The suppression of nuclear factor kappa B/microRNA 222 axis alleviates lipopolysaccharide-induced acute lung injury through increasing the alkylglyceronephosphate synthase expression.

BACKGROUND: Acute lung injury (ALI) is a serious and rapidly progressing pulmonary disorder with a high mortality rate. In this study, we aimed to investigate the relationship between miR-222 and NF-κB (p65) activation in ALI.

METHODS: ALI was induced in mice using lipopolysaccharide (LPS). Lung tissues and bronchoalveolar lavage fluid were collected for analysis. MH-S cell lines were used as an ALI model. Various techniques including histopathology, molecular analysis, and cell culture assays were employed.

RESULTS: Increased miR-222 levels were observed in the LPS-induced ALI mouse model. ALI mice exhibited severe lung pathology, inflammatory cell infiltration, edema, elevated W/D ratio, MPO activity, and increased TNFα, IL1, and IL6 levels, which were reversed by miR-222 antagomir, confirming miR-222's exacerbation of LPS-induced ALI. miR-222 directly targeted the 3'-UTR of alkylglyceronephosphate synthase (AGPS) mRNA, reducing its expression. AGPS is crucial for plasmalogen synthesis, which protects against oxidative stress. NF-κB (p-p65) levels were increased in ALI models, and LPS promoted the enrichment of the miR-222 promoter region, suggesting NF-κB (p65) involvement in miR-222 transcriptional regulation. The NF-κB/miR-222/AGPS axis played a significant role in ALI progression.

CONCLUSIONS: The present study indicates that NF-κB (p65) activates miR-222 transcription by enriching its promoter region, leading to increased miR-222 expression. Elevated miR-222 levels downregulate AGPS, thereby accelerating the progression of ALI. Targeting the NF-κB/miR-222/AGPS axis may hold promise as a therapeutic approach for ALI, although further research is needed to fully understand its significance.