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

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.

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.

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.