scholarly journals FORMATION OF ARROWHEAD COMPLEXES WITH HEAVY MEROMYOSIN IN A VARIETY OF CELL TYPES

1969 ◽  
Vol 43 (2) ◽  
pp. 312-328 ◽  
Author(s):  
Harunori Ishikawa ◽  
Richard Bischoff ◽  
Howard Holtzer
Keyword(s):  
Epithelial Cells ◽  
Actin Filaments ◽  
Cell Types ◽  
Nerve Cells ◽  
Collagen Fibrils ◽  
Heavy Meromyosin ◽  
Thin Filaments ◽  
Cellular Components

Heavy meromyosin (HMM) forms characteristic arrowhead complexes with actin filaments in situ. These complexes are readily visualized in sectioned muscle. Following HMM treatment similar complexes appear in sectioned fibroblasts, chondrogenic cells, nerve cells, and several types of epithelial cells. Thin filaments freshly isolated from chondrogenic cells also bind HMM and form arrowhead structures in negatively stained preparations. HMM-filament complexes are prominent in the cortex of a variety of normal metaphase and Colcemid-arrested metaphase cells. There is no detectable binding of HMM with other cellular components such as microtubules, 100-A filaments, tonofilaments, membranes, nuclei, or collagen fibrils. The significance of HMM-filament binding is discussed in view of the finding that arrowhead complexes form in types of cells not usually thought to contain actin filaments.

Identification and localization of extracellular Ca2+-sensing receptor in rat intestine

1998 ◽  
Vol 274 (1) ◽  
pp. G122-G130 ◽  
Author(s):  
Naibedya Chattopadhyay ◽  
Ivan Cheng ◽  
Kimberly Rogers ◽  
Daniela Riccardi ◽  
Amy Hall ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Large Intestine ◽  
Rat Kidney ◽  
Cell Types ◽  
Northern Analysis ◽  
Reaction Products ◽  
Polymerase Chain ◽  
Small Intestinal ◽  
Small And Large Intestine

The extracellular calcium ([Formula: see text])-sensing receptor (CaR) plays vital roles in [Formula: see text] homeostasis, but no data are available on its expression in small and large intestine. Polymerase chain reaction products amplified from reverse-transcribed duodenal RNA using CaR-specific primers showed >99% homology with the rat kidney CaR. Northern analysis with a CaR-specific cRNA probe demonstrated 4.1- and 7.5-kb transcripts in all intestinal segments. Immunohistochemistry with CaR-specific antisera showed clear basal staining of epithelial cells of small intestinal villi and crypts and modest apical staining of the former, whereas there was both basal and apical staining of colonic crypt epithelial cells. In situ hybridization and immunohistochemistry also demonstrated CaR expression in Auerbach’s myenteric plexus of small and large intestines and in the submucosa in the region of Meissner’s plexus. Our results reveal CaR expression in several cell types of small and large intestine, in which it may modulate absorptive and/or secretomotor functions.

scholarly journals Herpes Simplex Virus gE/gI Expressed in Epithelial Cells Interferes with Cell-to-Cell Spread

2003 ◽  
Vol 77 (4) ◽  
pp. 2686-2695 ◽  
Author(s):  
Wendy J. Collins ◽  
David C. Johnson
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Epithelial Cells ◽  
Cell Types ◽  
Cell Junctions ◽  
Neuronal Tissues ◽  
Extensive Cell ◽  
Simplex Virus ◽  
Cellular Components ◽  
Cell Spread

ABSTRACT The herpes simplex virus (HSV) glycoprotein heterodimer gE/gI plays an important role in virus cell-to-cell spread in epithelial and neuronal tissues. In an analogous fashion, gE/gI promotes virus spread between certain cell types in culture, e.g., keratinocytes and epithelial cells, cells that are polarized or that form extensive cell junctions. One mechanism by which gE/gI facilitates cell-to-cell spread involves selective sorting of nascent virions to cell junctions, a process that requires the cytoplasmic domain of gE. However, the large extracellular domains of gE/gI also appear to be involved in cell-to-cell spread. Here, we show that coexpression of a truncated form of gE and gI in a human keratinocyte line, HaCaT cells, decreased the spread of HSV between cells. This truncated gE/gI was found extensively at cell junctions. Expression of wild-type gE/gI that accumulates at intracellular sites, in the trans-Golgi network, did not reduce cell-to-cell spread. There was no obvious reduction in production of infectious HSV in cells expressing gE/gI, and virus particles accumulated at cell junctions, not at intracellular sites. Expression of HSV gD, which is known to bind virus receptors, also blocked cell-to-cell spread. Therefore, like gD, gE/gI appears to be able to interact with cellular components of cell junctions, gE/gI receptors which can promote HSV cell-to-cell spread.

