scholarly journals Alveolar Macrophages and Toll-like Receptor 4 Mediate Ventilated Lung Ischemia Reperfusion Injury in Mice

2012 ◽  
Vol 117 (4) ◽  
pp. 822-835 ◽  
Author(s):  
Arun Prakash ◽  
Kailin R. Mesa ◽  
Kevin Wilhelmsen ◽  
Fengyun Xu ◽  
Jeffrey M. Dodd-o ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Alveolar Macrophages ◽  
Interleukin 6 ◽  
Ischemia Reperfusion ◽  
Sterile Inflammation ◽  
Interleukin 1Β ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Lung Dysfunction

Background Ischemia-reperfusion (I-R) injury is a sterile inflammatory process that is commonly associated with diverse clinical situations such as hemorrhage followed by resuscitation, transient embolic events, and organ transplantation. I-R injury can induce lung dysfunction whether the I-R occurs in the lung or in a remote organ. Recently, evidence has emerged that receptors and pathways of the innate immune system are involved in recognizing sterile inflammation and overlap considerably with those involved in the recognition of and response to pathogens. Methods The authors used a mouse surgical model of transient unilateral left pulmonary artery occlusion without bronchial involvement to create ventilated lung I-R injury. In addition, they mimicked nutritional I-R injury in vitro by transiently depriving cells of all nutrients. Results Compared with sham-operated mice, mice subjected to ventilated lung I-R injury had up-regulated lung expression of inflammatory mediator messenger RNA for interleukin-1β, interleukin-6, and chemokine (C-X-C motif) ligand-1 and -2, paralleled by histologic evidence of lung neutrophil recruitment and increased plasma concentrations of interleukin-1β, interleukin-6, and high-mobility group protein B1 proteins. This inflammatory response to I-R required toll-like receptor-4 (TLR4). In addition, the authors demonstrated in vitro cooperativity and cross-talk between human macrophages and endothelial cells, resulting in augmented inflammatory responses to I-R. Remarkably, the authors found that selective depletion of alveolar macrophages rendered mice resistant to ventilated lung I-R injury. Conclusions The data reveal that alveolar macrophages and the pattern recognition receptor toll-like receptor-4 are involved in the generation of the early inflammatory response to lung I-R injury.

scholarly journals Toll-like receptor linked cytokine profiles in cerebrospinal fluid discriminate neurological infection from sterile inflammation

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Simone M Cuff ◽  
Joseph P Merola ◽  
Jason P Twohig ◽  
Matthias Eberl ◽  
William P Gray
Keyword(s):  
Cerebrospinal Fluid ◽  
Clinical Practice ◽  
Inflammatory Response ◽  
Nosocomial Infection ◽  
Pathway Analysis ◽  
Interleukin 6 ◽  
Sterile Inflammation ◽  
Interleukin 17 ◽  
Toll Like Receptor ◽  
Fluid Biomarker

