Artikel
Human Wharton’s jelly cells activate degenerative nucleus pulposus cells in vitro
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Veröffentlicht: | 6. November 2018 |
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Gliederung
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Objectives: In order to investigate the interaction between human Wharton's jelly cells (WJCs) and degenerative nucleus pulposus cells (NPCs)
Methods: Human WJCs were isolated from the fresh human umbilical cords and human degenerative NPCs were separated from the degenerative IVD tissue. The surface makers of the isolated WJCs were analyzed by the flow cytometry and then cells were fluorescently labeled before seeding with degenerative NPCs. With or without a direct cell-cell contact, the WJCs were cocultured with degenerative NPCs in 3 cell ratios of 25:75, 50:50, and 75:25. The individually cultured WJCs and NPCs with a total cell number of 6.0 x 104 were used as controls. After culturing for 7 days, real-time polymerase chain reaction (PCR) was performed to evaluate the gene expression in each group. The relative gene expression in the coculture groups was calculated using the gene expression of the housekeeping gene GAPDH as references.
Results and conclusion: The isolated WJCs positively expressed CD73, CD105, CD90, CD29, CD166 and human leukocyte antigen (HLA)-ABC, but negatively expressed CD34, CD45, and HLA-DR. After coculturing with 3 different WJCs:NPCs ratios for 7 days, the real-time polymerase chain reaction showed that the relative gene expression of NP-marker genes [aggrecan, type II collagen, and SRY-type HMG box-9 (SOX-9)] was significantly upgraded in all coculture groups (all P values < 0.05 compared with control groups). Coculture either with or without cell-cell contact significantly activated the expression of NP-maker genes than controls, but coculture with cell-cell contact yielded a higher gene expression than coculture without cell-cell contact. In coculturing with cell-cell contact and WJCs: NPCs of 25:75, the relative gene expression of aggrecan, type II collagen, SOX-9 for WJCs yielded the highest increase by 721-, 1507-, and 1463-folds, respectively (all P < 0.05 compared with WJCs control). In contrast, the highest relative gene expression of aggrecan, type II collagen, SOX-9 for NPCs was 112-, 84-, 109-folds, respectively, in coculture with cell-cell contact and in WJCs: NPCs of 75:25 (all P < 0.05 compared with NPCs control).
In conclusion, the data indicated that coculturing human WJCs with degenerative NPCs induced the NP-like cell differentiation of WJCs and restored the biological status of degenerative NPCs and coculture WJCs and NPCs with direct cell-cell contact yielded more favorable gene expressions.