Astaxanthin alleviates fine particulate matter (PM2.5)-induced lung injury in rats by suppressing ferroptosis and apoptosis

Mechanistic role of environmental toxicants in inducing cellular ferroptosis and its associated diseases

Due to exposure factors such as industrial exhaust, sewage discharge, pesticide runoff, automobile exhaust, and fuel combustion, environmental toxicants are widely present in daily life. Organisms are exposed to these environmental toxicants through contaminated air, food, and drinking water, and these environmental toxicants enter the human body and cause cytotoxicity and diseases through various pathways. As a new cell death mode that is different from cell necrosis, apoptosis, and autophagy, ferroptosis are mainly dysregulation of intracellular iron metabolism, lipid metabolism disorders, and the dysregulation of the antioxidant defense system, leading to lipid peroxidation and ultimately to the rupture of the cell membrane, damage, and cell death. Studies have shown that environmental toxicants induce a series of diseases, such as digestive diseases, urinary diseases, respiratory diseases, neurological disorders, and reproductive diseases, through the above mechanisms. We elaborate the mechanism of common environmental toxicants in inducing ferroptosis and the related systemic diseases mediated through the ferroptosis to provide the theoretical basis for preventing and treating environmental toxicant-related diseases. Nonetheless, our understanding of ferroptosis remains incomplete. For example, mechanisms and methods for the selective control of ferroptosis remain elusive, elucidating these mechanisms and strategies may be critical for leveraging knowledge of ferroptosis to treat related diseases.

Ferroptosis induced by environmental pollutants and its health implications

Environmental pollution represents a significant public health concern, with the potential health risks associated with environmental pollutants receiving considerable attention over an extended period. In recent years, a substantial body of research has been dedicated to this topic. Since the discovery of ferroptosis, an iron-dependent programmed cell death typically characterized by lipid peroxidation, in 2012, there have been significant advances in the study of its role and mechanism in various diseases. A growing number of recent studies have also demonstrated the involvement of ferroptosis in the damage caused to the organism by environmental pollutants, and the molecular mechanisms involved have been partially elucidated. The targeting of ferroptosis has been demonstrated to be an effective means of ameliorating the health damage caused by PM2.5, organic and inorganic pollutants, and ionizing radiation. This review begins by providing a summary of the most recent and important advances in ferroptosis. It then proceeds to offer a critical analysis of the health effects and molecular mechanisms of ferroptosis induced by various environmental pollutants. Furthermore, as is the case with all rapidly evolving research areas, there are numerous unanswered questions and challenges pertaining to environmental pollutant-induced ferroptosis, which we discuss in this review in an attempt to provide some directions and clues for future research in this field.

Astaxanthin mitigates doxorubicin-induced cardiotoxicity via inhibiting ferroptosis and autophagy: a study based on bioinformatic analysis and in vivo/vitro experiments

Background

Doxorubicin (DOX), a widely employed chemotherapeutic agent in cancer treatment, has seen restricted use in recent years owing to its associated cardiotoxicity. Current reports indicate that doxorubicin-induced cardiotoxicity (DIC) is a complex phenomenon involving various modes of cell death. Astaxanthin (ASX), a natural carotenoid pigment, has garnered significant attention for its numerous health benefits. Recent studies have shown that ASX has a broad and effective cardiovascular protective effect. Our study aims to investigate the protective effects of ASX against DIC and elucidate its underlying mechanisms. This has substantial practical significance for the clinical application of DOX.

Methods

Bioinformatic analyses were conducted using transcriptomic data from the gene expression omnibus (GEO) database to identify key mechanisms underlying DIC. Network pharmacology was employed to predict the potential pathways and targets through which ASX exerts its effects on DIC. In vitro experiments, following pretreatment with ASX, H9C2 cells were exposed to DOX. Cell viability, injury and the protein expression levels associated with ferroptosis and autophagy were assessed. In the animal experiments, rats underwent 4 weeks of gavage treatment with various doses of ASX, followed by intraperitoneal injections of DOX every 2 days during the final week. Histological, serum, and protein analyses were conducted to evaluate the effects of ASX on DIC.

