Copper in airborne fine particulate matter (PM2.5) from urban sites causes the upregulation of pro-inflammatory cytokine IL-8 in human lung epithelial A549 cells

Air-Liquid Interface Microfluidic Monitoring Sensor Platform for Studying Autophagy Regulation after PM2.5 Exposure

Undoubtedly, a deep understanding of PM2.5-induced tumor metastasis at the molecular level can contribute to improving the therapeutic effects of related diseases. However, the underlying molecular mechanism of fine particle exposure through long noncoding RNA (lncRNA) regulation in autophagy and, ultimately, lung cancer (LC) metastasis remains elusive; on the other hand, the related monitoring sensor platform used to investigate autophagy and cell migration is lacking. Herein, this study performed an air-liquid interface microfluidic monitoring sensor (AIMMS) platform to analyze human bronchial epithelial cells after PM2.5 stimulation. The multiomics analysis [RNA sequencing (RNA-seq) on lncRNA and mRNA expressions separately] showed that MALAT1 was highly expressed in the PM2.5 treatment group. Furthermore, RNA-seq analysis demonstrated that autophagy-related pathways were activated. Notably, the main mRNAs associated with autophagy regulation, including ATG4D, ATG12, ATG7, and ATG3, were upregulated. Inhibition or downregulation of MALAT1 inhibited autophagy via the ATG4D/ATG12/ATG7/ATG3 pathway after PM2.5 exposure and ultimately suppressed LC metastasis. Thus, based on the AIMMS platform, we found that MALAT1 might become a promising therapeutic target. Furthermore, this low-cost AIMMS system as a fluorescence sensor integrated with the cell-monitor module could be employed to study LC migration after PM2.5 exposure. With the fluorescence cell-monitoring module, the platform could be used to observe the migration of LC cells and construct the tumor metastasis model. In the future, several fluorescence probes, including nanoprobes, could be used in the AIMMS platform to investigate many other biological processes, especially cell interaction and migration, in the fields of toxicology and pharmacology.

Association of multiple blood metals and systemic atherosclerosis: A cross-sectional study in the CAD population

BACKGROUND

Coronary atherosclerotic disease (CAD) is often accompanied by peripheral atherosclerosis, resulting in a higher risk of ischemia and cardiovascular death. Exposure to metals is associated with atherosclerotic plaques at specific sites. However, less is known about the effects of mixed metals on systemic atherosclerotic burden in CAD patients.

OBJECTIVES

To investigate the association of metal mixtures with systemic atherosclerotic burden in a CAD population.

METHODS

A cross-sectional study including 1562 CAD patients from Southwest China was conducted. The levels of 10 blood metals were measured via inductively coupled plasma spectrometry. More than one vessel with a stenosis ≥50% vessel diameter was defined as CAD. Carotid and lower limb atherosclerosis was assessed by using ultrasound, and coronary atherosclerosis was quantified via arterial angiography. Systemic atherosclerosis was scored according to the presence or absence of lesions at the three sites and the total number of lesions. To investigate the combined impacts and interaction effects of metals, Bayesian kernel machine regression was used. Weighted quantile regression was used to identify the contributions of the metals.

RESULTS

Significant overall associations of mixed metals with systemic atherosclerotic burden were found. These positive overall associations were mainly driven by Cd, Cu and Pb in systemic atherosclerosis. The main contributing factors were As and Cu for coronary atherosclerosis as well as Cd, Cu and Pb for carotid and lower limb atherosclerosis. Cd and Pb or Cr can interact, and Pb interacts with age, sex and alcohol.

CONCLUSIONS

In CAD patients, exposure to combinations of metals was highly positively associated with systemic atherosclerotic burden. These significant trends were more pronounced in the peripheral arteries and carotid arteries. Controlling environmental metal exposure can contribute to reducing systemic atherosclerosis in CAD patients.

Sestrin2/Keap1/Nrf2 pathway regulates mucus hypersecretion in pulmonary epithelium induced by traffic-related PM2.5 and water-soluble extracts

The involvement of fine particulate matter (PM2.5) exposure in the progression of asthma has been extensively discussed in epidemiological and experimental evidence, which aroused widespread attention. Asthma is characterized by mucus hypersecretion. This study investigates the underlying toxic mechanism of traffic-related PM2.5 (TRPM2.5) and water-soluble extracts (WSE) on mucus hypersecretion in the lungs of rats with asthma and 16HBE cells. The ovalbumin-induced rats were administrated by instillation of TRPM2.5 and WSE in the trachea once three days for eight times. The results showed that TRPM2.5 and WSE had an adverse impact on mucus secretion. Specifically, conspicuous mucus stains and increased goblet cells in the bronchial epithelium by PAS staining were found in lung tissues of rats with asthma; MUC5AC gene and protein expression levels in lung tissues of rats with asthma and 16HBE cells were elevated. In addition, TRPM2.5 and WSE triggered oxidative damage via upregulation of malondialdehyde and myeloperoxidase as well as activation of the Sestrin2/Keap1/Nrf2 signaling pathway. Conversely, the knockdown of Sestrin2 effectively inhibited TRPM2.5 and WSE-induced mucus hypersecretion, oxidative stress, and Keap1/Nrf2 signaling pathway and its downstream target gene NQO1. Collectively, it was demonstrated that TRPM2.5 and WSE induced mucus hypersecretion mediated by the Sestrin2/Keap1/Nrf2 pathway.