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

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.

Transcriptional regulation of Znt family members znt4, znt5 and znt10 and their function in zinc transport in yellow catfish (Pelteobagrus fulvidraco)

The study characterized the transcriptionally regulatory mechanism and functions of three zinc (Zn) transporters (znt4, znt5 and znt10) in Zn2+ metabolism in yellow catfish (Pelteobagrus fulvidraco), commonly freshwater fish in China and other countries. We cloned the sequences of znt4 promoter, spanning from -1217 bp to +80 bp relative to TSS (1297 bp); znt5, spanning from -1783 bp to +49 bp relative to TSS (1832 bp) and znt10, spanning from -1923 bp to +190 bp relative to TSS (2113 bp). In addition, after conducting the experiments of sequential deletion of promoter region and mutation of potential binding site, we found that the Nrf2 binding site (-607/-621 bp) and Klf4 binding site (-5/-14 bp) were required on znt4 promoter, the Mtf-1 binding site (-1674/-1687 bp) and Atf4 binding site (-444/-456 bp) were required on znt5 promoter and the Atf4 binding site (-905/-918 bp) was required on znt10 promoter. Then, according to EMSA and ChIP, we found that Zn2+ incubation increased DNA affinity of Atf4 to znt5 or znt10 promoter, but decreased DNA affinity of Nrf2 to znt4 promoter, Klf4 to znt4 promoter and Mtf-1 to znt5 promoter. Using fluorescent microscopy, it was revealed that Znt4 and Znt10 were located in the lysosome and Golgi, and Znt5 was located in the Golgi. Finally, we found that znt4 knockdown reduced the zinc content of lysosome and Golgi in the control and zinc-treated group; znt5 knockdown reduced the zinc content of Golgi in the control and zinc-treated group and znt10 knockdown reduced the zinc content of Golgi in the zinc-treated group. High dietary zinc supplement up-regulated Znt4 and Znt5 protein expression. Above all, for the first time, we revealed that Klf4 and Nrf2 transcriptionally regulated the activities of znt4 promoter; Mtf-1 and Atf4 transcriptionally regulated the activities of znt5 promoter and Atf4 transcriptionally regulated the activities of znt10 promoter, which provided innovative regulatory mechanism of zinc transporting in yellow catfish. Our study also elucidated their subcellular location, and regulatory role of zinc homeostasis in yellow catfish.

Exploring the mechanism of intestinal injury induced by Bisphenol S in freshwater crayfish (Procambarus clarkii): Molecular and biochemical approaches

Bisphenol S (BPS) is extensively utilized in various industries such as plastic manufacturing, food packaging, and electronics. The release of BPS into aquatic environments has been observed to have negative impacts on aquatic ecosystems. Research has shown that exposure to BPS can have adverse effects on the health of aquatic animals. This study aimed to explore the mechanism of oxidative stress and endoplasmic reticulum stress induced in freshwater crayfish (Procambarus clarkii) by exposure to BPS (0 µg/L, 1 µg/L, 10 µg/L, and 100 µg/L) for 14 days. The results showed that BPS exposure resulted in elevated levels of reactive oxygen species (ROS) and malondialdehyde (MDA) and severe intestinal histological damage. In addition, oxidative stress can occur in the body by inhibiting the activity of antioxidant enzymes and the expression of related genes. BPS exposure induced a significant increase in the relative mRNA expression levels of inflammatory cytokines (NF-κB and TNF-α) and key unfolded protein response (UPR) related genes (Bip, Ire1, and Xbp1). At the same time, BPS exposure also induced up-regulation of apoptosis genes (Cytc and Casp3), suggesting that UPR and Nrf2-Keap1 signaling pathways may play a protective role in the process of apoptosis and oxidative stress. In conclusion, Our findings present the initial evidence that exposure to environmentally relevant levels of BPS can lead to intestinal injury through various pathways, highlighting concerns about the potential harm at a population level from BPS and other bisphenol analogs.

