摘要目的 观察人脐带间充质干细胞(hUCMSC)对糖尿病(DM)大鼠血糖的影响及对视网膜病变的治疗作用.方法 健康雄性Sprague-Dawley大鼠45只,随机分为正常对照组(A组)、DM组,分别为10、35只大鼠.DM组经尾静脉注射链脲佐菌素诱导DM模型.10周时,A组、DM组分别随机选取2只大鼠行视网膜血管铺片.DM组剩余的33只大鼠随机分为糖尿病视网膜病变组(B组)、尾静脉注射hUCMSC组(C组)、玻璃体腔注射hUCMSC组(D组),各组均为11只大鼠.A、B组不进行干预.干预后2、4、6、8周为观察处理时间点.各处理时间点前,连续3d每次随机选取2只大鼠检测随机血糖.DM组大鼠血糖与同期A组大鼠血糖比较,差异均有统计学意义(t=-64.400、-60.601、-44.065、-43.872,P=0.000).8周时从B、C、D组随机选取2只大鼠行视网膜血管铺片.免疫组织化学法观察视网膜脑源性神经营养因子(BDNF)阳性染色情况;实时荧光定量逆转录聚合酶链反应(RT-PCR)检测视网膜BDNFmRNA相对表达量.结果 干预后,不同处理时间点A、B、C、D组大鼠血糖比较,差异均有统计学意义(F=400.017、404.410、422.043、344.109,P=0.000);C组大鼠血糖与B、D组大鼠血糖比较,差异有统计学意义(t=4.447、4.990、P＜0.01).免疫组织化学染色结果显示,A组BDNF表达呈阳性,主要分布在神经节细胞层;B组BDNF表达呈弱阳性;C、D组BDNF表达增多.RT-PCR检测结果显示,4、6、8周时,B、C、D组间视网膜BDNF mRNA相对表达量比较,差异均有统计学意义(F=29.372、188.492、421.537,P=0.000);C、D组视网膜BDNF mRNA相对表达量与B组比较,差异均有统计学意义(t=66.781、72.401、63.880、88.423、75.120、83.002,P＜0.01);C组视网膜BDNF mRNA相对表达量与D组比较,仅8周时差异有统计学意义(t=127.321,P=0.005).结论 尾静脉注射hUCMSC能够显著降低大鼠血糖水平;尾静脉或玻璃体腔注射hUCMSC均可增加BDNF的表达.

abstractsObjective To observe the effects of human umbilical cord mesenchymal stem cells (hUCMSCs) on blood glucose levels and diabetic retinopathy in diabetes mellitus (DM) rats.Method A total of 45 healthy male Sprague-Dawley rats were randomly divided into normal control group (group A,10 rats) and DM group (33 rats).Diabetic model was established in DM group by tail vein injection of streptozotocin.The DM group was further randomly divided into 3 groups (11 rats in each group),including group B (no transplantation),group C (hUCMSC was injected through tail vein) and group D (hUCMSC was injected into the vitreous).Blood glucose,retina wholemont staining and expression of brain derived neurotrophic factor (BDNF) in the retina were measured at 2,4,6,8 weeks after hUCMSC injection.The blood glucose was significantly different between A-D groups before injection (t=-64.400,-60.601,-44.065,-43.872; P=0.000) BDNF expression was studied by real time fluorescence quantitative polymerase chain reaction (RT-PCR) and immunohistochemistry staining.Results The blood glucose was significantly different between A-D groups after hUCMSC injection (F=400.017,404.410,422.043,344.109; P=0.000),and between group C and group B/D (t=4.447,4.990; P＜0.01).Immuno-staining shown that BDNF was positive in ganglion cell layer (RGC) of group A,weak in group B while BDNF expression increased in group C/D.BDNF mRNA expression was significantly different between group B,C andDat 4,6 and 8 weeks after hUCMSC injection (F 29.372,188.492,421.537; P=0.000),and between group B and C/D (t=66.781,72.401,63.880,88.423,75.120,83.002; P＜0.01) by RT-PCR analysis.The BDNF mRNA expression was significantly different between C and D groups only at 8 weeks after hUCMSC injection (t =127.321,P =0.005).Conclusions Tail vein injection of hUCMSCs can significantly reduce the blood glucose levels of rats.Intravenous and intravitreal injection of hUCMSCs can increase the expression of BDNF.