NLRP3 inflammasome is involved in the mechanism of the mitigative effect of lycopene on sulfamethoxazole-induced inflammatory damage in grass carp kidneys

β-Sitosterol suppresses NLRP3 Inflammasome activation and Pyroptosis in myocardial ischemia/reperfusion injury via inhibition of PPARγ2

BACKGROUND

β-Sitosterol, a plant-derived sterol, has demonstrated potential therapeutic effects in cardiovascular diseases, particularly myocardial ischemia-reperfusion injury (MIRI). Our study investigates its underlying mechanism through regulation of pyroptosis.

METHODS

To understand the role of β-sitosterol in protecting cardiomyocytes, MIRI rats were treated with β-sitosterol. Rats' cardiac functions were monitored, and hearts were harvested for histology and Western Blot analysis. Immunofluorescence, immunoblot, enzyme-linked immunosorbent assay, as well as overexpression and knockdown techniques were utilized in this study to investigate the molecular mechanisms underlying the cardioprotective effects of β-sitosterol.

RESULTS

Our results showed that β-Sitosterol significantly reduced H/R-induced pyroptosis in cardiomyocytes by decreasing cleaved caspase-1, gasdermin D (GSDMD), interleukin-1β (IL-1β), and interleukin-18 (IL-18). Immunofluorescence staining confirmed suppression of NLRP3 inflammasome activation. Notably, β-Sitosterol inhibited pyroptosis induced by ATP and ATP/LPS through the regulation of PPARγ2. Moreover, PPARγ2 upregulation promoted ATP and ATP/LPS-induced pyroptosis through the NLRP3/caspase-1/GSDMD pathway. In vivo, β-sitosterol alleviates myocardial ischemia-reperfusion injury-induced cardiac dysfunction and myocardial fibrosis in rats.

CONCLUSIONS

These findings provide new evidence supporting β-sitosterol as a potential therapeutic agent for cardiovascular diseases involving ischemic injury. Its protective effects may be mediated through targeting PPARγ2 and modulating NLRP3-dependent pyroptosis.

Embryonic developmental toxicity to estuarine fish: Single and co-exposure to EHMC and its phototransformation products in Mugilogobius chulae

The ecological risks posed by organic ultraviolet filters (OUVFs) and their phototransformation products to estuarine ecosystems remain inadequately characterized. This study investigated the developmental toxicity in the early-life stages of the estuarine fish Mugilogobius chulae when exposed individually and jointly to 2-Ethylhexyl 4-methoxycinnamate (EHMC) and its phototransformation products (2-ethylhexanol (2-EH) and 4-methylbenzaldehyde (4-MBA)). The 120 h no-observed-effect concentration (NOEC) for embryonic malformations was > 34435 nM (10000 μg/L) for EHMC, 61429 nM (8000 μg/L) for 2-EH, and 10283 nM (1400 μg/L) for 4-MBA. This indicates that the phototransformation products exhibit greater developmental toxicity than the parent compound EHMC. Notably, co-exposure at environmentally relevant concentrations accelerated embryonic heart rate and hatching (p < 0.05). Gene expression analysis revealed that 2-EH and 4-MBA singularly downregulated the expression of the GDF2, while 2-EH additionally upregulated the expression of BMP4, MATN3, and TBX5 (p < 0.05). In contrast, co-exposure potentiated transcriptional alterations in cardiac development-related genes (TGFβ2, BMP2, BMP4, GDF2, FGF4, WNT3A, TBX5, and NKX2-5; p < 0.05). The individual exposure of 138 nM (EHMC), 307 nM (2-EH), and 294 nM (4-MBA) suppressed superoxide dismutase (SOD) activity. Moreover, 2-EH and 4-MBA additionally inhibiting glutathione S-transferase (GST), resulting in 3.7- and 4.1-fold increases in malondialdehyde (MDA) levels, respectively (p < 0.05). The mixture further exacerbated oxidative imbalance through SOD and GST reduction and catalase (CAT) induction (p < 0.05). These findings underscore the critical need to consider photochemical transformation products in ecological risk assessments of OUVFs in estuarine ecosystems.

Ferulic Acid Ameliorates Chromium-Induced Nephrotoxicity: Modulation of PERK/eIF2α/ATF4/CHOP, Nrf2, and Inflammatory Signaling

