Co-cultivation of progenitor cells enhanced osteogenic gene expression and angiogenesis potential .

OBJECTIVES

The efficiencies of osteogenesis and angiogenesis present challenges that need to be overcome before bone tissue engineering can be widely applied to clinical uses. We aimed to optimize an culture system to enhance osteogenesis and angiogenesis. We investigated if hematopoietic stem cells (HSCs) promoted osteogenesis when co-cultured with mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs).

METHODS

MSC/HSC, MSC/EPC/HSC, and MSC/EPC co-cultures were incubated for 21 days. Alkaline phosphatase (ALP) activity and calcium content were analyzed to assess mineralization. Expression levels of genes encoding osteogenesis-related proteins (ALP (), collagen type IA (), osteocalcin (), and osteopontin ()) were also evaluated by measuring mRNA levels at day 28. Angiogenesis was evaluated by tube-formation assay.

RESULTS

, , , and genes were upregulated in MSC/HSC and MSC/EPC/HSC co-cultures compared with the MSC/EPC group. Upregulation was strongest in the MSC/EPC/HSC co-cultures. There were no significant changes in ALP levels and calcium content, but ALP activity was slightly higher and calcium content was relatively lower in the MSC/EPC and MSC/EPC/HSC groups.

CONCLUSIONS

Co-culture of MSCs with HSCs or EPCs/HSCs upregulated the expression of osteogenesis-related genes but did not affect the efficiency of osteogenesis.