Figure 1.
Acute effects of acrolein exposure.
Western blot analysis of active cleaved caspase 3 (A), caspase 12 (B) and VEGF (C) in whole lung tissue homogenates. WB bands were normalized to beta-actin. **P<0.01; *P<0.05 when compared to a control group. Rats received a single i.p. injection of acrolein at 12 µmol/kg and were sacrificed 1, 2, 4 or 24 hours after the challenge. n = 4 animals per group, data are mean±S.E.
Figure 2.
Quantitative real-time PCR analysis of the Unfolded Protein Response (UPR)-related gene expression.
Rats received a single i.p. injection of acrolein at 12 µmol/kg and were sacrificed 1, 2, 4 or 24 hours after the challenge. n = 4 animals per group, data are mean±S.E.
Figure 3.
A. Section of a representative control rat lung showing normal alveolar structure. B. Section of a lung from a 24 µmol/kg acrolein treated rat showing enlarged airspaces. Magnification: 25×. Scale bars = 100 µm. C. Emphysema in acrolein treated lungs assessed by mean alveolar airspace area (µm2). Data generated from n = 4 animals/per group, values are mean±S.E. * P<0.05 compared with the control group
Figure 4.
TUNEL staining of rat lung sections.
A. Control rat lung section, showing only oneTUNEL-positive intra-alveolar cell (arrow). B. Lung section from a rat treated with 3 injections of 24 µmol/kg acrolein shows abundant TUNEL+ cells in the alveolar septa (arrows). Magnification: 400×. Scale bars = 50 µm. C. Apoptotic index (AI) of TUNEL staining was performed as described in Materials and Methods. n = 4 rats/per group, values are mean±S.E. ** P<0.01 compared with control rat group.
Figure 5.
Immunohistochemistry for cleaved caspase 3 counterstained with hematoxylin.
A. Control rat lung, showing a few caspase 3 positive cells in the alveolar septa (arrows). B. Lung tissue section from a set of treated with 12 µmol/kg acrolein, showing caspase 3 positive cells in the alveolar septa (arrows). Magnification: 400×. Scale bars = 50 µm. C. The apoptotic Index (AI) of immunohistochemistry for cleaved caspase 3 was calculated as described in Materials and Methods. D. Western blot analysis of cleaved caspase 3 protein in the lung tissue extracts. n = 4 rats/per group, values are mean±S.E. *P<0.05 and **P<0.01 when compared to the control group.
Figure 6.
Western blot analysis of VEGF (A) and caspase 12 (B) in lung tissue homogenates from chronically acrolein injected rats.
The VEGF (dimer and monomer) protein expression was normalized to beta-actin. *P<0.05; **P<0.01 when compared to the control group.
Figure 7.
Quantitative real-time PCR analysis of Unfolded Protein Response (UPR)-related gene expression in the 2 experimental rat groups (chronic challenge).
n = 4 rats/per group, values are mean±S.E. **P<0.01 when compared to the control group.
Figure 8.
Acrolein-protein adducts in COPD (A–C) and healthy (D, E) lungs.
In COPD lungs there is an abundant presence of acroleinated proteins in endothelial and smooth muscle cells of the small vessels (A), bronchoepithelial cells (B), and inflammatory cells (C). The enlarged section (C) shows intense staining of alveolar macrophages. Immunohistochemistry was performed on paraffin-embedded lung sections using a rabbit polyclonal anti-acrolein antibody (Novus Biologicals). There are very few acrolein-protein adducts in healthy lungs (D, E).