Polystyrene microplastics induce myocardial inflammation and cell death via the TLR4/NF-κB pathway in carp

Environmental toxicology of microplastic particles on fish: A review

The increase in plastic debris and its environmental impact has been a major concern for scientists. Physical destruction, chemical reactions, and microbial activity can degrade plastic waste into particles smaller than 5 mm, known as microplastics (MPs). MPs may eventually enter aquatic ecosystems through surface runoff. The accumulation of MPs in aquatic environments poses a potential threat to finfish, shellfish, and the ecological balance. This study investigated the effect of MP exposure on freshwater and marine fish. MPs could cause significant harm to fish, including physical damage, death, inflammation, oxidative stress, disruption of cell signalling and cellular biochemical processes, immune system suppression, genetic damage, and reduction in fish growth and reproduction rates. The activation of the detoxification system of fish exposed to MPs may be associated with the toxicity of MPs and chemical additives to plastic polymers. Furthermore, MPs can enhance the bioavailability of other xenobiotics, allowing these harmful substances to more easily enter and accumulate in fish. Accumulation of MPs and associated chemicals in fish can have adverse effects on the fish and humans who consume them, with these toxic substances magnifying as they move up the food chain. Changes in migration and reproduction patterns and disruptions in predator-prey relationships in fish exposed to MPs can significantly affect ecological dynamics. These interconnected changes can lead to cascading effects throughout aquatic ecosystems. Thus, implementing solutions like reducing plastic production, enhancing recycling efforts, using biodegradable materials, and improving waste management is essential to minimize plastic waste and its environmental impact.

Use of cardiac cell cultures from salmonids to measure the cardiotoxic effect of environmental pollutants

Environmental stressors such as micro- and nanosized plastic particles (MNPs) or crude oil have a detrimental effect on aquatic animals; however, the impact upon the cardiovascular system of fish remains relatively under-researched. This study presents a novel approach for investigating the effect of crude oil and MNPs on the cardiac system of fish. We used salmonid larvae and cardiac cell cultures derived from hearts of salmonid fish and exposed them to environmental stressors. Following exposure to plastic particles or crude oil, the larvae exhibited some variation in contraction rate. In contrast, significant alterations in the contraction rate were observed in all cardiac cell cultures. The greatest differences between the control and treatment groups were observed in cardiac cell cultures derived from older brown trout. Following 7 days of exposure to MNPs or crude oil in Atlantic salmon larval hearts or cardiac cell cultures, there were only minor responses noted in mRNA expression of the selected marker genes. These findings show the use of a novel in vitro technique contributing to the existing body of knowledge on the impact of MNPs and crude oil on the cardiovascular system of salmonids and the associated risk.

Efficacy of DHA-enriched phosphatidylserine and its underlying mechanism in alleviating polystyrene nanoplastics-induced hepatotoxicity in mice

OBJECTIVE

Plastic pollution has become a global pollution problem that cannot be ignored. As the main destination of human oral intake, the toxic effects of plastic on the digestive system represented by the intestine and liver are the focus of current research. Marine-derived DHA-PS has a variety of biological activities, mainly focusing on improving brain function and regulating lipid metabolism. However, whether it has an improvement effect on PS-NPs-induced hepato-intestinal injury and the underlying mechanism remain unclear.

METHODS

A murine liver injury model was established by gavage of PS-NPs for six weeks. By integrating approaches from lipidomics, transcriptomics, and gut microbiota analysis, the molecular mechanism by which DHA-PS alleviates PS-NPs-induced murine hepatotoxicity was explored through the "gut-liver axis".

RESULTS

Our findings reveal that prolonged exposure to PS-NPs results in significant murine liver damage and dysfunction, characterized by increased oxidative stress and inflammation, along with exacerbated hepatic lipid accumulation. Mechanistically, PS-NPs disrupt the hepatic SIRT1-AMPK pathway by suppressing the expression of SIRT1, AMPKα, and PPARα, while enhancing the expression of SREBP-1c, ultimately leading to disordered hepatic lipid metabolism. The sphingolipid and glycerophospholipid metabolic pathways were particularly affected. Additionally, in agreement with transcriptomic analyses, PS-NPs activate the hepatic TLR4/NF-κB pathway. At the same time, exposure to PS-NPs decreases the expression of ZO-1, occludin, and claudin-1, diminishes the relative abundance of beneficial gut bacteria (norank_f_Muribaculaceae, Akkermansia, and norank_f_norank_o_Clostridia_UCG-014), and increases the prevalence of pathogenic gut bacteria (Coriobacteriaceae_UCG-002 and Desulfovibrio), exacerbating liver injury through the gut-liver axis. However, administering DHA-PS (50 mg/kg) effectively alleviated these injuries.

