiliation(s)
- Susana E Moreno
- Departamento de Farmacologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | | | | | | | | | | | | |
Collapse
|
16
|
Shindou H, Ishii S, Yamamoto M, Takeda K, Akira S, Shimizu T. Priming effect of lipopolysaccharide on acetyl-coenzyme A:lyso-platelet-activating factor acetyltransferase is MyD88 and TRIF independent. THE JOURNAL OF IMMUNOLOGY 2005; 175:1177-83. [PMID: 16002720 DOI: 10.4049/jimmunol.175.2.1177] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
LPS has a priming effect on various stimuli. For instance, LPS priming enhances the production of platelet-activating factor (PAF), a proinflammatory lipid mediator that is induced by PAF itself. Among various enzymes responsible for PAF biosynthesis, acetyl-coenzyme A:1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine acetyltransferase is one of the enzymes activated by PAF receptor stimulation. In this study we investigated the priming effect of LPS on the acetyltransferase activation by PAF in TLR4-knockout (KO) mice, MyD88-KO mice, and Toll/IL-1R domain-containing adaptor inducing IFN-beta (TRIF)-KO mice. This enzyme was biphasically activated by LPS. Although the first peak occurred within 30 min in wild-type (WT), but not TLR4-KO or MyD88-KO, macrophages, the second phase reached a maximum within hours in WT, MyD88-KO, and TRIF-KO, but not in TLR4-KO, macrophages. Only in the second phase was the increase in acetyltransferase activity upon PAF receptor activation remarkably enhanced in WT, MyD88-KO, and TRIF-KO cells, but not in TLR4-KO cells. These data demonstrated that LPS exerted a priming effect on PAF receptor-mediated acetyltransferase activation through the TLR4-dependent, but MyD88- and TRIF-independent, pathway.
Collapse
MESH Headings
- Acetyl Coenzyme A/metabolism
- Acetyltransferases/metabolism
- Adaptor Proteins, Signal Transducing
- Adaptor Proteins, Vesicular Transport/deficiency
- Adaptor Proteins, Vesicular Transport/genetics
- Adaptor Proteins, Vesicular Transport/physiology
- Animals
- Antigens, Differentiation/genetics
- Antigens, Differentiation/physiology
- Cells, Cultured
- Enzyme Activation/drug effects
- Enzyme Activation/genetics
- Enzyme Activation/immunology
- Female
- Lipopolysaccharides/immunology
- Macrophages, Peritoneal/enzymology
- Macrophages, Peritoneal/immunology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mitogen-Activated Protein Kinases/antagonists & inhibitors
- Myeloid Differentiation Factor 88
- Phospholipid Ethers/pharmacology
- Platelet Activating Factor/metabolism
- Platelet Membrane Glycoproteins/metabolism
- Protein Kinase Inhibitors/pharmacology
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Immunologic/deficiency
- Receptors, Immunologic/genetics
- Receptors, Immunologic/physiology
- Signal Transduction/genetics
- Signal Transduction/immunology
- Toll-Like Receptor 4
Collapse
Affiliation(s)
- Hideo Shindou
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | | | | | | | | | | |
Collapse
|
17
|
Affiliation(s)
- N Lameire
- Renal Division, University Hospital, Ghent, Belgium.
| |
Collapse
|
18
|
Abstract
The pathophysiology of acute renal failure in sepsis is complex and includes intrarenal vasoconstriction, infiltration of inflammatory cells in the renal parenchyma, intraglomerular thrombosis, and obstruction of tubuli with necrotic cells and debris. Attempts to interfere pharmacologically with these dysfunctional pathways, including inhibition of inflammatory mediators, improvement of renal hemodynamics by amplifying vasodilator mechanisms and blocking vasoconstrictor mechanisms, and administration of growth factors to accelerate renal recovery, have yielded disappointing results in clinical trials. Interruption of leukocyte recruitment is a potential promising approach in the treatment of septic acute renal failure, but no data in humans are presently available. Activated protein C and steroid replacement therapy have been shown to reduce mortality in patients with sepsis and are now accepted adjunctive treatment options for sepsis in general.
