Search results for "intermediate filament"
showing 10 items of 103 documents
De novo expression of nonhepatocellular cytokeratins in Mallory body formation.
1998
Mallory bodies (MBs) are eosinophilic cytoplasmic inclusions observed predominantly in alcoholic liver disease. Although linked to disease activity, their pathogenesis is still unclear. Since intermediate filaments (cytokeratins) are major components of MBs, their cytokeratin polypeptide composition was analysed with monospecific antibodies for cytokeratins 7, 8, 14, 18, 19, and 20 by immunohistology. MBs were identified by light microscopy and ubiquitin immunostaining. All MBs were positive for cytokeratins 8 and 18. A significant percentage of the MBs was strongly positive for cytokeratins 19 and/or 20, which are not detectable in hepatocytes of normal liver and, in the case of cytokerati…
Imaging of Keratin Dynamics during the Cell Cycle and in Response to Phosphatase Inhibition
2004
Publisher Summary The characterization and development of autofluorescent proteins, most prominently of the green florescent protein, have provided tools to label cellular structures such that they can be examined in living cells. This chapter highlights the potential of live cell imaging in providing novel and unprecedented insights into the dynamic organization of the keratin cytoskeleton and outlines the important aspects of this method. The live cell imaging experiments suggest that the driving force behind the vectorial and dynamic keratin distribution patterns relies both on microtubules and microfilaments and their associated factors. The studies on the dynamics of the keratin cytosk…
Establishment and Characterization of Two Merkel Cell Tumor Cultures
1994
Two Merkel cell tumor cultures (MC-MA1, MC-MA2) have been established from metastases of typical Merkel cell tumors. The mestastases in vivo were characterized by co-expression of cytokeratins 8, 18, 19, 20 and neurofilaments, presence of intermediate filament whirls, expression of synaptophysin, neuron-specific enolase, and chromogranin A, rare and weak immunostaining for plakoglobin but absence of cadherins and desmoplakins. Both cultures grow, using supplemented RPMI medium on human irradiated fibroblast feeder layers, as loosely arranged floating small aggregates. Their karyotypes are mostly hyperdiploid. The mean doubling times were about 84 h in the first 8 months and later increased.…
Interaction between filaggrin mutations and neonatal cat exposure in atopic dermatitis
2020
Atopic dermatitis (AD) is a prevalent inflammatory skin disease. Loss-of-function mutations in filaggrin gene (FLG) represent the strongest genetic risk factors for AD, being strongly associated with early disease onset and persistence into adulthood.1 The epidermis of individuals with mutations in FLG is fundamentally different from normal skin being characterized by increased penetration of allergens.2 Recent birth cohort studies showed a significant interaction between cat ownership at birth and mutations in FLG (R501X, 2282del4) on the development of early-onset AD.3 This finding was replicated for the 2282del4 FLG mutation in a Dutch cohort study, and extended to further associate with…
Desmin-related neuromuscular disorders
1995
Desmin, the intermediate filament protein of skeletal muscle fibers, cardiac myocytes, and certain smooth muscle cells, is a member of the cytoskeleton linking Z-bands with the plasmalemma and the nucleus. The pathology of desmin in human neuromuscular disorders is always marked by increased amounts, diffusely or focally. Desmin is highly expressed in immature muscle fibers, both during fetal life and regeneration as well as in certain congenital myopathies, together with vimentin. Desmin is also enriched in neonatal myotonic dystrophy and small fibers in infantile spinal muscular atrophy. Focal accretion of desmin may be twofold, in conjunction with certain inclusion bodies, cytoplasmic an…
The identification and localization of two intermediate filament proteins in the tunic of Styela plicata (Tunicata, Styelidae).
2009
The intermediate filament (IF) proteins Styela C and Styela D from the tunicate Styela (Urochordata) are co-expressed in all epidermal cells and they are thought to behave as type I and type II keratins. These two IF proteins, Styela C and Styela D, were identified in immunoblots of proteins isolated from the tunic of Styela plicata. The occurrence and distribution of these proteins within the tunic of this ascidian was examined by means of immunofluorescence and immunoperoxidase techniques, using anti-Styela C and anti-Styela D antibodies. In addition, immuno-electron microscopy of the tunic showed that the two proteins are located in the cuticle layer and in the tunic matrix. These result…
Ectopic expression of desmin in the epidermis of transgenic mice permits development of a normal epidermis.
2002
Cell architecture is largely based on the interaction of cytoskeletal proteins, which include intermediate filaments (IF), microfilaments, microtubules, as well as their type-specific membrane-attachment structures and associated proteins. In order to further our understanding of IF proteins and to address the fundamental issue whether different IF perform unique functions in different tissues, we expressed a desmin transgene in the basal epidermis of mice. Ectopic expression of desmin led to the formation of an additional, keratin-independent IF cytoskeleton and did not interfere with the keratin-desmosome interaction. We show that ectopic expression of a type III IF protein in basal kerat…
The human gene encoding cytokeratin 20 and its expression during fetal development and in gastrointestinal carcinomas
1993
The differentiation of the predominant cell types of the mucosal epithelium of the mammalian gastrointestinal tract is characterized by increasing amounts of an intermediate-sized filament (IF) protein designated cytokeratin (CK) 20 which is a major cellular protein of mature enterocytes and goblet cells. Here we report the isolation of the human gene encoding CK 20, its complete nucleotide sequence and the amino acid sequence deduced therefrom that identifies this polypeptide (mol. wt. 48553) as a member of the type I-CK subfamily. Remarkable, however, is the comparably great sequence divergence of CK 20 from all other known type I-CKs, with only 58% identical amino acids in the conserved …
Chromophobe Renal Cell Carcinoma
1996
SUMMARY A case ofchromophobe renal cell carcinoma is reported in a 73 year-old man. Light microscopically, the tumor was composed of polygonal cells with a slightly eosinophilic and a fine reticular pattern, and a reaction of the cytoplasm with Hale's acid iron colloid. Ultrastructural analysis showed membranous microuesicles within the tumor cells, with degenerated mitochondria. Immunohistochemical profile against intermediate filaments was positive to cytokeratin 18 and negative against uimentin. Flow cytometry and cytogenetics revealed a predominant bypertriploid population. Few cases have been published with flow cytometry and cytogenetic findings. We report a new case.
Culture medium induced vimentin reorganization associates with enhanced baculovirus-mediated gene delivery.
2009
Baculoviruses can express transgenes under mammalian promoters in a wide range of vertebrate cells. However, the success of transgene expression is dependent on both the appropriate cell type and culture conditions. We studied the mechanism behind the substantial effect of the cell culture medium on efficiency of the baculovirus transduction in different cell lines. We tested six cell culture mediums; the highest transduction efficiency was detected in the presence of RPMI 1640 medium. Vimentin, a major component of type III intermediate filaments, was reorganized in the optimized medium, which associated with enhanced nuclear entry of baculoviruses. Accordingly, the phosphorylation pattern…