Pulmonary expression of receptor for advanced glycation end products and of its ligand high mobility group box-1 (HMGB1) during <i>Klebsiella pneumoniae</i> pneumonia.

<p>Representative view of a lung from a normal, uninfected wild-type mouse (A) displaying ubiquitous expression of RAGE on the surface of endothelium. <i>Arrow</i> indicates bronchial epithelium, being negative for RAGE staining. B, Absence of RAGE positivity in the lung of a RAGE^-/- mouse. C, Lungs from a wild-type mouse 48 h after the inoculation of <i>K</i>. <i>pneumoniae</i>. Original magnification, x10. D, Western blot was performed for HMGB1 in brochoalveolar lavage fluid (BALF) from wild-type mice at 0, 6, 24 and 48 h after <i>K</i>. <i>pneumoniae</i> intranasal inoculation (<i>n</i> = 3 mice per time point).</p

Cytokine and chemokine levels in lung homogenate and plasma 24 and 48 h after intanasal administration of <i>Klebsiella pneumoniae</i>.

<p>Cytokine and chemokine levels in lung homogenate and plasma 24 and 48 h after intanasal administration of <i>Klebsiella pneumoniae</i>.</p

Hepatocellular injury during <i>Klebsiella pneumoniae</i> pneumonia.

<p>Wild-type and RAGE^-/- mice were inoculated intranasally with 1 x 10⁴ CFUs <i>K</i>. <i>pneumoniae</i> and sacrificed after 24 and 48 h. Aspartate aminotransferase (AST, A) and alanine aminotransferase (ALT, B) in plasma of wild-type and RAGE^-/- mice. Data are expressed as box-and-whisker diagrams depicting the smallest observation, lower quartile, median, upper quartile and largest observation of 8–10 mice per genotype at each time point.</p

Cell counts, cytokine and chemokine levels in bronchoalveolar lavalge fluid after <i>Klebsiella</i> lipolysaccharide inoculation.

<p>Cell counts, cytokine and chemokine levels in bronchoalveolar lavalge fluid after <i>Klebsiella</i> lipolysaccharide inoculation.</p

Unchanged lung inflammation during <i>Klebsiella</i> pneumonia.

<p>Wild-type and RAGE^-/- mice were inoculated intranasally with 1 x 10⁴ CFUs <i>K</i>. <i>pneumoniae</i>. Representative hematoxylin-eosin stainings of lung tissue at 24 (A and B) and 48 (C and D) h post inoculation in wild-type (A and C) and RAGE^-/- (B and D) mice. Original magnification, x20. E, Graphical representation of the degree of lung inflammation at 24 and 48 h. F, Myeloperoxidase (MPO) levels in lung tissues. Data are expressed as box-and-whisker diagrams depicting the smallest observation, lower quartile, median, upper quartile and largest observation of 8–10 mice per genotype at each time point. * p < 0.05, compared with wild-type mice.</p

Increased mortality of receptor for advanced glycation end products deficient (RAGE^-/-) mice during <i>Klebsiella pneumoniae</i> pneumonia.

<p>Survival of wild-type and RAGE^-/- mice after intranasal inoculation with 1 x 10⁴ CFUs <i>K</i>. <i>pneumoniae</i>. Mortality was assessed for 14 days (<i>n</i> = 13–14 mice per genotype).</p

Receptor for advanced glycation end products deficiency enhances local bacterial outgrowth and dissemination during <i>Klebsiella pneumoniae</i> pneumonia <i>in vivo</i> and reduces <i>in vitro</i> phagocytosis of <i>Klebsiella pneumoniae</i> by neutrophils.

<p>Bacterial loads in lung homogenate (A), blood (B), liver (C) and spleen (D) were determined in wild-type and RAGE^-/- mice 24 and 48 h after intranasal inoculation 1 x 10⁴ CFUs <i>K</i>. <i>pneumoniae</i>. Data are expressed as box-and-whisker diagrams depicting the smallest observation, lower quartile, median, upper quartile and largest observation of 8–10 mice per genotype at each time point. E, Phagocytosis of growth-arrested viable Alexa647-SE labeled <i>Klebsiella pneumoniae</i> of neutrophils from wild type and RAGE^-/- mice at 37°C or 4°C. Phagocytosis was quantified as described in the Methods section. Data are expressed as box-and-whisker diagrams depicting the smallest observation, lower quartile, median, upper quartile and largest observation (of 4 mice for 4°C and 8 mice 37°C) per genotype. * p < 0.05, compared with wild-type mice.</p

Cytokine and chemokine levels in lungs and plasma.

<p>Lung cytokine (TNF-α, L-1β, IL-6, IL-10) (A–D), chemokine (KC and MIP-2) (E–F) and plasma cytokine (TNF-α, L-1β, IL-6 ) levels (G–I), 6, 24 and 48 hours after intranasal <i>K. pneumoniae</i> infection in Wt (grey) and <i>mrp14^−/−</i> mice (white). Data are expressed as box-and-whisker diagrams depicting the smallest observation, lower quartile, median, upper quartile and largest observation (8 mice per group at each time point). * p<0.05, ** p<0.01 versus Wt mice.</p

Growth inhibition of <i>Klebsiella</i> by mouse and human NETs is MRP8/14 dependent.

<p>3×10⁵ mouse neutrophils isolated from Wt and <i>mrp14^−/−</i> mice were induced to make neutrophil extracellular traps (NETs) and subsequently infected with 5000 cfu <i>K. pneumoniae</i>. Cfu counts were determined after incubation of 7 hours at 37°C (A). 5×10⁵ human neutrophils were induced to make NETs and pretreated with a rabbit polyclonal anti-MRP14 antibody (α-MRP14), an unspecific rabbit polyclonal control antibody (control IgG) or an excess of zinc and then infected with 100 cfu <i>Klebsiella</i>. Cfu counts were determined after incubation of 10 hours (B). Percentage bacterial growth in the presence of NETs was calculated based on bacterial counts relative to medium controls without NETs. Data are expressed as box-and-whisker diagrams depicting the smallest observation, lower quartile, median, upper quartile and largest observation of at least 5 replicates. *p<0.05 versus controls.</p

<i>Mrp14^−/−</i> mice show enhanced bacterial dissemination and increased mortality during pneumonia derived sepsis caused by <i>K. pneumoniae</i>.

<p>Bacterial loads in the lung (A), blood (B), spleen (C) and liver (D) of <i>K. pneumoniae</i> in Wt (grey) and <i>mrp14^−/−</i> mice (white). Data are expressed as box-and-whisker diagrams depicting the smallest observation, lower quartile, median, upper quartile and largest observation (8 mice per group at each time point). * p<0.05, ** p<0.01 versus Wt mice at the same time point. Survival of Wt and <i>mrp14^−/−</i> mice after intranasal inoculation of 10.000 (E) or 1.000 cfu (F) (n = 12–16 per group in each experiment).</p