Selenium-Containing Compound Ameliorates Lipopolysaccharide-Induced Acute Lung Injury via Regulating the MAPK/AP-1 Pathway

Inflammation - Abstract—Acute lung injury (ALI) is characterized by a series of inflammatory reactions and serves as the main cause of mortality in intensive care unit patients. Although...     

Artesunate Protects LPS-Induced Acute Lung Injury by Inhibiting TLR4 Expression and Inducing Nrf2 Activation

Artesunate, a derivative of artemisinin, has been reported to have anti-inflammatory property. However, few studies showed the protective effects of artesunate on lung injury. In this study, we aimed to investigate the effects of artesunate on LPS-induced lung injury in mice. The mice were treated with artesunate 1 h before or after LPS treatment. The effects of artesunate on lung MPO activity and malondialdehyde (MDA) content were detected. The lung wet/dry radio and the numbers of inflammatory cells in BALF were also measured. ELISA was used to evaluate the levels of TNF-α, IL-1β, and IL-6 in BALF. Western blot analysis was adapted to detect TLR4 and Nrf2 signaling pathways. The results showed that artesunate protected against LPS-induced ALI by decreasing the numbers of inflammatory cells, lung edema, MPO activity, and MDA content. Furthermore, artesunate significantly inhibited the levels of TNF-α, IL-1β, and IL-6. Artesunate also inhibited LPS-induced IL-6 and IL-8 production in the A549 cells. In addition, artesunate dose-dependently suppressed LPS-induced TLR4 expression and NF-κB activation. The expression of Nrf2 and HO-1 were also up-regulated by artesunate. The data suggest that artesunate possesses anti-inflammatory and anti-oxidant properties against LPS-induced ALI via inhibiting TLR4 signaling pathway and activating Nrf2 signaling pathway.     

Propofol Protects Rats and Human Alveolar Epithelial Cells Against Lipopolysaccharide-Induced Acute Lung Injury via Inhibiting HMGB1 Expression

High-mobility group box 1 (HMGB1) plays a key role in the development of acute lung injury (ALI). Propofol, a general anesthetic with anti-inflammatory properties, has been suggested to be able to modulate lipopolysaccharide (LPS)-induced ALI. In this study, we investigated the effects of propofol on the expression of HMGB1 in a rat model of LPS-induced ALI. Rats underwent intraperitoneal injection of LPS to mimic sepsis-induced ALI. Propofol bolus (1, 5, or 10 mg/kg) was infused continuously 30 min after LPS administration, followed by infusion at 5 mg/(kg?·?h) through the left femoral vein cannula. LPS increased wet to dry weight ratio and myeloperoxidase activity in lung tissues and caused the elevation of total protein and cells, neutrophils, macrophages, and neutrophils in bronchoalveolar lavage fluid (BALF). Moreover, HMGB1 and other cytokine levels were increased in BALF and lung tissues and pathological changes of lung tissues were excessively aggravated in rats after LPS administration. Propofol inhibited all the above effects. It also inhibited LPS-induced toll-like receptor (TLR)2/4 protein upexpression and NF-κB activation in lung tissues and human alveolar epithelial cells. Propofol protects rats and human alveolar epithelial cells against HMGB1 expression in a rat model of LPS-induced ALI. These effects may partially result from reductions in TLR2/4 and NF-κB activation.     

Ameliorative Effects of Oleuropein on Lipopolysaccharide-Induced Acute Lung Injury Model in Rats

Inflammation - Acute lung injury (ALI) is one of the most common causes of death in diseases with septic shock. Oleuropein, one of the important components of olive leaf, has antioxidant and...     

