人脐带间充质干细胞对大鼠视网膜光损伤的保护作用

目的观察体外人脐带间充质干细胞(human umbilical cord mesenchymal stem cells,hUCMSCs)能否由视网膜匀浆上清液诱导分化为神经样细胞及移植到视网膜光损伤大鼠玻璃体内后存活、迁移、整合及分化的情况。方法无菌条件下采集健康足月剖宫产胎儿的正常脐带组织,经2.5 g·L^-1胰蛋白酶和1 g·L^-1胶原酶消化、贴壁培养获得hUCMSCs。将CM-Dil标记的hUCMSCs注入光损伤大鼠玻璃体内,观察眼内整合分化情况,对正常对照组、光损伤组、PBS治疗组和hUCMSCs治疗组大鼠视网膜外核层层数和厚度进行对比分析。结果 hUCMSCs培养48 h后贴壁生长,呈长梭形,14 d后可见细胞融合成片。光损伤后大鼠视网膜外核层结构紊乱、细胞层数减少,厚度变薄,与正常对照组[(40.73±1.32)μm]相比,hUCMSCs治疗组[(31.28±1.79)μm]与PBS治疗组[(17.21±1.02)μm]及光损伤组[(12.68±1.42)μm]的视网膜外核层厚度均变薄(均为P<0.05)。与光损伤组相比,PBS治疗组和hUCMSCs治疗组视网膜外核层层数显著增加。结论 HUCMSCs移植到光损伤大鼠玻璃体内后能存活、迁移及整合到受损伤视网膜,hUCMSCs玻璃体内移植可抑制光损伤大鼠光感受器的凋亡。

Protective effects of human umbilical cord mesenchyme stem cells on light-induced retinal damage in rats

Objective　To investigate whether human umbilical cord mesenchymal stem cells （hUCMSCs） can be differentiated into neuron-like cells from the supernatant of retinal homogenate and the survival，migration，integration，differentiation after transplantation into the vitreous cavity of rats with retinal light damage.Methods　The normal umbilical cord tissue of healthy full-term pregnancy cesarean section was collected under aseptic conditions.The hUCMSCs were obtained after digesting with 2.5 g·L^-1 trypsin and 1 g·L^-1 collagenase followed by adherent culture.THE CM-DiI labeled hUCMSCs were injected into the vitreous cavity of light-damage rats to observe the intraocular integration and differentiation.The comparison of the number and the thickness of the outer nuclear layers （ONL） of rat retina in the normal control group，light damage group，PBS treatment group and hUCMSCs treatment group were analyzed.Results　After cultured for 48 hours，hUCMSCs grew adherently and became spindle-shaped.After 14 days，the cells were confluent.After light damage，the structure of the ONL of the rat retina was disordered，the number of cell layers were reduced and the thickness became thinner.When compared with the normal control group ［（40.73±1.32）μm］，the thickness of the ONL of retina were thinner both in the hUCMSCs treatment group ［（31.28±1.79）μm］，PBS treatment group ［（17.21±1.02）μm］ and the light damage group ［（12.68±1.42）μm］ （all P<0.05）.Compared with the light damage group，the number of layers in the ONL of retina increased significantly in the hUCMSCs group and the PBS group.Conclusion　HUCMSCs can survive，migrate and integrate into the injured retina after transplantation into the vitreous cavity of rats with light damage.The vitreous transplantation of hUCMSCs can inhibit the photoreceptor apoptosis in rats with light damage.