GATA3 contributes to radiation-induced lung injury by regulating ESM1-mediated NF-κB signaling and inflammatory responses

Radiation-induced lung injury (RILI) is damage to normal lung tissue caused by thoracic tumor radiotherapy (RT), but effective interventions are lacking and its molecular mechanisms remain unclear. This study aimed to investigate the role and regulatory mechanism of endothelial cell-specific molecule 1 (ESM1) in RILI and to explore the involvement of the GATA binding protein 3 (GATA3)/ESM1/nuclear factor kappa B (NF-κB) signaling axis in disease progression. The gene expression omnibus (GEO), search tool for the retrieval of interacting genes (STRING), JASPAR, and ensembl databases were used to obtain RILI-related information. Cell transfection was performed for gene knockdown and overexpression. Western blot, quantitative polymerase chain reaction (qPCR), and enzyme-linked immunosorbent assay (ELISA) were used to detect protein, messenger RNA (mRNA), and inflammatory factor expression levels, respectively. Dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP) were conducted to verify the binding between transcription factors and promoters. Hematoxylin–eosin (HE) staining and masson’s trichrome staining (Masson) were used to evaluate tissue lesions and pulmonary fibrosis. ESM1 was upregulated in RILI. Under radiation, knockdown of ESM1 inhibited NF-κB signaling and activated inhibitor of NF-κB alpha (IκBα) expression, while reduced the levels and expression of tumor necrosis factor-alpha (TNF-α)、interleukin-6 (IL-6)、IL-8、transforming growth factor-beta1 (TGF-β1)、diacylglycerol (DAG)、protein kinase C theta (PKCθ) and B-cell CLL 10 (Bcl 10), which was confirmed in RILI mouse models. The transcription factor GATA binding protein 3 (GATA3) bound the ESM1 promoter and activated its expression; knockdown of GATA3 showed effects similar to ESM1 knockdown, while overexpression of GATA3 restored the effects of ESM1 knockdown. HE staining showed that knockdown of GATA3 alleviated lung tissue lesions in RILI, Masson showed reduced pulmonary fibrosis, and knockdown of GATA3 also decreased respiratory rate and pulmonary edema and mitigated body weight loss in RILI mouse models. The transcription factor GATA3 positively regulate ESM1, thereby modulating the NF-κB pathway and the inflammatory response, which in turn affect the progression of RILI. • ESM1 is upregulated in RILI and acts as a key regulator. • Knockdown of ESM1 inhibits NF-κB signaling and reduces inflammatory mediators. • GATA3 targets ESM1 to drive RILI-induced lung injury and fibrosis. • Knockdown of GATA3 alleviates lung injury, pulmonary fibrosis, edema, and body weight loss in RILI models.