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Sample records for parietal cell secretory

  1. Two Rab proteins, vesicle-associated membrane protein 2 (VAMP-2) and secretory carrier membrane proteins (SCAMPs), are present on immunoisolated parietal cell tubulovesicles.

    PubMed Central

    Calhoun, B C; Goldenring, J R

    1997-01-01

    The tubulovesicles of gastric parietal cells sequester H+/K+-ATPase molecules within resting parietal cells. Stimulation of parietal cell secretion elicits delivery of intracellular H+/K+-ATPase to the apically oriented secretory canaliculus. Previous investigations have suggested that this process requires the regulated fusion of intracellular tubulovesicles with the canalicular target membrane. We have sought to investigate the presence of critical putative regulators of vesicle fusion on immunoisolated gastric parietal cell tubulovesicles. Highly purified tubulovesicles were prepared by gradient fractionation and immunoisolation on magnetic beads coated with monoclonal antibodies against the alpha subunit of H+/K+-ATPase. Western blot analysis revealed the presence of Rab11, Rab25, vesicle-associated membrane protein 2 (VAMP-2) and secretory carrier membrane proteins (SCAMPs) on immunoisolated vesicles. The same cohort of proteins was recovered on vesicles immunoisolated with monoclonal antibodies against SCAMPs and VAMP-2. In contrast, whereas immunoreactivities for syntaxin 1A/1B and synaptosome-associated protein (SNAP-25) were present in gradient-isolated vesicles, none of the immunoreactivity was associated with immunoisolated vesicles. The observation of VAMP-2 and two Rab proteins on immunoisolated H+/K+-ATPase-containing tubulovesicles supports the role for tubulovesicles in a regulated vesicle fusion process. In addition, the presence of SCAMPs along with Rab11 and Rab25 implicates the tubulovesicles as a critical apical recycling vesicle population. PMID:9230141

  2. Gastrin receptors on isolated canine parietal cells

    SciTech Connect

    Soll, A.H.; Amirian, D.A.; Thomas, L.P.; Reedy, T.J.; Elashoff, J.D.

    1984-05-01

    The receptors in the fundic mucosa that mediate gastrin stimulation of acid secretion have been studied. Synthetic human gastrin-17-I (G17) with a leucine substitution in the 15th position ((Leu15)-G17) was iodinated by chloramine T; high saturable binding was found to enzyme-dispersed canine fundic mucosal cells. /sup 127/I-(Leu15)-G17, but not /sup 127/I-G17, retained binding potency and biological activity comparable with uniodinated G17. Fundic mucosal cells were separated by size by using an elutriator rotor, and specific /sup 125/I-(Leu-15)-G17 binding in the larger cell fractions was highly correlated with the distribution of parietal cells. There was, however, specific gastrin binding in the small cell fractions, not accounted for by parietal cells. Using sequential elutriation and stepwise density gradients, highly enriched parietal and chief cell fractions were prepared; /sup 125/I-(Leu15)-G17 binding correlated positively with the parietal cell (r . 0.98) and negatively with chief cell content (r . -0.96). In fractions enriched to 45-65% parietal cells, specific /sup 125/I-(Leu15)-G17 binding was rapid, reaching a steady state at 37 degrees C within 30 min. Dissociation was also rapid, with the rate similar after 100-fold dilution or dilution plus excess pentagastrin. At a tracer concentration from 10 to 30 pM, saturable binding was 7.8 +/- 0.8% per 10(6) cells (mean +/- SE) and binding in the presence of excess pentagastrin accounted for 11% of total binding. G17 and carboxyl terminal octapeptide of cholecystokinin (26-33) were equipotent in displacing tracer binding and in stimulating parietal cell function ((/sup 14/C)aminopyrine accumulation), whereas the tetrapeptide of gastrin (14-17) had a much lower potency. Proglumide inhibited gastrin binding and selectively inhibited gastrin stimulation of parietal cell function.

  3. A biosynthetic regulated secretory pathway in constitutive secretory cells

    PubMed Central

    1996-01-01

    It has frequently been proposed that while the constitutive secretory pathway is present in all cells, the regulated secretory pathway is found only in specialized cells such as neuronal, endocrine, or exocrine types. In this study we provide evidence that suggests that this distinction is not as restrictive as proposed. We have identified a population of post-Golgi storage vesicles in several constitutive secretory cells using [35S]SO4-labeled glycosaminoglycan (GAG) chains as a marker. A fraction of this pool of vesicles can undergo exocytosis in response to stimuli such as cytoplasmic Ca2+ and phorbol esters. The effect of Ca2+ was demonstrated both in intact cells in the presence of the ionophore A23187 and in streptolysin-O-permeabilized semi-intact cells. N-ethylmaleiimide, under conditions known to block regulated and constitutive secretion, inhibited the stimulated secretion from these cells, suggesting that the observed release of labeled GAG chains was not due to a leakage artefact. Subcellular fractionation revealed that the stored GAG chains were in low-density membrane granules (d approximately 1.12 g/ml), whose size was greater than that of synaptic- like vesicles found in PC12 cells. In addition, in CHO cells that express epitope-tagged rab 3D, the labeled GAG chains were found to cofractionate with the exogenous rab protein. When expressed in the regulated cell line AtT-20, this tagged rab protein was found to colocalize with ACTH-containing dense-core granules by indirect immunofluorescence. Taken together, these results provide evidence for the presence of a cryptic regulated secretory pathway in "constitutive" cells and suggest that the regulated secretory pathway is more widespread amongst different cell types than previously believed. PMID:8682857

  4. Porosome: The Universal Secretory Portal in Cells

    NASA Astrophysics Data System (ADS)

    Jena, Bhanu

    2012-10-01

    In the past 50 years it was believed that during cell secretion, membrane-bound secretory vesicles completely merge at the cell plasma membrane resulting in the diffusion of intra-vesicular contents to the cell exterior and the compensatory retrieval of the excess membrane by endocytosis. This explanation made no sense or logic, since following cell secretion partially empty vesicles accumulate as demonstrated in electron micrographs. Furthermore, with the ``all or none'' mechanism of cell secretion by complete merger of secretory vesicle membrane at the cell plasma membrane, the cell is left with little regulation and control of the amount of content release. Moreover, it makes no sense for mammalian cells to possess such `all or none' mechanism of cell secretion, when even single-cell organisms have developed specialized and sophisticated secretory machinery, such as the secretion apparatus of Toxoplasma gondii, the contractile vacuoles in paramecium, or the various types of secretory structures in bacteria. Therefore, in 1993 in a News and Views article in Nature, E. Neher wrote ``It seems terribly wasteful that, during the release of hormones and neurotransmitters from a cell, the membrane of a vesicle should merge with the plasma membrane to be retrieved for recycling only seconds or minutes later.'' This conundrum in the molecular mechanism of cell secretion was finally resolved in 1997 following discovery of the ``Porosome,'' the universal secretory machinery in cells. Porosomes are supramolecular lipoprotein structures at the cell plasma membrane, where membrane-bound secretory vesicles transiently dock and fuse to release inravesicular contents to the outside during cell secretion. In the past decade, the composition of the porosome, its structure and dynamics at nm resolution and in real time, and its functional reconstitution into artificial lipid membrane, have all been elucidated. Since porosomes in exocrine and neuroendocrine cells measure 100-180 nm

  5. Secretory component: a glandular epithelial cell marker.

    PubMed Central

    Harris, J. P.; South, M. A.

    1981-01-01

    Secretory component (SC) has been demonstrated to be produced by both normal and malignantly transformed glandular epithelial cells. By an indirect immunofluorescent technique, this study surveys tumors of varied cellular origin in order to determine the reliability of SC as a marker for tumor cells derived from glandular epithelium. Both primary and metastatic tumors of glandular epithelial origin demonstrated SC fluorescence, while nonglandular epithelial tumors did not. This observation was extended to live single-cell preparations, which demonstrated intense cell-surface fluorescence only when glandular epithelial tumors cells were examined. Additionally, fixed, cytocentrifuged, single-cell preparations of glandular epithelial tumors demonstrated cytoplasmic SC fluorescence. When breast carcinoma was examined, all cases demonstrated SC, regardless of the degree of differentiation. This assay appears to have useful clinical application in that the finding of SC provides indication of the glandular epithelial origin of a malignantly transformed cell. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:6271014

  6. Ovarian serous carcinogenesis from tubal secretory cells.

    PubMed

    Zhang, Wenjing; Wei, Linxuan; Li, Lingmin; Yang, Binlie; Kong, Beihua; Yao, Guang; Zheng, Wenxin

    2015-11-01

    Due to a poor understanding of tumorigenesis, ovarian cancers remain the most lethal gynecologic malignancy and cause horrific deaths. In the last decade, a new dualistic model for ovarian cancer was proposed, wherein ovarian serous cancers are classified as either high-grade or low-grade, with each having different tumorigenic processes, and pathologic and clinical features. Surprisingly, both high- and low-grade ovarian serous cancers were recently found to originate not in the ovaries, but rather from the secretory cells of the fallopian tube, mostly from the tubal fimbriated ends. In this article, we review the evidentiary basis for the aforementioned paradigm shift in the cell origin of ovarian serous cancers, as well as its potential clinical implications. PMID:26174492

  7. [A cytoprotective chloride channel in gastric parietal cells].

    PubMed

    Sakai, H

    1999-08-01

    This review summarizes the regulatory mechanisms and physiological functions of the novel sub-pS Cl- channel (0.3 pS) that is present abundantly in the basolateral membrane of rabbit gastric parietal cells. The sub-pS Cl- channel is voltage-independent and inhibited by NPPB, a Cl- channel blocker. We found that this gastric Cl- channel is linked to three important physiological roles. First, the sub-pS Cl- channel has a housekeeping role through dominating the cell membrane potential. Although several types of cation channels are present, they do not significantly contribute to the membrane potential in the parietal cells. Second, the Cl- channel is activated by prostaglandin E2 via the EP3 receptor/Ca2-/nitric oxide (NO)/cGMP pathway. A vasodilator ecabapide also activates the channel by increasing the intracellular cGMP content. The NO/cGMP pathway-mediated opening of the sub-pS Cl- channel is essential for cytoprotection against ethanol-induced damage in the gastric parietal cells. The NO/cGMP-elicited cytoprotection is abolished by NPPB. To our knowledge, this Cl- channel is the first identified target for the cytoprotective NO/cGMP pathway. Third, the sub-pS Cl- channel is inhibited by the GTP-binding protein-mediated intracellular production of superoxide anion. Hydrogen peroxide and hydroxyl radicals have no effect on the channel activity. The intracellular superoxide anion acts as a messenger in the negative regulatory mechanism of the sub-pS Cl- channel. The similar sub-pS Cl- channel is also found in rat gastric parietal cells.

  8. Cytoplasmic calcium stimulates exocytosis in a plant secretory cell

    PubMed Central

    Tester, Mark; Zorec, Robert

    1992-01-01

    Although exocytosis is likely to occur in plant cells, the control of this process is the subject of speculation, as no direct measurements of vesicle fusion to the plasma membrane have been made. We used the patch clamp technique to monitor the secretory activity of single aleurone protoplasts by measuring membrane capacitance (Cm), while dialyzing the cytosol with different Ca2+ containing solutions. Secretory activity increased with [Ca2+]i ∼ 1 μM. This demonstrates directly the existence of exocytosis in plant cells, and suggests that both plant and animal cells share common mechanisms (cytosolic Ca2+) for the control of exocytotic secretion. PMID:19431846

  9. Characterization of Mast Cell Secretory Granules and Their Cell Biology

    PubMed Central

    Azouz, Nurit Pereg; Hammel, Ilan

    2014-01-01

    Exocytosis and secretion of secretory granule (SG) contained inflammatory mediators is the primary mechanism by which mast cells exert their protective immune responses in host defense, as well as their pathological functions in allergic reactions and anaphylaxis. Despite their central role in mast cell function, the molecular mechanisms underlying the biogenesis and secretion of mast cell SGs remain largely unresolved. Early studies have established the lysosomal nature of the mast cell SGs and implicated SG homotypic fusion as an important step occurring during both their biogenesis and compound secretion. However, the molecular mechanisms that account for key features of this process largely remain to be defined. A novel high-resolution imaging based methodology allowed us to screen Rab GTPases for their phenotypic and functional impact and identify Rab networks that regulate mast cell secretion. This screen has identified Rab5 as a novel regulator of homotypic fusion of the mast cell SGs that thereby regulates their size and cargo composition. PMID:24988214

  10. The ubiquitin ligase Mindbomb 1 coordinates gastrointestinal secretory cell maturation

    PubMed Central

    Capoccia, Benjamin J.; Jin, Ramon U.; Kong, Young-Yun; Peek, Richard M.; Fassan, Matteo; Rugge, Massimo; Mills, Jason C.

    2013-01-01

    After cell fate specification, differentiating cells must amplify the specific subcellular features required for their specialized function. How cells regulate such subcellular scaling is a fundamental unanswered question. Here, we show that the E3 ubiquitin ligase Mindbomb 1 (MIB1) is required for the apical secretory apparatus established by gastric zymogenic cells as they differentiate from their progenitors. When Mib1 was deleted, death-associated protein kinase–1 (DAPK1) was rerouted to the cell base, microtubule-associated protein 1B (MAP1B) was dephosphorylated, and the apical vesicles that normally support mature secretory granules were dispersed. Consequently, secretory granules did not mature. The transcription factor MIST1 bound the first intron of Mib1 and regulated its expression. We further showed that loss of MIB1 and dismantling of the apical secretory apparatus was the earliest quantifiable aberration in zymogenic cells undergoing transition to a precancerous metaplastic state in mouse and human stomach. Our results reveal a mechanistic pathway by which cells can scale up a specific, specialized subcellular compartment to alter function during differentiation and scale it down during disease. PMID:23478405

  11. Modeling Murine Gastric Metaplasia Through Tamoxifen-Induced Acute Parietal Cell Loss.

    PubMed

    Saenz, Jose B; Burclaff, Joseph; Mills, Jason C

    2016-01-01

    Parietal cell loss represents the initial step in the sequential progression toward gastric adenocarcinoma. In the setting of chronic inflammation, the expansion of the mucosal response to parietal cell loss characterizes a crucial transition en route to gastric dysplasia. Here, we detail methods for using the selective estrogen receptor modulator tamoxifen as a novel tool to rapidly and reversibly induce parietal cell loss in mice in order to study the mechanisms that underlie these pre-neoplastic events. PMID:27246044

  12. Bicarbonate transport in sheep parotid secretory cells.

    PubMed Central

    Steward, M C; Poronnik, P; Cook, D I

    1996-01-01

    1. Intracellular pH (pH1) was measured by microfluorimetry in secretory endpieces isolated from sheep parotid glands and loaded with the pH-sensitive fluoroprobe 2', 7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein (BCECF). 2. Stimulation with 1 microM acetylcholine (ACh) caused a large, transient decrease in pH1 of 0.37 +/- 0.02 pH units followed by a slower recovery. The transient, which was reduced by 60% in the absence of HCO3-, could be attributed mainly to HCO3- efflux. During sustained stimulation, pH1 increased to a value that exceeded the resting value by 0.083 +/- 0.023 pH units after 20 min. 3. The anion channel blocker NPPB (0.1 mM) reduced the transient acidification in response to ACh by 48% and raised pH1 during sustained stimulation. Simultaneous application of NPPB and ACh accelerated the re-alkalinization following the initial acidification, indicating that NPPB inhibits HCO3- efflux. 4. The stilbene derivative H2DIDS (0.5 mM) reduced the transient acidification in response to ACh by 76% but caused a marked decrease in pH1 during sustained stimulation. Simultaneous application of H2DIDS and ACh slowed the re-alkalinization following the initial acidification, indicating that the main effect of H2DIDS was to inhibit HCO3- accumulation. 5. In the absence of HCO3-, the recovery from an acid load was unaffected by ACh stimulation. Acid extrusion, although dependent on Na+, was not inhibited by amiloride (1 mM), clonidine (1 mM) or H2DIDS (0.5 mM) and was therefore provisionally attributed to a Na(+)-H+ exchanger isoform other than NHE1 or NHE2. 6. In the presence of HCO3-, the rate of recovery from an acid load was reduced during ACh stimulation, probably as a result of the increased efflux of HCO3-. Acid extrusion was dependent on Na+ and was significantly inhibited by H2DIDS. 7. We conclude that ACh-evoked HCO3- secretion in the sheep parotid gland differs from that in many other salivary glands by being driven predominantly by basolateral Na(+)-HCO3

  13. Unremitting Cell Proliferation in the Secretory Phase of Eutopic Endometriosis

    PubMed Central

    Franco-Murillo, Yanira; Miranda-Rodríguez, José Antonio; Rendón-Huerta, Erika; Montaño, Luis F.; Cornejo, Gerardo Velázquez; Gómez, Lucila Poblano; Valdez-Morales, Francisco Javier; Gonzalez-Sanchez, Ignacio

    2014-01-01

    Objective: Endometriosis is linked to altered cell proliferation and stem cell markers c-kit/stem cell factor (SCF) in ectopic endometrium. Our aim was to investigate whether c-kit/SCF also plays a role in eutopic endometrium. Design: Eutopic endometrium obtained from 35 women with endometriosis and 25 fertile eumenorrheic women was analyzed for in situ expression of SCF/c-kit, Ki67, RAC-alpha serine/threonine-protein kinase (Akt), phosphorylated RAC-alpha serine/threonin-protein kinase (pAkt), Glycogen synthase kinase 3 beta (GSK3β), and phosphorylated glycogen synthase kinase 3 beta (pGSK3β), throughout the menstrual cycle. Results: Expression of Ki67 and SCF was higher in endometriosis than in control tissue (P < .05) and greater in secretory rather than proliferative (P < .01) endometrium in endometriosis. Expression of c-kit was also higher in endometriosis although similar in both phases. Expression of Akt and GSK3β was identical in all samples and cycle phases, whereas pAkt and pGSK3β, opposed to control tissue, remained overexpressed in the secretory phase in endometriosis. Conclusion: Unceasing cell proliferation in the secretory phase of eutopic endometriosis is linked to deregulation of c-kit/SCF-associated signaling pathways. PMID:25194152

  14. Abnormal apocrine secretory cell mitochondria in a Huntington disease patient.

    PubMed

    Sidiropoulos, Christos; LeWitt, Peter; Hashimoto, Ken

    2012-12-15

    Over two decades, a 42-year old woman experienced the gradual onset of choreic involuntary movements, dystonia, and tics. Decreased caudate nucleus metabolism on 2-deoxyglucose PET scan and a heterozygous 49-CAG repeat expansion within the HTT gene established the diagnosis of HD, although no other family history was known. An axillary skin biopsy revealed a distinctive abnormality of mitochondria limited to the apocrine secretory cells on electron microscopy. All mitochondria were transformed into rounded structures with disrupted cristae and prominent myelin figures; many were enlarged up to 4 times the normal. Cytoplasm of apocrine secretory cells showed an abundance of lipid vacuoles, empty vesicles, and dense bodies. Biopsied skeletal muscle histology (light microscopy) was normal, as was a mitochondrial metabolism study. Biopsies from other HD patients have shown similar mitochondrial changes in cerebral neurons, muscle, fibroblasts, and lymphoblasts, adding to evidence for a systemic disturbance of mitochondria in HD.

  15. Role of aquaporins and regulation of secretory vesicle volume in cell secretion.

    PubMed

    Sugiya, H; Matsuki-Fukushima, M; Hashimoto, S

    2008-01-01

    In exocrine glands, secretory proteins synthesized in the rough endoplasmic reticulum (RER) exhibit vectorial transport from ER through a succession of membrane-bounded components such as Golgi complex, condensing vacuoles and secretory granules. The secretory granules migrate to particular locations within the cell close to the apical membrane prior to the release of their contents into the acinar lumen. Currently, to release intragranular contents, secretory granules have been demonstrated to transiently dock and fuse at 'porosome', a permanent cup-shaped structures at the cell membranes. Then swelling of secretory granules occurs to allow explusion of intragranular contents. In this process, water and ion fluxes in the granule membrane appear to contribute to maintain secretory granule integrity and morphology via osmoregulation in secretory granules. Aquaporins (AQPs) are a family of small, hydrophobic, integral membrane proteins, which function as channels to permeate water and small solutes. The AQPs reside constitutively at the plasma membrane in most cell types. However, recent studies have demonstrated that the AQPs are present in secretory granules in exocrine glands, synaptic vesicles and intracellular vesicles in liver and kidney, implying that AQPs in secretory granules and vesicles are involved in their volume regulation. This paper reviews the possible role of AQPs on secretory granules, especially in exocrine glands, in secretory function.

  16. Expression of ODC Antizyme Inhibitor 2 (AZIN2) in Human Secretory Cells and Tissues.

    PubMed

    Rasila, Tiina; Lehtonen, Alexandra; Kanerva, Kristiina; Mäkitie, Laura T; Haglund, Caj; Andersson, Leif C

    2016-01-01

    Ornithine decarboxylase (ODC) antizyme inhibitor 2 (AZIN2), originally called ODCp, is a regulator of polyamine synthesis that we originally identified and cloned. High expression of ODCp mRNA was found in brain and testis. We reported that AZIN2 is involved in regulation of cellular vesicle transport and / or secretion, but the ultimate physiological role(s) of AZIN2 is still poorly understood. In this study we used a peptide antibody (K3) to human AZIN2 and by immunohistochemistry mapped its expression in various normal tissues. We found high expression in the nervous system, in type 2 pneumocytes in the lung, in megakaryocytes, in gastric parietal cells co-localized with H,K-ATPase beta subunit, in selected enteroendocrine cells, in acinar cells of sweat glands, in podocytes, in macula densa cells and epithelium of collecting ducts in the kidney. The high expression of AZIN2 in various cells with secretory or vesicle transport activity indicates that the polyamine metabolism regulated by AZIN2 is more significantly involved in these events than previously appreciated. PMID:26963840

  17. Calcium dynamics in the secretory granules of neuroendocrine cells.

    PubMed

    Alvarez, Javier

    2012-01-01

    Cellular Ca(2+)signaling results from a complex interplay among a variety of Ca(2+) fluxes going across the plasma membrane and across the membranes of several organelles, together with the buffering effect of large numbers of Ca(2+)-binding sites distributed along the cell architecture. Endoplasmic and sarcoplasmic reticulum, mitochondria and even nucleus have all been involved in cellular Ca(2+) signaling, and the mechanisms for Ca(2+) uptake and release from these organelles are well known. In neuroendocrine cells, the secretory granules also constitute a very important Ca(2+)-storing organelle, and the possible role of the stored Ca(2+) as a trigger for secretion has attracted considerable attention. However, this possibility is frequently overlooked, and the main reason for that is that there is still considerable uncertainty on the main questions related with granular Ca(2+) dynamics, e.g., the free granular [Ca(2+)], the physical state of the stored Ca(2+) or the mechanisms for Ca(2+) accumulation and release from the granules. This review will give a critical overview of the present state of knowledge and the main conflicting points on secretory granule Ca(2+) homeostasis in neuroendocrine cells.

  18. Parietal Epithelial Cell Activation Marker in Early Recurrence of FSGS in the Transplant

    PubMed Central

    Fatima, Huma; Moeller, Marcus J.; Smeets, Bart; Yang, Hai-Chun; D’Agati, Vivette D.; Alpers, Charles E.

    2012-01-01

    Summary Background and objectives Podocyte loss is key in glomerulosclerosis. Activated parietal epithelial cells are proposed to contribute to pathogenesis of glomerulosclerosis and may serve as stem cells that can transition to podocytes. CD44 is a marker for activated parietal epithelial cells. This study investigated whether activated parietal epithelial cells are increased in early recurrent FSGS in transplant compared with minimal change disease. Design, setting, participants, & measurements CD44 staining in renal allograft biopsies from 12 patients with recurrent FSGS was performed and compared with native kidneys with minimal change disease or FSGS and normal control native and transplant kidneys without FSGS. CD44+ epithelial cells along Bowman’s capsule in the parietal epithelial cell location and over the glomerular tuft in the visceral epithelial cell location were assessed. Results Cases with early recurrent FSGS manifesting only foot process effacement showed significantly increased CD44+ visceral epithelial cells involving 29.0% versus 2.6% of glomeruli in minimal change disease and 0% in non-FSGS transplants. Parietal location CD44 positivity also was numerically increased in recurrent FSGS. In later transplant biopsies, glomeruli with segmental lesions had more CD44+ visceral epithelial cells than glomeruli without lesions. Conclusions Parietal epithelial cell activation marker is significantly increased in evolving FSGS versus minimal change disease, and this increase may distinguish early FSGS from minimal change disease. Whether parietal epithelial cell activation contributes to pathogenesis of sclerosis in idiopathic FSGS or is a regenerative/repair response to replace injured podocytes awaits additional study. PMID:22917699

  19. Epithelial Cell Culture from Human Adenoids: A Functional Study Model for Ciliated and Secretory Cells

    PubMed Central

    González, Claudia; Espinosa, Marisol; Sánchez, María Trinidad; Droguett, Karla; Ríos, Mariana; Fonseca, Ximena; Villalón, Manuel

    2013-01-01

    Background. Mucociliary transport (MCT) is a defense mechanism of the airway. To study the underlying mechanisms of MCT, we have both developed an experimental model of cultures, from human adenoid tissue of ciliated and secretory cells, and characterized the response to local chemical signals that control ciliary activity and the secretion of respiratory mucins in vitro. Materials and Methods. In ciliated cell cultures, ciliary beat frequency (CBF) and intracellular Ca2+ levels were measured in response to ATP, UTP, and adenosine. In secretory cultures, mucin synthesis and secretion were identified by using immunodetection. Mucin content was taken from conditioned medium and analyzed in the presence or absence of UTP. Results. Enriched ciliated cell monolayers and secretory cells were obtained. Ciliated cells showed a basal CBF of 10.7 Hz that increased significantly after exposure to ATP, UTP, or adenosine. Mature secretory cells showed active secretion of granules containing different glycoproteins, including MUC5AC. Conclusion. Culture of ciliated and secretory cells grown from adenoid epithelium is a reproducible and feasible experimental model, in which it is possible to observe ciliary and secretory activities, with a potential use as a model to understand mucociliary transport control mechanisms. PMID:23484122

  20. [The parietal cell mass and acid secretion: Helicobacter pylori does not induce changes in the course of a duodenal ulcer].

    PubMed

    Testino, G; Sumberaz, A; Cornaggia, M

    1995-12-01

    Some studies have postulated that Helicobacter pylori (HP) itself might be responsible for hypergastrinemia and acid secretion in duodenal ulcer (DU). In each DU patient parietal cell mass (expressed by a parietal index) and stimulated acid secretion (expressed by maximal acid output) were evaluated. The study has been conducted grouping DU patients in relation to HP infection in antral mucosa. HP infection does not modify parietal cell mass and stimulated acid secretion. Therefore, mild chronic hypergastrinemia induced by HP infection is not sufficient to justify any increase of parietal index and acid secretion. In fact, parietal cells and acid secretion remain higher in DU subjects independently from HP infection.

  1. Acid-induced secretory cell metaplasia in hamster bronchi

    SciTech Connect

    Christensen, T.G.; Lucey, E.C.; Breuer, R.; Snider, G.L.

    1988-02-01

    Hamsters were exposed to an intratracheal instillation of 0.5 ml of 0.08 N nitric, hydrochloric, or sulfuric acid to determine their airway epithelial response. Three weeks after exposure, the left intrapulmonary bronchi in Alcian blue/PAS-strained paraffin sections were evaluated for the amount of secretory product in the airway epithelium as a measure of secretory cell metaplasia (SCM). Compared to saline-treated control animals, all three acids caused statistically significant SCM. In addition to the bronchial lesion, all three acids caused similar interstitial fibrosis, bronchiolectasis, and bronchiolization of alveoli that varied in individual animals from mild to severe. In a separate experiment to study the persistence of the SCM, hamsters treated with a single instillation of 0.1 N nitric acid showed significant SCM 3, 7, and 17 weeks after exposure. There was a high correlation (r = 0.96) between a subjective assessment of SCM and objective assessment using a digital image-analysis system. We conclude that protons induce SCM independently of the associated anion; the SCM persists at least 17 weeks. Sulfuric acid is an atmospheric pollutant and nitric acid may form locally on the mucosa of lungs exposed to nitrogen dioxide. These acids may contribute to the development of maintenance of the SCM seen in the conducting airways of humans with chronic obstructive pulmonary disease.

  2. Fallopian tube secretory cell expansion: a sensitive biomarker for ovarian serous carcinogenesis

    PubMed Central

    Wang, Yiying; Li, Li; Wang, Yue; Tang, Sarah Ngocvi; Zheng, Wenxin

    2016-01-01

    Recent advances suggest that precancerous lesions of pelvic serous carcinoma originate from tubal secretory cells. The purpose of our study was to determine if an increased number of secretory cells vary with age or location in the fallopian tube and to examine its association with serous neoplasia. Three groups (benign control, high-risk, and pelvic serous carcinoma) of age-matched patients were studied. The age data were stratified into 10-year intervals ranging from 20-29 to older than 80. The number of secretory and ciliated cells from both tubal fimbria and ampulla segments was counted by microscopy and immunohistochemical staining methods. The data were analyzed by standard contingency table and Poisson distribution methods after age justification. We found that the absolute number of tubal secretory cells increased significantly with age in all three groups. But a more dramatic increase of secretory cells was observed in high-risk and pelvic serous carcinoma patients. Secretory cell expansion is more prevalent than secretory cell outgrowth in both fimbria and ampulla tubal segments and is significantly associated with serous neoplasia (p < 0.001). Furthermore, age remained a significant risk factor for serous neoplasia after age adjustment. These findings suggest that secretory cell expansion could serve as a potential sensitive biomarker for early serous carcinogenesis within the fallopian tube. The study also supports a relationship between serous neoplasia and increased secretory to ciliated cell ratios, and the relationship between frequency of secretory cell expansion within the fallopian tube and increasing age and-more significantly-presence of high-risk factors or co-existing serous cancers. PMID:27069556

  3. Vacuolar-type H+-ATPase-mediated proton transport in the rat parietal cell.

    PubMed

    Kopic, Sascha; Wagner, Maximilian E H; Griessenauer, Christoph; Socrates, Thenral; Ritter, Markus; Geibel, John P

    2012-03-01

    The vacuolar-type H-ATPase (V-ATPase) plays an important role in the active acidification of intracellular organelles. In certain specialized cells, such as the renal intercalated cell, apical V-ATPase can also function as a proton secretion pathway. In the parietal cells of the stomach, it has been thought that acid secretion is controlled solely via the H,K-ATPase. However, recent observations suggest that functional V-ATPase is necessary for acid secretion to take place. This study aimed to investigate and characterize the role of V-ATPase in parietal cell proton transport. Individual rat gastric glands were incubated with the pH-sensitive dye (BCECF) to monitor changes in intracellular pH in real time. Parietal cell V-ATPase activity was measured by quantifying the rate of intracellular alkalinization (ΔpH/minute) following an acid load, while excluding the contribution of non-V-ATPase proton transport mechanisms through pharmacological inhibition or ion substitution. Expression of V-ATPase was confirmed by immunohistochemistry. We observed concanamycin A-sensitive V-ATPase activity in rat parietal cells following intracellular acidification and H,K-ATPase inhibition. Furthermore, V-ATPase-mediated proton transport could be abolished by inhibiting trafficking mechanisms with paclitaxel and by stimulating H,K-ATPase with acid secretagogues. Our results propose that parietal cells contain a functional V-ATPase that can be mobilized using a microtubule network. V-ATPase may function as an auxiliary acid secretion or proton-buffering pathway in parietal cells, which is inactive during H,K-ATPase activity. Our findings may have important implications for patients experiencing acid breakthrough under proton pump inhibitor therapy.

  4. Secretory autophagy.

    PubMed

    Ponpuak, Marisa; Mandell, Michael A; Kimura, Tomonori; Chauhan, Santosh; Cleyrat, Cédric; Deretic, Vojo

    2015-08-01

    Autophagy, once viewed exclusively as a cytoplasmic auto-digestive process, has its less intuitive but biologically distinct non-degradative roles. One manifestation of these functions of the autophagic machinery is the process termed secretory autophagy. Secretory autophagy facilitates unconventional secretion of the cytosolic cargo such as leaderless cytosolic proteins, which unlike proteins endowed with the leader (N-terminal signal) peptides cannot enter the conventional secretory pathway normally operating via the endoplasmic reticulum and the Golgi apparatus. Secretory autophagy may also export more complex cytoplasmic cargo and help excrete particulate substrates. Autophagic machinery and autophagy as a process also affect conventional secretory pathways, including the constitutive and regulated secretion, as well as promote alternative routes for trafficking of integral membrane proteins to the plasma membrane. Thus, autophagy and autophagic factors are intimately intertwined at many levels with secretion and polarized sorting in eukaryotic cells. PMID:25988755

  5. Secretory phospholipase A2 induces dendritic cell maturation

    PubMed Central

    Perrin-Cocon, Laure; Agaugué, Sophie; Coutant, Frédéric; Masurel, Aurélie; Bezzine, Sofiane; Lambeau, Gérard; André, Patrice; Lotteau, Vincent

    2004-01-01

    High level of phospholipase A2 (PLA2) activity is found in serum and biological fluids during the acute phase response (APR). Extracellular PLA2 in fluids of patients with inflammatory diseases such as sepsis, acute pancreatitis or rheumatoid arthritis is also associated with propagation of inflammation. PLA2 activity is involved in the release of both pro- and anti-inflammatory lipid mediators from phospholipids of cellular membranes or circulating lipoproteins. PLA2 may thus generate signals that influence immune responses. Here, group III secretory PLA2s were tested for their ability to promote generation of functionally mature human dendritic cells (DC). PLA2 treatment of differentiating monocytes in the presence of GM-CSF and IL-4 yielded cells with phenotypical and functional characteristics of mature DC. This maturation was dependent on the dose of PLA2 and PLA2-generated DC stimulated interferon gamma secretion by allogeneic T cells. The effects of PLA2 on DC maturation was mainly dependent on enzyme activity and correlated with the activation of NF-κB, AP-1 and NFAT. The data suggest that transient increase in PLA2 activity generates signals that promote transition of innate to adaptive immunity during the APR. PMID:15259027

  6. Coordinate expression of parietal endodermal functions in hybrids of embryonal carcinoma and endodermal cells.

    PubMed Central

    Howe, W E; Oshima, R G

    1982-01-01

    A derivative, FOT5, of the F9 murine embryonal carcinoma cell line which is resistant to ouabain and thioguanine was fused with a near diploid parietal endodermal cell line, PFHR9, Hybrid clones (ENEC1 to ENEC5) were isolated in HAT Medium containing ouabain at a frequency of approximately 2 x 10(-4). The DNA contents and chromosome number of the ENEC hybrids were approximately the sum of those of the parents. Five hybrid cell lines examined in detail expressed the following parietal endodermal functions: plasminogen activator activity, basement membrane proteins, and endodermal cytoskeletal proteins. Embryonal carcinoma characteristic functions (tumorigenicity, a stage specific embryonic antigen, and high alkaline phosphatase activity) were extinguished in the hybrids. No hybrid clones with embryonal carcinoma morphology were observed among 1,358 hybrid clones examined. Hybrids, propagated for over 100 generations, continued to express endodermal functions and not embryonal carcinoma functions. The coordinate expression of endodermal functions and the extinction of embryonal carcinoma functions in the ENEC hybrids suggest that the parietal endodermal cells contain diffusible activities which extinguish embryonal carcinoma functions and possibly cause the embryonal carcinoma genome to express parietal endodermal characteristics. Images PMID:7202115

  7. Molecular insights into evolution of the vertebrate gut: focus on stomach and parietal cells in the marsupial, Macropus eugenii.

    PubMed

    Kwek, Joly; De Iongh, Robbert; Nicholas, Kevin; Familari, Mary

    2009-09-15

    Gastrulation in vertebrate embryos results in the formation of the primary germ layers: ectoderm, mesoderm and endoderm, which contain the progenitors of the tissues of the entire fetal body. Extensive studies undertaken in Xenopus, zebrafish and mouse have revealed a high degree of conservation in the genes and cellular mechanisms regulating endoderm formation. Nodal, Mix and Sox gene factor families have been implicated in the specification of the endoderm across taxa. Considerably less is known about endoderm development in marsupials. In this study we review what is known about the molecular aspects of endoderm development, focusing on evolution and development of the stomach and parietal cells and highlight recent studies on parietal cells in the stomach of Tammar Wallaby, Macropus eugenii. Although the regulation of parietal cells has been extensively studied, very little is known about the regulation of parietal cell differentiation. Intriguingly, during late-stage forestomach maturation in M. eugenii, there is a sudden and rapid loss of parietal cells, compared with the sharp increase in parietal cell numbers in the hindstomach region. This has provided a unique opportunity to study the development and regulation of parietal cell differentiation. A PCR-based subtractive hybridization strategy was used to identify candidate genes involved in this phenomenon. This will allow us to dissect the molecular mechanisms that underpin regulation of parietal cell development and differentiation, which have been a difficult process to study and provide markers that can be used to study the evolutionary origin of these cells in vertebrates.

  8. Mapping organelle motion reveals a vesicular conveyor belt spatially replenishing secretory vesicles in stimulated chromaffin cells.

    PubMed

    Maucort, Guillaume; Kasula, Ravikiran; Papadopulos, Andreas; Nieminen, Timo A; Rubinsztein-Dunlop, Halina; Meunier, Frederic A

    2014-01-01

    How neurosecretory cells spatially adjust their secretory vesicle pools to replenish those that have fused and released their hormonal content is currently unknown. Here we designed a novel set of image analyses to map the probability of tracked organelles undergoing a specific type of movement (free, caged or directed). We then applied our analysis to time-lapse z-stack confocal imaging of secretory vesicles from bovine Chromaffin cells to map the global changes in vesicle motion and directionality occurring upon secretagogue stimulation. We report a defined region abutting the cortical actin network that actively transports secretory vesicles and is dissipated by actin and microtubule depolymerizing drugs. The directionality of this "conveyor belt" towards the cell surface is activated by stimulation. Actin and microtubule networks therefore cooperatively probe the microenvironment to transport secretory vesicles to the periphery, providing a mechanism whereby cells globally adjust their vesicle pools in response to secretagogue stimulation. PMID:24489879

  9. Matrix metalloproteinase-9 expression is enhanced in renal parietal epithelial cells of zucker diabetic Fatty rats and is induced by albumin in in vitro primary parietal cell culture.

    PubMed

    Zhang, Yuanyuan; George, Jasmine; Li, Yun; Olufade, Rebecca; Zhao, Xueying

    2015-01-01

    As a subfamily of matrix metalloproteinases (MMPs), gelatinases including MMP-2 and MMP-9 play an important role in remodeling and homeostasis of the extracellular matrix. However, conflicting results have been reported regarding their expression level and activity in the diabetic kidney. This study investigated whether and how MMP-9 expression and activity were changed in glomerular epithelial cells upon albumin overload. In situ zymography, immunostaining and Western blot for renal MMP gelatinolytic activity and MMP-9 protein expression were performed in Zucker lean and Zucker diabetic rats. Confocal microscopy revealed a focal increase in gelatinase activity and MMP-9 protein in the glomeruli of diabetic rats. Increased glomerular MMP-9 staining was mainly observed in hyperplastic parietal epithelial cells (PECs) expressing claudin-1 in the diabetic kidneys. Interestingly, increased parietal MMP-9 was often accompanied by decreased staining for podocyte markers (nephrin and podocalyxin) in the sclerotic area of affected glomeruli in diabetic rats. Additionally, urinary excretion of podocyte marker proteins was significantly increased in association with the levels of MMP-9 and albumin in the urine of diabetic animals. To evaluate the direct effect of albumin on expression and activity of MMP-9, primary cultured rat glomerular PECs were incubated with rat serum albumin (0.25 - 1 mg/ml) for 24 - 48 hrs. MMP-9 mRNA levels were significantly increased following albumin treatment. Meanwhile, albumin administration resulted in a dose-dependent increase in MMP-9 protein and activity in culture supernatants of PECs. Moreover, albumin activated p44/42 mitogen-activated protein kinase (MAPK) in PECs. Inhibition of p44/42 MAPK suppressed albumin-induced MMP-9 secretion from glomerular PECs. Taken together, we have demonstrated that an up-regulation of MMP-9 in activated parietal epithelium is associated with a loss of adjacent podocytes in progressive diabetic nephropathy

  10. Polarized distribution of IQGAP proteins in gastric parietal cells and their roles in regulated epithelial cell secretion.

    PubMed

    Zhou, Rihong; Guo, Zhen; Watson, Charles; Chen, Emily; Kong, Rong; Wang, Wenxian; Yao, Xuebiao

    2003-03-01

    Actin cytoskeleton plays an important role in the establishment of epithelial cell polarity. Cdc42, a member of Rho GTPase family, modulates actin dynamics via its regulators, such as IQGAP proteins. Gastric parietal cells are polarized epithelial cells in which regulated acid secretion occurs in the apical membrane upon stimulation. We have previously shown that actin isoforms are polarized to different membrane domains and that the integrity of the actin cytoskeleton is essential for acid secretion. Herein, we show that Cdc42 is preferentially distributed to the apical membrane of gastric parietal cells. In addition, we revealed that two Cdc42 regulators, IQGAP1 and IQGAP2, are present in gastric parietal cells. Interestingly, IQGAP2 is polarized to the apical membrane of the parietal cells, whereas IQGAP1 is mainly distributed to the basolateral membrane. An IQGAP peptide that competes with full-length IQGAP proteins for Cdc42-binding in vitro also inhibits acid secretion in streptolysin-O-permeabilized gastric glands. Furthermore, this peptide disrupts the association of IQGAP and Cdc42 with the apical actin cytoskeleton and prevents the apical membrane remodeling upon stimulation. We propose that IQGAP2 forms a link that associates Cdc42 with the apical cytoskeleton and thus allows for activation of polarized secretion in gastric parietal cells.

  11. Potential mediation of prostaglandin E2 release from isolated human parietal cells by protein kinase C.

    PubMed

    Schepp, W; Schneider, J; Tatge, C; Schusdziarra, V; Classen, M

    1990-01-01

    Parietal cells are a major source of gastric mucosal prostaglandins in various species. We examined cholinergic stimulation of prostaglandin E2 (PGE2) release from human parietal cells; using activators of the protein kinase C we attempted to get an indirect insight into cellular mechanisms which control PGE2 release. Gastric mucosal specimens were obtained at surgery and the cells were dispersed by collagenase and pronase E. Parietal cells were enriched to 65-80% by a Percoll gradient, and were incubated for 30 min. PGE2 release into the medium (radioimmunoassay) was 74-126 pg/10(6) cells/30 min under basal conditions and was 2.6-fold increased by carbachol (10(-5) and 10(-4) M). Similarly, PGE2 release was stimulated by phospholipase C (20-200 mU/ml, 364% above basal), 1-oleoyl-2-acetyl-sn-glycerol (10(-9)-10(-5) M, 229%), 12-O-tetradecanoylphorbol-13-acetate (TPA; 10(-9)-10(-5) M, 283%) and calcium ionophore A23187 (10(-7)-10(-5) M, 219%). Simultaneous presence of A23187 and TPA synergistically induced stimulation which was slightly higher than the sum of the individual responses. N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide W-7, a putative calmodulin antagonist, inhibited TPA-induced PGE2 release at concentrations regarded specific for blocking calmodulin (IC50 = 1.5 X 0(-6) M). We conclude that in human parietal cells PGE2 is released upon cholinergic stimulation and that phospholipase C and protein kinase C are involved in the control of PGE2 release. We speculate that calmodulin might interact with a protein phosphorylated by protein kinase C to cause PGE2 release.

  12. Genetic Ablation of Parietal Cells in Transgenic Mice: A New Model for Analyzing Cell Lineage Relationships in the Gastric Mucosa

    NASA Astrophysics Data System (ADS)

    Canfield, Victor; West, A. Brian; Goldenring, James R.; Levenson, Robert

    1996-03-01

    The gastric mucosa of mammalian stomach contains several differentiated cell types specialized for the secretion of acid, digestive enzymes, mucus, and hormones. Understanding whether each of these cell lineages is derived from a common stem cell has been a challenging problem. We have used a genetic approach to analyze the ontogeny of progenitor cells within mouse stomach. Herpes simplex virus 1 thymidine kinase was targeted to parietal cells within the gastric mucosa of transgenic mice, and parietal cells were ablated by treatment of animals with the antiherpetic drug ganciclovir. Ganciclovir treatment produced complete ablation of parietal cells, dissolution of gastric glands, and loss of chief and mucus-producing cells. Termination of drug treatment led to the reemergence of all major gastric epithelial cell types and restoration of glandular architecture. Our results imply the existence of a pluripotent stem cell for the gastric mucosa. Parietal cell ablation should provide a model for analyzing cell lineage relationships within the stomach as well as mechanisms underlying gastric injury and repair.

  13. Modulation of dendritic cell function by Trichomonas vaginalis-derived secretory products.

    PubMed

    Song, Min-Ji; Lee, Jong-Joo; Nam, Young Hee; Kim, Tae-Gyun; Chung, Youn Wook; Kim, Mikyoung; Choi, Ye-Eun; Shin, Myeong Heon; Kim, Hyoung-Pyo

    2015-02-01

    Trichomoniasis caused by the parasitic protozoan Trichomonas vaginalis is the most common sexually transmitted disease in the world. Dendritic cells are antigen presenting cells that initiate immune responses by directing the activation and differentiation of naïve T cells. In this study, we analyzed the effect of Trichomonas vaginalis-derived Secretory Products on the differentiation and function of dendritic cells. Differentiation of bone marrow-derived dendritic cells in the presence of T. vaginalis-derived Secretory Products resulted in inhibition of lipopolysaccharide-induced maturation of dendritic cells, down-regulation of IL-12, and up-regulation of IL-10. The protein components of T. vaginalis-derived Secretory Products were shown to be responsible for altered function of bone marrow- derived dendritic cells. Chromatin immunoprecipitation assay demonstrated that IL-12 expression was regulated at the chromatin level in T. vaginalis-derived Secretory Productstreated dendritic cells. Our results demonstrated that T. vaginalis- derived Secretory Products modulate the maturation and cytokine production of dendritic cells leading to immune tolerance.

  14. Phospho-regulated ACAP4-Ezrin interaction is essential for histamine-stimulated parietal cell secretion.

    PubMed

    Ding, Xia; Deng, Hui; Wang, Dongmei; Zhou, Jiajia; Huang, Yuejia; Zhao, Xuannv; Yu, Xue; Wang, Ming; Wang, Fengsong; Ward, Tarsha; Aikhionbare, Felix; Yao, Xuebiao

    2010-06-11

    The ezrin-radixin-moesin proteins provide a regulated linkage between membrane proteins and the cortical cytoskeleton and also participate in signal transduction pathways. Ezrin is localized to the apical membrane of parietal cells and couples the protein kinase A activation cascade to the regulated HCl secretion. Our recent proteomic study revealed a protein complex of ezrin-ACAP4-ARF6 essential for volatile membrane remodeling (Fang, Z., Miao, Y., Ding, X., Deng, H., Liu, S., Wang, F., Zhou, R., Watson, C., Fu, C., Hu, Q., Lillard, J. W., Jr., Powell, M., Chen, Y., Forte, J. G., and Yao, X. (2006) Mol. Cell Proteomics 5, 1437-1449). However, knowledge of whether ACAP4 physically interacts with ezrin and how their interaction is integrated into membrane-cytoskeletal remodeling has remained elusive. Here we provide the first evidence that ezrin interacts with ACAP4 in a protein kinase A-mediated phosphorylation-dependent manner through the N-terminal 400 amino acids of ACAP4. ACAP4 locates in the cytoplasmic membrane in resting parietal cells but translocates to the apical plasma membrane upon histamine stimulation. ACAP4 was precipitated with ezrin from secreting but not resting parietal cell lysates, suggesting a phospho-regulated interaction. Indeed, this interaction is abolished by phosphatase treatment and validated by an in vitro reconstitution assay using phospho-mimicking ezrin(S66D). Importantly, ezrin specifies the apical distribution of ACAP4 in secreting parietal cells because either suppression of ezrin or overexpression of non-phosphorylatable ezrin prevents the apical localization of ACAP4. In addition, overexpressing GTPase-activating protein-deficient ACAP4 results in an inhibition of apical membrane-cytoskeletal remodeling and gastric acid secretion. Taken together, these results define a novel molecular mechanism linking ACAP4-ezrin interaction to polarized epithelial secretion.

  15. Estradiol increases cAMP in the oviductal secretory cells through a nongenomic mechanism.

    PubMed

    Oróstica, María L; Lopez, John; Rojas, Israel; Rocco, Jocelyn; Díaz, Patricia; Reuquén, Patricia; Cardenas, Hugo; Parada-Bustamante, Alexis; Orihuela, Pedro A

    2014-09-01

    In the rat oviduct, estradiol (E2) accelerates egg transport by a nongenomic action that requires previous conversion of E2 to methoxyestrogens via catechol-O-methyltranferase (COMT) and activation of estrogen receptor (ER) with subsequent production of cAMP and inositol triphosphate (IP3). However, the role of the different oviductal cellular phenotypes on this E2 nongenomic pathway remains undetermined. The aim of this study was to investigate the effect of E2 on the levels of cAMP and IP3 in primary cultures of secretory and smooth muscle cells from rat oviducts and determine the mechanism by which E2 increases cAMP in the secretory cells. In the secretory cells, E2 increased cAMP but not IP3, while in the smooth muscle cells E2 decreased cAMP and increased IP3. Suppression of protein synthesis by actinomycin D did not prevent the E2-induced cAMP increase, but this was blocked by the ER antagonist ICI 182 780 and the inhibitors of COMT OR 486, G protein-α inhibitory (Gαi) protein pertussis toxin and adenylyl cyclase (AC) SQ 22536. Expression of the mRNA for the enzymes that metabolizes estrogens, Comt, Cyp1a1, and Cyp1b1 was found in the secretory cells, but this was not affected by E2. Finally, confocal immunofluorescence analysis showed that E2 induced colocalization between ESR1 (ERα) and Gαi in extranuclear regions of the secretory cells. We conclude that E2 differentially regulates cAMP and IP3 in the secretory and smooth muscle cells of the rat oviduct. In the secretory cells, E2 increases cAMP via a nongenomic action that requires activation of COMT and ER, coupling between ESR1 and Gαi, and stimulation of AC.

  16. The organization of the secretory machinery in chromaffin cells as a major factor in modeling exocytosis

    PubMed Central

    Villanueva, José; Torregrosa-Hetland, Cristina J.; Gil, Amparo; González-Vélez, Virginia; Segura, Javier; Viniegra, Salvador; Gutiérrez, Luis M.

    2010-01-01

    The organization of cytoplasm in excitable cells was a largely ignored factor when mathematical models were developed to understand intracellular calcium and secretory behavior. Here we employed a combination of fluorescent evanescent and transmitted light microscopy to explore the F-actin cytoskeletal organization in the vicinity of secretory sites in cultured bovine chromaffin cells. This technique and confocal fluorescent microscopy show chromaffin granules associated with the borders of cortical cytoskeletal cages forming an intricate tridimensional network. Furthermore, the overexpression of SNAP-25 in these cells also reveals the association of secretory machinery clusters with the borders of these cytoskeletal cages. The importance of these F-actin cage borders is stressed when granules appear to interact and remain associated during exocytosis visualized in acridin orange loaded vesicles. These results will prompt us to propose a model of cytoskeletal cages, where the secretory machinery is associated with its borders. Both the calcium level and the secretory response are enhanced in this geometrical arrangement when compared with a random distribution of the secretory machinery that is not restricted to the borders of the cage. PMID:20885775

  17. Secretory end-feet, extracerebral cells, and cerebral sense organs in certain limicole oligochaete annelids.

    PubMed

    Golding, D W; Whittle, A C

    1975-01-01

    Secretory end-feet (or SEF) systems are present in Limnodrilus and Stylodrilus but are less highly organized than those of polychaetes. SEF contain secretory vesicles and abundant mitochondria. Typical neurosecretory terminals are not found within the brain although "neurosecretory" perikarya are present in all four species studied. In Limnodrilus, Stylodrilus and Enchytraeus extracerebral cells, of probable neurosecretory function, are invested by the pericapsular epithelium. Characteristically such cells bear several cilia. In these species and in Stylaria a pair of sensory cell groups is located anteriorly within the brain. These cells are ciliated but lack associated supporting cells. PMID:170709

  18. Insulin granules. Insulin secretory granules control autophagy in pancreatic β cells.

    PubMed

    Goginashvili, Alexander; Zhang, Zhirong; Erbs, Eric; Spiegelhalter, Coralie; Kessler, Pascal; Mihlan, Michael; Pasquier, Adrien; Krupina, Ksenia; Schieber, Nicole; Cinque, Laura; Morvan, Joëlle; Sumara, Izabela; Schwab, Yannick; Settembre, Carmine; Ricci, Romeo

    2015-02-20

    Pancreatic β cells lower insulin release in response to nutrient depletion. The question of whether starved β cells induce macroautophagy, a predominant mechanism maintaining energy homeostasis, remains poorly explored. We found that, in contrast to many mammalian cells, macroautophagy in pancreatic β cells was suppressed upon starvation. Instead, starved β cells induced lysosomal degradation of nascent secretory insulin granules, which was controlled by protein kinase D (PKD), a key player in secretory granule biogenesis. Starvation-induced nascent granule degradation triggered lysosomal recruitment and activation of mechanistic target of rapamycin that suppressed macroautophagy. Switching from macroautophagy to insulin granule degradation was important to keep insulin secretion low upon fasting. Thus, β cells use a PKD-dependent mechanism to adapt to nutrient availability and couple autophagy flux to secretory function.

  19. Apical vacuole formation by gastric parietal cells in primary culture: effect of low extracellular Ca2+

    PubMed Central

    Nakada, Stephanie L.; Machen, Terry E.; Forte, John G.

    2012-01-01

    In primary culture, the gastric parietal cell's deeply invaginated apical membrane, seen in microscopy by phalloidin binding to F-actin (concentrated in microvilli and a subapical web), is engulfed into the cell, separated from the basolateral membrane (which then becomes the complete plasma membrane), and converted, from a lacy interconnected system of canaliculi, into several separate vacuoles. In this study, vacuolar morphology was achieved by 71% of parietal cells 8 h after typical collagenase digestion of rabbit gastric mucosa, but the tight-junctional protein zonula occludens-1 (ZO-1) was completely delocalized after ∼2 h, when cells were ready for culturing. Use of low-Ca2+ medium (4 mM EGTA) to release cells quickly from gastric glands yielded parietal cells in which ZO-1 was seen in a small spot or ring, a localization quickly lost if these cells were then cultured in normal Ca2+ but remaining up to 20 h if they were cultured in low Ca2+. The cells in low Ca2+ mostly retained, at 20 h, an intermediate morphology of many bulbous canalicular expansions (“prevacuoles”), seemingly with narrow interconnections. Histamine stimulation of 20-h cells with intermediate morphology caused colocalization of proton-pumping H-K-ATPase with canaliculi and prevacuoles but little swelling of those structures, consistent with a remaining apical pore through which secreted acid could escape. Apparent canalicular interconnections, lack of stimulated swelling, and lingering ZO-1 staining indicate inhibition of membrane fission processes that separate apical from basolateral membrane and vacuoles from each other, suggesting an important role for extracellular Ca2+ in these, and possibly other, endocytotic processes. PMID:23099641

  20. Intracellular calcium signalling in rat parotid acinar cells that lack secretory vesicles.

    PubMed Central

    Liu, P; Scott, J; Smith, P M

    1998-01-01

    Secretory vesicles from pancreatic acinar cells have recently been shown to release Ca2+ after stimulation with Ins(1,4,5)P3 [Gerasimenko, Gerasimenko, Belan and Petersen, (1996) Cell 84, 473-480]. These observations have been used in support of the hypothesis that Ca2+ release from secretory vesicles could be an important component of stimulus secretion coupling in exocrine acinar cells. In the rat, ligation of the parotid duct causes a reversible atrophy of the parotid gland. Most notably, after atrophy the acinar cells are reduced in size and no longer contain secretory vesicles [Liu, Smith, and Scott (1996) J. Dent. Res. 74, 900]. We have measured cytosolic free-Ca2+ concentration ([Ca2+]i) in single, acutely isolated, rat parotid acinar cells, and compared Ca2+ mobilization in response to acetylcholine (ACh) stimulation in cells obtained from control animals to that in cells lacking secretory vesicles obtained after atrophy of the parotid gland. Application of 50-5000 nM ACh to control cells gave rise to a typical, dose-dependent, biphasic increase in [Ca2+]i, of which the later, plateau, phase was acutely dependent on the extracellular Ca2+ concentration. An identical pattern of response was observed with cells obtained from atrophic glands. Low concentrations of ACh (10-100 nM) occasionally produced [Ca2+]i oscillations of a similar pattern in cells from both control and atrophic glands. We were able to show that Ca2+ rises first in the apical pole of the cell and the increase then spreads to the rest of the cell in cells from control glands but not in cells from atrophic glands. However, at present we are unable to determine whether this is due to the lack of secretory vesicles or whether the separation is too small to measure in the smaller acinar cells obtained from atrophic glands. We conclude therefore, that secretory vesicles make no significant contribution to overall Ca2+ mobilization in rat parotid acinar cells, nor are they required for oscillatory

  1. Tracheobronchial epithelium of the sheep: IV. Lectin histochemical characterization of secretory epithelial cells.

    PubMed

    Mariassy, A T; Plopper, C G; St George, J A; Wilson, D W

    1988-09-01

    Conventional histochemical characterization of the mucus secretory apparatus is often difficult to reconcile with the biochemical analysis of respiratory secretions. This study was designed to examine the secretory glycoconjugates in airways using lectins with biochemically defined affinities for main sugar residues of mucus. We used five biotinylated lectins--DBA (Dolichos biflorus) and SBA (Glycine max) for N-acetyl galactosamine (galNAc), BSA I (Bandeiraea simplicifolia) and PNA (Arachis hypogea) for galactose (gal), and UEA I (Ulex europeus)--for detection of fucose (fuc) in HgCl2-fixed, paraffin-embedded, serially sectioned trachea, lobar and segmental bronchi and bronchioles of nine sheep. Lectins selectively localized the carbohydrate residues in luminal secretions, on epithelial cell surfaces, and in secretory cells. In proximal airways, the major carbohydrate residues in luminal secretions, cell surfaces, goblet cells, and glands were fuc and gal-NAc. PNA reacted mainly with apical granules of less than 10% of goblet cells, and gal residues were only detected in some of the mucous cells and on basolateral cell surfaces. Distal airways contained sparse secretion in the lumen, mucous cells contained weakly reactive fuc and gal-NAc, and the epithelial surfaces of Clara cells contained gal. Sugars abundant in the airway secretions were also the major component of cells in glands. We conclude that there is a correlation between specific sugar residues in secretory cells, glycocalyx, and luminal secretions in proximal and distal airways. This suggests that lectins may be used to obtain information about airway secretory cell composition from respiratory secretions. PMID:3189886

  2. Tracheobronchial epithelium of the sheep: IV. Lectin histochemical characterization of secretory epithelial cells.

    PubMed

    Mariassy, A T; Plopper, C G; St George, J A; Wilson, D W

    1988-09-01

    Conventional histochemical characterization of the mucus secretory apparatus is often difficult to reconcile with the biochemical analysis of respiratory secretions. This study was designed to examine the secretory glycoconjugates in airways using lectins with biochemically defined affinities for main sugar residues of mucus. We used five biotinylated lectins--DBA (Dolichos biflorus) and SBA (Glycine max) for N-acetyl galactosamine (galNAc), BSA I (Bandeiraea simplicifolia) and PNA (Arachis hypogea) for galactose (gal), and UEA I (Ulex europeus)--for detection of fucose (fuc) in HgCl2-fixed, paraffin-embedded, serially sectioned trachea, lobar and segmental bronchi and bronchioles of nine sheep. Lectins selectively localized the carbohydrate residues in luminal secretions, on epithelial cell surfaces, and in secretory cells. In proximal airways, the major carbohydrate residues in luminal secretions, cell surfaces, goblet cells, and glands were fuc and gal-NAc. PNA reacted mainly with apical granules of less than 10% of goblet cells, and gal residues were only detected in some of the mucous cells and on basolateral cell surfaces. Distal airways contained sparse secretion in the lumen, mucous cells contained weakly reactive fuc and gal-NAc, and the epithelial surfaces of Clara cells contained gal. Sugars abundant in the airway secretions were also the major component of cells in glands. We conclude that there is a correlation between specific sugar residues in secretory cells, glycocalyx, and luminal secretions in proximal and distal airways. This suggests that lectins may be used to obtain information about airway secretory cell composition from respiratory secretions.

  3. Secretory vesicles transiently dock and fuse at the porosome to discharge contents during cell secretion.

    PubMed

    Jena, Bhanu P

    2009-12-16

    In contrast with the observation in electron micrographs of partially empty vesicles in cells following secretion, it has been believed since the 1950s that during cell secretion, secretory vesicles completely merge at the cell plasma membrane, resulting in the diffusion of intravesicular contents to the cell exterior and the compensatory retrieval of the excess membrane by endocytosis. In the interim, a large body of work has been published arguing both for and against the complete merger of secretory vesicle membrane at the cell plasma membrane during secretion. The only definitive determination of the mechanism of cell secretion remained in its direct observation at nanometre resolution in live cells. In the past decade, this finally became a reality through the power and scope of the atomic force microscope, which has made it possible to resolve a major conundrum in cell biology. This paradigm shift in our understanding of cell secretion is briefly outlined here.

  4. Mouse Paneth Cell Secretory Responses to Cell Surface Glycolipids of Virulent and Attenuated Pathogenic Bacteria

    PubMed Central

    Tanabe, Hiroki; Ayabe, Tokiyoshi; Bainbridge, Brian; Guina, Tina; Ernst, Robert K.; Darveau, Richard P.; Miller, Samuel I.; Ouellette, Andre J.

    2005-01-01

    Mouse Paneth cells respond to bacteria and bacterial cell surface antigens by discharging secretory granules into the lumen of small intestinal crypts (T. Ayabe et al., Nat. Immunol. 1:113-118, 2000). To investigate mechanisms regulating these responses, purified surface glycolipid molecules with known acyl chain modifications and attenuated properties were tested for the ability to stimulate Paneth cell secretion. The antigens included lipopolysaccharide (LPS) from wild-type and msbB-null Escherichia coli and phoP-null and phoP-constitutive Salmonella enterica serovar Typhimurium strains, as well as LPS, lipid A, and lipoteichoic acid from Pseudomonas aeruginosa and Listeria monocytogenes grown in Mg2+-limited media. Measurements of total secreted protein, secreted lysozyme, and the bactericidal peptide activities of collected secretions showed that the purified antigens elicited similar secretory responses from Paneth cells in mouse crypts ex vivo, regardless of glycolipid acyl chain modification. Despite their impaired Tlr4 pathway, Paneth cells in ex vivo C3H/HeJ mouse crypts released equivalent amounts of bactericidal peptide activity in response to purified bacterial antigens, including lipid A. Thus, mouse Paneth cells respond equivalently to purified bacterial cell envelope glycolipids, regardless of functional Tlr4, the structural properties of glycolipid acyl chains, or their association with virulence in humans. PMID:15784576

  5. Secretory organelles in ECL cells of the rat stomach: an immunohistochemical and electron-microscopic study.

    PubMed

    Zhao, C M; Chen, D; Lintunen, M; Panula, P; Håkanson, R

    1999-12-01

    ECL cells are numerous in the rat stomach. They produce and store histamine and chromogranin-A (CGA)-derived peptides such as pancreastatin and respond to gastrin with secretion of these products. Numerous electron-lucent vesicles of varying size and a few small, dense-cored granules are found in the cytoplasm. Using confocal and electron microscopy, we examined these organelles and their metamorphosis as they underwent intracellular transport from the Golgi area to the cell periphery. ECL-cell histamine was found to occur in both cytosol and secretory vesicles. Histidine decarboxylase, the histamine-forming enzyme, was in the cytosol, while pancreastatin (and possibly other peptide products) was confined to the dense cores of granules and secretory vesicles. Dense-cored granules and small, clear microvesicles were more numerous in the Golgi area than in the docking zone, i.e. close to the plasma membrane. Secretory vesicles were numerous in both Golgi area and docking zone, where they were sometimes seen to be attached to the plasma membrane. Upon acute gastrin stimulation, histamine was mobilized and the compartment size (volume density) of secretory vesicles in the docking zone was decreased, while the compartment size of microvesicles was increased. Based on these findings, we propose the following life cycle of secretory organelles in ECL cells: small, electron-lucent microvesicles (pro-granules) bud off the trans Golgi network, carrying proteins and secretory peptide precursors (such as CGA and an anticipated prohormone). They are transformed into dense-cored granules (approximate profile diameter 100 nm) while still in the trans Golgi area. Pro-granules and granules accumulate histamine, which leads to their metamorphosis into dense-cored secretory vesicles. In the Golgi area the secretory vesicles have an approximate profile diameter of 150 nm. By the time they reach their destination in the docking zone, their profile diameter is between 200 and 500 nm

  6. Formation of concentric saccules in murine parietal cells after injection of diazo-oxo-norleucine.

    PubMed

    Michaels, J E

    1979-04-01

    After treatment with various chemical and physical agents, flattened or ring-like saccules may occur in the cytoplasm of parietal cells of the gastric glands of several species of mammals. In the current investigation, similar structures appeared after treatment with high dosages of diazo-oxo-norleucine (DON), a glutamine antagonist. A tentative sequence for their formation is suggested. Saccules formed of unit membrane became abundant in some parietal cells of the treated mice. Single saccules often had narrow lumens and peripheral distensions. The saccules, either singular or several stacked together, became progressively more curved, enclosing a region of cytoplasm that often contained glycogen-like particles and occasionally vesicles or other organelles. Many of the concentric saccules were close to an intracellular canaliculus. Membrane bound cytoplasm containing glycogen-like particles occasionally occurred in the canaliculi, suggesting that exocytosis had occurred. Cytochemistry revealed that glycoproteins were associated with the concentric saccules, probably located on the luminal surface. The glycogen-like particles in all locations stained in a manner characteristic of glycogen. It is suggested that the concentric saccules may form from vesicles of the tubulovesicular system.

  7. Parietal cell hyperplasia induced by long-term administration of antacids to rats.

    PubMed Central

    Mazzacca, G; Cascione, F; Budillon, G; D'Agostino, L; Cimino, L; Femiano, C

    1978-01-01

    Suspension of magnesium and aluminum hydroxide (30--60 mEq/24h) or a comparable volme of water was orally administered by gastric intubation to two groups of 20 male Wistar rats each over 60 days. The antacid treatment led to a significant increase in the height (0.464 +/- 0.02 mm v. 0.318 +/- 0.06) and in the volume (472 +/- 32 mm3v.328 +/- 45) of the fundic mucosa of the stomach, in the average count of parietal cells per unit area of the mucosa (32.37 +/- 1.8 v. 22.3 +/- 1.6), and in the total parietal cell population of the stomach (53.6 +/- 3.5 x 10(6) v. 43.2 +/- 3.7 x 10(6)). Furthermore fasting serum gastrin concentration was significantly higher in the antacid treated rats (81.2 +/- 7.4 pg/ml) than in control animals (56.9 +/- 6.9 pg/ml). PMID:710969

  8. Autoimmune gastritis and parietal cell reactivity in two children with abnormal intestinal permeability.

    PubMed

    Greenwood, Deanne L V; Crock, Patricia; Braye, Stephen; Davidson, Patricia; Sentry, John W

    2008-08-01

    Autoimmune gastritis is characterised by lymphocytic infiltration of the gastric submucosa, with loss of parietal and chief cells and achlorhydria. Often, gastritis is expressed clinically as cobalamin deficiency with megaloblastic anaemia, which is generally described as a disease of the elderly. Here, we report on two prepubertal children who developed autoimmune gastritis. One child developed autoimmune gastritis as part of a polyglandular autoimmune disease from a family with polyglandular autoimmune disease type II (PGA type II) and the other as part of a classic "thyro-gastric cluster," which may have been triggered by emotional trauma. Both children presented with normal small bowel biopsies, with abnormal gut permeability, which subsequently resolved. These patients are among the youngest reported to date. The immune systems targetted the gastric parietal cell autoantigens (ATP4A and ATP4B) in both children, similar to the elderly. The study of children with autoimmune gastritis and their families may provide additional insights into the disease's pathogenesis and may also lead to the identification of inheritable factors influencing susceptibility. This report underlines the necessity to screen paediatric patients with organ-specific autoimmune diseases for co-existent conditions. Children with polyglandular autoimmune disease are at particularly high risk.

  9. [Signal transudation pathways in parietal cells of the gastric mucosa in experimental stomach ulcer].

    PubMed

    Ostapchenko, L I; Drobins'ka, O V; Chaĭka, V O; Bohun, L I; Bohdanova, O V; Kot, L I; Haĭda, L M

    2009-01-01

    The goal of the presented work was the research of signal transduction mechanism in the rat gastric parietal cells under stomach ulcer conditions. In these cells activation of adenylate cyclase (increase of cAMP level and proteinkinase A activity) and phosphoinositide (increases [Ca2+]i; cGMP and phoshatidylinocitole levels; proteinkinase C, proteinkinase G, and calmodulin-dependent-proteinkinase activity) of signals pathway was shown. An increase of plasma membrane phospholipids (PC, PS, PE, PI, LPC) level was shown. Under conditions of influence of the stress factor the membran enzymes activity (H+, K+ -ATPase, 5'-AMPase, Na+, K+ -ATPase, Ca2+, Mg2+ -ATPase and H+, K+ -ATPase) was considerably increased. The intensification of lipid peroxidation processes in rats was demonstrated.

  10. Intestinal Neurogenin 3 Directs Differentiation of a Bipotential Secretory Progenitor to Endocrine Cell Rather than Goblet Cell Fate

    PubMed Central

    López-Díaz, Lymari; Jain, Renu N.; Keeley, Theresa M.; VanDussen, Kelli L.; Brunkan, Cynthia S.; Gumucio, Deborah L.; Samuelson, Linda C.

    2009-01-01

    Neurogenin 3 is essential for enteroendocrine cell development; however, it is unknown whether this transcription factor is sufficient to induce an endocrine program in the intestine or how it affects the development of other epithelial cells originating from common progenitors. In this study, the mouse villin promoter was used to drive Neurogenin 3 expression throughout the developing epithelium to measure the affect on cell fate. Although the general morphology of the intestine was unchanged, transgenic founder embryos displayed increased numbers of cells expressing the pan-endocrine marker chromogranin A. Accordingly, expression of several hormones and pro-endocrine transcription factors were increased in the transgenics suggesting that Neurogenin 3 stimulated a program of terminal enteroendocrine cell development. To test whether increased endocrine cell differentiation affected the development of other secretory cell lineages, we quantified goblet cells, the only other secretory cell formed in embryonic intestine. The Neurogenin 3-expressing transgenics had decreased numbers of goblet cells in correspondence to the increase in endocrine cells, with no change in the total secretory cell numbers. Thus, our data suggest that Neurogenin 3 can redirect the differentiation of bipotential secretory progenitors to endocrine rather than goblet cell fate. PMID:17706959

  11. Preservation of the secretory response of peritoneal mast cells in the absence of extracellular calcium.

    PubMed

    Bronner, C; Gies, J P; Vallé, A; Landry, Y

    1987-12-01

    The transfer of rat peritoneal mast cells from balanced salt solution to calcium-free buffer led to a time-dependent decrease in their response to compound 48/80 and to ionophore A23187. The concomittant absence of potassium from the calcium-free buffer enabled the mast cells to retain their secretory response. The increase in potassium level, with a parallel decrease in sodium to maintain osmolarity, led to a slight potentiation of the response to 48/80 and to a large but transient potentiation of the response to A23187. Mast cells can be considered nonexcitable. The apparent dependency upon extracellular calcium of mast cell secretory responses might be related to the presumed tight equilibrium between endoplasmic reticulum calcium stores and extracellular calcium. The control of this equilibrium by transmembrane gradients of monovalent ions is proposed. PMID:2446099

  12. Effect of oral acetylcysteine on tobacco smoke-induced secretory cell hyperplasia.

    PubMed

    Jeffery, P K; Rogers, D F; Ayers, M M

    1985-01-01

    The present investigation explores whether N-acetylcysteine (NAC) inhibits the secretory cell hyperplasia known to occur experimentally in specific pathogen-free (SPF) bronchitic rats. The animals were divided into 4 groups: no tobacco smoke (TS), no drug, no TS but NAC (1040 mg/kg body weight), TS but no drug, and TS plus NAC. NAC-treated animals showed no ill effects, TS exposed animals showed an initial fall in weight gain which never fully recovered (P less than 0.01): NAC did not protect. TS caused a significant increase (62-421%) in secretory cell number at all airway levels distal to the upper trachea (P less than 0.01) and NAC significantly inhibited it (P less than 0.01-0.05) in all, mostly in secretory cells containing acidic glycoprotein. TS exposure also induced a significant rise in epithelial cell concentration and of ciliated, mucous and especially basal cell number (P less than 0.001). NAC inhibited the mucous cell increase (P less than 0.001) and had 3 effects on the peak of dividing cells: it was (a) delayed until 3 days (b) greatly reduced in size and (c) prolonged at a lower level until its return to control values at 10 days of TS exposure. PMID:3862604

  13. Effect of oral acetylcysteine on tobacco smoke-induced secretory cell hyperplasia.

    PubMed

    Jeffery, P K; Rogers, D F; Ayers, M M

    1985-01-01

    The present investigation explores whether N-acetylcysteine (NAC) inhibits the secretory cell hyperplasia known to occur experimentally in specific pathogen-free (SPF) bronchitic rats. The animals were divided into 4 groups: no tobacco smoke (TS), no drug, no TS but NAC (1040 mg/kg body weight), TS but no drug, and TS plus NAC. NAC-treated animals showed no ill effects, TS exposed animals showed an initial fall in weight gain which never fully recovered (P less than 0.01): NAC did not protect. TS caused a significant increase (62-421%) in secretory cell number at all airway levels distal to the upper trachea (P less than 0.01) and NAC significantly inhibited it (P less than 0.01-0.05) in all, mostly in secretory cells containing acidic glycoprotein. TS exposure also induced a significant rise in epithelial cell concentration and of ciliated, mucous and especially basal cell number (P less than 0.001). NAC inhibited the mucous cell increase (P less than 0.001) and had 3 effects on the peak of dividing cells: it was (a) delayed until 3 days (b) greatly reduced in size and (c) prolonged at a lower level until its return to control values at 10 days of TS exposure.

  14. The phenotypes of podocytes and parietal epithelial cells may overlap in diabetic nephropathy

    PubMed Central

    Andeen, Nicole K.; Nguyen, Tri Q.; Steegh, Floor; Hudkins, Kelly L.; Najafian, Behzad; Alpers, Charles E.

    2015-01-01

    Reversal of diabetic nephropathy (DN) has been achieved in humans and mice, but only rarely and under special circumstances. Since progression of DN is related to podocyte loss, reversal of DN requires restoration of podocytes. Here we identified and quantified potential glomerular progenitor cells that could be a source for restored podocytes. DN was identified in 31 human renal biopsy cases and separated into morphologically early or advanced lesions. Markers of podocytes (WT-1, p57), parietal epithelial cells (claudin-1) and cell proliferation (Ki-67) were identified by immunohistochemistry. Podocyte density was progressively reduced with DN. Cells marking as podocytes (p57) were present infrequently on Bowman's capsule in controls, but significantly increased in histologically early DN. Ki-67 expressing cells were identified on the glomerular tuft and Bowman's capsule in DN, but rarely in controls. Cells marking as PECs were present on the glomerular tuft, particularly in morphologically advanced DN. These findings show evidence of phenotypic plasticity in podocyte and PEC populations and are consistent with studies in the BTBR ob/ob murine model in which reversibility of DN occurs with podocytes potentially regenerating from PEC precursors. Thus, our findings support, but do not prove, that podocytes may regenerate from PEC progenitors in human DN. If so, progression of DN may represent a modifiable net balance between podocyte loss and regeneration. PMID:26376129

  15. Computer modeling of gastric parietal cell: significance of canalicular space, gland lumen, and variable canalicular [K+].

    PubMed

    Crothers, James M; Forte, John G; Machen, Terry E

    2016-05-01

    A computer model, constructed for evaluation of integrated functioning of cellular components involved in acid secretion by the gastric parietal cell, has provided new interpretations of older experimental evidence, showing the functional significance of a canalicular space separated from a mucosal bath by a gland lumen and also shedding light on basolateral Cl(-) transport. The model shows 1) changes in levels of parietal cell secretion (with stimulation or H-K-ATPase inhibitors) result mainly from changes in electrochemical driving forces for apical K(+) and Cl(-) efflux, as canalicular [K(+)] ([K(+)]can) increases or decreases with changes in apical H(+)/K(+) exchange rate; 2) H-K-ATPase inhibition in frog gastric mucosa would increase [K(+)]can similarly with low or high mucosal [K(+)], depolarizing apical membrane voltage similarly, so electrogenic H(+) pumping is not indicated by inhibition causing similar increase in transepithelial potential difference (Vt) with 4 and 80 mM mucosal K(+); 3) decreased H(+) secretion during strongly mucosal-positive voltage clamping is consistent with an electroneutral H-K-ATPase being inhibited by greatly decreased [K(+)]can (Michaelis-Menten mechanism); 4) slow initial change ("long time-constant transient") in current or Vt with clamping of Vt or current involves slow change in [K(+)]can; 5) the Na(+)-K(+)-2Cl(-) symporter (NKCC) is likely to have a significant role in Cl(-) influx, despite evidence that it is not necessary for acid secretion; and 6) relative contributions of Cl(-)/HCO3 (-) exchanger (AE2) and NKCC to Cl(-) influx would differ greatly between resting and stimulated states, possibly explaining reported differences in physiological characteristics of stimulated open-circuit Cl(-) secretion (≈H(+)) and resting short-circuit Cl(-) secretion (>H(+)).

  16. Intracellular ion concentrations and cell volume during cholinergic stimulation of eccrine secretory coil cells

    SciTech Connect

    Takemura, T.; Sato, F.; Saga, K.; Suzuki, Y.; Sato, K. )

    1991-02-01

    Methacholine (MCh)-induced changes in intracellular concentrations of Na, K, and Cl (( Na)i, (K)i, and (Cl)i, respectively) and in cellular dry mass (a measure of cell shrinkage) were examined in isolated monkey eccrine sweat secretory coils by electron probe X-ray microanalysis using the peripheral standard method. To further confirm the occurrence of cell shrinkage during MCh stimulation, the change in cell volume of dissociated clear and dark cells were directly determined under a light microscope equipped with differential interference contrast (DIC) optics. X-ray microanalysis revealed a biphasic increase in cellular dry mass in clear cells during continuous MCh stimulation; an initial increase of dry mass to 158% (of control) followed by a plateau at 140%, which correspond to the decrease in cell volume of 37 and 29%, respectively. The latter agrees with the MCh-induced cell shrinkage of 29% in dissociated clear cells. The MCh-induced increase in dry mass in myoepithelial cells was less than half that of clear cells. During the steady state of MCh stimulation, both (K+)i and (Cl)i of clear cells decreased by about 45%, whereas (Na)i increased in such a way to maintain the sum of (Na) i + (K)i constant. There was a small (12-15 mM) increase in (Na)i and a decrease in (K)i in myoepithelial cells during stimulation with MCh. Dissociated dark cells failed to significantly shrink during MCh stimulation. The decrease in (Cl)i in the face of constant (Na)i + (K)i suggests the accumulation of unknown anion(s) inside the clear cell during MCh stimulation.

