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D Drenckhahn

Publications and source records attributed to D Drenckhahn.

At least 127 records · Page 7Linked to original sources
PubMed1986

Identification of actin-, alpha-actinin-, and vinculin-containing plaques at the lateral membrane of epithelial cells.

In this paper, a new type of spot desmosome-like junction (type II plaque) is described that is scattered along the entire lateral plasma membrane of rat and human intestinal epithelium. Ultrastructurally type II plaques differed from the classical type of epithelial spot desmosome ("macula adherens", further denoted as type I desmosome) by weak electron density of the membrane-associated plaque material, association of the plaques with microfilaments rather than intermediate filaments, and poorly visible material across the intercellular space. Thus, type II plaques resemble cross-sections of the zonula adherens. Immunofluorescence-microscopic studies were done using antibodies to a main protein associated with the plaques of type I desmosomes (desmoplakin I) and to the three major proteins located at the plaques of the zonula adherens (actin, alpha-actinin, and vinculin). Two types of plaques were visualized along the lateral surface of intestinal and prostatic epithelium: (a) the type I desmosomes, which were labeled with anti-desmoplakin but did not bind antibodies to actin, alpha-actinin, and vinculin, and (b) a further set of similarly sized plaques, which bound antibodies to actin, alpha-actinin, and vinculin but were not stained with anti-desmoplakin. Three-dimensional computer reconstruction of serial sections double-labeled with anti-desmoplakin and anti-alpha-actinin further confirmed that both types of plaques are spatially completely separated from each other along the lateral plasma membrane. The computer graphs further revealed that the actin-, alpha-actinin-, and vinculin-containing plaques have the tendency to form clusters, a feature also typical of type II plaques. It is suggested that the type II plaques represent spot desmosome-like intercellular junctions, which, like the zonula adherens, appear to be linked to the actin filament system. As the type II plaques cover a considerable part of the lateral cell surface, they might play a particular role in controlling cellular shape and intercellular adhesion.

Actinin↗
PubMed1985

Colocalization of band 3 with ankyrin and spectrin at the basal membrane of intercalated cells in the rat kidney.

An immunoreactive form of the anion channel protein of erythrocytes, band 3, has been identified in the rat kidney. It is found in the intercalated cells of the distal tubule and collecting ducts. Immunostaining specific for band 3 is confined to the basolateral plasma membrane of these cells, where this protein probably mediates the transport of bicarbonate across the tubular wall. Double-immunolabeling studies demonstrate that band 3 is colocalized with immunoreactive forms of ankyrin and spectrin along the basolateral plasma membrane. The polarized distribution of band 3 may be the result of the association of its cytoplasmic domain with ankyrin, which in turn links band 3 to spectrin and the cytoskeleton. These observations help to explain how the collecting ducts of the kidney can direct the transport of bicarbonate ions, thus maintaining the acid-base balance.

Animals↗
PubMed1985

The role of hemoglobin denaturation and band 3 clustering in red blood cell aging.

As hemoglobin begins to denature, it forms hemichromes that cross-link the major erythrocyte membrane-spanning protein, band 3, into clusters. These clusters provide the recognition site for antibodies directed against senescent cells. These antibodies bind to the aged red cell and trigger its removal from circulation.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1985

Relation of retinomotor responses and contractile proteins in vertebrate retinas.

Photoreceptors of many nonmammalian vertebrate species display pronounced light-dependent movements which are absent in mammalian species. In order to further analyze the molecular basis of receptor movements and of simultaneous migration of melanin granules in pigment epithelial processes, we investigated the distribution of actin, myosin and the actin-binding muscular proteins alpha-actinin and vinculin in the retina of various vertebrate species. The species investigated can be divided in two groups (i) those possessing retinomotor capacity (fish, frog, turtle, chick) and (ii) those in which retinomotor activities are negligible or absent (gecko, mouse, rat). Prominent bundles of actin filaments extending throughout the long axis of photoreceptor inner segments were only found in species possessing retinomotor capacity, while comparable actin filament bundles were absent or poorly developed in photoreceptors of species lacking significant retinomotor capacity. In all species examined, a well developed circumferential band of actin filaments was associated with the zonula adhaerens-like junctions between photoreceptors and Müller (glial) cells forming the external limiting membrane. This area was also identified as the exclusive site of myosin, alpha-actinin and vinculin (only in the chick, alpha-actinin-like immunoreactivity was also found along the photoreceptor actin filament bundles). Thus, the external limiting membrane may be important for both structural support and for providing a possible site of filament sliding for photoreceptor movements. In pigment epithelium actin, myosin, alpha-actinin and vinculin were concentrated circumferentially in the area of the terminal bar which has been previously shown to be contractile. In all species apical pigment-epithelial processes displayed actin-like fluorescence of varying intensities. Another site of actin-like staining were photoreceptor synaptic complexes which represent a well known site for synaptic plasticity. Immunoblotting studies on the avascular chick retina revealed polypeptide bands at Mr approximately 130 000, approximately 100 000, and 42 000 which were specific for vinculin, alpha-actinin and actin, respectively. A faint polypeptide band comigrating with thymus myosin heavy chain indicates myosin to be only a minor component of the retina (chick and fish).

