Sodium nitroprusside in the hematopoietic differentiation of rat bone marrow-derived mesenchymal stem cells in vivo / 中国组织工程研究

ABSTRACT

BACKGROUND: How dose sodium nitroprusside, as a vasodilatator, affect the potential of bone marrow-derived mesenchymal stem cells (MSCs) in hematopoietic differentiation?OBJECTIVE: To observe the changes during the differentiation of MSCs into hematopoietic cells after adding sodium nitroprusside, and compare the results with those of simple MSCs transplantation.DESIGN: A randomized grouping, controlled observation.SETTINGS Department of Microbiology and Immunology; Department of Pathophysiology, Guangdong Medical College.MATERIALS The experiments were carried out in Guangzhou Medical College in August 2006. Twenty-seven clean-degree balb/c mice of 7-8 weeks, were used as recipients, and were randomly divided into MSCs transplantation group (n =9), sodium nitroprusside+MSCs transplantation group (n =9) and blank control group (n =9). Another 4-week-old SD rat was selected as the MSCs donor. Sodium nitroprusside for injection (50 mg/piece) was provided by Beijing Double-Crane Modern Pharmaceutical Technology Co., Ltd (National drug approval No. H11020907).METHODS: ① Under aseptic condition, the femur of SD rat was collected. MSCs in it were isolated for culture and amplifying in vitro. MSCs of passages 6-7 were digested and centrifugated, and the density was adjusted to 1×109 L-1.Monoclonal antibody with fluorescence labeled was added into cell suspension, and the phenotype was detected with flow cytometry. ② Sodium nitroprusside (50 mg/piece) was adjusted to the terminal concentration of 200 mg/L by adding with saline. It should be used within 4 hours. ③ Before transplantation, all the mice were exposed to 5.0 Gy. X-ray for 4 hours, and the absorbed dose was 1.45 Gy per minute. After irradiation, mice in the MSCs transplantation group were directly infused via caudal vein with 0.3 mL MSCs suspension (containing 1.5×106 cells); The mice in the sodium nitroprusside+MSCstransplantation group were firstly injected with the dispensed 200 mg/L sodium nitroprusside (0.15 mL), and immediately infused with 0.3 mL MSCs suspension (containing 1.5×106 cells) after 1 minute; The mice in the blank control group were infused with isovolume serum-free culture medium. ④ At 60 days after transplantation,peripheral blood was drawn from orbits of the survived mice in each group, single cell suspensions of bone marrow and spleen were prepared after the mice were killed, the levels of rat-derived hematopoietic cells CD11a and CD45 were detected with flow cytometry.MAIN OUTCOME MEASURES: ① MSCs culture and amplification; ② Levels of rat-derived hematopoietic cells in different tissues.RESULTS: All the 27 balb/c mice as recipients survived to the end of the experiment. ① MSCs isolation and amplification The MSCs attached with uniform shapes of spindle and proliferated rapidly after culture for 3 days, and 90% of the cells were fused without overlapping at 6 days. The cells attached completely within 24 hours after passage,extended and became spindle again, rapidly proliferated and grew, and became fused completely at 3 days. ② Levels of rat-derived hematopoietic cells in different tissues In the MSCs transplantation group and sodium nitroprusside+MSCs transplantation group, Iow expressions of rat-derived CD11a and CD45 hematopoietic cells could be detected in peripheral blood, bone marrow and spleen, and they were obviously higher in the sodium nitroprusside+MSCs transplantation group than in the MSCs transplantation group (t=2.619, P ＜ 0.05), while negative ones in the blank control group.CONCLUSION: MSCs have the ability to differentiate into hematopoietic stem cells, which can be promoted by sodium nitroprusside.