GPCR signaling is required for blood-brain barrier formation in drosophila.
AuthorsSchwabe T, Bainton RJ, Fetter RD, Heberlein U, Gaul U,
JournalCell
PubMed ID16213218
'The blood-brain barrier of Drosophila is established by surface glia, which ensheath the nerve cord and insulate it against the potassium-rich hemolymph by forming intercellular septate junctions. The mechanisms underlying the formation of this barrier remain obscure. Here, we show that the G protein-coupled receptor (GPCR) Moody, the G protein ... More
Versatile, high-resolution anterograde labeling of vagal efferent projections with dextran amines.
'None of the anterograde tracers used to label and investigate vagal preganglionic neurons projecting to the viscera has proved optimal for routine and extensive labeling of autonomic terminal fields. To identify an alternative tracer protocol, the present experiment evaluated whether dextran conjugates, which have produced superior results in the CNS, ... More
Lysine-fixable dye tracing of exocytosis shows F-actin coating is a step that follows granule fusion in pancreatic acinar cells.
AuthorsTurvey MR, Thorn P
JournalPflugers Arch
PubMed ID15103465
'Exocytosis, the fusion of a vesicle with the plasma membrane, involves a complex cascade of cellular events. We set out to develop a method to identify changes in the distribution of proteins associated with exocytotic events in secretory epithelial cells. Our model system, the mouse pancreatic acinar cell, contains many ... More
A role for phosphoinositide 3-kinase in the completion of macropinocytosis and phagocytosis by macrophages.
AuthorsAraki N, Johnson MT, Swanson JA
JournalJ Cell Biol
PubMed ID8947549
'Phosphoinositide 3-kinase (PI 3-kinase) has been implicated in growth factor signal transduction and vesicular membrane traffic. It is thought to mediate the earliest steps leading from ligation of cell surface receptors to increased cell surface ruffling. We show here that inhibitors of PI 3-kinase inhibit endocytosis in macrophages, not by ... More
Sorting of membrane and fluid at the apical pole of polarized Madin-Darby canine kidney cells.
AuthorsLeung SM, Ruiz WG, Apodaca G
JournalMol Biol Cell
PubMed ID10848634
'When fluid-phase markers are internalized from opposite poles of polarized Madin-Darby canine kidney cells, they accumulate in distinct apical and basolateral early endosomes before meeting in late endosomes. Recent evidence suggests that significant mixing of apically and basolaterally internalized membrane proteins occurs in specialized apical endosomal compartments, including the common ... More
Mapping mechanisms and charting the time course of premature cell senescence and apoptosis: lysosomal dysfunction and ganglioside accumulation in endothelial cells.
AuthorsPatschan S, Chen J, Gealekman O, Krupincza K, Wang M, Shu L, Shayman JA, Goligorsky MS,
JournalAm J Physiol Renal Physiol
PubMed ID17928415
'Endothelial cells subjected to glycated collagen I develop premature senescence within 3-5 days, as revealed by increased senescence-associated beta-galactosidase activity, decreased proliferation, and an increase in cell size. Here, we analyzed the time course and possible mechanisms of this process. Lysosomal integrity studies revealed a rapid collapse of pH gradient ... More
Electroporation loading of calcium-sensitive dyes into the CNS.
AuthorsBonnot A, Mentis GZ, Skoch J, O'Donovan MJ
JournalJ Neurophysiol
PubMed ID15509647
'Calcium imaging of neural network function has been limited by the extent of tissue labeled or the time taken for labeling. We now describe the use of electroporation-an established technique for transfecting cells with genes-to load neurons with calcium-sensitive dyes in the isolated spinal cord of the neonatal mouse in ... More
Different fates of phagocytosed particles after delivery into macrophage lysosomes.
AuthorsOh YK, Swanson JA
JournalJ Cell Biol
PubMed ID8647890
'Phagocytosis in macrophages is often studied using inert polymer microspheres. An implicit assumption in these studies is that such particles contain little or no specific information in their structure that affects their intracellular fate. We tested that assumption by examining macrophage phagosomes containing different kinds of particles and found that ... More
Cell-specific induction of apoptosis by microinjection of cytochrome c. Bcl-xL has activity independent of cytochrome c release.
AuthorsLi F, Srinivasan A, Wang Y, Armstrong RC, Tomaselli KJ, Fritz LC
JournalJ Biol Chem
PubMed ID9374516
'Bcl-xL, an antiapoptotic member of the Bcl-2 family, inhibits programmed cell death in a broad variety of cell types. Recent reports have demonstrated that cytochrome c is released from mitochondria during apoptosis and have suggested that this release may be a critical step in the activation of proapoptotic caspases and ... More
In vivo diffusion analysis with quantum dots and dextrans predicts the width of brain extracellular space.
AuthorsThorne RG, Nicholson C
JournalProc Natl Acad Sci U S A
PubMed ID16567637
'Diffusion within the extracellular space (ECS) of the brain is necessary for chemical signaling and for neurons and glia to access nutrients and therapeutics; however, the width of the ECS in living tissue remains unknown. We used integrative optical imaging to show that dextrans and water-soluble quantum dots with Stokes-Einstein ... More
Hepatitis C virus glycoprotein complex localization in the endoplasmic reticulum involves a determinant for retention and not retrieval.
