scholarly journals Basal and angiopoietin-1–mediated endothelial permeability is regulated by sphingosine kinase-1

Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3489-3497 ◽  
Author(s):  
Xiaochun Li ◽  
Milena Stankovic ◽  
Claudine S. Bonder ◽  
Christopher N. Hahn ◽  
Michelle Parsons ◽  
...  
Keyword(s):  
Endothelial Permeability ◽  
Sphingosine Kinase ◽  
Dominant Negative ◽  
Sphingosine Kinase 1 ◽  
Sphingosine 1 Phosphate ◽  
Functional States ◽  
Interfering Rna ◽  
Angiopoietin 1

Abstract Endothelial cells (ECs) regulate the barrier function of blood vessels. Here we show that basal and angiopoietin-1 (Ang-1)–regulated control of EC permeability is mediated by 2 different functional states of sphingosine kinase-1 (SK-1). Mice depleted of SK-1 have increased vascular leakiness, whereas mice transgenic for SK-1 in ECs show attenuation of leakiness. Furthermore, Ang-1 rapidly and transiently stimulates SK-1 activity and phosphorylation, and induces an increase in intracellular sphingosine-1-phosphate (S1P) concentration. Overexpression of SK-1 resulted in inhibition of permeability similar to that seen for Ang-1, whereas knockdown of SK-1 by small interfering RNA blocked Ang-1-mediated inhibition of permeability. Transfection with SKS225A, a nonphosphorylatable mutant of SK-1, inhibited basal leakiness, and both SKS225A and a dominant-negative SK-1 mutant removed the capacity of Ang-1 to inhibit permeability. These effects were independent of extracellular S1P as knockdown or inhibition of S1P1, S1P2, or S1P3, did not affect the Ang-1 response. Thus, SK-1 levels in ECs powerfully regulate basal permeability in vitro and in vivo. In addition, the Ang-1–induced inhibition of leakiness is mediated through activation of SK-1, defining a new signaling pathway in the Ang-1 regulation of permeability.

scholarly journals Active Rac1 improves pathologic VEGF neovessel architecture and reduces vascular leak: mechanistic similarities with angiopoietin-1

Blood ◽  
2011 ◽  
Vol 117 (5) ◽  
pp. 1751-1760 ◽  
Author(s):  
Mien V. Hoang ◽  
Janice A. Nagy ◽  
Donald R. Senger
Keyword(s):  
Dominant Negative ◽  
Vascular Endothelial ◽  
Cortical Actin ◽  
Rac1 Activity ◽  
Cytoskeletal Dynamics ◽  
Sphingosine 1 Phosphate ◽  
Endothelial Growth Factor ◽  
Angiopoietin 1

Abstract Architecturally defective, leaky blood vessels typify pathologic angiogenesis induced by vascular endothelial growth factor-A (VEGF-A). Such neovascular defects aggravate disease pathology and seriously compromise the therapeutic utility of VEGF. Endothelial cell (EC) transduction with active L61Rac1 strongly improved VEGF-driven angiogenesis in vivo as measured by increased neovascular density, enhanced lumen formation, and reduced vessel leakiness. Conversely, transduction with dominant-negative N17Rac1 strongly inhibited neovascularization. In vitro, active L61Rac1 promoted organization of cortical actin filaments and vascular cords and improved EC-EC junctions, indicating that improved cytoskeletal dynamics are important to the mechanism by which active L61Rac1 rectifies VEGF-driven angiogenesis. SEW2871, a sphingosine 1-phosphate receptor-1 agonist that activates Rac1 in ECs, improved cord formation and EC-EC junctions in vitro similarly to active L61Rac. Moreover, SEW2871 administration in vivo markedly improved VEGF neovessel architecture and reduced neovascular leak. Angiopoietin-1, a cytokine that “normalizes” VEGF neovessels in vivo, activated Rac1 and improved cord formation and EC-EC junctions in vitro comparably to active L61Rac1, and a specific Rac1 inhibitor blocked these effects. These studies distinguish augmentation of Rac1 activity as a means to rectify the pathologic angioarchitecture and dysfunctionality of VEGF neovessels, and they identify a rational pharmacologic strategy for improving VEGF angiogenesis.