Hexavalent chromium (HVC) is a highly toxic heavy metal that induces organ damage especially to the kidney. It induces tubular damage and glomerular dysfunction basically through triggering inflammation, redox imbalance, and apoptotic cell death. The current study aimed at investigating the possible protective ability of ferulic acid (FA) against HVC-induced nephrotoxicity employing male Wistar rats as an experimental model. The results revealed the ability of FA to suppress the HVC-evoked renal tissue injury and to improve the renal function, as evidenced by enhanced histopathological picture, reduced levels of the tubular injury biomarker KIM- 1, and the glomerular dysfunction biomarkers serum cystatin C and urea, along with boosted glomerular filtration rate. At the molecular level, FA suppressed HVC-induced inflammation, as indicated by decreased nuclear NF-κB p65 protein abundance and phosphorylation, and reduced cyclooxygenase- 2, IL- 1β, and TNF-α levels. FA significantly alleviated the HVC-induced redox imbalance as demonstrated by reduced lipids and DNA oxidation, upregulation of Nrf2 signaling, improved activity of the antioxidant enzymes thioredoxin reductase, catalase, and glutathione peroxidase, along with significant elevation of the reduced glutathione level. FA inhibited apoptosis in the HVC-intoxicated rats as evidenced by reduced activity of the apoptotic marker caspase- 3 and modulation of BAX and Bcl2 proteins. Interestingly, FA suppressed the unfolded protein response signaling molecules including PERK, eIF2α, ATF4, and CHOP, which play essential roles in induction of apoptosis and inflammation. Together, these results underscore the nephroprotective impact of FA against HVC-evoked nephrotoxicity and highlight PERK, eIF2α, ATF4, CHOP, Nrf2, and NF-κB as potential molecular targets.

The role of pyroptosis in environmental pollutants-induced multisystem toxicities

The global ecosystem is adversely affected by environmental pollutants, which have numerous deleterious consequences on both the environment and human health. A multitude of human organs and systems, including the neurological, digestive, cardiovascular, reproductive, and respiratory systems, can be adversely affected by these pollutants. Pyroptosis is a form of programmed cell death, primarily involving the Caspase-1/Gasdermin D (GSDMD) classical inflammasome pathway, Caspase-4/5/11/GSDMD non-classical inflammasome pathway, Caspase-3/8 pathway, and other signaling pathways, which induce cell death and regulate the occurrence of inflammatory responses. Pyroptosis plays an important role in a range of diseases, including cancer, neurodegenerative diseases and cardiovascular disease. Evidence has emerged in recent years indicating that environmental pollutants exert various toxic effects by modulating pyroptosis. In this review, we examine hepatotoxicity, cardiovascular toxicity, nephrotoxicity, neurotoxicity, pulmonary toxicity, reproductive toxicity and the related mechanisms caused by environmental pollutants through the regulation of pyroptosis. We aim to provide theoretical references for future toxicity research on environmental pollutants.

Teleost GSDMEc regulates GSDMEa-mediated pyroptosis

INTRODUCTION

Gasdermin (GSDM) is a family of proteins that execute pyroptosis after being activated by caspase (CASP) cleavage. Mammals possess five GSDM members (A - E) with pyroptotic ability. Teleosts possess only one pyroptotic GSDM, GSDME, that exists in three orthologs, GSDMEa, b, and c. GSDMEa and GSDMEb are known to induce pyroptosis, but the function of GSDMEc is unknown.

OBJECTIVES

The present study aimed to elucidate the function of teleost GSDMEc and examine the interplay among teleost GSDME orthologs by using snakehead Channa argus as a representative species.

METHODS

Pyroptosis was assessed via microscopy and biochemical assays. GSDME cleavage, oligomerization, and membrane translocation were examined via immunoblotting. The interactions of GSDME products were examined using confocal microscopy and co-immunoprecipitation. GSDME knockdown in fish and in vivo bacterial infection were performed.

RESULTS

C. argus possessed three GSDME variants (CaGSDMEa, CaGSDMEc1, and CaGSDMEc2). CaGSDMEa was cleaved by C. argus CASP (CaCASP) 1/8 to produce an N-terminal fragment (NT), NT261, that induced pyroptosis. CaGSDMEc1 and CaGSDMEc2 were also cleaved by CaCASP1/8, but the resulting NTs, NT123 and NT108, respectively, were unable to induce pyroptosis. However, both NT123 and NT108 could bind and promote the pyroptotic activity of NT261 by facilitating NT261 oligomerization and membrane translocation. The interaction between NT261 and NT123/NT108 depended on a positively charged motif that is conserved in the metazoan GSDME and is essential to the membrane localization of NT123 and the pyroptotic activity of NT261. Bacterial infection induced CaGSDMEa/CaCASP8 activation and CaGSDMEc1/c2 cleavage in snakehead cells, resulting in pyroptosis, IL-1β/18 maturation cleavage, and extracellular DNA-net formation. CaGSDMEa/c1 knockdown significantly increased bacterial dissemination in fish tissues and reduced fish survival.

CONCLUSIONS

Our results revealed the functions and interactive mechanism of teleost GSDME orthologs, and provided new insights into the regulation of pyroptosis in lower vertebrates.

