Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 3 de 3
Filter
Add more filters










Database
Language
Publication year range
1.
Free Radic Res ; 48(10): 1190-9, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24985354

ABSTRACT

Robust production of reactive oxygen species (ROS) by phagocyte NADPH oxidase (phox) during the respiratory burst (RB) is a characteristic feature of eosinophil and neutrophil granulocytes. In these cells the voltage-gated proton channel (Hv1) is now considered as an ancillary subunit of the phox needed for intense ROS production. Multiple sources reported that the expression of phox subunits and RB is more intensive in eosinophils than in neutrophils. In most of these studies the eosinophils were not isolated from healthy individuals, and a comparative analysis of Hv1 expression had never been carried out. We performed a systematic comparison of the levels of essential phox subunits, Hv1 expression and ROS producing capacity between eosinophils and neutrophils of healthy individuals. The expression of phox components was similar, whereas the amount of Hv1 was ∼ 10-fold greater in eosinophils. Furthermore, Hv1 expression correlated with Nox2 expression only in eosinophils. Additionally, in confocal microscopy experiments co-accumulation of Hv1 and Nox2 at the cell periphery was observed in resting eosinophils but not in neutrophils. While phorbol-12-myristate-13-acetate-induced peak extracellular ROS release was ∼ 1.7-fold greater in eosinophils, oxygen consumption studies indicated that the maximal intensity of the RB is only ∼ 1.4-fold greater in eosinophils. Our data reinforce that eosinophils, unlike neutrophils, generate ROS predominantly extracellularly. In contrast to previous works we have found that the two granulocyte types display very similar phox subunit expression and RB capacity. The large difference in Hv1 expression suggests that its support to intense ROS production is more important at the cell surface.


Subject(s)
Eosinophils/metabolism , Ion Channels/metabolism , Neutrophils/metabolism , Respiratory Burst/physiology , Fluorescent Antibody Technique , Humans , Immunoblotting , Membrane Glycoproteins/metabolism , Microscopy, Confocal , NADPH Oxidase 2 , NADPH Oxidases/metabolism , Oxygen Consumption/physiology , Reactive Oxygen Species/metabolism
2.
Cell ; 107(1): 17-26, 2001 Oct 05.
Article in English | MEDLINE | ID: mdl-11595182

ABSTRACT

Directed cell migrations are important for development, but the signaling pathways and mechanisms responsible for guiding cell migration in vivo are poorly understood. Migration of border cells during Drosophila oogenesis is a simple and attractive model system in which to address these questions. We demonstrate that PVR, a receptor tyrosine kinase related to mammalian PDGF and VEGF receptors, acts in border cells to guide them to the oocyte. The oocyte is the source of a ligand for PVR, PDGF/VEGF factor 1 (PVF1). Intriguingly, the guidance function of PVR is largely redundant with that of EGFR. We present evidence implicating Rac and the Rac activator Mbc/DOCK180/CED-5 as mediators of the guidance signal.


Subject(s)
Cell Movement/physiology , Cytoskeletal Proteins , Drosophila Proteins , Drosophila melanogaster/physiology , Egg Proteins/metabolism , Insect Proteins/metabolism , Oocytes/physiology , Receptor Protein-Tyrosine Kinases/metabolism , Actins/metabolism , Amino Acid Sequence , Animals , Cytoskeleton/metabolism , Drosophila melanogaster/cytology , Egg Proteins/chemistry , Egg Proteins/genetics , ErbB Receptors/metabolism , Female , Humans , Immunoblotting , Insect Proteins/chemistry , Insect Proteins/genetics , Ligands , Microscopy, Fluorescence , Molecular Sequence Data , Oocytes/cytology , Oogenesis/physiology , Ovary/metabolism , Receptors, Growth Factor/metabolism , Receptors, Platelet-Derived Growth Factor/metabolism , Receptors, Vascular Endothelial Growth Factor , Sequence Alignment , Signal Transduction/physiology , rac GTP-Binding Proteins/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...