ABSTRACT
BACKGROUND:Stem cel therapy has been used for prevention and treatment of degenerative disc disease. Considering the special microenvironment in the intervertebral disc, the survival rate and differentiation ability of transplanted cels are decreased, which may lead to the poor efficacy of stem cel therapy. How to improve the survival ability and therapeutic effect of the transplanted cels is the focus of stem cel therapy for degenerative disc disease. OBJECTIVE: To investigate the effects of cobalt chloride combined with hypertonic solution pretreatment on bone marrow mesenchymal stem cels that wil be transplanted for treatment of degenerative disc disease. METHODS:(1)In vitro cel experiment: bone marrow mesenchymal stem cels were divided into three groups and subjected to normal culture medium (normal control group), 1% hypertonic mother solution (hypertonic group), 100 μmol/L cobalt chloride (hypoxia group), or 1% hypertonic mother solution plus 100 μmol/L cobalt chloride (combined group) for 1 week. Then, 2% hypertonic solution and 200 μmol/L cobalt chloride cobalt chloride were used to simulate the anaerobic and hypertonic environment intervenes in pretreated and untreated bone marrow mesenchymal stem cels for 24 hours. After that, RT-PCR was used to detect the expression of caspase-3 for apoptosis evaluation. (2)In vivo animal experiment: Sprague-Dawley rats were divided into model, cel transplantation and hypertonic plus hypoxic groups. Rat models of intervertebral disc degeneration were made in these three groups. After modeling, rats in these three groups were given no treatment, bone marrow mesenchymal stem cel transplantation or transplantation of bone marrow mesenchymal stem cels which were subjected to hypertonic and hypoxia pretreatments into the intervertebral disc. Two weeks later, immunohistochemistry and RT-PCR methods were used to detect cel distribution and related gene expression, respectively, thereby to evaluate the therapeutic effect of stem cels. RESULTS AND CONCLUSION: (1)In vitro cel experiment: caspase-3 mRNA expression was significantly reduced in pretreated bone marrow mesenchymal stem cels compared with the untreated cels (P < 0.05). (2)In vivo animal experiment: compared with the control group, the caspase-3 and interleukin-1β in the intervertebral disc and a number of degenerative indexes were decreased in the cel transplantation. Compared with the cel transplantation group, these indicators had better outcomes in the hypertonic plus hypoxic group (P < 0.05). These findings indicate that bone marrow mesenchymal stem cels have therapeutic potential for degenerative disc disease, and have better adaptability and transplantation effects by hypertonic and hypoxia pretreatments.