Inhibition of Mitochondrial Fatty Acid Oxidation Contributes to Development of Nonalcoholic Fatty Liver Disease Induced by Environmental Cadmium Exposure

Bioinformatic Analysis for Exploring Target Genes and Molecular Mechanisms of Cadmium-Induced Nonalcoholic Fatty Liver Disease and Targeted Drug Prediction

Cadmium (Cd) is a widely available metal that has been found to have a role in causing nonalcoholic fatty liver disease (NAFLD). However, the detailed toxicological targets and mechanisms by which Cd causes NAFLD are unknown. Therefore, the present work aims to reveal the main targets of action, cellular processes, and molecular pathways by which cadmium causes NAFLD. As shown in the bioinformatics analysis, there were 74 main targets of action for cadmium-induced NAFLD, hemopoietic cell kinase (HCK), EPH receptor A2 (EPHA2), MYC proto-oncogene (MYC), lysyl oxidase (LOX), dipeptidyl peptidase 7 (DPP7), nuclear factor erythroid 2-related factor 2 (NFE2L2), dual specificity phosphatase 6 (DUSP6), CD2 cytoplasmic tail binding protein 2 (CD2BP2), notch receptor 3 (NOTCH3), and phospholipase A2 group IVA (PLA2G4A) were screened as core genes. Testing these core genes in other databases, three differentially expressed genes, HCK, MYC, and DUSP6 were verified and used as targets for drug prediction in DsigDB; decitabine and retinoic acid were screened as potential therapeutic drugs for NAFLD based on the p-value and the combined score. The results of molecular docking showed that the predicted drugs can bind well to the core targets. In conclusion, cadmium is associated with NAFLD; the identified cadmium-toxicity targets, HCK, MYC, and DUSP6, may serve as biomarkers for the diagnosis of NAFLD and predicted drugs, decitabine and retinoic acid may have a potential role in the treatment of NAFLD.

Co-Exposure to Different Zinc Concentrations and High-Fat Diet Modules Endoplasmic Reticulum Stress and Lipotoxicity through the MTF-1/GPx7 Axis in Yellow Catfish (Pelteobagrus fulvidraco)

As industrialization and societal development accelerate, various organisms, including humans, are exposed to environmental hazards, such as zinc (Zn) and high-fat diet (HFD). These widespread exposures pose significant threats to public health; however, the combined effects and underlying mechanisms of these environmental factors on lipotoxicity remain unclear. In this study, the yellow catfish (Pelteobagrus fulvidraco) was used as a model to investigate the impact of different Zn levels and HFD coexposure on hepatic lipotoxicity. The results indicated that low concentrations of Zn (L-Zn) significantly reduced hepatic lipid accumulation, oxidative stress, and endoplasmic reticulum (ER) stress compared to HFD-only treatment, while high concentrations of Zn (H-Zn) exacerbated these effects. Mechanistically, L-Zn alleviated ER stress by scavenging H2O2 and O2•- within the ER via the MTF-1/GPx7 pathway. Glutathione peroxidase 7 (GPx7), an ER-resident antioxidant enzyme, played a crucial role in mitigating ER stress and lipotoxicity, with metal-responsive transcription factor 1 (MTF-1) identified as its regulator. This study is the first to demonstrate the dual role of Zn in hepatic lipotoxicity, revealing the Zn2+/MTF-1/GPx7 axis as a key modulator of ER stress and lipid metabolism. These findings highlight the importance of considering combined environmental exposures in public health and environmental risk assessments.

Nrf2 deficiency aggravates hepatic cadmium accumulation, inflammatory response and subsequent injury induced by chronic cadmium exposure in mice

Prolonged cadmium (Cd) exposure leads to Cd accumulation and oxidative damage in the liver. Nuclear factor erythroid-derived 2-like 2 (NRF2) plays a vital role in preventing acute hepatic toxicity of Cd. However, the participation of NRF2 in chronic liver injury, especially in the context of chronic Cd exposure, has rarely been investigated. Here, we explored the involvement of NRF2 in Cd-induced liver injury using Nrf2 knockout (Nrf2-KO) mice chronically exposed to Cd in drinking water (100 or 200 ppm) for up to 24 weeks. We found that absence of Nrf2 exacerbated the Cd-induced liver fibrosis, as evaluated by Masson's trichrome staining and increased expression of fibrosis-associated proteins. Mechanistic investigations using the liver tissues from the animals with 100 ppm Cd exposure for 16 weeks, in which no obvious hepatic fibrosis was observed in both genotypes, revealed that there were diminished expressions of antioxidant and detoxification genes and elevated Cd levels in the blood and liver of Nrf2-KO mice compared with those in wild-type (Nrf2-WT) under basal and/or Cd-exposed conditions. Notably, a bulk RNA-seq of the liver tissues showed lowered mRNA levels of genes related to xenobiotic and glutathione metabolic processes, but elevated mRNA expression of leukocyte migration pathway and adaptive immune pathway in Nrf2-KO mice relative to Nrf2-WT controls, either under basal or Cd-exposed conditions. Our findings demonstrated that Nrf2-KO mice are vulnerable to chronic Cd exposure-induced liver fibrosis, which is partially attributed to a compromised NRF2-mediated antioxidant response, lowered metallothionein expression and subsequent Cd accumulation and inflammatory response in the tissues.

Lentinan alleviates cadmium-induced kidney injury by reducing cadmium accumulation via promoting cadmium excretion and metallothionein synthesis and regulating silencing information regulator1/nuclear factor erythroid 2-related factor 2/nuclear factor kappa-B signaling pathway

Cadmium (Cd) is a widely distributed environmental heavy metal pollutant. It is extremely toxic to the kidney. This study investigated the potential mechanisms of action of lentinan (LNT), a fungal polysaccharide, on protecting against Cd-induced kidney injury in mice. Male Kunming mice were administered with CdCl2 (2.5 mg/kg/b.w.) by intragastric gavage and LNT in drinking water (1 mg/mL) for 10 weeks. Histological examination revealed that LNT reduced the glomerular atrophy, lymphocyte infiltration, tubular congestion, and collagen accumulation caused by Cd exposure. However, oral administration of LNT decreased Cd levels in kidney by promoting the excretion of Cd in feces and increasing the production of metallothionein (MT) in the kidney. In addition, LNT treatment alleviated Cd-induced kidney excessive mitophagy by upregulating silencing information regulator1 (SIRT1) and prevented subsequent oxidative stress and inflammatory responses by upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) and downregulating nuclear factor kappa-B (NF-κB) signaling pathways. Further, the protein expression levels of profibrotic factors, including Tgf-β1, alpha smooth muscle actin, and collagen type I alpha 1 chain, and the progression of fibrosis, were significantly reduced in the kidneys of mice treated with LNT. Collectively, our findings suggest that LNT can relieve the nephrotoxicity of Cd by decreasing its accumulation via promoting Cd excretion and MT synthesis and regulating the SIRT1/Nrf2/NF-κB signaling pathway.

Near-Native Imaging of Metal Ion-Initiated Cell State Transition

Metal ions are indispensable to life, as they can serve as essential enzyme cofactors to drive fundamental biochemical reactions, yet paradoxically, excess is highly toxic. Higher-order cells have evolved functionally distinct organelles that separate and coordinate sophisticated biochemical processes to maintain cellular homeostasis upon metal ion stimuli. Here, we uncover the remodeling of subcellular architecture and organellar interactome in yeast initiated by several metal ion stimulations, relying on near-native three-dimensional imaging, cryo-soft X-ray tomography. The three-dimensional architecture of intact yeast directly shows that iron or manganese triggers a hormesis-like effect that promotes cell proliferation. This process leads to the reorganization of organelles in the preparation for division, characterized by the polar distribution of mitochondria, an increased number of lipid droplets (LDs), volume shrinkage, and the formation of a hollow structure. Additionally, vesicle-like structures that detach from the vacuole are observed. Oppositely, cadmium or mercury causes stress-associated phenotypes, including mitochondrial fragmentation, LD swelling, and autophagosome formation. Notably, the organellar interactome, encompassing the interactions between mitochondria and LDs and those between the nuclear envelope and LDs, is quantified and exhibits alteration with multifaceted features in response to different metal ions. More importantly, the dynamics of organellar architecture render them more sensitive biomarkers than traditional approaches for assessing the cell state. Strikingly, yeast has a powerful depuration capacity to isolate and transform the overaccumulated cadmium in the vacuole, mitochondria, and cytoplasm as a high-value product, quantum dots. This work presents the possibility of discovering fundamental links between organellar morphological characteristics and the cell state.

Enantioselective Toxicity of Ibuprofen to Earthworms: Unraveling the Effect and Mechanism on Enhanced Toxicity of S-Ibuprofen Over R-Ibuprofen

With the global implementation of wastewater reuse, accurately assessing the soil ecological risk of chiral pollutants from wastewater necessitates a comprehensive understanding of their enantioselective toxicity to soil animals. Ibuprofen (IBU) is the most prevalent chiral pharmaceutical in municipal wastewater. However, its enantioselective toxicity toward soil animals and the underlying mechanism remain largely unknown. In this study, the toxicity of IBU enantiomers, S-IBU and R-IBU, to earthworms was evaluated at environmentally relevant concentrations (10 and 100 μg/L), simulating wastewater reuse for irrigation. The results demonstrated that IBU adversely affects the growth, reproduction, regeneration, defense systems, and metabolic processes of earthworms, with S-IBU exhibiting stronger toxic effects than R-IBU. The bioavailability assessment revealed that S-IBU was more readily absorbed by earthworms and converted to its enantiomer within earthworms than R-IBU. This is consistent with molecular docking results showing that S-IBU had stronger affinities for functional proteins associated with xenobiotic transport and transformation. The findings of this study highlight that S-IBU poses a higher risk than R-IBU to soil organisms under wastewater reuse scenarios and that the chirality of chemical pollutants in wastewater deserves more attention when implementing wastewater reuse. In addition, our study underscores that the differences in bioavailability and bioactivity may account for the enantioselective toxicity of chiral pollutants.

