Adenovirus-mediated Overexpression of FcγRIIB Attenuates Pulmonary Inflammation and Fibrosis.

Progressive fibrosing interstitial lung diseases (PF-ILDs) result in high mortality and lack effective therapies. The pathogenesis of PF-ILDs involves macrophages driving inflammation and irreversible fibrosis. Fc-γ receptors (FcγRs) regulate macrophages and inflammation, but their roles in PF-ILDs remain unclear. We characterized the expression of FcγRs and found upregulated FcγRIIB in human and mouse lungs after exposure to silica. FcγRIIB deficiency aggravated lung dysfunction, inflammation, and fibrosis in silica-exposed mice. Using single-cell transcriptomics and in vitro experiments, FcγRIIB was found in alveolar macrophages, where it regulated the expression of fibrosis-related genes Spp1 and Ctss. In mice with macrophage-specific overexpression of FcγRIIB and in mice treated with adenovirus by intratracheal instillation to upregulate FcγRIIB, silica-induced functional and histological changes were ameliorated. Our data from three genetic models and a therapeutic model suggest that FcγRIIB plays a protective role that can be enhanced by adenoviral overexpression, representing a potential therapeutic strategy for PF-ILDs.

Gefitinib and fostamatinib target EGFR and SYK to attenuate silicosis: a multi-omics study with drug exploration.

Silicosis is the most prevalent and fatal occupational disease with no effective therapeutics, and currently used drugs cannot reverse the disease progress. Worse still, there are still challenges to be addressed to fully decipher the intricated pathogenesis. Thus, specifying the essential mechanisms and targets in silicosis progression then exploring anti-silicosis pharmacuticals are desperately needed. In this work, multi-omics atlas was constructed to depict the pivotal abnormalities of silicosis and develop targeted agents. By utilizing an unbiased and time-resolved analysis of the transcriptome, proteome and phosphoproteome of a silicosis mouse model, we have verified the significant differences in transcript, protein, kinase activity and signaling pathway level during silicosis progression, in which the importance of essential biological processes such as macrophage activation, chemotaxis, immune cell recruitment and chronic inflammation were emphasized. Notably, the phosphorylation of EGFR (p-EGFR) and SYK (p-SYK) were identified as potential therapeutic targets in the progression of silicosis. To inhibit and validate these targets, we tested fostamatinib (targeting SYK) and Gefitinib (targeting EGFR), and both drugs effectively ameliorated pulmonary dysfunction and inhibited the progression of inflammation and fibrosis. Overall, our drug discovery with multi-omics approach provides novel and viable therapeutic strategies for the treatment of silicosis.

Pirfenidone ameliorates silica-induced lung inflammation and fibrosis in mice by inhibiting the secretion of interleukin-17A.

Silicosis is a global occupational disease characterized by lung dysfunction, pulmonary inflammation, and fibrosis, for which there is a lack of effective drugs. Pirfenidone has been shown to exert anti-inflammatory and anti-fibrotic properties in the lung. However, whether and how pirfenidone is effective against silicosis remains unknown. Here, we evaluated the efficacy of pirfenidone in the treatment of early and advanced silicosis in an experimental mouse model and explored its potential pharmacological mechanisms. We found that pirfenidone alleviated silica-induced lung dysfunction, secretion of inflammatory cytokines (TNF-α, IL-1ß, IL-6) and deposition of fibrotic proteins (collagen I and fibronectin) in both early and advanced silicosis models. Moreover, we observed that both 100 and 200 mg/kg pirfenidone can effectively treat early-stage silicosis, while 400 mg/kg was recommended for advanced silicosis. Mechanistically, antibody array and bioinformatic analysis showed that the pathways related to IL-17 secretion, including JAK-STAT pathway, Th17 differentiation, and IL-17 pathway, might be involved in the treatment of silicosis by pirfenidone. Further in vivo experiments confirmed that pirfenidone reduced the production of IL-17A induced by silica exposure via inhibiting STAT3 phosphorylation. Neutralizing IL-17A by anti-IL-17A antibody improved lung function and reduced pulmonary inflammation and fibrosis in silicosis animals. Collectively, our study has demonstrated that pirfenidone effectively ameliorated silica-induced lung dysfunction, pulmonary inflammation and fibrosis in mouse models by inhibiting the secretion of IL-17A.

Comparative Transcriptome Analyses Reveal a Transcriptional Landscape of Human Silicosis Lungs and Provide Potential Strategies for Silicosis Treatment.

