Cadmium-induced Oxidative Stress and Immunosuppression Mediated Mitochondrial Apoptosis via JNK-FoxO3a-PUMA pathway in Common Carp (Cyprinus carpio L.) Gills

Effects of antimony on antioxidant system, damage indexes of blood-brain barrier and ultrastructure of zebrafish (Danio rerio)

Antimony (Sb) and its compounds can be harmful to people and are known to cause cancer, so they are a key pollutant to control. This study investigated the influence of antimony on non-enzymatic antioxidants and the blood-brain barrier (BBB) in zebrafish(Danio rerio), a model organism that shares a high degree of genetic similarity with humans. Zebrafish were exposed to different doses of antimony in water for 7, 18, and 30 days. The results indicated that antimony accumulated most in the liver, followed by the gills, flesh, and brain, with the accumulation increasing as the exposure duration extends. Additionally, under identical antimony concentrations, the buildup in the four tissues was positively correlated with the duration of exposure. After 18 days of exposure, the total antioxidant capacity (T-AOC) and endogenous non-enzymatic antioxidants vitamin C (VC) and vitamin E (VE) decreased as a result of antimony ingestion in zebrafish, although cysteine secretion was increased in the liver, gills, and brain. The structural integrity of the BBB was compromised by the elevation of ApoE4 and MMP-9 levels as a result of antimony exposure, which led to the breakdown of the basal lamina, tight junctions, and nerve fibers in the brain. At this injured region, 5-HT and MBP were also able to easily enter and leave the BBB, albeit at variable rates. Additionally, when the antimony exposure level reached 16.58 mg·L-1, antimony penetrated the BBB and bound to erythrocytes, causing their lysis.

Hexavalent chromium damages intestinal cells and coelomocytes and impairs immune function in the echiuran worm Urechis unicinctus by causing oxidative stress and apoptosis

Hexavalent chromium (Cr(VI)) is a common pollutant in the marine environment, which impairs immunity and causes reproductive and heredity disorders in organisms. To clarify the immunotoxic effects of Cr (VI) on the marine worm Urechis unicinctus, we analyzed tissue damage and immune dysfunction caused by Cr (VI) in this organism at histopathologic, zymologic, apoptotic and molecular levels. The results indicated that the bioaccumulation of Cr (VI) bioaccumulation levels in coelomocytes was significantly higher than in the intestines and muscles. Pathological observation showed that Cr (VI) caused damage to the respiratory intestine, stomach and midgut. Cr (VI) also increased the replication of goblet cells and a reduction in the replication of epithelial cells. Meanwhile, Cr (VI) induced apoptosis of intestinal cells and coelomocytes, accompanied by an increase in the expression of Caspase-3, COX-2, and MyD88 in the intestine and coelomocytes. At the same time, Cr (VI) significantly affected the activities of antioxidant enzymes such as SOD, ACP, CAT, CAT, and GST, and increased H2O2 and MDA contents in U. unicinctus. Moreover, Cr (VI) exposure also up-regulated the transcription of hsc70, mt and jnk genes but decreased that of sod in the intestines. In contrast, Cr (VI) down-regulated the expression of sod, hsc70, mt, and jnk genes in coelomocytes. Collectively, Cr (VI) bioaccumulated in U. unicinctus cells and tissues, causing several histopathological changes, oxidative stress, and apoptosis of several cells in the organism, resulting in intestinal and coelomocyte damage and immune dysfunctioning.

Excessive heavy metal enrichment disturbs liver functions through the gut microbe in the great Himalayan leaf-nosed bat (Hipposideros armiger)

Heavy metal residues in natural ecosystems have emerged as a significant global environmental problem requiring urgent resolution. Because these elements are non-biodegradable, organisms can accumulate excessive levels of heavy metal elements into their tissues. Previous studies suggest that prolonged exposure to heavy metal enrichment poses comprehensive toxicity to various organs in vertebrates. However, few studies have focused on elucidating the molecular mechanism underlying the hepatotoxic effects of heavy metal enrichment in Chiroptera. In this study, 10 Hipposideros armiger individuals were dissected from Yingde City (YD, relatively pollution-free) and Chunwan City (CW, excessive heavy metals emission). Environmental samples were also obtained. To investigate the mechanism of heavy metal toxicity in bat livers, we employed a combination of multi-omics, pathology, and molecular biology methods. Our results revealed significant enrichment of Cd and Pb in the bat livers and food sources in the CW group (P<0.05). Furthermore, prolonged accumulation of heavy metals disrupted hepatic transcription profiles associated with the solute carriers family, the ribosome pathway, ATP usage, and heat shock proteins. Excessive heavy metal enrichment also altered the relative abundance of typical gut microbe taxa significantly (P<0.05), inhibiting tight-junction protein expression. We observed a significant decrease in the levels of superoxide dismutase, glutathione peroxidase, and glutathione (P<0.05), along with elevated reactive oxygen species (ROS) density and malondialdehyde content following excessive heavy metal enrichment. Additionally, hepatic fat accumulation and inflammation injuries were present under conditions of excessive heavy metal enrichment, while the contents of metabolism biomarkers significantly decreased (P<0.05). Consequently, prolonged heavy metal enrichment can induce hepatotoxicity by disturbing the microbes-gut-liver axis and hepatic transcription modes, leading to a decrease in overall metabolic activity in bats. Our study offers strategies for biodiversity conservation and highlights the importance of addressing environmental pollution to raise public awareness.

Probiotics in addressing heavy metal toxicities in fish farming: Current progress and perspective

Heavy metal contamination of aquatic environments adversely affects the health of aquatic organisms and consumption of fish contaminated with heavy metals poses serious health risks to humans. Among various strategies, probiotics (living microorganisms known to have beneficial effects on the host), which have been extensively applied in the aquaculture industry, could be helpful for heavy metal detoxification and remediation. Several probiotics, including Lactobacillus strains, exhibit heavy metal binding, high heavy metal tolerance, and other beneficial characteristics for the host. Notably, numerous probiotics have been reported to bind heavy metals and excrete them from the host. Various probiotic strains (Lactobacillus, Bacillus, Lactococcus, etc.) show beneficial effects in alleviating heavy metal toxicity in cultured fish species. Certain probiotic bacteria reduce the absorption and bioavailability of heavy metals by enhancing heavy metal detoxification and sequestration while preserving gut barrier function. This review summarises the toxic effects of selected heavy metals on the health of farmed fish and discusses the role of probiotic strains in remediating the consequential exposure-induced immune toxicity and oxidative stress. Moreover, we discussed the protective strategies of probiotics against heavy metal accumulation in various tissues and gut dysbiosis in fish to alleviate heavy metal toxicity in fish farming, thereby promoting a sustainable blue economy worldwide.

Cadmium exposure elicited dynamic RNA m6A modification and epi-transcriptomic regulation in the Pacific whiteleg shrimp Litopenaeus vannamei

N6-methyladenosine (m6A) methylation is the most prevalent post-transcriptional RNA modification in eukaryotic organisms, but its roles in the regulation of physiological resistance of marine crustaceans to heavy metal pollutants are poorly understood. In this study, the transcriptome-wide m6A RNA methylation profiles and dynamic m6A changes induced by acute Cd2+ exposure in the the pacific whiteleg shrimp Litopenaeus vannamei were comprehensively analyzed. Cd2+ toxicity caused a significant reduction in global RNA m6A methylation level, with major m6A regulators including the m6A methyltransferase METTL3 and the m6A binding protein YTHDF2 showing declined expression. Totally, 11,467 m6A methylation peaks from 6415 genes and 17,291 peaks within 7855 genes were identified from the Cd2+ exposure group and the control group, respectively. These m6A peaks were predominantly enriched in the 3' untranslated region (UTR) and around the start codon region of the transcripts. 7132 differentially expressed genes (DEGs) and 7382 differentially m6A-methylated genes (DMGs) were identified. 3186 genes showed significant changes in both gene expression and m6A methylation levels upon cadmium exposure, and they were related to a variety of biological processes and gene pathways. Notably, an array of genes associated with antioxidation homeostasis, transmembrane transporter activity and intracellular detoxification processes were significantly enriched, demonstrating that m6A modification may mediate the physiological responses of shrimp to cadmium toxicity via regulating ROS balance, Cd2+ transport and toxicity mitigation. The study would contribute to a deeper understanding of the evolutionary and functional significance of m6A methylation to the physiological resilience of decapod crustaceans to heavy metal toxicants.

Trace metals in the teleost fish gill: biological roles, uptake regulation, and detoxification mechanisms

In fish, the gill plays a vital role in regulating the absorption of trace metals and is also highly susceptible to metal toxicity. Trace metals such as iron (Fe), copper (Cu), zinc (Zn), and manganese (Mn) are involved in various catalytic activities and molecular binding within the gill, thereby supporting a range of physiological processes in this organ. While beneficial at normal levels, these metals can become toxic when present in excess. Conversely, nonessential metals like cadmium (Cd) and lead (Pb) can gain entry into gill cells through similar metal transport pathways, potentially interfering with various cellular processes. The transepithelial transport of these metals across the gill epithelium is governed by a variety of metal transport and metal binding proteins. These include the Cu transporter 1 (CTR1), divalent metal transporter 1 (DMT1), and members of the Zrt-/Irt-like protein (ZIP) and zinc transport (ZnT) families. Additionally, some of these metals can compete with major ions (e.g., calcium, sodium) for absorption sites in the gill. This complex crosstalk suggests an interdependent mechanism that balances metal uptake to meet physiological needs while preventing excessive accumulation. In this article, I review the roles of trace metals in proteins/enzymes that support the different functions in the gill of teleost fish. I also discuss current understanding of the pathways involved in regulating the branchial uptake of metals and their influence on ionic regulation, and the potential detoxification mechanisms in the gill. Finally, I summarize knowledge gaps and potential areas for further investigation.