Effects of low protein feed on hepato-intestinal health and muscle quality of grass carp (Ctenopharyngodon idellus)

In this study, grass carp (33.28 ± 0.05 g) were fed three diets for 8 weeks: control (crude protein [CP] 30%, crude lipid [CL] 6%), low protein (LP; CP16%, CL6%), and low protein with high-fat (LPHF; CP16%, CL10%). The final body weight decreased in the LP and LPHF groups compared to the Control (P < 0.05). Liver triglycerides, total cholesterol, and nonesterified fatty acids were higher in the LP group than the Control, whereas these indexes in the LPHF group were higher than those in the LP group (P < 0.05). The LP group had intestinal barrier damage, while the LPHF group had a slight recovery. TNF-α, IL-8, and IL-1β content were lower in the LP group than in the Control (P < 0.05), and even higher in the LPHF group (P < 0.05). The expressions of endoplasmic reticulum stress-related genes Activating transcription factor 6 (ATF-6) and Glucose-regulated protein (GRP78) were higher in the LPHF group against the LP group (P < 0.05). The IL-1β and TNF-α content negatively correlated with intestinal Actinomycetes and Mycobacterium abundance (P < 0.05). The muscle fiber diameter was smaller in both the LP and LPHF groups than the control (P < 0.05), with the LP group showing metabolites related to protein digestion and absorption, and LPHF group exhibiting metabolites related to taste transmission. The results demonstrate reducing dietary protein affects growth, causing liver lipid accumulation, reduced enteritis response, and increased muscle tightness, while increasing fat content accelerates fat accumulation and inflammation.

Assessing microbiological and heavy metal pollution in surface waters associated with potential human health risk assessment at fish ingestion exposure

Fish represent a significant source of nutrients but also cause negative health effects due to their bioaccumulation capacity for pollutants. The aim of this study was to examine the transfer of metals from the water of several rivers (Somes, Tisa, Sasar, Lapus, Lăpusel) to fish (Caras sp) tissue (subcutaneous fat, muscles, liver, intestines, kidneys, gills, brain, and eyes) and to identify and assess the carcinogenic and non-carcinogenic health risks of Arsenic (As), Cadmium (Cd), Nickel (Ni), Manganese (Mn), Cooper (Cu), Lead (Pb), Chromium (Cr) and Zinc (Zn) through the ingestion of fish (muscles and subcutaneous fat tissues). The obtained results indicated that a diet consisting of fish is particularly vulnerable, particularly in children compared to adults. The risk assessment results were below the threshold limit, although the fish samples contained heavy metals, with values exceeding the permitted limits of Fe (4.41-1604 mg/kg), Cr (727-4155 µg/kg), Zn (4.72-147 mg/kg), and Ni (333-2194 µg/kg). The studied surface waters are characterized by low and high degrees of pollution with heavy metals, as indicated by the heavy metal pollution index scores (HPI: 12.4-86.4) and the heavy metal evaluation index scores (HEI: 1.06-17.6). The considerable pollution levels are attributed to the high Mn content (0.61-49.7 µg/kg), which exceeded the limit up to fifty times. A consistent set of physico-chemical analysis (pH, electrical conductivity, total hardness, turbidity, chloride, sulphate, nitrate, nitrite, ammonium, Ca, Mg, Na, K) was analysed in water samples as well. Considering the water quality index scores (WQI: 16.0-25.2), the surface waters exhibited good quality. Microbiological results indicated the presence of Listeria monocytogenes and atypical colonies of coagulase-positive staphylococcus in fish. In contrast, the surface waters from which fish samples were collected were positive for Escherichia coli, and coliform bacteria intestinal Enterococci. Based on the study's results, it is recommended to exercise caution in the case of children related to the consumption of fish and using the waters for drinking purposes. This study provides important data of considerable novelty to the riparian population, researchers, and even policy makers on the quality status and potential levels of contamination of river waters, fish and the bioaccumulation of heavy metals in fish that may cause adverse effects on human health if consumed, and similarly the heavy metal pollution degree of waters and the non-carcinogenic risk of heavy metals through ingestion and skin absorption of water in children and adults (the study area is a significant source of fisheries).

