Construction of recombinant gene adenovirus containing human LIM mineralization protein-1 and its expression in bone marrow mesenchymal stem cells / 中国组织工程研究

ABSTRACT

BACKGROUND: LIM Mineralization protein 1 (LMP-1), an intracellular non-secretory protein, plays roles in bone calcification. Presently, it is found that LMP-1 can promote an increase in bone morphogenetic protein 2 and transforming growth factor ? 1. This indicates that LMP-1 may recruit a mass of ossified factors to participate in the differentiation of osteoblasts. OBJECTIVE: To construct human LMP-1 gene adenovirus recombinant with AdEasy adenovirus vector system, and to detect LMP-1 expression in infected rabbit bone marrow mesenchymal stem cells (BMSCs). DESIGN, TIME AND SETTING: An opening experiment was performed at the Central Laboratory of South West Hospital, Third Military Medical University of Chinese PLA from March 2006 to February 2007. MATERIALS: Three New Zealand rabbits were used to isolate bone marrow mesenchymal stem cells. Plasmid pIRES2-EGFP-LMP-1 carrying human LMP-1 gene was kept in Department of Orthopedics, Second Hospital Affiliated to Chongqing Medical University. AdEasy was presented by Dr. Tong-Chuan He from USA. Human embryo kidney 293 cells were gifted by Wang from Department of Clinical Laboratory of Chongqing Medical University. METHODS: LMP-1 gene with a sequence encoding His-tag was amplified by using pIRES2-EGFP-LMP-1 plasmid as a template for polymerase chain reaction (PCR) with a specially designed downstream primer. The target gene was cloned to the pMD18-T vector for sequencing. Once verified, the gene was cut out by double endonucleases, connected to the shuttle vector pAdTrack-CMV. The newly constructed vector was linearized by PmeⅠ following efficient homologous recombination with the backbone vector pAdEasy-1 in BJ5183. The correct recombinant pAd-LMP-1 was linearized with Pac I and transfected to HEK293 cell by means of mediated Lipofectamine. The titer of virus was measured after amplification and purification. The mRNA and protein expression of LMP-1 was detected in BMSCs, which were infected with Ad-LMP-1 at the most appropriate MOI, were detected by reverse transcription (RT)-PCR and Western blot, respectively. MAIN OUTCOME MEASURES: Plasmid pAd-LMP-1 identification, its titre and efficiency of infection. mRNA and protein expression of LMP-1 were detected by RT-PCR and Western blot, respectively. RESULTS: The recombinant plasmid pMD18-T-LMP-1 carrying LMP-1 gene with His-tag was successfully constructed. After packaging and amplification of the recombinant adenovirus, the 3.5?109 efu/ml titer of Ad-LMP-1 was obtained by CsCl gradient purification. The optimal efficiency infection was 50%-70%, which was get after Ad-LMP-1 infected BMSCs for 3 days at the most appropriate MOI 150. The mRNA and protein expression of LMP-1 in infected BMSCs had been proved. CONCLUSION: The recombinant adenovirus containing human LMP-1 gene with His-tag is successfully constructed. The BMSCs infected with recombinant adenovirus Ad-LMP-1 can effectively express LMP-1.