scholarly journals MiR-126-HMGB1-HIF-1 Axis Regulates Endothelial Cell Inflammation during Exposure to Hypoxia-Acidosis

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Jinxue Liu ◽  
Eileen Wei ◽  
Jianqin Wei ◽  
Wei Zhou ◽  
Keith A. Webster ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Inflammatory Responses ◽  
Hypoxia Inducible Factor ◽  
High Mobility ◽  
Vascular Diseases ◽  
B Cell Lymphoma ◽  
Low Flow ◽  
Luciferase Reporter ◽  
Primary Mouse ◽  
Enhanced Expression

Crosstalk between molecular regulators miR-126, hypoxia-inducible factor 1-alpha (HIF-1-α), and high-mobility group box-1 (HMGB1) contributes to the regulation of inflammation and angiogenesis in multiple physiological and pathophysiological settings. Here, we present evidence of an overriding role for miR-126 in the regulation of HMGB1 and its downstream proinflammatory effectors in endothelial cells subjected to hypoxia with concurrent acidosis (H/A). Methods. Primary mouse endothelial cells (PMEC) were exposed to hypoxia or H/A to simulate short or chronic low-flow ischemia, respectively. RT-qPCR quantified mRNA transcripts, and proteins were measured by western blot. ROS were quantified by fluorogenic ELISA and luciferase reporter assays employed to confirm an active miR-126 target in the HMGB1 3 ′ UTR. Results. Enhanced expression of miR-126 in PMECs cultured under neutral hypoxia was suppressed under H/A, whereas the HMGB1 expression increased sequentially under both conditions. Enhanced expression of HMGB1 and downstream inflammation markers was blocked by the premiR-126 overexpression and optimized by antagomiR. Compared with neutral hypoxia, H/A suppressed the HIF-1α expression independently of miR-126. The results show that HMGB1 and downstream effectors are optimally induced by H/A relative to neutral hypoxia via crosstalk between hypoxia signaling, miR-126, and HIF-1α, whereas B-cell lymphoma 2(Bcl2), a HIF-1α, and miR-126 regulated gene expressed optimally under neutral hypoxia. Conclusion. Inflammatory responses of ECs to H/A are dynamically regulated by the combined actions of hypoxia, miR-126, and HIF-1α on the master regulator HMGB1. The findings may be relevant to vascular diseases including atherosclerotic occlusion and interiors of plaque where coexisting hypoxia and acidosis promote inflammation as a defining etiology.

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 ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Survival Rate ◽  
Vascular Permeability ◽  
Inflammatory Responses ◽  
Vascular Endothelial Cells ◽  
High Mobility ◽  
Neutralizing Antibody ◽  
Dependent Manner ◽  
Vascular Integrity ◽  
In The Wild

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.

Abstract 267: Hemoglobin, Endothelial Cells, and TLRs. Common Connection?

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Christina Lisk ◽  
David Irwin
Keyword(s):  
Endothelial Cells ◽  
Messenger Rna ◽  
Time Course ◽  
Vascular Endothelial Cells ◽  
Vascular Diseases ◽  
Luciferase Reporter ◽  
Signaling Cascade ◽  
Pulmonary Vascular Disease ◽  
Luciferase Reporter Gene ◽  
Pulmonary Arterial

