scholarly journals Downregulation of TNF-α/TNF-R1 Signals by AT-Lipoxin A4 May Be a Significant Mechanism of Attenuation in SAP-Associated Lung Injury

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Suhui Yu ◽  
Jianming Xie ◽  
Yukai Xiang ◽  
Shengjie Dai ◽  
Dinglai Yu ◽  
...  

Our previous studies verified the potent anti-inflammatory effects against severe acute pancreatitis (SAP) of AT-Lipoxin A4 and their analogues. However, the anti-inflammatory effects of AT-Lipoxin A4 on SAP-associated lung injury are not thoroughly known. We used western blot, polymerase chain reaction (PCR), and immunofluorescence to investigate the downregulation of TNF-α signals in cellular and animal models of SAP-associated lung injury following AT-Lipoxin A4 intervention. In vitro, we found that AT-Lipoxin A4 markedly suppressed protein expression in TNF-α signals in human pulmonary microvascular endothelial cell, such as tumor necrosis factor receptor-associated factor 2 (TRAF2), TNF-R1-associated death domain (TRADD), receptor-interacting protein (RIP), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin. Moreover, AT-Lipoxin A4 inhibited downstream signals activated by TNF-α, including NF-κB/p65, JNK/MAPK, and ERK/MAPK. In vivo, AT-Lipoxin A4 significantly decreased pathological scores of the pancreas and lungs and the serum levels of IL-6 and TNF-α. Immunofluorescence, western blotting, and real-time PCR assay showed that AT-Lipoxin A4 significantly attenuated the expression of TNF-R1, TRADD, TRAF2, and RIP in the lungs of SAP rats. In addition, the activation of NF-κB was also downregulated by AT-Lipoxin A4 administration as compared with SAP rats. AT-Lipoxin A4 could inhibit the production of proinflammatory mediators and activation of TNF-α downstream signals such as NF-κB and MAPK. Downregulation of TNF-α signals by AT-Lipoxin A4 may be a significant mechanism in the attenuation of SAP-associated lung injury.

2021 ◽  
Author(s):  
Jinju Li ◽  
Rongge Shao ◽  
Qiuwen Xie ◽  
XueKe Du

Abstract Purpose:Ulinastatin (UTI) is an endogenous protease inhibitor with potent anti-inflammatory, antioxidant and organ protective effects. The inhibitor has been reported to ameliorate inflammatory lung injury but precise mechanisms remain unclear. Methods: An in vivo model of lung injury has been constructed by intratracheal infusion of lipopolysaccharide (LPS). The number of neutrophils and the phagocytosis of apoptotic neutrophils were observed by Diff- Quick method. Lung injury was observed by HE staining .BALF cells were counted by hemocytometer and concentrations of protein plus inflammatory factors were measured with a BCA test kit. During in vitro experiments, RAW264.7 cells were pretreated with UTI (1000 and 5000U/ mL), stained with CellTrackerTM Green B0DIPYTM and HL60 cells added with UV-induced apoptosis and PKH26 Red staining. The expression of ERK5\Mer related proteins was detected by western blot and immunofluorescence.Results: An in vivo model of lung injury has been constructed by intratracheal infusion of lipopolysaccharide (LPS). UTI treatment enhanced the phagocytotic effect of mouse alveolar macrophages on neutrophils, alleviated lung lesions, decreased the pro-inflammatory factor and total protein content of BALF and increased levels of anti-inflammatory factors. in vitro experiments ,UTI enhanced the phagocytosis of apoptotic bodies by RAW264.7 cells in a dose-dependent manner. Increased expression levels of ERK5 and Mer by UTI were shown by Western blotting and immunofluorescence.Conclusions: UTI mediated the activation of the ERK5/Mer signaling pathway, enhanced phagocytosis of neutrophils by macrophages and improved lung inflammation. The current study indicates potential new clinical approaches for accelerating the recovery from lung inflammation.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Quanxin Ma ◽  
Kai Wang ◽  
Qinqin Yang ◽  
Shun Ping ◽  
Weichun Zhao ◽  
...  

