Thymosin Beta-4 Recombinant Adeno-associated Virus Enhances Human Nucleus Pulposus Cell Proliferation and Reduces Cell Apoptosis and Senescence

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.