Actins↗
PubMed1984

Concentration of F-actin in synaptic formations of the hippocampus as visualized by staining with fluorescent phalloidin.

Polymerized actin (F-actin) was localized in the guinea pig hippocampus by fluorescent staining with rhodamine-labeled phalloidin. Phalloidin displayed a preferential affinity for the main synaptic areas where the fluorescence was confined to 0.5-1 micron particles, roughly the size of synaptic structures (dendritic spines and presynaptic terminals). These particles appeared to stud the surface of dendrites. Particularly large and strongly fluorescent particles mainly 1-3 micron in diameter were found in the termination zone of mossy fibres which form the largest synapses of the hippocampus. The apparent high concentration of F-actin in synaptic formations suggests a role for actin in synaptic function.

Actins↗
PubMed1984

Identification of immunoreactive forms of human erythrocyte band 3 in nonerythroid cells.

Antibodies directed to the cytoplasmic domain of human erythrocyte band 3, the major integral protein of the erythrocyte membrane which is thought to be the main anchoring site of the membrane cytoskeleton, were demonstrated in the present study to react with the membrane of various nonerythroid cells, such as human leucocytes, fibroblasts or human umbilical mesenchyme cells, amniotic epithelium and vascular smooth muscle. In cultured fibroblasts staining was confined to small dots and streaks associated with both the dorsal and ventral cell membrane. In human lymphocytes band 3 antigen accompanied capping of concanavalin A binding surface receptors. The immunoreactive form of band 3 in fibroblasts was shown by immunoblotting studies to be a polypeptide of approximately 60 000 dalton. This polypeptide is immunologically and electrophoretically related to a major immunoreactive form of band 3 naturally occurring in the red blood cell membrane. Considering the recent identification in nonerythroid cells of immunoreactive forms of other major components of the erythrocyte membrane cytoskeleton, the present observation in nucleated cells of a polypeptide related to erythrocyte band 3 may indicate some of the features of erythrocyte membrane architecture are also present in nonerythroid cells.

Animals↗
PubMed1983

Evidence for the association of villin with core filaments and rootlets of intestinal epithelial microvilli.

Villin, a 95,000 dalton polypeptide of intestinal brush border which is known to bundle or sever actin filaments in a Ca++-dependent manner, was localized in rat and chicken intestinal epithelium by means of immunocytochemistry at the light- and electron-microscopic levels. Specific antibodies to villin were raised in rabbits immunized with villin purified from chicken intestinal epithelium. Anti-villin bound selectively to the microvillus filament bundle from its tip down to the rootlets. These findings indicate that the well-known stability of rootlet filaments towards elevated Ca++ ion concentrations cannot be explained by the absence of villin. Therefore additional factors must exist which prevent the rootlets from Ca++-villin mediated disassembly.

Animals↗
PubMed1983

Distribution of actin and the actin-associated proteins myosin, tropomyosin, alpha-actinin, vinculin, and villin in rat and bovine exocrine glands.

Actin, myosin, and the actin-associated proteins tropomyosin, alpha-actinin, vinculin, and villin were localized in acinar cells of rat and bovine pancreas, parotid, and prostate glands by means of immunofluorescent staining of both frozen tissue sections and semithin sections of quick-frozen, freeze-dried, and plastic-embedded tissues. Antibodies to actin, myosin, tropomyosin, alpha-actinin, and villin reacted strongly with a narrow cytoplasmic band extending beneath the luminal border of acinar cells. The presence of villin, which has so far been demonstrated only in intestinal and kidney brush border, was further confirmed by antibody staining of blotted electrophoresis gels of whole acinar cell extracts. Fluorescently labelled phalloidin, which reacts specifically with F-actin, gave similar staining, within the cell apex to that obtained with antibodies to actin, myosin, tropomyosin, alpha-actinin, and villin. In contrast, immunostaining with antibodies to vinculin was restricted to the area of the junctional complex. Ultrastructurally, the apical immunoreactive band corresponded to a dense web composed of interwoven microfilaments, which could be decorated with heavy meromyosin. Outside this apical terminal web, antibodies to myosin and tropomyosin gave only a weak immunostaining (confined to the lateral cell borders) whereas antibodies to actin and alpha-actinin led to a rather strong bead-like staining along the lateral and basal cell membrane most probably marking microfilament-associated desmosomes. Anti-villin immunofluorescence was confined to the apical terminal web. It is suggested that the apical terminal web is important for the control of transport and access of secretory granules to the luminal plasma membrane and that villin, which is known to bundle or sever actin filaments in a Ca(++)-dependent manner, might participate in the regulation of actin polymerization within this strategically located network of contractile proteins.

