Conclusion
Down-regulation of CCL5 could protect WI-38 cells from LPS-induced inflammatory damage via inactivating JNK and NF-κB pathways.
Methods
Human fetal lung fibroblast WI-38 cells were subjected with lipopolysaccharide (LPS) to mimic an in vitro model of pneumonia. CCL5 was silenced by transfection with CCL5-targeted siRNA, and then cell viability, apoptosis, and the expressions of apoptosis-associated factors were respectively assessed by CCK-8 assay, flow cytometry and Western blot. Besides, expressions of CCL5 and pro-inflammatory factors were analyzed by qRT-PCR and Western blot. The secretions of pro-inflammatory factors were measured by ELISA. Finally, the expressions of main factors in JNK and NF-κB pathways were detected.
Results
LPS treatment suppressed cell viability, promoted cell apoptosis, and enhanced the secretion of IL-6, MCP-1, and TNF-α. Overexpression of CCL5 was found in LPS-treated cells. CCL5 silence protected WI-38 cells from LPS-induced inflammatory damage, with increasing cell viability, inhibiting cell apoptosis, and reducing the production of pro-inflammatory cytokines. Besides, CCL5 silence inhibited LPS-induced activations of JNK and NF-κB pathways.