1,4-Naphthoquinone-Coated Black Carbon, a Kind of Atmospheric Fine Particulate Matter, Affects Macrophage Fate: New Insights into Crosstalk between Necroptosis and Macrophage Extracellular Traps

1,2-bis(2,4,6-tribromophenoxy) ethane induces necroptosis via the co-competition of GAS5 and NUAK1 for miR-743a-5p in rat hepatocytes

The brominated flame retardant 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) widely used in manufacturing is inevitably released into the environment, resulting in the exposure of organisms to BTBPE. Therefore, it is particularly important to explore its toxic mechanism. The liver is one of the main accumulating organs of BTBPE, but the mechanism underlying BTBPE hepatotoxicity has not been thoroughly investigated. In our study, BTBPE was administered to Sprague-Dawley (SD) rats and rat hepatocytes (BRL cells) in vivo and in vitro, respectively, and HE staining, AO/EB staining, fluorescent probes, qPCR, immunofluorescence, and dual-luciferase reporter assays were performed. We investigated the mechanism of action of growth arrest-specific 5 (GAS5), miR-743a-5p, and NUAK family kinase 1 (NUAK1) in BTBPE-induced necroptosis from the perspective of competing endogenous RNAs (ceRNAs) using NUAK1 inhibitors, siRNAs, mimics, and overexpression plasmids. Our study showed that exposure to BTBPE caused necroptosis in the liver and BRL cells, accompanied by an oxidation-reduction imbalance and an inflammatory response. It is worth noting that NUAK1 is a newly discovered upstream regulatory target for necroptosis. In addition, miR-743a-5p was shown to inhibit necroptosis by targeting NUAK1 and down-regulating NUAK1. GAS5 upregulates NUAK1 expression by competitively binding to miR-743a-5p, thereby inducing necroptosis. This study demonstrated, for the first time, that the GAS5-miR-743a-5p-NUAK1 axis is involved in the regulation of necroptosis via ceRNAs. Thus, GAS5 and NUAK1 induce necroptosis by competitively binding to miR-743a-5p.

Effects of Probiotic Enterococcus faecium from Yak on the Intestinal Microflora and Metabolomics of Mice with Salmonella Infection

Salmonella spp. are pathogenic bacteria that cause diarrhea, abortion, and death in yak and severely harm livestock breeding. Therefore, it is vital to identify a probiotic that effectively antagonizes Salmonella. To the best of our knowledge, few prior studies have investigated the efficacy of Enterococcus faecium against Salmonella. Here, we evaluated the enteroprotective mechanism of E. faecium in a mouse Salmonella infection model using hematoxylin-eosin (H&E) staining, quantitative real-time polymerase chain reaction (Q-PCR) technology, microbial diversity sequencing, and metabonomics. Enterococcus faecium inhibited the proinflammatory cytokines IL-1β, IL-6, TNF-α, and IFN-γ and promoted the anti-inflammatory cytokine IL-10. The Firmicutes/Bacteroidota (F/B) ratio and the abundances of Firmicutes and Akkermansia were significantly higher in the E. faecium than in the Salmonella group. Metabonomics and microbial diversity sequencing disclosed five different metabolites with variable importance in the projection (VIP) > 3 that were characteristic of both the Salmonella and E. faecium groups. Combined omics revealed that Lactobacillus and Bacteroides were negatively and positively correlated, respectively, with cholic acid, while Desulfovibrio was positively correlated with lipids in both the control and Salmonella groups. Desulfovibrio was also positively correlated with lipids in both the Salmonella and E. faecium groups. Enterococcus faecium antagonizes Salmonella by normalizing the abundance of the intestinal microorganisms and modulating their metabolic pathways. Hence, it may efficaciously protect the host intestine against Salmonella infection.

Regulatory role of oxidative stress in retrorsine - Induced apoptosis and autophagy in primary rat hepatocytes

Pyrrolizidine alkaloids (PAs) are a group of naturally occurring alkaloids widely present in plants. PAs are highly hepatotoxic and have been documented to cause many incidents of human and animal poisoning. Retrorsine (RTS) is a pyrrolizidine alkaloid (PA) derived from the Compositae Senecio, which has been shown to cause hepatotoxicity. Human liver poisoning occurs through the consumption of RTS-contaminated food, and animals can also be poisoned by ingesting RTS-containing toxic plants. The mechanism of RTS-induced liver toxicity is not fully understood. In this study, we demonstrated that RTS-induced oxidative stress plays a pivotal role in RTS-induced liver toxicity involving apoptosis and autophagy. The results showed that RTS treatment in the cultured Primary rat hepatocytes caused cytotoxicity and release of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in a time- and dose-dependent manner. Our study showed that treatment of RTS induced ROS and MDA (malondialdehyde, a lipid peroxidation marker) in the hepatocytes, and reduced antioxidant capacity (GSH content, SOD activity), suggesting RTS treatment caused oxidative stress response in the hepatocytes. Furthermore, we found that RTS induced apoptosis and autophagy in the hepatocytes, and RTS-induced apoptosis and autophagy could be alleviated by ROS scavenger N-acetylcysteine (NAC) and the MAPK pathway inhibitors suggesting ROS/MAPK signaling pathway plays a role in RTS induced apoptosis and autophagy. Collectively, this study reveals the regulatory mechanism of oxidative stress in RTS-induced apoptosis and autophagy in the hepatocytes, providing important insights of molecular mechanisms of hepatotoxicity induced by RTS and related pyrrolizidine alkaloids in liver. This mechanism provides a basis for the prevention and treatment of PA poisoning in humans and animals.

