FGF10 ameliorates lipopolysaccharide-induced acute lung injury in mice via the BMP4-autophagy pathway

FGF10 protects against particulate matter-induced lung injury by inhibiting ferroptosis via Nrf2-dependent signaling

Particulate matter (PM) is considered the fundamental component of atmospheric pollutants and is associated with the pathogenesis of many respiratory diseases. Fibroblast growth factor 10 (FGF10) mediates mesenchymal-epithelial signaling and has been linked with the repair process of PM-induced lung injury (PMLI). However, the pathogenic mechanism of PMLI and the specific FGF10 protective mechanism against this injury are still undetermined. PM was administered in vivo into murine airways or in vitro to human bronchial epithelial cells (HBECs), and the inflammatory response and ferroptosis-related proteins SLC7A11 and GPX4 were assessed. The present research investigates the FGF10-mediated regulation of ferroptosis in PMLI mice models in vivo and HBECs in vitro. The results showed that FGF10 pretreatment reduced PM-mediated oxidative damage and ferroptosis in vivo and in vitro. Furthermore, FGF10 pretreatment led to reduced oxidative stress, decreased secretion of inflammatory mediators, and activation of the Nrf2-dependent antioxidant signaling. Additionally, silencing of Nrf2 using siRNA in the context of FGF10 treatment attenuated the effect on ferroptosis. Altogether, both in vivo and in vitro assessments confirmed that FGF10 protects against PMLI by inhibiting ferroptosis via the Nrf2 signaling. Thus, FGF10 can be used as a novel ferroptosis suppressor and a potential treatment target in PMLI.

FGF21 ameliorates septic liver injury by restraining proinflammatory macrophages activation through the autophagy/HIF-1α axis

INTRODUCTION

Sepsis, a systemic immune syndrome caused by severe trauma or infection, poses a substantial threat to the health of patients worldwide. The progression of sepsis is heavily influenced by septic liver injury, which is triggered by infection and cytokine storms, and has a significant impact on the tolerance and prognosis of septic patients. The objective of our study is to elucidate the biological role and molecular mechanism of fibroblast growth factor 21 (FGF21) in the process of sepsis.

OBJECTIVES

This study was undertaken in an attempt to elucidate the function and molecular mechanism of FGF21 in therapy of sepsis.

METHODS

Serum concentrations of FGF21 were measured in sepsis patients and septic mice. Liver injury was compared between mice FGF21 knockout (KO) mice and wildtype (WT) mice. To assess the therapeutic potential, recombinant human FGF21 was administered to septic mice. Furthermore, the molecular mechanism of FGF21 was investigated in mice with myeloid-cell specific HIF-1α overexpression mice (LyzM-CreDIO-HIF-1α) and myeloid-cell specific Atg7 knockout mice (Atg7△mye).

RESULTS

Serum level of FGF21 was significantly increased in sepsis patients and septic mice. Through the use of recombinant human FGF21 (rhFGF21) and FGF21 KO mice, we found that FGF21 mitigated septic liver injury by inhibiting the initiation and propagation of inflammation. Treatment with rhFGF21 effectively suppressed the activation of proinflammatory macrophages by promoting macroautophagy/autophagy degradation of hypoxia-inducible factor-1α (HIF-1α). Importantly, the therapeutic effect of rhFGF21 against septic liver injury was nullified in LyzM-CreDIO-HIF-1α mice and Atg7△mye mice.

CONCLUSIONS

Our findings demonstrate that FGF21 considerably suppresses inflammation upon septic liver injury through the autophagy/ HIF-1α axis.

FGF10 protects against LPS-induced epithelial barrier injury and inflammation by inhibiting SIRT1-ferroptosis pathway in acute lung injury in mice

Pulmonary alveolar epithelial cell injury is considered the main pathological and physiological change in acute lung injury. Ferroptosis in alveolar epithelial cells is one of crucial factors contributing to acute lung injury (ALI). Therefore, reducing ferroptosis and repair epithelial barrier is very necessary. More and more evidence suggested that FGF10 plays an important role in lung development and repair after injury. However, the relationship between FGF10 and ferroptosis remains unclear. This study aims to explore the regulatory role of FGF10 on ferroptosis in ALI. Differential gene expression analysis indicated that genes associated with ferroptosis showed that FGF10 can significantly alleviate LPS induced lung injury and epithelial barrier damage by decreasing levels of malonaldehyde(MDA), and lipid ROS. SIRT1 activator (Resveratrol) and inhibitor (EX527) are used in vivo showed that FGF10 protects ferroptosis of pulmonary epithelial cells through SIRT1 signal. Furthermore, knockdown of FGFR2 gene reduced the protective effect of FGF10 on acute lung injury in mice and SIRT1 activation. After the application of NRF2 inhibitor ML385 in vitro, the results showed that SIRT1 regulated the expression of ferroptosis related proteins NRF2, GPX4 and FTH1 are related to activation of NRF2. These data indicate that SIRT-ferroptosis was one of the critical mechanisms contributing to LPS-induced ALI. FGF10 is promising as a therapeutic candidate against ALI through inhibiting ferroptosis.

FGF10 attenuates allergic airway inflammation in asthma by inhibiting PI3K/AKT/NF-κB pathway

BACKGROUND

The effect of fibroblast growth factor 10 (Fgf10) against allergic asthma has remained unclear, despite its importance in lung development and homeostasis maintenance. The purpose of this study was to investigate the protective effect and potential mechanism of Fgf10 on asthma.

METHOD

House Dust Mite (HDM)-induced asthma mice were administered recombinant Fgf10 intranasally during activation. Flow cytometry and ELISA were performed to determine type of inflammatory cells and type 2 cytokines levels in bronchoalveolar lavage fluid (BALF). Hematoxylin and eosin (H&E) and periodic acid - Schiff (PAS) staining of lung sections were conducted to evaluate histopathological assessment. Transcriptome profiling was analyzed using RNA-seq, followed by bioinformatics and network analyses to investigate the potential mechanisms of Fgf10 in asthma. RT-qPCR was also used to search for and validate differentially expressed genes in human Peripheral Blood Mononuclear Cells (PBMCs).

RESULTS

Exogenous administration of Fgf10 alleviated HDM-induced inflammation and mucus secretion in lung tissues of mice. Fgf10 also significantly inhibited the accumulation of eosinophils and type 2 cytokines (IL-4, IL-5, and IL-13) in BALF. The PI3K/AKT/NF-κB pathway may mediate the suppressive impact of Fgf10 on the asthma inflammation. Through RNA-seq analysis, the intersection of 71 differentially expressed genes (DEGs) was found between HDM challenge and Fgf10 treatment. GO and KEGG enrichment analyses indicated a strong correlation between the DEGs and different immune response. Immune infiltration analysis predicted the differential infiltration of five types of immune cells, such as NK cells, dendritic cells, monocytes and M1 macrophages. PPI analysis determined hub genes such as Irf7, Rsad2, Isg15 and Rtp4. Interestingly, above genes were consistently altered in human PBMCs in asthmatic patients.

CONCLUSION

Asthma airway inflammation could be attenuated by Fgf10 in this study, suggesting that it could be a potential therapeutic target.