Feibi decoction-medicated serum inhibits lipopolysaccharide-induced inflammation in RAW264.7 cells and BMDMs

FBR2 modulates ferroptosis via the SIRT3/p53 pathway to ameliorate pulmonary fibrosis

Background

Idiopathic Pulmonary Fibrosis (IPF), an interstitial lung disease of unknown etiology, remains incurable with current therapies, which fail to halt disease progression or restore lung function. However, Feibi Recipe No. 2 (FBR2), a clinically validated traditional Chinese medicine formula, exhibits potential as an IPF treatment.

Objective

This study aimed to investigate the regulatory effect of FBR2 on ferroptosis through the SIRT3/p53 pathway and its therapeutic potential in improving IPF.

Methods

Pulmonary fibrosis was induced in C57BL/6J mice by intratracheal instillation of Bleomycin (BLM), followed by FBR2 treatment via gavage. Assessments encompassed histopathology, ELISA for cytokine detection, IHC and Western blot for protein expression analysis, and qRT-PCR for gene expression quantification. Transmission electron microscopy (TEM) was used to observe mitochondrial morphology. The roles of Erastin and the SIRT3 inhibitor 3-TYP were also explored to elucidate FBR2's mechanisms of action.

Results

FBR2 treatment significantly mitigated BLM-induced lung injury in mice, as evidenced by improved body weight and survival rates, and reduced levels of inflammatory cytokines, including IL-6 and TNF-α. FBR2 decreased collagen deposition in lung tissue, as shown by Masson's staining and IHC detection of Col-I and α-SMA, confirming its anti-fibrotic effects. It also reduced iron and MDA levels in lung tissue, increased GSH-Px activity, improved mitochondrial morphology, and enhanced the expression of GPX4 and SLC7A11, indicating its ferroptosis-inhibitory capacity. Furthermore, FBR2 increased SIRT3 levels and suppressed p53 and its acetylated forms, promoting the translocation of p53 from the nucleus to the cytoplasm where it co-localized with SIRT3. The protective effects of FBR2 were reversed by Erastin, confirming the central role of ferroptosis in pulmonary fibrosis treatment. The use of 3-TYP further confirmed FBR2's intervention in ferroptosis and cellular senescence through the SIRT3/p53 pathway.

Conclusion

FBR2 shows therapeutic potential in a BLM-induced pulmonary fibrosis mouse model, with its effects mediated through modulation of the ferroptosis pathway via the SIRT3/p53 mechanism. This study provides novel evidence for the targeted treatment of IPF and offers further insights into its pathogenesis.

Number 2 Feibi Recipe Ameliorates Pulmonary Fibrosis by Inducing Autophagy Through the GSK-3β/mTOR Pathway

Number 2 Feibi Recipe (N2FBR) is a traditional Chinese medicine formula for treating idiopathic pulmonary fibrosis. N2FBR inhibits H₂O₂-mediated oxidative stress damage in alveolar epithelial cells by increasing autophagy, as we previously demonstrated. However, it is unknown if similar mechanisms occur in vivo. We established a pulmonary fibrosis model by instilling bleomycin (BLM) from the airway to examine the effects of N2FBR on pulmonary fibrosis and investigate its probable mechanism in this work. We discovered that N2FBR treatment effectively alleviated interstitial fibrosis as well as collagen deposition, primarily in upregulating SOD, GSH-Px, T-AOC and downregulating MDA content. N2FBR also increased the expression of LC3B, Beclin-1, LAMP1, TFEB and downregulated the expression of p62, legumain. N2FBR treatment boosted the production of autophagosomes, according to the results of the TEM observation. Furthermore, we explored that N2FBR exerted its anti-oxidative stress and pro-autophagy effects via GSK-3β/mTOR signalling pathway. Therefore, these results provide further evidence for the protective effect of N2FBR in pulmonary fibrosis. Our findings could have ramifications for the development of antifibrosis therapies.