ObjectiveTo prepare a composite scaffold using bladder acellular matrix (BACM) and polyurethane (PU) for bladder repair and regeneration, and to evaluate its mechanical properties and biocompatibility. MethodsFresh bladder tissues were obtained from New Zealand rabbits and then treated with 1%SDS and 1%Triton X-100 to obtain BACM. The BACM was combined with PU to fabricate PU-BACM composite scaffold. The tensile strength and elongation at break of BACM and PU-BACM scaffolds were tested. Scaffolds and extracts of scaffolds were prepared to evaluate the biocompatibility. For cell-proliferation analysis, cell counting kit 8 method was used at 1, 3, 5, and 7 days after co-culture of human bladder smooth muscle cell (HBSMC) and scaffolds. The cell cycle was tested by flow cytometry after HBSMC co-cultured with extracts of scaffolds and DMEM culture medium (control group) for 24 hours. Finally, 12 New Zealand rabbits were used to establish the model of bladder repair and regeneration. Incision of 5 mm was made on the bladder, and PU-BACM scaffold was sutured with the incision. The rabbits were sacrificed at 10, 20, 40, and 60 days after surgery to observe the inflammatory cell infiltration, new tissues formation, and regeneration of epithelium by HE staining. ResultsThe tensile strength of BACM and PU-BACM composite scaffold was (5.78 ± 0.85) N and (11.88 ± 3.21) N, and elongation at break was 14.46%±3.21% and 23.14%±1.32% respectively, all showing significant diffeence (t=3.182, P=0.034；t=4.332, P=0.012). The cell-proliferation rates of controls, PU, BACM, and PU-BACM were 36.78%±1.21%, 30.49%±0.89%, 18.92%±0.84%, and 22.42%±1.55%, it was significantly higher in PU-BACM than BACM (P<0.05). In the bladder repair and regeneration experiment, inflammatory cell infiltration was observed at 10 days after operation, and reduced at 20 days after implantation. In the meanwhile, the degradation of scaffolds was observed in vivo. The regeneration of epithelium could be observed after 40 days of implantation. At 60 days after implantation, in situ bladder tissue formed. ConclusionPU-BACM composite scaffold has higher mechanical properties and better biocompatibility than BACM scaffold. PU-BACM composite scaffold will not lead to strong immune response, and new bladder tissue can form in the in vivo rabbit bladder repair experiment. These results can provide research basis and theoretical data for further study.
Objective To study the protective effects of bone marrow mesenchymal stem cells (BMSCs) of rhesus monkeys on porcine islets from hypoxia/reoxygenation (H/R)-induced injury. Methods BMSCs were isolated and cultured from the marrow of 5 adult rhesus monkeys (weighing, 6-10 kg) by adherent monocytes. Islets were isolated and purified from the pancreas of 5 neonatal porcine (3-5 days old) by collagenase V digestion method, and were cultured with or without BMSCs, and exposed to hypoxia (1%O2) for 12 hours and reoxygenation for 24 or 48 hours, respectively. The experiment was divided into 4 groups: normal islet group (group A), normal islet + BMSCs group (Group B), H/R islet group (group C), and H/R islet + BMSCs group (group D). The survival rate of islets was calculated by fluorescein diacetate/propidium iodide (PI) staining. The viability of the islet cells was detected by cell counting kit 8. Apoptotic rate of islet cells was tested using Annexin V-FITC/PI labeling and flow cytometry. The stimulation index (SI) of islet function was analyzed by glucose-stimulated insulin secretion assay. Results The islet cell cluster of group C was more dispersed than that of groups A and B, and group C had more death cells; and the islet cell cluster of group D was more complete and the survival rate was higher than those of group C. The survival rate of islet was 90.2% ± 9.1%, 88.3% ± 5.9%, 52.3% ± 12.1%, and 71.4% ± 11.5% in groups A, B, C, and D respectively, it was significantly lower in groups C and D than in groups A and B (P lt; 0.05), but it was significantly higher in group D than in group C (P lt; 0.05). After coculture of BMSCs and islet at the ratio of 1 ∶ 10 and 1 ∶ 20 in group D, the viability of islet cells was significantly higher than that in group C (P lt; 0.05). The apoptotic rate was 27.1% ± 3.2%, 24.0% ± 1.0%, 64.3% ± 1.8%, and 46.2% ± 1.4% in groups A, B, C, and D respectively, it was significantly higher in groups C and D than that in groups A and B (P lt; 0.05), but it was significantly lower in group D than in group C (P lt; 0.05). There was no significant difference in SI between groups A and B at each time point (P gt; 0.05), but it was significantly lower in group C than in groups A and B (P lt; 0.05); and it was significantly higher in group D than in group C at 24 and 72 hours (P lt; 0.05). Conclusion BMSCs of rhesus monkeys can protect islet vitality and function from H/R-induced injury.