  17. Myosin Va facilitates the distribution of secretory granules in the F-actin rich cortex of PC12 cells.

    PubMed

    Rudolf, Rüdiger; Kögel, Tanja; Kuznetsov, Sergei A; Salm, Thorsten; Schlicker, Oliver; Hellwig, Andrea; Hammer, John A; Gerdes, Hans-Hermann

    2003-04-01

    Neuroendocrine secretory granules, the storage organelles for neuropeptides and hormones, are formed at the trans-Golgi network, stored inside the cell and exocytosed upon stimulation. Previously, we have reported that newly formed secretory granules of PC12 cells are transported in a microtubule-dependent manner from the trans-Golgi network to the F-actin-rich cell cortex, where they undergo short directed movements and exhibit a homogeneous distribution. Here we provide morphological and biochemical evidence that myosin Va is associated with secretory granules. Expression of a dominant-negative tail domain of myosin Va in PC12 cells led to an extensive clustering of secretory granules close to the cell periphery, a loss of their cortical restriction and a strong reduction in their motility in the actin cortex. Based on this data we propose a model that implies a dual transport system for secretory granules: after microtubule-dependent delivery to the cell periphery, secretory granules exhibit a myosin Va-dependent transport leading to their restriction and even dispersal in the F-actin-rich cortex of PC12 cells. PMID:12615975

  18. Secretory vesicle transport velocity in living cells depends on the myosin-V lever arm length.

    PubMed

    Schott, Daniel H; Collins, Ruth N; Bretscher, Anthony

    2002-01-01

    Myosins are molecular motors that exert force against actin filaments. One widely conserved myosin class, the myosin-Vs, recruits organelles to polarized sites in animal and fungal cells. However, it has been unclear whether myosin-Vs actively transport organelles, and whether the recently challenged lever arm model developed for muscle myosin applies to myosin-Vs. Here we demonstrate in living, intact yeast that secretory vesicles move rapidly toward their site of exocytosis. The maximal speed varies linearly over a wide range of lever arm lengths genetically engineered into the myosin-V heavy chain encoded by the MYO2 gene. Thus, secretory vesicle polarization is achieved through active transport by a myosin-V, and the motor mechanism is consistent with the lever arm model.

  19. Stimulation of acid secretion and phosphoinositol production by rat parietal cell muscarinic M sub 2 receptors

    SciTech Connect

    Pfeiffer, A.; Rochlitz, H.; Herz, A.; Paumgartner, G. )

    1988-04-01

    The muscarinic receptor system involved in hydrogen production by enriched rat gastric parietal cells was investigated. Muscarinic receptor density determined by (N-methyl-{sup 3}H)scopolamine binding was 8,100/cell. The receptor appeared to be of the M{sub 2} muscarinic receptor subtype, since it had a low affinity (K{sub d} 189 nM) for the M{sub 1} receptor antagonist pirenzepine compared with atropine. Receptor activation by carbachol rapidly augmented levels of polyphosphoinositides, indicating an activation of phospholipase C. The dose-response relations for the increase in inositol phosphates closely paralleled the binding of carbachol to muscarinic receptors. The inositol phosphate response was antagonized by pirenzepine with a K{sub i} of 177 nM. the stimulation of inositol phosphate levels by carbachol correlated well with the stimulation of ({sup 14}C)aminopyrine uptake, determine as an index of acid secretion. The muscarinic agonists oxotremorine, pilocarpine, and bethanechol elicited partial increases in inositol phosphates at maximal drug concentrations, and these partial increases correlated with their ability to stimulate ({sup 14}C)aminopyrine uptake. These data indicate that inositolpolyphosphates may be a second messenger of M{sub 2} receptors stimulating acid secretion.

  20. Monoclonal Antibodies as Probes for Unique Antigens in Secretory Cells of Mixed Exocrine Organs

    NASA Astrophysics Data System (ADS)

    Basbaum, C. B.; Mann, J. K.; Chow, A. W.; Finkbeiner, W. E.

    1984-07-01

    In the past, it has been difficult to identify the secretory product and control mechanisms associated with individual cell types making up mixed exocrine organs. This report establishes the feasibility of using immunological methods to characterize both the biochemical constituents and regulatory mechanisms associated with secretory cells in the trachea. Monoclonal antibodies directed against components of tracheal mucus were produced by immunizing mice with dialyzed, desiccated secretions harvested from tracheal organ culture. An immunofluorescence assay revealed that of the total 337 hybridomas screened, 100 produced antibodies recognizing goblet cell granules; 64, gland cell granules; and 3, antigen confined to the ciliated apical surface of the epithelium. The tracheal goblet cell antibody described in this report was strongly cross-reactive with intestinal goblet cells, as well as with a subpopulation of submandibular gland cells, but not with cells of Brunner's glands or the ciliated cell apical membrane. The serous cell antibody was not cross-reactive with goblet, Brunner's gland, or submandibular cells, or the ciliated cell apical membrane. The antibody directed against the apical membrane of ciliated cells did not cross-react with gland or goblet cells or the apical membrane of epithelial cells in the duodenum. Monoclonal antibodies, therefore, represent probes by which products unique to specific cells or parts of cells in the trachea can be distinguished. The antibodies, when used in enzyme immunoassays, can be used to quantitatively monitor secretion by individual cell types under a variety of physiological and pathological conditions. They also provide the means for purification and characterization of cell-specific products by immunoaffinity chromatography.

  1. A fast method to study the secretory activity of neuroendocrine cells at the ultrastructural level.

    PubMed

    Van Herp, F; Coenen, T; Geurts, H P M; Janssen, G J A; Martens, G J M

    2005-04-01

    Cryo field emission scanning electron microscopy (cryo-FE-SEM) is a versatile technique that allows the investigation of the three-dimensional organization of cells at the ultrastructural level over a wide range of magnifications. Unfortunately, cryopreparation of the specimens for this technique remains cumbersome, in particular because ice crystal formation must be prevented during freezing. Here we report that a light prefixation with glutaraldehyde and incubation in glycerol as cryoprotectant or a high-pressure freezing approach are both excellent procedures for cryopreparation of animal cells to be used in combination with cryo-FE-SEM. Using the proopiomelanocortin-producing intermediate pituitary melanotrope cells of Xenopus laevis as a physiologically inducible neuroendocrine system, we compared the ultrastructural characteristics of inactive and hyperactive neuroendocrine cells. The overall quality of the ultrastructural images was comparable for the two cryopreparation procedures, although some fine structures were better conserved using high-pressure freezing. Melanotrope cells in a secretory inactive state contained numerous storage granules and a poorly developed endoplasmic reticulum (ER), while large amounts of rough ER were present in hyperactive cells. Thus, the cryo-FE-SEM approach described here allows a fast ultrastructural study on the secretory activity of neuroendocrine cells.

  2. A molecular profile of the mouse gastric parietal cell with and without exposure to Helicobacter pylori

    PubMed Central

    Mills, Jason C.; Syder, Andrew J.; Hong, Chieu V.; Guruge, Janaki L.; Raaii, Farhang; Gordon, Jeffrey I.

    2001-01-01

    The parietal cell (PC) plays an important role in normal gastric physiology and in common diseases of the stomach. Although the genes involved in acid secretion are well known, there is limited molecular information about other aspects of PC function. We have generated a comprehensive database of genes expressed preferentially in PCs relative to other gastric mucosal cell lineages. PCs were purified from FVB/N mouse stomachs by lectin panning. cRNA generated from PC-enriched (PC+) and PC-depleted (PC−) populations were used to query oligonucleotide-based microarrays. False-positive signals were filtered by using a new algorithm for noise reduction and selected results independently audited by real-time quantitative reverse transcription (RT)-PCR. The annotated database of 240 genes reveals previously unappreciated aspects of cellular function, including factors that may mediate PC regulation of gastric stem cell proliferation. PC+ and PC− expression profiles were also prepared from germ-free mice 2 and 8 weeks after colonization with a clinical isolate of Helicobacter pylori (Hp)—the pathogen that produces acid-peptic disease (gastritis, ulcers) in humans. Whereas PC+ gene expression was remarkably constant, the PC− fractions demonstrated a robust, evolving host response, with increased expression of genes involved in cell motility/migration, extracellular matrix interactions, and IFN responses. The consistency of PC+ gene expression allowed identification of a cohort of 92 genes enriched in PCs under all conditions studied. These genes provide a molecular profile that can be used to define this epithelial lineage under a variety of physiologic, pharmacologic, and pathologic stimuli. PMID:11717430

  3. [Effect of plant hormones on the components of secretory pathway in human normal and tumor cells].

    PubMed

    Vil'danova, M S; Savitskaia, M A; Onishchenko, G E; Smirnova, E A

    2014-01-01

    Plant hormones play a key role in plant growth and differentiation. Many hormones are known as potential antitumor agents, yet others appear to affect the secretory activity and are produced by mammalian cells as pro-inflammatory cytokines. The goal of this research was to study the effect of abscisic and gibberellic acids on the secretory system of human cultured epidermoid carcinoma cells A431 and keratinocytes HaCat. Immunocytochemical and morphometric analysis demonstrated that subtoxic concentration of plant hormones induced the broadening of the ER network and increased the size of Golgi complex. Electron microscopy studies confirmed the hypertrophic changes of the Golgi apparatus, specifically, the swelling of cisternae in the trans-compartment of dictyosomes after exposure to abscisic acid, and swelling of cis- and trans-compartment of dictyosomes after exposure to abscisic acid, and swelling of cis- and trans-compartments of dictyosomes after exposure to gibberellic acid. Using of Click-iT technique allowed to detect the elevation of the total protein synthesis only in A431 cells exposed to abscisic acid. Cumulative data suggests that, under these conditions, the hypertrophy of Golgi apparatus may reflect the enhanced secretory activity of cells. In other experiments, the hypertrophy of Golgi is not related to increased protein synthesis and therefore may suggest the stress-related changes of ER and Golgi apparatus. Our results demonstrate that morphologically similar reaction of cellular organelles, such as hypertrophy of Golgi apparatus, is the result of different functional activities, and that molecular mechanisms underlying the changes induced in cells need further investigations. PMID:25696996

  4. Pancreatic β-Cell Adaptive Plasticity in Obesity Increases Insulin Production but Adversely Affects Secretory Function.

    PubMed

    Alarcon, Cristina; Boland, Brandon B; Uchizono, Yuji; Moore, Patrick C; Peterson, Bryan; Rajan, Suryalekha; Rhodes, Olivia S; Noske, Andrew B; Haataja, Leena; Arvan, Peter; Marsh, Bradly J; Austin, Jotham; Rhodes, Christopher J

    2016-02-01

    Pancreatic β-cells normally produce adequate insulin to control glucose homeostasis, but in obesity-related diabetes, there is a presumed deficit in insulin production and secretory capacity. In this study, insulin production was assessed directly in obese diabetic mouse models, and proinsulin biosynthesis was found to be contrastingly increased, coupled with a significant expansion of the rough endoplasmic reticulum (without endoplasmic reticulum stress) and Golgi apparatus, increased vesicular trafficking, and a depletion of mature β-granules. As such, β-cells have a remarkable capacity to produce substantial quantities of insulin in obesity, which are then made available for immediate secretion to meet increased metabolic demand, but this comes at the price of insulin secretory dysfunction. Notwithstanding, it can be restored. Upon exposing isolated pancreatic islets of obese mice to normal glucose concentrations, β-cells revert back to their typical morphology with restoration of regulated insulin secretion. These data demonstrate an unrealized dynamic adaptive plasticity of pancreatic β-cells and underscore the rationale for transient β-cell rest as a treatment strategy for obesity-linked diabetes. PMID:26307586

  5. Secretory clusterin inhibits osteoclastogenesis by attenuating M-CSF-dependent osteoclast precursor cell proliferation

    SciTech Connect

    Choi, Bongkun; Kang, Soon-Suk; Kang, Sang-Wook; Min, Bon-Hong; Lee, Eun-Jin; Song, Da-Hyun; Kim, Sang-Min; Song, Youngsup; Yoon, Seung-Yong; Chang, Eun-Ju

    2014-07-18

    Highlights: • We describe the expression and secretion of clusterin in osteoclasts. • Endogenous clusterin deficiency does not affect osteoclast formation. • Exogenous treatment with secretory clusterin decreases osteoclast differentiation. • Secretory clusterin attenuates osteoclast precursor cell proliferation by inhibiting M-CSF-mediated ERK activation. - Abstract: Secretory clusterin (sCLU)/apolipoprotein J is a multifunctional glycoprotein that is ubiquitously expressed in various tissues. Reduced sCLU in the joints of patients with bone erosive disease is associated with disease activity; however, its exact role has yet to be elucidated. Here, we report that CLU is expressed and secreted during osteoclastogenesis in mouse bone marrow-derived macrophages (BMMs) that are treated with receptor activator of nuclear factor kappa-B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). CLU-deficient BMMs obtained from CLU{sup −/−} mice exhibited no significant alterations in OC differentiation in comparison with BMMs obtained from wild-type mice. In contrast, exogenous sCLU treatment significantly inhibited OC formation in both BMMs and OC precursor cultures. The inhibitory effect of sCLU was more prominent in BMMs than OC precursor cultures. Interestingly, treating BMMs with sCLU decreased the proliferative effects elicited by M-CSF and suppressed M-CSF-induced ERK activation of OC precursor cells without causing apoptotic cell death. This study provides the first evidence that sCLU reduces OC formation by inhibiting the actions of M-CSF, thereby suggesting its protective role in bone erosion.

  6. Effect of adenosine and adenosine analogs on ( sup 14 C)aminopyrine accumulation by rabbit parietal cells

    SciTech Connect

    Ota, S.; Hiraishi, H.; Terano, A.; Mutoh, H.; Kurachi, Y.; Shimada, T.; Ivey, K.J.; Sugimoto, T. )

    1989-12-01

    Adenosine receptors that modulate adenylate cyclase activity have been identified recently in a number of tissues. Adenosine A2 receptor is stimulatory to adenylate cyclase, whereas adenosine A1 receptor is inhibitory to adenylate cyclase. We investigated the effect of adenosine and its analogs on (14C)aminopyrine accumulation by rabbit parietal cells. Rabbit gastric mucosal cells were isolated by enzyme digestion. Parietal cells were enriched by nonlinear percoll gradients. (14C)Aminopyrine accumulation was used as an indicator of acid secretion. The effect of 2-chloroadenosine on histamine-stimulated (14C)aminopyrine accumulation was studied. The effects of N-ethylcarboxamideadenosine, 2-chloroadenosine, stable analogs of adenosine, and adenosine on (14C)aminopyrine accumulation were assessed. Cyclic AMP content of parietal cells was determined by radioimmunoassay. Histamine and carbachol, known secretagogues, stimulated (14C)aminopyrine accumulation. 2-Chloroadenosine did not suppress histamine-stimulated (14C)aminopyrine accumulation. 2-Chloroadenosine, N-ethylcarboxamideadenosine, and adenosine dose dependently increased (14C)aminopyrine accumulation. The order of potency was N-ethylcarboxamideadenosine greater than 2-chloroadenosine greater than adenosine. 8-Phenyltheophylline and theophylline, adenosine-receptor antagonists, or cimetidine did not have significant effects on the increase of AP uptake induced by 2-chloroadenosine. Coadministration of dipyridamole, and adenosine uptake inhibitor, augmented the effect of adenosine on (14C)aminopyrine accumulation. 2-Chloroadenosine, N-ethylcarboxamideadenosine, and adenosine each induced a significant increase in cellular cyclic AMP. We conclude that there may be adenosine A2 receptors on rabbit parietal cells which modulate gastric acid secretion.

  7. Myosin Va Transports Dense Core Secretory Vesicles in Pancreatic MIN6 β-CellsV⃞

    PubMed Central

    Varadi, Aniko; Tsuboi, Takashi; Rutter, Guy A.

    2005-01-01

    The role of unconventional myosins in neuroendocrine cells is not fully understood, with involvement suggested in the movement of both secretory vesicles and mitochondria. Here, we demonstrate colocalization of myosin Va (MyoVa) with insulin in pancreatic β-cells and show that MyoVa copurifies with insulin in density gradients and with the vesicle marker phogrin-enhanced green fluorescent protein upon fluorescence-activated sorting of vesicles. By contrast, MyoVa immunoreactivity was poorly colocalized with mitochondrial or other markers. Demonstrating an important role for MyoVa in the recruitment of secretory vesicles to the cell surface, a reduction of MyoVa protein levels achieved by RNA interference caused a significant decrease in glucose- or depolarization-stimulated insulin secretion. Similarly, expression of the dominant-negative–acting globular tail domain of MyoVa decreased by ∼50% the number of vesicles docked at the plasma membrane and by 87% the number of depolarization-stimulated exocytotic events detected by total internal reflection fluorescence microscopy. We conclude that MyoVa-driven movements of vesicles along the cortical actin network are essential for the terminal stages of regulated exocytosis in β-cells. PMID:15788565

  8. Abnormal ion content, hydration and granule expansion of the secretory granules from cystic fibrosis airway glandular cells

    SciTech Connect

    Baconnais, S.; Delavoie, F. |; Zahm, J.M.; Milliot, M.; Castillon, N.; Terryn, C.; Banchet, V.; Michel, J.; Danos, O.; Merten, M.; Chinet, T.; Zierold, K.; Bonnet, N.; Puchelle, E. , E-Mail: edith.puchelle@univ-reims.fr; Balossier, G.

    2005-10-01

    The absence or decreased expression of cystic fibrosis transmembrane conductance regulator (CFTR) induces increased Na{sup +} absorption and hyperabsorption of the airway surface liquid (ASL) resulting in a dehydrated and hyperviscous ASL. Although the implication of abnormal airway submucosal gland function has been suggested, the ion and water content in the Cystic Fibrosis (CF) glandular secretory granules, before exocytosis, is unknown. We analyzed, in non-CF and CF human airway glandular cell lines (MM-39 and KM4, respectively), the ion content in the secretory granules by electron probe X-ray microanalysis and the water content by quantitative dark field imaging on freeze-dried cryosections. We demonstrated that the ion content (Na{sup +}, Mg{sup 2+}, P, S and Cl{sup -}) is significantly higher and the water content significantly lower in secretory granules from the CF cell line compared to the non-CF cell line. Using videomicroscopy, we observed that the secretory granule expansion was deficient in CF glandular cells. Transfection of CF cells with CFTR cDNA or inhibition of non-CF cells with CFTR{sub inh}-172, respectively restored or decreased the water content and granule expansion, in parallel with changes in ion content. We hypothesize that the decreased water and increased ion content in glandular secretory granules may contribute to the dehydration and increased viscosity of the ASL in CF.

  9. Secretory prostate apoptosis response (Par)-4 sensitizes multicellular spheroids (MCS) of glioblastoma multiforme cells to tamoxifen-induced cell death

    PubMed Central

    Jagtap, Jayashree C.; Parveen, D.; Shah, Reecha D.; Desai, Aarti; Bhosale, Dipali; Chugh, Ashish; Ranade, Deepak; Karnik, Swapnil; Khedkar, Bhushan; Mathur, Aaishwarya; Natesh, Kumar; Chandrika, Goparaju; Shastry, Padma

    2014-01-01

    Glioblastoma multiforme (GBM) is the most malignant form of brain tumor and is associated with resistance to conventional therapy and poor patient survival. Prostate apoptosis response (Par)-4, a tumor suppressor, is expressed as both an intracellular and secretory/extracellular protein. Though secretory Par-4 induces apoptosis in cancer cells, its potential in drug-resistant tumors remains to be fully explored. Multicellular spheroids (MCS) of cancer cells often acquire multi-drug resistance and serve as ideal experimental models. We investigated the role of Par-4 in Tamoxifen (TAM)-induced cell death in MCS of human cell lines and primary cultures of GBM tumors. TCGA and REMBRANT data analysis revealed that low levels of Par-4 correlated with low survival period (21.85 ± 19.30 days) in GBM but not in astrocytomas (59.13 ± 47.26 days) and oligodendrogliomas (58.04 ± 59.80 days) suggesting low PAWR expression as a predictive risk factor in GBM. Consistently, MCS of human cell lines and primary cultures displayed low Par-4 expression, high level of chemo-resistance genes and were resistant to TAM-induced cytotoxicity. In monolayer cells, TAM-induced cytotoxicity was associated with enhanced expression of Par-4 and was alleviated by silencing of Par-4 using specific siRNA. TAM effectively induced secretory Par-4 in conditioned medium (CM) of cells cultured as monolayer but not in MCS. Moreover, MCS were rendered sensitive to TAM-induced cell death by exposure to conditioned medium (CM)-containing Par-4 (derived from TAM-treated monolayer cells). Also TAM reduced the expression of Akt and PKCζ in GBM cells cultured as monolayer but not in MCS. Importantly, combination of TAM with inhibitors to PI3K inhibitor (LY294002) or PKCζ resulted in secretion of Par-4 and cell death in MCS. Since membrane GRP78 is overexpressed in most cancer cells but not normal cells, and secretory Par-4 induces apoptosis by binding to membrane GRP78, secretory Par-4 is an

  10. [Analysis of the effect of diabetes type 2 duration on beta cell secretory function and insulin resistance].

    PubMed

    Popović, Ljiljana; Zamaklar, Miroslava; Lalić, Katarina; Vasović, Olga

    2006-01-01

    Diabetes type 2 is a chronic metabolic disorder. Pathogenesis of diabetes type 2 results from the impaired insulin secretion, impaired insulin action and increased endogenous glucose production. Diabetes evolves through several phases characterized by qualitative and quantitative changes of beta cell secretory function. The aim of our study was to analyze the impact of diabetes duration on beta cell secretory function and insulin resistance. The results indicated significant negative correlation of diabetes duration and fasting insulinemia, as well as beta cell secretory function assessed by HOMA beta index. Our study also found significant negative correlation of diabetes duration and insulin resistance assessed by HOMA IR index. Significant positive correlation was established between beta cell secretory capacity (fasting insulinemia and HOMA beta) and insulin resistance assessed by HOMA IR index, independently of diabetes duration. These results indicate that: beta cell secretory capacity, assessed by HOMA beta index, significantly decreases with diabetes duration. In parallel with decrease of fasting insulinemia, reduction of insulin resistance assessed by HOMA IR index was found as well.

  11. Modeling F-actin cortex influence on the secretory properties of neuroendocrine cells

    PubMed Central

    Gil, Amparo

    2011-01-01

    Chromaffin cells are considered as one of the most valuable models to study regulated exocytosis. In these cells, like in other neuroendocrine systems, an intricate cortical cytoskeleton acts as a retentive network impeding vesicle access to plasma membrane. Therefore, during stimulation this structure suffers a transient reorganization allowing active transport of vesicles toward secretory sites. Interestingly, a combination of confocal microscopy studies and mathematical modeling is showing us new aspects of the influence of cortical cytoskeleton in shaping the secretory properties of excitable cells. In this new vision the F-actin-myosin II cortical cytoskeleton is organized forming polygonal cages with the molecular machinery of exocytosis composed by SNARE proteins and voltage-dependent calcium channels associating with its border. In this way the cytoskeleton not only holds together the essential elements acting during secretion, but we proposed that could also act as a structural factor opposing to the free diffusion of the calcium signal and therefore sustains high levels of the intracellular signal triggering exocytosis. PMID:21966558

  12. The Effect of Parietal Cell and Truncal Vagotomy on Gastric and Duodenal Contractile Activity of the Unanesthetized Dog

    PubMed Central

    Walker, G. Daly; Stewart, John J.; Bass, Paul

    1974-01-01

    The antral-duodenal contractile relationship was studied in control, after parietal cell vagotomy and truncal vagotomy conditions using extraluminal strain gage transducers. All conditions were investigated under interdigestive and digestive states and after insulin, bethanechol and histamine. After parietal cell vagotomy, there was minimal alteration of the antral-duodenal relationship in both the interdigestive and digestive states. The number and amplitude of contractions on both the antrum and duodenum (as reflected by a motility index) were not changed from control by the various stimulants. The one exception was that histamine markedly stimulated the duodenal contractile activity. In the truncal vagotomy condition, there was a total disruption of the antral-duodenal relationship in the interdigestive and digestive states. There was a significant decrease in the number and amplitude of contractions occurring on the antrum during the interdigestive and after insulin stimulation. Food was ineffective in stimulating the antrum in 2 of 3 dogs. In contrast, motor activity of the duodenum was minimally influenced by truncal vagotomy. In conclusion, parietal cell vagotomy has minimal disruptive effects on the antralduodenal relationship while truncal vagotomy reduces antral contractile activity. PMID:4835504

  13. Beta-agonists and secretory cell number and intracellular glycoproteins in airway epithelium. The effect of isoproterenol and salbutamol.

    PubMed Central

    Jones, R.; Reid, L.

    1979-01-01

    This study describes the effect of systemic administration of the beta-adrenergic agonists isoproterenol and salbutamol on the secretory cell populations in seven regions of rat airway epithelium (three extrapulmonary and four intrapulmonary) and on the size of salivary glands and heart. Isoproterenol (a nonselective beta-adrenergic agonist) significantly increases secretory cell number in all airway regions except the midtrachea; salbutamol (a selective beta 2 agonist) increases secretory cell number only in proximal and peripheral regions. The absolute number of secretory cells is greatest in the most peripheral region after isoproterenol administration and in the most proximal region after salbutamol, although both drugs produce the greatest relative increase at the periphery. In proximal and, particularly, peripheral regions, the increase by isoproterenol (less than 3- and 14-fold, respectively) is greater than by salbutamol (less than 2- and less than 3-fold, respectively). In all airway regions, both drugs modify intracellular glycoprotein in the secretory cell population; within a given region, modification is much the same. In the most proximal region, the population of cells synthesizing only granules of neutral glycoprotein significantly increases while in other regions increase is in cells synthesizing only granules of acid. A significant shift in glycoprotein synthesis occurs whether or not the secretory cell population is increased, which suggests that existing as well as newly appearing cells modify their product. Isoproterenol significantly increases the size of the parotid and submaxillary glands; salbutamol increases the size of the parotid only. Isoproterenol significantly increases the weight of both ventricles of the heart; salbutamol has no such effect. PMID:36762

  14. Calcineurin is universally involved in vesicle endocytosis at neuronal and nonneuronal secretory cells.

    PubMed

    Wu, Xin-Sheng; Zhang, Zhen; Zhao, Wei-Dong; Wang, Dongsheng; Luo, Fujun; Wu, Ling-Gang

    2014-05-22

    Calcium influx triggers and accelerates endocytosis in nerve terminals and nonneuronal secretory cells. Whether calcium/calmodulin-activated calcineurin, which dephosphorylates endocytic proteins, mediates this process is highly controversial for different cell types, developmental stages, and endocytic forms. Using three preparations that previously produced discrepant results (i.e., large calyx-type synapses, conventional cerebellar synapses, and neuroendocrine chromaffin cells containing large dense-core vesicles), we found that calcineurin gene knockout consistently slowed down endocytosis, regardless of cell type, developmental stage, or endocytic form (rapid or slow). In contrast, calcineurin and calmodulin blockers slowed down endocytosis at a relatively small calcium influx, but did not inhibit endocytosis at a large calcium influx, resulting in false-negative results. These results suggest that calcineurin is universally involved in endocytosis. They may also help explain the discrepancies among previous pharmacological studies. We therefore suggest that calcineurin should be included as a key player in mediating calcium-triggered and -accelerated vesicle endocytosis.

  15. Intravenous infusion of L-isomers of phenylalanine and tryptophan stimulate gastric acid secretion at physiologic plasma concentrations in normal subjects and after parietal cell vagotomy.

    PubMed Central

    McArthur, K E; Isenberg, J I; Hogan, D L; Dreier, S J

    1983-01-01

    To determine whether intravenous infusion of individual amino acids stimulated gastric acid secretion in man, graded doses of phenylalanine, tryptophan, glycine, alanine, histidine, and NaCl control were infused on separate days in nine healthy subjects. Intravenous infusion of phenylalanine and tryptophan significantly stimulated gastric acid secretion to 50 and 52%, respectively, of the acid secretory response to intragastric peptone. Intravenous alanine and histidine were without effect, whereas glycine produced a slight response. Serum gastrin concentrations did not significantly change during intravenous amino acid infusion, except in response to 0.1 M phenylalanine. However, the increase in serum gastrin occurred 2 h after acid secretion had significantly increased in response to the 0.025 M phenylalanine infusion. Plasma amino acid concentrations were measured during intravenous amino acid infusion and in response to a steak meal in five of the subjects. At a time when acid secretion was significantly increased during intravenous infusion of phenylalanine and tryptophan, plasma amino acids were similar to, or less than, that observed after the steak meal, suggesting that circulating levels of these three amino acids have a physiologic effect on gastric secretion in man. Intravenous infusion of a combination of graded doses of phenylalanine plus a continuous infusion of 0.01 M tryptophan shifted the dose-response curve to the left and resulted in a significantly greater response than to either amino acid alone. In five subjects with parietal cell vagotomy, intravenous phenylalanine and tryptophan stimulated acid secretion, whereas histidine was without effect, similar to normal subjects. These studies indicate that intravenous infusion of small amounts of phenylalanine (0.025 M, 3.1 mmol/h) and tryptophan (0.01 M, 1.25 mmol/h) stimulated gastric acid secretion at plasma concentrations similar to those observed after a steak meal, suggesting a physiologic role

  16. SORCS1 is necessary for normal insulin secretory granule biogenesis in metabolically stressed β cells.

    PubMed

    Kebede, Melkam A; Oler, Angie T; Gregg, Trillian; Balloon, Allison J; Johnson, Adam; Mitok, Kelly; Rabaglia, Mary; Schueler, Kathryn; Stapleton, Donald; Thorstenson, Candice; Wrighton, Lindsay; Floyd, Brendan J; Richards, Oliver; Raines, Summer; Eliceiri, Kevin; Seidah, Nabil G; Rhodes, Christopher; Keller, Mark P; Coon, Joshua L; Audhya, Anjon; Attie, Alan D

    2014-10-01

    We previously positionally cloned Sorcs1 as a diabetes quantitative trait locus. Sorcs1 belongs to the Vacuolar protein sorting-10 (Vps10) gene family. In yeast, Vps10 transports enzymes from the trans-Golgi network (TGN) to the vacuole. Whole-body Sorcs1 KO mice, when made obese with the leptin(ob) mutation (ob/ob), developed diabetes. β Cells from these mice had a severe deficiency of secretory granules (SGs) and insulin. Interestingly, a single secretagogue challenge failed to consistently elicit an insulin secretory dysfunction. However, multiple challenges of the Sorcs1 KO ob/ob islets consistently revealed an insulin secretion defect. The luminal domain of SORCS1 (Lum-Sorcs1), when expressed in a β cell line, acted as a dominant-negative, leading to SG and insulin deficiency. Using syncollin-dsRed5TIMER adenovirus, we found that the loss of Sorcs1 function greatly impairs the rapid replenishment of SGs following secretagogue challenge. Chronic exposure of islets from lean Sorcs1 KO mice to high glucose and palmitate depleted insulin content and evoked an insulin secretion defect. Thus, in metabolically stressed mice, Sorcs1 is important for SG replenishment, and under chronic challenge by insulin secretagogues, loss of Sorcs1 leads to diabetes. Overexpression of full-length SORCS1 led to a 2-fold increase in SG content, suggesting that SORCS1 is sufficient to promote SG biogenesis. PMID:25157818

  17. SORCS1 is necessary for normal insulin secretory granule biogenesis in metabolically stressed β cells

    PubMed Central

    Kebede, Melkam A.; Oler, Angie T.; Gregg, Trillian; Balloon, Allison J.; Johnson, Adam; Mitok, Kelly; Rabaglia, Mary; Schueler, Kathryn; Stapleton, Donald; Thorstenson, Candice; Wrighton, Lindsay; Floyd, Brendan J.; Richards, Oliver; Raines, Summer; Eliceiri, Kevin; Seidah, Nabil G.; Rhodes, Christopher; Keller, Mark P.; Coon, Joshua L.; Audhya, Anjon; Attie, Alan D.

    2014-01-01

    We previously positionally cloned Sorcs1 as a diabetes quantitative trait locus. Sorcs1 belongs to the Vacuolar protein sorting-10 (Vps10) gene family. In yeast, Vps10 transports enzymes from the trans-Golgi network (TGN) to the vacuole. Whole-body Sorcs1 KO mice, when made obese with the leptinob mutation (ob/ob), developed diabetes. β Cells from these mice had a severe deficiency of secretory granules (SGs) and insulin. Interestingly, a single secretagogue challenge failed to consistently elicit an insulin secretory dysfunction. However, multiple challenges of the Sorcs1 KO ob/ob islets consistently revealed an insulin secretion defect. The luminal domain of SORCS1 (Lum-Sorcs1), when expressed in a β cell line, acted as a dominant-negative, leading to SG and insulin deficiency. Using syncollin-dsRed5TIMER adenovirus, we found that the loss of Sorcs1 function greatly impairs the rapid replenishment of SGs following secretagogue challenge. Chronic exposure of islets from lean Sorcs1 KO mice to high glucose and palmitate depleted insulin content and evoked an insulin secretion defect. Thus, in metabolically stressed mice, Sorcs1 is important for SG replenishment, and under chronic challenge by insulin secretagogues, loss of Sorcs1 leads to diabetes. Overexpression of full-length SORCS1 led to a 2-fold increase in SG content, suggesting that SORCS1 is sufficient to promote SG biogenesis. PMID:25157818

  18. Regulation by L channels of Ca(2+)-evoked secretory responses in ouabain-treated chromaffin cells.

    PubMed

    De Pascual, Ricardo; Colmena, Inés; Ruiz-Pascual, Lucía; Baraibar, Andrés Mateo; Egea, Javier; Gandía, Luis; García, Antonio G

    2016-10-01

    It is known that the sustained depolarisation of adrenal medullary bovine chromaffin cells (BCCs) with high K(+) concentrations produces an initial sharp catecholamine release that subsequently fades off in spite depolarisation persists. Here, we have recreated a sustained depolarisation condition of BCCs by treating them with the Na(+)/K(+) ATPase blocker ouabain; in doing so, we searched experimental conditions that permitted the development of a sustained long-term catecholamine release response that could be relevant during prolonged stress. BCCs were perifused with nominal 0Ca(2+) solution, and secretion responses were elicited by intermittent application of short 2Ca(2+) pulses (Krebs-HEPES containing 2 mM Ca(2+)). These pulses elicited a biphasic secretory pattern with an initial 30-min period with secretory responses of increasing amplitude and a second 30-min period with steady-state, non-inactivating responses. The initial phase was not due to gradual depolarisation neither to gradual increases of the cytosolic calcium transients ([Ca(2+)]c) elicited by 2Ca(2+) pulses in BBCs exposed to ouabain; both parameters increased soon after ouabain addition. Νifedipine blocked these responses, and FPL64176 potentiated them, suggesting that they were triggered by Ca(2+) entry through non-inactivating L-type calcium channels. This was corroborated by nifedipine-evoked blockade of the L-type Ca(2+) channel current and the [Ca(2+)]c transients elicited by 2Ca(2+) pulses. Furthermore, the plasmalemmal Na(+)/Ca(2+) exchanger (NCX) blocker SEA0400 caused a mild inhibition followed by a large rebound increase of the steady-state secretory responses. We conclude that these two phases of secretion are mostly contributed by Ca(2+) entry through L calcium channels, with a minor contribution of Ca(2+) entry through the reverse mode of the NCX.

  19. Role of membrane oxidation in controlling the activity of human group IIa secretory phospholipase A(2) toward apoptotic lymphoma cells.

    PubMed

    Gibbons, Elizabeth; Nelson, Jennifer; Anderson, Lynn; Brewer, Kelly; Melchor, Stephanie; Judd, Allan M; Bell, John D

    2013-02-01

    The membranes of healthy lymphocytes normally resist hydrolysis by secretory phospholipase A(2). However, they become susceptible during the process of apoptosis. Previous experiments have demonstrated the importance of certain physical changes to the membrane during cell death such as a reduction in membrane lipid order and exposure of phosphatidylserine on the membrane surface. Nevertheless, those investigations also showed that at least one additional factor was required for rapid hydrolysis by the human group IIa phospholipase isozyme. This study was designed to test the possibility that oxidation of membrane lipids is the additional factor. Flow cytometry and confocal microscopy with a fluorescent probe of oxidative potential suggested that oxidation of the plasma membrane occurs during apoptosis stimulated by thapsigargin. When oxidative potential was high, the activity of human group IIa secretory phospholipase A(2) was enhanced 30- to 100-fold compared to that observed with conditions sufficient for maximal hydrolysis by other secretory phospholipase A(2) isoforms. Direct oxidation of cell membranes with either of two oxidizing agents also stimulated hydrolysis by secretory phospholipase A(2). Both oxidizers caused externalization of phosphatidylserine, but a change in lipid order did not always occur. These results demonstrated that membrane oxidation strongly stimulates human group IIa secretory phospholipase A(2) activity toward apoptotic cells. Interestingly, the change in membrane order, previously thought to be imperative for high rates of hydrolysis, was not required when membrane lipids were oxidized. Whether phosphatidylserine exposure is still necessary with oxidation remains unresolved since the two events could not be deconvoluted.

  20. Deletion of glutamate dehydrogenase in beta-cells abolishes part of the insulin secretory response not required for glucose homeostasis.

    PubMed

    Carobbio, Stefania; Frigerio, Francesca; Rubi, Blanca; Vetterli, Laurène; Bloksgaard, Maria; Gjinovci, Asllan; Pournourmohammadi, Shirin; Herrera, Pedro L; Reith, Walter; Mandrup, Susanne; Maechler, Pierre

    2009-01-01

    Insulin exocytosis is regulated in pancreatic ss-cells by a cascade of intracellular signals translating glucose levels into corresponding secretory responses. The mitochondrial enzyme glutamate dehydrogenase (GDH) is regarded as a major player in this process, although its abrogation has not been tested yet in animal models. Here, we generated transgenic mice, named betaGlud1(-/-), with ss-cell-specific GDH deletion. Our results show that GDH plays an essential role in the full development of the insulin secretory response. In situ pancreatic perfusion revealed that glucose-stimulated insulin secretion was reduced by 37% in betaGlud1(-/-). Furthermore, isolated islets with either constitutive or acute adenovirus-mediated knock-out of GDH showed a 49 and 38% reduction in glucose-induced insulin release, respectively. Adenovirus-mediated re-expression of GDH in betaGlud1(-/-) islets fully restored glucose-induced insulin release. Thus, GDH appears to account for about 40% of glucose-stimulated insulin secretion and to lack redundant mechanisms. In betaGlud1(-/-) mice, the reduced secretory capacity resulted in lower plasma insulin levels in response to both feeding and glucose load, while body weight gain was preserved. The results demonstrate that GDH is essential for the full development of the secretory response in beta-cells. However, maximal secretory capacity is not required for maintenance of glucose homeostasis in normo-caloric conditions.

  1. Myosin 2 Maintains an Open Exocytic Fusion Pore in Secretory Epithelial Cells

    PubMed Central

    Bhat, Purnima

    2009-01-01

    Many studies have implicated F-actin and myosin 2 in the control of regulated secretion. Most recently, evidence suggests a role for the microfilament network in regulating the postfusion events of vesicle dynamics. This is of potential importance as postfusion behavior can influence the loss of vesicle content and may provide a new target for drug therapy. We have investigated the role of myosin 2 in regulating exocytosis in secretory epithelial cells by using novel assays to determine the behavior of the fusion pore in individual granules. We immunolocalize myosin 2A to the apical region of pancreatic acinar cells, suggesting it is this isoform that plays a role in granule exocytosis. We further show myosin 2 phosphorylation increased on cell stimulation, consistent with a regulatory role in secretion. Importantly, in a single-cell, single-granule secretion assay, neither the myosin 2 inhibitor (−)-blebbistatin nor the myosin light chain kinase inhibitor ML-9 had any effect on the numbers of granules stimulated to fuse after cell stimulation. These data indicate that myosin 2, if it has any action on secretion, must be targeting postfusion granule behavior. This interpretation is supported by direct study of fusion pore opening in which we show that (−)-blebbistatin and ML-9 promote fusion pore closure and decrease fusion pore lifetimes. Our work now adds to a growing body of evidence showing that myosin 2 is an essential regulator of postfusion granule behavior. In particular, in the case of the secretory epithelial cells, myosin 2 activity is necessary to maintain fusion pore opening. PMID:19158378

  2. Ionic and secretory response of pancreatic islet cells to minoxidil sulfate

    SciTech Connect

    Antoine, M.H.; Hermann, M.; Herchuelz, A.; Lebrun, P. )

    1991-07-01

    Minoxidil sulfate is an antihypertensive agent belonging to the new class of vasodilators, the K+ channel openers. The present study was undertaken to characterize the effects of minoxidil sulfate on ionic and secretory events in rat pancreatic islets. The drug unexpectedly provoked a concentration-dependent decrease in 86Rb outflow. This inhibitory effect was reduced in a concentration-dependent manner by glucose and tolbutamide. Minoxidil sulfate did not affect 45Ca outflow from islets perfused in the presence of extracellular Ca++ and absence or presence of glucose. However, in islets exposed to a medium deprived of extracellular Ca++, the drug provoked a rise in 45Ca outflow. Whether in the absence or presence of extracellular Ca++, minoxidil sulfate increased the cytosolic free Ca++ concentration of islet cells. Lastly, minoxidil sulfate increased the release of insulin from glucose-stimulated pancreatic islets. These results suggest that minoxidil sulfate reduces the activity of the ATP-sensitive K+ channels and promotes an intracellular translocation of Ca++. The latter change might account for the effect of the drug on the insulin-releasing process. However, the secretory response to minoxidil sulfate could also be mediated, at least in part, by a modest Ca++ entry.

  3. Ovulation in Drosophila is controlled by secretory cells of the female reproductive tract.

    PubMed

    Sun, Jianjun; Spradling, Allan C

    2013-01-01

    How oocytes are transferred into an oviduct with a receptive environment remains poorly known. We found that glands of the Drosophila female reproductive tract, spermathecae and/or parovaria, are required for ovulation and to promote sperm storage. Reducing total secretory cell number by interferring with Notch signaling during development blocked ovulation. Knocking down expression after adult eclosion of the nuclear hormone receptor Hr39, a master regulator of gland development, slowed ovulation and blocked sperm storage. However, ovulation (but not sperm storage) continued when only canonical protein secretion was compromised in adult glands. Our results imply that proteins secreted during adulthood by the canonical secretory pathway from female reproductive glands are needed to store sperm, while a non-canonical glandular secretion stimulates ovulation. Our results suggest that the reproductive tract signals to the ovary using glandular secretions, and that this pathway has been conserved during evolution. DOI:http://dx.doi.org/10.7554/eLife.00415.001. PMID:23599892

  4. Glomerular parietal epithelial cells of adult murine kidney undergo EMT to generate cells with traits of renal progenitors

    PubMed Central

    G, Swetha; Chandra, Vikash; Phadnis, Smruti; Bhonde, Ramesh

    2011-01-01

    Abstract Glomerular parietal epithelial cells (GPECs) are known to revert to embryonic phenotype in response to renal injury. However, the mechanism of de-differentiation in GPECs and the underlying cellular processes are not fully understood. In the present study, we show that cultured GPECs of adult murine kidney undergo epithelial-mesenchymal transition (EMT) to generate cells, which express CD24, CD44 and CD29 surface antigens. Characterization by qRT-PCR and immunostaining of these clonogenic cells demonstrate that they exhibit metastable phenotype with co-expression of both epithelial (cytokeratin-18) and mesenchymal (vimentin) markers. Transcript analysis by qRT-PCR revealed high expression of metanephric mesenchymal (Pax-2, WT-1, Six-1, Eya-1, GDNF) and uteric bud (Hoxb-7, C-Ret) genes in these cells, indicating their bipotent progenitor status. Incubation of GPECs with EMT blocker Prostaglandin E2, resulted in low expression of renal progenitor markers reflecting the correlation between EMT and acquired stemness in these cells. Additional in vitro renal commitment assays confirmed their functional staminality. When injected into E13.5 kidney rudiments, the cells incorporated into the developing kidney primordia and co-culture with E13.5 spinal cord resulted in branching and tubulogenesis in these cells. When implanted under renal capsule of unilaterally nephrectomized mice, these cells differentiated into immature glomeruli and vascular ducts. Our study demonstrates that EMT plays a major role in imparting plasticity to terminally differentiated GPECs by producing metastable cells with traits of kidney progenitors. The present study would improve our understanding on epithelial cell plasticity, furthering our knowledge of its role in renal repair and regeneration. PMID:19840197

  5. Regulation of Cl/HCO3 exchange in gastric parietal cells.

    PubMed Central

    Thomas, H A; Machen, T E

    1991-01-01

    Microspectrofluorimetry of the fluorescent indicators 2',7'-bis-(2-carboxyethyl)-5(and-6)carboxyfluorescein and 6-methoxy-N-(3-sulfopropyl)-quinolinium was used to measure intracellular pH (pHi), intracellular Cl (Cli), and transmembrane fluxes of HCO3 and Cl in single parietal cells (PC) in isolated rabbit gastric glands incubated in HCO3/CO2-buffered solutions. Steady-state pHi was 7.2 in both resting (50 microM cimetidine) and stimulated (100 microM histamine) PCs. Transmembrane anion (HCO3 or Cl) flux rates during Cl removal from or readdition to the perfusate were the same in resting and stimulated PCs. These rates increased at alkaline pHi, though this pHi dependence was small in the physiological range. Maximum velocity (Vmax) for Cl influx or HCO3 efflux was 80-110 mM/min at pHi 7.6-7.8, and the Km for extracellular concentrations of Cl (Clo) was 25 mM; in the physiological range (pHi 7.1-7.3), Vmax for anion fluxes was approximately 50 mM/min. Steady-state Cli in the unstimulated PC was 62 +/- 5 mM, but on histamine stimulation, Cli decreased rapidly to 25 mM and then increased back to a steady-state level of 44 mM. HCO3 fluxes due to Cl removal or readdition were completely blocked by 0.5 mM 4,4'-diisothiocyanatodihydrostilbene-2,2'-disulfonic acid (H2DIDS), but Cl fluxes were only inhibited by 80%. H2DIDS did not inhibit the decrease in Cli that occurred with histamine treatment. Diphenylamine carboxylate (0.5 mM) inhibited Cl flux by only 50% and caused no additional inhibition of Cl flux when used in conjunction with H2DIDS. Transmembrane anion fluxes during solution Cl removal or readdition occurred 80% through the anion exchanger at the basal membrane and 20% through other pathway(s), presumably the Cl channel in the apical membrane. We conclude that the increase in transport activity via the Cl/HCO3 exchanger that occurs during histamine-induced increases in HCl secretion is due mostly to the decrease in Cli. In the resting cell with Cli = 62 m

  6. The story of cell secretion: events leading to the discovery of the 'porosome' - the universal secretory machinery in cells.

    PubMed

    Jeftinija, S

    2006-01-01

    Cell secretion has come of age, and a century old quest has been elegantly solved. We have come a long way since earlier observations of what appeared to be 'fibrillar regions' at the cell plasma membrane, and electrophysiological studies suggesting the presence of 'fusion pores' at the cell plasma membrane where secretion occurs. Finally, the fusion pore or 'porosome' has been discovered, and its morphology and dynamics determined at nm resolution and in real time in live secretory cells. The porosome has been isolated, its composition determined and it has been both structurally and functionally reconstituted in artificial lipid membrane. The discovery of the porosome as the universal secretory machinery in cells and the discovery of the molecular mechanism of vesicular content expulsion during cell secretion have finally enabled a clear understanding of this important cellular process. This review outlines the fascinating and exciting journey leading to the discovery of the porosome, ultimately solving one of the most difficult, significant, and fundamental cellular process -cell secretion.

  7. Twenty years after parietal cell vagotomy or selective vagotomy antrectomy for treatment of duodenal ulcer. Final report.

    PubMed Central

    Jordan, P H; Thornby, J

    1994-01-01

    OBJECTIVE: This study was a prospective, randomized evaluation of parietal cell vagotomy (PCV) and selective vagotomy-antrectomy (SV-A) in the treatment of duodenal ulcer. BACKGROUND DATA: Operative treatment of duodenal ulcer is associated with mortality and mechanical and metabolic morbidity. At the time that surgeons appear to have succeeded in developing operations with low morbidity and mortality, the number of patients requiring elective operation has decreased partly because of the simultaneous, dramatic improvement in medical therapy. Nevertheless, surgical therapy still is important, especially in certain socioeconomic environments. METHODS: After a pilot study of PCV, 200 patients with duodenal ulcers were randomized to PCV or SV-A. One surgeon was responsible for the operations and follow-up studies. An attempt was made to evaluate all patients annually in the hospital. Gastric analyses were performed on each visit, for which the patient gave his/her consent. RESULTS: There was no operative mortality. The recurrence rate-by-life table analysis was less (p < 0.003) after SV-A than PCV. Dumping was greater (p < 0.001), and there was no difference in the frequency of diarrhea after SV-A compared with PCV. The percentage of patients with grades Visick I or Visick II was not different for the two operations, but more patients were graded Visick I after PCV than after SV-A. CONCLUSIONS: Selective vagotomy-antrectomy and parietal cell vagotomy are effective and safe operations, when used appropriately. Selective vagotomy-antrectomy is preferable for patients with pyloric and prepyloric ulcers and pyloric obstruction. Parietal cell vagotomy is the authors' choice for duodenal ulcer patients because of the occasional patient who becomes disabled by SV-A. PMID:8092897

  8. Isoprenoid biosynthesis. Metabolite profiling of peppermint oil gland secretory cells and application to herbicide target analysis.

    PubMed

    Lange, B M; Ketchum, R E; Croteau, R B

    2001-09-01

    Two independent pathways operate in plants for the synthesis of isopentenyl diphosphate and dimethylallyl diphosphate, the central intermediates in the biosynthesis of all isoprenoids. The mevalonate pathway is present in the cytosol, whereas the recently discovered mevalonate-independent pathway is localized to plastids. We have used isolated peppermint (Mentha piperita) oil gland secretory cells as an experimental model system to study the effects of the herbicides fosmidomycin, phosphonothrixin, methyl viologen, benzyl viologen, clomazone, 2-(dimethylamino)ethyl diphosphate, alendronate, and pamidronate on the pools of metabolites related to monoterpene biosynthesis via the mevalonate-independent pathway. A newly developed isolation protocol for polar metabolites together with an improved separation and detection method based on liquid chromatography-mass spectrometry have allowed assessment of the enzyme targets for a number of these herbicides.

  9. Senescent Vascular Smooth Muscle Cells Drive Inflammation Through an Interleukin-1α–Dependent Senescence-Associated Secretory Phenotype

    PubMed Central

    Gardner, Sarah E.; Humphry, Melanie; Bennett, Martin R.

    2015-01-01

    Objective— Vascular smooth muscle cells (VSMCs) that become senescent are both present within atherosclerotic plaques and thought to be important to the disease process. However, senescent VSMCs are generally considered to only contribute through inaction, with failure to proliferate resulting in VSMC- and collagen-poor unstable fibrous caps. Whether senescent VSMCs can actively contribute to atherogenic processes, such as inflammation, is unknown. Approach and Results— We find that senescent human VSMCs develop a proinflammatory state known as a senescence-associated secretory phenotype. Senescent human VSMCs release high levels of multiple cytokines and chemokines driven by secreted interleukin-1α acting in an autocrine manner. Consequently, the VSMC senescence-associated secretory phenotype promotes chemotaxis of mononuclear cells in vitro and in vivo. In addition, senescent VSMCs release active matrix metalloproteinase-9, secrete less collagen, upregulate multiple inflammasome components, and prime adjacent endothelial cells and VSMCs to a proadhesive and proinflammatory state. Importantly, maintaining the senescence-associated secretory phenotype places a large metabolic burden on senescent VSMCs, such that they can be selectively killed by inhibiting glucose utilization. Conclusions— Senescent VSMCs may actively contribute toward the chronic inflammation associated with atherosclerosis through the interleukin-1α–driven senescence-associated secretory phenotype and the priming of adjacent cells to a proatherosclerotic state. These data also suggest that inhibition of this potentially important source of chronic inflammation in atherosclerosis requires blockade of interleukin-1α and not interleukin-1β. PMID:26139463

  10. Association of syntaxin 3 and vesicle-associated membrane protein (VAMP) with H+/K(+)-ATPase-containing tubulovesicles in gastric parietal cells.

    PubMed Central

    Peng, X R; Yao, X; Chow, D C; Forte, J G; Bennett, M K

    1997-01-01

    H+/K(+)-ATPase is the proton pump in the gastric parietal cell that is responsible for gastric acid secretion. Stimulation of acid secretion is associated with a reorganization of the parietal cells resulting in the incorporation of H+/K(+)-ATPase from a cytoplasmic membrane pool, the tubulovesicle compartment, into the apical canalicular membrane. To better characterize the role of membrane trafficking events in the morphological and physiological changes associated with acid secretion from parietal cells, we have characterized the expression and localization of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) in these cells. Each of the six different SNARE proteins examined [syntaxins 1 through 4 of 25-kDa synaptosome-associated protein, and vesicle-associated membrane protein] were found to be expressed in parietal cells. Furthermore, two of these SNAREs, vesicle-associated membrane protein and syntaxin 3, were associated with H+/K(+)-ATPase-containing tubulovesicles while the remainder were excluded from this compartment. The expression of syntaxin 1 and synaptosome-associated protein of 25 kDa in parietal cells, two SNAREs previously thought to be restricted to neuroendocrine tissues, suggests that parietal cells may utilize membrane trafficking machinery that is similar to that utilized for regulated exocytosis in neurons. Furthermore, the localization of syntaxin 3, a putative target membrane SNARE, to the tubulovesicle compartment indicates that syntaxin 3 may have an alternative function. These observations support a role for intracellular membrane trafficking events in the regulated recruitment of H+/K(+)-ATPase to the plasma membrane after parietal cell stimulation. Images PMID:9188093

  11. Serglycin determines secretory granule repertoire and regulates natural killer cell and cytotoxic T lymphocyte cytotoxicity.

    PubMed

    Sutton, Vivien R; Brennan, Amelia J; Ellis, Sarah; Danne, Jill; Thia, Kevin; Jenkins, Misty R; Voskoboinik, Ilia; Pejler, Gunnar; Johnstone, Ricky W; Andrews, Daniel M; Trapani, Joseph A

    2016-03-01

    The anionic proteoglycan serglycin is a major constituent of secretory granules in cytotoxic T lymphocyte (CTL)/natural killer (NK) cells, and is proposed to promote the safe storage of the mostly cationic granule toxins, granzymes and perforin. Despite the extensive defects of mast cell function reported in serglycin gene-disrupted mice, no comprehensive study of physiologically relevant CTL/NK cell populations has been reported. We show that the cytotoxicity of serglycin-deficient CTL and NK cells is severely compromised but can be partly compensated in both cell types when they become activated. Reduced intracellular granzyme B levels were noted, particularly in CD27(+) CD11b(+) mature NK cells, whereas serglycin(-/-) TCR-transgenic (OTI) CD8 T cells also had reduced perforin stores. Culture supernatants from serglycin(-/-) OTI T cells and interleukin-2-activated NK contained increased granzyme B, linking reduced storage with heightened export. By contrast, granzyme A was not significantly reduced in cells lacking serglycin, indicating differentially regulated trafficking and/or storage for the two granzymes. A quantitative analysis of different granule classes by transmission electronmicroscopy showed a selective loss of dense-core granules in serglycin(-/-) CD8(+) CTLs, although other granule types were maintained quantitatively. The findings of the present study show that serglycin plays a critical role in the maturation of dense-core cytotoxic granules in cytotoxic lymphocytes and the trafficking and storage of perforin and granzyme B, whereas granzyme A is unaffected. The skewed retention of cytotoxic effector molecules markedly reduces CTL/NK cell cytotoxicity, although this is partly compensated for as a result of activating the cells by physiological means.

  12. Xbp1-based engineering of secretory capacity enhances the productivity of Chinese hamster ovary cells.

    PubMed

    Tigges, Marcel; Fussenegger, Martin

    2006-05-01

    A variety of successful transcription and translation engineering strategies implemented during the past decade have driven the specific productivity of mammalian cells to an apparent limit. Restricted post-translation competence has since been considered the major bottleneck preventing mammalian cells from fully exploiting their physiologic production capacity in a biopharmaceutical manufacturing scenario. Through ectopic expression of the human transcription factor Xbp1 (X-box-binding-protein 1), evolved to manage plasma cell differentiation and coordinate the unfolded protein response, we have specifically expanded the endoplasmic reticulum and the Golgi of transgenic Chinese hamster ovary (CHO-K1)-derived cell lines with a resulting increase in overall production capacity. Xbp-1-based engineering of secretory bottlenecks was compatible with a variety of different promoter–product gene configurations suggesting that Xbp-1 induces generic production increases in CHO-K1 cell derivatives. Secretion engineering, illustrated here by Xbp1-based reprogramming of the post-translational processing machinery, provides a first insight into mastering a major system bottleneck which impacts biopharmaceutical manufacturing of secreted protein therapeutics.

  13. Excretory-secretory products (ESP) from Fasciola hepatica induce tolerogenic properties in myeloid dendritic cells.

    PubMed

    Falcón, Cristian; Carranza, Franco; Martínez, Fernando F; Knubel, Carolina P; Masih, Diana T; Motrán, Claudia C; Cervi, Laura

    2010-09-15

    Fasciola hepatica is a helminth trematode that migrates through the host tissues until reaching bile ducts where it becomes an adult. During its migration the parasite releases different excretory-secretory products (ESP), which are in contact with the immune system. In this study, we focused on the effect of ESP on the maturation and function of murine bone marrow derived-dendritic cells (DC). We found that the treatment of DC with ESP failed to induce a classical maturation of these cells, since ESP alone did not activate DC to produce any cytokines, although they impaired the ability of DC to be activated by TLR ligands and also their capacity to stimulate an allospecific response. In addition, using an in vitro ovalbumin peptide-restricted priming assay, ESP-treated DC exhibited a capacity to drive Th2 and regulatory T cell (Treg) polarization of CD4(+) cells from DO11.10 transgenic mice. This was characterized by increased IL-4, IL-5, IL-10 and TGF-beta production and the expansion of CD4(+)CD25(+)Foxp3(+) cells. Our results support the hypothesis that ESP from F. hepatica modulate the maturation and function of DC as part of a generalized immunosuppressive mechanism that involves a bias towards a Th2 response and Treg development.

  14. Three-dimensional ultrastructural analyses of anterior pituitary gland expose spatial relationships between endocrine cell secretory granule localization and capillary distribution

    PubMed Central

    Yoshitomi, Munetake; Ohta, Keisuke; Kanazawa, Tomonoshin; Togo, Akinobu; Hirashima, Shingo; Uemura, Kei-ichiro; Okayama, Satoko; Morioka, Motohiro; Nakamura, Kei-ichiro

    2016-01-01

    Endocrine and endothelial cells of the anterior pituitary gland frequently make close appositions or contacts, and the secretory granules of each endocrine cell tend to accumulate at the perivascular regions, which is generally considered to facilitate secretory functions of these cells. However, three-dimensional relationships between the localization pattern of secretory granules and blood vessels are not fully understood. To define and characterize these spatial relationships, we used scanning electron microscopy (SEM) three-dimensional reconstruction method based on focused ion-beam slicing and scanning electron microscopy (FIB/SEM). Full three-dimensional cellular architectures of the anterior pituitary tissue at ultrastructural resolution revealed that about 70% of endocrine cells were in apposition to the endothelial cells, while almost 30% of endocrine cells were entirely isolated from perivascular space in the tissue. Our three-dimensional analyses also visualized the distribution pattern of secretory granules in individual endocrine cells, showing an accumulation of secretory granules in regions in close apposition to the blood vessels in many cases. However, secretory granules in cells isolated from the perivascular region tended to distribute uniformly in the cytoplasm of these cells. These data suggest that the cellular interactions between the endocrine and endothelial cells promote an uneven cytoplasmic distribution of the secretory granules. PMID:27796315

  15. Reg4+ deep crypt secretory cells function as epithelial niche for Lgr5+ stem cells in colon

    PubMed Central

    Sasaki, Nobuo; Sachs, Norman; Wiebrands, Kay; Ellenbroek, Saskia I. J.; Fumagalli, Arianna; Lyubimova, Anna; Begthel, Harry; van den Born, Maaike; van Es, Johan H.; Karthaus, Wouter R.; Li, Vivian S. W.; López-Iglesias, Carmen; Peters, Peter J.; van Rheenen, Jacco; van Oudenaarden, Alexander; Clevers, Hans

    2016-01-01

    Leucine-rich repeat-containing G-protein coupled receptor 5-positive (Lgr5+) stem cells reside at crypt bottoms of the small and large intestine. Small intestinal Paneth cells supply Wnt3, EGF, and Notch signals to neighboring Lgr5+ stem cells. Whereas the colon lacks Paneth cells, deep crypt secretory (DCS) cells are intermingled with Lgr5+ stem cells at crypt bottoms. Here, we report regenerating islet-derived family member 4 (Reg4) as a marker of DCS cells. To investigate a niche function, we eliminated DCS cells by using the diphtheria-toxin receptor gene knocked into the murine Reg4 locus. Ablation of DCS cells results in loss of stem cells from colonic crypts and disrupts gut homeostasis and colon organoid growth. In agreement, sorted Reg4+ DCS cells promote organoid formation of single Lgr5+ colon stem cells. DCS cells can be massively produced from Lgr5+ colon stem cells in vitro by combined Notch inhibition and Wnt activation. We conclude that Reg4+ DCS cells serve as Paneth cell equivalents in the colon crypt niche. PMID:27573849

  16. Reg4+ deep crypt secretory cells function as epithelial niche for Lgr5+ stem cells in colon.

    PubMed

    Sasaki, Nobuo; Sachs, Norman; Wiebrands, Kay; Ellenbroek, Saskia I J; Fumagalli, Arianna; Lyubimova, Anna; Begthel, Harry; van den Born, Maaike; van Es, Johan H; Karthaus, Wouter R; Li, Vivian S W; López-Iglesias, Carmen; Peters, Peter J; van Rheenen, Jacco; van Oudenaarden, Alexander; Clevers, Hans

    2016-09-13

    Leucine-rich repeat-containing G-protein coupled receptor 5-positive (Lgr5(+)) stem cells reside at crypt bottoms of the small and large intestine. Small intestinal Paneth cells supply Wnt3, EGF, and Notch signals to neighboring Lgr5(+) stem cells. Whereas the colon lacks Paneth cells, deep crypt secretory (DCS) cells are intermingled with Lgr5(+) stem cells at crypt bottoms. Here, we report regenerating islet-derived family member 4 (Reg4) as a marker of DCS cells. To investigate a niche function, we eliminated DCS cells by using the diphtheria-toxin receptor gene knocked into the murine Reg4 locus. Ablation of DCS cells results in loss of stem cells from colonic crypts and disrupts gut homeostasis and colon organoid growth. In agreement, sorted Reg4(+) DCS cells promote organoid formation of single Lgr5(+) colon stem cells. DCS cells can be massively produced from Lgr5(+) colon stem cells in vitro by combined Notch inhibition and Wnt activation. We conclude that Reg4(+) DCS cells serve as Paneth cell equivalents in the colon crypt niche.

  17. MicroRNA-193a Regulates the Transdifferentiation of Human Parietal Epithelial Cells toward a Podocyte Phenotype

    PubMed Central

    Kietzmann, Leonie; Guhr, Sebastian S.O.; Meyer, Tobias N.; Ni, Lan; Sachs, Marlies; Panzer, Ulf; Stahl, Rolf A.K.; Saleem, Moin A.; Kerjaschki, Dontscho; Gebeshuber, Christoph A.

    2015-01-01

    Parietal epithelial cells have been identified as potential progenitor cells in glomerular regeneration, but the molecular mechanisms underlying this process are not fully defined. Here, we established an immortalized polyclonal human parietal epithelial cell (hPEC) line from naive human Bowman’s capsule cells isolated by mechanical microdissection. These hPECs expressed high levels of PEC-specific proteins and microRNA-193a (miR-193a), a suppressor of podocyte differentiation through downregulation of Wilms’ tumor 1 in mice. We then investigated the function of miR-193a in the establishment of podocyte and PEC identity and determined whether inhibition of miR-193a influences the behavior of PECs in glomerular disease. After stable knockdown of miR-193a, hPECs adopted a podocyte-like morphology and marker expression, with decreased expression levels of PEC markers. In mice, inhibition of miR-193a by complementary locked nucleic acids resulted in an upregulation of the podocyte proteins synaptopodin and Wilms’ tumor 1. Conversely, overexpression of miR-193a in vivo resulted in the upregulation of PEC markers and the loss of podocyte markers in isolated glomeruli. Inhibition of miR-193a in a mouse model of nephrotoxic nephritis resulted in reduced crescent formation and decreased proteinuria. Together, these results show the establishment of a human PEC line and suggest that miR-193a functions as a master switch, such that glomerular epithelial cells with high levels of miR-193a adopt a PEC phenotype and cells with low levels of miR-193a adopt a podocyte phenotype. miR-193a–mediated maintenance of PECs in an undifferentiated reactive state might be a prerequisite for PEC proliferation and migration in crescent formation. PMID:25270065

  18. Stichopin-containing nerves and secretory cells specific to connective tissues of the sea cucumber.

    PubMed

    Tamori, Masaki; Saha, Apurba Kumar; Matsuno, Akira; Noskor, Sukumar Chandra; Koizumi, Osamu; Kobayakawa, Yoshitaka; Nakajima, Yoko; Motokawa, Tatsuo

    2007-09-22

    Stichopin, a 17-amino acid peptide isolated from a sea cucumber, affects the stiffness change of the body-wall catch connective tissues and the contraction of the body-wall muscles. The localization of stichopin in sea cucumbers was studied by indirect immunohistochemistry using antiserum against stichopin. Double staining was performed with both stichopin antiserum and 1E11, the monoclonal antibody specific to echinoderm nerves. A stichopin-like immunoreactivity (stichopin-LI) was exclusively found in the connective tissues of various organs. Many fibres and cells with processes were stained by both the anti-stichopin antibody and 1E11. They were found in the body-wall dermis and the connective tissue layer of the cloacae and were suggested to be connective tissue-specific nerves. Oval cells with stichopin-LI (OCS) without processes were found in the body-wall dermis, the connective tissue sheath of the longitudinal body-wall muscles, the connective tissue layer of the tube feet and tentacles, and the connective tissue in the radial nerves separating the ectoneural part from the hyponeural part. Electron microscopic observations of the OCSs in the radial nerves showed that they were secretory cells. The OCSs were located either near the well-defined neural structures or near the water-filled cavities, such as the epineural sinus and the canals of the tube feet. The location near the water-filled cavities might suggest that stichopin was secreted into these cavities to function as a hormone.

  19. Free and complexed-secretory immunoglobulin A triggers distinct intestinal epithelial cell responses.

    PubMed

    Salerno-Goncalves, R; Safavie, F; Fasano, A; Sztein, M B

    2016-09-01

    Secretory immunoglobulin A (SIgA) antibodies play an important role in protecting the mucosal surfaces against pathogens and maintaining homeostasis with the commensal microbiota. Because a substantial portion of the gut microbiota is coated with SIgA, we hypothesized that microbiota-SIgA complexes are important for the maintenance of gut homeostasis. Here we investigated the relationship between microbiota-SIgA complexes and inflammatory epithelial cell responses. We used a multi-cellular three-dimensional (3D) organotypical model of the human intestinal mucosa composed of an intestinal epithelial cell line and primary human lymphocytes/monocytes, endothelial cells and fibroblasts. We also used human SIgA from human colostrum, and a prominent bacterial member of the first colonizers, Escherichia coli, as a surrogate commensal. We found that free and microbiota-complexed SIgA triggered different epithelial responses. While free SIgA up-regulated mucus production, expression of polymeric immunoglobulin receptor (pIgR) and secretion of interleukin-8 and tumoir necrosis factor-α, microbiota-complexed SIgA mitigated these responses. These results suggest that free and complexed SIgA have different functions as immunoregulatory agents in the gut and that an imbalance between the two may affect gut homeostasis. PMID:27084834

  20. Agglutinating secretory IgA preserves intestinal epithelial cell integrity during apical infection by Shigella flexneri.

    PubMed

    Mathias, Amandine; Longet, Stéphanie; Corthésy, Blaise

    2013-08-01

    Shigella flexneri, by invading intestinal epithelial cells (IECs) and inducing inflammatory responses of the colonic mucosa, causes bacillary dysentery. Although M cells overlying Peyer's patches are commonly considered the primary site of entry of S. flexneri, indirect evidence suggests that bacteria can also use IECs as a portal of entry to the lamina propria. Passive delivery of secretory IgA (SIgA), the major immunoglobulin secreted at mucosal surfaces, has been shown to protect rabbits from experimental shigellosis, but no information exists as to its molecular role in maintaining luminal epithelial integrity. We have established that the interaction of virulent S. flexneri with the apical pole of a model intestinal epithelium consisting of polarized Caco-2 cell monolayers resulted in the progressive disruption of the tight junction network and actin depolymerization, eventually resulting in cell death. The lipopolysaccharide (LPS)-specific agglutinating SIgAC5 monoclonal antibody (MAb), but not monomeric IgAC5 or IgGC20 MAbs of the same specificity, achieved protective functions through combined mechanisms, including limitation of the interaction between S. flexneri and epithelial cells, maintenance of the tight junction seal, preservation of the cell morphology, reduction of NF-κB nuclear translocation, and inhibition of proinflammatory mediator secretion. Our results add to the understanding of the function of SIgA-mediated immune exclusion by identifying a mode of action whereby the formation of immune complexes translates into maintenance of the integrity of epithelial cells lining the mucosa. This novel mechanism of protection mediated by SIgA is important to extend the arsenal of effective strategies to fight against S. flexneri mucosal invasion. PMID:23753631

  1. Agglutinating Secretory IgA Preserves Intestinal Epithelial Cell Integrity during Apical Infection by Shigella flexneri

    PubMed Central

    Mathias, Amandine; Longet, Stéphanie

    2013-01-01

    Shigella flexneri, by invading intestinal epithelial cells (IECs) and inducing inflammatory responses of the colonic mucosa, causes bacillary dysentery. Although M cells overlying Peyer's patches are commonly considered the primary site of entry of S. flexneri, indirect evidence suggests that bacteria can also use IECs as a portal of entry to the lamina propria. Passive delivery of secretory IgA (SIgA), the major immunoglobulin secreted at mucosal surfaces, has been shown to protect rabbits from experimental shigellosis, but no information exists as to its molecular role in maintaining luminal epithelial integrity. We have established that the interaction of virulent S. flexneri with the apical pole of a model intestinal epithelium consisting of polarized Caco-2 cell monolayers resulted in the progressive disruption of the tight junction network and actin depolymerization, eventually resulting in cell death. The lipopolysaccharide (LPS)-specific agglutinating SIgAC5 monoclonal antibody (MAb), but not monomeric IgAC5 or IgGC20 MAbs of the same specificity, achieved protective functions through combined mechanisms, including limitation of the interaction between S. flexneri and epithelial cells, maintenance of the tight junction seal, preservation of the cell morphology, reduction of NF-κB nuclear translocation, and inhibition of proinflammatory mediator secretion. Our results add to the understanding of the function of SIgA-mediated immune exclusion by identifying a mode of action whereby the formation of immune complexes translates into maintenance of the integrity of epithelial cells lining the mucosa. This novel mechanism of protection mediated by SIgA is important to extend the arsenal of effective strategies to fight against S. flexneri mucosal invasion. PMID:23753631

  2. Enhanced cell-surface display and secretory production of cellulolytic enzymes with Saccharomyces cerevisiae Sed1 signal peptide.

    PubMed

    Inokuma, Kentaro; Bamba, Takahiro; Ishii, Jun; Ito, Yoichiro; Hasunuma, Tomohisa; Kondo, Akihiko

    2016-11-01

    Recombinant yeast strains displaying aheterologous cellulolytic enzymes on their cell surfaces using a glycosylphosphatidylinositol (GPI) anchoring system are a promising strategy for bioethanol production from lignocellulosic materials. A crucial step for cell wall localization of the enzymes is the intracellular transport of proteins in yeast cells. Therefore, the addition of a highly efficient secretion signal sequence is important to increase the amount of the enzymes on the yeast cell surface. In this study, we demonstrated the effectiveness of a novel signal peptide (SP) sequence derived from the Saccharomyces cerevisiae SED1 gene for cell-surface display and secretory production of cellulolytic enzymes. Gene cassettes with SP sequences derived from S. cerevisiae SED1 (SED1SP), Rhizopus oryzae glucoamylase (GLUASP), and S. cerevisiae α-mating pheromone (MFα1SP) were constructed for cell-surface display of Aspergillus aculeatus β-glucosidase (BGL1) and Trichoderma reesei endoglucanase II (EGII). These gene cassettes were integrated into the S. cerevisiae genome. The recombinant strains with the SED1SP showed higher cell-surface BGL and EG activities than those with the conventional SP sequences (GLUASP and MFα1SP). The novel SP sequence also improved the secretory production of BGL and EG in S. cerevisiae. The extracellular BGL activity of the recombinant strains with the SED1SP was 1.3- and 1.9-fold higher than the GLUASP and MFα1SP strains, respectively. Moreover, the utilization of SED1SP successfully enhanced the secretory production of BGL in Pichia pastoris. The utilization of the novel SP sequence is a promising option for highly efficient cell-surface display and secretory production of heterologous proteins in various yeast species. Biotechnol. Bioeng. 2016;113: 2358-2366. © 2016 Wiley Periodicals, Inc. PMID:27183011

  3. [Identification of Ca2+ release channels in salivary glands secretory cells of Chironomus plumosus L].

    PubMed

    Man'ko, V V; Bychkova, S V; Klevets', M Iu

    2004-01-01

    The presence of two types of well-characterised Ca2+ release channels, namely IP3-receptors (Ins(1,4,5)P3Rs) and ryanodine-receptors (RyRs), was detected in the salivary glands secretory cells of Chironomus plumosus L. For this aim different blockators and activators of these Ca2+ -transport systems were used. The conditions for permeabilization of these cells by saponine were experimentally chosen for their more intensive action. It was shown that IP3 decreased calcium content in saponine-treated gland tissue by (41.14 +/- 11.75)%. The effect of IP3 was not observed under condition of heparin and eosin Y presence in the incubation medium, but heparin alone did not cause any action on calcium content in saponine-treated gland tissue. The observed effects of IP3 are supposed to be the evidences of Ins (1,4,5)P3Rs presence in the intracellular membrane of this object. It was also shown that calcium content in intact gland tissue increased by (67.12 +/- 22.60)% in presence of heparin (500 mkg/ml) in the incubation medium. This effect of heparin was also observed with presence of verapamil (100 mkM) and eosin Y (5, 20 mkM) in incubation medium. So, this effect is not connected with function of voltage-gated Ca2+ -channels and Ca2+ -pumps. Ryanodine in concentration of 5nM decreased calcium content in saponine-treated gland tissue by (35.18 +/- 3.87)% but it caused the increase of calcium content at high concentration (500 nM) by (40.72 +/- 12.52)%. It improved the presence of RyRs in intracellular membrane of secretory cells of this object. Besides, these channels, perhaps, belong to "non-sensitive" to caffeine, because caffeine did not affect calcium content in the gland tissue neither in presence nor with absence of eosin Y. PMID:15909419

  4. P2X7 Receptors Trigger ATP Exocytosis and Modify Secretory Vesicle Dynamics in Neuroblastoma Cells*

    PubMed Central

    Gutiérrez-Martín, Yolanda; Bustillo, Diego; Gómez-Villafuertes, Rosa; Sánchez-Nogueiro, Jesús; Torregrosa-Hetland, Cristina; Binz, Thomas; Gutiérrez, Luis Miguel; Miras-Portugal, María Teresa; Artalejo, Antonio R.

    2011-01-01

    Previously, we reported that purinergic ionotropic P2X7 receptors negatively regulate neurite formation in Neuro-2a (N2a) mouse neuroblastoma cells through a Ca2+/calmodulin-dependent kinase II-related mechanism. In the present study we used this cell line to investigate a parallel though faster P2X7 receptor-mediated signaling pathway, namely Ca2+-regulated exocytosis. Selective activation of P2X7 receptors evoked exocytosis as assayed by high resolution membrane capacitance measurements. Using dual-wavelength total internal reflection microscopy, we have observed both the increase in near-membrane Ca2+ concentration and the exocytosis of fluorescently labeled vesicles in response to P2X7 receptor stimulation. Moreover, activation of P2X7 receptors also affects vesicle motion in the vertical and horizontal directions, thus, involving this receptor type in the control of early steps (docking and priming) of the secretory pathway. Immunocytochemical and RT-PCR experiments evidenced that N2a cells express the three neuronal SNAREs as well as vesicular nucleotide and monoamine (VMAT-1 and VMAT-2) transporters. Biochemical measurements indicated that ionomycin induced a significant release of ATP from N2a cells. Finally, P2X7 receptor stimulation and ionomycin increased the incidence of small transient inward currents, reminiscent of postsynaptic quantal events observed at synapses. Small transient inward currents were dependent on extracellular Ca2+ and were abolished by Brilliant Blue G, suggesting they were mediated by P2X7 receptors. Altogether, these results suggest the existence of a positive feedback mechanism mediated by P2X7 receptor-stimulated exocytotic release of ATP that would act on P2X7 receptors on the same or neighbor cells to further stimulate its own release and negatively control N2a cell differentiation. PMID:21292765

  5. Expression of S100 beta in sensory and secretory cells of the vertebrate inner ear

    NASA Technical Reports Server (NTRS)

    Fermin, C. D.; Martin, D. S.

    1995-01-01

    We evaluated anti-S100 beta expression in the chick (Gallus domesticus) inner ear and determined that: 1) the monomer anti-S100 beta is expressed differentially in the vestibular and auditory perikarya; 2) expression of S100 beta in the afferent nerve terminals is time-related to synapse and myelin formation; 3) the expression of the dimer anti-S100 alpha alpha beta beta and monomer anti-S100 beta overlaps in most inner ear cell types. Most S100 alpha alpha beta beta positive cells express S100 beta, but S100 beta positive cells do not always express S100 alpha alpha beta beta. 4) the expression of S100 beta is diffused over the perikaryal cytoplasm and nuclei of the acoustic ganglia but is concentrated over the nuclei of the vestibular perikarya. 6) S100 beta is expressed in secretory cells, and it is co-localized with GABA in sensory cells. 7) Color thresholding objective quantitation indicates that the amount of S100 beta was higher (mean 22, SD +/- 4) at E19 than at E9 (mean 34, SD +/- 3) in afferent axons. 8) Moreover, S100 beta was unchanged between E11-E19 in the perikaryal cytoplasm, but did change over the nuclei. At E9, 74%, and at E21, 5% of vestibular perikarya were positive. The data suggest that S100 beta may be physically associated with neuronal and ionic controlling cells of the vertebrate inner ear, where it could provide a dual ionic and neurotrophic modulatory function.

  6. Measurement of the intracellular ph in human stomach cells: a novel approach to evaluate the gastric acid secretory potential of coffee beverages.

    PubMed

    Weiss, Carola; Rubach, Malte; Lang, Roman; Seebach, Elisabeth; Blumberg, Simone; Frank, Oliver; Hofmann, Thomas; Somoza, Veronika

    2010-02-10

    As the consumption of coffee beverages sometimes is reported to cause gastric irritation, for which an increased stomach acid secretion is one of the promoting factors, different processing technologies such as steam-treatment have been developed to reduce putative stomach irritating compounds. There is evidence-based data neither on the effect of detailed processing variations nor on individual coffee components affecting the proton secretory activity (PSA). This work aimed at developing a screening model suitable for investigating the effects of commercial coffee beverages and components thereof on human parietal cells. Human gastric cancer cells (HGT-1) were treated with reconstituted freeze-dried coffee beverages prepared from customary coffee products such as regular coffee (RC, n = 4), mild bean coffee (MBC, n = 5), stomach friendly coffee (SFC, n = 4), and SFC decaffeinated (SFCD, n = 3). PSA was analyzed by flow cytometry using the pH-sensitive dye SNARF-AM. Treatment of the cells with MBC did not result in a PSA different from RC treatment (p cells treated with SFC (p

  7. Molecular mechanisms involved in secretory vesicle recruitment to the plasma membrane in beta-cells.

    PubMed

    Varadi, Aniko; Ainscow, E K; Allan, V J; Rutter, G A

    2002-04-01

    Glucose stimulates the release of insulin in part by activating the recruitment of secretory vesicles to the cell surface. While this movement is known to be microtubule-dependent, the molecular motors involved are undefined. Active kinesin was found to be essential for vesicle translocation in live beta-cells, since microinjection of cDNA encoding dominant-negative KHC(mut) (motor domain of kinesin heavy chain containing a Thr(93)-->Asn point mutation) blocked vesicular movements. Moreover, expression of KHC(mut) strongly inhibited the sustained, but not acute, stimulation of secretion by glucose. Thus, vesicles released during the first phase of insulin secretion exist largely within a translocation-independent pool. Kinesin-driven anterograde movement of vesicles is then necessary for the sustained (second phase) of insulin release. Kinesin may, therefore, represent a novel target for increases in intracellular ATP concentrations in response to elevated extracellular glucose and may be involved in the ATP-sensitive K+channel-independent stimulation of secretion by the sugar.