AuthorsDuvet S, Cocquerel L, Pillez A, Cacan R, Verbert A, Moradpour D, Wychowski C, Dubuisson J
JournalJ Biol Chem
PubMed ID9822684
'The hepatitis C virus (HCV) genome encodes two envelope glycoproteins (E1 and E2). These glycoproteins interact to form a noncovalent heterodimeric complex which in the cell accumulates in endoplasmic reticulum (ER)-like structures. The transmembrane domain of E2, at least, is involved in HCV glycoprotein complex localization in this compartment. In ... More
Endotoxin priming of neutrophils requires endocytosis and NADPH oxidase-dependent endosomal reactive oxygen species.
NADPH oxidase 2 (Nox2)-generated reactive oxygen species (ROS) are critical for neutrophil (polymorphonuclear leukocyte (PMN)) microbicidal function. Nox2 also plays a role in intracellular signaling, but the site of oxidase assembly is unknown. It has been proposed to occur on secondary granules. We previously demonstrated that intracellular NADPH oxidase-derived ROS ... More
Distribution and dynamics of Lamp1-containing endocytic organelles in fibroblasts deficient in BLOC-3.
Late endosomes and lysosomes of mammalian cells in interphase tend to concentrate in the perinuclear region that harbors the microtubule-organizing center. We have previously reported abnormal distribution of these organelles - as judged by reduced percentages of cells displaying pronounced perinuclear accumulation - in mutant fibroblasts lacking BLOC-3 (for ;biogenesis ... More
The parasitophorous vacuole membrane surrounding intracellular Toxoplasma gondii functions as a molecular sieve.
AuthorsSchwab JC, Beckers CJ, Joiner KA
JournalProc Natl Acad Sci U S A
PubMed ID8290555
The obligate intracellular protozoan parasite Toxoplasma gondii creates and enters into a unique membrane-bounded cytoplasmic compartment, the parasitophorous vacuole, when invading mammalian host cells. By microinjecting polar fluorescent molecules into individual T. gondii-infected fibroblasts, we show here that the parasitophorous vacuole membrane (PVM) surrounding the parasite functions as a molecular ... More
A fate map for the 32-cell stage of Rana pipiens.
AuthorsSaint-Jeannet JP, Dawid IB
JournalDev Biol
PubMed ID7813792
A fate map of the progeny derived from all blastomeres of the 32-cell stage embryo of the leopard frog Rana pipiens has been generated. Embryos presenting regular cleavages were injected into two pairs of blastomeres with fluorescein- and Texas red-lysine dextran. By stage 21, embryos were sectioned and the tissue ... More
Fluorescent tracers as potential candidates for double labeling of descending brain neurons in larval lamprey.
AuthorsZhang L, McClellan AD
JournalJ Neurosci Methods
PubMed ID9874141
In larval lamprey, seven fluorescent tracers were tested as potential candidates for retrograde double labeling of descending brain neurons: Fluoro Gold (FG); fluorescein dextran amine (FDA); True Blue (TB); cascade blue dextran amine (CBDA); Fast Blue (FB); Texas red dextran amine (TRDA); and tetramethylrhodamine dextran amine (RDA). The first tracer ... More
Mutations in the Drosophila hook gene inhibit endocytosis of the boss transmembrane ligand into multivesicular bodies.
AuthorsKrämer H, Phistry M
JournalJ Cell Biol
PubMed ID8682859
Transmembrane ligands can be internalized across cell boundaries into receptor-expressing cells. In the developing Drosophila eye imaginal disc, the bride of sevenless transmembrane protein (boss) is expressed on the surface of R8 cells. After internalization into neighboring R7 cells, the boss protein accumulates in multivesicular bodies. In a search for ... More
Does lineage determine the dopamine phenotype in the tadpole hypothalamus?: A quantitative analysis.
AuthorsHuang S, Moody SA
JournalJ Neurosci
PubMed ID1348272
The ancestry of dopaminergic (DA) neurons in the Xenopus laevis hypothalamus was investigated by combining intracellular lineage dye injections of 16- and 32-cell blastomeres with the immunofluorescent detection of tyrosine hydroxylase at tadpole stages. At these stages, DA neurons in the hypothalamus comprise a discrete nucleus that contains from 22 ... More
Cellular and molecular barriers to gene transfer by a cationic lipid.
AuthorsZabner J, Fasbender AJ, Moninger T, Poellinger KA, Welsh MJ
JournalJ Biol Chem
PubMed ID7642560
Cationic lipids are widely used for gene transfer in vitro and show promise as a vector for in vivo gene therapy applications. However, there is limited understanding of the cellular and molecular mechanisms involved. We investigated the individual steps in cationic lipid-mediated gene transfer to cultured cell lines. We used ... More
The neural plate specifies somite size in the Xenopus laevis gastrula.