Feasibility of SOX-9 eukaryotic expression plasmid in transfection of rabbit bone marrow stromal cells

Zhongshi XU; Deming XIAO; Bowen LIN; Xiaohu LU; Ran LI

ABSTRACT

BACKGROUND:

SOX-9 plays an important role in occurrence and development of cartilaginous tissues,enhances agglutination of mesenchymal cells,has structural domains of transcriptional activation,and can directly regulate the transcription,

OBJECTIVE:

To construct pDC316-SOX-9 plasmid for transfection of rabbit bone marrow stromal cells (BMSCs) using SOX-9 gene,and to investigate the effects of SOX-9 gene on growth characteristics of BMSCs and product expression. DESIGN,TIME AND

SETTING:

The cell gene engineering in vitro experiment was performe,d at the Beijing Institute of Genome, Chinese Academy of Scienees from June 2006 to January 2007.MATERIALS Eight SPF New Zealand rabbits aged 6 weeks were used for culture of BMSCs.

METHODS:

pDC316-SOX-9 plasmid was used for transfection of rabbit BMSCs by liposome mediated method,Cell transfection included a SOX-9 plasmid transfection group,a blank plasmid group and a blank control group (only treatment of liposome). MAIN OUTCOME

MEASURES:

Cell morphology; growth activity; The SOX-9 protein expression in rabbit BMSCs were detected by immunohistochemistry,hematoxylin-eosin staining,reserve transcriptase-polymcrase chain reaction (RT-PCR) and enzyme-labeled immunosorbent assay (ELISA).

RESULTS:

Some cell colonies were detected at 4 days after pDC316-SOX-9 plasmid transfection.Spindle-shaped cells were collected after clone amplification.Cells in the blank control group gradually died over time.Cell activities in the SOX-9 plasmid transfeetion group and the blank plasmid group significantly prolonged,reached a peak at 2 weeks of transfection,and then gradually decreased.At 6 days,BMSCs were yellow in the SOX-9 plasmid transfection group following immunohistochemistry,expressing SOX-9 protein.Hematoxyliu-eosin staining showed many dikaryocytes,rich cell proliferation,similar to chondroblasts.No SOX-9 protein expression and unproductive cell proliferation in the blank plasmid group.SOX-9 mRNA was detected in the SOX-9 plasmid transfection group,but SOX-9 mRNA was not detected in the blank plasmid group and blank control group.SOX-9 levels were significantly higher in the SOX-9 plasmid transfection group than in the blank plasmid group and blank control group at 24,48 and 72 hours,1,2 weeks (P＜ 0.01).

CONCLUSION:

Rabbit BMSCs were successfully transfected with pDC316-SOX-9 plasmid to enhance cell growth activity and to persistently stably secrete SOX-9 protein,resulting in the differentiation of BMSCs into cartilages.