骨髓间充质干细胞在碘酸钠注射大鼠视网膜下的分化

Differentiation of transplanted-bone marrow mesenchymal stem cells in subretinal space of sodium iodate-injected rats

目的研究骨髓间充质干细胞(BMMSCs)在视网膜色素上皮(RPE)受损的大鼠模型眼中的分化情况。方法体外培养Wistar大鼠的BMMSCs,用病毒上清液转染EGFP,移植到经静脉注射NaIO3破坏RPE细胞的大鼠的视网膜下腔,用免疫荧光标记的方法对BMMSCs进行追踪并观察术后5周的分化情况。结果BMMSCs的EGFP转染比例可达到76·9%,术后第5周可见BMMSCs位于视网膜下区域,未整合入神经视网膜层,并表达角蛋白(CK)、视紫红质(rhodopsin)和胶质纤维酸性蛋白(GFAP)。结论BMMSCs植入RPE受损伤的大鼠视网膜下腔后可存活,并表达RPE细胞、光感受器细胞和星形胶质细胞的特异性标志。

Objective Disfunction of retinal pigment epithelium （RPE） is a major cause of visual loss,especially agerelated macular degeneration,therefore transplantation of bone marrow mesenchymal stem cells （BMMSCs）into retinal space may hold a promise for the treatment of these diseases. The aim of the study was to observe the differentiation of rat bone marrow mesenchymal stem cells（BMMSCs） in subretinal space of sodium iodate-injected rats. Methods Twenty Wistar rats aged 6 weeks were divided into experimental group and control group averagely and randomly, Sodium iodate was injected via a caudal vein at a total dose of 40 mg/kg 4 days prior to transplantation to damaged RPE. Harvested BMMSCs were characterized by flow cytometry. The BMMSCs were transfected with enhanced green fluorescent protein （EGFP） and the transduction efficiency was analyzed by fluorescence microscopy and flow cytometry. BMMSCs transfected with EGFP were injected into the subretinal space of sodium iodate-injected rats. The differentiation of BMMSCs was traced by immunoflurescent labeling at the 5th week after the surgery. Results The BMMSCs showed spindle-like in shape and expressed CD90 but not CD45. The transduction efficiency of BMMSCs for EGFP attached 76. 9% ,however,no cell labelled by EGFP was found in PBS control group. Viable BMMSCs were detected 5 weeks after transplantation mainly in the subretinal space rather than retina. The pan-cytokeratin,glial fibrillary acidic protein（GFAP） ,and rhodopsin were expressed in the ceils labeled by EGFP. Conclusion BMMSCs transplantated into the subretinal space of sodium iodate-injected rats can differentiate into epithelium,photoreceptor and glial lineage.