MLKL triggers NLRP3 activation in sodium arsenite-induced myocardial necroinflammation

Prolonged exposure to arsenic elevates the risk of developing a range of cardiovascular disorders. However, the mechanisms underlying myocardial damage from arsenic exposure remain elusive. Our earlier research suggest that drinking arsenic-contaminated water can lead to substantial inflammatory and necrotic injury in the myocardium of rats. This study was to ascertain whether mixed lineage kinase domain-like protein (MLKL) triggers Nod-like receptor protein-3 (NLRP3) activation during arsenic-induced myocardial necroinflammation in H9C2 cardiomyocytes and Mlkl knockout C57BL/6 mice. We demonstrated that arsenic exposure induces necroptosis by activating the receptor-interacting serine/threonine-protein kinase-3 (RIPK3)/MLKL pathway in vivo and in vitro. Consistent with our hypotheses, we found that necroptosis inhibitors (RIPK1 inhibitor necrostatin-1 [Nec-1], RIPK3 inhibitor [GSK-872], MLKL inhibitor [NSA]) and Mlkl genetic knockout can partially protect against arsenic-induced inflammatory damage. Additionally, these strategies can downregulate the expression of key proteins associated with the activation of the NLRP3 inflammasome, including NLRP3, Caspase-1, and interleukin-1β (IL-1β). Taken together, our findings demonstrate that MLKL triggers NLRP3 inflammasome activation and plays an essential role in arsenic-induced myocardial necroinflammation.

The mechanism of lycopene alleviating cadmium-inhibited glucose uptake ability of epithelioma papulosum cyprini cells: miR-375, oxidative stress, and actin cytoskeleton dysfunction

Cadmium (Cd) poses a threat to fish and human health. Carp is the most widely farmed fish, and it is necessary to study the mechanism of Cd toxicity and effective mitigation methods for Cd poisoning in carps. We previously found that Cd up-regulated miR-375 in common carp spleens, and that IRS1, a factor involved in glucose (GLU) uptake, was a potential target gene of miR-375. However, whether Cd can decrease GLU uptake ability in fish remains unknown. Oxidative stress (OS) and actin cytoskeleton dysfunction (ACD) can take part in the mechanisms of GLU uptake ability reduction. Lycopene (Lyc) is a natural plant antioxidant, and epithelioma papulosum cyprini (EPC) cells are a model cell to study carps. Therefore, we conducted experiments with Cd or/and Lyc treatments to investigate the mechanisms of Lyc alleviating Cd-cytotoxicity on EPC cells from the perspectives of miR-375, OS, ACD, and GLU uptake ability. We found that Lyc mitigated Cd-caused miR-375 increase, OS, ACD, and GLU uptake ability reduction. Moreover, miR-375 overexpression/knockdown experiments demonstrated that miR-375 mediated OS, ACD, and GLU uptake ability reduction and targeted regulated IRS1-PI3K-AKT. Furthermore, NAC intervention experiment demonstrated that ROS mediated ACD and the reduction of GLU uptake via ROS/IRS1-PI3K-AKT. Taken together, Lyc alleviated Cd-decreased GLU uptake ability via miR-375-ROS/IRS1-PI3K-AKT and miR-375/IRS1-PI3K-AKT pathways in EPC cells. Our findings highlighted significant role of miR-375 in Cd-induced toxicity and elucidated the mechanism by which Lyc alleviated Cd-induced toxicity. Our study can provide new information and new targets for resisting environmental pollutant stress in animals.

Myricetin alleviates the mechanism of IL-1β production caused by the endocrine-disrupting chemical Di(2-ethylhexyl) phthalate in RAW 264.7 cells

Myricetin, a flavonoid present in numerous fruits, vegetables, and medicinal plants, is recognized for its potent antioxidant, anti-inflammatory, and anti-cancer activities. Nevertheless, its involvement in mitigating inflammation caused by the endocrine-disrupting chemical Di(2-ethylhexyl) phthalate (DEHP), commonly used in polyvinyl chloride (PVC) manufacturing to improve flexibility, has not been investigated. Here, we found that DEHP markedly increased IL-1β production through inflammatory pathways in RAW 264.7 murine macrophages. Treatment with myricetin at a concentration of 10 μM significantly reduced the elevated IL-1β levels. Myricetin achieves this by inhibiting the activation of protein kinase C (PKC) and extracellular signal-regulated kinase (ERK), which are driven by reactive oxygen species (ROS), thereby suppressing IL-1β transcription via nuclear factor-kappa B (NF-κB). Additionally, myricetin prevents ROS-induced activation of the NLRP3 inflammasome and subsequent caspase-1 activation, further decreasing IL-1β production. These dual actions highlight myricetin's therapeutic potential in countering the oxidative stress-mediated inflammatory pathways triggered by environmental toxins like DEHP.

Lycopene mitigates paclitaxel-induced cognitive impairment in mice; Insights into Nrf2/HO-1, NF-κB/NLRP3, and GRP-78/ATF-6 axes