CONCLUSION

This study was the first to employ multi-omics techniques to elucidate the potential mechanisms underlying hepatotoxicity induced by PS-NPs, thereby supporting the use of DHA-PS as a dietary supplement to mitigate the effects of nanoplastic pollutants.

Quercetin attenuates SiO2-induced ZBP-1-mediated PANoptosis in mouse neuronal cells via the ROS/TLR4/NF-κb pathway

With the increasing development of the society, silicon dioxide (SiO2) has been used in various fields, such as agriculture, food industry, etc., and its residues can pose a potential health threat to organisms. Quercetin (Que) is a potent free radical scavenger commonly found in plants. C57BL/6 mice were chosen to established a mouse model of SiO2 exposure and Que antagonism to investigate the mechanism of action of Que in rescuing the toxic damage of SiO2 on mouse cerebellum tissue. The results showed that cytoplasmic vacuolization, and inflammatory cell infiltration caused by SiO2 were alleviated by the addition of Que, and reduced oxidative stress in mouse cerebellum, alleviated the activation of TLR4 pathway induced by SiO2, and substantially reduced the occurrence of ZBP-1-mediated PANoptosis induced by SiO2 exposure in mouse cerebellum. In NS20Y cells, the oxidative stress activator (Elesclomol) and inhibitor N-acetyl cysteine (NAC), and the NF-κB activator 2 (NA2) were added. Elesclomol and NAC confirm the involvement of ROS in regulating the TLR4/NF-κB pathway, the TLR4/NF-κB pathway regulated ZBP-1-mediated PANoptosis in cerebellum and NS20Y cells induced by SiO2 exposure. In conclusion, the present experimental data suggest that Que mitigates the onset of ZBP-1-mediated PANoptosis in neuronal cells induced by SiO2 through the ROS/TLR4/NF-κB pathway. The present experimental findings help to understand the detoxification effect of Que in more tissues and provide an important reference for the rescue of organisms in long-term SiO2 environment.

Green tea polyphenols alleviate TBBPA-induced gastric inflammation and apoptosis by modulating the ROS-PERK/IRE-1/ATF6 pathway in mouse models

Green tea polyphenols (GTP), an important phytochemical in the daily human diet, bind to various cellular receptors and exert anti-inflammatory and antioxidant benefits. The environmental contaminant tetrabromobisphenol A (TBBPA) enters the digestive system through multiple pathways, resulting in oxidative stress (OS), gastroenteritis, and mucosal injury. The aim of this study was to explore the molecular mechanisms of TBBPA-induced gastritis in mice treated with GTP in vivo and in an in vitro model. The results showed that exposure to TBBPA increased reactive oxygen species (ROS) levels, activated oxidative stress (OS) induced endoplasmic reticulum stress (ERS), and the expression of endoplasmic reticulum stress-related factors (e.g., GRP78, PERK, IRE-1, ATF-6, etc.) increased. The inflammatory pathway NF-κB was activated, and the pro-inflammatory factors TNF-α, IL-1β, and IL-6 increased, while triggering a cascade reaction mediated by caspase-3. However, the addition of GTP could inhibit OS, restore the balance of endoplasmic reticulum homeostasis, and improve the inflammatory infiltration and apoptosis of gastric mucosal epithelial cells. Therefore, GTP alleviated ERS, reduced inflammation and apoptosis, and restored the gastric mucosal barrier by alleviating TBBPA-induced OS in mouse gastric tissues and GES-1 cells. This provides basic information for exploring the antioxidant mechanism of GTP and further investigating the toxic effects of TBBPA on mouse gastric mucosa.

Dietary kelp meal improves serum antioxidants, intestinal immunity, and lipid metabolism in hybrid snakehead (Channa maculata ♀ × Channa argus ♂)

BACKGROUND

Dietary kelp possesses a variety of useful biological qualities but does not have a toxic effect on the host. In this study, we examine how kelp dietary supplementation enhances the serum biochemistry, intestinal immunity, and metabolism of hybrid snakehead. A total of 810 juvenile hybrid snakeheads (Channa maculata ♀ × Channa argus ♂), with an initial average weight of 11.4 ± 0.15 g, were allocated randomly to three treatment groups (three replicates per group). The fish were fed for 60 days with isonitrogenous and isolipidic diets. The groups were the control group (C) (20% high-gluten flour), the medium replacement group (MR) (10% high-gluten flour and 10% kelp meal), and the full replacement group (FR) (0% high-gluten flour and 15% kelp meal).

RESULTS

The results showed that dietary kelp increased the activity of serum antioxidant enzymes significantly and decreased the content of serum malondialdehyde (MDA) in hybrid snakeheads, with significant changes in the FR group (P < 0.05). The intestinal morphology results showed that dietary kelp helped to increase the specific surface area of intestinal villi, which was beneficial for intestinal digestion and absorption. According to transcriptome and quantitative real-time polymerase chain reaction (qRT-PCR) analysis, dietary kelp can improve the expression of intestinal immunity and metabolism-related pathways. Among them, immune-related genes MHC1 and HSPA1 were significantly up-regulated, and IGH, MHC2, and IL-8 were significantly down-regulated (P < 0.05). Lipid metabolism-related genes DGAT2, FABP2, RXRα, and PLPP1 were all significantly up-regulated (P < 0.05).