Microplastics have additive effects on cadmium accumulation and toxicity in Rice flower carp (Procypris merus)

Procypris merus, a local fish species found in Guangxi, China is often exposed to both microplastics (MPs) and Cd. However, it remains unclear how these two pollutants affect P. merus. Therefore, we investigated the effects of MPs on Cd accumulation in P. merus. To this end, P. merus was separately exposed to Cd and MPs (500 μg/L) or their combination for 14 days. We found that MPs enhanced Cd accumulation in liver and gills of P. merus. Further, both the single-contaminant (MP and Cd) and combined treatments resulted in lesions in these two tissues, with more severe damage associated with the combined treatment. Even though the effect of MP on the antioxidant defense system of P. merus was limited, the Cd-only and combined treatments considerably affected the antioxidant parameters of P. merus, with the combined treatment showing a stronger effect. GO and KEGG analyses revealed that the differentially expressed genes (DEGs; TNF-related apoptosis-inducing ligand receptor, trail-r) in the Cd-only treatment group were enriched for immune-related GO terms and cell growth and death related pathways, indicating that Cd toxicity affected immune defense in P. merus. The MP-only treatment downregulated DEGs (acyl-CoA synthetase long chain family member 1a, acsl1a) related to lipid metabolism, possibly leading to lipid accumulation in the liver. The combined treatment also upregulated DEGs (aspartate aminotransferase 1, ast 1) associated with immune-related GO terms and amino acid metabolism pathways, suggesting that it affected immune function in P. merus, thereby negatively impacting its health. Results indicated that MPs have additive effects on Cd accumulation and toxicity in rice flower carp. Consequently, MPs ingested by P. merus can promote Cd accumulation, more adverse effects on the health may occur after combined exposure, which can eventually reach humans through the food chain and pose potential risks to human health.

Ferulic acid attenuates difenoconazole exposure induced liver injury in carp by modulating oxidative damage, inflammation and apoptosis

Difenoconazole (DFZ) is a widely used triazole fungicide in agricultural production. However, the presence of DFZ residue in the environment poses a significant risk to non-target organisms. Ferulic acid (FA) is a phenolic compound known for its antioxidant and anti-inflammatory properties. This study aims to investigate the hepatic damage caused by DFZ in carp and explore the mechanism through which FA alleviates this damage. The findings revealed that FA enhanced the antioxidant capability of the carp's liver and reduced the accumulation of reactive oxygen species (ROS) in the liver tissue. Moreover, FA regulated the transcriptional levels of inflammation-related factors, effectively preventing the inflammatory response triggered by the NF-κB signaling pathway. Additionally, TUNEL results demonstrated that DFZ initiated apoptosis, while dietary supplementation with FA decreased the protein expression levels of Bax and Cytochrome C (Cyt c) and the transcriptional levels of bax, caspase3, caspase9, p53 genes. Furthermore, FA increased the protein expression and transcriptional levels of Bcl-2. In conclusion, FA protects against liver injury induced by DFZ exposure in carp by modulating oxidative damage, inflammation, and apoptosis.

Combined neurotoxicity of aged microplastics and thiamethoxam in the early developmental stages of zebrafish (Daniorerio)

Microplastics (MPs) pollution, together with its consequential effect on aquatic biota, represent a burgeoning environmental concern that has garnered significant scholarly attention. Thiamethoxam (TMX), a prevalently utilized neonicotinoid insecticide, is renowned for its neurotoxic impact and selective action against targeted pests. The aquatic environment serves as a receptacle for numerous pollutants, such as MPs and neonicotinoid insecticides. However, there is currently a lack of comprehensive understanding regarding the toxic effects of co-exposure to aged MPs and neonicotinoid insecticides in aquatic organisms. Therefore, we endeavor to elucidate the deleterious impacts of aged polystyrene (PS) and TMX on zebrafish (Danio rerio) larvae when present at environmentally relevant concentrations, and to reveal the underlying molecular mechanisms driving these effects. Our study showed that exposure to aged PS, TMX, or their combination notably inhibited the heart rate and locomotion of zebrafish larvae, with a pronounced effect observed under combined exposure. Aged PS and TMX were found to diminish the activity of antioxidative enzymes (SOD, CAT, and GST), elevate MDA levels, and disrupt neurotransmitter homeostasis (5-HT, GABA and ACh). Notably, the mixtures exhibited synergistic effects. Moreover, gene expression related to oxidative stress (e.g., gstr1, gpx1a, sod1, cat1, p38a, ho-1, and nrf2b) and neurotransmission (e.g., ache, ChAT, gat1, gabra1, 5ht1b, and 5ht1aa) was significantly altered upon co-exposure to aged PS and TMX in larval zebrafish. In summary, our findings support the harmful effects of aged MPs and the neonicotinoid insecticides they carry on aquatic organisms. Results from this study enhance our understanding of the biological risks of MPs and insecticides, as well as help fill existing knowledge gaps on neonicotinoid insecticides and MPs coexistence toxicity in aquatic environment.

Using heat shock protein (HSP) inducers as an approach to increase the viability of sterlet (Pisces; Acipenseridae; Acipenser ruthenus) cells against environmental diazinon toxicity

Diazinon (DZN) is an organophosphate pesticide frequently used in agriculture and released into aquatic environments. In this study, sterlet sturgeon cells were exposed to DZN to investigate possible defense mechanisms via HSP induction (HSPi). Liver, kidney, and gill cells of Acipenser ruthenus were isolated and cultured and then treated with HSPi (Pro-Tex®, amygdalin, and a novel pirano-piranazole-based synthesized compound: SZ) in the presence and absence of DZN. MTT assays were used to evaluate the effects of different HSPis and their combinations with DZN. Western blotting analysis was conducted to evaluate HSP27, HSP70, and HSP90 expression patterns in each group. The highest rates of caspase-3 and caspase-8 activities were found in the DZN group, whereas HSPi treatment resulted in the lowest rates. The combination of HSPi+DZN resulted in increased HSP levels and antioxidant parameters but decreased cortisol, immune parameters, and metabolic enzymes. Many of the studied parameters (caspases, acetylcholinesterase, antioxidant, immune, and metabolic parameters) showed significant correlations with HSP expression, indicating that HSPs may be associated with markers of sterlet cell health. The results of this study demonstrate that using HSP inducers may be a powerful and reliable way to increase A. ruthenus resistance prior to exposure to DZN.

Histopathological effects of long-term exposure to realistic concentrations of cadmium in the hepatopancreas of Sparus aurata juveniles

In recent decades, cadmium has emerged as an environmental stressor in aquatic ecosystems due to its persistence and toxicity. It can enter water bodies from various natural and anthropogenic sources and, once introduced into aquatic systems, can accumulate in sediments and biota, leading to bioaccumulation and biomagnification in the food chain. For this reason, the effects of cadmium on aquatic life remain an area of ongoing research and concern. In this paper, a multidisciplinary approach was used to assess the effects of long-term exposure to an environmental concentration on the hepatopancreas of farmed juveniles of sea bream, Sparus aurata. After determining metal uptake, metallothionein production was assessed to gain insight into the organism's defence response. The effects were also assessed by histological and ultrastructural analyses. The results indicate that cadmium accumulates in the hepatopancreas at significant concentrations, inducing structural and functional damage. Despite the parallel increase in metallothioneins, fibrosis, alterations in carbohydrate distribution and endocrine disruption were also observed. These effects would decrease animal fitness although it did not translate into high mortality or reduced growth. This could depend on the fact that the animals were farmed, protected from the pressure deriving from having to search for food or escape from predators. Not to be underestimated is the return to humans, as this species is edible. Understanding the behaviour of cadmium in aquatic systems, its effects at different trophic levels and the potential risks to human health from the consumption of contaminated seafood would therefore be essential for informed environmental management and policy decisions.

Impaired intestinal immunity and microbial diversity in common carp exposed to cadmium

Waterborne cadmium (Cd) accumulates in the fish intestine and causes irreversible toxicity by disrupting intestinal immunity and microbial diversity. To explore the toxicity of environmentally available high Cd concentration on intestinal immunity and microbial diversity of fish, we selected the widely used bioindicator model species, Common carp (Cyprinus carpio). Literature review and Cd pollution data supported sequential doses of 0.2, 0.4, 0.8, 1.6, 3.2, and 6.4 mg/L Cd for 30 days. Based on intestinal tissue Cd accumulation, previous studies, and environmentally available Cd data, 0.4 and 1.6 mg/L Cd were selected for further studies. Intestinal Cd bioaccumulation increased significantly to ~100 times in fish exposed to 1.6 mg/L Cd. We observed villous atrophy, increased goblet cells with mucus production, muscularis erosion, and thickened lamina propria due to intense inflammatory cell infiltration in the intestine at this Cd concentration. Cd-induced immunosuppression occurred with increased lysozyme, alkaline phosphate (AKP), and acid phosphate (ACP). High levels of catalase (CAT), total antioxidant capacity (T-AOC), malondialdehyde (MDA), and hydrogen peroxide (H2O2) suggested induced oxidative stress and poor metabolism by α-amylase and lipase suppression for Cd toxicity. Proteobacteria (41.2 %), Firmicutes (21.8 %), and Bacteroidetes (17.5 %) were the dominant bacterial phyla in the common carp intestine. Additionally, potential pathogenic Cyanobacteria increased in Cd-treated fish. The decrease of beneficiary bacteria like Aeromonas, and Cetobacterium indicated Cd toxicity. Overall, these findings indicate harmful consequences of high Cd concentration in the intestinal homeostasis and health status of fish.

Environment-relevant concentrations of cadmium induces necroptosis and inflammation; baicalein maintains gill homeostasis through suppressing ROS/ER stress signaling in common carps (Cyprinus carpio L.)

Cadmium (Cd) is a major contaminant in natural environments and exerts adverse effects on aquatic biota at low concentrations. Gill is as vital respiratory organ and may cause pollutants to enter fish during gas exchange. Baicalein (BAI), as a kind of flavonoids, possess antioxidant properties through inactivating free radicals. To confirm the potential effects and approaches of BAI addition in maintaining the gill stability, 90 common carps (Cyprinus carpio L.) were selected and randomly divided into water environment exposure group (0.22 mg/L Cd) and/or feed added with 0.10 g/kg BAI for 30 days. The analysis of ion content in serum showed that Cd exposure disturbed ion homeostasis, and BAI could reduce serum Cd concentration. The histopathological results of gills showed that Cd exposure caused gill tissue lesions and structural damage, and BAI feeding effectively alleviated this damage. In addition, BAI could enhance antioxidant activity and activate Nrf2/HO-1 axis, thereby reducing oxidative stress and endoplasmic reticulum (ER) stress. Moreover, BAI lightened cytokine imbalance, inflammatory response, and necroptosis. Overall, the results indicated that BAI feeding could maintain gill homeostasis against Cd poisoning via the ROS/ER stress signaling. This trial revealed the properties of BAI resistance to metal Cd in aquaculture and partially elucidated its mechanism.

