Erythropoietin promotes network formation of transplanted adipose tissue-derived microvascular fragments

• Published in: European cells & materials 2018-05, Vol.35, p.268-280
• Main Authors: Karschnia, P, Scheuer, C, Heß, A, Später, T, Menger, M D, Laschke, M W
• Format: Article
• Language: English
• Subjects: Adipose Tissue - blood supply; Animals; autologous chondrocyte implantation; cartilage; Erythropoietin - pharmacology; Extracellular Matrix - drug effects; Extracellular Matrix - metabolism; foetal bovine serum; human chondrocytes; Human platelet lysate; Mice, Inbred C57BL; Microscopy, Fluorescence; Microvessels - drug effects; Microvessels - transplantation; Neovascularization, Physiologic - drug effects; Platelet Endothelial Cell Adhesion Molecule-1 - metabolism; Stemulate
• ISSN: 1473-2262
• DOI: 10.22203/eCM.v035a19

The seeding of tissue constructs with adipose tissue-derived microvascular fragments (ad-MVF) is an emerging pre-vascularisation strategy. Ad-MVF rapidly reassemble into new microvascular networks after in vivo implantation. Herein it was analysed whether this process was improved by erythropoietin (EPO). Ad-MVF were isolated from green fluorescent protein (GFP)+ as well as wild-type C57BL/6 mice and cultivated for 24 h in medium supplemented with EPO (20 IU/mL) or vehicle. Freshly isolated, non-cultivated ad-MVF served as controls. Protein expression, cell viability and proliferation of ad-MVF were assessed by proteome profiler array and fluorescence microscopy. GFP+ ad-MVF were seeded on collagen-glycosaminoglycan matrices, which were implanted into dorsal skinfold chambers of C57BL/6 mice, to analyse their vascularisation over 14 d by intravital fluorescence microscopy, histology and immunohistochemistry. Cultivation up-regulated the expression of pro- and anti-angiogenic factors within both vehicle- and EPO-treated ad-MVF when compared with non-cultivated controls. Moreover, EPO treatment suppressed cultivation-associated apoptosis and significantly increased the number of proliferating endothelial cells in ad-MVF when compared with vehicle-treated and non-cultivated ad-MVF. Accordingly, implanted matrices seeded with EPO-treated ad-MVF exhibited an improved vascularisation, as indicated by a significantly higher functional microvessel density. The matrices of the three groups contained a comparably large fraction of GFP+ microvessels originating from the ad-MVF, whereas the tissue surrounding the matrices seeded with EPO-treated ad-MVF exhibited a significantly increased microvessel density when compared with the other two groups. These findings indicated that EPO represents a promising cytokine to further boost the excellent vascularisation properties of ad-MVF in tissue-engineering applications.