Effect of indirect co-culture system on differentiation of bone marrow mesenchymal stem cells into nucleus pulposus-like cells

Wu Hai-jun; Yin He-ping; Hu Ji-ping; Liu Cong; Li Shu-wen; Bai Ming; Du Zhi-cai

doi:10.3969/j.issn.2095-4344.2016.45.003

Abstract：BACKGROUND:Mesenchymal stem cel s (MSCs) for the treatment of degenerative disc diseases present a new therapeutic strategy for the structural and functional recovery of the degenerative intervertebral disc. <br> OBJECTIVE:To study the differentiation potential of rabbit bone marrow MSCs (BMSCs) into nucleus pulposus-like cel s. <br> METHODS:Passage 3 BMSCs and nucleus pulosus cells (NPCs) extracted from rabbits were assigned into simple BMSCs culture, simple NPCs culture or co-culture group. In the former two groups, BMSCs or NPCs were cultured in 6-well culture plates. In the co-culture group, passage 3 BMSCs and NPCs were cultured on the upper or lower layer of the 6-well Transwell chamber, respectively. Cell morphology was observed by inverted contrast phase microscope. At 7 days of culture, immunocytochemistry, RT-PCR and western blot were used to examine the expression levels of type II collagen and aggrecan. <br> RESULTS AND CONCLUSION:At 7 days of co-culture, BMSCs were polygonal or short spindle-shaped, with no fiber-like changes, and cel morphology was close to that of NPCs. Additional y, the expression levels of type II col agen and aggrecan in the BMSCs co-cultured with NPCs were similar to those in the NPCs cultured alone, but significantly higher than those in the BMSCs culture only. Overal , these results show that coculture of BMSCs with NPCs can induce BMSCs differentiating into an NPCs phenotype, indicating that BMSCs may provide sufficient sources of cel s for the biological treatment of degenerative disc diseases.