C-X-C-Chemokine-Receptor-Type-4 Inhibitor AMD3100 Attenuates Pulmonary Inflammation and Fibrosis in Silicotic Mice

Evaluation and the mechanism of ShengXian and JinShuiLiuJun decoction in the treatment of silicotic fibrosis: An integrated network pharmacology, life omics, and experimental validation study

BACKGROUND

Silicosis is a systemic disease characterized by extensive fibrosis due to prolonged exposure to silica dust, with rising incidence rates significantly impacting global public health. ShengXian and JinShuiLiuJun Decoction (SXD) is a Chinese medicinal preparation containing a variety of medicinal plants. It has shown notable clinical efficacy in treating silicotic fibrosis in China. However, the precise mechanisms underlying its therapeutic effects remain unclear. This study integrates network pharmacology, multi-omics analysis, and experimental validation to investigate the potential mechanisms by which SXD treats silicotic fibrosis.

OBJECTIVE

The study aims to investigate the therapeutic efficacy of SXD in treating silicotic fibrosis and to elucidate its underlying molecular mechanisms.

METHODS

HPLC-Q-TOF-MS was used to identify the active components of SXD, and combined with network pharmacology, metabolomics, and transcriptomics, the mechanism of SXD in treating silicotic fibrosis was explored from multiple perspectives. The therapeutic effect of SXD was assessed through HE staining, Masson staining, Micro CT imaging, pulmonary function tests, and hydroxyproline content in lung tissue. Finally, network pharmacology and multi-omics findings were validated using molecular docking. CETSA, immunofluorescence, SPR, and Western blotting were used to analyze key factors in the NF-κB pathway at the animal, cellular, and molecular levels.

RESULTS

SXD treatment improved lung function in silicosis rats, reduced inflammatory cell infiltration, collagen deposition, fibrosis and other pathological changes, and inhibited the protein expression of TNF-α, IL-17A, and IL-1β, and NF-κB in lung tissue. HPLC-Q-TOF-MS combined with network pharmacology identified key compounds such as Liquiritigenin, 3-Methoxynobiletin, Isomangiferin, Hesperidin, shogaol, and Ligustroflavone, which likely exert therapeutic effects through the TNF, IL-17, NF-κB, and TGF-β signaling pathways. Transcriptomics and metabolomics results revealed that SXD up-regulated the expression of NF-κB pathway-related genes (NFKBIA, NFKBIZ) and key regulators of the retinol metabolism pathway, while down-regulating pro-inflammatory genes (IL1B, IL17A, IL6). Experimental findings confirmed that SXD suppressed the expression of NF-κB pathway-related proteins and upstream activators TNF-α, IL-17A, and IL-1β, as well as their receptors, in both lung tissue and cellular models. Additionally, SXD-containing serum had a direct, non-toxic effect on MRC-5 cells, effectively inhibiting collagen expression and TGF-β secretion. SXD also had a positive effect on collagen production and extracellular matrix (ECM) aggregation in fibroblasts. Molecular dynamics studies showed that SXD directly binds to NF-κB and IκB.

CONCLUSION

SXD exerts therapeutic effects on silicotic fibrosis by inhibiting NF-κB signaling transduction mediated by TNF-α, IL-17A, and IL-1β, and suppressing fibroblast activation.

Crystalline silica on the lung-environment interface: Impact on immunity, epithelial cells, and therapeutic perspectives for autoimmunity

Crystalline silica (the most abundant form of silicon dioxide) is a natural element that is ubiquitous in the Earth's crust. Chronic personal or professional exposure has been implicated in various pathologies, including silicosis and autoimmune diseases since the early 20th century. More recently, a specific pathogenic role for crystalline silica has been identified through its impact on lung epithelial cells as well as immune cells present at this organism barrier. This review summarizes the current in vitro and in vivo knowledge regarding the physiopathology of crystalline silica at the lung-environment interface, discusses its effects on innate and adaptive immune cells and epithelial cells, and reviews current therapeutic perspectives explored in mouse models to alleviate its impact, especially on autoimmune phenotypes.