Chemotherapy-induced cognitive impairment, referred to as "chemobrain", is widely acknowledged as a significant adverse effect of cancer therapy. Paclitaxel, a chemotherapeutic drug, has been reported to cause cognitive impairment clinically and in animal models. However, the precise mechanisms are not fully understood. The current study explored the potential neuroprotective effect of lycopene in paclitaxel-induced cognitive impairment in mice and its potential underlying mechanisms. Mice were randomly allocated into six groups: control, paclitaxel-treated (10 mg/kg), lycopene-treated (5, 10, and 20 mg/kg) + paclitaxel, and lycopene alone-treated (20 mg/kg) groups. The effect of lycopene treatment on behavioral function and histological examination was assessed. Lycopene (20 mg/kg) was selected for additional investigation into the underlying mechanisms. Lycopene treatment counteracted paclitaxel-induced oxidative stress by reducing lipid peroxidation and enhancing catalase levels. Additionally, lycopene-treated mice demonstrated a significant elevation in nuclear factor erythroid 2-related factor 2 with no significant effect on hemeoxygenase-1. Moreover, paclitaxel administration elevated endoplasmic reticulum stress markers; glucose-regulated protein78, activating Transcription Factor 6, C/EBP homologous protein, and apoptosis marker annexin V which were significantly reduced by lycopene treatment. Furthermore, lycopene mitigated paclitaxel-induced neuroinflammation through the reduction of the levels of the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome axis markers; nuclear factor-κB, NLRP3, caspase-1, interleukin-1β, and interleukin-18. Our study findings may provide new evidence that lycopene mitigates paclitaxel-induced cognitive impairment in mice by reversing oxidative stress, endoplasmic reticulum stress, and inflammatory mechanisms.

Prenatal exposure to bisphenol A causes reproductive damage in F1 male rabbits due to inflammation and oxidative stress

Bisphenol A (BPA) is used extensively in producing industrial chemicals such as plastic products, resin, and paper coatings. Concerns have been expressed regarding its possible detrimental consequences, especially on the reproductive system of mammals. Despite extensive study in this domain, there has been no targeted examination of the impact of BPA on F1 generation rabbits. BPA exposure model was developed in pregnant female rabbits to examine the effects of BPA on reproductive hormones, cellular apoptosis, oxidative stress, inflammatory response, and tissue integrity in weaning rabbits. The results indicated that BPA exposure triggered an inflammatory response and oxidative stress, consequently impacting the reproductive system of weaned rabbits and altering reproductive hormone levels. By modulation of the Nrf2 and NF-κB axes, BPA could influence the expression of antioxidant enzymes and inflammatory mediators in the rabbit reproductive system, leading to cell apoptosis and tissue damage. These results underscore the importance of monitoring BPA exposure during pregnancy and emphasize the necessity of implementing measures to mitigate its potential effects on the reproductive health of offspring.

Ferulic acid alleviates cardiac injury by inhibiting avermectin-induced oxidative stress, inflammation and apoptosis

Avermectin (AVM) is a broad-spectrum antibiotic from the macrolide class, extensively employed in fisheries and aquaculture. Nevertheless, its indiscriminate utilisation has resulted in a substantial accumulation of remnants in the aquatic ecosystem, potentially inflicting significant harm to the cardiovascular system of aquatic species. Ferulic acid (FA) is a naturally occurring compound in wheat grain husks. It possesses potent anti-inflammatory and antioxidant properties, which can help reduce cardiovascular damage. Additionally, its affordability makes it an excellent option for aquaculture usage as a feed additive. This article explored the potential of FA as a feed additive to protect against AVM-induced heart damage in carp. We subjected carp to AVM for 30 days and provided them with a diet of 400 mg/kg of FA. FA substantially reduced the pathogenic damage to heart tissue caused by AVM, as shown through hematoxylin-eosin staining. The biochemical analysis revealed that FA markedly enhanced the activity of antioxidant enzymes catalase (CAT), glutathione (GSH), and total antioxidant capacity (T-AOC) while reducing the malondialdehyde (MDA) content. Furthermore, qPCR analysis demonstrated a substantial increase in the mRNA levels of transforming growth factor-β1 (tgf-β1) and interleukin-10 (il-10) simultaneously, significantly reducing the expression levels of interleukin-10 (il-6), interleukin-1β (il-1β), tumor necrosis factor-α (tnf-α) and inductible nitric oxide synthase (inos). Through the mitochondrial apoptotic route, FA reduced AVM-induced cell death in carp heart cells by upregulating bcl-2 while downregulating the mRNA expression levels of bax, fas, caspase8 and caspase9. In summary, FA alleviated cardiac injury by inhibiting AVM-induced oxidative stress, inflammatory response, and apoptosis in carp heart tissue.

Sodium selenite antagonizes trimethyl tin-induced chicken hepatotoxic hepatitis through the RNS/NF-κB/NLRP3 pathway

Trimethyl tin (TMT) is a good stabilizer for plastic products but is also a toxic environmental pollutant. Selenium has good antioxidant and anti-inflammatory properties and has been widely used in the poultry industry. However, it has not been reported whether selenium enrichment can antagonize TMT-induced viral hepatitis in poultry. To fill this gap, AA broiler models exposed to TMT for 42 d were established and fed a Se-enriched diet at the same time. H&E staining showed that selenium could significantly alleviate TMT-induced liver inflammation. Further analysis of the underlying mechanism revealed that TMT induced nitrosation stress (RNS), increased NO content and iNOS expression, which in turn activated the NF-κB/NLRP3 pathway and induced pyroptosis. However, selenium enrichment can reverse this situation, that is, reduce the occurrence of RNS, reduce the degree of pyroptosis, and thus alleviate the occurrence of inflammation. In our study, we demonstrated for the first time that TMT could induce hepatotoxicity other than neurotoxicity in poultry and that selenium could antagonize TMT-induced hepatotoxic hepatitis in chickens through the RNS/NF-κB/NLRP3 pathway.