Significance of TLR4/MyD88 expression in breast cancer

Objective: To investigate the expression of TLR4/MyD88 in breast cancer, and explore the relationship between their expression and breast cancer tumor growth and invasion. Methods: We examined the protein expression of TLR4 and MyD88 in 60 cases of histologically confirmed breast cancer. The relationship of their protein expressions with clinical features including age at diagnosis, tumor size and stage, lymph node metastasis and distant metastasis were analyzed. Results: The IHC results showed that TLR4 and MyD88 were expressed in 63.3% (38/60) and 58.3% (35/60) of malignant breast tumors respectively. TLR4 expression in breast cancer were significantly higher than in fibroadenoma (n = 4, 20.0%) and adjacent normal tissues (n = 2, 10.0%) (P < 0.001). MyD88 expression in breast cancer were also significantly higher than in fibroadenoma (n = 4, 20.0%) and adjacent normal tissue (n = 3, 15.0%) (P < 0.001). The gene expressions of TLR4 and MyD88 were significantly higher in breast cancer than in fibroadenoma and adjacent normal tissues (P < 0.05). The protein expressions of TLR4 and MyD88 were also significantly associated with poor clinical features (P < 0.05). Conclusion: TLR4 and MyD88 expression might be associated with breast cancer growth and regional and distant metastases.     

Anti-Inflammatory Effects of Apigenin in Lipopolysaccharide-Induced Inflammatory in Acute Lung Injury by Suppressing COX-2 and NF-kB Pathway

This study aims to evaluate the possible mechanisms responsible for the anti-inflammatory effects of apigenin lipopolysaccharide (LPS)-induced inflammatory in acute lung injury. In this study, the anti-inflammatory effects of apigenin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice and the possible mechanisms involved in this protection were investigated. Pretreatment with apigenin prior to the administration of intratracheal LPS significantly induced a decrease in lung wet weight/dry weight ratio in total leukocyte number and neutrophil percent in the bronchoalveolar lavage fluid (BALF) and in IL-6 and IL-1β, the tumor neurosis factor-α (TNF-α) in the BALF. These results showed that anti-inflammatory effects of apigenin against the LPS-induced ALI may be due to its ability of primary inhibition of cyclooxygenase-2 (COX-2) gene expression and nuclear factor kB (NF-kB) gene expression of lung. The results presented here suggest that the protective mechanism of apigenin may be attributed partly to decreased production of proinflammatory cytokines through the inhibition of COX-2 and NF-kB activation. The results support that use of apigenin is beneficial in the treatment of ALI.     

Glutamine Supplementation Attenuates the Inflammation Caused by LPS-Induced Acute Lung Injury in Mice by Regulating the TLR4/MAPK Signaling Pathway

Bacterial infection is one of the main causes of bovine respiratory disease (BRD), which can cause tremendous losses for the herd farming industry worldwide. l-Glutamine (GLN), a neutral amino acid, has been reported to have anti-inflammatory properties. This study aims to explore the potential protective effects and mechanisms of GLN on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in mice. Forty ICR mice were randomly divided into four groups (n = 10): a PBS intratracheal instillation group, a LPS intratracheal instillation group, a GLN gavage group, and a LPS+GLN group (GLN was given 1 h before the LPS stimulation). Twelve hours after LPS administration, the lung tissue and blood were collected. The results showed that the concentrations of IL-6, IL-8, and IL-1β; the protein abundance of the toll-like receptor 4 (TLR4), phosphorylated p38 (p-p38), phosphorylated ERK1/2 (p-ERK1/2), and phosphorylated JNK (p-JNK); and the expression level of genes associated with inflammation, such as IL-1β, IL-8, TNF-α, IL-6, TLR4, p38, ERK1/2, and JNK, were significantly increased in the LPS group compared with those in the PBS group. However, these increases were attenuated by GLN pretreatment in the LPS+GLN group. Furthermore, the pathological change of the structure of lung tissue from the LPS group was obvious compared to that from the PBS group; however, with GLN administration, these pathological changes were alleviated. Additionally, the secretion level of mucus and the percentage of positive MUC5AC staining on the epithelial surface area of the airway increased dramatically in the LPS group; however, GLN pretreatment in the LPS+GLN group markedly decreased these phenomena compared with that of the LPS group. These results indicate that GLN supplementation ameliorates LPS-induced ALI in mice and this effect may be mediated by the TLR4/MAPK signaling pathway.

