Polystyrene microplastics induce pulmonary fibrosis by promoting alveolar epithelial cell ferroptosis through cGAS/STING signaling.

Polystyrene microplastics (PS-MPs) are new types of environmental pollutant that have garnered significant attention in recent years since they were found to cause damage to the human respiratory system when they are inhaled. The pulmonary fibrosis is one of the serious consequences of PS-MPs inhalation. However, the impact and underlying mechanisms of PS-MPs on pulmonary fibrosis are not clear. In this study, we studied the potential lung toxicity and PS-MPs-developed pulmonary fibrosis by long-term intranasal inhalation of PS-MPs. The results showed that after exposing to the PS-MPs, the lungs of model mouse had different levels of damage and fibrosis. Meanwhile, exposing to the PS-MPs resulted in a markedly decrease in glutathione (GSH), an increase in malondialdehyde (MDA), and iron overload in the lung tissue of mice and alveolar epithelial cells (AECs). These findings suggested the occurrence of PS-MP-induced ferroptosis. Inhibitor of ferroptosis (Fer-1) had alleviated the PS-MPs-induced ferroptosis. Mechanically, PS-MPs triggered cell ferroptosis and promoted the development of pulmonary fibrosis via activating the cGAS/STING signaling pathway. Inhibition of cGAS/STING with G150/H151 attenuated pulmonary fibrosis after PS-MPs exposure. Together, these data provided novel mechanistic insights of PS-MPs-induced pulmonary fibrosis and a potential therapeutic paradigm.

GW4869 Can Inhibit Epithelial-Mesenchymal Transition and Extracellular HSP90α in Gefitinib-Sensitive NSCLC Cells.

Objective: GW4869 is an exosomal inhibitor. It is necessary to delay the occurrence of gefitinib resistance during non-small-cell lung cancer (NSCLC) treatment. This study aimed to investigate the anti-tumor effects of GW4869 on epithelial-mesenchymal transition (EMT) and expression of extracellular heat shock protein 90α (eHSP90α) that contributes to acquired resisitance. Our study provides a new sight into the treatment of EGFR-mutated NSCLC. Materials and Methods: We performed western blotting to detect levels of EMT and eHSP90α. Wound healing and transwell assays were performed to evaluate the behavioral dynamics of EMT. A nude mouse model of HCC827 was established in vivo. Results: GW4869 inhibited the expression of eHSP90α, EMT, invasion and migration abilities of HCC827 and PC9. GW4869 enhanced sensitivity to gefitinib in BALB/c nude mice bearing tumors of HCC827. Conclusion: These studies suggest that GW4869 can inhibit EMT and extracellular HSP90α, providing new strategies for enhancing gefitinib sensitivity in NSCLC.

RNF130 protects against pulmonary fibrosis through suppressing aerobic glycolysis by mediating c-myc ubiquitination.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a chronic and fatal disease,characterized by an excessive accumulation of extracellular matrix (ECM) proteins in response to chronic lung injury. Current evidence suggests that metabolic reprogramming is always accompanied by myofibroblast activation in IPFof whichthe underlying mechanisms remain unclear. Ring finger protein 130 (RNF130), was demonstrated involved in multiple diseases. However, whether RNF130 plays a critical role in the pathogenesis of IPF needs to be clarified. METHODS: We first investigated the expression of RNF130 in pulmonary fibrosis in vivo and in vitro. We then observed the effect and explored the molecular mechanism of RNF130 on the transition of fibroblast to myofibroblast and aerobic glycolysis. Further, we assessed the effects of adeno-associated virus (AAV)-induced RNF130 overexpression in the pulmonary fibrosis model, conducting pulmonary function, assessment of collagen depositionusing the hydroxyproline assay, and biochemical and histopathological analyses. RESULTS: We found that RNF130 was down-regulated in lung tissues of mice with bleomycin-induced pulmonary fibrosis and lung fibroblasts treated with transforming growth factor-ß1 (TGF-ß1). Then we demonstrated that RNF130 inhibitedthe transition of fibroblast to myofibroblast by suppressing aerobic glycolysis. Mechanistically, we revealed that RNF130 promotedc-myc ubiquitination and degradation, while c-myc overexpression reverses the inhibitory effects of RNF130. Importantly, pulmonary function, collagen deposition and fibroblast differentiation were significantly alleviated in adeno-associated virus serotype (AAV)6-RNF130 treated mice, which further validated the contribution of RNF130/c-myc signaling axis in pulmonary fibrosis pathological process. CONCLUSIONS: In summary, RNF130 participates in the pathogenesis of pulmonary fibrosis by inhibiting the transition of fibroblast to myofibroblast and aerobic glycolysis through promoting c-myc ubiquitination and degradation. Targeting RNF130-c-myc axismightrepresent a promising strategy to alleviate the progression of IPF.