Affiliations: [a] Department Tissue Engineering and Regenerative Medicine (TERM), University Hospital Wuerzburg, Wuerzburg, Germany
| [b] Fraunhofer Translational Center Regenerative Therapies TLC-RT, Fraunhofer Institute for Silicate Research ISC, Wuerzburg, Germany
| [c] IZKF Group Tissue Regeneration in Musculoskeletal Diseases, University Hospital Wuerzburg, Wuerzburg, Germany
| [d] Orthopedic Center for Musculoskeletal Research, University of Wuerzburg, Wuerzburg, Germany
| [e] Institute of Chemistry and Biotechnology, Zuerich University of Applied Sciences (ZHAW), Waedenswil, Switzerland
| [f]
Competence Center Tissue Engineering for Drug Discover (TEDD), ZHAW, Waedenswil, Switzerland
Correspondence:
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Corresponding author: Antje Kremer, Department Tissue Engineering and Regenerative Medicine (TERM),
University Hospital Wuerzburg, Roentgenring 11, 97070 Wuerzburg, Germany. Tel.: +49 931 31 83429;
Fax: +49 931 31 81068; E-mail: antje.kremer@uni-wuerzburg.de.
Abstract: BACKGROUND:Prolyl hydroxylase inhibitors (PHIs) are promising compounds to promote angiogenesis by stabilizing hypoxia-inducible factor-1α (HIF-1α), a master regulator of angiogenesis. Increased HIF-1α presence induces expression of proangiogenic genes such as vascular endothelial growth factor (VEGF). OBJECTIVE:We investigated the pharmacological induction of hypoxia via the PHI ciclopirox olamine (CPX) as angiogenesis strategy on human dermal microvascular endothelial cell (hd-mvEC) spheroids directly and indirectly via activating human mesenchymal stem cells (hMSCs). METHODS:HMSCs were isolated from bone marrow and hd-mvECs from foreskin biopsies. MSC-conditioned medium after CPX stimulation (MSC-CM CPX) was analyzed by VEGF ELISA and Proteome Profiler™ Human Angiogenesis Array. Direct stimulation with CPX and indirect stimulation via MSC-CM CPX were compared in sprouting assays of hd-mvEC spheroids. RESULTS:Direct stimulation with CPX significantly increased sprouting of hd-mvEC spheroids. MSC-CM CPX also induced sprouting from hd-mvEC spheroids, which was mediated by angiogenic VEGF and other proangiogenic factors that had been produced by stimulated hMSCs. CONCLUSIONS:The stimulation with CPX increased the proangiogenic response of hd-mvECs and hMSCs. The direct stimulation of hd-mvECs with CPX has the potential to replace external VEGF supplementation. Thus, CPX can induce angiogenesis in ECs even in the absence of auxiliary cells demonstrating a promising proangiogenic approach.