Introduction: Patients suffering from chronic hereditary hemolytic anemic syndromes, such as sickle cell disease (SCD) and thalassemia, are often at risk for systemic and pulmonary vascular disease. It has been suggested that chronic exposure to cell free hemoglobin (CFH) may contribute to some vascular diseases associated with these syndromes such as pulmonary arterial hypertension. To date, the vasculotoxic effects of CFH have mostly been attributed to its pro-oxidant and nitric oxide scavenging characteristics. However, emerging evidence suggests CFH may contribute to inflammation by directly activating a signaling cascade event by binding to a pattern recognition receptor (PRR) or a toll like receptor (TLR) on vascular endothelial cells. Hypothesis: We hypothesized that CFH would increase the activity of transcription factors, NF-κb and HIF-1α, via a MyD88-dependent pathway. Methods: Human microvascular endothelial cells (HMEC) were transfected with either an NF-κB or HIF-1α luciferase reporter gene and treated with CFH (ferrous, ferric, and ferryl forms) in the presence or absence of SOD, catalase, dexamethasome, MyD88 inhibitor, or, the PHD inhibitor, DMOG. Messenger RNA for HIF-1α and HIF-2 were also measured after treatments. Results: All three states of hemoglobin increased NF-κB and HIF-1α activity in a dose response fashion, with ferryl inducing the greatest activity of both NF-κB and HIF-1α. Time course studies showed that NF-κB and HIF-1α activity tracked together. A unique synergy was noted with co-treatment of ferryl and DMOG. Co-treatment with SOD or catalase did not inhibit the CFH-induced NF-κB or HIF-1α response. Dexamthasome and MyD88 inhibition reduced the CFH-induced NF-κB and HIF-1α activity. Conclusion: Our results support the hypothesis, that CFH may activate a TLR or PRR signaling cascade subsequently activating MyD88-NF-κB and HIF-1α. Our data, that showed SOD and/or catalase did not block CFH effects, suggests that this event is not mediated by CFH pro-oxidant characteristics. CFH-induced HIF-1α was blocked by NF-κB inhibition with either, Dexamethasome or MyD88 inhibition emphasizing the importance of NF-κB in the HIF-1α pathway.

Mediators released from LPS-challenged lungs induce inflammatory responses in liver vascular endothelial cells and neutrophilic leukocytes

2009 ◽  
Vol 297 (6) ◽  
pp. G1066-G1076 ◽  
Author(s):  
N. Markovic ◽  
L. A. McCaig ◽  
J. Stephen ◽  
S. Mizuguchi ◽  
R. A. W. Veldhuizen ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Inflammatory Response ◽  
Inflammatory Responses ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial ◽  
Ros Production ◽  
Proinflammatory Mediators ◽  
Primary Mouse ◽  
Mouse Lungs

The systemic inflammatory response plays an important role in the progression of acute lung injury (ALI) to multiple organ dysfunction syndrome (MODS). However, the role of lung-derived inflammatory mediators in induction of the inflammatory response in remote organs is poorly understood. To address the above, we investigated the effects of lung inflammation on induction of inflammatory response(s) in the liver in vitro. Inflammation in mouse lungs was induced by intranasal administration of lipopolysaccharide (LPS; 1 mg/ml) followed by mechanical ventilation using the isolated perfused mouse lung method to obtain and characterize lung perfusate from the pulmonary circulation. LPS administration to mouse lungs resulted in an increased release of inflammation-relevant cytokines and chemokines into the perfusate (Luminex assay) compared with the saline-controls. Subsequently, primary mouse liver vascular endothelial cells (LVEC) or mouse polymorphonuclear leukocytes (PMN) in vitro were stimulated with the perfusate obtained from saline- or LPS-challenged lungs and assessed for various inflammation-relevant end points. The obtained results indicate that stimulation of LVEC with perfusate obtained from LPS-challenged lungs results in 1) reactive oxygen species (ROS) production; 2) activation of NF-κB; and 3) expression of E-selectin, ICAM-1, and VCAM-1 and a subsequent increase in PMN rolling and adhesion to LVEC. In addition, perfusate from LPS-challenged lung induced activation of PMN with respect to increased ROS production and upregulation of cell surface levels of adhesion molecules MAC-1 and VLA-4. Heat-inactivation of the perfusate obtained from LPS-challenged lungs was very effective in suppressing increased proadhesive phenotype (i.e., E-selectin and ICAM-1 expression) in LVEC, whereas targeted inhibition (immunoneutralization) of TNF-α and/or IL-6 in LPS-lung perfusate had no effect. Taken together, these findings indicate that multiple proinflammatory mediators (proteinaceous in nature) released from inflamed lungs act synergistically to induce systemic activation of circulating PMN and promote inflammatory responses in liver vascular endothelial cells.

