糖尿病大鼠主动脉内皮细胞膜结构的原子力显微镜观察和三维重建

Morphologic Observation and 3D Reconstruction of Aortic Endothelial Cells in Diabetic Rats with the Use of Atomic Force Microscope

观察糖尿病大鼠主动脉内皮细胞膜形态的动态变化,了解持续高血糖对内皮细胞结构的影响。取胸主动脉,用原子力显微镜观察内皮细胞并进行三维重建。结果显示对照组内皮细胞表面有许多绒毛样突起、窗孔样结构和虫蚀样小凹等结构,内皮仅有少量的颗粒样物质黏附;糖尿病内皮细胞绒毛样突起减少,内皮细胞类似风化岩石样外观,同时颗粒样物质黏附增多,尤其以12周最为显著;虫蚀样小凹7周开始变深,12周直径增加明显,但在12周的数量减少,以小型的小凹减少明显。三维重建后的图像显示对照组内皮细胞较平滑,而糖尿病组表面突起增多,失去平滑的外观,其平均粗糙度随着时间延长从7周起逐渐增加。提示高血糖状态可破坏血管内皮细胞的结构,使其粗糙度增加和蛋白颗粒黏附,同时细胞膜上虫蚀样小凹变深扩大,出入胞功能加强。

This experiment was designed to observe the morphologic changes of aortic endothelial cells in diabetic rats and to investigate the influence of hyperglycemia. Diabetic rats were used and their aortic endothelial cells were observed under atomic force microscope, then these pictures were 3D reconstructed. The results showed that numerous microvilli and round window-hollow-like structures and insect- bitten-like caveloae were scattered on the surface of the vascular endothelia, and a few ball-like granules were adhering to the endothelial cells. In diabetic rats, microvilli decreased and the cells looked as if they were weather-beaten rocks. The adhering ball-like granules in the diabetic group were significantly more than those in the control group. They were most numerous at 12 weeks. The insect-bitten-like caveloae began deepening at 7 weeks, and their diameters markedly increased at 12 weeks, but they decreased in number. After 3D figures were reconstructed, the surface of cells manifested smoothness. However, in diabetic rats, the morphology of their endothelial cells was characterized by roughness and small surface projections. The quantitative results showed that the average roughness increased gradually as the experiment time prolonged. These indicate that excess sugar in the blood may destroy the endothelial structure, make the cells rougher, and hence cause the protein granules to adhere onto the endothelial cells. At the same time, the deepening and enlargement of the insect-bitten-like caveloae may indicate the increasing endocytosis.