Lycopene alleviates 5-fluorouracil-induced nephrotoxicity by modulating PPAR-γ, Nrf2/HO-1, and NF-κB/TNF-α/IL-6 signals

5-Fluorouracil (5-FU) is one of the most used anticancer drugs. However, its nephrotoxicity-associated drawback is of clinical concern. Lycopene (LYC) is a red carotenoid with remarkable anti-inflammatory and anti-oxidative properties. In this study, rats were divided randomly into five groups: control, lycopene (10 mg) (10 mg/kg/day; P.O), 5-FU (30 mg/kg/day; i.p.), Lycopene (5 mg) + 5-FU (5 mg/kg + 30 mg/kg/day), and lycopene (10 mg) + 5-FU (10 mg/kg + 30 mg/kg/day). LYC attenuated the loss of renal function induced by 5-FU in a dose-dependent manner. Rats co-treated with LYC had lower serum urea, creatinine, uric acid and KIM-1 levels, and a higher serum albumin level than those receiving 5-FU alone. Furthermore, co-treatment with the high dose of LYC maintained renal oxidant-antioxidant balance by ameliorating/preventing the loss of antioxidants and the elevation of malondialdehyde. Rats treated with 5-FU had markedly lower renal levels of PPAR-gamma, HO-1, Nfr2, and Il-10 and higher levels of NF-kB, TNF-alpha, and IL6 compared to the control rats. Co-treatment with LYC attenuated the reduction in PPAR-gamma, HO-1, Nfr2, and IL-10 levels and moderated the elevated levels of NF-kB, TNF-alpha, and IL-6. The kidneys from rats co-treated with lycopene (10 mg) + 5-FU did not show the degenerative changes in the glomerular tufts and tubules observed for the rats treated with 5-FU alone. In conclusion, LYC is a promising therapeutic strategy for attenuating 5-FU-induced nephrotoxicity through the restoration of antioxidant activities and inhibition of inflammatory responses by modulating PPAR-γ, Nrf2/HO-1, and NF-κB/TNF-α/IL-6, signals.

Characterization of NLRP3 inflammasome components in the endangered Chinese giant salamander (Andrias davidianus)

Chinese giant salamander (Andrias davidianus) is the largest extant urodela species and has unique evolutionary position. Studying the immune system of Chinese giant salamander contributes to understanding the evolution of immune systems of vertebrates. The NLR-related protein 3 (NLRP3) inflammasome comprised of NLRP3, ASC and caspase-1 play important roles in the host innate immunity. However, little is know about the NLRP3 inflammasome components in Chinese giant salamander. In this study, the NLRP3, apoptosis-associated speck-like protein (ASC) and caspase-1 (adaNLRP3, adaASC and adaCaspase-1) were characterized from Chinese giant salamander. The proteins of these three genes shared similar motifs and structures with their mammalian counterparts, with a PYD motif, a nucleotide-binding domain (NACHT) motif, and four leucine-rich repeat domain (LRR) motifs identified in adaNLRP3, a pyrin domain (PYD) motif and a caspase recruitment domain (CARD) motif in adaASC, and a CARD motif and a CASc motif in adaCaspase-1. These three genes were constitutively expressed in the skin, heart, lung, kidney, muscle, brain, spleen, and liver of Chinese giant salamander. Following Aeromonas hydrophia infection, all the three genes were up-regulated in various tissues. Molecular docking analysis revealed that the key residues involved in forming the adaNLRP3/adaASC complex were located in the PYD motifs, and that involved in forming the adaASC/adaCaspase-1 complex were located in the CARD motifs. Further analysis revealed that the hydrogen bonds and salt bridges had crucial roles in the formation of adaNLRP3/acaASC and adaASC/adaCaspase-1 complexes. To the best of our knowledge, this is the first report on the NLRP3 inflammasome components in Chinese giant salamander which will be helpful in further understanding the function of the NLRP3 inflammasome and in elucidating its role in the immune response to microbes.

Lycopene mitigates atrazine-induced hypothalamic neural stem cell senescence by modulating the integrated stress response pathway

BACKGROUND

Atrazine, a widely used herbicide, has become a major pollutant in agricultural water bodies. Pesticide contamination, including atrazine, is linked to a high incidence of age-related neurodegenerative diseases, suggesting its neurotoxic potential. Lycopene, a potent antioxidant, is renowned for its diverse pharmacological effects, especially its neuroprotective properties. However, the underlying pharmacological mechanisms of lycopene and its impact on potential pathways against atrazine-induced hypothalamic damage have not been elucidated.

PURPOSE

Our study aimed to elucidate how lycopene ameliorates hypothalamic injury triggered by atrazine exposure, with a special focus on the pluripotency of neural stem cells (NSCs) and pathways involved in cell senescence.