Collapse
|
19
|
Mariano F, Bussolati B, Migliori M, Russo S, Triolo G, Camussi G. Platelet-activating factor synthesis by neutrophils, monocytes, and endothelial cells is modulated by nitric oxide production. Shock 2003; 19:339-44. [PMID: 12688545 DOI: 10.1097/00024382-200304000-00008] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Nitric oxide (NO) and platelet-activating factor (PAF) can modulate the interaction between endothelial lining and circulating leukocytes. Several studies implicated the production of PAF and NO in the pathogenesis of microcirculatory alterations occurring in septic shock. However, the reciprocal interaction between PAF and NO has not been fully elucidated. In the present study, we evaluated whether the basal synthesis of NO could modulate the production of PAF by neutrophils (PMN), monocytes (MO), and endothelial cells (EC) unstimulated or stimulated with lipopolysaccharides (LPS) or tumor necrosis factor (TNF). PMN, MO, and EC, when incubated with N(omega)-nitro-L-arginine methyl ester (L-NAME) spontaneously synthesized PAF, with an early peak at 30 min. The effective inhibition of NO production was visualized on MO cells as generation of fluorescence reactivity by cell-permeable NO reactive dye DAF-2 DA. Also, monomethyl-L-arginine (L-NMMA) induced PAF synthesis by PMN, whereas the biologically inactive D-enantiomers of NAME (D-NAME) and of NMMA (D-NMMA) did not. Stimulation of PMN with L-NAME in presence of the exogenous NO donor nitroprusside, of the NO secondary mediator cGMP, or of the NO synthase substrate L-arginine reduced PAF synthesis, suggesting the involvement of an NO-dependent pathway on the modulation of PAF synthesis. The synthesis of PAF was enhanced by combined treatment with L-NAME and TNF or LPS. These results indicate an inhibitor effect of NO on the spontaneous and TNF or LPS-induced synthesis of PAF by human PMN, MO, and EC.
Collapse
Affiliation(s)
- Filippo Mariano
- Department of Area of Medicine, Nephrology and Dialysis Unit, CTO Hospital, Turin, Italy
| | | | | | | | | | | |
Collapse
|
20
|
Ronco C, Bellomo R. Acute renal failure and multiple organ dysfunction in the ICU: from renal replacement therapy (RRT) to multiple organ support therapy (MOST). Int J Artif Organs 2003; 25:733-47. [PMID: 12296458 DOI: 10.1177/039139880202500801] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Renal replacement therapy (RRT) has evolved from the concept that we need to treat the dysfunction of a single organ (the kidney). As intensive care units have become more and more complex, it has become clear that the majority of patients with acute renal failure often have dysfunction of several other organs. In order to facilitate single organ support in this setting, continuous renal replacement therapy (CRRT) techniques have been developed. However, CRRT has opened the door to the concept that targeting renal support as the only goal of extracorporeal blood purification may be a simplistic view of our therapeutic aims. In this article we argue that it is now time to move from the simple goal of achieving adequate renal support. The proper goal of extracorporeal blood purification in ICU should be multi-organ support therapy (MOST). We explain why MOST represents the most logical future conceptual and practical evolution of CRRT and illustrates the biological rationale, supplying animal and clinical evidence that confirms the need to move rapidly in this direction theoretically, practically and technologically.
Collapse
Affiliation(s)
- C Ronco
- Department of Nephrology, Dialysis and Transplantation, St Bortolo Hospital, Vicenza, Italy.
| | | |
Collapse
|
21
|
|
22
|
Tetta C, Bellomo R, Ronco C. Artificial organ treatment for multiple organ failure, acute renal failure, and sepsis: recent new trends. Artif Organs 2003; 27:202-13. [PMID: 12662203 DOI: 10.1046/j.1525-1594.2003.00963.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sepsis remains the major cause of mortality worldwide, claiming millions of lives each year. The past decade has seen major advances in the understanding of the biological mechanisms involved in this complex process. Unfortunately, no definitive therapy yet exists that can successfully treat sepsis and its complications. At variance with targeting single mediators, therapeutic intervention aimed at the nonselective removal of pro- and anti-inflammatory mediators seems a rational concept and a possible key to successful extracorporeal therapies. A further advantage may lie in the continuous nature of such therapy. With such continuous therapy, sequentially appearing peaks of systemic mediator overflow may be attenuated and persistently high plasma levels reduced. This theoretical framework is proposed as the underlying biological rationale for a series of innovative modalities in sepsis. In this editorial, we will review recent animal and human trials that lend support to this concept. We will also review the importance of treatment dose during continuous renal replacement therapy as a major factor affecting survival in critically ill patients with acute renal failure. Additionally, we will review novel information related to other blood purification techniques using large pore membranes or plasma filtration with adsorbent perfusion. Although these approaches are still in the early stages of clinical testing, they are conceptually promising and might represent an important advance.
Collapse
|
23
|
Interpreting the Mechanisms of CRRT in Sepsis: The Peak Concentration Hypothesis. Intensive Care Med 2003. [DOI: 10.1007/978-1-4757-5548-0_62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
24
|
Palevsky PM, Bunchman T, Tetta C. The Acute Dialysis Quality Initiative--part V: operational characteristics of CRRT. ADVANCES IN RENAL REPLACEMENT THERAPY 2002; 9:268-72. [PMID: 12382230 DOI: 10.1053/jarr.2002.35567] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This report represents the consensus statement of the ADQI workgroup addressing the operational characteristics of continuous renal replacement therapy (CRRT). Issues addressed included the specific operational characteristics of continuous hemofiltration (HF), continuous hemodialysis (HD), and continuous hemodiafiltration (HDF) and the impact of these different modalities on solute removal. The relative roles of arteriovenous (AV) and venovenous (VV) modalities of therapy were also evaluated. The workgroup also addressed the optimal components of a CRRT system from an operational standpoint.