scholarly journals Expression of Membrane-associated Mucins MUC1 and MUC4 in Major Human Salivary Glands

2002 ◽  
Vol 50 (6) ◽  
pp. 811-820 ◽  
Author(s):  
Bing Liu ◽  
Jessica R. Lague ◽  
David P. Nunes ◽  
Paul Toselli ◽  
Frank G. Oppenheim ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Salivary Glands ◽  
Acinar Cells ◽  
Cell Types ◽  
Northern Blotting ◽  
Submandibular Glands ◽  
Human Genes ◽  
Mucin Layer ◽  
Different Cell Types

Mucins are high molecular weight glycoproteins secreted by salivary glands and epithelial cells lining the digestive, respiratory, and reproductive tracts. These glyco-proteins, encoded in at least 13 distinct human genes, can be subdivided into gel-forming and membrane-associated forms. The gel-forming mucin MUC5B is secreted by mucous acinar cells in major and minor salivary glands, but little is known about the expression pattern of membrane-associated mucins. In this study, RT-PCR and Northern blotting demonstrated the presence of transcripts for MUC1 and MUC4 in both parotid and submandibular glands, and in situ hybridization localized these transcripts to epithelial cells lining striated and excretory ducts and in some serous acinar cells. The same cellular distribution was observed by immunohistochemistry. Soluble forms of both mucins were detected in parotid secretion after immunoprecipitation with mucin-specific antibodies. These studies have shown that membrane-associated mucins are produced in both parotid and submandibular glands and that they are expressed in different cell types than gel-forming mucins. Although the function of these mucins in the oral cavity remains to be elucidated, it is possible that they both contribute to the epithelial protective mucin layer and act as receptors initiating one or more intracellular signal transduction pathways.

scholarly journals Localization of Cytochrome P450 CYP2S1 Expression in Human Tissues by In Situ Hybridization and Immunohistochemistry

2005 ◽  
Vol 53 (5) ◽  
pp. 549-556 ◽  
Author(s):  
Sirkku T. Saarikoski ◽  
Harriet A.-L. Wikman ◽  
Gillian Smith ◽  
C. Henrik J. Wolff ◽  
Kirsti Husgafvel-Pursiainen
Keyword(s):  
Cytochrome P450 ◽  
In Situ Hybridization ◽  
Epithelial Cells ◽  
Cellular Localization ◽  
Tumor Development ◽  
Tissue Microarrays ◽  
Cell Types ◽  
Human Tissues ◽  
Expression Levels

CYP2S1 is a recently discovered dioxin-inducible member of the cytochrome P450 superfamily. It has been shown to be involved in the metabolism of some aromatic hydrocarbons as well as retinoic acid, suggesting a role in biotransformation of both exogenous and endogenous compounds. In this study, we used mRNA in situ hybridization and immunohistochemistry to investigate the cellular localization of CYP2S1 in various human tissues using tissue microarrays. High expression levels were observed mainly in epithelial cell types, especially in the epithelia frequently exposed to xenobiotics. In the respiratory tract, the expression was strong in nasal cavity, bronchi, and bronchioli, whereas it was low in the alveolar lining cells. Similarly, CYP2S1 was highly expressed in the epithelial cells throughout the gastrointestinal tract. Strong epithelial expression was also observed in uterine cervix, urinary bladder, and skin. In many exocrine glands (e.g., adrenal gland and pancreas), secretory epithelial cells showed moderate to strong expression levels. In the liver, the expression was low. CYP2S1 was highly expressed in epithelial cells that are major targets for carcinogen exposure and common progenitor cells to tumor development. Indeed, we found strong CYP2S1 expression in many tumors of epithelial origin.

scholarly journals Golgi-derived vesicles from developing epithelial cells bind actin filaments and possess myosin-I as a cytoplasmically oriented peripheral membrane protein.