CONCLUSION

Dietary kelp can effectively improve the antioxidant function of hybrid snakeheads, improve intestinal morphology, reduce intestinal inflammation, and promote intestinal lipid synthesis and transportation, thereby improving intestinal immunity and metabolic functions. © 2024 Society of Chemical Industry.

Plastic particle impacts on the cardiovascular system and angiogenesis potential

The extensive application of plastics in different sectors such as packaging, building, textiles, consumer products, and several industries has increased in recent years. Emerging data have confirmed that plastic wastes and segregates are problematic issues in aquatic and terrestrial ecosystems. The decomposition of plastic particles (PPs) leads to the release of microplastics (MPs) and nanoplastics (NPs) into the surrounding environment and entry of these particles will be problematic in unicellular and multicellular creatures. It was suggested that PPs can easily cross all biological barriers and reach different organs, especially the cardiovascular system, with the potential to modulate several molecular pathways. It is postulated that the direct interaction of PPs with cellular and subcellular components induces genotoxicity and cytotoxicity within the cardiovascular system. Meanwhile, being inert carriers, PPs can intensify the toxicity of other contaminants inside the cardiovascular system. Here, in this review article, several underlying mechanisms related to PP toxicity in the cardiovascular system were discussed in detail.

Effect of micro- and nanoplastic particles on human macrophages

Micro- and nanoplastics (MNPs) are ubiquitous in the environment, resulting in the uptake of MNPs by a variety of organisms, including humans, leading to particle-cell interaction. Human macrophages derived from THP-1 cell lines take up Polystyrene (PS), a widespread plastic. The question therefore arises whether primary human macrophages also take up PS micro- and nanobeads (MNBs) and how they react to this stimulation. Major aim of this study is to visualize this uptake and to validate the isolation of macrophages from peripheral blood mononuclear cells (PBMCs) to assess the impact of MNPs on human macrophages. Uptake of macrophages from THP-1 cell lines and PBMCs was examined by transmission electron microscopy (TEM), scanning electron microscopy and live cell imaging. In addition, the reaction of the macrophages was analyzed in terms of metabolic activity, cytotoxicity, production of reactive oxygen species (ROS) and macrophage polarization. This study is the first to visualize PS MNBs in primary human cells using TEM and live cell imaging. Metabolic activity was size- and concentration-dependent, necrosis and ROS were increased. The methods demonstrated in this study outline an approach to assess the influence of MNP exposure on human macrophages and help investigating the consequences of worldwide plastic pollution.

High-fat diet disrupts the gut microbiome, leading to inflammation, damage to tight junctions, and apoptosis and necrosis in Nyctereutes procyonoides intestines

Given the burgeoning Nyctereutes procyonoides breeding industry and its growing scale, it is imperative to investigate the impact of high-fat diets on the health of these animals. This study involved 30 male Nyctereutes procyonoides of comparable weights (3 kg ±0.5), randomly assigned to either a control group or a high-fat diet group (n = 15 each). The latter group was fed a mixture of lard and basal diet in a 2:5 ratio, establishing a high-fat diet model in Nyctereutes procyonoides. This diet induced diarrhea and histopathological changes in the Nyctereutes procyonoides. Analysis of the small intestine contents using 16S rRNA sequencing revealed a high-fat diet-induced disruption in the gut microbiota. Specifically, Escherichia-Shigella emerged as the biomarker in the high-fat diet group (P = 0.049), while Vagococcus was prevalent in the control group (P = 0.049), indicating a significant increase in harmful bacteria in the high-fat diet group. Furthermore, this disrupted gut flora correlated with inflammation and oxidative stress, as evidenced by marked increases in TNF-α (P < 0.01), IL-1β (P < 0.05), and IL-6 (P < 0.05) levels, measured via q-PCR, Western blot, and oxidative stress assays. In addition, q-PCR analysis revealed significant upregulation of apoptosis and necrosis markers, including Bax, Caspase3, Caspase9, Caspase12, RIPK3, and RIPK1 (P < 0.01 to P < 0.001), and a concurrent downregulation of the anti-apoptotic gene Bcl-2 (P < 0.01) in the high-fat diet group, consistent with protein expression trends. These findings suggest that a high-fat diet alters the gut microbiome toward a more harmful bacterial composition, escalating inflammatory responses and intestinal tissue permeability, culminating in intestinal cell apoptosis and necrosis.IMPORTANCEThis study examines the impact of high-fat diets on Nyctereutes procyonoides. Our research established a Nyctereutes procyonoides model on a high-fat diet, revealing significant health impacts, such as diarrhea, histological anomalies, and alterations in the gut microbiota. These findings emphasize the importance of preventing health issues and promoting sustainable industry growth. They highlight the significant impact of diet on gut microbiota and overall animal health.

