Morphology of the keratin filament network in palm and sole skin: evidence for site-dependent features based on stereological analysis

1996 ◽  
Vol 288 (2) ◽  
pp. 55-62 ◽  
Author(s):  
O. Swensson ◽  
R. A. J. Eady
Keyword(s):  
Stereological Analysis ◽  
Keratin Filament ◽  
Filament Network

Novel Electron Tomographic Methods to Study the Morphology of Keratin Filament Networks

2010 ◽  
Vol 16 (4) ◽  
pp. 462-471 ◽  
Author(s):  
Michaela Sailer ◽  
Katharina Höhn ◽  
Sebastian Lück ◽  
Volker Schmidt ◽  
Michael Beil ◽  
...  
Keyword(s):  
High Pressure ◽  
Low Voltage ◽  
Signal To Noise Ratio ◽  
3D Structure ◽  
Signal To Noise ◽  
Freeze Dried ◽  
Keratin Filaments ◽  
Keratin Filament ◽  
Noise Ratio ◽  
Filament Network

AbstractThe three-dimensional (3D) keratin filament network of pancreatic carcinoma cells was investigated with different electron microscopical approaches. Semithin sections of high-pressure frozen and freeze substituted cells were analyzed with scanning transmission electron microscope (STEM) tomography. Preservation of subcellular structures was excellent, and keratin filaments could be observed; however, it was impossible to three-dimensionally track the individual filaments. To obtain a better signal-to-noise ratio in transmission mode, we observed ultrathin sections of high-pressure frozen and freeze substituted samples with low-voltage (30 kV) STEM. Contrast was improved compared to 300 kV, and individual filaments could be observed. The filament network of samples prepared by detergent extraction was imaged by high-resolution scanning electron microscopy (SEM) with very good signal-to-noise ratio using the secondary electron signal and the 3D structure could be elucidated by SEM tomography. In freeze-dried samples it was possible to discern between keratin filaments and actin filaments because the helical arrangement of actin subunits in the F-actin could be resolved. When comparing the network structures of the differently prepared samples, we found no obvious differences in filament length and branching, indicating that the intermediate filament network is less susceptible to preparation artifacts than the actin network.

scholarly journals p38 MAPK-dependent shaping of the keratin cytoskeleton in cultured cells

2007 ◽  
Vol 177 (5) ◽  
pp. 795-807 ◽  
Author(s):  
Stefan Wöll ◽  
Reinhard Windoffer ◽  
Rudolf E. Leube
Keyword(s):  
P38 Mapk ◽  
Intermediate Filament ◽  
Cultured Cells ◽  
Physiological Stress ◽  
Tissue Homeostasis ◽  
Epithelial Tissue ◽  
Down Regulation ◽  
Granule Formation ◽  
Keratin Filament ◽  
Filament Network

Plasticity of the resilient keratin intermediate filament cytoskeleton is an important prerequisite for epithelial tissue homeostasis. Here, the contribution of stress-activated p38 MAPK to keratin network organization was examined in cultured cells. It was observed that phosphorylated p38 colocalized with keratin granules that were rapidly formed in response to orthovanadate. The same p38p recruitment was noted during mitosis, in various stress situations and in cells producing mutant keratins. In all these situations keratin 8 became phosphorylated on S73, a well-known p38 target site. To demonstrate that p38-dependent keratin phosphorylation determines keratin organization, p38 activity was pharmacologically and genetically modulated: up-regulation induced keratin granule formation, whereas down-regulation prevented keratin filament network disassembly. Furthermore, transient p38 inhibition also inhibited keratin filament precursor formation and mutant keratin granule dissolution. Collectively, the rapid and reversible effects of p38 activity on keratin phosphorylation and organization in diverse physiological, stress, and pathological situations identify p38-dependent signalling as a major intermediate filament–regulating pathway.

scholarly journals Mouse differentiation-specific keratins 1 and 10 require a preexisting keratin scaffold to form a filament network.

1993 ◽  
Vol 120 (5) ◽  
pp. 1251-1261 ◽  
Author(s):  
T Kartasova ◽  
D R Roop ◽  
K A Holbrook ◽  
S H Yuspa
Keyword(s):  
Epithelial Cells ◽  
Intermediate Filament ◽  
Filament Formation ◽  
Stable Transfectants ◽  
Cytoskeletal Network ◽  
Filament Bundles ◽  
Keratin Filament ◽  
Differentiation Stage ◽  
Nih 3T3 ◽  
Filament Network

