Characterization of endothelial colony-forming cells from peripheral blood samples of adult horses.

This study focuses on isolating and understanding the features of a specific type of cells, endothelial colony-forming cells (ECFCs), from the peripheral blood of adult horses. The researchers explored the characteristics of these cells and suggested their possible therapeutic use in equine diseases associated with reduced or slow blood flow.

Research Methodology

• The researchers collected jugular venous blood samples from 24 adult horses.
• The blood samples were cultured in a special growth medium designed for developing endothelial cells.
• The isolated ECFCs were characterised using functional assays, which check the cell’s ability to function properly by measuring the uptake of fluorescence-labeled acetylated low-density lipoprotein (DiI-Ac-LDL) and the capacity to form vascular tubules in vitro.
• An indirect immunofluorescence assay and flow cytometry technique were used to assess the expression of endothelial (CD34, CD105, vascular endothelial growth factor receptor 2, and von Willebrand factor) and hematopoietic (CD14) cell markers. These are molecules found on the surface of cells that can help identify their type or stage of development.
• The researchers evaluated the number of cell divisions before the cells reached senescence, or old age. This determination involved monitoring the DiI-Ac-LDL uptake, vascular tubule formation, and growth rates of cells over time.

Results

• The samples from three horses produced colonies with characteristic endothelial morphology and substantial development on expansion after about 12 days.
• The equine ECFCs were found to have the capacity to form vascular tubules in vitro and demonstrated uptake of DiI-Ac-LDL, indicating a healthy function.
• However, the tubule formation and DiI-Ac-LDL uptake ability began to decrease by the fifth passage (cycle of cell growth).
• Equine ECFCs tested positive for endothelial markers including von Willebrand factor, vascular endothelial growth factor receptor 2, CD34, CD105, and CD14, confirming their identity.

Conclusions

• ECFCs can be successfully isolated from the peripheral blood samples of horses. Their characteristics were found to be consistent with those of ECFCs from other species, presenting them as a potential therapy in equine diseases associated with poor blood flow or delayed vascularization.