1993 ◽  
Vol 120 (1) ◽  
pp. 117-127 ◽  
Author(s):  
K R Fath ◽  
D R Burgess
Keyword(s):  
Epithelial Cells ◽  
Membrane Protein ◽  
Actin Filaments ◽  
Equilibrium Density ◽  
Marker Enzyme ◽  
Dependent Manner ◽  
Golgi Membranes ◽  
Myosin I ◽  
Peripheral Membrane Protein

In the intestinal brush border, the mechanoenzyme myosin-I links the microvillus core actin filaments with the plasma membrane. Previous immunolocalization shows that myosin-I is associated with vesicles in mature enterocytes (Drenckhahn, D., and R. Dermietzel. 1988. J. Cell Biol. 107:1037-1048) suggesting a potential role mediating vesicle motility. We now report that myosin-I is associated with Golgi-derived vesicles isolated from cells that are rapidly assembling brush borders in intestinal crypts. Crypt cells were isolated in hyperosmotic buffer, homogenized, and fractionated using differential- and equilibrium-density centrifugation. Fractions containing 50-100-nm vesicles, a similar size to those observed in situ, were identified by EM and were shown to contain myosin-I as demonstrated by immunoblotting and immunolabel negative staining. Galactosyltransferase, a marker enzyme for trans-Golgi membranes was present in these fractions, as was alkaline phosphatase, which is an apical membrane targeted enzyme. Galactosyltransferase was also present in vesicles immuno-purified with antibodies to myosin-I. Villin, a marker for potential contamination from fragmented microvilli, was absent. Myosin-I was found to reside on the vesicle "outer" or cytoplasmic surface for it was accessible to exogenous proteases and intact vesicles could be immunolabeled with myosin-I antibodies in solution. The bound myosin-I could be extracted from the vesicles using NaCl, KI and Na2CO3, suggesting that it is a vesicle peripheral membrane protein. These vesicles were shown to bundle actin filaments in an ATP-dependent manner. These results are consistent with a role for myosin-I as an apically targeted motor for vesicle translocation in epithelial cells.

scholarly journals In Vitro Studies of Mechanisms of Lung Injury in the Rodent

1991 ◽  
Vol 19 (4_part_1) ◽  
pp. 419-427 ◽  
Author(s):  
Leah A. Cohn ◽  
Kenneth B. Adler
Keyword(s):  
Epithelial Cells ◽  
Cell Types ◽  
Lung Cells ◽  
Serum Free Medium ◽  
Collagen Gels ◽  
Respiratory Epithelial Cells ◽  
Respiratory Epithelial ◽  
Air Liquid Interface

In order to better define the responses of lung cells to potentially pathogenic insults, primary cell cultures of dissociated respiratory epithelial cells have been established. These epithelial cells have been obtained from various areas of the respiratory tract ranging from the trachea to the alveolus and the cultures have been demonstrated to mimic the differentiated state of these cell types as observed in situ. Several procedures which enhance the differentiated state have been evaluated, which include maintenance on more physiologically-relevant substrata, such as collagen gels, use of defined serum-free medium and use of air/liquid interface systems. These approaches have allowed intracellular responses of respiratory epithelium to toxic insult to be better defined.

In situ localization of S1-labeled actin filaments in chick lens epithelial cells

1984 ◽  
Vol 38 (6) ◽  
pp. 593-603 ◽  
Author(s):  
A.R. Roth ◽  
N.S. Rafferty ◽  
A. Telser ◽  
W. Goossens ◽  
D.L. Scholz
Keyword(s):  
Epithelial Cells ◽  
Actin Filaments ◽  
Lens Epithelial Cells ◽  
Chick Lens

Tentacular ultrastructure and feeding behaviour of Neopentadactyla mixta (Holothuroidea: Dendrochirota)

