Increased m6A-RNA methylation and demethylase FTO suppression is associated with silica-induced pulmonary inflammation and fibrosis

Copper oxide nanoparticles induce pulmonary inflammation via triggering cellular cuproptosis

Copper oxide nanoparticles (CuO NPs) are increasingly used in various industrial fields, and the toxicity of CuO NPs raises concerns. However, the CuO NPs-induced pulmonary inflammation and the underlying mechanism have not been fully illustrated. Cellular cuproptosis provides a new perspective to elucidate the toxicity of CuO NPs. Here, we exposed C57BL/6 mice and murine alveolar macrophage cells (MH-S) to CuO NPs, respectively. A suspension of 2 mg/mL CuO NPs was directly once administered by intratracheal instillation, and mice were sacrificed on day 7. The histopathology results showed that CuO NPs induced pulmonary inflammation in C57BL/6 mice. CuO NPs increased Cu2 + levels by 203.0 % in mouse lung tissues. Also, CuO NPs increased the cuproptosis-related indicators of ferredoxin (FDX1), dihydrolipoamide succinyltransferase (DLST), dihydrolipoamide acetyltransferase (DLAT) and Cu transporter 1 (CTR1) in both mouse lung tissues and MH-S cells. Transcript sequencing and non-targeted metabolomics indicated that CuO NPs induced cellular cuproptosis and inflammatory responses both in vivo and in vitro. Interleukin-17a (IL-17A) was remarkably increased in the process of CuO NPs-induced cellular cuproptosis. Additionally, interference of FDX1 reduced cellular cuproptosis and decreased the release of IL-17A. In summary, CuO NPs increased the accumulation of intracellular Cu2+ and the expressions of cuproptosis-related proteins, induced FDX1-mediated cuproptosis, and led to pulmonary inflammation in mice. This study highlights the respiratory toxicity of CuO NPs and reveals a unique cuproptosis-driven mechanism underlying the CuO NPs-induced pulmonary inflammation.

Epigenetic targets and their inhibitors in the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a deadly lung disease characterized by fibroblast proliferation, excessive extracellular matrix buildup, inflammation, and tissue damage, resulting in respiratory failure and death. Recent studies suggest that impaired interactions among epithelial, mesenchymal, immune, and endothelial cells play a key role in IPF development. Advances in bioinformatics have also linked epigenetics, which bridges gene expression and environmental factors, to IPF. Despite the incomplete understanding of the pathogenic mechanisms underlying IPF, recent preclinical studies have identified several novel epigenetic therapeutic targets, including DNMT, EZH2, G9a/GLP, PRMT1/7, KDM6B, HDAC, CBP/p300, BRD4, METTL3, FTO, and ALKBH5, along with potential small-molecule inhibitors relevant for its treatment. This review explores the pathogenesis of IPF, emphasizing epigenetic therapeutic targets and potential small molecule drugs. It also analyzes the structure-activity relationships of these epigenetic drugs and summarizes their biological activities. The objective is to advance the development of innovative epigenetic therapies for IPF.

Green tea polyphenol alleviates silica particle-induced lung injury by suppressing IL-17/NF-κB p65 signaling-driven inflammation

BACKGROUND

Silicosis, an interstitial lung disease caused by inhalation of silica particles, poses a significant health concern globally. Green tea polyphenol (TP) stands out as a promising therapeutic candidate, yet its specific protective effects and in-depth mechanisms against silicosis have not been thoroughly investigated.

PURPOSE

This study aimed to systematically assess the protective potential of TP against silicosis and to elucidate the underlying mechanisms of its action.

METHODS

A combination of physiological, transcriptomic, molecular, and computational techniques was employed. HPLC was used to identify the components of TP, and its antioxidant properties were tested with DPPH and ABTS assays. The effects of TP on lung injury were assessed in silicosis mice using histopathology, qRT-PCR, and western blot. Transcriptomic analysis was applied to explore the differentially expressed genes and pathways in response to TP intervention. In vitro studies with mouse alveolar macrophages (MH-S) examined TP's effects on cell viability, proliferation, apoptosis, and inflammation responses. Integrated qRT-PCR, western blot, immunohistochemistry, and molecular docking were performed to confirm the molecular mechanism underlying the protective effects of TP against silicosis.

RESULTS

TP effectively attenuated pulmonary inflammation and fibrosis in silicosis mice, as evidenced by significant reductions in inflammation and fibrotic markers. Moreover, TP's therapeutic benefits were linked to its cytoprotective effects on alveolar macrophages, notably its ability to protect MH-S cells from silica particle-induced apoptosis, inhibition of proliferation, and inflammatory response, underscoring its targeted protective effects at the cellular level. Mechanistically, TP exerted its anti-silicosis activity by targeting key pathways implicated in inflammatory responses, notably through the inhibition of the IL-17/NF-κB p65 signaling cascade. Molecular docking simulations corroborated these findings, demonstrating favorable binding affinities between TP's bioactive components (EGC, ECG, and EGCG) and crucial proteins (IL-17A, IL-17F, p65, TNF-α, IL-6, and IL-1β) involved in the IL-17/NF-κB p65 signaling pathway. This pathway inhibition led to a significant decrease in the production of pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1β, thus mitigated silicosis.

CONCLUSION

TP demonstrates efficacy in alleviating silica particle-induced lung injury by suppressing inflammation through the IL-17/NF-κB p65 signaling pathway, underscoring its potential as a valuable natural compound for silicosis management.

Mefunidone alleviates silica-induced inflammation and fibrosis by inhibiting the TLR4-NF-κB/MAPK pathway and attenuating pyroptosis in murine macrophages

AIMS

Silicosis is the most common and severe type of pneumoconiosis, imposing a substantial disease burden and economic loss on patients and society. The pathogenesis and key targets of silicosis are not yet clear, and there are currently no effective treatments available. Therefore, we conducted research on mefunidone (MFD), a novel antifibrotic drug, to explore its efficacy and mechanism of action in murine silicosis.

METHODS

Acute 7-day and chronic 28-day silicosis models were constructed in C57BL/6J mice by the intratracheal instillation of silica and subsequently treated with MFD to assess its therapeutic potential. The effects of MFD on silica-induced inflammation, pyroptosis, and fibrosis were further investigated using immortalized mouse bone marrow-derived macrophages (iBMDMs).

RESULTS

In the 7-day silica-exposed mouse models, MFD treatment significantly alleviated pulmonary inflammation and notably reduced macrophage infiltration into the lung tissue. RNA-sequencing analysis of silica-induced iBMDMs followed by gene set enrichment analysis revealed that MFD profoundly influenced cytokine-cytokine receptor interactions, chemokine signaling, and the toll-like receptor signaling pathways. MFD treatment also markedly reduced the secretion of inflammatory cytokines and chemokines from silica-exposed iBMDMs. Moreover, MFD effectively downregulated the activation of the TLR4-NF-κB/MAPK signaling pathway induced by silica and mitigated the upregulation of pyroptosis markers. Additionally, MFD treatment significantly suppressed the activation of fibroblasts and alveolar epithelial cells co-cultured with silica-exposed mouse macrophages. Ultimately, in the 28-day silica-exposed mouse models, MFD administration led to a substantial reduction in the severity of pulmonary fibrosis.

CONCLUSION

MFD mitigates silica-induced pulmonary inflammation and fibrosis in mice by suppressing the TLR4-NF-κB/MAPK signaling pathway and reducing pyroptotic responses in macrophages. MFD could potentially emerge as a novel therapeutic agent for the treatment of silicosis.