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

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

Review of cadmium toxicity effects on fish: Oxidative stress and immune responses

Cadmium (Cd) in aquatic environments can cause environmental toxicity to fish and induce oxidative stress owing to an excessive production of reactive oxygen species in fish bodies. Fish have developed various antioxidant systems to protect themselves from reactive oxygen species; thus, a change in antioxidant responses in fish can be a criterion for evaluating oxidative stress resulting from Cd exposure. Because Cd exposure may be recognized as an exogenous substance by a fish body, it may lead to the stimulation or suppression of its immune system. Various immune responses can be assessed to evaluate Cd toxicity in fish. This review aimed to identify the impacts of Cd exposure on oxidative stress and immunotoxicity in fish as well as identify accurate indicators of Cd toxicity in aquatic ecosystems.

Effects of cadmium exposure on metabolism, antioxidant defense, immune function, and the hepatopancreas transcriptome of Cipangopaludina cathayensis

Cadmium (Cd) is a common contaminant in aquatic environments. However, little is known about the mechanisms underlying Cd toxicity in the freshwater snail Cipangopaludina cathayensis (Heude, 1890). This study to investigate the toxic effects of Cd on the standard metabolism, antioxidant activities, immune function, and hepatopancreas transcriptome profiles of C. cathayensis. C. cathayensis was exposed to 0.25, 0.5, 1.0, or 1.5 mg/L Cd for 3 h, with results showing that Cd significantly inhibited oxygen consumption and ammonia excretion and disrupted the respiratory metabolism of C. cathayensis. In addition, the O:N ratio dropped below 7, indicating that C. cathayensis may rely exclusively on proteins as an energy source under Cd stress. To understand how Cd impacts the antioxidant activities, immune function, and transcriptional profiles, C. cathayensis were exposed to 0.5 (low exposure, L14) or 1.5 (high exposure, H14) mg/L Cd for 14 days. Our results indicate that Cd exposure leads to oxidative stress and immunosuppression, with the latter effect being larger for exposure to higher Cd concentrations. A total of 2172 differentially expressed genes (DEGs) were identified by transcriptome analysis of the hepatopancreas, of which 885 were upregulated and 1287 were downregulated. Gene ontology and KEGG analyses revealed that the DEGs in the H14 group are enriched for energy generation terms and the "oxidative phosphorylation" pathway, respectively. Therefore, up-regulation of energy metabolism may be an adaptive strategy under Cd stress. Moreover, several genes involved in antioxidant activity were downregulated, whereas genes related to reactive oxygen species generation were upregulated. In addition, many immunity-related genes were identified within the DEGs, indicating that Cd toxicity may affect immune defense. Further, DEGs in the H14 group were enriched for disease-associated pathways. Taken together, our results indicate that Cd exposure leads to metabolic disorders, oxidative stress, and immunosuppression and thus may potentially contribute to disease outbreaks.

Effects of cadmium chloride and biofertilizer (Bacilar) on biochemical parameters of freshwater fish, Alburnus mossulensis

Fish in wild are often faced with various types of xenobiotics, that may display synergistic or antagonistic effects. In this study, we aim to examine how exposure to agrochemical compound (Bacilar) and cadmium (CdCl₂) alone and in combination affect biochemical parameters (lactate dehydrogenase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, alanine aminotransferase; creatine phosphokinase (CKP), cholinesterase) and oxidative stress (total antioxidant capacity, catalase, malondialdehyde and protein carbonyl concentrations) of freshwater fish Alburnus mossulensis. Fish were exposed to two concentrations of Bacilar (0.3, and 0.6 mL L^-1) and to 1 mg L^-1 cadmium chloride alone and in combination for 21 days. Results showed that fish accumulate Cd in their body, with the highest rate in individuals exposed to Cd in combination with Bacilar. Both xenobiotics in fish liver induced the activation of liver enzymes suggesting hepatotoxic effects, with the greatest impact in co-exposed groups. A significant decrease in the hepatocyte's total antioxidant capacity indicates the collapse of the antioxidant defense in fish exposed to Cd and Bacilar. A decrease in the antioxidant biomarkers was followed by increased oxidative damage of lipids and proteins. We also reported altered function in the muscle of individuals exposed to Bacilar and Cd seen as decreased activities in CKP and butyrylcholinesterase. Overall, our results point to the toxicity of both Bacilar and Cd on fish but also to their synergistic effects on Cd bioaccumulation, oxidative stress, and liver and muscle damage. This study highlights the need for evaluating the use of agrochemicals and their possible additive effects on non-target organisms.

Beneficial effects of Chrysin on Cadmium-induced nephrotoxicity in rats: Modulating the levels of Nrf2/HO-1, RAGE/NLRP3, and Caspase-3/Bax/Bcl-2 signaling pathways

Cadmium (Cd) is a toxic heavy metal that targets the kidney directly in the body. Chrysin (CHR) is a natural flavonoid with many properties such as antioxidant, anti-inflammatory and anti-apoptotic. The current study discloses new evidence as regards of the curative effects of CHR on Cd-induced nephrotoxicity by regulating oxidative stress, apoptosis, autophagy, and inflammation. Cd was administered orally at a dose of 25 mg/kg body weight alone or in combination with orally administered CHR (25 and 50 mg/kg body weight) for 7 days. Biochemical, molecular, and histological methods were used to investigate inflammation, apoptosis, autophagy, and oxidant pathways in renal tissue. Renal function tests were also evaluated. Cd caused an increase in serum toxicity markers, lipid peroxidation and a decrease in the activities of antioxidant enzymes. Nrf-2 triggered inflammatory responses by suppressing HO-1 and NQO1 mRNA transcripts and increasing NF-κB, TNF-α, IL-1β and iNOS mRNA transcripts. Cd caused inflammasome by increasing RAGE and NLRP3 mRNA transcripts. In addition, Cd application caused apoptosis by increasing Bax, Apaf-1 and Caspase-3 mRNA transcripts and decreasing Bcl-2 mRNA transcript level. It caused autophagy by increasing the activity of Beclin-1 level. CHR treatment had the opposite effect on all these values and reduced the damage caused by all these signal pathways. Overall, the data of this study indicate that renal damage associated with Cd toxicity could be ameliorated by CHR administration.

Cadmium induced time-dependent kidney injury in common carp via mitochondrial pathway: Impaired mitochondrial energy metabolism and mitochondrion-dependent apoptosis

Toxic effect of heavy metal cadmium (Cd) on fish kidneys had been reported. Mitochondrion is an important organelle for maintaining kidney function, while its role in Cd-induced kidney injury in common carp remained unclarified. In this experiment, we established a poisoning model of common carp with Cd exposure (0.26 mg/L) for 15, 30, and 45 days. Serum biochemistry determination, histological observation, TUNEL assay, qRT-PCR, Western blot, and integrated biomarker response (IBR) were applied to assess the nephrotoxicity of Cd to common carp. Our results displayed that Cd exposure increased the levels of serum biochemical indexes (UREA, CRE, and UA), indicating kidney injury. We further revealed via histological observation that Cd damaged structural integrity of kidneys, as evidenced by renal glomerulus and renal tubular injury, hallmark phenotypes of apoptosis, and mitochondrial damage, suggesting that mitochondria damage and apoptosis were involved in Cd-induced kidney injury. Moreover, Cd exposure decreased ATPase (Na⁺/K⁺-ATPase, Ca²⁺-ATPase, Mg²⁺-ATPase, and Ca²⁺Mg²⁺-ATPase) activities as well as PGC-1a and Mfn2 levels, while increased Drp1 and PINK1 levels as well as LC3-II/LC3-I ratio, which indicated that Cd-impaired renal energy metabolism was related to mitochondrial dysfunction. Additionally, we found that Cd induced oxidative stress (abnormal levels of SOD, CAT, GPX, MDA, and H₂O₂) in kidneys, which was involved in triggering mitochondrial dysfunction and further impairing mitochondrial energy metabolism. Moreover, the occurrence of mitochondria-dependent apoptosis was found after Cd-exposure in common carp kidneys, as indicated by enhanced levels of Bax, CytC, APAF1, Caspase-9, and Caspase-3, while declined level of Bcl-2. Subsequently, we confirmed a time-dependent nephrotoxicity of Cd to common carp via IBR assessment. In conclusion, Cd induced time-dependent nephrotoxicity in common carp via mitochondrial pathway. This mitochondria-oriented study shed light on underlying mechanisms of Cd-induced renal pathologies and provided a theoretical basis for evaluating Cd toxicity to aquatic organisms.

Effect of HSPA8 gene on the proliferation, apoptosis and immune function of HD11 cells

HSPA8 (Heat shock 70 kDa protein 8) is a molecular chaperone involved in a variety of cellular processes. This gene may affect the proliferation, apoptosis and immune function of chicken macrophages, but the specific mechanism remains unclear. The purpose of this study was to explore the effect of the HSPA8 gene on the proliferation, apoptosis and immune function of chicken macrophages. In this study, a chicken HSPA8 overexpression plasmid, interference fragment and corresponding controls were transfected into HD11 cells, and then the expression of the HSPA8 gene, cell proliferation, cell cycle, apoptosis rate and immune function of each group were detected. The results showed that transfection of the HSPA8 overexpression plasmid significantly upregulated the level of HSPA8 expression in HD11 cells compared with the control; significantly promoted the proliferation of HD11 cells and the expression of PCNA, CCND1 and CCNB3; decreased the number of cells in the G1 phase and increased the number of cells in the S phase; decreased the rate of apoptosis and upregulated the expression of Bcl-2; and promoted the expression of the LPS-induced cytokines IL-1β, IL-6 and TNF-α. Transfection of the HSPA8 interference fragment significantly downregulated the level of HSPA8 expression in HD11 cells; significantly inhibited the proliferation of HD11 cells and the expression of PCNA, CCND1 and CDK1; increased the number of cells in the G1 phase and decreased the number of cells in the S phase; increased the rate of apoptosis, downregulated the expression of Bcl-2 and upregulated the expression levels of Fas and FasL; and inhibited the expression of the LPS-induced cytokines IL-1β and NF-κB. The results suggested that HSPA8 promotes the proliferation of and inhibits the apoptosis of HD11 cells and has a proinflammatory effect.

