Objective To investigate the protective effects of bone marrow mesenchymal stromal cells ( BMSCs ) on spinal cord injury ( SCI ) model of rats and its potential mechanism. Methods Totally 60 adult SD rats were randomly divided into 3 groups: sham group ( n = 20 ), SCI group ( n = 20 ) and BMSCs group ( n = 20 ). Model of spinal cord injury was established by modified Allen’ s assay. From the first day after injury, motor function of the rats’ hind limb was evaluated by BBB ( Basso Beattie and Bresnahan ) scores and Catwalk gait analysis and detection at 14 d. Content of myeloperoxidase ( MPO ), malondialdehyde ( MDA ), superoxide dismutase ( SOD ) in spinal cord tissue and levels of tumor necrosis factor-α ( TNF-α ), interleukin-6 ( IL-6 ), interleukin-10 ( IL-10 ) in serum were determined by ELISA analysis. Pathological changes of spinal cord tissues were observed with HE staining. Results Compared with the model group, the content of MPO in injured spinal cord at 12h after injury in BMSCs group decreased from ( 149.7 ± 28.4 ) nmol / mg to ( 116.0 ± 29.2 ) nmol / mg, MDA levels decreased from ( 58.1 ± 3.3 ) U / g to ( 41.7 ± 2.6 ) U / g, at 6 h after injury TNF-α levels in serum decreased from ( 439.8 ± 12.8 ) pg / ml to ( 314.6 ± 17.6 ) pg / ml, IL-6 levels decreased from ( 364.7 ± 16.9 ) pg / ml to ( 232.9 ± 15.2 ) pg / ml while SOD activity increased from ( 194.6 ± 14.3) U / mg to ( 362.0 ± 13.6 ) U / mg, IL-10 levels increased from ( 291.3 ± 9.8 ) pg / ml to ( 377.9 ± 17.9 ) pg / ml ( P < 0.05 ). Compared with the SCI group, BBB scores and catwalk gait analysis improved significantly at 14 d after injury in BMSCs group ( P < 0.05 ). The pathological injury of spinal cord was relieved in BMSCs group. Conclusions BMSCs administration improves the motor function after spinal cord injury. Its potential mechanism may be the inhibition of inflammatory reaction and oxidative stress reaction.

BACKGROUND:The elderly hip fracture patients with chronic obstructive pulmonary disease (COPD) have a higher postoperative mortality than those only with hip fractures. In recent years, it has become an issue of concerns. Because the mechanism is unknown, however, there are no effective clinical interventions for these patients. OBJECTIVE:To observe the effect of bone marrow stromal stem cel s (BMSCs) on the level of pulmonary inflammation in aged rats with chronic obstructive pulmonary disease (COPD) after hip fractures. METHODS:Thirty male Sprague-Dawley rats, 12 months old, were exposed to smoking for 4 months and randomized into three groups, smoking, smoking+hip fracture+normal saline, smoking+hip fracture+BMSCs groups. Animal models of hip fracture were made in the latter two groups. Twenty-four hours after hip fracture, the lower lobe and peripheral blood samples were taken from al rats in the three groups, to evaluate the pathological changes of lung tissue and detect levels of inflammatory factors in the lung tissue and peripheral blood. RESULTS AND CONCLUSION:After closed hip fracture, aged COPD rats exhibited inflammatory cel infiltration, mucus secretion, airway stenosis or occlusion;the levels of interleukin-6, tumor necrosis factor-αand interleukin-10 in the lung tissue and peripheral blood were increased. After intravenous injection of BMSCs, the pathological changes of the lung tissue were reduced, and the levels of pro-inflammatory factors, tumor necrosis factor-αand interleukin-6, decreased, but the level of anti-inflammatory factor interleukin-10 further increased, which were significantly different from those in the normal saline group (P<0.05). These findings indicate that BMSCs can relieve acute lung injury in aged COPD rats with hip fractures.

目的 探讨β淀粉样蛋白(amyloid β,Aβ)在大鼠脊髓损伤(spinal cord injury,SCI)后的表达变化及γ分泌酶抑制剂DAPT对其作用机制的影响.方法 选用雌性SD大鼠117只,随机分成3组:假手术组(Sham组,31只)、脊髓损伤组(SCI组,43只)、干预组(DAPT组,43只),采用Allen's打击法制作大鼠脊髓损伤模型,DAPT组于造模前及术后给予DAPT药物溶液胃管灌注,并于术后6h、ld、3d、7d、14 d、21 d、28 d取血液、脑脊液及损伤段脊髓组织,分别行酶联免疫吸附试验(ELISA)检测血清和脑脊液Aβ水平,免疫印迹法(Western blot)检测脊髓组织淀粉样前体蛋白(amyloid precursor protein,APP)、β淀粉样蛋白、轴突生长抑制因子受体(neurite growth inhibitor receptor 1,NgRl)、Rho相关激酶2(Rho related kinase 2,Rock2)蛋白水平,免疫组化分析观察Aβ表达并计数阳性细胞,采用BBB评分评估大鼠后肢运动功能恢复情况.结果 SCI组大鼠Aβ水平明显高于Sham组(P＜0.05),血清和脑脊液中Aβ水平在SCI后6h开始升高,3d时达到高峰,7d时降至正常水平,应用DAPT能够明显降低SCI后Aβ水平(P＜0.05);脊髓损伤后3 d SCI组Aβ、NgR1、Rock2蛋白水平较Sham组明显升高(P＜0.05),DAPT组Aβ、NgR1、Rock2蛋白水平较SCI组明显降低(P＜0.05);免疫组化分析可见损伤区脊髓Aβ阳性细胞明显增多,DAPT组Aβ阳性细胞数明显少于SCI组(P＜0.05);DAPT组大鼠BBB评分明显高于SCI组(P＜0.05);SCI大鼠血清和脑脊液Aβ水平与运动功能BBB评分呈负相关(P＜0.05).结论 大鼠SCI后Aβ表达上调,通过应用γ分泌酶抑制剂DAPT减少Aβ表达能够促进运动功能恢复,其机制可能是通过下调NgR1蛋白表达、抑制Rho/Rock通路激活,从而减少白质区髓鞘结构损伤.

