MAPK/AP-1 and ROS participated in ratio- and time-dependent interaction effects of deoxynivalenol and cadmium on HT-29 cells

Combined Toxicity Assessment of Deoxynivalenol and Pb2+ on HK-2 Cells Involved in Excessive ROS-Induced Ferroptosis

The cocontamination of food by several mycotoxins and heavy metals poses significant health risks, and their combined toxic effects remain poorly understood. Particularly, specific studies exploring their combined impact on ferroptosis remain limited. In this work, we investigated the combined toxic effects of a mycotoxin, called deoxynivalenol (DON), and a heavy metal, called plumbum (Pb), and explored the potential mechanisms of DON and Pb co-occurrence via excessive ROS-induced ferroptosis in HK-2 cells. It was found that combined toxicity of DON and Pb2+ showed a synergism at low concentrations and an antagonism at high concentrations. The increase of the ROS level and iron content as well as the change expression of four ferroptosis marker proteins were observed in DON and Pb2+ individual and combined groups. Furthermore, the addition of ferroptosis inhibitor Fer-1 could mitigate the imbalance of oxidative stress and ferroptosis. Our results suggest that the co-occurrence of DON and Pb2+ might pose a slight threat to the nephrotoxicity due to the interactions related to the excessive ROS-induced ferroptosis, which would provide valuable insights into their potential combined toxic impacts to human and animal health.

Cell signaling and epigenetic regulation of nicotine-induced carcinogenesis

Nicotine, a naturally occurring tobacco alkaloid responsible for tobacco addiction, has long been considered non-carcinogenic. However, emerging evidence suggests that nicotine may possess carcinogenic properties in mice and could be a potential carcinogen in humans. This review aims to summarize the potential molecular mechanisms underlying nicotine-induced carcinogenesis, with a specific focus on epigenetic regulation and the activation of nicotinic acetylcholine receptors (nAChRs) in addition to genotoxicity and excess reactive oxygen species (ROS). Additionally, we explore a novel hypothesis regarding nicotine's carcinogenicity involving the downregulation of stem-loop binding protein (SLBP), a critical regulator of canonical histone mRNA, and the polyadenylation of canonical histone mRNA. By shedding light on these mechanisms, this review underscores the need for further research to elucidate the carcinogenic potential of nicotine and its implications for human health.

In Vitro Assessment of Ozone-Treated Deoxynivalenol by Measuring Cytotoxicity and Wheat Quality

Deoxynivalenol (DON), a trichothecene mycotoxin, could lead to cytotoxicity in both animal bodies and plant seed cells. Ozone degradation technology has been applied to DON control. However, the safety and quality of the contaminated grain after DON degradation are largely obscured. In this work, we evaluated the cytotoxicity of ozone-treated DON through seed germination experiments and cytotoxicity tests. Cell experiments showed that the inhibition rate of HepG2 viability gradually increased within the concentrations of 1-10 mg/L of DON, alongside which an IC50 (half maximal inhibitory concentration) of 9.1 mg/L was determined. In contrast, degrading DON had no significant inhibitory effect on cell growth. Moreover, a 1-10 mg/L concentration of DON increased production of a large amount of reactive oxygen radicals in HepG2, with obvious fluorescence color development. However, fluorescence intensity decreased after DON degradation. Further, DON at a concentration of >1 mg/L significantly inhibited the germination of mung bean seeds, whereas no significant inhibition of their germination or growth were observed if DON degraded. Changes in total protein content, fatty acid value, and starch content were insignificant in wheat samples suffering ozone degradation, compared to the untreated group. Lastly, the ozone-treated wheat samples exhibited higher tenacity and whiteness. Together, our study indicated that the toxicity of DON-contaminated wheat was significantly reduced after ozone degradation.

From ribosome to ribotoxins: understanding the toxicity of deoxynivalenol and Shiga toxin, two food borne toxins