The overlooked impact of cadmium on the progression of chronic hepatitis and the onset of renal failure in advanced cirrhosis

The mechanism of hepatocyte destruction in chronic hepatitis is not completely understood, while renal failure in individuals with advanced cirrhosis is a significant concern. It is well known that smokers who are chronically infected with hepatitis B and C viruses (HBV, HCV) have a poor prognosis. In the present review, we propose a novel hypothesis that environmental exposure to a nephrotoxic metal pollutant, cadmium (Cd) may contribute to hepatocyte destruction and, subsequently, affect the duration of chronic hepatitis. The metal binding protein, metallothionein (MT) sequesters cadmium as CdMT complexes, and effectively neutralize its adverse effects. Cadmium can cause the damage to hepatocytes, only when it is in an unbound form. In addition to its ability to bind cadmium, MT can act as a scavenger of reactive oxygen species (ROS). However, the cellular MT levels may decrease, when ROS is excessively produced under the pathologic chronic viral hepatitis conditions, especially while the cellular levels of zinc may also be low. Zinc is an endogenous inducer of MT, and is required for maximal MT expression. High ROS levels in the hepatocytes diminishes MT binding to metals. Consequently, the proportion of unbound Cd is increased and thus there is more hepatic damage. Hepatic damage leads to a copious release of CdMT into the circulation. This significant cadmium load, which occurs after hepatic damage, and in some cases, muscle atrophy, induces kidney damage with resultant renal failure in advanced cirrhosis.

Insufficient FUNDC1-dependent mitophagy due to early environmental cadmium exposure triggers mitochondrial redox imbalance to aggravate diet-induced lipotoxicity

Cadmium (Cd) is a toxic contaminant widely spread in natural and industrial environments. Adolescent exposure to Cd increases risk for obesity-related morbidity in young adults including type 2 diabetes and metabolic dysfunction-associated steatotic liver disease (MASLD). Despite this recognition, the direct impact of adolescent Cd exposure on the progression of MASLD later in life, and the mechanisms underlying these effects, remain unclear. Here, adolescent rats received control diet or diets containing 2 mg Cd2+/kg feed for 4 weeks, and then HFD containing 15% lard or control diet in young adult rats was selected for 6 weeks to clarify this issue. Data firstly showed that HFD-fed rats in young adulthood due to adolescent Cd exposure exhibited more severe MASLD, evidenced by increased liver damage, disordered serum and hepatic lipid levels, and activated NLRP3 inflammasome. Hepatic transcriptome analysis revealed the potential effects of mitochondrial dysfunction in aggravated MASLD due to Cd exposure. Verification data further confirmed that mitochondrial structure and function were targeted and disrupted during this process, shown by broken mitochondrial ridges, decreased mitochondrial membrane potential, imbalanced mitochondrial dynamic, insufficient ATP concentration, and enhanced mitochondrial ROS generation. However, mitophagy is inactively involved in clearance of damaged mitochondria induced by early Cd in HFD condition due to inhibited mitophagy receptor FUNDC1. In contrast, FUNDC1-dependent mitophagy activation prevents lipotoxicity aggravated by early Cd via suppressing mitochondrial ROS generation. Collectively, our data show that insufficient FUNDC1-dependent mitophagy can drive the transition from HFD-induced MASLD to MASH, and accordingly, these findings will provide a better understanding of potential mechanism of diet-induced metabolic diseases in the context of early environmental Cd exposure.

Activating PPARβ/δ-Mediated Fatty Acid β-Oxidation Mitigates Mitochondrial Dysfunction Co-induced by Environmentally Relevant Levels of Molybdenum and Cadmium in Duck Kidneys

Cadmium (Cd) and high molybdenum (Mo) pose deleterious effects on health. Prior studies have indicated that exposure to Mo and Cd leads to damage in duck kidneys, but limited studies have explored this damage from the perspective of fatty acid metabolism. In this study, 40 healthy 8-day-old ducks were randomly assigned to four groups and fed a basic diet containing Cd (4 mg/kg Cd) or Mo (100 mg/kg Mo) or both. Kidney tissues were harvested on the 16th week. Results demonstrated that Cd and/or Mo inhibited mitochondrial fatty acid β-oxidation and disrupted mitochondrial dynamics, along with significant suppression of peroxisome proliferator-activated receptor β/δ (PPARβ/δ) protein in duck kidneys. In vitro study, duck renal tubular epithelial cells were exposed for 12 h to either Mo (480 μM Mo), Cd (2.5 μM Cd), and GW0742 (0.3 μM, a potent agonist of PPARβ/δ) alone or in combination. The results demonstrated that Cd and/or Mo led to marked fatty acid oxidation deficiency and mitochondrial dysfunction and that PPARβ/δ protein was involved in the process. Altogether, this study found that activating PPARβ/δ-mediated fatty acid β-oxidation mitigates mitochondrial dysfunction co-induced by Mo and Cd in duck kidneys.

Unraveling cadmium-driven liver inflammation with a focus on arachidonic acid metabolites and TLR4/ IκBα /NF-κB pathway

Epidemiological studies have demonstrated exposure to cadmium ion (Cd2+) is significantly associated with the incidence and aggravation of nonalcoholic fatty liver disease (NAFLD) to non-alcoholic steatohepatitis (NASH). Cd2+ exposure could alter lipid metabolism, and changed lipid metabolites are significantly associated with NASH. Arachidonic acid (ArA) is an omega-6 polyunsaturated fatty acid. Promotion of ArA synthesis and profile changes by Cd2+ exposure potentially to cause NAFLD. ArA metabolism pathway has been identified to enrich in Cd2+ exposure-facilitated NASH. ArA could be generation an impressive metabolic profile through mainly three pathways, including Cyclooxygenases (COX), Lipoxygenases (LOX) and Cytochrome P450 (CYP450) pathway. However, the functions of these metabolites and underlying mechanism in hepatic inflammation are still not clear. In present study, by integrative transcriptomics and metabolomics analysis, we identified that the fatty acid metabolic process and the pro-inflammatory NF-κB signaling pathway were enriched in Cd2+-regulated differentially expressed genes (DEGs) and Cd2+-altered differential metabolites, such as, fatty acid biosynthesis, degradation, and ArA metabolism. The metabolites levels of LOX pathway products 5-HETE and leukotriene C4 (LTC4), and COX catalytic product prostaglandin D2 (PGD2) were significantly elevated in Cd2+ exposed mouse livers. 5-HETE, LTC4, and PGD2 were significantly positive correlated with NF-κB signaling. In addition, the synthase of 20-Hydroxyeicosatetraenoic acid (20-HETE), CYP450 gene 4 family (CYP4A32), was also involved in NF-κB signaling network. Results from both in vitro and in vivo proved that Cd2+ exposure increased ArA metabolite to PGD2 and 20-HETE, and upregulated the mRNA level of their catalytic enzyme PGDS and CYP4A32. Cd2+-induced ArA metabolite to PGD2 and 20-HETE promoted activation of TLR4/IκBα/NF-κB signaling and pro-inflammatory of hepatocytes. Our study explores novel molecular mechanism of Cd2+ exposure-aggravated liver diseases and provides potential novel targets for in hepatic inflammatory treatments and prevention.

Ecological risks of high-ammonia environment with inhibited growth of Daphnia magna: Disturbed energy metabolism and oxidative stress

High ammonia pollution is a common problem in water bodies. However, research on the mechanisms underlying the toxic effects on organisms at different nutritional levels is still insufficient. Herein, based on the environmental concentration, the toxic effects of high ammonia pollution on Daphnia magna were investigated. Overall, the feeding and filtration rates of D. magna were significantly decreased by ammonia. Growth inhibition of D. magna by ammonia was confirmed by the decreased body length. After ammonia exposure, the metabolic status of D. magna changed, the correlation network weakened, and the correlations between metabolites were disrupted. Changes occurred in metabolites primarily involved in oxidative stress, fatty acid oxidation, tricarboxylic acid cycle, and protein digestion, absorption, and synthesis, which were validated through alterations in multiple biomarkers. In addition, mitochondrial function was evaluated and was found to inhibit mitochondrial activity, which was accompanied by a decreased marker of mitochondrial activity contents and ATPase activity. Thus, the results suggested that energy metabolism and oxidative stress were involved in ammonia-induced growth toxicity. This study provides new insights into the impact of ammonia on aquatic ecological health.