METHODS

Mice were administered lycopene and/or atrazine via gavage for 21 days. The C17.2 NSC cell line and specific molecular inhibitors were utilized to examine the potential protective effects of lycopene in vitro. Morphological changes and ultrastructural damage in the hypothalamus were observed by hematoxylin-eosin staining and transmission electron microscopy, respectively. The mechanisms of action of lycopene were explored through various methods, including senescence β-galactosidase staining, multiplex immunofluorescence, Western blotting and qRT‒PCR.

RESULTS

Our results indicated that lycopene notably ameliorated atrazine-induced histological and ultrastructural damage, as well as the loss of intact and mature neurons in mouse hypothalami. Additionally, hypothalamic NSCs (HtNSCs) and microglia were recruited to areas of neuronal injury after atrazine exposure; intriguingly, lycopene treatment reduced this recruitment. Through in vivo and in vitro assays, we elucidated the outcomes of atrazine-induced HtNSC recruitment and neuronal loss, along with the neuroprotective mechanisms of lycopene. Mechanistically, lycopene prevents atrazine-induced senescence in HtNSCs and enhances their proliferation and differentiation by inhibiting the integrated stress response (ISR) signaling pathway, thus promoting the renewal of damaged neurons in the hypothalamus.

CONCLUSIONS

Collectively, the results of the present study reveal, for the first time, that lycopene mitigates atrazine-induced HtNSC senescence by modulating the ISR signaling pathway. These findings offer novel insights into the role of lycopene in preventing and alleviating NSC senescence and suggest its potential development as a new therapy for neurodegenerative diseases.

New Insights into the Toxic Effects of Different Sizes of Nanosilica Particles in Food on the Mouse Bladder: Involving Epithelial-Mesenchymal Transition

Animals are widely exposed to nanosilica as a food additive. However, the negative effects of such nanosilica particles on animals' bladders are unclear. In the present study, we investigated the impact of MPs-SiO2 on mouse bladder and the underlying mechanisms. Mouse and MBEC cell models exposed to MPs-SiO2 with different particle sizes were established. At the same time, aminoguanidine hydrochloride (RNS inhibitor) and NF-κB activator were used to further explore its mechanism in vitro. We found that MPs-SiO2 of three sizes could induce RNS-induced pyroptosis causing EMT both in vitro and in vivo. After inhibiting RNS, the expression of related proteins in downstream pathways was decreased, and fibrosis was alleviated. The above situation was reversed by the addition of NF-κB activator. Furthermore, our data suggest that 300 nm MPs-SiO2 particles have a greater impact on the bladder than 50 nm particles. This study revealed the potential health risks of MPs-SiO2 and provided new insights into the toxicology of MPs-SiO2.

New insights into evodiamine attenuates IPEC-J2 cells pyroptosis induced by T-2 toxin - Activating Keap1-Nrf2/NF-κB signaling pathway through binding with Keap1

T-2 toxin (T-2) is a highly toxic mycotoxin with a molecular weight of 466.52 g/mol. Evodiamine (EV), an alkaloid component of Evodia, has anti-inflammation and antioxidant properties. As a receptor of oxidative stress, Keap1 with a molecular weight of 70 kDa, is a molecular switch that controls the Nrf2 signaling pathway. In this paper, the effect of EV on Keap1-Nrf2/NF-κB pathway was investigated. Based on our research outcomes, it was observed that T-2 exposure substantially increased IPEC-J2 cells intracellular ROS levels and MDA accumulation, decreased SOD and CAT activities, disrupted intestinal tight junction (ZO-1, occludin, and claudin-1), and up-regulated pyroptosis-related protein (ASC, NLRP3, caspase-1, GSDMD, IL-1β, and IL-18). Additionally, EV could bind well with Keap1, the separating it from Nrf2, promoting Nrf2 into the nucleus, enhanced antioxidant enzyme activities, reduced the production of ROS, down-regulated NF-κB expression, alleviated T-2-induced pyroptosis, and restored tight junction protein expression. However, after treatment with the Nrf2 inhibitor ML385, ML385 reversed the protective effect of EV on IPEC-J2 cells. Collectively, EV can activate the Keap1-Nrf2/NF-κB signaling pathway via binding to Keap1, exert anti-inflammatory and antioxidant effects, inhibit the pyroptosis of IPEC-J2 cells triggered by T-2, and retore intestinal barrier function.

Silicon dioxide particles induce DNA oxidative damage activating the AIM2-mediated PANoptosis in mice cerebellum

Silicon dioxide (SiO2) particles are novel materials with wide-ranging applications across various fields, posing potential neurotoxic effects. This study investigates the toxicological mechanisms of SiO2 particles of different sizes on murine cerebellar tissue and cells. Six-week-old C57BL/6 mice were orally administered SiO2 particles of three sizes (1 μm, 300 nm, 50 nm) for 21 days to establish an in vivo model, and mice cerebellar astrocytes (C8-D1A cells) were cultured in vitro. Indicators of oxidative stress, DNA damage, and the PANoptosis pathway were detected using methods such as immunofluorescence staining, comet assay, western blotting, and qRT-PCR. The results show that SiO2 particles induce oxidative stress leading to DNA oxidative damage. The aberrant DNA is recognized by AIM2 (absent in melanoma 2), which activates the assembly of the PANoptosome complex, subsequently triggering PANoptosis. Furthermore, the extent of damage is inversely correlated with the size of SiO2 particles. This study elucidates the toxicological mechanism of SiO2 particles causing cerebellar damage via PANoptosis, extending research on PANoptosis in neurotoxicology, and aiding in the formulation of stricter safety standards and protective measures to reduce the potential toxic risk of SiO2 particles to humans.