     

The Effects of Morin on Lipopolysaccharide-Induced Acute Lung Injury by Suppressing the Lung NLRP3 Inflammasome

In previous study, the anti-inflammatory effect of morin had been found. In this study, we investigated anti-inflammatory effects of morin on acute lung injury using lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. The cell counting in the bronchoalveolar lavage fluid (BALF) was measured. The animal lung edema degree was evaluated by wet/dry weight (W/D) ratio. The superoxidase dismutase (SOD) activity and myeloperoxidase (MPO) activity were assayed by SOD and MPO kits, respectively. The levels of inflammatory mediators including tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-18, and IL-6 were assayed by enzyme-linked immunosorbent assay method. Pathological changes of lung tissues were observed by hematoxylin and eosin (HE) staining. The protein level of lung NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome was measured by Western blotting. The data showed that treatment with the morin markedly attenuated inflammatory cell numbers in the BALF, decreased lung NLRP3 inflammasome protein level, and improved SOD activity and inhibited MPO activity. Histological studies demonstrated that morin substantially inhibited LPS-induced neutrophils in lung tissue compared with model group. The results indicated that the morin had a protective effect on LPS-induced ALI in mice.     

miR-377-5p靶向IRAK1通过抑制JNK信号通路改善脑缺血再灌注大鼠神经损伤和炎性反应

目的 探究miR-377-5p对脑缺血再灌注(ischemia/reperfusion,I/R)大鼠神经损伤和炎性反应的作用及机制.方法 通过生物信息学预测到miR-377-5p与白介素1受体相关激酶(interleukin-1 receptor-associated kinases,IRAK1)靶向关系.SD大鼠随机...     

Antiphospholipid Antibodies Induce a Pro-Inflammatory Response in First Trimester Trophoblast Via the TLR4/MyD88 Pathway

Problem  Women with antiphospholipid antibodies (aPL) are at risk for recurrent miscarriage, pre-eclampsia, and pre-term labor. aPL target the placenta directly by binding to beta₂-glycoprotein I (β₂GPI) expressed on the surface of trophoblast cells. The objective of this study was to determine the effects of aPL on trophoblast function and the mechanisms involved.
Method of study  First trimester trophoblast cells were treated with anti-β₂GPI monoclonal antibodies and patient-derived aPL, after which cell survival and function was evaluated.
Results  We report that anti-β₂GPI antibodies trigger an inflammatory response in trophoblast, characterized by increased secretion of interleukin (IL)-8, MCP-1, GRO-α, and IL-1β, and that this occurs in a TLR-4/MyD88-dependent manner. At high concentrations, these antibodies also induce caspase-mediated cell death. This was attenuated upon disabling of the MyD88 pathway, suggesting that anti-β₂GPI-induced inflammatory mediators compromise trophoblast survival by acting in an autocrine/paracrine manner. Enhanced IL-8, GRO-α, and IL-1β secretion also occurred when trophoblast cells were incubated with antibodies from patients with antiphospholipid syndrome. Heparin, which acts as a pro-survival factor in human trophoblast, attenuated the anti-β₂GPI antibody-mediated cell death, and also the pro-inflammatory response, but only at high concentrations.
Conclusion  These findings demonstrate that aPL triggers a placental inflammatory response via the TLR-4/MyD88 pathway, which in turn compromises trophoblast survival. Thus, the TLR-4/MyD88 pathway may provide a new therapeutic target to improve pregnancy outcome in antiphospholipid syndrome patients.     

H_2S通过抑制TLR4/MyD88/PI3K信号通路减轻尿源性脓毒血症诱导的急性肾损伤

目的:探讨硫化氢(H_2S)减轻尿源性脓毒血症诱导的急性肾损伤的作用机制。方法:40只新西兰白兔随机分为对照组、假手术组、脓毒血症模型组、脓毒血症模型Na HS处理组和脓毒血症模型Na HS联合TAK-242(TLR4抑制剂)处理组,每组8只。各组分别按分组处理72 h后,采用HE染色观察兔肾组织病理学变化;使用全自动生化分析仪检测血尿素氮(BUN)和血清肌酐(SCr)水平;采用ELISA法检测血液中中性粒细胞明胶酶相关脂质运载蛋白(NGAL)、肾损伤分子1(KIM-1)、降钙素原(PCT)以及炎症因子白细胞介素1β(IL-1β)、白细胞介素6(IL-6)和肿瘤坏死因子α(TNF-α)的水平;采用Western blot检测TLR4/MyD88/PI3K信号通路相关蛋白的表达。结果:与对照组相比,脓毒血症兔肾组织呈现明显损伤,Na HS处理后肾脏病理明显改善,且血液中BUN、SCr、NGAL、KIM-1、PCT、IL-1β、IL-6和TNF-α水平显著提高(P 0.05),但Na HS处理或联合TAK-242处理后显著降低;脓毒血症兔肾脏组织中的TLR4、MyD88、p-PI3K和p-Akt蛋白水平显著升高;Na HS处理或抑制TLR4则显著抑制TLR4/MyD88/PI3K信号通路激活。结论:H_2S可能通过抑制TLR4/MyD88/PI3K信号通路减少炎症因子及肾损伤因子的释放,从而有效减轻尿源性脓毒血症诱导的急性肾损伤。     