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.

Microplastics induced endoplasmic reticulum stress to format an inflammation and cell death in hepatocytes of carp (Cyprinus carpio)

Microplastics (MPs) are a serious threat to the living environment of aquatic organisms. However, there are fewer studies on the toxicity of microplastics to freshwater organisms. This study aimed to establish a polystyrene microplastics (PS-MPs) model by feeding carp (Cyprinus carpio) PS-MP (1000 ng/L) particles 8 μm in size. HE staining revealed a mass of inflammatory cells infiltrated in the carp hepatopancreas. The activities of alkaline phosphatase (AKP), aspartate transaminase (AST), lactate dehydrogenase (LDH), and alanine transaminase (ALT) were strengthened considerably, suggesting that PS-MPs cause injury to the hepatopancreas of carp. Real-Time polymerase chain reaction and western blotting results indicated increased levels of glucose-regulated protein 78 (GRP78), (PKR)-like ER kinase (PERK), eukaryotic translation initiation Factor 2α (EIF2α) and activating transcription Factor 4 (ATF4) genes and increased levels of inflammatory factors downstream of endoplasmic reticulum stress (ERs) thioredoxin-interacting protein (TXNIP), NOD-like receptor protein 3 (NLRP3), interleukin-18 (IL-18), interleukin-1β (IL-1β), and caspase 1. Increased expression of microtubule-associated protein-2 (LC3II), autophagy-related 5 (ATG5) and autophagy-related 12 (ATG12) genes revealed that PS-MPs promoted autophagy in carp hepatocytes. The enhanced expression of the Caspase 12, Caspase 3, and Bax genes suggested that PS-MPs led to the apoptosis of carp hepatocytes. These results suggest that PS-MPs result in serious injury to the hepatopancreas of carp. The present study of PS-MPs in freshwater fish from the aspect of endoplasmic reticulum stress was conducted to provide references and suggestions for toxicological studies of PS-MPs in freshwater environments.

Exploring the interactions between metabolic dysfunction-associated fatty liver disease and micronutrients: from molecular mechanisms to clinical applications

Metabolic (dysfunction)-associated fatty liver disease (MAFLD) has emerged as a significant global health concern, representing a major cause of liver disease worldwide. This condition spans a spectrum of histopathologic stages, beginning with simple fatty liver (MAFL), characterized by over 5% fat accumulation, and advancing to metabolic (dysfunction)-associated steatohepatitis, potentially leading to hepatocellular carcinoma. Despite extensive research, there remains a substantial gap in effective therapeutic interventions. This condition's progression is closely tied to micronutrient levels, crucial for biological functions like antioxidant activities and immune efficiency. The levels of these micronutrients exhibit considerable variability among individuals with MAFLD. Moreover, the extent of deficiency in these nutrients can vary significantly throughout the different stages of MAFLD, with disease progression potentially exacerbating these deficiencies. This review focuses on the role of micronutrients, particularly vitamins A, D, E, and minerals like iron, copper, selenium, and zinc, in MAFLD's pathophysiology. It highlights how alterations in the homeostasis of these micronutrients are intricately linked to the pathophysiological processes of MAFLD. Concurrently, this review endeavors to harness the existing evidence to propose novel therapeutic strategies targeting these vitamins and minerals in MAFLD management and offers new insights into disease mechanisms and treatment opportunities in MAFLD.