  8. Mast cell mediators: their differential release and the secretory pathways involved.

    PubMed

    Moon, Tae Chul; Befus, A Dean; Kulka, Marianna

    2014-01-01

    Mast cells (MC) are widely distributed throughout the body and are common at mucosal surfaces, a major host-environment interface. MC are functionally and phenotypically heterogeneous depending on the microenvironment in which they mature. Although MC have been classically viewed as effector cells of IgE-mediated allergic diseases, they are also recognized as important in host defense, innate and acquired immunity, homeostatic responses, and immunoregulation. MC activation can induce release of pre-formed mediators such as histamine from their granules, as well as release of de novo synthesized lipid mediators, cytokines, and chemokines that play diverse roles, not only in allergic reactions but also in numerous physiological and pathophysiological responses. Indeed, MC release their mediators in a discriminating and chronological manner, depending upon the stimuli involved and their signaling cascades (e.g., IgE-mediated or Toll-like receptor-mediated). However, the precise mechanisms underlying differential mediator release in response to these stimuli are poorly known. This review summarizes our knowledge of MC mediators and will focus on what is known about the discriminatory release of these mediators dependent upon diverse stimuli, MC phenotypes, and species of origin, as well as on the intracellular synthesis, storage, and secretory processes involved.

  9. Mast Cell Mediators: Their Differential Release and the Secretory Pathways Involved

    PubMed Central

    Moon, Tae Chul; Befus, A. Dean; Kulka, Marianna

    2014-01-01

    Mast cells (MC) are widely distributed throughout the body and are common at mucosal surfaces, a major host–environment interface. MC are functionally and phenotypically heterogeneous depending on the microenvironment in which they mature. Although MC have been classically viewed as effector cells of IgE-mediated allergic diseases, they are also recognized as important in host defense, innate and acquired immunity, homeostatic responses, and immunoregulation. MC activation can induce release of pre-formed mediators such as histamine from their granules, as well as release of de novo synthesized lipid mediators, cytokines, and chemokines that play diverse roles, not only in allergic reactions but also in numerous physiological and pathophysiological responses. Indeed, MC release their mediators in a discriminating and chronological manner, depending upon the stimuli involved and their signaling cascades (e.g., IgE-mediated or Toll-like receptor-mediated). However, the precise mechanisms underlying differential mediator release in response to these stimuli are poorly known. This review summarizes our knowledge of MC mediators and will focus on what is known about the discriminatory release of these mediators dependent upon diverse stimuli, MC phenotypes, and species of origin, as well as on the intracellular synthesis, storage, and secretory processes involved. PMID:25452755

  10. SNAP23 is selectively expressed in airway secretory cells and mediates baseline and stimulated mucin secretion

    PubMed Central

    Ren, Binhui; Azzegagh, Zoulikha; Jaramillo, Ana M.; Zhu, Yunxiang; Pardo-Saganta, Ana; Bagirzadeh, Rustam; Flores, Jose R.; Han, Wei; Tang, Yong-jun; Tu, Jing; Alanis, Denise M.; Evans, Christopher M.; Guindani, Michele; Roche, Paul A.; Rajagopal, Jayaraj; Chen, Jichao; Davis, C. William; Tuvim, Michael J.; Dickey, Burton F.

    2015-01-01

    Airway mucin secretion is important pathophysiologically and as a model of polarized epithelial regulated exocytosis. We find the trafficking protein, SNAP23 (23-kDa paralogue of synaptosome-associated protein of 25 kDa), selectively expressed in secretory cells compared with ciliated and basal cells of airway epithelium by immunohistochemistry and FACS, suggesting that SNAP23 functions in regulated but not constitutive epithelial secretion. Heterozygous SNAP23 deletant mutant mice show spontaneous accumulation of intracellular mucin, indicating a defect in baseline secretion. However mucins are released from perfused tracheas of mutant and wild-type (WT) mice at the same rate, suggesting that increased intracellular stores balance reduced release efficiency to yield a fully compensated baseline steady state. In contrast, acute stimulated release of intracellular mucin from mutant mice is impaired whether measured by a static imaging assay 5 min after exposure to the secretagogue ATP or by kinetic analysis of mucins released from perfused tracheas during the first 10 min of ATP exposure. Together, these data indicate that increased intracellular stores cannot fully compensate for the defect in release efficiency during intense stimulation. The lungs of mutant mice develop normally and clear bacteria and instilled polystyrene beads comparable to WT mice, consistent with these functions depending on baseline secretion that is fully compensated. PMID:26182382

  11. YAP Induces High-Grade Serous Carcinoma in Fallopian Tube Secretory Epithelial Cells

    PubMed Central

    Hua, Guohua; Lv, Xiangmin; He, Chunbo; Remmenga, Steven W.; Rodabough, Kerry J.; Dong, Jixin; Yang, Liguo; Lele, Subodh M.; Yang, Peixin; Zhou, Jin; Karst, Alison; Drapkin, Ronny I.; Davis, John S.; Wang, Cheng

    2015-01-01

    Accumulating evidence indicates that ovarian high-grade serous carcinoma (HGSC) originates from Fallopian tube secretory epithelial cells (FTSECs). However, the molecular mechanisms underlying the initiation and progression of HGSC derived from FTSECs remains unclear. In the present study, we found that the Hippo/YAP signaling pathway plays a critical role in the initiation and progression of Fallopian tube and ovarian HGSC. Importantly, YAP was overexpressed in inflammatory and cancerous Fallopian tube tissues. Further, overexpression of wild-type YAP, or constitutively active YAP in immortalized FTSECs, induced cell proliferation, migration, colony formation, and tumorigenesis. Moreover, the Hippo/YAP and the fibroblast growth factor (FGF) signaling pathways formed an autocrine/paracrine positive feedback loop to drive the progression of the FTSECs-derived HGSC. Evidence in this study strongly suggests that combined therapy with inhibitors of YAP (such as verteporfin) and FGFRs (such as BGJ398) can provide a novel therapeutic strategy to treat Fallopian tube and ovarian HGSC. PMID:26364602

  12. Effect of chronic exposure to antipsychotic medication on cell numbers in the parietal cortex of macaque monkeys.

    PubMed

    Konopaske, Glenn T; Dorph-Petersen, Karl-Anton; Pierri, Joseph N; Wu, Qiang; Sampson, Allan R; Lewis, David A

    2007-06-01

    Both in vivo and post-mortem investigations have demonstrated smaller volumes of the whole brain and of certain brain regions in individuals with schizophrenia. It is unclear to what degree such smaller volumes are due to the illness or to the effects of antipsychotic medication treatment. Indeed, we recently reported that chronic exposure of macaque monkeys to haloperidol or olanzapine, at doses producing plasma levels in the therapeutic range in schizophrenia subjects, was associated with significantly smaller total brain weight and volume, including an 11.8-15.2% smaller gray matter volume in the left parietal lobe. Consequently, in this study we sought to determine whether these smaller volumes were associated with lower numbers of the gray matter's constituent cellular elements. The use of point counting and Cavalieri's principle on Nissl-stained sections confirmed a 14.6% smaller gray matter volume in the left parietal lobe from antipsychotic-exposed monkeys. Use of the optical fractionator method to estimate the number of each cell type in the gray matter revealed a significant 14.2% lower glial cell number with a concomitant 10.2% higher neuron density. The numbers of neurons and endothelial cells did not differ between groups. Together, the findings of smaller gray matter volume, lower glial cell number, and higher neuron density without a difference in total neuron number in antipsychotic-exposed monkeys parallel the results of post-mortem schizophrenia studies, and raise the possibility that such observations in schizophrenia subjects might be due, at least in part, to antipsychotic medication effects. PMID:17063154

  13. Application of dendritic cells stimulated with Trichinella spiralis excretory-secretory antigens alleviates experimental autoimmune encephalomyelitis.

    PubMed

    Sofronic-Milosavljevic, L J; Radovic, I; Ilic, N; Majstorovic, I; Cvetkovic, J; Gruden-Movsesijan, A

    2013-06-01

    The parasitic nematode, Trichinella spiralis (T. spiralis), exerts an immunomodulatory effect on the host immune response through excretory-secretory products (ES L1) released from encysted muscle larvae. Our model of combined T. spiralis infection and experimental autoimmune encephalomyelitis (EAE) in Dark Agouti (DA) rats demonstrated a significant reduction in EAE severity in infected animals. Recently, we have created an immune status characteristic for the live infection by in vivo application of dendritic cells (DCs) stimulated with ES L1 products of T. spiralis muscle larvae. Moreover, these cells were able to ameliorate EAE when applied 7 days before EAE induction. ES L1-stimulated DCs increased production of IL-4, IL-10 and TGF-β, and decreased production of IFN-γ and IL-17, both at the systemic level and in target organs. A significant increase in the proportion of CD4+CD25+Foxp3+ T cells was found among spleen cells, and CNS infiltrates from DA rats treated with ES L1-stimulated DCs before EAE induction, compared to controls injected with unstimulated DCs. Regulatory T cells, together with elevated levels of IL-10 and TGF-β, are most likely involved in restraining the production of Th1 and Th17 cytokines responsible for autoimmunity and thus are responsible for the beneficial effect of ES L1-educated DCs on the course of EAE. Our results show that ES L1 antigen-stimulated DCs are able not only to provoke, but also to sustain anti-inflammatory and regulatory responses regardless of EAE induction, with subsequent amelioration of EAE, or even protection from the disease.

  14. Group V and X secretory phospholipase A2 prevents adenoviral infection in mammalian cells

    PubMed Central

    Mitsuishi, Michiko; Masuda, Seiko; Kudo, Ichiro; Murakami, Makoto

    2005-01-01

    sPLA2 (secretory phospholipase A2) enzymes have been implicated in various biological events, yet their precise physiological functions remain largely unresolved. In the present study we show that group V and X sPLA2s, which are two potent plasma membrane-acting sPLA2s, are capable of preventing host cells from being infected with an adenovirus. Bronchial epithelial cells and lung fibroblasts pre-expressing group V and X sPLA2s showed marked resistance to adenovirus-mediated gene delivery in a manner dependent on their catalytic activity. Although adenovirus particles were insensitive to recombinant group V and X sPLA2s, direct addition of these enzymes to 293A cells suppressed both number and size of adenovirus plaque formation. Group V and X sPLA2s retarded the entry of adenovirus into endosomes. Moreover, adenoviral infection was suppressed by LPC (lysophosphatidylcholine), a membrane-hydrolytic product of these sPLA2s. Thus hydrolysis of the plasma membrane by these sPLA2s may eventually lead to the protection of host cells from adenovirus entry. Given that group V and X sPLA2s are expressed in human airway epithelium and macrophages and that the expression of endogenous group V sPLA2 is upregulated by virus-related stimuli in these cells, our present results raise the possibility that group V and X sPLA2s may play a role in innate immunity against adenoviral infection in the respiratory tract. PMID:16146426

  15. Secretory cells of the supraoptic nucleus have central as well as neurohypophysial projections.

    PubMed

    Inyushkin, A N; Orlans, H O; Dyball, R E J

    2009-10-01

    Conventional neuroanatomical methods may fail to demonstrate the presence of axons that are finer than 1 microm in diameter because such processes are near or below the limit of resolution of the light microscope. The presence of such axons can, however, be readily demonstrated by recording. The most easily interpreted type of recording for this purpose is the demonstration of antidromic activation of the cell body following stimulation of the region through which the axon passes. We have exploited this technique in the hypothalamus and have demonstrated the presence of double axonal projections or axons branching very near the cell bodies of the secretory cells of the neurohypophysial system in the rat supraoptic nucleus. We found that a small proportion of supraoptic magnocellular cells could be antidromically activated both from the neural stalk and from elsewhere in the hypothalamus, including the suprachiasmatic nucleus (8 cells of a total of 182) and the antero-ventral third ventricular region (AV3V; 4 of 182 cells) near the organum vasculosum of the lamina terminalis (OVLT). Collision of antidromic and orthodromic spikes showed that the cells were clearly antidromically (rather than synaptically, or orthodromically) activated from both sites. A stimulus applied to one of the axons prevented propagation of a spike evoked by a pulse delivered to the other axon until sufficient time had elapsed after the first stimulus for the resultant spike to have propagated from the first stimulus site along one cell process (towards the cell body or branch point), and from this point along the other axonal branch to the second stimulus site (there was also a short additional delay period during which the axon at the site of the second stimulus recovered from its absolute refractory period). If the interval between the stimuli was progressively reduced, there came a point where the second spike failed. Such a clear demonstration of dual projections in a system where the

  16. Reverse immunoaffinity chromatography: application to the purification of the 60- to 90-kDa gastric parietal cell autoantigen associated with autoimmune gastritis.

    PubMed

    Goldkorn, I; Gleeson, P A; Toh, B H

    1991-05-01

    Previous attempts to purify autoantigens by affinity chromatography using the total IgG from autoantibody-positive sera have not been very successful. We describe here a novel method using parietal cell autoantibodies, isolated on a crude autoantigen immunoabsorbent column, for the purification of the 60- to 90-kDa gastric parietal cell antigen targeted in autoimmune gastritis. The 60- to 90-kDa parietal cell antigen was first enriched 2.5-fold from a 0.5% Triton X-100 extract of total pig gastric mucosal membranes by DEAE-Sepharose 4B chromatography. The fraction containing the 60- to 90-kDa antigen was directly coupled to CNBr-activated Sepharose 4B to produce an immunoadsorbent column for the "reverse" purification of the specific parietal cell autoantibodies from pooled gastric parietal cell autoantibody-positive human sera. A 0.5% Triton X-100 extract of pig gastric mucosal membranes was initially precleared by sequential passage through Protein A-Sepharose 4B and normal human Ig-Sepharose 4B columns. The 60- to 90-kDa gastric parietal cell antigen (approximately 10 micrograms) was then purified from this precleared Triton X-100 membrane extract by affinity chromatography on a 1-ml column of purified autoantibody-Sepharose 4B, followed by preparative sodium dodecyl sulfate-polyacrylamide gel electrophonesis. This method, incorporating a "reverse" immunoaffinity chromatography step, has general applicability for the purification of tissue autoantigens using highly specific autoantibodies present in the sera of humans and experimental animals with a variety of other autoimmune diseases.

  17. Limonene Synthase, the Enzyme Responsible for Monoterpene Biosynthesis in Peppermint, Is Localized to Leucoplasts of Oil Gland Secretory Cells1

    PubMed Central

    Turner, Glenn; Gershenzon, Jonathan; Nielson, Erik E.; Froehlich, John E.; Croteau, Rodney

    1999-01-01

    Circumstantial evidence based on ultrastructural correlation, specific labeling, and subcellular fractionation studies indicates that at least the early steps of monoterpene biosynthesis occur in plastids. (4S)-Limonene synthase, which is responsible for the first dedicated step of monoterpene biosynthesis in mint species, appears to be translated as a preprotein bearing a long plastidial transit peptide. Immunogold labeling using polyclonal antibodies raised to the native enzyme demonstrated the specific localization of limonene synthase to the leucoplasts of peppermint (Mentha × piperita) oil gland secretory cells during the period of essential oil production. Labeling was shown to be absent from all other plastid types examined, including the basal and stalk cell plastids of the secretory phase glandular trichomes. Furthermore, in vitro translation of the preprotein and import experiments with isolated pea chloroplasts were consistent in demonstrating import of the nascent protein to the plastid stroma and proteolytic processing to the mature enzyme at this site. These experiments confirm that the leucoplastidome of the oil gland secretory cells is the exclusive location of limonene synthase, and almost certainly the preceding steps of monoterpene biosynthesis, in peppermint leaves. However, succeeding steps of monoterpene metabolism in mint appear to occur outside the leucoplasts of oil gland cells. PMID:10398724

  18. Secretory phospholipase A(2) predicts impending acute chest syndrome in sickle cell disease.

    PubMed

    Styles, L A; Aarsman, A J; Vichinsky, E P; Kuypers, F A

    2000-11-01

    Acute chest syndrome (ACS) is the leading cause of death in sickle cell disease. Severe ACS often develops in the course of a vaso-occlusive crisis (VOC), but currently there are no predictors for its development. Secretory phospholipase A(2) (sPLA(2)), a potent inflammatory mediator, is elevated in ACS, and previous work suggests that sPLA(2) predicts impending ACS. We prospectively evaluated sPLA(2) concentration during 21 admissions for VOC; 6 of these patients went on to develop ACS. Elevation of sPLA(2) was detected all 6 patients 24 to 48 hours before ACS was clinically diagnosed. Adding the requirement for fever raised the specificity of sPLA(2) to 87% while retaining 100% sensitivity. These data indicate that sPLA(2) can be useful in alerting the clinician to patients with impending ACS. In addition, sPLA(2) may be useful for instituting early therapies to prevent or reduce the clinical morbidity of ACS. PMID:11050014

  19. A role for secretory phospholipase A2 and C-reactive protein in the removal of injured cells.

    PubMed

    Hack, C E; Wolbink, G J; Schalkwijk, C; Speijer, H; Hermens, W T; van den Bosch, H

    1997-03-01

    The acute phase response is initiated in response to infection or physical trauma and is characterized by an increase in the levels of some plasma proteins. Here, Erik Hack and colleagues suggest that the combined actions of two of these acute phase proteins, secretory phospholipase A2 and C-reactive protein, may serve to promote phagocytosis of injured cells and tissue debris, thereby enhancing inflammation and tissue damage.

  20. Decrease in an Inwardly Rectifying Potassium Conductance in Mouse Mammary Secretory Cells after Forced Weaning

    PubMed Central

    Kamikawa, Akihiro; Sugimoto, Shota; Ichii, Osamu; Kondoh, Daisuke

    2015-01-01

    Mammary glands are physiologically active in female mammals only during nursing. Immediately after weaning, most lactation-related genes are downregulated and milk production ceases. In our previous study, we have detected an inwardly rectifying potassium channel (Kir) 2.1-like current in mammary secretory (MS) cells freshly isolated from lactating mice. This current is highly sensitive to external Ba2+. The potassium permeability of the Kir channels may contribute to the secretion and/or preservation of ions in milk. We hypothesized that the functions of the Kir channels in MS cells are regulated after weaning. To test this hypothesis, we examined the effect of forced weaning on the Ba2+-sensitive Kir current and Kir2.1 expression in the mouse mammary glands. Twenty-four hours after weaning, the lumina of mammary acini were histologically enlarged by milk accumulation. The whole-cell patch-clamp analyses showed that the Ba2+-sensitive Kir current in the post-weaning MS cells was smaller than in the lactating MS cells. The inward conductances of the current in the lactating and post-weaning cells were 4.25 ± 0.77 and 0.93 ± 0.34 nS, respectively. Furthermore, real-time PCR and Western blot analyses showed that Kir2.1 mRNA and protein expression decreased in the post-weaning mammary gland (mRNA, 90% reduction; protein, 47% reduction). Moreover, the local milk accumulation caused by teat sealing decreased Kir conductance in MS cells (2.74 ± 0.45 and 0.36 ± 0.27 nS for control and sealed mammary glands, respectively). This was concomitant with the reduction in the Kir2.1 mRNA expression. Our results suggest that milk stasis after weaning immediately decreases the Kir conductance in MS cells. This decrease in the Kir conductance may be partly caused by the reduction in the Kir2.1 mRNA and protein expression. These alterations during the post-weaning period may be involved in the cessation of ion secretion and/or preservation in the milk. PMID:26484867

  1. Glucose metabolism and glutamate analog acutely alkalinize pH of insulin secretory vesicles of pancreatic beta-cells.

    PubMed

    Eto, Kazuhiro; Yamashita, Tokuyuki; Hirose, Kenzo; Tsubamoto, Yoshiharu; Ainscow, Edward K; Rutter, Guy A; Kimura, Satoshi; Noda, Mitsuhiko; Iino, Masamitsu; Kadowaki, Takashi

    2003-08-01

    We studied acute changes of secretory vesicle pH in pancreatic beta-cells with a fluorescent pH indicator, lysosensor green DND-189. Fluorescence was decreased by 0.66 +/- 0.10% at 149 +/- 16 s with 22.2 mM glucose stimulation, indicating that vesicular pH was alkalinized by approximately 0.016 unit. Glucose-responsive pH increase was observed when cytosolic Ca2+ influx was blocked but disappeared when an inhibitor of glycolysis or mitochondrial ATP synthase was present. Glutamate dimethyl ester (GME), a plasma membrane-permeable analog of glutamate, potentiated glucose-stimulated insulin secretion at 5 mM without changing cellular ATP content or cytosolic Ca2+ concentration ([Ca2+]). Application of GME at basal glucose concentration decreased DND-189 fluorescence by 0.83 +/- 0.19% at 38 +/- 2 s. These results indicated that the acutely alkalinizing effect of glucose on beta-cell secretory vesicle pH was dependent on glucose metabolism but independent of modulations of cytosolic [Ca2+]. Moreover, glutamate derived from glucose may be one of the mediators of this alkalinizing effect of glucose, which may have potential relevance to the alteration of secretory function by glutamate.

  2. N-hypermannose glycosylation disruption enhances recombinant protein production by regulating secretory pathway and cell wall integrity in Saccharomyces cerevisiae.

    PubMed

    Tang, Hongting; Wang, Shenghuan; Wang, Jiajing; Song, Meihui; Xu, Mengyang; Zhang, Mengying; Shen, Yu; Hou, Jin; Bao, Xiaoming

    2016-01-01

    Saccharomyces cerevisiae is a robust host for heterologous protein expression. The efficient expression of cellulases in S. cerevisiae is important for the consolidated bioprocess that directly converts lignocellulose into valuable products. However, heterologous proteins are often N-hyperglycosylated in S. cerevisiae, which may affect protein activity. In this study, the expression of three heterologous proteins, β-glucosidase, endoglucanase and cellobiohydrolase, was found to be N-hyperglycosylated in S. cerevisiae. To block the formation of hypermannose glycan, these proteins were expressed in strains with deletions in key Golgi mannosyltransferases (Och1p, Mnn9p and Mnn1p), respectively. Their extracellular activities improved markedly in the OCH1 and MNN9 deletion strains. Interestingly, truncation of the N-hypermannose glycan did not increase the specific activity of these proteins, but improved the secretion yield. Further analysis showed OCH1 and MNN9 deletion up-regulated genes in the secretory pathway, such as protein folding and vesicular trafficking, but did not induce the unfolded protein response. The cell wall integrity was also affected by OCH1 and MNN9 deletion, which contributed to the release of secretory protein extracellularly. This study demonstrated that mannosyltransferases disruption improved protein secretion through up-regulating secretory pathway and affecting cell wall integrity and provided new insights into glycosylation engineering for protein secretion. PMID:27156860

  3. N-hypermannose glycosylation disruption enhances recombinant protein production by regulating secretory pathway and cell wall integrity in Saccharomyces cerevisiae

    PubMed Central

    Tang, Hongting; Wang, Shenghuan; Wang, Jiajing; Song, Meihui; Xu, Mengyang; Zhang, Mengying; Shen, Yu; Hou, Jin; Bao, Xiaoming

    2016-01-01

    Saccharomyces cerevisiae is a robust host for heterologous protein expression. The efficient expression of cellulases in S. cerevisiae is important for the consolidated bioprocess that directly converts lignocellulose into valuable products. However, heterologous proteins are often N-hyperglycosylated in S. cerevisiae, which may affect protein activity. In this study, the expression of three heterologous proteins, β-glucosidase, endoglucanase and cellobiohydrolase, was found to be N-hyperglycosylated in S. cerevisiae. To block the formation of hypermannose glycan, these proteins were expressed in strains with deletions in key Golgi mannosyltransferases (Och1p, Mnn9p and Mnn1p), respectively. Their extracellular activities improved markedly in the OCH1 and MNN9 deletion strains. Interestingly, truncation of the N-hypermannose glycan did not increase the specific activity of these proteins, but improved the secretion yield. Further analysis showed OCH1 and MNN9 deletion up-regulated genes in the secretory pathway, such as protein folding and vesicular trafficking, but did not induce the unfolded protein response. The cell wall integrity was also affected by OCH1 and MNN9 deletion, which contributed to the release of secretory protein extracellularly. This study demonstrated that mannosyltransferases disruption improved protein secretion through up-regulating secretory pathway and affecting cell wall integrity and provided new insights into glycosylation engineering for protein secretion. PMID:27156860

  4. Increased density of DISC1-immunoreactive oligodendroglial cells in fronto-parietal white matter of patients with paranoid schizophrenia.

    PubMed

    Bernstein, Hans-Gert; Jauch, Esther; Dobrowolny, Henrik; Mawrin, Christian; Steiner, Johann; Bogerts, Bernhard

    2016-09-01

    Profound white matter abnormalities have repeatedly been described in schizophrenia, which involve the altered expression of numerous oligodendrocyte-associated genes. Transcripts of the disrupted-in-schizophrenia 1 (DISC1) gene, a key susceptibility factor in schizophrenia, have recently been shown to be expressed by oligodendroglial cells and to negatively regulate oligodendrocyte differentiation and maturation. To learn more about the putative role(s) of oligodendroglia-associated DISC1 in schizophrenia, we analyzed the density of DISC1-immunoreactive oligodendrocytes in the fronto-parietal white matter in postmortem brains of patients with schizophrenia. Compared with controls (N = 12) and cases with undifferentiated/residual schizophrenia (N = 6), there was a significantly increased density of DISC1-expressing glial cells in paranoid schizophrenia (N = 12), which unlikely resulted from neuroleptic treatment. Pathophysiologically, over-expression of DISC1 protein(s) in white matter oligodendrocytes might add to the reduced levels of two myelin markers, 2',3'-cyclic-nucleotide 3'-phosphodiesterase and myelin basic protein in schizophrenia. Moreover, it might significantly contribute to cell cycle abnormalities as well as to deficits in oligodendroglial cell differentiation and maturation found in schizophrenia.

  5. Excretory/secretory products of the carcinogenic liver fluke are endocytosed by human cholangiocytes and drive cell proliferation and IL6 production.

    PubMed

    Chaiyadet, Sujittra; Smout, Michael; Johnson, Michael; Whitchurch, Cynthia; Turnbull, Lynne; Kaewkes, Sasithorn; Sotillo, Javier; Loukas, Alex; Sripa, Banchob

    2015-10-01

    Liver fluke infection caused by Opisthorchis viverrini remains a major public health problem in many parts of Asia including Thailand, Lao PDR, Vietnam and Cambodia, where there is a strikingly high incidence of cholangiocarcinoma (CCA - hepatic cancer of the bile duct epithelium). Among other factors, uptake of O. viverrini excretory/secretory products (OvES) by biliary epithelial cells has been postulated to be responsible for chronic inflammation and proliferation of cholangiocytes, but the mechanisms by which cells internalise O. viverrini excretory/secretory products are still unknown. Herein we incubated normal human cholangiocytes (H69), human cholangiocarcinoma cells (KKU-100, KKU-M156) and human colon cancer (Caco-2) cells with O. viverrini excretory/secretory products and analysed the effects of different endocytic inhibitors to address the mechanism of cellular uptake of ES proteins. Opisthorchis viverrini excretory/secretory products was internalised preferentially by liver cell lines, and most efficiently/rapidly by H69 cells. There was no evidence for trafficking of ES proteins to cholangiocyte organelles, and most of the fluorescence was detected in the cytoplasm. Pretreatment with clathrin inhibitors significantly reduced the uptake of O. viverrini excretory/secretory products, particularly by H69 cells. Opisthorchis viverrini excretory/secretory products induced proliferation of liver cells (H69 and CCA lines) but not intestinal (Caco-2) cells, and proliferation was blocked using inhibitors of the classical endocytic pathways (clathrin and caveolae). Opisthorchis viverrini excretory/secretory products drove IL6 secretion by H69 cells but not Caco-2 cells, and cytokine secretion was significantly reduced by endocytosis inhibitors. This the first known study to address the endocytosis of helminth ES proteins by host epithelial cells and sheds light on the pathways by which this parasite causes one of the most devastating forms of cancer in south

  6. Excretory/secretory products of the carcinogenic liver fluke are endocytosed by human cholangiocytes and drive cell proliferation and IL6 production.

    PubMed

    Chaiyadet, Sujittra; Smout, Michael; Johnson, Michael; Whitchurch, Cynthia; Turnbull, Lynne; Kaewkes, Sasithorn; Sotillo, Javier; Loukas, Alex; Sripa, Banchob

    2015-10-01

    Liver fluke infection caused by Opisthorchis viverrini remains a major public health problem in many parts of Asia including Thailand, Lao PDR, Vietnam and Cambodia, where there is a strikingly high incidence of cholangiocarcinoma (CCA - hepatic cancer of the bile duct epithelium). Among other factors, uptake of O. viverrini excretory/secretory products (OvES) by biliary epithelial cells has been postulated to be responsible for chronic inflammation and proliferation of cholangiocytes, but the mechanisms by which cells internalise O. viverrini excretory/secretory products are still unknown. Herein we incubated normal human cholangiocytes (H69), human cholangiocarcinoma cells (KKU-100, KKU-M156) and human colon cancer (Caco-2) cells with O. viverrini excretory/secretory products and analysed the effects of different endocytic inhibitors to address the mechanism of cellular uptake of ES proteins. Opisthorchis viverrini excretory/secretory products was internalised preferentially by liver cell lines, and most efficiently/rapidly by H69 cells. There was no evidence for trafficking of ES proteins to cholangiocyte organelles, and most of the fluorescence was detected in the cytoplasm. Pretreatment with clathrin inhibitors significantly reduced the uptake of O. viverrini excretory/secretory products, particularly by H69 cells. Opisthorchis viverrini excretory/secretory products induced proliferation of liver cells (H69 and CCA lines) but not intestinal (Caco-2) cells, and proliferation was blocked using inhibitors of the classical endocytic pathways (clathrin and caveolae). Opisthorchis viverrini excretory/secretory products drove IL6 secretion by H69 cells but not Caco-2 cells, and cytokine secretion was significantly reduced by endocytosis inhibitors. This the first known study to address the endocytosis of helminth ES proteins by host epithelial cells and sheds light on the pathways by which this parasite causes one of the most devastating forms of cancer in south

  7. [IP3-sensitive Ca(2+)-channels of endoplasmic reticulum in secretory cells of the rat exorbital lacrimal gland].

    PubMed

    Kotliarova, A B; Man'ko, V V

    2013-01-01

    The role of inositol-1,4,5-trisphosphate of (IP3)-sensitive Ca2+ channels in Ca2+ homeostasis maintenance under activation of M-cholinergic receptors and P2Y receptors in the secretory cells of the rat lacrimal gland was investigated. The study was carried out on intact and permeabilized secretory cells of exorbital lacrimal glands of rats. The cells were isolated using the modified Herzog, Sides, Miller method (1976) and permeabilized with digitonin (50 mg per 0.5 million cells). The functioning of the Ca(2+)-transport systems was estimated by changes of Ca2+ content in the studied cells, which was determined by the spectrophotometric method using arsenazo III. It was shown that IP3-sensitive Ca2+ channels (IP3Rs) of investigated cells are directly inhibited by 2-APB (10 microM/l). On the other hand, the channels are activated by IP3, cholinomimetic (carbacholine) and purine receptor agonist (ATP). When both M-cholinergic receptors and P2Y receptors were activated Ca2+ was released from the same IP3-sensitive store because the effects of ATP and carbacholine at high concentrations (1mM/l and 10 microM/l, respectively) on the Ca2+ content were non-additive. The presence of the store-operated Ca(2+)-channels in secretory cells of the lacrimal gland is confirmed by the observed increase of cellular Ca2+ content as a result of Ca2+ mobilization from the store by carbacholine or thapsigargin and following restoration of Ca2+ concentration in the extracellular solution.

  8. Release of ATP during host cell killing by enteropathogenic E. coli and its role as a secretory mediator.

    PubMed

    Crane, John K; Olson, Ruth A; Jones, Heather M; Duffey, Michael E

    2002-07-01

    Enteropathogenic Escherichia coli (EPEC) causes severe, watery diarrhea in children. We investigated ATP release during EPEC-mediated killing of human cell lines and whether released adenine nucleotides function as secretory mediators. EPEC triggered a release of ATP from all human cell lines tested: HeLa, COS-7, and T84 (colon cells) as measured using a luciferase kit. Accumulation of ATP in the supernatant medium was enhanced if an inhibitor of 5'-ectonucleotidase was included and was further enhanced if an ATP-regenerating system was added. In the presence of the inhibitor/regenerator, ATP concentrations in the supernatant medium reached 1.5-2 microM 4 h after infection with wild-type EPEC strains. In the absence of the inhibitor/regenerator system, extracellular ATP was rapidly broken down to ADP, AMP, and adenosine. Conditioned medium from EPEC-infected cells triggered a brisk chloride secretory response in intestinal tissues studied in the Ussing chamber (rabbit distal colon and T84 cell monolayers), whereas conditioned medium from uninfected cells and sterile filtrates of EPEC bacteria did not. The short-circuit current response to EPEC-conditioned medium was completely reversed by adenosine receptor blockers, such as 8-(p-sulfophenyl)-theophylline and MRS1754. EPEC killing of host cells releases ATP, which is broken down to adenosine, which in turn stimulates secretion via apical adenosine A2b receptors. These findings provide new insight into how EPEC causes watery diarrhea. PMID:12065294

  9. Modulation of oligosaccharide processing in an exocrine secretory glycoprotein of rat parotid cells by beta-adrenoreceptor activation.

    PubMed

    Kousvelari, E E; Banerjee, D K; Grant, S R; Baum, B J

    1988-01-01

    Such stimulation of rat parotid acinar cells in vitro modulated the rate of processing of N-linked oligosaccharides in a high-molecular weight (220 kdalton) secretory glycoprotein. Conversion of polymannose-type oligosaccharides to complex-type oligosaccharides was evaluated by sensitivity to endoglucosaminidase H and alpha-mannosidase, and with a specific inhibitor of glucosidases I/II. Oligosaccharide maturation in the 220 kdalton glycoprotein required one-third to half less time in cells exposed to the beta-adrenergic agonist isoproterenol than in controls. PMID:2971345

  10. Impact of simulated microgravity on the secretory and adhesive activity of cultured human vascular endothelial cells.

    NASA Astrophysics Data System (ADS)

    Rudimov, Evgeny; Buravkova, Ludmila; Pogodina, Margarita; Andrianova, Irina

    The layer of vascular endothelial cells (ECs) is a dynamic,disseminated organ that perform the function of an interface between the blood and vascular wall. The endothelial monolayer is able to quickly respond to changes in the microenvironment due to its synthesis of vasoactive substances, chemokines, adhesion molecules expression, etc. ECs are highly sensitive to gravitational changes and capable of short-term and long-term responses (Sangha et al., 2001; Buravkova et al., 2005; Infanger et al., 2006, 2007. However, the question remains how to reflect the impact of microgravity on endothelium under the inflammatory process. Therefore, the aim of this study was to investigate secretory and adhesive activity of human umbilical vein endothelial cells (HUVECs) during simulated microgravity and TNF-a activation. HUVECs were isolated according to Gimbrone et al. (1978) in modification A. Antonov (1981) and used for experiments at 2-4 passages. HUVECs were activated by low level of TNF-a (2 ng/ml). Microgravity was generated by Random Positioning Machine (RPM, Dutch Space, Leiden) placed into the thermostat at 37°C. After 24 hours of clinorotation we measured adhesion molecules expression on the cell surface (ICAM-1, VCAM-1, PECAM-1, E-selectin, CD144, endoglin (CD105)) and cell viability using a flow cytometry. To evaluate the level of target gene expression was used the real time RT-PCR. IL-6 and IL-8 concentration was measured in the conditioned medium of HUVECs by using the ELISA test. We found that simulated microgravity within 24 hours caused a decrease of ICAM-1, CD144, and E-selectin expression, at the same time not affect the cell viability, endoglin and PECAM-1 expression on the surface HUVEC. Furthermore, there were no changes of the level of IL-6 and IL-8 gene expression and their products in the culture medium. TNF-activated HUVECs showed an increase in gene expression of interleukins and molecules involved in the adhesion process, which also was confirmed

  11. Elevation of susceptibility to ozone-induced acute tracheobronchial injury in transgenic mice deficient in Clara cell secretory protein

    SciTech Connect

    Plopper, C.G. . E-mail: cgplopper@ucdavis.edu; Mango, G.W.; Hatch, G.E.; Wong, V.J.; Toskala, E.; Reynolds, S.D.; Tarkington, B.K.; Stripp, B.R.

    2006-05-15

    Increases in Clara cell abundance or cellular expression of Clara cell secretory protein (CCSP) may cause increased tolerance of the lung to acute oxidant injury by repeated exposure to ozone (O{sub 3}). This study defines how disruption of the gene for CCSP synthesis affects the susceptibility of tracheobronchial epithelium to acute oxidant injury. Mice homozygous for a null allele of the CCSP gene (CCSP-/-) and wild type (CCSP+/+) littermates were exposed to ozone (0.2 ppm, 8 h; 1 ppm, 8 h) or filtered air. Injury was evaluated by light and scanning electron microscopy, and the abundance of necrotic, ciliated, and nonciliated cells was estimated by morphometry. Proximal and midlevel intrapulmonary airways and terminal bronchioles were evaluated. There was no difference in airway epithelial composition between CCSP+/+ and CCSP-/- mice exposed to filtered air, and exposure to 0.2 ppm ozone caused little injury to the epithelium of both CCSP+/+ and CCSP-/- mice. After exposure to 1.0 ppm ozone, CCSP-/- mice suffered from a greater degree of epithelial injury throughout the airways compared to CCSP+/+ mice. CCSP-/- mice had both ciliated and nonciliated cell injury. Furthermore, lack of CCSP was associated with a shift in airway injury to include proximal airway generations. Therefore, we conclude that CCSP modulates the susceptibility of the epithelium to oxidant-induced injury. Whether this is due to the presence of CCSP on the acellular lining layer surface and/or its intracellular distribution in the secretory cell population needs to be defined.

  12. Elevation of susceptibility to ozone-induced acute tracheobronchial injury in transgenic mice deficient in Clara cell secretory protein.

    PubMed

    Plopper, C G; Mango, G W; Hatch, G E; Wong, V J; Toskala, E; Reynolds, S D; Tarkington, B K; Stripp, B R

    2006-05-15

    Increases in Clara cell abundance or cellular expression of Clara cell secretory protein (CCSP) may cause increased tolerance of the lung to acute oxidant injury by repeated exposure to ozone (O3). This study defines how disruption of the gene for CCSP synthesis affects the susceptibility of tracheobronchial epithelium to acute oxidant injury. Mice homozygous for a null allele of the CCSP gene (CCSP-/-) and wild type (CCSP+/+) littermates were exposed to ozone (0.2 ppm, 8 h; 1 ppm, 8 h) or filtered air. Injury was evaluated by light and scanning electron microscopy, and the abundance of necrotic, ciliated, and nonciliated cells was estimated by morphometry. Proximal and midlevel intrapulmonary airways and terminal bronchioles were evaluated. There was no difference in airway epithelial composition between CCSP+/+ and CCSP-/- mice exposed to filtered air, and exposure to 0.2 ppm ozone caused little injury to the epithelium of both CCSP+/+ and CCSP-/- mice. After exposure to 1.0 ppm ozone, CCSP-/- mice suffered from a greater degree of epithelial injury throughout the airways compared to CCSP+/+ mice. CCSP-/- mice had both ciliated and nonciliated cell injury. Furthermore, lack of CCSP was associated with a shift in airway injury to include proximal airway generations. Therefore, we conclude that CCSP modulates the susceptibility of the epithelium to oxidant-induced injury. Whether this is due to the presence of CCSP on the acellular lining layer surface and/or its intracellular distribution in the secretory cell population needs to be defined.

  13. Lactoferrin and free secretory component of human milk inhibit the adhesion of enteropathogenic Escherichia coli to HeLa cells

    PubMed Central

    de Araújo, Andréa Nascimento; Giugliano, Loreny Gimenes

    2001-01-01

    Background Diarrhoea caused by Escherichia coli is an important cause of infant morbidity and mortality in developing countries. Enteropathogenic Escherichia coli (EPEC) is considered one of the major causes of diarrhoea in children living in developing countries. The ability of diarrhoeagenic strains of E. coli to adhere to and colonize the intestine is the first step towards developing the disease. EPEC strains adhere to enterocytes and HeLa cells in a characteristic pattern known as localized adherence. Many epidemiological studies of diarrhoea have shown that breast-feeding protects infants from intestinal infections. Both immunoglobulin and non-immunoglobulin elements of human milk are thought to contribute to the protection from diarrhoeal agents. Results The effects of human milk and its protein components on the localized adherence of EPEC were investigated. Non-immunoglobulin components of human milk responsible for the inhibition of EPEC adhesion to HeLa cells were isolated by chromatographic fractionation of human whey proteins. Besides secretory immunoglobulin A, which has been previously reported to affect the adhesion of EPEC, free secretory component (fSC) and lactoferrin (Lf) were isolated. Even in concentrations lower than those usually found in whole milk, fSC and Lf were able to inhibit the adhesion of EPEC. α-lactalbumin was also isolated, but showed no activity on EPEC adhesion. Conclusions This study demonstrated that the immunoglobulin fraction, the free secretory component and lactoferrin of human milk inhibit EPEC adhesion to HeLa cells. These results indicate that fSC and Lf may be important non-specific defence factors against EPEC infections. PMID:11690544

  14. Detection of activated parietal epithelial cells on the glomerular tuft distinguishes early focal segmental glomerulosclerosis from minimal change disease.

    PubMed

    Smeets, Bart; Stucker, Fabien; Wetzels, Jack; Brocheriou, Isabelle; Ronco, Pierre; Gröne, Hermann-Josef; D'Agati, Vivette; Fogo, Agnes B; van Kuppevelt, Toin H; Fischer, Hans-Peter; Boor, Peter; Floege, Jürgen; Ostendorf, Tammo; Moeller, Marcus J

    2014-12-01

    In rodents, parietal epithelial cells (PECs) migrating onto the glomerular tuft participate in the formation of focal segmental glomerulosclerosis (FSGS) lesions. We investigated whether immunohistologic detection of PEC markers in the initial biopsies of human patients with first manifestation of idiopathic nephrotic syndrome with no immune complexes can improve the sensitivity to detect sclerotic lesions compared with standard methods. Ninety-five renal biopsies were stained for claudin-1 (PEC marker), CD44 (activated PECs), and LKIV69 (PEC matrix); 38 had been diagnosed as early primary FSGS and 57 as minimal change disease. PEC markers were detected on the tuft in 87% of the biopsies of patients diagnosed as primary FSGS. PEC markers were detected in FSGS lesions from the earliest stages of disease. In minimal change disease, no PEC activation was observed by immunohistology. However, in 25% of biopsies originally diagnosed as minimal change disease the presence of small lesions indicative of a sclerosing process were detected, which were undetectable on standard periodic acid-Schiff staining, even though only a single histologic section for each PEC marker was evaluated. Staining for LKIV69 detected lesions with the highest sensitivity. Two novel PEC markers A-kinase anchor protein 12 and annexin A3 exhibited similar sensitivity. In summary, detection of PECs on the glomerular tuft by immunostaining improves the differentiation between minimal change disease and primary FSGS and may serve to guide clinical decision making.

  15. M3-subtype muscarinic receptor that controls intracellular calcium release and inositol phosphate accumulation in gastric parietal cells.

    PubMed

    Leonard, A; Cuq, P; Magous, R; Bali, J P

    1991-07-25

    The muscarinic receptor subtype which triggers acid secretion was investigated in isolated rabbit gastric parietal cells. Cytosolic free Ca2+ concentration ([Ca2+]i), measured with the fluorescent indicator FURA-2, increased rapidly after full agonist (carbachol) stimulation (6-8 sec), then returned to an intermediate sustained value. Other M2-agonists, oxotremorine and arecoline, produced a partial [Ca2+]i increase, whereas M1-agonists, pilocarpine and [4-m-chlorophenylcarbamoyloxyl]-2-butynyl-trimethylammonium, were without any significant effect. [Ca2+]i rise was inhibited by selective muscarinic antagonists: atropine greater than 4-diphenylacetoxy-N-methyl-piperidine methbromide greater than quinuclidinylbenzilate (QNB) greater than pirenzepine greater than 11-[[2-[(diethylamino)methyl]-1-piperidinyl]acetyl]-5,11-dihydro-6H- pyrido[2,3-b][1,4]benzodiazepine-6-one, this sequence being characteristic of the involvement of an M3-subtype. This inhibition was shown to be stereoselective; dexetimide and (-)QNB were more potent than levetimide and (+)QNB. The IC50 values for inhibition of [Ca2+]i increase by muscarinic antagonists were in good agreement with those obtained for inhibition of phospholipase C activation. In conclusion, the muscarinic receptor that controls acid secretion appears to be of the M3-subtype and the biochemical events coupled to the activation of this receptor system are also controlled through the same subtype. PMID:1651079

  16. Hydrogen sulfide induces hyperpolarization and decreases the exocytosis of secretory granules of rat GH3 pituitary tumor cells.

    PubMed

    Mustafina, Alsu N; Yakovlev, Aleksey V; Gaifullina, Aisylu Sh; Weiger, Thomas M; Hermann, Anton; Sitdikova, Guzel F

    2015-10-01

    The aim of the present study was to evaluate the effects of hydrogen sulfide (H2S) on the membrane potential, action potential discharge and exocytosis of secretory granules in neurosecretory pituitary tumor cells (GH3). The H2S donor - sodium hydrosulfide (NaHS) induced membrane hyperpolarization, followed by truncation of spontaneous electrical activity and decrease of the membrane resistance. The NaHS effect was dose-dependent with an EC50 of 152 μM (equals effective H2S of 16-19 μM). NaHS effects were not altered after inhibition of maxi conductance calcium-activated potassium (BK) channels by tetraethylammonium or paxilline, but were significantly reduced after inhibition or activation of ATP-dependent potassium channels (KATP) by glibenclamide or by diazoxide, respectively. In whole-cell recordings NaHS increased the amplitude of KATP currents, induced by hyperpolarizing pulses and subsequent application of glibenclamide decreased currents to control levels. Using the fluorescent dye FM 1-43 exocytosis of secretory granules was analyzed in basal and stimulated conditions (high K(+) external solution). Prior application of NaHS decreased the fluorescence of the cell membrane in both conditions which links with activation of KATP currents (basal secretion) and activation of KATP currents and BK-currents (stimulated exocytosis). We suggest that H2S induces hyperpolarization of GH3 cells by activation of KATP channels which results in a truncation of spontaneous action potentials and a decrease of hormone release.

  17. A secretory cell type develops alongside multiciliated cells, ionocytes and goblet cells, and provides a protective, anti-infective function in the frog embryonic mucociliary epidermis

    PubMed Central

    Dubaissi, Eamon; Rousseau, Karine; Lea, Robert; Soto, Ximena; Nardeosingh, Siddarth; Schweickert, Axel; Amaya, Enrique; Thornton, David J.; Papalopulu, Nancy

    2014-01-01

    The larval epidermis of Xenopus is a bilayered epithelium, which is an excellent model system for the study of the development and function of mucosal and mucociliary epithelia. Goblet cells develop in the outer layer while multiciliated cells and ionocytes sequentially intercalate from the inner to the outer layer. Here, we identify and characterise a fourth cell type, the small secretory cell (SSC). We show that the development of these cells is controlled by the transcription factor Foxa1 and that they intercalate into the outer layer of the epidermis relatively late, at the same time as embryonic hatching. Ultrastructural and molecular characterisation shows that these cells have an abundance of large apical secretory vesicles, which contain highly glycosylated material, positive for binding of the lectin, peanut agglutinin, and an antibody to the carbohydrate epitope, HNK-1. By specifically depleting SSCs, we show that these cells are crucial for protecting the embryo against bacterial infection. Mass spectrometry studies show that SSCs secrete a glycoprotein similar to Otogelin, which may form the structural component of a mucus-like protective layer, over the surface of the embryo, and several potential antimicrobial substances. Our study completes the characterisation of all the epidermal cell types in the early tadpole epidermis and reinforces the suitability of this system for the in vivo study of complex epithelia, including investigation of innate immune defences. PMID:24598166

  18. Storage and degradation of secretory proteins in adenomatous and secondary hyperplastic parathyroid cells. An immunoelectron microscope study.

    PubMed

    Berger, G; Berger, F; Billard, F; Danowski, J; Vauzelle, J L

    1989-01-01

    Parathyroid hormone (PTH) and chromogranin A/secretory protein-I (SP-I) have been localized on immunoelectron microscopy in double-fixed tissues from adenomatous and secondary hyperplastic parathyroid glands. Storage organelles, identified on the basis of their consistent labelling, included tow morphologically distinct varieties of granules/vesicles; the mature granules and the progranules. The former consisted of dense, mostly rounded, medium to large-sized bodies which were strongly labelled and predominant in the proximity of the cell membrane. The other variety of body included a spectrum of small pale vesicles/granules which were mainly located in the Golgi area. Because their morphology and their labelling pattern varied other bodies were assumed to be engaged in degradation or cleavage of the secretory proteins. These bodies comprised crinophagic structures, that is to say multivesicular bodies and large Golgi-related vesicles, as well as a number of atypical solid bodies. Whereas most of the granulated cells stored a mature or a maturing population of vesicles/granules, the process of maturation appeared to be either absent or incomplete in a number of cells from some glands. The major defects were frequently associated with an unusual labelling pattern of the Golgi area and selectively affected groups of cells from all the transitional oxyphil cell adenomas. The minor defects concerned individual cells of different types present in both categories of glands. The present data suggest that in hyperfunctioning glands, the type of hormone processing depends on the capacity of each cell in progranule maturation and that the maturation capacity may decrease dramatically in adenomatous or chronically hyperstimulated cells of the transitional oxyphil type. PMID:2505443

  19. Illuminating cellular structure and function in the early secretory pathway by multispectral 3D imaging in living cells

    NASA Astrophysics Data System (ADS)

    Rietdorf, Jens; Stephens, David J.; Squire, Anthony; Simpson, Jeremy; Shima, David T.; Paccaud, Jean-Pierre; Bastiaens, Philippe I.; Pepperkok, Rainer

    2000-04-01

    Membrane traffic between the endoplasmic reticulum (ER) and the Golgi complex is regulated by two vesicular coat complexes, COPII and COPI. COPII has been implicated in selective packaging of anterograde cargo into coated transport vesicles budding from the ER. COPI-coated vesicles are proposed to mediate recycling of proteins from the Golgi complex to the ER. We have used multi spectral 3D imaging to visualize COPI and COPII behavior simultaneously with various GFP-tagged secretory markers in living cells. This shows that COPII and COPI act sequentially whereby COPI association with anterograde transport complexes is involved in microtubule-based transport and the en route segregation of ER recycling molecules from secretory cargo within TCS in transit to the Golgi complex. We have also investigated the possibility to discriminate spectrally GFP fusion proteins by fluorescence lifetime imaging. This shows that at least two, and possibly up to three GFP fusion proteins can be discriminated and localized in living cells using a single excitation wavelength and a single broad band emission filter.

  20. Mammary Analogue Secretory Carcinoma.

    PubMed

    Stevens, Todd M; Parekh, Vishwas

    2016-09-01

    Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland tumor that shares the same histologic appearance and ETV6 gene (12p13) rearrangement as secretory carcinoma of the breast. Prior to its recognition, MASC cases were commonly labeled acinic cell carcinoma and adenocarcinoma, not otherwise specified. Despite distinctive histologic features, MASC may be difficult to distinguish from other salivary gland tumors, in particular zymogen-poor acinic cell carcinoma and low-grade salivary duct carcinoma. Although characteristic morphologic and immunohistochemical features form the basis of a diagnosis of MASC, the presence of an ETV6-NTRK3 gene fusion is confirmatory. Given its recent recognition the true prognostic import of MASC is not yet clearly defined. PMID:27575269

  1. Perturbations in maturation of secretory proteins and their association with endoplasmic reticulum chaperones in a cell culture model for epithelial ischemia.

    PubMed Central

    Kuznetsov, G; Bush, K T; Zhang, P L; Nigam, S K

    1996-01-01

    The effects of ischemia on the maturation of secretory proteins are not well understood. Among several events that occur during ischemia-reperfusion are a rapid and extensive decrease in ATP levels and an alteration of cellular oxidative state. Since the normal folding and assembly of secretory proteins are mediated by endoplasmic reticulum (ER) molecular chaperones, the function of which depends on ATP and maintenance of an appropriate redox environment, ischemia might be expected to perturb folding of secretory proteins. In this study, whole animal and cultured cell models for the epithelial ischemic state were used to examine this possibility. After acute kidney ischemia, marked increases in the mRNA levels of the ER chaperones glucose-regulated protein (grp)78/immunoglobulin-binding protein (BiP), grp94, and ER protein (ERp)72 were noted. Likewise, when cellular ATP was depleted to less than 10% of control with antimycin A, mRNA levels of BiP, ERp72, and grp94 were increased in kidney and thyroid epithelial cell culture models. Since the signal for the up-regulation of these stress proteins is believed to be the accumulation of misfolded/misassembled secretory proteins in the ER, their induction after ischemia in vivo and antimycin treatment of cultured cells suggests that maturation of secretory proteins in the ER lumen might indeed be perturbed. To analyze the effects of antimycin A on the maturation of secretory proteins, we studied the fate of thyroglobulin (Tg), a large oligomeric secretory glycoprotein, the folding and assembly of which seems to require a variety of ER chaperones. Treatment of cultured thyroid epithelial cells with antimycin A greatly inhibited ( > 90%) the secretion of Tg. Sucrose density gradient analysis revealed that in antimycin A-treated cells Tg associates into large macromolecular complexes which, by immunofluorescence, appeared to localize to the ER. Furthermore, coimmunoprecipitation studies after antimycin A treatment

  2. Unique secretory dynamics of tissue plasminogen activator and its modulation by plasminogen activator inhibitor-1 in vascular endothelial cells.

    PubMed

    Suzuki, Yuko; Mogami, Hideo; Ihara, Hayato; Urano, Tetsumei

    2009-01-01

    We analyzed the secretory dynamics of tissue plasminogen activator (tPA) in EA.hy926 cells, an established vascular endothelial cell (VEC) line producing GFP-tagged tPA, using total internal reflection-fluorescence (TIR-F) microscopy. tPA-GFP was detected in small granules in EA.hy926 cells, the distribution of which was indistinguishable from intrinsically expressed tPA. Its secretory dynamics were unique, with prolonged (> 5 minutes) retention of the tPA-GFP on the cell surface, appearing as fluorescent spots in two-thirds of the exocytosis events. The rapid disappearance (mostly by 250 ms) of a domain-deletion mutant of tPA-GFP possessing only the signal peptide and catalytic domain indicates that the amino-terminal heavy chain of tPA-GFP is essential for binding to the membrane surface. The addition of PAI-1 dose-dependently facilitated the dissociation of membrane-retained tPA and increased the amounts of tPA-PAI-1 high-molecular-weight complexes in the medium. Accordingly, suppression of PAI-1 synthesis in EA.hy926 cells by siRNA prolonged the dissociation of tPA-GFP, whereas a catalytically inactive mutant of tPA-GFP not forming complexes with PAI-1 remained on the membrane even after PAI-1 treatment. Our results provide new insights into the relationship between exocytosed, membrane-retained tPA and PAI-1, which would modulate cell surface-associated fibrinolytic potential.

  3. A Western Blot-based Investigation of the Yeast Secretory Pathway Designed for an Intermediate-Level Undergraduate Cell Biology Laboratory

    ERIC Educational Resources Information Center

    Hood-DeGrenier, Jennifer K.

    2008-01-01

    The movement of newly synthesized proteins through the endomembrane system of eukaryotic cells, often referred to generally as the secretory pathway, is a topic covered in most intermediate-level undergraduate cell biology courses. An article previously published in this journal described a laboratory exercise in which yeast mutants defective in…

  4. Morphometric studies of secretory granule formation in mouse pancreatic acinar cells. Dissecting the early structural changes following pilocarpine injection

    PubMed Central

    HAMMEL, ILAN; SHOR-HAZAN, OSNAT; ELDAR, TORA; AMIHAI, DINA; LEW, SYLVIA

    1999-01-01

    Secretory granule formation in pancreatic acinar cells is known to involve massive membrane flow. In previous studies we have undertaken morphometry of the regranulation mechanism in these cells and in mast cells as a model for cellular membrane movement. In our current work, electron micrographs of pancreatic acinar cells from ICR mice were taken at several time points after extensive degranulation induced by pilocarpine injection in order to investigate the volume changes of rough endoplasmic reticulum (RER), nucleus, mitochondria and autophagosomes. At 2–4 h after stimulation, when the pancreatic cells demonstrated a complete loss of granules, this was accompanied by an increased proportion of autophagosomal activity. This change primarily reflected a greatly increased proportion of profiles retaining autophagic vacuoles containing recognisable cytoplasmic structures such as mitochondria, granule profiles and fragments of RER. The mitochondrial structures reached a significant maximal size 4 h following injection (before degranulation 0.178±0.028 μm3; at 4 h peak value, 0.535±0.109 μm3). Nucleus size showed an early volume increase approaching a maximum value 2 h following degranulation. The regranulation span was thus divided into 3 stages. The first was the membrane remodelling stage (0–2 h). During this period the volume of the RER and secretory granules was greatly decreased. At the intermediate stage (2–4 h) a significant increase of the synthesis zone was observed within the nucleus. The volume of the mitochondria was increasing. At the last step, the major finding was a significant granule accumulation in parallel with an active Golgi zone. PMID:10227666

  5. Heterologous processing of rat prosomatostatin to somatostatin-14 by PC2: requirement for secretory cell but not the secretion granule.

    PubMed Central

    Galanopoulou, A S; Seidah, N G; Patel, Y C

    1995-01-01

    The role of PC2 in prosomatostatin (PSS) processing was investigated in GH3/GH4C1 pituitary cells. These cells are sparsely granulated, express different amounts of PC2 and no PC1. We described heterologous processing of rat PSS (rPSS) co-expressed with PC2 in stably transfected cells, correlate PC2 protein levels under different conditions of transfection with efficiency of PSS processing to somatostatin-14 (SS-14), determine the effect of modulating cell granularity on enzyme expression and PSS processing, and compare the relative potency of PC2 with that of PC1, PSS and cleavage products were monitored by HPLC and radioimmunoassay of SS-like immunoreactivity (SSLI). Radioimmunoassay analysis of N-terminal PC2-like immunoreactivity (PC2 LI) in GH4C1:rPSS, GH4C1:rPSS + PC2 and GH3:rPSS transfectants showed a gradient of PC2 protein of 1:2.6:3.4 in cell extracts and 1:4.7:9 in secretion media from these cells respectively. The concentration of PC2 protein correlated with SS-14 conversion efficiency was 36 +/- 3% in GH4C1:rPSS cells, 56 +/- 7% in GH4C1:rPSS-PC2 cells and 100% in GH3:rPSS cells. Treatment of GH4C1:rPSS + PC2 cells with epidermal growth factor, insulin, and beta-estradiol to induce granules, significantly increased basal and forskolin-stimulated co-release of SS LI and PC2 LI, but had no influence on SS-14 processing efficiency. Hormone treatment led to a small increase in the ratio of mature PC2 (68 kDa) to proPC2 (75 kDa) forms. PC1 stably transfected in GH4C1 cells produced significantly greater SS-14 conversion (62% in cells, 66% in media) compared with PC2 transfectants (53% in cells, 47% in media) These results provide the first proof that PC2 can effect dibasic processing of mammalian PSS, and, along with PC1, qualifies as an authentic SS-14 convertase. The activity of PC2 requires the milieu of the secretory cell but not the secretory granule. Images Figure 1 Figure 2 Figure 3 Figure 6 PMID:7575441

  6. Type II secretory phospholipase A2 binds to ischemic flip-flopped cardiomyocytes and subsequently induces cell death.

    PubMed

    Nijmeijer, R; Willemsen, M; Meijer, C J L M; Visser, C A; Verheijen, R H; Gottlieb, R A; Hack, C E; Niessen, H W M

    2003-11-01

    Type II secretory phospholipase A2 (sPLA2) is a cardiovascular risk factor. We recently found depositions of sPLA2 in the necrotic center of infarcted human myocardium and normally appearing cardiomyocytes adjacent to the border zone. The consequences of binding of sPLA2 to ischemic cardiomyocytes are not known. To explore a potential effect of sPLA2 on ischemic cardiomyocytes at a cellular level we used an in vitro model. The cardiomyocyte cell line H9c2 or adult cardiomyocytes were isolated from rabbits that were incubated with sPLA2 in the presence of metabolic inhibitors to mimic ischemia-reperfusion conditions. Cell viability was established with the use of annexin V and propidium iodide or 7-aminoactinomycin D. Metabolic inhibition induced an increase of the number of flip-flopped cells, including a population that did not stain with propidium iodide and that was caspase-3 negative. sPLA2 bound to the flip-flopped cells, including those negative for caspase-3. sPLA2 binding induced cell death in these latter cells. In addition, sPLA2 potentiated the binding of C-reactive protein (CRP) to these cells. We conclude that by binding to flip-flopped cardiomyocytes, including those that are caspase-3 negative and presumably reversibly injured, sPLA2 may induce cell death and tag these cells with CRP.

  7. Optofluidic platform for real-time monitoring of live cell secretory activities using Fano resonance in gold nanoslits.

    PubMed

    Wu, Shu-Han; Lee, Kuang-Li; Chiou, Arthur; Cheng, Xuanhong; Wei, Pei-Kuen

    2013-10-25

    An optofluidic platform for real-time monitoring of live cell secretory activities is constructed via Fano resonance in a gold nanoslit array. Large-area and highly sensitive gold nanoslits with a period of 500 nm are fabricated on polycarbonate films using the thermal-annealed template-stripping method. The coupling between gap plasmon resonance in the slits and surface plasmon polariton Bloch waves forms a sharp Fano resonance with intensity sensitivity greater than 11 000% per refractive index unit. The nanoslit array is integrated with a cell-trapping microfluidic device to monitor dynamic secretion of matrix metalloproteinase 9 (MMP-9) from human acute monocytic leukemia cells in situ. Upon continuous lipopolysaccharide (LPS) stimulation, MMP-9 secretion is detected within 2 h due to ultrahigh surface sensitivity and close proximity of the sensor to the target cells. In addition to the advantage of detecting early cell responses, the sensor also allows interrogation of cell secretion dynamics. Furthermore, the average secretion per cell measured using our system well matches previous reports while it requires orders of magnitude less cells. The optofluidic platform may find applications in fundamental studies of cell functions and diagnostics based on secretion signals.

  8. Senescence-Associated Secretory Phenotypes Reveal Cell-Nonautonomous Functions of Oncogenic RAS and the p53 Tumor Suppressor

    SciTech Connect

    Coppé, Jean-Philippe; Patil, Christopher; Rodier, Francis; Sun, Yu; Munoz, Denise; Goldstein, Joshua; Nelson, Peter; Desprez, Pierre-Yves; Campisi, Judith

    2008-10-24

    Cellular senescence suppresses cancer by arresting cell proliferation, essentially permanently, in response to oncogenic stimuli, including genotoxic stress. We modified the use of antibody arrays to provide a quantitative assessment of factors secreted by senescent cells. We show that human cells induced to senesce by genotoxic stress secrete myriad factors associated with inflammation and malignancy. This senescence-associated secretory phenotype (SASP) developed slowly over several days and only after DNA damage of sufficient magnitude to induce senescence. Remarkably similar SASPs developed in normal fibroblasts, normal epithelial cells, and epithelial tumor cells after genotoxic stress in culture, and in epithelial tumor cells in vivo after treatment of prostate cancer patients with DNA-damaging chemotherapy. In cultured premalignant epithelial cells, SASPs induced an epithelial-mesenchyme transition and invasiveness, hallmarks of malignancy, by a paracrine mechanism that depended largely on the SASP factors interleukin (IL)-6 and IL-8. Strikingly, two manipulations markedly amplified, and accelerated development of, the SASPs: oncogenic RAS expression, which causes genotoxic stress and senescence in normal cells, and functional loss of the p53 tumor suppressor protein. Both loss of p53 and gain of oncogenic RAS also exacerbated the promalignant paracrine activities of the SASPs. Our findings define a central feature of genotoxic stress-induced senescence. Moreover, they suggest a cell-nonautonomous mechanism by which p53 can restrain, and oncogenic RAS can promote, the development of age-related cancer by altering the tissue microenvironment.

  9. Loss of ascl1a prevents secretory cell differentiation within the zebrafish intestinal epithelium resulting in a loss of distal intestinal motility

    PubMed Central

    Roach, Gillian; Wallace, Rachel Heath; Cameron, Amy; Ozel, Rifat Emrah; Hongay, Cintia F.; Baral, Reshica; Andreescu, Silvana; Wallace, Kenneth N.

    2013-01-01

    The vertebrate intestinal epithelium is renewed continuously from stem cells at the base of the crypt in mammals or base of the fold in fish over the life of the organism. As stem cells divide, newly formed epithelial cells make an initial choice between a secretory or enterocyte fate. This choice has previously been demonstrated to involve Notch signaling as well as Atonal and Her transcription factors in both embryogenesis and adults. Here, we demonstrate that in contrast to the atoh1 in mammals, ascl1a is responsible for formation of secretory cells in zebrafish. ascl1a−/− embryos lack all intestinal epithelial secretory cells and instead differentiate into enterocytes. ascl1a−/− embryos also fail to induce intestinal epithelial expression of deltaD suggesting that ascl1a plays a role in initiation of Notch signaling. Inhibition of Notch signaling increases the number of ascl1a and deltaD expressing intestinal epithelial cells as well as the number of developing secretory cells during two specific time periods: between 30 and 34 hpf and again between 64 and 74 hpf. Loss of enteroendocrine products results in loss of anterograde motility in ascl1a−/− embryos. 5HT produced by enterochromaffin cells is critical in motility and secretion within the intestine. We find that addition of exogenous 5HT to ascl1a−/− embryos at near physiological levels (measured by differential pulse voltammetry) induce anterograde motility at similar levels to wild type velocity, distance, and frequency. Removal or doubling the concentration of 5HT in WT embryos does not significantly affect anterograde motility, suggesting that the loss of additional enteroendocrine products in ascl1a−/− embryos also contributes to intestinal motility. Thus, zebrafish intestinal epithelial cells appear to have a common secretory progenitor from which all subtypes form. Loss of enteroendocrine cells reveals the critical need for enteroendocrine products in maintenance of normal

  10. Loss of ascl1a prevents secretory cell differentiation within the zebrafish intestinal epithelium resulting in a loss of distal intestinal motility.

    PubMed

    Roach, Gillian; Heath Wallace, Rachel; Cameron, Amy; Emrah Ozel, Rifat; Hongay, Cintia F; Baral, Reshica; Andreescu, Silvana; Wallace, Kenneth N

    2013-04-15

    The vertebrate intestinal epithelium is renewed continuously from stem cells at the base of the crypt in mammals or base of the fold in fish over the life of the organism. As stem cells divide, newly formed epithelial cells make an initial choice between a secretory or enterocyte fate. This choice has previously been demonstrated to involve Notch signaling as well as Atonal and Her transcription factors in both embryogenesis and adults. Here, we demonstrate that in contrast to the atoh1 in mammals, ascl1a is responsible for formation of secretory cells in zebrafish. ascl1a-/- embryos lack all intestinal epithelial secretory cells and instead differentiate into enterocytes. ascl1a-/- embryos also fail to induce intestinal epithelial expression of deltaD suggesting that ascl1a plays a role in initiation of Notch signaling. Inhibition of Notch signaling increases the number of ascl1a and deltaD expressing intestinal epithelial cells as well as the number of developing secretory cells during two specific time periods: between 30 and 34hpf and again between 64 and 74hpf. Loss of enteroendocrine products results in loss of anterograde motility in ascl1a-/- embryos. 5HT produced by enterochromaffin cells is critical in motility and secretion within the intestine. We find that addition of exogenous 5HT to ascl1a-/- embryos at near physiological levels (measured by differential pulse voltammetry) induce anterograde motility at similar levels to wild type velocity, distance, and frequency. Removal or doubling the concentration of 5HT in WT embryos does not significantly affect anterograde motility, suggesting that the loss of additional enteroendocrine products in ascl1a-/- embryos also contributes to intestinal motility. Thus, zebrafish intestinal epithelial cells appear to have a common secretory progenitor from which all subtypes form. Loss of enteroendocrine cells reveals the critical need for enteroendocrine products in maintenance of normal intestinal motility. PMID

  11. Loss of ascl1a prevents secretory cell differentiation within the zebrafish intestinal epithelium resulting in a loss of distal intestinal motility.

    PubMed

    Roach, Gillian; Heath Wallace, Rachel; Cameron, Amy; Emrah Ozel, Rifat; Hongay, Cintia F; Baral, Reshica; Andreescu, Silvana; Wallace, Kenneth N

    2013-04-15

    The vertebrate intestinal epithelium is renewed continuously from stem cells at the base of the crypt in mammals or base of the fold in fish over the life of the organism. As stem cells divide, newly formed epithelial cells make an initial choice between a secretory or enterocyte fate. This choice has previously been demonstrated to involve Notch signaling as well as Atonal and Her transcription factors in both embryogenesis and adults. Here, we demonstrate that in contrast to the atoh1 in mammals, ascl1a is responsible for formation of secretory cells in zebrafish. ascl1a-/- embryos lack all intestinal epithelial secretory cells and instead differentiate into enterocytes. ascl1a-/- embryos also fail to induce intestinal epithelial expression of deltaD suggesting that ascl1a plays a role in initiation of Notch signaling. Inhibition of Notch signaling increases the number of ascl1a and deltaD expressing intestinal epithelial cells as well as the number of developing secretory cells during two specific time periods: between 30 and 34hpf and again between 64 and 74hpf. Loss of enteroendocrine products results in loss of anterograde motility in ascl1a-/- embryos. 5HT produced by enterochromaffin cells is critical in motility and secretion within the intestine. We find that addition of exogenous 5HT to ascl1a-/- embryos at near physiological levels (measured by differential pulse voltammetry) induce anterograde motility at similar levels to wild type velocity, distance, and frequency. Removal or doubling the concentration of 5HT in WT embryos does not significantly affect anterograde motility, suggesting that the loss of additional enteroendocrine products in ascl1a-/- embryos also contributes to intestinal motility. Thus, zebrafish intestinal epithelial cells appear to have a common secretory progenitor from which all subtypes form. Loss of enteroendocrine cells reveals the critical need for enteroendocrine products in maintenance of normal intestinal motility.

  12. Albumin-induced apoptosis of glomerular parietal epithelial cells is modulated by extracellular signal-regulated kinase 1/2

    PubMed Central

    Ohse, Takamoto; Krofft, Ron D.; Wu, Jimmy S.; Eddy, Allison A.; Pippin, Jeffrey W.; Shankland, Stuart J.

    2012-01-01

    Background. The biological role(s) of glomerular parietal epithelial cells (PECs) is not fully understood in health or disease. Given its location, PECs are constantly exposed to low levels of filtered albumin, which is increased in nephrotic states. We tested the hypothesis that PECs internalize albumin and increased uptake results in apoptosis. Methods. Confocal microscopy of immunofluorescent staining and immunohistochemistry were used to demonstrate albumin internalization in PECs and to quantitate albumin uptake in normal mice and rats as well as experimental models of membranous nephropathy, minimal change disease/focal segmental glomerulosclerosis and protein overload nephropathy. Fluorescence-activated cell sorting analysis was performed on immortalized cultured PECs exposed to fluorescein isothiocyanate (FITC)-labeled albumin in the presence of an endosomal inhibitor or vehicle. Apoptosis was measured by Hoechst staining in cultured PECs exposed to bovine serum albumin. Levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (p-ERK1/2) were restored by retroviral infection of mitogen-activated protein kinase (MEK) 1/2 and reduced by U0126 in PECs exposed to high albumin levels in culture and apoptosis measured by Hoechst staining. Results. PECs internalized albumin normally, and this was markedly increased in all of the experimental disease models (P < 0.05 versus controls). Cultured immortalized PECs also internalize FITC-labeled albumin, which was reduced by endosomal inhibition. A consequence of increased albumin internalization was PEC apoptosis in vitro and in vivo. Candidate signaling pathways underlying these events were examined. Data showed markedly reduced levels of phosphorylated extracellular signal-regulated kinase 1 and 2 (ERK1/2) in PECs exposed to high albumin levels in nephropathy and in culture. A role for ERK1/2 in limiting albumin-induced apoptosis was shown by restoring p-ERK1/2 by retroviral infection, which reduced

  13. Dense core secretory vesicles revealed as a dynamic Ca2+ store in neuroendocrine cells with a vesicle-associated membrane protein aequorin chimaera

    PubMed Central

    Mitchell, Kathryn J.; Pinton, Paolo; Varadi, Aniko; Tacchetti, Carlo; Ainscow, Edward K.; Pozzan, Tullio; Rizzuto, Rosario; Rutter, Guy A.

    2001-01-01

    The role of dense core secretory vesicles in the control of cytosolic-free Ca2+ concentrations ([Ca2+]c) in neuronal and neuroendocrine cells is enigmatic. By constructing a vesicle-associated membrane protein 2–synaptobrevin.aequorin chimera, we show that in clonal pancreatic islet β-cells: (a) increases in [Ca2+]c cause a prompt increase in intravesicular-free Ca2+ concentration ([Ca2+]SV), which is mediated by a P-type Ca2+-ATPase distinct from the sarco(endo) plasmic reticulum Ca2+-ATPase, but which may be related to the PMR1/ATP2C1 family of Ca2+ pumps; (b) steady state Ca2+ concentrations are 3–5-fold lower in secretory vesicles than in the endoplasmic reticulum (ER) or Golgi apparatus, suggesting the existence of tightly bound and more rapidly exchanging pools of Ca2+; (c) inositol (1,4,5) trisphosphate has no impact on [Ca2+]SV in intact or permeabilized cells; and (d) ryanodine receptor (RyR) activation with caffeine or 4-chloro-3-ethylphenol in intact cells, or cyclic ADPribose in permeabilized cells, causes a dramatic fall in [Ca2+]SV. Thus, secretory vesicles represent a dynamic Ca2+ store in neuroendocrine cells, whose characteristics are in part distinct from the ER/Golgi apparatus. The presence of RyRs on secretory vesicles suggests that local Ca2+-induced Ca2+ release from vesicles docked at the plasma membrane could participate in triggering exocytosis. PMID:11571310

  14. Dense core secretory vesicles revealed as a dynamic Ca(2+) store in neuroendocrine cells with a vesicle-associated membrane protein aequorin chimaera.

    PubMed

    Mitchell, K J; Pinton, P; Varadi, A; Tacchetti, C; Ainscow, E K; Pozzan, T; Rizzuto, R; Rutter, G A

    2001-10-01

    The role of dense core secretory vesicles in the control of cytosolic-free Ca(2+) concentrations ([Ca(2+)](c)) in neuronal and neuroendocrine cells is enigmatic. By constructing a vesicle-associated membrane protein 2-synaptobrevin.aequorin chimera, we show that in clonal pancreatic islet beta-cells: (a) increases in [Ca(2+)](c) cause a prompt increase in intravesicular-free Ca(2+) concentration ([Ca(2+)]SV), which is mediated by a P-type Ca(2+)-ATPase distinct from the sarco(endo) plasmic reticulum Ca(2+)-ATPase, but which may be related to the PMR1/ATP2C1 family of Ca(2+) pumps; (b) steady state Ca(2+) concentrations are 3-5-fold lower in secretory vesicles than in the endoplasmic reticulum (ER) or Golgi apparatus, suggesting the existence of tightly bound and more rapidly exchanging pools of Ca(2+); (c) inositol (1,4,5) trisphosphate has no impact on [Ca(2+)](SV) in intact or permeabilized cells; and (d) ryanodine receptor (RyR) activation with caffeine or 4-chloro-3-ethylphenol in intact cells, or cyclic ADPribose in permeabilized cells, causes a dramatic fall in [Ca(2+)](SV). Thus, secretory vesicles represent a dynamic Ca(2+) store in neuroendocrine cells, whose characteristics are in part distinct from the ER/Golgi apparatus. The presence of RyRs on secretory vesicles suggests that local Ca(2+)-induced Ca(2+) release from vesicles docked at the plasma membrane could participate in triggering exocytosis.

  15. Identification of chondroitin sulfate E proteoglycans and heparin proteoglycans in the secretory granules of human lung mast cells

    SciTech Connect

    Stevens, R.L.; Austen, K.F. ); Fox, C.C.; Lichtenstein, L.M. )

    1988-04-01

    The predominant subclasses of mast cells in both the rat and the mouse can be distinguished from one another by their preferential synthesis of {sup 35}S-labeled proteoglycans that contain either heparin or oversulfated chondroitin sulfate glycosaminoglycans. Although ({sup 35}S)heparin proteoglycans have been isolated from human lung mast cells of 40-70% purity and from a skin biopsy specimen of a patient with urticaria pigmentosa, no highly sulfated chondroitin sulfate proteoglycan has been isolated from any enriched or highly purified population of human mast cells. The authors demonstrate that human lung mast cells of 96% purity incorporate ({sup 35}S)sulfate into separate heparin and chondroitin sulfate proteoglycans in an {approx}2:1 ratio. As assessed by HPLC of the chondroitinase ABC digests, the chondroitin ({sup 35}S)sulfate proteoglycans isolated from these human lung mast cells contain the same unusual chondroitin sulfate E disaccharide that is present in proteoglycans produced by interleukin 3-dependent mucosal-like mouse mast cells. Both the chondroitin ({sup 35}S)sulfate E proteoglycans and the ({sup 35}S)heparin proteoglycans were exocytosed from the ({sup 35}S)sulfate-labeled cells via perturbation of the IgE receptor, indicating that both types of {sup 35}S-labeled proteoglycans reside in the secretory granules of these human lung mast cells.

  16. Four distinct secretory pathways serve protein secretion, cell surface growth, and peroxisome biogenesis in the yeast Yarrowia lipolytica.

    PubMed Central

    Titorenko, V I; Ogrydziak, D M; Rachubinski, R A

    1997-01-01

    We have identified and characterized mutants of the yeast Yarrowia lipolytica that are deficient in protein secretion, in the ability to undergo dimorphic transition from the yeast to the mycelial form, and in peroxisome biogenesis. Mutations in the SEC238, SRP54, PEX1, PEX2, PEX6, and PEX9 genes affect protein secretion, prevent the exit of the precursor form of alkaline extracellular protease from the endoplasmic reticulum, and compromise peroxisome biogenesis. The mutants sec238A, srp54KO, pex2KO, pex6KO, and pex9KO are also deficient in the dimorphic transition from the yeast to the mycelial form and are affected in the export of only plasma membrane and cell wall-associated proteins specific for the mycelial form. Mutations in the SEC238, SRP54, PEX1, and PEX6 genes prevent or significantly delay the exit of two peroxisomal membrane proteins, Pex2p and Pex16p, from the endoplasmic reticulum en route to the peroxisomal membrane. Mutations in the PEX5, PEX16, and PEX17 genes, which have previously been shown to be essential for peroxisome biogenesis, affect the export of plasma membrane and cell wall-associated proteins specific for the mycelial form but do not impair exit from the endoplasmic reticulum of either Pex2p and Pex16p or of proteins destined for secretion. Biochemical analyses of these mutants provide evidence for the existence of four distinct secretory pathways that serve to deliver proteins for secretion, plasma membrane and cell wall synthesis during yeast and mycelial modes of growth, and peroxisome biogenesis. At least two of these secretory pathways, which are involved in the export of proteins to the external medium and in the delivery of proteins for assembly of the peroxisomal membrane, diverge at the level of the endoplasmic reticulum. PMID:9271399

  17. Isoprenoid Biosynthesis. Metabolite Profiling of Peppermint Oil Gland Secretory Cells and Application to Herbicide Target Analysis1

    PubMed Central

    Lange, B. Markus; Ketchum, Raymond E.B.; Croteau, Rodney B.

    2001-01-01

    Two independent pathways operate in plants for the synthesis of isopentenyl diphosphate and dimethylallyl diphosphate, the central intermediates in the biosynthesis of all isoprenoids. The mevalonate pathway is present in the cytosol, whereas the recently discovered mevalonate-independent pathway is localized to plastids. We have used isolated peppermint (Mentha piperita) oil gland secretory cells as an experimental model system to study the effects of the herbicides fosmidomycin, phosphonothrixin, methyl viologen, benzyl viologen, clomazone, 2-(dimethylamino)ethyl diphosphate, alendronate, and pamidronate on the pools of metabolites related to monoterpene biosynthesis via the mevalonate-independent pathway. A newly developed isolation protocol for polar metabolites together with an improved separation and detection method based on liquid chromatography-mass spectrometry have allowed assessment of the enzyme targets for a number of these herbicides. PMID:11553758

  18. Isolation of a sesquiterpene synthase expressing in specialized epithelial cells surrounding the secretory cavities in rough lemon (Citrus jambhiri).

