Differentiation into osteoblasts from marrow mesenchymal stem cells of rabbits transfected by human bone morphogenetic protein-7 gene

Yan KANG; Weiming LIAO; Puyi SHENG; Longjuan ZHANG

ABSTRACT

BACKGROUND:

At present, bone morphogenetic protein (BMP) is the only cytokine characterized as the ability of osteoblast, and it can promote marrow mesenchymal stem cells (MSCs) differentiating into chondroblast and osteoblast.

OBJECTIVE:

To investigate the differentiation into osteoblast from MSCs of rabbits transfected by human bone morphogenetic protein-7 (hBMP-7) gene with genetic engineering technique.

DESIGN:

Single sample observation.

SETTING:

Department of Orthopaedics, the First Hospital Affiliated to Sun Yat-sen University. MATERIALS pcDNA1.1/AMP-hBMP7 plasmid.

METHODS:

The experiment was completed at the Surgery Laboratory of the First Hospital Affiliated to Sun Yat-sen University from May 2004 to March 2005. MSCs of rabbits were cultured with whole bone marrow technique, transfected with pcDNA1.1/AMP-hBMP7 and pcDNA1.1/AMP plasmids respectively in vitro, and left the blank controls. Transcription and expression of transfected genes were detected so as to observe form and growth of cells. Component of calcium content in cytoplasm was measured and osteogenic phenotype was identified with alkaline phosphatase (ALP) staining, calcium salts staining and transmission electron microscopy (TEM).MAIN OUTCOME

MEASURES:

① Form and growth of MSCs of rabbits; ② evaluation of expressive product; ③ results of ALP staining (Ca-Co technique); ④ results of chinalizarin staining; ⑤ results of TEM; ⑥ results of scanning electron m icroscopy (SEM); ⑦ assay of osteocalcin.

RESULTS:

hBMP-7 gene was contained in MSCs after transfection and expressed the relevant mRNA. Cellular form changed a little after expression of amid genes, but growth curve did not changed as compared with that in non-transfected group. Expression of osteocalcin was increased as compared with that in non-transfected group, and ALP staining and calcium salts staining of transfected cells were positive.

CONCLUSION:

Transfection of hBMP-7 gene can promote MSCs of rabbits differentiating into osteoblast.