Isolation,purification and identification of rat annulus fibrosus-derived stem cells by adherent method combined with fibronectin differential adhesion method / 中国组织工程研究

ABSTRACT

BACKGROUND:At present,bone marrow mesenchymal stem cells are the main seed cells used in cell therapy for the treatment of intervertebral disc degeneration.However,the use of bone marrow mesenchymal stem cells as seed cells for the regeneration of fibrous rings is at risk of heterotopic ossification and teratoma at the repair site.Therefore,it is of great economic and social significance to find a new kind of seed cells for tissue engineering of annulus fibrosus for the treatment of intervertebral disc degeneration. OBJECTIVE:To isolate and purify rat annulus fibrosus-derived stem cells by adherent method combined with fibronectin differential adhesion screening method,and to observe its purification effect and biological characteristics. METHODS:Annulus fibrosus tissue was obtained from a SD rat intervertebral disc.Primary annulus fibrosus-derived stem cells were obtained by the mechanical-enzymatic digestion method.Annulus fibronectin differential adhesion method was used to purify annulus fibrosus-derived stem cells.Morphological changes and proliferation of cells were observed through a microscope.The expression levels of stem cell markers were detected by immunofluorescence technique and qPCR.The screened cells were subjected to multi-lineage cell differentiation and characteristic gene detection. RESULTS AND CONCLUSION:(1)The purified cells grew well,and most of them were angular and star-shaped multi-process cells,which had good proliferation ability.(2)Cells were positive for cell membrane surface antigens CD73,CD90 and CD105,while negative for CD45 and CD34.(3)After specific induction,cells could successfully differentiate into osteoblasts,chondroblasts and lipoblasts.(4)Collagen-I,Runx-2 after osteogenic induction,Collagen Ⅱ,Sox-9 after chondrogenic induction,and PPAR-γ and LPL after lipogenic induction were highly expressed in cells,and the difference was significant compared with that before induction(P<0.05).(5)These findings confirm that the adherent method combined with fibronectin differential adhesion method is effective enough to screen,isolate and purify rat annulus fibrosus-derived stem cells,and has good cell biological properties,good proliferation ability and multiple differentiation potential.