-
Respiratory Care Aug 2007
Topics: Bodily Secretions; Chest Wall Oscillation; Drainage; Humans; Respiratory Therapy; United States
PubMed: 17650351
DOI: No ID Found -
Archives of Pathology & Laboratory... Apr 2005
Topics: Bodily Secretions; Humans; Male; Prostate
PubMed: 15794686
DOI: 10.5858/2005-129-543-NCA -
Islets May 2020Virus-mediated gene knockdown in intact pancreatic islets is technically challenging due to poor infection of the center of the islet. Because the cells that do not have...
Virus-mediated gene knockdown in intact pancreatic islets is technically challenging due to poor infection of the center of the islet. Because the cells that do not have knockdown have normal insulin secretion, measuring changes in insulin secretion after gene knockdown is challenging. We describe a method to monitor insulin secretion from only the beta cells with knockdown of a gene of interest in intact islets using a single lentivirus containing a guide RNA, a luciferase insulin secretion reporter and a dCas9-KRAB cassette. This method allows rapid and inexpensive monitoring of insulin secretion from only those beta cells with knockdown, circumventing the problem of incomplete islet infection.
Topics: Animals; Bodily Secretions; CRISPR-Associated Protein 9; CRISPR-Cas Systems; Gene Editing; Gene Knockdown Techniques; Insulin; Islets of Langerhans; Mice; RNA Interference
PubMed: 32579048
DOI: 10.1080/19382014.2020.1752072 -
Methods in Molecular Biology (Clifton,... 2024Bacterial protein secretion systems serve to translocate substrate proteins across up to three biological membranes, a task accomplished by hydrophobic,...
Bacterial protein secretion systems serve to translocate substrate proteins across up to three biological membranes, a task accomplished by hydrophobic, membrane-spanning macromolecular complexes. The overexpression, purification, and biochemical characterization of these complexes is often difficult, thus impeding progress in understading structure and function of these systems. Blue native (BN) polyacrylamide gel electrophoresis (PAGE) allows for the investigation of these transmembrane complexes right from their originating membranes, without the need of long preparative steps, and is amenable to the parallel characterization of a number of samples under near-native conditions. Here, we present protocols for sample preparation, one-dimensional BN PAGE and two-dimensional BN/SDS PAGE, as well as for downstream analysis by staining, immunoblotting, and mass spectrometry on the example of the type III secretion system encoded on Salmonella pathogenicity island 1.
Topics: Native Polyacrylamide Gel Electrophoresis; Bacterial Secretion Systems; Bodily Secretions; Cell Membrane; Electrophoresis, Gel, Two-Dimensional
PubMed: 37930539
DOI: 10.1007/978-1-0716-3445-5_22 -
Journal of Extracellular Vesicles Sep 2022Extracellular vesicle (EV) secretion enables cell-cell communication in multicellular organisms. During development, EV secretion and the specific loading of signalling...
Extracellular vesicle (EV) secretion enables cell-cell communication in multicellular organisms. During development, EV secretion and the specific loading of signalling factors in EVs contributes to organ development and tissue differentiation. Here, we present an in vivo model to study EV secretion using the fat body and the haemolymph of the fruit fly, Drosophila melanogaster. The system makes use of tissue-specific EV labelling and is amenable to genetic modification by RNAi. This allows the unique combination of microscopic visualisation of EVs in different organs and quantitative biochemical purification to study how EVs are generated within the cells and which factors regulate their secretion in vivo. Characterisation of the system revealed that secretion of EVs from the fat body is mainly regulated by Rab11 and Rab35, highlighting the importance of recycling Rab GTPase family members for EV secretion. We furthermore discovered a so far unknown function of Rab14 along with the kinesin Klp98A in EV biogenesis and secretion.
Topics: Animals; Bodily Secretions; Drosophila Proteins; Drosophila melanogaster; Endosomes; Extracellular Vesicles; Kinesins; Signal Transduction; rab GTP-Binding Proteins
PubMed: 36103151
DOI: 10.1002/jev2.12263 -
The Canadian Veterinary Journal = La... Jun 1965
Review
Topics: Animals; Bodily Secretions; Gonadotropins; Physiology
PubMed: 14319228
DOI: No ID Found -
Proceedings. Biological Sciences Jan 2014Mating rituals in the animal kingdom are often quite extraordinary, in particular when mating is traumatic. We here describe the exceptional traumatic mating behaviour...
