Human umbilical cord Wharton's jelly-derived mesenchymal stem cells protect against interleukin-1beta induced degeneration of nucleus pulposus cells / 中国组织工程研究

ABSTRACT

BACKGROUND: Human umbilical cord Wharton's jelly-derived mesenchymal stem cells (hWJCs) via transplantation are able to survive in a dog model of intervertebral disc degeneration and to partially restore the height of the intervertebral disc. However, there is no study on whether hWJCs can repair nucleus pulposus cells after inflammatory injury as yet. OBJECTIVE: To observe the protective effect of hWJCs on interleukin-1β induced rat nucleus pulposus degeneration.METHODS: Nucleus pulposus cells at passage 3 from Sprague-Dawley rats were divided into three groups (1) normal control group cultured in culture medium containing fetal bovine serum for 24 hours, and then cultured in complete medium for 24 hours; (2) intervention group with interleukin-1β intervention for 24 hours, followed by culture in the complete medium for 24 hours; (3) co-culture group with interleukin-1β intervention for 24 hours, followed by culture in the complete medium for non-direct co-culture with hWJCs for 24 hours. Annexin V-FITC/propidium iodide (PI) double staining and flow cytometry were used in succession to measure the apoptosis rate of nucleus pulposus cells in each group. The ADAMTS-4, MMPs-3 and TIMP-1 expression in nucleus pulposus cells was observed though RT-PCR. The activities of caspase-3, caspase-8 and caspase-9 were determined by caspase kit.RESULTS AND CONCLUSION: The apoptosis rates were ranked as follows the intervention group > co-culture group > normal control group, and there were significant differences between groups (P < 0.05). Compared with the control group,the expression levels of ADAMTS-4 and MMPs-3 were significantly higher and the expression level of TIMP-1 was significantly lower in the intervention and co-culture groups (P < 0.05). Compared with the intervention group, the expression levels of ADAMTS-4 and MMPs-3 were significantly lower and the expression level of TIMP-1 was significantly higher in the co-culture group (P < 0.05). The expression activities of caspase-3, caspase-8 and caspase-9 were highest in the intervention group, followed by the co-culture group, and lowest in the normal control group, and there were significant differences between groups (P < 0.05). To conclude, hWJCs has obviously inhibitory effect on the apoptosis of degenerated nucleus pulposus cells induced by interleukin-1β.