UTP potentiates fMLP- or IL-8-induced ROS production in a time-dependent manner

<p><b>Copyright information:</b></p><p>Taken from "The priming effect of extracellular UTP on human neutrophils: Role of calcium released from thapsigargin-sensitive intracellular stores"</p><p></p><p>Purinergic Signalling 2005;1(4):359-368.</p><p>Published online Jan 2005</p><p>PMCID:PMC2096557.</p><p></p> Human neutrophils were isolated and ROS production was measured as described under Materials and methods. (A) and (B) The effect of fMLP (10 nM) or IL-8 (10 nM) was measured when administered alone (empty bars) or simultaneously with 10 µM UTP (closed bars). (C) and (D) The effect of fMLP or IL-8 was measured when added at different intervals after the addition of UTP. Averages ± SEM of peak luminescence signal measured in 4–6 experiments are shown. The luminescence peak measured upon the addition of a final concentration of 200 µM of HO to medium containing isoluminol (5 µM) and horseradish peroxidase (1 U/ml) corresponds to 100 U on the -axes. (* < 0.05)

The effect of thapsigargin on the potentiating effect of UTP on fMLP-induced ROS production

<p><b>Copyright information:</b></p><p>Taken from "The priming effect of extracellular UTP on human neutrophils: Role of calcium released from thapsigargin-sensitive intracellular stores"</p><p></p><p>Purinergic Signalling 2005;1(4):359-368.</p><p>Published online Jan 2005</p><p>PMCID:PMC2096557.</p><p></p> Isolated neutrophils were incubated for 20 min with solvent (tracings in (A)) or 100 nM thapsigargin ( tracing in (B)). UTP (10 µM) and fMLP (10 nM) were added as indicated in each panel. Vertical bar corresponds to the luminescence peak measured upon the addition of a final concentration of 200 µM of HO to medium containing isoluminol (5 µM) and horseradish peroxidase (1 U/ml). Tracings are representative for data shown in Figure . (C) Thapsigargin (100 nM) was added to fura-2 loaded neutrophils resuspended in calcium-free medium. Intracellular calcium concentration was recorded as described under Materials and methods

UTP and ATP potentiate fMLP- or IL-8-induced ROS production in a dose-dependent manner

<p><b>Copyright information:</b></p><p>Taken from "The priming effect of extracellular UTP on human neutrophils: Role of calcium released from thapsigargin-sensitive intracellular stores"</p><p></p><p>Purinergic Signalling 2005;1(4):359-368.</p><p>Published online Jan 2005</p><p>PMCID:PMC2096557.</p><p></p> Human neutrophils were isolated and ROS production was measured as described under Materials and methods. The effect of 10 nM fMLP (A) or 10 nM IL-8 (B) was measured when administered alone or 1 min after the addition of increasing concentrations of UTP (circles) or ATP (squares). Averages ± SEM of peak luminescence signal measured in 3–5 experiments are shown. The luminescence peak measured upon the addition of a final concentration of 200 µM of HO to medium containing isoluminol (5 µM) and horseradish peroxidase (1 U/ml) corresponds to 100 U on the -axes. (* < 0.05 when compared to the values measured in the absence of nucleotides.

Nucleotides potentiate the increase of free cytosolic calcium triggered by fMLP or IL-8 in a dose-dependent manner

<p><b>Copyright information:</b></p><p>Taken from "The priming effect of extracellular UTP on human neutrophils: Role of calcium released from thapsigargin-sensitive intracellular stores"</p><p></p><p>Purinergic Signalling 2005;1(4):359-368.</p><p>Published online Jan 2005</p><p>PMCID:PMC2096557.</p><p></p> (A) and (B) Human neutrophils were isolated and intracellular calcium increase was measured as described under Materials and methods. The effect of fMLP (10 nM) or IL-8 (10 nM) was measured when administered 2 min after the addition of different concentrations of UTP (circles) or ATP (squares). Averages ± SEM of peak intracellular calcium concentrations measured in 4–5 experiments are shown. (C) Representative tracings obtained in neutrophils stimulated with chemoattractant alone (10 nM fMLP or 10 nM IL-8) or with nucleotide (10 µM UTP or 10 µM ATP) followed by chemoattractant. The reagents were added to cell suspensions where indicated on each individual tracing