Fig. 1

Obesity aggravates LPS-induced pulmonary macrophage activation and ALI. A Body weight of Lean and DIO mice during normal chow and high-fat diet feeding, respectively. n = 24 in the Lean mice group and n = 80 in the DIO mice group. B H&E staining illustrating the extent of lung pathological damage and corresponding lung injury scores. C LDH activity in lung tissue was assessed using an LDH activity assay kit. D Wet-to-dry weight ratio of the lungs. E Protein concentration in the BALF supernatant was determined using the BCA protein quantitation kit. F Immunofluorescent labeling of macrophages. Macrophages are labeled in red (F4/80) and nuclei in blue (DAPI). F4/80-positive cells were counted using FLOWJO software. Scale bar, 50 µm. G, H RT-qPCR assessment of mRNA levels of M1 macrophage markers (iNOS and CD86) and M2 macrophage markers (Arg-1 and CD206) in lung tissues. I–K ELISA measurements of protein levels of TNF-α, IL-1β, and IL-6 in lung tissues. Data are expressed as the mean ± SD, *P < 0.05. **P < 0.01. ***P < 0.001. ****P < 0.0001