Lung-Homing of Endothelial Progenitor Cells and Airway Vascularization Is Only Partially Dependant on Eosinophils in a House Dust Mite-Exposed Mouse Model of Allergic Asthma.

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Lung-Homing of Endothelial Progenitor Cells and Airway Vascularization Is Only Partially Dependant on Eosinophils in a House Dust Mite-Exposed Mouse Model of Allergic Asthma.

PLoS One. 2014;9(10):e109991

Authors: Sivapalan N, Wattie J, Inman MD, Sehmi R

Abstract
BACKGROUND: Asthmatic responses involve a systemic component where activation of the bone marrow leads to mobilization and lung-homing of progenitor cells. This traffic may be driven by stromal cell derived factor-1 (SDF-1), a potent progenitor chemoattractant. We have previously shown that airway angiogenesis, an early remodeling event, can be inhibited by preventing the migration of endothelial progenitor cells (EPC) to the lungs. Given intranasally, AMD3100, a CXCR4 antagonist that inhibits SDF-1 mediated effects, attenuated allergen-induced lung-homing of EPC, vascularization of pulmonary tissue, airway eosinophilia and development of airway hyperresponsiveness. Since SDF-1 is also an eosinophil chemoattractant, we investigated, using a transgenic eosinophil deficient mouse strain (PHIL) whether EPC lung accumulation and lung vascularization in allergic airway responses is dependent on eosinophilic inflammation.
METHODS: Wild-type (WT) BALB/c and eosinophil deficient (PHIL) mice were sensitized to house dust mite (HDM) using a chronic exposure protocol and treated with AMD3100 to modulate SDF-1 stimulated progenitor traffic. Following HDM challenge, lung-extracted EPCs were enumerated along with airway inflammation, microvessel density (MVD) and airway methacholine responsiveness (AHR).
RESULTS: Following Ag sensitization, both WT and PHIL mice exhibited HDM-induced increase in airway inflammation, EPC lung-accumulation, lung angiogenesis and AHR. Treatment with AMD3100 significantly attenuated outcome measures in both groups of mice. Significantly lower levels of EPC and a trend for lower vascularization were detected in PHIL versus WT mice.
CONCLUSIONS: This study shows that while allergen-induced lung-homing of endothelial progenitor cells, increased tissue vascularization and development lung dysfunction can occur in the absence of eosinophils, the presence of these cells worsens the pathology of the allergic response.

PMID: 25279605 [PubMed – as supplied by publisher]

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Bidirectional Cross-Regulation between the Endothelial Nitric Oxide Synthase and ?-Catenin Signaling Pathways.

Bidirectional Cross-Regulation between the Endothelial Nitric Oxide Synthase and ?-Catenin Signaling Pathways.

Cardiovasc Res. 2014 Jul 25;

Authors: Warboys CM, Chen N, Zhang Q, Shaifta Y, Vanderslott G, Passacquale G, Hu Y, Xu Q, Ward JP, Ferro A

Abstract
AIMS: ?-catenin has been shown to be regulated by inducible nitric oxide synthase (NOS) in endothelial cells. We investigated here whether ?-catenin interacts with and regulates endothelial NOS (eNOS) and whether eNOS activation promotes ?-catenin signaling.
METHODS AND RESULTS: We identified ?-catenin as a novel eNOS binding protein in human umbilical vein endothelial cells (HUVECs) by mass spectroscopy and western blot analyses of ?-catenin and eNOS immunoprecipitates. This was confirmed by in situ proximity ligation assay. eNOS activity, assessed by cGMP production and eNOS phosphorylation (Ser1177), was enhanced in ?-catenin(-/-) mouse pulmonary endothelial cells (MPECs) relative to wild type MPECs. eNOS activation (using adenosine, salbutamol, thrombin or histamine), or application of an NO donor (spermine NONOate) or cGMP-analogue (8-bromo-cGMP) caused nuclear translocation of ?-catenin in HUVEC as shown by western blotting of nuclear extracts. Exposure to spermine NONOate, 8-bromo-cGMP or sildenafil (a phosphodiesterase type 5 inhibitor) also increased the expression of ?-catenin-dependent transcripts, IL-8 and cyclin D1. Stimulation of wild type MPECs with basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), spermine NONOate, 8-bromo-cGMP or sildenafil increased tube length relative to controls in an angiogenesis assay. These responses were abrogated in ?-catenin(-/-) MPECs, with the exception of that to bFGF which is NO-independent. In C57BL/6 mice, subcutaneous VEGF-supplemented Matrigel plugs containing ?-catenin(-/-) MPECs exhibited reduced angiogenesis compared to plugs containing wild type MPECs. Angiogenesis was not altered in bFGF-supplemented Matrigel.
CONCLUSIONS: These data reveal bidirectional cross talk and regulation between the NO-cGMP and ?-catenin signaling pathways.

PMID: 25062958 [PubMed – as supplied by publisher]

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Effect of Cilostazol Endothelial Progenitor Cells and Collateral Formation in Peripheral Occlusive Artery Disease (PAOD)

Condition:   Peripheral Arterial Diseases
Intervention:   Drug: Active comparator (cilostazol) and Placebo comparator
Sponsors:   National Cheng-Kung University Hospital;   National Cheng-Kung University Hospital;   Department of Health, Executive Yuan, R.O.C. (Taiwan)
Active, not recruiting – verified September 2013

View full post on ClinicalTrials.gov: asthma | received in the last 14 days