犬膀胱移行上皮细胞的体外连续培养及生物学特征观察

目的探讨犬膀胱移行上皮细胞体外连续培养和纯化方法,为进一步构建组织工程尿路上皮组织提供实验依据。方法无菌获取幼犬膀胱组织,0.125%胰蛋白酶消化获取单细胞悬液,于上皮细胞无血清培养基中培养。采用0.05%胰蛋白酶和0.02?TA消化、纯化细胞,动态观察细胞形态变化和增殖情况,MTT法绘制生长曲线;透射电镜观察细胞超微结构;SABC法对培养的细胞进行免疫组织化学鉴定;并采用流式细胞仪检测不同代次细胞的细胞周期和倍体水平。结果采用酶消化法能从4～6cm2的膀胱黏膜组织中分离获取(1～5)×106个细胞。原代培养接种24h后可见大量细胞贴壁,第7天细胞生长融合达80%～90%,细胞排列呈典型的铺路石样。MTT法测定第3代细胞在传代培养7d生长达高峰;传代并纯化的细胞纯度高,无成纤维细胞污染,至第4～6代细胞仍保持良好形态。透射电镜下,可见上皮细胞特征性张力微丝和细胞间桥粒连接。细胞角蛋白AE1/AE3免疫组织化学染色,胞浆呈棕黄色阳性反应。不同代次细胞均为二倍体细胞。结论酶消化法能从较少的膀胱组织中分离获取足量、较纯的膀胱移行上皮细胞,细胞在无血清培养基中能连续传代扩增,可以满足进一步构建组织工程尿路上皮组织的需要。

EXPERIMENTAL STUDY ON CHARACTERIZATION OF NORMAL CANINE BLADDER TRANSITIONAL EPITHELIAL CELLS CULTURED IN VITRO

Objective To explore an effective method to culture and purify canine bladder transitional epithelial cells. Methods Bladder tissue was obtained from healthy puppy under sterile conditions. Bladder mucosa was removed from the remaining tissue with fine scissor and minced into small pieces, and then were dissociated into single cell suspensions with 0.125% trypsin. The bladder epithelial cells were cultured in defined keratinocyte serum free medium. The cells were passaged and purified by 0.05% trypsin and 0.02% EDTA. Morphological characterization were studied under inverted phase contrast microscope and transmission electron microscope. Expression of cell specific marker protein was assessed by immunohistochemistry. Results Canine bladder transitional epithelial cells could be efficiently cultivated and expanded in serum-free medium without fibroblast contamination. The cells could be passaged 4-6 times without a distinguished decrease in cell proliferation. The cells were characterized by well-developed micro-filament and desmosome junction under transmission electron microscope. Immunohistochemical staining with broadly reacting anti-cytokeratin antibodies (AE1/AE3) confirmed the epithelial phenotype of the cells.Different generations of cells showed diploid cells. Conclusion A large number of bladder transitional epithelial cells can be obtained from small bladder tissue with our digestion method. The cultured bladder epithelial cells can be proliferated to sufficient quantities for further reconstructive purposes.