The mechanism of selenium regulating the permeability of vascular endothelial cells through selenoprotein O

Vascular diseases, a leading cause of death in human, are strongly associated with pathological damage to blood vessels. The selenoprotein (Sel) have been reported to play important roles in vascular disease. However, the role of SelO in vascular disease has not been conclusively investigated. The present experiment was to investigate the regulatory mechanism of the effect of SelO on the permeability of vascular endothelial. The H.E staining, FITC-Dextran staining, Dil-AC-LDL staining and FITC-WGA staining showed that vascular structure was damaged, and intercellular junctions were disrupted with selenium (Se)-deficient. Immunohistochemistry, qPCR and Western blot revealed decreased expression of the adhesion plaque proteins vinculin, talin and paxillin, decreased expression of the vascular connectivity effector molecules connexin, claudin-1 and E-cadherin and increased expression of JAM-A and N-cadherin, as well as decreased expression of the ZO-1 signaling pathways ZO-1, Rock, rhoGEF, cingulin and MLC-2. In a screening of 24 Sel present in mice, SelO showed the most pronounced changes in vascular tissues, and a possible association between SelO and vascular intercellular junction effectors was determined using IBM SPSS Statistics 25. Silencing of SelO, vascular endothelial intercellular junction adverse effects present. The regulatory relationship between SelO and vascular endothelial intercellular junctions was determined. The results showed that Se deficiency lead to increased vascular endothelial permeability and vascular tissue damage by decreasing SelO expression, suggesting a possible role for SelO in regulating vascular endothelial permeability.

Tea polyphenols alleviate TBBPA-induced inflammation, ferroptosis and apoptosis via TLR4/NF-κB pathway in carp gills

The extensive application of Tetrabromobisphenol A (TBBPA) leads to the pollution of part of the water environment and brings great safety risks to aquatic animals. As a natural extract, tea polyphenols (TPs) have antioxidant and anti-inflammatory effects. Gills are one of the immune organs of fish and constitute the first line of defense of the immune system. However, it was unclear whether TPs could mitigate TBBPA-induced gills injury. Therefore, an animal model was established to investigate the effect of TPs on TBBPA-induced gills. The results indicated that TBBPA changed the coefficient and tissue morphology of carp gills. In addition, TBBPA induced oxidative stress and inflammation, leading to ferroptosis and apoptosis in carp gills. Dietary addition of TPs significantly improved the antioxidant capacity of carp, effectively inhibited the overexpression of TLR4/NF-κB and its mediated inflammatory response. Moreover, TPs restored iron metabolism, reduced the expression of pro-apoptotic factors thereby alleviating ferroptosis and apoptosis in carp gills. This study enriched the protective effect of TPs and provided a new way to improve the innate immunity of carp.

Polyethylene microplastics induced inflammation via the miR-21/IRAK4/NF-κB axis resulting to endoplasmic reticulum stress and apoptosis in muscle of carp

As a widespread environmental pollutant, microplastics pose a great threat to the tissues and organs of aquatic animals. The carp's muscles are necessary for movement and survival. However, the mechanism of injury of polyethylene microplastics (PE-MPs) to carp muscle remains unclear. Therefore, in this study, PE-MPs with the diameter of 8 μm and the concentration of 1000 ng/L were used to feed carp for 21 days, and polyethylene microplastic treatment groups was established. The results showed that PE-MPs could cause structural abnormalities and disarrangement of muscle fibers, and aggravate oxidative stress in muscles. Exposure to PE-MPs reduced microRNA (miR-21) in muscle tissue, negatively regulated Interleukin-1 Receptor Associated Kinase 4 (IRAK4), activated Nuclear Factor Kappa-B (NF-κB) pathway, induced inflammation, and led to endoplasmic reticulum stress and apoptosis. The present study provides different targets for the prevention of muscle injury induced by polyethylene microplastics.

Effect of polypropylene microplastics on virus resistance in spotted sea bass (Lateolabrax maculatus)

Microplastics (MPs) pollution is a hot issue of global concern. Polypropylene microplastics (PP-MPs) age quickly in the marine environment and break down into smaller particles because of their relatively low temperature resistance, poor ultraviolet resistance, and poor antioxidant capacity, making them one of the major pollutants in the ocean. We assessed whether long-term exposure to micron-sized PP-MPs influences fish susceptibility to viral diseases. We found that exposure to PP-MPs (1-6 μm and 10-30 μm) at concentrations of 500 and 5000 μg/L resulted in uptake into spleen and kidney tissues of Lateolabrax maculatus. Increased activation of melanomacrophage centers was visible in histopathological sections of spleen from fish exposed to PP-MPs, and greater deterioration was observed in the spleen of fish infected by largemouth bass ulcerative syndrome virus after PP-MPs exposure. Additionally, exposure to PP-MPs led to significant cytotoxicity and a negative impact on the antiviral ability of cells. PP-MPs exposure had inhibitory or toxic effects on the immune system in spotted sea bass, which accelerated virus replication in vivo and decreased the expression of the innate immune- and acquired immune related genes in spleen and kidney tissues, thus increasing fish susceptibility to viral diseases. These results indicate that the long-term presence of micron-sized PP-MPs might impact fish resistance to disease, thereby posing a far-reaching problem for marine organisms.

