脐血干细胞对1型糖尿病大鼠血糖及PDX-1、MafA表达水平的影响

Effect of umbilical cord blood stem cells on blood glucose levels and PDX-1 and Maf A levels in type 1 diabetic rats

背景:1型糖尿病是一种自身免疫性疾病,以胰腺β细胞选择性破坏,导致患者体内胰岛素分泌绝对不足为特征。脐血干细胞具有多分化潜能,在体内外均可以诱导分化为胰岛细胞,发挥出一定的降糖作用。目的:探讨脐血干细胞对1型糖尿病大鼠血糖水平及胰腺组织PDX-1、Maf A表达的影响。方法:30只SD大鼠随机分为3组,每组10只,治疗组和模型组大鼠建立1型糖尿病模型,造模成功后,治疗组尾静脉一次性注射脐血干细胞,正常组给予相同体积的生理盐水,模型组给予相同体积的脐血干细胞缓冲液。采用口服葡萄糖耐量试验评价大鼠胰岛功能,苏木精-伊红染色观察大鼠胰腺形态,Western blot和PCR检测胰腺组织PDX-1、Maf A蛋白和m RNA表达。结果与结论:1模型组和治疗组大鼠0,30,60,90 min的血糖值均显著高于正常组,差异均有显著性意义(P<0.05);120 min时间点模型组血糖值显著高于正常组(P<0.05);治疗组则与正常组之间差异无显著性意义(P>0.05)。2模型组胰岛数量出现下降,边界模糊不清,呈不规则形态,治疗组胰岛数量出现一定的减少,但尚维持清晰的结构。3治疗组PDX-1及Maf A表达水平与正常组比较差异无显著性意义(P>0.05),但显著高于模型组(P<0.05)。以上结果表明,脐血干细胞可以显著降低1型糖尿病大鼠的血糖水平,改善胰岛功能及胰腺组织形态,并具有上调PDX-1、Maf A表达的作用。

BACKGROUND： Type 1 diabetes mellitus is an autoimmune disease, which is characterized as the selective destruction of pancreatic beta cells in the body, resulting in the lack of insulin secretion. Umbilical cord blood stem cells have the potential to differentiate into islet cells in vitro and in vivo, which play a certain hypoglycemic effect. OBJECTIVE： To explore the effects of umbilical cord blood stem cells on blood glucose levels and PDX-1 and Maf A levels in the pancreatic tissue of type 1 diabetic rats. METHODS： Thirty Sprague-Dawley rats were randomly divided into three groups, with 10 rats in each group. In treatment and model groups, type 1 diabetes mellitus modes were established. After modeling, the treatment group was given a single tail vein injection of umbilical cord blood stem cells; the normal control group was given the same volume of normal saline; the model group was given the same volume of umbilical cord blood stem cell buffer solution. Oral glucose tolerance test was adopted to assess the islet function of rats; hematoxylin-eosin staining was used to observe the pancreatic morphology of rats; western blot and PCR methods were employed to detect expressions of PDX-1 and Maf A in pancreatic tissues at protein and m RNA levels. RESULTS AND CONCLUSION：（1） Compared with the normal control group, the levels of blood glucose in the model and treatment groups were significantly higher at 0, 30, 60, 90 minutes（P〈0.05）. At 120 minutes, the blood glucose level in the model group was significantly higher than that in the normal control group（P〈0.05）, but there was no difference between the treatment and normal control groups（P〉0.05）.（2） The number of isletsin the model group was decreased, and the boundary was unclear and irregular; in the treatment group, the number of islets was decreased, but the boundary was still clear.（3） The expressions of PDX-1 and Maf A in the treatment group were similar to those in the normal control group（P〉0.05）, but significantly higher than those in the model group（P〈0.05）. These findings suggest that the umbilical cord blood stem cell transplantation can significantly reduce the blood glucose levels in type 1 diabetic rats, improve the function of islet and morphology of pancreas, and up-reuglate the expressions of PDX-1 and Maf A.