Saharan dust induces the lung disease-related cytokines granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor

Models to evaluate the pulmonary toxicity of desert dust and what we have learned from them so far: a mini-review

Millions of people worldwide are exposed to aerosolised desert dust and are at risk of the adverse respiratory health effects it causes. This mini-review gives an overview of the study types that can be used to assess the respiratory toxicity of desert dust and the insights gained from these studies. We highlight the main advantages and disadvantages of epidemiological, in vivo, and in vitro studies. Regarding in vitro studies, we discuss models of increasing complexity, i.e., traditional submerged cell cultures, air-liquid interface cultures, organ-on-a-chip models, organoids, and precision-cut lung slices. Epidemiological studies have shown increased short-term mortality and exacerbated acute and chronic respiratory diseases after desert dust events. In contrast, a connection to the onset of chronic diseases is more difficult to prove. In vivo and in vitro studies have particularly addressed the cellular and molecular effects of desert dust. It was found that desert dust activates immune cells and induces the expression of inflammatory cytokines and oxidative stress markers. The specific effects and their extent vary between dust samples from different sources. The investigation of the role of the composition is still immature and needs further effort including more extensive screenings. The advancement of easy-to-handle and realistic pulmonary in vitro models is required to automate screenings, support mechanistic insights, and enable the assessment of long-term exposure scenarios. In agreement with striving to develop new approach methodologies, such advancements can reduce and replace animal experiments and strongly benefit the translatability of research outcomes to human health protection.

Assessment of air pollutant O3 pulmonary exposure using a bronchus-on-chip model coupling with atmospheric simulation chamber

Heavy air pollution is now a serious public health issue. Many studies have shown strong connections between ozone (O3) with the occurrence and development of various respiratory diseases. However, the exact mechanism is still a matter of debate. In this work, we developed a human bronchial epithelial cells (HBECs) chip that differentiates different functional cell groups of ciliated, goblet, and club cells to model the pulmonary bronchial barrier function. Concurrently, we designed an Atmospheric-Biochemical-Chip reactor (ABC-reactor), a system that could simulate different levels of O3 and particle matter. Coupling the HBECs-on-chip model with ABC-reactor, we investigated the effects of O3 at 400 ppbv and 200 ppbv on the pulmonary bronchial barrier. Our results showed that O3 at 400 ppbv severely disrupted the bronchial barrier and upregulated the expression of pro-inflammatory cytokines. However, 200 ppbv of O3 did not cause severe barrier impairment but induced cellular dysfunction, apoptosis, and reduced immune response. These suggest that bronchial trauma does exist at 200 ppbv of O3 but is not easily detected by the body due to the reduced inflammatory response. However, more research is needed to understand if the trauma induced by 200 ppbv of O3 is reversible and the interaction mechanism between O3 and PM2.5.

Saharan dust and respiratory health: Understanding the link between airborne particulate matter and chronic lung diseases (Review)

Saharan dust storms, which originate from the Sahara desert, have a significant impact on global health, especially on respiratory conditions of populations exposed to fine particulate matter that travels across continents. Dust events, characterized by the transport of mineral dust such as quartz and feldspar, lead to the suspension of particulate matter in the atmosphere, capable of traversing long distances and affecting air quality adversely. Emerging research links these dust episodes with increased incidence and exacerbation of lung diseases, including asthma and chronic obstructive pulmonary disease, especially during peak dust emission seasons from November to March. The present review aims to synthesize existing scientific evidence concerning the respiratory health impacts of Saharan dust, examining the environmental dynamics of dust transmission, the physical and chemical properties of dust particles, and their biological effects on human health. Further, it assesses epidemiological studies and discusses public health strategies for mitigating adverse health outcomes. Given the complexity of interactions between atmospheric dust particles and respiratory health, this review also highlights critical research gaps that need attention to better understand and manage the health risks associated with Saharan dust.

Toxic effect and mRNA mechanism of moon dust simulant induced pulmonary inflammation in rats

Moon dust presents a significant hazard to manned moon exploration missions, yet our understanding of its toxicity remains limited. The objective of this study is to investigate the pattern and mechanism of lung inflammation induced by subacute exposure to moon dust simulants (MDS) in rats. SD rats were exposed to MDS and silica dioxide through oral and nasal inhalation for 6 hours per day continuously for 15 days. Pathological analysis indicated that the toxicity of MDS was lower than that of silica dioxide. MDS led to a notable recruitment and infiltration of macrophages in the rat lungs. Material characterization and biochemical analysis revealed that SiO2, Fe2O3, and TiO2 could be crucial sources of MDS toxicity. The study revealed that MDS-induced oxidative stress response can lead to pulmonary inflammation, which potentially may progress to lung fibrosis. Transcriptome sequencing revealed that MDS suppresses the PI3K-AKT signaling pathway, triggers the Tnfr2 non-classical NF-kB pathway and IL-17 signaling pathway, ultimately causing lung inflammation and activating predominantly antioxidant immune responses. Moreover, the study identified the involvement of upregulated genes IL1b, csf2, and Sod2 in regulating immune responses in rat lungs, making them potential key targets for preventing pulmonary toxicity related to moon dust exposure. These findings are expected to aid in safeguarding astronauts against the hazardous effects of moon dust and offer fresh insights into the implications and mechanisms of moon dust toxicity.