Complementary effects of ciclopirox olamine, a prolyl hydroxylase inhibitor and sphingosine 1-phosphate on fibroblasts and endothelial cells in driving capillary sprouting

Endothelial activation is a key early event in vascular complications of Type 1 diabetes. The nonobese diabetic (NOD) mouse is a well-characterized model of Type 1 diabetes. We previously reported that Type 1 diabetic NOD mice have increased endothelial activation, with increased production of monocyte chemoattractant protein (MCP)-1 and IL-6, and a 30% increase of surface VCAM-1 expression leading to a fourfold increase in monocyte adhesion to the endothelium. Sphingosine-1-phosphate (S1P) prevents monocyte:endothelial interactions in these diabetic NOD mice. Incubation of diabetic NOD endothelial cells (EC) with S1P (100 nmol/l) reduced ERK1/2 phosphorylation by 90%, with no significant changes in total ERK1/2 protein. In the current study, we investigated the mechanism of S1P action on ERK1/2 to reduce activation of diabetic endothelium. S1P caused a significant threefold increase in mitogen-activated kinase phosphatase-3 (MKP-3) expression in EC. MKP-3 selectively regulates ERK1/2 activity through dephosphorylation. Incubation of diabetic NOD EC with S1P and the S1P1-selective agonist SEW2871 significantly increased expression of MKP-3 and reduced ERK1/2 phosphorylation, while incubation with the S1P1/S1P3 antagonist VPC23019 decreased the expression of MKP-3, both results supporting a role for S1P1 in MKP-3 regulation. To mimic the S1P-mediated induction of MKP-3 diabetic NOD EC, we overexpressed MKP-3 in human aortic endothelial cells (HAEC) cultured in elevated glucose (25 mmol/l). Overexpression of MKP-3 in glucose-cultured HAEC decreased ERK1/2 phosphorylation and resulted in decreased monocyte:endothelial interactions in a static monocyte adhesion assay. Finally, we used small interfering RNA to MKP-3 and observed increased monocyte adhesion. Moreover, S1P was unable to inhibit monocyte adhesion in the absence of MKP-3. Thus, one mechanism for the anti-inflammatory action of S1P in diabetic EC is inhibition of ERK1/2 phosphorylation through induction of MKP-3 expression via the S1P-S1P1 receptor axis.

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A Novel Hypoxia-Inducible Factor−Prolyl Hydroxylase Inhibitor (GSK1278863) for Anemia in CKD: A 28-Day, Phase 2A Randomized Trial

American Journal of Kidney Diseases ◽

10.1053/j.ajkd.2015.11.021 ◽

2016 ◽

Vol 67 (6) ◽

pp. 861-871 ◽

Cited By ~ 79

Author(s):

Richard A. Brigandi ◽

Brendan Johnson ◽

Coreen Oei ◽

Mark Westerman ◽

Gordana Olbina ◽

...

Keyword(s):

Randomized Trial ◽

Hypoxia Inducible Factor ◽

Prolyl Hydroxylase ◽

Prolyl Hydroxylase Inhibitor

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Distinct signals via Rho GTPases and Src drive shape changes by thrombin and sphingosine-1-phosphate in endothelial cells

Journal of Cell Science ◽

10.1242/jcs.115.12.2475 ◽

2002 ◽

Vol 115 (12) ◽

pp. 2475-2484 ◽

Cited By ~ 3

Author(s):

Valérie Vouret-Craviari ◽

Christine Bourcier ◽

Etienne Boulter ◽

Ellen Van Obberghen-Schilling

Keyword(s):

