培养的血管平滑肌细胞表型转变过程中张力纤维及中间丝变化的扫描电镜观察

Changes of Stress Fibers and Intermediate Filaments of Cultured Vascular Smooth Muscle Cells During Phenotypic Modulation——A Scanning Electron Microscope Observation

为揭示体外培养的血管平滑肌细胞(VSMC)在表型转变过程中张力纤维及中间丝三维构筑的变化,采用Triton消化和扫描电镜技术,对不同表型的VSMC进行了观察。结果证实,收缩型VSMC胞质中含大量平行排列的张力纤维;中问丝则密布于张力纤维之间,形成支撑和连接张力纤维的复杂网络。随着VSMC由收缩型向合成型转变,胞核附近的中间丝逐渐向细胞周边胞质分布,以至核周出现明显的“中间丝稀疏区”。张力纤维亦逐渐分解变细,且在部分合成型VSMC中完全消失。本文对上述变化的可能机制进行了讨论。

To reveal changes in three dimensional architecture of stress fibers and intermediate filaments of vascular smooth muscle cells (VSMC) during phenotypic modulation, cultured rabbit aortic SMCs at different phenotypic stages were extracted with Triton X-100 and observed under scanning electron microscope.The results showed the contractile VSMCs display a filament architecture characterized by a larger number of thick and parallel-arrayed stress fibers which interconnected by a complex network of randomly arrayed intermediate filaments. During the phenotypic modulation of the VSMCs from contractile toward synthetic phenotype the intermediate filaments in the central part of the cell gradually redistributed toward the peripheral cytoplasm, so that an obvious perinuclear intermediate filament-paucity areas occurred in most of the modulated cells. Stress fibers also partly disassembled during VSMC phenotypic modulation and were even completely lost in some of the synthetic SMCs. The reasons for these changes were discussed.