scholarly journals Leucine-rich Repeats and Immunoglobulin 1 (LRIG1) Ameliorates Liver Fibrosis and Hepatic Stellate Cell Activation via Inhibiting Sphingosine Kinase 1 (SphK1)/Sphingosine-1-Phosphate (S1P) Pathway

2020 ◽  
Author(s):  
Wei Zhan ◽  
Xin Liao ◽  
Zhongsheng Chen ◽  
Lianghe Li ◽  
Tian Tian ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Hepatic Stellate Cell ◽  
Stellate Cell ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Sphingosine 1 Phosphate ◽  
Leucine Rich Repeats ◽  
Tgf Β1

To detect the leucine-rich repeats and immunoglobulin 1 (LRIG1) ameliorated liver fibrosis and hepatic stellate cell (HSC) activation via inhibiting sphingosine kinase 1 (SphK1)/Sphingosine-1-Phosphate (S1P) pathway. C57BL/6 male mice (eight weeks old) were intraperitoneal injection with 10% carbon tetrachloride (CCl4) as an in vivo model. The LX-2 cells were induced as amodel for in vitro study by TGF-β (10 ng/mL). The Hematoxylin-eosin (HE) staining, Masson staining, and Sirius red staining results showed that CCl4 caused serious fibrosis and injury in liver tissue, high expression of type I collagen α1 chain (Col1α1) and α-smooth muscle actin (α-SMA) in liver tissue, while the LRIG1 expression level was significantly decreased in LX-2 cell lines. The LRIG1 ameliorated CCl4-induced liver fibrosis, indicated by the fibronectin, α-SMA, LRIG1, SphK1, Col1α1, fibrin Connexin 1 (Fn1), tissue inhibitor of metalloproteinase-1 (TIMP1), sphingosine-1-phosphate (S1P), transforming growth factor-beta 1 (TGF-β1) expression level changes. Similar results were observed in TGF-β1 treated of LX-2 cells. However, the effects were attenuated by treatment with LRIG1. Moreover, SphK1 inhibitors abrogated the effect of LRIG1 on fibrosis. These results demonstrated that LRIG1 improved liver fibrosis in vitro and in vivo via suppressing the SphK1/S1P pathway, indicating its potential use in the treatment of liver fibrosis.

Sphingosine kinase 1 regulates lysyl oxidase through STAT3 in hyperoxia-mediated neonatal lung injury

Thorax ◽  
2021 ◽  
pp. thoraxjnl-2020-216469
Author(s):  
Alison W Ha ◽  
Tao Bai ◽  
David L Ebenezer ◽  
Tanvi Sethi ◽  
Tara Sudhadevi ◽  
...  
Keyword(s):  
Lung Injury ◽  
Lysyl Oxidase ◽  
Critical Role ◽  
Sphingosine Kinase ◽  
In Vivo Studies ◽  
Sphingosine Kinase 1 ◽  
Neonatal Lung ◽  
Neonatal Lung Injury

IntroductionNeonatal lung injury as a consequence of hyperoxia (HO) therapy and ventilator care contribute to the development of bronchopulmonary dysplasia (BPD). Increased expression and activity of lysyl oxidase (LOX), a key enzyme that cross-links collagen, was associated with increased sphingosine kinase 1 (SPHK1) in human BPD. We, therefore, examined closely the link between LOX and SPHK1 in BPD.MethodThe enzyme expression of SPHK1 and LOX were assessed in lung tissues of human BPD using immunohistochemistry and quantified (Halo). In vivo studies were based on Sphk1−/− and matched wild type (WT) neonatal mice exposed to HO while treated with PF543, an inhibitor of SPHK1. In vitro mechanistic studies used human lung microvascular endothelial cells (HLMVECs).ResultsBoth SPHK1 and LOX expressions were increased in lungs of patients with BPD. Tracheal aspirates from patients with BPD had increased LOX, correlating with sphingosine-1-phosphate (S1P) levels. HO-induced increase of LOX in lungs were attenuated in both Sphk1−/− and PF543-treated WT mice, accompanied by reduced collagen staining (sirius red). PF543 reduced LOX activity in both bronchoalveolar lavage fluid and supernatant of HLMVECs following HO. In silico analysis revealed STAT3 as a potential transcriptional regulator of LOX. In HLMVECs, following HO, ChIP assay confirmed increased STAT3 binding to LOX promoter. SPHK1 inhibition reduced phosphorylation of STAT3. Antibody to S1P and siRNA against SPNS2, S1P receptor 1 (S1P1) and STAT3 reduced LOX expression.ConclusionHO-induced SPHK1/S1P signalling axis plays a critical role in transcriptional regulation of LOX expression via SPNS2, S1P1 and STAT3 in lung endothelium.