Ketamine attenuates high mobility group box-1–induced inflammatory responses in endothelial cells

2016 ◽  
Vol 200 (2) ◽  
pp. 593-603 ◽  
Author(s):  
Zhaohui Liu ◽  
Zhengping Wang ◽  
Guangwei Han ◽  
Lina Huang ◽  
Jihong Jiang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Inflammatory Responses ◽  
High Mobility ◽  
High Mobility Group

scholarly journals Cell-Type-Specific Regulation of Degradation of Hypoxia-Inducible Factor 1α: Role of Subcellular Compartmentalization

2006 ◽  
Vol 26 (12) ◽  
pp. 4628-4641 ◽  
Author(s):  
Xiaowei Zheng ◽  
Jorge L. Ruas ◽  
Renhai Cao ◽  
Florian A. Salomons ◽  
Yihai Cao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Fluorescent Protein ◽  
Hypoxia Inducible Factor ◽  
Cell Type ◽  
Distinct Cell Type ◽  
Hypoxia Inducible Factor 1Α ◽  
Primary Mouse ◽  
Cell Type Specific ◽  
Subcellular Compartmentalization ◽  
Specific Regulation

ABSTRACT The hypoxia-inducible factor-1α (HIF-1α) is a transcription factor that mediates adaptive cellular responses to decreased oxygen availability (hypoxia). At normoxia, HIF-1α is targeted by the von Hippel-Lindau tumor suppressor protein (pVHL) for degradation by the ubiquitin-proteasome pathway. In the present study we have observed distinct cell-type-specific differences in the ability of various tested pVHL-interacting subfragments to stabilize HIF-1α and unmask its function at normoxia. These properties correlated with differences in subcellular compartmentalization and degradation of HIF-1α. We observed that the absence or presence of nuclear localization or export signals differently affected the ability of a minimal HIF-1α peptide spanning residues 559 to 573 of mouse HIF-1α to stabilize endogenous HIFα and induce HIF-driven reporter gene activity in two different cell types (primary mouse endothelial and HepG2 hepatoma cells). Degradation of HIF-1α occurred mainly in the cytoplasm of HepG2 cells, whereas it occurs with equal efficiency in nuclear and cytoplasmic compartments of primary endothelial cells. Consistent with these observations, green fluorescent protein-HIF-1α is differently distributed during hypoxia and reoxygenation in hepatoma and endothelial cells. Consequently, we propose that differential compartmentalization of degradation of HIF-1α and the subcellular distribution of HIF-1α may account for cell-type-specific differences in stabilizing HIF-1α protein levels under hypoxic conditions.

Cellular response to hypoxia involves signaling via Smad proteins

Blood ◽  
2003 ◽  
Vol 101 (6) ◽  
pp. 2253-2260 ◽  
Author(s):  
Hong Zhang ◽  
Hasan O. Akman ◽  
Eric L. P. Smith ◽  
Jin Zhao ◽  
Joanne E. Murphy-Ullrich ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Cellular Response ◽  
Transforming Growth Factor ◽  
Inflammatory Responses ◽  
Umbilical Vein ◽  
Hypoxia Inducible Factor ◽  
Transforming Growth Factor Β ◽  
Smad Proteins ◽  
Umbilical Vein Endothelial Cells

The transforming growth factor-β (TGF-β) family of cytokines regulates vascular development and inflammatory responses. We have recently shown that exposure of human umbilical vein endothelial cells (HUVECs) to hypoxia (1% O2) increases gene expression and bioactivation of TGF-β2 and induces its downstream effectors, Smad proteins (Smads), to associate with DNA. In the present study, we show that hypoxia-induced TGF-β2 gene expression is dependent on thrombospondin-1–mediated bioactivation of latent TGF-β. Blocking TGF-β2 but not TGF-β1 in hypoxic endothelial cell cultures inhibited induction of the TGF-β2 gene, indicating that an autocrine mechanism driven by bioactivation of TGF-β2 leads to its gene expression in hypoxic HUVECs. Exposure of HUVECs to hypoxia resulted in phosphorylation and nuclear transportation of Smad2 and Smad3 proteins as well as stimulation of transcriptional activities of Smad3 and the transcription factor hypoxia-inducible factor-1α and culminated in up-regulation of TGF-β2 gene expression. Autocrine regulation of TGF-β2 production in hypoxia may involve cross-talk between Smad3 and HIF-1α signaling pathways, and could be an important mechanism by which endothelial cells respond to hypoxic stress.

