摘要目的 探讨生长分化因子11(GDF11)对糖尿病大鼠下肢缺血部位中血流恢复及血管新生的作用,以及对缺血肌肉中缺氧诱导因子1α(HIF1α)及血管内皮生长因子(VEGF)表达的影响.方法60只200~220 g SD大鼠,通过注射链脲佐菌素建立糖尿病模型,筛选空腹血糖≥16.7 mmol/L大鼠40只,饲养12周后建立下肢缺血模型,随机分为4组:糖尿病下肢缺血模型+磷酸缓冲液组(PBS组)、糖尿病下肢缺血模型+GDF11重组蛋白治疗组(GDF11组)、糖尿病下肢缺血模型+IgG Ab组(IgG Ab组)、糖尿病下肢缺血模型+GDF11抗体组(GDF11 Ab组).其中GDF11组在建模后连续14d给予腹腔注射GDF11重组蛋白(0.1 mg/kg),PBS组注射等量PBS溶液;GDF11 Ab组通过腹腔注射GDF11抗体100 μg,IgG Ab组则注射等量IgG Ab,1周2次连续2周.分别在建模后0、7、14天,采用激光多普勒血流仪检测各组下肢血流灌注情况,免疫荧光染色测定CD31,判断缺血部位肌肉毛细血管数量,免疫印迹检测各组HIF1α、VEGF蛋白表达情况.结果 GDF11组缺血下肢血流量第7、14天较PBS组明显升高,而GDF11 Ab组第14天缺血下肢血流量较IgG Ab组降低.与之一致,GDF11干预后缺血下肢周围微血管增多,而GDF11 Ab组较对照组微血管减少,同时,免疫印迹法发现GDF11干预后HIF1α、VEGF表达升高,而GDF11 Ab干预后其表达降低.结论 GDF11治疗可促进糖尿病大鼠下肢缺血恢复,其作用可能与提高缺血状态下促血管生成因子HIF1α及VEGF蛋白的表达,增加微血管数量有关.

abstractsObjective To investigate the effects and possible mechanism of growth differentiation factor 11 (GDF11)on angiogenesis in diabetic hindlimb ischemia. Methods Sixty SD rats were used in this study. Diabetes was induced by intraperitoneal injection of streptozotocin. 3 days after streptozotocin administration, 40 rats with plasma glucose concentration≥16.7 mmol/L were selected in the subsequent experiments. 12 weeks after diabetes was induced,the left femoral artery and all the sides branches were dissected free and excised. After resection of the left femoral artery,rats were randomized to four groups:PBS group(n=10),GDF11 group(n=10),IgG Ab group (n=10),or GDF11 Ab group(n=10). After 0,7,and 14 days,the serial blood flows were measured by a Laser Doppler perfusion image(LDPI)analyzer. To detect capillary endothelial cell,the sections of muscles were reacted with anti-CD31 monoclonal antibodies,and subsequently reacted with Cy3-conjugated anti-rabbit IgG antibody. The expression levels of HIF1α and VEGF were detected by western blotting. Results In GDF11 group significantly increased the blood perfusion and capillary density of ischemia hindlimb of the diabetic rats were found,which was correlated to an increased level of HIF1α and VEGF. In contrast, GDF11 Ab could lead to the opposite effects. Conclusion GDF11 treatment promotes the recovery of diabetic hindlimb ischemia, which may be related to the improvement of expression of HIF1 alpha and VEGF.