The role of MyD88 and TLR4 in the LPS-mimetic activity of Taxol

Taxol can mimic bacterial lipopolysaccharide (LPS) by activating mouse macrophages in a cell cycle-independent, LPS antagonist-inhibitable manner. Macrophages from C3H/HeJ mice, which have a spontaneous mutation in Toll-like receptor 4 (TLR4), are hyporesponsive to both LPS and Taxol, suggesting that LPS and Taxol may share a signaling pathway involving TLR4. To determine whether TLR4 and its interacting adaptor molecule MyD88 are necessary for Taxol's LPS mimetic actions, we examined Taxol responses of primary macrophages from genetically defective mice lacking either TLR4 (C57BL/10ScNCr) or MyD88 (MyD88 knockout). When stimulated with Taxol, macrophages from wild-type mice responded robustly by secreting both TNF and NO, while macrophages from either TLR4-deficient C57BL/10ScNCr mice or MyD88 knockout mice produced only minimal amounts of TNF and NO. Taxol-induced NF-kappa B-driven luciferase activity was reduced after transfection of RAW 264.7 macrophages with a dominant negative version of mouse MyD88. Taxol-induced microtubule-associated protein kinase (MAPK) activation and NF-kappa B nuclear translocation were absent from TLR4-null macrophages, but were preserved in MyD88 knockout macrophages with a slight delay in kinetics. Neither Taxol-induced NF-kappa B activation, nor I kappa B degradation was affected by the presence of phosphatidylinositol 3-kinase inhibitors. These results suggest that Taxol and LPS not only share a TLR4/MyD88-dependent pathway in generating inflammatory mediators, but also share a TLR4-dependent/MyD88-independent pathway leading to activation of MAPK and NF-kappa B.     

Resolvin D1 Alleviates the Lung Ischemia Reperfusion Injury via Complement,Immunoglobulin, TLR4, and Inflammatory Factors in Rats

Lung ischemia-reperfusion injury (LIRI) is still an unsolved medical issue, which negatively affects the prognosis of many lung diseases. The aim of this study is to determine the effects of RvD1 on LIRI and the potential mechanisms involved. The results revealed that the levels of complement, immunoglobulin, cytokines, sICAM-1, MPO, MDA, CINC-1, MCP-1, ANXA-1, TLR4, NF-κBp65, apoptosis index, and pulmonary permeability index were increased, whereas the levels of SOD, GSH-PX activity, and oxygenation index were decreased in rats with LIRI. Except for ANXA-1, these responses induced by LIRI were significantly inhibited by RvD1 treatment. In addition, LIRI-induced structure damages of lung tissues were also alleviated by RvD1 as shown by H&E staining and transmission electron microscopy. The results suggest that RvD1 may play an important role in protection of LIRI via inhibition of complement, immunoglobulin, and neutrophil activation; down-regulation of TLR4/NF-κB; and the expression of a variety of inflammatory factors.     

