Neutrophil infiltration is frequently observed in lung cancer tissues. Extracellular RNAs (exRNAs) may facilitate tumor progression. The present study investigated the cross-talk of tumor exRNAs and neutrophil extracellular traps (NETs) in lung cancer. Lewis lung carcinoma (LLC) cells were cultured with the deprived sera. And the cell culture supernatants (CCS) were analyzed in vitro and in vivo . The results revealed that exRNAs from lung cancer CCS promoted the inflammatory cytokine interleukin-1β and reduced the vascular cell adhesion molecule-1 expression in lung epithelial cells. Lung cancer CCS-treated epithelial cells induced the production of NETs. By contrast, NETs reduced the tight junction protein claudin-5 in epithelial cells. Furthermore, NETs caused the necrosis of epithelial cells, which resulted in the release of exRNAs. In mice, lung cancer cells instilled in the lung recruited neutrophils and initiated NETs. In patients with lung cancer, NETs were also observed. These results suggested that exRNAs in the cell culture supernatant may indirectly induce NETs and contribute to lung cancer oncogenesis.

Overproduction of pro-inflammatory cytokines in the aged, which is called inflammaging, leads to the deterioration of periodontitis. Toll-like receptor 4 (TLR4) plays a role in the regulation of cellular senescence, and its expression increases with age. However, there has been limited research into the molecular mechanisms underlying the onset of periodontal inflammaging, and the interplay between TLR4 and inflammaging. In the present study, wild-type and TLR4 gene knockout mice were used to investigate the activation of the TLR4 pathway in mouse periodontitis and the expression of the nucleotide-binding and oligomerization domain-like receptor 3 (NLRP3) inflammasome, an upstream immune checkpoint during the development of inflammaging. Activation of TLR4 in a mouse model of periodontitis enhanced the expression of a senescence-associated secretory phenotype (SASP), which boosted the inflammaging process. Conversely, TLR4 activation downregulated the expression of B cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) and promoted the priming of NLRP3 inflammasome, both of which are regulators of SASP. Treating gingival fibroblasts with Bmi-1 inhibitor PTC209, it was demonstrated that TLR4 activated the NLRP3 pathway and the inflammaging process by suppressing Bmi-1. In addition, there was a significant reduction in the expression of Bmi-1 expression in the gingiva of patients with periodontitis compared with healthy controls. In conclusion, the present study demonstrated that TLR4 acted by inhibiting Bmi-1 to enhance the NLRP3 pathway and SASP factors. This cascade of reactions may contribute to the senescence of the periodontium.

Lung cancer is the leading cause of cancer-associated mortality. Tumor-associated neutrophils represent a large portion of inflammatory cells within the lung tumor microenvironment. However, the roles of neutrophil extracellular traps (NETs) in lung cancer remain unclear. In the present study, it was identified that Lewis lung carcinoma cells actively released the danger-associated molecular pattern protein high mobility group box 1 (HMGB1). Furthermore, HMGB1 in lung cancer cell supernatants promoted the formation of neutrophil extracellular traps (NETs), which was dependent on Toll-like receptor 4 (TLR4). The downstream molecules of TLR4, including myeloid differentiation factor 88, TIR-domain-containing adapter-inducing interferon-β, p38 mitogen-activated protein kinases (p38 MAPKs) and extracellular signal-regulated kinases (ERKs), were activated during the formation of NETs. In addition, inhibition of p38 MAPKs or ERKs significantly decreased NETs. Morphine, an additional ligand for TLR4, aggravated the NETs induced by lung cancer cells. The present study revealed novel mechanisms in tumor-associated NET formation.

Background Vascular calcification (VC), associated with enhanced cardiovascular morbidity and mortality, is characterized by the osteogenic transdifferentiation of vascular smooth muscle cells. Inflammation promotes VC initiation and progression. Interleukin (IL)‐29, a newly discovered member of type III interferon, has recently been implicated in the pathogenesis of autoimmune diseases. Here we evaluated the role of IL‐29 in the VC process and underlying inflammatory mechanisms. Methods and Results The mRNA expression of IL‐29 was significantly increased and positively associated with an increase in BMP2 (bone morphogenetic protein 2) mRNA level in calcified carotid arteries from patients with coronary artery disease or chronic kidney disease. IL‐29 and BMP2 proteins are colocalized in human calcified arteries. IL‐29 binding to its specific receptor IL‐28Rα (IL‐28 receptor α) (IL‐29/IL‐28Rα) inhibited the proliferation of rat vascular smooth muscle cells without altering cell apoptosis or migration. IL‐29 promoted the calcification of rat vascular smooth muscle cells and their osteogenic transdifferentiation in vitro as well as the rat aortic ring calcification ex vivo, induced by the calcification medium or osteogenic medium. The procalcification effect of IL‐29 was reduced by pharmacological inhibition of IL‐29/IL‐28Rα binding as well as suppression of janus kinase 2/signal transducer and activator of transcription pathway activation, accompanied by decreased BMP2 expression in the cultured rat vascular smooth muscle cells. Conclusions These results suggest an important role of IL‐29 in VC development, at least partly, via activating the janus kinase 2/signal transducer and activator of transcription 3 signaling. Inhibition of IL‐29 or its specific receptor, IL‐28Rα, may provide a novel strategy to reduce VC in patients with vascular diseases.