Impaired Sphingosine-1-Phosphate Synthesis Induces Preeclampsia by Deactivating Trophoblastic YAP (Yes-Associated Protein) Through S1PR2 (Sphingosine-1-Phosphate Receptor-2)-Induced Actin Polymerizations

Hypertension ◽  
2021 ◽  
Author(s):  
Jiujiang Liao ◽  
Yangxi Zheng ◽  
Mingyu Hu ◽  
Ping Xu ◽  
Li Lin ◽  
...  
Keyword(s):  
Actin Polymerization ◽  
Sphingosine Kinase ◽  
Actin Dynamics ◽  
Extravillous Trophoblast ◽  
Trophoblast Invasion ◽  
Hippo Signaling ◽  
Dependent Manner ◽  
Sphingosine Kinase 1 ◽  
Sphingosine 1 Phosphate

Incomplete spiral artery remodeling, caused by impaired extravillous trophoblast invasion, is a fundamental pathogenic process associated with malplacentation and the development of preeclampsia. Nevertheless, the mechanisms controlling this regulation of trophoblast invasion are largely unknown. We report that sphingosine-1-phosphate synthesis and expression is abundant in healthy trophoblast, whereas in pregnancies complicated by preeclampsia the placentae are associated with reduced sphingosine-1-phosphate and lower SPHK1 (sphingosine kinase 1) expression and activity. In vivo inhibition of sphingosine kinase 1 activity during placentation in pregnant mice led to decreased placental sphingosine-1-phosphate production and defective placentation, resulting in a preeclampsia phenotype. Moreover, sphingosine-1-phosphate increased HTR8/SVneo (immortalized trophoblast cells) cell invasion in a Hippo-signaling–dependent transcriptional coactivator YAP (Yes-associated protein) dependent manner, which is activated by S1PR2 (sphingosine-1-phosphate receptor-2) and downstream RhoA/ROCK induced actin polymerization. Mutation-based YAP-5SA demonstrated that sphingosine-1-phosphate activation of YAP could be either dependent or independent of Hippo signaling. Together, these findings suggest a novel pathogenic pathway of preeclampsia via disrupted sphingosine-1-phosphate metabolism and signaling-induced, interrupted actin dynamics and YAP deactivation; this may lead to potential novel intervention targets for the prevention and management of preeclampsia.

Selective inhibition of sphingosine kinase-1 protects adipose tissue against LPS-induced inflammatory response in Zucker diabetic fatty rats

2014 ◽  
Vol 307 (5) ◽  
pp. E437-E446 ◽  
Author(s):  
Monica Tous ◽  
Raquel Ferrer-Lorente ◽  
Lina Badimon
Keyword(s):  
Adipose Tissue ◽  
Inflammatory Response ◽  
Sphingosine Kinase ◽  
Selective Inhibition ◽  
Mrna Levels ◽  
Sphingosine Kinase 1 ◽  
Zucker Diabetic Fatty Rats ◽  
Cc Chemokines ◽  
Interfering Rna

