Macrophages express a cell surface receptor which mediates phagocytosis and pinocytosis of particles solutes containing mannose (fucose N-acetylglucosamine are also ligands for the receptor). An apparently identical protein has been isolated from human placenta. Proteolytic fragments placental were sequenced so that oligonucleotide probes complementary to cDNA could be generated. These used isolate clones covering entire coding portion mRNA receptor. Confirmation these encode was obtained by...

Mannose-lactoperoxidase, a neoglycoprotein prepared by reaction of lactoperoxidase with cyanomethyl 1-thiomannoside, bound to alveolar macrophages at 4 degrees C (Kd = 5.8 X 10(-8) M) and was rapidly internalized 37 (K uptake 2 M). Mannose-lactoperoxidase binding were blocked yeast mannan, mannose-lactoperoxidase inhibited 125I-labeled mannose-BSA (bovine serum albumin). Radioiodination cells surface-bound carried out in the presence glucose oxidase. A major polypeptide (175 kDa)...

Protein kinase C (PKC) is a family of kinases that are implicated in plethora diseases, including cancer and cardiovascular disease. PKC isoforms can have different, sometimes opposing, effects these disease states. Toll-like receptors (TLRs) pattern recognition bind pathogens stimulate the secretion cytokines. It has long been known inhibitors reduce LPS-stimulated cytokine by macrophages, linking activation to TLR signaling. Recent studies shown PKC- α , -<mml:math...

Abstract The binding of Ab (IgG)-opsonized particles by FcγRs on macrophages results in phagocytosis the and generation a respiratory burst. Both IgG-stimulated burst involve activation protein kinase C (PKC). However, specific PKC isoforms required for these responses have yet to be identified. We studied involvement IgG-mediated mouse macrophage-like cell line, RAW 264.7. Like primary monocyte/macrophages, their was calcium independent diacylglycerol sensitive, consistent with novel...

The abundant surface glycolipid, promastigote lipophosphoglycan (LPG), of Leishmania promastigotes was isolated and reconstituted onto the hydrophobic silica beads. These beads bound to both macrophages monocytes, suggesting that phagocytes possess a receptor(s) capable recognizing LPG. LPG were unable bind from individuals with genetic deficiency in CD18 complex leukocyte integrins (CR3, p150,95, LFA-1), one or more these receptors required for binding Individual members depleted by plating...

Abnormal proliferation and migration of vascular smooth muscle cells (SMCs) are the key events in progression neointima formation response to injury. The goal this study is investigate functional role a potent oncogene yes-associated protein (YAP) SM phenotypic modulation vitro vivo.In cell culture vivo both mouse rat arterial injury models YAP expression significantly induced correlated with SMC synthetic phenotype. Overexpression promotes while attenuating contractile gene expression....

Fusion of intracellular membrane-bound compartments is a common step in the transport macromolecules along endocytic and secretory pathways. A large number factors active fusion process or its regulation have been identified; however, actual sequence events leading to membrane still unknown. In this study, we assessed possible role for PLA2 endosome by using an vitro reconstitution assay examining endocytosis intact cells. Several inhibitors blocked broken-cell preparation. Inhibition was...

Abstract Leukocyte chemoattractants are known to stimulate signaling pathways that involve Rho family GTPases. Direct evidence for the regulation of leukocyte cytoskeleton by GTPases and their effector targets is limited. The p21-activated kinases (PAKs) specific activated GTP-bound Rac Cdc42, have been proposed as regulators chemoattractant-driven actin cytoskeletal changes in fibroblasts. PAK1 co-localizes with F-actin cortical structures stimulated fibroblasts, mutants induce membrane...

A receptor which recognizes glycoproteins bearing terminal mannose residues has been isolated from human placental membranes.Washed membranes were solubilized with buffer containing 1% Triton X-100 and applied to a mannose-Sepharose affinity column.The column was eluted 200 m M cholate.The major protein exhibited molecular weight of 175 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis.The binds 12'I-labeled mannosylated bovine serum albumin in saturable fashion dissociation...

Rabbit alveolar macrophages express a plasma-membrane receptor that recognizes glycoprotein ligands bearing terminal mannose, fucose or N-acetylglucosamine residues. Macrophage membranes were washed extensively with buffers containing high salt and mannose EDTA to remove endogenously bound ligand, before Triton X-100 extraction. The extracts chromatographed on mannose-Sepharose. Elution followed by dialysis second mannose-Sepharose step elution, produced preparation migrated as single...

Macrophages are a heterogeneous and plastic population of cells whose phenotype changes in response to their environment. Macrophage biologists utilize peritoneal (pMAC) bone marrow-derived macrophages (BMDM) for vitro studies. Given that pMACs mature vivo while BMDM ex differentiated from stem cells, it is likely responses differ under experimental conditions. Surprisingly little known about how compare the same conditionals. While morphologically similar with respect forward side scatter...

Protein kinase C (PKC) plays a prominent role in immune signaling, and the paradigms for isoform selective signaling are beginning to be elucidated. Real-time microscopy was combined with molecular biochemical approaches demonstrate PKC-ε Fcγ receptor (FcγR)–dependent phagocytosis. RAW 264.7 macrophages were transfected GFP-conjugated PKC isoforms, GFP movement followed during phagocytosis of fluorescent IgG–opsonized beads. PKC-ε, but not PKC-δ, concentrated around accumulation transient;...