Abstract Rapid determination of an infective aetiology causing neurological inflammation in the cerebrospinal fluid can be challenging in clinical practice. Post-surgical nosocomial infection is difficult to diagnose accurately, as it occurs on a background of altered cerebrospinal fluid composition due to the underlying pathologies and surgical procedures involved. There is additional diagnostic difficulty after external ventricular drain or ventriculoperitoneal shunt surgery, as infection is often caused by pathogens growing as biofilms, which may fail to elicit a significant inflammatory response and are challenging to identify by microbiological culture. Despite much research effort, a single sensitive and specific cerebrospinal fluid biomarker has yet to be defined which reliably distinguishes infective from non-infective inflammation. As a result, many patients with suspected infection are treated empirically with broad-spectrum antibiotics in the absence of definitive diagnostic criteria. To begin to address these issues, we examined cerebrospinal fluid taken at the point of clinical equipoise to diagnose cerebrospinal fluid infection in 14 consecutive neurosurgical patients showing signs of inflammatory complications. Using the guidelines of the Infectious Diseases Society of America, six cases were subsequently characterized as infected and eight as sterile inflammation. Twenty-four contemporaneous patients with idiopathic intracranial hypertension or normal pressure hydrocephalus were included as non-inflamed controls. We measured 182 immune and neurological biomarkers in each sample and used pathway analysis to elucidate the biological underpinnings of any biomarker changes. Increased levels of the inflammatory cytokine interleukin-6 and interleukin-6-related mediators such as oncostatin M were excellent indicators of inflammation. However, interleukin-6 levels alone could not distinguish between bacterially infected and uninfected patients. Within the patient cohort with neurological inflammation, a pattern of raised interleukin-17, interleukin-12p40/p70 and interleukin-23 levels delineated nosocomial bacteriological infection from background neuroinflammation. Pathway analysis showed that the observed immune signatures could be explained through a common generic inflammatory response marked by interleukin-6 in both nosocomial and non-infectious inflammation, overlaid with a toll-like receptor-associated and bacterial peptidoglycan-triggered interleukin-17 pathway response that occurred exclusively during infection. This is the first demonstration of a pathway dependent cerebrospinal fluid biomarker differentiation distinguishing nosocomial infection from background neuroinflammation. It is especially relevant to the commonly encountered pathologies in clinical practice, such as subarachnoid haemorrhage and post-cranial neurosurgery. While requiring confirmation in a larger cohort, the current data indicate the potential utility of cerebrospinal fluid biomarker strategies to identify differential initiation of a common downstream interleukin-6 pathway to diagnose nosocomial infection in this challenging clinical cohort.

Vitamin D inhibits lipopolysaccharide-induced inflammatory response potentially through the Toll-like receptor 4 signalling pathway in the intestine and enterocytes of juvenile Jian carp (Cyprinus carpio var. Jian)

2015 ◽  
Vol 114 (10) ◽  
pp. 1560-1568 ◽  
Author(s):  
Jun Jiang ◽  
Dan Shi ◽  
Xiao-Qiu Zhou ◽  
Long Yin ◽  
Lin Feng ◽  
...  
Keyword(s):  
Vitamin D ◽  
Inflammatory Response ◽  
Mrna Expression ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Jian Carp ◽  
Pre Treatment ◽  
Inflammatory Effect

AbstractThe present study was conducted to investigate the anti-inflammatory effect of vitamin D both in juvenile Jian carp (Cyprinus carpio var. Jian) in vivo and in enterocytes in vitro. In primary enterocytes, exposure to 10 mg lipopolysaccharide (LPS)/l increased lactate dehydrogenase activity in the culture medium (P<0·05) and resulted in a significant loss of cell viability (P<0·05). LPS exposure increased (P<0·05) the mRNA expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-8), which was decreased by pre-treatment with 1,25-dihydroxyvitamin D (1,25D3) in a dose-dependent manner (P<0·05). Further results showed that pre-treatment with 1,25D3 down-regulated Toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (Myd88) and NF-κB p65 mRNA expression (P<0·05), suggesting potential mechanisms against LPS-induced inflammatory response. In vivo, intraperitoneal injection of LPS significantly increased TNF-α, IL-1β, IL-6 and IL-8 mRNA expression in the intestine of carp (P<0·05). Pre-treatment of fish with vitamin D3 protected the fish intestine from the LPS-induced increase of TNF-α, IL-1β, IL-6 and IL-8 mainly by downregulating TLR4, Myd88 and NF-κB p65 mRNA expression (P<0·05). These observations suggest that vitamin D could inhibit LPS-induced inflammatory response in juvenile Jian carp in vivo and in enterocytes in vitro. The anti-inflammatory effect of vitamin D is mediated at least in part by TLR4-Myd88 signalling pathways in the intestine and enterocytes of juvenile Jian carp.