Astilbin antagonizes developmental cardiotoxicity after cadmium exposure in chicken embryos by inhibiting endoplasmic reticulum stress and maintaining calcium homeostasis

Cadmium (Cd) is a dangerous heavy metal with high toxicity that is known to impair development. Astilbin (ASB) is a protective flavonoid compound. We aimed to explore whether ASB can antagonize the myocardial developmental toxicity of Cd exposure. Cd (2 µg) and/or ASB (0.002 µg) were injected into embryonized eggs that were 1 day old. Histological examinations revealed Cd-induced ventricular dilation, reduced wall thickness, and disrupted myocardial fiber connections, while co-administration of ASB mitigated these effects. Electron microscopy confirmed ASB's ability to counteract Cd-induced myocardial cell myofibril damage. Real-time quantitative PCR (QRT-PCR) and western blot (WB) molecular investigations revealed that Cd increased endoplasmic reticulum stress in myocardial tissue and primary cardiomyocytes, as shown by raised expression of stress-related genes (GRP78, XBP1, GRP94, ATF4, ATF6, IRE1, and CHOP). Moreover, Cd disrupted calcium homeostasis, affecting important genes linked to Ca2+ channels and causing an excess of Ca2+ in the cytoplasm. In addition, we detected genes related to development and differentiation-related genes in myocardial tissue and primary cardiomyocytes. The results showed that the downregulation of transcription factors in the IrxA cluster, Mefs, and Tbxs families after Cd exposure indicated that cardiac transcription was hindered and cardiac markers (TnnT2, TnnC1, Gata4, Gata6, and Nkx2-5) were abnormally expressed. ASB successfully mitigated these disturbances. During the cell cycle, primary cardiomyocytes undergo growth arrest in flow cytometry. These results suggest that the maturation and differentiation of cardiomyocytes are inhibited after Cd exposure, and ASB has an antagonistic effect on Cd. The present study indicated that Cd could trigger developmental cardiotoxicity in chicken embryos and primary cardiomyocytes by endoplasmic reticulum stress and Ca2+ overload, respectively, while ASB has an antagonistic effect.

Polyethylene microplastics cause apoptosis via the MiR-132/CAPN axis and inflammation in carp ovarian

Microplastics (MPs) are widely distributed pollutants in the environment and accumulate in the aquatic environment due to human activities. Carp, a common edible aquatic organism, has been found to accumulate MPs in body. MicroRNA (miRNAs) is a non-coding short RNA that regulates protein expression by binding to target genes in various physiological processes such as proliferation, differentiation and apoptosis. The ovary is a crucial role in carp reproduction. In this study, we established a model of carp exposed to polyethylene microplastics (PE-MPs) in the aquatic environment to investigate the specific mechanism of PE-MPs causing ovarian injury and the involvement of miR-132/calpain (CAPN) axis. H&E stained sections revealed that PE-PMs induced inflammation in ovarian tissues and impaired oocyte development. TUNEL analysis showed an increased rate of apoptosis in ovarian cells treated with PE-PMs. RT-PCR and Western Blot assays confirmed that exposure to PE-MPs significantly decreased miR-132 expression while increasing CAPN expression at both mRNA and protein levels. The concentration of calcium ions was significantly increased in tissues, leading to CAPN enzyme activity increase. The expression of mitochondrial damage-related genes (bax, AIF, cyt-c, caspase-7, caspase-9, and caspase-3) was higher while the expression of anti-apoptotic genes (bcl-2 and bcl-xl) was lower. Protein levels of bax, AIF, caspase-3, bcl-2 and bcl-xl changed accordingly with the genetic alterations. Additionally, we discovered that PE-MPs can activate the p65 factor through the TRAF6/NF-kB pathway resulting in elevated production of pro-inflammatory factors IL-6, IL-1β and TNF-a which contribute to ovarian inflammation development. This study investigates the impact of PE-MPs on carp ovarian function and provides insights into miRNAs' role and their target genes.