HMGB1 contributes to the development of acute lung injury after hemorrhage

2005 ◽  
Vol 288 (5) ◽  
pp. L958-L965 ◽  
Author(s):  
Jae Yeol Kim ◽  
Jong Sung Park ◽  
Derek Strassheim ◽  
Ivor Douglas ◽  
Fernando Diaz del Valle ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Blood Loss ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Plasma Concentrations ◽  
High Mobility ◽  
Pulmonary Endothelial Cells ◽  
Hmgb1 Expression

High mobility group box 1 (HMGB1) is a novel late mediator of inflammatory responses that contributes to endotoxin-induced acute lung injury and sepsis-associated lethality. Although acute lung injury is a frequent complication of severe blood loss, the contribution of HMGB1 to organ system dysfunction in this setting has not been investigated. In this study, HMGB1 was detected in pulmonary endothelial cells and macrophages under baseline conditions. After hemorrhage, in addition to positively staining endothelial cells and macrophages, neutrophils expressing HMGB1 were present in the lungs. HMGB1 expression in the lung was found to be increased within 4 h of hemorrhage and then remained elevated for more than 72 h after blood loss. Neutrophils appeared to contribute to the increase in posthemorrhage pulmonary HMGB1 expression since no change in lung HMGB1 levels was found after hemorrhage in mice made neutropenic with cyclophosphamide. Plasma concentrations of HMGB1 also increased after hemorrhage. Blockade of HMGB1 by administration of anti-HMGB1 antibodies prevented hemorrhage-induced increases in nuclear translocation of NF-κB in the lungs and pulmonary levels of proinflammatory cytokines, including keratinocyte-derived chemokine, IL-6, and IL-1β. Similarly, both the accumulation of neutrophils in the lung as well as enhanced lung permeability were reduced when anti-HMGB1 antibodies were injected after hemorrhage. These results demonstrate that hemorrhage results in increased HMGB1 expression in the lungs, primarily through neutrophil sources, and that HMGB1 participates in hemorrhage-induced acute lung injury.

Sulforaphane Reduces HMGB1-Mediated Septic Responses and Improves Survival Rate in Septic Mice

2017 ◽  
Vol 45 (06) ◽  
pp. 1253-1271 ◽  
Author(s):  
In-Chul Lee ◽  
Dae Yong Kim ◽  
Jong-Sup Bae
Keyword(s):  
Endothelial Cells ◽  
Survival Rate ◽  
Inflammatory Responses ◽  
Inflammatory Diseases ◽  
Leukocyte Adhesion ◽  
Umbilical Vein ◽  
Cecal Ligation ◽  
High Mobility ◽  
Umbilical Vein Endothelial Cells

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.

scholarly journals Epac1 Blocks NLRP3 Inflammasome to Reduce IL-1βin Retinal Endothelial Cells and Mouse Retinal Vasculature

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Youde Jiang ◽  
Li Liu ◽  
Elizabeth Curtiss ◽  
Jena J. Steinle
Keyword(s):  
Endothelial Cells ◽  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Inflammatory Responses ◽  
Interleukin 1 ◽  
High Mobility ◽  
Conditional Knockout ◽  
Retinal Vasculature ◽  
Retinal Endothelial Cells ◽  
Caspase 1

Inflammation is an important component of diabetic retinal damage. We previously reported that a novelβ-adrenergic receptor agonist, Compound 49b, reduced Toll-like receptor 4 (TLR4) signaling in retinal endothelial cells (REC) grown in high glucose. Others reported that TLR4 activates high-mobility group box 1 (HMGB1), which has been associated with the NOD-like receptor 3 (NLRP3) inflammasome. Thus, we hypothesized that Epac1, a downstream mediator ofβ-adrenergic receptors, would block TLR4/HMGB1-mediated stimulation of the NLRP3 inflammasome, leading to reduced cleavage of caspase-1 and interleukin-1 beta (IL-1β). We generated vascular specific conditional knockout mice for Epac1 and used REC grown in normal and high glucose treated with an Epac1 agonist and/or NLRP3 siRNA. Protein analyses were done for Epac1, TLR4, HMGB1, NLRP3, cleaved caspase-1, and IL-1β. Loss of Epac1 in the mouse retinal vasculature significantly increased all of the inflammatory proteins. Epac1 effectively reduced high glucose-induced increases in TLR4, HMGB1, cleaved caspase-1, and IL-1βin REC. Taken together, the data suggest that Epac1 reduces formation of the NLRP3 inflammasome to reduce inflammatory responses in the retinal vasculature.

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