The alleviation of difenoconazole-induced kidney injury in common carp (Cyprinus carpio) by silybin: Involvement of inflammation, oxidative stress, and apoptosis

Triazole fungicides, such as difenoconazole (DFZ), are frequently used to control fungus in crops that pollute water. The common carp (Cyprinus carpio) (hereafter referred to as "carp") is an excellent bio-indicator of water quality. The seeds of the silymarin plant contain a flavonolignan called silybin (SYB), which is used to treat liver disease. To explore SYB's involvement in DFZ-triggered kidney damage in carps, an H&E assay was conducted, and ROS level was also examined. The results demonstrated that SYB alleviated DFZ-induced destruction of kidney tissue structure in carps, as well as alleviating the elevation of kidney ROS level in carps. RT-qPCR and Western blot were used to detect inflammation-, oxidative stress- and apoptosis-related factors at mRNA level and protein level. The experimental findings indicated that relative to the DFZ group, SYB + DFZ co-treatment reduced inflammation-related mRNA level of il-6, il-1β and tnf-α, elevated mRNA level of il-10. It also reduced protein expression levels of NF-κB and iNOS. In addition, SYB + DFZ co-treatment reduced DFZ-induced increase in the oxidative stress-related mRNA indicators sod and cat, and decreased the protein expression levels of Nrf2 and NQO1. SYB reduced the DFZ-induced increase in pro-apoptotic gene Bax mRNA and protein expression levels and the DFZ-induced decrease in anti-apoptotic gene Bcl-2 mRNA and protein expression levels. In summary, SYB potentially mitigates DFZ-induced kidney damage in carp by addressing inflammation, oxidative stress, and apoptosis. Our results establish a theoretical foundation for the clinical advancement of freshwater carp feeds.

Palmitic acid activates NLRP3 inflammasome through NF-κB and AMPK-mitophagy-ROS pathways to induce IL-1β production in large yellow croaker (Larimichthys crocea)

Studies on marine fish showed that vegetable oils substituted for excessive fish oil increased interleukin-1β (IL-1β) production. However, whether the nucleotide-binding oligomerization domain, leucine-rich repeat-containing family, pyrin domain-containing-3 (NLRP3) inflammasome has a substantial role in fatty acid-induced IL-1β production in fish remains unclear. The associated specific mechanism is also unknown. In this study, nlrp3, caspase-1 and apoptosis-associated speck-like protein containing a CARD (asc) were successfully cloned, and NLRP3 inflammasome consisted of NLRP3, caspase-1 and ASC in large yellow croaker. Primary hepatocytes of fish incubated with palmitic acid (PA) exhibited the highest expression of pro-inflammatory genes (il-1β and tnfα) and NLRP3 inflammasome related genes (nlrp3, caspase-1 and asc), caspase-1 activity and IL-1β production among different treatments. Furthermore, PA-induced NLRP3 inflammasome activation was confirmed to require two signals: the first signal was that PA promoted the NF-κB (P65) protein into the nucleus, and NF-κB increased NLRP3 promoter activity and nlrp3 transcription. The second signal was that PA inhibited AMPK phosphorylation and decreased mitophagy by inhibiting the expression of PINK and parkin proteins, thereby damaging the mitochondria that could not be effectively cleared. Mitochondrial damage generated excessive amounts of reactive oxygen species, which activated the NLRP3 inflammasome and then induced caspase-1 activity and IL-1β production. Therefore, excessive dietary PA activated NLRP3 inflammasome through NF-κB and AMPK-mitophagy-ROS pathways to induce IL-1β production, thereby leading to inflammation in fish.

MicroRNA-146b protects kidney injury during urinary tract infections by modulating macrophage polarization

IMPORTANCE

Kidney injury during acute urinary tract infections (UTIs) caused by uropathogenic Escherichia coli (UPEC) is an important public health problem. However, how kidney injury develops during UPEC infection is still unclear. Although antibiotic therapy is currently an effective treatment for UTI, it cannot avoid kidney injury. MicroRNAs have gained extensive attention as essential molecules capable of regulating the autoimmune response. Among these, microRNA-146b (miR-146b) is involved in regulating inflammatory responses. In the present study, we demonstrated that miR-146b played an essential role in the development of kidney injury during UTIs caused by UPEC. The results showed that miR-146b may suppress M1 macrophage polarization and alleviate acute kidney injury. Furthermore, the miR-146b activator, agomir, in order to upregulate miR-146b, was effective in treating kidney damage by inhibiting the activation of M1 macrophages. In conclusion, our findings elucidated the mechanisms by which miR-146b alleviated kidney injury induced by UTIs, shed new light on the relationship between microRNA and bacterial infection, and provided a novel therapeutic target for treating this common bacterial infection.