Collapse
Affiliation(s)
- Paul M Palevsky
- VA Pittsburgh Healthcare System and Renal-Electrolyte Division, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. palevsky+@pitt.edu
| | | | | |
Collapse
|
25
|
Cuschieri J, Gourlay D, Bulger E, Garcia I, Jelacic S, Maier RV. Platelet-activating factor priming of inflammatory cell activity requires cellular adherence. Surgery 2002; 132:157-66. [PMID: 12219006 DOI: 10.1067/msy.2002.125170] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Platelet-activating factor (PAF) primes tissue-fixed inflammatory cells, but has no effect on circulating cells. Adherence of inflammatory cells leads to cytoskeletal reorganization, which is essential for optimal inflammatory function. The purpose of this study was to investigate whether cellular adherence plays a role in PAF priming of inflammatory cells. METHODS Differentiated THP-1 cells were maintained under adherent and nonadherent conditions. Selected cells were pretreated with PAF, followed by endotoxin stimulation. Cellular and nuclear proteins were analyzed by Western blot for components of the Toll-like receptor-mediated signaling cascade. Cytokine analysis was performed by enzyme-linked immunosorbent assay. RESULTS Endotoxin led to activation of interleukin (IL)-1-associated kinase, extracellular signal-regulated kinase 1/2 and p38, and nuclear translocation of nuclear factor-kappaB, all of which were significantly enhanced by previous cellular adherence. PAF led to priming only under adherent conditions, demonstrated by increased IL-1-associated kinase and extracellular signal-regulated kinase 1/2 activity; nuclear factor-kappaB translocation; and IL-6, IL-8, and tumor necrosis factor-alpha production over non-PAF-treated cells. PAF had no significant effect on p38 activity or IL-10 production under any condition. CONCLUSIONS PAF primes mononuclear cells by increasing Toll-mediated signaling only under adherent conditions. This, therefore, would limit PAF-induced priming in vivo to foci of stimulated adherent inflammatory cells with little effect systemically on circulating cells.
Collapse
Affiliation(s)
- Joseph Cuschieri
- Department of Surgery, University of Cincinnati, Ohio 45267-0558, USA
| | | | | | | | | | | |
Collapse
|
26
|
Affiliation(s)
- Nestor Schor
- Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, Brasil
| |
Collapse
|
27
|
Abstract
Despite the considerable advances made in understanding the pathophysiology of systemic inflammation during critical illness, clinical progress has been elusive as it remains a very deadly condition. Cortisol and thyroid hormone levels can be as predictive of outcome as the commonly used severity parameters (i.e. APACHE). Indeed, levels of endocrine humoral substances such as arachidonic acids, nitric oxide, endothelin, calcitonin precursors, leptin and adenosine correlate with the severity and outcome of critical illness. Furthermore, calcitonin precursors represent a potentially new hormokine paradigm, being transcriptionally activated in all cells in response to infection. The cytokines are immune markers that often correlate with severity and outcome, but their release is transient. In contrast, the so-called acute phase proteins, such as C-reactive protein and serum amyloid A, are highly sensitive to inflammatory activity and can be important markers of severity and outcome. Leukocyte esterase, adhesion molecules, platelet activating factor and activated protein C are additional humoral immune markers; the replacement of the latter has been shown to be a promising therapeutic option. Natriuretic peptides are neurocrine humoral markers that have important cardiovascular implications. The level of macrophage migrating inhibitory factor, released by the pituitary, is elevated in sepsis and counteracts glucocorticoid action. Cellular markers to severe stress include the enhanced expression of protective substances in the form of heat shock proteins. High mobility group-1 is a DNA-binding protein and a late mediator of the inflammatory response. Apoptotic markers such as the soluble fas ligand are also elevated in inflammation. In summary, during critical illness, the endocrine, immune and nervous systems elaborate a multitude of humoral markers, the roles of which merit further scrutiny in order to improve therapeutic outcome.
