Comparison of different culture conditions for smooth muscle cell differentiation of human umbilical cord vein CD146+ perivascular cells

Stem cell-based small-diameter vascular grafts in dynamic culture

Purpose: Transplantation of autologous and/or allogeneic blood vessels is the most convenient treatment for vascular diseases. With regard to extensive need for blood vessels, developments in vascular tissue engineering are contributing greatly. In this study, our aim is to create intact small-diameter tubular vascular grafts cultivated in pulsatile flow bioreactor. Materials and Methods: CD146+ cell-based small-diameter vascular grafts were fabricated with ECM/glycosaminoglycans and polyurethane nanofibers. Characterization of the vascular graft was performed by SEM and WST-1. To mimic blood circulation in the bioreactor, human CD34+ cells cultured in megakaryocytes/platelets medium; then these cells were transferred inside of the vascular graft to mimic blood circulation. Cell differentiation was evaluated by flow cytometry and colony assay. Wright-Giemsa staining and polyploidy analysis were performed to show the differentiated cell population inside of the vascular graft. Anti-thrombogenic properties of the blood vessel were demonstrated by IF. Results: Polyurethane nanofibers provided a suitable environment for Human umbilical cord vein endothelial cells (HUVECs), and no significant cytotoxic effect was observed. Scanning electron microscopy (SEM) analysis of the tubular graft showed that under perfusion HUVECs, smooth muscle cells (SMCs) and fibroblasts formed layers that aligned on each other, respectively. The vascular graft was strong with a tensile strength of 0.70 MPa and elastic modulus of 0.007 GPa. When cultured in a bioreactor system, platelet adhesion to the vascular graft was remarkably low. Conclusion: In conclusion, this vascular graft may hold the potential to regenerate functional small-diameter vessels for cardiovascular tissue repair.

Transcriptome and proteome profiles of human umbilical cord vein CD146+ stem cells

In this study we used two different techniques in order to isolate pericytes from the wall of human umbilical cord vein and get two different groups of cells were named as "pellet and primer cells". These groups were compared with each other according to their morphologies and stem cell marker expressions. Also, these two different populations were compared with each other and with human bone marrow mesenchymal stem cells (BM-MSCs) according to their transcriptomic profiles. Then, pellet cells proteomic profiles were determined. Our results showed that morphologies and cell surface marker expressions of pellet cells and primer cells are similar. On the other hand, according to immunofluorescence staining results, in contrast to primer cells, pellet cells showed positive NG2 and PDGFR-β staining. As a result of gene expression profiling, pellet cells have upregulated genes related with muscle, neural and immune cell differentiation, development and pluripotency. On the other hand, primer cells have upregulated adhesion pathway-related genes. In addition to differences between pellet and primer cells, the gene expression profiles of these cell groups are also different from BM-MSCs. The results of transcriptome and proteome analysis of pellet cells were in consistent with each other.

Generation of human umbilical cord vein CD146+ perivascular cell origined three-dimensional vascular construct

Small-diameter vascular grafts are needed for the treatment of coronary artery diseases in the case of limited accessibility of the autologous vessels. Synthetic scaffolds have many disadvantages so in recent years vascular constructs (VCs) made from cellularized natural scaffolds was seen to be very promising but number of studies comprising this area is very limited. In our study, our aim is to generate fully natural triple-layered VC that constitutes all the layers of blood vessel with vascular cells. CD146+ perivascular cells (PCs) were isolated from human umbilical cord vein (HUCV) and differentiated into smooth muscle cells (SMCs) and fibroblasts. They were then combined with collagen type I/elastin/dermatan sulfate and collagen type I/fibrin to form tunica media and tunica adventitia respectively. HUCV endothelial cells (ECs) were seeded on the construct by cell sheet engineering method after fibronectin and heparin coating. Characterization of the VC was performed by immunolabeling, histochemical staining and electron microscopy (SEM and TEM). Differentiated cells were identified by means of immunofluorescent (IF) labeling. SEM and TEM analysis of VCs revealed the presence of three histologic tunicae. Collagen and elastic fibers were observed within the ECM by histochemical staining. The vascular endothelial growth factor receptor expressing ECs in tunica intima; α-SMA expressing SMCs in tunica media and; the tenascin expressing fibroblasts in tunica adventitia were detected by IF labeling. In conclusion, by combining natural scaffolds and vascular cells differentiated from CD146+ PCs, VCs can be generated layer by layer. This study will provide a preliminary blood vessel model for generation of fully natural small-diameter vascular grafts.