Ribosomes that synthesize proteins are among the most central and evolutionarily conserved organelles. Given the key role of proteins in cellular functions, prokaryotic and eukaryotic pathogens have evolved potent toxins to inhibit ribosomal functions and weaken their host. Many of these ribotoxin-producing pathogens are associated with food. For example, food can be contaminated with bacterial pathogens that produce the ribotoxin Shiga toxin, but also with the fungal ribotoxin deoxynivalenol. Shiga toxin cleaves ribosomal RNA, while deoxynivalenol binds to and inhibits the peptidyl transferase center. Despite their distinct modes of action, both groups of ribotoxins hinder protein translation, but also trigger other comparable toxic effects, which depend or not on the activation of the ribotoxic stress response. Ribotoxic stress response-dependent effects include inflammation and apoptosis, whereas ribotoxic stress response-independent effects include endoplasmic reticulum stress, oxidative stress, and autophagy. For other effects, such as cell cycle arrest and cytoskeleton modulation, the involvement of the ribotoxic stress response is still controversial. Ribotoxins affect one organelle yet induce multiple toxic effects with multiple consequences for the cell. The ribosome can therefore be considered as the cellular "Achilles heel" targeted by food borne ribotoxins. Considering the high toxicity of ribotoxins, they pose a substantial health risk, as humans are highly susceptible to widespread exposure to these toxins through contaminated food sources.

Deoxynivalenol: Emerging Toxic Mechanisms and Control Strategies, Current and Future Perspectives

Deoxynivalenol (DON) is the most frequently present mycotoxin contaminant in food and feed, causing a variety of toxic effects in humans and animals. Currently, a series of mechanisms involved in DON toxicity have been identified. In addition to the activation of oxidative stress and the MAPK signaling pathway, DON can activate hypoxia-inducible factor-1α, which further regulates reactive oxygen species production and cancer cell apoptosis. Noncoding RNA and signaling pathways including Wnt/β-catenin, FOXO, and TLR4/NF-κB also participate in DON toxicity. The intestinal microbiota and the brain-gut axis play a crucial role in DON-induced growth inhibition. In view of the synergistic toxic effect of DON and other mycotoxins, strategies to detect DON and control it biologically and the development of enzymes for the biodegradation of various mycotoxins and their introduction in the market are the current and future research hotspots.

Cigarette smoke triggers calcium overload in mouse hippocampal neurons via the ΔFOSB-CACNA2D1 axis to impair cognitive performance

A growing body of evidence shows that cigarette smoking impairs cognitive performance. The 'Calcium Hypothesis' theory of neuronopathies reveals a critical role of aberrant calcium signaling in compromised cognitive functions. However, the underlying implications of abnormalities in calcium signaling in the neurotoxicity induced by cigarette smoke (CS) have not yet been identified. CACNA2D1, an important auxiliary subunit involved in the composition of voltage-gated calcium channels (VGCCs), was reported to affect the calcium signaling in neurons by facilitating VGCCs-mediated Ca²⁺ influx. ΔFOSB, an alternatively-spliced product of the Fosb gene, is an activity-dependent transcription factor induced robustly in the brain in response to environmental stimuli such as CS. Interestingly, our preliminary bioinformatics analysis revealed a significant co-expression between ΔFOSB and CACNA2D1 in brain tissues of patients with neurodegenerative diseases characterized by progressive cognitive decline. Therefore, we hypothesized that the activation of the ΔFOSB-CACNA2D1 axis in response to CS exposure might cause dysregulation of calcium homeostasis in hippocampal neurons via VGCCs-mediated Ca²⁺ influx, thereby contributing to cognitive deficits. To this end, the present study established a CS-induced mouse model of hippocampus-dependent cognitive impairment, in which the activation of the ΔFOSB-CACNA2D1 axis accompanied by severe calcium overload was observed in the mouse hippocampal tissues. More importantly, ΔFOSB knockdown-/overexpression-mediated inactivation/activation of the ΔFOSB-CACNA2D1 axis interdicted/mimicked CS-induced dysregulation of calcium homeostasis followed by severe cellular damage in HT22 mouse hippocampal neurons. Mechanistically speaking, a further ChIP-qPCR assay confirmed the physical interaction between transcription factor ΔFOSB and the Cacna2d1 gene promoter, suggesting a direct transcriptional regulation of the Cacna2d1 gene by ΔFOSB. Overall, our current work aims to deliver a unique insight into the neurotoxic mechanisms induced by CS to explore potential targets for intervention.

