The intermediate filament system of the keratinizing mouse forestomach epithelium: Coexpression of keratins of internal squamous epithelia and of epidermal keratins in differentiating cells

1988 ◽  
Vol 253 (1) ◽  
Author(s):  
J�rgen Schweizer ◽  
Martin Rentrop ◽  
Roswitha Nischt ◽  
Mitsuru Kinjo ◽  
Hermelita Winter
Keyword(s):  
Intermediate Filament ◽  
Filament System ◽  
Squamous Epithelia

The presence or absence of a vimentin-type intermediate filament network affects the shape of the nucleus in human SW-13 cells

1994 ◽  
Vol 107 (6) ◽  
pp. 1593-1607 ◽  
Author(s):  
A.J. Sarria ◽  
J.G. Lieber ◽  
S.K. Nordeen ◽  
R.M. Evans
Keyword(s):  
Electron Microscopy ◽  
Intermediate Filament ◽  
Nuclear Morphology ◽  
Intermediate Filament Protein ◽  
Mosaic Pattern ◽  
Expression Plasmid ◽  
Vimentin Expression ◽  
Filament System ◽  
Filament Protein ◽  
Filament Network

Human SW-13 cells express the intermediate filament protein vimentin in a mosaic pattern (Hedberg, K. K. and Chen, L. B. (1986). Exp. Cell Res. 163, 509–517). We have isolated SW-13 clones that do (vim+) or do not (vim-) synthesize vimentin as analyzed using anti-intermediate filament immunofluorescence, electron microscopy and two-dimensional gel analysis of detergent-extracted preparations. Vimentin is the only cytoplasmic intermediate filament protein present in the vim+ cells, and the vim- cells do not contain any detectable cytoplasmic intermediate filament system. The presence or absence of intermediate filaments did not observably affect the distribution of mitochondria, endoplasmic reticulum, microtubules or actin stress fibers when these structures were visualized by fluorescence microscopy. However, electron microscopy and anti-lamin A/C immunofluorescence studies showed that nuclear morphology in vim- cells was frequently characterized by large folds or invaginations, while vim+ cells had a more regular or smooth nuclear shape. When vim- cells were transfected with a mouse vimentin expression plasmid, the synthesis of a mouse vimentin filament network restored the smooth nuclear morphology characteristic of vim+ cells. Conversely, when vim+ cells were transfected with a carboxy-terminally truncated mutant vimentin, expression of the mutant protein disrupted the organization of the endogenous vimentin filaments and resulted in nuclei with a prominently invaginated morphology. These results indicated that in SW-13 cells the vimentin filament system affects the shape of the nucleus.

The nanomechanical properties of rat fibroblasts are modulated by interfering with the vimentin intermediate filament system

2011 ◽  
Vol 174 (3) ◽  
pp. 476-484 ◽  
Author(s):  
Marija Plodinec ◽  
Marko Loparic ◽  
Rosmarie Suetterlin ◽  
Harald Herrmann ◽  
Ueli Aebi ◽  
...  
Keyword(s):  
Intermediate Filament ◽  
Nanomechanical Properties ◽  
Filament System ◽  
Rat Fibroblasts ◽  
Vimentin Intermediate Filament

Desmin knockout muscles generate lower stress and are less vulnerable to injury compared with wild-type muscles

2000 ◽  
Vol 279 (4) ◽  
pp. C1116-C1122 ◽  
Author(s):  
Michel Sam ◽  
Sameer Shah ◽  
Jan Fridén ◽  
Derek J. Milner ◽  
Yassemi Capetanaki ◽  
...  
Keyword(s):  
Intermediate Filament ◽  
Muscle Force ◽  
Mechanical Energy ◽  
Eccentric Contraction ◽  
Null Mouse ◽  
Wild Type ◽  
Lower Stress ◽  
Filament System ◽  
Muscle Types

The functional role of the skeletal muscle intermediate filament system was investigated by measuring the magnitude of muscle force loss after cyclic eccentric contraction (EC) in normal and desmin null mouse extensor digitorum longus muscles. Isometric stress generated was significantly greater in wild-type (313 ± 8 kPa) compared with knockout muscles (276 ± 13 kPa) before EC ( P < 0.05), but 1 h after 10 ECs, both muscle types generated identical levels of stress (∼250 kPa), suggesting less injury to the knockout. Differences in injury susceptibility were not explained by the different absolute stress levels imposed on wild-type versus knockout muscles (determined by testing older muscles) or by differences in fiber length or mechanical energy absorbed. Morphometric analysis of longitudinal electron micrographs indicated that Z disks from knockout muscles were more staggered (0.36 ± 0.03 μm) compared with wild-type muscles (0.22 ± 0.03 μm), which may indicate that the knockout cytoskeleton is more compliant. These data demonstrate that lack of the intermediate filament system decreases isometric stress production and that the desmin knockout muscle is less vulnerable to mechanical injury.

Desmin cytoskeletal modifications after a bout of eccentric exercise in the rat

2002 ◽  
Vol 283 (4) ◽  
pp. R958-R963 ◽  
Author(s):  
Ilona A. Barash ◽  
David Peters ◽  
Jan Fridén ◽  
Gordon J. Lutz ◽  
Richard L. Lieber
Keyword(s):  
Eccentric Exercise ◽  
Intermediate Filament ◽  
Tibialis Anterior ◽  
Muscle Injury ◽  
Eccentric Contractions ◽  
Protective Effects ◽  
Structural Explanation ◽  
Filament System ◽  
Single Bout ◽  
Recovery Times

Desmin content and immunohistochemical appearance were measured in tibialis anterior muscles of rats subjected to a single bout of 30 eccentric contractions (ECs). Ankle torque was measured before EC and at various recovery times, after which immunohistochemical and immunoblot analyses were performed. Torque decreased by ∼50% immediately after EC and fully recovered 168 h later ( P < 0.001). Loss of desmin staining was maximal 12 h after EC and recovered by 72 h. Immunoblots unexpectedly demonstrated a significant increase in the desmin-to-actin ratio by 72 h after EC ( P < 0.01) and was still increasing after 168 h ( P < 0.0001). These data demonstrate a relatively rapid qualitative loss of desmin immunostaining immediately after a single EC bout but a tremendous quantitative increase in desmin content 72–168 h later. This dynamic restructuring of the muscle's intermediate filament system may be involved in the mechanism of EC-induced muscle injury and may provide a structural explanation for the protective effects observed in muscle after a single EC bout.

Sign in / Sign up

Export Citation Format

Share Document