Cadmium stress alleviates lipid accumulation caused by chiral penthiopyrad through regulating endoplasmic reticulum stress and mitochondrial dysfunction in zebrafish liver

The coexistence of cadmium (Cd) can potentiate (synergism) or reduce (antagonism) the pesticide effects on organisms, which may change with chiral pesticide enantiomers. Previous studies have reported the toxic effects of chiral penthiopyrad on lipid metabolism in zebrafish (Danio rerio) liver. The Cd effects and toxic mechanism on lipid accumulation were investigated from the perspective of endoplasmic reticulum (ER) stress and mitochondrial dysfunction. The coexistence of Cd increased the concentrations of penthiopyrad and its metabolites in zebrafish. Penthiopyrad exposure exhibited significant effects on lipid metabolism and mitochondrial function-related indicators, which were verified by lipid droplets and mitochondrial damage in subcellular structures. Moreover, penthiopyrad activated the genes of ER unfolded protein reaction (UPR) and Ca2+ permeable channels, and S-penthiopyrad exhibited more serious effects on ER stress with ER hyperplasia than R-penthiopyrad. As a mitochondrial uncoupler, the coexistence of Cd could decrease lipid accumulation by alleviating ER stress and mitochondrial dysfunction, and these effects were the most significant for R-penthiopyrad. There were antagonistic effects between Cd and penthiopyrad, which could reduce the damage caused by penthiopyrad in zebrafish, thus increasing the bioaccumulation of penthiopyrad in zebrafish. These findings highlighted the importance and necessity of evaluating the ecological risks of metal-chiral pesticide mixtures.

Environmental Cadmium Exposure Exacerbated Bone Loss in NAFLD Mice

Due to rapid urbanization and industrialization, Cadmium (Cd) contamination is widespread. Meanwhile, the prevalence of nonalcoholic fatty liver disease (NAFLD) has been increasing. Cd is linked to bone damage. However, the osteotoxicity of environmental Cd exposure in NAFLD remains unclear. Therefore, this study aimed to investigate the effects and potential mechanisms of Cd on bone metabolism in NAFLD mice. NAFLD mice were treated with 50 mg/L cadmium chloride in drinking water for 12 weeks. Bone microstructures were scanned by Micro-CT. Liver lipid droplets and fibrosis were measured by histopathological staining. Insulin tolerance tests were performed in mice. RT-PCR and Western blot were performed to analyse hepatic inflammation factors. Results show no damage in healthy mice exposed to Cd. However, Cd exacerbated liver fibrosis and significantly reduced cancellous bone mineral density and decreased the number and thickness of trabecular bone in NAFLD mice. Additionally, the morphology of trabecular bone transformed from a plate structure to a rod structure in NAFLD mice after Cd exposure. The underlying mechanism appears to be related to the Cd-induced direct or indirect toxicity. Exacerbated liver fibrosis, increased inflammatory factors (TGF-β and IL-1β), and reduced lecithin-cholesterol acyltransferase (LCAT) and insulin-like growth factor-1 (IGF-1) might contribute to bone damages. Collectively, our study illustrates that despite lower dosing Cd exposure did not induce bone damages in healthy mice, Cd caused bone loss in NAFLD mice. Therefore, it is recommended that individuals with metabolic disorders should avoid working in Cd pollution environment and consuming cadmium-contaminated food and water.

In-situ remediation of cadmium contamination in paddy fields: from rhizosphere soil to rice kernel

Cadmium (Cd) has become an important heavy metal pollutant because of its strong migration and high toxicity. The industrial production process aggravated the Cd pollution in rice fields. Human exposure to Cd through rice can cause kidney damage, emphysema, and various cardiovascular and metabolic diseases, posing a grave threat to health. As modern technology develops, the Cd accumulation model in rice and in-situ remediation of Cd pollution in cornfields have been extensively studied and applied, so it is necessary to sort out and summarize them systematically. Therefore, this paper reviewed the primary in-situ methods for addressing heavy metal contamination in rice paddies, including chemical remediation (inorganic-organic fertilizer remediation, nanomaterials, and composite remediation), biological remediation (phytoremediation and microbial remediation), and crop management remediation technologies. The factors that affect Cd transformation in soil and Cd migration in crops, the advantages and disadvantages of remediation techniques, remediation mechanisms, and the long-term stability of remediation were discussed. The shortcomings and future research directions of in situ remediation strategies for heavily polluted paddy fields and genetic improvement strategies for low-cadmium rice varieties were critically proposed. To sum up, this review aims to enhance understanding and serve as a reference for the appropriate selection and advancement of remediation technologies for rice fields contaminated with heavy metals.

Luteolin alleviates cadmium-induced metabolism disorder through antioxidant and anti-inflammatory mechanisms in chicken kidney

Cadmium (Cd) is a common environmental pollutant associated with an increased incidence of renal metabolic diseases. Luteolin (Lut), a natural flavonoid, is widely used for its multifaceted therapeutic properties in inflammatory diseases. However, whether Lut protects against Cd-induced nephrotoxicity is still equivocal. The present study investigated the effects of Lut supplementation on renal oxidative stress, inflammation and metabolism and their related mechanisms. Therefore, 40 chickens were treated with Cd and/or Lut with automatic water and free food intake for 1 mo and then the kidney tissues were collected to explore this issue. In this study, Cd exposure induced renal glycolipid metabolism disorders and resultant kidney damage by periodic acid Schiff (PAS) staining, Oil Red O staining, total cholesterol (TC), triglyceride (TG), and glucose (Glu) levels in kidney, which were significantly ameliorated by Lut. Moreover, Lut also normalized the expression levels of factors related to Cd-disturbed glycolipid metabolism, improving metabolic homeostasis, and contributing to alleviating kidney damage. Furthermore, Lut demonstrated therapeutic potential against Cd-induced renal oxidative stress and inflammation by enhancing antioxidant capacity and inhibiting cytokine production in the kidney tissues. Mechanistically, Lut activated the AMPK/SIRT1/FOXO1 signaling pathway, attenuating oxidative stress and inflammatory responses, ameliorating the metabolic disturbance. In conclusion, these observations demonstrate that Lut treatment activates AMPK/SIRT1/FOXO1 signaling pathway, decreases oxidative stress and inflammation response, which may contribute to prevent Cd-induced metabolism disorder and consequent kidney damage.

Cadmium exposure induces changes in gut microbial composition and metabolic function in long-tailed dwarf hamsters, Cricetulus longicaudatus

Numerous studies have demonstrated that exposure to cadmium disrupts the diversity and composition of the gut microbiota, resulting in damage to organ tissue. However, there remains a lack of comprehensive understanding regarding the broader ecological reality associated with this phenomenon. In this study, we conducted a thorough evaluation of the effects of different concentrations of Cd (6, 12, 24, and 48 mg/L) over a period of 35 consecutive days on the organ viscera and the gut microbiota of long-tailed dwarf hamsters, Cricetulus longicaudatus (Rodentia: Cricetidae), using histopathological analysis, 16S rDNA, and metagenome sequencing. Our findings revealed that the results suggest that Cd exposure induced liver, spleen, and kidney damage, potentially leading to increased intestinal permeability and inflammation. These alterations were accompanied by significant perturbations in the gut microbiota composition, particularly affecting potentially pathogenic bacteria such as Prevotella and Treponema within the gut ecosystem. Consequently, host susceptibility to underlying diseases was heightened due to these changes. Notably though, Cd exposure did not significantly impact the overall structure of the gut microbiota itself. Additionally, Cd exposure induced significant changes in the metabolic functions, with the pathways related to disease and environmental information processing notably enhanced, possibly indicating stronger innate defense mechanisms against external injuries among wild mammals exposed to Cd. This study offers a novel approach to comprehensively evaluate the significant impact of Cd pollution on ecosystems by investigating both structural and functional alterations in the digestive system, as well as disruptions in intestinal flora among wild mammals.

Mechanisms of Phytoremediation by Resveratrol against Cadmium Toxicity

Cadmium (Cd) toxicity poses a significant threat to human health and the environment due to its widespread occurrence and persistence. In recent years, considerable attention has been directed towards exploring natural compounds with potential protective effects against Cd-induced toxicity. Among these compounds, resveratrol (RV) has emerged as a promising candidate, demonstrating a range of beneficial effects attributed to its antioxidant and anti-inflammatory properties. This literature review systematically evaluates the protective role of RV against Cd toxicity, considering the various mechanisms of action involved. A comprehensive analysis of both in vitro and in vivo studies is conducted to provide a comprehensive understanding of RV efficacy in mitigating Cd-induced damage. Additionally, this review highlights the importance of phytoremediation strategies in addressing Cd contamination, emphasizing the potential of RV in enhancing the efficiency of such remediation techniques. Through the integration of diverse research findings, this review underscores the therapeutic potential of RV in combating Cd toxicity and underscores the need for further investigation to elucidate its precise mechanisms of action and optimize its application in environmental and clinical settings.