Exposure to acute waterborne cadmium caused severe damage on lipid metabolism of freshwater fish, revealed by nuclear lipid droplet deposition in hepatocytes of rare minnow

Cadmium (Cd) is a widely distributed aquatic toxic heavy metal with the potential to disrupt fish metabolism; however, more research is needed to clarify the underlying mechanisms. In the present study, rare minnows (Gobiocypris rarus) were used to detect the effects of cadmium on freshwater fish lipid metabolism and its underlying mechanism by histopathological observation, measurement of serum and liver biochemical indexes, and analysis of gene expression in terms of lipid oxidation, synthesis and transport. Here, severe damage, such as cytoplasmic lipid droplet (LD) accumulation, ectopic deposition of LDs, and the appearance of nuclear LDs (nLDs), was detected after exposure to 2.0 mg/L or higher concentrations (2.5 and 2.8 mg/L CdCl₂) for 96 h. Other damage included abnormal increases in rough endoplasmic reticulum (RER) lamellae in a fingerprint or concentric circle pattern and necrosis of hepatocytes, and which was observed in the livers of fish exposed to 2.0 mg/L CdCl_2.. Both hepatic and serum lipids, such as triglycerides and total cholesterol, were significantly increased after exposure to 2.0 mg/L CdCl₂, as was serum lipase (LPS). Hepatic lipase and lipoprotein lipase remained unchanged, in accordance with the unchanged hepatic mRNA transcripts of PPARɑ. Furthermore, the mRNA transcripts of both SCD and SQLE were significantly decreased. Moreover, hepatic and serum low-density and high-density lipoprotein cholesterol showed significant changes, which were accompanied by a significant increase and decrease in hepatic APOAI and APOB100 mRNA levels, respectively. All the results indicate the presence of severe damage to hepatic lipid metabolism and that disrupted lipid transport may play a key role in the accumulation of hepatic LDs. In addition, the hepatic nLDs of nonmammalian vertebrates and their location across the nuclear envelope are intriguing, suggesting that large-size nLDs are a common marker for severe liver damage.

Molybdenum fertilizer improved antioxidant capacity of Chinese Merino sheep under compound contamination

To investigate the response of different levels of molybdenum (Mo) fertilizer to Chinese Merino sheep (Junken Type) grazing on natural heavy metal-contaminated meadows, this study was carried out in the Bayanbulak Grassland lying in the northwest of Xinjiang Uygur Autonomous Region, China. A total of 24-hm2 polluted meadows were fenced and were randomly divided into four groups (3 replication/group and 2 hm2/replication) applied 0-kg Mo, 1-kg Mo, 2-kg Mo, and 3-kg Mo (ammonium molybdate tetrahydrate) per hectare for the CON group, group I, group II, and group III, respectively. Seventy-two healthy 1-year-old Chinese Merino sheep (45.56 ± 2.35 kg) were randomly assigned to the tested pastures for 90 days. Compared with the CON group, the Mo content from fertilized groups and the Se content from group II and group III in serums and livers were significantly increased (P < 0.05), and the Cu content from fertilized groups in serums and livers was significantly decreased (P < 0.05). The levels of blood Hb and RBC, and the activities of serum SOD, CAT, GSH-Px, and Cp in group III, were significantly higher (P < 0.05) than those in the CON group, group I, and group II. Serum MDA content in group III was significantly lower (P < 0.05) than that in the other three groups. In summary, Mo fertilization improved the antioxidant capacity of grazing sheep and also reduced the toxic damage to Chinese Merino sheep grazing on natural grasslands contaminated by heavy metals, but Mo poisoning caused by excessive fertilization should be prevented.

Cadmium effects on the freshwater teleost Prochilodus lineatus: Accumulation and biochemical, genotoxic, and behavioural biomarkers

In order to evaluate the effects of Cd, juveniles of the Neotropical fish Prochilodus lineatus were exposed to 1 and 10 μg L^-1 Cd, for 24 and 96 h. Fish exposed to Cd showed metal accumulation in the gills, kidney, and liver, an increase in DNA damage in erythrocytes, and an increase in lipid peroxidation (LPO) in the kidney. Cd exposure also caused a reduction in catalase activity, metallothionein induction, and LPO in the liver. Cd stimulated the swimming activity of exposed fish, resulting in longer swimming times and distances travelled, especially for the shortest exposure time. Changes in acetylcholinesterase activity (AChE) in the muscle and brain are probably related to these behavioural responses. These results show that Cd affects the functioning of several organs in P. lineatus, which is indicated by the genotoxic damage and changes in the AChE and swimming pattern of the exposed fish.

Ammonia-induced oxidative stress triggered proinflammatory response and apoptosis in pig lungs

Ammonia, a common toxic gas, is not only one of the main causes of haze, but also can enter respiratory tract and directly affect the health of humans and animals. Pig was used as an animal model for exploring the molecular mechanism and dose effect of ammonia toxicity to lung. In this study, the apoptosis of type II alveolar epithelial cells was observed in high ammonia exposure group using transmission electron microscopy. Gene and protein expression analysis using transcriptome sequencing and western blot showed that low ammonia exposure induced T-cell-involved proinflammatory response, but high ammonia exposure repressed the expression of DNA repair-related genes and affected ion transport. Moreover, high ammonia exposure significantly increased 8-hydroxy-2-deoxyguanosine (8-OHdG) level, meaning DNA oxidative damage occurred. In addition, both low and high ammonia exposure caused oxidative stress in pig lungs. Integrated analysis of transcriptome and metabolome revealed that the up-regulation of LDHB and ND2 took part in high ammonia exposure-affected pyruvate metabolism and oxidative phosphorylation progress, respectively. Inclusion, oxidative stress mediated ammonia-induced proinflammatory response and apoptosis of porcine lungs. These findings may provide new insights for understanding the ammonia toxicity to workers in livestock farms and chemical fertilizer plants.

A novel cadmium detoxification pathway in Tri-spine horseshoe crab (Tachypleus tridentatus): A 430-million-years-ago organism

Marine and intertidal heavy metal pollution has been a major concern in recent years. Tachypleus tridentatus has existed on earth for more than 430 million years. It has suffered a sharp decline in population numbers caused by environmental pollution and anthropogenic disturbance for almost 40 years. However, the effects of heavy metal pollution on juvenile T. tridentatus have not been reported. Here we show the mechanism of cadmium (Cd) detoxification in juvenile T. tridentatus using integrated antioxidant indexes and transcriptomic and metabolomic analysis. High Cd²⁺ concentration caused oxidative stress in juvenile T. tridentatus. The hazards increase with increasing Cd²⁺ concentration in juvenile T. tridentatus. Transcriptomics and metabolomics analyses concluded that high Cd²⁺ concentration resulted in the imbalance of glycerophospholipid metabolism in juvenile T. tridentatus to detoxify Cd. Our results offer a rationale for protective measures and further studies of heavy metal stress in T. tridentatus.

Slow and steady hurts the crab: Effects of chronic and acute microplastic exposures on a filter feeder crab

Microplastics are a widespread environmental contaminant. Although detrimental effects on aquatic organisms are well documented, little is known about the long-term effects of microplastic exposure to filter-feeding organisms at ecologically realistic levels. This study investigates the effects of environmentally relevant concentrations of polyethylene micro beads ranging in size from 3 to 30 μm, on the physiology and energetics of a coastal filter-feeding crab Petrolisthes laevigatus. We evaluated the impact of microplastics by exposing P. laevigatus to two different concentrations and exposure times: i) a chronic exposure for five months at 250 particles L^-1, and ii) an acute exposure for 48 h at 20,800 particles L^-1, ~80 times higher than the chronic exposure. The results showed that only chronic exposures elicited negative effects on the coastal crab in both, metabolic and physiological parameters. Our findings demonstrate a strong correlation between the ingestion rate and weight loss, even at low concentrations, the crabs exhibited severe nutritional damage as a result of long-term microplastic exposure. By contrast, acute exposure revealed no significant effects to the crabs, a possible explanation for this being short-term compensatory responses. These results suggest that environmentally relevant concentrations of microplastics are harmful to marine organisms, and they should be evaluated during realistic temporal scales, as their effects strongly dependent on the exposure time. Our results also suggest that the effects of microplastics have been likely underestimated to date, due to the dominance of short-term exposures (acute) reported in the current literature.

Salvia miltiorrhiza polysaccharides alleviate florfenicol-induced inflammation and oxidative stress in chick livers by regulating phagosome signaling pathway

Florfenicol (FFC) is a commonly used antibiotic in animal breeding, especially in broiler breeding. Previous studies found that FFC could affect the liver function of chickens. However, the mechanisms underlying the effects of FFC on liver function are still not completely clear. Moreover, the research on drugs that antagonize FFC hepatotoxicity is relatively lacking. Salvia miltiorrhiza polysaccharides (SMPs) have been proved to have obvious liver protection effects. Therefore, we exposed chicks to FFC at the clinically recommended dose of 0.15 g/L. At the same time, 0.15 g/L FFC and 5 g/L SMPs were given to another group of chicks. After 5 days of continuous administration, the livers of chicks from different treatment groups were sequenced by transcriptome and proteome. Based on the analysis of sequencing data, we also focused on the detection of inflammation and oxidation indicators related to the phagosome signaling pathway with significant enrichment of differential factors in the livers of chicks. The results showed that some significantly differentially expressed genes and proteins induced by FFC were enriched in the phagosome signaling pathway, and they increased the expression levels of inflammatory factors and peroxides. However, SMPs intervention significantly reversed the tendency of FFC to alter phagosome signaling pathways and reduced the expression levels of inflammatory factors and peroxides. In conclusion, FFC caused liver inflammation and oxidative stress in chicks by regulating the phagosome signaling pathway. Meanwhile, SMPs could improve the adverse effects of FFC on the phagosome signaling pathway. This study provided new insights into the ameliorative effects and mechanisms of SMPs on hepatotoxicity of FFC.