Veronicastrum axillare is a traditional medical plant in China which is widely used in folk medicine due to its versatile biological activities, especially for its anti-inflammatory effects. However, the detailed mechanism underlying this action is not clear. Here, we studied the protective effects of V. axillare against acute lung injury (ALI), and we further explored the pharmacological mechanisms of this action. We found that pretreatment with V. axillare suppressed the release of proinflammatory cytokines in the serum of ALI mice. Histological analysis of lung tissue demonstrated that V. axillare inhibited LPS-induced lung injury, improved lung morphology, and reduced the activation of nuclear factor-κB (NF-κB) in the lungs. Furthermore, the anti-inflammatory actions of V. axillare were investigated in vitro. We observed that V. axillare suppressed the mRNA expression of interleukin-1β (IL-1β), IL-6, monocyte chemotactic protein-1 (MCP-1), cyclooxygenase-2 (COX-2), and tumor necrosis factor-α (TNF-α) in RAW264.7 cells challenged with LPS. Furthermore, pretreatment of V. axillare in vitro reduced the phosphorylation of p65 and IκB-α which is activated by LPS. In conclusion, our data firstly demonstrated that the anti-inflammatory effects of V. axillare against ALI were achieved through downregulation of the NF-κB signaling pathway, thereby reducing the production of inflammatory mediators.


mBio ◽  
2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiao Wang ◽  
Mikael Sjölinder ◽  
Yumin Gao ◽  
Yi Wan ◽  
Hong Sjölinder

ABSTRACTNeisseria meningitidiscolonizes the nasopharyngeal mucosa of healthy populations asymptomatically, although the bacterial surface is rich in motifs that activate the host innate immunity. What determines the tolerant host response to this bacterium in asymptomatic carriers is poorly understood. We demonstrated that the conserved meningococcal surface protein NhhA orchestrates monocyte (Mo) differentiation specifically into macrophage-like cells with a CD200Rhiphenotype (NhhA-Mφ). In response to meningococcal stimulation, NhhA-Mφ failed to produce proinflammatory mediators. Instead, they upregulated interleukin-10 (IL-10) and Th2/regulatory T cell (Treg)-attracting chemokines, such as CCL17, CCL18, and CCL22. Moreover, NhhA-Mφ were highly efficient in eliminating bacteria. Thein vivovalidity of these findings was corroborated using a murine model challenged withN. meningitidissystematically or intranasally. The NhhA-modulated immune response protected mice from septic shock; Mo/Mφ depletion abolished this protective effect. Intranasal administration of NhhA induced an anti-inflammatory response, which was associated withN. meningitidispersistence at the nasopharynx.In vitrostudies demonstrated that NhhA-triggered Mo differentiation occurred upon engaged Toll-like receptor 1 (TLR1)/TLR2 signaling and extracellular signal-regulated kinase (ERK) and Jun N-terminal protein kinase (JNK) activation and required endogenously produced IL-10 and tumor necrosis factor alpha (TNF-α). Our findings reveal a strategy that might be adopted byN. meningitidisto maintain asymptomatic nasopharyngeal colonization.IMPORTANCENeisseria meningitidisis an opportunistic human-specific pathogen that colonizes the nasopharyngeal mucosa asymptomatically in approximately 10% of individuals. Very little is known about how this bacterium evades immune activation during the carriage stage. Here, we observed thatN. meningitidis, via the conserved surface protein NhhA, skewed monocyte differentiation into macrophages with a CD200Rhiphenotype. Bothin vivoandin vitrodata demonstrated that these macrophages, upon meningococcal infection, played an important role in forming a homeostatic immune microenvironment through their capacity to eliminate invading bacteria and to generate anti-inflammatory mediators. This work provides novel insight into the mechanisms underlying the commensal persistence ofN. meningitidis.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zengjie Zheng ◽  
Hailong Jiang ◽  
Yan Huang ◽  
Jie Wang ◽  
Lei Qiu ◽  
...  