    PubMed

    Uji, Yuya; Ozawa, Rika; Shishido, Hodaka; Taniguchi, Shiduku; Takabayashi, Junji; Akimitsu, Kazuya; Gomi, Kenji

    2015-05-15

    Volatile terpenoids such as monoterpenes and sesquiterpenes play multiple roles in plant responses and are synthesized by terpene synthases (TPSs). We have previously isolated a partial TPS gene, RlemTPS4, that responds to microbial attack in rough lemon. In this study, we isolated a full length RlemTPS4 cDNA from rough lemon. RlemTPS4 localized in the cytosol. The recombinant RlemTPS4 protein was obtained using a prokaryotic expression system and GC-MS analysis of the terpenes produced by the RlemTPS4 enzymatic reaction determined that RlemTPS4 produces some sesquiterpenes such as δ-elemene. The RlemTPS4 gene was specifically expressed in specialized epithelial cells surrounding the oil secretory cavities in rough lemon leaf tissue.

  19. Prohormone processing in the trans-Golgi network: endoproteolytic cleavage of prosomatostatin and formation of nascent secretory vesicles in permeabilized cells

    PubMed Central

    1993-01-01

    Many peptide hormones are synthesized as larger precursors which undergo endoproteolytic cleavage at paired basic residues to generate a bioactive molecule. Morphological evidence from several laboratories has implicated either the TGN or immature secretory granules as the site of prohormone cleavage. To identify the site where prohormone cleavage is initiated, we have used retrovirally infected rat anterior pituitary GH3 cells which express high levels of prosomatostatin (proSRIF) (Stoller, T. J., and D. Shields. J. Cell Biol. 1988. 107:2087- 2095). By incubating these cells at 20 degrees C, a temperature that prevents exit from the Golgi apparatus, proSRIF accumulated quantitatively in the TGN and no proteolytic processing was evident; processing resumed upon shifting the cells back to 37 degrees C. After the 20 degrees C block, the cells were mechanically permeabilized and pro-SRIF processing determined. Cleavage of proSRIF to the mature hormone was approximately 35-50% efficient, required incubation at 37 degrees C and ATP hydrolysis, but was independent of GTP or cytosol. The in vitro ATP-dependent proSRIF processing was inhibited by inclusion of chloroquine, a weak base, CCCP, a protonophore, or by preincubating the permeabilized cells with low concentrations of N- ethylmaleimide, an inhibitor of vacuolar-type ATP-dependent proton pumps. These data suggest that: (a) proSRIF cleavage is initiated in the TGN, and (b) this reaction requires an acidic pH which is facilitated by a Golgi-associated vacuolar-type ATPase. A characteristic feature of polypeptide hormone-producing cells is their ability to store the mature hormone in dense core secretory granules. To investigate the mechanism of protein sorting to secretory granules, the budding of nascent secretory vesicles from the TGN was determined. No vesicle formation occurred at 20 degrees C; in contrast, at 37 degrees C, the budding of secretory vesicles was approximately 40% efficient and was dependent on ATP

  20. Pob1 ensures cylindrical cell shape by coupling two distinct rho signaling events during secretory vesicle targeting.

    PubMed

    Nakano, Kentaro; Toya, Mika; Yoneda, Aki; Asami, Yukiko; Yamashita, Akira; Kamasawa, Naomi; Osumi, Masako; Yamamoto, Masayuki

    2011-06-01

    Proper cell morphogenesis requires the co-ordination of cell polarity, cytoskeletal organization and vesicle trafficking. The Schizosaccharomyces pombe mutant pob1-664 has a curious lemon-like shape, the basis of which is not understood. Here, we found abundant vesicle accumulation in these cells, suggesting that Pob1 plays a role in vesicle trafficking. We identified Rho3 as a multicopy suppressor of this phenotype. Because Rho3 function is related to For3, an actin-polymerizing protein, and Sec8, a component of the exocyst complex, we analyzed their functional relationship with Pob1. Pob1 was essential for the formation of actin cables (by interacting with For3) and for the polarized localization of Sec8. Although neither For3 nor Sec8 is essential for polarized growth, their simultaneous disruption prevented tip growth and yielded a lemon-like cell morphology similar to pob1-664. Thus, Pob1 may ensure cylindrical cell shape of S. pombe by coupling actin-mediated vesicle transport and exocyst-mediated vesicle tethering during secretory vesicle targeting.

  1. Involvement of conventional kinesin in glucose-stimulated secretory granule movements and exocytosis in clonal pancreatic beta-cells.

    PubMed

    Varadi, Aniko; Ainscow, Edward K; Allan, Victoria J; Rutter, Guy A

    2002-11-01

    Recruitment of secretory vesicles to the cell surface is essential for the sustained secretion of insulin in response to glucose. At present, the molecular motors involved in this movement, and the mechanisms whereby they may be regulated, are undefined. To investigate the role of kinesin family members, we labelled densecore vesicles in clonal beta-cells using an adenovirally expressed, vesicle-targeted green fluorescent protein (phogrin.EGFP), and employed immunoadsorption to obtain highly purified insulin-containing vesicles. Whereas several kinesin family members were expressed in this cell type, only conventional kinesin heavy chain (KHC) was detected in vesicle preparations. Expression of a dominant-negative KHC motor domain (KHC(mut)) blocked all vesicular movements with velocity >0.4 micro m second(-1), which demonstrates that kinesin activity was essential for vesicle motility in live beta-cells. Moreover, expression of KHC(mut) strongly inhibited the sustained, but not acute, stimulation of secretion by glucose. Finally, vesicle movement was stimulated by ATP dose-dependently in permeabilized cells, which suggests that glucose-induced increases in cytosolic [ATP] mediate the effects of the sugar in vivo, by enhancing kinesin activity. These data therefore provide evidence for a novel mechanism whereby glucose may enhance insulin release.

  2. Co-distribution of glycoconjugates and H(+), K(+)-ATPase in the parietal cells of the greater horseshoe bat, Rhinolophus ferrumequinum (Schreber, 1774).

    PubMed

    Scillitani, Giovanni; Mastrodonato, Maria; Liquori, Giuseppa Esterina; Ferri, Domenico

    2010-05-01

    Histochemical, lectin-histochemical, and immunohistochemical analyses were performed on parietal cells of the greater horseshoe bat, Rhinolophus ferrumequinum, to clarify the composition and distribution of oligosaccharide chains in the beta-subunit of the protonic pump H(+),K(+)-ATPase. PAS, Alcian Blue (pH 2.5) and Alcian Blue (pH 1.0) stainings detected only neutral glycoconjugates. Lectin-binding analyses included LTA, UEA-I, ConA, SBA, BSI-B4, AAA, DBA, PNA, and WGA. WGA-and PNA-bindings were also tested after beta-elimination to detect O-linked glycans. Parietal cells were negative for binding to LTA and UEA-I, and to PNA and WGA after beta-elimination, indicating the lack of (1,2) fucosylated residues and of N-linked glycans, respectively. Immunohistochemical tests with anti-alpha- and anti-beta-H(+),K(+)-ATPase were positive. Two alternative patterns of glycoconjugate distribution were found, i.e. a perinuclear and a diffuse one, indicating localization in the intracellular canaliculus and in the tubulovesicular system of the parietal cells, respectively. Both the subunits of the H(+),K(+)-ATPase and the galactosyl/galactosaminyl residues were co-distributed in both the perinuclear and the diffuse patterns, suggesting that the residues are part of the protonic pump. Glycosyl/glycosaminyl and mannosyl groups were concentrated in the tubulovesicular system, and fucosylated residues were found almost exclusively in the intracellular canaliculi; thus they are probably not included in the oligosaccharide chains of beta-H(+),K(+)-ATPase. These findings indicate that the oligosaccharide chains linked to the beta-H(+),K(+)-ATPase subunit in R. ferrumequinum have distinct features compared to the other mammals studied and confirms the taxon specificity of the chains in the proton pump.

  3. Proteomic identification of potential Clonorchis sinensis excretory/secretory products capable of binding and activating human hepatic stellate cells.

    PubMed

    Wang, Xiaoyun; Hu, Fengyu; Hu, Xuchu; Chen, Wenjun; Huang, Yan; Yu, Xinbing

    2014-08-01

    Epidemiological and experimental evidence demonstrated that Clonorchis sinensis is an important risk factor of hepatic fibrosis and cholangiocarcinoma. C. sinensis excretory/secretory products (CsESPs) are protein complex including proteases, antioxidant enzymes, and metabolic enzymes, which may contribute to pathogenesis of liver fluke-associated hepatobiliary diseases. However, potential CsESP candidates involved into hepatic fibrosis and cholangiocarcinoma still remain to be elucidated. In the present study, we performed proteomic identification of CsESP candidates capable of binding and activating human hepatic stellate cell line LX-2. Immunofluorescence analysis confirmed the interaction of CsESPs with LX-2 cell membrane. LX-2 cells could be stimulated by CsESPs from 24 h post incubation (p < 0.05). Specifically, 50 μg/ml of CsESPs showed the strongest effect on cell proliferation in methyl thiazolyl tetrazolium (MTT) assay which could also be demonstrated by flow cytometry analysis (p < 0.01). Furthermore, expression level of human type III collagen in LX-2 cells treated with CsESPs was significantly higher than that in control cells measured by molecular beacon and semiquantitative reverse transcription (RT)-PCR approaches (p < 0.01). Finally, CsESPs before and after incubation with LX-2 cells were subjected to two-dimensional gel electrophoresis (2-DE) analysis and matrix associated laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry analysis. Nine proteins with abundance change above threefold were Rho GTPase-activating protein, mitochondrial cytochrome c oxidase subunit Va, α-enolase, phospholipase C, interleukin-15, insect-derived growth factor, cytochrome c oxidase subunit VI, DNAH1 protein, and kinesin light chain. Taken together, we identified potential CsESP candidates capable of binding and activating human hepatic stellate cells, providing more direct evidences that are previously unknown to accelerate strategies

  4. Effects of mastoparan upon the late stages of the ACTH secretory pathway of AtT-20 cells.

    PubMed Central

    McFerran, B. W.; Guild, S. B.

    1995-01-01

    1. The mouse AtT-20/D16-16 anterior pituitary tumour cell line was used as a model system for the study of the effects of mastoparan upon the late stages of the adrenocorticotrophin (ACTH) secretory pathway. 2. Mastoparan (10(-8)-10(-5) M), an activator of heterotrimeric guanosine 5'-triphosphate binding proteins (G-proteins), stimulated ACTH secretion from electrically-permeabilized AtT-20 cells in a concentration-dependent manner in the effective absence of calcium ions with a threshold of 10(-6) M. Guanosine 5'-O-(3-thiotriphosphate) (GTP-gamma-S) (10(-8)-10(-4) M) also stimulated ACTH secretion from electrically-permeabilized AtT-20 cells in a concentration-dependent manner in the effective absence of calcium ions with a threshold of 10(-6) M. This GTP-gamma-S-evoked secretion is consistent with previous studies which demonstrated that a G-protein, termed GE, mediates calcium evoked ACTH secretion from AtT-20 cells. GTP-gamma-S-evoked secretion however was not as great as that obtained in response to mastoparan. 3. Both mastoparan (10(-5) M) and GTP-gamma-S (10(-4) M) stimulated ACTH secretion from electrically-permeabilized AtT20 cells in a time-dependent manner. A time of 30 min was adopted as the standard incubation period for the study of both mastoparan and GTP-gamma-S-stimulated ACTH secretion from permeabilized AtT-20 cells. 4. Mastoparan (10(-8)-10(-5) M) stimulated ACTH secretion from permeabilized AtT-20 cells to the same extent in the presence and absence of the protein kinase C (PKC) inhibitor, chelerythrine chloride (10(-5) M).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7582493

  5. Effect of oral N-acetylcysteine (NAC) on volume and albumin content of respiratory tract fluid but not on epithelial secretory cell number in "smoking" rats.

    PubMed

    Robinson, N; Brattsand, R; Dahlbäck, M

    1990-03-01

    This study was designed to look at the effect of N-acetylcysteine (NAC) on epithelial secretory cells and the respiratory tract fluid volume and albumin content from the lower airways of "bronchitic" rats. Rats were exposed either to tobacco smoke (TS), TS and NAC, or NAC alone. TS caused a significant increase in epithelial secretory cell number which was not reduced by concomitant NAC administration; NAC alone had no effect on cell numbers. TS increased respiratory tract fluid volume and albumin content by a small but non-significant amount, whereas TS and NAC increased the volume and albumin content by a greater and significant amount; NAC alone was also shown to significantly increase both fluid volume and albumin content. PMID:2340888

  6. Effect of oral N-acetylcysteine (NAC) on volume and albumin content of respiratory tract fluid but not on epithelial secretory cell number in "smoking" rats.

    PubMed

    Robinson, N; Brattsand, R; Dahlbäck, M

    1990-03-01

    This study was designed to look at the effect of N-acetylcysteine (NAC) on epithelial secretory cells and the respiratory tract fluid volume and albumin content from the lower airways of "bronchitic" rats. Rats were exposed either to tobacco smoke (TS), TS and NAC, or NAC alone. TS caused a significant increase in epithelial secretory cell number which was not reduced by concomitant NAC administration; NAC alone had no effect on cell numbers. TS increased respiratory tract fluid volume and albumin content by a small but non-significant amount, whereas TS and NAC increased the volume and albumin content by a greater and significant amount; NAC alone was also shown to significantly increase both fluid volume and albumin content.

  7. Differentiation of Mucilage Secretory Cells of the Arabidopsis Seed Coat1

    PubMed Central

    Western, Tamara L.; Skinner, Debra J.; Haughn, George W.

    2000-01-01

    In some plant species, including Arabidopsis, fertilization induces the epidermal cells of the outer ovule integument to differentiate into a specialized seed coat cell type with a unique morphology and containing large quantities of polysaccharide mucilage (pectin). Such seed coat mucilage cells are necessary for neither viability nor germination under normal laboratory conditions. Thus, the Arabidopsis seed coat offers a unique system with which to use genetics to identify genes controlling cell morphogenesis and complex polysaccharide biosynthesis and secretion. As a first step in the application of this system, we have used microscopy to investigate the structure and differentiation of Arabidopsis seed coat mucilage cells, including cell morphogenesis and the synthesis, secretion, and extrusion of mucilage. During seed coat development in Arabidopsis, the epidermal cells of the outer ovule integument grow and differentiate into cells that produce large quantities of mucilage between the primary cell wall and plasma membrane. Concurrent with mucilage production, the cytoplasm is shaped into a column in the center of the cell. Following mucilage secretion the cytoplasmic column is surrounded by a secondary cell wall to form a structure known as the columella. Thus, differentiation of the seed coat mucilage cells involves a highly regulated series of events including growth, morphogenesis, mucilage biosynthesis and secretion, and secondary cell wall synthesis. PMID:10677428

  8. Histological characterization of the special venom secretory cells in the stinger of rays in the northern waters of Persian Gulf and Oman Sea.

    PubMed

    Dehghani, Hadi; Sajjadi, Mir Masoud; Parto, Paria; Rajaian, Hamid; Mokhlesi, Amin

    2010-06-01

    Rays are common elasmobranches in the northern waters of Persian Gulf and Oman Sea that may have one or more mineralized serrated stingers on the whip-like tail. The stingers are covered by epidermal cells among which some can produce venom. When these animals are dorsally touched, the stinger can be introduced into the aggressor by a whip reflex mechanism of the tail when the pectoral fins are touched, causing severe mechanical injuries and inoculating the venom. The exact localization of the venom secretory cells in the stinger of different species is controversial, but it is known that the cells are preferentially located in the ventro-lateral grooves in marine stingrays. A comparative morphological characterization of the stinger epidermal tissue of different ray species in the northern part of Persian Gulf and Oman Sea was carried out in this study. EDTA was used for decalcification of stings and conventional histological processes were subsequently employed. The results indicated that structure of dermis and epidermis layers of stings in all species are similar to the structure of corresponding layers in other parts of fish's body. The results of the present study have shown that all examined species of Dasyatidae family, but not Myliobatidae and Gymnuridae families, had venom secretory cells. Distribution of venom secretory cells varies in each species and is often located around or inside the stinger ventro-lateral grooves. These differences among the stingers of various species may explain the envenomation severity in these species.

  9. Proteomic Analysis of Excretory-Secretory Products of Mesocestoides corti Metacestodes Reveals Potential Suppressors of Dendritic Cell Functions

    PubMed Central

    Vendelova, Emilia; Camargo de Lima, Jeferson; Lorenzatto, Karina Rodrigues; Monteiro, Karina Mariante; Mueller, Thomas; Veepaschit, Jyotishman; Grimm, Clemens; Brehm, Klaus; Hrčková, Gabriela; Lutz, Manfred B.; Ferreira, Henrique B.

    2016-01-01

    Accumulating evidences have assigned a central role to parasite-derived proteins in immunomodulation. Here, we report on the proteomic identification and characterization of immunomodulatory excretory-secretory (ES) products from the metacestode larva (tetrathyridium) of the tapeworm Mesocestoides corti (syn. M. vogae). We demonstrate that ES products but not larval homogenates inhibit the stimuli-driven release of the pro-inflammatory, Th1-inducing cytokine IL-12p70 by murine bone marrow-derived dendritic cells (BMDCs). Within the ES fraction, we biochemically narrowed down the immunosuppressive activity to glycoproteins since active components were lipid-free, but sensitive to heat- and carbohydrate-treatment. Finally, using bioassay-guided chromatographic analyses assisted by comparative proteomics of active and inactive fractions of the ES products, we defined a comprehensive list of candidate proteins released by M. corti tetrathyridia as potential suppressors of DC functions. Our study provides a comprehensive library of somatic and ES products and highlight some candidate parasite factors that might drive the subversion of DC functions to facilitate the persistence of M. corti tetrathyridia in their hosts. PMID:27736880

  10. Modulation of dendritic cell function by the radiation-mediated secretory protein γ-synuclein

    PubMed Central

    Kang, S-M; Kim, M-H; Song, K-H; Jung, S-Y; Ahn, J; Hwang, S-G; Lee, J-H; Lim, D-S; Song, J-Y

    2015-01-01

    Recently, γ-synuclein (SNCG), which is also known as breast cancer-specific gene-1, has been demonstrated to be an adverse and aggressive marker in breast cancer. In our previous study, SNCG was significantly upregulated in irradiated human breast cancer cells. The aim of this study was to investigate whether radiation-induced, tumor-derived SNCG can influence dendritic cell (DC) function in immune systems. The phenotypical and functional changes of DCs in the presence or absence of SNCG were investigated by FACS analysis, ELISA, and real-time PCR. The ability of SNCG-treated DCs to influence T cells was also examined by coculturing with T cells. The treatment of DCs with SNCG protein inhibited the surface expression of the co-stimulatory molecules CD40 and CD86, and decreased the mRNA levels of pro-inflammatory cytokines. The SNCG-treated DCs inhibited T-cell proliferation slightly, but distinctively increased the population of regulatory T cells. In addition, the production of TGF-β from T cells was significantly increased when they were cocultured with SNCG-treated DCs. Taken together, these results demonstrate that tumor-derived SNCG contributes to immunosuppressive effects via the inhibition of DC differentiation and activation, thus making it a potential target for cancer treatment. PMID:27551446

  11. MicroRNA-34a Induces Vascular Smooth Muscle Cells Senescence by SIRT1 Downregulation and Promotes the Expression of Age-Associated Pro-inflammatory Secretory Factors.

    PubMed

    Badi, Ileana; Burba, Ilaria; Ruggeri, Clarissa; Zeni, Filippo; Bertolotti, Matteo; Scopece, Alessandro; Pompilio, Giulio; Raucci, Angela

    2015-11-01

    Arterial aging is a major risk factor for the occurrence of cardiovascular diseases. The aged artery is characterized by endothelial dysfunction and vascular smooth muscle cells altered physiology together with low-grade chronic inflammation. MicroRNA-34a (miR-34a) has been recently implicated in cardiac, endothelial, and endothelial progenitor cell senescence; however, its contribution to aging-associated vascular smooth muscle cells phenotype has not been explored so far. We found that miR-34a was highly expressed in aortas isolated from old mice. Moreover, its well-known target, the longevity-associated protein SIRT1, was significantly downregulated during aging in both endothelial cells and vascular smooth muscle cells. Increased miR-34a as well as decreased SIRT1 expression was also observed in replicative-senescent human aortic smooth muscle cells. miR-34a overexpression in proliferative human aortic smooth muscle cells caused cell cycle arrest along with enhanced p21 protein levels and evidence of cell senescence. Furthermore, miR-34a ectopic expression induced pro-inflammatory senescence-associated secretory phenotype molecules. Finally, SIRT1 protein significantly decreased upon miR-34a overexpression and restoration of its levels rescued miR-34a-dependent human aortic smooth muscle cells senescence, but not senescence-associated secretory phenotype factors upregulation. Taken together, our findings suggest that aging-associated increase of miR-34a expression levels, by promoting vascular smooth muscle cells senescence and inflammation through SIRT1 downregulation and senescence-associated secretory phenotype factors induction, respectively, may lead to arterial dysfunctions.

  12. Isolation and Characterization of Mutants Defective in Seed Coat Mucilage Secretory Cell Development in Arabidopsis1

    PubMed Central

    Western, Tamara L.; Burn, Joanne; Tan, Wei Ling; Skinner, Debra J.; Martin-McCaffrey, Luke; Moffatt, Barbara A.; Haughn, George W.

    2001-01-01

    In Arabidopsis, fertilization induces the epidermal cells of the outer ovule integument to differentiate into a specialized seed coat cell type producing extracellular pectinaceous mucilage and a volcano-shaped secondary cell wall. Differentiation involves a regulated series of cytological events including growth, cytoplasmic rearrangement, mucilage synthesis, and secondary cell wall production. We have tested the potential of Arabidopsis seed coat epidermal cells as a model system for the genetic analysis of these processes. A screen for mutants defective in seed mucilage identified five novel genes (MUCILAGE-MODIFIED [MUM]1–5). The seed coat development of these mutants, and that of three previously identified ones (TRANSPARENT TESTA GLABRA1, GLABRA2, and APETALA2) were characterized. Our results show that the genes identified define several events in seed coat differentiation. Although APETALA2 is needed for differentiation of both outer layers of the seed coat, TRANSPARENT TESTA GLABRA1, GLABRA2, and MUM4 are required for complete mucilage synthesis and cytoplasmic rearrangement. MUM3 and MUM5 may be involved in the regulation of mucilage composition, whereas MUM1 and MUM2 appear to play novel roles in post-synthesis cell wall modifications necessary for mucilage extrusion. PMID:11706181

  13. Macrophage secretory products selectively stimulate dermatan sulfate proteoglycan production in cultured arterial smooth muscle cells

    SciTech Connect

    Edwards, I.J.; Wagner, W.D.; Owens, R.T. )

    1990-03-01

    Arterial dermatan sulfate proteoglycan has been shown to increase with atherosclerosis progression, but factors responsible for this increase are unknown. To test the hypothesis that smooth muscle cell proteoglycan synthesis may be modified by macrophage products, pigeon arterial smooth muscle cells were exposed to the media of either cholesteryl ester-loaded pigeon peritoneal macrophages or a macrophage cell line P388D1. Proteoglycans radiolabeled with (35S)sulfate and (3H)serine were isolated from culture media and smooth muscle cells and purified following precipitation with 1-hexadecylpyridinium chloride and chromatography. Increasing concentrations of macrophage-conditioned media were associated with a dose-response increase in (35S)sulfate incorporation into secreted proteoglycans, but there was no change in cell-associated proteoglycans. Incorporation of (3H)serine into total proteoglycan core proteins was not significantly different (5.2 X 10(5) dpm and 5.5 X 10(5) disintegrations per minute (dpm) in control and conditioned media-treated cultures, respectively), but selective effects were observed on individual proteoglycan types. Twofold increases in dermatan sulfate proteoglycan and limited degradation of chondroitin sulfate proteoglycan were apparent based on core proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Immunoinhibition studies indicated that interleukin-1 was involved in the modulation of proteoglycan synthesis by macrophage-conditioned media. These data provide support for the role of macrophages in alteration of the matrix proteoglycans synthesized by smooth muscle cells and provide a mechanism to account for the reported increased dermatan sulfate/chondroitin sulfate ratios in the developing atherosclerotic lesion.

  14. Regulation of gene expression and secretory functions in oxygen-sensing pheochromocytoma cells.

    PubMed

    Conforti, L; Kobayashi, S; Beitner-Johnson, D; Conrad, P W; Freeman, T; Millhorn, D E

    1999-04-01

    The cellular response to hypoxia is complex. Specialized oxygen chemosensitive cells that are excitable respond to reduced O2 by membrane depolarization, altered gene expression, and neurotransmitter secretion. We have used the O2-sensitive pheochromocytoma (PC12) cell line to investigate the cellular response to hypoxia. Here, we present evidence that membrane depolarization and increased intracellular free Ca2+ are major regulatory events in these cells. Membrane depolarization is mediated by the inhibition of a slow-inactivating voltage-dependent potassium (K) channel. Evidence from molecular biology and patch-clamp studies indicate that the O2-sensitive K channel is a member of the Kv1 family. We also reviewed findings on the regulation of gene expression in PC12 cells during hypoxia. An increase in intracellular free Ca2+ is required for hypoxia-induced transcription of a number of genes including tyrosine hydroxylase (TH), the rate-limiting enzyme in the synthesis of catecholamine neurotransmitters, and several of the immediate early genes. We also reviewed the role of dopamine (DA) and adenosine (ADO) receptors in regulation of membrane depolarization and gene expression. PMID:10385038

  15. Bisphenol A modulates receptivity and secretory function of human decidual cells: an in vitro study.

    PubMed

    Mannelli, Chiara; Szóstek, Anna Z; Lukasik, Karolina; Carotenuto, Claudiopietro; Ietta, Francesca; Romagnoli, Roberta; Ferretti, Cristina; Paulesu, Luana; Wołczynski, Slawomir; Skarzynski, Dariusz Jan

    2015-08-01

    The human endometrium is a fertility-determining tissue and a target of steroid hormones' action. Endocrine disruptors (EDs) can exert adverse effects on the physiological function of the decidua at the maternal-fetal interface. We examined the potential effects of an ED, bisphenol A (BPA), on endometrial maturation/decidualization, receptivity, and secretion of decidual factors (biomarkers). In vitro decidualized, endometrial stromal cells from six hysterectomy specimens were treated with 1  pM-1  μM of BPA, for 24  h and assessed for cell viability and proliferation. Three non-toxic concentrations of BPA (1  μM, 1  nM, and 1  pM) were selected to study its influence on secretion of cell decidualization biomarkers (IGF-binding protein and decidual prolactin (dPRL)), macrophage migration inhibitory factor (MIF) secretion, and hormone receptors' expression (estrogen receptors (ERα and ERβ); progesterone receptors (PRA and PRB); and human chorionic gonadotropin (hCG)/LH receptor (LH-R)). The results showed a decrease in cell viability (P<0.001) in response to BPA at the level of 1  mM. At the non-toxic concentrations used, BPA perturbed the expression of ERα, ERβ, PRA, PRB, and hCG/LH-R (P<0.05). Furthermore, 1  μM of BPA reduced the mRNA transcription of dPRL (P<0.05). Secretion of MIF was stimulated by all BPA treatments, the lowest concentration (1  pM) being the most effective (P<0.001). The multi-targeted disruption of BPA on decidual cells, at concentrations commonly detected in the human population, raises great concern about the possible consequences of exposure to BPA on the function of decidua and thus its potential deleterious effect on pregnancy. PMID:26021997

  16. In situ localization of gene transcriptions for monoterpene synthesis in irregular parenchymic cells surrounding the secretory cavities in rough lemon (Citrus jambhiri).

    PubMed

    Yamasaki, Yumiko; Akimitsu, Kazuya

    2007-11-01

    A cDNA (RlemispF) encoding 2-C-methyl-d-erythritol 2,4-cyclodiphosphate synthase, an enzyme of the methyl erythritol phosphate (MEP) pathway, and two homologs (RlemTPS1 and RlemTPS2) of citrus monoterpene synthase cDNA were isolated from the rough lemon (Citrus jambhiri). Transient localization of all or a part of RlemispF fused to a green fluorescence protein using particle gun-mediated DNA delivery localized RlemispF in the chloroplast. Transcripts of RlemispF and other monoterpene synthase genes are constitutively expressed in leaves of rough lemon. Transcript accumulations of RlemispF and RlemTPS1 were not induced by microbe attacks, but microbe attack weakly induced RlemTPS2 expression. Wounding decreased RlemispF expression. RlemispF and two different monoterpene synthase genes were specifically expressed in the epithelial tissue cells with dense cytoplasm that surround secretory cavities, which form a broadly round package containing a large volume of essential oils composed of monoterpenes. Interestingly, although expressions of RlemTPS1 and RlemTPS2 were detected at both mature and developing secretory cavities, the RlemispF-expressing cells were found more at around developing secretory cavities.

  17. [NUCLEAR STRUCTURE IN THE SECRETORY CELLS OF MAMMARY GLANDS IN LACTATING AND NON-LACTATING RATS].

    PubMed

    Tyutina, K V; Skopichev, V G; Bogolyubov, D S; Bogolyubova, I O

    2016-01-01

    The features of structural and functional organization of the main nuclear compartments and distribution of their key molecular components (chromatin-remodeling protein ATRX, RNA polymerase I and II, and the splicing factor SC35) has been studied in the nuclei of mammary gland cells at different functional states. No significant differences between the nuclei of the cells in the lactating and non-lactating mammary glands have been revealed at the ultrastructural level. At the same time, photometric analysis has revealed higher intensity of nucleoplasmic immunofluorescent staining of mammary glands in the lactating animals when antibodies against the proteins ATRX and SC35 were used. Apparently, this observation reflects the changes of the structural and functional status of chromatin as well as the redistribution of splicing factors between the sites of their deposition and transcription. PMID:27228661

  18. Melanoma cell lysosome secretory burst neutralizes the CTL-mediated cytotoxicity at the lytic synapse

    PubMed Central

    Khazen, Roxana; Müller, Sabina; Gaudenzio, Nicolas; Espinosa, Eric; Puissegur, Marie-Pierre; Valitutti, Salvatore

    2016-01-01

    Human melanoma cells express various tumour antigens that are recognized by CD8+ cytotoxic T lymphocytes (CTLs) and elicit tumour-specific responses in vivo. However, natural and therapeutically enhanced CTL responses in melanoma patients are of limited efficacy. The mechanisms underlying CTL effector phase failure when facing melanomas are still largely elusive. Here we show that, on conjugation with CTL, human melanoma cells undergo an active late endosome/lysosome trafficking, which is intensified at the lytic synapse and is paralleled by cathepsin-mediated perforin degradation and deficient granzyme B penetration. Abortion of SNAP-23-dependent lysosomal trafficking, pH perturbation or impairment of lysosomal proteolytic activity restores susceptibility to CTL attack. Inside the arsenal of melanoma cell strategies to escape immune surveillance, we identify a self-defence mechanism based on exacerbated lysosome secretion and perforin degradation at the lytic synapse. Interfering with this synaptic self-defence mechanism might be useful in potentiating CTL-mediated therapies in melanoma patients. PMID:26940455

  19. Identification of Pathways in Liver Repair Potentially Targeted by Secretory Proteins from Human Mesenchymal Stem Cells

    PubMed Central

    Winkler, Sandra; Hempel, Madlen; Brückner, Sandra; Tautenhahn, Hans-Michael; Kaufmann, Roland; Christ, Bruno

    2016-01-01

    Background: The beneficial impact of mesenchymal stem cells (MSC) on both acute and chronic liver diseases has been confirmed, although the molecular mechanisms behind it remain elusive. We aim to identify factors secreted by undifferentiated and hepatocytic differentiated MSC in vitro in order to delineate liver repair pathways potentially targeted by MSC. Methods: Secreted factors were determined by protein arrays and related pathways identified by biomathematical analyses. Results: MSC from adipose tissue and bone marrow expressed a similar pattern of surface markers. After hepatocytic differentiation, CD54 (intercellular adhesion molecule 1, ICAM-1) increased and CD166 (activated leukocyte cell adhesion molecule, ALCAM) decreased. MSC secreted different factors before and after differentiation. These comprised cytokines involved in innate immunity and growth factors regulating liver regeneration. Pathway analysis revealed cytokine-cytokine receptor interactions, chemokine signalling pathways, the complement and coagulation cascades as well as the Januskinase-signal transducers and activators of transcription (JAK-STAT) and nucleotide-binding oligomerization domain-like receptor (NOD-like receptor) signalling pathways as relevant networks. Relationships to transforming growth factor β (TGF-β) and hypoxia-inducible factor 1-α (HIF1-α) signalling seemed also relevant. Conclusion: MSC secreted proteins, which differed depending on cell source and degree of differentiation. The factors might address inflammatory and growth factor pathways as well as chemo-attraction and innate immunity. Since these are prone to dysregulation in most liver diseases, MSC release hepatotropic factors, potentially supporting liver regeneration. PMID:27409608

  20. Matrix stiffness-modulated proliferation and secretory function of the airway smooth muscle cells.

    PubMed

    Shkumatov, Artem; Thompson, Michael; Choi, Kyoung M; Sicard, Delphine; Baek, Kwanghyun; Kim, Dong Hyun; Tschumperlin, Daniel J; Prakash, Y S; Kong, Hyunjoon

    2015-06-01

    Multiple pulmonary conditions are characterized by an abnormal misbalance between various tissue components, for example, an increase in the fibrous connective tissue and loss/increase in extracellular matrix proteins (ECM). Such tissue remodeling may adversely impact physiological function of airway smooth muscle cells (ASMCs) responsible for contraction of airways and release of a variety of bioactive molecules. However, few efforts have been made to understand the potentially significant impact of tissue remodeling on ASMCs. Therefore, this study reports how ASMCs respond to a change in mechanical stiffness of a matrix, to which ASMCs adhere because mechanical stiffness of the remodeled airways is often different from the physiological stiffness. Accordingly, using atomic force microscopy (AFM) measurements, we found that the elastic modulus of the mouse bronchus has an arithmetic mean of 23.1 ± 14 kPa (SD) (median 18.6 kPa). By culturing ASMCs on collagen-conjugated polyacrylamide hydrogels with controlled elastic moduli, we found that gels designed to be softer than average airway tissue significantly increased cellular secretion of vascular endothelial growth factor (VEGF). Conversely, gels stiffer than average airways stimulated cell proliferation, while reducing VEGF secretion and agonist-induced calcium responses of ASMCs. These dependencies of cellular activities on elastic modulus of the gel were correlated with changes in the expression of integrin-β1 and integrin-linked kinase (ILK). Overall, the results of this study demonstrate that changes in matrix mechanics alter cell proliferation, calcium signaling, and proangiogenic functions in ASMCs.

  1. Matrix stiffness-modulated proliferation and secretory function of the airway smooth muscle cells

    PubMed Central

    Shkumatov, Artem; Thompson, Michael; Choi, Kyoung M.; Sicard, Delphine; Baek, Kwanghyun; Kim, Dong Hyun; Tschumperlin, Daniel J.; Prakash, Y. S.

    2015-01-01

    Multiple pulmonary conditions are characterized by an abnormal misbalance between various tissue components, for example, an increase in the fibrous connective tissue and loss/increase in extracellular matrix proteins (ECM). Such tissue remodeling may adversely impact physiological function of airway smooth muscle cells (ASMCs) responsible for contraction of airways and release of a variety of bioactive molecules. However, few efforts have been made to understand the potentially significant impact of tissue remodeling on ASMCs. Therefore, this study reports how ASMCs respond to a change in mechanical stiffness of a matrix, to which ASMCs adhere because mechanical stiffness of the remodeled airways is often different from the physiological stiffness. Accordingly, using atomic force microscopy (AFM) measurements, we found that the elastic modulus of the mouse bronchus has an arithmetic mean of 23.1 ± 14 kPa (SD) (median 18.6 kPa). By culturing ASMCs on collagen-conjugated polyacrylamide hydrogels with controlled elastic moduli, we found that gels designed to be softer than average airway tissue significantly increased cellular secretion of vascular endothelial growth factor (VEGF). Conversely, gels stiffer than average airways stimulated cell proliferation, while reducing VEGF secretion and agonist-induced calcium responses of ASMCs. These dependencies of cellular activities on elastic modulus of the gel were correlated with changes in the expression of integrin-β1 and integrin-linked kinase (ILK). Overall, the results of this study demonstrate that changes in matrix mechanics alter cell proliferation, calcium signaling, and proangiogenic functions in ASMCs. PMID:25724668

  2. Secretory and basal cells of the epithelium of the tubular glands in the male Mullerian gland of the caecilian Uraeotyphlus narayani (Amphibia: Gymnophiona).

    PubMed

    George, Jancy M; Smita, Matthew; Kadalmani, Balamuthu; Girija, Ramankutty; Oommen, Oommen V; Akbarsha, Mohammad A

    2004-12-01

    Caecilians are exceptional among the vertebrates in that males retain the Mullerian duct as a functional glandular structure. The Mullerian gland on each side is formed from a large number of tubular glands connecting to a central duct, which either connects to the urogenital duct or opens directly into the cloaca. The Mullerian gland is believed to secrete a substance to be added to the sperm during ejaculation. Thus, the Mullerian gland could function as a male accessory reproductive gland. Recently, we described the male Mullerian gland of Uraeotyphlus narayani using light and transmission electron microscopy (TEM) and histochemistry. The present TEM study reports that the secretory cells of both the tubular and basal portions of the tubular glands of the male Mullerian gland of this caecilian produce secretion granules in the same manner as do other glandular epithelial cells. The secretion granules are released in the form of structured granules into the lumen of the tubular glands, and such granules are traceable to the lumen of the central duct of the Mullerian gland. This is comparable to the situation prevailing in the epididymal epithelium of several reptiles. In the secretory cells of the basal portion of the tubular glands, mitochondria are intimately associated with fabrication of the secretion granules. The structural and functional organization of the epithelium of the basal portion of the tubular glands is complicated by the presence of basal cells. This study suggests the origin of the basal cells from peritubular tissue leukocytes. The study also indicates a role for the basal cells in acquiring secretion granules from the neighboring secretory cells and processing them into lipofuscin material in the context of regression of the Mullerian gland during the period of reproductive quiescence. In these respects the basal cells match those in the epithelial lining of the epididymis of amniotes.

  3. Secretory and basal cells of the epithelium of the tubular glands in the male Mullerian gland of the caecilian Uraeotyphlus narayani (Amphibia: Gymnophiona).

    PubMed

    George, Jancy M; Smita, Matthew; Kadalmani, Balamuthu; Girija, Ramankutty; Oommen, Oommen V; Akbarsha, Mohammad A

    2004-12-01

    Caecilians are exceptional among the vertebrates in that males retain the Mullerian duct as a functional glandular structure. The Mullerian gland on each side is formed from a large number of tubular glands connecting to a central duct, which either connects to the urogenital duct or opens directly into the cloaca. The Mullerian gland is believed to secrete a substance to be added to the sperm during ejaculation. Thus, the Mullerian gland could function as a male accessory reproductive gland. Recently, we described the male Mullerian gland of Uraeotyphlus narayani using light and transmission electron microscopy (TEM) and histochemistry. The present TEM study reports that the secretory cells of both the tubular and basal portions of the tubular glands of the male Mullerian gland of this caecilian produce secretion granules in the same manner as do other glandular epithelial cells. The secretion granules are released in the form of structured granules into the lumen of the tubular glands, and such granules are traceable to the lumen of the central duct of the Mullerian gland. This is comparable to the situation prevailing in the epididymal epithelium of several reptiles. In the secretory cells of the basal portion of the tubular glands, mitochondria are intimately associated with fabrication of the secretion granules. The structural and functional organization of the epithelium of the basal portion of the tubular glands is complicated by the presence of basal cells. This study suggests the origin of the basal cells from peritubular tissue leukocytes. The study also indicates a role for the basal cells in acquiring secretion granules from the neighboring secretory cells and processing them into lipofuscin material in the context of regression of the Mullerian gland during the period of reproductive quiescence. In these respects the basal cells match those in the epithelial lining of the epididymis of amniotes. PMID:15487004

  4. Landmark Control and Updating of Self-Movement Cues Are Largely Maintained in Head Direction Cells After Lesions of the Posterior Parietal Cortex

    PubMed Central

    Calton, Jeffrey L.; Turner, Carol S.; Cyrenne, De-Laine M.; Lee, Brian R.; Taube, Jeffrey S.

    2009-01-01

    Head direction (HD) cells discharge as a function of the rat’s directional orientation with respect to its environment. Because animals with posterior parietal cortex (PPC) lesions exhibit spatial and navigational deficits, and the PPC is indirectly connected to areas containing HD cells, we determined the effects of bilateral PPC lesions on HD cells recorded in the anterodorsal thalamus. HD cells from lesioned animals had similar firing properties compared to controls and their preferred firing directions shifted a corresponding amount following rotation of the major visual landmark. Because animals were not exposed to the visual landmark until after surgical recovery, these results provide evidence that the PPC is not necessary for visual landmark control or the establishment of landmark stability. Further, cells from lesioned animals maintained a stable preferred firing direction when they foraged in the dark and were only slightly less stable than controls when they self-locomoted into a novel enclosure. These findings suggest that PPC does not play a major role in the use of landmark and self-movement cues in updating the HD cell signal, or in its generation. PMID:18729636

  5. A multi-stage process including transient polyploidization and EMT precedes the emergence of chemoresistent ovarian carcinoma cells with a dedifferentiated and pro-inflammatory secretory phenotype

    PubMed Central

    Rohnalter, Verena; Roth, Katrin; Finkernagel, Florian; Adhikary, Till; Obert, Julia; Dorzweiler, Kristina; Bensberg, Maike; Müller-Brüsselbach, Sabine; Müller, Rolf

    2015-01-01

    DNA-damaging drugs induce a plethora of molecular and cellular alterations in tumor cells, but their interrelationship is largely obscure. Here, we show that carboplatin treatment of human ovarian carcinoma SKOV3 cells triggers an ordered sequence of events, which precedes the emergence of mitotic chemoresistant cells. The initial phase of cell death after initiation of carboplatin treatment is followed around day 14 by the emergence of a mixed cell population consisting of cycling, cell cycle-arrested and senescent cells. At this stage, giant cells make up >80% of the cell population, p21 (CDKN1A) in strongly induced, and cell numbers remain nearly static. Subsequently, cell death decreases, p21 expression drops to a low level and cell divisions increase, including regular mitoses of giant cells and depolyploidization by multi-daughter divisions. These events are accompanied by the upregulation of stemness markers and a pro-inflammatory secretory phenotype, peaking after approximately 14 days of treatment. At the same time the cells initiate epithelial to mesenchymal transition, which over the subsequent weeks continuously increases, concomitantly with the emergence of highly proliferative, migratory, dedifferentiated, pro-inflammatory and chemoresistant cells (SKOV3-R). These cells are anchorage-independent and grow in a 3D collagen matrix, while cells on day 14 do not survive under these conditions, indicating that SKOV3-R cells were generated thereafter by the multi-stage process described above. This process was essentially recapitulated with the ovarian carcinoma cell line IGROV-1. Our observations suggest that transitory cells characterized by polyploidy, features of stemness and a pro-inflammatory secretory phenotype contribute to the acquisition of chemoresistance. PMID:26503466

  6. Secretory Expression and Purification of Respiratory Syncytial Virus G and F Proteins in Human Cells.

    PubMed

    Jadhao, Samadhan J; Anderson, Larry J

    2016-01-01

    Respiratory syncytial virus (RSV) is one of the leading causes of range of symptoms from mild upper to serious lower respiratory virus infections in infants, immunocompromised individuals, and the elderly. Despite many decades of research and development, a licensed RSV vaccine is not available for use in human. Since the RSV F and G proteins induce neutralizing antibodies and confer protection from infection, they are important for understanding disease and for developing vaccines and access to purified, expressed proteins is important to RSV research and diagnostics. We describe methods to produce recombinant RSV F and G proteins in human cells and purify these proteins using Ni Sepharose affinity chromatography. PMID:27464687

  7. Far-infrared radiation inhibits proliferation, migration, and angiogenesis of human umbilical vein endothelial cells by suppressing secretory clusterin levels.

    PubMed

    Hwang, Soojin; Lee, Dong-Hoon; Lee, In-Kyu; Park, Young Mi; Jo, Inho

    2014-04-28

    Far-infrared (FIR) radiation is known to lessen the risk of angiogenesis-related diseases including cancer. Because deficiency of secretory clusterin (sCLU) has been reported to inhibit angiogenesis of endothelial cells (EC), we investigated using human umbilical vein EC (HUVEC) whether sCLU mediates the inhibitory effects of FIR radiation. Although FIR radiation ranging 3-25μm wavelength at room temperature for 60min did not alter EC viability, further incubation in the culture incubator (at 37°C under 5% CO2) after radiation significantly inhibited EC proliferation, in vitro migration, and tube formation in a time-dependent manner. Under these conditions, we found decreased sCLU mRNA and protein expression in HUVEC and decreased sCLU protein secreted in culture medium. Expectedly, the replacement of control culture medium with the FIR-irradiated conditioned medium significantly decreased wound closure and tube formation of HUVEC, and vice versa. Furthermore, neutralization of sCLU with anti-sCLU antibody also mimicked all observed inhibitory effects of FIR radiation. Moreover, treatment with recombinant human sCLU protein completely reversed the inhibitory effects of FIR radiation on EC migration and angiogenesis. Lastly, vascular endothelial growth factor also increased sCLU secretion in the culture medium, and wound closure and tube formation of HUVEC, which were significantly reduced by FIR radiation. Our results demonstrate a novel mechanism by which FIR radiation inhibits the proliferation, migration, and angiogenesis of HUVEC, via decreasing sCLU.

  8. COBRA-LIKE2, a member of the glycosylphosphatidylinositol-anchored COBRA-LIKE family, plays a role in cellulose deposition in arabidopsis seed coat mucilage secretory cells.

    PubMed

    Ben-Tov, Daniela; Abraham, Yael; Stav, Shira; Thompson, Kevin; Loraine, Ann; Elbaum, Rivka; de Souza, Amancio; Pauly, Markus; Kieber, Joseph J; Harpaz-Saad, Smadar

    2015-03-01

    Differentiation of the maternally derived seed coat epidermal cells into mucilage secretory cells is a common adaptation in angiosperms. Recent studies identified cellulose as an important component of seed mucilage in various species. Cellulose is deposited as a set of rays that radiate from the seed upon mucilage extrusion, serving to anchor the pectic component of seed mucilage to the seed surface. Using transcriptome data encompassing the course of seed development, we identified COBRA-LIKE2 (COBL2), a member of the glycosylphosphatidylinositol-anchored COBRA-LIKE gene family in Arabidopsis (Arabidopsis thaliana), as coexpressed with other genes involved in cellulose deposition in mucilage secretory cells. Disruption of the COBL2 gene results in substantial reduction in the rays of cellulose present in seed mucilage, along with an increased solubility of the pectic component of the mucilage. Light birefringence demonstrates a substantial decrease in crystalline cellulose deposition into the cellulosic rays of the cobl2 mutants. Moreover, crystalline cellulose deposition into the radial cell walls and the columella appears substantially compromised, as demonstrated by scanning electron microscopy and in situ quantification of light birefringence. Overall, the cobl2 mutants display about 40% reduction in whole-seed crystalline cellulose content compared with the wild type. These data establish that COBL2 plays a role in the deposition of crystalline cellulose into various secondary cell wall structures during seed coat epidermal cell differentiation. PMID:25583925

  9. siRNA knock-down of mutant torsinA restores processing through secretory pathway in DYT1 dystonia cells

    PubMed Central

    Hewett, Jeffrey W.; Nery, Flávia C.; Niland, Brian; Ge, Pei; Tan, Pamela; Hadwiger, Philipp; Tannous, Bakhos A.; Sah, Dinah W.Y.; Breakefield, Xandra O.

    2008-01-01

    Most cases of the dominantly inherited movement disorder, early onset torsion dystonia (DYT1) are caused by a mutant form of torsinA lacking a glutamic acid residue in the C-terminal region (torsinAΔE). TorsinA is an AAA+ protein located predominantly in the lumen of the endoplasmic reticulum (ER) and nuclear envelope apparently involved in membrane structure/movement and processing of proteins through the secretory pathway. A reporter protein Gaussia luciferase (Gluc) shows a reduced rate of secretion in primary fibroblasts from DYT1 patients expressing endogenous levels of torsinA and torsinAΔE when compared with control fibroblasts expressing only torsinA. In this study, small interfering RNA (siRNA) oligonucleotides were identified, which downregulate the levels of torsinA or torsinAΔE mRNA and protein by over 65% following transfection. Transfection of siRNA for torsinA message in control fibroblasts expressing Gluc reduced levels of luciferase secretion compared with the same cells non-transfected or transfected with a non-specific siRNA. Transfection of siRNA selectively inhibiting torsinAΔE message in DYT fibroblasts increased luciferase secretion when compared with cells non-transfected or transfected with a non-specific siRNA. Further, transduction of DYT1 cells with a lentivirus vector expressing torsinA, but not torsinB, also increased secretion. These studies are consistent with a role for torsinA as an ER chaperone affecting processing of proteins through the secretory pathway and indicate that torsinAΔE acts to inhibit this torsinA activity. The ability of allele-specific siRNA for torsinAΔE to normalize secretory function in DYT1 patient cells supports its potential role as a therapeutic agent in early onset torsion dystonia. PMID:18258738

  10. Identification of a cKit+ Colonic Crypt Base Secretory Cell That Supports Lgr5+ Stem Cells in Mice

    PubMed Central

    Rothenberg, Michael E.; Nusse, Ysbrand; Kalisky, Tomer; Lee, John J.; Dalerba, Piero; Scheeren, Ferenc; Lobo, Neethan; Kulkarni, Subhash; Sim, Sopheak; Qian, Dalong; Beachy, Philip A.; Pasricha, Pankaj J.; Quake, Stephen R.; Clarke, Michael F.

    2013-01-01

    Background & Aims Paneth cells contribute to the small intestinal niche of Lgr5+ stem cells. Although the colon also contains Lgr5+ stem cells, it does not contain Paneth cells. We investigated the existence of colonic Paneth-like cells that have a distinct transcriptional signature and support Lgr5+ stem cells. Methods We used multicolor fluorescence-activated cell sorting to isolate different subregions of colon crypts, based on known markers, from dissociated colonic epithelium of mice. We performed multiplexed single-cell gene expression analysis with quantitative reverse transcriptase polymerase chain reaction followed by hierarchical clustering analysis to characterize distinct cell types. We used immunostaining and fluorescence-activated cell sorting analyses with in vivo administration of a Notch inhibitor and in vitro organoid cultures to characterize different cell types. Results Multicolor fluorescence-activated cell sorting could isolate distinct regions of colonic crypts. Four major epithelial subtypes or transcriptional states were revealed by gene expression analysis of selected populations of single cells. One of these, the goblet cells, contained a distinct cKit/CD117+ crypt base subpopulation that expressed Dll1, Dll4, and epidermal growth factor, similar to Paneth cells, which were also marked by cKit. In the colon, cKit+ goblet cells were interdigitated with Lgr5+ stem cells. In vivo, this colonic cKit+ population was regulated by Notch signaling; administration of a γ-secretase inhibitor to mice increased the number of cKit+ cells. When isolated from mouse colon, cKit+ cells promoted formation of organoids from Lgr5+ stem cells, which expressed Kitl/stem cell factor, the ligand for cKit. When organoids were depleted of cKit+ cells using a toxin-conjugated antibody, organoid formation decreased. Conclusions cKit marks small intestinal Paneth cells and a subset of colonic goblet cells that are regulated by Notch signaling and support Lgr5+stem

  11. Parietal cheiro-oral syndrome.

    PubMed

    Yasuda, Y; Watanabe, T; Ogura, A

    2000-12-01

    Cheiro-oral syndrome due to a parietal lesion has been reported in conjuction with a brain tumor, infarction and migraine. Only six reports of cheiro-oral syndrome due to a parietal infarction have been reported to date. We treated a 45-year-old woman with cheiro-oral syndrome due to a parietal infarction. Her sensory disturbance was characterized by paresthesia in the lower face and hand on the left side, and severe involvement of stereognosis and graphesthesia in the left hand. The pathogenesis of parietal cheiro-oral syndrome is discussed.

  12. Hydrogen potassium adenosine triphosphatase activity inhibition and downregulation of its expression by bioactive fraction DLBS2411 from Cinnamomum burmannii in gastric parietal cells

    PubMed Central

    Tjandrawinata, Raymond R; Nailufar, Florensia; Arifin, Poppy F

    2013-01-01

    This study assessed the gastric acid antisecretory effect of DLBS2411 fractionated from Cinnamomum burmannii. Hydrogen potassium adenosine triphosphatase (H+/K+ ATPase) activity and its gene expression were observed, and the antioxidant activity of DLBS2411 was also investigated. Treatment of DLBS2411 decreased the level of H+/K+ ATPase messenger RNA expression on human embryonic kidney 293 cells and rat gastric parietal cells in a dose-dependent manner, in vitro and ex vivo. DLBS2411 also acted as a competitive inhibitor by showing inhibition in gastric H+/K+ ATPase activity at various pHs. In gastric ulcer animal models induced with indomethacin and ethanol, DLBS2411showed a reduction in the number of petechiae, suggesting that the fraction also confers gastroprotective activity. Moreover, DLBS2411 was also found to have potent antioxidant activity. Taken together, DLBS2411 is a promising novel agent for the management of dyspepsia, a condition of hyperacidity and diseases in the stomach requiring gastroprotection. PMID:24101879

  13. Apraxia and the Parietal Lobes

    ERIC Educational Resources Information Center

    Goldenberg, Georg

    2009-01-01

    The widely held belief in a central role of left parietal lesions for apraxia can be traced back to Liepmann's model of a posterior to anterior stream converting mental images of intended action into motor execution. Although this model has undergone significant changes, its modern descendants still attribute the parietal contribution to the…

  14. Antiparietal cell antibody test

    MedlinePlus

    APCA; Anti-gastric parietal cell antibody; Atrophic gastritis - anti-gastric parietal cell antibody; Gastric ulcer - anti-gastric parietal cell antibody; Pernicious anemia - anti-gastric parietal cell antibody; Vitamin B12 - anti- ...

  15. Secretory diarrhoea: mechanisms and emerging therapies

    PubMed Central

    Thiagarajah, Jay R.; Donowitz, Mark; Verkman, Alan S.

    2016-01-01

    Diarrhoeal disease remains a major health burden worldwide. Secretory diarrhoeas are caused by certain bacterial and viral infections, inflammatory processes, drugs and genetic disorders. Fluid secretion across the intestinal epithelium in secretory diarrhoeas involves multiple ion and solute transporters, as well as activation of cyclic nucleotide and Ca2+ signalling pathways. In many secretory diarrhoeas, activation of Cl− channels in the apical membrane of enterocytes, including the cystic fibrosis transmembrane conductance regulator and Ca2+-activated Cl− channels, increases fluid secretion, while inhibition of Na+ transport reduces fluid absorption. Current treatment of diarrhoea includes replacement of fluid and electrolyte losses using oral rehydration solutions, and drugs targeting intestinal motility or fluid secretion. Therapeutics in the development pipeline target intestinal ion channels and transporters, regulatory proteins and cell surface receptors. This Review describes pathogenic mechanisms of secretory diarrhoea, current and emerging therapeutics, and the challenges in developing antidiarrhoeal therapeutics. PMID:26122478

  16. The 60- to 90-kDa parietal cell autoantigen associated with autoimmune gastritis is a beta subunit of the gastric H+/K(+)-ATPase (proton pump).

    PubMed

    Toh, B H; Gleeson, P A; Simpson, R J; Moritz, R L; Callaghan, J M; Goldkorn, I; Jones, C M; Martinelli, T M; Mu, F T; Humphris, D C

    1990-08-01

    Autoantibodies in the sera of patients with pernicious anemia recognize, in addition to the alpha subunit of the gastric H+/(+)-ATPase, an abundant gastric microsomal glycoprotein of apparent Mr 60,000-90,000. Herein we have colocalized the glycoprotein and the alpha subunit of the gastric H+/K(+)-ATPase to the tubulovesicular membranes of the parietal cell by immunogold electron microscopy. Moreover, the glycoprotein and the alpha subunit were coimmunoprecipitated, and copurified by immunoaffinity chromatography, with an anti-glycoprotein monoclonal antibody. The pig glycoprotein was purified by chromatography on tomato lectin-Sepharose, and five tryptic peptides from the purified glycoprotein were partially sequenced. The complete amino acid sequence, deduced from the nucleotide sequence of overlapping cDNA clones, showed 33% similarity to the sequence of the beta subunit of the pig kidney Na+/K(+)-ATPase. We therefore propose that the 60- to 90-kDa glycoprotein autoantigen is the beta subunit of the gastric H+/K(+)-ATPase and that the alpha and beta subunits of the proton pump are major targets for autoimmunization in autoimmune gastritis.

  17. Interaction of the Pseudomonas aeruginosa secretory products pyocyanin and pyochelin generates hydroxyl radical and causes synergistic damage to endothelial cells. Implications for Pseudomonas-associated tissue injury.

    PubMed Central

    Britigan, B E; Roeder, T L; Rasmussen, G T; Shasby, D M; McCormick, M L; Cox, C D

    1992-01-01

    Pyocyanin, a secretory product of Pseudomonas aeruginosa, has the capacity to undergo redox cycling under aerobic conditions with resulting generation of superoxide and hydrogen peroxide. By using spin trapping techniques in conjunction with electron paramagnetic resonance spectrometry (EPR), superoxide was detected during the aerobic reduction of pyocyanin by NADH or porcine endothelial cells. No evidence of hydroxyl radical formation was detected. Chromium oxalate eliminated the EPR spectrum of the superoxide-derived spin adduct resulting from endothelial cell exposure to pyocyanin, suggesting superoxide formation close to the endothelial cell plasma membrane. We have previously reported that iron bound to the P. aeruginosa siderophore pyochelin (ferripyochelin) catalyzes the formation of hydroxyl free radical from superoxide and hydrogen peroxide via the Haber-Weiss reaction. In the present study, spin trap evidence of hydroxyl radical formation was detected when NADH and pyocyanin were allowed to react in the presence of ferripyochelin. Similarly, endothelial cell exposure to pyocyanin and ferripyochelin also resulted in hydroxyl radical production which appeared to occur in close proximity to the cell surface. As assessed by 51Cr release, endothelial cells which were treated with pyocyanin or ferripyochelin alone demonstrated minimal injury. However, endothelial cell exposure to the combination of pyochelin and pyocyanin resulted in 55% specific 51Cr release. Injury was not observed with the substitution of iron-free pyochelin and was diminished by the presence of catalase or dimethyl thiourea. These data suggest the possibility that the P. aeruginosa secretory products pyocyanin and pyochelin may act synergistically via the generation of hydroxyl radical to damage local tissues at sites of pseudomonas infection. PMID:1469082

  18. Human microRNA-24 modulates highly pathogenic avian-origin H5N1 influenza A virus infection in A549 cells by targeting secretory pathway furin.

    PubMed

    Loveday, Emma-Kate; Diederich, Sandra; Pasick, John; Jean, François

    2015-01-01

    A common critical cellular event that many human enveloped viruses share is the requirement for proteolytic cleavage of the viral glycoprotein by furin in the host secretory pathway. For example, the furin-dependent proteolytic activation of highly pathogenic (HP) influenza A (infA) H5 and H7 haemagglutinin precursor (HA0) subtypes is critical for yielding fusion-competent infectious virions. In this study, we hypothesized that viral hijacking of the furin pathway by HP infA viruses to permit cleavage of HA0 could represent a novel molecular mechanism controlling the dynamic production of fusion-competent infectious virus particles during the viral life cycle. We explored the biological role of a newly identified furin-directed human microRNA, miR-24, in this process as a potential post-transcriptional regulator of the furin-mediated activation of HA0 and production of fusion-competent virions in the host secretory pathway. We report that miR-24 and furin are differentially expressed in human A549 cells infected with HP avian-origin infA H5N1. Using miR-24 mimics, we demonstrated a robust decrease in both furin mRNA levels and intracellular furin activity in A549 cells. Importantly, pretreatment of A549 cells with miR-24 mimicked these results: a robust decrease of H5N1 infectious virions and a complete block of H5N1 virus spread that was not observed in A549 cells infected with low-pathogenicity swine-origin infA H1N1 virus. Our results suggest that viral-specific downregulation of furin-directed microRNAs such as miR-24 during the life cycle of HP infA viruses may represent a novel regulatory mechanism that governs furin-mediated proteolytic activation of HA0 glycoproteins and production of infectious virions.

  19. Quantitative description of the spatial arrangement of organelles in a polarised secretory epithelial cell: the salivary gland acinar cell

    PubMed Central

    MAYHEW, TERRY M.

    1999-01-01

    Previous quantitative descriptions of cellular ultrastructure have focused on spatial content (volume, surface area and number of organelles and membrane domains). It is possible to complement such descriptions by also quantifying spatial arrangements. Hitherto, applications of stereological methods for achieving this (notably, estimation of covariance and pair correlation functions) have been confined to organ and tissue levels. This study explores 3-dimensional subcellular arrangements of key organelles within acinar cells of rabbit parotid salivary glands, highly polarised epithelial cells specialised for exocrine secretion of α-amylase. It focuses on spatial arrangements of secretion product stores (zymogen granules), rough endoplasmic reticulum (RER) and mitochondria. Systematic random samples of electron microscopical fields of view from 3 rabbits were analysed using test grids bearing linear dipole probes of different sizes. Unbiased estimates of organelle volume densities were obtained by point counting and estimates of covariance and pair correlation functions by dipole counting. Plots of pair correlation functions against dipole length identified spatial arrangement differences between organelle types. Volumes within RER and mitochondrial compartments were positively correlated with themselves at distances below 4 μm and 2 μm respectively but were essentially randomly arranged at longer distances. In sharp contrast, zymogen granules were not randomly arranged. They were clustered at distances below 6–7 μm and more widely scattered at greater distances. These findings provide quantitative confirmation of the polarised arrangement of zymogen granules within acinar cells and further support for the relative invariance of biological organisation between subjects. PMID:10337960

  20. Sensory syndromes in parietal stroke.

    PubMed

    Bassetti, C; Bogousslavsky, J; Regli, F

    1993-10-01

    We studied 20 patients with an acute parietal stroke with hemisensory disturbances but no visual field deficit and no or only slight motor weakness, without thalamic involvement on CT or MRI and found three main sensory syndromes. (1) The pseudothalamic sensory syndrome consists of a faciobrachiocrural impairment of elementary sensation (touch, pain, temperature, vibration). All patients have an inferior-anterior parietal stroke involving the parietal operculum, posterior insula, and, in all but one patient, underlying white matter. (2) The cortical sensory syndrome consists of an isolated loss of discriminative sensation (stereognosis, graphesthesia, position sense) involving one or two parts of the body. These patients show a superior-posterior parietal stroke. (3) The atypical sensory syndrome consists of a sensory loss involving all modalities of sensation in a partial distribution. Parietal lesions of different topography are responsible for this clinical picture, which probably represents a minor variant of the two previous sensory syndromes. Neuropsychological dysfunction was present in 17 patients. The only constant association was between conduction aphasia and right-sided pseudothalamic sensory deficit. We conclude that parietal stroke can cause different sensory syndromes depending on the topography of the underlying lesion. Sensory deficits can be monosymptomatic but never present as a "pure sensory stroke" involving face, arm, leg, and trunk together.

  1. A functional cyclic AMP response element plays a crucial role in neuroendocrine cell type-specific expression of the secretory granule protein chromogranin A.

    PubMed Central

    Wu, H; Mahata, S K; Mahata, M; Webster, N J; Parmer, R J; O'Connor, D T

    1995-01-01

    Chromogranin A, a soluble acidic protein, is a ubiquitous component of secretory vesicles throughout the neuroendocrine system. We reported previously the cloning and initial characterization of the mouse chromogranin A gene promoter, which showed that the promoter contains both positive and negative domains and that a proximal promoter spanning nucleotides -147 to +42 bp relative to the transcriptional start site is sufficient for neuroendocrine cell type-specific expression. The current study was undertaken to identify the particular elements within this proximal promoter that control tissue-specific expression. We found that deletion or point mutations in the potential cAMP response element (CRE) site at -68 bp virtually abolished promoter activity specifically in neuroendocrine (PC12 chromaffin or AtT20 corticotrope) cells, with little effect on activity in control (NIH3T3 fibroblast) cells; thus, the CRE box is necessary for neuroendocrine cell type-specific activity of the chromogranin A promoter. Furthermore, the effect of the CRE site is enhanced in the context of intact (wild-type) promoter sequences between -147 and -100 bp. DNase I footprint analysis showed that these regions (including the CRE box) bind nuclear proteins present in both neuroendocrine (AtT20) and control (NIH3T3) cells. In AtT20 cells, electrophoretic mobility shift assays and factor-specific antibody supershifts showed that an oligonucleotide containing the chromogranin A CRE site formed a single, homogeneous protein-DNA complex containing the CRE-binding protein CREB. However, in control NIH3T3 cells we found evidence for an additional immunologically unrelated protein in this complex. A single copy of this oligonucleotide was able to confer neuroendocrine-specific expression to a heterologous (thymidine kinase) promoter, albeit with less fold selectivity than the full proximal chromogranin A promoter. Hence, the CRE site was partially sufficient to explain the neuroendocrine cell type

  2. The Secretory Pathway Kinases

    PubMed Central

    Sreelatha, Anju; Kinch, Lisa N.; Tagliabracci, Vincent S.

    2015-01-01

    Protein phosphorylation is a nearly universal post-translation modification involved in a plethora of cellular events. Even though phosphorylation of extracellular proteins had been observed, the identity of the kinases that phosphorylate secreted proteins remained a mystery until recently. Advances in genome sequencing and genetic studies have paved the way for the discovery of a new class of kinases that localize within the endoplasmic reticulum, Golgi apparatus and the extracellular space. These novel kinases phosphorylate proteins and proteoglycans in the secretory pathway and appear to regulate various extracellular processes. Mutations in these kinases cause human disease, thus underscoring the biological importance of phosphorylation within the secretory pathway. PMID:25862977

  3. Quality control in the secretory assembly line.

    PubMed Central

    Helenius, A

    2001-01-01

    As a rule, only proteins that have reached a native, folded and assembled structure are transported to their target organelles and compartments within the cell. In the secretory pathway of eukaryotic cells, this type of sorting is particularly important. A variety of molecular mechanisms are involved that distinguish between folded and unfolded proteins, modulate their intracellular transport, and induce degradation if they fail to fold. This phenomenon, called quality control, occurs at several levels and involves different types of folding sensors. The quality control system provides a stringent and versatile molecular sorting system that guaranties fidelity of protein expression in the secretory pathway. PMID:11260794

  4. Navigating from hippocampus to parietal cortex

    PubMed Central

    Whitlock, Jonathan R.; Sutherland, Robert J.; Witter, Menno P.; Moser, May-Britt; Moser, Edvard I.

    2008-01-01

    The navigational system of the mammalian cortex comprises a number of interacting brain regions. Grid cells in the medial entorhinal cortex and place cells in the hippocampus are thought to participate in the formation of a dynamic representation of the animal's current location, and these cells are presumably critical for storing the representation in memory. To traverse the environment, animals must be able to translate coordinate information from spatial maps in the entorhinal cortex and hippocampus into body-centered representations that can be used to direct locomotion. How this is done remains an enigma. We propose that the posterior parietal cortex is critical for this transformation. PMID:18812502

  5. Production of N-acetylgalactosaminyl-transferase 2 (GalNAc-T2) fused with secretory signal Igκ in insect cells.

    PubMed

    Horynová, Milada; Takahashi, Kazuo; Hall, Stacy; Renfrow, Matthew B; Novak, Jan; Raška, Milan

    2012-02-01

    The human UDP-N-acetyl-α-d-galactosamine:polypeptide N-acetylgalactosaminyl-transferase 2 (GalNAc-T2) is one of the key enzymes that initiate synthesis of hinge-region O-linked glycans of human immunoglobulin A1 (IgA1). We designed secreted soluble form of human GalNAc-T2 as a fusion protein containing mouse immunoglobulin light chain kappa secretory signal and expressed it using baculovirus and mammalian expression vectors. The recombinant protein was secreted by insect cells Sf9 and human HEK 293T cells in the culture medium. The protein was purified from the media using affinity Ni-NTA chromatography followed by stabilization of purified protein in 50mM Tris-HCl buffer at pH 7.4. Although the purity of recombinant GalNAc-T2 was comparable in both expression systems, the yield was higher in Sf9 insect expression system (2.5mg of GalNAc-T2 protein per 1L culture medium). The purified soluble recombinant GalNAc-T2 had an estimated molecular mass of 65.8kDa and its amino-acid sequence was confirmed by mass-spectrometric analysis. The enzymatic activity of Sf9-produced recombinant GalNAc-T2 was determined by the quantification of enzyme-mediated attachment of GalNAc to synthetic IgA1 hinge-region peptide as the acceptor and UDP-GalNAc as the donor. In conclusion, murine immunoglobulin kappa secretory signal was used for production of secreted enzymatically active GalNAc-T2 in insect baculovirus expression system.

  6. Activation of MAPK Is Required for ROS Generation and Exocytosis in HMC-1 Cells Induced by Trichomonas vaginalis-Derived Secretory Products

    PubMed Central

    Narantsogt, Giimaa; Min, Arim; Nam, Young Hee; Lee, Young Ah; Kim, Kyeong Ah; Agvaandaram, Gurbadam; Dorjsuren, Temuulen; El-Benna, Jamel; Shin, Myeong Heon

    2015-01-01

    Trichomonas vaginalis is a flagellated protozoan parasite that causes vaginitis and cervicitis in women and asymptomatic urethritis and prostatitis in men. Mast cells have been reported to be predominant in vaginal smears and vaginal walls of patients infected with T. vaginalis. Mitogen-activated protein kinase (MAPK), activated by various stimuli, have been shown to regulate the transcriptional activity of various cytokine genes in mast cells. In this study, we investigated whether MAPK is involved in ROS generation and exocytotic degranulation in HMC-1 cells induced by T. vaginalis-derived secretory products (TvSP). We found that TvSP induces the activation of MAPK and NADPH oxidase in HMC-1 cells. Stimulation with TvSP induced phosphorylation of MAPK and p47phox in HMC-1 cells. Stimulation with TvSP also induced up-regulation of CD63, a marker for exocytosis, along the surfaces of human mast cells. Pretreatment with MAPK inhibitors strongly inhibited TvSP-induced ROS generation and exocytotic degranulation. Finally, our results suggest that TvSP induces intracellular ROS generation and exocytotic degranulation in HMC-1 via MAPK signaling. PMID:26537039

  7. Activation of MAPK Is Required for ROS Generation and Exocytosis in HMC-1 Cells Induced by Trichomonas vaginalis-Derived Secretory Products.

    PubMed

    Narantsogt, Giimaa; Min, Arim; Nam, Young Hee; Lee, Young Ah; Kim, Kyeong Ah; Agvaandaram, Gurbadam; Dorjsuren, Temuulen; El-Benna, Jamel; Shin, Myeong Heon

    2015-10-01

    Trichomonas vaginalis is a flagellated protozoan parasite that causes vaginitis and cervicitis in women and asymptomatic urethritis and prostatitis in men. Mast cells have been reported to be predominant in vaginal smears and vaginal walls of patients infected with T. vaginalis. Mitogen-activated protein kinase (MAPK), activated by various stimuli, have been shown to regulate the transcriptional activity of various cytokine genes in mast cells. In this study, we investigated whether MAPK is involved in ROS generation and exocytotic degranulation in HMC-1 cells induced by T. vaginalis-derived secretory products (TvSP). We found that TvSP induces the activation of MAPK and NADPH oxidase in HMC-1 cells. Stimulation with TvSP induced phosphorylation of MAPK and p47(phox) in HMC-1 cells. Stimulation with TvSP also induced up-regulation of CD63, a marker for exocytosis, along the surfaces of human mast cells. Pretreatment with MAPK inhibitors strongly inhibited TvSP-induced ROS generation and exocytotic degranulation. Finally, our results suggest that TvSP induces intracellular ROS generation and exocytotic degranulation in HMC-1 via MAPK signaling.

  8. Role of interferon-gamma against invasion by Toxoplasma gondii in a human monocytic cell line (THP1): involvement of the parasite's secretory phospholipase A2.

    PubMed

    Gómez Marín, J E; Bonhomme, A; Guenounou, M; Pinon, J M

    1996-05-01

    We examined the role of IFN gamma in protection against Toxoplasma gondii in the monocytoid cell line THP1. The addition of IFN gamma to cultured infected THP1 cells reduced the number of parasitized cells without altering intracellular multiplication during the first 24 hr. This reduction was potentiated by bacterial lipopolysaccharide (LPS). We also examined the role of an enzyme important for T. gondii cellular invasion, secretory phospholipase-A2 (sPLA2) and its relation with IFN gamma-induced protection. Treatment of cells or parasites with a specific inhibitor of sPLA2 significantly reduced the number of infected cells at 6 hr. The addition of exogenous sPLA2 from Naja naja venom did not interfere with the protective effect of IFN gamma and conferred protection when used alone. PLA2 activity was measured in supernatants of parasites maintained in the presence of IFN gamma, and the results suggested that IFN gamma opposes cell invasion by T. gondii by suppressing parasite production of PLA2.

  9. Macrophageal/microglial cell activation and cerebral injury induced by excretory-secretory products secreted by Paragonimus westermani.

    PubMed

    Lee, Jae-Chul; Cho, Geum-Sil; Kwon, Jae Hyun; Shin, Myeong Heon; Lim, Ji Hyae; Kim, Won-Ki

    2006-02-01

    Cerebral paragonimiasis causes various neurological disorders including seizures, visual impairment and hemiplegia. The excretory-secretory product (ESP) released by Paragonimus westermani has a cysteine protease activity and plays important roles in its migration in the host tissue and modulation of host immune responses. To gain more insight into the pathogenesis of ESP in the brain, we investigated the inflammatory reaction and cerebral injury following microinjection of ESP into rat striatum. The size of injury was maximally observed 3 days after microinjection of ESP and then declined to control levels as astrocytes have repopulated the injury. ED1-positive monocytes and microglia were confluently found inside the injury. The mRNA expression of inducible nitric oxide synthase (iNOS) occurred as early as 9h after ESP injection and then declined to control levels within 1 day. The iNOS inhibitor aminoguanidine largely decreased the expression of iNOS but did not reduce the size of lesion caused by ESP. Interestingly, however, heat inactivation of ESP caused a decrease of injury formation with no altered expression of iNOS. The data indicate that ESP produces brain tissue injury by recruiting activated monocytes/microglia via heat-labile protease activity.

  10. Difference in distribution of membrane proteins between low- and high-density secretory granules in parotid acinar cells

    SciTech Connect

    Fujita-Yoshigaki, Junko . E-mail: yoshigaki.junko@nihon-u.ac.jp; Katsumata, Osamu; Matsuki, Miwako; Yoshigaki, Tomoyoshi; Furuyama, Shunsuke; Sugiya, Hiroshi

    2006-05-26

    Secretory granules (SGs) are considered to be generated as immature granules and to mature by condensation of their contents. In this study, SGs of parotid gland were separated into low-, medium-, and high-density granule fractions by Percoll-density gradient centrifugation, since it was proposed that the density corresponds to the degree of maturation. The observation with electron microscopy showed that granules in the three fractions were very similar. The average diameter of high-density granules was a little but significantly larger than that of low-density granules. Although the three fractions contained amylase, suggesting that they are all SGs, distribution of membrane proteins was markedly different. Syntaxin6 and VAMP4 were localized in the low-density granule fraction, while VAMP2 was concentrated in the high-density granule fraction. Immunoprecipitation with anti-syntaxin6 antibody caused coprecipitation of VAMP2 from the medium-density granule fraction without solubilization, but not from Triton X-100-solubilized fraction, while VAMP4 was coprecipitated from both fractions. Therefore, VAMP2 is present on the same granules, but is separated from syntaxin6 and VAMP4, which are expected to be removed from immature granules. These results suggest that the medium-density granules are intermediates from low- to high-density granules, and that the membrane components of SGs dynamically change by budding and fusion during maturation.

  11. Influence of colchicine and vinblastine on the intracellular migration of secretory and membrane glycoproteins: I. Inhibition of glycoprotein migration in various rat cell types as shown by light microscope radioautography after injection of 3H-fucose

    SciTech Connect

    Bennett, G.; Parsons, S.; Carlet, E.

    1984-08-01

    Previous studies have shown that colchicine and vinblastine inhibit secretion in many cell types by interrupting the normal intracellular migration of secretory products. In the present work, radioautography has been used to study the effects of these drugs on migration of membrane and secretory glycoproteins in a variety of cell types. Young (40 gm) rats were given a single intravenous injection of colchicine (4.0 mg) or vinblastine (2.0 mg). At 10 min after colchicine and 30 min after vinblastine administration, the rats were injected with 3H-fucose. Control rats received 3H-fucose only. All rats were sacrificed 90 min after 3H-fucose injection and their tissues processed for light microscope radioautography. Examination of secretory cell types such as ameloblasts and thyroid follicular cells in control animals revealed reactions of approximately equal intensity over the Golgi region and over extracellular secretion products, while in drug-treated rats most of the reaction was confined to the Golgi region. In a variety of other cell types, including endocrine cells (e.g., hepatocytes) and cells generally considered as nonsecretory (e.g., intestinal columnar cells), reaction in control animals occurred both over the Golgi region and over various portions of the cell surface. In drug-treated animals, a strong Golgi reaction was present, but reaction over the cell surface was weak or absent. These results indicate that in many cell types, colchicine and vinblastine inhibit migration out of the Golgi region not only of secretory glycoproteins, but also of membrane glycoproteins destined for the plasma membrane.

  12. Scanning electron microscopy of the endometrium during the secretory phase.

    PubMed Central

    Motta, P M; Andrews, P M

    1976-01-01

    Scanning electron microscopy was used to study the surface morphology of the rabbit endometrium during the secretory phase of the oestrous cycle. The free surfaces of ciliated and of inactive active secretory cells are described. Changes in secretory cell surface morphology resulting from accumulation and secretion of material involve the apparent retraction of microvilli and the formation of one or more bulbous protrusions of the cell's apical surface. These protrusions may be relatively smooth surfaced or exhibit long slender micro-extensions. The protrusions grow in size and are eventually pinched off. Loss of the bulbous protrusions often leaves behind crater-like invaginations of the cell's surface. Secretory cells adjacent to the endometrial glands are the first to exhibit signs of mucin accumulation and secretion. The single cilium of a secretory cell is not apparently affected by the secretory process. Signs of ciliated and secretory cell degeneration, and possible sloughing, are also described. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 PMID:1033932

  13. Alpha1-adrenoceptors trigger the snake venom production cycle in secretory cells by activating phosphatidylinositol 4,5-bisphosphate hydrolysis and ERK signaling pathway.

    PubMed

    Kerchove, Celine M; Luna, Milene S A; Zablith, Mariana B; Lazari, Maria F M; Smaili, Soraya S; Yamanouye, Norma

    2008-08-01

    Loss of venom from the venom gland after biting or manual extraction leads to morphological changes in venom secreting cells and the start of a cycle of production of new venom. We have previously shown that stimulation of both alpha- and beta-adrenoceptors in the secretory cells of the venom gland is essential for the onset of the venom production cycle in Bothrops jararaca. We investigated the signaling pathway by which the alpha-adrenoceptor initiates the venom production cycle. Our results show that the alpha(1)-adrenoceptor subtype is present in venom gland of the snake. In quiescent cells, stimulation of alpha(1)-adrenoceptor with phenylephrine increased the total inositol phosphate concentration, and this effect was blocked by the phospholipase C inhibitor U73122. Phenylephrine mobilized Ca(2+) from thapsigargin-sensitive stores and increased protein kinase C activity. In addition, alpha(1)-adrenoceptor stimulation increased the activity of ERK 1/2, partially via protein kinase C. Using RT-PCR approach we obtained a partial sequence of a snake alpha(1)-adrenoceptor (260 bp) with higher identity with alpha(1D) and alpha(1B)-adrenoceptors from different species. These results suggest that alpha(1)-adrenoceptors in the venom secreting cells are probably coupled to a G(q) protein and trigger the venom production cycle by activating the phosphatidylinositol 4,5-bisphosphate and ERK signaling pathway.

