Background:Thymosin beta-4 (TB-4) is considered key roles in tissue development,maintenance and pathological processes.The study aimed to prove TB-4 positive biological function on nucleus pulposus (NP) cell apoptosis and slowing the process of cell aging while increasing the cell proliferation.Methods:TB-4 recombinant adeno-associated virus (AAV) was constructed and induced to human NP cells.Cell of same group were cultured without gene modification as controlled group.Proliferation capacity and cell apoptosis were observed during 6 passages of the cells.Morphology and expression of the TB-4 gene were documented as parameter of cell activity during cell passage.Results:NP cells with TB-4 transfection has normal TB-4 expression and exocytosis.NP cells with TB-4 transfection performed significantly higher cell activity than that at the control group in each generation.TB-4 recombinant AAV-transfected human NP cells also show slower cell aging,lower cell apoptosis and higher cell proliferation than control group.Conclusions:TB-4 can prevent NP cell apoptosis,slow NP cell aging and promote NP cell proliferation.AAV transfection technique was able to highly and stably express TB-4 in human NP cells,which may provide a new pathway for innovation in the treatment of intervertebral disc degenerative diseases.