Silicosis is a fatal occupational lung disease which currently has no effective clinical cure. Recent studies examining the underlying mechanism of silicosis have primarily examined experimental models, which may not perfectly reflect the nature of human silicosis progression. A comprehensive profiling of the molecular changes in human silicosis lungs is urgently needed. Here, we conducted RNA sequencing (RNA-seq) on the lung tissues of 10 silicosis patients and 7 non-diseased donors. A total of 2,605 differentially expressed genes (DEGs) and critical pathway changes were identified in human silicosis lungs. Further, the DEGs in silicosis were compared with those in idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary diseases (COPD), to extend current knowledge about the disease mechanisms and develop potential drugs. This analysis revealed both common and specific regulations in silicosis, along with several critical genes (e.g., MUC5AC and FGF10), which are potential drug targets for silicosis treatment. Drugs including Plerixafor and Retinoic acid were predicted as potential candidates in treating silicosis. Overall, this study provides the first transcriptomic fingerprint of human silicosis lungs. The comparative transcriptome analyses comprehensively characterize pathological regulations resulting from silicosis, and provide valuable cues for silicosis treatment.

Blocking FcγRIIB in Smooth Muscle Cells Reduces Hypertension.

[Figure: see text].

A novel pathophysiological classification of silicosis models provides some new insights into the progression of the disease.

Silicosis is caused by massive inhalation of silica-based particles, which leads to pulmonary inflammation, pulmonary fibrosis and lung dysfunction. Currently, the pathophysiological process of silicosis has not been well studied. Here, we defined the progression of silicosis as four stages by unsupervised clustering analysis: normal stage, inflammatory stage, progressive stage and fibrotic stage. Specifically, in normal stage, the lung function was normal, and no inflammation or fibrosis was detected in the lung tissue. Inflammatory stage showed a remarkable pulmonary inflammation but mild fibrosis and lung dysfunction. In progressive stage, significant lung dysfunction was observed, while pulmonary inflammation and fibrosis continued to deteriorate. Fibrotic stage revealed the most severe pulmonary fibrosis and lung dysfunction but no significant deterioration in inflammation. Since the common features were founded in both silicosis patients and rodents, we speculated that the pathophysiological processes of silicosis in patients might be similar to the rodents. Collectively, our new classification identified the process of silicosis, clarified the pathophysiological features of each stage, and provided some new insights for the progression of the disease.

[Angiotensin II promotes the expression of TXNIP through angiotensin II type 1 receptor in islet ß cells].

This study investigated the effect of angiotensin II (Ang II) on apoptosis and thioredoxin-interacting protein (TXNIP) expression in INS-1 islet cells and the underlying mechanism. INS-1 cells cultured in vitro were treated with different concentration of Ang II for different time, and the viability was measured using cell counting kit-8 (CCK-8). After treatment with 1 × 10-6 mol/L Ang II for 24 h, flow cytometry and Western blot were used to measure the cell apoptosis, and Western blot was used to analyze the protein expression of TXNIP, carbohydrate response element-binding protein (ChREBP) and angiotensin II type 1 receptor (AT1R). Real-time PCR was used to detect TXNIP and ChREBP mRNA expression. IF/ICC was used to observe the TXNIP, ChREBP and AT1R expression. The results showed that Ang II reduced cell viability and induced the expression of TXNIP in a dose- and time-dependent manner (P < 0.05, n = 6) compared with the control group. Ang II induced apoptosis and up-regulated the expression of ChREBP and AT1R (P < 0.05, n = 6). AT1R inhibitor, telmisartan (TM), blocked Ang II-induced TXNIP and ChREBP overexpression (P < 0.05, n = 6) and inhibited Ang II-induced apoptosis. Taken together, Ang II increased ChREBP activation through AT1R, which subsequently increased TXNIP expression and promoted cell apoptosis. These findings suggest a therapeutic potential of targeting TXNIP in preventing Ang II-induced INS-1 cell apoptosis in diabetes.

[Adenovirus-mediated overexpression of thioredoxin interaction protein inhibits INS-1 islet ß cell proliferation].

Diabetes can cause a significant increase in the expression of thioredoxin (Trx)-interacting protein (TXNIP), which binds to Trx and inhibits its activity. The present study was aimed to investigate the effect of TXNIP on proliferation of rat INS-1 islet ß cells and the underlying mechanism. TXNIP overexpressing adenovirus vectors (Ad-TXNIP-GFP and Ad-TXNIPc247s-GFP) were constructed and used to infect INS-1 cells. Ad-TXNIPc247s-GFP vector carries a mutant C247S TXNIP gene, and its expression product (TXNIPc247s) cannot attach and inhibit Trx activity. The expression of TXNIP was detected by real-time PCR and Western blot. EdU and Ki67 methods were used to detect cell proliferation. Protein phosphorylation levels of ERK and AKT were detected by Western blot. The results showed that both TXNIP and TXNIPc247s protein overexpressions inhibited the proliferation of INS-1 cells, and the former's inhibitory effect was greater. Moreover, both of the two kinds of overexpressions inhibited the phosphorylation of ERK and AKT. These results suggest that TXNIP overexpression may inhibit the proliferation of INS-1 cells through Trx-dependent and non-Trx-dependent pathways, and the mechanism involves the inhibition of ERK and AKT phosphorylation.