Resveratrol alleviates imidacloprid-induced mitochondrial apoptosis, necroptosis, and immune dysfunction in chicken lymphocyte lines by inhibiting the ROS/MAPK signaling pathway

Imidacloprid (IMI) is a neonicotinoid insecticide with the highest global market share, and IMI exposure in the environment can negatively affect many nontarget organisms (a general term for organisms affected by drugs other than target organisms). Resveratrol (RSV), a non-flavonoid polyphenolic organic compound derived from peanuts, grapes, and other plants, has anti-inflammatory and antioxidant effects. It is currently unclear how RSV protects against cell damage caused by IMI. Therefore, we established an experimental model of chicken lymphocyte lines exposed to 110 μg/mL IMI and/or 0.5 μM RSV for 24 h. According to the experimental results, IMI markedly raised intracellular reactive oxygen species levels and diminished the activity of the cellular antioxidant enzymes (CAT, SOD, and GPx), leading to MDA accumulation and decreased T-AOC. JNK, ERK, and P38, the essential components of the mitogen-activated protein kinase (MAPK) signaling pathway, were also expressed more when IMI was present. Additionally, IMI resulted in upregulation of mitochondrial apoptosis (Caspase 3, Caspase 9, Bax, and Cyt-c) and necroptosis (Caspase 8, RIPK1, RIPK3, and MLKL) related factors expression, downregulation of Bcl-2 expression, induction of upregulation of cytokine IL-6 and TNF-α expression, and downregulation of IFN-γ expression. The combined treatment of RSV and IMI significantly reduced cellular oxidative stress levels, inhibited the MAPK signaling pathway, and alleviated IMI-induced mitochondrial apoptosis, necroptosis, and immune dysfunction. To summarize, RSV antagonized IMI-induced mitochondrial apoptosis, necroptosis, and immune dysfunction in chicken lymphocyte lines by inhibiting the ROS/MAPK signaling pathway.

Molecular mechanism of selenium against lead-induced apoptosis in chicken brainstem relating to heat shock protein, selenoproteins, and inflammatory cytokines

Extensive application of lead (Pb) brought about environmental pollution and toxic reactions of organisms. Selenium (Se) has the effect of antagonizing Pb poisoning in humans and animals. However, it is still unclear how Pb causes brainstem toxicity. In the present study, we wanted to investigate whether Se can alleviate Pb toxicity in chicken brainstems by reducing apoptosis. One hundred and eighty chickens were randomly divided into four groups, namely the control group, the Se group, the Pb group, and the Se/Pb group. Morphological examination, ultrastructural observation, relative mRNA expressions of genes on heat shock proteins (HSPs); selenoproteins; inflammatory cytokines; and apoptosis-related factors were investigated. The results showed that Pb exposure led to tissue damage and apoptosis in chicken brainstems. Furthermore, an atypical expression of HSPs (HSP27, HSP40, HSP60, HSP70, and HSP90); selenoprotein family glutathione peroxidase (GPx) 1, GPx2, GPx3, and GPx4), thioredoxin reductases (Txnrd) (Txnrd1, Txnrd2, and Txnrd3), dio selenoprotein famliy (diodothyronine deiodinases (Dio)1, Dio2, and Dio3), as well as other selenoproteins (selenoprotein (Sel)T, SelK, SelS, SelH, SelM, SelU, SelI, SelO, Selpb, selenoprotein n1 (Sepn1), Sepp1, Sepx1, Sepw1, 15-kDa selenoprotein (Sep15), and selenophosphate synthetases 2 (SPS2)); inflammatory cytokines (Interleukin 2 (IL-2), IL-4, IL-6, IL-12β, IL-17, and Interferon-γ (IFN-γ)); and apoptosis-related genes (B-cell lymphoma-2 (Bcl-2), tumor protein 53 (p53), Bcl-2 Associated X (Bax), Cytochrome c (Cyt c), and Caspase-3) were identified. An inflammatory reaction and apoptosis were induced in chicken brainstems after exposure to Pb. Se alleviated the abnormal expression of HSPs, selenoproteins, inflammatory cytokines, and apoptosis in brainstem tissues of chickens treated with Pb. The results indicated that HSPs, selenoproteins, inflammatory, and apoptosis were involved in Se-resisted Pb poisoning. Overall, Se had resistance effect against Pb poisoning, and can be act as an antidote for Pb poisoning in animals.