【Abstract】 Objective To explore good methods for isolation and purification of rat islets. Methods The isletswere isolated from male SD rat pancreata by a collagenase perfusion method and purified by a modified method: added 4 kinds of Euro-Ficoll of different densities (F1: D=1.132, F2: D=1.108, F4: D=1.069, F5: D=1.023), discontinuous density gradient centrifuge the tube at 2 000 r/min for 20 minutes at 4℃ , then the islets between F1 and F2 were collected. The purity of islets was assessed by dithizone staining with islets counted and scored for size. Islets viabil ity was assessed by fluorescin diacetate / propidium iodide. The function of purified islets was judged by the test of insul in release and islets transplantation. Results After an improved method for optimized isolation and purification, (920±122) IEQ purified islets were obtained from one rat. Both the purity and viabil ity of islets were over 90%. The amount of insul in secretion was (18.25±0.32) mU/L and (36.70±3.57) mU/Lat 2.2 mmol/ L and 22.2 mmol/L concentration of glucose respectively, there was significant difference between the two phases(P lt; 0.05). The insul in release index was 2.01±0.15. Under 1 000 IEQ islets transplantation, the normal glucose level could beremained in diabetic rats. Conclusion High purity and high viabil ity islet cells can be got through improved collagenase perfusion and centrifugation on gradients method.
【摘要】 目的 探讨同种异基因骨髓间充质干细胞（bone mesenchamal stem cells，BMSC）静脉输注对大鼠到小鼠胰岛移植物的功能保护和小鼠糖尿病状态改善。 方法 全骨髓培养法获得C57BL/6小鼠BMSC。不连续梯度离心法分离纯化Sprague-Dawley（SD）大鼠胰岛，将300胰岛当量的胰岛单独或与BMSC联合移植入链脲菌素诱导的糖尿病BALB/c小鼠肾包膜下，并通过尾静脉在移植后0、3和5 d注射CM-DiI标记的BMSC 5×105/只，对照组给于磷酸盐缓冲溶液。移植后监测血糖，第9天处死小鼠，取肝、脾、胸腺、淋巴结和移植胰岛的肾脏，冰冻切片，荧光显微镜观察CM-DiI标记细胞的组织分布；免疫荧光法观察移植物中胰岛素和胰高血糖素表达，评价胰岛的功能。 结果 BMSC静脉输注后主要分布于胸腺，其次是脾脏和淋巴结，肾和肝组织中未观察到BMSC；BMSC联合胰岛移植组血糖控制水平优于其他组，且在第7天的口服糖耐量实验优于单纯胰岛移植组。 结论 与胰岛联合移植的BMSC对受者免疫器官和组织有明显的趋向性，且对胰岛细胞的体内存活有一定保护作用。【Abstract】 Objective To research on the protection function by the allogeneic rat bone mesenchymal stem cells (BMSC) on rat to mouse islet transplantation and the improvement of diabetic state in mouse. Methods BMSC were prepared from C57BL/6 mouse bone marrow cells and identified by flow cytometry (FCM). Islets were isolated from Sprague-Dawley (SD) rats with Ficoll discontinuous centrifugation. CM-DiI labeled BMSC at 5×105 for one mouse were intravenously infused into STZ induced diabetic BALB/c mice after rat to mouse islet transplantation at day 0, 3 and 5. Mice with PBS intravenously infused after islet transplantation were set as the negative controls. Blood glucose was monitored every day at the first 3 days after transplantation, and then monitored every two days. At day 9 after transplantation, spleen, thymus, lymph nods, liver and islets recipient kidney were harvested. Ice slices were prepared and CM-DiI labeled cells were investigated with fluorescence microscope. Results CM-DiI-labeled BMSC were mainly distributed in thymus followed by spleen and lymph nodes. In liver and kidney, there was no red fluorescence observed. The blood sugar control for combined BMSC infusion group was superior to other groups, and the control level of islet combined BMSC infusion group were better than single islet transplantation group in OGTT at day 7. Conclusion Allogeneic BMSC can sustain the insulin secretion of islets in vivo and tend to distribute in immune organs or adenoid tissues after infusion.