Protective Effect of Ginsenoside Rb1 Nanoparticles Against Contrast-Induced Nephropathy by Inhibiting High Mobility Group Box 1 Gene/Toll-Like Receptor 4/NF-κB Signaling Pathway

2021 ◽  
Vol 17 (10) ◽  
pp. 2085-2098
Author(s):  
Shuai Zhou ◽  
Shan Lu ◽  
Sen Guo ◽  
Luosha Zhao ◽  
Zhanying Han ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Protective Effect ◽  
High Mobility ◽  
High Mobility Group ◽  
Ginsenoside Rb1 ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Contrast Induced Nephropathy

With the progress made in the widespread application of interventional radiology procedures, there has been an increasing number of patients who suffer from cardiovascular diseases and go through imaging and interventional treatment with iodine contrast medium (ICM) year by year. In turn, there has been an increasing amount of concern over acute kidney injury (AKI) brought about by ICM. As evidenced by numerous studies, the initiation of inflammatory response plays a critical role in the development of ICM-induced AKI. Correspondingly, the strategy of targeting renal inflammatory response and cytokine release could provide an effective solution to mitigating the ICM-induced AKI. Moreover, Ginsenoside Rb1 (GRb1) constitutes one of the major active components of ginseng and features a wide range of vital biological functions. Judging from the research findings, GRb1 could impose antioxidant and anti-inflammatory effects on cardiovascular diseases, in addition to lung, liver and kidney diseases. However, reports on whether GRb1 could impose a protective effect against contrast-induced nephropathy (CIN) are absent. In this study, we have examined the therapeutic effects imposed by GRb1 as well as the potential molecular mechanism by establishing an in vivo and in vitro model of CIN. In addition, we have set up a mouse model of CIN through sequential intravenous injection of indomethacin, N(ω)-nitro-Larginine methyl ester (L-NAME), and iopromide. To further enhance the bioavailability of GRb1, we have encapsulated GRb1 with polyethylene glycol (PEG)/poly lactic-co-glycolic acid (PLGA) nanocarriers to generate GRb1 nanoparticles (NPs) conducting the in vivo experiments. During the in vitro experiments, we have adopted GRb1 to treat NRK-52E cells or cells transfected with the high mobility group box 1 gene (HMGB1) overexpression plasmid. As shown by the in vivo experimental results, GRb1 NPs could evidently improve the renal dysfunction in CIN, diminish the extent of apoptosis of tubular epithelial cells, and reduce the expression of high mobility group box 1 (HMGB1) and cytokines (tumor necrosis factor (TNF-α), interleukin (IL) 6 and IL-1β). In addition, GRb1 NPs are found to be capable of preventing the activation of Toll-like receptor 4 (TLR4)/NF-κB signaling pathway triggered by contrast medium. The in vitro experimental results have exactly confirmed the findings of the in vivo experiments. In the meantime, through the observation of the in vitro assays, overexpression of HMGB1 can partially counteract the beneficial effects imposed by GRb1. Judging from our research data, GRb1 could impose a protective effect against CIN by inhibiting inflammatory response via HMGB1/TLR4/NF-κB pathway, whereas HMGB1 constitutes a critical molecular target of GRb1.

Toll-Like Receptor 4 Mediates the Early Inflammatory Response After Cold Ischemia/Reperfusion

2007 ◽  
Vol 84 (10) ◽  
pp. 1279-1287 ◽  
Author(s):  
David J. Kaczorowski ◽  
Atsunori Nakao ◽  
Kevin P. Mollen ◽  
Raghuveer Vallabhaneni ◽  
Ryujiro Sugimoto ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Ischemia Reperfusion ◽  
Toll Like Receptor ◽  
Cold Ischemia ◽  
Toll Like Receptor 4 ◽  
Early Inflammatory Response

scholarly journals Oxidative stress generated by hemorrhagic shock recruits Toll-like receptor 4 to the plasma membrane in macrophages

2006 ◽  
Vol 203 (8) ◽  
pp. 1951-1961 ◽  
Author(s):  
Kinga A. Powers ◽  
Katalin Szászi ◽  
Rachel G. Khadaroo ◽  
Patrick S. Tawadros ◽  
John C. Marshall ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Plasma Membrane ◽  
Hemorrhagic Shock ◽  
Lipid Rafts ◽  
Ischemia Reperfusion ◽  
Resonance Energy ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
H2o2 Treatment

