Knockdown of ARHGDIB promotes autophagy and reduces inflammation in LPS-induced alveolar epithelial cells via the PRKACB/NF-κB pathway.

Background: Acute lung injury (ALI) is a critical clinical condition with high mortality, necessitating the development of more effective therapeutic strategies. Rho Guanine nucleotide dissociation inhibitor (GDP) beta (ARHGDIB) has been shown to exert protective effects against noxious stimuli in various disease models.

Objective: In this study, we investigated whether ARHGDIB knockdown had a protective effect on lipopolysaccharide (LPS)-induced injury in alveolar epithelial cells and elucidated its underlying molecular mechanisms.

Material and methods: Mouse alveolar epithelial cells that were isolated from the lung of a 5-month-old female mouse (MLE-12) were treated with LPS, followed by ARHGDIB knockdown and overexpression of protein kinase A (PKA)-activated catalytic subunit β (PRKACB). Oxidative stress and apoptosis were assessed, while inflammatory cytokine levels were quantified using enzyme-linked immunosorbent serologic assays. Autophagy and PRKACB/nuclear factor kappa B (NF-κB) pathway activation was evaluated by Western blot analysis. Results: LPS upregulated ARHGDIB expression in alveolar epithelial cells. Silencing ARHGDIB significantly reduced oxidative stress inflammation, and promoted autophagy in LPS-treated MLE-12 cells. ARHGDIB knockdown modulated the PRKACB/NF-κB signaling pathway, thereby promoting autophagy and alleviating LPS-induced cellular injury.

Conclusion: This regulatory mechanism significantly reduced oxidative stress and inflammatory responses in alveolar epithelial cells, highlighting the protective role of ARHGDIB silencing in LPS-induced lung injury.