Inflammation and apoptosis pathways mediated the stress response of Litopenaeus vannamei to acute cold and air exposure during waterless live transportation: Based on ultrastructure and transcriptome

the combination of acute cold (AC) and waterless duration (WD) constitutes the major environmental stress and induces the damage or even mortality to shrimp L. vannamei during live transport, whereas the responding mechanism to AC + WD at molecular level remains unknown. The present study aims to clarify the responding mechanism of L. vannamei to AC + WD stress by ultrastructural observation and transcriptomic analysis on hepatopancreas tissue. The results showed that the dramatical oxidative stress induced by AC + WD significantly mediated the alteration of amino acids and energy metabolism. Furthermore, KEGG pathway enrichment analysis revealed that the genes including DDO, GOT1, IDH1 and BBOX1 involved in energy metabolism and were significantly down-regulated, while some apoptosis- and inflammation-related genes such as DRONC, AP-1, and COX-2 were significantly up-regulated under AC + WD stress in comparison with those at normal control (all p < 0.05 or 0.01). These findings suggested that metabolic processes mediate the stress-induced damages of L. vannamei during waterless transport. Moreover, the significant overexpression of apoptosis-and inflammation-related proteins, and levels of inflammation cytokines in serum of shrimps strongly demonstrated the implication of inflammation and apoptosis pathways in stress-induced ultrastructural damage. These findings deepen our understanding into the response mechanisms of L. vannamei to AC + WD stress and provide the potential controlling biomarkers for transportation management.

Combined toxicity of food-borne mycotoxins and heavy metals or pesticides

Food can be contaminated by multiple classes of toxic substances, mainly including mycotoxins, heavy metals and pesticides, which leads to a possibility of simultaneous exposure to two or more food contaminants for humans. Thus, it is necessary to examine whether the combined exposure could result in enhanced toxicity. Initially, the studies on the combined toxicity of food contaminants mainly focus on the mixtures of same classes of food contaminants due to their co-occurrence feature in foodstuffs, such as mixtures of mycotoxins or mixtures of heavy metals. Given the possibility that consumers are likely exposed to mixtures of different classes of food contaminants, recently, studies on the combined toxicity of different classes of food contaminants have been receiving increasing attentions. In this review article, we summarize the findings of combined toxicity studies related to co-exposure to food-borne mycotoxins and other classes of food contaminants mainly heavy metals or pesticides, and propose issues that need to be addressed in future studies for more accurately performing risk assessment of co-exposure to mycotoxins and other classes of food contaminants.

The toxicity of cooking oil fumes on human bronchial epithelial cells through ROS-mediated MAPK, NF-κB signaling pathways and NLRP3 inflammasome

Cooking oil fumes (COFs) are the main pollutants in kitchen and indoor air, which threaten human health. Exposure to COFs may lead to respiratory diseases and impair pulmonary function. To investigate the toxicity of COFs on human bronchial epithelial cells (Beas-2B) and explore the underlying mechanisms, MTT assay was conducted to detect the viability of Beas-2B. Intracellular reactive oxygen species (ROS) levels and nitric oxide (NO) levels were determined with DCFH-DA assay and DAF-FM assay. The expression of genes involved in inflammation were measured with quantitative real-time PCR (qRT-PCR). The phosphorylation and the expression of proteins related to Mitogen-activated protein kinase (MAPK), NF-κB signaling pathways were measured with western blot. Our results revealed that COFs decreased cell viability, increased the ROS levels and NO levels and induced apoptosis in Beas-2B cells. The results of qRT-PCR and western blot showed that the expression of NLRP3, p65, iNOS, IL-1β, and the factors related to oxidative stress and inflammation increased, NF-κB signaling pathway and MAPK signaling pathway were activated. This study provided some useful information to evaluate the toxicity of COFs and revealed the possible mechanism for the damage on respiratory system induced by COFs.

Hexavalent chromium induces centrosome amplification through ROS-ATF6-PLK4 pathway in colon cancer cells

Centrosome amplification (CA) refers to a numerical increase in centrosomes resulting in cells with more than two centrosomes. CA has been shown to initiate tumorigenesis and increase the invasive potential of cancer cells in genetically modified experimental models. Hexavalent chromium is a recognized carcinogen that causes CA and tumorigenesis as well as promotes cancer metastasis. Thus, CA appears to be a biological link between chromium and cancer. In the present study we investigated how chromium triggers CA. Our results showed that a sub-toxic concentration of chromium induced CA in HCT116 colon cancer cells, resulted in the production of reactive oxygen species (ROS), activated ATF6 without causing endoplasmic reticulum stress, and upregulated the protein level of PLK4. Inhibition of ROS production, ATF6 activation, or PLK4 upregulation attenuated CA. Inhibition of ROS using N-acetyl-L-cysteine (NAC) inhibited chromium-induced activation of ATF6 and upregulation of PLK4. ATF6-specific siRNA knocked down the protein level and activation of ATF6, and upregulated PLK4, with no effect on ROS production. Knockdown of PLK4 protein had no effect on chromium-induced ROS production or activation of ATF6. In conclusion, our results suggest that hexavalent chromium induces CA via the ROS-ATF6-PLK4 pathway and provides molecular targets for inhibiting chromium-mediated CA, which may be useful for the assessment of CA in chromium-promoted tumorigenesis and cancer cell metastasis. This article is protected by copyright. All rights reserved.

