| First Author | Wang W | Year | 2016 |
| Journal | Am J Physiol Lung Cell Mol Physiol | Volume | 311 |
| Issue | 2 | Pages | L494-506 |
| PubMed ID | 27371731 | Mgi Jnum | J:236476 |
| Mgi Id | MGI:5806187 | Doi | 10.1152/ajplung.00001.2016 |
| Citation | Wang W, et al. (2016) Macrophage micro-RNA-155 promotes lipopolysaccharide-induced acute lung injury in mice and rats. Am J Physiol Lung Cell Mol Physiol 311(2):L494-506 |
| abstractText | Micro-RNA (miR)-155 is a novel gene regulator with important roles in inflammation. Herein, our study aimed to explore the role of miR-155 in LPS-induced acute lung injury(ALI). ALI in mice was induced by intratracheally delivered LPS. Loss-of-function experiments performed on miR-155 knockout mice showed that miR-155 gene inactivation protected mice from LPS-induced ALI, as manifested by preserved lung permeability and reduced lung inflammation compared with wild-type controls. Bone marrow transplantation experiments identified leukocytes, but not lung parenchymal-derived miR-155-promoted acute lung inflammation. Real-time PCR analysis showed that the expression of miR-155 in lung tissue was greatly elevated in wild-type mice after LPS stimulation. In situ hybridization showed that miR-155 was mainly expressed in alveolar macrophages. In vitro experiments performed in isolated alveolar macrophages and polarized bone marrow-derived macrophages confirmed that miR-155 expression in macrophages was increased in response to LPS stimulation. Conversely, miR-155 gain-of-function in alveolar macrophages remarkably exaggerated LPS-induced acute lung injury. Molecular studies identified the inflammation repressor suppressor of cytokine signaling (SOCS-1) as the downstream target of miR-155. By binding to the 3'-UTR of the SOCS-1 mRNA, miR-155 downregulated SOCS-1 expression, thus, permitting the inflammatory response during lung injury. Finally, we generated a novel miR-155 knockout rat strain and showed that the proinflammatory role of miR-155 was conserved in rats. Our study identified miR-155 as a proinflammatory factor after LPS stimulation, and alveolar macrophages-derived miR-155 has an important role in LPS-induced ALI. |
