Aim of the study
This study aimed to investigate the protective effect and possible mechanism of IST in lipopolysaccharide (LPS)-induced acute lung injury in mice. Materials and
Conclusions
These results suggest that IST improves the characteristics of ALI by inhibiting the expression of the PFKFB3-mediated glycolytic pathway and may be a potential anti-inflammatory agent for inflammation-related lung diseases.
Methods
In vitro, RAW264.7 cells and BMDMs were stimulated with LPS, and the level of NO and inflammatory factors TNF-α, IL-1β, and IL-6 were detected by Griess reagent and ELISA, respectively. The effect of IST on the levels of PFKFB3 and its downstream proteins (p-STAT3, p-p65) in cells was assayed by western blotting. Lactate and glycolytic phenotypes were detected by lactate kit and Seahorse assay. In vivo, a mouse model of acute lung injury was induced by LPS, and the levels of inflammatory factors were measured by ELISA. Expression of PFKFB3 and its downstream proteins (p-STAT3, p-p65) in mouse alveolar macrophages by western blotting analysis. Lung permeability assessment by Evans Blue dye assay. H&E staining and Immunocytochemistry were used to observe the protection of IST against lung injury.
Results
IST significantly reduced LPS-induced expression of PFKFB3 and its downstream proteins (p-STAT3, p-p65). The inhibition of PFKFB3 has an impact on the glycolytic phenotype, such as a reduction in the rate of extracellular acidification (ECAR) and elevated lactate levels, and an increase in the rate of cellular oxygen consumption (OCR). Furthermore, IST inhibited LPS-induced NO release and increased the expression of pro-inflammatory factors TNF-α, IL-1β, and IL-6. In vivo, IST reduced pulmonary edema in LPS-induced acute lung injury, improved lung function, and reduced levels of inflammatory factors and lactate secretion. Conclusions: These results suggest that IST improves the characteristics of ALI by inhibiting the expression of the PFKFB3-mediated glycolytic pathway and may be a potential anti-inflammatory agent for inflammation-related lung diseases.