Endothelial Cells ◽

Rho Gtpases ◽

Actin Polymerization ◽

Morphological Changes ◽

Umbilical Vein ◽

Cell Spreading ◽

Actin Binding ◽

Sphingosine 1 Phosphate ◽

And Migration ◽

Umbilical Vein Endothelial Cells

Soluble mediators such as thrombin and sphingosine-1-phosphate regulate morphological changes in endothelial cells that affect vascular permeability and new blood vessel formation. Although these ligands activate a similar set of heterotrimeric G proteins, thrombin causes cell contraction and rounding whereas sphingosine-1-phosphate induces cell spreading and migration. A functional requirement for Rho family GTPases in the cytoskeletal responses to both ligands has been established, yet the dynamics of their regulation and additional signaling mechanisms that lead to such opposite effects remain poorly understood. Using a pull-down assay to monitor the activity of Rho GTPases in human umbilical vein endothelial cells, we find significant temporal and quantitative differences in RhoA and Rac1 activation. High levels of active RhoA rapidly accumulate in cells in response to thrombin whereas Rac1 is inhibited. In contrast, sphingosine-1-phosphate addition leads to comparatively weak and delayed activation of RhoA and it activates Rac1. In addition, we show here that sphingosine-1-phosphate treatment activates a Src family kinase and triggers recruitment of the F-actin-binding protein cortactin to sites of actin polymerization at the rim of membrane ruffles. Both Src and Rac pathways are essential for lamellipodia targeting of cortactin. Further, Src plays a determinant role in sphingosine-1-phosphate-induced cell spreading and migration. Taken together these data demonstrate that the thrombin-induced contractile and immobile phenotype in endothelial cells reflects both robust RhoA activation and Rac inhibition, whereas Src- and Rac-dependent events couple sphingosine-1-phosphate receptors to the actin polymerizing machinery that drives the extension of lamellipodia and cell migration.

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Abstract 1746: Insulin Like Growth Factor Binding Protein-3 (IGFBP-3) Mediates Vascular Repair By HDL Receptor Activation And Sphingosine Kinase (SK-1)/Sphingosine 1-Phosphate (S1P) Dependent Nitric Oxide (NO) Generation

Circulation ◽

10.1161/circ.118.suppl_18.s_381-c ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Sergio Li Calzi ◽

Jennifer L Kielczewski ◽

Evan McFarland ◽

Kyung Hee Chang ◽

Aqeela Afzal ◽

...

Keyword(s):

Endothelial Cells ◽

Umbilical Vein ◽

Scavenger Receptor ◽

Receptor Activation ◽

Hematopoietic Stem ◽

Beneficial Effects ◽

Sphingosine 1 Phosphate ◽

Active Motor ◽

Umbilical Vein Endothelial Cells ◽

Igfbp 3

Purpose: We demonstrated that IGFBP-3 stimulates hematopoietic stem cells (HSC) to differentiate into endothelial cells, form capillaries, and stabilize the vasculature (Chang, et al, PNAS 2007). Local IGFBP- 3 production is increased by hypoxia and facilitates the homing of HSC to areas of injury. In the circulation, IGFBP-3 is bound to HDL. In this study, we investigated the signaling pathways responsible for the robust migratory effects of IGFBP-3. Methods: The effects of IGFBP-3 on NO generation in human vascular precursors (CD 34 + , CD14 − ), human lung microvascular endothelial cells, and human umbilical vein endothelial cells were examined using DAF-FM fluorescence. Western analysis was use for detection of eNOS and vasodilator-stimulated phosphoprotein (VASP), which redistributes to lamellipodia forming an active motor complex that supports motility and is phosphorylated in response to NO. Localization of VASP was performed by immunohistochemistry. SK-1 was assessed following IGFBP-3 stimulation. Results: In CD34 + cells and endothelial cells, IGFBP-3 stimulated eNOS phosphorylation at Ser1177 (102 ± 1.8%, P = 0.0002) and increased NO generation (275 ± 50%, P = 0.05) by increasing SK-1 and S1P generation. IGFBP-3 was bound and internalized by the HDL receptor, scavenger receptor 1B (SR1B). NO generation following IGFBP-3 exposure was reduced by SK inhibitors or SR-1B blocking antibody pretreatment (35 ± 5%, P < 0.02). IGFBP-3 generated NO increased phosphorylation of VASP at Ser239 and promoted the redistribution of VASP to lamellipodia. Conclusions: IGFBP-3 effects on cell migration are NO dependent and mediated in part by activation of the HDL receptor SR1B suggesting that some of the beneficial effects of HDL are mediated by the association of IGFBP-3.

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