Co-culture Induces Human Bone Marrow-drived Mesenchymal Stem Cell Differentiation And Modulation Of The Nucleus Pulposus Cell Phenotype

Backgroud:Most people in our countries will suffer from low back pain at some point in their lives and as such it is recognized as a frequent and increasing health problem. Although low back pain is a multifactorial condition, one of the main causes is thought to be degeneration of the intervertebral disc (IVDD). The current clinical method include conservative treatment and surgical treatment intervention, but all the methods are only symptomatic treatments, can not fundamentally slow down or even reverse the disc degeneration. At present,the cell engineering has been a direction of biological treatment for IVDD. Thereinto,use BMSCs transplant to delay or even repair IVDD become a research hotspot.Some research suggests that, in vitro co-culture, cellular interactions between BMSCs and NPCs may both stimulate MSC differentiation to an NP-like phenotype and also stimulate the endogenous NP cell population to regain a nondegenerate phenotype and consequently enhance matrix synthesis for self-repair. Here, we investigate the differences in interaction between human MSCs and NP cells from both nondegenerate and degenerate discs during in vitro co-culture.Objective:To investigate the interaction between human bone marrow-drived mesenchymal stem cell (BMSCs)and nucleus pulposus cells (NPCs) from both nondegenerate and degenerate discs during in vitro co-culture, and make a comparison.Methods:The isolation and identification of BMSCs and NPCs was performed on bone marrow blood and nucleus pulposus from either disk degeneration patients or scoliosis patients.Five groups were designed as follows:A group (BMSCs group), B group (degenerated NPCs group), C group(nondegenerated NPCs group), D group (BMSCs with degenerated NPCs co-cultured group and) E group (BMSCs with nondegenerated NPCs co-cultured group).Choose the armless transwell as the carrier of Co-culture.In the system,the bottom of the upper slots is polycarbonate permeable membranes (pore0.4u m), The cells will be separated by the semipermeable membrane,meanwhile, the cell factors can across the membrane and take effect.The mRNA expression of of collagen â…¡, SOX-9and Aggrecan of these two types of cells were assessed using quantitative real-time PCR after7days.Result:Compared with A group, The mRNA expression of of collagenâ…¡, SOX-9and Aggrecan significantly upregulated in D and E groups.Compared with E group, The mRNA expression was upregulated in D group (p<0.05).Compared with B group, The mRNA expression of D group increased (p<0.01). Compared with C group, The mRNA expression of E group also increased (p<0.01).Conelusion:1. During co-culture process, the interaction between BMSCs and NPCs can stimulate BMSCs differentiate to an NP-like phenotype.2. Compared with nondegenerate NPCs, co-culture with degenerate NPCs can more significantly stimulate BMSCs differentiating to an NP-like phenotype.3. At the same time, BMSCs can regulate both nondegenerate and degenerate NPCs.