Macrophagic Stabilin-1 Restored Disruption of Vascular Integrity Caused by Sepsis

2018 ◽  
Vol 118 (10) ◽  
pp. 1776-1789 ◽  
Author(s):  
Wonhwa Lee ◽  
Seung-Yoon Park ◽  
Youngbum Yoo ◽  
Soon-Young Kim ◽  
Jung-Eun Kim ◽  
...  

AbstractSepsis develops because of overwhelming inflammatory responses to bacterial infection, and disrupts vascular integrity. Stabilin-1 (STAB-1) is a phagocytic receptor, which mediates efferocytosis in a phosphatidylserine (PS)-dependent manner. STAB-1 is expected to play important roles in efferocytosis during sepsis. Here, we determined the role of STAB-1 in maintaining and restoring vascular integrity. Macrophages and vascular endothelial cells were used to assess the effect of STAB-1 on survival rate, phagocytic activity, vascular permeability and transendothelial migration (TEM). Additionally, we investigated whether the high-mobility group box 1 (HMGB1)-receptor for advanced glycated end products complex interfered with the binding of Stab1 to PS. Mortality rate was higher in the Stab1-knockout mice than in the wild-type mice, and STAB-1 deficiency was related to reduced macrophage-mediated efferocytosis and the disruption of vascular integrity, which increased vascular permeability, and enhanced TEM. STAB-1 deficiency promoted lung injury, and elevated the expression of sepsis markers. The exogenous application of the anti-HMGB1 neutralizing antibody improved efferocytosis, vascular integrity and survival rate in sepsis. Collectively, our findings indicated that STAB-1 regulated and maintained vascular integrity through the clearance of infected apoptotic endothelial cells. Moreover, our results suggested that interventions targeting vascular integrity by STAB-1 signalling are promising therapeutic approaches to sepsis.

2009 ◽  
Vol 102 (08) ◽  
pp. 352-359 ◽  
Author(s):  
Haichao Wang ◽  
Yiting Tang ◽  
Zhang Fan ◽  
Ben Lv ◽  
Xianzhong Xiao ◽  
...  

SummaryHigh-mobility group box 1 protein (HMGB1), an abundant nuclear protein, was recently established as a proinflammatory mediator of experimental sepsis.Although extracellular HMGB1 has been found in atherosclerotic plaques, its potential role in the pathogenesis of atherothrombosis remains elusive. In the present study, we determined whether HMGB1 induces tissue factor (TF) expression in vascular endothelial cells (ECs) and macrophages. Our data showed that HMGB1 stimulated ECs to express TF (but not TF pathway inhibitor) mRNA and protein in a concentration and time-dependent manner. Blockade of cell surface receptors (including TLR4, TLR2, and RAGE) with specific neutralising antibodies partially reduced HMGB1-induced TF expression. Moreover, HMGB1 increased expression of Egr-1 and nuclear translocation of NF-κB (c-Rel/p65) in ECs. Taken together, our data suggest that HMGB1 induces TF expression in vascular endothelial cells via cell surface receptors (TLR4, TLR2, and RAGE), and through activation of transcription factors (NF-κB and Egr-1).


2017 ◽  
Vol 45 (06) ◽  
pp. 1253-1271 ◽  
Author(s):  
In-Chul Lee ◽  
Dae Yong Kim ◽  
Jong-Sup Bae

Sulforaphane (SFN), a natural isothiocyanate present in cruciferous vegetables such as broccoli and cabbage, is effective in preventing carcinogenesis, diabetes, and inflammatory responses. Inhibition of high mobility group box 1 (HMGB1) and restoration of endothelial integrity is emerging as an attractive therapeutic strategy in the management of severe sepsis or septic shock. In this study, we examined the effects of SFN on HMGB1-mediated septic responses and survival rate in a mouse sepsis model. The anti-inflammatory activities of SFN were monitored based on its effects on lipopolysaccharide (LPS)- or cecal ligation and puncture (CLP)-mediated release of HMGB1. The antiseptic activities of SFN were determined by measuring permeability, leukocyte adhesion and migration, and the activation of pro-inflammatory proteins in HMGB1-activated human umbilical vein endothelial cells (HUVECs) and mice. SFN inhibited the release of HMGB1 and downregulated HMGB1-dependent inflammatory responses in human endothelial cells. SFN also inhibited HMGB1-mediated hyperpermeability and leukocyte migration in mice. In addition, treatment with SFN reduced CLP-induced release of HMGB1 and sepsis-related mortality and pulmonary injury in vivo. Our results indicate that SFN is a possible therapeutic agent that can be used to treat various severe vascular inflammatory diseases via the inhibition of the HMGB1 signaling pathway.