1,2-bis(2,4,6-tribromophenoxy) ethane, a novel brominated flame retardant, disrupts intestinal barrier function via the IRX3/NOS2 axis in rat small intestine

Novel brominated flame retardants are widely used in electronics, textiles, furniture, and other products; they can enter the human body through ingestion and respiration and cause harm to the human body, and have been proven to have potential biological toxicity and accumulation effects. 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) is a widely used novel brominated flame retardant; however, there is a lack of research on its mechanism of toxicity, particularly that of intestinal toxicity. Currently, studies on the functionality of iroquois homeobox 3 (IRX3) are extremely limited. In our study, BTBPE was administered to Sprague-Dawley (SD) rats and rat small intestinal crypt epithelial cells (IEC6 cells) in vivo and in vitro, respectively, and hematoxylin and eosin (HE), immunohistochemical, Alcian blue-periodic acid-Schiff (AB-PAS), CCK8, acridine orange/ethidium bromide (AO/EB), fluorescent probes, qPCR, western blotting, and immunofluorescence analyses were performed. To explore the damage mechanism of BTBPE, we used siRNA to silence IRX3 and iNOs-IN-1 (yeast extract-peptone-wheat; YPW) to inhibit nitric oxide synthase 2 (NOS2). The results showed that BTBPE exposure caused inflammation and necroptosis in the jejunum and ileum, as well as destruction of the tight junctions and mucus layer. Moreover, BTBPE activated the IRX3/NOS2 axis both in vivo and in vitro. Silencing IRX3 or inhibiting NOS2 inhibits necroptosis and restores tight junctions in IEC6 cells. In conclusion, our study found that in the jejunum, ileum, and IEC6 cells, BTBPE exposure caused necroptosis and tight junction destruction by activating the IRX3/NOS2 axis. Blocking the IRX3/NOS2 axis can effectively inhibit necroptosis and restore tight junction. In addition, BTBPE exposure caused inflammation and loss of the mucous layer in the jejunum and ileum. Our study is the first to explore the mechanism of intestinal damage caused by BTBPE exposure and to discover new biological functions regulated by the IRX3/NOS2 axis, providing new research directions for necroptosis and tight junctions.

Evodiamine alleviates DEHP-induced hepatocyte pyroptosis, necroptosis and immunosuppression in grass carp through ROS-regulated TLR4 / MyD88 / NF-κB pathway

Di (2-ethylhexyl) phthalate (DEHP) is a neuroendocrine disruptor that can cause multi-tissue organ damage by inducing oxidative stress. Evodiamine (EVO) is an indole alkaloid with anti-inflammatory, antitumor, and antioxidant pharmacological activity. In this manuscript, the effects of DEHP and EVO on the pyroptosis, necroptosis and immunology of grass carp hepatocytes (L8824) were investigated using DCFH-DA staining, PI staining, IF staining, AO/EB staining, LDH kit, qRT-PCR and protein Western blot. The results showed that DEHP exposure upregulated reactive oxygen species (ROS) levels, promoted the expression of TLR4/MyD88/NF-κB pathway, increased the expression of genes involved in cell pyroptosis pathway (LDH, NLRP3, ASC, caspase1, IL-1β, IL-18 and GSDMD) and necroptosis-related genes (RIPK1, RIPK3 and MLKL). The expression of DEHP can also affect immune function, which can be demonstrated by variationsin the activation of antimicrobial peptides (LEAP2, HEPC, and β-defensin) and inflammatory cytokines (TNF-α, IL-2, IL-6 and IL-10). EVO regulates cellular antioxidant capacity by inhibiting ROS burst, reduces DEHP-induced cell pyroptosis and necroptosis to some extent, and restores cellular immune function, after co-exposure with EVO. The TLR4 pathway was inhibited by the co-treatment of TLR4 inhibitor TLR-IN-C34 and DEHP, which attenuated the expression of cell pyroptosis, necroptosis, and immunosuppression. Thus, DEHP induced pyroptosis, necroptosis and abnormal immune function in L8824 cells by activating TLR4/MyD88/NF-κB pathway. In addition, EVO has a therapeutic effect on DEHP-induced toxic injury. This study further provides a theoretical basis for the risk assessment of plasticizer DEHP on aquatic organisms.