膜转运体Megalin、Cubilin在C57小鼠肾发生发育中的时空表达研究  

Spatio-temporal expression of membrane transporters,Megalin and Cubilin,in renal development of C57BL/6 mice

作　　者：罗美 翟效月[2] 马云胜 LUO Mei;ZHAI Xiaoyue;MA Yunsheng(Electron Microscope Room,School of Life Sciences,Jinzhou Medical University,Jinzhou,Liaoning Province,121001;Department of Histology and Embryology,China Medical University,Shenyang,Liaoning Province,110001;Department of Morphology,Medical College of Jinzhou Medical University,Jinzhou,Liaoning Province,121001,China)

机构地区：[1]锦州医科大学生科院电镜室,辽宁锦州121001 [2]中国医科大学组织学与胚胎学教研室,沈阳110001 [3]锦州医科大学医疗学院形态学教研室,辽宁锦州121001

出　　处：《陆军军医大学学报》2024年第5期434-441,共8页Journal of Army Medical University

基　　金：国家自然科学基金面上项目(30871313);辽宁省教育厅高校基本科研项目(LJKMZ20222086)。

摘　　要：目的观察膜转运体Megalin、Cubilin在发生发育小鼠肾内的分布,从而揭示它们在肾发生发育中相应功能分化的时空规律。方法C57BL/6小鼠按雌雄1∶1合笼饲养,并于胚(胎)龄(Ed)E10、12、14、16、18 d,及生后日龄(Pd)P1、3、7、14、28、42 d,分离胎鼠、仔鼠或成鼠的肾脏。应用改良的块染技术对不同发育阶段的肾脏组织进行整体固定及染色,分别进行常规石蜡包埋,制成连续的石蜡切片(5μm)。选取连续切片中目标切片,采用免疫组织化学技术和免疫荧光技术对不同发育阶段的小鼠肾脏膜转运体Megalin和Cubilin进行定位,观察其在不同发育阶段的表达情况。结果Megalin和Cubilin在E10 d的中肾管上皮细胞开始有表达,E12 d时表达于肾脏输尿管芽上皮细胞的近腔面游离缘,二者主要以共表达模式存在。E14 d以后在发生发育小鼠肾脏的“逗号”小体、“S”型小体上皮细胞的游离缘呈弱表达,于肾脏近端小管的上皮细胞游离缘表达明显,偶尔可见在未发育成熟的血管球有弱表达。Megalin和Cubilin在细段、远端小管、集合管系统以及间质部分都未见表达。结论膜转运体Megalin和Cubilin在中肾管、输尿管芽、“逗号”小体、“S”型小体,以及近端小管的依次表达规律提示小鼠肾脏在中肾形成时期就开始有蛋白或多肽的转运功能。此外,二者稳定地出现在较为成熟的近端小管,较弱地出现在未成熟近端小管,表明其重吸收蛋白质的功能与近端小管结构的成熟度有关。Objective To observe the distribution of membrane transporters,Megalin and Cubilin,in the renal development of mice,and to reveal the temporal and spatial rules of their functional differentiation during renal development.Methods C57BL/6 mice were housed in a female/male ratio of 1∶1,and the kidneys were isolated at embryonic(Ed)ages of E10,E12,E14,E16 and E18 d,and postnatal ages of P1,P3,P7,P14,P28 and P42 d.A modified block staining technique was applied to fix and stain the whole kidney tissues at different developmental stages,and conventional paraffin and resin 812 embedding were performed to make continuous paraffin sections(5μm).The target sections in the continuous sections were selected,and immunohistochemical and immunofluorescence assays were used to localize the mouse kidney membrane transporters Megalin and Cubilin at different developmental stages,and to observe their expression levels.Results Megalin and Cubilin were expressed in the epithelial cells of the mesonephric tubules at E10d,and in the proximal luminal surface on the epithelial cells in the ureteric buds of the kidneys at E12d,with co-expression in the proximal luminal surface on the epithelial cells in the ureteric buds of the kidneys,and were expressed weakly in the free margin of the epithelial cells of comma cells and S-shaped cells in the kidneys of the mice at the onset of the developmental process from E14d,and were expressed in the free margins of epithelial cells of proximal tubules of the kidneys.Megalin and Cubilin were not expressed in the fine segments,the distal tubules,the collecting duct system,or the mesangial portion of the kidney.Conclusion The sequential expression pattern of the membrane transporters Megalin and Cubilin in the mesonephric tubules,ureteric buds,comma vesicles,S-shaped vesicles,and proximal tubules suggests that the mouse kidney begins to have a protein or polypeptide transport function during the period of mesonephric formation.In addition,both proteins appear stably in the more mature proximal tub

关 键 词：肾脏 发生发育 MEGALIN CUBILIN 膜转运体 

分 类 号：R322.61[医药卫生—人体解剖和组织胚胎学] R329.26[医药卫生—基础医学] R341