Copper is known to play a role in iron recycling from macrophages. To examine whether cellular copper status affects expression of the iron exporter ferroportin-1 (FPN1), J774 macrophage cells were exposed to 10-100 microM CuSO(4) for up to 20 h. Copper treatment significantly increased FPN1 mRNA in a dose- and time-dependent manner. After 20 h, 100 microM CuSO(4) up-regulated FPN1 transcript l...

The effects of glycoinositolphospholipid (GIPL), from the pathogenic protozoan Trypanosoma cruzi, and its isolated glycan and lipid (dihydroceramide) components, were investigated in J774 cells and primary macrophages. Isolated GIPL ceramide, but not intact GIPL or its glycan, induced intense fluid phase endocytosis when added exogenously. In the presence of the cytokine IFN-gamma, GIPL ceramid...

Amastigotes of Leishmania major have a great ability to evade destruction in host cells. This study investigated the activation in resident, inflammatory macrophages and J774 cells in vitro treated with lipopolysaccharide (LPS), soluble Leishmania antigen (SLA), calcium ionophore (CaI) and magnesium (Mg2+) alone or combined. An increase in nitric oxide (NO) production was observed in J774 or in...

A gene fusion system based on plasmid pBBR1MCS and the expression of green fluorescent protein was developed for Brucella suis, allowing isolation of constitutive and inducible genes. Bacteria containing promoter fusions of chromosomal DNA to gfp were visualized by fluorescence microscopy and examined by flow cytometry. Twelve clones containing gene fragments induced inside J774 murine macropha...

We have studied the effects of extracellular nucleotides on the cytosolic free calcium concentration [( Ca2+]i) in J774 macrophages using quin2 and indo-1 as indicator dyes. Micromolar quantities of ATP induced a biphasic increase in [Ca2+]i: a rapid and transient increase (peak I) which was due to mobilization of Ca2+ from intracellular stores and a second more sustained elevation (peak II) du...

We have reported previously that in the presence of an osmotic gradient, facilitative glucose transporters (GLUTs) act as a transmembrane pathway for water flow. Here, we find evidence that they also allow water passage in the absence of an osmotic gradient. We applied the linear diffusion technique to measure the diffusional permeability (Pd) of tritiated water (3H-H2O) through plasma membrane...