Isolation, culture and identification of nucleus pulposus-derived mesenchymal stem cells from adult rats in vitro

Rui Yun-feng; Wang Shan-zheng; Xie Xin-hui; Sun Ming-hui; Lin Yu-cheng; Li Gang; Wang Chen

doi:10.3969/j.issn.2095-4344.2013.49.018

Abstract：BACKGROUND:Currently, cellular composition and the features of the nucleus pulposus are stil not to be clarified. <br> OBJECTIVE:To establish the in vitro culture system of rat nucleus pulposus-derived mesenchymal stem cells and to identify their multi-lineage differentiation potential. <br> METHODS:Mesenchymal stem cells from the nucleus pulposus tissues of Sprague-Dawley rats were cultured in vitro. Then, cells at passage 3 were induced to differentiate into osteoblasts, adipocytes and chondrocytes as experimental group. cells cultured with basic culture medium served as controls. <br> RESULTS AND CONCLUSION:cells isolated from rat nucleus pulposus could form the sunflower-like colonies and exhibit clone-like growth when they cultured at a low density. cells at passage 3 became homogeneous and exhibited fibroblast-like morphology. After 28 days of osteogenic induction, arizarin red positive signals were detected in the experimental group. The mRNA expressions of RunX2, osteopontin and osteocalcin were significantly increased in the experimental group, compared to the control group (P<0.05). After 21 days of adipogenic induction, oil red-O positive cells were detected in the experimental group. The mRNA expressions of C/EBPαand PPARγ2 were significantly increased in the experimental group, compared to the control group (P<0.05). After 21 days of chondrogenic induction, safranin O/fast green staining was positive in the experimental group. The mRNA expressions of aggrecan and Col2a1 were significantly increased in the experimental group, compared to the control group (P<0.05). Our findings in this study suggested that nucleus pulposus-derived mesenchymal stem cells could be isolated from the Sprague-Dawley rat nucleus pulposus and exhibited clonal-like growth when they were cultured in vitro. These cells were confirmed to have the potential to differentiate into adipocytes, osteoblasts and chondrocytes in vitro.