Stress Fibers in situ in Proximal Tubules of the Rat Kidney

Cell Structure and Function

Tohru Murakami¹  Harunori Ishikawa¹ 

[1] Department of Anatomy, Gunma University School of Medicine

关键词: stress fibers;    renal tubule;    actin;    confocal laser microscopy;    immunofluorescence microscopy;   

DOI  :  10.1247/csf.16.231

学科分类：分子生物学，细胞生物学和基因

来源: Japan Society for Cell Biology

【 摘 要 】

References(30)Cited-By(13)Actin bundles in proximal tubules of the rat kidney were examined by immunofluorescence and confocal laser microscopy with special reference to their three-dimensional distribution and identification as stress fibers. Renal tubular segments were prepared from the fresh renal cortex by simple homogenization and centrifugation, and fixed in formaldehyde for staining with fluorescent dye-labeled phalloidin. Segments of the proximal tubules could be identified easily on the bases of their diameter, the height of epithelial cells and prominent brush borders. Confocal laser microscopy clearly demonstrated the overall distribution of actin bundles in the whole-mount proximal tubular segments. Actin bundles in the basal cytoplasm of epithelial cells were observed to run parallel to each other and at a right angle to the tubular axis. In the stereo views reconstructed from serial optical sections, the basal actin bundles appeared as straight rods with both ends tapered. They varied in length and width and extended rather short distances of not more than 10 μm. Often, two or more actin bundles were longitudinally aligned in tandem. Some bundles showed irregular bandings along their length. Each bundle was composed of tightly packed actin filaments which could be decorated with heavy meromyosin subfragment-1 to display a bi-directional arrangement within the bundle. Immunostaining of cryostat sections showed that actin bundles contained myosin and vinculin. Enzymatically isolated proximal tubules contracted upon addition of Mg-ATP. These observations collectively suggest that the actin bundles at the base of renal promixal tubule epithelial cells can be listed among the examples of stress fibers in situ.

【 授权许可】

Unknown