  14. Osteopontin is a myosphere-derived secretory molecule that promotes angiogenic progenitor cell proliferation through the phosphoinositide 3-kinase/Akt pathway

    SciTech Connect

    Ogata, Takehiro; Ueyama, Tomomi . E-mail: tueyama@kuhp.kyoto-u.ac.jp; Nomura, Tetsuya; Asada, Satoshi; Tagawa, Masashi; Nakamura, Tomoyuki; Takahashi, Tomosaburo; Matsubara, Hiroaki; Oh, Hidemasa . E-mail: hidemasa@kuhp.kyoto-u.ac.jp

    2007-07-27

    We have reported that skeletal myosphere-derived progenitor cells (MDPCs) can differentiate into vascular cells, and that MDPC transplantation into cardiomyopathic hearts improves cardiac function. However, the autocrine/paracrine molecules and underlying mechanisms responsible for MDPC growth have not yet been determined. To explore the molecules enhancing the proliferation of MDPCs, we performed serial analysis of gene expression and signal sequence trap methods using RNA isolated from MDPCs. We identified osteopontin (OPN), a secretory molecule, as one of most abundant molecules expressed in MDPCs. OPN provided a proliferative effect for MDPCs. MDPCs treated with OPN showed Akt activation, and inhibition of the phosphoinositide 3-kinase (PI3K)/Akt pathway repressed the proliferative effect of OPN. Furthermore, OPN-pretreated MDPCs maintained their differentiation potential into endothelial and vascular smooth muscle cells. These findings indicate an important role of OPN as an autocrine/paracrine molecule in regulating the proliferative growth of muscle-derived angiogenic progenitor cells via the PI3K/Akt pathway.

  15. Refining the Value of Secretory Phospholipase A2 as a Predictor of Acute Chest Syndrome in Sickle Cell Disease: Results of a Feasibility Study (PROACTIVE)

    PubMed Central

    Styles, Lori; Wager, Carrie G.; Labotka, Richard J.; Smith-Whitley, Kim; Thompson, Alexis A.; Lane, Peter A.; McMahon, Lillian E.C; Miller, Robin; Roseff, Susan; Iyer, Rathi; Hsu, Lewis L.; Castro, Oswaldo; Ataga, Kenneth; Onyekwere, Onyinye; Okam, Maureen; Bellevue, Rita; Miller, Scott T.

    2012-01-01

    Acute chest syndrome (ACS) is defined as fever, respiratory symptoms and a new pulmonary infiltrate in an individual with sickle cell disease (SCD). Nearly half of ACS episodes occur in SCD patients already hospitalized, potentially permitting pre-emptive therapy in high-risk patients. Simple transfusion of red blood cells may abort ACS if given to patients hospitalized for pain who develop fever and elevated levels of secretory phospholipase A2 (sPLA2). In a feasibility study (PROACTIVE; ClinicalTrials.gov NCT00951808), patients hospitalized for pain who developed fever and elevated sPLA2 were eligible for randomization to transfusion or observation; all others were enrolled in an observational arm. Of 237 enrolled, only 10 were randomized; one of the four to receive transfusion had delayed treatment. Of 233 subjects receiving standard care, 22 developed ACS. A threshold level of sPLA2 ≥ 48 ng/ml gave optimal sensitivity (73%), specificity (71%) and accuracy (71%), but a positive predictive value of only 24%. The predictive value of sPLA2 was improved in adults and patients with chest or back pain, lower haemoglobin concentration and higher white blood cell counts; and those receiving less than two-thirds maintenance fluids. The hurdles identified in PROACTIVE should facilitate design of a larger, definitive, phase 3 randomized controlled trial. PMID:22463614

  16. Cell type-specific gene expression in the neuroendocrine system. A neuroendocrine-specific regulatory element in the promoter of chromogranin A, a ubiquitous secretory granule core protein.

    PubMed Central

    Wu, H; Rozansky, D J; Webster, N J; O'Connor, D T

    1994-01-01

    The acidic secretory protein chromogranin A universally occurs in amine and peptide hormone and neurotransmitter storage granules throughout the neuroendocrine system. What factors govern the activity of the chromogranin A gene, to yield such a widespread yet neuroendocrine-selective pattern of expression? To address this question, we isolated the mouse chromogranin A gene promoter. The promoter conferred cell type-specific expression in several neuroendocrine cell types (adrenal medullary chromaffin cells, anterior pituitary corticotropes, and anterior pituitary somatolactotropes) but not in control (fibroblast or kidney) cells. In neuroendocrine cells, analysis of promoter deletions established both positive and negative transcriptional regulatory domains. A distal positive domain (-4.8/-2.2 kbp) was discovered, as well as negative (-258/-181 bp) and positive (-147/-61 bp) domains in the proximate promoter. The proximate promoter contained a minimal neuroendocrine-specific element between -77 and -61 bp. Sequence alignment of the mouse promoter with corresponding regions in rat and bovine clones indicated that the mouse sequence shares over 85% homology with rat and 52% with bovine promoters. DNaseI footprinting and electrophoretic gel mobility shift assays demonstrated the presence of nuclear factors in neuroendocrine cells that recognized the proximate promoter. We conclude that the chromogranin A promoter contains both positive and negative domains governing its cell type-specific pattern of transcription, and that a small proximate region of the promoter, containing novel as well as previously described elements, interacts specifically with neuroendocrine nuclear proteins, and is thereby sufficient to ensure widespread neuroendocrine expression of the gene. Images PMID:8040254

  17. An unusual type of secretory cell in the ventral pedal gland of the gastropod mollusc Buccinum undatum L.

    PubMed

    Price, N R; Hunt, S

    1976-01-01

    The ventral pedal gland in the foot of the mature female whelk Buccinum undatum L. consists of a shallow pouch containing a layer of elongated cells which partially penetrate a basement membrane overlying layers of smooth muscle. This glandular epithelium contains acid mucopolysaccharide cells, ciliated and interstitial cells as well as the upper part of a new type of subepidermal gland cell. These gland cells consist of an elongated extracellular tubular duct formed by an invagination of the cell membrane and lined by numerous microvilli. Into this duct are discharged packets of a densely staining secretion. The secretion packets are produced in Golgi regions around the nuclei of the cells and are passed up through the cell to the base of the duct through or along an extensive assemblage of microtubules. The secretion packets show organized internal structure and may contain aromatic aldehydes and protein associated with the sclerotization of the egg capsules, which pass through the gland after leaving the genital tract.

  18. Group V secretory phospholipase A2 reveals its role in house dust mite-induced allergic pulmonary inflammation by regulation of dendritic cell function

    PubMed Central

    Giannattasio, Giorgio; Fujioka, Daisuke; Xing, Wei; Katz, Howard R.; Boyce, Joshua A.; Balestrieri, Barbara

    2010-01-01

    We have previously shown that group V secretory phospholipase A2 (sPLA2) regulates phagocytosis of zymosan and Candida albicans by a mechanism that depends on fusion of phagosomes with late endosomes in macrophages. Here we report that group V sPLA2 (Pla2g5)-null mice exposed to an extract of house dust mite Dermatophagoides farinae (Df) had markedly reduced pulmonary inflammation and goblet cell metaplasia compared to wild-type (WT) mice. Pla2g5-null mice had also impaired Th2-type adaptive immune responses to Df compared to WT mice. Pla2g5-null bone marrow-derived dendritic cells (BMDCs) activated by Df had delayed intracellular processing of allergen and impaired allergen-dependent maturation, a pattern recapitulated by the native lung DCs of Df-challenged mice. Adoptively transferred Df-loaded Pla2g5-null BMDCs were less able than Df-loaded WT BMDCs to induce pulmonary inflammation and Th2 polarization in WT mice. However, Pla2g5-null recipients transferred with WT or Pla2g5-null Df-loaded BMDCs exhibited significantly reduced local inflammatory responses to Df, even though the transfer of WT BMDCs still induced an intact Th2 cytokine response in regional lymph nodes. Thus, the expression of group V sPLA2 in APC regulates Ag processing and maturation of dendritic cells, and contributes to pulmonary inflammation and immune response against Df. Furthermore, an additional yet to be identified resident cell type is essential for the development of pulmonary inflammation, likely a cell in which group V sPLA2 is upregulated by Df and whose function is also regulated by group V sPLA2. PMID:20817863

  19. Cysteine-rich secretory protein 3 plays a role in prostate cancer cell invasion and affects expression of PSA and ANXA1.

    PubMed

    Pathak, Bhakti R; Breed, Ananya A; Apte, Snehal; Acharya, Kshitish; Mahale, Smita D

    2016-01-01

    Cysteine-rich secretory protein 3 (CRISP-3) is upregulated in prostate cancer as compared to the normal prostate tissue. Higher expression of CRISP-3 has been linked to poor prognosis and hence it has been thought to act as a prognostic marker for prostate cancer. It is proposed to have a role in innate immunity but its role in prostate cancer is still unknown. In order to understand its function, its expression was stably knocked down in LNCaP cells. CRISP-3 knockdown did not affect cell viability but resulted in reduced invasiveness. Global gene expression changes upon CRISP-3 knockdown were identified by microarray analysis. Microarray data were quantitatively validated by evaluating the expression of seven candidate genes in three independent stable clones. Functional annotation of the differentially expressed genes identified cell adhesion, cell motility, and ion transport to be affected among other biological processes. Prostate-specific antigen (PSA, also known as Kallikrein 3) was the top most downregulated gene whose expression was also validated at protein level. Interestingly, expression of Annexin A1 (ANXA1), a known anti-inflammatory protein, was upregulated upon CRISP-3 knockdown. Re-introduction of CRISP-3 into the knockdown clone reversed the effect on invasiveness and also led to increased PSA expression. These results suggest that overexpression of CRISP-3 in prostate tumor may maintain higher PSA expression and lower ANXA1 expression. Our data also indicate that poor prognosis associated with higher CRISP-3 expression could be due to its role in cell invasion. PMID:26369530

  20. Cysteine-rich secretory protein 3 plays a role in prostate cancer cell invasion and affects expression of PSA and ANXA1.

    PubMed

    Pathak, Bhakti R; Breed, Ananya A; Apte, Snehal; Acharya, Kshitish; Mahale, Smita D

    2016-01-01

    Cysteine-rich secretory protein 3 (CRISP-3) is upregulated in prostate cancer as compared to the normal prostate tissue. Higher expression of CRISP-3 has been linked to poor prognosis and hence it has been thought to act as a prognostic marker for prostate cancer. It is proposed to have a role in innate immunity but its role in prostate cancer is still unknown. In order to understand its function, its expression was stably knocked down in LNCaP cells. CRISP-3 knockdown did not affect cell viability but resulted in reduced invasiveness. Global gene expression changes upon CRISP-3 knockdown were identified by microarray analysis. Microarray data were quantitatively validated by evaluating the expression of seven candidate genes in three independent stable clones. Functional annotation of the differentially expressed genes identified cell adhesion, cell motility, and ion transport to be affected among other biological processes. Prostate-specific antigen (PSA, also known as Kallikrein 3) was the top most downregulated gene whose expression was also validated at protein level. Interestingly, expression of Annexin A1 (ANXA1), a known anti-inflammatory protein, was upregulated upon CRISP-3 knockdown. Re-introduction of CRISP-3 into the knockdown clone reversed the effect on invasiveness and also led to increased PSA expression. These results suggest that overexpression of CRISP-3 in prostate tumor may maintain higher PSA expression and lower ANXA1 expression. Our data also indicate that poor prognosis associated with higher CRISP-3 expression could be due to its role in cell invasion.

  1. Molecular Characterization of Severin from Clonorchis sinensis Excretory/Secretory Products and Its Potential Anti-apoptotic Role in Hepatocarcinoma PLC Cells

    PubMed Central

    He, Lei; Wang, Xiaoyun; Liang, Pei; Chen, Wenjun; Bian, Meng; Ren, Mengyu; Lin, Jinsi; Liang, Chi; Xu, Jin; Wu, Zhongdao; Li, Xuerong; Huang, Yan; Yu, Xinbing

    2013-01-01

    Background Clonorchiasis, caused by the infection of Clonorchis sinensis (C. sinensis), is a kind of neglected tropical disease, but it is highly related to cholangiocarcinoma and hepatocellular carcinoma (HCC). It has been well known that the excretory/secretory products of C. sinensis (CsESPs) play key roles in clonorchiasis associated carcinoma. From genome and transcriptome of C. sinensis, we identified one component of CsESPs, severin (Csseverin), which had three putative gelsolin domains. Its homologues are supposed to play a vital role in apoptosis resistance of tumour cell. Methodology/Principal Findings There was significant similarity in tertiary structures between human gelsolin and Csseverin by bioinformatics analysis. We identified that Csseverin expressed at life stage of adult worm, metacercaria and egg by the method of quantitative real-time PCR and western blotting. Csseverin distributed in vitellarium and intrauterine eggs of adult worm and tegument of metacercaria by immunofluorence assay. We obtained recombinant Csseverin (rCsseverin) and confirmed that rCsseverin could bind with calciumion in circular dichroism spectrum analysis. It was demonstrated that rCsseverin was of the capability of actin binding by gel overlay assay and immunocytochemistry. Both Annexin V/PI assay and mitochondrial membrane potential assay of human hepatocarcinoma cell line PLC showed apoptosis resistance after incubation with different concentrations of rCsseverin. Morphological analysis, apoptosis-associated changes of mitochondrial membrane potential and Annexin V/PI apoptosis assay showed that co-incubation of PLC cells with rCsseverin in vitro led to an inhibition of apoptosis induced by serum-starved for 24 h. Conclusions/Significance Collectively, the molecular properties of Csseverin, a molecule of CsESPs, were characterized in our study. rCsseverin could cause obvious apoptotic inhibition in human HCC cell line. Csseverin might exacerbate the process of HCC

  2. Expression of secretory phospholipase A2 enzymes in lungs of humans with pneumonia and their potential prostaglandin-synthetic function in human lung-derived cells

    PubMed Central

    Masuda, Seiko; Murakami, Makoto; Mitsuishi, Michiko; Komiyama, Kazuo; Ishikawa, Yukio; Ishii, Toshiharu; Kudo, Ichiro

    2004-01-01

    Although a number of sPLA2 (secretory phospholipase A2) enzymes have been identified in mammals, the localization and functions of individual enzymes in human pathologic tissues still remain obscure. In the present study, we have examined the expression and function of sPLA2s in human lung-derived cells and in human lungs with pneumonia. Group IID, V and X sPLA2s were expressed in cultured human bronchial epithelial cells (BEAS-2B) and normal human pulmonary fibroblasts with distinct requirement for cytokines (interleukin-1β, tumour necrosis factor α and interferon-γ). Lentivirus- or adenovirus-mediated transfection of various sPLA2s into BEAS-2B or normal human pulmonary fibroblast cells revealed that group V and X sPLA2s increased arachidonate release and prostaglandin production in both cell types, whereas group IIA and IID sPLA2s failed to do so. Immunohistochemistry of human lungs with pneumonia demonstrated that group V and X sPLA2s were widely expressed in the airway epithelium, interstitium and alveolar macrophages, in which group IID sPLA2 was also positive, whereas group IIA sPLA2 was restricted to the pulmonary arterial smooth muscle layers and bronchial chondrocytes, and group IIE and IIF sPLA2s were minimally detected. These results suggest that group V and X sPLA2s affect lung pathogenesis by facilitating arachidonate metabolism or possibly through other functions. PMID:15509193

  3. Trichuris suis excretory secretory products (ESP) elicit interleukin-6 (IL-6) and IL-10 secretion from intestinal epithelial cells (IPEC-1).

    PubMed

    Parthasarathy, G; Mansfield, L S

    2005-08-10

    Immune responses to gastrointestinal helminth infections have received increasing attention due to similarities to allergen-induced responses. In fact, the whipworm parasite of swine, Trichuris suis, has been used in beginning clinical trials as an antidote to inflammatory bowel disease. This strategy was based on this similarity and the recognition that other worms have been documented to induce anti-inflammatory responses in the host. In an effort to understand the basis for this response, we hypothesized that the proteins and peptides secreted by T. suis stimulate local intestinal epithelial cells to produce anti-inflammatory cytokines. To test this hypothesis in a correlate system of the natural swine host, T. suis excretory secretory products (ESP) were used to treat both differentiated and undifferentiated intestinal pig epithelial cells (IPEC-1) in vitro as a model for the effect on villus tip and crypt epithelial cells in the vicinity of the worms. IPEC-1 were exposed to low-level doses (0.3mg/ml) of T. suis ESP, and IL-4, IL-6 and IL-10 cytokine responses were measured by an enzyme-linked immunosorbant assay (ELISA). IL-6 was the predominant cytokine produced, accompanied by moderate IL-10 secretion from both differentiated and undifferentiated cells. As expected, IL-4 was not produced by IPEC-1. Additionally, IL-6 and IL-10 cytokines were produced within 24h, suggesting that these two cytokines form part of the primary host response to T. suis infections. These data suggest that T. suis ESP could enhance host immune responses and modulation through the induction of enteric IL-6 and IL-10.

  4. De novo expression of sodium-glucose cotransporter SGLT2 in Bowman’s capsule coincides with replacement of parietal epithelial cell layer with proximal tubule-like epithelium

    PubMed Central

    Tabatabai, Niloofar M.; North, Paula E.; Regner, Kevin R.; Kumar, Suresh N.; Duris, Christine B.; Blodgett, Amy B.

    2014-01-01

    In kidney nephron, parietal epithelial cells line the Bowman’s capsule and function as a permeability barrier for the glomerular filtrate. Bowman’s capsule cells with proximal tubule epithelial morphology have been found. However, the effects of tubular metaplasia in Bowman’s capsule on kidney function remain poorly understood. Sodium-glucose cotransporter 2 (SGLT2) plays a major role in reabsorption of glucose in the kidney and is expressed on brush border membrane of epithelial cells in the early segment of the proximal tubule. We hypothesized that SGLT2 is expressed in tubularized Bowman’s capsule and used our novel antibody to test this hypothesis. Immunohistochemical analysis was performed with our SGLT2 antibody on C57BL/6 mouse kidney prone to have tubularized Bowman’s capsules. Cell membrane was examined with periodic acid-Schiff stain. The results showed that SGLT2 was localized on brush border membrane of the proximal tubules in young and adult mice. Bowman’s capsules were lined mostly with normal brush border-less parietal epithelial cells in young mice while they were almost completely covered with proximal tubule-like cells in adult mice. Regardless of age, SGLT2 was expressed on brush border membrane of the tubularized Bowman’s capsule but did not co-localize with nephrin in the glomerulus. SGLT2-expressing tubular cells expanded from the urinary pole towards the vascular pole of the Bowman’s capsule. This study identified the localization of SGLT2 in the Bowman’s capsule. Bowman’s capsules with tubular metaplasia may acquire roles in reabsorption of filtered glucose and sodium. PMID:24906870

  5. Expression Quantitative Trait Locus Mapping Studies in Mid-secretory Phase Endometrial Cells Identifies HLA-F and TAP2 as Fecundability-Associated Genes.

    PubMed

    Burrows, Courtney K; Kosova, Gülüm; Herman, Catherine; Patterson, Kristen; Hartmann, Katherine E; Velez Edwards, Digna R; Stephenson, Mary D; Lynch, Vincent J; Ober, Carole

    2016-07-01

    Fertility traits in humans are heritable, however, little is known about the genes that influence reproductive outcomes or the genetic variants that contribute to differences in these traits between individuals, particularly women. To address this gap in knowledge, we performed an unbiased genome-wide expression quantitative trait locus (eQTL) mapping study to identify common regulatory (expression) single nucleotide polymorphisms (eSNPs) in mid-secretory endometrium. We identified 423 cis-eQTLs for 132 genes that were significant at a false discovery rate (FDR) of 1%. After pruning for strong LD (r2 >0.95), we tested for associations between eSNPs and fecundability (the ability to get pregnant), measured as the length of the interval to pregnancy, in 117 women. Two eSNPs were associated with fecundability at a FDR of 5%; both were in the HLA region and were eQTLs for the TAP2 gene (P = 1.3x10-4) and the HLA-F gene (P = 4.0x10-4), respectively. The effects of these SNPs on fecundability were replicated in an independent sample. The two eSNPs reside within or near regulatory elements in decidualized human endometrial stromal cells. Our study integrating eQTL mapping in a primary tissue with association studies of a related phenotype revealed novel genes and associated alleles with independent effects on fecundability, and identified a central role for two HLA region genes in human implantation success. PMID:27447835

  6. Expression Quantitative Trait Locus Mapping Studies in Mid-secretory Phase Endometrial Cells Identifies HLA-F and TAP2 as Fecundability-Associated Genes.

    PubMed

    Burrows, Courtney K; Kosova, Gülüm; Herman, Catherine; Patterson, Kristen; Hartmann, Katherine E; Velez Edwards, Digna R; Stephenson, Mary D; Lynch, Vincent J; Ober, Carole

    2016-07-01

    Fertility traits in humans are heritable, however, little is known about the genes that influence reproductive outcomes or the genetic variants that contribute to differences in these traits between individuals, particularly women. To address this gap in knowledge, we performed an unbiased genome-wide expression quantitative trait locus (eQTL) mapping study to identify common regulatory (expression) single nucleotide polymorphisms (eSNPs) in mid-secretory endometrium. We identified 423 cis-eQTLs for 132 genes that were significant at a false discovery rate (FDR) of 1%. After pruning for strong LD (r2 >0.95), we tested for associations between eSNPs and fecundability (the ability to get pregnant), measured as the length of the interval to pregnancy, in 117 women. Two eSNPs were associated with fecundability at a FDR of 5%; both were in the HLA region and were eQTLs for the TAP2 gene (P = 1.3x10-4) and the HLA-F gene (P = 4.0x10-4), respectively. The effects of these SNPs on fecundability were replicated in an independent sample. The two eSNPs reside within or near regulatory elements in decidualized human endometrial stromal cells. Our study integrating eQTL mapping in a primary tissue with association studies of a related phenotype revealed novel genes and associated alleles with independent effects on fecundability, and identified a central role for two HLA region genes in human implantation success.

  7. Expression Quantitative Trait Locus Mapping Studies in Mid-secretory Phase Endometrial Cells Identifies HLA-F and TAP2 as Fecundability-Associated Genes

    PubMed Central

    Kosova, Gülüm; Patterson, Kristen; Hartmann, Katherine E.; Velez Edwards, Digna R.; Stephenson, Mary D.; Lynch, Vincent J.; Ober, Carole

    2016-01-01

    Fertility traits in humans are heritable, however, little is known about the genes that influence reproductive outcomes or the genetic variants that contribute to differences in these traits between individuals, particularly women. To address this gap in knowledge, we performed an unbiased genome-wide expression quantitative trait locus (eQTL) mapping study to identify common regulatory (expression) single nucleotide polymorphisms (eSNPs) in mid-secretory endometrium. We identified 423 cis-eQTLs for 132 genes that were significant at a false discovery rate (FDR) of 1%. After pruning for strong LD (r2 >0.95), we tested for associations between eSNPs and fecundability (the ability to get pregnant), measured as the length of the interval to pregnancy, in 117 women. Two eSNPs were associated with fecundability at a FDR of 5%; both were in the HLA region and were eQTLs for the TAP2 gene (P = 1.3x10-4) and the HLA-F gene (P = 4.0x10-4), respectively. The effects of these SNPs on fecundability were replicated in an independent sample. The two eSNPs reside within or near regulatory elements in decidualized human endometrial stromal cells. Our study integrating eQTL mapping in a primary tissue with association studies of a related phenotype revealed novel genes and associated alleles with independent effects on fecundability, and identified a central role for two HLA region genes in human implantation success. PMID:27447835

  8. Vaccination with Legionella pneumophila membranes induces cell-mediated and protective immunity in a guinea pig model of Legionnaires' disease. Protective immunity independent of the major secretory protein of Legionella pneumophila.

    PubMed Central

    Blander, S J; Horwitz, M A

    1991-01-01

    We have examined the capacity of Legionella pneumophila membranes to induce cell-mediated immune responses and protective immunity in a guinea pig model of Legionnaires' disease. Guinea pigs immunized by aerosol with L. pneumophila membranes developed strong cell-mediated immune responses to L. pneumophila membranes as demonstrated by cutaneous delayed-type hypersensitivity and in vitro splenic lymphocyte proliferation. Guinea pigs immunized by aerosol or by subcutaneous inoculation with L. pneumophila membranes developed strong protective immunity against lethal aerosol challenge with L. pneumophila. Overall, in six independent experiments, 39 of 49 (80%) guinea pigs immunized with L. pneumophila membranes survived challenge compared with 2 of 40 (5%) sham-immunized controls (P = 2 x 10(-13). In contrast, guinea pigs immunized by aerosol with formalin-killed L. pneumophila did not develop either a strong cell-mediated immune response to L. pneumophila antigens or protective immunity to lethal aerosol challenge. The capacity of L. pneumophila membranes to induce protective immunity was independent of the major secretory protein of L. pneumophila, which we previously demonstrated is an immunoprotective molecule. Purified L. pneumophila membranes did not contain detectable major secretory protein (MSP) on immunoblots; immunization of guinea pigs with L. pneumophila membranes did not induce anti-MSP antibody; and guinea pigs developed comparable protective immunity after immunization with membranes from either an L. pneumophila strain that secretes the major secretory protein or an isogenic mutant that does not. This study demonstrates that (a) immunization with L. pneumophila membranes but not formalin-killed L. pneumophila induces strong cell-mediated immune responses and protective immunity, (b) L. pneumophila membranes contain immunoprotective molecules distinct from the major secretory protein of L. pneumophila, and (c) L. pneumophila membranes have potential as

  9. SHP-2 Phosphatase Prevents Colonic Inflammation by Controlling Secretory Cell Differentiation and Maintaining Host-Microbiota Homeostasis.

    PubMed

    Coulombe, Geneviève; Langlois, Ariane; De Palma, Giada; Langlois, Marie-Josée; McCarville, Justin L; Gagné-Sanfaçon, Jessica; Perreault, Nathalie; Feng, Gen-Sheng; Bercik, Premysl; Boudreau, François; Verdu, Elena F; Rivard, Nathalie

    2016-11-01

    Polymorphisms in the PTPN11 gene encoding for the tyrosine phosphatase SHP-2 were described in patients with ulcerative colitis. We have recently demonstrated that mice with an intestinal epithelial cell-specific deletion of SHP-2 (SHP-2(IEC-KO) ) develop severe colitis 1 month after birth. However, the mechanisms by which SHP-2 deletion induces colonic inflammation remain to be elucidated. We generated SHP-2(IEC-KO) mice lacking Myd88 exclusively in the intestinal epithelium. The colonic phenotype was histologically analyzed and cell differentiation was determined by electron microscopy and lysozyme or Alcian blue staining. Microbiota composition was analyzed by 16S sequencing. Results show that innate defense genes including those specific to Paneth cells were strongly up-regulated in SHP-2-deficient colons. Expansion of intermediate cells (common progenitors of the Goblet and Paneth cell lineages) was found in the colon of SHP-2(IEC-KO) mice whereas Goblet cell number was clearly diminished. These alterations in Goblet/intermediate cell ratio were noticed 2 weeks after birth, before the onset of inflammation and were associated with significant alterations in microbiota composition. Indeed, an increase in Enterobacteriaceae and a decrease in Firmicutes were observed in the colon of these mice, indicating that dysbiosis also occurred prior to inflammation. Importantly, loss of epithelial Myd88 expression inhibited colitis development in SHP-2(IEC-KO) mice, rescued Goblet/intermediate cell ratio, and prevented NFκB hyperactivation and inflammation. These data indicate that SHP-2 is functionally important for the maintenance of appropriate barrier function and host-microbiota homeostasis in the large intestine. J. Cell. Physiol. 231: 2529-2540, 2016. © 2016 The Authors. Journal of Cellular Physiology published by Wiley Periodicals, Inc.

  10. [Endoplasmic-mitochondrial Ca(2+)-functional unit: dependence of respiration of secretory cells on activity of ryanodine- and IP3 - sensitive Ca(2+)-channels].

    PubMed

    Velykopols'ka, O Iu; Man'ko, B O; Man'ko, V V

    2012-01-01

    Using Clark oxygen electrode, dependence of mitochondrial functions on Ca(2+)-release channels activity of Chironomus plumosus L. larvae salivary glands suspension was investigated. Cells were ATP-permeabilized in order to enable penetration of exogenous oxidative substrates. Activation of plasmalemmal P2X-receptors (as well as P2Y-receptors) per se does not modify the endogenous respiration of salivary gland suspension. That is, Ca(2+)-influx from extracellular medium does not influence functional activity of mitochondria, although they are located along the basal part of the plasma membrane. Activation of RyRs intensifies endogenous respiration and pyruvate-malate-stimulated respiration, but not succinate-stimulated respiration. Neither activation of IP3Rs (via P2Y-receptors activation), nor their inhibition alters endogenous respiration. Nevertheless, IP3Rs inhibition by 2-APB intensifies succinate-stimulated respiration. All abovementioned facts testify that Ca2+, released from stores via channels, alters functional activity of mitochondria, and undoubtedly confirm the existence of endoplasmic-mitochondrial Ca(2+)-functional unit in Ch. plumosus larvae salivary glands secretory cells. In steady state of endoplasmic-mitochondrial Ca(2+)-functional unit the spontaneous activity of IP3Rs is observed; released through IP3Rs, Ca2+ is accumulated in mitochondria via uniporter and modulates oxidative processes. Activation of RyRs induces the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to the active state, which is required to intensify cell respiration and oxidative phosphorylation. As expected, the transition of endoplasmic-mitochondrial Ca(2+)-functional unit to inactivated state (i. e. inhibition of Ca(2+)-release channels at excessive [Ca2+]i) limits the duration of signal transduction, has protective nature and prevents apoptosis.

  11. Docking of Secretory Vesicles Is Syntaxin Dependent

    PubMed Central

    de Wit, Heidi; Cornelisse, L. Niels; Toonen, Ruud F.G.; Verhage, Matthijs

    2006-01-01

    Secretory vesicles dock at the plasma membrane before they undergo fusion. Molecular docking mechanisms are poorly defined but believed to be independent of SNARE proteins. Here, we challenged this hypothesis by acute deletion of the target SNARE, syntaxin, in vertebrate neurons and neuroendocrine cells. Deletion resulted in fusion arrest in both systems. No docking defects were observed in synapses, in line with previous observations. However, a drastic reduction in morphologically docked secretory vesicles was observed in chromaffin cells. Syntaxin-deficient chromaffin cells showed a small reduction in total and plasma membrane staining for the docking factor Munc18-1, which appears insufficient to explain the drastic reduction in docking. The sub-membrane cortical actin network was unaffected by syntaxin deletion. These observations expose a docking role for syntaxin in the neuroendocrine system. Additional layers of regulation may have evolved to make syntaxin redundant for docking in highly specialized systems like synaptic active zones. PMID:17205130

  12. Characterization of antigenic structures in auto-immune atrophic gastritis with pernicious anaemia. The parietal cell H,K-ATPase and the chief cell pepsinogen are the two major antigens.

    PubMed

    Mårdh, S; Song, Y H

    1989-08-01

    Using isolated cells and subcellular fractions from pig gastric mucosa, antigenic structures with specific binding of IgG from sera of patients with auto-immune atrophic gastritis were characterized by means of immunoblotting and enzyme-linked immunosorbent assay. In immunoblotting experiments using mucosal cells as the antigen source, two dominating bands of 94 and 41 kDa were found. The two major antigens were identified as the H,K-ATPase (94 kDa), which constitutes the parietal cell acid pump, and pepsinogen (41 kDa) located in the chief cells. There was also a small but significant binding of antibodies to a preparation of Na,K-ATPase, an enzyme which is about 60% homologous to H,K-ATPase. Commercial preparations of hog gastric pepsinogen and pepsin bound pernicious anaemia IgG with equal efficacy. When sera from seven patients with the diagnosis pernicious anaemia were tested, all were found to contain auto-antibodies against H,K-ATPase as well as pepsinogen. In intact, isolated H,K-ATPase-containing vesicles the cytosolic part of the ATPase molecule is facing the outside of the vesicles. Both intact and trypsinized vesicles were incubated with patient sera and with a monoclonal antibody against H,K-ATPase. Pernicious anaemia IgG was found to bind to a cytosolic, trypsin-resistant structure, but the binding of the monoclonal antibody was lost upon trypsinization. The present results indicate that intracellular structures of the gastric mucosa, due to cell damage, may be exposed to immune-competent cells, which do not recognize these structures as 'self'.

  13. Monoclonal immunoglobulin A antibodies directed against cholera toxin prevent the toxin-induced chloride secretory response and block toxin binding to intestinal epithelial cells in vitro.

    PubMed Central

    Apter, F M; Lencer, W I; Finkelstein, R A; Mekalanos, J J; Neutra, M R

    1993-01-01

    Secretory immunoglobulin A (IgA) antibodies directed against cholera toxin (CT) are thought to be important in resistance to oral challenge with virulent Vibrio cholerae, although alternative mechanisms for protection of intestinal epithelia against CT-induced fluid secretion have been proposed. The ability of anti-CT IgA to block the effects of CT on human enterocytes has not been directly tested because of the lack of a well-defined in vitro intestinal epithelial cell system to directly measure toxin action and the limited availability of purified anti-CT IgA antibodies. We have generated hybridomas that produce monoclonal IgA and IgG antibodies directed against CT by fusion of Peyer's patch cells with mouse myeloma cells after oral-systemic immunization of mice with CT and CT B-subunit protein. All of the anti-CT antibodies recognized the B subunit. Three clones (designated anti-CTB IgA-1, IgA-2, and IgA-3) which produced IgA antibodies in dimeric and polymeric forms were selected. Checkerboard immunoblotting demonstrated that IgA-1 recognized an epitope distinct from that recognized by IgA-2 and IgA-3 and that none of the antibodies were directed against the binding site of GM1, the intestinal cell membrane toxin receptor. The protective capacity of these IgAs was tested in vitro with human T84 colon carcinoma cells grown on permeable supports as confluent monolayers of polarized enterocytes. When each anti-CTB IgA was mixed with 10 nM CT and applied to the apical surfaces of T84 cell monolayers, all three IgAs blocked CT-induced Cl- secretion in a dose-dependent manner and completely inhibited binding of rhodamine-labelled CT to apical cell membranes. Thus, monoclonal anti-CTB IgA antibodies are sufficient to protect human enterocytes in vitro against CT binding and action. Images PMID:7693598

  14. Ricinus communis L. stem bark extracts regulate ovarian cell functions and secretory activity and their response to Luteinising hormone.

    PubMed

    Nath, S; Kadasi, A; Grossmann, R; Sirotkin, A V; Kolesarova, A; Talukdar, A D; Choudhury, M D

    2015-01-01

    Ricinus communis L. has ethnopharmacological contraceptive reputation but its stem bark has unexplored mechanisms of action in female reproductive system. In the present study, the effect of methanolic and aqueous extracts from the stem bark of the plant was examined on basic porcine ovarian granulosa cell functions and its response to Luteinising hormone (LH)-the upstream hormonal regulator. Systemic treatment of methanolic and aqueous extracts stimulated cell proliferation (proliferating cell nuclear antigen, PCNA) and also promoted cell apoptosis (caspase-3). Aqueous extract has inverted the stimulatory effect of LH on PCNA but not on caspase-3. Methanolic extract stimulated as well as inhibited progesterone release and stimulated testosterone secretion. Whereas aqueous extract inhibited both steroid releases and suppressed the stimulatory effect of LH on progesterone release and promoted the inhibitory effect of LH on testosterone release. In conclusion, the present study unveils the mechanism of action of R. communis stem bark in in vitro condition. These suggest its possible contraceptive efficacy by exerting its regulatory role over LH and on basic ovarian cell functions and secretion activity. PMID:26311247

  15. Ricinus communis L. stem bark extracts regulate ovarian cell functions and secretory activity and their response to Luteinising hormone.

    PubMed

    Nath, S; Kadasi, A; Grossmann, R; Sirotkin, A V; Kolesarova, A; Talukdar, A D; Choudhury, M D

    2015-01-01

    Ricinus communis L. has ethnopharmacological contraceptive reputation but its stem bark has unexplored mechanisms of action in female reproductive system. In the present study, the effect of methanolic and aqueous extracts from the stem bark of the plant was examined on basic porcine ovarian granulosa cell functions and its response to Luteinising hormone (LH)-the upstream hormonal regulator. Systemic treatment of methanolic and aqueous extracts stimulated cell proliferation (proliferating cell nuclear antigen, PCNA) and also promoted cell apoptosis (caspase-3). Aqueous extract has inverted the stimulatory effect of LH on PCNA but not on caspase-3. Methanolic extract stimulated as well as inhibited progesterone release and stimulated testosterone secretion. Whereas aqueous extract inhibited both steroid releases and suppressed the stimulatory effect of LH on progesterone release and promoted the inhibitory effect of LH on testosterone release. In conclusion, the present study unveils the mechanism of action of R. communis stem bark in in vitro condition. These suggest its possible contraceptive efficacy by exerting its regulatory role over LH and on basic ovarian cell functions and secretion activity.

  16. Involvement of multiple protein kinase C isozymes in the ACTH secretory pathway of AtT-20 cells.

    PubMed Central

    McFerran, B. W.; MacEwan, D. J.; Guild, S. B.

    1995-01-01

    1. The mouse AtT-20/D16-16 anterior pituitary tumour cell line was used as a model system for the study of protein kinase C (PKC)-mediated enhancement of calcium- and guanine nucleotide-evoked adrenocorticotrophin (ACTH) secretion. 2. A profile of the PKC isozymes present in AtT-20 cells was obtained by Western blotting analysis and it was found that AtT-20 cells express the alpha, beta, epsilon and zeta isoforms of PKC. 3. PKC isozymes were activated by the use of substances reported to activate particular isoforms of the enzyme. The effects of these substances were investigated in both intact and electrically-permeabilized cells. Phorbol 12-myristate 13-acetate (PMA, EC50 = 1 +/- 0.05 nM, which activates all isozymes of PKC, except the zeta isozyme), thymeleatoxin (TMX, EC50 = 10 +/- 0.5 nM, which activates the alpha, beta and gamma isozymes) and 12-deoxyphorbol 13-phenylacetate 20-acetate (dPPA, EC50 = 3 +/- 0.5 nM, a beta 1-selective isozyme activator) all stimulated ACTH secretion from intact cells in a concentration-dependent manner. Maximal TMX stimulated ACTH secretion was of a similar degree to that obtained in response to PMA but maximal dPPA-stimulated ACTH secretion was only 60-70% of that obtained in response to PMA or TMX. 4. Calcium stimulated ACTH secretion from electrically-permeabilized cells over the concentration-range of 100 nM to 10 microM. PMA (100 nM), TMX (100 nM) but not dPPA (100 nM) enhanced the amount of ACTH secreted at every concentration of calcium investigated.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1 PMID:7670732

  17. Larval excretory-secretory products from the parasite Schistosoma mansoni modulate HSP70 protein expression in defence cells of its snail host, Biomphalaria glabrata

    PubMed Central

    Zahoor, Zahida; Davies, Angela J.; Kirk, Ruth S.; Rollinson, David

    2010-01-01

    Synthesis of heat shock proteins (HSPs) following cellular stress is a response shared by many organisms. Amongst the HSP family, the ∼70 kDa HSPs are the most evolutionarily conserved with intracellular chaperone and extracellular immunoregulatory functions. This study focused on the effects of larval excretory-secretory products (ESPs) from the parasite Schistosoma mansoni on HSP70 protein expression levels in haemocytes (defence cells) from its snail intermediate host Biomphalaria glabrata. S. mansoni larval stage ESPs are known to interfere with haemocyte physiology and behaviour. Haemocytes from two different B. glabrata strains, one which is susceptible to S. mansoni infection and one which is resistant, both showed reduced HSP70 protein levels following 1 h challenge with S. mansoni ESPs when compared to unchallenged controls; however, the reduction observed in the resistant strain was less marked. The decline in intracellular HSP70 protein persisted for at least 5 h in resistant snail haemocytes only. Furthermore, in schistosome-susceptible snails infected by S. mansoni for 35 days, haemocytes possessed approximately 70% less HSP70. The proteasome inhibitor, MG132, partially restored HSP70 protein levels in ESP-challenged haemocytes, demonstrating that the decrease in HSP70 was in part due to intracellular degradation. The extracellular signal-regulated kinase (ERK) signalling pathway appears to regulate HSP70 protein expression in these cells, as the mitogen-activated protein-ERK kinase 1/2 (MEK1/2) inhibitor, U0126, significantly reduced HSP70 protein levels. Disruption of intracellular HSP70 protein expression in B. glabrata haemocytes by S. mansoni ESPs may be a strategy employed by the parasite to manipulate the immune response of the intermediate snail host. PMID:20182834

  18. Quantification of mesenchymal stem cell growth rates through secretory and excretory biomolecules in conditioned media via Fresnel reflection.

    PubMed

    Ahmad, Harith; Thambiratnam, Kavintheran; Zulkifli, Ahmad Z; Lawrence, Anthony; Jasim, Ali A; Kunasekaran, Wijenthiran; Musa, Sabri; Gnanasegaran, Nareshwaran; Vasanthan, Punitha; Jayaraman, Pukana; Kasim, Noor H A; Govindasamy, Vijayendran; Shahrir, Mohammad S; Harun, Sulaiman W

    2013-09-30

    An efficient and low cost optical method for directly measuring the concentration of homogenous biological solutes is proposed and demonstrated. The proposed system operates by Fresnel reflection, with a flat-cleaved single-mode fiber serving as the sensor probe. A laser provides a 12.9 dBm sensor signal at 1,550 nm, while a computer-controlled optical power meter measures the power of the signal returned by the probe. Three different mesenchymal stem cell (MSC) lines were obtained, sub-cultured and trypsinized daily over 9 days. Counts were measured using a haemocytometer and the conditioned media (CM) was collected daily and stored at -80 °C. MSCs release excretory biomolecules proportional to their growth rate into the CM, which changes the refractive index of the latter. The sensor is capable of detecting changes in the number of stem cells via correlation to the change in the refractive index of the CM, with the measured power loss decreasing approximately 0.4 dB in the CM sample per average 1,000 cells in the MSC subculture. The proposed system is highly cost-effective, simple to deploy, operate, and maintain, is non-destructive, and allows reliable real-time measurement of various stem cell proliferation parameters.

  19. Quantification of Mesenchymal Stem Cell Growth Rates through Secretory and Excretory Biomolecules in Conditioned Media via Fresnel Reflection

    PubMed Central

    Ahmad, Harith; Thambiratnam, Kavintheran; Zulkifli, Ahmad Z.; Lawrence, Anthony; Jasim, Ali A.; Kunasekaran, Wijenthiran; Musa, Sabri; Gnanasegaran, Nareshwaran; Vasanthan, Punitha; Jayaraman, Pukana; Kasim, Noor H. A.; Govindasamy, Vijayendran; Shahrir, Mohammad S.; Harun, Sulaiman W.

    2013-01-01

    An efficient and low cost optical method for directly measuring the concentration of homogenous biological solutes is proposed and demonstrated. The proposed system operates by Fresnel reflection, with a flat-cleaved single-mode fiber serving as the sensor probe. A laser provides a 12.9 dBm sensor signal at 1,550 nm, while a computer-controlled optical power meter measures the power of the signal returned by the probe. Three different mesenchymal stem cell (MSC) lines were obtained, sub-cultured and trypsinized daily over 9 days. Counts were measured using a haemocytometer and the conditioned media (CM) was collected daily and stored at −80 °C. MSCs release excretory biomolecules proportional to their growth rate into the CM, which changes the refractive index of the latter. The sensor is capable of detecting changes in the number of stem cells via correlation to the change in the refractive index of the CM, with the measured power loss decreasing approximately 0.4 dB in the CM sample per average 1,000 cells in the MSC subculture. The proposed system is highly cost-effective, simple to deploy, operate, and maintain, is non-destructive, and allows reliable real-time measurement of various stem cell proliferation parameters. PMID:24084118

  20. Secretory IgA synthesis in Kwashiorkor.

    PubMed

    Beatty, D W; Napier, B; Sinclair-Smith, C C; McCabe, K; Hughes, E J

    1983-09-01

    The synthesis of intestinal secretory IgA was studied in in vitro cultures of duodenal mucosal biopsies from children with Kwashiorkor. Production of secretory IgA was measured by the incorporation of radioactive label and visualized following PAGE and autoradiography. Results obtained before and after nutritional rehabilitation demonstrate an enhanced synthesis of sIgA in children with acute Kwashiorkor. Histological examination of plasma cells in the biopsy tissue confirms a twofold increase in IgA staining plasma cells in acute Kwashiorkor. Peripheral blood B lymphocytes in acute Kwashiorkor however, showed a reduction in IgA synthesis in the acute stage. These results suggest an effective mucosal sIgA response to the increased intestinal antigen load in Kwashiorkor.

  1. Molecular bases of K+ secretory cells in the inner ear: shared and distinct features between birds and mammals

    PubMed Central

    Wilms, Viviane; Köppl, Christine; Söffgen, Chris; Hartmann, Anna-Maria; Nothwang, Hans Gerd

    2016-01-01

    In the cochlea, mammals maintain a uniquely high endolymphatic potential (EP), which is not observed in other vertebrate groups. However, a high [K+] is always present in the inner ear endolymph. Here, we show that Kir4.1, which is required in the mammalian stria vascularis to generate the highly positive EP, is absent in the functionally equivalent avian tegmentum vasculosum. In contrast, the molecular repertoire required for K+ secretion, specifically NKCC1, KCNQ1, KCNE1, BSND and CLC-K, is shared between the tegmentum vasculosum, the vestibular dark cells and the marginal cells of the stria vascularis. We further show that in barn owls, the tegmentum vasculosum is enlarged and a higher EP (~+34 mV) maintained, compared to other birds. Our data suggest that both the tegmentum vasculosum and the stratified stria vascularis evolved from an ancestral vestibular epithelium that already featured the major cell types of the auditory epithelia. Genetic recruitment of Kir4.1 specifically to strial melanocytes was then a crucial step in mammalian evolution enabling an increase in the cochlear EP. An increased EP may be related to high-frequency hearing, as this is a hallmark of barn owls among birds and mammals among amniotes. PMID:27680950

  2. Retrovirus-mediated expression of preprosomatostatin in rat pituitary GH3 cells: targeting of somatostatin to the regulated secretory pathway.

    PubMed

    Fleischer, N; Liker, H; Stoller, T; D'Ambra, R; Shields, D

    1989-10-01

    Somatostatin (SRIF) is a 14-amino acid peptide hormone that is synthesized as part of a larger precursor, prepro-SRIF, consisting of a signal peptide and a proregion of 80-90 amino acids; mature SRIF is located at the carboxyl-terminus of the precursor. We have used a recombinant retroviral expression vector encoding anglerfish prepor-SRIF-I to infect rat pituitary GH3 cells. The aim of these studies was to investigate the intracellular storage and secretion of the total pool of endogenous GH compared to that of SRIF. Several clonal lines of GH3 cells expressing high or low levels of SRIF were treated with TRH, forskolin, or depolarizing concentrations of potassium, and the levels of intracellular and secreted GH or SRIF were determined using highly sensitive RIAs. Approximately 65% of the total GH was secreted basally, whereas less than 20% of the SRIF-immunoreactive material was basally secreted. Forskolin treatment or potassium depolarization stimulated GH release, but only about 50% above basal levels. In contrast, SRIF secretion was stimulated approximately 5-fold in response to these secretagogues. Based on its lower basal rate of secretion compared to GH and its enhanced release in response to a variety of secretagogues, we conclude that the heterologously expressed SRIF is preferentially targeted to the regulated pathway in GH3 cells. PMID:2575212

  3. Identification of endothelin 1 and big endothelin 1 in secretory vesicles isolated from bovine aortic endothelial cells.

    PubMed

    Harrison, V J; Barnes, K; Turner, A J; Wood, E; Corder, R; Vane, J R

    1995-07-01

    Vesicles containing endothelin 1 (ET-1) were isolated from bovine aortic endothelial cells (BAECs) by fractionation of homogenates on sucrose density gradients by ultracentrifugation. The vesicles were localized at the 1.0/1.2 M sucrose interface using a specific anti-ET-1-(16-21) RIA. Identification of ET-1 and big ET-1 in this fraction was confirmed by HPLC analysis combined with RIA. Morphological examination of the ET-1-enriched fraction by electron microscopy identified clusters of vesicles approximately 100 nm in diameter. Immunostaining of ultrathin cryosections prepared from the vesicle fraction for ET-1 or big ET-1 showed clusters of 15-nm gold particles attached to or within vesicles. Immunofluorescence staining of whole BAECs using a specific ET-1-(16-21) IgG purified by affinity chromatography revealed punctate granulation of the cell cytoplasm viewed under light microscopy. This distinct pattern of staining was shown by confocal light microscopy to be intracellular. Immunofluorescence staining of whole cells with a polyclonal antiserum for big ET-1-(22-39) showed a defined perinuclear localization of precursor molecule. Hence, several different approaches have demonstrated that ET-1 and big ET-1 are localized within intracellular vesicles in BAECs, suggesting that these subcellular compartments are an important site for processing of big ET-1 by endothelin-converting enzyme.

  4. Potential of yeast secretory vesicles in biodelivery systems.

    PubMed

    Kutralam-Muniasamy, Gurusamy; Flores-Cotera, Luis B; Perez-Guevara, Fermin

    2015-06-01

    Membranous vesicular organelles (MVOs), such as secretory vesicles and exosomes, perform a variety of biological functions ranging from secretion to cellular communication in eukaryotic cells. Exosomes, particularly those of mammalian cells, have been widely studied as potential carriers in human therapeutic applications. However, no study has yet demonstrated the use of yeast secretory vesicles for such applications. Therefore, we explore here the current state of knowledge on yeast secretory vesicles and their potential use in therapeutic delivery systems. We focus on the characteristics shared by exosomes and yeast secretory vesicles to provide insights into the use of the latter as delivery vehicles. From this perspective, we speculate on the potential application of post-Golgi vesicles (PGVs) in the biomedical field. PMID:25843637

  5. 660 nm Red LED Induces Secretory Leukocyte Protease Inhibitor (SLPI) in Lipopolysaccharide-Stimulated RAW264.7 Cell.

    PubMed

    Jeong, Soon-Jeong; Choi, Baik-Dong; Lee, Hye-Yon; Hwang, Young-Hyoun; Kim, Byung-Hoon; Cho, Yong-Ick; Yun, Je-Jung; Lee, Byung-Ho; Jeong, Moon-Jin

    2015-08-01

    SLPI acts as a modulator of the innate immune responses of macrophages, neutrophils and odontoblasts, and LPS-inducible anti-inflammatory cytokine to suppress the production of pro-inflammatory products by macrophages. Many studies have revealed the effects of light emitting diodes (LEDs) on the tissue repair and inflammatory responses. Although the anti-inflammatory mechanisms of irradiation with LEDs in gingival fibroblasts are known, the effects of 660 nm red LEDs on the inflammation remain unclear. Moreover, there is no report regarding the molecular mechanism for the relationship between SLPI and biological effects of LEDs. The effects of 660 nm red LEDs on inflammation with SLPI were investigated by examining the effects of 660 nm LED on the SLPI expression of RAW264.7 cells after LPS stimulation. This paper reports that the 660 nm red LED induced SLPI expression or reduced the LPS response, and inhibited NF-κB activation directly, leading to the suppression of pro-inflammatory cytokines, such as TNF-α and IL-1β, suggesting that it might be a useful wavelength LED for inflammation therapy.

  6. Effects of methanolic extracts from edible plants on endogenous secretory receptor for advanced glycation end products induced by the high glucose incubation in human endothelial cells

    PubMed Central

    Okada, Yoshinori; Okada, Mizue

    2015-01-01

    Background: In diabetic populations, endogenous secretory receptor for advanced glycation end products (esRAGE) levels may be related to the degree of diabetic complications or to the protection from diabetic complications. Objective: We investigated the impact of 29 methanolic extracts from edible plants on esRAGE production in human umbilical vein endothelial cells (HUVECs) cultured in high (4.5 g/L) glucose. Materials and Methods: Edible plants were minced, and extracts were obtained with methanol overnight. The methanolic extracts from 29 edible plants were evaporated in a vacuum. For screening study purposes, HUVECs were seeded in culture dishes (1.5 × 105 cells). Then, HUVECs were incubated with 1 g/L or 4.5 g/L of glucose in SFM CS-C medium treated with methanolic extracts from edible plants (MEEP) for 96 h. Determination of esRAGE production in the cell culture-derived supernatants was performed by colorimetric ELISA. The 8-hydroxydeoxyguanosine (8-OHdG) level was determined by using the 8-OHdG Check ELISA kit. Peroxynitrite-dependent oxidation of 2’, 7’-dichlorodihydrofluorescein to 2’, 7’-dichlorofluorescein was estimated based on the method described by Crow. Because MEEP were methanolic extracts, we measured their total phenolic content (TPC). TPC was measured with a modified version of the Folin–Ciocalteu method. Results: The results showed eight extracts increased esRAGE production. The extract from white radish sprouts showed the highest esRAGE production activity, and then eggplant, carrot peel, young sweet corn, Jew's marrow, broad bean, Japanese radish and cauliflower. In order to understand the mechanism of esRAGE production, the eight extracts were examined for DNA damage, peroxynitrite scavenging activity, and TPC in correlation with their esRAGE production. The results showed esRAGE production correlates with the peroxynitrite level and TPC. Conclusion: This study supports the utilization of these eight extracts in folk medicine for

  7. Somatostatin-14, somatostatin-28, and prosomatostatin[1-10] are independently and efficiently processed from prosomatostatin in the constitutive secretory pathway in islet somatostatin tumor cells (1027B2).

    PubMed

    Patel, Y C; Galanopoulou, A S; Rabbani, S N; Liu, J L; Ravazzola, M; Amherdt, M

    1997-08-01

    We have characterized the biosynthetic origin of somatostatin-14 (SS-14), SS-28, and pro-SS[1-10] from pro-SS (PSS) in 1027B2 rat islet tumor cells. Because these cells lack regulated secretion and show unresponsiveness of the SS gene to cAMP, we have additionally carried out morphological and functional studies to elucidate the molecular defect in cAMP signalling and to localize the sites of PSS maturation along the secretory pathway. Cell extracts and secretion media were analysed by high performance liquid chromatography and specific C- and N-terminal radioimmunoassays. Electron microscopic sampling of 1027B2 cell cultures showed that most cells had very few dense core secretory granules for heterogeneous sizes. The cells expressed the endoproteases furin, PC1, and PC2 and contained large quantities of fully processed SS-14 and SS-28 with very little unprocessed PSS (ratio SS-14:SS-28:PSS = 39:51:10%). They secreted high concentrations of SS-14, SS-28, and PSS[1-10] constitutively along with PC1 and PC2. Pulse-chase studies demonstrated that PSS is rapidly (within 15 min), and efficiently processed to SS-14, SS-28, and PSS[1-10] via separate biosynthetic pathways: PSS --> SS-14 + 8 kDa; PSS --> SS-28 + 7 kDa; PSS --> PSS[1-10]. Monensin reduced intracellular SS-like immunoreactivity without altering processing efficiency. Transfection with the catalytic subunit of protein kinase A (PKA-C) activated SS promoter-CAT activating indicating that the defect in cAMP-dependent signaling in 1027B2 cells lies at the level of PKA-C. PKA-C overexpression failed to alter the ratio of processed SS-14 and SS-28. These results demonstrate that SS-14, SS-28, and PSS[1-10] are independently synthesized from PSS and that efficient precursor processing can occur within the constitutive secretory pathway in the relative absence of dense core secretory vesicles. PMID:9296377

  8. Influence of colchicine and vinblastine on the intracellular migration of secretory and membrane glycoproteins: II. Inhibition of secretion of thyroglobulin in rat thyroid follicular cells as visualized by radioautography after 3H-fucose injection

    SciTech Connect

    Wild, G.; Bennett, G.

    1984-08-01

    Young (40 gm) rats were given a single intravenous injection of colchicine (4.0 mg) or vinblastine (2.0 mg). At 10 min after colchicine and 30 min after vinblastine administration, the rats were injected with 3H-fucose. Control rats received 3H-fucose only. All rats were sacrificed 90 min after 3H-fucose injection and their tissues processed for radioautography. In thyroid follicular cells of control animals, at this time interval, 57% of the total label was associated with colloid and secretory vesicles in the apical cytoplasm while 27% was localized in the Golgi apparatus and neighboring vesicles. In experimental animals, the proportion of label in colloid and apical vesicles was reduced by more than 69% after colchicine and more than 83% after vinblastine treatment. The proportion of label in the Golgi region, on the other hand, increased by more than 125% after colchicine and more than 179% after vinblastine treatment. Within the Golgi region, the great majority of the label was associated with secretory vesicles which accumulated adjacent to the trans face of the Golgi stacks. It is concluded that the drugs do not interfere with passage of newly synthesized thyroglobulin from the Golgi saccules to nearby secretory vesicles, but do inhibit intracellular migration of these vesicles to the cell apex. In most cells the number of vesicles in the apical cytoplasm diminished, but this was not always the case, suggesting that exocytosis may also be partially inhibited. The loss of microtubules in drug-treated cells suggests that the microtubules may be necessary for intracellular transport of thyroglobulin.

  9. SOX10-positive salivary gland tumors: a growing list, including mammary analogue secretory carcinoma of the salivary gland, sialoblastoma, low-grade salivary duct carcinoma, basal cell adenoma/adenocarcinoma, and a subgroup of mucoepidermoid carcinoma.

    PubMed

    Hsieh, Min-Shu; Lee, Yi-Hsuan; Chang, Yih-Leong

    2016-10-01

    Transcription factor SRY-related HMG-box 10 (SOX10) is an important marker for melanocytic, schwannian, myoepithelial, and some salivary gland tumors. The aim of this study was to investigate SOX10 expression more thoroughly in the salivary gland neoplasms, including mammary analogue secretory carcinoma and hyalinizing clear cell carcinoma harboring specific genetic rearrangements. A new rabbit monoclonal anti-SOX10 antibody (clone EP268) was used to examine SOX10 expression in 14 different types of salivary gland tumors. We found that acinic cell carcinoma (AciCC), adenoid cystic carcinoma, mammary analogue secretory carcinoma (MASC), epithelial-myoepithelial carcinoma, low-grade salivary duct carcinoma, sialoblastoma, basal cell adenocarcinoma, basal cell adenoma, and pleomorphic adenoma were SOX10 positive. Salivary duct carcinoma, lymphoepithelial carcinoma, hyalinizing clear cell carcinoma, and oncocytoma were SOX10 negative. Earlier, mucoepidermoid carcinoma (MEC) was considered a SOX10-negative tumor. This study identified a subgroup of SOX10-positive MEC cases with characteristic polygonal epithelial cells, pale-to-eosinophilic cytoplasm, and colloid-like dense eosinophilic material. Our data show SOX10 expression can be observed in salivary gland tumors with either one of the 4 cell types: acinic cells, cuboidal ductal cells with low-grade cytologic features, basaloid cells, and myoepithelial cells. In this article we thoroughly evaluated SOX10 expression in salivary gland tumors. SOX10 is useful in the differential diagnosis between myoepithelial carcinoma with clear cell features and hyalinizing clear cell carcinoma. It can also be used to discriminate low-grade salivary duct carcinoma from high-grade ones. Pathologists should be cautious with the interpretation of SOX10 positivity in salivary gland tumors, and correlation with histologic feature is mandatory.

  10. SOX10-positive salivary gland tumors: a growing list, including mammary analogue secretory carcinoma of the salivary gland, sialoblastoma, low-grade salivary duct carcinoma, basal cell adenoma/adenocarcinoma, and a subgroup of mucoepidermoid carcinoma.

    PubMed

    Hsieh, Min-Shu; Lee, Yi-Hsuan; Chang, Yih-Leong

    2016-10-01

    Transcription factor SRY-related HMG-box 10 (SOX10) is an important marker for melanocytic, schwannian, myoepithelial, and some salivary gland tumors. The aim of this study was to investigate SOX10 expression more thoroughly in the salivary gland neoplasms, including mammary analogue secretory carcinoma and hyalinizing clear cell carcinoma harboring specific genetic rearrangements. A new rabbit monoclonal anti-SOX10 antibody (clone EP268) was used to examine SOX10 expression in 14 different types of salivary gland tumors. We found that acinic cell carcinoma (AciCC), adenoid cystic carcinoma, mammary analogue secretory carcinoma (MASC), epithelial-myoepithelial carcinoma, low-grade salivary duct carcinoma, sialoblastoma, basal cell adenocarcinoma, basal cell adenoma, and pleomorphic adenoma were SOX10 positive. Salivary duct carcinoma, lymphoepithelial carcinoma, hyalinizing clear cell carcinoma, and oncocytoma were SOX10 negative. Earlier, mucoepidermoid carcinoma (MEC) was considered a SOX10-negative tumor. This study identified a subgroup of SOX10-positive MEC cases with characteristic polygonal epithelial cells, pale-to-eosinophilic cytoplasm, and colloid-like dense eosinophilic material. Our data show SOX10 expression can be observed in salivary gland tumors with either one of the 4 cell types: acinic cells, cuboidal ductal cells with low-grade cytologic features, basaloid cells, and myoepithelial cells. In this article we thoroughly evaluated SOX10 expression in salivary gland tumors. SOX10 is useful in the differential diagnosis between myoepithelial carcinoma with clear cell features and hyalinizing clear cell carcinoma. It can also be used to discriminate low-grade salivary duct carcinoma from high-grade ones. Pathologists should be cautious with the interpretation of SOX10 positivity in salivary gland tumors, and correlation with histologic feature is mandatory. PMID:27327192

  11. RFP tags for labeling secretory pathway proteins

    SciTech Connect

    Han, Liyang; Zhao, Yanhua; Xu, Pingyong; Huan, Shuangyan

    2014-05-09

    Highlights: • Membrane protein Orai1 can be used to report the fusion properties of RFPs. • Artificial puncta are affected by dissociation constant as well as pKa of RFPs. • Among tested RFPs mOrange2 is the best choice for secretory protein labeling. - Abstract: Red fluorescent proteins (RFPs) are useful tools for live cell and multi-color imaging in biological studies. However, when labeling proteins in secretory pathway, many RFPs are prone to form artificial puncta, which may severely impede their further uses. Here we report a fast and easy method to evaluate RFPs fusion properties by attaching RFPs to an environment sensitive membrane protein Orai1. In addition, we revealed that intracellular artificial puncta are actually colocalized with lysosome, thus besides monomeric properties, pKa value of RFPs is also a key factor for forming intracellular artificial puncta. In summary, our current study provides a useful guide for choosing appropriate RFP for labeling secretory membrane proteins. Among RFPs tested, mOrange2 is highly recommended based on excellent monomeric property, appropriate pKa and high brightness.

  12. Secretory pathway of cellulase: a mini-review

    PubMed Central

    2013-01-01

    Cellulase plays an important role in modern industry and holds great potential in biofuel production. Many different types of organisms produce cellulase, which go through secretory pathways to reach the extracellular space, where enzymatic reactions take place. Secretory pathways in various cells have been the focus of many research fields; however, there are few studies on secretory pathways of cellulases in the literature. It is therefore necessary and important to review the current knowledge on the secretory pathways of cellulases. In this mini-review, we address the subcellular locations of cellulases in different organisms, discuss the secretory pathways of cellulases in different organisms, and examine the secretory mechanisms of cellulases. These sections start with a description of general secreted proteins, advance to the situation of cellulases, and end with the knowledge of cellulases, as documented in UniProt Knowledgebase (UniProtKB). Finally, gaps in existing knowledge are highlighted, which may shed light on future studies for biofuel engineering. PMID:24295495

  13. Progressive bilateral thinning of the parietal bones

    SciTech Connect

    Cederlund, C.G.; Andren, L.; Olivecrona, H.

    1982-03-01

    Observation of a case of progressive bilateral parietal thinning within a period of 14 years induced us to study skull films of 3 636 consecutive patients. Parietal thinning was found in 86 patients (2.37%). It was more common in women, with a sex ratio of 1:1.9. The mean age of the females was 72 years, and that of the males 63 years. Previous skull films of 25 of these patients were available and showed progression in 10. It is concluded that parietal thinning is a slowly progressive disease of middle-aged and old patients and is not an anatomical variant or congenital dysplasia of the dipole.

  14. The secretory pathway of protists: spatial and functional organization and evolution.

    PubMed Central

    Becker, B; Melkonian, M

    1996-01-01

    All cells secrete a diversity of macromolecules to modify their environment or to protect themselves. Eukaryotic cells have evolved a complex secretory pathway consisting of several membrane-bound compartments which contain specific sets of proteins. Experimental work on the secretory pathway has focused mainly on mammalian cell lines or on yeasts. Now, some general principles of the secretory pathway have become clear, and most components of the secretory pathway are conserved between yeast cells and mammalian cells. However, the structure and function of the secretory system in protists have been less extensively studied. In this review, we summarize the current knowledge about the secretory pathway of five different groups of protists: Giardia lamblia, one of the earliest lines of eukaryotic evolution, kinetoplastids, the slime mold Dictyostelium discoideum, and two lineages within the "crown" of eukaryotic cell evolution, the alveolates (ciliates and Plasmodium species) and the green algae. Comparison of these systems with the mammalian and yeast system shows that most elements of the secretory pathway were presumably present in the earliest eukaryotic organisms. However, one element of the secretory pathway shows considerable variation: the presence of a Golgi stack and the number of cisternae within a stack. We suggest that the functional separation of the plasma membrane from the nucleus-endoplasmic reticulum system during evolution required a sorting compartment, which became the Golgi apparatus. Once a Golgi apparatus was established, it was adapted to the various needs of the different organisms. PMID:8987360

  15. The secretory pathway of protists: spatial and functional organization and evolution.

    PubMed

    Becker, B; Melkonian, M

    1996-12-01

    All cells secrete a diversity of macromolecules to modify their environment or to protect themselves. Eukaryotic cells have evolved a complex secretory pathway consisting of several membrane-bound compartments which contain specific sets of proteins. Experimental work on the secretory pathway has focused mainly on mammalian cell lines or on yeasts. Now, some general principles of the secretory pathway have become clear, and most components of the secretory pathway are conserved between yeast cells and mammalian cells. However, the structure and function of the secretory system in protists have been less extensively studied. In this review, we summarize the current knowledge about the secretory pathway of five different groups of protists: Giardia lamblia, one of the earliest lines of eukaryotic evolution, kinetoplastids, the slime mold Dictyostelium discoideum, and two lineages within the "crown" of eukaryotic cell evolution, the alveolates (ciliates and Plasmodium species) and the green algae. Comparison of these systems with the mammalian and yeast system shows that most elements of the secretory pathway were presumably present in the earliest eukaryotic organisms. However, one element of the secretory pathway shows considerable variation: the presence of a Golgi stack and the number of cisternae within a stack. We suggest that the functional separation of the plasma membrane from the nucleus-endoplasmic reticulum system during evolution required a sorting compartment, which became the Golgi apparatus. Once a Golgi apparatus was established, it was adapted to the various needs of the different organisms.

  16. ATP: The crucial component of secretory vesicles.

    PubMed

    Estévez-Herrera, Judith; Domínguez, Natalia; Pardo, Marta R; González-Santana, Ayoze; Westhead, Edward W; Borges, Ricardo; Machado, José David

    2016-07-12

    The colligative properties of ATP and catecholamines demonstrated in vitro are thought to be responsible for the extraordinary accumulation of solutes inside chromaffin cell secretory vesicles, although this has yet to be demonstrated in living cells. Because functional cells cannot be deprived of ATP, we have knocked down the expression of the vesicular nucleotide carrier, the VNUT, to show that a reduction in vesicular ATP is accompanied by a drastic fall in the quantal release of catecholamines. This phenomenon is particularly evident in newly synthesized vesicles, which we show are the first to be released. Surprisingly, we find that inhibiting VNUT expression also reduces the frequency of exocytosis, whereas the overexpression of VNUT drastically increases the quantal size of exocytotic events. To our knowledge, our data provide the first demonstration that ATP, in addition to serving as an energy source and purinergic transmitter, is an essential element in the concentration of catecholamines in secretory vesicles. In this way, cells can use ATP to accumulate neurotransmitters and other secreted substances at high concentrations, supporting quantal transmission.

  17. Fasciola hepatica excretory-secretory products induce CD4+T cell anergy via selective up-regulation of PD-L2 expression on macrophages in a Dectin-1 dependent way.

    PubMed

    Guasconi, Lorena; Chiapello, Laura S; Masih, Diana T

    2015-07-01

    Fasciola hepatica excretory-secretory products (FhESP) induce immunomodulatory effects on macrophages. Previously, we demonstrated that these effects are dependent on Dectin-1. Therefore, the aim of this study was to determine how this affects the CD4 T-cells immune response. We observed that FhESP induce an increased expression of PD-L2 in macrophages via Dectin-1. Furthermore, in co-cultures with CD4 T-cell we observed a suppressive effect on proliferative response, down-modulation of IFN-γ and up-modulation of IL-10 via Dectin-1 on macrophages. These results suggest that FhESP induce T-cell anergy via selective up-regulation of PD-L2 expression on macrophages in a Dectin-1 dependent way.

  18. Genetics Home Reference: enlarged parietal foramina

    MedlinePlus

    ... parietal foramina is an inherited condition of impaired skull development. It is characterized by enlarged openings (foramina) ... that form the top and sides of the skull. This condition is due to incomplete bone formation ( ...

  19. Attentional functions of parietal and frontal cortex.

    PubMed

    Peers, Polly V; Ludwig, Casimir J H; Rorden, Chris; Cusack, Rhodri; Bonfiglioli, Claudia; Bundesen, Claus; Driver, Jon; Antoun, Nagui; Duncan, John

    2005-10-01

    A model of normal attentional function, based on the concept of competitive parallel processing, is used to compare attentional deficits following parietal and frontal lobe lesions. Measurements are obtained for visual processing speed, capacity of visual short-term memory (VSTM), spatial bias (bias to left or right hemifield) and top-down control (selective attention based on task relevance). The results show important differences, but also surprising similarities, in parietal and frontal lobe patients. For processing speed and VSTM, deficits are selectively associated with parietal lesions, in particular lesions of the temporoparietal junction. We discuss explanations based on either grey matter or white matter lesions. In striking contrast, measures of attentional weighting (spatial bias and top-down control) are predicted by simple lesion volume. We suggest that attentional weights reflect competition between broadly distributed object representations. Parietal and frontal mechanisms work together, both in weighting by location and weighting by task context.

  20. Parietal eye nerve in the fence lizard.

    PubMed

    EAKIN, R M; STEBBINS, R C

    1959-12-01

    A nerve from the parietal eye of the western fence lizard, Sceloporus occidentalis, is described as leaving inconspicuously from the third-eye and extending caudally under the dura mater and then ventrally along the left anterolateral surface of the epiphysis to the habenular commissure of the brain. The existence of a parietal nerve must be considered in interpreting the effects of parietalectomy. PMID:13819089

  1. Dramatic Cataplexy Improvement Following Right Parietal Surgery

    PubMed Central

    Fam, David J.; Shammi, Prathiba; Mainprize, Todd G.; Murray, Brian J.

    2015-01-01

    This is the case of a 34-year-old woman with severe narcolepsy with cataplexy who experienced a dramatic reduction in cataplexy symptoms after resection of a right parietal astrocytoma. The patient underwent detailed neurological exam, neuropsychological testing, polysomnography and multiple sleep latency testing following surgery. Citation: Fam DJ, Shammi P, Mainprize TG, Murray BJ. Dramatic cataplexy improvement following right parietal surgery. J Clin Sleep Med 2015;11(7):829–830. PMID:25902819

  2. Intrinsic connections and architectonics of posterior parietal cortex in the rhesus monkey

    SciTech Connect

    Pandya, D.N.; Seltzer, B.

    1982-01-10

    By means of autoradiographic and ablation-degeneration techniques, the intrinsic cortical connections of the posterior parietal cortex in the rhesus monkey were traced and correlated with a reappraisal of cerebral architectonics. Two major rostral-to-caudal connectional sequences exist. One begins in the dorsal postcentral gyrus (area 2) and proceeds, through architectonic divisions of the superior parietal lobule (areas PE and PEc), to a cortical region on the medial surface of the parietal lobe (area PGm). This area has architectonic features similar to those of the caudal inferior parietal lobule (area PG). The second sequence begins in the ventral post/central gyrus (area 2) and passes through the rostral inferior parietal lobule (areas PG and PFG) to reach the caudal inferior parietal lobule (area PG). Both the superior parietal lobule and the rostral inferior parietal lobule also send projections to various other zones located in the parietal opercular region, the intraparietal sulcus, and the caudalmost portion of the cingulate sulcus. Areas PGm and PG, on the other hand, project to each other, to the cingulate region, to the caudalmost portion of the superior temporal gyrus, and to the upper bank of the superior temporal sulcus. Finally, a reciprocal sequence of connections, directed from caudal to rostral, links together many of the above-mentioned parietal zones. With regard to the laminar pattern of termination, the rostral-to-caudal connections are primarily distributed in the form of cortical ''columns'' while the caudal-to-rostral connections are found mainly over the first cortical cell layer.

  3. Proteolysis in the secretory pathway

    SciTech Connect

    Guzowski, D.E.; Bienkowski, R.S.

    1987-05-01

    Many secretory proteins are degraded intracellularly rather than secreted, however the location of this catabolic process is not known. The authors have tested the hypothesis that the degradation occurs in the organelles of the secretory pathway. Slices of rat liver were incubated with (/sup 14/C)leucine for 3 h and then incubated under chase conditions for 30 min. The tissue was homogenized and the Golgi apparatus, smooth endoplasmic reticulum (sER) and rough endoplasmic reticulum (rER) were isolated by ultracentrifugation on a discontinuous sucrose gradient. The organelles were incubated in 0.3M sucrose-50 mM citrate (pH 4) for 8-12 h at 37 C; control samples were incubated at 4 C. Percent degradation was calculated as the amount of acid soluble radioactivity released relative to total radioactivity in the sample. Proteolysis in the organelles incubated at 37 C was as follows: Golgi: 15-25%; sER: 10-20%; rER: 10-20%. Proteolysis at 4 C was negligible in all cases. These results support the hypothesis that the compartments of the secretory pathway are capable of degrading newly synthesized secretory proteins.

  4. Identification of Wnt/β-catenin signaling pathway in dermal papilla cells of human scalp hair follicles: TCF4 regulates the proliferation and secretory activity of dermal papilla cell.

    PubMed

    Xiong, Ya; Liu, Yi; Song, Zhiqiang; Hao, Fei; Yang, Xichuan

    2014-01-01

    It is clear that the dermal papilla cell (DPC), which is located at the bottom of the hair follicle, is a special mesenchymal component, and it plays a leading role in regulating hair follicle development and periodic regeneration. Recent studies showed that the Wnt signaling pathway through β-catenin (canonical Wnt signaling pathway) is an essential component in maintaining the hair-inducing activity of the dermal papilla and growth of hair papilla cells. However, the intrinsic pathways and regulating mechanism are largely unknown. In the previous work, we constructed a cDNA subtractive library of DPC and first found that the TCF4 gene, as a key factor of Wnt signaling pathway, was expressed as the upregulated gene of the hair follicle in low-passage DPC. This study was to explore the role of TCF4 in regulating the proliferation and secretory activity of DPC. We constructed a pcDNA3.0-TCF4 expression vector and transfected it into DPC to achieve stable expression by bangosome 2000. Furthermore, we used the method of chemosynthesis to synthesize three pairs of TCF4 siRNA and transfected them into DPC. Meanwhile, we compared the transfection group and non-transfection group. We first proposed that there was expression difference in TCF4 in DPC under different biological condition. This study may have a high impact on the molecular mechanism of follicular lesions and provide a new vision for the treatment of clinic diseases.

  5. Navigating actions through the rodent parietal cortex

    PubMed Central

    Whitlock, Jonathan R.

    2014-01-01

    The posterior parietal cortex (PPC) participates in a manifold of cognitive functions, including visual attention, working memory, spatial processing, and movement planning. Given the vast interconnectivity of PPC with sensory and motor areas, it is not surprising that neuronal recordings show that PPC often encodes mixtures of spatial information as well as the movements required to reach a goal. Recent work sought to discern the relative strength of spatial vs. motor signaling in PPC by recording single unit activity in PPC of freely behaving rats during selective changes in either the spatial layout of the local environment or in the pattern of locomotor behaviors executed during navigational tasks. The results revealed unequivocally a predominant sensitivity of PPC neurons to locomotor action structure, with subsets of cells even encoding upcoming movements more than 1 s in advance. In light of these and other recent findings in the field, I propose that one of the key contributions of PPC to navigation is the synthesis of goal-directed behavioral sequences, and that the rodent PPC may serve as an apt system to investigate cellular mechanisms for spatial motor planning as traditionally studied in humans and monkeys. PMID:24860475

  6. Spiperone: evidence for uptake into secretory granules.

    PubMed Central

    Dannies, P S; Rudnick, M S; Fishkes, H; Rudnick, G

    1984-01-01

    Spiperone, a dopamine antagonist widely used as a specific ligand for dopamine and serotonin receptors, is actively accumulated into the F4C1 strain of rat pituitary tumor cells. The accumulation of 10 nM [3H]spiperone was linear for 3 min and reached a steady state after 10 min. Spiperone accumulation was reduced 50% by preincubation with 5 microM reserpine, an inhibitor of biogenic amine transport into secretory granules, and was also blocked by monensin and ammonium chloride, both of which increase the pH of intracellular storage organelles. Uptake was not affected by replacing sodium in the buffer with lithium at equimolar concentrations. Spiperone at 1 microM inhibited by over 50% serotonin transport into membrane vesicles isolated from platelet dense granules; this concentration inhibited the Na+-dependent plasma membrane transport system less than 10%. The data indicate spiperone specifically interacts with the secretory granule amine transport system and suggest that this transport system is found in the F4C1 pituitary cell strain as well as in platelets and neurons. The data also suggest that experiments utilizing spiperone to measure dopamine and serotonin receptors be interpreted with caution. PMID:6584920

  7. Isotonic water transport in secretory epithelia.

    PubMed

    Swanson, C H

    1977-01-01

    The model proposed by Diamond and Bossert [1] for isotonic water transport has received wide acceptance in recent years. It assumes that the local driving force for water transport is a standing osmotic gradient produced in the lateral intercellular spaces of the epithelial cell layer by active solute transport. While this model is based on work done in absorptive epithelia where the closed to open direction of the lateral space and the direction of net transport are the same, it has been proposed that the lateral spaces could also serve as the site of the local osmotic gradients for water transport in secretory epithelia, where the closed to open direction of the lateral space and net transport are opposed, by actively transporting solute out of the space rather than into it. Operation in the backward direction, however, requires a lower than ambient hydrostatic pressure within the lateral space which would seem more likely to cause the space to collapse with loss of function. On the other hand, most secretory epithelia are characterized by transport into a restricted ductal system which is similar to the lateral intercellular space in the absorptive epithelia in that its closed to open direction is the same as that of net transport. In vitro micropuncture studies on the exocrine pancreas of the rabbit indicate the presence of a small but statistically significant increase in juice osmolality, 6 mOsm/kg H(2)O, at the site of electrolyte and water secretion in the smallest extralobular ducts with secretin stimulation which suggests that the ductal system in the secretory epithelia rather than the lateral intercellular space is the site of the local osmotic gradients responsible for isotonic water transport. PMID:331693

  8. Some features of secretory systems in plants.

    PubMed

    Juniper, B E; Gilchrist, A J; Robins, R J

    1977-09-01

    Recent work on secretion in plants is reviewed, with emphasis on the anatomy and physiology of root cap cells in higher plants, the stalked glands of Drosera capensis, and the secretory mechanism of Dionaea muscipula. Cells of the root cap of higher plants switch from a geo-perceptive role to one of mucilage secretion at maturation. Features of this process, the role of the Golgi and the pathway for mucilage distribution are reviewed. In contrast, the stalked glands of the leaves of Drosera capensis are much longer lived and have a complex anatomy. The mechanisms for mucilage secretion, protein absorption and the role of the cell membranes in the internal secretion of the protein are described, using data from X-ray microscopv. The secretion of fluid and protein by Dionaea is stimulated by various nitrogen-containing compounds. Uric acid, often excreted by captured insects, is particularly effective in this respect.

