p-Smad2/3 immunoreactivity induced by silica instillation.

<p>Photomicrographs of lung parenchyma of wild-type (WT; <i>A, C</i> and <i>E</i>) and P2X7 receptor knockout (KO; <i>B, E</i> and <i>F</i>) mice 14 days after instillation of silica particles (<i>C-F</i>) or saline (<i>A, B</i>). Bars: 1100 µm (<i>A, B</i>); 180 µm (<i>C-F</i>). Arrows: reactive inflammatory (<i>C, E, F</i>) and epithelial cells (<i>D</i>). Asterisk: aggregates of reactive cells. <i>G:</i> quantification of p-Smad2/3 immunoreactivity in silica WT and KO mice. Box plots show median values of 5–7 animals in each group with a statistical cut off of ±10–90%, with respective SD (15 random non-coincident fields/animal). ***p <0.001.