Trimethyltin chloride exposure induces apoptosis and necrosis and impairs islet function through autophagic interference

Trimethyltin chloride (TMT) is a highly toxic organotin compound often used in plastic heat stabilizers, chemical pesticides, and wood preservatives. TMT accumulates mainly through the environment and food chain. Exposure to organotin compounds is associated with disorders of glucolipid metabolism and obesity. The mechanism by which TMT damages pancreatic tissue is unclear. For this purpose, a subacute exposure model of TMT was designed for this experiment to study the mechanism of damage by TMT on islet. The fasting blood glucose and blood lipid content of mice exposed to TMT were significantly increased. Histopathological and ultrastructural observation and analysis showed that the TMT-exposed group had inflammatory cell infiltration and necrosis. Then, mouse pancreatic islet tumour cells (MIN-6) were treated with TMT. Autophagy levels were detected by fluorescence microscopy. Real-time quantitative polymerase chain reaction and Western blotting were used for verification. A large amount of autophagy occurred at a low concentration of TMT but stagnated at a high concentration. Excessive autophagy activates apoptosis when exposed to low levels of TMT. With the increase in TMT concentration, the expression of necrosis-related genes increased. Taken together, different concentrations of TMT induced apoptosis and necrosis through autophagy disturbance. TMT impairs pancreatic (islet β cell) function.

Ferulic acid alleviates carp brain damage and growth inhibition caused by avermectin by modulating the Nrf2/Keap1 and NF-κB signaling pathways

The increasing concern over environmental pollution caused by the pesticide avermectin used in aquaculture has attracted significant attention. The use of avermectin, a neurotoxic pesticide, in aquatic environments leads to toxic effects on non-target organisms, particularly causing harm to fish. The phenolic compound ferulic acid possesses excellent anti-inflammatory and antioxidant capabilities. This study was conducted by establishing a chronic exposure experiment to avermectin, proposes the use of ferulic acid as a dietary additive to protect the carp brain from damage caused by exposure to avermectin. Furthermore, it investigates the anti-inflammatory and antioxidant effects of ferulic acid in the carp brain under chronic exposure to avermectin. The experimental results demonstrate that ferulic acid can alleviate brain tissue inflammation and oxidative stress by modulating the Nrf2/Keap1 and NF-κB signaling pathways. It protects the carp brain from chronic avermectin-induced damage, preserves the integrity of the carp blood-brain barrier, enhances the levels of feeding factors, and thereby alleviates carp growth inhibition. These findings provide new therapeutic strategies and a theoretical foundation for the sustainable development of carp aquaculture.

Cypermethrin induces apoptosis, autophagy and inflammation via ERS-ROS-NF-κB axis in hepatocytes of carp (Cyprinus carpio)

Cypermethrin (CYP, IUPAC name: [cyano-(3-phenoxyphenyl)methyl] 3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane-1-carboxylate) is a pyrethroid insecticide that poses a threat to the health of humans and aquatic animals due to its widespread use and environmental contamination. However, the mechanism of CYP on apoptosis, autophagy and inflammation in hepatocytes of carp (Cyprinus carpio) is unknown. We hypothesized that CYP caused damage to hepatocytes through the endoplasmic reticulum stress (ERS) pathway, CCK-8 was used to detect the toxic effects of different doses of CYP on hepatocytes, and finally low (L, 10 μM), medium (M, 40 μM), and high (H, 80 μM) doses of CYP was selected to construct the model. ROS staining, oxidative stress-related indices (MDA, CAT, T-AOC, SOD), AO/EB staining, MDC staining, and the expression levels of related genes were detected using qRT-PCR and western blot. Our results showed that CYP exposure resulted in an increase in ROS production, an increase in MDA content, and a decrease in the activity of CAT, SOD, and T-AOC in hepatocytes; the proportion of apoptotic, necrotic, and autophagic cells increased significantly in a dose-dependent manner. We also found that CYP exposure increased the expression levels of endoplasmic reticulum-related genes (GRP78, PERK, IRE-1, ATF-6 and CHOP), apoptosis (Bcl-2, Bax, Caspase-3, Caspase-9 and Cyt-c) and autophagy-related genes (LC3b, Beclin1 and P62) also showed dose-dependent changes, and the expression levels of inflammation-related genes (NF-κB, TNF-α, IL-1β, IL-6) were also significantly elevated. Thus, we demonstrated that CYP exposure caused apoptosis, autophagy and inflammation in hepatocytes via ERS-ROS-NF-κB axis. This research contributes to our understanding of the molecular mechanisms underlying CYP-induced damage in hepatocytes of carp (Cyprinus carpio).