Nano-selenium and Macleaya cordata Extracts Improved Immune Function and Reduced Oxidative Damage of Sows and IUGR Piglets After Heat Stress of Sows in Late Gestation

To investigate the effects of nano-selenium (nano-Se) and Macleaya cordata extracts (MCE) on immune function and oxidative damage of sows and intrauterine growth retardation (IUGR) piglets exposed to heat stress (HS) in large-scale farms, a 2 × 2 factorial design was adopted in this test, and the two factors were nano-Se (0, 0.50 mg/kg) and MCE (0, 500 mg/kg). A total of 80 sows ([Landrace × Yorkshire] × Duroc, parity 2) were used in a 25-day trial from day 90 of gestation to delivery with 20 replications per group and 1 sow per replication. The dietary treatments of sows were as follows: (1) CON group, basic diet (0.30 mg/kg added Se, sodium selenite); (2) Nano-Se group, basic diet (0.00 mg/kg added Se) + 0.50 mg/kg added nano-Se; (3) MCE group, basic diet (0.00 mg/kg added Se) + 500 mg/kg added MCE; and (4) Combined group, basic diet (0.00 mg/kg added Se) + 0.50 mg/kg added nano-Se and 500 mg/kg added MCE. The activities of serum SOD, CAT, and GSH-Px of sows and IUGR piglets were significantly increased in MCE group and combined group, and the MDA content was extremely decreased. There were extreme differences in serum IgG level of sows and IUGR piglets, colostrum, and serum IgM level of IUGR piglets in MCE group and combined group compared with CON group. Maternal combined diets increased greatly the levels of serum IL-10 and IFN-γ of sows and IUGR piglets, and decreased extremely the contents of serum IL-1β and TNF-α. MCE alone or combination with nano-Se in sow diets decreased greatly mRNA level of Hsp70 and increased mRNA level of Hsp27 in sows and IUGR piglets. In conclusion, nano-Se and/or MCE can be added to sow diets for the amelioration of HS-induced oxidative damage through improving immune function.

Toxic Effects of Cadmium on Fish

Large amounts of enriched cadmium (Cd) in the environment seriously threatens the healthy and sustainable development of the aquaculture industry and greatly restricts the development of the food processing industry. Studying the distribution and toxic effects of Cd in fish, as well as the possible toxic effects of Cd on the human body, is very significant. A large number of studies have shown that the accumulation and distribution of Cd in fish are biologically specific, cause tissue differences, and seriously damage the integrity of tissue structure and function, the antioxidant defense system, the reproductive regulation system, and the immune system. The physiological, biochemical, enzyme, molecular, and gene expression levels change with different concentrations and times of Cd exposure, and these changes are closely related to the target sites of Cd action and tissues in fish. Therefore, the toxic effects of Cd on fish occur with multiple tissues, systems, and levels.

Identification of a necroptosis-related prognostic gene signature associated with tumor immune microenvironment in cervical carcinoma and experimental verification

Cervical carcinoma (CC) has been associated with high morbidity, poor prognosis, and high intratumor heterogeneity. Necroptosis is the significant cellular signal pathway in tumors which may overcome tumor cells’ apoptosis resistance. To investigate the relationship between CC and necroptosis, we established a prognostic model based on necroptosis-related genes for predicting the overall survival (OS) of CC patients. The gene expression data and clinical information of cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) patients were obtained from The Cancer Genome Atlas (TCGA). We identified 43 differentially expressed necroptosis-related genes (NRGs) in CESC by examining differential gene expression between CESC tumors and normal tissues, and 159 NRGs from the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Gene ontology (GO) and KEGG enrichment analysis illustrated that the genes identified were mainly related to cell necrosis, extrinsic apoptosis, Influenza A, I − kappaB kinase/NF − kappaB, NOD − like receptor, and other signaling pathways. Subsequently, least absolute shrinkage and selection operator (LASSO) regression and univariate and multivariate Cox regression analyses were used to screen for NRGs that were correlated with patient prognosis. A prognostic signature that includes CAMK2A, CYBB, IL1A, IL1B, SLC25A5, and TICAM2 was established. Based on the prognostic model, patients were stratified into either the high-risk or low-risk subgroups with distinct survival. Receiver operating characteristic (ROC) curve analysis was used to identify the predictive accuracy of the model. In relation to different clinical variables, stratification analyses were performed to demonstrate the associations between the expression levels of the six identified NRGs and the clinical variables in CESC. Immunohistochemical (IHC) validation experiments explored abnormal expressions of these six NRGs in CESC. We also explored the relationship between risk score of this necroptosis signature and expression levels of some driver genes in TCGA CESC database and Gene Expression Omnibus (GEO) datasets. Significant relationships between the six prognostic NRGs and immune-cell infiltration, chemokines, tumor mutation burden (TMB), microsatellite instability (MSI), and immune checkpoints in CESC were discovered. In conclusion, we successfully constructed and validated a novel NRG signature for predicting the prognosis of CC patients and might also play a crucial role in the progression and immune microenvironment in CC.

Condensed Tannins Improved Immune Functions and Reduced Environmental Pollution of Captive Sichuan Black Goat Kids Under Cadmium Toxicity

To investigate the effects of condensed tannins (CT) on immune functions and nitrogen (N) emissions of captive Sichuan black goat kids under cadmium (Cd) toxicity, a total of 18 Sichuan black goat kids (2 months old, 9.6 ± 1.2 kg) were randomly used in this 30-day trial. The dietary treatments were (1) CON group, basic diet; (2) Cd group, basic diet + oral 10 mg Cd/kg·BW; and (3) CT group, Cd group + 400 mg/kg CT. Oral Cd supplementation significantly decreased the Cu and Fe contents in serums and livers of captive Sichuan black goat kids (P < 0.05), but adding CT in the Cd group increased the Fe and Mo contents and decreased the Cd content in serums and livers (P < 0.05). Additional CT supplementation in the Cd group extremely increased the activities of serum SOD, GSH-Px, and CAT (P < 0.05), and greatly decreased the serum MDA content (P < 0.05). The CT supplementation in the Cd group also extremely increased the concentrations of serum IgG, IgM, and IgA (P < 0.05), and greatly decreased the contents of IL-6, IL-1β, and TNF-α in serums (P < 0.05). Adding CT in the Cd group significantly increased the apparent digestibility of CP and EE and decreased the urinary nitrogen (UN) content (P < 0.05, Table 7). In conclusion, the application of additional CT improved antioxidant capacities and immune functions of captive black goats under Cd toxicity, then reduced the oxidative stress and toxic damage of Cd contamination. CT also improved the N digestibility and reduced the N emission, which was helpful to reduce environmental pollution.

The Role of PTEN/PI3K/AKT Signaling Pathway in Apoptosis of Liver Cells in Cocks with Manganese Toxicity

PTEN/PI3K/AKT signaling pathway is an important pathway for cell proliferation and apoptosis. Exposure to excess manganese (Mn) can cause damage in organisms. However, whether Mn toxicity can cause apoptosis is still not clear. In order to explore the mechanism of PTEN/PI3K/AKT signaling pathway responsible for Mn-induced apoptotic injury, 160 Hyline cocks were divided into four groups; there were the control group (Con group), the low-dose Mn group (L group), the medium-dose Mn group (M group), and the high-dose Mn group (H group). The cocks in Con group, L group, M group, and H group were fed with MnCl₂ diet containing 100, 600, 900, and 1800 mg/kg, respectively. The growth status of cocks in each group was observed on days 30, 60, and 90. Thirty cocks were randomly selected from each group and sacrificed on day 90 for optical microscope observation and fluorescence microscopic observation, as well as for transcription-level expression of apoptosis-related genes and heat shock proteins (HSPs) in the liver. The results showed that the growth status of cocks was gradually depressed with the extension of feeding time and with the increase of Mn dose_. On day 90, the results of optical microscope observation and fluorescence microscope observation showed that damage and apoptosis appeared in the cock liver cells under Mn exposure groups. The results of transcription-level detection of apoptosis-related genes and HSPs indicated that Mn exposure upregulated eleven pro-apoptotic genes (including RIP1, RIP3, MLKL, Bax, Caspase-3, FADD, Cyt-C, ERK, JNK, Caspase-8, and P38) and downregulated one anti-apoptotic gene Bcl-2, further meaning that exposure to Mn-induced apoptosis in cock liver cells and PTEN/PI3K/AKT signaling pathway took part in molecular mechanism of apoptosis caused by excess Mn. Moreover, in our experiment, the increase of four HSPs (including HSP27, HSP40, HSP60, and HSP70) was found after Mn treatment for 90 days, which indicated that Mn stress triggered HSPs and HSPs were involved in molecular mechanism of Mn poisoning in cock livers. In addition, we also found there was upregulated dose-dependent manner in fifteen detected genes and there was downregulated dose-dependent manner in Bcl-2, indicating that the apoptosis caused by Mn poisoning in cock liver cells was dose-dependent.

MicroRNA-122 overexpression promotes apoptosis and tumor suppressor gene expression induced by microcystin-leucine arginine in mouse liver

Microcystin-leucine arginine (MC-LR), an important hepatoxin, has the effect of promoting hepatocarcinogenesis. MicroRNA-122 (miR-122), an important tumor suppressor in liver, plays an important role in promoting cell apoptosis. Previous studies found that the expression of miR-122 was reduced after MC-LR exposure in liver. In this study, C57BL/6 mice were exposed to saline, negative control agomir, and MC-LR with or without miR-122 agomir transfection. The results indicated that MC-LR promoted the expressions of tumor suppressor genes and decreased the expressions of anti-apoptotic proteins B cell lymphoma-2 (Bcl-2) and Bcl-2-like 2 (Bcl-w), causing hepatocyte apoptosis. Under MC-LR exposure, miR-122 agomir transfection could further increase the expressions of tumor suppressor genes and the release of cytochrome-c (Cyt-c) and decrease the expressions of Bcl-2 and Bcl-w. In conclusion, miR-122 reduction can mitigate MC-LR-induced apoptosis to a certain extent, which in turn, it is likely to have contributed to MC-LR-induced hepatocarcinogenesis.