  9. Development and Essential Oil Content of Secretory Glands of Sage (Salvia officinalis) 1

    PubMed Central

    Venkatachalam, K. V.; Kjonaas, Robert; Croteau, Rodney

    1984-01-01

    Scanning electron microscopy of sage (Salvia officinalis L.) leaves confirmed the presence of two basic types of glandular trichomes consisting of a capitate stalked form containing a multicellular stalk and surmounted by a unicellular secretory head, and a capitate sessile form containing a unicellular stalk and unicellular, or multicellular, secretory head. In the latter type, secretory activity and filling of the subcuticular cavity may begin at virtually any stage of the division cycle affording fully developed glands containing from one to twelve cells in the secretory head. Gas liquid chromatographic analysis of the oil content of the most numerous gland species (capitate stalked, capitate sessile with one and with eight secretory cells) indicated only minor quantitative differences in essential oil composition. Thus, each gland type is capable of producing the four major monoterpene families (p-menthanes, pinanes, bornanes and thujanes) characteristic of sage. Images Fig. 1 PMID:16663786

  10. Development and essential oil content of secretory glands of sage (Salvia officinalis)

    SciTech Connect

    Venkatachalam, K.V.; Kjonaas, R.; Croteau, R.

    1984-09-01

    Scanning electron microscopy of sage (Salvia officinalis L.) leave confirmed the presence of two basic types of glandular trichomes consisting of a capitate stalked form containing a multicellular stalk and surmounted by a unicellular secretory head, and a capitate sessile form containing a unicellular stalk and unicellular, or multicellular, secretory head. In the latter type, secretory activity and filling of the subcuticular cavity may begin at virtually any stage of the division cycle affording fully developed glands containing from one to twelve cells in the secretory head. Gas liquid chromatographic analysis of the oil content of the most numerous gland species (capitate stalked, capitate sessile with one and with eight secretory cells) indicated only minor quantitative differences in essential oil composition. Thus, each gland type is capable of producing the four major monoterpene families (p-menthanes, pinanes, bornanes and thujanes) characteristic of sage. 21 references, 2 figures.

  11. Development and Essential Oil Content of Secretory Glands of Sage (Salvia officinalis).

    PubMed

    Venkatachalam, K V; Kjonaas, R; Croteau, R

    1984-09-01

    Scanning electron microscopy of sage (Salvia officinalis L.) leaves confirmed the presence of two basic types of glandular trichomes consisting of a capitate stalked form containing a multicellular stalk and surmounted by a unicellular secretory head, and a capitate sessile form containing a unicellular stalk and unicellular, or multicellular, secretory head. In the latter type, secretory activity and filling of the subcuticular cavity may begin at virtually any stage of the division cycle affording fully developed glands containing from one to twelve cells in the secretory head. Gas liquid chromatographic analysis of the oil content of the most numerous gland species (capitate stalked, capitate sessile with one and with eight secretory cells) indicated only minor quantitative differences in essential oil composition. Thus, each gland type is capable of producing the four major monoterpene families (p-menthanes, pinanes, bornanes and thujanes) characteristic of sage. PMID:16663786

  12. Secretory function of adipose tissue.

    PubMed

    Kuryszko, J; Sławuta, P; Sapikowski, G

    2016-01-01

    There are two kinds of adipose tissue in mammals: white adipose tissue - WAT and brown adipose tissue - BAT. The main function of WAT is accumulation of triacylglycerols whereas the function of BAT is heat generation. At present, WAT is also considered to be an endocrine gland that produces bioactive adipokines, which take part in glucose and lipid metabolism. Considering its endocrine function, the adipose tissue is not a homogeneous gland but a group of a few glands which act differently. Studies on the secretory function of WAT began in 1994 after discovery of leptin known as the satiation hormone, which regulates body energy homeostasis and maintainence of body mass. Apart from leptin, the following belong to adipokines: adiponectin, resistin, apelin, visfatin and cytokines: TNF and IL 6. Adiponectin is a polypeptide hormone of antidiabetic, anti-inflammatory and anti-atherogenic activity. It plays a key role in carbohydrate and fat metabolism. Resistin exerts a counter effect compared to adiponectin and its physiological role is to maintain fasting glycaemia. Visfatin stimulates insulin secretion and increases insulin sensitivity and glucose uptake by muscle cells and adipocytes. Apelin probably increases the insulin sensitivity of tissues. TNF evokes insulin resistance by blocking insulin receptors and inhibits insulin secretion. Approximately 30% of circulating IL 6 comes from adipose tissue. It causes insulin resistance by decreasing the expression of insulin receptors, decreases adipogenesis and adiponectin and visfatin secretion, and stimulates hepatic gluconeogenesis. In 2004, Bays introduced the notion of adiposopathy, defined as dysfunction of the adipose tissue, whose main feature is insulin and leptin resistance as well as the production of inflammatory cytokines: TNF and IL 6 and monocyte chemoattractant protein. This means that excess of adipose tissue, especially visceral adipose tissue, leads to the development of a chronic subclinical

  13. Copper trafficking to the secretory pathway.

    PubMed

    Lutsenko, Svetlana

    2016-09-01

    Copper (Cu) is indispensible for growth and development of human organisms. It is required for such fundamental and ubiquitous processes as respiration and protection against reactive oxygen species. Cu also enables catalytic activity of enzymes that critically contribute to the functional identity of many cells and tissues. Pigmentation, production of norepinephrine by the adrenal gland, the key steps in the formation of connective tissue, neuroendocrine signaling, wound healing - all these processes require Cu and depend on Cu entering the secretory pathway. To reach the Cu-dependent enzymes in a lumen of the trans-Golgi network and various vesicular compartments, Cu undertakes a complex journey crossing the extracellular and intracellular membranes and staying firmly on course while traveling in a cytosol. The proteins that assist Cu in this journey by mediating its entry, distribution, and export, have been identified. The accumulating data also indicate that the current model of cellular Cu homeostasis is still a "skeleton" that has to be fleshed out with many new details. This review summarizes recent data on the mechanisms responsible for Cu transfer to the secretory pathway. The emerging new concepts and gaps in our knowledge are discussed. PMID:27603756

  14. Spatial updating in human parietal cortex

    NASA Technical Reports Server (NTRS)

    Merriam, Elisha P.; Genovese, Christopher R.; Colby, Carol L.

    2003-01-01

    Single neurons in monkey parietal cortex update visual information in conjunction with eye movements. This remapping of stimulus representations is thought to contribute to spatial constancy. We hypothesized that a similar process occurs in human parietal cortex and that we could visualize it with functional MRI. We scanned subjects during a task that involved remapping of visual signals across hemifields. We observed an initial response in the hemisphere contralateral to the visual stimulus, followed by a remapped response in the hemisphere ipsilateral to the stimulus. We ruled out the possibility that this remapped response resulted from either eye movements or visual stimuli alone. Our results demonstrate that updating of visual information occurs in human parietal cortex.

  15. Parietal Lobes in Schizophrenia: Do They Matter?

    PubMed Central

    Yildiz, Murat; Borgwardt, Stefan J.; Berger, Gregor E.

    2011-01-01

    Objective. Despite observations that abnormal parietal lobe (PL) function is associated with psychotic-like experiences, our knowledge about the nature of PL involvement in schizophrenia is modest. The objective of this paper is to investigate the role of the PL in schizophrenia. Method. Medline databases were searched for English language publications using the following key words: parietal lobe, combined with schizophrenia, lesions, epilepsy, cognition, rare genetic disorders, MRI, fMRI, PET, and SPECT, respectively, followed by cross-checking of references. Results. Imaging studies in childhood onset schizophrenia suggest that grey matter abnormalities start in parietal and occipital lobes and proceed to frontal regions. Although, the findings are inconsistent, several studies with patients at risk to develop schizophrenia indicate early changes in the PL. Conclusions. We want to propose that in a proportion of individuals with emerging schizophrenia structural and functional alterations may start in the PL and progress to frontal regions. PMID:22937268

  16. Posterior parietal cortex and developmental dyslexia.

    PubMed

    Jaśkowski, Piotr; Rusiak, Patrycja

    2005-01-01

    Dyslexia is defined as a specific reading disorder despite normal intelligence and conventional teaching. One of the most influential theories attempting to explain problems suffered by dyslexics assumes that dyslexia is caused by deficits of the magnocellular system. This system, generally responsible for processing fast sensory information, projects mostly to the parietal cortex. Consistent with this theory, dyslexics should have problems with tasks which specifically involve parietal cortex. In the article, we review data and show that, indeed, dyslexics have problems with fast attention shifts, show some symptoms of mild unilateral neglect syndrome and have abnormal saccadic and pursuit eye movements. Little is known about visuo-motor coordination and mental rotation, the tasks in which the parietal cortex is thought to play important roles.

  17. Cytodiagnosis of secretory carcinoma of the breast: a report on two cases.

    PubMed

    Jena, Madhusmita; Shariff, Shameem

    2010-12-01

    Secretory carcinoma of the breast is a rare (<1%) low grade breast carcinoma which shows distinct features at histology. Diagnosis of this carcinoma at fine needle aspiration cytology (FNAC) is difficult. Two cases of secretory carcinoma of the breast presenting as a breast mass, one in a 24-year-old female and the other in a 40-year-old female are reported, highlighting their appearance at FNAC. In both the cases the aspirates were cellular and consisted of clusters and single cells with uniform round nuclei showing minimal nuclear atypia. Most of the cells had moderate to abundant cytoplasm with prominent intracytoplasmic vacuoles. Many cells showed a plasmacytoid appearance and others were binucleate. A typical amphophilic bubbly cytoplasm of the tumor cells was observed. Both cases were confirmed as secretory carcinoma on histology. The differences in cell morphology at FNAC of secretory carcinoma of the breast from other breast carcinomas, and its utility of making a preoperative diagnosis are discussed.

  18. Interactions of pathogen-containing compartments with the secretory pathway.

    PubMed

    Canton, Johnathan; Kima, Peter E

    2012-11-01

    A subgroup of intracellular pathogens reside and replicate within membrane-bound compartments often termed pathogen-containing compartments (PCC). PCCs navigate around a wide range of host cell vesicles and organelles. In light of the perils of engaging with vesicles of the endocytic pathway, most PCCs modulate their interactions with endocytic vesicles while a few avoid those interactions. The secretory pathway constitutes another important grouping of vesicles and organelles in host cells. Although the negative consequences of engaging with the secretory pathway are not known, there is evidence that PCCs interact differentially with vesicles and organelles in this pathway as well. In this review, we consider three prokaryote pathogens and two protozoan parasites for which there is information on the interactions of their PCCs with the secretory pathway. Current understandings of the molecular interactions as well as the metabolic benefits that accompany those interactions are discussed. Not unexpectedly, our understanding of the extent of these interactions is variable. An underlying theme that is brought to the fore is that PCCs establish preferential interactions with distinct compartments of the secretory pathway.

  19. Secretory breast cancer. Case report

    PubMed Central

    LOMBARDI, A.; MAGGI, S.; BERSIGOTTI, L.; LAZZARIN, G.; NUCCETELLI, E.; AMANTI, C.

    2013-01-01

    Summary: Secretory carcinoma of the breast is a rare tumor initially described in children but occurring equally in adult population. This unusual breast cancer subtype has a generally favorable prognosis, although several cases have been described in adults with increased aggressiveness and a risk of metastases. However, surgery is still considered the most appropriate treatment for this pathology. We describe the case of a 50 – year-old woman who has undergone a breast conservative surgery for a little tumor, preoperatively diagnosticated by a fine needle aspiration biopsy (FNAB) as a well differentiated infiltrating carcinoma. PMID:23660165

  20. Secretory breast cancer. Case report.

    PubMed

    Lombardi, A; Maggi, S; Bersigotti, L; Lazzarin, G; Nuccetelli, E; Amanti, C

    2013-04-01

    Secretory carcinoma of the breast is a rare tumor initially described in children but occurring equally in adult population. This unusual breast cancer subtype has a generally favorable prognosis, although several cases have been described in adults with increased aggressiveness and a risk of metastases. However, surgery is still considered the most appropriate treatment for this pathology. We describe the case of a 50 -year-old woman who has undergone a breast conservative surgery for a little tumor, preoperatively diagnosticated by a fine needle aspiration biopsy (FNAB) as a well differentiated infiltrating carcinoma.

  1. Transcriptional regulation of secretory capacity by bZip transcription factors

    PubMed Central

    FOX, Rebecca M.

    2015-01-01

    Cells of specialized secretory organs expand their secretory pathways to accommodate the increased protein load necessary for their function. The endoplasmic reticulum (ER), the Golgi apparatus and the secretory vesicles, expand not only the membrane components but also the protein machinery required for increased protein production and transport. Increased protein load causes an ER stress response akin to the Unfolded Protein Response (UPR). Recent work has implicated several bZip transcription factors in the regulation of protein components of the early secretory pathway necessary to alleviate this stress. Here, we highlight eight bZip transcription factors in regulating secretory pathway component genes. These include components of the three canonical branches of the UPR–ATF4, XBP1, and ATF6, as well as the five members of the Creb3 family of transcription factors. We review findings from both invertebrate and vertebrate model systems suggesting that all of these proteins increase secretory capacity in response to increased protein load. Finally, we propose that the Creb3 family of factors may have a dual role in secretory cell differentiation by also regulating the pathways necessary for cell cycle exit during terminal differentiation. PMID:25821458

  2. From visual affordances in monkey parietal cortex to hippocampo-parietal interactions underlying rat navigation.

    PubMed Central

    Arbib, M A

    1997-01-01

    This paper explores the hypothesis that various subregions (but by no means all) of the posterior parietal cortex are specialized to process visual information to extract a variety of affordances for behaviour. Two biologically based models of regions of the posterior parietal cortex of the monkey are introduced. The model of the lateral intraparietal area (LIP) emphasizes its roles in dynamic remapping of the representation of targets during a double saccade task, and in combining stored, updated input with current visual input. The model of the anterior intraparietal area (AIP) addresses parietal-premotor interactions involved in grasping, and analyses the interaction between the AIP and premotor area F5. The model represents the role of other intraparietal areas working in concert with the inferotemporal cortex as well as with corollary discharge from F5 to provide and augment the affordance information in the AIP, and suggests how various constraints may resolve the action opportunities provided by multiple affordances. Finally, a systems-level model of hippocampo parietal interactions underlying rat navigation is developed, motivated by the monkey data used in developing the above two models as well as by data on neurones in the posterior parietal cortex of the monkey that are sensitive to visual motion. The formal similarity between dynamic remapping (primate saccades) and path integration (rat navigation) is noted, and certain available data on rat posterior parietal cortex in terms of affordances for locomotion are explained. The utility of further modelling, linking the World Graph model of cognitive maps for motivated behaviour with hippocampal-parietal interactions involved in navigation, is also suggested. These models demonstrate that posterior parietal cortex is not only itself a network of interacting subsystems, but functions through cooperative computation with many other brain regions. PMID:9368931

  3. Lipids implicated in the journey of a secretory granule: from biogenesis to fusion.

    PubMed

    Tanguy, Emeline; Carmon, Ophélie; Wang, Qili; Jeandel, Lydie; Chasserot-Golaz, Sylvette; Montero-Hadjadje, Maité; Vitale, Nicolas

    2016-06-01

    The regulated secretory pathway begins with the formation of secretory granules by budding from the Golgi apparatus and ends by their fusion with the plasma membrane leading to the release of their content into the extracellular space, generally following a rise in cytosolic calcium. Generation of these membrane-bound transport carriers can be classified into three steps: (i) cargo sorting that segregates the cargo from resident proteins of the Golgi apparatus, (ii) membrane budding that encloses the cargo and depends on the creation of appropriate membrane curvature, and (iii) membrane fission events allowing the nascent carrier to separate from the donor membrane. These secretory vesicles then mature as they are actively transported along microtubules toward the cortical actin network at the cell periphery. The final stage known as regulated exocytosis involves the docking and the priming of the mature granules, necessary for merging of vesicular and plasma membranes, and the subsequent partial or total release of the secretory vesicle content. Here, we review the latest evidence detailing the functional roles played by lipids during secretory granule biogenesis, recruitment, and exocytosis steps. In this review, we highlight evidence supporting the notion that lipids play important functions in secretory vesicle biogenesis, maturation, recruitment, and membrane fusion steps. These effects include regulating various protein distribution and activity, but also directly modulating membrane topology. The challenges ahead to understand the pleiotropic functions of lipids in a secretory granule's journey are also discussed. This article is part of a mini review series on Chromaffin cells (ISCCB Meeting, 2015).

  4. Syndecan-1 in the Mouse Parietal Peritoneum Microcirculation in Inflammation

    PubMed Central

    Kowalewska, Paulina M.; Patrick, Amanda L.; Fox-Robichaud, Alison E.

    2014-01-01

    Background The heparan sulfate proteoglycan syndecan-1 (CD138) was shown to regulate inflammatory responses by binding chemokines and cytokines and interacting with adhesion molecules, thereby modulating leukocyte trafficking to tissues. The objectives of this study were to examine the expression of syndecan-1 and its role in leukocyte recruitment and chemokine presentation in the microcirculation underlying the parietal peritoneum. Methods Wild-type BALB/c and syndecan-1 null mice were stimulated with an intraperitoneal injection of Staphylococcus aureus LTA, Escherichia coli LPS or TNFα and the microcirculation of the parietal peritoneum was examined by intravital microscopy after 4 hours. Fluorescence confocal microscopy was used to examine syndecan-1 expression in the peritoneal microcirculation using fluorescent antibodies. Blocking antibodies to adhesion molecules were used to examine the role of these molecules in leukocyte-endothelial cell interactions in response to LTA. To determine whether syndecan-1 co-localizes with chemokines in vivo, fluorescent antibodies to syndecan-1 were co-injected intravenously with anti-MIP-2 (CXCL2), anti-KC (CXCL1) or anti-MCP-1 (CCL2). Results and Conclusion Syndecan-1 was localized to the subendothelial region of peritoneal venules and the mesothelial layer. Leukocyte rolling was significantly decreased with LPS treatment while LTA and TNFα significantly increased leukocyte adhesion compared with saline control. Leukocyte-endothelial cell interactions were not different in syndecan-1 null mice. Antibody blockade of β2 integrin (CD18), ICAM-1 (CD54) and VCAM-1 (CD106) did not decrease leukocyte adhesion in response to LTA challenge while blockade of P-selectin (CD62P) abrogated leukocyte rolling. Lastly, MIP-2 expression in the peritoneal venules was not dependent on syndecan-1 in vivo. Our data suggest that syndecan-1 is expressed in the parietal peritoneum microvasculature but does not regulate leukocyte recruitment

  5. Atrophy of the Parietal Lobe in Preclinical Dementia

    ERIC Educational Resources Information Center

    Jacobs, Heidi I. L.; Van Boxtel, Martin P. J.; Uylings, Harry B. M.; Gronenschild, Ed H. B. M.; Verhey, Frans R.; Jolles, Jelle

    2011-01-01

    Cortical grey matter atrophy patterns have been reported in healthy ageing and Alzheimer disease (AD), but less consistently in the parietal regions of the brain. We investigated cortical grey matter volume patterns in parietal areas. The grey matter of the somatosensory cortex, superior and inferior parietal lobule was measured in 75 older adults…

  6. The left parietal cortex and motor attention.

    PubMed

    Rushworth, M F; Nixon, P D; Renowden, S; Wade, D T; Passingham, R E

    1997-09-01

    The posterior parietal cortex, particularly in the right hemisphere, is crucially important for covert orienting; lesions impair the ability to disengage the focus of covert orienting attention from one potential saccade target to another (Posner, M. I. et al., Journal of Neuroscience, 1984, 4, 1863-1874). We have developed a task where precues allow subjects to covertly prepare subsequent cued hand movements, as opposed to an orienting or eye movement. We refer to this process as motor attention to distinguish it from orienting attention. Nine subjects with lesions that included the left parietal cortex and nine subjects with lesions including the right parietal cortex were compared with control subjects on the task. The left hemisphere subjects showed the same ability as controls to engage attention to a movement when they were forewarned by a valid precue. The left hemisphere subjects, however, were impaired in their ability to disengage the focus of motor attention from one movement to another when the precue was incorrect. The results support the existence of two distinct attentional systems allied to the orienting and limb motor systems. Damage to either system causes analogous problems in disengaging from one orienting/movement target to another. The left parietal cortex, particularly the supramarginal gyrus, is associated with motor attention. All the left hemisphere subjects had ideomotor apraxia and had particular problems performing sequences of movements. We suggest that the well documented left hemisphere and apraxic impairment in movement sequencing is the consequence of a difficulty in shifting the focus of motor attention from one movement in a sequence to the next. PMID:9364496

  7. Secretory function in subplate neurons during cortical development

    PubMed Central

    Kondo, Shinichi; Al-Hasani, Hannah; Hoerder-Suabedissen, Anna; Wang, Wei Zhi; Molnár, Zoltán

    2015-01-01

    Subplate cells are among the first generated neurons in the mammalian cerebral cortex and have been implicated in the establishment of cortical wiring. In rodents some subplate neurons persist into adulthood. Here we would like to highlight several converging findings which suggest a novel secretory function of subplate neurons during cortical development. Throughout the postnatal period in rodents, subplate neurons have highly developed rough endoplasmic reticulum (ER) and are under an ER stress condition. By comparing gene expression between subplate and layer 6, we found that several genes encoding secreted proteins are highly expressed in subplate neurons. One of these secreted proteins, neuroserpin, encoded by the serpini1 gene, is localized to the ER in subplate cells. We propose that subplate might influence cortical circuit formation through a transient secretory function. PMID:25859180

  8. Regulation of secretory granule size by the precise generation and fusion of unit granules

    PubMed Central

    Hammel, Ilan; Lagunoff, David; Galli, Stephen J

    2010-01-01

    Abstract Morphometric evidence derived from studies of mast cells, pancreatic acinar cells and other cell types supports a model in which the post-Golgi processes that generate mature secretory granules can be resolved into three steps: (1) fusion of small, Golgi-derived progranules to produce immature secretory granules which have a highly constrained volume; (2) transformation of such immature granules into mature secretory granules, a process often associated with a reduction in the maturing granule’s volume, as well as changes in the appearance of its content and (3) fusion of secretory granules of the smallest size, termed ‘unit granules’, forming granules whose volumes are multiples of the unit granule’s volume. Mutations which perturb this process can cause significant pathology. For example, Chediak–Higashi syndrome / lysosomal trafficking regulator (CHS)/(Lyst) mutations result in giant secretory granules in a number of cell types in human beings with the Chediak–Higashi syndrome and in ‘beige’ (Lystbg/Lystbg) mice. Analysis of the secretory granules of mast cells and pancreatic acinar cells in Lyst-deficient beige mice suggests that beige mouse secretory granules retain the ability to fuse randomly with other secretory granules no matter what the size of the fusion partners. By contrast, in normal mice, the pattern of granule–granule fusion occurs exclusively by the addition of unit granules, either to each other or to larger granules. The normal pattern of fusion is termed unit addition and the fusion evident in cells with CHS/Lyst mutations is called random addition. The proposed model of secretory granule formation has several implications. For example, in neurosecretory cells, the secretion of small amounts of cargo in granules constrained to a very narrow size increases the precision of the information conveyed by secretion. By contrast, in pancreatic acinar cells and mast cells, large granules composed of multiple unit granules

  9. Oil Secretory System in Vegetative Organs of Three Arnica Taxa: Essential Oil Synthesis, Distribution and Accumulation.

    PubMed

    Kromer, Krystyna; Kreitschitz, Agnieszka; Kleinteich, Thomas; Gorb, Stanislav N; Szumny, Antoni

    2016-05-01

    Arnica, a genus including the medicinal species A. montana, in its Arbo variety, and A. chamissonis, is among the plants richest in essential oils used as pharmaceutical materials. Despite its extensive use, the role of anatomy and histochemistry in the internal secretory system producing the essential oil is poorly understood. Anatomical sections allowed differentiation between two forms of secretory structures which differ according to their distribution in plants. The first axial type is connected to the vascular system of all vegetative organs and forms canals lined with epithelial cells. The second cortical type is represented by elongated intercellular spaces filled with oil formed only between the cortex cells of roots and rhizomes at maturity, with canals lacking an epithelial layer.Only in A. montana rhizomes do secretory structures form huge characteristic reservoirs. Computed tomography illustrates their spatial distribution and fusiform shape. The axial type of root secretory canals is formed at the interface between the endodermis and cortex parenchyma, while, in the stem, they are located in direct contact with veinal parenchyma. The peripheral phloem parenchyma cells are arranged in strands around sieve tube elements which possess a unique ability to accumulate large amounts of oil bodies. The cells of phloem parenchyma give rise to the aforementioned secretory structures while the lipid components (triacylglycerols) stored there support the biosynthesis of essential oils by later becoming a medium in which these oils are dissolved. The results indicate the integrity of axial secretory structures forming a continuous system in vegetative plant organs. PMID:26936790

  10. Oil Secretory System in Vegetative Organs of Three Arnica Taxa: Essential Oil Synthesis, Distribution and Accumulation.

    PubMed

    Kromer, Krystyna; Kreitschitz, Agnieszka; Kleinteich, Thomas; Gorb, Stanislav N; Szumny, Antoni

    2016-05-01

    Arnica, a genus including the medicinal species A. montana, in its Arbo variety, and A. chamissonis, is among the plants richest in essential oils used as pharmaceutical materials. Despite its extensive use, the role of anatomy and histochemistry in the internal secretory system producing the essential oil is poorly understood. Anatomical sections allowed differentiation between two forms of secretory structures which differ according to their distribution in plants. The first axial type is connected to the vascular system of all vegetative organs and forms canals lined with epithelial cells. The second cortical type is represented by elongated intercellular spaces filled with oil formed only between the cortex cells of roots and rhizomes at maturity, with canals lacking an epithelial layer.Only in A. montana rhizomes do secretory structures form huge characteristic reservoirs. Computed tomography illustrates their spatial distribution and fusiform shape. The axial type of root secretory canals is formed at the interface between the endodermis and cortex parenchyma, while, in the stem, they are located in direct contact with veinal parenchyma. The peripheral phloem parenchyma cells are arranged in strands around sieve tube elements which possess a unique ability to accumulate large amounts of oil bodies. The cells of phloem parenchyma give rise to the aforementioned secretory structures while the lipid components (triacylglycerols) stored there support the biosynthesis of essential oils by later becoming a medium in which these oils are dissolved. The results indicate the integrity of axial secretory structures forming a continuous system in vegetative plant organs.

  11. Discovery and characterization of secretory IgD in rainbow trout: secretory IgD is produced through a novel splicing mechanism

    USGS Publications Warehouse

    Ramirez-Gomez, F.; Greene, W.; Rego, K.; Hansen, J.D.; Costa, G.; Kataria, P.; Bromage, E.S.

    2012-01-01

    The gene encoding IgH δ has been found in all species of teleosts studied to date. However, catfish (Ictalurus punctatus) is the only species of fish in which a secretory form of IgD has been characterized, and it occurs through the use of a dedicated δ-secretory exon, which is absent from all other species examined. Our studies have revealed that rainbow trout (Oncorhynchus mykiss) use a novel strategy for the generation of secreted IgD. The trout secretory δ transcript is produced via a run-on event in which the splice donor site at the end of the last constant domain exon (D7) is ignored and transcription continues until a stop codon is reached 33 nt downstream of the splice site, resulting in the production of an in-frame, 11-aa secretory tail at the end of the D7 domain. In silico analysis of several published IgD genes suggested that this unique splicing mechanism may also be used in other species of fish, reptiles, and amphibians. Alternative splicing of the secretory δ transcript resulted in two δ-H chains, which incorporated Cμ1 and variable domains. Secreted IgD was found in two heavily glycosylated isoforms, which are assembled as monomeric polypeptides associated with L chains. Secretory δ mRNA and IgD+ plasma cells were detected in all immune tissues at a lower frequency than secretory IgM. Our data demonstrate that secretory IgD is more prevalent and widespread across taxa than previously thought, and thus illustrate the potential that IgD may have a conserved role in immunity.

  12. A senescence secretory switch mediated by PI3K/AKT/mTOR activation controls chemoprotective endothelial secretory responses.

    PubMed

    Bent, Eric H; Gilbert, Luke A; Hemann, Michael T

    2016-08-15

    Cancer therapy targets malignant cells that are surrounded by a diverse complement of nonmalignant stromal cells. Therapy-induced damage of normal cells can alter the tumor microenvironment, causing cellular senescence and activating cancer-promoting inflammation. However, how these damage responses are regulated (both induced and resolved) to preserve tissue homeostasis and prevent chronic inflammation is poorly understood. Here, we detail an acute chemotherapy-induced secretory response that is self-limiting in vitro and in vivo despite the induction of cellular senescence. We used tissue-specific knockout mice to demonstrate that endothelial production of the proinflammatory cytokine IL-6 promotes chemoresistance and show that the chemotherapeutic doxorubicin induces acute IL-6 release through reactive oxygen species-mediated p38 activation in vitro. Doxorubicin causes endothelial senescence but, surprisingly, without a typical senescence secretory response. We found that endothelial cells repress senescence-associated inflammation through the down-regulation of PI3K/AKT/mTOR signaling and that reactivation of this pathway restores senescence-associated inflammation. Thus, we describe a mechanism by which damage-associated paracrine secretory responses are restrained to preserve tissue homeostasis and prevent chronic inflammation. PMID:27566778

  13. Secretory protein trafficking in Giardia intestinalis.

    PubMed

    Hehl, Adrian B; Marti, Matthias

    2004-07-01

    Early diverged extant organisms, which may serve as convenient laboratory models to look for and study evolutionary ancient features of eukaryotic cell biology, are rare. The diplomonad Giardia intestinalis, a protozoan parasite known to cause diarrhoeal disease, has become an increasingly popular object of basic research in cell biology, not least because of a genome sequencing project nearing completion. Commensurate with its phylogenetic status, the Giardia trophozoite has a very basic secretory system and even lacks hallmark structures such as a morphologically identifiable Golgi apparatus. The cell's capacity for protein sorting is nevertheless unimpeded, exemplified by its ability to cope with massive amounts of newly synthesized cyst wall proteins and glycans, which are sorted to dedicated Golgi-like compartments termed encystation-specific vesicles (ESVs) generated from endoplasmic reticulum (ER)-derived transport intermediates. This soluble bulk cargo is kept strictly separate from constitutively transported variant surface proteins during export, a function that is dependent on the stage-specific recognition of trafficking signals. Encysting Giardia therefore provide a unique system for the study of unconventional, Golgi-independent protein trafficking mechanisms in the broader context of eukaryotic endomembrane organization and evolution. PMID:15225300

  14. Neuroendocrine secretory protein 7B2: structure, expression and functions.

    PubMed Central

    Mbikay, M; Seidah, N G; Chrétien, M

    2001-01-01

    7B2 is an acidic protein residing in the secretory granules of neuroendocrine cells. Its sequence has been elucidated in many phyla and species. It shows high similarity among mammals. A Pro-Pro-Asn-Pro-Cys-Pro polyproline motif is its most conserved feature, being carried by both vertebrate and invertebrate sequences. It is biosynthesized as a precursor protein that is cleaved into an N-terminal fragment and a C-terminal peptide. In neuroendocrine cells, 7B2 functions as a specific chaperone for the proprotein convertase (PC) 2. Through the sequence around its Pro-Pro-Asn-Pro-Cys-Pro motif, it binds to an inactive proPC2 and facilitates its transport from the endoplasmic reticulum to later compartments of the secretory pathway where the zymogen is proteolytically matured and activated. Its C-terminal peptide can inhibit PC2 in vitro and may contribute to keep the enzyme transiently inactive in vivo. The PC2-7B2 model defines a new neuroendocrine paradigm whereby proteolytic activation of prohormones and proneuropeptides in the secretory pathway is spatially and temporally regulated by the dynamics of interactions between converting enzymes and their binding proteins. Interestingly, unlike PC2-null mice, which are viable, 7B2-null mutants die early in life from Cushing's disease due to corticotropin ('ACTH') hypersecretion by the neurointermediate lobe, suggesting a possible involvement of 7B2 in secretory granule formation and in secretion regulation. The mechanism of this regulation is yet to be elucidated. 7B2 has been shown to be a good marker of several neuroendocrine cell dysfunctions in humans. The possibility that anomalies in its structure and expression could be aetiological causes of some of these dysfunctions warrants investigation. PMID:11439082

  15. Autologus parietal grafts in preprosthethic surgery

    PubMed Central

    GHERLONE, E.F.; VINCI, R.; D’AVERSA, L.

    2010-01-01

    SUMMARY Edentulous patients usually request implant supported/fixed rehabilitation. Ridge resorption after teeth loss usually affect three-dimensional implant position. Vertical and/or horizontal bone augmentation procedures are often the only choice the clinician has to deliver prosthetic guided restoration. Gold standard for augmentation procedures such as sinus lift, onlay or inlay grafts, is still autologous bone. The patient in this report underwent a pre-prosthetic reconstruction of the jaws with parietal bone, followed by fixtures insertion and fixed prosthetic rehabilitation. This clinical report aims to underline the importance of multidisciplinary treatment to optimize the results of the rehabilitation. PMID:23285358

  16. MiR-100-3p and miR-877-3p regulate overproduction of IL-8 and IL-1β in mesangial cells activated by secretory IgA from IgA nephropathy patients.

    PubMed

    Liang, Yan; Zhao, Guoqiang; Tang, Lin; Zhang, Junjun; Li, Tianfang; Liu, Zhangsuo

    2016-10-01

    IgA nephropathy (IgAN) is the most common type of primary glomerulonephritis, characterized by mesangial deposition of pathogenic IgA and the injury to mesangial cells. Our previous studies indicate that secretory IgA (SIgA) plays an important role in the pathogenesis of IgAN, and miR-16 is involved in destructive process in mesangial cells mediated by the SIgA from IgAN patients. Our current study aimed to study the role of miRNAs in the effect of SIgA from IgAN patients on mesangial cells. MicroRNA microarray and cytokines assay were performed to obtain the differential microRNAs expression profile in human renal mesangial cells stimulated by SIgA from IgAN patients (P-SIgA) with the cells treated by SIgA from healthy subjects (N-SgA) as control. The microRNAs with the most significant differences in microarray analysis were validated by quantitative RT-PCR. Among them, miR-100-3p and miR-877-3p were selected to predict target gene related to cytokines detecting in this study. Fifty-six differentially expressed microRNAs were chosen and 17 microRNAs with the most prominent changes were validated. Compared with N-SIgA, P-SIgA increased the production of interleukin (IL)-1β, IL-8, monocyte chemotactic protein-1 and transforming growth factor-β1. In addition, we for the first time demonstrated that over-production of IL-8 induced by the SIgA was regulated by down-expression of miR-100-3p in mesangial cells. Similarly, IL-1β over-production was regulated by down-expression of miR-877-3p. Our findings represent a pathogenic microRNAs expression profiling in human mesangial cells activated by P-SIgA. Furthermore, we provide a new explanation characterizing the molecular mechanism responsible for the regulation of IL-1β and IL-8 production in P-SIgA-triggered mesangial cells.

  17. RNAi knockdown of parafusin inhibits the secretory pathway.

    PubMed

    Liu, Li; Wyroba, Elzbieta; Satir, Birgit H

    2011-10-01

    Several glycolytic enzymes and their isoforms have been found to be important in cell signaling unrelated to glycolysis. The involvement of parafusin (PFUS), a member of the phosphoglucomutase (PGM) superfamily with no phosphoglucomutase activity, in Ca(2+)-dependent exocytosis has been controversial. This protein was first described in Paramecium tetraurelia, but is widely found. Earlier work showed that parafusin is a secretory vesicle scaffold component with unusual post-translational modifications (cyclic phosphorylation and phosphoglucosylation) coupled to stages in the exocytic process. Using RNAi, we demonstrate that parafusin synthesis can be reversibly blocked, with minor or no effect on other PGM isoforms. PFUS knockdown produces an inhibition of dense core secretory vesicle (DCSV) synthesis leading to an exo(-) phenotype. Although cell growth is unaffected, vesicle content is not packaged properly and no new DCSVs are formed. We conclude that PFUS and its orthologs are necessary for proper scaffold maturation. Because of this association, parafusin is an important signaling component for regulatory control of the secretory pathway.

  18. Chronic Insulin Exposure Induces ER Stress and Lipid Body Accumulation in Mast Cells at the Expense of Their Secretory Degranulation Response

    PubMed Central

    Balajadia, Januaria; Shimoda, Lori M. N.; Sung, Carl; Turner, Helen

    2015-01-01

    Lipid bodies (LB) are reservoirs of precursors to inflammatory lipid mediators in immunocytes, including mast cells. LB numbers are dynamic, increasing dramatically under conditions of immunological challenge. We have previously shown in vitro that insulin-influenced lipogenic pathways induce LB biogenesis in mast cells, with their numbers attaining steatosis-like levels. Here, we demonstrate that in vivo hyperinsulinemia resulting from high fat diet is associated with LB accumulation in murine mast cells and basophils. We characterize the lipidome of purified insulin-induced LB, and the shifts in the whole cell lipid landscape in LB that are associated with their accumulation, in both model (RBL2H3) and primary mast cells. Lipidomic analysis suggests a gain of function associated with LB accumulation, in terms of elevated levels of eicosanoid precursors that translate to enhanced antigen-induced LTC4 release. Loss-of-function in terms of a suppressed degranulation response was also associated with LB accumulation, as were ER reprogramming and ER stress, analogous to observations in the obese hepatocyte and adipocyte. Taken together, these data suggest that chronic insulin elevation drives mast cell LB enrichment in vitro and in vivo, with associated effects on the cellular lipidome, ER status and pro-inflammatory responses. PMID:26263026

  19. UNDERSTANDING THE PARIETAL LOBE SYNDROME FROM A NEUROPHYSIOLOGICAL AND EVOLUTIONARY PERSPECTIVE

    PubMed Central

    Caminiti, Roberto; Chafee, Matthew V.; Battaglia-Mayer, Alexandra; Averbeck, Bruno B.; Crowe, David A.; Georgopoulos, Apostolos P.

    2010-01-01

    In human and non-human primates parietal cortex is formed by a multiplicity of areas. For those of the Superior Parietal Lobule (SPL) there exists a certain homology between man and macaques. As a consequence, Optic Ataxia, a disturbed visual control of hand reaching, has similar features in man and monkeys. Establishing such correspondence has proven difficult for the areas of the Inferior Parietal Lobule (IPL). This difficulty depends on many factors. First, no physiological information is available in man on the dynamic properties of cells in the IPL. Second, the number of IPL areas identified in the monkey is paradoxically higher that that so far described in man, although this issue will probably be reconsidered in future years, thanks to comparative imaging studies. Third, the consequences of parietal lesions in monkeys do not always match those observed in humans. This is another paradox if one considers that, in certain cases, the functional properties of neurons in the monkeys IPL would predict the presence of behavioral skills, such as construction capacity, that however do not seem to emerge in the wild. Therefore, Constructional Apraxia, which is well characterized in man, has never been described in monkeys and apes. Finally, only certain aspects, i.e. hand Directional Hypokinesia and Gaze Apraxia (Balint's Psychic Paralysis of Gaze), of the multifaceted syndrome Hemispatial Neglect have been described in monkeys. These similarities, differences and paradoxes, among many others, make the study of the evolution and function of parietal cortex a challenging “case”. PMID:20550568

  20. Physiological implications of the abnormal absence of the parietal foramen in a late Permian cynodont (Therapsida)

    NASA Astrophysics Data System (ADS)

    Benoit, Julien; Abdala, Fernando; Van den Brandt, Marc J.; Manger, Paul R.; Rubidge, Bruce S.

    2015-12-01

    The third eye (pineal eye), an organ responsible for regulating exposure to sunlight in extant ectotherms, is located in an opening on the dorsal surface of the skull, the parietal foramen. The parietal foramen is absent in extant mammals but often observed in basal therapsids, the stem-group to true mammals. Here, we report the absence of the parietal foramen in a specimen of Cynosaurus suppostus, a Late Permian cynodont from South Africa (SA). Comparison with Procynosuchus delaharpeae, a contemporaneous non-mammalian cynodont from SA, demonstrates that the absence of this foramen is an abnormal condition for such a basal species. Because seasonality was marked during the Late Permian in SA, it is proposed that the third eye was functionally redundant in Cynosaurus, possibly due to the acquisition of better thermoregulation or the evolution of specialized cells in the lateral eyes to compensate for the role of the third eye.

  1. Group V Secretory Phospholipase A2 Amplifies the Induction of Cyclooxygenase 2 and Delayed Prostaglandin D2 Generation in Mouse Bone Marrow Culture-Derived Mast Cells in a Strain-Dependent Manner.

    PubMed Central

    Diaz, Bruno L.; Satake, Yoshiyuki; Kikawada, Eriya; Balestrieri, Barbara; Arm, Jonathan P.

    2006-01-01

    Activation of bone marrow-derived mast cells (BMMC) with stem cell factor (SCF) or IgE and antigen elicits exocytosis and an immediate phase of prostaglandin (PG) D2 and leukotriene (LT) C4 generation. Activation of BMMC by SCF, IL-1β and IL-10 elicits a delayed phase of PGD2 generation dependent on cyclooxygenase (COX) 2 induction. Cytosolic phospholipase A2 α provides arachidonic acid in both phases and amplifies COX-2 induction. Pharmacological experiments implicate an amplifying role for secretory (s) PLA2. We used mice lacking the gene encoding group V sPLA2 (Pla2g5 −/−) to definitively test its role in eicosanoid generation by BMMC. Pla2g5 −/− BMMC on a C57BL/6 genetic background showed a modest reduction in exocytosis and immediate PGD2 generation after activation with SCF or with IgE and antigen, while LTC4 generation was not modified. Delayed-phase PGD2 generation and COX-2 induction were reduced ~35% in C57BL/6 Pla2g5 −/− BMMC and were restored by exogenous PGE2. There was no deficit in either phase of eicosanoid generation by Pla2g5 −/− BMMC on a BALB/c background. Thus, group V sPLA2 amplifies COX-2 expression and delayed phase PGD2 generation in a strain-dependent manner; it has at best a limited role in immediate eicosanoid generation by BMMC. PMID:17064958

  2. Mammary analogue secretory carcinoma mimicking salivary adenoma.

    PubMed

    Williams, Lindsay; Chiosea, Simion I

    2013-12-01

    Mammary analogue secretory carcinoma (MASC) is a recently described salivary gland tumor characterized by ETV6 translocation. It appears that prior studies have identified MASC by reviewing salivary gland carcinomas, such as acinic cell carcinoma and adenocarcinoma, not otherwise specified. To address the possibility of MASC mimicking benign salivary neoplasms we reviewed 12 salivary gland (cyst)adenomas diagnosed prior to the discovery of MASC. One encapsulated (cyst)adenoma of the parotid gland demonstrated features of MASC. The diagnosis was confirmed by fluorescence in situ hybridization with an ETV6 break-apart probe. An unusual complex pattern of ETV6 rearrangement with duplication of the telomeric/distal ETV6 probe was identified. This case illustrates that MASC may mimic salivary (cyst)adenomas. To more accurately assess true clinical and morphologic spectrum of MASC, future studies may have to include review of salivary (cyst)adenomas. The differential diagnosis of MASC may have to be expanded to include cases resembling salivary (cyst)adenomas.

  3. Platelet‐Rich Plasma Increases Growth and Motility of Adipose Tissue‐Derived Mesenchymal Stem Cells and Controls Adipocyte Secretory Function

    PubMed Central

    D'Esposito, Vittoria; Passaretti, Federica; Perruolo, Giuseppe; Ambrosio, Maria Rosaria; Valentino, Rossella; Oriente, Francesco; Raciti, Gregory A.; Nigro, Cecilia; Miele, Claudia; Sammartino, Gilberto; Beguinot, Francesco

    2015-01-01

    ABSTRACT Adipose tissue‐derived mesenchymal stem cells (Ad‐MSC) and platelet derivatives have been used alone or in combination to achieve regeneration of injured tissues. We have tested the effect of platelet‐rich plasma (PRP) on Ad‐MSC and adipocyte function. PRP increased Ad‐MSC viability, proliferation rate and G1‐S cell cycle progression, by at least 7‐, 2‐, and 2.2‐fold, respectively, and reduced caspase 3 cleavage. Higher PRP concentrations or PRPs derived from individuals with higher platelet counts were more effective in increasing Ad‐MSC growth. PRP also accelerated cell migration by at least 1.5‐fold. However, PRP did not significantly affect mature adipocyte viability, differentiation and expression levels of PPAR‐γ and AP‐2 mRNAs, while it increased leptin production by 3.5‐fold. Interestingly, PRP treatment of mature adipocytes also enhanced the release of Interleukin (IL)‐6, IL‐8, IL‐10, Interferon‐γ, and Vascular Endothelial Growth Factor. Thus, data are consistent with a stimulatory effect of platelet derivatives on Ad‐MSC growth and motility. Moreover, PRP did not reduce mature adipocyte survival and increased the release of pro‐angiogenic factors, which may facilitate tissue regeneration processes. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc. J. Cell. Biochem. 116: 2408–2418, 2015. © 2015 The Authors. Journal of Cellular Biochemistry Published by Wiley Periodicals, Inc. PMID:26012576

  4. Ionic, electrical, and secretory effects of protein kinase C activation in mouse pancreatic B-cells: studies with a phorbol ester

    SciTech Connect

    Bozem, M.; Nenquin, M.; Henquin, J.C.

    1987-09-01

    The phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) was used to study the effects of protein kinase C activation on stimulus-secretion coupling in mouse pancreatic B-cells. At a nonstimulatory concentration of glucose (3 mM), 100 nM TPA, but not 10 nM TPA, slightly and slowly increased insulin release and /sup 45/Ca/sup 2 +/ efflux and decreased /sup 86/Rb/sup +/ efflux, but did not affect the membrane potential of B-cells. At a threshold concentration of glucose (7 mM), 100 nM TPA markedly increased insulin release without triggering electrical activity in B-cells. At a stimulatory concentration of glucose (10 mM), TPA caused a dose-dependent irreversible increase in insulin release, /sup 45/Ca/sup 2 +/ efflux, and /sup 86/Rb/sup +/ efflux and slightly augmented islet cAMP levels. Omission of extracellular Ca/sup 2 +/ abolished the effects of 10 nM TPA and partially inhibited those of 100 nM TPA on insulin release and /sup 45/Ca/sup 2 +/ efflux. In contrast, their effect on /sup 86/Rb/sup +/ efflux was paradoxically augmented. Glucose-induced electrical activity in B-cells was only marginally affected by TPA; the duration of the slow waves with spikes was not modified, but a small shortening of the polarized intervals raised their frequency and slightly increased the overall activity. This increase was significant only with 10 nM TPA, whereas only 100 nM TPA brought about a minute increase in /sup 45/Ca/sup 2 +/ influx. These results thus show that TPA induces insulin release or potentiates glucose-induced insulin release without mimicking or amplifying the initial ionic and electrical signals triggered by glucose. They suggest that protein kinase C activation affects stimulus-secretion coupling by modulating intracellular and/or nonelectrogenic membrane events.

  5. A secretory kinase complex regulates extracellular protein phosphorylation

    PubMed Central

    Cui, Jixin; Xiao, Junyu; Tagliabracci, Vincent S; Wen, Jianzhong; Rahdar, Meghdad; Dixon, Jack E

    2015-01-01

    Although numerous extracellular phosphoproteins have been identified, the protein kinases within the secretory pathway have only recently been discovered, and their regulation is virtually unexplored. Fam20C is the physiological Golgi casein kinase, which phosphorylates many secreted proteins and is critical for proper biomineralization. Fam20A, a Fam20C paralog, is essential for enamel formation, but the biochemical function of Fam20A is unknown. Here we show that Fam20A potentiates Fam20C kinase activity and promotes the phosphorylation of enamel matrix proteins in vitro and in cells. Mechanistically, Fam20A is a pseudokinase that forms a functional complex with Fam20C, and this complex enhances extracellular protein phosphorylation within the secretory pathway. Our findings shed light on the molecular mechanism by which Fam20C and Fam20A collaborate to control enamel formation, and provide the first insight into the regulation of secretory pathway phosphorylation. DOI: http://dx.doi.org/10.7554/eLife.06120.001 PMID:25789606

  6. Alterations in hepatic pericanalicular cytoplasm during enhanced bile secretory activity.

    PubMed

    Jones, A L; Schmucker, D L; Mooney, J S; Ockner, R K; Adler, R D

    1979-04-01

    In an attempt to demonstrate the morphology of the bile secretory apparatus, male rats were restrained and maintained on an isocaloric diet with (experimental) and without (control) taurocholate, which was continuously infused via a duodenal cannula. This method of taurocholate administration promotes a 2-fold increase in the bile acid pool size and bile secretory rate and increases the transport maximum of taurocholate by approximately 50%. After 48 hours, the livers from both the control and experimental animals were perfusion-fixed and whole hepatocytes as well as pericanalicular cytoplasm (defined as a 1-micron. wide zone of cytoplasm adjacent to the bile canaliculus) in both centrolobular and periportal cells were subjected to a stereologic analysis. Although taurocholate infusion produced relatively few changes in the amounts of organelles or inclusionswithin hepatocytes, it caused highly significant increases in the amount ofGolgi-rich area, Golgi membranes, and the number of vesicles with diameters greater than 1000 A in the pericanalicular area of cytoplasm. In addition to these changes, which occurred in both central and periportal zones, decreases in the volume of lysosomes and the surface area of smooth surfaced endoplasmic reticulum were observed. These data provide new evidence that the "bile secretory apparatus" may encompass several hepatocellular components which include the Golgi complex and a vesicular transport system.

  7. Atrophy of the parietal lobe in preclinical dementia.

    PubMed

    Jacobs, Heidi I L; Van Boxtel, Martin P J; Uylings, Harry B M; Gronenschild, Ed H B M; Verhey, Frans R; Jolles, Jelle

    2011-03-01

    Cortical grey matter atrophy patterns have been reported in healthy ageing and Alzheimer disease (AD), but less consistently in the parietal regions of the brain. We investigated cortical grey matter volume patterns in parietal areas. The grey matter of the somatosensory cortex, superior and inferior parietal lobule was measured in 75 older adults (38 cognitively stable and 37 individuals with cognitive decline after 3 years). Dementia screening 6 years after scanning resulted in nine AD cases from the cognitively stable (n=3) and cognitive decline group (n=6), who were assigned to a third group, the preclinical AD group. When regional differences in cortical volume in the parietal lobe areas were compared between groups, significant differences were found between either the cognitive decline or stable group on the one hand and preclinical AD individuals on the other hand in the inferior parietal lobule. Group membership was best predicted by the grey matter volume of the inferior parietal lobule, compared to the other parietal lobe areas. The parietal lobe was characterised by a differential atrophy pattern based on cognitive status, which is in agreement with the 'last-developed-first-atrophied' principle. Future studies should investigate the surplus value of the inferior parietal lobe as a potential marker for the diagnosis of AD compared to other brain regions, such as the medial temporal lobe and the prefrontal lobe. PMID:21130554

  8. Orchestration of secretory protein folding by ER chaperones

    PubMed Central

    Gidalevitz, Tali; Stevens, Fred; Argon, Yair

    2013-01-01

    The endoplasmic reticulum is a major compartment of protein biogenesis in the cell, dedicated to production of secretory, membrane and organelle proteins. The secretome has distinct structural and post-translational characteristics, since folding in the ER occurs in an environment that is distinct in terms of its ionic composition, dynamics and requirements for quality contol. The folding machinery in the ER therefore includes chaperones and folding enzymes that introduce, monitor and react to disulfide bonds, glycans, and fluctuations of luminal calcium. We describe the major chaperone networks in the lumen and discuss how they have distinct modes of operation that enable cells to accomplish highly efficient production of the secretome. PMID:23507200

  9. Malignant pilomatricoma in the parietal area.

    PubMed

    Kondo, Takeshi; Tanaka, Yoshio

    2006-01-01

    A 27-year-old Japanese woman presented with a 2.5-cm nodular subcutaneous lesion in the parietal area. The nodule was well demarcated and situated in the dermis and subcutis. Histologically, the tumor was diagnosed as malignant pilomatricoma. The tumor was excised, the postoperative course was uneventful, no evidence of local recurrence or distant metastasis was observed, and the patient continues to be under close follow-up. Malignant pilomatricoma, a locally aggressive counterpart of benign pilomatricoma, is also referred to as pilomatrix carcinoma. Most cases are excised as benign tumors; however, when the excision is incomplete local recurrence is likely, and distant metastases have also been reported. Histologically, the diagnosis can be challenging because no clear histologic criteria are available. Because of the rarity of malignant pilomatricoma, no welldefined standards in the surgical management of this neoplasm have been established. Moreover, since distant metastases have been described, close followup of the lesion is requisite.

  10. The pathology of parietal pleural plaques

    PubMed Central

    Roberts, G. Hefin

    1971-01-01

    The incidence, morbid anatomy, histology, and relationship of hyaline pleural plaques to exposure to asbestos has been studied. Plaques were found in 12·3% of 334 hospital necropsies (in an urban population in Glasgow, 41 cases). In 85·3% (35 cases) asbestos bodies were found in the lungs. There is evidence of a dose-response relationship between the number of asbestos bodies found in the lungs and the presence of pleural plaques. The selective distribution of plaques within the pleural cavities suggests that mechanical factors play a part in their localization. Histological examination contributed little to understanding the mechanism of plaque formation; that asbestos bodies have been detected in only a few cases suggest that their presence in the parietal pleura is not essential to plaque formation. The suggested mechanisms of plaque formation are discussed. Images PMID:5556121

  11. AP-1 and clathrin are essential for secretory granule biogenesis in Drosophila

    PubMed Central

    Burgess, Jason; Jauregui, Miluska; Tan, Julie; Rollins, Janet; Lallet, Sylvie; Leventis, Peter A.; Boulianne, Gabrielle L.; Chang, Henry C.; Le Borgne, Roland; Krämer, Helmut; Brill, Julie A.

    2011-01-01

     Regulated secretion of hormones, digestive enzymes, and other biologically active molecules requires the formation of secretory granules. Clathrin and the clathrin adaptor protein complex 1 (AP-1) are necessary for maturation of exocrine, endocrine, and neuroendocrine secretory granules. However, the initial steps of secretory granule biogenesis are only minimally understood. Powerful genetic approaches available in the fruit fly Drosophila melanogaster were used to investigate the molecular pathway for biogenesis of the mucin-containing “glue granules” that form within epithelial cells of the third-instar larval salivary gland. Clathrin and AP-1 colocalize at the trans-Golgi network (TGN) and clathrin recruitment requires AP-1. Furthermore, clathrin and AP-1 colocalize with secretory cargo at the TGN and on immature granules. Finally, loss of clathrin or AP-1 leads to a profound block in secretory granule formation. These findings establish a novel role for AP-1– and clathrin-dependent trafficking in the biogenesis of mucin-containing secretory granules. PMID:21490149

  12. HID-1 is required for homotypic fusion of immature secretory granules during maturation

    PubMed Central

    Du, Wen; Zhou, Maoge; Zhao, Wei; Cheng, Dongwan; Wang, Lifen; Lu, Jingze; Song, Eli; Feng, Wei; Xue, Yanhong; Xu, Pingyong; Xu, Tao

    2016-01-01

    Secretory granules, also known as dense core vesicles, are generated at the trans-Golgi network and undergo several maturation steps, including homotypic fusion of immature secretory granules (ISGs) and processing of prehormones to yield active peptides. The molecular mechanisms governing secretory granule maturation are largely unknown. Here, we investigate a highly conserved protein named HID-1 in a mouse model. A conditional knockout of HID-1 in pancreatic β cells leads to glucose intolerance and a remarkable increase in the serum proinsulin/insulin ratio caused by defective proinsulin processing. Large volume three-dimensional electron microscopy and immunofluorescence imaging reveal that ISGs are much more abundant in the absence of HID-1. We further demonstrate that HID-1 deficiency prevented secretory granule maturation by blocking homotypic fusion of immature secretory granules. Our data identify a novel player during the early maturation of immature secretory granules. DOI: http://dx.doi.org/10.7554/eLife.18134.001 PMID:27751232

  13. Engineering of a Secretory Active Three-Dimensional Lacrimal Gland Construct on the Basis of Decellularized Lacrimal Gland Tissue.

    PubMed

    Spaniol, Kristina; Metzger, Marco; Roth, Mathias; Greve, Burkhard; Mertsch, Sonja; Geerling, Gerd; Schrader, Stefan

    2015-10-01

    Lacrimal gland (LG) insufficiency is a main cause for severe dry eye leading to pain, visual impairment, and eventually loss of sight. Engineering of transplantable LG tissue with secretory capacity is a desirable goal. In this study, a three-dimensional decellularized LG (DC-LG) scaffold with preserved LG morphology was generated by treatment with 1% sodium deoxycholate and DNase solution using porcine LG tissue. To address clinical applicability, the primary in vitro culture of secretory active LG cells from a small tissue biopsy of 1.5 mm diameter was introduced and compared with an established isolation method by enzymatic digestion. Cells from both isolation methods depicted an epithelial phenotype, maintained their secretory capacity for up to 30 days, and exhibited progenitor cell capacity as measured by aldehyde dehydrogenase-1 activity, side population assay, and colony-forming units. Cells from passage 0 were reseeded into the DC-LG and secretory active cells migrated into the tissue. The cells resembled an LG-like morphology and the constructs showed secretory activity. These results demonstrate the possibility of engineering a secretory competent, three-dimensional LG construct using LG cells expanded from a small tissue biopsy and DC-LG as a matrix that provides the native structure and physiological niche for these cells.

  14. Multiphoton fluorescence lifetime imaging shows spatial segregation of secondary metabolites in Eucalyptus secretory cavities.

    PubMed

    Heskes, A M; Lincoln, C N; Goodger, J Q D; Woodrow, I E; Smith, T A

    2012-07-01

    Multiphoton fluorescence lifetime imaging provides an excellent tool for imaging deep within plant tissues while providing a means to distinguish between fluorophores with high spatial and temporal resolution. Ideal candidates for the application of multiphoton fluorescence lifetime imaging to plants are the embedded secretory cavities found in numerous species because they house complex mixtures of secondary metabolites within extracellular lumina. Previous investigations of this type of structure have been restricted by the use of sectioned material resulting in the loss of lumen contents and often disorganization of the delicate secretory cells; thus it is not known if there is spatial segregation of secondary metabolites within these structures. In this paper, we apply multiphoton fluorescence lifetime imaging to investigate the spatial arrangement of metabolites within intact secretory cavities isolated from Eucalyptus polybractea R.T. Baker leaves. The secretory cavities of this species are abundant (up to 10 000 per leaf), large (up to 6 nL) and importantly house volatile essential oil rich in the monoterpene 1,8-cineole, together with an immiscible, non-volatile component comprised largely of autofluorescent oleuropeic acid glucose esters. We have been able to optically section into the lumina of secretory cavities to a depth of ∼80 μm, revealing a unique spatial organization of cavity metabolites whereby the non-volatile component forms a layer between the secretory cells lining the lumen and the essential oil. This finding could be indicative of a functional role of the non-volatile component in providing a protective region of low diffusivity between the secretory cells and potentially autotoxic essential oil.

  15. Mandatory Housing Requirements: The Constitutionality of Parietal Rules

    ERIC Educational Resources Information Center

    Iowa Law Review, 1975

    1975-01-01

    Analyzes the validity of parietal rules under both the due process and equal protection clauses of the Fourteenth Amendment. Models of substantive due process and equal protection are developed and applied to the various types of parietal rules that have been implemented at universities throughout the nation. (Author/JT)

  16. The Ypt1 GTPase is essential for the first two steps of the yeast secretory pathway.

    PubMed

    Jedd, G; Richardson, C; Litt, R; Segev, N

    1995-11-01

    Small GTPases of the rab family are involved in the regulation of vesicular transport. The restricted distribution of each of these proteins in mammalian cells has led to the suggestion that different rab proteins act at different steps of transport (Pryer, N. K., L. J. Wuestehube, and R. Sheckman. 1992. Annu Rev. Biochem. 61:471-516; Zerial, M., and H. Stenmark. 1993. Curr. Opin. Cell Biol. 5:613-620). However, in this report we show that the Ypt1-GTPase, a member of the rab family, is essential for more than one step of the yeast secretory pathway. We determined the secretory defect conferred by a novel ypt1 mutation by comparing the processing of several transported glycoproteins in wild-type and mutant cells. The ypt1-A136D mutant has a change in an amino acid that is conserved among rab GTPases. This mutation leads to a rapid and tight secretory block upon a shift to the restrictive temperature, and allows for the identification of the specific steps in the secretory pathway that directly require Ypt1 protein (Ypt1p). The ypt1-A136D mutant exhibits tight blocks in two secretory steps, ER to cis-Golgi and cis- to medial-Golgi, but later steps are unaffected. Thus, it is unlikely that Ypt1p functions as the sole determinant of fusion specificity. Our results are more consistent with a role for Ypt1/rab proteins in determining the directionality or fidelity of protein sorting.

  17. Secretory immunity with special reference to the oral cavity

    PubMed Central

    Brandtzaeg, Per

    2013-01-01

    The two principal antibody classes present in saliva are secretory IgA (SIgA) and IgG; the former is produced as dimeric IgA by local plasma cells (PCs) in the stroma of salivary glands and is transported through secretory epithelia by the polymeric Ig receptor (pIgR), also named membrane secretory component (SC). Most IgG in saliva is derived from the blood circulation by passive leakage mainly via gingival crevicular epithelium, although some may be locally produced in the gingiva or salivary glands. Gut-associated lymphoid tissue (GALT) and nasopharynx-associated lymphoid tissue (NALT) do not contribute equally to the pool of memory/effector B cells differentiating to mucosal PCs throughout the body. Thus, enteric immunostimulation may not be the best way to activate the production of salivary IgA antibodies although the level of specific SIgA in saliva may still reflect an intestinal immune response after enteric immunization. It remains unknown whether the IgA response in submandibular/sublingual glands is better related to B-cell induction in GALT than the parotid response. Such disparity is suggested by the levels of IgA in submandibular secretions of AIDS patients, paralleling their highly upregulated intestinal IgA system, while the parotid IgA level is decreased. Parotid SIgA could more consistently be linked to immune induction in palatine tonsils/adenoids (human NALT) and cervical lymph nodes, as supported by the homing molecule profile observed after immune induction at these sites. Several other variables influence the levels of antibodies in salivary secretions. These include difficulties with reproducibility and standardization of immunoassays, the impact of flow rate, acute or chronic stress, protein loss during sample handling, and uncontrolled admixture of serum-derived IgG and monomeric IgA. Despite these problems, saliva is an easily accessible biological fluid with interesting scientific and clinical potentials. PMID:23487566

  18. The secretory membrane system studied in real-time. Robert Feulgen Prize Lecture, 2001.

    PubMed

    Lippincott-Schwartz, J

    2001-08-01

    The discovery and development of green fluorescent protein (GFP) from the jellyfish, Aequorea victoria, has revolutionized studies on protein localization and dynamics by allowing direct observation of a protein's life history and pathway in living cells, previously only deduced from genetic, biochemical, or immunolabeling studies. Applied to the secretory membrane system, which regulates delivery of newly synthesized proteins and lipids to the cell surface, GFP-based studies are providing important new insights into the maintenance and biogenesis of organelles, as well as the origin, pathway, and fate of secretory transport intermediates.

  19. The secretory membrane system studied in real-time. Robert Feulgen Prize Lecture, 2001.

    PubMed

    Lippincott-Schwartz, J

    2001-08-01

    The discovery and development of green fluorescent protein (GFP) from the jellyfish, Aequorea victoria, has revolutionized studies on protein localization and dynamics by allowing direct observation of a protein's life history and pathway in living cells, previously only deduced from genetic, biochemical, or immunolabeling studies. Applied to the secretory membrane system, which regulates delivery of newly synthesized proteins and lipids to the cell surface, GFP-based studies are providing important new insights into the maintenance and biogenesis of organelles, as well as the origin, pathway, and fate of secretory transport intermediates. PMID:11685538

  20. A Highly Sensitive Assay for Monitoring the Secretory Pathway and ER Stress

    PubMed Central

    Breakefield, Xandra O.; Tannous, Bakhos A.

    2007-01-01

    Background The secretory pathway is a critical index of the capacity of cells to incorporate proteins into cellular membranes and secrete proteins into the extracellular space. Importantly it is disrupted in response to stress to the endoplasmic reticulum that can be induced by a variety of factors, including expression of mutant proteins and physiologic stress. Activation of the ER stress response is critical in the etiology of a number of diseases, such as diabetes and neurodegeneration, as well as cancer. We have developed a highly sensitive assay to monitor processing of proteins through the secretory pathway and endoplasmic reticulum (ER) stress in real-time based on the naturally secreted Gaussia luciferase (Gluc). Methodology/Principle Findings An expression cassette for Gluc was delivered to cells, and its secretion was monitored by measuring luciferase activity in the conditioned medium. Gluc secretion was decreased down to 90% when these cells were treated with drugs that interfere with the secretory pathway at different steps. Fusing Gluc to a fluorescent protein allowed quantitation and visualization of the secretory pathway in real-time. Expression of this reporter protein did not itself elicit an ER stress response in cells; however, Gluc proved very sensitive at sensing this type of stress, which is associated with a temporary decrease in processing of proteins through the secretory pathway. The Gluc secretion assay was over 20,000-fold more sensitive as compared to the secreted alkaline phosphatase (SEAP), a well established assay for monitoring of protein processing and ER stress in mammalian cells. Conclusions/Significance The Gluc assay provides a fast, quantitative and sensitive technique to monitor the secretory pathway and ER stress and its compatibility with high throughput screening will allow discovery of drugs for treatment of conditions in which the ER stress is generally induced. PMID:17593970

  1. Secretory pathway Ca2+/Mn2+-ATPase isoform 2 and lactation: specific localization of plasmalemmal and secretory pathway Ca2+ pump isoforms in the mammary gland

    SciTech Connect

    Faddy, Helen M.; Smart, Chanel E.; Xu, Ren; Lee, Genee Y.; Kenny, Paraic A.; Feng, Mingye; Rao, Rajini; Brown, Melissa A.; Bissell, Mina J.; Roberts-Thomson, Sarah J.; Monteith, Gregory R.

    2008-04-09

    The supply of calcium to the developing neonate via milk is an important physiological process. Until recently the mechanism for the enrichment of milk with calcium was thought to be almost entirely mediated via the secretory pathway. However, recent studies suggest that a specific isoform of the plasma membrane calcium ATPase, PMCA2, is the primary mechanism for calcium transport into milk, highlighting a major role for apical calcium transport. We compared the expression of the recently identified secretory calcium ATPase, SPCA2, and SPCA1, in the mouse mammary gland during different stages of development. SPCA2 levels increased over 35 fold during lactation, while SPCA1 increased only a modest two fold. The potential importance of SPCA2 in lactation was also highlighted by its localization to luminal secretory cells of the mammary gland during lactation, while SPCA1 was expressed throughout the cells of the mammary gland. We also observed major differences in the localization of PMCA2 and PMCA1 during lactation. Using the SCp2 mouse mammary epithelial cell 3D culture model, differences in the sub-cellular distribution of PMCA2 and PMCA1 were clear. These studies highlight the likely specific roles of PMCA2 and SPCA2 in lactation, and link the recently characterized SPCA2 calcium pump to the supply of calcium into milk and the regulation of Golgi resident enzymes important in lactation. They also indicate that calcium transport into milk is a complex interplay between apical and secretory pathways.

  2. Auxilin facilitates membrane traffic in the early secretory pathway.

    PubMed

    Ding, Jingzhen; Segarra, Verónica A; Chen, Shuliang; Cai, Huaqing; Lemmon, Sandra K; Ferro-Novick, Susan

    2016-01-01

    Coat protein complexes contain an inner shell that sorts cargo and an outer shell that helps deform the membrane to give the vesicle its shape. There are three major types of coated vesicles in the cell: COPII, COPI, and clathrin. The COPII coat complex facilitates vesicle budding from the endoplasmic reticulum (ER), while the COPI coat complex performs an analogous function in the Golgi. Clathrin-coated vesicles mediate traffic from the cell surface and between the trans-Golgi and endosome. While the assembly and structure of these coat complexes has been extensively studied, the disassembly of COPII and COPI coats from membranes is less well understood. We describe a proteomic and genetic approach that connects the J-domain chaperone auxilin, which uncoats clathrin-coated vesicles, to COPII and COPI coat complexes. Consistent with a functional role for auxilin in the early secretory pathway, auxilin binds to COPII and COPI coat subunits. Furthermore, ER-Golgi and intra-Golgi traffic is delayed at 15°C in swa2Δ mutant cells, which lack auxilin. In the case of COPII vesicles, we link this delay to a defect in vesicle fusion. We propose that auxilin acts as a chaperone and/or uncoating factor for transport vesicles that act in the early secretory pathway.

  3. Stress modulates intestinal secretory immunoglobulin A

    PubMed Central

    Campos-Rodríguez, Rafael; Godínez-Victoria, Marycarmen; Abarca-Rojano, Edgar; Pacheco-Yépez, Judith; Reyna-Garfias, Humberto; Barbosa-Cabrera, Reyna Elizabeth; Drago-Serrano, Maria Elisa

    2013-01-01

    Stress is a response of the central nervous system to environmental stimuli perceived as a threat to homeostasis. The stress response triggers the generation of neurotransmitters and hormones from the hypothalamus pituitary adrenal axis, sympathetic axis and brain gut axis, and in this way modulates the intestinal immune system. The effects of psychological stress on intestinal immunity have been investigated mostly with the restraint/immobilization rodent model, resulting in an up or down modulation of SIgA levels depending on the intensity and time of exposure to stress. SIgA is a protein complex formed by dimeric (dIgA) or polymeric IgA (pIgA) and the secretory component (SC), a peptide derived from the polymeric immunoglobulin receptor (pIgR). The latter receptor is a transmembrane protein expressed on the basolateral side of gut epithelial cells, where it uptakes dIgA or pIgA released by plasma cells in the lamina propria. As a result, the IgA-pIgR complex is formed and transported by vesicles to the apical side of epithelial cells. pIgR is then cleaved to release SIgA into the luminal secretions of gut. Down modulation of SIgA associated with stress can have negative repercussions on intestinal function and integrity. This can take the form of increased adhesion of pathogenic agents to the intestinal epithelium and/or an altered balance of inflammation leading to greater intestinal permeability. Most studies on the molecular and biochemical mechanisms involved in the stress response have focused on systemic immunity. The present review analyzes the impact of stress (mostly by restraint/immobilization, but also with mention of other models) on the generation of SIgA, pIgR and other humoral and cellular components involved in the intestinal immune response. Insights into these mechanisms could lead to better therapies for protecting against pathogenic agents and avoiding epithelial tissue damage by modulating intestinal inflammation. PMID:24348350

  4. A signal sequence is sufficient for green fluorescent protein to be routed to regulated secretory granules.

    PubMed

    El Meskini, R; Jin, L; Marx, R; Bruzzaniti, A; Lee, J; Emeson, R; Mains, R

    2001-02-01

    To investigate trafficking in neuroendocrine cells, green fluorescent protein (GFP) tags were fused to various portions of the preproneuropeptide Y (NPY) precursor. Two neuroendocrine cell lines, AtT-20 corticotrope tumor cells and PC-12 pheochromocytoma cells, along with primary anterior pituitary cells, were examined. Expression of chimeric constructs did not disrupt trafficking or regulated secretion of endogenous ACTH and prohormone convertase 1 in AtT-20 cells. Western blot and immunocytochemical analyses demonstrated that the chimeric constructs remained intact, as long as the Lys-Arg cleavage site within preproNPY was deleted. GFP was stored in, and released from, regulated granules in cells expressing half of the NPY precursor fused to GFP, and also in cells in which only the signal sequence of preproNPY was fused to GFP. Thus, in neuroendocrine cells, entering the lumen of the secretory pathway is sufficient to target GFP to regulated secretory granules.

  5. Morphological docking of secretory vesicles

    PubMed Central

    2010-01-01

    Calcium-dependent secretion of neurotransmitters and hormones is essential for brain function and neuroendocrine-signaling. Prior to exocytosis, neurotransmitter-containing vesicles dock to the target membrane. In electron micrographs of neurons and neuroendocrine cells, like chromaffin cells many synaptic vesicles (SVs) and large dense-core vesicles (LDCVs) are docked. For many years the molecular identity of the morphologically docked state was unknown. Recently, we resolved the minimal docking machinery in adrenal medullary chromaffin cells using embryonic mouse model systems together with electron-microscopic analyses and also found that docking is controlled by the sub-membrane filamentous (F-)actin. Currently it is unclear if the same docking machinery operates in synapses. Here, I will review our docking assay that led to the identification of the LDCV docking machinery in chromaffin cells and also discuss whether identical docking proteins are required for SV docking in synapses. PMID:20577884

  6. The Ca2+/H+ antiporter TMEM165 expression, localization in the developing, lactating and involuting mammary gland parallels the secretory pathway Ca2+ATPase (SPCA1)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plasma membrane Ca2+-ATPase 2 (PMCA2) knockout mice showed that ~ 60 % of calcium in milk is transported across the mammary cells apical membrane by PMCA2. The remaining milk calcium is thought to arrive via the secretory pathway through the actions of secretory pathway Ca2+-ATPase’s 1 and/or 2 (SP...

  7. Aging and secretory reserve capacity of major salivary glands.

    PubMed

    Ghezzi, E M; Ship, J A

    2003-10-01

    A loss of acinar cells occurs with aging, while salivary production remains age-stable in healthy adults. It is hypothesized that a secretory reserve exists to preserve function despite a loss of acinar cells in normal aging. The purpose of this double-blind, placebo-controlled, crossover study was to determine age-related differences in salivary response to an anti-sialogogue (glycopyrrolate). Thirty-six healthy subjects (18 young--20-38 yrs; 18 older--60-77 yrs) received 4.0 microg/kg i.v. glycopyrrolate. Parotid and submandibular/sublingual saliva samples and xerostomia questionnaire responses were collected. Variables calculated for each subject were: times to initial and maximum suppression and xerostomic complaint; time to recovery; and durations of suppression and complaint. Salivary function was more adversely affected in older persons. There were no consistent age-associated questionnaire response differences. These findings suggest that salivary gland output is more adversely affected by an anti-sialogogue in healthy older vs. younger adults, supporting the secretory reserve hypothesis of salivary function. PMID:14514768

  8. Coordinated activation of the secretory pathway during notochord formation in the Xenopus embryo

    PubMed Central

    Tanegashima, Kosuke; Zhao, Hui; Rebbert, Martha L.; Dawid, Igor B.

    2009-01-01

    Summary We compared the transcriptome in the developing notochord of Xenopus laevis embryos with that of other embryonic regions. A coordinated and intense activation of a large set of secretory pathway genes was observed in the notochord, but not in notochord precursors in the axial mesoderm at early gastrula stage. The genes encoding Xbp1 and Creb3l2 were also activated in the notochord. These two transcription factors are implicated in the activation of secretory pathway genes during the unfolded protein response, where cells react to the stress of a build-up of unfolded proteins in their endoplasmic reticulum. Xbp1 and Creb3l2 are differentially expressed but not differentially activated in the notochord. Reduction of expression of Xbp1 or Creb3l2 by injection of antisense morpholinos led to strong deficits in notochord but not somitic muscle development. In addition, the expression of some, but not all, genes encoding secretory proteins was inhibited by injection of xbp1 morpholinos. Furthermore, expression of activated forms of Xbp1 or Creb3l2 in animal explants could activate a similar subset of secretory pathway genes. We conclude that coordinated activation of a battery of secretory pathway genes mediated by Xbp1 and Creb/ATF factors is a characteristic and necessary feature of notochord formation. PMID:19793890

  9. Parietal damage impairs learning of a visuomotor tracking skill.

    PubMed

    Cavaco, Sara; Anderson, Steven W; Chen, Kuan-Hua; Teixeira-Pinto, Armando; Damasio, Hanna

    2015-12-01

    This study evaluated the consequences of damage to the parietal lobe for learning a visuomotor tracking skill. Thirty subjects with a single unilateral brain lesion (13 with and 17 without parietal damage) and 23 demographically comparable healthy subjects performed the Rotary Pursuit task. For each group, time on target increased significantly across the four learning blocks. Subjects with parietal lesions had smaller improvements on the Rotary Pursuit from the 1st to the 4th block than subjects with lesions in other brain areas and healthy comparison subjects. The improvements on task performance from the 1st to the 2nd and from the 1st to the 3rd learning blocks were similar between groups. The parietal lobe appears to play an important role in the acquisition of a new visuomotor tracking skill, in particular during a relatively late phase of learning. PMID:26536523

  10. Parietal damage impairs learning of a visuomotor tracking skill.

    PubMed

    Cavaco, Sara; Anderson, Steven W; Chen, Kuan-Hua; Teixeira-Pinto, Armando; Damasio, Hanna

    2015-12-01

    This study evaluated the consequences of damage to the parietal lobe for learning a visuomotor tracking skill. Thirty subjects with a single unilateral brain lesion (13 with and 17 without parietal damage) and 23 demographically comparable healthy subjects performed the Rotary Pursuit task. For each group, time on target increased significantly across the four learning blocks. Subjects with parietal lesions had smaller improvements on the Rotary Pursuit from the 1st to the 4th block than subjects with lesions in other brain areas and healthy comparison subjects. The improvements on task performance from the 1st to the 2nd and from the 1st to the 3rd learning blocks were similar between groups. The parietal lobe appears to play an important role in the acquisition of a new visuomotor tracking skill, in particular during a relatively late phase of learning.

  11. [Solitary fibrous tumor of the parietal pleura resected by video-assisted thoracic surgery; report of a case].

    PubMed

    Hayama, Makio; Maeda, Hiroya

    2010-06-01

    A 35-year-old male was admitted to our hospital for further examination of abnormal shadow on chest X-ray. Contrast-enhanced chest computed tomography (CT) showed a clear-shaped tumor with homogenous enhancement, measuring 25 x 20 mm in size, which had enlarged, compared with chest CT of 2 years before. The tumor appeared to be based partially on the parietal pleura. Under the diagnosis of solitary fibrous tumor (SFT) originated from the visceral or parietal pleura, video-assisted thoracic surgery (VATS) was performed. Under thoracoscopy, the tumor was pedunculated and arose from the parietal pleura. The tumor was resected completely. The pathologic findings revealed proliferation of spindle cells and collagen fibers without malignant aspects. Immuno-histochemical findings showed positive immunostaining for CD34 and vimentin in the tumor cells. These findings confirmed that the tumor was SFT.

  12. Parietal cortex and representation of the mental Self

    PubMed Central

    Lou, Hans C.; Luber, Bruce; Crupain, Michael; Keenan, Julian P.; Nowak, Markus; Kjaer, Troels W.; Sackeim, Harold A.; Lisanby, Sarah H.