Copper, Iron, Cadmium, and Arsenic, All Generated in the Universe: Elucidating Their Environmental Impact Risk on Human Health Including Clinical Liver Injury

Humans are continuously exposed to various heavy metals including copper, iron, cadmium, and arsenic, which were specifically selected for the current analysis because they are among the most frequently encountered environmental mankind and industrial pollutants potentially causing human health hazards and liver injury. So far, these issues were poorly assessed and remained a matter of debate, also due to inconsistent results. The aim of the actual report is to thoroughly analyze the positive as well as negative effects of these four heavy metals on human health. Copper and iron are correctly viewed as pollutant elements essential for maintaining human health because they are part of important enzymes and metabolic pathways. Healthy individuals are prepared through various genetically based mechanisms to maintain cellular copper and iron homeostasis, thereby circumventing or reducing hazardous liver and organ injury due to excessive amounts of these metals continuously entering the human body. In a few humans with gene aberration, however, liver and organ injury may develop because excessively accumulated copper can lead to Wilson disease and substantial iron deposition to hemochromatosis. At the molecular level, toxicities of some heavy metals are traced back to the Haber Weiss and Fenton reactions involving reactive oxygen species formed in the course of oxidative stress. On the other hand, cellular homeostasis for cadmium and arsenic cannot be provided, causing their life-long excessive deposition in the liver and other organs. Consequently, cadmium and arsenic represent health hazards leading to higher disability-adjusted life years and increased mortality rates due to cancer and non-cancer diseases. For unknown reasons, however, liver injury in humans exposed to cadmium and arsenic is rarely observed. In sum, copper and iron are good for the human health of most individuals except for those with Wilson disease or hemochromatosis at risk of liver injury through radical formation, while cadmium and arsenic lack any beneficial effects but rather are potentially hazardous to human health with a focus on increased disability potential and risk for cancer. Primary efforts should focus on reducing the industrial emission of hazardous heavy metals.

SIRT1: Harnessing multiple pathways to hinder NAFLD

Non-alcoholic fatty liver disease (NAFLD) encompasses hepatic steatosis, non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma. It is the primary cause of chronic liver disorders, with a high prevalence but no approved treatment. Therefore, it is indispensable to find a trustworthy therapy for NAFLD. Recently, mounting evidence illustrates that Sirtuin 1 (SIRT1) is strongly associated with NAFLD. SIRT1 activation or overexpression attenuate NAFLD, while SIRT1 deficiency aggravates NAFLD. Besides, an array of therapeutic agents, including natural compounds, synthetic compounds, traditional Chinese medicine formula, and stem cell transplantation, alleviates NALFD via SIRT1 activation or upregulation. Mechanically, SIRT1 alleviates NAFLD by reestablishing autophagy, enhancing mitochondrial function, suppressing oxidative stress, and coordinating lipid metabolism, as well as reducing hepatocyte apoptosis and inflammation. In this review, we introduced the structure and function of SIRT1 briefly, and summarized the effect of SIRT1 on NAFLD and its mechanism, along with the application of SIRT1 agonists in treating NAFLD.

Environmental cadmium exposure perturbs systemic iron homeostasis via hemolysis and inflammation, leading to hepatic ferroptosis in common carp (Cyprinus carpio L.)

Cadmium (Cd) pollution is considered a pressing challenge to eco-environment and public health worldwide. Although it has been well-documented that Cd exhibits various adverse effects on aquatic animals, it is still largely unknown whether and how Cd at environmentally relevant concentrations affects iron metabolism. Here, we studied the effects of environmental Cd exposure (5 and 50 μg/L) on iron homeostasis and possible mechanisms in common carp. The data revealed that Cd elevated serum iron, transferrin saturation and iron deposition in livers and spleens, leading to the disruption of systemic iron homeostasis. Mechanistic investigations substantiated that Cd drove hemolysis by compromising the osmotic fragility and inducing defective morphology of erythrocytes. Cd concurrently exacerbated hepatic inflammatory responses, resulting in the activation of IL6-Stat3 signaling and subsequent hepcidin transcription. Notably, Cd elicited ferroptosis through increased iron burden and oxidative stress in livers. Taken together, our findings provide evidence and mechanistic insight that environmental Cd exposure could undermine iron homeostasis via erythrotoxicity and hepatotoxicity. Further investigation and ecological risk assessment of Cd and other pollutants on metabolism-related effects is warranted, especially under the realistic exposure scenarios.

Zinc attenuates sulfamethoxazole-induced lipotoxicity by reversing sulfamethoxazole-induced mitochondrial dysfunction and lysosome impairment in a freshwater teleost

Sulfamethoxazole (SMZ) and zinc (Zn) are widespread harmful materials in aquatic ecosystems and cause toxic effects to aquatic animals under their individual exposure. Although they often co-exist in aquatic environments, little is known about their joint effects and mechanism influencing aquatic animals. Herein, SMZ induced mitochondrial and lysosomal dysfunction, inhibited autophagy flux, and induced lipotoxicity. However, SMZ-induced changes of these physiological and metabolic processes above were reversed by Zn exposure, indicating the antagonism between Zn and SMZ. SOD1-knockdown abrogated the reversing effects of Zn on mitochondria dysfunction and autophagy flux blockage induced by SMZ, suggesting that SOD1 was essential for Zn to reverse SMZ-induced mitochondria dysfunction and autophagy impairment. Our further investigation found that Zn regulated STAT3 translocation to lysosomes and mitochondria to attenuate SMZ-induced lipotoxicity, and SOD1 was required for these processes. Mechanistically, STAT3 was associated with ATP6V1 A in a coiled-coil domain-dependent manner, and pS710-STAT3-and pY753-STAT3-independent manners. Moreover, SMZ suppressed autophagic degradation of damaged mitochondria via inhibiting interaction between STAT3 and ATP6V1 A and increasing pS710-STAT3 level; SMZ impaired mitochondrial β-oxidation via decreasing pY753-STAT3 level and STAT3 mitochondrial localization. Zn reversed these SMZ-induced effects to alleviate SMZ-induced lipotoxicity. Taken together, our data showed that SMZ impaired mitochondrial β-oxidation and lysosomal acidification via the downregulation of SOD1, leading to lipotoxicity, and that Zn reversed SMZ-induced changes of these important biological processes and attenuated SMZ-induced lipotoxicity. Thus, our study identified previously unidentified mechanisms for the antagonistic mechanisms of Zn and SMZ on aquatic animals, which provided novel insights into the environmental risk assessments of the joint exposure between heavy metals and antibiotics in the aquatic organisms.

Dissecting the role of cadmium, lead, arsenic, and mercury in non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

The objective of the present study was to review the existing epidemiological and laboratory findings supporting the role of toxic metal exposure in non-alcoholic fatty liver disease (NAFLD). The existing epidemiological studies demonstrate that cadmium (Cd), lead (Pb), arsenic (As), and mercury (Hg) exposure was associated both with an increased risk of NAFLD and altered biochemical markers of liver injury. Laboratory studies demonstrated that metal exposure induces hepatic lipid accumulation resulting from activation of lipogenesis and inhibition of fatty acid β-oxidation due to up-regulation of sterol regulatory element-binding protein 1 (SREBP-1), carbohydrate response element binding protein (ChREBP), peroxisome proliferator-activated receptor γ (PPARγ), and down-regulation of PPARα. Other metabolic pathways involved in this effect may include activation of reactive oxygen species (ROS)/extracellular signal-regulated kinase (ERK) and inhibition of AMP-activated protein kinase (AMPK) signaling. The mechanisms of hepatocyte damage during development of metal-induced hepatic steatosis were shown to involve oxidative stress, endoplasmic reticulum stress, pyroptosis, ferroptosis, and dysregulation of autophagy. Induction of inflammatory response contributing to progression of NAFLD to non-alcoholic steatohepatitis (NASH) upon toxic metal exposure was shown to be mediated by up-regulation of nuclear factor κB (NF-κB) and activation of NRLP3 inflammasome. Moreover, epigenetic effects of the metals, as well as their effect on gut microbiota and gut wall integrity were also shown to mediate their role in NAFLD development. Despite being demonstrated for Cd, Pb, and As, the contribution of these mechanisms into Hg-induced NAFLD is yet to be estimated. Therefore, further studies are required to clarify the intimate mechanisms underlying the relationship between heavy metal and metalloid exposure and NAFLD/NASH to reveal the potential targets for treatment and prevention of metal-induced NAFLD.

Zaluzanin C Alleviates Inflammation and Lipid Accumulation in Kupffer Cells and Hepatocytes by Regulating Mitochondrial ROS

Zaluzanin C (ZC), a sesquiterpene lactone isolated from Laurus nobilis L., has been reported to have anti-inflammatory and antioxidant effects. However, the mechanistic role of ZC in its protective effects in Kupffer cells and hepatocytes has not been elucidated. The purpose of this study was to elucidate the efficacy and mechanism of action of ZC in Kupffer cells and hepatocytes. ZC inhibited LPS-induced mitochondrial ROS (mtROS) production and subsequent mtROS-mediated NF-κB activity in Kupffer cells (KCs). ZC reduced mRNA levels of pro-inflammatory cytokines (Il1b and Tnfa) and chemokines (Ccl2, Ccl3, Ccl4, Cxcl2 and Cxcl9). Tumor necrosis factor (TNF)-α-induced hepatocyte mtROS production was inhibited by ZC. ZC was effective in alleviating mtROS-mediated mitochondrial dysfunction. ZC enhanced mitophagy and increased mRNA levels of fatty acid oxidation genes (Pparα, Cpt1, Acadm and Hadha) and mitochondrial biosynthetic factors (Pgc1α, Tfam, Nrf1 and Nrf2) in hepatocytes. ZC has proven its anti-lipid effect by improving lipid accumulation in hepatocytes by enhancing mitochondrial function to facilitate lipid metabolism. Therefore, our study suggests that ZC may be an effective compound for hepatoprotection by suppressing inflammation and lipid accumulation through regulating mtROS.