Obesity is associated with a state of chronic inflammation. The chemokine (C-C motif) ligand 5 (CCL5) has been proposed to modulate the inflammatory response in adipose tissue (AT). However, the mechanisms underlying CCL5 upregulation in AT remain undefined. The objective of the present study was to evaluate whether the enzyme sphingosine kinase-1 (SK1) would modulate the expression of CCL5 and other inflammatory biomarkers in primary adipocytes and its potential role in lipopolysaccharide (LPS)-induced AT inflammation in a rat model of diabetes. To address this, LPS-stimulated primary adipocytes and 3T3-L1 cells were treated with a SK inhibitor, and the expression of Ccl5 and other CC chemokines were studied. Moreover, the effect of SK1 knockdown on cytokine production was analyzed in 3T3-L1 cells by transfection of SK1-specific small-interfering RNA (siRNA). The anti-inflammatory effects of SK inhibitor in AT were also investigated in vivo using the Zucker lean normoglycemic control (ZLC) rats. LPS treatment stimulated Ccl5, IL-6, pentraxin 3 ( Ptx3), and Tnfα mRNA expression in primary adipocytes and 3T3-L1 cells, whereas pharmacologically and siRNA-mediated SK1 inhibition strongly reduced mRNA levels of proinflammatory cytokines in these cells. Similarly, administration of SK inhibitor to ZLC rats prevented the LPS-induced inflammatory response in AT. Our data demonstrate a role for SK1 in endotoxin-induced cytokine expression in adipocytes and suggest that inhibition of SK1 may be a potential therapeutic tool in the prevention and treatment of chronic and common metabolic disorders, including obesity, insulin-resistance, and type 2 diabetes.

scholarly journals Coordinated regulation of AP2 uncoating from clathrin-coated vesicles by rab5 and hRME-6

2008 ◽  
Vol 183 (3) ◽  
pp. 499-511 ◽  
Author(s):  
Sophia Semerdjieva ◽  
Barry Shortt ◽  
Emma Maxwell ◽  
Sukhdeep Singh ◽  
Paul Fonarev ◽  
...  
Keyword(s):  
Dominant Negative ◽  
Coated Vesicles ◽  
Nucleotide Exchange ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor ◽  
Steady State Levels ◽  
Endocytic Vesicles ◽  
Interfering Rna

Here we investigate the role of rab5 and its cognate exchange factors rabex-5 and hRME-6 in the regulation of AP2 uncoating from endocytic clathrin-coated vesicles (CCVs). In vitro, we show that the rate of AP2 uncoating from CCVs is dependent on the level of functional rab5. In vivo, overexpression of dominant-negative rab5S34N, or small interfering RNA (siRNA)–mediated depletion of hRME-6, but not rabex-5, resulted in increased steady-state levels of AP2 associated with endocytic vesicles, which is consistent with reduced uncoating efficiency. hRME-6 guanine nucleotide exchange factor activity requires hRME-6 binding to α-adaptin ear, which displaces the ear-associated μ2 kinase AAK1. siRNA-mediated depletion of hRME-6 increases phospho-μ2 levels, and expression of a phosphomimetic μ2 mutant increases levels of endocytic vesicle-associated AP2. Depletion of hRME-6 or rab5S35N expression also increases the levels of phosphoinositide 4,5-bisphosphate (PtdIns(4,5)P2) associated with endocytic vesicles. These data are consistent with a model in which hRME-6 and rab5 regulate AP2 uncoating in vivo by coordinately regulating μ2 dephosphorylation and PtdIns(4,5)P2 levels in CCVs.

Sphingosine 1-Phosphate Produced by Sphingosine Kinase 2 Intrinsically Controls Platelet Aggregation In Vitro and In Vivo

2015 ◽  
Vol 117 (4) ◽  
pp. 376-387 ◽  
Author(s):  
Nicole Urtz ◽  
Florian Gaertner ◽  
Marie-Luise von Bruehl ◽  
Sue Chandraratne ◽  
Faridun Rahimi ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 2 ◽  
Sphingosine 1 Phosphate

scholarly journals Bivalirudin Attenuates Thrombin-Induced Endothelial Hyperpermeability via S1P/S1PR2 Category: Original Articles

2021 ◽  
Vol 12 ◽  
Author(s):  
Haowen Ye ◽  
Yizhi Zhang ◽  
Yihui Huang ◽  
Biao Li ◽  
Ruhao Cao ◽  
...  
Keyword(s):  
Protective Effect ◽  
Umbilical Vein ◽  
Endothelial Permeability ◽  
Control Group ◽  
Sphingosine 1 Phosphate ◽  
Organ Tissue ◽  
Probe Assay ◽  
Umbilical Vein Endothelial Cells