Distribution, toxicity, interactive effects, and detection of ochratoxin and deoxynivalenol in food: A review

Mycotoxins are secondary metabolites of fungi that cause severe damage to agricultural products and food in the food supply chain. These detrimental pollutants have been directly linked with poor socioeconomic patterns and human health issues. Among the natural micropollutants, ochratoxin A (OTA) and deoxynivalenol (DON) are widely distributed in food materials. The primary occurrence of these mycotoxins is reported in almost all cereal grains and fresh agro-products. Both mycotoxins have shown harmful effects, such as nephrotoxic, hepatotoxic, and genotoxic effects, in humans due to their complex structural formation during the degradation/acetylation reaction. In addition, improper preharvest, harvest, and postharvest handling tend to lead to the formation of OTA and DON in various food commodities, which allows different harmful fungicides in practice. Therefore, this review provides more insight into the distribution and toxicity of OTA/DON in the food matrix and human health. Furthermore, the interactive effects of OTA/DON with co-contaminated organic and inorganic compounds are discussed. Finally, international regulation and mitigation strategies for detoxication are critically evaluated to meet food safety and good agriculture practices.

Melatonin prevents allergic airway inflammation in epicutaneously sensitized mice

PURPOSE

The pathological process of atopic dermatitis (AD) progressing into other types of allergic diseases such as asthma and allergic rhinitis during the first several years of life is often referred to as the atopic march. Although the phenomenon of atopic march has been recognized for decades, how asthma stems from AD is still not fully understood, confounding a universal strategy to effectively protect people from the atopic march.

METHODS

We established experimental atopic march mice by first inducing allergic dermatitis with 0.5% fluorescein isothiocyante (FITC) applied to the skin, followed by an ovalbumin (OVA) airway challenge. In addition, by examining serum immunoglobulin (Ig) concentrations, airway cytokines, the levels of oxidative stress markers, histopathological changes in lung tissue and airway hyperresponsiveness (AHR), we were able to validate the successful establishment of the model. Furthermore, by detecting the attenuating effects of melatonin (MT) and the levels of oxidative stress in the atopic march mice, we explored the potential molecular mechanisms involved in the development of atopic march.

RESULTS

By successfully establishing an experimental atopic march mouse model, we were able to demonstrate that overproduction of oxidative stress in the lung significantly up-regulated the activation of nuclear factor-κB (NF-κB) signaling pathways causing thymic stromal lymphopoietin (TSLP) release, which further promotes the development of atopic march.

CONCLUSIONS

To mitigate the development of the atopic march, antioxidants such as MT may be imperative to inhibit NF-κB activation in the lung, especially after the onset of AD.

Deoxynivalenol photocatalytic detoxification products alleviate intestinal barrier damage and gut flora disorder in BLAB/c mice

Deoxynivalenol (DON), a trichothecene mycotoxin, is one of the most globally prevalent mycotoxins mainly produced by Fusarium species. DON exposure can cause spectrum of symptoms such as nausea, vomiting, gastroenteritis, growth retardation, immunosuppression, and intestinal flora disorders in humans and animals. Therefore, the implication of DON degradation technology is of great significance for food safety. Recently, photocatalytic degradation technology has been applied for DON control. However, the toxicity of the intermediates identified in the degradation process was often ignored. In this work, based on previous successful degradation of DON and evaluation of the in vitro toxicity of DON photocatalytic detoxification products (DPDPs), we further studied the in vivo toxicity of DPDPs and mainly explored their effects on intestinal barrier function and intestinal flora in mice. The results demonstrated that the DPDPs treated with photocatalyst for 120 min effectively increased the expression of intestinal tight junction proteins and improved the disorder of gut flora. Meanwhile, compared with DON-exposed mice, the DPDPs reduced the level of inflammation and oxidative stress of intestinal tissue, and improved growth performance, enterohepatic circulation, energy metabolism, and autonomic activity. All the results indicated that the toxicity of the DPDPs irradiated for 120 min was much lower than that of DON or even nontoxic. Therefore, we hope that this photocatalytic degradation technology can be used as a promising tool for the detoxification of mycotoxins.