Cadmium exposure dysregulates purine metabolism and homeostasis across the gut-liver axis in a mouse model

Cadmium (Cd) exposure has been associated with the development of enterohepatic circulation disorders and hyperuricemia, but the possible contribution of chronic low-dose Cd exposure to disease progression is still need to be explored. A mouse model of wild-type mice (WT) and Uox-knockout mice (Uox-KO) to find out the toxic effects of chronic low-dose Cd exposure on liver purine metabolism by liquid chromatography-mass spectrometry (LC-MS) platform and associated intestinal flora. High throughput omics analysis including metabolomics and transcriptomics showed that Cd exposure can cause disruption of purine metabolism and energy metabolism. Cd changes several metabolites associated with purine metabolism (xanthine, hypoxanthine, adenosine, uridine, inosine) and related genes, which are associated with elevated urate levels. Microbiome analysis showed that Cd exposure altered the disturbance of homeostasis in the gut. Uox-KO mice were more susceptible to Cd than WT mice. Our findings extend the understanding of potential toxicological interactions between liver and gut microbiota and shed light on the progression of metabolic diseases caused by Cd exposure.

Dietary intake of household cadmium-contaminated rice caused genome-wide DNA methylation changes on gene/hubs related to metabolic disorders and cancers

Cadmium (Cd) contamination in food has raised broad concerns in food safety and human health. The toxicity of Cd to animals/humans have been widely reported, yet little is known about the health risk of dietary Cd intake at the epigenetic level. Here, we investigated the effect of a household Cd-contaminated rice (Cd-rice) on genome-wide DNA methylation (DNAm) changes in the model mouse. Feeding Cd-rice increased kidney Cd and urinary Cd concentrations compared with the Control rice (low-Cd rice), whereas supplementation of ethylenediamine tetraacetic acid iron sodium salt (NaFeEDTA) in the diet significantly increased urinary Cd and consequently decreased kidney Cd concentrations. Genome-wide DNAm sequencing revealed that dietary Cd-rice exposure caused the differentially methylated sites (DMSs), which were mainly located in the promoter (32.5%), downstream (32.5%), and intron (26.1%) regions of genes. Notably, Cd-rice exposure induced hypermethylation at the promoter sites of genes Caspase-8 and interleukin-1β (Il-1β), and consequently, their expressions were down-regulated. The two genes are critical in apoptosis and inflammation, respectively. In contrast, Cd-rice induced hypomethylation of the gene midline 1 (Mid1), which is vital to neurodevelopment. Furthermore, 'pathways in cancer' was significantly enriched as the leading canonical pathway. Supplementation of NaFeEDTA partly alleviated the toxic symptoms and DNAm alternations induced by Cd-rice exposure. These results highlight the broad effects of elevated dietary Cd intake on the level of DNAm, providing epigenetic evidence on the specific endpoints of health risks induced by Cd-rice exposure.

Moderate maternal nutrient reduction in pregnancy alters fatty acid oxidation and RNA splicing in the nonhuman primate fetal liver

Fetal liver tissue collected from a nonhuman primate (NHP) baboon model of maternal nutrient reduction (MNR) at four gestational time points (90, 120, 140, and 165 days gestation [dG], term in the baboon is ∼185 dG) was used to quantify MNR effects on the fetal liver transcriptome. 28 transcripts demonstrated different expression patterns between MNR and control livers during the second half of gestation, a developmental period when the fetus undergoes rapid weight gain and fat accumulation. Differentially expressed transcripts were enriched for fatty acid oxidation and RNA splicing-related pathways. Increased RNA splicing activity in MNR was reflected in greater abundances of transcript splice variant isoforms in the MNR group. It can be hypothesized that the increase in splice variants is deployed in an effort to adapt to the poor in utero environment and ensure near-normal development and energy metabolism. This study is the first to study developmental programming across four critical gestational stages during primate fetal liver development and reveals a potentially novel cellular response mechanism mediating fetal programming in response to MNR.

Sex, Nutrition, and NAFLD: Relevance of Environmental Pollution

Non-alcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease and represents an increasing public health issue given the limited treatment options and its association with several other metabolic and inflammatory disorders. The epidemic, still growing prevalence of NAFLD worldwide cannot be merely explained by changes in diet and lifestyle that occurred in the last few decades, nor from their association with genetic and epigenetic risk factors. It is conceivable that environmental pollutants, which act as endocrine and metabolic disruptors, may contribute to the spreading of this pathology due to their ability to enter the food chain and be ingested through contaminated food and water. Given the strict interplay between nutrients and the regulation of hepatic metabolism and reproductive functions in females, pollutant-induced metabolic dysfunctions may be of particular relevance for the female liver, dampening sex differences in NAFLD prevalence. Dietary intake of environmental pollutants can be particularly detrimental during gestation, when endocrine-disrupting chemicals may interfere with the programming of liver metabolism, accounting for the developmental origin of NAFLD in offspring. This review summarizes cause-effect evidence between environmental pollutants and increased incidence of NAFLD and emphasizes the need for further studies in this field.

Glyphosate-induced autophagy inhibition results in hepatic steatosis via mediating epigenetic reprogramming of PPARα in roosters

Glyphosate (Gly) is the most widely used herbicide with well-defined hepatotoxic effects, but the underlying mechanisms of Gly-induced hepatic steatosis remain largely unknown. In this study, a rooster model combined with primary chicken embryo hepatocytes was established to dissect the progresses and mechanisms of Gly-induced hepatic steatosis. Data showed that Gly exposure caused liver injury with disrupted lipid metabolism in roosters, manifested by significant serum lipid profile disorder and hepatic lipid accumulation. Transcriptomic analysis revealed that PPARα and autophagy-related pathways played important roles in Gly-induced hepatic lipid metabolism disorders. Further experimental results suggested that autophagy inhibition was involved in Gly-induced hepatic lipid accumulation, which was confirmed by the effect of classic autophagy inducer rapamycin (Rapa). Moreover, data substantiated that Gly-mediated autophagy inhibition caused nuclear increase of HDAC3, which altered epigenetic modification of PPARα, leading to fatty acid oxidation (FAO) inhibition and subsequently lipid accumulation in the hepatocytes. In summary, this study provides novel evidence that Gly-induced autophagy inhibition evokes the inactivation of PPARα-mediated FAO and concomitant hepatic steatosis in roosters by mediating epigenetic reprogramming of PPARα.

Evaluation of phytoremediation potential and resistance of Gladiolus grandiflora L. against cadmium stress

Although irrigation water is a fundamental need for plant growth, it is also a source of pollutants if contaminated with harmful materials like cadmium (Cd). Irrigation water possessing abundant Cd causes damage to soil, plants, animals and ultimately human beings through the food chain. A pot experiment was conducted to evaluate the gladiolus (Gladiolus grandiflora L.) potential of Cd accumulation and the capability of the plant to be an economically beneficial choice in presence of high Cd irrigation water supply. Artificially prepared four levels of Cd irrigation water were applied to the plants viz., 30, 60, 90 and 120 mg L^-1. The results revealed that 30 mg L^-1 Cd had no difference in all growth-related parameters when compared to the control. Photosynthesis rate, stomatal conductance and transpiration rate along with plant height and spike length were reduced with high accumulation levels of Cd in plants. The main plant portion for Cd storage found in Gladiolus grandiflora L was corm where the amount of Cd was 10-12 times higher than the amount found in leaves, and 2-4 times more than the stem. This deportment was further established by the translocation factor (TF). In corm to shoot TF and corm to stem TF, the factor reduced with increasing Cd levels, while, in corm to leaves TF, Cd levels were statistically non-significant. From corm to shoot TF value of 0.68 and 0.43 in case of 30 and 60 mg L^-1, Cd treatments indicates good phytoremediation potential of Gladiolus in low and moderate Cd-polluted environments. Conclusively, the study reveals the good capability of Gladiolus grandiflora L. to harvest Cd from the soil and water in reasonably good amount with sufficient potential to grow under irrigation-based Cd stress. Under revelations of the study, Gladiolus grandiflora L appeared as a Cd accumulator which could potentially be used as a sustainable approach for phytoremediation of Cd.

Remediation effects and mechanisms of typical minerals combined with inorganic amendment on cadmium-contaminated soil: a field study in wheat

The remediation of cadmium (Cd)-contaminated soil has gained much attention recently because Cd in soil threatens human health through the food chain. Although tremendous progress has been made in the remediation of Cd-contaminated soil in rice acid soil system, the mechanism and effects of Cd-contaminated soil remediation under these amendments in wheat weak alkaline soil are still limited. In this study, the remediation effect and related mechanism of Cd in weakly alkaline soil were carried out using zeolite, diatomite, and sodium bentonite as the main remediation components, supplemented by calcium dihydrogen phosphate and fulvic acid. The results of field experiments showed that the concentration of Cd reduced by 27.3 ~ 31.2% in rhizosphere soil and 34.3 ~ 54.2% in non-rhizosphere soil, and the maximum reduction rate of Cd concentration in wheat grain was 25.5%. The main factors affecting the concentration of Cd in wheat grains include the change in exchangeable Cd, the absorption capacity of wheat root, and the inhibitory effect on Cd transport from stem to grain in this paper. In general, this work provides a new potential management feasible pathway to alleviate the Cd toxicity of weakly alkaline soil and wheat grain.

