Vitamin D improves endothelial barrier integrity and counteracts inflammatory effects on endothelial progenitor cells.

Endothelial colony-forming cells (ECFCs), a proliferative subpopulation of endothelial progenitor cells, are involved in angiogenesis and endothelial repair. In this study, we investigated endothelial barrier characteristics of ECFCs, whether vitamin D supports cell-cell adhesion and barrier integrity, and how it affects ECFC mobilization and actin dynamics. Although ECFC barrier was disrupted under inflammatory conditions, this effect was rescued by vitamin D treatment, leading to higher stability of an ECFC monolayer. Furthermore, vitamin D enhanced ECFC mobilization toward directional migration. In addition, immunocytochemistry, quantitative real-time PCR, and immunoblotting analysis showed that vitamin D increased endothelial interconnections through vascular endothelial cadherin (VE-cadherin) junctions and by impacting cell dynamics through cofilin and VE-cadherin phosphorylation. Our results suggest that vitamin D treatment efficiently counteracts inflammation in an ECFC monolayer, resulting in higher ECFC barrier integrity. This study provides evidence of a new beneficial effect of vitamin D for ECFC homeostasis.-Schröder-Heurich, B., von Hardenberg, S., Brodowski, L., Kipke, B., Meyer, N., Borns, K., von Kaisenberg, C. S., Brinkmann, H., Claus, P., von Versen-Höynck, F. Vitamin D improves endothelial barrier integrity and counteracts inflammatory effects on endothelial progenitor cells.

Low Ethanol Concentrations Promote Endothelial Progenitor Cell Capacity and Reparative Function.

BACKGROUND: Endothelial progenitor cells (EPCs) are recruited to injured endothelium and contribute to its regeneration. There is evidence that moderate ethanol consumption prevents the development and progression of atherosclerosis in a variety of in vitro and in vivo models and increases the mobilization of progenitor cells. Furthermore, there are studies that identified ethanol at low concentration as a therapeutic tool to mobilize progenitor cells in peripheral blood. At the same time, the cell number of EPCs represents a close link to cardiovascular system constitution and function and contributes to cardiovascular risk. The aim of this study was to evaluate the effect of low dose ethanol on typical features of endothelial colony-forming cells (ECFCs), a proliferative subtype of EPCs. METHODS AND RESULTS: We tested whether ethanol impacts the functional abilities of ECFC (e.g., migration, tube formation, and proliferation) using in vitro assays, the intercommunication of ECFC by exploring cell surface molecules by flow cytometry, and the expression of (anti-)angiogenic molecules by ELISA. Low concentrations of ethanol concentration promoted migration, proliferation, and tubule formation of ECFC. The expression of the cell surface marker VE-cadherin, a protein which plays an important role in cell-cell interaction, was enhanced by ethanol, while (anti-)angiogenic molecule expression was not impacted. CONCLUSION: Ethanol at moderate concentrations increases the angiogenic abilities of endothelial progenitor cells thus possibly contributing to vasoprotection.