Interleukin-34 induces pulmonary inflammation in a murine model of lipopolysaccharide-induced acute lung injury

The cytokine interleukin-34 （ IL-34 ） was recently described. However, its role in the lungs is not well understood. IL-34 binds to the colony stimulating factor-1 receptor, thereby enhancing tissue macrophage maturation and differentiation. Macrophages are essential to the airway inflammation process and acute lung injury （ ALI ） . This study aimed to evaluate the role of IL-34 in ALI establishment. The bronchoalveolar lavage fluid （ BALF ） and lung tissues were collected. The cells of the human peripheral blood monocyte cell line THP-1 and the human airway epithelial cell line BEAS-2B were with LPS in vitro . The total in the than in the factor- α （ TNF- α） in THP-1 cells. Furthermore, TNF- α stimulation induced the IL-34 production in BEAS-2B cells. These results suggest that IL-34 induction in the epithelial cells may enhance pulmonary inflammation and fibrosis in the murine model of LPS-induced acute lung injury.