2019 ◽  
Author(s):  
Shangze Gao ◽  
Hidenori Wake ◽  
Masakiyo Sakaguchi ◽  
Dengli Wang ◽  
Youhei Takahashi ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jun-ichi Takino ◽  
Takuma Sato ◽  
Takumi Kanetaka ◽  
Kasumi Okihara ◽  
Kentaro Nagamine ◽  
...  

AbstractAdvanced glycation end-products (AGEs) are formed by the non-enzymatic reaction of sugars and proteins. Among the AGEs, glyceraldehyde-derived toxic AGEs (TAGE) are associated with various diseases, including diabetic complications such as diabetic retinopathy (DR). The risk of developing DR is strongly associated with poor glycemic control, which causes AGE accumulation and increases AGE-induced vascular permeability. We previously reported that Ras guanyl nucleotide releasing protein 2 (RasGRP2), which activates small G proteins, may play an essential role in the cell response to toxicity when exposed to various factors. However, it is not known whether RasGRP2 prevents the adverse effects of TAGE in vascular endothelial cells. This study observed that TAGE enhanced vascular permeability by disrupting adherens junctions and tight junctions via complex signaling, such as ROS and non-ROS pathways. In particular, RasGRP2 protected adherens junction disruption, thereby suppressing vascular hyper-permeability. These results indicate that RasGRP2 is an essential protective factor of vascular permeability and may help develop novel therapeutic strategies for AGE-induced DR.


Author(s):  
Tatsuro Saruga ◽  
Tadaatsu Imaizumi ◽  
Shogo Kawaguchi ◽  
Kazuhiko Seya ◽  
Tomoh Matsumiya ◽  
...  

AbstractC-X-C motif chemokine 10 (CXCL10) is an inflammatory chemokine and a key molecule in the pathogenesis of rheumatoid arthritis (RA). Melanoma differentiation-associated gene 5 (MDA5) is an RNA helicase that plays a role in innate immune and inflammatory reactions. The details of the regulatory mechanisms of CXCL10 production and the precise role of MDA5 in RA synovitis have not been fully elucidated. The aim of this study was to examine the role of MDA5 in regulating CXCL10 expression in cultured human rheumatoid fibroblast-like synoviocytes (RFLS). RFLS was stimulated with Toll-like receptor 3 (TLR3) ligand polyinosinic:polycytidylic acid (poly I:C), a synthetic double-stranded RNA mimetic. Expression of interferon beta (IFN-β), MDA5, and CXCL10 was measured by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), western blotting, and enzyme-linked immunosorbent assay. A neutralizing antibody of IFN-β and siRNA-mediated MDA5 knockdown were used to determine the role of these molecules in regulating CXCL10 expression downstream of TLR3 signaling in RFLS. Poly I:C induced IFN-β, MDA5, and CXCL10 expression in a concentration- and time-dependent manner. IFN-β neutralizing antibody suppressed the expression of MDA5 and CXCL10, and knockdown of MDA5 decreased a part of CXCL10 expression (p < 0.001). The TLR3/IFN-β/CXCL10 axis may play a crucial role in the inflammatory responses in RA synovium, and MDA5 may be partially involved in this axis.


2021 ◽  
Author(s):  
Yi-Ting Yeh ◽  
Danielle E. Skinner ◽  
Ernesto Criado-Hidalgo ◽  
Natalie Shee Chen ◽  
Antoni Garcia-De Herreros ◽  
...  

AbstractThe eggs of the parasitic blood fluke, Schistosoma, are the main drivers of the chronic pathologies associated with schistosomiasis, a disease of poverty afflicting approximately 220 million people worldwide. Eggs laid by Schistosoma mansoni in the bloodstream of the host are encapsulated by vascular endothelial cells (VECs), the first step in the migration of the egg from the blood stream into the lumen of the gut and eventual exit from the body. The biomechanics associated with encapsulation and extravasation of the egg are poorly understood. We demonstrate that S. mansoni eggs induce VECs to form two types of membrane extensions during encapsulation; filopodia that probe eggshell surfaces and intercellular nanotubes that presumably facilitate VEC communication. Encapsulation efficiency, the number of filopodia and intercellular nanotubes, and the length of these structures depend on the egg’s vitality and, to a lesser degree, its maturation state. During encapsulation, live eggs induce VEC contractility and membranous structures formation, in a Rho/ROCK pathway-dependent manner. Using elastic hydrogels embedded with fluorescent microbeads as substrates to culture VECs, live eggs induce VECs to exert significantly greater contractile forces during encapsulation than dead eggs, which leads to 3D deformations on both the VEC monolayer and the flexible substrate underneath. These significant mechanical deformations cause the VEC monolayer tension to fluctuate with eventual rupture of VEC junctions, thus facilitating egg transit out of the blood vessel. Overall, our data on the mechanical interplay between host VECs and the schistosome egg improve our understanding of how this parasite manipulates its immediate environment to maintain disease transmission.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Purum Kang ◽  
Seung Ho Han ◽  
Hea Kyung Moon ◽  
Jeong-Min Lee ◽  
Hyo-Keun Kim ◽  
...  

