Oral Mucosa Harbors a High Frequency of Endothelial Cells: A Novel Postnatal Cell Source for Angiogenic Regeneration

Taohong Siwu-Containing Serum Enhances Angiogenesis in Rat Aortic Endothelial Cells by Regulating the VHL/HIF-1α/VEGF Signaling Pathway

Background

The incidence of bone fracture and bone-related diseases is increasing every year. Angiogenesis plays a vital role in fracture healing and bone repair. This study assessed the benefits of Taohong Siwu (TSW) decoction on angiogenesis in isolated rat aortic endothelial cells (RAEC) treated with TSW-containing serum.

Methods

The components of TSW decoction were analyzed by liquid chromatography-mass spectrometry (LC-MS). TSW-containing serum was prepared by gavage of TSW decoction to Sprague-Dawley (SD) rats. The effects of TSW-containing serum on the viability, migration, wound healing, and angiogenesis of RAEC were detected by the MTT, transwell, wound healing, and Matrigel lumen formation assays, respectively. In addition, the effects of an HIF-1α inhibitor on TSW-containing serum-induced RAEC were also assessed. The effects of TSW-containing serum on the expression of the HIF-1α signaling pathway were evaluated by qRT-PCR and western blot analysis.

Results

LC-MS revealed that TSW decoction primarily contained isomaltulose, choline, D-gluconic acid, L-pipecolic acid, hypotaurine, albiflorin, and tryptophan. TSW-containing serum significantly increased the viability, migration, wound healing, and angiogenesis of RAEC in a dose-dependent manner. Furthermore, our results demonstrated that HIF-1α and VEGF expressions were increased in the cells of TSW-containing serum groups, whereas VHL expression was decreased. The effects of TSW-containing serum were reversed by treatment with an HIF-1α inhibitor.

Conclusion

These results suggested that TSW decoction enhanced angiogenesis by regulating the VHL/HIF-1α/VEGF signaling pathway.

Endothelial and smooth muscle cells derived from human cardiac explants demonstrate angiogenic potential and suitable for design of cell-containing vascular grafts

Background

Endothelial and smooth muscle cells are considered promising resources for regenerative medicine and cell replacement therapy. It has been shown that both types of cells are heterogeneous depending on the type of vessels and organs in which they are located. Therefore, isolation of endothelial and smooth muscle cells from tissues relevant to the area of research is necessary for the adequate study of specific pathologies. However, sources of specialized human endothelial and smooth muscle cells are limited, and the search for new sources is still relevant. The main goal of our study is to demonstrate that functional endothelial and smooth muscle cells can be obtained from an available source—post-surgically discarded cardiac tissue from the right atrial appendage and right ventricular myocardium.

Methods

Heterogeneous primary cell cultures were enzymatically isolated from cardiac explants and then grown in specific endothelial and smooth muscle growth media on collagen IV-coated surfaces. The population of endothelial cells was further enriched by immunomagnetic sorting for CD31, and the culture thus obtained was characterized by immunocytochemistry, ultrastructural analysis and in vitro functional tests. The angiogenic potency of the cells was examined by injecting them, along with Matrigel, into immunodeficient mice. Cells were also seeded on characterized polycaprolactone/chitosan membranes with subsequent analysis of cell proliferation and function.

Results

Endothelial cells isolated from cardiac explants expressed CD31, VE-cadherin and VEGFR2 and showed typical properties, namely, cytoplasmic Weibel-Palade bodies, metabolism of acetylated low-density lipoproteins, formation of capillary-like structures in Matrigel, and production of extracellular matrix and angiogenic cytokines. Isolated smooth muscle cells expressed extracellular matrix components as well as α-actin and myosin heavy chain. Vascular cells derived from cardiac explants demonstrated the ability to stimulate angiogenesis in vivo. Endothelial cells proliferated most effectively on membranes made of polycaprolactone and chitosan blended in a 25:75 ratio, neutralized by a mixture of alkaline and ethanol. Endothelial and smooth muscle cells retained their functional properties when seeded on the blended membranes.

Conclusions

We established endothelial and smooth muscle cell cultures from human right atrial appendage and right ventricle post-operative explants. The isolated cells revealed angiogenic potential and may be a promising source of patient-specific cells for regenerative medicine.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-017-1156-1) contains supplementary material, which is available to authorized users.