Analysis of particulate matter-induced alteration of genes and related signaling pathways in the respiratory system.

Airborne particulate matter (PM) is a global environmental risk factor threatening human health and is a major cause of cardiovascular and respiratory disease-associated death. Current studies on PM exposure have been limited to large-scale cohort and epidemiological investigations, emphasizing the need for detailed individual-level studies to uncover specific differentially expressed genes and their associated signaling mechanisms. Herein, we revealed that PM exposure significantly upregulated inflammatory and immune responses, such as cytokine-mediated signaling pathways, complement system, and the activation and migration of immune cells in gene set enrichment analysis of our RNA sequencing (RNAseq) data. Remarkably, we discovered that the broad gene expression and signaling pathways mediated by macrophages were predominantly expressed in the respiratory system following PM exposure. Consistent with these observations, individual PMs, classified by aerodynamic size and origin, significantly promoted macrophage recruitment to the lungs in the mouse lung inflammation model. Additionally, we confirmed that RNAseq observations from the respiratory system were reproduced in murine bone marrow-derived macrophages and the alveolar macrophage cell line MH-S after individual PM exposure. Our findings demonstrated that PM exposure augmented broad inflammatory and immune responses in the respiratory system and suggested the reinforcement of global strategies for reducing particulate air pollution to prevent respiratory diseases and their exacerbation.

Artemisia gmelinii Extract Attenuates Particulate Matter-Induced Neutrophilic Inflammation in a Mouse Model of Lung Injury.

Particulate matter (PM) induces and augments oxidative stress and inflammation, leading to respiratory diseases. Although Artemisia gmelinii Weber ex Stechm has antioxidant and anti-inflammatory effects, there are no reports on whether Artemisia gmelinii extract (AGE) regulates lung inflammation in a PM-induced model. Thus, we investigated the protective effects of AGE using a PM-induced mouse lung inflammation model. AGE significantly decreased the expression of inflammatory chemokines, neutrophil extracellular trap formation, and the total number of inflammatory cells in the bronchoalveolar lavage fluid (BALF). Furthermore, AGE attenuated lung inflammation through the suppression of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)/mitogen-activated protein kinase (MAPK) signaling pathway, while promoting the nuclear factor erythroid-2-related factor 2 (NRF2)/heme oxygenase-1 (HO-1) signaling pathway in lung tissues. Concordant with these observations, AGE suppressed inflammatory cytokines, chemokines, reactive oxygen species, NETosis, myeloperoxidase, and neutrophil elastase by decreasing the mRNA expression of High mobility group box 1, Runt-related transcription factor 1, and Kruppel-like factor 6 in differentiated HL-60 cells. In summary, our data demonstrated that AGE suppresses PM-induced neutrophil infiltration, lung damage, and pulmonary inflammation by suppressing NF-κB/MAPK signaling pathways and enhancing the NRF2/HO-1 signaling pathway. These findings suggest that AGE administration is an effective approach for preventing and treating PM-induced respiratory inflammation.

Bulb of Lilium longiflorum Thunb Extract Fermented with Lactobacillus acidophilus Reduces Inflammation in a Chronic Obstructive Pulmonary Disease Model.

Chronic obstructive pulmonary disease (COPD), one of the leading causes of death worldwide, is caused by repeated exposure to harmful matter, such as cigarette smoke. Although Lilium longiflorum Thunb (LLT) has anti-inflammatory effects, there is no report on the fermented LLT bulb extract regulating lung inflammation in COPD. Thus, we investigated the protective effect of LLT bulb extract fermented with Lactobacillus acidophilus 803 in COPD mouse models induced by cigarette smoke extract (CSE) and porcine pancreas elastase (PPE). Oral administration of the fermented product (LS803) suppressed the production of inflammatory mediators and the infiltration of immune cells involving neutrophils and macrophages, resulting in protective effects against lung damage. In addition, LS803 inhibited CSE- and LPS-induced IL-6 and IL-8 production in airway epithelial H292 cells as well as suppressed PMA-induced formation of neutrophil extracellular traps in HL-60 cells. In particular, LS803 significantly repressed the elevated IL-6 and MIP-2 production after CSE and LPS stimulation by suppressing the activity of the nuclear factor kappa-light-chain-enhancer of activated B (NFκB) in mouse peritoneal macrophages. Therefore, our results suggest that the fermented product LS803 is effective in preventing and alleviating lung inflammation.