Transcriptome reveals overview of Ca2+ dose-dependent metabolism disorders in zebrafish larvae after Cd2+ exposure

Cadmium (Cd), a ubiquitous environmental hazardous heavy metal, poses a significant threat to the health of aquatic organisms, including teleosts. Although the toxic profile of Cd is well recognized, little is known regarding the overall view of toxic responses to varying aquatic environmental parameters (e.g., water hardness) at an individual level. Herein, differences in water hardness were partially mimicked by adjusting Ca²⁺ levels in E3 medium. As an in vivo model, zebrafish embryos were exposed to variable Ca²⁺ levels (NV, normal Ca²⁺; LV, low Ca²⁺; HV, high Ca²⁺) alone or combined with 30.7 µg/L Cd²⁺ (NC, LC, and HC, respectively) until 144 hr post-fertilization. The genome-wide transcriptome revealed differentially expressed genes between groups. Functional enrichment analysis found that biological processes related to metabolism, particularly lipid metabolism, were significantly disrupted in NC and LC treatments, while a remission was observed in the HC group. Biochemical assays confirmed that the decrease in Ca²⁺ enhanced synthesis, inhibited mobilization and increased the storage of lipids in Cd²⁺ treatments. This study suggests that the toxic effect of Cd on biological pathways will be influenced by Ca²⁺, which will improve the toxicological understanding and facilitate accurate assessment of Cd.

Hepatoprotective Effects of Taurine Against Cadmium-Induced Liver Injury in Female Mice

Cadmium (Cd), a heavy metal contaminant, seriously threatens human and animal health. Taurine (Tau) has been used against hepatotoxicity caused by different environmental toxins. However, it has not been elucidated whether Tau exerts its protective function against Cd-induced hepatotoxicity. The aim of this study was thus to evaluate the ameliorative function of Tau (500 mg/kg body weight intraperitoneally) on Cd-induced (2 mg/kg body weight intraperitoneally) liver toxicity in mice for 14 days. The histopathologic and ultrastructure changes as well as alterations in indexes related to liver function, antioxidant biomarkers, inflammatory, and apoptosis were evaluated. The results showed that Tau alleviated the vacuolar degeneration, nuclear condensation, mitochondria swelling, and cristae lysis of hepatocytes induced by Cd. In addition, Tau treatment significantly reduced the ALT, AST levels in serum, and inflammatory factor TNF-α and IL-1β in liver tissue. Furthermore, Tau treatment decreased the Bax/Bcl-2 ratio and cleaved caspase-3 protein expression levels. Taken together, these observations demonstrate that Tau has an important hepatic protective function against the inflammation and apoptosis induced by Cd.

A New In Vivo Zebrafish Bioassay Evaluating Liver Steatosis Identifies DDE as a Steatogenic Endocrine Disruptor, Partly through SCD1 Regulation

Non-alcoholic fatty liver disease (NAFLD), which starts with liver steatosis, is a growing worldwide epidemic responsible for chronic liver diseases. Among its risk factors, exposure to environmental contaminants, such as endocrine disrupting compounds (EDC), has been recently emphasized. Given this important public health concern, regulation agencies need novel simple and fast biological tests to evaluate chemical risks. In this context, we developed a new in vivo bioassay called StAZ (Steatogenic Assay on Zebrafish) using an alternative model to animal experimentation, the zebrafish larva, to screen EDCs for their steatogenic properties. Taking advantage of the transparency of zebrafish larvae, we established a method based on fluorescent staining with Nile red to estimate liver lipid content. Following testing of known steatogenic molecules, 10 EDCs suspected to induce metabolic disorders were screened and DDE, the main metabolite of the insecticide DDT, was identified as a potent inducer of steatosis. To confirm this and optimize the assay, we used it in a transgenic zebrafish line expressing a blue fluorescent liver protein reporter. To obtain insight into DDE's effect, the expression of several genes related to steatosis was analyzed; an up-regulation of scd1 expression, probably relying on PXR activation, was found, partly responsible for both membrane remodeling and steatosis.

Silicon-mediated regulation of cadmium transport and activation of antioxidant defense system enhances Pennisetum glaucum resistance to cadmium stress

Pennisetum glaucum is an important forage grass for livestock. However, the large accumulation of cadmium (Cd) in plant tissues increases the risk of heavy metals entering the food chain in Cd-contaminated soils. Silicon (Si) can inhibit cadmium (Cd) uptake and enhance tolerance of plant to Cd toxicity, but whether and how Si alleviates Cd toxicity in grass and the underlying mechanisms are unclear. The present study explored the differential mechanisms of silicon-induced Cd transport in apoplast and symplast, Cd distribution in root tissue and antioxidant defense system in P. glaucum under Cd stress through hydroponic and pot experiments. The present results showed that exogenous Si supply significantly reduced Cd concentrations in apoplast and symplast; Si treatment increased monosilicic acid concentration in apoplast and symplast of the roots and shoots under Cd stress. Elemental analysis of root microdomains showed that Si treatment increased the distribution of Cd and Si in the endodermis by 42.6% and 14.0%, respectively. Si alleviated the adverse influences of Cd on plant growth, which were manifested in root morphological traits and root activity. In addition, Si addition significantly increased the activities of catalase and superoxide dismutase by 37.0% and 72.7%, and improved the efficiency of the ascorbate-glutathione cycle in Cd-stress shoots. Furthermore, Si significantly reduced the contents of hydrogen peroxide and superoxide anion in Cd-stressed shoots by 16.6% and 48.7%, respectively. These findings demonstrate that Si enhances the resistance of P. glaucum to Cd stress through regulating Cd transport pathways and activating antioxidant defense systems.

Associations of metal mixtures with metabolic-associated fatty liver disease and non-alcoholic fatty liver disease: NHANES 2003-2018

Objective

The hepatotoxicity of exposure to a single heavy metal has been examined in previous studies. However, there is limited evidence on the association between heavy metals mixture and non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD). This study aims to investigate the associations of 13 urinary metals, individually and jointly, with NAFLD, MAFLD, and MAFLD components.

Methods

This study included 5,548 adults from the National Health and Nutrition Examination Survey (NHANES) 2003-2018. Binary logistic regression was used to explore the associations between individual metal exposures and MAFLD, NAFLD, and MAFLD components. Bayesian kernel machine regression (BKMR) and Quantile-based g-computation (QGC) were used to investigate the association of metal mixture exposure with these outcomes.

Results

In single metal analysis, increased levels of arsenic [OR 1.09 (95%CI 1.03-1.16)], dimethylarsinic acid [1.17 (95%CI 1.07-1.27)], barium [1.22 (95%CI 1.14-1.30)], cobalt [1.22 (95%CI 1.11-1.34)], cesium [1.35 (95%CI 1.18-1.54)], molybdenum [1.45 (95%CI 1.30-1.62)], antimony [1.18 (95%CI 1.08-1.29)], thallium [1.49 (95%CI 1.33-1.67)], and tungsten [1.23 (95%CI 1.15-1.32)] were significantly associated with MAFLD risk after adjusting for potential covariates. The results for NAFLD were similar to those for MAFLD, except for arsenic, which was insignificantly associated with NAFLD. In mixture analysis, the overall metal mixture was positively associated with MAFLD, NAFLD, and MAFLD components, including obesity/overweight, diabetes, and metabolic dysfunction. In both BKMR and QGC models, thallium, molybdenum, tungsten, and barium mainly contributed to the positive association with MAFLD.

Conclusion

Our study indicated that exposure to heavy metals, individually or cumulatively, was positively associated with NAFLD, MAFLD, and MAFLD components, including obesity/overweight, diabetes, and metabolic dysfunction. Additional research is needed to validate these findings in longitudinal settings.

Role of FOXO3a Transcription Factor in the Regulation of Liver Oxidative Injury

Oxidative stress has been identified as a key mechanism in liver damage caused by various chemicals. The transcription factor FOXO3a has emerged as a critical regulator of redox imbalance. Multiple post-translational changes and epigenetic processes closely regulate the activity of FOXO3a, resulting in synergistic or competing impacts on its subcellular localization, stability, protein-protein interactions, DNA binding affinity, and transcriptional programs. Depending on the chemical nature and subcellular context, the oxidative-stress-mediated activation of FOXO3a can induce multiple transcriptional programs that play crucial roles in oxidative injury to the liver by chemicals. Here, we mainly review the role of FOXO3a in coordinating programs of genes that are essential for cellular homeostasis, with an emphasis on exploring the regulatory mechanisms and potential application of FOXO3a as a therapeutic target to prevent and treat liver oxidative injury.

Subcellular-Level Mitochondrial Energy Metabolism Response in the Fat Body of the German Cockroach Fed Abamectin

Mitochondria are the leading organelle for energy metabolism. The toxic effects of environmental toxicants on mitochondrial morphology, energy metabolism, and their determination of cell fate have already been broadly studied. However, minimal research exists on effects of environmental toxicants such as pesticides on mitochondrial energy metabolism at in vitro subcellular level, particularly from an omics perspectives (e.g., metabolomics). Here, German cockroach (Blattella germanica) was fed diets with (0.01 and 0.001 mg/mL) and without abamectin, and highly purified fat body mitochondria were isolated. Swelling measurement confirmed abnormal mitochondrial swelling caused by abamectin stress. The activity of two key mitochondrial energy metabolism-related enzymes, namely succinic dehydrogenase and isocitrate dehydrogenase, was significantly affected. The metabolomic responses of the isolated mitochondria to abamectin were analyzed via untargeted liquid chromatography/mass spectrometry metabolomics technology. Fifty-two differential metabolites (DMs) were identified in the mitochondria between the 0.001 mg/mL abamectin-fed and the control groups. Many of these DMs were significantly enriched in pathways involved in ATP production and energy consumption (e.g., oxidative phosphorylation, TCA cycle, and pentose phosphate pathway). Nineteen of the DMs were typically related to energy metabolism. This study is valuable for further understanding mitochondrial toxicology under environmental toxicants, particularly its subcellular level.