Mulberrin alleviates triclocarban induced hepatic apoptosis and inflammation by regulating the ROS/NF-κB pathway in grass carp

Triclocarban (TCC) is commonly used in household, personal care and industrial products and has been frequently detected in different aquatic ecosystems. Mulberrin (Mul) is a key component of the traditional Chinese medicine Romulus Mori with antioxidant and anti-inflammatory properties. The present study aimed to investigate the hepatotoxic effects of TCC in aquatic organisms and explore the protective roles of Mul. Herein, we found that exposure to TCC at environmentally realistic concentrations (5 μg/L) could impair liver function, along with impaired antioxidant defense and infiltration of inflammatory cells. Additionally, we found that TCC increased the ratio of TUNEL staining positive cells, accompanied by upregulation of pro-apoptotic protein (Bax, caspase3 and caspase9), and downregulation of anti-apoptotic proteins (Bcl2). In contrast, Mul supplementation reversed the hepatic pathological damage, ROS elevation, and apoptosis induced by TCC, likely due to hyperactivation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling. Additionally, Mul supplementation suppressed the mRNA levels of proinflammatory factors (TNF-α, IL-1β, IFN-γ, IL-6 and IL-8) and enhanced the mRNA levels of anti-inflammatory factors (TGFβ1, TGFβ2, IL4, IL10 and IL11) in the liver of carp. We also discovered that Mul supplementation suppressed TCC-induced nuclear nuclear factor κB (NF-κB) elevation. In conclusion, Mul enhances Nrf2 signaling cascades and counteracts the NF-κB inflammatory program to rescue hepatotoxicity induced by TCC, providing new insights into the hepatotoxic effects of TCC and potential protection strategies for heart injury induced by TCC.

Microplastics induced inflammation and apoptosis via ferroptosis and the NF-κB pathway in carp

Microplastics (MPs), a new class of pollutant that threatens aquatic biodiversity, are becoming increasingly prevalent around the world. Fish growth may be severely inhibited by microplastics, resulting in severe mortality. Exposure to microplastics increases the likelihood of intestinal injuries, but the underlying mechanisms remain equivocal. The objective of this study was to investigate the potential toxic mechanisms underlying microplastic-induced intestinal injury in fish and to assist researchers in identifying novel therapeutic targets. In this study, a model of carp exposed to microplastics was established successfully. Histological observation showed that exposure to polyethylene microplastics caused damage to the intestinal mucosal surface and a significant increase in goblet cells, which aggregated on the surface of the mucosa. The mucosal layer was observed to fall off. Lymphocytes in the intestinal wall proliferated and aggregated. TUNEL staining showed that apoptosis occurred in the group exposed to microplastics. The qPCR results showed that the expression of Ferroptosis apoptotic factors COX-2 and ACSL4 was upregulated, while the expression of TFRC, FIH1, SLC7A11, and GPX4 was downregulated. The NF-κB pathway (p-p65, IκBα), inflammatory cytokines (TNF-α, IL-8, IL-6) and apoptosis genes (Bax, Caspase3) were upregulated. Semi-quantitative detection of related proteins by Western blotting was consistent with the gene expression results. In addition, the ELISA assay showed that lipid peroxidation and inflammatory cytokines (TNF-α, IL-1β, IL-6) were increased in the microplastic exposed group. To conclude, lipid peroxidation induced by microplastics activates the NF-κB pathway and causes ferroptosis, ultimately resulting in intestinal damage and cellular apoptosis.

Rosmarinic acid alleviates intestinal inflammatory damage and inhibits endoplasmic reticulum stress and smooth muscle contraction abnormalities in intestinal tissues by regulating gut microbiota

The host-bacterial interactions play the key role in inflammatory bowel disease (IBD). Dysbiosis of the intestinal flora can lead to pathological changes in the intestine. Rosmarinic acid (RA) is a natural phenolic acid compound with antioxidant, anti-cancer, anti-inflammatory, anti-apoptotic, anti-fibrotic, and anti-bacterial activities that has a palliative effect on acute IBD. We have established an in vivo model for mice. Histological staining was performed to directly observe RA alterations in the intestinal tract. The alteration of RA on mouse intestinal flora was observed by 16S rRNA high-throughput sequencing, and the effect of RA on intestinal mechanism of action was detected by qPCR and western blot. The results showed that RA had a significant protective effect on the intestine. RA upregulated the abundance of Lactobacillus johnsonii and Candidatus Arthromitus sp SFB-mouse-NL and downregulated the abundance of Bifidobacterium pseudolongum, Escherichia coli, and Romboutsia ilealis. RA downregulated the expressions of ROCK, RhoA, CaM, MLC, MLCK, ZEB1, ZO-1, ZO-2, occludin, E-cadherin, IL-1β, IL-6, TNF-α, GRP78, PERK, IRE1, ATF6, CHOP, Caspase12, Caspase9, Caspase3, Bax, Cytc, RIPK1, RIPK3, MLKL, and upregulated the expression of IL-10 and Bcl-2. These results displayed that RA inhibited the inflammation, which is caused by tight junction damage, by repairing intestinal flora dysbiosis, relieved endoplasmic reticulum stress, inhibited cell death, and corrected smooth muscle contractile dysregulation. The results of this study revealed RA could have a protective effect on the small intestine of mice by regulating intestinal flora. IMPORTANCE Inflammatory bowel disease (IBD) is a chronic, relapsing, remitting disorder of the gastrointestinal system. In this study, we investigated the protective effects of rosmarinic acid on the intestinal tract. The results showed that RA was effective in reducing inflammatory damage, endoplasmic reticulum stress, smooth muscle contraction abnormalities, and regulating intestinal flora disorders.

