Cell culture of human degenerative intervertebral disc

BACKGROUND： There are no reports about adult degenerative disc cell culture model currently. This establishment of disc cell culture is the cellular basis of intervertebral disc tissue engineering. OBJECTIVE： To establish cell culture models from human degenerative intervertebral disc, and to settle the cytology base of disc tissue engineering. DESIGN AND SETTING： The controlled observational experiment with regard to cytology was performed in Shandong Institute of Orthopaedics and Traumatology. MATERIALS： Five degenerative intervertebral disc patients were recruited from Department of Orthopaedics, Affiliated Hospital of Qingdao University Medical College, including one case in L2-3, three cases in L4-5 and one case in L5-S1. METHODS： Five samples were taken from the operational disectomy for lumbar disc herniation, and these samples were cultured using enzymatic digestion cell culture and tissue cell culture method differently. All the samples were cultured with HAMF12 medium with the addition of 10% and 20% fetal bovine serum. The morphology of the cultured cell was observed with Giemsa staining and transmission electron microscopy respectively. MAIN OUTCOME MEASURES： ①Cellular growth; ②Morphology of the cultured cells; ③Ultrastructure of the cultured cells. RESULTS： By means of enzymatic digestion cell culture and tissue cell culture method, numerous degenerative lumbar disc cells were obtained and successfully subcultured. The cell secretions around the cultured cells may influence the growth of these cells. Destroying the secretions, the cultured cells could be highly proliferated. The degenerative intervertebral disc cells were proliferated vigorously in HAMF12 medium with 20% fetal bovine serum compared with that with 10% fetal bovine serum. The notochordal cell was observed in all the specimens. CONCLUSION： The adult degenerative disc can be used to obtain the required cell for tissue engineering.

Transplantation of gene-modified nucleus pulposus cells reverses rabbit intervertebral disc degeneration

Background Intervertebral disc degeneration is the main cause of low back pain. The purpose of this study was to explore potential methods for reversing the degeneration of lumbar intervertebral discs by transplantation of gene-modified nucleus pulposus cells into rabbit degenerative lumbar intervertebral discs after transfecting rabbit nucleus pulposus cells with adeno-associated virus 2 （AAV2）-mediated connective tissue growth factor （CTGF） and tissue inhibitor of metalloproteinases 1 （TIMP1） genes in vitro. Methods Computer tomography （CT）-guided percutaneous annulus fibrosus injury was performed to build degenerative lumbar intervertebral disc models in 60 New Zealand white rabbits, rAAV2-CTGF-IRES-TIMPI-transfected rabbit nucleus pulposus cells were transplanted into degenerative lumbar intervertebral discs （transplantation group）, phosphate-buffered saline （PBS） was injected into degenerative lumbar intervertebral discs （degeneration control group） and normal lumbar intervertebral discs served as a blank control group. After 6, 10 and 14 weeks, the disc height index （DHI） and signal intensity in intervertebral discs were observed by X-ray and magnetic resonance imaging （MRI） analysis The expression of CTGF and TIMP1 in nucleus pulposus tissue was determined by Western blotting analysis, the synthesis efficiency of proteoglycan was determined by a 35S-sulfate incorporation assay, and the mRNA expression of type II collagen and proteoglycan was detected by RT-PCR. Results MRI confirmed that degenerative intervertebral discs appeared two weeks after percutaneous puncture. Transgenic nucleus pulposus cell transplantation could retard the rapid deterioration of the DHI. MRI indicated that degenerative intervertebral discs were relieved in the transplantation group compared with the degeneration control group. The expression of collagen II mRNA and proteoglycan mRNA was significantly higher in the transplantation group and the blank control group compared with the degeneration control group （P 〈0.05）. Conclusions CT-guided percutaneous puncture can successfully build rabbit degenerative intervertebral disc models. Both CTGF and TIMPl-transfected cell transplantation helps to maintain disc height, and promotes the biosynthesis of tvDe II collaQen and proteoalvcan in intervertebral discs, reversinq the de（：ieneration of intervertebral discs.