CONSTRUCTING ADENO-ASSOCIATED VIRUS-TGFβ_3 AND COMPARING ITS BIOLOGICAL EFFECT ON PROTEOGLYCAN SYNTHESIS IN DEDIFFERENTIATED NUCLEUS PULPOUS CELLS WITH ADENOVIRUS-TGFβ_1

Objective To construct adeno-associated virus (AAV) expression system for transforming growth factor β3 (TGFβ3) and detect its biological effect on proteoglycan synthesis of the earlier and later dedifferentiated rabbit lumbar disc nucleus pulpous (NP) cells, which was compared with that of adenovirus (AV) expression system for TGFβ1. Methods TGFβ3 gene was obtained using PCR. Its upstream contained restriction enzyme site Kpn Ⅰ, and its downstream contained restriction enzyme site SalⅠ. Using the restriction enzyme sites of PCR product of TGFβ3 and the corresponding multiple cloning site (MCS) in plasmid AAV, TGFβ3 was subcloned into AAV. The recombinant plasmid AAV-TGFβ3 was transfected into H293 cells with LipofectamineTM 2000, and the expression of TGFβ3 gene was detected using immunofluorescent analysis. After AAV-TGFβ3 virus particle with infectious activity was packaged, TGFβ3 expression in NP cells was detected by immunoblotting, and its biological effect on proteoglycan synthesis was detected by antonopulos method and compared with that of AV-TGFβ1 in the earlier and later dedifferentiated NP cells. Results For the earlier dedifferentiated NP cells, AAV-TGFβ3 slowly and stably enhanced proteoglycan synthesis, but AV-TGFβ1 rapidly and transiently enhanced its synthesis. For the later dedifferentiated NP cells, AAV-TGFβ3 stably enhanced proteoglycan synthesis, but AV-TGFβ1 inhibited its synthesis. Conclusion AAV expression system can mediate TGFβ3 gene to be expressed stably, and AAV-TGFβ3 can enhance proteoglycan synthesis of the earlier and later dedifferentiated NP cells.

CONSTRUCTING AAV-TGFβ_1 AND COMPARISING ITS BIOLOGICAL EFFECTS ON PROTEOGLYCAN SYNTHESIS OF NUCLEUS PULPOUS CELLS WITH AV-TGFβ_1

Objective To construct adeno-associated virus express system for TGFβ1 (AAV-TGFβ1) and compare its biological effects on proteoglycan synthesis of the rabbit lumbar disc nucleus pulpous (NP) cells with adenovirus (Ad) express system for TGFβ1 (AV-TGFβ1). Methods TGFβ1 gene was obtained by polymerase chain reactions (PCR). The upstream of TGFβ1 contained restriction enzyme site of EcoR Ⅰ, and the restriction enzyme site of Sal Ⅰ was at the downstream of TGFβ1. Using the multiple cloning sites (MCS) in plasmid AAV and the corresponding contained restriction enzyme site in PCR product of TGFβ1, TGFβ1 gene was subcloned into AAV. The recombinant plasmid AAV-TGFβ1 was detected by restriction enzyme digestion and DNA sequencing. Then, AAV-TGFβ1 virus was packaged and TGFβ1 expression mediated by AAV was detected by immunofluence analysis in H293 cells. AAV transfection rate to NP cells was evaluated with AAV-PEGF. After NP cells were respectively transfected by AAV-TGFβ1 virus and AV-TGFβ1 virus, proteoglycan synthesis was detected and compared by using Antonopulos methods. Results DNA sequencing revealed that the PCR-amplified TGFβ1 gene was consistent with NCBI Gene Bank. The recombinant plasmid was proved to be constructed successfully by restriction enzyme digestion. AAV could be transfected into NP cells and mediate an efficient expression of TGFβ1 protein. AV-TGFβ1 virus could quickly enhance the proteoglycan synthesis of the NP cells, but its biological effect was transient. AAV-TGFβ1 virus could enhance stably proteoglycan synthesis. Conclusion AAV-TGFβ1 virus was successful constructed and enhanced stably proteoglycan synthesis of NP cells.