Collapse
Affiliation(s)
- E S Nylén
- Department of Medicine, Section of Endocrinology, George Washington University School of Medicine, Veterans Affairs Medical Center, Washington, DC, USA
| | | |
Collapse
|
28
|
Mariano F, Tetta C, Guida G, Triolo G, Camussi G. Hemofiltration reduces the serum priming activity on neutrophil chemiluminescence in septic patients. Kidney Int 2001; 60:1598-605. [PMID: 11576379 DOI: 10.1046/j.1523-1755.2001.00974.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Priming of the polymorphonuclear neutrophil (PMN) response has been implicated in the activation of oxidative burst and tissue injury in patients with septic shock and acute renal failure (ARF). This study evaluated whether hemofiltration (HF) removes substances able to enhance the oxidative burst of PMNs. METHODS Chemiluminescence (CL) priming activity induced by sera and ultrafiltrates of seven patients with septic shock, multiorgan dysfunction syndrome, and ARF (ARF/HF group) and of 10 uremic stable patients (Control/HF group) was evaluated on normal human PMNs stimulated with bacterial formyl-methionyl-leucyl-phenylalanine (FMLP). Patients submitted to HF were studied by determining blood and ultrafiltrate interleukin-8 (IL-8), platelet-activating factor (PAF), and CL priming activity at the beginning (T0), and after four hours (T4) of treatment. RESULTS Preincubation of normal human PMNs with sera and ultrafiltrates from septic patients induced a potent priming of CL activity in subsequent FMLP stimulation. In the ARF/HF group, the prefilter blood concentrations of IL-8 and CL PMN-priming activity significantly decreased during the four hours of HF treatment, with a loss of IL-8 in the ultrafiltrate of 6930 (median, range 4292 to 9282) ng per four hours. PAF detected in the ultrafiltrate and associated with the membrane (7.3 ng, range 1.45 to 9.89) was minimal. In the ARF/HF group, a significantly positive correlation between CL PMN-priming activity and IL-8 concentrations was observed. The CL priming activity in blood and ultrafiltrates was reduced to 55 and 46% by preabsorption with monoclonal antibody (mAb) anti-IL-8. In contrast, the PAF receptor antagonist WEB 2170 did not affect CL priming activity. In the control/HF group, the CL PMN-priming activity was significantly lower than in the ARF/HF group and was independent of IL-8. CONCLUSIONS Sera from septic patients demonstrate an enhanced CL priming activity on PMNs. This activity is reduced by ultrafiltration and is due, at least in part, to ultrafiltered IL-8.
Collapse
Affiliation(s)
- F Mariano
- Department of Area of Medicine, Nephrology and Dialysis Unit, CTO Hospital, Turin, Italy
| | | | | | | | | |
Collapse
|
29
|
Affiliation(s)
- P E Marik
- Trauma Life Support Center, Mercy Hospital of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | | |
Collapse
|
30
|
Reed CE, Milton DK. Endotoxin-stimulated innate immunity: A contributing factor for asthma. J Allergy Clin Immunol 2001; 108:157-66. [PMID: 11496229 DOI: 10.1067/mai.2001.116862] [Citation(s) in RCA: 143] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Exposure to airborne endotoxin in infancy may protect against asthma by promoting enhanced T(H)1 response and tolerance to allergens. On the other hand, later in life, it adversely affects patients with asthma. Endotoxin binding to receptors on macrophages and other cells generates IL-12, which inhibits IgE responses. It also generates cytokines like IL-1, TNF-alpha, and IL-8, which cause inflammation. These signal transduction pathways resemble those leading to the generation of cytokines, such as IL-4, IL-13, and IL-5, which are responsible for the inflammation of IgE-mediated allergic disease. The main difference seems to be that endotoxin recruits neutrophils, but IgE recruits eosinophils, and the details of the tissue injury from these granulocytes differ. Sources of airborne endotoxin include many agricultural dusts, aerosols from contaminated water in many industrial plants, contaminated heating and air-conditioning systems, mist-generating humidifiers, and damp or water-damaged homes. Acute inhalation of high concentrations of endotoxin can cause fever, cough, and dyspnea. Chronic inhalation of lesser amounts causes chronic bronchitis and emphysema and is associated with airway hyperresponsiveness. Airborne endotoxin adversely affects patients with asthma in 3 ways: (1) by increasing the severity of the airway inflammation; (2) by increasing the susceptibility to rhinovirus-induced colds; and (3) by causing chronic bronchitis and emphysema with development of irreversible airway obstruction after chronic exposure of adults. The most effective management is mitigating exposure. The potential of drug treatments requires further clinical investigation.
Collapse
Affiliation(s)
- C E Reed
- Allergic Disease Research Laboratory, Mayo Clinic, Rochester, MN, USA
| | | |
Collapse
|
31
|
Alkhuja S, Alkhalil C, Menkel R. Acute renal failure: expect the unexpected. Ren Fail 2001; 23:265-7. [PMID: 11417958 DOI: 10.1081/jdi-100103498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- S Alkhuja
- Department of Medicine, St. Barnabas Hospital, Cornell University Medical College, Bronx, New York 10457, USA.
| | | | | |
Collapse
|