Figure 2.

Effects of lung transplantation of bone marrow-derived macrophages (BMDMs) on resolution of VILI. A: flow diagram indicating timelines for experimental interventions. Following depletion of alveolar macrophages with clodronate liposome (CLOD), mice were mechanically ventilated with a high tidal volume (20 mL/kg) (MV) for 4 h. On day 1 after mechanical ventilation, PBS or Tlr4^+/+ or TLR4^−/− bone marrow-derived macrophages (BMDMs) were intratracheally administered to alveolar macrophage-depleted mice. Lung inflammatory injury was assessed on day 4 after ventilation. B: TLR4 protein expression in BMDMs. C: wet-to-dry (W/D) lung weight ratio. D: protein concentrations in the bronchoalveolar lavage (BAL) fluid. E: representative lung histology. Hematoxylin and eosin staining of sections of lungs. Magnification, ×20; inset, ×40. All images for control and treatment groups were collected at the same time under the same conditions. F: quantification of histopathological lung injury scores. G: polymorphonuclear neutrophils (PMN) counts in the BAL fluid. n = 6 lungs (from 3 male and 3 female mice). **P < 0.01, one-way ANOVA with Bonferroni post hoc test. Data represent means ± SD. TLR4, Toll-like receptor 4; VILI, ventilator-induced lung injury.