Preventive and Therapeutic Effects of Thymol in a Lipopolysaccharide-Induced Acute Lung Injury Mice Model

Acute lung injury (ALI) is a life-threatening syndrome which causes a high mortality rate worldwide. In traditional medicine, lots of aromatic plants—such as some Thymus species—are used for treatment of various lung diseases including pertussis, bronchitis, and asthma. Thymol, one of the primary active constituent derived from Thymus vulgaris (thyme), has been reported to exhibit potent anti-microbial, anti-oxidant, and anti-inflammatory activities in vivo and in vitro. The present study aims to investigate the protective effects of thymol in lipopolysaccharide (LPS)-induced lung injury mice model. In LPS-challenged mice, treatment with thymol (100 mg/kg) before or after LPS challenge significantly improved pathological changes in lung tissues. Thymol also inhibited the LPS-induced inflammatory cells influx, TNF-α and IL-6 releases, and protein concentration in bronchoalveolar lavage fluid (BALF). Additionally, thymol markedly inhibited LPS-induced elevation of MDA and MPO levels, as well as reduction of SOD activity. Further study demonstrated that thymol effectively inhibited the NF-κB activation in the lung. Taken together, these results suggested that thymol might be useful in the therapy of acute lung injury.     

TLR2、TLR4 及 MyD88 高表达与 Cm 呼吸道感染肺组织炎症相关

目的:探讨沙眼衣原体呼吸道感染过程中C3H/ HeN(C3H)小鼠过度炎症反应的机制。方法:C3H 与C57BL/6(C57)小鼠鼻腔吸入1伊103 IFU 沙眼衣原体小鼠肺炎菌株(Cm),建立沙眼衣原体小鼠肺炎模型,使用RT-PCR 检测感染后不同时间点小鼠肺组织Toll 样受体TLR2、TLR4 及转导蛋白MyD88 mRNA 的表达。结果:使用1伊103 IFU 的Cm 呼吸道感染C3H与C57BL/6(C57)诱导小鼠衣原体肺炎,Cm 感染在高易感性的C3H 小鼠及低易感的C57 小鼠均诱导Toll 样受体的表达,但在感染后第7 天及第14 天,高易感的C3H 小鼠肺组织中TLR2 和TLR4 mRNA 的表达均显著高于C57 小鼠,尤其TLR2(P<0.001 或P<0.05),进一步研究发现Cm 呼吸道感染C3H 小鼠肺组织MyD88mRNA 的表达也显著高于C57 小鼠,并在感染后第14 天仍维持高表达。结论:Cm 呼吸道感染诱导TLR2、TLR4 及MyD88 在高易感的C3H 小鼠肺组织高表达,可能与C3H 小鼠肺组织过度炎症反应相关。     

Dimethyl Sulfoxide Attenuates Acute Lung Injury Induced by Hemorrhagic Shock/Resuscitation in Rats

Inflammation following hemorrhagic shock/resuscitation (HS/RES) induces acute lung injury (ALI). Dimethyl sulfoxide (DMSO) possesses anti-inflammatory and antioxidative capacities. We sought to clarify whether DMSO could attenuate ALI induced by HS/RES. Male Sprague-Dawley rats were allocated to receive either a sham operation, sham plus DMSO, HS/RES, or HS/RES plus DMSO, and these were denoted as the Sham, Sham?+?DMSO, HS/RES, or HS/RES?+?DMSO group, respectively (n?=?12 in each group). HS/RES was achieved by drawing blood to lower mean arterial pressure (40–45 mmHg for 60 min) followed by reinfusion with shed blood/saline mixtures. All rats received an intravenous injection of normal saline or DMSO immediately before resuscitation or at matching points relative to the sham groups. Arterial blood gas and histological assays (including histopathology, neutrophil infiltration, and lung water content) confirmed that HS/RES induced ALI. Significant increases in pulmonary expression of tumor necrosis factor-α (TNF-α), malondialdehyde, nuclear factor-kappa B (NF-κB), inducible nitric oxide synthase (iNOS), and cyclooxygenase 2 (COX-2) confirmed that HS/RES induced pulmonary inflammation and oxidative stress. DMSO significantly attenuated the pulmonary inflammation and ALI induced by HS/RES. The mechanisms for this may involve reducing inflammation and oxidative stress through inhibition of pulmonary NF-κB, TNF-α, iNOS, and COX-2 expression.     