    2004-01-01

    For a coherent and meaningful life, conscious self-representation is mandatory. Such explicit “autonoetic consciousness” is thought to emerge by retrieval of memory of personally experienced events (“episodic memory”). During episodic retrieval, functional imaging studies consistently show differential activity in medial prefrontal and medial parietal cortices. With positron-emission tomography, we here show that these medial regions are functionally connected and interact with lateral regions that are activated according to the degree of self-reference. During retrieval of previous judgments of Oneself, Best Friend, and the Danish Queen, activation increased in the left lateral temporal cortex and decreased in the right inferior parietal region with decreasing self-reference. Functionally, the former region was preferentially connected to medial prefrontal cortex, the latter to medial parietal. The medial parietal region may, then, be conceived of as a nodal structure in self-representation, functionally connected to both the right parietal and the medial prefrontal cortices. To determine whether medial parietal cortex in this network is essential for episodic memory retrieval with self-representation, we used transcranial magnetic stimulation over the region to transiently disturb neuronal circuitry. There was a decrease in the efficiency of retrieval of previous judgment of mental Self compared with retrieval of judgment of Other with transcranial magnetic stimulation at a latency of 160 ms, confirming the hypothesis. This network is strikingly similar to the network of the resting conscious state, suggesting that self-monitoring is a core function in resting consciousness. PMID:15096584

  13. Analysis of Protein Localization and Secretory Pathway Function Using the Yeast "Saccharomyces Cerevisiae"

    ERIC Educational Resources Information Center

    Vallen, Elizabeth

    2002-01-01

    The isolation and characterization of mutants has been crucial in understanding a number of processes in the field of cell biology. In this exercise, students examine the effects of mutations in the secretory pathway on protein localization. Yeast strains deficient for synthesis of histidinol dehydrogenase are transformed with a plasmid encoding a…

  14. Yeast secretory expression of insulin precursors.

    PubMed

    Kjeldsen, T

    2000-09-01

    Since the 1980s, recombinant human insulin for the treatment of diabetes mellitus has been produced using either the yeast Saccharomyces cerevisiae or the prokaryote Escherichia coli. Here, development of the insulin secretory expression system in S. cerevisiae and its subsequent optimisation is described. Expression of proinsulin in S. cerevisiae does not result in efficient secretion of proinsulin or insulin. However, expression of a cDNA encoding a proinsulin-like molecule with deletion of threonine(B30) as a fusion protein with the S. cerevisiae alpha-factor prepro-peptide (leader), followed either by replacement of the human proinsulin C-peptide with a small C-peptide (e.g. AAK), or by direct fusion of lysine(B29) to glycine(A1), results in the efficient secretion of folded single-chain proinsulin-like molecules to the culture supernatant. The secreted single-chain insulin precursor can then be purified and subsequently converted to human insulin by tryptic transpeptidation in organic aqueous medium in the presence of a threonine ester. The leader confers secretory competence to the insulin precursor, and constructed (synthetic) leaders have been developed for efficient secretory expression of the insulin precursor in the yeasts S. cerevisiae and Pichia pastories. The Kex2 endoprotease, specific for dibasic sites, cleaves the leader-insulin precursor fusion protein in the late secretory pathway and the folded insulin precursor is secreted to the culture supernatant. However, the Kex2 endoprotease processing of the pro-peptide-insulin precursor fusion protein is incomplete and a significant part of the pro-peptide-insulin precursor fusion protein is secreted to the culture supernatant in a hyperglycosylated form. A spacer peptide localised between the leader and the insulin precursor has been developed to optimise Kex2 endoprotease processing and insulin precursor fermentation yield. PMID:11030562

  15. Islet secretory granules contain cytochrome b561.

    PubMed

    Mackin, R B; Jones, D P; Noe, B D

    1986-08-01

    A cytochrome has been detected in secretory granules prepared from anglerfish islets of Langerhans. The heme moiety was determined to be of the b type, and the dithionite-reduced cytochrome exhibited an alpha-band maximum at 561 nm with an extinction coefficient of 13.8 mM-1 X cm-1. The protein was present at a concentration of 40 +/- 4 pmol/mg of secretory granule protein. The cytochrome was found to be an integral membrane protein and to be reduced by ascorbic acid but not by NADH, NADPH, reduced glutathione (GSH), or succinate. Because of the similarity to previously characterized secretory granule cytochrome b561's from neuroendocrine tissues, this cytochrome is also referred to as cytochrome b561. Although its function has not yet been elucidated, the apparent specificity for ascorbate suggests that it may be a component of the ascorbate-dependent peptidyl-glycine alpha-amidating monooxygenase system that functions in the amidation of islet hormones. PMID:3525285

  16. Widespread occurrence of expressed fungal secretory peroxidases in forest soils.

    PubMed

    Kellner, Harald; Luis, Patricia; Pecyna, Marek J; Barbi, Florian; Kapturska, Danuta; Krüger, Dirk; Zak, Donald R; Marmeisse, Roland; Vandenbol, Micheline; Hofrichter, Martin

    2014-01-01

    Fungal secretory peroxidases mediate fundamental ecological functions in the conversion and degradation of plant biomass. Many of these enzymes have strong oxidizing activities towards aromatic compounds and are involved in the degradation of plant cell wall (lignin) and humus. They comprise three major groups: class II peroxidases (including lignin peroxidase, manganese peroxidase, versatile peroxidase and generic peroxidase), dye-decolorizing peroxidases, and heme-thiolate peroxidases (e.g. unspecific/aromatic peroxygenase, chloroperoxidase). Here, we have repeatedly observed a widespread expression of all major peroxidase groups in leaf and needle litter across a range of forest ecosystems (e.g. Fagus, Picea, Acer, Quercus, and Populus spp.), which are widespread in Europe and North America. Manganese peroxidases and unspecific peroxygenases were found expressed in all nine investigated forest sites, and dye-decolorizing peroxidases were observed in five of the nine sites, thereby indicating biological significance of these enzymes for fungal physiology and ecosystem processes. Transcripts of selected secretory peroxidase genes were also analyzed in pure cultures of several litter-decomposing species and other fungi. Using this information, we were able to match, in environmental litter samples, two manganese peroxidase sequences to Mycena galopus and Mycena epipterygia and one unspecific peroxygenase transcript to Mycena galopus, suggesting an important role of this litter- and coarse woody debris-dwelling genus in the disintegration and transformation of litter aromatics and organic matter formation.

  17. Widespread Occurrence of Expressed Fungal Secretory Peroxidases in Forest Soils

    PubMed Central

    Kellner, Harald; Luis, Patricia; Pecyna, Marek J.; Barbi, Florian; Kapturska, Danuta; Krüger, Dirk; Zak, Donald R.; Marmeisse, Roland; Vandenbol, Micheline; Hofrichter, Martin

    2014-01-01

    Fungal secretory peroxidases mediate fundamental ecological functions in the conversion and degradation of plant biomass. Many of these enzymes have strong oxidizing activities towards aromatic compounds and are involved in the degradation of plant cell wall (lignin) and humus. They comprise three major groups: class II peroxidases (including lignin peroxidase, manganese peroxidase, versatile peroxidase and generic peroxidase), dye-decolorizing peroxidases, and heme-thiolate peroxidases (e.g. unspecific/aromatic peroxygenase, chloroperoxidase). Here, we have repeatedly observed a widespread expression of all major peroxidase groups in leaf and needle litter across a range of forest ecosystems (e.g. Fagus, Picea, Acer, Quercus, and Populus spp.), which are widespread in Europe and North America. Manganese peroxidases and unspecific peroxygenases were found expressed in all nine investigated forest sites, and dye-decolorizing peroxidases were observed in five of the nine sites, thereby indicating biological significance of these enzymes for fungal physiology and ecosystem processes. Transcripts of selected secretory peroxidase genes were also analyzed in pure cultures of several litter-decomposing species and other fungi. Using this information, we were able to match, in environmental litter samples, two manganese peroxidase sequences to Mycena galopus and Mycena epipterygia and one unspecific peroxygenase transcript to Mycena galopus, suggesting an important role of this litter- and coarse woody debris-dwelling genus in the disintegration and transformation of litter aromatics and organic matter formation. PMID:24763280

  18. A highway for war and peace: the secretory pathway in plant-microbe interactions.

    PubMed

    Wang, Dong; Dong, Xinnian

    2011-07-01

    Secretion of proteins and other molecules is the primary means by which a cell interacts with its surroundings. The overall organization of the secretory system is remarkably conserved among eukaryotes, and many of the components have been investigated in detail in animal models. Plant cells, because of their sessile lifestyle, are uniquely reliant on the secretory pathway to respond to changes in their environments, either abiotic, such as the absence of nutrients, or biotic, such as the presence of predators or pathogens. In particular, most plant pathogens are extracellular, which demands a robust and efficient host secretory system directed at the site of attack. Here, we present a summary of recent advances in our understanding of the molecular details of the secretory pathway during plant-microbe interactions. Secretion is required not only for the delivery of antimicrobial molecules, but also for the biogenesis of cell surface sensors to detect microbes. The deposition of extracellular material is important in the defense against classical bacterial pathogens as well as in the so-called 'non-host' resistance. Finally, boosting the protein secretion capacity is vital for avoiding infection as well as for achieving symbiosis, even though in the latter case, the microbes are engulfed in intracellular compartments. The emerging evidence indicates that secretion provides an essential interface between plant hosts and their associated microbial partners.

  19. Analysis of protein localization and secretory pathway function using the yeast Saccharomyces cerevisiae.

    PubMed

    Vallen, Elizabeth

    2002-01-01

    The isolation and characterization of mutants has been crucial in understanding a number of processes in the field of cell biology. In this exercise, students examine the effects of mutations in the secretory pathway on protein localization. Yeast strains deficient for synthesis of histidinol dehydrogenase are transformed with a plasmid encoding a chimeric protein. The chimera contains a signal sequence fused to histidinol dehydrogenase. A strain with a defect in the translocation of secretory proteins into the endoplasmic reticulum (ER) accumulates sufficient histidinol dehydrogenase in the cytoplasm to grow on media lacking histidine. In contrast, yeast proficient for secretion, or yeast with secretion defects later in the pathway, are unable to grow on media lacking histidine. Student analysis of the experimental yeast transformants and appropriate controls allows investigation into the effects of conditional defects in the secretory pathway on both cell viability and protein localization. The exercise is usually performed in a manner that allows students to execute a number of techniques common in molecular biology laboratories, including plasmid minipreps, restriction digestions, and Southern blots. Student understanding and enjoyment of the exercise was assessed by laboratory reports, oral and written examinations, and questionnaires. After completion of these experiments, students can describe the utility of protein fusions, the roles of mutant analysis in cell biology, and the steps taken by proteins transiting the secretory pathway.

  20. Analysis of Protein Localization and Secretory Pathway Function Using the Yeast Saccharomyces cerevisiae

    PubMed Central

    2002-01-01

    The isolation and characterization of mutants has been crucial in understanding a number of processes in the field of cell biology. In this exercise, students examine the effects of mutations in the secretory pathway on protein localization. Yeast strains deficient for synthesis of histidinol dehydrogenase are transformed with a plasmid encoding a chimeric protein. The chimera contains a signal sequence fused to histidinol dehydrogenase. A strain with a defect in the translocation of secretory proteins into the endoplasmic reticulum (ER) accumulates sufficient histidinol dehydrogenase in the cytoplasm to grow on media lacking histidine. In contrast, yeast proficient for secretion, or yeast with secretion defects later in the pathway, are unable to grow on media lacking histidine. Student analysis of the experimental yeast transformants and appropriate controls allows investigation into the effects of conditional defects in the secretory pathway on both cell viability and protein localization. The exercise is usually performed in a manner that allows students to execute a number of techniques common in molecular biology laboratories, including plasmid minipreps, restriction digestions, and Southern blots. Student understanding and enjoyment of the exercise was assessed by laboratory reports, oral and written examinations, and questionnaires. After completion of these experiments, students can describe the utility of protein fusions, the roles of mutant analysis in cell biology, and the steps taken by proteins transiting the secretory pathway. PMID:12669100

  1. Unique biological function of cathepsin L in secretory vesicles for biosynthesis of neuropeptides.

    PubMed

    Funkelstein, Lydiane; Beinfeld, Margery; Minokadeh, Ardalan; Zadina, James; Hook, Vivian

    2010-12-01

    Neuropeptides are essential for cell-cell communication in the nervous and neuroendocrine systems. Production of active neuropeptides requires proteolytic processing of proneuropeptide precursors in secretory vesicles that produce, store, and release neuropeptides that regulate physiological functions. This review describes recent findings indicating the prominent role of cathepsin L in secretory vesicles for production of neuropeptides from their protein precursors. The role of cathepsin L in neuropeptide production was discovered using the strategy of activity-based probes for proenkephalin-cleaving activity for identification of the enzyme protein by mass spectrometry. The novel role of cathepsin L in secretory vesicles for neuropeptide production has been demonstrated in vivo by cathepsin L gene knockout studies, cathepsin L gene expression in neuroendocrine cells, and notably, cathepsin L localization in neuropeptide-containing secretory vesicles. Cathepsin L is involved in producing opioid neuropeptides consisting of enkephalin, β-endorphin, and dynorphin, as well as in generating the POMC-derived peptide hormones ACTH and α-MSH. In addition, NPY, CCK, and catestatin neuropeptides utilize cathepsin L for their biosynthesis. The neuropeptide-synthesizing functions of cathepsin L represent its unique activity in secretory vesicles, which contrasts with its role in lysosomes. Interesting evaluations of protease gene knockout studies in mice that lack cathepsin L compared to those lacking PC1/3 and PC2 (PC, prohormone convertase) indicate the key role of cathepsin L in neuropeptide production. Therefore, dual cathepsin L and prohormone convertase protease pathways participate in neuropeptide production. Significantly, the recent new findings indicate cathepsin L as a novel 'proprotein convertase' for production of neuropeptides that mediate cell-cell communication in health and disease.

  2. PICK1 Deficiency Impairs Secretory Vesicle Biogenesis and Leads to Growth Retardation and Decreased Glucose Tolerance

    PubMed Central

    Jansen, Anna M.; Jin, Chunyu; Rickhag, Mattias; Lund, Viktor K.; Jensen, Morten; Bhatia, Vikram; Sørensen, Gunnar; Madsen, Andreas N.; Xue, Zhichao; Møller, Siri K.; Woldbye, David; Qvortrup, Klaus; Huganir, Richard; Stamou, Dimitrios; Kjærulff, Ole; Gether, Ulrik

    2013-01-01

    Secretory vesicles in endocrine cells store hormones such as growth hormone (GH) and insulin before their release into the bloodstream. The molecular mechanisms governing budding of immature secretory vesicles from the trans-Golgi network (TGN) and their subsequent maturation remain unclear. Here, we identify the lipid binding BAR (Bin/amphiphysin/Rvs) domain protein PICK1 (protein interacting with C kinase 1) as a key component early in the biogenesis of secretory vesicles in GH-producing cells. Both PICK1-deficient Drosophila and mice displayed somatic growth retardation. Growth retardation was rescued in flies by reintroducing PICK1 in neurosecretory cells producing somatotropic peptides. PICK1-deficient mice were characterized by decreased body weight and length, increased fat accumulation, impaired GH secretion, and decreased storage of GH in the pituitary. Decreased GH storage was supported by electron microscopy showing prominent reduction in secretory vesicle number. Evidence was also obtained for impaired insulin secretion associated with decreased glucose tolerance. PICK1 localized in cells to immature secretory vesicles, and the PICK1 BAR domain was shown by live imaging to associate with vesicles budding from the TGN and to possess membrane-sculpting properties in vitro. In mouse pituitary, PICK1 co-localized with the BAR domain protein ICA69, and PICK1 deficiency abolished ICA69 protein expression. In the Drosophila brain, PICK1 and ICA69 co-immunoprecipitated and showed mutually dependent expression. Finally, both in a Drosophila model of type 2 diabetes and in high-fat-diet-induced obese mice, we observed up-regulation of PICK1 mRNA expression. Our findings suggest that PICK1, together with ICA69, is critical during budding of immature secretory vesicles from the TGN and thus for vesicular storage of GH and possibly other hormones. The data link two BAR domain proteins to membrane remodeling processes in the secretory pathway of peptidergic endocrine

  3. Mechanisms of spatial attention control in frontal and parietal cortex.

    PubMed

    Szczepanski, Sara M; Konen, Christina S; Kastner, Sabine

    2010-01-01

    Theories of spatial attentional control have been largely based upon studies of patients suffering from visuospatial neglect, resulting from circumscribed lesions of frontal and posterior parietal cortex. In the intact brain, the control of spatial attention has been related to a distributed frontoparietal attention network. Little is known about the nature of the control mechanisms exerted by this network. Here, we used a novel region-of-interest approach to relate activations of the attention network to recently described topographic areas in frontal cortex [frontal eye field (FEF), PreCC/IFS (precentral cortex/inferior frontal sulcus)] and parietal cortex [intraparietal sulcus areas (IPS1-IPS5) and an area in the superior parietal lobule (SPL1)] to examine their spatial attention signals. We found that attention signals in most topographic areas were spatially specific, with stronger responses when attention was directed to the contralateral than to the ipsilateral visual field. Importantly, two hemispheric asymmetries were found. First, a region in only right, but not left SPL1 carried spatial attention signals. Second, left FEF and left posterior parietal cortex (IPS1/2) generated stronger contralateral biasing signals than their counterparts in the right hemisphere. These findings are the first to characterize spatial attention signals in topographic frontal and parietal cortex and provide a neural basis in support of an interhemispheric competition account of spatial attentional control. PMID:20053897

  4. Gastric parietal cell antigens of 60-90, 92, and 100-120 kDa associated with autoimmune gastritis and pernicious anemia. Role of N-glycans in the structure and antigenicity of the 60-90-kDa component.

    PubMed

    Goldkorn, I; Gleeson, P A; Toh, B H

    1989-11-01

    Thirty-four human sera containing parietal cell autoantibodies (PCA) specifically immunoprecipitated two antigens, with apparent molecular masses of 60-90 kDa and 100-120 kDa under nonreducing conditions and 60-90 kDa and 120-150 kDa under reducing conditions, from porcine gastric membrane extracts. A third antigen of 92 kDa was only observed in immunoprecipitates analyzed under reducing conditions. By immunoblotting, 24 of the 34 PCA-positive sera reacted with only the 60-90-kDa antigen, three reacted with a broad 60-120-kDa smear, one reacted only with a 92-kDa antigen and six did not react. Reactivity with the 60-90-kDa antigen was observed with gastric membranes from dog, pig, rat, and rabbit. Twenty PCA-negative sera did not react with these components by immunoprecipitation or immunoblotting. PCA reactivity with the 60-90-kDa antigen was abolished when the gastric membranes were (a) digested with Pronase, (b) reduced with 100 mM dithiothreitol, (c) treated with sodium periodate, or (d) digested with N-glycanase. The 60-90-kDa and 100-120-kDa components were insensitive to neuraminidase treatment. N-glycanase digestion of 125I-labeled antigens purified by immunoprecipitation and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis collapsed the 60-90-kDa antigen to a sharp 34-kDa band; the 100-120-kDa component was unaffected. These observations suggest that (i) parietal cell antigens comprise three components of 60-90, 92, and 100-120 kDa; (ii) the epitopes differ in conformational sensitivity; (iii) the 60-90-kDa antigen is a conserved molecule comprising a 34-kDa core protein extensively glycosylated with N-linked oligosaccharides; (iv) sialic acid residues are not present in the 60-90- and 100-120-kDa molecules, and (v) the carbohydrate and protein moieties of the 60-90-kDa molecule are required for antibody binding.

  5. The key target of neuroprotection after the onset of ischemic stroke: secretory pathway Ca2+-ATPase 1

    PubMed Central

    Li, Li-hua; Tian, Xiang-rong; Hu, Zhi-ping

    2015-01-01

    The regulatory mechanisms of cytoplasmic Ca2+ after myocardial infarction-induced Ca2+ overload involve secretory pathway Ca2+-ATPase 1 and the Golgi apparatus and are well understood. However, the effect of Golgi apparatus on Ca2+ overload after cerebral ischemia and reperfusion remains unclear. Four-vessel occlusion rats were used as animal models of cerebral ischemia. The expression of secretory pathway Ca2+-ATPase 1 in the cortex and hippocampus was detected by immunoblotting, and Ca2+ concentrations in the cytoplasm and Golgi vesicles were determined. Results showed an overload of cytoplasmic Ca2+ during ischemia and reperfusion that reached a peak after reperfusion. Levels of Golgi Ca2+ showed an opposite effect. The expression of Golgi-specific secretory pathway Ca2+-ATPase 1 in the cortex and hippocampus decreased before ischemia and reperfusion, and increased after reperfusion for 6 hours. This variation was similar to the alteration of calcium in separated Golgi vesicles. These results indicate that the Golgi apparatus participates in the formation and alleviation of calcium overload, and that secretory pathway Ca2+-ATPase 1 tightly responds to ischemia and reperfusion in nerve cells. Thus, we concluded that secretory pathway Ca2+-ATPase 1 plays an essential role in cytosolic calcium regulation and its expression can be used as a marker of Golgi stress, responding to cerebral ischemia and reperfusion. The secretory pathway Ca2+-ATPase 1 can be an important neuroprotective target of ischemic stroke. PMID:26487855

  6. Influence of experimental hypokinesia on gastric secretory function

    NASA Technical Reports Server (NTRS)

    Markova, O. O.; Vavryshchuk, V. I.; Rozvodovskyy, V. I.; Proshcheruk, V. A.

    1980-01-01

    The gastric secretory function of rats was studied in 4, 8, 16 and 30 day hypokinesia. Inhibition of both the gastric juice secretory and acid producing functions was found. The greatest inhibition was observed on day 8 of limited mobility. By days 16 and 30 of the experiment, a tendency of the gastric secretory activity to return to normal was observed, although it remained reduced.

  7. [Microbiocenosis of parietal mucin in the gastrointestinal tract of rats].

    PubMed

    Vorob'ev, A A; Nesvizhskiĭ, Iu V; Bogdanova, E A; Korneev, L M

    2005-01-01

    The qualitative and quantitative composition of the microbial community in parietal mucin at different areas of the gastrointestinal tract (GIT) of rats was revealed. The pronounced variability in the quantitative and qualitative characteristics of microbiocenosis in parietal mucin of rats at different sections was revealed. The differences were most pronounced in the passage from upper to lower GIT sections, the large intestine found to be the richest biocenosis. The microbial composition of rat feces was faintly associated with the GIT parietal microbiocenosis. The individual areas of GIT mucosa were unique of their microbial characteristics and organization. This makes it possible to regard them as relatively independent biotopes and indicates that it is impossible to evaluate the microbial community by one of the colonic mucosal sifes. PMID:16438365

  8. Enlarged parietal foramina: a rare forensic autopsy finding.

    PubMed

    Durão, Carlos; Carpinteiro, Dina; Pedrosa, Frederico; Machado, Marcos P; Cunha, Eugénia

    2016-05-01

    Enlarged parietal foramina (EPF) are a quite rare developmental defect of the parietal bone which has to be distinguished from the normal small parietal foramina. We report a forensic case of an individual found in an advanced state of putrefaction in his own house with an undetermined cause of death. No evidence of trauma was observed, and the toxicological exam was negative. The victim was a 40-year-old man with a history of epilepsy. The large biparietal foramina, a rare anatomical variation and unusual autopsy finding, were observed at autopsy. The recognition of anatomical variations is important to avoid false interpretations and conclusions and has a significant potential as an identity factor, thus contributing to positive identification.

  9. Psychological distress and salivary secretory immunity.

    PubMed

    Engeland, C G; Hugo, F N; Hilgert, J B; Nascimento, G G; Junges, R; Lim, H-J; Marucha, P T; Bosch, J A

    2016-02-01

    Stress-induced impairments of mucosal immunity may increase susceptibility to infectious diseases. The present study investigated the association of perceived stress, depressive symptoms, and loneliness with salivary levels of secretory immunoglobulin A (S-IgA), the subclasses S-IgA1, S-IgA2, and their transporter molecule Secretory Component (SC). S-IgA/SC, IgA1/SC and IgA2/SC ratios were calculated to assess the differential effects of stress on immunoglobulin transport versus availability. This study involved 113 university students, in part selected on high scores on the UCLA Loneliness Scale and/or the Beck Depression Inventory. Stress levels were assessed using the Perceived Stress Scale. Unstimulated saliva was collected and analysed for total S-IgA and its subclasses, as well as SC and total salivary protein. Multiple linear regression analyses, adjusted for gender, age, health behaviours, and concentration effects (total protein) revealed that higher perceived stress was associated with lower levels of IgA1 but not IgA2. Perceived stress, loneliness and depressive symptoms were all associated with lower IgA1/SC ratios. Surprisingly, higher SC levels were associated with loneliness and depressive symptoms, indicative of enhanced transport activity, which explained a lower IgA1/SC ratio (loneliness and depression) and IgA2/SC ratio (depression). This is the first study to investigate the effects of protracted psychological stress across S-IgA subclasses and its transporter SC. Psychological stress was negatively associated with secretory immunity, specifically IgA1. The lower immunoglobulin/transporter ratio that was associated with higher loneliness and depression suggested a relative immunoglobulin depletion, whereby availability was not keeping up with enhanced transport demand.

  10. FRONTAL AND PARIETAL CORTEX CONTRIBUTIONS TO ACTION MODIFICATION

    PubMed Central

    Mutha, Pratik K.; Stapp, Lee H.; Sainburg, Robert L.; Haaland, Kathleen Y.

    2014-01-01

    Successful achievement of task goals depends critically on the ability to adjust ongoing actions in response to environmental changes. The neural substrates underlying action modification have been a topic of great controversy: both, posterior parietal cortex and frontal regions, particularly prefrontal cortex have been previously identified as crucial in this regard, with most studies arguing in favor of one or the other. We aimed to address this controversy and understand whether frontal and parietal regions might play distinct roles during action modification. We tested ipsilesional arm performance of 27 stroke patients with focal lesions to frontal or parietal regions of the left or right cerebral hemisphere, and left or right arm performance of 18 healthy subjects on the classic double-step task in which a target is unpredictably displaced to a new location, requiring modification of the ongoing action. Only right hemisphere frontal lesions adversely impacted the timing of initiation of the modified response, while only left hemisphere parietal lesions impaired the accuracy of the modified action. Patients with right frontal lesions tended to complete the ongoing action to the initially displayed baseline target and initiated the new movement after a significant delay. In contrast, patients with left parietal damage did not accurately reach the new target location, but compared to the other groups, initiated the new action during an earlier phase of motion, before their baseline action was complete. Our findings thus suggest distinct, hemisphere specific contributions of frontal and parietal regions to action modification, and bring together, for the first time, disparate sets of prior findings about its underlying neural substrates. PMID:24763127

  11. Immunomodulatory action of mycobacterial secretory proteins.

    PubMed

    Trajkovic, Vladimir; Natarajan, Krishnamurthy; Sharma, Pawan

    2004-04-01

    The recently discovered RD1 locus encodes proteins that are actively secreted by pathogenic mycobacteria, including Mycobacterium tuberculosis. Since they are missing in non-tuberculous mycobacteria, these proteins are promising not only as candidates for vaccination and diagnostic tests, but also in understanding mycobacterial evasion of protective immunity in susceptible individuals. Here we analyze the possible role of M. tuberculosis secretory proteins in immunity against tuberculosis, with emphasis on their immunomodulatory action and the potential involvement in mycobacterial subversion of the host immune defense.

  12. "Secretory" Carcinoma of the Skin Mimicking Secretory Carcinoma of the Breast: Case Report and Literature Review.

    PubMed

    Huang, Sixia; Liu, Yan; Su, Jing; Liu, Jianying; Guo, Xiaoning; Mei, Fang; Zheng, Jie; Liao, Songlin

    2016-09-01

    Secretory carcinoma is a unique kind of adenocarcinoma. It has distinct histological features and a special genetic change, that is, t (12; 15) (p13; q25) translocation which leads to the expression of the ETV6-NTRK3 fusion gene. Secretory carcinoma has been found to occur both in the breast and salivary gland. Here the authors present a case of 22-year-old woman with a unique cutaneous neoplasm located at the axilla. The tumor was characterized histologically with the formation of round to ovoid microcysts and papillary structure, which was similar to the secretory carcinoma of the breast and salivary gland. Furthermore, the gene sequence analysis of reverse-transcription polymerase chain reaction products demonstrated the expression of the ETV6-NTRK3 fusion gene. To the authors' knowledge, this is the first case of secretory carcinoma from the skin which has the same genetic change as those from the breast and salivary gland. Local excision was performed on this patient. She had been followed up for nearly 1 year. No recurrence or metastasis was found yet. PMID:26981741

  13. Influence of colchicine and vinblastine on the intracellular migration of secretory and membrane glycoproteins: III. Inhibition of intracellular migration of membrane glycoproteins in rat intestinal columnar cells and hepatocytes as visualized by light and electron-microscope radioautography after 3H-fucose injection

    SciTech Connect

    Bennett, G.; Carlet, E.; Wild, G.; Parsons, S.

    1984-08-01

    In the present work, the effects of these drugs on migration of membrane glycoproteins have been examined at the ultrastructural level in duodenal villous columnar cells and hepatocytes. Young (40 gm) rats were given a single intravenous injection of colchicine (4.0 mg) or vinblastine (2.0 mg). At 10 min after colchicine and 30 min after vinblastine administration, the rats were injected with 3H-fucose. Control rats received 3H-fucose only. All rats were sacrificed 90 min after 3H-fucose injection and their tissues processed for radioautography. In duodenal villous columnar cells, 3H-fucose labeling of the apical plasma membrane was reduced by 51% after colchicine and by 67% after vinblastine treatment; but there was little change in labeling of the lateral plasma membrane. Labeling of the Golgi apparatus increased. This suggests that labeled glycoproteins destined for the apical plasma membrane were inhibited from leaving the Golgi region, while migration to the lateral plasma membrane was not impaired. In hepatocytes, labeling of the sinusoidal plasma membrane was reduced by 83% after colchicine and by 85% after vinblastine treatment. Labeling of the lateral plasma membrane also decreased, although not so dramatically. Labeling of the Golgi apparatus and neighboring secretory vesicles increased. This indicates that the drugs inhibited migration of membrane glycoproteins from the Golgi region to the various portions of the plasma membrane. Accumulation of secretory vesicles at the sinusoidal front suggests that exocytosis may also have been partially inhibited. In both cell types, microtubules almost completely disappeared after drug treatment. Microtubules may, therefore, be necessary for intracellular transport of membrane glycoproteins, although the possibility of a direct action of these drugs on Golgi or plasma membranes must also be considered.

  14. Secretory pattern of canine growth hormone

    SciTech Connect

    French, M.B.; Vaitkus, P.; Cukerman, E.; Sirek, A.; Sirek, O.V.

    1987-02-01

    The aim of this paper was to define the secretory pattern of growth hormone (GH) under basal conditions in fasted, conscious, male dogs accustomed to handling. Blood samples were withdrawn from a cephalic vein at 15-min intervals. In this way, any ultradian rhythms, if present, could be detected within the frequency range of 0.042-2 cycles/h. In addition, samples were drawn at either 1- or 2.5-min intervals for 2.5 or 5 h to determine whether frequency components greater than 2 cycles/h were present. GH was measured by radioimmunoassay and the raw data were submitted to time series analysis employing power spectral estimation by means of fast Fourier transformation techniques. Peak plasma levels were up to 12 times higher than the baseline concentration of approx. 1 ng/ml. Spectral analysis revealed an endogenous frequency of 0.22 cycles/h, i.e., a periodicity of 4.5 h/cycle. The results indicate that under basal conditions the secretory bursts of canine GH are limited to one peak every 4.5 h.

  15. Neurexin-1α contributes to insulin-containing secretory granule docking.

    PubMed

    Mosedale, Merrie; Egodage, Sonya; Calma, Rei C; Chi, Nai-Wen; Chessler, Steven D

    2012-02-24

    Neurexins are a family of transmembrane, synaptic adhesion molecules. In neurons, neurexins bind to both sub-plasma membrane and synaptic vesicle-associated constituents of the secretory machinery, play a key role in the organization and stabilization of the presynaptic active zone, and help mediate docking of synaptic vesicles. We have previously shown that neurexins, like many other protein constituents of the neurotransmitter exocytotic machinery, are expressed in pancreatic β cells. We hypothesized that the role of neurexins in β cells parallels their role in neurons, with β-cell neurexins helping to mediate insulin granule docking and secretion. Here we demonstrate that β cells express a more restricted pattern of neurexin transcripts than neurons, with a clear predominance of neurexin-1α expressed in isolated islets. Using INS-1E β cells, we found that neurexin-1α interacts with membrane-bound components of the secretory granule-docking machinery and with the granule-associated protein granuphilin. Decreased expression of neurexin-1α, like decreased expression of granuphilin, reduces granule docking at the β-cell membrane and improves insulin secretion. Perifusion of neurexin-1α KO mouse islets revealed a significant increase in second-phase insulin secretion with a trend toward increased first-phase secretion. Upon glucose stimulation, neurexin-1α protein levels decrease. This glucose-induced down-regulation may enhance glucose-stimulated insulin secretion. We conclude that neurexin-1α is a component of the β-cell secretory machinery and contributes to secretory granule docking, most likely through interactions with granuphilin. Neurexin-1α is the only transmembrane component of the docking machinery identified thus far. Our findings provide new insights into the mechanisms of insulin granule docking and exocytosis.

  16. Searching for mammary analogue [corrected] secretory carcinoma of salivary gland among its mimics.

    PubMed

    Pinto, Andre; Nosé, Vania; Rojas, Claudia; Fan, Yao-Shan; Gomez-Fernandez, Carmen

    2014-01-01

    Mammary analog secretory carcinoma of salivary gland is a recently described entity with unique morphologic, clinical, and genetic characteristics, including the characteristic t(12;15)(p13;q25) with ETV6-NTRK3 translocation found in secretory carcinomas of the breast. Before their initial description, these salivary gland tumors were generally diagnosed as acinic cell carcinoma or adenocarcinoma. For the purpose of this study, all cases of salivary gland acinic cell carcinoma, cribriform cystadenocarcinoma, and adenocarcinoma, not otherwise specified (NOS), diagnosed over a 10-year period were retrieved from our surgical pathology files. There were a total of 11 cases diagnosed as acinic cell carcinoma, 10 cases of adenocarcinoma, NOS, and 6 cases of cribriform cystadenocarcinoma. All slides were reviewed by two pathologists (AP, CGF) and tumors that show morphologic features of mammary analog secretory carcinoma according to the recent literature were selected. This process narrowed down the initial number to six cases originally diagnosed as acinic cell carcinoma, three cases originally diagnosed as adenocarcinoma, NOS, and one case originally diagnosed as cribriform cystadenocarcinoma. The 10 cases were subjected to immunohistochemistry for S-100, mammaglobin, and ANO1, as well as fluorescence in situ hybridization analysis for t(12;15)(p13;q25) with ETV6-NTRK3 fusion rearrangement. The ETV6-NTRK3 gene rearrangement was detected in three tumors. These three tumors, initially diagnosed as acinic cell carcinomas, stained positive for S-100 and mammaglobin, and negative for ANO1 by immunohistochemistry. Two of the three patients were male (2/3). In summary, mammary analog secretory carcinoma is a newly described diagnostic entity that should be in the differential diagnosis of salivary gland tumors that morphologically mimic other neoplasms, mainly acinic cell carcinomas. They differ from conventional acinic cell tumors immunohistochemically and molecularly

  17. Phosphorylation of αSNAP is Required for Secretory Organelle Biogenesis in Toxoplasma gondii.

    PubMed

    Stewart, Rebecca J; Ferguson, David J P; Whitehead, Lachlan; Bradin, Clare H; Wu, Hong J; Tonkin, Christopher J

    2016-02-01

    Upon infection, apicomplexan parasites quickly invade host cells and begin a replicative cycle rapidly increasing in number over a short period of time, leading to tissue lysis and disease. The secretory pathway of these highly polarized protozoan parasites tightly controls, in time and space, the biogenesis of specialized structures and organelles required for invasion and intracellular survival. In other systems, regulation of protein trafficking can occur by phosphorylation of vesicle fusion machinery. Previously, we have shown that Toxoplasma gondii αSNAP - a protein that controls the disassembly of cis-SNARE complexes--is phosphorylated. Here, we show that this post-translational modification is required for the correct function of αSNAP in controlling secretory traffic. We demonstrate that during intracellular development conditional expression of a non-phosphorylatable form of αSNAP results in Golgi fragmentation and vesiculation of all downstream secretory organelles. In addition, we show that the vestigial plastid (termed apicoplast), although reported not to be reliant on Golgi trafficking for biogenesis, is also affected upon overexpression of αSNAP and is much more sensitive to the levels of this protein than targeting to other organelles. This work highlights the importance of αSNAP and its phosphorylation in Toxoplasma organelle biogenesis and exposes a hereto fore-unexplored mechanism of regulation of vesicle fusion during secretory pathway trafficking in apicomplexan parasites.

  18. Regulated phosphorylation of secretory granule membrane proteins of the rat parotid gland

    SciTech Connect

    Marino, C.R.; Castle, J.D.; Gorelick, F.S. )

    1990-07-01

    An antiserum raised against purified rat parotid secretory granule membrane proteins has been used to identify organelle-specific protein phosphorylation events following stimulation of intact cells from the rat parotid gland. After lobules were prelabeled with ({sup 32}P)orthophosphate and exposed to secretagogues, phosphoproteins were immunoprecipitated with the granule membrane protein antiserum, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and visualized by autoradiography. Parallel studies of stimulated amylase release were performed. Isoproterenol treatment of parotid lobules resulted in an increase in the phosphate content of immunoprecipitable 60- and 72-kDa proteins that correlated with amylase release in a time-dependent manner. Forskolin addition mimicked these effects, but only the isoproterenol effects were reversed by propranolol treatment. To confirm the specificity of the antiserum to the secretory granule membrane fraction, subcellular isolation techniques were employed following in situ phosphorylation. The 60- and 72-kDa phosphoproteins were immunoprecipitated from both a particulate fraction and a purified secretory granule fraction. Furthermore, the extraction properties of both species suggest that they are integral membrane proteins. These findings support the possibility that stimulus-regulated secretion may involve phosphorylation of integral membrane proteins of the exocrine secretory granule.

  19. Systems biology of the secretory pathway: what have we learned so far?

    PubMed

    Farhan, Hesso

    2015-07-01

    Several RNAi screens were performed in search for regulators of the secretory pathway. These screens were performed in different organisms and cell lines and relied on different readouts. Therefore, they have only little overlap among their hits, leading to the question of what we have learned from this approach so far and how these screens contributed towards an integrative understanding of the endomembrane system. The aim of this review is to revisit these screens and discuss their strengths and weaknesses as well as potential reasons for their failure to overlap with each other. As with secretory trafficking, RNAi screens were also performed on other cellular processes such as cell migration and autophagy, both of which were shown to be intimately linked to secretion. Another aim of this review is to compare the outcome of the RNAi screens on secretion, autophagy and cell migration and ask whether the functional genomic approaches have uncovered potential mechanistic insights into the links between these processes.

  20. Mitochondrial Dysfunction Induces Senescence with a Distinct Secretory Phenotype.

    PubMed

    Wiley, Christopher D; Velarde, Michael C; Lecot, Pacome; Liu, Su; Sarnoski, Ethan A; Freund, Adam; Shirakawa, Kotaro; Lim, Hyung W; Davis, Sonnet S; Ramanathan, Arvind; Gerencser, Akos A; Verdin, Eric; Campisi, Judith

    2016-02-01

    Cellular senescence permanently arrests cell proliferation, often accompanied by a multi-faceted senescence-associated secretory phenotype (SASP). Loss of mitochondrial function can drive age-related declines in the function of many post-mitotic tissues, but little is known about how mitochondrial dysfunction affects mitotic tissues. We show here that several manipulations that compromise mitochondrial function in proliferating human cells induce a senescence growth arrest with a modified SASP that lacks the IL-1-dependent inflammatory arm. Cells that underwent mitochondrial dysfunction-associated senescence (MiDAS) had lower NAD+/NADH ratios, which caused both the growth arrest and prevented the IL-1-associated SASP through AMPK-mediated p53 activation. Progeroid mice that rapidly accrue mtDNA mutations accumulated senescent cells with a MiDAS SASP in vivo, which suppressed adipogenesis and stimulated keratinocyte differentiation in cell culture. Our data identify a distinct senescence response and provide a mechanism by which mitochondrial dysfunction can drive aging phenotypes. PMID:26686024

  1. Impairments in Tactile Search Following Superior Parietal Damage

    ERIC Educational Resources Information Center

    Skakoon-Sparling, Shayna P.; Vasquez, Brandon P.; Hano, Kate; Danckert, James

    2011-01-01

    The superior parietal cortex is critical for the control of visually guided actions. Research suggests that visual stimuli relevant to actions are preferentially processed when they are in peripersonal space. One recent study demonstrated that visually guided movements towards the body were more impaired in a patient with damage to superior…

  2. Parietal cortex mediates perceptual Gestalt grouping independent of stimulus size.

    PubMed

    Grassi, Pablo R; Zaretskaya, Natalia; Bartels, Andreas

    2016-06-01

    The integration of local moving elements into a unified gestalt percept has previously been linked to the posterior parietal cortex. There are two possible interpretations for the lack of involvement of other occipital regions. The first is that parietal cortex is indeed uniquely functionally specialized to perform grouping. Another possibility is that other visual regions can perform grouping as well, but that the large spatial separation of the local elements used previously exceeded their neurons' receptive field (RF) sizes, preventing their involvement. In this study we distinguished between these two alternatives. We measured whole-brain activity using fMRI in response to a bistable motion illusion that induced mutually exclusive percepts of either an illusory global Gestalt or of local elements. The stimulus was presented in two sizes, a large version known to activate IPS only, and a version sufficiently small to fit into the RFs of mid-level dorsal regions such as V5/MT. We found that none of the separately localized motion regions apart from parietal cortex showed a preference for global Gestalt perception, even for the smaller version of the stimulus. This outcome suggests that grouping-by-motion is mediated by a specialized size-invariant mechanism with parietal cortex as its anatomical substrate.

  3. Human posterior parietal cortex mediates hand-specific planning

    PubMed Central

    Valyear, Kenneth F.; Frey, Scott H.

    2015-01-01

    The processes underlying action planning are fundamental to adaptive behavior and can be influenced by recent motor experience. Here, we used a novel fMRI Repetition Suppression (RS) design to test the hypotheses that action planning unfolds more efficiently for successive actions made with the same hand. More efficient processing was predicted to correspond with both faster response times (RTs) to initiate actions and reduced fMRI activity levels – RS. Consistent with these predictions, we detected faster RTs for actions made with the same hand and accompanying fMRI-RS within bilateral posterior parietal cortex and right-lateralized parietal operculum. Within posterior parietal cortex, these RS effects were localized to intraparietal and superior parietal cortices. These same areas were more strongly activated for actions involving the contralateral hand. The findings provide compelling new evidence for the specification of action plans in hand-specific terms, and indicate that these processes are sensitive to recent motor history. Consistent with computational efficiency accounts of motor history effects, the findings are interpreted as evidence for comparatively more efficient processing underlying action planning when successive actions involve the same versus opposite hand. PMID:25842294

  4. Parietal network underlying movement control: disturbances during subcortical electrostimulation.

    PubMed

    Almairac, Fabien; Herbet, Guillaume; Moritz-Gasser, Sylvie; Duffau, Hugues

    2014-07-01

    Our understanding of brain movement control has changed over the last two decades. Recent findings in the monkey and in humans have led to a parallel and interconnected network. Nevertheless, little is known about these networks. Here, we present two cases of patients with a parietal low-grade glioma. They underwent surgery under local anesthesia with cortical and subcortical mapping. For patient 1, subcortical electrostimulation immediately posterior to thalamocortical fibers induced movement disorders, with an inhibition of leg and arm movements medially and, more laterally, an acceleration of arm movement. For patient 2, electrostimulation of white matter immediately posterior to thalamocortical fibers induced an inhibition of both arm movement. It means that the detected fibers in the parietal lobe may be involved in the motor control modulation. They are distributed veil-like immediately posterior to thalamocortical pathways and could correspond to a fronto-parietal movement control subnetwork. These two cases highlight the major role of the subcortical connectivity in movement regulation, involving parietal lobe, thus the necessity to be identified and preserved during brain surgery.

  5. Left inferior parietal lobe engagement in social cognition and language.

    PubMed

    Bzdok, Danilo; Hartwigsen, Gesa; Reid, Andrew; Laird, Angela R; Fox, Peter T; Eickhoff, Simon B

    2016-09-01

    Social cognition and language are two core features of the human species. Despite distributed recruitment of brain regions in each mental capacity, the left parietal lobe (LPL) represents a zone of topographical convergence. The present study quantitatively summarizes hundreds of neuroimaging studies on social cognition and language. Using connectivity-based parcellation on a meta-analytically defined volume of interest (VOI), regional coactivation patterns within this VOI allowed identifying distinct subregions. Across parcellation solutions, two clusters emerged consistently in rostro-ventral and caudo-ventral aspects of the parietal VOI. Both clusters were functionally significantly associated with social-cognitive and language processing. In particular, the rostro-ventral cluster was associated with lower-level processing facets, while the caudo-ventral cluster was associated with higher-level processing facets in both mental capacities. Contrarily, in the (less stable) dorsal parietal VOI, all clusters reflected computation of general-purpose processes, such as working memory and matching tasks, that are frequently co-recruited by social or language processes. Our results hence favour a rostro-caudal distinction of lower- versus higher-level processes underlying social cognition and language in the left inferior parietal lobe. PMID:27241201

  6. 21 CFR 866.5380 - Free secretory component immuno-logical test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... immunochemical techniques free secretory component (normally a portion of the secretory IgA antibody molecule) in body fluids. Measurement of free secretory component (protein molecules) aids in the diagnosis...

  7. 21 CFR 866.5380 - Free secretory component immuno-logical test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... immunochemical techniques free secretory component (normally a portion of the secretory IgA antibody molecule) in body fluids. Measurement of free secretory component (protein molecules) aids in the diagnosis...

  8. Giant secretory granules in the ducts of the parotid and submandibular glands of the slow loris.

    PubMed

    Tandler, B; Pinkstaff, C A; Nagato, T; Phillips, C J

    1996-06-01

    The parotid and submandibular glands of a slow loris, a rare Southeast Asian primate, were obtained after the head had been perfused by fixative for a study of the brain. These tissues were processed by conventional means for electron microscopy. Glands also were obtained at autopsy from 2 other lorises, fixed by immersion in formalin, and subjected to a battery of tests for glycoconjugates. In the parotid gland, a short segment of the proximal striated duct lacks both basal striations and any sign of secretory activity. The major portion of the striated duct consists of tall cells that contain a spectrum of secretory granules, some larger than the nuclei (many granules are > 9 mum in diameter). These granules, which are delimited by a single membrane, are capable of chain exocytosis. Many of the giant granules have bundles of cytofilaments (4.5-6.5 nm) in apparent association with their surface. Occasional cells contain numerous small granules. Duct cells with or without granules lack basal striations. The granules contain neutral glycoconjugates but no acidic glycoconjugates. Some, but not all, interlobular excretory ducts also have secretory granules that run the gamut from tiny to giant. Exactly the same situation occurs in the submandibular gland. Unlike other primates, which may have duct cells that contain only a few tiny granules in their apices, the cells in both the striated and excretory ducts in the slow loris appear to be specialized for secretion rather than for transport. The biofunction of the giant granules is unknown.

  9. Functional connectivity of parietal cortex during temporal selective attention.

    PubMed

    Tyler, Sarah C; Dasgupta, Samhita; Agosta, Sara; Battelli, Lorella; Grossman, Emily D

    2015-04-01

    Perception of natural experiences requires allocation of attention towards features, objects, and events that are moving and changing over time. This allocation of attention is controlled by large-scale brain networks that, when damaged, cause widespread cognitive deficits. In particular, damage to ventral parietal cortex (right lateralized TPJ, STS, supramarginal and angular gyri) is associated with failures to selectively attend to and isolate features embedded within rapidly changing visual sequences (Battelli, Pascual-Leone, & Cavanagh, 2007; Husain, Shapiro, Martin, & Kennard, 1997). In this study, we used fMRI to investigate the neural activity and functional connectivity of intact parietal cortex while typical subjects judged the relative onsets and offsets of rapidly flickering tokens (a phase discrimination task in which right parietal patients are impaired). We found two regions in parietal cortex correlated with task performance: a bilateral posterior TPJ (pTPJ) and an anterior right-lateralized TPJ (R aTPJ). Both regions were deactivated when subjects engaged in the task but showed different patterns of functional connectivity. The bilateral pTPJ was strongly connected to nodes within the default mode network (DMN) and the R aTPJ was connected to the attention network. Accurate phase discriminations were associated with increased functional correlations between sensory cortex (hMT+) and the bilateral pTPJ, whereas accuracy on a control task was associated with yoked activity in the hMT+ and the R aTPJ. We conclude that temporal selective attention is particularly sensitive for revealing information pathways between sensory and core cognitive control networks that, when damaged, can lead to nonspatial attention impairments in right parietal stroke patients. PMID:25747530

  10. The challenge of improved secretory production of active pharmaceutical ingredients in Saccharomyces cerevisiae: a case study on human insulin analogs.

    PubMed

    Kazemi Seresht, Ali; Palmqvist, Eva A; Schluckebier, Gerd; Pettersson, Ingrid; Olsson, Lisbeth

    2013-10-01

    The yeast Saccharomyces cerevisiae has widely been used as a host for the production of heterologous proteins. Great attention has been put on improved secretory production of active pharmaceutical ingredients, and the secretory pathway of this eukaryotic host has been the playground of diverse strain engineering studies, aiming at enhanced cellular capacities for folding and trafficking of the target proteins. However, the cellular quality assessment for secretory proteins remains mostly unpredictable, and different target proteins often do not picture similar secretion yields, underlining the dependency of efficient secretion on the physicochemical properties of the protein of interest. In this study, two human insulin analog precursors (IAPs) with minor differences in their amino acid sequences were used as model secretory proteins. No differences between cells expressing these two proteins were found in the IAP transcript levels, gene copy numbers, or intra-cellularly accumulated proteins, yet a more than sevenfold difference in their secretion yields was found. Physiological characterization of cells expressing these proteins in batch processes revealed no significant difference in their specific growth rate, but an altered overflow metabolism. Global transcriptome analysis carried out in chemostat experiments pinpointed distinct steps during the protein maturation pathway to be differentially regulated and indicated an increased degradation of the IAP with the low secretion yield. In silico protein structure modeling of the IAPs suggested a difference in conformational stability, induced by the amino acid substitution, which most likely resulted in disparity in trafficking through the secretory pathway and thus a large difference in secretion yields. PMID:23592021

  11. Overproduction of a Model Sec- and Tat-Dependent Secretory Protein Elicits Different Cellular Responses in Streptomyces lividans.

    PubMed

    Gullón, Sonia; Marín, Silvia; Mellado, Rafael P

    2015-01-01

    Streptomyces lividans is considered an efficient host for the secretory production of homologous and heterologous proteins. To identify possible bottlenecks in the protein production process, a comparative transcriptomic approach was adopted to study cellular responses during the overproduction of a Sec-dependent model protein (alpha-amylase) and a Tat-dependent model protein (agarase) in Streptomyces lividans. The overproduction of the model secretory proteins via the Sec or the Tat route in S. lividans does elicit a different major cell response in the bacterium. The stringent response is a bacterial response to nutrients' depletion, which naturally occurs at late times of the bacterial cell growth. While the induction of the stringent response at the exponential phase of growth may limit overall productivity in the case of the Tat route, the induction of that response does not take place in the case of the Sec route, which comparatively is an advantage in secretory protein production processes. Hence, this study identifies a potential major drawback in the secretory protein production process depending on the secretory route, and provides clues to improving S. lividans as a protein production host.

  12. Calcium-containing phosphopeptides pave the secretory pathway for efficient protein traffic and secretion in fungi.

    PubMed

    Martín, Juan F

    2014-01-01

    Casein phosphopeptides (CPPs) containing chelated calcium drastically increase the secretion of extracellular homologous and heterologous proteins in filamentous fungi. Casein phosphopeptides released by digestion of alpha - and beta-casein are rich in phosphoserine residues (SerP). They stimulate enzyme secretion in the gastrointestinal tract and enhance the immune response in mammals, and are used as food supplements. It is well known that casein phosphopeptides transport Ca2+ across the membranes and play an important role in Ca2+ homeostasis in the cells. Addition of CPPs drastically increases the production of heterologous proteins in Aspergillus as host for industrial enzyme production. Recent proteomics studies showed that CPPs alter drastically the vesicle-mediated secretory pathway in filamentous fungi, apparently because they change the calcium concentration in organelles that act as calcium reservoirs. In the organelles calcium homeostasis a major role is played by the pmr1 gene, that encodes a Ca2+/Mn2+ transport ATPase, localized in the Golgi complex; this transporter controls the balance between intra-Golgi and cytoplasmic Ca2+ concentrations. A Golgi-located casein kinase (CkiA) governs the ER to Golgi directionality of the movement of secretory proteins by interacting with the COPII coat of secretory vesicles when they reach the Golgi. Mutants defective in the casein-2 kinase CkiA show abnormal targeting of some secretory proteins, including cytoplasmic membrane amino acid transporters that in ckiA mutants are miss-targeted to vacuolar membranes. Interestingly, addition of CPPs increases a glyceraldehyde-3-phpshate dehydrogenase protein that is known to associate with microtubules and act as a vesicle/membrane fusogenic agent. In summary, CPPs alter the protein secretory pathway in fungi adapting it to a deregulated protein traffic through the organelles and vesicles what results in a drastic increase in secretion of heterologous and also of

  13. Secretory vesicle swelling by atomic force microscopy.

    PubMed

    Cho, Sang-Joon; Jena, Bhanu P

    2006-01-01

    The swelling of secretory vesicles has been implicated in exocytosis, but the underlying mechanism of vesicle swelling remained unknown. Earlier studies from our laboratory demonstrated the association of the alpha-subunit of heterotrimeric GTP-binding protein G(alphai3) with zymogen granule membrane and implicated its involvement in vesicle swelling. Mas7, an active mastoparan analog known to stimulate Gi proteins, was found to stimulate the GTPase activity of isolated zymogen granules and cause swelling. Increase in vesicle size in the presence of GTP, NaF, and Mas7 were irreversible and found to be KCl sensitive. However, Ca2+ had no effect on zymogen granule size. Taken together, these results indicated that zymogen granules, the membrane-bound secretory vesicles in exocrine pancreas, swell in response to GTP mediated by a G(alphai3) protein. Subsequently, our studies demonstrated that the water channel aquaporin-1 (AQP1) is also present at the zymogen granule membrane and participates in rapid GTP-induced and G(alphai3)-mediated vesicular water gating and swelling. Isolated zymogen granules exhibit low basal water permeability. However, exposure of granules to GTP results in a marked potentiation of water entry. Treatment of zymogen granules with the known water channel inhibitor Hg2+ is accompanied by a reversible loss in both the basal and GTP-stimulable water entry and vesicle swelling. Introduction of AQP1-specific antibody raised against the carboxy-terminal domain of AQP1 blocked GTP-stimulable swelling of vesicles. Our results demonstrate that AQPI associated at the zymogen granule membrane is involved in basal GTP-induced and G(alphai3)-mediated rapid gating of water into zymogen granules of the exocrine pancreas.

  14. Airway Secretory microRNAome Changes during Rhinovirus Infection in Early Childhood

    PubMed Central

    Gutierrez, Maria J.; Gomez, Jose L.; Perez, Geovanny F.; Pancham, Krishna; Val, Stephanie; Pillai, Dinesh K.; Giri, Mamta; Ferrante, Sarah; Freishtat, Robert; Rose, Mary C.; Preciado, Diego; Nino, Gustavo

    2016-01-01

    Background Innate immune responses are fine-tuned by small noncoding RNA molecules termed microRNAs (miRs) that modify gene expression in response to the environment. During acute infections, miRs can be secreted in extracellular vesicles (EV) to facilitate cell-to-cell genetic communication. The purpose of this study was to characterize the baseline population of miRs secreted in EVs in the airways of young children (airway secretory microRNAome) and examine the changes during rhinovirus (RV) infection, the most common cause of asthma exacerbations and the most important early risk factor for the development of asthma beyond childhood. Methods Nasal airway secretions were obtained from children (≤3 yrs. old) during PCR-confirmed RV infections (n = 10) and age-matched controls (n = 10). Nasal EVs were isolated with polymer-based precipitation and global miR profiles generated using NanoString microarrays. We validated our in vivo airway secretory miR data in an in vitro airway epithelium model using apical secretions from primary human bronchial epithelial cells (HBEC) differentiated at air-liquid interface (ALI). Bioinformatics tools were used to determine the unified (nasal and bronchial) signature airway secretory miRNAome and changes during RV infection in children. Results Multiscale analysis identified four signature miRs comprising the baseline airway secretory miRNAome: hsa-miR-630, hsa-miR-302d-3p, hsa- miR-320e, hsa-miR-612. We identified hsa-miR-155 as the main change in the baseline miRNAome during RV infection in young children. We investigated the potential biological relevance of the airway secretion of hsa-mir-155 using in silico models derived from gene datasets of experimental in vivo human RV infection. These analyses confirmed that hsa-miR-155 targetome is an overrepresented pathway in the upper airways of individuals infected with RV. Conclusions Comparative analysis of the airway secretory microRNAome in children indicates that RV infection

  15. Overlapping representations for reach depth and direction in caudal superior parietal lobule of macaques.

    PubMed

    Hadjidimitrakis, Kostas; Dal Bo', Giulia; Breveglieri, Rossella; Galletti, Claudio; Fattori, Patrizia

    2015-10-01

    Reaching movements in the real world have typically a direction and a depth component. Despite numerous behavioral studies, there is no consensus on whether reach coordinates are processed in separate or common visuomotor channels. Furthermore, the neural substrates of reach depth in parietal cortex have been ignored in most neurophysiological studies. In the medial posterior parietal area V6A, we recently demonstrated the strong presence of depth signals and the extensive convergence of depth and direction information on single neurons during all phases of a fixate-to-reach task in 3-dimensional (3D) space. Using the same task, in the present work we examined the processing of direction and depth information in area PEc of the caudal superior parietal lobule (SPL) in three Macaca fascicularis monkeys. Across the task, depth and direction had a similar, high incidence of modulatory effect. The effect of direction was stronger than depth during the initial fixation period. As the task progressed toward arm movement execution, depth tuning became more prominent than directional tuning and the number of cells modulated by both depth and direction increased significantly. Neurons tuned by depth showed a small bias for far peripersonal space. Cells with directional modulations were more frequently tuned toward contralateral spatial locations, but ipsilateral space was also represented. These findings, combined with results from neighboring areas V6A and PE, support a rostral-to-caudal gradient of overlapping representations for reach depth and direction in SPL. These findings also support a progressive change from visuospatial (vergence angle) to somatomotor representations of 3D space in SPL.

  16. Further observations on the fine structure of the parietal eye of lizards.

    PubMed

    EAKIN, R M; WESTFALL, J A

    1960-10-01

    An electron microscopical study of the third eye of the Western Fence Lizard, Sceloporus occidentalis, fixed with 1 per cent osmium tetroxide, pH 7.4-7.6, for 16 to 20 hours at 0 degrees C., revealed the following new facts. The fibrillar system of the retinal photoreceptor consists of nine double fibrils enclosed in a sheath. Pigment cells and lens cells possess similar systems. Two short cylindrical centrioles are associated with the fibrillar apparatus: one, from which striated rootlets extend inward, lies at the base of the fibrils, with the other at an oblique angle to the axis of the system. A Golgi complex, whorls of endoplasmic reticulum, lipid (?) droplets, and other organelles and inclusions in the photoreceptors are described. An axon leads from the base of the photoreceptor into the nervous layer of the retina which consists of many nerve fibers and large ganglion cells. Although the pattern of neural connections has not yet been determined, some synapses were found. The parietal nerve consists of about 250 non-medullated fibers. The capsule of the eye usually has a layer of iridocytes, which contain rows of guanine (?) rods. A few parietal eyes of the Granite Night Lizard, Xantusia henshawi, were also examined. Large lipid (?) droplets occur in the bases of their receptoral processes.

  17. Further observations on the fine structure of the parietal eye of lizards.

    PubMed

    EAKIN, R M; WESTFALL, J A

    1960-10-01

    An electron microscopical study of the third eye of the Western Fence Lizard, Sceloporus occidentalis, fixed with 1 per cent osmium tetroxide, pH 7.4-7.6, for 16 to 20 hours at 0 degrees C., revealed the following new facts. The fibrillar system of the retinal photoreceptor consists of nine double fibrils enclosed in a sheath. Pigment cells and lens cells possess similar systems. Two short cylindrical centrioles are associated with the fibrillar apparatus: one, from which striated rootlets extend inward, lies at the base of the fibrils, with the other at an oblique angle to the axis of the system. A Golgi complex, whorls of endoplasmic reticulum, lipid (?) droplets, and other organelles and inclusions in the photoreceptors are described. An axon leads from the base of the photoreceptor into the nervous layer of the retina which consists of many nerve fibers and large ganglion cells. Although the pattern of neural connections has not yet been determined, some synapses were found. The parietal nerve consists of about 250 non-medullated fibers. The capsule of the eye usually has a layer of iridocytes, which contain rows of guanine (?) rods. A few parietal eyes of the Granite Night Lizard, Xantusia henshawi, were also examined. Large lipid (?) droplets occur in the bases of their receptoral processes. PMID:13725484

  18. FURTHER OBSERVATIONS ON THE FINE STRUCTURE OF THE PARIETAL EYE OF LIZARDS

    PubMed Central

    Eakin, Richard M.; Westfall, Jane A.

    1960-01-01

    An electron microscopical study of the third eye of the Western Fence Lizard, Sceloporus occidentalis, fixed with 1 per cent osmium tetroxide, pH 7.4–7.6, for 16 to 20 hours at 0°C., revealed the following new facts. The fibrillar system of the retinal photoreceptor consists of nine double fibrils enclosed in a sheath. Pigment cells and lens cells possess similar systems. Two short cylindrical centrioles are associated with the fibrillar apparatus: one, from which striated rootlets extend inward, lies at the base of the fibrils, with the other at an oblique angle to the axis of the system. A Golgi complex, whorls of endoplasmic reticulum, lipid (?) droplets, and other organelles and inclusions in the photoreceptors are described. An axon leads from the base of the photoreceptor into the nervous layer of the retina which consists of many nerve fibers and large ganglion cells. Although the pattern of neural connections has not yet been determined, some synapses were found. The parietal nerve consists of about 250 non-medullated fibers. The capsule of the eye usually has a layer of iridocytes, which contain rows of guanine (?) rods. A few parietal eyes of the Granite Night Lizard, Xantusia henshawi, were also examined. Large lipid (?) droplets occur in the bases of their receptoral processes. PMID:13725484

  19. Prefrontal-parietal function: from foraging to foresight.

    PubMed

    Genovesio, Aldo; Wise, Steven P; Passingham, Richard E

    2014-02-01

    Comparative neuroanatomy shows that new prefrontal areas emerged during the evolution of anthropoid primates to augment prefrontal, parietal, and temporal areas that had evolved in earlier primates. We recently proposed that the new anthropoid areas reduce foraging errors by generating goals from current contexts and learning to do so rapidly, sometimes based on single events. Among the contexts used to generate these goals, the posterior parietal cortex provides the new prefrontal areas with information about relational metrics such as order, number, duration, length, distance and proportion, which play a crucial role in foraging choices. Here we propose that this specialized network later became adapted to support the human capacity for reasoning and general problem-solving.

  20. Kinesin-related Smy1 enhances the Rab-dependent association of myosin-V with secretory cargo

    PubMed Central

    Lwin, Kyaw Myo; Li, Donghao; Bretscher, Anthony

    2016-01-01

    The mechanisms by which molecular motors associate with specific cargo is a central problem in cell organization. The kinesin-like protein Smy1 of budding yeast was originally identified by the ability of elevated levels to suppress a conditional myosin-V mutation (myo2-66), but its function with Myo2 remained mysterious. Subsequently, Myo2 was found to provide an essential role in delivery of secretory vesicles for polarized growth and in the transport of mitochondria for segregation. By isolating and characterizing myo2 smy1 conditional mutants, we uncover the molecular function of Smy1 as a factor that enhances the association of Myo2 with its receptor, the Rab Sec4, on secretory vesicles. The tail of Smy1—which binds Myo2—its central dimerization domain, and its kinesin-like head domain are all necessary for this function. Consistent with this model, overexpression of full-length Smy1 enhances the number of Sec4 receptors and Myo2 motors per transporting secretory vesicle. Rab proteins Sec4 and Ypt11, receptors for essential transport of secretory vesicles and mitochondria, respectively, bind the same region on Myo2, yet Smy1 functions selectively in the transport of secretory vesicles. Thus a kinesin-related protein can function intimately with a myosin-V and its receptor in the transport of a specific cargo. PMID:27307583

  1. Overlapping Parietal Activity in Memory and Perception: Evidence for the Attention to Memory Model

    ERIC Educational Resources Information Center

    Cabeza, Roberto; Mazuz, Yonatan S.; Stokes, Jared; Kragel, James E.; Woldorff, Marty G.; Ciaramelli, Elisa; Olson, Ingrid R.; Moscovitch, Morris

    2011-01-01

    The specific role of different parietal regions to episodic retrieval is a topic of intense debate. According to the Attention to Memory (AtoM) model, dorsal parietal cortex (DPC) mediates top-down attention processes guided by retrieval goals, whereas ventral parietal cortex (VPC) mediates bottom-up attention processes captured by the retrieval…

  2. Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation

    ERIC Educational Resources Information Center

    Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin

    2011-01-01

    Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…

  3. Impairments in tactile search following superior parietal damage.

    PubMed

    Skakoon-Sparling, Shayna P; Vasquez, Brandon P; Hano, Kate; Danckert, James

    2011-08-01

    The superior parietal cortex is critical for the control of visually guided actions. Research suggests that visual stimuli relevant to actions are preferentially processed when they are in peripersonal space. One recent study demonstrated that visually guided movements towards the body were more impaired in a patient with damage to superior parietal cortex. Whereas past studies have explored disordered movement in optic ataxic patients, there has been less exploration of space perception in terms of search capacity in this population. In addition, there is some debate concerning the relationship between deficits of visuomotor control and impaired attention/perception in optic ataxia. Given that the dorsal stream has been implicated in the spatial processing of stimuli in peripersonal space, and damage to this region is known to cause optic ataxia, we felt that further investigation was warranted. We examined tactile search behavior in the fronto-parallel and radial planes in a patient with right superior parietal damage and optic ataxia. We used a pegboard with removable cylindrical pegs that allowed for the reorganization of targets between trials. To better characterize three-dimensional search behavior, we included both horizontal and vertical search conditions. Results showed that the patient spent more time searching, was more accurate and revisited more targets in right versus left space. Interestingly, the patient spent the majority of her time specifically searching the lower right quadrant of the stimulus array. Further analysis revealed lower target detection rates along the outer borders of the pegboard on all sides. The search pattern observed here is unusual considering that all targets were within arm's reach. The present experiment demonstrates that damage to superior parietal cortex impairs tactile search and biases exploration towards lower right peripersonal space.

  4. Neuronal oscillations form parietal/frontal networks during contour integration.

    PubMed

    Castellano, Marta; Plöchl, Michael; Vicente, Raul; Pipa, Gordon

    2014-01-01

    The ability to integrate visual features into a global coherent percept that can be further categorized and manipulated are fundamental abilities of the neural system. While the processing of visual information involves activation of early visual cortices, the recruitment of parietal and frontal cortices has been shown to be crucial for perceptual processes. Yet is it not clear how both cortical and long-range oscillatory activity leads to the integration of visual features into a coherent percept. Here, we will investigate perceptual grouping through the analysis of a contour categorization task, where the local elements that form contour must be linked into a coherent structure, which is then further processed and manipulated to perform the categorization task. The contour formation in our visual stimulus is a dynamic process where, for the first time, visual perception of contours is disentangled from the onset of visual stimulation or from motor preparation, cognitive processes that until now have been behaviorally attached to perceptual processes. Our main finding is that, while local and long-range synchronization at several frequencies seem to be an ongoing phenomena, categorization of a contour could only be predicted through local oscillatory activity within parietal/frontal sources, which in turn, would synchronize at gamma (>30 Hz) frequency. Simultaneously, fronto-parietal beta (13-30 Hz) phase locking forms a network spanning across neural sources that are not category specific. Both long range networks, i.e., the gamma network that is category specific, and the beta network that is not category specific, are functionally distinct but spatially overlapping. Altogether, we show that a critical mechanism underlying contour categorization involves oscillatory activity within parietal/frontal cortices, as well as its synchronization across distal cortical sites.

  5. Neuronal oscillations form parietal/frontal networks during contour integration.

    PubMed

    Castellano, Marta; Plöchl, Michael; Vicente, Raul; Pipa, Gordon

    2014-01-01

    The ability to integrate visual features into a global coherent percept that can be further categorized and manipulated are fundamental abilities of the neural system. While the processing of visual information involves activation of early visual cortices, the recruitment of parietal and frontal cortices has been shown to be crucial for perceptual processes. Yet is it not clear how both cortical and long-range oscillatory activity leads to the integration of visual features into a coherent percept. Here, we will investigate perceptual grouping through the analysis of a contour categorization task, where the local elements that form contour must be linked into a coherent structure, which is then further processed and manipulated to perform the categorization task. The contour formation in our visual stimulus is a dynamic process where, for the first time, visual perception of contours is disentangled from the onset of visual stimulation or from motor preparation, cognitive processes that until now have been behaviorally attached to perceptual processes. Our main finding is that, while local and long-range synchronization at several frequencies seem to be an ongoing phenomena, categorization of a contour could only be predicted through local oscillatory activity within parietal/frontal sources, which in turn, would synchronize at gamma (>30 Hz) frequency. Simultaneously, fronto-parietal beta (13-30 Hz) phase locking forms a network spanning across neural sources that are not category specific. Both long range networks, i.e., the gamma network that is category specific, and the beta network that is not category specific, are functionally distinct but spatially overlapping. Altogether, we show that a critical mechanism underlying contour categorization involves oscillatory activity within parietal/frontal cortices, as well as its synchronization across distal cortical sites. PMID:25165437

  6. Neuronal oscillations form parietal/frontal networks during contour integration

    PubMed Central

    Castellano, Marta; Plöchl, Michael; Vicente, Raul; Pipa, Gordon

    2014-01-01

    The ability to integrate visual features into a global coherent percept that can be further categorized and manipulated are fundamental abilities of the neural system. While the processing of visual information involves activation of early visual cortices, the recruitment of parietal and frontal cortices has been shown to be crucial for perceptual processes. Yet is it not clear how both cortical and long-range oscillatory activity leads to the integration of visual features into a coherent percept. Here, we will investigate perceptual grouping through the analysis of a contour categorization task, where the local elements that form contour must be linked into a coherent structure, which is then further processed and manipulated to perform the categorization task. The contour formation in our visual stimulus is a dynamic process where, for the first time, visual perception of contours is disentangled from the onset of visual stimulation or from motor preparation, cognitive processes that until now have been behaviorally attached to perceptual processes. Our main finding is that, while local and long-range synchronization at several frequencies seem to be an ongoing phenomena, categorization of a contour could only be predicted through local oscillatory activity within parietal/frontal sources, which in turn, would synchronize at gamma (>30 Hz) frequency. Simultaneously, fronto-parietal beta (13–30 Hz) phase locking forms a network spanning across neural sources that are not category specific. Both long range networks, i.e., the gamma network that is category specific, and the beta network that is not category specific, are functionally distinct but spatially overlapping. Altogether, we show that a critical mechanism underlying contour categorization involves oscillatory activity within parietal/frontal cortices, as well as its synchronization across distal cortical sites. PMID:25165437

  7. [The endocranial parietal vascular traces in the hominid line].

    PubMed

    Saban, R

    1977-03-01

    The study of the grooves traced by the middle meningeal veins on the parietal bone or the endocast of Hominid fossils shows different patterns which correspond to each evolutive stage. Height types are characterised among the Hominids (Australopithecines, Archanthropines, Paleanthropines and Neanthropines): I, robust Australopithecine type; II, gracile Australopithecine type; III, earliest Pithecanthropine type; IV, evolved Pithecanthropine type; V, Preneandertal type; VI, neandertal type; VII, Neanthropine type; VIII, modern type. PMID:405108

  8. Helicobacter pylori and its interaction with chief and parietal cells.

    PubMed Central

    Cave, D. R.

    1996-01-01

    Helicobacter pylori has been shown, along with other Helicobacter species to produce effector molecules that induce substantial physiological changes on acid and pepsin secretion. The effects are clinically evident, and long-term achlorhydria may be a risk factor for gastric cancer. Further identification and characterization of the factors may lead to additional understanding of gastric physiology. PMID:9041695

  9. Gestalt perception is associated with reduced parietal beta oscillations.

    PubMed

    Zaretskaya, Natalia; Bartels, Andreas

    2015-05-15

    The ability to perceive composite objects as a whole is fundamental for visual perception in a complex and cluttered natural environment. This ability may be mediated by increased communication between neural representations of distinct object elements, and has been linked to increased synchronization of oscillatory brain activity in the gamma band. Previous studies of perceptual grouping either guided attention between local and global aspects of a given stimulus or manipulated its physical properties to achieve grouped and ungrouped perceptual conditions. In contrast to those studies, we fully matched the physical properties underlying global and local percepts using a bistable stimulus that causes the viewer to perceive either local motion of multiple elements or global motion of two illusory shapes without any external change. To test the synchronization hypothesis we recorded brain activity with EEG, while human participants viewed the stimulus and reported changes in their perception. In contrast to previous findings we show that power of the beta-band was lower during perception of global Gestalt than during that of local elements. Source localization places these differences in the posterior parietal cortex, overlapping with a site previously associated with both attention and Gestalt perception. These findings reveal a role of parietal beta-band activity in internally, rather than externally or attention-driven processes of Gestalt perception. They also add to the growing evidence for shared neural substrates of attention and Gestalt perception, both being linked to parietal cortex.

  10. Bottom-up Visual Integration in the Medial Parietal Lobe.

    PubMed

    Pflugshaupt, Tobias; Nösberger, Myriam; Gutbrod, Klemens; Weber, Konrad P; Linnebank, Michael; Brugger, Peter

    2016-03-01

    Largely based on findings from functional neuroimaging studies, the medial parietal lobe is known to contribute to internally directed cognitive processes such as visual imagery or episodic memory. Here, we present 2 patients with behavioral impairments that extend this view. Both had chronic unilateral lesions of nearly the entire medial parietal lobe, but in opposite hemispheres. Routine neuropsychological examination conducted >4 years after the onset of brain damage showed little deficits of minor severity. In contrast, both patients reported persistent unusual visual impairment. A comprehensive series of tachistoscopic experiments with lateralized stimulus presentation and comparison with healthy participants revealed partial visual hemiagnosia for stimuli presented to their contralesional hemifield, applying inferential single-case statistics to evaluate deficits and dissociations. Double dissociations were found in 4 experiments during which participants had to integrate more than one visual element, either through comparison or formation of a global gestalt. Against the background of recent neuroimaging findings, we conclude that of all medial parietal structures, the precuneus is the most likely candidate for a crucial involvement in such bottom-up visual integration.

  11. Early recurrence and ongoing parietal driving during elementary visual processing

    PubMed Central

    Plomp, Gijs; Hervais-Adelman, Alexis; Astolfi, Laura; Michel, Christoph M.

    2015-01-01

    Visual stimuli quickly activate a broad network of brain areas that often show reciprocal structural connections between them. Activity at short latencies (<100 ms) is thought to represent a feed-forward activation of widespread cortical areas, but fast activation combined with reciprocal connectivity between areas in principle allows for two-way, recurrent interactions to occur at short latencies after stimulus onset. Here we combined EEG source-imaging and Granger-causal modeling with high temporal resolution to investigate whether recurrent and top-down interactions between visual and attentional brain areas can be identified and distinguished at short latencies in humans. We investigated the directed interactions between widespread occipital, parietal and frontal areas that we localized within participants using fMRI. The connectivity results showed two-way interactions between area MT and V1 already at short latencies. In addition, the results suggested a large role for lateral parietal cortex in coordinating visual activity that may be understood as an ongoing top-down allocation of attentional resources. Our results support the notion that indirect pathways allow early, evoked driving from MT to V1 to highlight spatial locations of motion transients, while influence from parietal areas is continuously exerted around stimulus onset, presumably reflecting task-related attentional processes. PMID:26692466

  12. Parietal endoderm secreted S100A4 promotes early cardiomyogenesis in embryoid bodies

    SciTech Connect

    Stary, Martina; Schneider, Mikael; Sheikh, Soren P.; Weitzer, Georg . E-mail: georg.weitzer@meduniwien.ac.at

    2006-05-05

    Cardiomyogenesis is influenced by factors secreted by anterior-lateral and extra-embryonic endoderm. Differentiation of embryonic stem cells in embryoid bodies allows to study the influence of growth factors on cardiomyogenesis. By these means SPARC was identified as a new factor enhancing cardiomyogenesis [M. Stary, W. Pasteiner, A. Summer, A. Hrdina, A. Eger, G. Weitzer, Parietal endoderm secreted SPARC promotes early cardiomyogenesis in vitro, Exp. Cell Res. 310 (2005) 331-341]. Here we report a similar and new function for S100A4, a calcium-binding protein of the EF-hand type. S100A4 is secreted by parietal endoderm and promotes early differentiation and proliferation of cardiomyocytes. Oligomeric S100A4 supports cardiomyogenesis in a concentration-dependent manner, whereas inhibition of autocrine S100A4 severely attenuates cardiomyogenesis. S100A4 specifically influences transcription in differentiating cardiomyocytes, as evident from increased expression of cardiac transcription factor genes nkx2.5 and mef2C. These data suggest that S100A4, like SPARC, plays a supportive role in early in vitro cardiomyogenesis.

  13. Scene-Selectivity and Retinotopy in Medial Parietal Cortex

    PubMed Central

    Silson, Edward H.; Steel, Adam D.; Baker, Chris I.

    2016-01-01

    Functional imaging studies in human reliably identify a trio of scene-selective regions, one on each of the lateral [occipital place area (OPA)], ventral [parahippocampal place area (PPA)], and medial [retrosplenial complex (RSC)] cortical surfaces. Recently, we demonstrated differential retinotopic biases for the contralateral lower and upper visual fields within OPA and PPA, respectively. Here, using functional magnetic resonance imaging, we combine detailed mapping of both population receptive fields (pRF) and category-selectivity, with independently acquired resting-state functional connectivity analyses, to examine scene and retinotopic processing within medial parietal cortex. We identified a medial scene-selective region, which was contained largely within the posterior and ventral bank of the parieto-occipital sulcus (POS). While this region is typically referred to as RSC, the spatial extent of our scene-selective region typically did not extend into retrosplenial cortex, and thus we adopt the term medial place area (MPA) to refer to this visually defined scene-selective region. Intriguingly MPA co-localized with a region identified solely on the basis of retinotopic sensitivity using pRF analyses. We found that MPA demonstrates a significant contralateral visual field bias, coupled with large pRF sizes. Unlike OPA and PPA, MPA did not show a consistent bias to a single visual quadrant. MPA also co-localized with a region identified by strong differential functional connectivity with PPA and the human face-selective fusiform face area (FFA), commensurate with its functional selectivity. Functional connectivity with OPA was much weaker than with PPA, and similar to that with face-selective occipital face area (OFA), suggesting a closer link with ventral than lateral cortex. Consistent with prior research, we also observed differential functional connectivity in medial parietal cortex for anterior over posterior PPA, as well as a region on the lateral

  14. Scene-Selectivity and Retinotopy in Medial Parietal Cortex.

    PubMed

    Silson, Edward H; Steel, Adam D; Baker, Chris I

    2016-01-01

    Functional imaging studies in human reliably identify a trio of scene-selective regions, one on each of the lateral [occipital place area (OPA)], ventral [parahippocampal place area (PPA)], and medial [retrosplenial complex (RSC)] cortical surfaces. Recently, we demonstrated differential retinotopic biases for the contralateral lower and upper visual fields within OPA and PPA, respectively. Here, using functional magnetic resonance imaging, we combine detailed mapping of both population receptive fields (pRF) and category-selectivity, with independently acquired resting-state functional connectivity analyses, to examine scene and retinotopic processing within medial parietal cortex. We identified a medial scene-selective region, which was contained largely within the posterior and ventral bank of the parieto-occipital sulcus (POS). While this region is typically referred to as RSC, the spatial extent of our scene-selective region typically did not extend into retrosplenial cortex, and thus we adopt the term medial place area (MPA) to refer to this visually defined scene-selective region. Intriguingly MPA co-localized with a region identified solely on the basis of retinotopic sensitivity using pRF analyses. We found that MPA demonstrates a significant contralateral visual field bias, coupled with large pRF sizes. Unlike OPA and PPA, MPA did not show a consistent bias to a single visual quadrant. MPA also co-localized with a region identified by strong differential functional connectivity with PPA and the human face-selective fusiform face area (FFA), commensurate with its functional selectivity. Functional connectivity with OPA was much weaker than with PPA, and similar to that with face-selective occipital face area (OFA), suggesting a closer link with ventral than lateral cortex. Consistent with prior research, we also observed differential functional connectivity in medial parietal cortex for anterior over posterior PPA, as well as a region on the lateral

  15. Secretory Pathway-Dependent Localization of the Saccharomyces cerevisiae Rho GTPase-Activating Protein Rgd1p at Growth Sites

    PubMed Central

    Lefèbvre, Fabien; Prouzet-Mauléon, Valérie; Hugues, Michel; Crouzet, Marc; Vieillemard, Aurélie; McCusker, Derek; Thoraval, Didier

    2012-01-01

    Establishment and maintenance of cell polarity in eukaryotes depends upon the regulation of Rho GTPases. In Saccharomyces cerevisiae, the Rho GTPase activating protein (RhoGAP) Rgd1p stimulates the GTPase activities of Rho3p and Rho4p, which are involved in bud growth and cytokinesis, respectively. Consistent with the distribution of Rho3p and Rho4p, Rgd1p is found mostly in areas of polarized growth during cell cycle progression. Rgd1p was mislocalized in mutants specifically altered for Golgi apparatus-based phosphatidylinositol 4-P [PtdIns(4)P] synthesis and for PtdIns(4,5)P2 production at the plasma membrane. Analysis of Rgd1p distribution in different membrane-trafficking mutants suggested that Rgd1p was delivered to growth sites via the secretory pathway. Rgd1p may associate with post-Golgi vesicles by binding to PtdIns(4)P and then be transported by secretory vesicles to the plasma membrane. In agreement, we show that Rgd1p coimmunoprecipitated and localized with markers specific to secretory vesicles and cofractionated with a plasma membrane marker. Moreover, in vivo imaging revealed that Rgd1p was transported in an anterograde manner from the mother cell to the daughter cell in a vectoral manner. Our data indicate that secretory vesicles are involved in the delivery of RhoGAP Rgd1p to the bud tip and bud neck. PMID:22447923

  16. Electron microprobe analysis of human labial gland secretory granules in cystic fibrosis

    SciTech Connect

    Izutsu, K.; Johnson, D.; Schubert, M.; Wang, E.; Ramsey, B.; Tamarin, A.; Truelove, E.; Ensign, W.; Young, M.