Results

The bioinformatics analysis revealed that ferroptosis and autophagy are closely associated with the development of DIC. ASX may exert an anti-DIC effect by modulating ferroptosis and autophagy. The experimental results show that ASX significantly mitigates DOX-induced myocardial tissue damage, inflammatory response, oxidative stress, and damage to H9C2 cells. Mechanistically, ASX markedly ameliorates levels of ferroptosis and autophagy both in vitro and in vivo. Specifically, ASX upregulates solute carrier family 7 member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4), while downregulating the expression of transferrin receptor 1 (TFRC), ferritin heavy chain (FTH1) and ferritin light chain (FTL). Additionally, ASX enhances the expression of P62 and decreases levels of Beclin1 and microtubule-associated proteins light chain 3 (LC3).

Conclusion

Our results indicate that ferroptosis and autophagy are critical factors influencing the occurrence and progression of DOX-induced cardiotoxicity. ASX can alleviate DIC by inhibiting ferroptosis and autophagy.

Sinensetin, a polymethoxyflavone from citrus fruits, ameliorates LPS-induced acute lung injury by suppressing Txnip/NLRP3/Caspase-1/GSDMD signaling-mediated inflammatory responses and pyroptosis

Sinensetin (SIN), a polymethoxylated flavonoid, exists widely in citrus fruits with abundant biological activities, such as antioxidant and anti-inflammatory properties, delaying the progression of lung fibers and ameliorating inflammatory lung injury. Herein, an in vivo model of LPS-induced acute lung injury (ALI) in mice and an in vitro model of LPS + IFN-γ-induced M1 polarization in RAW264.7 cells were established to assess the effects and molecular mechanisms of SIN in ameliorating ALI. In the present study, the results showed that SIN significantly reduced BALF IL1β, IL6, and TNF-α levels and neutrophil infiltration, inhibited lung tissue COX2 and iNOS expression, reduced serum and lung tissue inflammatory factor levels, and attenuated lung tissue inflammatory infiltration and ROS levels in animal experiments. RNA sequencing analysis showed that SIN markedly inhibited the expression of inflammation-related pathway genes such as NOD-like receptor signaling. Further mechanistic studies confirmed that SIN significantly inhibited the dissociation of Txnip and Trx-1 and decreased the expression of NLRP3, ASC, pro-Caspase-1, cleavage Caspase-1 p10, NEK7, Caspase-8, IL1β, IL18, and GSDMD. Meanwhile, SIN docked to NLRP3 with strong affinity and bound stably in the hydrophobic docking pocket. Similarly, the same results were observed in in vitro macrophage M1 polarization experiments. In conclusion, the results revealed that SIN ameliorated the onset and progression of ALI by inhibiting Txnip/NLRP3/Caspase-1/GSDMD signaling-mediated inflammatory responses and pyroptosis. These findings emphasize the significant role of SIN in ameliorating ALI and provide insights into the strategy for exploring the functional effects of foods.

Association between carotenoids and the prevalence of chronic obstructive pulmonary disease in the United States

BACKGROUND

Previous studies mainly concentrated on examining the correlation between single carotenoids and Chronic obstructive pulmonary disease (COPD). However, these findings have been inconsistent.

OBJECTIVES

This study aimed to evaluate both the individual and overall associations of carotenoids with the prevalence of COPD.

METHODS

This study comprised 2,939 participants chosen from the National Health and Nutrition Examination Survey (NHANES) 2017-2018. The logistic regression, quantile-based G-computation regression (qgcomp), and Bayesian kernel machine regression (BKMR) models were employed to explore the association between carotenoids and the prevalence of COPD. Mediation analyses were also conducted to explore the underlying mechanism of carotenoids on COPD.

RESULTS

Individuals diagnosed with COPD had significantly lower serum carotenoid concentrations than those without COPD. We found a negative relationship between combined carotenoids and the prevalence of COPD, and lutein and zeaxanthin and alpha cryptoxanthin were identified as the main contributors to this negative association. Moreover, eosinophil acted as a mediator in the relationship between lutein and zeaxanthin, alpha cryptoxanthin, and the prevalence of COPD, with mediating proportions of 2.75 % and 3.67 %.

CONCLUSION

A negative association was observed between combined carotenoids and COPD prevalence, with lutein and zeaxanthin, and alpha cryptoxanthin identified as the main contributors. Eosinophils could potentially mediate the association between carotenoids and COPD.