Aims: To explore the role of the Sphingosine 1-Phosphate (S1P)/Receptor2 (S1PR2) pathway in thrombin-induced hyperpermeability (TIP) and to test whether bivalirudin can reverse TIP via the S1P-S1PRs pathway.Methods and Results: Using western blot, we demonstrated that Human umbilical vein endothelial cells (HUVECs) that were cultured with 2 U/ml thrombin showed significantly increased S1PR2 expression while S1PR1and three kept unchanged. Such increment was attenuated by JTE-013 pretreatment and by presence of bivalirudin. Exposure of 2 U/ml of thrombin brought a higher level of S1P both intracellularly and extracellularly within the HUVECs by using ELISA detecting. Thrombin induced S1P and S1PR2 increment was restored by usage of PF543 and bivalirudin. Bivalirudin alone did not influenced the level of S1P and S1PR1,2, and S1PR3 compare to control group. As a surrogate of cytoskeleton morphology, phalloidin staining and immunofluorescence imaging were used. Blurry cell edges and intercellular vacuoles or spaces were observed along thrombin-exposed HUVECs. Presence of JTE-013 and bivalirudin attenuated such thrombin-induced permeability morphological change and presence of heparin failed to show the protective effect. Transwell chamber assay and probe assay were used to measure and compare endothelial permeability in vitro. An increased TIP was observed in HUVECs cultured with thrombin, and coculture with bivalirudin, but not heparin, alleviated this increase. JTE-013 treatment yielded to similar TIP alleviating effect. In vivo, an Evans blue assay was used to test subcutaneous and organ microvascular permeability after the treatment of saline only, thrombin + saline, thrombin + bivalirudin, thrombin + heparin or thrombin + JTE-013. Increased subcutaneous and organ tissue permeability after thrombin treatment was observed in thrombin + saline and thrombin + heparin groups while treatment of bivalirudin and JTE-013 absent this effect.Conclusion: S1P/S1PR2 mediates TIP by impairing vascular endothelial barrier function. Unlike heparin, bivalirudin effectively blocked TIP by inhibiting the thrombin-induced S1P increment and S1PR2 expression, suggesting the novel endothelial protective effect of bivalirudin under pathological procoagulant circumstance.

scholarly journals ST-2191, an Anellated Bismorpholino Derivative of Oxy-Fingolimod, Shows Selective S1P1 Agonist and Functional Antagonist Potency In Vitro and In Vivo

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5134
Author(s):  
Bisera Stepanovska Tanturovska ◽  
Aleksandra Zivkovic ◽  
Faik Imeri ◽  
Thomas Homann ◽  
Burkhard Kleuser ◽  
...  
Keyword(s):  
Sphingosine Kinase ◽  
Lymphoid Tissues ◽  
Cell Trafficking ◽  
T Cell Trafficking ◽  
Sphingosine Kinase 2 ◽  
S1p Receptors ◽  
Sphingosine 1 Phosphate ◽  
Lymphocyte Number

Sphingosine 1-phosphate (S1P) is an extensively studied signaling molecule that contributes to cell proliferation, survival, migration and other functions through binding to specific S1P receptors. The cycle of S1P1 internalization upon S1P binding and recycling to the cell surface when local S1P concentrations are low drives T cell trafficking. S1P1 modulators, such as fingolimod, disrupt this recycling by inducing persistent S1P1 internalization and receptor degradation, which results in blocked egress of T cells from the secondary lymphoid tissues. The approval of these compounds for the treatment of multiple sclerosis has placed the development of S1PR modulators in the focus of pharmacological research, mostly for autoimmune indications. Here, we report on a novel anellated bismorpholino derivative of oxy-fingolimod, named ST-2191, which exerts selective S1P1 agonist and functional antagonist potency. ST-2191 is also effective in reducing the lymphocyte number in mice, and this effect is not dependent on phosphorylation by sphingosine kinase 2 for activity. These data show that ST-2191 is a novel S1P1 modulator, but further experiments are needed to analyze the therapeutic impact of ST-2191 in animal models of autoimmune diseases.

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