    1985-06-01

    X-ray microanalysis of freeze-dried labial gland cryosections revealed that Na concentration was doubled and the Ca/S concentration ratio was decreased in secretory granules of labial glands from patients with cystic fibrosis (CF) when compared with glands from normal subjects. Other results suggested that the decrease in the Ca/S concentration ratio resulted from an increase in S concentration. These findings imply that mucous granules in labial saliva showed a CF-related increase in Na and S content, and such changes would be expected to affect the rheology of the mucus after exocytosis. In contrast with a previous study in human parotid glands, no evidence was found for CF-related changes in cytoplasmic or nuclear Na, K, and Ca concentrations. Significant elemental differences were found between secretory granules and nuclei and cytoplasm of control cells.

  17. Augmentation of arginase Ⅱ expression in the human endometrial epithelium in the secretory phase.

    PubMed

    Tajima, Makiko; Harada, Tatsuya; Ishikawa, Tomonori; Iwahara, Yuki; Kubota, Toshiro

    2012-01-01

    L-arginine is the common substrate for arginase and nitric oxide synthase (NOS). Arginase converts L-arginine to urea and L-ornithine. L-Ornithine is the principal precursor for the production of polyamines and L-proline, which are required for cell proliferation and collagen synthesis. Endothelial NOS is expressed in the human endometrial glandular epithelium, but the expression and physiological roles of arginase in the human endometrium are not clear. The objective of this study was to investigate the expression and distribution patterns of arginases Ⅰ (A-Ⅰ) and Ⅱ (A-Ⅱ) in the human endometrium by using immunohistochemistry, reverse transcription-polymerase chain reaction (RTPCR), and western blotting. A-Ⅰ and A-Ⅱ were detected by immunohistochemistry in human endometrial epithelial cells during the proliferative and secretory phases of the menstrual cycle. RT-PCR showed that A-Ⅰ and A-Ⅱ mRNA were expressed in human endometrial tissue. Western blotting analysis results showed the expression of A-Ⅱ protein. Immunohistochemistry and western blotting results showed that expression levels of A-Ⅱ were significantly higher in the secretory phase than in the proliferative phase. Increased A-Ⅱ levels in the secretory phase may be responsible for endometrial growth by increasing polyamines and proline products. PMID:23897115

  18. Are there salvage routes within the general secretory pathway in yeast?

    PubMed

    Gozalbo, D; Martínez, J P; Sentandreu, R

    1992-04-01

    It is generally accepted that both extracellular protein secretion and plasma membrane expansion in yeast occur basically as in higher eukaryotic cells. In addition to the constitutive (default) secretory pathway, some specialized mammalian cells possess a regulated route which at present has not been detected in yeast. However, there is a body of experimental results suggesting that under certain circumstances export of integral plasma membrane and exocellular proteins may take place through alternative (salvage) pathways. The existence of these latter routes would enable the yeast cell to adapt more efficiently to distinct or adverse conditions requiring the secretion of discrete amounts of specific sets of proteins.

  19. A Novel Mutation of DAX-1 Associated with Secretory Azoospermia

    PubMed Central

    Yang, Lihua; Liu, Yuchen; Diao, Ruiying; Cai, Zhiming; Li, Honggang; Gui, Yaoting

    2015-01-01

    Secretory azoospermia is a severe form of male infertility caused by unknown factors. DAX-1 is predominantly expressed in mammalian reproductive tissues and plays an important role in spermatogenesis because Dax-1 knockout male mice show spermatogenesis defects. To examine whether DAX-1 is involved in the pathogenesis of secretory azoospermia in humans, we sequenced all of the exons of DAX-1 in 776 patients diagnosed with secretory azoospermia and 709 proven fertile men. A number of coding mutations unique to the patient group, including two synonymous mutations and six missense mutations, were identified. Of the missense mutations, our functional assay demonstrated that the V385L mutation caused the reduced functioning of DAX-1. This novel mutation (p. V385L) of DAX-1 is the first to be identified in association with secretory azoospermia, thereby highlighting the important role of DAX-1 in spermatogenesis. PMID:26207377

  20. A Novel Mutation of DAX-1 Associated with Secretory Azoospermia.

    PubMed

    Mou, Lisha; Xie, Nie; Yang, Lihua; Liu, Yuchen; Diao, Ruiying; Cai, Zhiming; Li, Honggang; Gui, Yaoting

    2015-01-01

    Secretory azoospermia is a severe form of male infertility caused by unknown factors. DAX-1 is predominantly expressed in mammalian reproductive tissues and plays an important role in spermatogenesis because Dax-1 knockout male mice show spermatogenesis defects. To examine whether DAX-1 is involved in the pathogenesis of secretory azoospermia in humans, we sequenced all of the exons of DAX-1 in 776 patients diagnosed with secretory azoospermia and 709 proven fertile men. A number of coding mutations unique to the patient group, including two synonymous mutations and six missense mutations, were identified. Of the missense mutations, our functional assay demonstrated that the V385L mutation caused the reduced functioning of DAX-1. This novel mutation (p. V385L) of DAX-1 is the first to be identified in association with secretory azoospermia, thereby highlighting the important role of DAX-1 in spermatogenesis. PMID:26207377

  1. An Alternative Terminal Step of the General Secretory Pathway in Staphylococcus aureus

    PubMed Central

    Craney, Arryn; Dix, Melissa M.; Adhikary, Ramkrishna; Cravatt, Benjamin F.

    2015-01-01

    ABSTRACT Type I signal peptidase (SPase) is essential for viability in wild-type bacteria because the terminal step of the bacterial general secretory pathway requires its proteolytic activity to release proteins from their membrane-bound N-terminal leader sequences after translocation across the cytoplasmic membrane. Here, we identify the Staphylococcus aureus operon ayrRABC (SA0337 to SA0340) and show that once released from repression by AyrR, the protein products AyrABC together confer resistance to the SPase inhibitor arylomycin M131 by providing an alternate and novel method of releasing translocated proteins. Thus, the derepression of ayrRABC allows cells to bypass the essentiality of SPase. We demonstrate that AyrABC functionally complements SPase by mediating the processing of the normally secreted proteins, albeit in some cases with reduced efficiency and either without cleavage or via cleavage at a site N-terminal to the canonical SPase cleavage site. Thus, ayrRABC encodes a secretion stress-inducible alternate terminal step of the general secretory pathway. Importance  Addressing proteins for proper localization within or outside a cell in both eukaryotes and prokaryotes is often accomplished with intrinsic signals which mediate membrane translocation and which ultimately must be removed. The canonical enzyme responsible for the removal of translocation signals is bacterial type I signal peptidase (SPase), which functions at the terminal step of the general secretory pathway and is thus essential in wild-type bacteria. Here, we identify a four-gene operon in S. aureus that encodes an alternate terminal step of the general secretory pathway and thus makes SPase nonessential. The results have important implications for protein secretion in bacteria and potentially for protein trafficking in prokaryotes and eukaryotes in general. PMID:26286693

  2. Methods to Purify and Assay Secretory Pathway Kinases.

    PubMed

    Tagliabracci, Vincent S; Wen, Jianzhong; Xiao, Junyu

    2016-01-01

    Members of the four-jointed and VLK families of secretory pathway kinases appear to be responsible for the phosphorylation of secreted proteins and proteoglycans. These enzymes have been implicated in many biological processes and mutations in several of these kinases cause human diseases. Here, we describe methods to purify and assay two members of the four-jointed family of secretory kinases: the Fam20C protein kinase and the Fam20B proteoglycan kinase. PMID:27632012

  3. Cathepsin L participates in the production of neuropeptide Y in secretory vesicles, demonstrated by protease gene knockout and expression.

    PubMed

    Funkelstein, Lydiane; Toneff, Thomas; Hwang, Shin-Rong; Reinheckel, Thomas; Peters, Christoph; Hook, Vivian

    2008-07-01

    Neuropeptide Y (NPY) functions as a peptide neurotransmitter and as a neuroendocrine hormone. The active NPY peptide is generated in secretory vesicles by proteolytic processing of proNPY. Novel findings from this study show that cathepsin L participates as a key proteolytic enzyme for NPY production in secretory vesicles. Notably, NPY levels in cathepsin L knockout (KO) mice were substantially reduced in brain and adrenal medulla by 80% and 90%, respectively. Participation of cathepsin L in producing NPY predicts their colocalization in secretory vesicles, a primary site of NPY production. Indeed, cathepsin L was colocalized with NPY in brain cortical neurons and in chromaffin cells of adrenal medulla, demonstrated by immunofluorescence confocal microscopy. Immunoelectron microscopy confirmed the localization of cathepsin L with NPY in regulated secretory vesicles of chromaffin cells. Functional studies showed that coexpression of proNPY with cathepsin L in neuroendocrine PC12 cells resulted in increased production of NPY. Furthermore, in vitro processing indicated cathepsin L processing of proNPY at paired basic residues. These findings demonstrate a role for cathepsin L in the production of NPY from its proNPY precursor. These studies illustrate the novel biological role of cathepsin L in the production of NPY, a peptide neurotransmitter, and neuroendocrine hormone.

  4. Topographic Organization for Delayed Saccades in Human Posterior Parietal Cortex

    PubMed Central

    Schluppeck, Denis; Glimcher, Paul; Heeger, David J.

    2008-01-01

    Posterior parietal cortex (PPC) is thought to play a critical role in decision making, sensory attention, motor intention, and/or working memory. Research on the PPC in non-human primates has focused on the lateral intraparietal area (LIP) in the intraparietal sulcus (IPS). Neurons in LIP respond after the onset of visual targets, just before saccades to those targets, and during the delay period in between. To study the function of posterior parietal cortex in humans, it will be crucial to have a routine and reliable method for localizing specific parietal areas in individual subjects. Here, we show that human PPC contains at least two topographically organized regions, which are candidates for the human homologue of LIP. We mapped the topographic organization of human PPC for delayed (memory guided) saccades using fMRI. Subjects were instructed to fixate centrally while a peripheral target was briefly presented. After a further 3-s delay, subjects made a saccade to the remembered target location followed by a saccade back to fixation and a 1-s inter-trial interval. Targets appeared at successive locations “around the clock” (same eccentricity, ≈30° angular steps), to produce a traveling wave of activity in areas that are topographically organized. PPC exhibited topographic organization for delayed saccades. We defined two areas in each hemisphere that contained topographic maps of the contralateral visual field. These two areas were immediately rostral to V7 as defined by standard retinotopic mapping. The two areas were separated from each other and from V7 by reversals in visual field orientation. However, we leave open the possibility that these two areas will be further subdivided in future studies. Our results demonstrate that topographic maps tile the cortex continuously from V1 well into PPC. PMID:15817644

  5. Observing secretory granules with a multiangle evanescent wave microscope.

    PubMed Central

    Rohrbach, A

    2000-01-01

    In total internal reflection fluorescence microscopy (TIRFM), fluorophores near a surface can be excited with evanescent waves, which decay exponentially with distance from the interface. Penetration depths of evanescent waves from 60 nm to 300 nm were generated by varying the angle of incidence of a laser beam. With a novel telecentric multiangle evanescent wave microscope, we monitored and investigated both single secretory granules and pools of granules in bovine chromaffin cells. By measuring the fluorescence intensity as a function of penetration depth, it is possible through a Laplace transform to obtain the fluorophore distribution as a function of axial position. We discuss the extent to which it is possible to determine distances and diameters of granules with this microscopy technique by modeling the fluorescent volumes of spheres in evanescent fields. The anisotropic near-field detection of fluorophores and the influence of the detection point-spread function are considered. The diameters of isolated granules between 70 nm and 300 nm have been reconstructed, which is clearly beyond the resolution limit of a confocal microscope. Furthermore, the paper demonstrates how evanescent waves propagate along surfaces and scatter at objects with a higher refractive index. TIRFM will have a limited applicability for quantitative measurements when the parameters used to define evanescent waves are not optimally selected. PMID:10777760

  6. Role of NBCe1 and AE2 in Secretory Ameloblasts

    PubMed Central

    Paine, Michael L.; Snead, Malcolm L.; Wang, HongJun; Abuladze, Natalia; Pushkin, Alexander; Liu, Weixin; Kao, Li Yo; Wall, Susan M.; Kim, Young-Hee; Kurtz, Ira

    2008-01-01

    The H+/base transport processes that control the pH of the microenvironment adjacent to ameloblasts are not currently well understood. Mice null for the AE2 anion exchanger have abnormal enamel. In addition, patients with mutations in the electrogenic sodium bicarbonate cotransporter NBCe1 and mice lacking NBCe1 have enamel abnormalities. These observations suggest that AE2 and NBCe1 play important roles in amelogenesis. The present study aimed to understand the roles of AE2 and NBC1 in ameloblasts. The data showed that NBCe1 is expressed at the basolateral membrane of secretory ameloblasts, whereas AE2 is expressed at the apical membrane. Transcripts for AE2a and NBCe1-B were detected in RNA isolated from cultured ameloblast-like LS8 cells. Our data are the first evidence that AE2 and NBCe1 are expressed in ameloblasts in vivo in a polarized fashion thereby providing a mechanism for ameloblast transcellular bicarbonate secretion in the process of enamel formation and maturation. PMID:18362326

  7. Small molecules intercept Notch signaling and the early secretory pathway.

    PubMed

    Krämer, Andreas; Mentrup, Torben; Kleizen, Bertrand; Rivera-Milla, Eric; Reichenbach, Daniela; Enzensperger, Christoph; Nohl, Richard; Täuscher, Eric; Görls, Helmar; Ploubidou, Aspasia; Englert, Christoph; Werz, Oliver; Arndt, Hans-Dieter; Kaether, Christoph

    2013-11-01

    Notch signaling has a pivotal role in numerous cell-fate decisions, and its aberrant activity leads to developmental disorders and cancer. To identify molecules that influence Notch signaling, we screened nearly 17,000 compounds using automated microscopy to monitor the trafficking and processing of a ligand-independent Notch-enhanced GFP (eGFP) reporter. Characterization of hits in vitro by biochemical and cellular assays and in vivo using zebrafish led to five validated compounds, four of which induced accumulation of the reporter at the plasma membrane by inhibiting γ-secretase. One compound, the dihydropyridine FLI-06, disrupted the Golgi apparatus in a manner distinct from that of brefeldin A and golgicide A. FLI-06 inhibited general secretion at a step before exit from the endoplasmic reticulum (ER), which was accompanied by a tubule-to-sheet morphological transition of the ER, rendering FLI-06 the first small molecule acting at such an early stage in secretory traffic. These data highlight the power of phenotypic screening to enable investigations of central cellular signaling pathways. PMID:24077179

  8. The complete general secretory pathway in gram-negative bacteria.

    PubMed Central

    Pugsley, A P

    1993-01-01

    The unifying feature of all proteins that are transported out of the cytoplasm of gram-negative bacteria by the general secretory pathway (GSP) is the presence of a long stretch of predominantly hydrophobic amino acids, the signal sequence. The interaction between signal sequence-bearing proteins and the cytoplasmic membrane may be a spontaneous event driven by the electrochemical energy potential across the cytoplasmic membrane, leading to membrane integration. The translocation of large, hydrophilic polypeptide segments to the periplasmic side of this membrane almost always requires at least six different proteins encoded by the sec genes and is dependent on both ATP hydrolysis and the electrochemical energy potential. Signal peptidases process precursors with a single, amino-terminal signal sequence, allowing them to be released into the periplasm, where they may remain or whence they may be inserted into the outer membrane. Selected proteins may also be transported across this membrane for assembly into cell surface appendages or for release into the extracellular medium. Many bacteria secrete a variety of structurally different proteins by a common pathway, referred to here as the main terminal branch of the GSP. This recently discovered branch pathway comprises at least 14 gene products. Other, simpler terminal branches of the GSP are also used by gram-negative bacteria to secrete a more limited range of extracellular proteins. PMID:8096622

  9. Neural activity in the parietal eye of a lizard.

    PubMed

    MILLER, W H; WOLBARSHT, M L

    1962-01-26

    Electrical signs of activity in response to illumination of the parietal eye of the American chameleon, Anolis carolinensis, have been investigated. The responses were of two types. Under conditions of direct-coupled amplification, with glass pipette electrodes recording extracellularly from the retinal surface, the response consisted of an increase in negativity maintained throughout prolonged illumination. With capacitance-coupled amplification and metal electrodes, brisk mass discharges of nerve impulses were detected at the onset and cessation of illumination. During illumination a less vigorous maintained discharge was observed.

  10. Environmental reduplication associated with right frontal and parietal lobe injury.

    PubMed Central

    Ruff, R L; Volpe, B T

    1981-01-01

    Four patients with environmental reduplication, a specific form of spatial disorientation and confabulation are described. The patients maintained that their hospital rooms were located in their homes. Each patients had evidence of right frontal or right parietal injury based upon computed tomography, neurosurgery, and neuropsychological testing. The factors associated with environmental reduplication were: impaired spatial perception and visual memory, inability of the patients to recognise the inconsistency between their believed location and their actual location, confusion soon after admission to hospital, and a strong desire to be at home. PMID:7264684

  11. Tracking individual secretory vesicles during exocytosis reveals an ordered and regulated process

    PubMed Central

    Donovan, Kirk W.

    2015-01-01

    Post-Golgi secretory vesicle trafficking is a coordinated process, with transport and regulatory mechanisms to ensure appropriate exocytosis. While the contributions of many individual regulatory proteins to this process are well studied, the timing and dependencies of events have not been defined. Here we track individual secretory vesicles and associated proteins in vivo during tethering and fusion in budding yeast. Secretory vesicles tether to the plasma membrane very reproducibly for ∼18 s, which is extended in cells defective for membrane fusion and significantly lengthened and more variable when GTP hydrolysis of the exocytic Rab is delayed. Further, the myosin-V Myo2p regulates the tethering time in a mechanism unrelated to its interaction with exocyst component Sec15p. Two-color imaging of tethered vesicles with Myo2p, the GEF Sec2p, and several exocyst components allowed us to document a timeline for yeast exocytosis in which Myo2p leaves 4 s before fusion, whereas Sec2p and all the components of the exocyst disperse coincident with fusion. PMID:26169352

  12. A pediatric case of mammary analogue secretory carcinoma within the parotid.

    PubMed

    Quattlebaum, S Craig; Roby, Brianne; Dishop, Megan K; Said, M Sherif; Chan, Kenny

    2015-01-01

    Mammary analogue secretory carcinoma (MASC) is a recently described entity in the differential diagnosis of salivary gland tumors. It is notable for a characteristic t(12;15)(p13;q25) translocation that results in a unique fusion protein, ETV6-NTRK3. While several studies have retrospectively identified this translocation in cases previously diagnosed as a different salivary malignancy, there have been relatively few cases where this translocation was identified on initial pathology results, and fewer still in a pediatric population. We present a case of a 15 year old female with a slowly enlarging, painless, left facial mass. MRI demonstrated a cystic mass extending into the deep lobe of the parotid, and she underwent parotidectomy. The tumor cells stained positive for S100 and CK19. ETV6 translocation was present, confirming the diagnosis. Mammary analogue secretory carcinoma is a recently described tumor of the salivary glands, which often masquerades as more common primary salivary gland tumors and cysts. More research is needed to characterize the typical behavior of this neoplasm and the optimal treatment regimen. With identification of its characteristic translocation, mammary analogue secretory carcinoma can be easily differentiated from its more prevalent counterparts, and should therefore remain within the differential of the pathologist and head and neck surgeon. PMID:26545463

  13. Cysteine-Rich Atrial Secretory Protein from the Snail Achatina achatina: Purification and Structural Characterization

    PubMed Central

    Shabelnikov, Sergey; Kiselev, Artem

    2015-01-01

    Despite extensive studies of cardiac bioactive peptides and their functions in molluscs, soluble proteins expressed in the heart and secreted into the circulation have not yet been reported. In this study, we describe an 18.1-kDa, cysteine-rich atrial secretory protein (CRASP) isolated from the terrestrial snail Achatina achatina that has no detectable sequence similarity to any known protein or nucleotide sequence. CRASP is an acidic, 158-residue, N-glycosylated protein composed of eight alpha-helical segments stabilized with five disulphide bonds. A combination of fold recognition algorithms and ab initio folding predicted that CRASP adopts an all-alpha, right-handed superhelical fold. CRASP is most strongly expressed in the atrium in secretory atrial granular cells, and substantial amounts of CRASP are released from the heart upon nerve stimulation. CRASP is detected in the haemolymph of intact animals at nanomolar concentrations. CRASP is the first secretory protein expressed in molluscan atrium to be reported. We propose that CRASP is an example of a taxonomically restricted gene that might be responsible for adaptations specific for terrestrial pulmonates. PMID:26444993

  14. The role of prefrontal and parietal cortices in esthetic appreciation of representational and abstract art: a TMS study.

    PubMed

    Cattaneo, Zaira; Lega, Carlotta; Gardelli, Chiara; Merabet, Lotfi B; Cela-Conde, Camilo J; Nadal, Marcos

    2014-10-01

    To explain the biological foundations of art appreciation is to explain one of our species' distinctive traits. Previous neuroimaging and electrophysiological studies have pointed to the prefrontal and the parietal cortex as two critical regions mediating esthetic appreciation of visual art. In this study, we applied transcranial magnetic stimulation (TMS) over the left prefrontal cortex and the right posterior parietal cortex while participants were evaluating whether they liked, and by how much, a particular painting. By depolarizing cell membranes in the targeted regions, TMS transiently interferes with the activity of specific cortical areas, which allows clarifying their role in a given task. Our results show that both regions play a fundamental role in mediating esthetic appreciation. Critically though, the effects of TMS varied depending on the type of art considered (i.e. representational vs. abstract) and on participants' a-priori inclination toward one or the other.

  15. Sylvian fissure and parietal anatomy in children with autism spectrum disorder.

    PubMed

    Knaus, Tracey A; Tager-Flusberg, Helen; Foundas, Anne L

    2012-01-01

    Autism spectrum disorder (ASD) is characterized by deficits in social functioning and language and communication, with restricted interests or stereotyped behaviors. Anatomical differences have been found in the parietal cortex in children with ASD, but parietal subregions and associations between Sylvian fissure (SF) and parietal anatomy have not been explored. In this study, SF length and anterior and posterior parietal volumes were measured on MRI in 30 right-handed boys with ASD and 30 right-handed typically developing boys (7-14 years), matched on age and non-verbal IQ. There was leftward SF and anterior parietal asymmetry, and rightward posterior parietal asymmetry, across groups. There were associations between SF and parietal asymmetries, with slight group differences. Typical SF asymmetry was associated with typical anterior and posterior parietal asymmetry, in both groups. In the atypical SF asymmetry group, controls had atypical parietal asymmetry, whereas in ASD there were more equal numbers of individuals with typical as atypical anterior parietal asymmetry. We did not find significant anatomical-behavioral associations. Our findings of more individuals in the ASD group having a dissociation between cortical asymmetries warrants further investigation of these subgroups and emphasizes the importance of investigating anatomical relationships in addition to group differences in individual regions. PMID:22713374

  16. Protein modifications in the plant secretory pathway: current status and practical implications in molecular pharming.

    PubMed

    Faye, Loïc; Boulaflous, Aurelia; Benchabane, Meriem; Gomord, Véronique; Michaud, Dominique

    2005-03-01

    Plants have become, over the last ten years, a suitable alternative to microbial and animal cell factories for the production of clinically-useful, therapeutic proteins. Besides the well known advantage of low-cost and large-scale production of safe and biologically active mammalian proteins, plants also are able to perform most post-translational maturations required for biological activity and suitable pharmacokinetics of recombinant therapeutic proteins. In this short review we focus on glycosylation and proteolytic processing of plant-made pharmaceuticals during their transport through the plant cell's secretory pathway. We also address the practical implications of these important processes on the effectiveness of plant molecular pharming systems.

  17. Sorting of cyst wall proteins to a regulated secretory pathway during differentiation of the primitive eukaryote, Giardia lamblia.

    PubMed

    Reiner, D S; McCaffery, M; Gillin, F D

    1990-10-01

    Giardia lamblia, which belongs to the earliest identified lineage to diverge from the eukaryotic line of descent, is one of many protists reported to lack a Golgi apparatus. Our recent finding of a developmentally regulated secretory pathway in G. lamblia makes it an ideal organism with which to test the hypothesis that the Golgi may be more readily demonstrated in actively secreting cells. These ultrastructural studies now show that a regulated pathway of transport and secretion of cyst wall antigens via a novel class of large, osmiophilic secretory vesicles, the encystation-specific vesicles (ESV), is assembled during encystation of G. lamblia. Early in encystation, cyst antigens are localized in simple Golgi membrane stacks and concentrated within enlarged Golgi cisternae which appear to be precursors of ESV. This would represent an unusual mechanism of secretory vesicle biogenesis. Later in differentiation, cyst antigens are localized within ESV, which transport them to the plasma membrane and release them by exocytosis to the nascent cell wall. ESV are not observed after completion of the cyst wall. In contrast to the regulated transport of cyst wall proteins, we demonstrate a distinct constitutive lysosomal pathway. During encystation, acid phosphatase activity is localized in endoplasmic reticulum, Golgi, and small constitutive peripheral vacuoles which function as lysosomes. However, acid phosphatase activity is not detectable in ESV. These studies show that G. lamblia, an early eukaryote, is capable of carrying out Golgi-mediated sorting of proteins to distinct regulated secretory and constitutive lysosomal pathways.

  18. Right parietal cortex mediates recognition memory for melodies.

    PubMed

    Schaal, Nora K; Javadi, Amir-Homayoun; Halpern, Andrea R; Pollok, Bettina; Banissy, Michael J

    2015-07-01

    Functional brain imaging studies have highlighted the significance of right-lateralized temporal, frontal and parietal brain areas for memory for melodies. The present study investigated the involvement of bilateral posterior parietal cortices (PPCs) for the recognition memory of melodies using transcranial direct current stimulation (tDCS). Participants performed a recognition task before and after tDCS. The task included an encoding phase (12 melodies), a retention period, as well as a recognition phase (24 melodies). Experiment 1 revealed that anodal tDCS over the right PPC led to a deterioration of overall memory performance compared with sham. Experiment 2 confirmed the results of Experiment 1 and further showed that anodal tDCS over the left PPC did not show a modulatory effect on memory task performance, indicating a right lateralization for musical memory. Furthermore, both experiments revealed that the decline in memory for melodies can be traced back to an interference of anodal stimulation on the recollection process (remember judgements) rather than to familiarity judgements. Taken together, this study revealed a causal involvement of the right PPC for memory for melodies and demonstrated a key role for this brain region in the recollection process of the memory task. PMID:25959620

  19. Fronto-parietal network supports context-dependent speech comprehension

    PubMed Central

    Smirnov, Dmitry; Glerean, Enrico; Lahnakoski, Juha M.; Salmi, Juha; Jääskeläinen, Iiro P.; Sams, Mikko; Nummenmaa, Lauri

    2014-01-01

    Knowing the context of a discourse is an essential prerequisite for comprehension. Here we used functional magnetic resonance imaging (fMRI) to disclose brain networks supporting context-dependent speech comprehension. During fMRI, 20 participants listened to 1-min spoken narratives preceded by pictures that were either contextually matching or mismatching with the narrative. Matching pictures increased narrative comprehension, decreased hemodynamic activity in Broca׳s area, and enhanced its functional connectivity with left anterior superior frontal gyrus, bilateral inferior parietal cortex, as well as anterior and posterior cingulate cortex. Further, the anterior (BA 45) and posterior (BA 44) portions of Broca׳s area differed in their functional connectivity patterns. Both BA 44 and BA 45 have shown increased connectivity with right angular gyrus and supramarginal gyrus. Whereas BA 44 showed increased connectivity with left angular gyrus, left inferior/middle temporal gyrus and left postcentral gyrus, BA 45 showed increased connectivity with right posterior cingulate cortex, right anterior inferior frontal gyrus, lateral occipital cortex and anterior cingulate cortex. Our results suggest that a fronto-parietal functional network supports context-dependent narrative comprehension, and that Broca׳s area is involved in resolving ambiguity from speech when appropriate contextual cues are lacking. PMID:25218167

  20. Parietal cortex mediates conscious perception of illusory gestalt.

    PubMed

    Zaretskaya, Natalia; Anstis, Stuart; Bartels, Andreas

    2013-01-01

    Grouping local elements into a holistic percept, also known as spatial binding, is crucial for meaningful perception. Previous studies have shown that neurons in early visual areas V1 and V2 can signal complex grouping-related information, such as illusory contours or object-border ownerships. However, relatively little is known about higher-level processes contributing to these signals and mediating global Gestalt perception. We used a novel bistable motion illusion that induced alternating and mutually exclusive vivid conscious experiences of either dynamic illusory contours forming a global Gestalt or moving ungrouped local elements while the visual stimulation remained the same. fMRI in healthy human volunteers revealed that activity fluctuations in two sites of the parietal cortex, the superior parietal lobe and the anterior intraparietal sulcus (aIPS), correlated specifically with the perception of the grouped illusory Gestalt as opposed to perception of ungrouped local elements. We then disturbed activity at these two sites in the same participants using transcranial magnetic stimulation (TMS). TMS over aIPS led to a selective shortening of the duration of the global Gestalt percept, with no effect on that of local elements. The results suggest that aIPS activity is directly involved in the process of spatial binding during effortless viewing in the healthy brain. Conscious perception of global Gestalt is therefore associated with aIPS function, similar to attention and perceptual selection. PMID:23303932

  1. Increased parietal activity after training of interference control.

    PubMed

    Oelhafen, Stephan; Nikolaidis, Aki; Padovani, Tullia; Blaser, Daniela; Koenig, Thomas; Perrig, Walter J

    2013-11-01

    Recent studies suggest that computerized cognitive training leads to improved performance in related but untrained tasks (i.e. transfer effects). However, most study designs prevent disentangling which of the task components are necessary for transfer. In the current study, we examined whether training on two variants of the adaptive dual n-back task would affect untrained task performance and the corresponding electrophysiological event-related potentials (ERPs). Forty three healthy young adults were trained for three weeks with a high or low interference training variant of the dual n-back task, or they were assigned to a passive control group. While n-back training with high interference led to partial improvements in the Attention Network Test (ANT), we did not find transfer to measures of working memory and fluid intelligence. ERP analysis in the n-back task and the ANT indicated overlapping processes in the P3 time range. Moreover, in the ANT, we detected increased parietal activity for the interference training group alone. In contrast, we did not find electrophysiological differences between the low interference training and the control group. These findings suggest that training on an interference control task leads to higher electrophysiological activity in the parietal cortex, which may be related to improvements in processing speed, attentional control, or both.

  2. Parietal cortex mediates conscious perception of illusory gestalt.

    PubMed

    Zaretskaya, Natalia; Anstis, Stuart; Bartels, Andreas

    2013-01-01

    Grouping local elements into a holistic percept, also known as spatial binding, is crucial for meaningful perception. Previous studies have shown that neurons in early visual areas V1 and V2 can signal complex grouping-related information, such as illusory contours or object-border ownerships. However, relatively little is known about higher-level processes contributing to these signals and mediating global Gestalt perception. We used a novel bistable motion illusion that induced alternating and mutually exclusive vivid conscious experiences of either dynamic illusory contours forming a global Gestalt or moving ungrouped local elements while the visual stimulation remained the same. fMRI in healthy human volunteers revealed that activity fluctuations in two sites of the parietal cortex, the superior parietal lobe and the anterior intraparietal sulcus (aIPS), correlated specifically with the perception of the grouped illusory Gestalt as opposed to perception of ungrouped local elements. We then disturbed activity at these two sites in the same participants using transcranial magnetic stimulation (TMS). TMS over aIPS led to a selective shortening of the duration of the global Gestalt percept, with no effect on that of local elements. The results suggest that aIPS activity is directly involved in the process of spatial binding during effortless viewing in the healthy brain. Conscious perception of global Gestalt is therefore associated with aIPS function, similar to attention and perceptual selection.

  3. Sleep Related Hypermotor Seizures with a Right Parietal Onset

    PubMed Central

    Gibbs, Steve A.; Figorilli, Michela; Casaceli, Giuseppe; Proserpio, Paola; Nobili, Lino

    2015-01-01

    Nocturnal frontal lobe epilepsy (NFLE) is a syndrome characterized by the occurrence of sleep related seizures of variable complexity and duration. Hypermotor seizures (HMS) represent a classic manifestation of this syndrome, associated with a perturbation of the ventromesial frontal cortex and anterior cingulate gyrus regions. Nevertheless, in recent years, reports have showed that the seizure onset zone (SOZ) need not be of frontal origin to generate HMS. Here we report an unusual case of a patient presenting with a seven-year history of drug-resistant sleep related HMS arising from the mesial parietal region. The presence of an infrequent feeling of levitation before the HMS was key to suspecting a subtle focal cortical dysplasia in the right precuneus region. A stereo-EEG investigation confirmed the extra-frontal seizure onset of the HMS and highlighted the interrelationship between unstable sleep and seizure precipitation. Citation: Gibbs SA, Figorilli M, Casaceli G, Proserpio P, Nobili L. Sleep related hypermotor seizures with a right parietal onset. J Clin Sleep Med 2015;11(8):953–955. PMID:25902821

  4. Frontal and parietal lobe activation during transitive inference in humans.

    PubMed

    Acuna, Bettina D; Eliassen, James C; Donoghue, John P; Sanes, Jerome N

    2002-12-01

    Cortical areas engaged in knowledge manipulation during reasoning were identified with functional magnetic resonance imaging (MRI) while participants performed transitive inference (TI) on an ordered list of 11 items (e.g. if A < B and B < C, then A < C). Initially, participants learned a list of arbitrarily ordered visual shapes. Learning occurred by exposure to pairs of list items that were adjacent in the sequence. Subsequently, functional MR images were acquired as participants performed TI on non-adjacent sequence items. Control tasks consisted of height comparisons (HT) and passive viewing (VIS). Comparison of the TI task with the HT task identified activation resulting from TI, termed 'reasoning', while controlling for rule application, decision processes, perception, and movement, collectively termed 'support processes'. The HT-VIS comparison revealed activation related to support processes. The TI reasoning network included bilateral prefrontal cortex (PFC), pre-supplementary motor area (preSMA), premotor area (PMA), insula, precuneus, and lateral posterior parietal cortex. By contrast, cortical regions activated by support processes included the bilateral supplementary motor area (SMA), primary motor cortex (M1), somatic sensory cortices, and right PMA. These results emphasize the role of a prefrontal-parietal network in manipulating information to form new knowledge based on familiar facts. The findings also demonstrate PFC activation beyond short-term memory to include mental operations associated with reasoning. PMID:12427681

  5. Right parietal cortex mediates recognition memory for melodies.

    PubMed

    Schaal, Nora K; Javadi, Amir-Homayoun; Halpern, Andrea R; Pollok, Bettina; Banissy, Michael J

    2015-07-01

    Functional brain imaging studies have highlighted the significance of right-lateralized temporal, frontal and parietal brain areas for memory for melodies. The present study investigated the involvement of bilateral posterior parietal cortices (PPCs) for the recognition memory of melodies using transcranial direct current stimulation (tDCS). Participants performed a recognition task before and after tDCS. The task included an encoding phase (12 melodies), a retention period, as well as a recognition phase (24 melodies). Experiment 1 revealed that anodal tDCS over the right PPC led to a deterioration of overall memory performance compared with sham. Experiment 2 confirmed the results of Experiment 1 and further showed that anodal tDCS over the left PPC did not show a modulatory effect on memory task performance, indicating a right lateralization for musical memory. Furthermore, both experiments revealed that the decline in memory for melodies can be traced back to an interference of anodal stimulation on the recollection process (remember judgements) rather than to familiarity judgements. Taken together, this study revealed a causal involvement of the right PPC for memory for melodies and demonstrated a key role for this brain region in the recollection process of the memory task.

  6. Prospore membrane formation defines a developmentally regulated branch of the secretory pathway in yeast.

    PubMed

    Neiman, A M

    1998-01-12

    Spore formation in yeast is an unusual form of cell division in which the daughter cells are formed within the mother cell cytoplasm. This division requires the de novo synthesis of a membrane compartment, termed the prospore membrane, which engulfs the daughter nuclei. The effect of mutations in late-acting genes on sporulation was investigated. Mutation of SEC1, SEC4, or SEC8 blocked spore formation, and electron microscopic analysis of the sec4-8 mutant indicated that this inability to produce spores was caused by a failure to form the prospore membrane. The soluble NSF attachment protein 25 (SNAP-25) homologue SEC9, by contrast, was not required for sporulation. The absence of a requirement for SEC9 was shown to be due to the sporulation-specific induction of a second, previously undescribed, SNAP-25 homologue, termed SPO20. These results define a developmentally regulated branch of the secretory pathway and suggest that spore morphogenesis in yeast proceeds by the targeting and fusion of secretory vesicles to form new plasma membranes in the interior of the mother cell. Consistent with this model, the extracellular proteins Gas1p and Cts1p were localized to an internal compartment in sporulating cells. Spore formation in yeast may be a useful model for understanding secretion-driven cell division events in a variety of plant and animal systems.

  7. Exocytosis of Alphaherpesvirus Virions, Light Particles, and Glycoproteins Uses Constitutive Secretory Mechanisms

    PubMed Central

    Hogue, Ian B.; Scherer, Julian

    2016-01-01

    ABSTRACT Many molecular and cell biological details of the alphaherpesvirus assembly and egress pathway remain unclear. Recently we developed a live-cell fluorescence microscopy assay of pseudorabies virus (PRV) exocytosis, based on total internal reflection fluorescence (TIRF) microscopy and a virus-encoded pH-sensitive fluorescent probe. Here, we use this assay to distinguish three classes of viral exocytosis in a nonpolarized cell type: (i) trafficking of viral glycoproteins to the plasma membrane, (ii) exocytosis of viral light particles, and (iii) exocytosis of virions. We find that viral glycoproteins traffic to the cell surface in association with constitutive secretory Rab GTPases and exhibit free diffusion into the plasma membrane after exocytosis. Similarly, both virions and light particles use these same constitutive secretory mechanisms for egress from infected cells. Furthermore, we show that viral light particles are distinct from cellular exosomes. Together, these observations shed light on viral glycoprotein trafficking steps that precede virus particle assembly and reinforce the idea that virions and light particles share a biogenesis and trafficking pathway. PMID:27273828

  8. The inhibitory effect of propofol on Kv2.1 potassium channel in rat parietal cortical neurons.

    PubMed

    Zhang, Yan-Zhuo; Zhang, Rui; Zeng, Xian-Zhang; Song, Chun-Yu

    2016-03-11

    Excessive K(+) efflux via activated voltage-gated K(+) channels can deplete intracellular K(+) and lead to long-lasting membrane depolarization which will promote neuronal apoptosis during ischemia/hypoxia injury. The Kv2.1 potassium channel was the major component of delayed rectifier potassium current (Ik) in pyramidal neurons in cortex and hippocampus. The neuronal protective effect of propofol has been proved. Delayed rectifier potassium current (Ik) has been shown to have close relationship with neuronal damage. The study was designed to test the inhibitory effect of propofol on Kv2.1 potassium channel in rat parietal cortical neurons. Whole-cell patch clamp recordings and Western blot analysis were used to investigate the electrophysiological function and protein expression of Kv2.1 in rat parietal cortical neurons after propofol treatment. We found that propofol concentration-dependently inhibited Ik in pyramidal neurons. Propofol also caused a downward shift of the I-V curve of Ik at 30μM concentration. Propofol significantly inhibited the expression of Kv2.1 protein level at 30μM, 50μM, 100μM concentration. In conclusion, our data showed that propofol could inhibit Ik, probably via depressing the expression of Kv2.1 protein in rat cerebral parietal cortical neurons.

  9. The role of right and left parietal lobes in the conceptual processing of numbers.

    PubMed

    Cappelletti, Marinella; Lee, Hwee Ling; Freeman, Elliot D; Price, Cathy J

    2010-02-01

    Neuropsychological and functional imaging studies have associated the conceptual processing of numbers with bilateral parietal regions (including intraparietal sulcus). However, the processes driving these effects remain unclear because both left and right posterior parietal regions are activated by many other conceptual, perceptual, attention, and response-selection processes. To dissociate parietal activation that is number-selective from parietal activation related to other stimulus or response-selection processes, we used fMRI to compare numbers and object names during exactly the same conceptual and perceptual tasks while factoring out activations correlating with response times. We found that right parietal activation was higher for conceptual decisions on numbers relative to the same tasks on object names, even when response time effects were fully factored out. In contrast, left parietal activation for numbers was equally involved in conceptual processing of object names. We suggest that left parietal activation for numbers reflects a range of processes, including the retrieval of learnt facts that are also involved in conceptual decisions on object names. In contrast, number selectivity in right parietal cortex reflects processes that are more involved in conceptual decisions on numbers than object names. Our results generate a new set of hypotheses that have implications for the design of future behavioral and functional imaging studies of patients with left and right parietal damage. PMID:19400672

  10. Tubal function in chronic secretory otitis media in children.

    PubMed

    Poulsen, G; Tos, M

    1977-01-01

    In 100 children (150 ears) with chronic secretory otitis media the function of the Eustachian tube during treatment with grommet was investigated by air equalisation methods. Tubal function proved poor in the great majority at the beginning of the treatment, but towards its completion there was some improvement. After extrusion of the grommet, tubal function was investigated on the same material by tympanometry. 34% had normal middle-ear pressure initially, and 43% 12-18 months after closure of the perforation. There was no relation between tubal function shown by air equalisation methods and by tympanometry, and the air equalisation methods proved of less value than tympanometry in assessing the course and prognosis of secretory otitis. The pathogenetic theories - the ex vacuo and the secretory theory - are discussed in relation to the chronic tubal dysfunction found to be the most common direct cause of the disease.

  11. Distinct Molecular Events during Secretory Granule Biogenesis Revealed by Sensitivities to Brefeldin A

    PubMed Central

    Fernandez, Carlos J.; Haugwitz, Michael; Eaton, Benjamin; Moore, Hsiao-Ping H.

    1997-01-01

    The biogenesis of peptide hormone secretory granules involves a series of sorting, modification, and trafficking steps that initiate in the trans-Golgi and trans-Golgi network (TGN). To investigate their temporal order and interrelationships, we have developed a pulse–chase protocol that follows the synthesis and packaging of a sulfated hormone, pro-opiomelanocortin (POMC). In AtT-20 cells, sulfate is incorporated into POMC predominantly on N-linked endoglycosidase H-resistant oligosaccharides. Subcellular fractionation and pharmacological studies confirm that this sulfation occurs at the trans-Golgi/TGN. Subsequent to sulfation, POMC undergoes a number of molecular events before final storage in dense-core granules. The first step involves the transfer of POMC from the sulfation compartment to a processing compartment (immature secretory granules, ISGs): Inhibiting export of pulse-labeled POMC by brefeldin A (BFA) or a 20°C block prevents its proteolytic conversion to mature adrenocorticotropic hormone. Proteolytic cleavage products were found in vesicular fractions corresponding to ISGs, suggesting that the processing machinery is not appreciably activated until POMC exits the sulfation compartment. A large portion of the labeled hormone is secreted from ISGs as incompletely processed intermediates. This unregulated secretory process occurs only during a limited time window: Granules that have matured for 2 to 3 h exhibit very little unregulated release, as evidenced by the efficient storage of the 15-kDa N-terminal fragment that is generated by a relatively late cleavage event within the maturing granule. The second step of granule biogenesis thus involves two maturation events: proteolytic activation of POMC in ISGs and a transition of the organelle from a state of high unregulated release to one that favors intracellular storage. By using BFA, we show that the two processes occurring in ISGs may be uncoupled: although the unregulated secretion from ISGs is

  12. Cathepsin L in secretory vesicles functions as a prohormone-processing enzyme for production of the enkephalin peptide neurotransmitter

    PubMed Central

    Yasothornsrikul, Sukkid; Greenbaum, Doron; Medzihradszky, Katalin F.; Toneff, Thomas; Bundey, Richard; Miller, Ruthellen; Schilling, Birgit; Petermann, Ivonne; Dehnert, Jessica; Logvinova, Anna; Goldsmith, Paul; Neveu, John M.; Lane, William S.; Gibson, Bradford; Reinheckel, Thomas; Peters, Christoph; Bogyo, Matthew; Hook, Vivian

    2003-01-01

    Multistep proteolytic mechanisms are essential for converting proprotein precursors into active peptide neurotransmitters and hormones. Cysteine proteases have been implicated in the processing of proenkephalin and other neuropeptide precursors. Although the papain family of cysteine proteases has been considered the primary proteases of the lysosomal degradation pathway, more recent studies indicate that functions of these enzymes are linked to specific biological processes. However, few protein substrates have been described for members of this family. We show here that secretory vesicle cathepsin L is the responsible cysteine protease of chromaffin granules for converting proenkephalin to the active enkephalin peptide neurotransmitter. The cysteine protease activity was identified as cathepsin L by affinity labeling with an activity-based probe for cysteine proteases followed by mass spectrometry for peptide sequencing. Production of [Met]enkephalin by cathepsin L occurred by proteolytic processing at dibasic and monobasic prohormone-processing sites. Cellular studies showed the colocalization of cathepsin L with [Met]enkephalin in secretory vesicles of neuroendocrine chromaffin cells by immunofluorescent confocal and immunoelectron microscopy. Functional localization of cathepsin L to the regulated secretory pathway was demonstrated by its cosecretion with [Met]enkephalin. Finally, in cathepsin L gene knockout mice, [Met]enkephalin levels in brain were reduced significantly; this occurred with an increase in the relative amounts of enkephalin precursor. These findings indicate a previously uncharacterized biological role for secretory vesicle cathepsin L in the production of [Met]enkephalin, an endogenous peptide neurotransmitter. PMID:12869695

  13. Identification and cloning of a novel isoform of mouse secretory leukocyte protease inhibitor, mSLPI-beta, overexpressed in murine leukemias and a highly liver metastatic tumor, IMC-HA1 cells.

    PubMed

    Morita, M; Arakawa, H; Nishimura, S

    1999-01-01

    Several genes showing transcriptional alteration in a highly liver metastatic murine carcinoma cell line, IMC-HA1, were identified by mRNA differential display system. Among them, a gene identical to mSLPI was isolated as mSLPI-alpha and -beta. They were produced through an alternative splicing. Their full-length cDNA sequences were determined, and their expression in various murine tumors and normal tissues was analysed. The deduced translation product of mSLPI-alpha showed 59% identity to hSLPI. Although mSLPI-beta had the same 103-amino-acid sequence from the carboxyl terminus, the amino terminus showed hydrophilicity opposite mSLPI-alpha or hSLPI. The mSLPI-alpha was expressed ubiquitously in various tumor cell lines. Interestingly, however, mSLPI-beta expression was only observed in P388 and L1210 leukemias and IMC-HA1 cells, and in lower amounts in three normal tissues (thymus, lung and spleen), suggesting that mSLPI, and in particular the unusual splicing product, mSLPI-beta, plays a specific role in these cells, including malignant processes of tumor cells.

  14. Dissociable parietal systems for primacy and subsequent memory effects.

    PubMed

    Sommer, Tobias; Rose, Michael; Büchel, Christian

    2006-05-01

    The frequently observed superior memory for the first items on a list is referred to as primacy. The aetiology of this effect in terms of cognitive processes and their neural substrate is subject to an ongoing debate. However, the brain areas generally involved in successful encoding are well described by subsequent memory studies in which activity during encoding is correlated with memory performance. We employed an object-location association paradigm to differentiate the neural correlate of the primacy from the subsequent memory effect. Activity in the intraparietal sulcus predicted memory performance across all encoding positions. Increased activity in the inferior parietal lobe and angular gyrus resulted exclusively in a more efficient encoding of the first item presented. These areas are part of the ventral frontoparietal network involved in stimulus driven attention. Our results implicate the relatively elevated attention to the first item probably due to its contextual distinctiveness, as a major contributor to the primacy effect.

  15. [Parietal-scar endometriosis after cesarean section: a rare entity].

    PubMed

    El Fahssi, Mohammed; Lomdo, Massama; Bounaim, Ahmed; Ali, Abdelmounaim Ait; Sair, Khalid

    2016-01-01

    Wall endometriosis is a rare clinical entity whose pathophysiology remains unclear. It occurs most frequently after gynecologic or obstetric surgery. We report the case of a patient with cyclic pain at the caesarean section scar. Clinical examination showed a 5 cm mass in the right iliac fossa. Tomodensitometry revealed a tissue density mass (45mm on the major axis). Hence, the decision to perform a wide excision of the lesion. Anatomo-pathological examination confirmed the diagnosis of parietal endometriosis. Postoperative sequelae were simple with a follow-up period of 20 months with no recurrence of the mass or of the pain. Our study highlights the characteristics of this disease to allow the health practitioner to understand the importance of diagnosis, of early treatment of this disease as well as of the possibility to prevent it during each gynecologic or obstetric surgery. PMID:27642418

  16. Transient contribution of left posterior parietal cortex to cognitive restructuring

    PubMed Central

    Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

    2015-01-01

    Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring. PMID:25775998

  17. Sleep Related Hypermotor Seizures with a Right Parietal Onset.

    PubMed

    Gibbs, Steve A; Figorilli, Michela; Casaceli, Giuseppe; Proserpio, Paola; Nobili, Lino

    2015-08-01

    Nocturnal frontal lobe epilepsy (NFLE) is a syndrome characterized by the occurrence of sleep related seizures of variable complexity and duration. Hypermotor seizures (HMS) represent a classic manifestation of this syndrome, associated with a perturbation of the ventromesial frontal cortex and anterior cingulate gyrus regions. Nevertheless, in recent years, reports have showed that the seizure onset zone (SOZ) need not be of frontal origin to generate HMS. Here we report an unusual case of a patient presenting with a seven-year history of drug-resistant sleep related HMS arising from the mesial parietal region. The presence of an infrequent feeling of levitation before the HMS was key to suspecting a subtle focal cortical dysplasia in the right precuneus region. A stereo-EEG investigation confirmed the extra-frontal seizure onset of the HMS and highlighted the interrelationship between unstable sleep and seizure precipitation. PMID:25902821

  18. Herpes Simplex Encephalitis of the Parietal Lobe: A Rare Presentation

    PubMed Central

    Tkachenko, Lara; Moisi, Marc; Rostad, Steven; Umeh, Randle; Zwillman, Michael E; Tubbs, R. Shane; Page, Jeni; Newell, David W.; Delashaw, Johnny B

    2016-01-01

    A 69-year-old female with a history of breast cancer and hypertension presented with a rare case of herpes simplex encephalitis (HSE) isolated to her left parietal lobe. The patient’s first biopsy was negative for herpes simplex virus (HSV) I/II antigens, but less than two weeks later, the patient tested positive on repeat biopsy. This initial failure to detect the virus and the similarities between HSE and symptoms of intracranial hemorrhage (ICH) suggests repeat testing for HSV in the presence of ICH. Due to the frequency of patients with extra temporal HSE, a diagnosis of HSE should be more readily considered, particularly when a patient may not be improving and a concrete diagnosis has not been solidified. PMID:27774355

  19. A parietal memory network revealed by multiple MRI methods.

    PubMed

    Gilmore, Adrian W; Nelson, Steven M; McDermott, Kathleen B

    2015-09-01

    The manner by which the human brain learns and recognizes stimuli is a matter of ongoing investigation. Through examination of meta-analyses of task-based functional MRI and resting state functional connectivity MRI, we identified a novel network strongly related to learning and memory. Activity within this network at encoding predicts subsequent item memory, and at retrieval differs for recognized and unrecognized items. The direction of activity flips as a function of recent history: from deactivation for novel stimuli to activation for stimuli that are familiar due to recent exposure. We term this network the 'parietal memory network' (PMN) to reflect its broad involvement in human memory processing. We provide a preliminary framework for understanding the key functional properties of the network. PMID:26254740

  20. Diverse spatial reference frames of vestibular signals in parietal cortex

    PubMed Central

    Chen, Xiaodong; DeAngelis, Gregory C; Angelaki, Dora E

    2013-01-01

    Summary Reference frames are important for understanding how sensory cues from different modalities are coordinated to guide behavior, and the parietal cortex is critical to these functions. We compare reference frames of vestibular self-motion signals in the ventral intraparietal area (VIP), parietoinsular vestibular cortex (PIVC), and dorsal medial superior temporal area (MSTd). Vestibular heading tuning in VIP is invariant to changes in both eye and head positions, indicating a body (or world)-centered reference frame. Vestibular signals in PIVC have reference frames that are intermediate between head- and body-centered. In contrast, MSTd neurons show reference frames between head- and eye-centered, but not body-centered. Eye and head position gain fields were strongest in MSTd and weakest in PIVC. Our findings reveal distinct spatial reference frames for representing vestibular signals, and pose new challenges for understanding the respective roles of these areas in potentially diverse vestibular functions. PMID:24239126

  1. Scalp Medical Tattooing Technique to Camouflage Bifid Parietal Whorls

    PubMed Central

    You, Seung Hyun

    2016-01-01

    Background: To the best of the authors’ knowledge, no reports have described cosmetic problems arising from the hair direction around the parietal whorl (PW). This study was performed to evaluate the efficacy of scalp medical tattooing technique for camouflaging bifid PWs. Methods: We retrospectively examined the outcomes of scalp medical tattooing in 38 patients who were admitted for camouflage of a bifid PW. Results: All patients’ cosmetic appearance was judged, by both the patients and the surgeon, to be markedly improved. No specific complications occurred, such as infection, hair loss in the operative field, or other problems. Conclusion: Scalp medical tattooing appears to be an effective method that helps to camouflage the see-through appearance of bifid PWs. PMID:27200232

  2. Subcortical mapping of calculation processing in the right parietal lobe.

    PubMed

    Della Puppa, Alessandro; De Pellegrin, Serena; Lazzarini, Anna; Gioffrè, Giorgio; Rustemi, Oriela; Cagnin, Annachiara; Scienza, Renato; Semenza, Carlo

    2015-05-01

    Preservation of calculation processing in brain surgery is crucial for patients' quality of life. Over the last decade, surgical electrostimulation was used to identify and preserve the cortical areas involved in such processing. Conversely, subcortical connectivity among different areas implicated in this function remains unclear, and the role of surgery in this domain has not been explored so far. The authors present the first 2 cases in which the subcortical functional sites involved in calculation were identified during right parietal lobe surgery. Two patients affected by a glioma located in the right parietal lobe underwent surgery with the aid of MRI neuronavigation. No calculation deficits were detected during preoperative assessment. Cortical and subcortical mapping were performed using a bipolar stimulator. The current intensity was determined by progressively increasing the amplitude by 0.5-mA increments (from a baseline of 1 mA) until a sensorimotor response was elicited. Then, addition and multiplication calculation tasks were administered. Corticectomy was performed according to both the MRI neuronavigation data and the functional findings obtained through cortical mapping. Direct subcortical electrostimulation was repeatedly performed during tumor resection. Subcortical functional sites for multiplication and addition were detected in both patients. Electrostimulation interfered with calculation processing during cortical mapping as well. Functional sites were spared during tumor removal. The postoperative course was uneventful, and calculation processing was preserved. Postoperative MRI showed complete resection of the tumor. The present preliminary study shows for the first time how functional mapping can be a promising method to intraoperatively identify the subcortical functional sites involved in calculation processing. This report therefore supports direct electrical stimulation as a promising tool to improve the current knowledge on

  3. Transport and quality control of MHC class I molecules in the early secretory pathway.

    PubMed

    Springer, Sebastian

    2015-06-01

    Folding and peptide binding of major histocompatibility complex (MHC) class I molecules have been thoroughly researched, but the mechanistic connection between these biochemical events and the progress of class I through the early secretory pathway is much less well understood. This review focuses on the question how the partially assembled forms of class I (which lack high-affinity peptide and/or the light chain beta-2 microglobulin) are retained inside the cell. Such investigations offer researchers exciting chances to understand the connections between class I structure, conformational dynamics, peptide binding kinetics and thermodynamics, intracellular transport, and antigen presentation.

  4. Tracheal and bronchial polymeric immunoglobulin secretory immune system (PISIS) development in a porcine model.

    PubMed

    Guzman-Bautista, E R; Ramirez-Estudillo, M C; Rojas-Gomez, O I; Vega-Lopez, M A

    2015-12-01

    Polymeric immunoglobulins (pIgs) mucosal secretion is mediated by the pIg secretory immune system (PISIS), which is composed of J-chain (JC) and antibody (IgM/IgA) producing cells (JC-AbPC), pIg receptor (pIgR) epithelial cell expression and the efficient release of secretory Igs (SIgs) to the mucosal lumen. A poor development or disturbances in this system may cause higher infection susceptibility, as observed in young and elderly people. In spite of this system's importance, few detailed studies regarding its development have been described in the lower respiratory tract of humans. Because the porcine model has been reported as an option for translational medicine to humans, we studied the tracheal and bronchial PISIS development in healthy, non-vaccinated, SPF, miniature Vietnamese pigs from birth to adulthood using immunohistochemistry and ELISAs. Our results demonstrated that pIgR was present at birth, and its expression increased with age. In contrast, JC-AbPC were low in neonatal pigs; however, colostrum was a source of IgM, SIgA, total IgA and IgG in respiratory secretions (trachea and bronchoalveolar lavages, nasal secretion and saliva) in piglets. JC-AbPC steadily increased in post-weaned, young and adult pigs, correlating with considerable increases in secretory and total Igs in the trachea and bronchi. These data suggest a compensatory role of maternal Igs at the respiratory mucosa in the absence of a structured PISIS before weaning. Furthermore, monomeric Igs (IgG and IgA) may also play an important role in respiratory protection and deserves a more thorough study. PMID:26188097

  5. Stimulus-secretion coupling in the developing exocrine pancreas: secretory responsiveness to cholecystokinin

    PubMed Central

    1986-01-01

    We have studied the onset of secretory responsiveness to cholecystokinin (CCK) during development of the rat exocrine pancreas. Although acinar cells of the fetal pancreas (1 d before birth) are filled with zymogen granules containing the secretory protein, alpha- amylase, the rate of amylase secretion from pancreatic lobules incubated in vitro was not increased in response to CCK. In contrast, the rate of CCK-stimulated amylase discharge from the neonatal pancreas (1 d after birth) was increased four- to eightfold above that of the fetal gland. The postnatal amplification of secretory responsiveness was not associated with an increase in the number or cell surface expression of 125I-CCK binding sites. When 125I-CCK-33 binding proteins were analyzed by affinity crosslinking, two proteins of Mr 210,000 and 100,000-160,000 were labeled specifically in both fetal and neonatal pancreas. To determine if cell surface receptors for CCK in the fetal pancreas are functional and able to generate a rise in the cytosolic [Ca++], we measured 45Ca++ efflux from tracer-loaded lobules. 45Ca++ efflux from both fetal and neonatal pancreas was comparably increased by CCK, indicating CCK-induced Ca++ mobilization and elevated cytosolic [Ca++]. The Ca++ ionophore A23187 also stimulated the rate of 45Ca++ extrusion from pancreas of both ages. Increased amylase secretion occurred concurrently with A23187-stimulated 45Ca++ efflux in neonatal pancreas, but not in the fetal gland. A23187 in combination with dibutyryl cAMP potentiated amylase release from the neonatal gland, but not from fetal pancreas. Similarly, the protein kinase C activator, phorbol dibutyrate, did not increase the rate of secretion from the fetal gland when added alone or in combination with A23187 or CCK. We suggest that CCK-receptor interaction in the fetal pancreas triggers intracellular Ca++ mobilization. However, one or more signal transduction events distal to Ca++ mobilization have not yet matured. The onset of

  6. The Role of Right and Left Parietal Lobes in the Conceptual Processing of Numbers

    ERIC Educational Resources Information Center

    Cappelletti, Marinella; Lee, Hwee Ling; Freeman, Elliot D.; Price, Cathy J.

    2010-01-01

    Neuropsychological and functional imaging studies have associated the conceptual processing of numbers with bilateral parietal regions (including intraparietal sulcus). However, the processes driving these effects remain unclear because both left and right posterior parietal regions are activated by many other conceptual, perceptual, attention,…

  7. The Contribution of the Inferior Parietal Cortex to Spoken Language Production

    ERIC Educational Resources Information Center

    Geranmayeh, Fatemeh; Brownsett, Sonia L. E.; Leech, Robert; Beckmann, Christian F.; Woodhead, Zoe; Wise, Richard J. S.

    2012-01-01

    This functional MRI study investigated the involvement of the left inferior parietal cortex (IPC) in spoken language production (Speech). Its role has been apparent in some studies but not others, and is not convincingly supported by clinical studies as they rarely include cases with lesions confined to the parietal lobe. We compared Speech with…

  8. Differences in biomechanical properties and thickness among frontal and parietal bones in a Japanese sample.

    PubMed

    Torimitsu, Suguru; Nishida, Yoshifumi; Takano, Tachio; Yajima, Daisuke; Inokuchi, Go; Makino, Yohsuke; Motomura, Ayumi; Chiba, Fumiko; Yamaguchi, Rutsuko; Hashimoto, Mari; Hoshioka, Yumi; Iwase, Hirotaro

    2015-07-01

    The aim of this study was to assess the mechanical properties and thickness of adult frontal and parietal bones. The heads of 114 Japanese cadavers (78 male cadavers and 36 female cadavers) of known age and sex were used. A total of 912 cranial samples, 8 from each skull, were collected. Samples were imaged using multidetector computed tomography to measure sample thickness. The fracture load of each sample was measured using a bending test with calculation of flexural strength. Statistical analyses demonstrated no significant bilateral difference in either the mechanical properties or thickness of frontal or parietal bones. The mechanical properties and thicknesses of frontal bones were significantly greater than those of parietal bones regardless of sex. Therefore, the skull may have a great ability to resist frontal impacts compared with parietal impacts. In female samples, parietal bones were found to have a more uniform structure when compared with male samples. Male parietal bones were found to be thicker at medial sites than at lateral sites. This study also revealed parietal bones at lateral sites in female samples were thicker than in male samples. No strong association was observed between age and flexural strength of frontal or parietal bones. However, the fracture load was negatively correlated with age most likely due to the reduction of thickness.

  9. Clinical applications of the radioimmunoassay of secretory tuberculoprotein.

    PubMed Central

    Straus, E; Wu, N; Quraishi, M A; Levine, S

    1981-01-01

    A radioimmunoassay that measures a specific secretory tuberculoprotein was used to detect Mycobacterium tuberculosis in 9 of 30 liquid cultures of sputum. The accumulation of immunoreactive material in liquid cultures containing isoniazid was shown to reflect in vitro susceptibility of mycobacteria to the antibiotic effects of the drug. PMID:6789332

  10. Separation of rat pituitary secretory granules by continuous flow electrophoresis

    NASA Technical Reports Server (NTRS)

    Hayes, Daniel; Exton, Carrie; Salada, Thomas; Shellenberger, Kathy; Waddle, Jenny; Hymer, W. C.

    1990-01-01

    The separation of growth hormone-containing cytoplasmic secretory granules from the rat pituitary gland by continuous flow electrophoresis is described. The results are consistent with the hypothesis that granule subpopulations can be separated due to differences in surface charge; these, in turn, may be related to the oligomeric state of the hormone.

  11. Medical management of secretory syndromes related to gastroenteropancreatic neuroendocrine tumours.

    PubMed

    Dimitriadis, Georgios K; Weickert, Martin O; Randeva, Harpal S; Kaltsas, Gregory; Grossman, Ashley

    2016-09-01

    Although recent epidemiological evidence indicates that the prevalence of non-functioning gastroenteropancreatic (GEP) neuroendocrine tumours (NETs) is rising, a significant number of GEP-NETs still present with symptoms related to the secretion of biologically active substances leading to the development of distinct clinical syndromes. In the past, these syndromes were associated with substantial morbidity and mortality due to the lack of specific therapies; however, since the introduction of long-acting somatostatin analogues and medications such as proton pump inhibitors, their control has been greatly improved. As a result, nowadays, the main cause of morbidity and mortality in GEP-NETs is mostly directly related to tumour growth and the extent of metastatic disease. However, in some patients with functioning tumours and extensive disease, control of the secretory syndrome still remains problematic, necessitating the employment of several cytoreductive techniques, which may not always be sufficient. Recently, new agents directed against tumour growth, or exerting increased binding activity to receptors expressed in these tumours, or interfering with the synthetic pathway of some of the compounds secreted by these tumours, have been developed. Since there are no specific guidelines addressing the totality of the management of the secretory syndromes related to GEP-NETs, this review aims at critically analysing the medical management of previously recognised secretory syndromes; it also addresses areas of uncertainty, assesses the newer therapeutic developments and also addresses recently described but poorly characterised secretory syndromes related to GEP-NETs. PMID:27461388

  12. Utility of mammaglobin immunohistochemistry as a proxy marker for the ETV6-NTRK3 translocation in the diagnosis of salivary mammary analogue secretory carcinoma.

    PubMed

    Bishop, Justin A; Yonescu, Raluca; Batista, Denise; Begum, Shahnaz; Eisele, David W; Westra, William H

    2013-10-01

    Mammary analogue secretory carcinoma is a recently described salivary gland neoplasm defined by ETV6-NTRK3 gene fusion. Mammary analogue secretory carcinoma's morphology is not entirely specific and overlaps with other salivary gland tumors. Documenting ETV6 rearrangement is confirmatory, but most laboratories are not equipped to perform this test. As mammary analogue secretory carcinomas are positive for mammaglobin, immunohistochemistry could potentially replace molecular testing as a confirmatory test, but the specificity of mammaglobin has not been evaluated across a large and diverse group of salivary gland tumors. One hundred thirty-one salivary gland neoplasms were evaluated by routine microscopy, mammaglobin immunohistochemistry, and ETV6 break-apart fluorescent in situ hybridization. The cases included 15 mammary analogue secretory carcinomas, 44 adenoid cystic carcinomas, 33 pleomorphic adenomas, 18 mucoepidermoid carcinomas, 10 acinic cell carcinomas, 4 adenocarcinomas not otherwise specified, 3 polymorphous low-grade adenocarcinomas, 3 salivary duct carcinomas, and 1 low-grade cribriform cystadenocarcinoma. All 15 mammary analogue secretory carcinomas harbored the ETV6 translocation and were strongly mammaglobin positive. None of the 116 other tumors carried the ETV6 translocation; however, mammaglobin staining was present in 1 (100%) of 1 low-grade cribriform cystadenocarcinoma, 2 (67%) of 3 polymorphous low-grade adenocarcinomas, 2 (67%) of 3 salivary duct carcinomas, 2 (11%) of 18 mucoepidermoid carcinomas, and 2 (6%) of 33 pleomorphic adenomas. Mammaglobin is highly sensitive for mammary analogue secretory carcinoma, but immunostaining can occur in a variety of tumors that do not harbor the ETV6 translocation. Strategic use of mammaglobin immunostaining has a role in the differential diagnosis of salivary gland neoplasms, but it should not be indiscriminately used as a confirmatory test for mammary analogue secretory carcinoma.

  13. Chrysotile and tremolite asbestos fibres in the lungs and parietal pleura of Corsican goats

    PubMed Central

    Dumortier, P; Rey, F; Viallat, J; Broucke, I; Boutin, C; De Vuyst, P

    2002-01-01

    Methods: Ten goats from areas with asbestos outcrops and two from other areas were slaughtered. Fibre content of lung and parietal pleural samples was determined by analytical transmission electron microscopy. Results: Both chrysotile and tremolite fibres were detected. In the exposed goats, the geometric mean concentrations of asbestos fibres longer than 1 µm were 0.27 x 106 fibres/g dry lung tissue and 1.8 x 106 fibres/g dry pleural tissue. Asbestos fibres were not detected in the lungs of the two control goats. Chrysotile fibres shorter than 5 µm were predominant in the parietal pleura. Tremolite fibres accounted for 78% and 86% of the fibres longer than 5 µm in lung and parietal pleural samples, respectively. Conclusions: Environmental exposure in northeast Corsica results in detectable chrysotile and tremolite fibre loads in the lung and parietal pleura of adult goats. Tremolite fibres of dimensions with a high carcinogenic potency are detected in the parietal pleura. PMID:12205241

  14. Dissociable Temporo-Parietal Memory Networks Revealed by Functional Connectivity during Episodic Retrieval

    PubMed Central

    Hirose, Satoshi; Kimura, Hiroko M.; Jimura, Koji; Kunimatsu, Akira; Abe, Osamu; Ohtomo, Kuni; Miyashita, Yasushi; Konishi, Seiki

    2013-01-01

    Episodic memory retrieval most often recruits multiple separate processes that are thought to involve different temporal regions. Previous studies suggest dissociable regions in the left lateral parietal cortex that are associated with the retrieval processes. Moreover, studies using resting-state functional connectivity (RSFC) have provided evidence for the temporo-parietal memory networks that may support the retrieval processes. In this functional MRI study, we tested functional significance of the memory networks by examining functional connectivity of brain activity during episodic retrieval in the temporal and parietal regions of the memory networks. Recency judgments, judgments of the temporal order of past events, can be achieved by at least two retrieval processes, relational and item-based. Neuroimaging results revealed several temporal and parietal activations associated with relational/item-based recency judgments. Significant RSFC was observed between one parahippocampal region and one left lateral parietal region associated with relational recency judgments, and between four lateral temporal regions and another left lateral parietal region associated with item-based recency judgments. Functional connectivity during task was found to be significant between the parahippocampal region and the parietal region in the RSFC network associated with relational recency judgments. However, out of the four tempo-parietal RSFC networks associated with item-based recency judgments, only one of them (between the left posterior lateral temporal region and the left lateral parietal region) showed significant functional connectivity during task. These results highlight the contrasting roles of the parahippocampal and the lateral temporal regions in recency judgments, and suggest that only a part of the tempo-parietal RSFC networks are recruited to support particular retrieval processes. PMID:24009657

  15. SLAH3-type anion channel expressed in poplar secretory epithelia operates in calcium kinase CPK-autonomous manner.

    PubMed

    Jaborsky, Mario; Maierhofer, Tobias; Olbrich, Andrea; Escalante-Pérez, María; Müller, Heike M; Simon, Judy; Krol, Elzbieta; Cuin, Tracey Ann; Fromm, Jörg; Ache, Peter; Geiger, Dietmar; Hedrich, Rainer

    2016-05-01

    Extrafloral nectaries secrete a sweet sugar cocktail that lures predator insects for protection from foraging herbivores. Apart from sugars and amino acids, the nectar contains the anions chloride and nitrate. Recent studies with Populus have identified a type of nectary covered by apical bipolar epidermal cells, reminiscent of the secretory brush border epithelium in animals. Border epithelia operate transepithelial anion transport, which is required for membrane potential and/or osmotic adjustment of the secretory cells. In search of anion transporters expressed in extrafloral nectaries, we identified PttSLAH3 (Populus tremula × Populus tremuloides SLAC1 Homologue3), an anion channel of the SLAC/SLAH family. When expressed in Xenopus oocytes, PttSLAH3 displayed the features of a voltage-dependent anion channel, permeable to both nitrate and chloride. In contrast to the Arabidopsis SLAC/SLAH family members, the poplar isoform PttSLAH3 is independent of phosphorylation activation by protein kinases. To understand the basis for the autonomous activity of the poplar SLAH3, we generated and expressed chimera between kinase-independent PttSLAH3 and kinase-dependent Arabidopsis AtSLAH3. We identified the N-terminal tail and, to a lesser extent, the C-terminal tail as responsible for PttSLAH3 kinase-(in)dependent action. This feature of PttSLAH3 may provide the secretory cell with a channel probably controlling long-term nectar secretion. PMID:26831448

  16. DHRSX, a novel non-classical secretory protein associated with starvation induced autophagy.

    PubMed

    Zhang, Guoying; Luo, Yang; Li, Ge; Wang, Lanlan; Na, Daxiang; Wu, Xiaotong; Zhang, Yingmei; Mo, Xiaoning; Wang, Lu

    2014-01-01

    Dehydrogenase/reductase (SDR family) X-linked (DHRSX) is a novel human gene without any substantial functional annotation and was initially cloned and identified in our laboratory. In this study, we present evidence that it encodes a non-classical secretory protein and promotes starvation induced autophagy. Using the Baf.A1 assay and N-terminal sequencing, we showed that DHRSX is secreted in a non-classical form. We expressed and purified a recombinant human GST-DHRSX fusion protein. Functional studies revealed that HeLa and U2OS cells overexpressing DHRSX or treated with the GST-DHRSX fusion protein exhibited higher levels of starvation-induced autophagy, resulting in increased endogenous LC3-II levels, a punctate GFP-LC3 distribution, and structures associated with autophagy, with a lower accumulation of autophagy substrates such as p62 and polyQ80. Accordingly, knockdown of endogenous DHRSX through specific siRNAs reduced LC3-II levels obviously in U2OS cells induced by starvation. Collectively, these results demonstrate that DHRSX is a novel non-classical secretory protein involved in the positive regulation of starvation induced autophagy and provide a new avenue for research on this protein family and autophagy regulation.

  17. Short-term memory deficit after focal parietal damage.

    PubMed

    Markowitsch, H J; Kalbe, E; Kessler, J; von Stockhausen, H M; Ghaemi, M; Heiss, W D

    1999-12-01

    The neuropsychological symptomatology is reported for a 44-year-old patient of normal intelligence, EE, after removal of a circumscribed left hemispheric tumor the major part of which was located in the angular gyrus and in the subcortical white matter. EE had a distinct and persistent short-term memory impairment together with an equally severe impairment in transcoding numbers. On the other hand, his performance was flawless in calculation tasks and in all other tests involving number processing. Impairments in language tests could be attributed to his short-term memory deficit, which furthermore was characterized by a strong primacy effect in the absence of a recency effect. His graphomotoric output was temporarily inhibited. The patient, with a strong left-sided dominance, manifested a bi-hemispherical activation of the Broca and Wernicke regions in a positron-emission-tomographic investigation when required to produce verbs which he was to derive from nouns. The findings in EE suggest that unilateral and restricted lateral parietal damage can result in a profound short-term memory deficit together with a transcoding deficit for stimuli extending over only a few digits or syllables in the absence of any symptoms of the Gerstmann syndrome.

  18. Spatial invariance of visual receptive fields in parietal cortex neurons.

    PubMed

    Duhamel, J R; Bremmer, F; Ben Hamed, S; Graf, W

    1997-10-23

    Spatial information is conveyed to the primary visual cortex in retinal coordinates. Movement trajectory programming, however, requires a transformation from this sensory frame of reference into a frame appropriate for the selected part of the body, such as the eye, head or arms. To achieve this transformation, visual information must be combined with information from other sources: for instance, the location of an object of interest can be defined with respect to the observer's head if the position of the eyes in the orbit is known and is added to the object's retinal coordinates. Here we show that in a subdivision of the monkey parietal lobe, the ventral intraparietal area (VIP), the activity of visual neurons is modulated by eye-position signals, as in many other areas of the cortical visual system. We find that individual receptive fields of a population of VIP neurons are organized along a continuum, from eye to head coordinates. In the latter case, neurons encode the azimuth and/or elevation of a visual stimulus, independently of the direction in which the eyes are looking, thus representing spatial locations explicitly in at least a head-centred frame of reference. PMID:9349815

  19. Contralesional neglect in monkeys with small unilateral parietal cortical ablations.

    PubMed

    Marshall, J W B; Baker, H F; Ridley, R M

    2002-10-17

    Transient contralesional spatial neglect, in addition to motor impairment in the contralesional arm, is sometimes seen in patients following cerebral infarction in the right hemisphere and is seen following experimental occlusion of the right middle cerebral artery in primates. To test whether contralesional visuospatial neglect arises from a disruption of the forward flow of information from the striate cortex through the dorsal territory of the middle cerebral artery, we made a small strip suction ablation in the right parietal cortex from the medial edge of the dorsal cortical surface to the posterior ventral edge of the superior temporal gyrus in marmoset monkeys. These monkeys did not exhibit a motor impairment, or misreaching, with the contralesional arm. When they were unrestrained and free to use either arm, they were impaired at finding rewards in their contralesional space and in choosing the nearer of two rewards hidden in ipsilesional space (i.e. they had an ultra-ipsilesional bias in ipsilesional space). Comparison of performance under four conditions in a task in which the monkeys were constrained to reach into each hemispace with each arm separately indicated that they were impaired at reaching into contralesional, but not ipsilesional, space with either arm but they did not exhibit any impairment confined to the contralesional arm. These impairments in contralesional space were transient suggesting that the monkeys were able to re-align their egocentric spatial coordinates to obviate these deficits.

  20. TMS of posterior parietal cortex disrupts visual tactile multisensory integration

    PubMed Central

    Pasalar, Siavash; Ro, Tony; Beauchamp, Michael S.

    2010-01-01

    Functional neuroimaging studies have implicated a number of brain regions, especially the posterior parietal cortex (PPC), as being potentially important for visual–tactile multisensory integration. However, neuroimaging studies are correlational and do not prove the necessity of a region for the behavioral improvements that are the hallmark of multisensory integration. To remedy this knowledge gap, we interrupted activity in the PPC, near the junction of the anterior intraparietal sulcus and the postcentral sulcus, using MRI-guided transcranial magnetic stimulation (TMS) while subjects localized touches delivered to different fingers. As the touches were delivered, subjects viewed a congruent touch video, an incongruent touch video, or no video. Without TMS, a strong effect of multisensory integration was observed, with significantly better behavioral performance for discrimination of congruent multisensory touch than for unisensory touch alone. Incongruent multisensory touch produced a smaller improvement in behavioral performance. TMS of the PPC eliminated the behavioral advantage of both congruent and incongruent multisensory stimuli, reducing performance to unisensory levels. These results demonstrate a causal role for the PPC in visual–tactile multisensory integration. Taken together with converging evidence from other studies, these results support a model in which the PPC contains a map of space around the hand that receives input from both the visual and somatosensory modalities. Activity in this map is likely to be the neural substrate for visual–tactile multisensory integration. PMID:20584182

  1. Time Adaptation Shows Duration Selectivity in the Human Parietal Cortex.

    PubMed

    Hayashi, Masamichi J; Ditye, Thomas; Harada, Tokiko; Hashiguchi, Maho; Sadato, Norihiro; Carlson, Synnöve; Walsh, Vincent; Kanai, Ryota

    2015-01-01

    Although psychological and computational models of time estimation have postulated the existence of neural representations tuned for specific durations, empirical evidence of this notion has been lacking. Here, using a functional magnetic resonance imaging (fMRI) adaptation paradigm, we show that the inferior parietal lobule (IPL) (corresponding to the supramarginal gyrus) exhibited reduction in neural activity due to adaptation when a visual stimulus of the same duration was repeatedly presented. Adaptation was strongest when stimuli of identical durations were repeated, and it gradually decreased as the difference between the reference and test durations increased. This tuning property generalized across a broad range of durations, indicating the presence of general time-representation mechanisms in the IPL. Furthermore, adaptation was observed irrespective of the subject's attention to time. Repetition of a nontemporal aspect of the stimulus (i.e., shape) did not produce neural adaptation in the IPL. These results provide neural evidence for duration-tuned representations in the human brain. PMID:26378440

  2. Time Adaptation Shows Duration Selectivity in the Human Parietal Cortex

    PubMed Centr