Abstract Snake has been used for centuries as a traditional Chinese medicine, especially for therapeutic treatment for inflammatory diseases; however, its mechanisms of action and active constituents remain controversial. In our study, a tumor necrosis factor receptor 1 (TNFR1) selective binding peptide, Hydrostatin-SN1 (H-SN1), which was screened from a Hydrophis cyanocinctus venom gland T7 phage display library, was shown to exhibit significant anti-inflammatory activity in vitro and in vivo. As a TNFR1 antagonist, it reduced cytotoxicity mediated by TNF-α in L929 fibroblasts and effectively inhibited the combination between TNF-α with TNFR1 in surface plasmon resonance analysis. H-SN1 was also shown to suppress TNFR1–associated signaling pathways as it minimized TNF-α-induced NF-кB and MAPK activation in HEK293 embryonic kidney and HT29 adenocarcinoma cell lines. We next determined the effect of H-SN1 in vivo using a murine model of acute colitis induced by dextran sodium sulfate, demonstrating that H-SN1 lowered the clinical parameters of acute colitis including the disease activity index and histologic scores. H-SN1 also inhibited TNF/TNFR1 downstream targets at both mRNA and protein levels. These results indicate that H-SN1 might represent a suitable candidate for use in the treatment of TNF-α-associated inflammatory diseases such as inflammatory bowel diseases.


2017 ◽  
Vol 45 (01) ◽  
pp. 137-157 ◽  
Author(s):  
Jian-Jung Chen ◽  
Chung-Chun Huang ◽  
Heng-Yuan Chang ◽  
Pei-Ying Li ◽  
Yu-Chia Liang ◽  
...  

Scutellaria baicalensis has been widely used as both a dietary ingredient and traditional herbal medicine in Taiwan to treat inflammation, cancer, and bacterial and viral infections of the respiratory tract and gastrointestinal tract. This paper aims to investigate the in vitro and in vivo anti-inflammatory effects of S. baicalensis. In HPLC analysis, the fingerprint chromatogram of the water extract of S. baicalensis (WSB) was established. The anti-inflammatory effects of WSB were inverstigated using lipopolysaccharide (LPS)-stimulated mouse macrophage (RAW264.7) in vitro and LPS-induced lung injury in vivo. WSB attenuated the production of LPS-induced nitric oxide (NO), tumor necrosis factor-alpha (TNF-[Formula: see text], interleukin-[Formula: see text] (IL-1[Formula: see text], and IL-6 in vitro and in vivo. Pretreatment with WSB markedly reduced the LPS-induced histological alterations in lung tissues. Furthermore, WSB significantly reduced the number of total cells and the protein concentration levels in the BALF. WSB blocked protein expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), phosphorylation of I[Formula: see text]B-[Formula: see text] protein and MAPKs in LPS-stimulated RAW 264.7 cells and LPS-induce lung injury was also blocked. This study suggests that WSB possesses anti-inflammatory effects in vitro and in vivo, and the results suggested that WSB may be a potential therapeutic candidate for the treatment of inflammatory diseases.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yiyi Jin ◽  
Jianchang Qian ◽  
Xin Ju ◽  
Xiaodong Bao ◽  
Li Li ◽  
...  

Inflammation is a key factor in the pathogenesis of ALI. Therefore, suppression of inflammatory response could be a potential strategy to treat LPS-induced lung injury. Osthole, a natural coumarin extract, has been reported to protect against acute kidney injury through an anti-inflammatory mechanism, but its effect on ALI is poorly understood. In this study, we investigated whether osthole ameliorates inflammatory sepsis-related ALI. Results from in vitro studies indicated that osthole treatment inhibited the LPS-induced inflammatory response in mouse peritoneal macrophages through blocking the nuclear translocation of NF-κB. Consistently, the in vivo studies indicated that osthole significantly prolonged the survival of septic mice which was accompanied by inflammation suppression. In the ALI mouse model, osthole effectively inhibited the development of lung tissue injury, leukocytic recruitment, and cytokine productions, which was associated with inhibition of NF-κB nuclear translocation. These findings provide evidence that osthole was a potent inhibitor of NF-κB and inflammatory injury and suggest that it could be a promising anti-inflammatory agent for therapy of septic shock and acute lung injury.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seongchan Kim ◽  
Shin Young Kim ◽  
Seung Joon Rho ◽  
Seung Hoon Kim ◽  
So Hyang Song ◽  
...  