Blocking CTLA-4 promotes pressure overload-induced heart failure via activating Th17 cells

Targeting cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) with specific antibody offers long-term benefits for cancer immunotherapy but can cause severe adverse effects in the heart. This study aimed to investigate the role of anti-CTLA-4 antibody in pressure overload-induced cardiac remodeling and dysfunction. Transverse aortic constriction (TAC) was used to induce cardiac hypertrophy and heart failure in mice. Two weeks after the TAC treatment, mice received anti-CTLA-4 antibody injection twice a week at a dose of 10 mg/kg body weight. The administration of anti-CTLA-4 antibody exacerbated TAC-induced decline in cardiac function, intensifying myocardial hypertrophy and fibrosis. Further investigation revealed that anti-CTLA-4 antibody significantly elevated systemic inflammatory factors levels and facilitated the differentiation of T helper 17 (Th17) cells in the peripheral blood of TAC-treated mice. Importantly, anti-CTLA-4 mediated differentiation of Th17 cells and hypertrophic phenotype in TAC mice were dramatically alleviated by the inhibition of interleukin-17A (IL-17A) by an anti-IL-17A antibody. Furthermore, the C-X-C motif chemokine receptor 4 (CXCR4) antagonist AMD3100, also reversed anti-CTLA-4-mediated cardiotoxicity in TAC mice. Overall, these results suggest that the administration of anti-CTLA-4 antibody exacerbates pressure overload-induced heart failure by activating and promoting the differentiation of Th17 cells. Targeting the CXCR4/Th17/IL-17A axis could be a potential therapeutic strategy for mitigating immune checkpoint inhibitors-induced cardiotoxicity.

CXCR4/CXCL12 axis: "old" pathway as "novel" target for anti-inflammatory drug discovery

Inflammation is the body's defense response to exogenous or endogenous stimuli, involving complex regulatory mechanisms. Discovering anti-inflammatory drugs with both effectiveness and long-term use safety is still the direction of researchers' efforts. The inflammatory pathway was initially identified to be involved in tumor metastasis and HIV infection. However, research in recent years has proved that the CXC chemokine receptor type 4 (CXCR4)/CXC motif chemokine ligand 12 (CXCL12) axis plays a critical role in the upstream of the inflammatory pathway due to its chemotaxis to inflammatory cells. Blocking the chemotaxis of inflammatory cells by CXCL12 at the inflammatory site may block and alleviate the inflammatory response. Therefore, developing CXCR4 antagonists has become a novel strategy for anti-inflammatory therapy. This review aimed to systematically summarize and analyze the mechanisms of action of the CXCR4/CXCL12 axis in more than 20 inflammatory diseases, highlighting its crucial role in inflammation. Additionally, the anti-inflammatory activities of CXCR4 antagonists were discussed. The findings might help generate new perspectives for developing anti-inflammatory drugs targeting the CXCR4/CXCL12 axis.

2-Deoxy-D-glucose ameliorates inflammation and fibrosis in a silicosis mouse model by inhibiting hypoxia-inducible factor-1α in alveolar macrophages

Inhaling silica causes the occupational illness silicosis, which mostly results in the gradual fibrosis of lung tissue. Previous research has demonstrated that hypoxia-inducible factor-1α (HIF-1α) and glycolysis-related genes are up-regulated in silicosis. The role of 2-deoxy-D-glucose (2-DG) as an inhibitor of glycolysis in silicosis mouse models and its molecular mechanisms remain unclear. Therefore, we used 2-DG to observe its effect on pulmonary inflammation and fibrosis in a silicosis mouse model. Furthermore, in vitro cell experiments were conducted to explore the specific mechanisms of HIF-1α. Our study found that 2-DG down-regulated HIF-1α levels in alveolar macrophages induced by silica exposure and reduced the interleukin-1β (IL-1β) level in pulmonary inflammation. Additionally, 2-DG reduced silica-induced pulmonary fibrosis. From these findings, we hypothesize that 2-DG reduced glucose transporter 1 (GLUT1) expression by inhibiting glycolysis, which inhibits the expression of HIF-1α and ultimately reduces transcription of the inflammatory cytokine, IL-1β, thus alleviating lung damage. Therefore, we elucidated the important regulatory role of HIF-1α in an experimental silicosis model and the potential defense mechanisms of 2-DG. These results provide a possible effective strategy for 2-DG in the treatment of silicosis.