Lycopene abolishes typical polyhalogenated carbazoles (PHCZs)-induced hepatic injury in yellow catfish (Pelteobagrus fulvidraco): Involvement of ROS/PI3K-AKT/NF-κB signaling

Aquatic ecosystems are being more contaminated with polyhalogenated carbazoles (PHCZs), which raising concerns about their impact on aquatic organisms. Lycopene (LYC) exhibits several beneficial properties for fish via enhance antioxidant defenses and improve immunity. In this study, we attempted to investigate the hepatotoxic effects of typical PHCZs 3, 6-dichlorocarbazole (3,6-DCCZ) and the protective mechanisms of LYC. In this study, we found that yellow catfish (Pelteobagrus fulvidraco) exposure to 3,6-DCCZ (1.2 mg/L) resulted in hepatic inflammatory infiltration and disordered hepatocyte arrangement. Besides, we observed that 3,6-DCCZ exposure resulted in hepatic reactive oxygen species (ROS) overproduction and excessive autophagosome accumulation, accompanied with inhibition of phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) pathway. Subsequently, we confirmed that 3,6-DCCZ exposure triggered hepatic uncontrolled inflammatory response via activation of nuclear factor-κB (NF-κB) pathway, along with decreased plasma complement C3 (C3) and complement C4 (C4) levels. Meanwhile, yellow catfish exposed to 3,6-DCCZ exhibit an increased hepatic apoptosis phenomenon, as evidenced by the elevated number of positive TUNEL cells and upregulated expression of caspase3 and cytochrome C (CytC). In contrast, LYC treatment could alleviate the 3,6-DCCZ-induced pathological changes, hepatic ROS accumulation, autophagy, inflammatory response and apoptosis. To sum up, this study provided the demonstration that LYC exerts hepatoprotective effects to alleviate 3,6-DCCZ-induced liver damage by inihibiting ROS/PI3K-AKT/NF-κB signaling in yellow catfish.

Polyethylene microplastics trigger cell apoptosis and inflammation via inducing oxidative stress and activation of the NLRP3 inflammasome in carp gills

Microplastics cause varying degrees of damage to aquatic organisms. Exposure to microplastics contaminated water, the gills are among the first tissues, after the skin, to be affected by microplastics. As an essential immune organ, prolonged stimulation by microplastics disrupts immune function not only in the gills but throughout the body, yet the underlying mechanisms remain elusive. A model of gill injury from exposure to polyethylene (PE) microplastics was developed in this study. H&E staining revealed that polyethylene microplastics caused gill inflammation, vascular remodeling, and mucous cell proliferation. An increase in collagen indicates severe tissue damage. Additional analysis showed that polyethylene microplastics profoundly exacerbated oxidative stress in the gills. TUNEL assay demonstrated cell apoptosis induced by polyethylene microplastic. The mRNA levels were subsequently quantified using RT-PCR. The results showed that polyethylene microplastics increased the expression of the nuclear factor-κB (NF-κB) pathway (NF-κB p65, IKKα, IKKβ) and apoptosis biomarkers (p53, caspase-3, caspase-9, and Bax). Nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasomes, which is an influential component of innate immunity, were overactive. What's more, the pro-inflammatory factors (TNF-α, IFN-γ, IL-2, IL-6, IL-8, IL-1β) that induce immune disorder also increased significantly, while the anti-inflammatory factors (IL-4, IL-10) decreased significantly. These results suggested that oxidative stress acted as an activation signal of apoptosis triggered by the NF-κB pathway and activating the NLRP3 inflammasome to promote inflammatory immune responses. The present study provided a different target for the prevention of toxin-induced gill injury under polyethylene microplastics.

Involvement and characterization of NLRCs and pyroptosis-related genes in Nile tilapia (Oreochromis niloticus) immune response

Pyroptosis is an inflammatory and programmed cell death initiated by the formation of the inflammasome, which consists of NLR, ASC, and Caspase. Pyroptosis has received growing attention due to its association with innate immunity and various diseases. However, the involvement and induction of the NLRCs and pyroptosis-related genes in fish immunity remain poorly studied. In this study, several NLRCs and pyroptosis-related genes in Nile tilapia (Oreochromis niloticus) were identified and characterized. Their involvement in bacterial infection and expression profiles in Nile tilapia lymphocyte responses were also assessed. Overall, three NLRC members (NOD1, NOD2, and NLRC3) and five pyroptosis-related genes (ASC1, Caspase1, Gsdme, NLRP3, and NLRP14) in Nile tilapia were cloned and characterized. The transcript levels of these molecules were broadly distributed in various tissues with comparatively high expression in the gills, intestine, and spleen. Their transcripts were also induced during Streptococcus agalactiae or Aeromonas hydrophila infection. Moreover, they were primarily expressed in T cells, NCCs, and Mo/Mφ and showed antibacterial and partially antiviral responses. The present study lays a theoretical foundation for further investigation of the pyroptosis mechanisms in fish as well as the evolution of the antiviral roles of pyroptosis in vertebrates.