Differentiation from Bone Marrow Stem Cells into neuronal-like Cells Induced by Fetal Spinal Cord Tissue

BACKGROUND: It is demonstrated that bone marrow stem cells (BMSCs) can generate neurosphere structures, which is similar to Cloning sphere of neuron-specific enolase (NSE), in a specially induced system in vitro; therefore, BMSCs draw more and more attention as seed cells to repair central nerve injury. OBJECTIVE: To investigate the differentiation from BMSCs into neuron-like cells induced by fetal spinal cord tissue. DESIGN: Observational study. SETTING: Department of Spine Surgery, Second People’s Hospital of Shenzhen. MATERIALS: SD rats (16 pregnant days old and 2 months old) were provided by Animal Center, Tongji Medical College, Huazhong University of Science and Technology. Single antibody of NSE, multi-antibody of glial fibrillary acidic protein (GFAP) and single antibody of neurofilament (NF200) were provided by Wuhan Boster Company. METHODS: The experiment was carried out in Immune Opening Laboratory and Central Laboratory, Basic Medical Department, Tongji Medical College, Huazhong University of Science and Technology in September 2006. Bones of lower extremities of rats were collected to centrifuge BMSCs. Fetal spinal cord tissue homogenate was extracted from 16 pregnant days old rats to make inducing solution and induce differentiation of BMSCs. Otherwise, embryo muscle tissue was used to make muscle tissue homogenate as the same way so as to regard as the controls. MAIN OUTCOME MEASURES: BMSCs underwent morphological observation after induction; in addition, anti-NSE, NF200 and anti-GFAP were used to label neurons and astrocytes, respectively. Ten non-overlapping sights were randomly selected from positive reactive-induced cells after immunohistochemical staining under optic microscope to calculate ratio of positive cells of NSE and NF200 counting for total numbers of cells. RESULTS: ①Morphological changes of BMSCs after induction: During early induction, optic microscope indicated that soma of partial cells rebounded; whose apophysis was long and thin: apophysis of differentiated cells grew gradually and intercrossed each other, It was similar to nerve cells and some branches were similar to dendrite branches. However, morphological changes of cells in the control group were not obvious. ②Expression of relevant antigens differentiated from BMSC5 into neuron-like cells at one week after induction: Most cells in spinal cord homogenate group expressed as positive NSE and NF200; a few of cells expressed as GFAP. While, positive staining of nerve cell antibody was not observed in the control group: meanwhile, positive reaction of nerve cell antigen was not observed in the control group, too. Immunohistochemistry examination demonstrated that positive rates of NSE and NF200 expressions were (68±1.7)% and (76.2±2.9)%, respectively. CONCLUSION: Fetal spinal cord tissue homogenate can induce differentiation from BMSCs into neuron-like cells.