Oxidative stress generated by ischemia/reperfusion is known to prime inflammatory cells for increased responsiveness to subsequent stimuli, such as lipopolysaccharide (LPS). The mechanism(s) underlying this effect remains poorly elucidated. These studies show that alveolar macrophages recovered from rodents subjected to hemorrhagic shock/resuscitation expressed increased surface levels of Toll-like receptor 4 (TLR4), an effect inhibited by adding the antioxidant N-acetylcysteine to the resuscitation fluid. Consistent with a role for oxidative stress in this effect, in vitro H2O2 treatment of RAW 264.7 macrophages similarly caused an increase in surface TLR4. The H2O2-induced increase in surface TLR4 was prevented by depleting intracellular calcium or disrupting the cytoskeleton, suggesting the involvement of receptor exocytosis. Further, fluorescent resonance energy transfer between TLR4 and the raft marker GM1 as well as biochemical analysis of the raft components demonstrated that oxidative stress redistributes TLR4 to lipid rafts in the plasma membrane. Preventing the oxidant-induced movement of TLR4 to lipid rafts using methyl-β-cyclodextrin precluded the increased responsiveness of cells to LPS after H2O2 treatment. Collectively, these studies suggest a novel mechanism whereby oxidative stress might prime the responsiveness of cells of the innate immune system.

scholarly journals Endogenous HMGB1 contributes to ischemia-reperfusion-induced myocardial apoptosis by potentiating the effect of TNF-α/JNK

2011 ◽  
Vol 300 (3) ◽  
pp. H913-H921 ◽  
Author(s):  
Hu Xu ◽  
Yongwei Yao ◽  
Zhaoliang Su ◽  
Yunbo Yang ◽  
Raymond Kao ◽  
...  
Keyword(s):  
Ischemia Reperfusion ◽  
Myocardial Inflammation ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Myocardial Apoptosis ◽  
Apoptosis Inhibition ◽  
Tnf Α ◽  
Myocyte Apoptosis ◽  
Jnk Activation

High-mobility group box 1 (HMGB1) is a nuclear protein that has been implicated in the myocardial inflammation and injury induced by ischemia-reperfusion (I/R). The purpose of the present study was to assess the role of HMGB1 in myocardial apoptosis induced by I/R. In vivo, myocardial I/R induced an increase in myocardial HMGB1 expression and apoptosis. Inhibition of HMGB1 (A-box) ameliorated the I/R-induced myocardial apoptosis. In vitro, isolated cardiac myocytes were challenged with anoxia-reoxygenation (A/R; in vitro correlate to I/R). A/R-challenged myocytes also generated HMGB1 and underwent apoptosis. Inhibition of HMGB1 attenuated the A/R-induced myocyte apoptosis. Exogenous HMGB1 had no effect on myocyte apoptosis. However, inhibition of HMGB1 attenuated myocyte TNF-α production after the A/R was challenged; surprisingly, HMGB1 itself did not induce myocyte TNF-α production. Exogenous TNF-α induced a moderate proapoptotic effect on the myocytes, an effect substantially potentiated by coadministration of HMGB1. It is generally accepted that apoptosis induced by TNF-α is regulated by the balance of activation of c-Jun NH2-terminal kinase (JNK) and NF-κB. Indeed, in the present study, TNF-α increased the phosphorylation status of JNK and p65, a subunit of NF-κB; HMGB1 greatly potentiated TNF-α-induced JNK phosphorylation. Furthermore, inhibition of JNK (SP-600125) prevented the myocyte apoptosis induced by a TNF-α/HMGB1 cocktail. Finally, A/R increased HMGB1 production in both wild-type and toll-like receptor 4-deficient myocytes; however, deficiency in toll-like receptor 4 diminished A/R-induced myocyte apoptosis, TNF-α, and JNK activation. Our results indicate that myocyte-derived HMGB1 and TNF-α work in concert to promote I/R-induced myocardial apoptosis through JNK activation.

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