Knockdown of CXCL3-inhibited apoptosis and inflammation in lipopolysaccharide-treated BEAS-2B and HPAEC through inactivating MAPKs pathway.

BACKGROUND: CXCL3 (C-X-C motif chemokine ligand 3) is a member of chemokines family, which binds to the receptor to recruit neutrophils to lungs, thus participating in the pathogenesis of asthmatic lung. The role of CXCL3 in sepsis-induced acute lung injury is investigated here. METHODS: Human lung epithelial cell line (BEAS-2B) and human pulmonary artery endothelial cell line (HPAEC) were treated with lipopolysaccharides (LPS). MTT and flow cytometry were performed to detect cell viability and apoptosis, respectively. Enzyme-linked immunosorbent assay (ELISA) and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to assess the levels of inflammatory factors. RESULTS: Treatment with LPS resulted in the decrease of cell viability in BEAS-2B and HPAEC. CXCL3 was particularly upregulated in LPS-treated BEAS-2B and HPAE cells. Knockdown of CXCL3 enhanced viability and suppressed apoptosis i006E LPS-treated BEAS-2B and HPAE cells. Knockdown of CXCL3 also upregulated TNF-α, IL-1ß, and IL-18 in LPS-treated BEAS-2B and HPAE cells. Moreover, knockdown of CXCL3 suppressed the activation of mitogen-activated protein kinases (MAPKs) signaling in LPS-treated BEAS-2B and HPAE cells through downregulation of p-ERK1/2, p-p38, and p-JNK. On the other hand, overexpression of CXCL3 caused completely opposite results in LPS-treated BEAS-2B and HPAE cells. CONCLUSION: Knockdown of CXCL3 exerted antiapoptotic and anti-inflammatory effects against LPS-treated BEAS-2B and HPAE cells, at least partially, through inactivation of MAPKs signaling, suggesting a potential strategy for the intervention of sepsis-induced acute lung injury.

PLCE1 alleviates lipopolysaccharide-induced acute lung injury by inhibiting PKC and NF-κB signaling pathways.

BACKGROUND: Acute lung injury (ALI) is a clinical syndrome characterized by hyperosmotic pulmonary edema and increased alveolar fluid. Phospholipase C epsilon-1 (PLCE1), identified as a member of phospholipase family, and the relationship between PLCE1 and lung injury is not clear. OBJECTIVE: To assess the possible role of Phospholipase C Epsilon 1 (PLCE1) in Acute lung injury (ALI) progression and related mechanisms. MATERIALS AND METHODS: The effects of LPS and PLCE1 on cell viability and apoptosis were examined by MTT and flow cytometry. Also, the level of PLCE1 was controlled by transfection of its plasmid and shRNA. The inflammatory response in response to PLCE1 overexpression or ablation was analyzed by quantitative PCR and ELISA assay. And the involvement of PKC and NF-κB signal pathway were detected by Immunoblot. RESULTS: In this study, we developed a LPS-induced ALI cell model. We found PLCE1 was upregulated in LPS-induced pneumonia cells and affected cell viability. Also, knockdown of PLCE1 reduced LPS-induced apoptosis of pneumonia cells. In addition, depletion of PLCE1 suppressed LPS-induced secretion of proinflammatory cytokines in pneumonia cells. Mechanically, we found depletion of PLCE1 inhibited PKC and NF-κB signal pathway, and therefore alleviated LPS-induced ALI. CONCLUSION: We therefore thought PLCE1 could serve as a promising drug for ALI.