Mating rituals in the animal kingdom are often quite extraordinary, in particular when mating is traumatic. We here describe the exceptional traumatic mating behaviour of the currently undescribed sea slug, Siphopteron sp. 1. Similar to four congeners, Siphopteron sp. 1 routinely exhibits traumatic secretion transfer through a stylet-like penis appendage. Contrary to previous descriptions, however, prostate secretions are injected centrally into the partner's forehead, representing, to our knowledge, the first-known instance of 'cephalo-traumatic secretion transfer'. We further provide a comparative quantification of within- and between-species variation in injection sites and derive a potential neurophysiological function of prostate secretions that are injected close to, or into, the central nervous system.
Topics: Animals; Bodily Secretions; Central Nervous System; Gastropoda; Hermaphroditic Organisms; Sexual Behavior, Animal; Species Specificity
PubMed: 24225459
DOI: 10.1098/rspb.2013.2424 -
Recent Progress in Hormone Research 1963
-
MSphere Dec 2020In yeast, many proteins are found in both the cytoplasmic and extracellular compartments, and consequently it can be difficult to distinguish nonconventional secretion...
In yeast, many proteins are found in both the cytoplasmic and extracellular compartments, and consequently it can be difficult to distinguish nonconventional secretion from cellular leakage. Therefore, we monitored the extracellular glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity of intact cells as a specific marker for nonconventional secretion. Extracellular GAPDH activity was proportional to the number of cells assayed, increased with incubation time, and was dependent on added substrates. Preincubation of intact cells with 100 μM dithiothreitol increased the reaction rate, consistent with increased access of the enzyme after reduction of cell wall disulfide cross-links. Such treatment did not increase cell permeability to propidium iodide, in contrast to effects of higher concentrations of reducing agents. An amine-specific membrane-impermeant biotinylation reagent specifically inactivated extracellular GAPDH. The enzyme was secreted again after a 30- to 60-min lag following the inactivation, and there was no concomitant increase in propidium iodide staining. There were about 4 × 10 active GAPDH molecules per cell at steady state, and secretion studies showed replenishment to that level 1 h after inactivation. These results establish conditions for specific quantitative assays of cell wall proteins in the absence of cytoplasmic leakage and for subsequent quantification of secretion rates in intact cells. Eukaryotic cells secrete many proteins, including many proteins that do not follow the classical secretion pathway. Among these, the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is unexpectedly found in the walls of yeasts and other fungi and in extracellular space in mammalian cell cultures. It is difficult to quantify extracellular GAPDH, because leakage of just a little of the very large amount of cytoplasmic enzyme can invalidate the determinations. We used enzymatic assays of intact cells while also maintaining membrane integrity. The results lead to estimates of the amount of extracellular enzyme and its rate of secretion to the wall in intact cells. Therefore, enzyme assays under controlled conditions can be used to investigate nonconventional secretion more generally.
Topics: Bodily Secretions; Cell Membrane Permeability; Cell Wall; Cytoplasm; Flow Cytometry; Glyceraldehyde-3-Phosphate Dehydrogenases; Saccharomyces cerevisiae
PubMed: 33328349
DOI: 10.1128/mSphere.01027-20 -
Methods in Cell Biology 2003Pheochromocytoma-derived cell lines such as PC12 cells maintain a differentiated neuroendocrine phenotype and have been widely used as a convenient model system for a... (Review)
Review
Pheochromocytoma-derived cell lines such as PC12 cells maintain a differentiated neuroendocrine phenotype and have been widely used as a convenient model system for a wide variety of cell biological studies on neurotrophin action, monoamine biogenesis, protein trafficking, and secretory vesicle dynamics. This chapter reviews a number of methods that are useful for studies of the regulated dense core vesicle secretory pathway. This includes protocols for maintaining cells and preserving their phenotype. A variety of assays are discussed for monitoring secretion in intact or permeable cells and in transfected cells. Specific methods for immunocytochemical studies in permeable cells are discussed. Finally, protocols for high-efficiency PC12 cell transfections and the isolation of stably transfected cell lines are provided.
Topics: Animals; Bodily Secretions; Cell Culture Techniques; Cells, Cultured; Cytosol; Immunohistochemistry; Models, Biological; Nerve Tissue Proteins; Neurons; Neurosecretory Systems; PC12 Cells; Rats
PubMed: 12884694
DOI: 10.1016/s0091-679x(03)01012-4