Actinin↗
PubMed1983

Evidence for the concentration of F-actin and myosin in synapses and in the plasmalemmal zone of axons.

Fluorescent staining with phalloidin, a specific probe for F-actin, and antibodies to non-muscle myosin from thymus was used to localize actin and myosin in brain neurons of the rat. Phalloidin and anti-myosin displayed a preferential affinity for synaptic formations in the cerebellum, the brain stem, the spinal cord and the retina. The conclusion that F-actin and myosin are concentrated in synaptic terminals was further established by simultaneous staining of isolated rat brain synaptosomes with phalloidin and anti-thymus myosin as well as by the demonstration of a selective affinity of anti-thymus myosin for a 200 000-Mr protein band in gel electrophoretograms of synaptic fractions. Apart from synaptic areas, phalloidin and anti-thymus myosin reacted also, albeit rather weakly, with a narrow circumferential layer located in the area of the plasma membrane of virtually all axons in the white matter and the spinal roots. The spatial coexistence of myosin and actin in brain synapses and axons is of particular interest in view of various dynamic functions that have been proposed for axonal and synaptic actin.

Actins↗
PubMed1983

Antibody to thymus myosin: its immunological characterization and use for immunocytochemical localization of myosin in vertebrate nonmuscle cells.

Thymus myosin differs immunologically from smooth muscle and striated muscle myosin isoenzymes. In the enzyme linked immunosorbent assay a moderate degree of cross reaction was observed between anti-thymus myosin and myosin from chicken gizzard (about 50% of the titer of the homologous reaction). In contrast, the cross reactivity between thymus myosin and antibodies to gizzard myosin was very low (about 5%) and no significant cross reaction was observed between thymus myosin and antibodies to striated muscle myosin and vice versa (below 1%). Antibodies to thymus myosin were further distinguished from antibodies to gizzard and striated muscle myosin by their reaction with both smooth muscle and a very broad spectrum of vertebrate nonmuscle cells. Nonmuscle cells reacting with anti-thymus myosin included (1) cell types which did not display any detectable affinity for anti-gizzard myosin (e.g. lymphocytes, polymorphonuclear leucocytes, vascular endothelium, adrenal chromaffine cells) and (2) cell types which reacted with anti-gizzard myosin as well (e.g. intestinal epithelial brush border, thymic epithelial cells, liver cells and stress fibres of cultured cells). These results illustrate, that anti-thymus myosin is a potent tool for investigating the intracellular localization of myosin in most if not all vertebrate nonmuscle cells. With respect to lymphatic tissue the present findings indicate that lymphocyte maturation appears to be accompanied by an increased level of expression of myosin and filamentous actin (the latter was visualized by labelled phalloidin). On the ultrastructural level, gold labelled antibodies to thymus myosin bound preferentially to the head region of in vitro assembled thymus myosin filaments. In cultured cells (PtK1) the antibodies showed a particular affinity for stress fibre densities, and in lymphocytes the anti-myosin label (immunoperoxidase) displayed a more or less diffuse distribution which was similar to the distribution of actin filaments (identified by decoration with heavy meromyosin).

Actins↗
PubMed1983

Corneal lipidosis in rats treated with amphiphilic cationic drugs.

The purpose of this study was to investigate whether generalized lipidosis experimentally induced by cationic amphiphilic drugs in rats is regularly associated with lipidotic alterations in the cornea. After chronic oral treatment with chlorphentermine, iprindole, or tamoxifen all animals showed clear lipidosis-like alterations in corneal cells. After chronic oral treatment with chloroquine and quinacrine the results were variable and unpredictable; however, consistent lipidosis-like alterations were found when chloroquine was applied locally onto the cornea. The present results show that basically the cornea of rats is involved in drug-induced lipidosis. For toxicological studies it must be kept in mind, however, that the reactions of rat cornea may be unreliable and less marked than in the cornea of human beings.

Animals↗
PubMed1982

The inhibition of bovine and rat parotid deoxyribonuclease I by skeletal muscle actin. A biochemical and immunocytochemical study.

