LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 3 of total 3

Search options

  1. Article ; Online: Channels and Transporters of the Pulmonary Lamellar Body in Health and Disease

    Paul Dietl / Manfred Frick

    Cells, Vol 11, Iss 45, p

    2022  Volume 45

    Abstract: The lamellar body (LB) of the alveolar type II (ATII) cell is a lysosome-related organelle (LRO) that contains surfactant, a complex mix of mainly lipids and specific surfactant proteins. The major function of surfactant in the lung is the reduction of ... ...

    Abstract The lamellar body (LB) of the alveolar type II (ATII) cell is a lysosome-related organelle (LRO) that contains surfactant, a complex mix of mainly lipids and specific surfactant proteins. The major function of surfactant in the lung is the reduction of surface tension and stabilization of alveoli during respiration. Its lack or deficiency may cause various forms of respiratory distress syndrome (RDS). Surfactant is also part of the innate immune system in the lung, defending the organism against air-borne pathogens. The limiting (organelle) membrane that encloses the LB contains various transporters that are in part responsible for translocating lipids and other organic material into the LB. On the other hand, this membrane contains ion transporters and channels that maintain a specific internal ion composition including the acidic pH of about 5. Furthermore, P2X 4 receptors, ligand gated ion channels of the danger signal ATP, are expressed in the limiting LB membrane. They play a role in boosting surfactant secretion and fluid clearance. In this review, we discuss the functions of these transporting pathways of the LB, including possible roles in disease and as therapeutic targets, including viral infections such as SARS-CoV-2.
    Keywords lysosome related organelle (LRO) ; surfactant ; alveolus ; exocytosis ; purinergic signaling ; ivermectin ; Biology (General) ; QH301-705.5
    Subject code 572
    Language English
    Publishing date 2022-12-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  2. Article ; Online: IL-13 Impairs Tight Junctions in Airway Epithelia

    Hanna Schmidt / Peter Braubach / Carolin Schilpp / Robin Lochbaum / Kathrin Neuland / Kristin Thompson / Danny Jonigk / Manfred Frick / Paul Dietl / Oliver H. Wittekindt

    International Journal of Molecular Sciences, Vol 20, Iss 13, p

    2019  Volume 3222

    Abstract: Interleukin-13 (IL-13) drives symptoms in asthma with high levels of T-helper type 2 cells (T h 2-cells). Since tight junctions (TJ) constitute the epithelial diffusion barrier, we investigated the effect of IL-13 on TJ in human tracheal epithelial cells. ...

    Abstract Interleukin-13 (IL-13) drives symptoms in asthma with high levels of T-helper type 2 cells (T h 2-cells). Since tight junctions (TJ) constitute the epithelial diffusion barrier, we investigated the effect of IL-13 on TJ in human tracheal epithelial cells. We observed that IL-13 increases paracellular permeability, changes claudin expression pattern and induces intracellular aggregation of the TJ proteins zonlua occludens protein 1, as well as claudins. Furthermore, IL-13 treatment increases expression of ubiquitin conjugating E2 enzyme UBE2Z. Co-localization and proximity ligation assays further showed that ubiquitin and the proteasomal marker PSMA5 co-localize with TJ proteins in IL-13 treated cells, showing that TJ proteins are ubiquitinated following IL-13 exposure. UBE2Z upregulation occurs within the first day after IL-13 exposure. Proteasomal aggregation of ubiquitinated TJ proteins starts three days after IL-13 exposure and transepithelial electrical resistance (TEER) decrease follows the time course of TJ-protein aggregation. Inhibition of JAK/STAT signaling abolishes IL-13 induced effects. Our data suggest that that IL-13 induces ubiquitination and proteasomal aggregation of TJ proteins via JAK/STAT dependent expression of UBE2Z, resulting in opening of TJs. This may contribute to barrier disturbances in pulmonary epithelia and lung damage of patients with inflammatory lung diseases.
    Keywords lung ; epithelia ; interleukin 13 ; tight junction ; UBE2Z ; ubiquitin ; Biology (General) ; QH301-705.5 ; Chemistry ; QD1-999
    Language English
    Publishing date 2019-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

  3. Article ; Online: Fusion-activated Ca(2+) entry

    Pika Miklavc / Manfred Frick / Oliver H Wittekindt / Thomas Haller / Paul Dietl

    PLoS ONE, Vol 5, Iss 6, p e

    an "active zone" of elevated Ca(2+) during the postfusion stage of lamellar body exocytosis in rat type II pneumocytes.

    2010  Volume 10982

    Abstract: Ca(2+) is essential for vesicle fusion with the plasma membrane in virtually all types of regulated exocytoses. However, in contrast to the well-known effects of a high cytoplasmic Ca(2+) concentration ([Ca(2+)](c)) in the prefusion phase, the occurrence ...

    Abstract Ca(2+) is essential for vesicle fusion with the plasma membrane in virtually all types of regulated exocytoses. However, in contrast to the well-known effects of a high cytoplasmic Ca(2+) concentration ([Ca(2+)](c)) in the prefusion phase, the occurrence and significance of Ca(2+) signals in the postfusion phase have not been described before.We studied isolated rat alveolar type II cells using previously developed imaging techniques. These cells release pulmonary surfactant, a complex of lipids and proteins, from secretory vesicles (lamellar bodies) in an exceptionally slow, Ca(2+)- and actin-dependent process. Measurements of fusion pore formation by darkfield scattered light intensity decrease or FM 1-43 fluorescence intensity increase were combined with analysis of [Ca(2+)](c) by ratiometric Fura-2 or Fluo-4 fluorescence measurements. We found that the majority of single lamellar body fusion events were followed by a transient (t(1/2) of decay = 3.2 s) rise of localized [Ca(2+)](c) originating at the site of lamellar body fusion. [Ca(2+)](c) increase followed with a delay of approximately 0.2-0.5 s (method-dependent) and in the majority of cases this signal propagated throughout the cell (at approximately 10 microm/s). Removal of Ca(2+) from, or addition of Ni(2+) to the extracellular solution, strongly inhibited these [Ca(2+)](c) transients, whereas Ca(2+) store depletion with thapsigargin had no effect. Actin-GFP fluorescence around fused LBs increased several seconds after the rise of [Ca(2+)](c). Both effects were reduced by the non-specific Ca(2+) channel blocker SKF96365.Fusion-activated Ca(2+)entry (FACE) is a new mechanism that leads to [Ca(2+)](c) transients at the site of vesicle fusion. Substantial evidence from this and previous studies indicates that fusion-activated Ca(2+) entry enhances localized surfactant release from type II cells, but it may also play a role for compensatory endocytosis and other cellular functions.
    Keywords Medicine ; R ; Science ; Q
    Subject code 500
    Language English
    Publishing date 2010-06-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    Full text online

    More links

    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top