BACKGROUND: Platelet-rich plasma gel serves as a three-dimensional scaffold in which stem cel s can exhibit a three-dimensional growth. Meanwhile, platelet-rich plasma gel can release large amounts of growth factors to promote the proliferation and differentiation of adipose-derived mesenchymal stem cel s. OBJECTIVE: To explore the repair effect of injection of autologous platelet rich plasma-adipose derived mesenchymal stem cel s complex on rabbit intervertebral disc degeneration. METHODS: Rabbit arterial blood was extracted to prepare autologous platelet-rich plasma using secondary centrifugal method, and adipose-derived mesenchymal stem cel s were isolated from the fat tissue of rabbit scapular area. Then, adipose-derived mesenchymal stem cel s-platelet-rich plasma gel complex was prepared. New Zealand white rabbits were randomized into control group, model group, platelet-rich plasma gel group and complex group (adipose-derived mesenchymal stem cel s-platelet-rich plasma gel complex). Intervertebral disc degeneration model was made in the latter three groups using puncture method. At 2 weeks after modeling, corresponding materials were injected into the disc in the four groups, respectively. RESULTS AND CONCLUSION: After intervertebral disc degeneration in rabbits, the intervertebral gap was significantly reduced, the nucleus pulposus signal was obviously decreased, nucleus pulposus matrix appeared to have a high density and to be deeply stained. The symptoms above mentioned were improved significantly after intervention with the platelet-rich plasma gel or the complex of adipose-derived mesenchymal stem cel s-platelet-rich plasma gel, while the latter was better in curative effects. Injection of platelet-rich plasma gel and adipose-derived mesenchymal stem cel s-platelet-rich plasma gel complex can reduce the influence of disc degeneration, and the effect of adipose-derived mesenchymal stem cel s-platelet-rich plasma gel complex is more outstanding.

Objective To study the effect of auto-platelet rich plasma(PRP) gel stents produced by centrifugation on proliferation of adipose derived stem cells(ADSCs) and release of growth factors.Methods Auto-PRP gel stents were produced by two or three centrifugations of arterial blood from New Zealand rabbits.Platelet concentration in such stents were measured.After the absolute platelet concentration in auto PRP gel stents was adjusted to 1 000×109/L by adding DMEM,the volume fraction of auto-PRP gel stents into which DMEM was added was adjusted to 30%,40%,50% and 60% of the absolute platelet concentration.Auto-PRP gel stents containing only DMEM served as a blank control group.Fluorescence-stained ADSCs were then implanted into auto-PRP gel stents and counted for 7 consecutive days.Cell growth curve was plotted.Survival rate and proliferation activity of ADSCs were analyzed by MTT colorimetry on days 2-4 and 6.TGF-β1 and collagen-Ⅱ levels in ADSCs were measured by ELISA.Results The platelet concentration in auto-PRP gel stents produced by two and three centrifugations was(1 320.5±227.3)×109/L and(1 724.5±316.3)×109/L respectively,which was 5.4-fold and 7.1 –fold higher than that in the whole blood(P < 0.05).The platelet concentration in auto-PRP gel stents produced by three centrifugations was higher than that in auto-PRP gel stents produced by two centrifugations(P < 0.05).The number of ADSCs in auto-PRP gel stents produced by two or three centrifugations reached its peak which was(1.02±0.13)×104and(1.00±0.14)×104respectively when the platelet concentration was 500×109/L(P > 0.05).The proliferation activity and the number of ADSCs in auto-PRP gel stents reached their peak when the platelet concentration was 500×109/L,and the TGF-β1 and collagen-Ⅱ levels were significantly higher when the platelet concentration was 500×109/L than when the platelet concentration was lower or higher than 500×109/L(P < 0.05).Conclusion The detection rate of platelets is higher in auto-PRP gel stents produced by three centrifugations than by two centrifugations.However,no significant difference can be found in promoting proliferation of ADSCs in auto-PRP gel stents produced by two or three centrifugations.The proliferation and activity of ADSCs reach their peak when the platelet concentration is 500×109/L in auto-PRP gel stents,which may be the optimal concentration for preparation of PRP.