Gut microbiota-bile acid-intestinal Farnesoid X receptor signaling axis orchestrates cadmium-induced liver injury

Cadmium (Cd) is a widely prevalent environmental pollutant that accumulates in the liver and induces liver injury. The mechanism of Cd-induced liver injury remains elusive. Our study aimed to clarify the mechanism by which changes in the gut microbiota contribute to Cd-induced liver injury. Here, a murine model of liver injury induced by chronic Cd exposure was used. Liver injury was assessed by biochemistry and histopathology. Expression profiles of genes involved in bile acid (BA) homeostasis, inflammation and injury were assessed via Realtime-PCR and Western-blot. 16S rRNA gene sequencing and mass spectrometry-based metabolomics were used to investigate changes in the gut microbiota and its metabolites in the regulation of Cd-induced liver injury. Here, we showed that Cd exposure induced hepatic ductular proliferation, hepatocellular damage and inflammatory infiltration in mice. Cd exposure induced gut microbiota dysbiosis and reduced the fecal bile salt hydrolase activity leading to an increase of tauro-β-muricholic acid levels in the intestine. Cd exposure decreased intestine FXR/FGF-15 signaling and promoted hepatic BA synthesis. Furthermore, the mice receiving fecal microbiota transplantation from Cd-treated mice showed reduced intestinal FXR/FGF-15 signaling, increased hepatic BA synthesis, and liver injury. However, the depletion of the commensal microbiota by antibiotics failed to change these indices in Cd-treated mice. Finally, the administration of the intestine-restricted FXR agonist fexaramine attenuated the liver injury, improved the intestinal barrier, and decreased hepatic BA synthesis in the Cd-treated mice. Our study identified a new mechanism of Cd-induced liver injury. Cd-induced gut microbiota dysbiosis, decreased feces BSH activity, and increased intestinal T-βMCA levels led to an inhibition of intestinal FXR/FGF-15 signaling and an increase in hepatic BA synthesis, ultimately facilitating the development of hepatic ductular proliferation, inflammation, and injury in mice. This study expands our understanding of the health hazards caused by environmental Cd pollution.

Per- and Polyfluoroalkyl Substances (PFASs) Impair Lipid Metabolism in Rana nigromaculata: A Field Investigation and Laboratory Study

Per- and polyfluoroalkyl substances (PFASs) are ubiquitous environmental pollutants, causing environmental threats and public health concerns, but information regarding PFAS hepatotoxicity remains elusive. We investigated the effects of PFASs on lipid metabolism in black-spotted frogs through a combined field and laboratory study. In a fluorochemical industrial area, PFASs seriously accumulate in frog tissues. PFAS levels in frog liver tissues are positively related to the hepatosomatic index along with triglyceride (TG) and cholesterol (TC) contents. In the laboratory, frogs were exposed to 1 and 10 μg/L PFASs, respectively (including PFOA, PFOS, and 6:2 Cl-PFESA). At 10 μg/L, PFASs change the hepatic fatty acid composition and significantly increase the hepatic TG content by 1.33 to 1.87 times. PFASs induce cross-talk accumulation of TG, TC, and their metabolites between the liver and serum. PFASs can bind to LXRα and PPARα proteins, further upregulate downstream lipogenesis-related gene expression, and downregulate lipolysis-related gene expression. Furthermore, lipid accumulation induced by PFASs is alleviated by PPARα and LXRα antagonists, suggesting the vital role of PPARα and LXRα in PFAS-induced lipid metabolism disorders. This work first reveals the disruption of PFASs on hepatic lipid homeostasis and provides novel insights into the occurrence and environmental risk of PFASs in amphibians.

Solution chemistry mechanisms of exogenous silicon influencing the speciation and bioavailability of cadmium in alkaline paddy soil

The mechanism of silicon (Si) influencing cadmium (Cd) speciation and bioavailability in alkaline paddy soil solution remains unclear. Therefore, this study sought to elucidate the effect of Si on Cd by combining chemical analysis and rice pot experiments. In this work, the effects of Na₂SiO₃ alkalinity and the differences in Na⁺ were eliminated in all treatments, and the Cd speciation in soil solutions was determined in-situ using a Field-Donnan membrane technology (DMT) cell. Additionally, rice yields and the Cd content in various parts of the rice plant were studied. The results showed that Si application significantly increased rice biomass by 32% (P < 0.05) while significantly reduced the Cd content in brown rice by 52% (P < 0.01) and the free Cd²⁺ concentration in the soil solution. Further analysis of the interaction of Si and Cd using Fourier transform-infrared spectroscopy (FT-IR), Raman, and X-ray photoelectron spectroscopy (XPS) indicated that a Si-Cd complex was formed by Cd and Si-O groups. In summary, Si changed the chemical speciation of Cd in the alkaline soil solution and formed a water-soluble Si-Cd complex that the rice could not absorb, consequently reducing Cd bioavailability.

Effects of the Gut Microbiota and Barrier Function on Melatonin Efficacy in Alleviating Liver Injury

Environmental cadmium (Cd) exposure has been associated with severe liver injury. In contrast, melatonin (Mel) is a candidate drug therapy for Cd-induced liver injury due to its diverse hepatoprotective activities. However, the precise molecular mechanism by which Mel alleviates the Cd-induced liver injury, as well as the Mel–gut microbiota interaction in liver health, remains unknown. In this study, mice were given oral gavage CdCl2 and Mel for 10 weeks before the collection of liver tissues and colonic contents. The role of the gut microbiota in Mel’s efficacy in alleviating the Cd-induced liver injury was evaluated by the gut microbiota depletion technique in the presence of antibiotic treatment and gut microbiota transplantation (GMT). Our results revealed that the oral administration of Mel supplementation mitigated liver inflammation, endoplasmic reticulum (ER) stress and mitophagy, improved the oxidation of fatty acids, and counteracted intestinal microbial dysbiosis in mice suffering from liver injury. It was interesting to find that neither Mel nor Cd administration induced any changes in the liver of antibiotic-treated mice. By adopting the GMT approach where gut microbiota collected from mice in the control (CON), Cd, or Mel + Cd treatment groups was colonized in mice, it was found that gut microbiota was involved in Cd-induced liver injury. Therefore, the gut microbiota is involved in the Mel-mediated mitigation of ER stress, liver inflammation and mitophagy, and the improved oxidation of fatty acids in mice suffering from Cd-induced liver injury.

Progress in Nonalcoholic Fatty Liver Disease: SIRT Family Regulates Mitochondrial Biogenesis

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis, insulin resistance, mitochondrial dysfunction, inflammation, and oxidative stress. As a group of NAD+-dependent III deacetylases, the sirtuin (SIRT1-7) family plays a very important role in regulating mitochondrial biogenesis and participates in the progress of NAFLD. SIRT family members are distributed in the nucleus, cytoplasm, and mitochondria; regulate hepatic fatty acid oxidation metabolism through different metabolic pathways and mechanisms; and participate in the regulation of mitochondrial energy metabolism. SIRT1 may improve NAFLD by regulating ROS, PGC-1α, SREBP-1c, FoxO1/3, STAT3, and AMPK to restore mitochondrial function and reduce steatosis of the liver. Other SIRT family members also play a role in regulating mitochondrial biogenesis, fatty acid oxidative metabolism, inflammation, and insulin resistance. Therefore, this paper comprehensively introduces the role of SIRT family in regulating mitochondrial biogenesis in the liver in NAFLD, aiming to further explain the importance of SIRT family in regulating mitochondrial function in the occurrence and development of NAFLD, and to provide ideas for the research and development of targeted drugs. Relatively speaking, the role of some SIRT family members in NAFLD is still insufficiently clear, and further research is needed.

Environmental Toxicants and NAFLD: A Neglected yet Significant Relationship

The liver is an organ of vital importance in the body; it is the center of metabolic activities and acts as the primary line of defense against toxic compounds. Exposure to environmental toxicants is an unavoidable fallout from rapid industrialization across the world and is even higher in developing countries. Technological development and industrialization have led to the release of toxicants such as pollutant toxic gases, chemical discharge, industrial effluents, pesticides and solvents, into the environment. In the last few years, a growing body of evidence has shed light on the potential impact of environmental toxicants on liver health, in particular, on non-alcoholic fatty liver disease (NAFLD) incidence and progression. NAFLD is a multifactorial disease linked to metabolic derangement including diabetes and other complications. Environmental toxicants including xenobiotics and pollutants may have a direct or indirect steatogenic/fibrogenic impact on the liver and should be considered as risk factors associated with NAFLD. This review discusses the contribution of environmental toxicants toward the increasing disease burden of NAFLD.