Nano‑selenium alleviates the pyroptosis of cardiovascular endothelial cells in chicken induced by decabromodiphenyl ether through ERS-TXNIP-NLRP3 pathway

Decabromodiphenyl ether (BDE-209) is one of the most widely used flame retardants that can infect domestic and wildlife through contaminated feed. Nano‑selenium (Nano-Se) has the advantage of enhancing the anti-oxidation of cells. Nonetheless, it remains uncertain whether Nano-Se can alleviate vascular Endothelial cells damage caused by BDE-209 exposure in chickens. Therefore, we established a model with 60 1-day-old chickens, and administered BDE-209 intragastric at a ratio of 400 mg/kg bw/d, and mixed Nano-Se intervention at a ratio of 1 mg/kg in the feed. The results showed that BDE-209 could induce histopathological and ultrastructural changes. Additionally, exposure to BDE-209 led to cardiovascular endoplasmic reticulum stress (ERS), oxidative stress and thioredoxin-interacting protein (TXNIP)-pyrin domain-containing protein 3 (NLRP3) pathway activation, ultimately resulting in pyroptosis. Using the ERS inhibitor 4-PBA in Chicken arterial endothelial cells (PAECs) can significantly reverse these changes. The addition of Nano-Se can enhance the body's antioxidant capacity, inhibit the activation of NLRP3 inflammasome, and reduce cellular pyroptosis. These results suggest that Nano-Se can alleviate the pyroptosis of cardiovascular endothelial cells induced by BDE-209 through ERS-TXNIP-NLRP3 pathway. This study provides new insights into the toxicity of BDE-209 in the cardiovascular system and the therapeutic effects of Nano-Se.

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.

Selenium Deficiency Causes Iron Death and Inflammatory Injury Through Oxidative Stress in the Mice Gastric Mucosa

Selenium (Se) is a trace element essential for the maintenance of normal physiological functions in living organisms. Oxidative stress is a state in which there is an imbalance between oxidative and antioxidant effects in the body. A deficiency of Se can make the body more inclined to oxidation, which can induce related diseases. The aim of this experimental study was to investigate the mechanisms by which Se deficiency affects the digestive system through oxidation. The results showed that Se deficiency treatment led to a decrease in the levels of GPX4 and antioxidant enzymes and an increase in the levels of ROS, MDA, and lipid peroxide (LPO) in the gastric mucosa. Oxidative stress was activated. Triple stimulation of ROS, Fe2+, and LPO induced iron death. The TLR4/NF-κB signaling pathway was activated, inducing an inflammatory response. The expression of the BCL family and caspase family genes was increased, leading to apoptotic cell death. Meanwhile, the RIP3/MLKL signaling pathway was activated, leading to cell necrosis. Taken together, Se deficiency can induce iron death through oxidative stress. Meanwhile, the production of large amounts of ROS activated the TLR4/NF-κB signaling pathway, leading to apoptosis and necrosis of the gastric mucosa.

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.

Composition, Release, and Transformation of Earthworm Tissue-Bound Residues of Tetrabromobisphenol A in Soil

Earthworms accumulate organic pollutants to form earthworm tissue-bound residues (EBRs); however, the composition and fate of EBRs in soil remain largely unknown. Here, we investigated the fate of tetrabromobisphenol A (TBBPA)-derived EBRs in soil for 250 days using a 14C-radioactive isotope tracer and the geophagous earthworm Metaphire guillelmi. The EBRs of TBBPA in soil were rapidly transformed into nonextractable residues (NERs), mainly in the form of sequestered and ester-linked residues. After 250 days of incubation, 4.9% of the initially applied EBRs were mineralized and 69.3% were released to extractable residues containing TBBPA and its transformation products (TPs, generated mainly via debromination, O-methylation, and skeletal cleavage). Soil microbial activity and autolytic enzymes of earthworms jointly contributed to the release process. In their full-life period, the earthworms overall retained 24.1% TBBPA and its TPs in soil and thus prolonged the persistence of these pollutants. Our study explored, for the first time, the composition and fate of organic pollutant-derived EBRs in soil and indicated that the decomposition of earthworms may release pollutants and cause potential environmental risks of concern, which should be included in both environmental risk assessment and soil remediation using earthworms.

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.

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.