TBBPA causes inflammation and cell death via the ROS/NF-κB pathway in the gastric mucosa

Tetrabromobisphenol A (TBBPA) is a common brominated flame retardant that has a wide range of toxic effects on organisms. However, the mechanism of the toxic effects of TBBPA on the digestive system has rarely been studied. The purpose of this study was to investigate the mechanism of TBBPA toxicity on the gastric mucosa. In this study, TBBPA (mixed with corn oil) was administered by gavage at doses of 0 mg/kg (CG), 10 mg/kg and 20 mg/kg. The results showed that the levels of ROS, MDA and LPO were increased, and the activities of antioxidant enzymes were decreased. Large amounts of ROS activated the NF-κB pathway, leading to the development of an inflammatory response. The expression of BCL family and Caspase (Cas) family genes was increased, inducing apoptosis. The RIP3/MLKL pathway was activated, leading to cell necrosis. In summary, TBBPA can cause damage to the gastric mucosa through oxidative stress, leading to increased ROS activation of the NF-κB pathway. Treatment with the antioxidant NAC alleviated the damage to the gastric mucosa caused by TBBPA.

Zinc deficiency causes oxidative stress, endoplasmic reticulum stress, apoptosis and inflammation in hepatocytes in grass carp

A lack of the trace element zinc (Zn) in freshwater environments causes slow growth and malnutrition and affects the normal biological functions of organisms. In this study, a Zn deficiency model of grass carp hepatocytes was established with TPEN. Acetylcysteine (NAC) was used as an inhibitor. TPEN was added to L8824 cell culture medium, and LDH, AST, ALT, and AKP activities were enhanced in a Zn-deficient environment, leading to abnormal hepatopancreas function. Fluorescence microscopy showed an increase in ROS levels, and antioxidant enzyme activity assays revealed that SOD, CAT, GSH-PX, and T-AOC activities were decreased, indicating oxidative stress caused by Zn deficiency. The RT‒PCR results showed that the mRNA expression of GRP78, PERK, EIF2α, ATF4, and Chop was increased due to the addition of TPEN. Calcium kits showed increased Ca²⁺ levels. The RT‒PCR results showed that the mRNA expression levels of Caspase-12, Caspase-9, Caspase-3, and PARP apoptotic were increased due to the addition of TPEN. RT‒PCR and ELISA showed that the expression levels of interleukin-1β (IL-1β), interleukin-8 (IL-8), tumour necrosis factor (TNF-α), and inducible nitric oxide synthase (iNOS) were increased. This led to the conclusion that Zn deficiency in the freshwater environment caused inflammation and apoptosis in hepatocytes in grass carp. For the first time, apoptosis caused by endoplasmic reticulum stress in grass carp hepatocytes due to Zn deficiency was studied in the context of Ca²⁺. The present study provided some insight into the adverse effects of Zn deficiency in freshwater environments on fish.

Selenium deficiency induced inflammation and apoptosis via NF-κB and MAPKs pathways in muscle of common carp (Cyprinus carpio L.)

Selenium (Se), one of the essential trace elements of fish, regulates immune system function and maintains immune homeostasis. Muscle is the important tissue that generate movement and maintain posture. At present, there are few studies on the effects of Se deficiency on carp muscle. In this experiment, carps were fed with dietary with different Se content to successfully establish a Se deficiency model. Low-Se dietary led to the decrease of Se content in muscle. Histological analysis showed that Se deficiency resulted in muscle fiber fragmentation, dissolution, disarrangement and increased myocyte apoptosis. Transcriptome revealed a total of 367 differentially expressed genes (DEGs) were screened, including 213 up-regulated DEGs and 154 down-regulated DEGs. Bioinformatics analysis showed that DEGs were concentrated in oxidation-reduction process, inflammation and apoptosis, and were related to NF-κB and MAPKs pathways. Further exploration of the mechanism showed that Se deficiency led to excessive accumulation of ROS, decreased the activity of antioxidant enzymes, and also resulted in increased expression of the NF-κB and MAPKs pathways. In addition, Se deficiency significantly increased the expressions of TNF-α, IL-1β and IL-6, and the pro-apoptotic factors BAX, p53, caspase-7 and caspase-3, while decreased the expressions of anti-apoptotic factors Bcl-2 and Bcl-xl. In conclusion, Se deficiency reduced the activities of antioxidant enzymes and led to excessive accumulation of ROS, which caused oxidative stress and affected the immune function of carp, leading to muscle inflammation and apoptosis.