Rat and bovine parotid gland and pancreas contain deoxyribonuclease I (DNAase I) activities in different amounts. The DNAase I activity in tissue homogenates of bovine and rat parotid gland can be inhibited by addition of monomeric actin, as with the enzyme of bovine pancreas. The isolated DNAase I species from bovine and rat parotid gland differ in their molecular weights and also in their affinities for monomeric actin, being lowest for rat parotid DNAase I (5 X 10(6)M(-1). Antibodies raised against rat and bovine parotid and bovine pancreatic DNAase I can be used to study the subcellular localization of DNAase I in these tissues by indirect immunofluorescence. DNAase I was found to be confined solely to the secretory granules of the tissue from which it was isolated.

Actins↗
PubMed1981

Distribution of nerve growth factor in the submandibular gland of the male and female mouse. A re-examination by use of an improved immunohistochemical procedure.

Nerve growth factor (NGF) was localized in the mouse submandibular gland by means of indirect immunofluorescence applied to 0.5 micron-thick sections of freeze-dried, plastic-embedded tissue. The antibody to NGF (IgG-fraction) was raised in rabbits immunized with pure 2.5 S NGF from submandibular glands of adult male mice. In the male gland anti-NGF bound selectively to the secretory granules was present in the cells of the granular ducts. Immunoreactive granules extended from the perinuclear region toward the apical pole. In the female gland immunoreactive cells and granules were considerably less abundant than in males. Immunofluorescence was confined to individual secretory cells located in the wall of the granular striated duct. In the present study no support was found for the hypothesis suggesting that immunoreactive NGF is formed within the secretory granules during their transport from the perinuclear region to the apical pole.

Animals↗
PubMed1981

Evidence for exclusive adrenergic innervation of feather muscles (mm. pennati) in the chicken. Histochemical studies and experiments with 5-hydroxydopamine.

Feather follicles in the avian skin are interconnected by well-defined bundles of smooth muscle cells, which are responsible for the erection and depression of feathers and thus play an important role in thermoregulation. The depressing and erecting muscle bundles were found to receive a very dense supply of unmyelinated nerve fibres that displayed ultrastructural and histochemical characteristics of noradrenergic axons (formaldehyde- and glyoxylic acid-induced catecholamine fluorescence; uptake to 5-hydroxydopamine). No nerve fibres were encountered showing histochemical acetylcholinesterase activity. There was no indication of the presence of peptidergic or purinergic nerve endings. The neuromuscular space usually ranged from 40-60 nm in width and contained a basal lamina. Occasionally, this space was reduced to approximately 20 nm. At such close neuromuscular contacts a basal lamina was lacking, and focal densities beneath the pre- and postsynaptic plasma membrane were observed. Since no gap junctions between muscle cells were detected, the dense supply with noradrenergic nerve fibres indicates a high amount of directly innervated smooth muscle cells. An additional finding of the present study was the observation that high local concentrations of 5-hydroxydopamine led to degeneration of noradrenergic nerve endings.

Adrenergic Fibers↗
PubMed1981

Fibroblastic and dendritic reticulum cells of lymphoid tissue. Ultrastructural, histochemical, and 3H-thymidine labeling studies.

Fibroblastic reticulum cells of different lymphoid organs were investigated to clarify their relationship to other stationary cells of the lymphoid tissue and to fibroblasts of the connective tissue. Fibroblastic reticulum cells have many ultrastructural characteristics of fibroblasts but differ from them in containing prominent bundles of microfilaments and in reacting strongly with antibodies to smooth muscle type myosin and actin. The fibroblastic reticulum cell may be thus classified as a myofibroblast. Enzyme-histochemical studies showed that fibroblastic reticulum cells contain a definite alkaline phosphatase isoenzyme. During ontogeny fibroblastic and dendritic reticulum cells are derived from the local mesenchyme and may be considered as primary stationary reticulum cells. During the formation of the follicle in the splenic white pulp in young rats fibroblastic and dendritic reticulum cells show a different turnover which speaks in favor of a proliferation of dendritic reticulum cells or their precursors in follicle formation.

Alkaline Phosphatase↗
PubMed1980

Immunocytochemical localization of myosin in the brush border region of the intestinal epithelium.

Myosin was localized in rat intestinal epithelium by means of indirect immunofluorescence and immunoelectron microscopy (unlabeled antibody peroxidase method), using a specific antibody to myosin from chicken gizzard. Immunoreactivity was localized in the apical cytoplasm, where it was concentrated along the rootlets of the microvillar filament bundles and in the terminal web. A model of microvillar contraction is proposed.

Animals↗