Distinct responses from triglyceride and cholesterol metabolism in common carp (Cyprinus carpio) upon environmental cadmium exposure

Due to high persistence and bioavailability, Cadmium (Cd) is one of the most prevalent environmental contaminants, posing an elevating threat to the ecosystems. It has been evidenced that high-dose Cd elicits deleterious effects on aquatic organisms, but the potential toxicities of Cd at environmentally relevant concentrations remains underappreciated. In this study, we used common carp to investigate how environmental Cd exposure affects triglyceride (TG) and cholesterol metabolism and underlying mechanisms. The data indicated that Cd resulted in the shift of TG from the liver to blood and the movement of cholesterol in the opposite direction, ultimately giving rise to the storage of crude lipid in liver and muscle, especially hepatic cholesterol retention. Cholesterol, instead of TG, became the principal cause during the progression of hepatic lipid accumulation. Mechanistic investigations at transcriptional and translational levels further substantiated that Cd blocked hepatic biosynthesis of TG and enhanced TG efflux out of the liver and fatty acid β-oxidation, which collectively led to the compromised TG metabolism in the liver and accelerated TG export to the serum. Additionally, strengthened synthesis, retarded export and oxidation of cholesterol detailed the hepatic prominent cholesterol retention. Taken together, our results demonstrated that environmental exposure to Cd perturbed lipid metabolism through triggering distinct responses from hepatic TG and cholesterol homeostasis. These indicated that environmental factors (such as waterborne Cd) could be a potential contributor to the prevalence of non-alcoholic fatty-liver disease in aquaculture and more efforts should be devoted to the ecological risk assessment of pollutants under environmental scenarios.

Health risk assessment of commercial fish and shrimp from the North Persian Gulf

BACKGROUND

Bioaccumulation of trace metals in the food web demands continuous monitoring of seafood safety. Here, the food safety of commercial fish bluespot mullet Crenimugil seheli, deep flounder Pseudorhombus elevates, and Jinga shrimp Metapenaeus affinis was assessed from commercial and industrial region of the West Bandar Abbas, the North Persian Gulf, for the first time.

METHODS

For this purpose, concentrations of trace metals Ni, Zn, Cu, Cr, Cd, and Pb, and their health risks were investigated.

RESULTS

Results showed the average concentration of all trace metals in all species was below concentrations proposed by WHO/FAO/USEPA. The finding on risk assessment of three species indicated three species are safe for daily consumption. Long-term consumption of three species would not pose potential non-carcinogenic health risk. However, it would result in carcinogenic effects from the ingestion of trace metals Ni, Cr, and Cd.

CONCLUSIONS

The data emphasizes the need for the continuous monitoring in this industrial region in the future to manage and control pollutant sources and to ensure the quality of seafood.

Environmental exposure to low-dose perfluorohexanesulfonate promotes obesity and non-alcoholic fatty liver disease in mice fed a high-fat diet

Perfluorohexanesulfonate (PFHxS) is one of the most prevalent perfluoroalkyls. It is widely distributed in both abiotic and biotic environments because of its prevalence and bioaccumulative properties. Exposure to PFHxS has been associated with the higher serum liver functions associated with steatosis in obese people. This study explores the impact of chronic exposure to low-dose PFHxS on predisposition to non-alcoholic fatty liver disease (NAFLD) as well as on metabolic functions in diet-induced obese mice. Results showed that 12-week exposure to PFHxS at a dose of 450 μg/L through drinking water significantly promoted obesity and metabolic syndrome in male C57 mice fed a high-fat diet. The PFHxS exposure markedly aggravated hepatic symptoms resembling NAFLD and caused systematic metabolic disorders as well as gut dysbiosis in the obese mice. Key genes of hepatic lipid metabolism, inflammation, and fibrosis were strongly altered, while gut microflora that have been associated with obesity and pathogenesis of NAFLD, including the Bacteroides/Firmicutes ratio, Desulfovibrio, Mucispirillum, and Akkermansia, were significantly affected by the PFHxS exposure. The findings of this study suggest that environmental PFHxS exposure is a tangible risk factor for metabolic diseases such as NAFLD, especially among obese individuals.

Zinc oxide/graphene oxide nanocomposites efficiently inhibited cadmium-induced hepatotoxicity via releasing Zn ions and up-regulating MRP1 expression

Environmental cadmium (Cd) pollution has been verified to associated with various hepatic diseases, as Cd has been classified as one of the TOP 20 Hazardous Substances and liver is the main target of Cd poisoning. However, to design efficient hepatic antidotes with excellent detoxification capacity and reveal their underlying mechanism(s) are still challenges in Cd detoxification. Herein, ZnO/GO nanocomposites with favorable biocompatibility was uncovered their advanced function against Cd-elicited liver damage at the in situ level in vivo by 9.4 T magnetic resonance imaging (MRI). To explore the cellular detoxification mechanism, ZnO/GO nanocomposites was found to effectively inhibit the cyto- and geno-toxicity of Cd with the maximum antagonistic efficiency to be approximately 90%. Mechanistically, ZnO/GO nanocomposites competitively inhibited the cellular Cd uptake through releasing Zn ions, and significantly promoted Cd excretion via targeting the efflux pump of multidrug resistance associated protein1 (MRP1), which was confirmed by mass spectra and immunohistochemical analysis in kidney, a main excretion organ of Cd. Our data provided a novel approach against Cd-elicited hepatotoxic responses by constructed ZnO/GO nanocomposites both in vitro and in vivo, which may have promising application in prevention and detoxification for Cd poisoning.

Sirt3-Sod2-mROS-Mediated Manganese Triggered Hepatic Mitochondrial Dysfunction and Lipotoxicity in a Freshwater Teleost

Exposure to excessive manganese (Mn) is toxic to humans and animals. However, the toxic effects and mechanisms of excessive Mn influencing the vertebrates have been highly overlooked. In the present study, dietary Mn overload significantly increased hepatic lipid and Mn contents, decreased superoxide dismutase 2 (Sod2) activity, increased the Sod2 acetylation level, and induced mitochondrial dysfunction; Mn induced mitochondrial dysfunction through Mtf1/sirtuin 3 (Sirt3)-mediated acetylation of Sod2 at the sites K55 and K70. Meanwhile, mitochondrial oxidative stress was involved in Mn-induced lipotoxicity. Mechanistically, Mn-induced lipotoxicity was via oxidative stress-induced Hsf1 nucleus translocation and its DNA binding capacity to the regions of a peroxisome proliferator-activated receptor g (pparg) promoter, which in turn induced the transcription of lipogenic-related target genes. For the first time, our study demonstrated that Mn-induced hepatic lipotoxicity via a mitochondrial oxidative stress-dependent Hsf1/Pparg pathway and Mtf1/sirt3-mediated Sod2 acetylation participated in mitochondrial dysfunction. Considering that lipid metabolism and lipotoxicity are widely used as the biomarkers for environmental assessments of pollutants, our study provided innovative and important insights into Mn toxicological and environmental evaluation in aquatic environments.

Whole Transcriptome Profiling of the Effects of Cadmium on the Liver of the Xiangxi Yellow Heifer

Cadmium (Cd) is a major heavy metal toxicant found in industrial zones. Humans and animals are exposed to it through their diet, which results in various physiological problems. In the current study, the toxic effects of Cd on the liver were investigated by whole-transcriptome sequencing (RNA-seq) of the livers of Xiangxi heifers fed a diet with excess Cd. We randomly divided six healthy heifers into two groups. The first group received a control diet, whereas the second group received Cd-exceeding diets for 100 days. After 100 days, the livers were collected. A total of 551 differentially expressed mRNAs, 24 differentially expressed miRNAs, and 169 differentially expressed lncRNAs were identified (p < 0.05, |log2FC| >1). Differentially expressed genes (DEGs) were analyzed by gene ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses. We found that under Cd exposure, DEGs were enriched in the adenosine 5'-monophosphate-activated protein kinase pathway, which is involved in autophagy regulation, and the peroxisome proliferator-activated receptor pathway, which is involved in lipid metabolism. In addition, the apolipoprotein A4 gene, which has anti-inflammatory and antioxidant effects, the anti-apoptotic gene ATPase H+/K+ transporting the nongastric alpha2 subunit, and the cholesterol metabolism-associated gene endothelial lipase gene were significantly downregulated. C-X-C motif chemokine ligand 3, cholesterol 7α-hydroxylase, and stearoyl-CoA desaturase, which are involved in the development of fatty liver, were significantly upregulated. These genes revealed the main effects of Cd on the liver of Xiangxi yellow heifers. The current study provides insightful information regarding the DEGs involved in autophagy regulation, apoptosis, lipid metabolism, anti-inflammation, and antioxidant enzyme activity. These may serve as useful biomarkers for predicting and treating Cd-related diseases in the future.

Chronic exposure to low-dose cadmium facilitated nonalcoholic steatohepatitis in mice by suppressing fatty acid desaturation

Exposure to cadmium (Cd), a toxic metal, is epidemiologically linked to nonalcoholic steatohepatitis (NASH) in humans. However, the role of Cd in NASH remains to be fully elucidated. This study employed a novel murine NASH model to investigate the effects of chronic low-dose Cd on hepatic pathology and its underlying mechanisms. NASH is characterized by lipid accumulation, extensive cell death, and persistent inflammation in the liver. We found that treatment with Cd in drinking water (10 mg/L) for 6 or 12 weeks significantly boosted hepatic fat deposition, increased hepatocyte destruction, and amplified inflammatory responses in mice, confirming that low-dose Cd can facilitate NASH development in vivo. Mechanistically, chronic Cd exposure reshaped the hepatic transcriptional landscape, with PPAR-mediated fatty acid metabolic pathways being the most significantly altered. In particular, Cd repressed fatty acid desaturation, leading to the accumulation of saturated fatty acids whose lipotoxicity exacerbated cell death and, consequently, inflammatory activation. In summary, we validated the causal effects of chronic low-dose Cd on NASH in vivo and identified the fatty acid desaturation program as a novel target for Cd to instigate hepatopathological alterations.