Nano-Selenium and Macleaya cordata Extracts Improved Immune Functions of Intrauterine Growth Retardation Piglets under Maternal Oxidation Stress

Intrauterine growth retardation (IUGR) is the main death cause of newborn piglets in large-scale farms. To investigate the effects of maternal nano-selenium (nano-Se) and Macleaya cordata extracts (MCE) on immune functions of IUGR piglets in large scale farms, a 2 × 2 factorial design was adopted in this test, and two factors were nano-Se (0, 0.50 mg/kg) and MCE (0, 500 mg/kg). A total of 32 ternary hybrid sows (Landrace × Yorkshire × Duroc, parity 2) were used in this 25-day trial from day 90 of pregnancy to delivery. The dietary treatments were as follows: (1) CON group, basic diet (0.0 mg/kg Se); (2) Nano-Se group, basic diet + 0.50 mg/kg added Se (nano-Se); (3) MCE group, basic diet + 500 mg/kg added MCE; (4) Combined group, basic diet + 0.50 mg/kg added nano-Se and 500 mg/kg added MCE. Maternal nano-Se or combination of nano-Se and MCE diets extremely increased the superoxide dismutase (SOD), catalase (CAT), superoxide dismutase (GSH-Px) contents in the serum and liver of IUGR offspring (P < 0.05), and MCE supplementation in sow diets remarkably increased the serum superoxide dismutase (SOD), catalase (CAT), and superoxide dismutase (GSH-Px) contents of IUGR piglets (P < 0.05). Adding nano-Se, MCE, or nano-Se and MCE to sow diets decreased the malondialdehyde (MDA) content in the serum and liver of IUGR piglets (P < 0.05). The supplementation of nano-Se and combined diets extremely increased the activities of immunoglobulin G (IgG) and immunoglobulin A (IgA) in the serum and liver of IUGR offspring (P < 0.05). Maternal nano-Se, MCE, and combined diets greatly decreased the levels of tumor necrosis factor-alpha (TNF-α), interleukin 6 (IL-6), and interleukin-1β (IL-1β) in the serum and liver of IUGR piglets (P < 0.05). Together, the application of nano-Se and/or MCE to sow diets improved antioxidant capacities and immune functions of IUGR offspring, and alleviated oxidative stress.

Taurine inhibits hydrogen peroxide-induced oxidative stress, inflammatory response and apoptosis in liver of Monopterus albus

Fish are extremely vulnerable to environmental stimulation and produce oxidative stress. Among them, hydrogen peroxide is an oxidative stress source that cannot be ignored in fish, which can cause physical disorders, inflammation and even death. Taurine was revealed to reduce oxidative damage and inflammation caused by toxic substances, but whether it can reduce toxicity of rice field eel caused by H₂O₂ has not been determined. Thus, the intervention effects of taurine on H₂O₂-induced oxidative stress, inflammation, apoptosis, and autophagy in rice field eel. The results showed that oxidative injury in the liver was determined after H₂O₂ injection, as indicated by enhanced serum AST and ALT activities, inhibited the antioxidant function (increased MDA and ROS contents, decreased antioxidant enzymes, inhibited nrf2 transcription level), and induced inflammatory response (upregulated il-1β, il-6, il-8, and il-12β gene expression, downregulated tgf-β1 gene expression, activated the transcription level of nf-κb, tlr-3, and tlr-7). In addition, bax, caspase3, beclin1, and Lc3B gene expression were significantly upregulated after H₂O₂ injection, while bcl2 and p62 gene expression were downregulated, leading to the occurrence of apoptosis and autophagy. In contrast, adding 0.2 and 0.5% taurine to feed significantly alleviated this damage, as indicated by the recovery of the aforementioned bioindicators, and the effect of 0.5% taurine addition is better than 0.2%. Overall, these results suggested that taurine can relieve the liver toxicity induced by H₂O₂, which enriched the toxic mechanism of H₂O₂ on fish and provided evidence for the protective effect of taurine on liver.

Ethyl Acetate Fraction of Hedyotis diffusa Willd Induces Apoptosis via JNK/Nur77 Pathway in Hepatocellular Carcinoma Cells

Background

Hepatocellular carcinoma (HCC) is characterized by poor diagnosis and high mortality. Novel and efficient therapeutic agents are urgently needed for the treatment. Hedyotis diffusa Willd (HDW) is used to treat cancers, especially HCC in China.

Purpose

The study aimed to identify the main anti-HCC extract in HDW and to explore the mechanism of the active extract.

Materials and Methods

The high-performance liquid chromatography-quadrupole-time of flight mass spectrometry (HPLC-QTOF-MS) method was used for the simultaneous determination of main compounds in the ethyl acetate fraction of HDW (EHDW). The toxicity test of different HDW fractions was carried out on larvae at 2 day-post-fertilization (dpf) for 72 h. The in vivo anti-HCC effect of different HDW fractions was evaluated on a zebrafish tumor model by immersion administration. The antiproliferative effect of HDW fractions was determined with MTT assay, as well as hematoxylin and eosin (HE) staining assay. Hoechst 33258 staining was used to observe changes in nucleus morphology. Flow cytometry analysis was used to investigate apoptosis induction. Western blot analysis was used to examine apoptosis-related proteins, and key proteins in JNK/Nur77 signaling pathway. SP600125 was served to validate the apoptotic mechanism.

Results

EHDW showed the strongest tumor cell growth inhibitory effect on zebrafish tumor model. Further study revealed that EHDW induced apoptosis in zebrafish tumor model and in cultured Hep3B cells. Meanwhile, it has been shown that the levels of BCL2-associated X (Bax), cytochrome c (cyto c), cleaved-caspase 3, and poly-ADP-ribose polymerase (PARP) cells were upregulated. In contrast, the level of antiapoptotic B cell lymphoma-2 (Bcl-2) was downregulated in Hep3B cells. Additionally, EHDW activated JNK/Nur77 pathway by increasing the levels of p-JNK(Thr183/Tyr185) and p-Nur77(Ser351). Further study showed that blockage of JNK by SP600125 reversed EHDW-induced JNK/Nur77 pathway and the downstream apoptotic proteins.

Conclusion

In conclusion, EHDW exerted the anti-HCC effect, which may be attributed to the activation of JNK/Nur77 pathway. This study supported the rationale of HDW as an HCC therapeutic agent.

Immunosuppression participated in complement activation-mediated inflammatory injury caused by 4-octylphenol via TLR7/IκBα/NF-κB pathway in common carp (Cyprinus carpio) gills

4-octylphenol (4-OP), a toxic estrogenic environmental pollutant, can threaten aquatic animal and human health. However, toxic effect of 4-OP on fish has not been reported. To investigate molecular mechanism of gill poisoning caused by 4-OP exposure, a carp 4-OP poisoning model was established, and then blood and gills were collected on day 60. The results demonstrated that gill was a target organ attacked by 4-OP, and exposure to 4-OP caused carp gill inflammatory injury. There were 1605 differentially expressed genes (DEGs, including 898 up-regulated DEGs and 707 down-regulated DEGs). KEGG and GO were used to further analyze obtained 1605 DEGs, indicating that complement activation, immune response, and inflammatory response participated in the mechanism of 4-OP-caused carp gill inflammatory injury. Our data at transcription level further revealed that 4-OP caused complement activation through triggering complement component 3a/complement component 3a receptor (C3a/C3aR) axis and complement component 5a/complement component 5a receptor 1 (C5a/C5aR1) axis, induced immunosuppression through the imbalances of T helper (Th) 1/Th2 cells and regulatory T (Treg)/Th17 cells, as well as caused inflammatory injury via toll like receptor 7/inhibitor kappa B alpha/nuclear factor-kappa B (TLR7/IκBα/NF-κB) pathway. Taken together, immunosuppression participated in complement activation-mediated inflammatory damage in carp gills after 4-OP treatment. The findings of this study will provide pioneering information and theoretical support for the mechanism of 4-OP poisoning, and will provide reference for the assessment of estrogenic environmental pollution risk.

Oxidative stress links the tumour suppressor p53 with cell apoptosis induced by cigarette smoke

This study was to investigate the effects of oxidative stress in cigarette smoke (CS)-induced cell apoptosis in mice with emphysema. Thirty-two mice were divided into four groups: the control group, the CS group, the CS + Pifithrin-α group, and the CS + NAC group. Pathological changes and apoptosis in lung tissue of mice were detected. The activity of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC) were measured using spectrophotometer. The proteins expression of p53, Bcl-2, Bax, and caspase-3 were determined by western blot. The results showed that cell apoptosis, lung structural damage, and the activity of MDA, as well as the expression of apoptosis-related proteins Bax, total caspase-3, and cleaved caspase-3 were increased in CS-treated mice. The activity of SOD, CAT, and T-AOC, as well as the expression of anti-apoptosis protein Bcl-2 were decreased in CS-treated mice when compared with the control group. However, Pifithrin-α (p53 inhibitor) and N-Acetylcysteine (NAC) could reduce cell apoptosis, lung structural damage and oxidative stress, accelerate the expression of Bcl-2, while suppressing the expression of Bax, total caspase-3 and cleaved caspase-3. More importantly, the treatment with NAC even inhibited the expression of p53. In conclusions, oxidative stress linking the p53 is involved in cell apoptosis in CS-treated emphysema mice.