ObjectiveTo explore the optimal conditions of rat model of hyperuricemia (HUA) induced by different doses of potassium oxanate (PO) combined with adenine, and to provide reference for the treatment of HUA.MethodsMale Sprague-Dawley rats (220-240 g body weight) were divided into normal control group, potassium oxanate (1000, 1500 mg/kg) and adenine (0, 50, 100 mg/kg) combined model groups, with 8 rats in each group. After 5 weeks of intragastric administration, blood were collected from tail vein of rats every week, and serum uric acid, creatinine and blood urea nitrogen level were measured. At the 6th week, the changes of the pathological characteristics, expression of inflammatory and fibrosis-related factors in the kidneys were observed.ResultsIn the 1500 mg/kg potassium oxanate combined with 100 mg/kg adenine group, rats died after 2 weeks of molding, and the survival rate at the 6th week was 62.5%; but there was no significant difference between the other groups and the normal control group in survival rate (P>0.05). Compared with the normal group, the level of serum uric acid in each model group increased significantly after 1 week of molding (P<0.05), but recovered to the pre-model level after stopping intragastric administration in week 6. After 5 weeks, in model groups the levels of serum creatinine and blood urea nitrogen were higher than those in the normal control group; and the inflammation and fibrosis-related factors mRNA and protein expression of kidney tissue in model groups increased with the increase of ademine dose, and there was a significant difference in the PO 1 000 mg/kg with adenine 100 mg/kg group, PO 1 500 mg/kg with Adenine 50 mg/kg group compared to the normal control group (P<0.05). The results of renal anatomy and histology testing in rats showed that with the increased of the dosage of PO and adenine in the model groups, the increase of white deposition of renal medulla, tubulointerstitial fibrosis, and tubular epithelial cell necrosis was found, and the glomerular atrophy aggravated. Compared with the indexes in the normal control group, the expression levels of inflammation and fibrosis related genes and proteins in the 50 mg/kg adenine combined with 1 500 mg/kg PO group were higher, and inflammatory cell infiltration and fibrosis were observed, which was consistent with the clinical manifestation of hyperuricemia induced renal injury.ConclusionPO (1500 mg/kg) combined with adenine (50 mg/kg) can establish a stable hyperuricemic nephropathy model in rats.
Objective To establish a method to isolate the CD4+CD25+ regulatory T cells (Tregs) and to identify the purity and function of these cells. Methods The peripheral blood (8 mL) were collected from the great saphenous vein of 10 rhesus monkeys (4 females and 6 males, aged 4-5 years, and weighing 5-8 kg). The mononuclear cells were isolated with density gradient centrifugation. CD4+ T cells were separated by the Magnetic cell sorting (MACS) negative selection and MACS positive selection. The cell yield rate, the cell viability, and the cell purity were compared between MACS negative selection and MACS positive selection. In CD4+ MACS negative selection, the anti-biotin MicroBeads and biotin-antibody cocktai in CD4+CD25+ Tregs isolation kit non-human primate were used, and in MACS positive selection, the anti-APC MicroBeads in CD4+CD25+ Tregs isolation kit non-human primate and CD4-APC were used. The CD4+ T cells separated by positive selection were selected to obtain CD4+CD25 Tregs with CD25 MicroBeads. The purity, activity, the FoxP3 level, and the suppressive function to concanavalin A (ConA) activated autologous CD4+CD24- effective T cells (Teffs) of CD4+CD25+ Tregs were detected by flow cytometry. Results After CD4+ T cells were separated by MACS negative selection and MACS positive selection, the cell viabilities were all up to 95%, showing no significant difference (P gt; 0.05). The cell yield rate and purity of CD4+ T cells by positive selection were significantly higher than those of CD4+ T cells by negative selection (P lt; 0.05). CD4+CD25+ Tregs can be successfully isolated by MACS double positive selection. The classifying purity was 76.2% ± 8.6%; the cell activity was 93.3% ± 4.7%; and the level of FoxP3 was 74.2% ± 6.9%. The CD4+CD25+ Tregs had suppressive effect on ConA activated autologous CD4+CD25- Teffs. Conclusion MACS double positive selection can be used to isolate high-purity CD4+CD25+ Tregs from the peripheral blood of rhesus monkeys and the process does not influence the activity of CD4+CD25+ Tregs.
【摘要】目的 报道四川大学华西医院首例胰肾联合移植。方法 2007年3月我院对1例2型糖尿病合并肾功能衰竭患者成功施行了胰肾联合移植手术，将肾脏移植于左侧髂窝，胰腺移植于右侧髂窝，胰腺移植采用肠道-体循环回流术式。结果 术后第1 d C-肽升至正常水平，第4 d血肌酐恢复正常，第11 d血尿素氮恢复正常，血糖逐渐趋于稳定，第16 d完全停用胰岛素，术后3周OGTT结果显示移植胰腺功能正常。随访6个月移植胰腺、肾脏功能正常，没有发生手术相关并发症。结论 胰肾联合移植是治疗2型糖尿病合并肾功能衰竭的有效手段。