Abstract Phagocytosis is a specialized function of neutrophils and macrophages that requires coordination multiple biochemical biophysical events. Considerable progress has been made in identifying the membrane receptors involved phagocytosis, but intracellular signaling pathways are necessary for particle ingestion poorly understood. In an effort to address this complex question, we investigated role arachidonic acid (AA) uptake yeast IgG-coated E (EIgG) or C-coated E. Human monocytes,...

Abstract Protein kinase C (PKC) plays a prominent role in immune signaling. To elucidate the signal transduction respiratory burst and isoform-specific function of PKC during FcγR-mediated phagocytosis, we used live, digital fluorescence imaging mouse microglial cells expressing GFP-tagged molecules. βI PKC, εPKC, diacylglycerol (DGK) β dynamically transiently accumulated around IgG-opsonized beads (BIgG). Moreover, accumulation p47phox, an essential cytosolic component NADPH oxidase...

Abstract Previous studies demonstrated that both protein kinase C (PKC) and arachidonic acid (AA) are required for IgG-mediated phagocytosis by human monocytes. We have characterized a calcium-independent "phagocytic" phospholipase A2 (designated pPL) mediates release. The present were designed to order PKC pPL in the phagocytic signaling pathway. inhibitors staurosporine calphostin caused coordinated decrease of IgG-opsonized erythrocytes PLA2 activators mastoparan melittin restored...

Abstract Resveratrol, a naturally occurring stilbene with antitumor properties, caused mitogen-activated protein kinase [MAPK, extracellular signal-regulated 1/2 (ERK1/2)] activation, nuclear translocation of Ser15-phosphorylated p53, and p53-dependent apoptosis in hormone-insensitive DU145 prostate cancer cells. Exposure these cells to epidermal growth factor (EGF) for up 4 hours resulted brief activation MAPK followed by inhibition resveratrol-induced signal transduction, p53...

The biosynthesis and processing of the human mannose receptor has been studied in monocyte-derived macrophages. Adherent cells were labeled for 60 min with Trans35S (a mixture 35S-labeled methionine cysteine), chased, subjected to immunoprecipitation by antibody raised against placental receptor. immunoprecipitated a single protein molecular mass 162 kDa; precipitation could be inhibited results presented demonstrate that is synthesized as 154-kDa precursor which processed kDa 90 min....

Missense mutations in AHI1 result the neurodevelopmental ciliopathy called Joubert syndrome.Mutations decrease cilia formation, alter its localization and stability, change binding to HAP1 NPHP1.Mutations affect ciliogenesis, protein localization, AHI1-protein interactions.This study begins describe how missense can cause syndrome. Mutations syndrome (JBTS), a ciliopathy, characterized by midbrain-hindbrain malformations motor/cognitive deficits. Here, we show that primary (PC) formation is...

ABSTRACT Arachidonic acid is essential for antibody-mediated phagocytosis but its role in this process has not been defined. The phospholipase A2 inhibitor bromoenol lactone decreases arachidonic release and arrests phagocytosis; effect bypassed by the addition of to lactone-treated cells. In morphological study, monocytes treated with accumulate electronlucent vesicles cytoplasm underlying bound targets. are contiguous plasma membrane as they labeled cationized ferritin connected determined...

Protein kinase C-epsilon (PKC-epsilon) translocates to phagosomes and promotes uptake of IgG-opsonized targets. To identify the regions responsible for this concentration, green fluorescent protein (GFP)-protein mutants were tracked during phagocytosis in response exogenous lipids. Deletion diacylglycerol (DAG)-binding epsilonC1 epsilonC1B domains, or point mutant epsilonC259G, decreased accumulation at membrane translocation DAG. Quantitation GFP revealed that epsilonC1, was significantly...

Rac1 and Rac2 are capable of stimulating superoxide production in vitro, but their targeting functional mechanisms still unknown. In the present study, we found that Rac1, 2, 3 all accumulate at phagosome during Fc gammaR-mediated phagocytosis, order accumulation (Rac1 > Rac3 Rac2) depends on net positive charge polybasic (PB) regions (183-188 aa). Although GFP-tagged prenylated PB Rac isoforms (GFP-Rac(PB)) 6 Ala (GFP-6A) accumulated GFP-Rac2(PB) GFP-6A showed weak through a linear...

Abstract Inhibition of arachidonate release down- regulates immunoglobulin G-mediated phagocytosis. This requirement is selective for IgG- opsonized targets, suggesting that may act as a second messenger Fcγ receptor-mediated Here we report the characterization phospholipase, activated during phagocytosis, releases from phosphatidylethanolamine in absence intracellular calcium ([Ca]i ≤ 2 nM). In vitro, phospholipase with these characteristics was detected soluble and particulate fractions...

Stroke, caused by carotid plaque rupture, is a major cause of death in the United States. Whereas vulnerable human plaques have higher Fc receptor (FcγR) expression than their stable counterparts, how FcγR impacts histology unknown. We investigated role FcγRIIb development and stability apolipoprotein (Apo)e−/− Apoe−/−FcγRIIb−/− double knockout (DKO) animals.Plaques were induced implantation shear stress‐modifying cast around artery. Plaque length stenosis followed longitudinally using...