Brucella abortus induces Irgm3 and Irga6 expression via type-I IFN by a MyD88-dependent pathway,without the requirement of TLR2, TLR4, TLR5 and TLR9

The innate immune system senses bacterial pathogens by pattern recognition receptors, such as the well-characterised Toll-like Receptors (TLR). The activation of TLR signalling cascades depends on several adaptor proteins, among which MyD88 plays a key role in triggering innate immune responses. Here, we show in murine macrophages that Brucella abortus triggers expression of the interferon-inducible resistance proteins (IRGs, p47 GTPases) via type-I IFN secretion at late time points, when Brucella has reached its replication niche. This induction requires the adaptor molecule MyD88 but does not involve the TLRs normally implicated in sensing Gram-negative bacteria, namely TLR2, TLR4, TLR5 and TLR9. Brucella mutants lacking the functional VirB type-IV secretion system were not capable of inducing Irgm3 and Irga6 expression, suggesting that the type-IV secretion system is part of the triggering of the activation process. Our data suggest that Brucella is recognized intracellularly by an unknown receptor, different from the conventional ones used for Gram-negative sensing, but one that nevertheless signals through MyD88.     

Essential role for TLR4 and MyD88 in the development of chronic intestinal nematode infection

Expulsion of the gastrointestinal nematode Trichuris muris is mediated by a T helper 2 type response involving IL-4 and IL-13. Here we show that Th1 response-associated susceptibility is dependent on activation signals mediated by MyD88 and Toll-like receptor 4 (TLR4). TLR4- and MyD88-deficient mice are highly resistant to chronic T. muris infection and develop strong antigen-specific Th2 responses in mucosa-associated lymphoid tissues. Hence, TLR4 and MyD88 are involved not only in the development of pro-inflammatory responses against bacterial pathogens but are also crucially involved in responses against multicellular organisms such as helminths. These results provide the first demonstration of the critical role of TLR4 and MyD88 in bridging the innate and acquired immune response during gastrointestinal nematode infection.     

Inhibition of SOCs Attenuates Acute Lung Injury Induced by Severe Acute Pancreatitis in Rats and PMVECs Injury Induced by Lipopolysaccharide

Acute lung injury (ALI) is a critical complication of the severe acute pancreatitis (SAP), characterized by increased pulmonary permeability with high mortality. Pulmonary microvascular endothelial cells (PMVECs) injury and apoptosis play a key role in ALI. Previous studies indicated that store-operated calcium entry (SOCE) could regulate a variety of cellular processes. The present study was to investigate the effects of SOCE inhibition on ALI induced by SAP in Sprague-Dawley rats, and PMVECs injury induced by lipopolysaccharide (LPS). Rat model of SAP-associated ALI were established by the retrograde infusion of sodium deoxycholate. Serum levels of amylase, TNF-α, and IL-6, histological changes, water content of the lung, oxygenation index, and ultrastructural changes of PMVECs were examined in ALI rats with or without store-operated Ca²⁺ channels (SOCs) pharmacological inhibitor (2-aminoethoxydiphenyl borate, 2-APB) pretreatment. For in vitro studies, PMVECs were transiently transfected with or without small interfering RNA (siRNA) against calcium release-activated calcium channel protein1 (Orai1) and stromal interaction molecule1 (STIM1), the two main molecular constituents of SOCs, then exposed to LPS. The viability of PMVECs was determined. The expression of STIM1, Orai1, Bax, and caspase3, both in lung tissue and in PMVECs, were assessed by quantitative real-time PCR and western blot. Administration of sodium deoxycholate upregulated the expression of SOCs proteins in lung tissue. Similarly, the SOCs proteins were increased in PMVECs induced by LPS. 2-APB reduced the serum levels of amylase, TNF-α, and IL-6, and attenuated lung water content and histological findings. In addition, the decreased oxygenation index and ultrastructural damage in PMVECs associated with SAP were ameliorated after administration of 2-APB. Knockdown of STIM1 and Orai1 inhibited LPS-induced PMVECs death. Furthermore, blockade of SOCE significantly suppressed Orai1, STIM1, Bax, and caspase3 expression both in vivo and in vitro. These results suggest that SOCE may play a critical role in SAP-associated ALI and the protective effects of inhibition of SOCs could be mediated, at least partially, by restraining mitochondrial associated apoptosis of PMVECs.