AbstractOxidative stress plays important roles in inflammatory responses during acute lung injury (ALI). Recently, nanoconstruct (Nano)-based drug-delivery systems have shown promise in many models of inflammation. In this study, we evaluated the anti-inflammatory effects of N-acetylcysteine (NAC) loaded in a biocompatible Nano using a rat model of ALI. We synthesized a Nano with a good NAC-releasing capacity using porous silica Nano, which was used to produce Nano/NAC complexes. For in vivo experiments, Sprague–Dawley rats were intraperitoneally administered NAC or Nano/NAC 30 min after intratracheal instillation of lipopolysaccharide. After 6 h, bronchoalveolar lavage fluids and lung tissues were collected. The anti-oxidative effect of the Nano/NAC complex was confirmed by demonstrating reduced levels of reactive oxygen species after treatment with the Nano/NAC in vitro. In vivo experiments also showed that the Nano/NAC treatment may protect against LPS‐induced ALI thorough anti‐oxidative and anti‐inflammatory effects, which may be attributed to the inactivation of the NF‐κB and MAPK pathways. In addition, the effects of Nano/NAC treatment were shown to be superior to those of NAC alone. We suggest the therapeutic potential of Nano/NAC treatment as an anti‐inflammatory agent against ALI. Furthermore, our study can provide basic data for developing nanotechnology-based pharmacotherapeutics for ALI.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xiyue Zhang ◽  
Li Du ◽  
Jinrong Zhang ◽  
Chunyan Li ◽  
Jie Zhang ◽  
...  

Acute lung injury (ALI) is a respiratory disease that leads to death in severe cases. Hordenine (Hor), a barley-derived natural product, has various biological activities, including anti-inflammatory, and anti-oxidation activities. We investigated the effect of Hor on lipopolysaccharide-induced ALI and its potential mechanism. The anti-inflammatory effects of Hor were detected using in vivo and in vitro models by enzyme-linked immunosorbent assay, real-time polymerase chain reaction, western blotting, and molecular docking simulations. Hor inhibited increases in the levels of inflammatory factors both in vivo and in vitro, and its anti-inflammatory effect inhibited activation of protein kinase B, nuclear factor-κB, and mitogen-activated protein kinase signaling. Hor alleviated lipopolysaccharide-induced ALI by inhibiting inflammatory cytokine increases in vivo and in vitro and shows potential for preventing inflammatory disease.


2008 ◽  
Vol 82 (19) ◽  
pp. 9600-9614 ◽  
Author(s):  
Sandy S. Tungteakkhun ◽  
Maria Filippova ◽  
Jonathan W. Neidigh ◽  
Nadja Fodor ◽  
Penelope J. Duerksen-Hughes

ABSTRACT High-risk strains of human papillomavirus, such as types 16 and 18, have been etiologically linked to cervical cancer. Most cervical cancer tissues are positive for both the E6 and E7 oncoproteins, since it is their cooperation that results in successful transformation and immortalization of infected cells. We have reported that E6 binds to tumor necrosis factor receptor 1 and to Fas-associated death domain (FADD) and, in doing so, prevents E6-expressing cells from responding to apoptotic stimuli. The binding site of E6 to FADD localizes to the first 23 amino acids of FADD and has now been further characterized by the use of deletion and site-directed mutants of FADD in pull-down and functional assays. The results from these experiments revealed that mutations of serine 16, serine 18, and leucine 20 obstruct FADD binding to E6, suggesting that these residues are part of the E6 binding domain on FADD. Because FADD does not contain the two previously identified E6 binding motifs, the LxxφLsh motif, and the PDZ motif, a novel binding domain for E6 has been identified on FADD. Furthermore, peptides that correspond to this region can block E6/FADD binding in vitro and can resensitize E6-expressing cells to apoptotic stimuli in vivo. These results demonstrate the existence of a novel E6 binding domain.


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