Keratins 1 (K1) and 10 (K10) are the predominant cytoskeletal intermediate filaments of epidermal cells during transition from the proliferative to the terminal differentiation stage. In situ, formation of the K1/K10 intermediate filament network occurs in the cytoplasm of cells with a preexisting cytoskeleton composed of keratins 5 and 14. To define cytoskeletal interactions permissive for formation of the K1/K10 filamentous network, active copies of mouse K1 and K10 genes were introduced into fibroblasts (NIH 3T3) which do not normally express these proteins. Transient and stable transfectants, as well as heterokaryons produced by fusions with epithelial cells, were evaluated for expression of K1 and K10 proteins and filament formation using specific antibodies. In contrast to keratin pairs K5/K14 and K8/K18, the K1/K10 pair failed to form an extensive keratin filament network on its own, although small isolated dense K1/K10 filament bundles were observed throughout the cytoplasm by EM. K1 and K10 filaments integrated only into the preexisting K5/K14 network upon fusion of the NIH 3T3 (K1/K10) cells with epithelial cells expressing endogenous K5/K14 or with NIH 3T3 cells which were transfected with active copies of the K5 and K14 genes. When combinations of active recombinant gene constructs for keratins 1, 5, 10, and 14 were tested in transient NIH 3T3 transfections, the most intact cytokeratin network observed by immunofluorescence was formed by the K5/K14 pair. The K1/K14 pair was capable of forming a cytoskeletal network, but the network was poorly developed, and usually perinuclear. Transfection of K10 in combination with K5 or K1 resulted in cytoplasmic agglomerates, but not a cytoskeleton. These results suggest that the formation of the suprabasal cytoskeleton in epidermis is dependent on the preexisting basal cell intermediate filament network. Furthermore, restrictions on filament formation appear to be more stringent for K10 than for K1.

scholarly journals Damaged Keratin Filament Network Caused by KRT5 Mutations in Localized Recessive Epidermolysis Bullosa Simplex

2021 ◽  
Vol 12 ◽  
Author(s):  
Fuying Chen ◽  
Lei Yao ◽  
Xue Zhang ◽  
Yan Gu ◽  
Hong Yu ◽  
...  
Keyword(s):  
Epidermolysis Bullosa ◽  
Mapk Signaling ◽  
Epidermolysis Bullosa Simplex ◽  
Protein Levels ◽  
Keratin 5 ◽  
Keratin Filament ◽  
Filament Network ◽  
Keratin Intermediate Filaments ◽  
Desmosomal Protein

Epidermolysis bullosa simplex (EBS) is a blistering dermatosis that is mostly caused by dominant mutations in KRT5 and KRT14. In this study, we investigated one patient with localized recessive EBS caused by novel homozygous c.1474T > C mutations in KRT5. Biochemical experiments showed a mutation-induced alteration in the keratin 5 structure, intraepidermal blisters, and collapsed keratin intermediate filaments, but no quantitative change at the protein levels and interaction between keratin 5 and keratin 14. Moreover, we found that MAPK signaling was inhibited, while desmosomal protein desmoglein 1 (DSG1) was upregulated upon KRT5 mutation. Inhibition of EGFR phosphorylation upregulated DSG1 levels in an in vitro model. Collectively, our findings suggest that this mutation leads to localized recessive EBS and that keratin 5 is involved in maintaining DSG1 via activating MAPK signaling.

scholarly journals Hemidesmosomes Show Abnormal Association with the Keratin Filament Network in Junctional Forms of Epidermolysis Bullosa

1998 ◽  
Vol 110 (2) ◽  
pp. 132-137 ◽  
Author(s):  
James R. McMillan ◽  
John A. McGrath ◽  
Michael J. Tidman ◽  
Robin A.J. Eady
Keyword(s):  
Epidermolysis Bullosa ◽  
Keratin Filament ◽  
Filament Network

scholarly journals Measuring the regulation of keratin filament network dynamics

2013 ◽  
Vol 110 (26) ◽  
pp. 10664-10669 ◽  
Author(s):  
M. Moch ◽  
G. Herberich ◽  
T. Aach ◽  
R. E. Leube ◽  
R. Windoffer
Keyword(s):  
Network Dynamics ◽  
Keratin Filament ◽  
Filament Network

Collapse of the keratin filament network through the expression of mutant keratin 6c observed in a case of focal plantar keratoderma

2013 ◽  
Vol 40 (7) ◽  
pp. 553-557 ◽  
Author(s):  
Akiharu Kubo ◽  
Yuiko Oura ◽  
Takashige Hirano ◽  
Yumi Aoyama ◽  
Showbu Sato ◽  
...  
Keyword(s):  
Keratin Filament ◽  
Filament Network

scholarly journals 3D in vivo imaging of the keratin filament network in the mouse stratum granulosum reveals profilaggrin-dependent regulation of keratin bundling

2019 ◽  
Vol 94 (3) ◽  
pp. 346-349
Author(s):  
Keiko Usui ◽  
Nanako Kadono ◽  
Yuki Furuichi ◽  
Keiichiro Shiraga ◽  
Takashi Saitou ◽  
...  
Keyword(s):  
In Vivo Imaging ◽  
Stratum Granulosum ◽  
Keratin Filament ◽  
Filament Network
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