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Abstract Acute lung injury (ALI) is a type of diffuse lung inflammation with a high mortality rate. Studies show that miR-155 plays an important role in inflammation. Here, we investigated the role of miR-155 in lipopolysaccharide (LPS)-induced ALI. The mice with bone marrow transplantation between MiR-155 knockout and wild-type were used as animal models of LPS-induced sepsis. In response to LPS injection, ALI was less severe in miR-155 knockout mice than in wild-type mice, and mainly manifested as reduced pulmonary vascular leakage, pulmonary edema, and neutrophil infiltration. The expression levels of Ang-2 and apoptosis-associated caspases-3 and -9, as well as myosin light chain (MLC) phosphorylation in the lungs were also decreased. A bone marrow transplantation experiment showed that miR-155 expressed in bone marrow-derived lymphocytes rather than lung parenchymal lymphocytes promoted inflammation. Findings suggest that miR-155 expressed in bone marrow-derived lymphocytes promoted LPS-induced ALI through the modulation of the Ang-2-Tie-2 pathway. Highlights • Deletion of miR-155 inhibited the Ang2-Tie2 signaling pathway. • MiR-155 knockout inhibited phosphorylation of MLCK and MLC. • MiR-155 expressed in bone marrow-derived lymphocytes promoted inflammation. [ABSTRACT FROM AUTHOR]

1,25-dihydroxyvitamin D 3 and its analog (paricalcitol) have beneficial effects on multiple systems and diseases, including myocarditis. However, the therapeutic effect of cholecalciterol cholesterol emulsion (CCE) on myocarditis and the role of pyroptosis in the progress of myocarditis have not been determined. The objective of this study was to investigate the effect of CCE on experimental autoimmune myocarditis and its underlying mechanisms. The ratio of heart weight to body weight was decreased after CCE treatment compared with vehicle-treated controls. In addition, CCE improved the general status of mice, suppressed myocardial apoptosis, and inhibited the pyroptosis signaling pathway. Therefore, CCE can ameliorate experimental autoimmune myocarditis by downregulating the pyroptosis signaling pathway. [ABSTRACT FROM AUTHOR]