Physiological Performance, Antioxidant and Immune Status, Columnaris Resistance, and Growth of Nile Tilapia That Received Alchemilla vulgaris-Supplemented Diets

The current perspective is a pioneering trial to assess the efficacy of the dietary supplementation of Alchemilla vulgaris powder (AVP) in the diet of Nile tilapia (Oreochromis niloticus) on growth performance, blood picture, hepatic and renal biomarkers, immune status, and serum and tissue antioxidant capacity and to investigate the resistance against Flavobacterium columnare challenge. Fish (n = 360) were distributed into six groups (three replicates each) and received increasing AVP supplementation levels (0, 2, 4, 6, 8, and 10 g kg-1) for 60 days. Furthermore, fish were exposed to the bacterial challenge of a virulent F. columnare strain and maintained under observation for 12 days. During the observation period, clinical signs and the cumulative mortality percentage were recorded. The results demonstrated that the growth performance, feed conversion ratio, and hematological profile were noticeably enhanced in the AVP-supplemented groups compared to the control. The most promising results of weight gain and feed conversion ratio were recorded in the groups with 6, 8, and 10 g AVP kg-1 diets in a linear regression trend. The levels of hepatorenal function indicators were maintained in a healthy range in the different dietary AVP-supplemented groups. In a dose-dependent manner, fish fed AVP dietary supplements displayed significant augmented serum levels of innate immune indicators (lysozyme, nitric oxide, and complement 3) and antioxidant biomarkers (Catalase (CAT), superoxide dismutase (SOD), total antioxidant (TAC), and reduced glutathione (GSH) with a marked decrease in myeloperoxidase (MPO) and malondialdehyde (MDA) levels). Likewise, hepatic CAT and SOD activities were significantly improved, and the opposite trend was recorded with hepatic MDA. The highest AVP-supplemented dose (10 g/kg) recorded the highest immune-antioxidant status. Based on the study findings, we highlight the efficacy of AVP as a nutraceutical dietary supplementation for aquaculture to enhance growth, physiological performance, and immune-antioxidant status and as a natural economic antibacterial agent in O. niloticus for sustaining aquaculture. It could be concluded that the dietary supplementation of 10 g AVP/kg enhanced O. niloticus growth, physiological performance, immune-antioxidant status, and resistance against F. columnare.

Selenium Deficiency Induces Apoptosis and Necroptosis Through ROS/MAPK Signal in Human Uterine Smooth Muscle Cells

Selenium (Se) is one of the essential trace elements; its deficiency induces ROS production and cell death in cardiomyocytes, skeletal muscle cells, and vascular smooth muscle cells, but it is still not clear the impact of Se deficiency on human uterine smooth muscle cells (HUSMCs). To investigate the effect of low Se on the mRNA expression of selenoproteins, the mRNA and protein expression of apoptosis and necroptosis of HUSMCs and their mechanism, Se deficient HUSMCs mode was established through culturing with 1% FBS containing 0 ng/mL, 0.7 ng/mL, and 7 ng/mL Se, and 10% FBS was as the control group. Then, the apoptosis and necroptosis rates, intracellular ROS content and the expression levels of selenoproteins, apoptosis, necroptosis, MAPK pathway-related genes were examined under different Se concentrations. The results showed that Se deficiency led to the augment of cell apoptosis and necroptosis in HUSMCs (p < 0.05), downregulated (p < 0.05) 19 selenoproteins (GPX1, GPX2, GPX3, GPX4, GPX6, Dio3, Txnrd2, Txnrd3, SEPHS2, SEL15, SELH, SELI, SELM, SELN, SELO, SELS, SELT, SELV, and SELW), while Dio2, SELK, Txnrd1, and MSRB1 were not affected by Se deficiency (p ≥ 0.05). In addition, Se deficiency led to increased intracellular ROS content, p-P38 and p-JNK gene expression levels (p < 0.05), the mitochondrial apoptosis pathway Bax, Casp9 and Cle-Casp3 protein expression levels (p < 0.05), and decreased Bcl2 protein expression level (p < 0.05), simultaneously, increased necroptosis marker genes RIP1, RIP3, and MLKL protein expression levels (p < 0.05) with a dose-dependent pattern. The above results indicate that Se deficiency induces HUSMCs apoptosis and necroptosis through the ROS/MAPK pathway and is closely related to selenoproteins.

Effects of Foliar Application of Nano-molybdenum Fertilizer on Copper Metabolism of Grazing Chinese Merino Sheep (Junken Type) on Natural Grasslands Under Copper and Cadmium Stress

In recent decades, the groundwater contaminated by mineral development and metal smelting has seriously polluted natural grasslands, resulting in heavy metal residues in soils and forages exceeding the standard, especially copper (Cu) and cadmium (Cd). After animals intake contaminated forages, heavy metals may accumulate in animal tissues and threaten human health through the food chain. Previous studies found that molybdenum (Mo) fertilizer from ammonium molybdate or potassium molybdate could alleviate the decrease of antioxidant capacity caused by heavy metal poisoning, but the application of nano-Mo fertilizer in sheep is still lacking. To investigate the effects of nano-Mo fertilizer on Cu metabolism of grazing Chinese Merino sheep (Junken Type) on natural pastures under Cu and Cd stress, fertilizing experiment was carried out in the Bayanbulak Grassland in the northwest of Xinjiang Uygur Autonomous Region, China. A total of 24 hm² fenced grassland contaminated by heavy metals was randomly divided into four groups (3 replications/group and 2 hm²/replication). The experimental groups were applied 0 g Mo, 100 g Mo, 200 g Mo, and 300 g Mo per hectare for the control group, group I, group II, and group III, respectively, through foliar spraying fertilization. A total of 72 Chinese Merino sheep (1 year old, 43.8 ± 2.3 kg) grazing on polluted natural grasslands, with 18 sheep per group, were randomly assigned to the experimental pastures for 30 days. The results showed that the Mo content in soil in group II and group III nwas higher than that in the control group (P < 0.05); the Cd content in soil in group II and group III was lower than that in the control group (P < 0.05), and the Cu content in soil in fertilized pastures was lower than that in the control group (P < 0.05). The Mo content in herbage in fertilized pastures was higher than that in the control group (P < 0.05), and the content of Cu in herbage in fertilized pastures was lower than that in the control group (P < 0.05). The contents of iron (Fe) and Mo in blood and liver of grazing animals from fertilized pastures were higher than that in the control group (P < 0.05). The Cd content in blood of grazing animals in group II and group III was lower than that in the control group (P < 0.05). The Cu content in blood and liver of grazing animals in fertilized pastures was lower than that in the control group (P < 0.05). The content of selenium (Se) in blood of grazing animals in group II and group III was higher than that in the control group (P < 0.05). The levels of blood including hemoglobin (Hb), erythrocyte count (RBC), and packed cell volume (PCV) in group II and group III were higher than that in the control group (P < 0.05). The white blood cell (RBC) count in group II and group III was lower than that in the control group (P < 0.05). The activities of serum superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and ceruloplasmin (Cp) in group II and group III were higher than that in the control group (P < 0.05). The content of malondialdehyde (MDA) in group II and group III was lower than that in the control group (P < 0.05). In conclusion, the application of nano-Mo fertilizer on Cu- and Cd-contaminated grasslands changed the contents of mineral elements in soil, forage, and blood of grazing sheep, improved the antioxidant capacity, affected the Cu metabolism of grazing Chinese Merino sheep caused by Cu and Cd pollutions, and alleviated the toxic damage of heavy metal pollutions.

Nano-Molybdenum and Macleaya cordata Extracts Improved Antioxidant Capacity of Grazing Nanjiang Brown Goats on Copper and Cadmium-Contaminated Prairies

To investigate the effects of nano-ammonium octamolybdate (nano-Mo) and Macleaya cordata extracts (MCE) on antioxidant capacity of grazing Nanjiang brown goats on natural prairies under Cu and Cd stress, a 2 × 2 factorial design was adopted in this test, and two factors were nano-Mo (0, 10 mg/kg) and MCE (0, 3000 mg/kg). 24 hm² polluted grassland was used in this 30-day trial and was equally divided into twelve fenced units. A total of 36 Nanjiang brown goats (1 year old) with an average body weight (BW) of 40.9 ± 2.1 kg were used in this test. The dietary treatments were (1) CON group, basic diet; (2) Nano-Mo group, basic diet + 10 mg/kg added Mo (nano-Mo); (3) MCE group, basic diet + 3000 mg/kg added MCE; and (4) combined group, basic diet + 10 mg/kg added nano-Mo and 3000 mg/kg added MCE. Nano-Mo or combination of nano-Mo and MCE diets significantly decreased the Cu content in serum and the liver of grazing goats (P < 0.05) and increased the Fe and Mo contents in serum and the liver (P < 0.05). The supplementation of nano-Mo, MCE, and combined diets extremely increased the levels of blood Hb, RBC, and PCV (P < 0.05), as well as the activities of serum SOD, GSH-Px, CAT, and Cp (P < 0.05), and greatly decreased the blood WBC content (P < 0.05) and the serum MDA content (P < 0.05). In conclusion, the application of nano-Mo and/or MCE diets on contaminated grasslands changed the contents of mineral elements in serum and the liver of grazing goats, reduced oxidative stress, and improved antioxidant capacity. The combination of nano-Mo and MCE can alleviate the toxic damage of combined heavy metal contaminations.

Proteome and transcriptome explore the mechanism of Salvia miltiorrhiza polysaccharides to relieve florfenicol-induced kidney injury in broilers

This experiment explored the mechanism of Salvia miltiorrhiza polysaccharides (SMPs) on florfenicol (FFC)-induced kidney injury in broilers. Ninety healthy 1-day-old Arbor Acres broilers were randomly divided into 3 groups with 6 replicates in each group and 5 chickens in each replicate. The three groups included control group, model group (0.15 g/L FFC), and SMPs group (0.15 g/L FFC + 5.00 g/L SMPs). After 5 days of experimental period, blood was collected, and kidney tissues were extracted. Renal injury was evaluated by serum biochemical indicators and pathological sections. Renal oxidative stress indexes were detected; transcriptomics and proteomics were used to comprehensively analyze the effects of SMPs on broiler kidney injury. The results showed that the model group inhibited average day gain (P < 0.01) and significantly adjusted blood urea nitrogen (BUN), uric acid (UA), and creatinine (Cr) (P < 0.01 or P < 0.05). The histological observation of the kidneys in the model group showed abnormal morphology, and the oxidative stress parameters showed that FFC induced oxidative stress in the kidneys. Comprehensive transcriptome proteomic analysis data showed phosphoribose pyrophosphate synthase 2 (PRPS2), cytochrome 2AC1 (CYP2AC1), cytochrome 2D6 (CYP2D6), glutathione transferase (GST), and sulfotransferase 1B (SULT1B) expression levels changed. It is worth noting that our data showed that supplementation of 5.00 g/L SMPs in drinking water reversed the changes in BUN, Cr, and daily weight gain (P < 0.05) and relieved the abnormal kidney morphology caused by FFC. After SMPs processing, it improved the detoxification process of drug-metabolizing enzymes and improved the oxidative stress state induced by FFC. Therefore, SMPs reduced the nephrotoxicity caused by FFC by promoting drug-metabolizing enzymes and alleviating oxidative stress in the kidneys.

