Osteogenic differentiation potential of bone marrow stem cells compared to umbilical cord blood stem cells

الملخص EN

Runx2 and Osterix are the key transcription factors initiating and regulating the ear-ly osteogenesis and late mineralization of bone.

Regenerative medicine is an evolving field of medical researches; this field holds the promise of regenerating damaged tissues and organs in the body by replacing damaged tissue and by stimulating the body's own repair mechanisms to heal previously irreparable tissues or organs.

Aim: to investigate the osteogenic differentiation potential of mesenchymal stem cells isolated from human bone marrow (BM) and umbilical cord blood (UCB).

Methods: Mononuclear cells isolated from human UCB and BM were differentiated into spindle shaped fibrous mesenchymal stem cells (MSCs) in Dulbecco modified Eagle’s medium (DMEM) with 10% fetal bovine serum.

These progenitor cells were further examined for their abil-ity to differentiate into osteoblasts by culture in osteogenic differentiation media containing; dexamethazone and ascorbate-2phosphate and by the detection set of osteogenic genes expres-sion including; Runx-2 and Osterix, and the markers of osteogenic genes differentiation: Collagen1 and alkaline phosphatase (ALP).

Results: Runx-2 gene was significantly expressed about 7 fold in BM derived cells treated for 24 hours compared to control sample (which was not treated by osteogenic differentiation media) (7.2±1.1 vs.

1.0±0.1, p=0.02).

In addition, there was significantly expression about 3 to 4 folds in UCB compared to control sample (3.4±0.4 vs.

0.6±0.1, p= 0.04).

We also found that Osterix gene expression was significantly increased in BM MSCs treated samples for 24 hours about 3 folds relative to control (3.2±0.4 vs.

1.0±0.14, p= 0.02) and increased in UCB-MSCs samples treated for 24-72 hours about 2-4 folds respectively compared to control sample (2.1±0.5 vs.

0.7±0.09, p= 0.07).

Conclusions: we conclude that i) UCBMSCs are capable of minerali-zation when cultured in osteogenic medium and would be a better cell source for treatment of osteogenic repair.

ii) A significant change in osteogenic genes expression was found between both sources of mesenchymal stem cells indicating that BM MSCs have a higher osteogenic dif-ferentiation potential than UCB MSCs although UCB MSCs had proven to be an alternative source for mesenchymal stem cells and these cells are successfully differentiated into osteoblasts.