1983 ◽  
Vol 63 (2) ◽  
pp. 301-311 ◽  
Author(s):  
Timothy B. Smith
Keyword(s):  
Fine Structure ◽  
Epithelial Cells ◽  
Feeding Behaviour ◽  
Cell Types ◽  
Nerve Cells ◽  
Secretory Cells ◽  
Suspension Feeding ◽  
Adhesive Secretion

Suspension-feeding in the holothurian Neopentadactyla mixta (Östergren), 1898 is accomplished by an adhesive secretion synthesized in modified retractable discs of epithelial cells located on the terminal tentacular nodes. Besides secretory cells, each disc epithelium is composed of three other cell types: ciliated, granular and nerve cells. The fine structure and possible functions of the epithelium are described with reference to the behaviour of tentacles during feeding and the observations are compared with existing information on holothuroid feeding mechanisms.

scholarly journals Increase in actin contents and elongation of apical projections in retinal pigmented epithelial cells during development of the chicken eye.

1985 ◽  
Vol 101 (2) ◽  
pp. 590-596 ◽  
Author(s):  
K Owaribe ◽  
G Eguchi
Keyword(s):  
Epithelial Cells ◽  
Actin Filaments ◽  
Immunofluorescence Microscopy ◽  
Photoreceptor Cells ◽  
Optical Diffraction ◽  
Heavy Meromyosin ◽  
Actin Bundles ◽  
The Core ◽  
Sds Page ◽  
Retinal Pigmented Epithelial Cells

The structural and biochemical changes of cytoskeletal components of retinal pigmented epithelial cells were studied during the development of chicken eyes. When the cytoskeletal components of the pigmented epithelial cells from various stages of development were examined by SDS PAGE, actin contents in the cells markedly increased between the 15-d-old and hatching stages. Immunofluorescence microscopy showed that chicken pigmented epithelial cells have two types of actin bundles. One is the circumferential bundle associated with the zonula adherens region as previously reported (Owaribe, K., and H. Masuda, 1982, J. Cell Biol., 95:310-315). The other is the paracrystalline bundle forming the core of the apical projections. The increase in actin contents after the 15-d-old stage is accompanied by the formation and elongation of core filaments of apical projections in the cells. During this period the apical projections extend into extracellular space among outer and inner segments of photoreceptor cells. Accompanying this change is an elongation of the paracrystalline bundles of actin filaments in the core of the projection. By electron microscopy, the bundles decorated with muscle heavy meromyosin showed unidirectional polarity, and had transverse striations with approximately 12-nm intervals, as determined by optical diffraction of electron micrographs. Since the shape of these bundles was not altered in the presence or absence of Ca2+, they seemed not to have villin-like proteins. Unlike the circumferential bundles, the paracrystalline bundles did not contract when exposed to Mg-ATP. These observations indicate that the paracrystalline bundles are structurally and functionally different from the circumferential actin bundles.

scholarly journals Evidence for actin involvement in cardiac Z-lines and Z-line analogues.

1983 ◽  
Vol 96 (2) ◽  
pp. 435-442 ◽  
Author(s):  
M Yamaguchi ◽  
R M Robson ◽  
M H Stromer
Keyword(s):  
Electron Microscopy ◽  
Actin Filaments ◽  
Muscle Fibers ◽  
Opposite Polarity ◽  
Dense Material ◽  
Heavy Meromyosin ◽  
Thin Filaments ◽  
Electron Dense Material ◽  
Before And After

Canine and feline cardiac Z-lines and Z-rods were examined by electron microscopy before and after digestion of muscle fibers with Ca2+-activated protease (CAF). Removal by CAF of electron-dense material which covers Z-lines and Z-rods exposed interdigitating longitudinal filaments (6-7 nm in diameter) apparently continuous with thin filaments of the respective I-bands. The newly exposed longitudinal filaments of CAF-treated Z-lines and of CAF-treated Z-rods bound heavy meromyosin and therefore are actin. The width of Z-lines and length of Z-rods are determined by the amount of overlap of actin filaments of opposite polarity. The oblique filaments in Z-lines and Z-rods are responsible for the perpendicular periodicity of Z-lines and Z-rods, and are attributed to alpha-actinin.

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