The Effects of Oral Administration of Molybdenum Fertilizers on Immune Function of Nanjiang Brown Goat Grazing on Natural Pastures Contaminated by Mixed Heavy Metal

Mineral development and metal smelting seriously polluted the surrounding groundwater and soil, threatening human health through the food chain. To investigate the effects of different sources of molybdenum (Mo) fertilizers on immune function of Nanjiang brown goats grazing on natural pastures under compound pollutions, fertilizing experiment was carried out in Liangshan Yi Nationality Prefecture of the Western Sichuan Plateau, China. Eighteen square hectometers of polluted meadows were fenced and were randomly divided into three groups (3 replications/group and 2 hm²/replication). A total of 54 healthy Nanjiang brown goats with an average BW of 31.6 ± 1.5 kg (1 year old) were used to this 30-day test (18 goats per group). The goats from CON group, AM group, and PM group were orally supplemented with deionized water, 15 mg Mo/BW·d (ammonium molybdate tetrahydrate), and 15 mg Mo/BW·d (potassium molybdate), respectively. Compared to CON group, the serum Fe content of grazing animals from AM group and PM group was 10.05% and 3.45% higher (P < 0.05), and the serum Cu content of grazing animals from AM group and PM group was 69.05% and 67.86% lower, respectively (P < 0.05). Mo fertilization significantly increased the levels of blood Hb, RBC, and PCV, and the activities of serum SOD, GSH-Px, CAT, and Cp of grazing goats (P < 0.05), and also extremely decreased the MDA content of experimental goats fed Mo compared to the control goats (P < 0.05). Compared to CON group, the activities of serum IgG, IgA, IgM, IL-2, and TNF-α of grazing animals from AM group and PM group were significantly increased (P < 0.05), and the levels of serum IL-6 and IL-1β of grazing goats from AM group and PM group were extremely decreased (P < 0.05). In summary, oral Mo fertilizers can alter the contents of serum mineral elements, reduce oxidative stress, improve immune function, and relieve the toxic damage of goats grazing on contaminated natural grasslands.

Interference with zinc homeostasis and oxidative stress induction as probable mechanisms for cadmium-induced embryo-toxicity in zebrafish

The present study was conducted to provide new insights into the mechanisms that may be responsible for cadmium (Cd)-induced toxicity in zebrafish larvae as well as the role of the trace element zinc (Zn) in reversing Cd harmful effects. For this purpose, zebrafish eggs were exposed to Cd or/and Zn for 96 h. The effects on morphological aspect; mortality rate; Cd, Zn, and metallothionein (MT) levels; oxidative stress biomarkers; as well as molecular expression of some genes involved in Zn metabolism (Zn-MT, ZIP10, and ZnT1) and in antioxidant defense system (Cu/Zn-SOD, CAT and GPx) were examined. Our results showed that Cd toxicity was exerted, initially, by an interference with Zn metabolism. Thus, Cd was able to modify the expression of the corresponding genes so as to ensure its intracellular accumulation at the expense of Zn, causing its depletion. An oxidative stress was then generated, representing the second mode of Cd action which resulted in developmental anomalies and subsequently mortality. Interestingly, significant corrections have been noted following Zn supplementation based, essentially, on its ability to interact with the toxic metal. The increases of Zn bioavailability, the improvement of the oxidative status, as well as changes in Zn transporter expression profile are part of the protection mechanisms. The decrease of Cd-induced MTs after Zn supplement, both at the protein and the mRNA level, suggests that the protection provided by Zn is ensured through mechanisms not involving MT expression but which rather depend on the oxidative status.

Bioaccumulation of manganese and its effects on oxidative stress and immune response in juvenile groupers (Epinephelus moara ♀ × E. lanceolatus ♂)

We evaluated the effects of Mn in juvenile Yunlong groupers (Epinephelus moara ♀ × E. lanceolatus ♂). The groupers were exposed to Mn²⁺ (0, 0.5, 1, 2, and 4 mg/L) for 30 days after which they were assessed. The results indicate the accumulation of Mn in fish depended on dose and time. Mn²⁺ accumulation in tissues occurred in the following order: liver > gills > intestine > muscle. The concentrations of SOD and CAT in the fish significantly increased after 10 and 20 days of treatment with 4 mg/L Mn²⁺ but decreased after 30 days. Similarly, GSH and GPx levels increased after 10 days of exposure to 2 and 4 mg/L Mn²⁺ but decreased after 20 and 30 days of exposure. Additionally, malondialdehyde levels significantly increased after exposing the fish to 2 and 4 mg/L Mn²⁺ for 10, 20, and 30 days. In addition, liver HSP70 and HSP90 levels significantly increased at days 20 and 30 in all fish exposed to Mn²⁺. In addition, when Mn²⁺ concentration was 1, 2, and 4 mg/L, liver C3 and C4 levels were significantly increased after 10, 20, and 30 days. Conversely, the levels of LZM and IgM significantly decreased. Mn²⁺ also significantly upregulated the expression of genes associated with immunity (tlr3, tnf-α, il-1β, and il-6) in the fish, which suggests that it induces immunotoxicity by altering the immune response. Overall, the findings showed that Mn²⁺ can disrupt grouper health by bioaccumulating in the fish and subsequently inducing oxidative stress and immune responses. These results can help elucidate the mechanism by which manganese induces toxicity in marine fish. Additionally, they provide a new perspective regarding the detrimental effects of heavy metals in fish.

A new discovery of polystyrene microplastics toxicity: The injury difference on bladder epithelium of mice is correlated with the size of exposed particles

Microplastics (MPs), as widespread hazardous substances in the environment, can cause potential adverse effects on biological health. However, reports on the toxic effects of different diameters MPs on urinary system are limited. Here, we investigated the types and mechanisms of damage to mice bladder epithelial cells treated with diameter (1-10 μm and 50-100 μm) polystyrene microplastics (PS-MPs). The results showed that exposure to PS-MPs of both diameters resulted in necroptosis and inflammation to bladder epithelium. However, 1-10 μm PS-MPs posed more severe necroptosis and 50-100 μm PS-MPs led to a higher degree of inflammatory injury at the same exposure concentration. Mechanistically, PS-MPs were found to induce necroptosis as well as p-NFκB-mediated inflammation by triggering oxidative stress and excessive release of reactive oxygen species (ROS). Furthermore, N-Acetyl-l-cysteine (NAC) attenuated the toxic effects of PS-MPs on bladder epithelial cells. In conclusion, our study demonstrated for the first time that PS-MPs caused necroptosis and inflammation in mice bladders tissues, and the difference of injury correlates with the size of PS-MPs particles.

Genome-wide mining of gpx gene family provides new insights into cadmium stress responses in common carp (Cyprinus carpio)

Glutathione peroxidase (Gpx) is an important member of antioxidant enzymes, which can play a vital role in metabolizing reactive oxygen species (ROS) and in maintaining cell homeostasis. In order to study the evolutionary dynamics of gpx gene family in allotetraploid fish species, we identified a total of 14 gpx genes in common carp Cyprinus carpio, while 9 gpx genes were discovered in the diploid progenitor-like species Poropuntius huangchuchieni. Comparative genomic analysis and phylogenetic analysis revealed that the common carp gpx genes had significant expansion and were divided into five distinct subclades. Exon-intron distribution patterns and conserved motif analysis revealed highly conserved evolutionary patterns. Transcript profiles suggested that different gpx genes had specific patterns of regulation during early embryonic development. In adult tissues, gpx genes had a relatively broad expression distribution, most of which were highly expressed in the gills, intestines, and gonads. RT-qPCR studies showed that most gpx genes were downregulated during the initial cd²⁺ treatment stage. Dietary supplementation of Bacillus coagulans at different concentrations (Group 2 of 1.0 × 10⁷ cfu/g, Group 3 of 1.0 × 10⁸ cfu/g, and Group 4 of 1.0 × 10⁹ cfu/g) induced different regulatory responses of gpx subclades. This result suggested that the appropriate concentration of B. coagulans can improve gpx gene expression when exposed to heavy metal cadmium treatment, which may play a vital role in the resistance to oxidative stress and immune responses. This study has expanded our understanding of the functional evolution of the gpx gene family in common carp.

Effects of Probiotics on the Growth Performance, Antioxidant Functions, Immune Responses, and Caecal Microbiota of Broilers Challenged by Lipopolysaccharide

We aimed to study the effects of dietary Bacillus coagulans (B. coagulans) and Lactobacillus plantarum (L. plantarum) on broilers challenged by Escherichia coli lipopolysaccharide (LPS). One-day-old Cobb 500 chicks (360) were divided randomly into three treatment groups for 47 days: no supplementation (control, CON), B. coagulans supplementation (BC), and L. plantarum supplementation (LA). Broilers were routinely fed for 42 days and intraperitoneally injected with 500 μg LPS per kg body weight at 43, 45, and 47 days of age, respectively. Samples were collected 3 h after the last injection. At 1-21 days of age, the ADG in the BC and LA groups was higher than that in the CON group, and the feed to gain ratio (F/G) in the BC group was significantly decreased (P < 0.05). Compared with that in CON birds, the ADG was increased and the F/G was decreased in the BC and LA birds at 22-42 and 1-42 days of age, respectively (P < 0.05). After LPS stimulation, the endotoxin (ET), diamine oxidase (DAO), and D-lactic acid (D-LA) levels in the BC group were lower than those in the CON group (P < 0.05). The IgY, IgA, and IgM contents in the BC group and the IgY and IgM contents in the LA group were higher than those in the CON group (P < 0.05). The pro-inflammatory factor and interferon-β (IFN-β) contents (P < 0.05) decreased, and the anti-inflammatory factor content in the serum (P < 0.05) increased in the BC and LA groups. Compared with the CON and LA treatments, the BC treatment increased the concentrations of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and catalase (CAT), and decreased that of malondialdehyde (MDA) (P < 0.05). In contrast with the CON treatment, the BC and LA treatments increased the abundance of Ruminococcaceae and reduced that of Desulfovibrio (P < 0.05). Moreover, BC increased the abundance of beneficial bacteria. Overall, supplementation with B. coagulans and L. plantarum promoted the growth of broilers, improved their immunity and antioxidant capacity, and alleviated the LPS-stimulated inflammatory response by regulating the intestinal flora.