Early growth response 1/Krüppel-like factor 5 pathway inhibitor alleviates lipopolysaccharide-induced lung injury by promoting autophagy

Abstract

Early transcription factors play critical roles in the development of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Early growth response 1 (EGR1) is a transcription factor essential for various biological processes, including regulation of metabolism, differentiation, and inflammation. However, its role in ALI has been poorly reported. In this study, we aimed to determine the effect of EGR1 on ALI to gain insights into the theoretical basis for further treatment of ALI. By employing concerted molecular biology techniques, we showed that EGR1 protein was upregulated in mice. EGR1 protein was upregulated in mice and human lung epithelial cells in response to lipopolysaccharide (LPS) stimulation. EGR1 knockdown promoted autophagy and reduced LPS-induced pro-inflammatory mediator production. EGR1 was preferentially bound to the GCGTGGGCG motif region and EGR1-binding peak-related genes were mainly enriched in autophagy and injury stress-related pathways. Additionally, EGR1 promoted Krüppel-like factor 5 (KLF5) transcription by binding to the KLF5 promoter region, and KLF5 knockdown significantly decreased inflammatory damage, suggesting that EGR1 promotes ALI progression by regulating KLF5 expression. Furthermore, ML264, an inhibitor of the EGR1/KLF5 pathway axis, displayed a protective role in ALI to reduce inflammation. In conclusion, our findings demonstrate the potential of EGR1 knockdown to inhibit KLF5 and promote autophagy, further reducing the inflammatory response to mitigate ALI/ARDS. The EGR1/KLF5 pathway axis may be a valuable therapeutic target for the treatment of ALI/ARDS.

Keywords: Acute lung injury; Acute respiratory distress syndrome; Autophagy; Early growth response 1; Krüppel-like factor 5; ML264.