Proliferative activity of nucleus pulposus cells in human intervertebral disc and intervention with yishen huoxue tongluo recipe / 中国组织工程研究

ABSTRACT

BACKGROUND: The relationship between nuclear factor (NF)-kB signaling pathway and intervertebral disc degeneration is a hotspot in the field of orthopedics. In-depth investigation on various signaling pathways in the intervertebral disc contributes to understanding the mechanism of intervertebral disc degeneration. OBJECTIVE: To investigate the regulation of the serum containing Yishen Huoxue Tongluo Recipe on the NF-kB signal pathway of human intervertebral disc nucleus pulposus cells under different hydrostatic pressures, attempting to explore the possible therapeutic mechanism and target of Yishen Huoxue Tongluo Recipe in the treatment of degenerative diseases of the intervertebral disc from the perspective of molecular biology. METHODS: Passage 3 Human intervertebral disc nucleus pulposus cells were divided into eight groups and were cultured in the drug-containing serum of Yishen Huoxue Tongluo Recipe. The cells were intervened for 2, 4, and 6 hours under different hydrostatic loading conditions (0.3,1, and 3 MPa). The morphology and growth of nucleus pulposus cells were observed by an inverted phase contrast microscope. Ultrastructural changes of intervertebral disc nucleus pulposus cells were observed by a transmission electron microscopy. Cell counting kit-8 method was used to detect the proliferation activity of nucleus pulposus cells. Annexin V-FITC/Propidium Iodide apoptotic kit was used to double-stain nucleus pulposus cells to detect the cell apoptotic rate. Western blot method was used to detect the changes of NF-kB p65, Collagen II, ADAMTS-4, MMP-13 and Caspase-3 in nucleus pulposus cells. RESULTS AND CONCLUSION: (1) Under the same pressure and time, the morphology and growth of nucleus pulposus cells in the pressure+drug-containing serum groups were better than those in the normal pressure group and the simple pressure groups. Among them, the 0.3 and 1 MPa pressure+drug-containing serum groups had more intact cell morphology and better cell growth than the 3 MPa pressure+ drug-containing serum group. (2) The proliferative activity of nucleus pulposus cells was higher in the pressure+drug-containing serum group, and there was a significant difference between the 0.3 MPa pressure+drug-containing serum group and the 0.3 MPa simple pressure group (P < 0.05). (3) The apoptotic rate of nucleus pulposus cells in the pressure+drug-containing serum group was lower than that in the normal pressure group and simple pressure intervention group (P < 0.05). (4) The expression of Collagen II and Caspase-3 increased in the pressure+drug-containing serum group, while the expression of NF-kappa B p65, ADAMTS-4 and MMP-13 decreased in the pressure+drug-containing serum group (P < 0.05). To conclude, Yishen Huoxue Tongluo Recipe can increase cell activity, reduce cell apoptosis and effectively delay the degeneration of nucleus pulposus cells. Its mechanism is likely to promote the expression of Collagen II and Caspase-3 through the NF-kB signaling pathway of nucleus pulposus cells of intervertebral disc, and inhibit the expression of NF-kB p65, ADAMTS-4 and MMP-13.