The purpose of the present study is to examine the effects of essential oil ofCitrus bergamiaRisso (bergamot, BEO) on intracellular Ca2+in human umbilical vein endothelial cells. Fura-2 fluorescence was used to examine changes in intracellular Ca2+concentration[Ca2+]i. In the presence of extracellular Ca2+, BEO increased[Ca2+]i, which was partially inhibited by a nonselective Ca2+channel blocker La3+. In Ca2+-free extracellular solutions, BEO increased[Ca2+]iin a concentration-dependent manner, suggesting that BEO mobilizes intracellular Ca2+. BEO-induced[Ca2+]iincrease was partially inhibited by a Ca2+-induced Ca2+release inhibitor dantrolene, a phospholipase C inhibitor U73122, and an inositol 1,4,5-triphosphate (IP3)-gated Ca2+channel blocker, 2-aminoethoxydiphenyl borane (2-APB). BEO also increased[Ca2+]iin the presence of carbonyl cyanide m-chlorophenylhydrazone, an inhibitor of mitochondrial Ca2+uptake. In addition, store-operated Ca2+entry (SOC) was potentiated by BEO. These results suggest that BEO mobilizes Ca2+from primary intracellular stores via Ca2+-induced and IP3-mediated Ca2+release and affect promotion of Ca2+influx, likely via an SOC mechanism.


1993 ◽  
Vol 264 (5) ◽  
pp. H1493-H1497 ◽  
Author(s):  
M. Grafe ◽  
C. Bossaller ◽  
K. Graf ◽  
W. Auch-Schwelk ◽  
C. R. Baumgarten ◽  
...  

The degradation of bradykinin by angiotensin-converting-enzyme (ACE) activity in cultured human endothelial cells was studied by direct measurement of bradykinin and by its effect on the release of endothelium-derived relaxing factors. The half-life of exogenous bradykinin (10,000 pg/ml) was calculated from the decay of the bradykinin concentration as 46 +/- 2 min in cell monolayers, 133 +/- 15 min in conditioned medium, and 24 +/- 2 min in homogenates. Most of the bradykinin-degrading activity in cell monolayers could be inhibited in a concentration-dependent manner by the ACE inhibitors lisinopril, ramiprilat, and captopril. Bradykinin-degrading activity was released into the culture medium containing one-fourth of the bradykinin-degrading activity found in the presence of cell monolayers. In cell homogenates higher unspecific bradykinin-degrading activities were present. The functional consequence of bradykinin degradation was demonstrated by the potentiating effect of ramiprilat on the generation of endothelium-derived relaxing factors nitric oxide and prostacyclin from endothelial cells. The study supports the concept of increased vasodilatory effects of bradykinin during ACE inhibition.


2016 ◽  
Vol 38 (6) ◽  
pp. 2139-2151 ◽  
Author(s):  
Won Seok Yang ◽  
Nam Jeong Han ◽  
Jin Ju Kim ◽  
Mee Jeong Lee ◽  
Su-Kil Park

Background/Aims: Toll-like receptor 4 (TLR4) interacts with endogenous substances as well as lipopolysaccharide. We explored whether TLR4 is implicated in tumor necrosis factor-α (TNF-α) signal transduction in human aortic endothelial cells. Methods: The pathway was evaluated by transfection of siRNAs, immunoprecipitation and Western blot analysis. Results: TNF-α activated spleen tyrosine kinase (Syk) within 10 min, which led to endothelin-1 (ET-1) production. TLR4 was also rapidly activated by TNF-α stimulation, as shown by recruitment of interleukin-1 receptor-associated kinase 1 to TLR4 and its adaptor molecule, myeloid differentiation factor 88 (MyD88). siRNA depletion of TLR4 markedly attenuated TNF-α-induced Syk activation and ET-1 production. TLR4 inhibitor (CLI-095), TLR4-neutralizing antibody and siRNA depletion of MyD88 also attenuated TNF-α-induced Syk activation. Syk was co-immunoprecipitated with TLR4, and TNF-α activated Syk bound to TLR4. High-mobility group box 1 (HMGB1) was rapidly released and associated with TLR4 after TNF-α stimulation with a peak at 5 min, which was prevented by N-acetylcysteine, an antioxidant. Glycyrrhizin (HMGB1 inhibitor), HMGB1-neutralizing antibody and siRNA depletion of HMGB1 all suppressed TNF-α-induced Syk activation and ET-1 production. Conclusion: Upon TNF-α stimulation, TLR4 is activated by HMGB1 that is immediately released after the generation of reactive oxygen species, and plays a crucial role in the signal transduction.


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