Humic-like components in dissolved organic matter inhibit cadmium sequestration by sediment.

China's lakes are plagued by cadmium (Cd) pollution. Dissolved organic matter (DOM) significantly regulates Cd(II) transport properties at the sediment-water interface. Understanding the effects of different DOM components on the transportation properties of Cd(II) at the sediment-water interface is essential. In this study, typical DOM from different sources was selected to study Cd(II) mobility at the sediment-water interface. Results showed that terrestrial-derived DOM (fulvic acids, FA) and autochthonous-derived DOM (α-amylase, B1) inhibit Cd(II) sequestration by sediments (42.5% and 5.8%, respectively), while anthropogenic-derived DOM (sodium dodecyl benzene sulfonate, SDBS) increased the Cd(II) adsorption capacity by sediments by 2.8%. Fluorescence quenching coupling with parallel factor analysis (EEM-PARAFAC) was used to characterize different DOM components. The results showed that FA contains three kinds of components (C1, C3: protein-like components, C2: humic-like components); SDBS contains two kinds of components (C1, C2: protein-like components); B1 contains three kinds of components (C1, C2: protein-like components, C3: humic-like components).Three complex reaction models were used to characterize the ability of Cd(II) complex with DOM, and it was found that the humic-like component could hardly be complex with Cd(II). Accordingly, humic-like components compete for Cd(II) adsorption sites on the sediment surface and inhibit Cd(II) adsorption from sediments. Fourier transform infrared spectroscopy (FTIR) of the sediment surface before and after Cd(II) addition was analyzed and proved the competitive adsorption theory. This study provides a better understanding of the Cd(II) mobilization behavior at the sediment-water interface and indicates that the input of humic-like DOM will increase the bioavailability of Cd.

Pristine/magnesium-loaded biochar and ZVI affect rice grain arsenic speciation and cadmium accumulation through different pathways in an alkaline paddy soil.

Cadmium (Cd) and arsenic (As) co-contamination has threatened rice production and food safety. It is challenging to mitigate Cd and As contamination in rice simultaneously due to their opposite geochemical behaviors. Mg-loaded biochar with outstanding adsorption capacity for As and Cd was used for the first time to remediate Cd/As contaminated paddy soils. In addition, the effect of zero-valent iron (ZVI) on grain As speciation accumulation in alkaline paddy soils was first investigated. The effect of rice straw biochar (SC), magnesium-loaded rice straw biochar (Mg/SC), and ZVI on concentrations of Cd and As speciation in soil porewater and their accumulation in rice tissues was investigated in a pot experiment. Addition of SC, Mg/SC and ZVI to soil reduced Cd concentrations in rice grain by 46.1%, 90.3% and 100%, and inorganic As (iAs) by 35.4%, 33.1% and 29.1%, respectively, and reduced Cd concentrations in porewater by 74.3%, 96.5% and 96.2%, respectively. Reductions of 51.6% and 87.7% in porewater iAs concentrations were observed with Mg/SC and ZVI amendments, but not with SC. Dimethylarsinic acid (DMA) concentrations in porewater and grain increased by a factor of 4.9 and 3.3, respectively, with ZVI amendment. The three amendments affected grain concentrations of iAs, DMA and Cd mainly by modulating their translocation within plant and the levels of As(III), silicon, dissolved organic carbon, iron or Cd in porewater. All three amendments (SC, Mg/SC and ZVI) have the potential to simultaneously mitigate Cd and iAs accumulation in rice grain, although the pathways are different.

Enhanced Cd2+ removal from aqueous solution using olivine and magnesite combination: New insights into the mechanochemical synergistic effect.

In this study, an efficient stabilizer material for cadmium (Cd2+) treatment was successfully prepared by simply co-milling olivine with magnesite. Several analytical methods including XRD, TEM, SEM and FTIR, combined with theoretical calculations (DFT), were used to investigate mechanochemical interfacial reaction between two minerals, and the reaction mechanism of Cd removal, with ion exchange between Cd2+ and Mg2+ as the main pathway. A fixation capacity of Cd2+ as high as 270.61 mg/g, much higher than that of the pristine minerals and even the individual/physical mixture of milled olivine and magnesite, has been obtained at optimized conditions, with a neutral pH value of the solution after treatment to allow its direct discharge. The as-proposed Mg-based stabilizer with various advantages such as cost benefits, green feature etc., will boosts the utilization efficiency of natural minerals over the elaborately prepared adsorbents.

A new insight into the straw decomposition associated with minerals: Promoting straw humification and Cd immobilization.

Organic matter (OM) derived from the decomposition of crop residues plays a key role as a sorbent for cadmium (Cd) immobilization. Few studies have explored the straw decomposition processes with the presence of minerals, and the effect of newly generated organo-mineral complexes on heavy metal adsorption. In this study, we investigated the variations in structure and composition during the rice straw decomposition with or without minerals (goethite and kaolinite), as well as the adsorption behavior and mechanisms by which straw decomposition affects Cd immobilization. The degree of humification of extracted straw organic matter was assessed using excitation-emission matrix (EEM) fluorescence and Ultraviolet-visible spectroscopy (UV-vis), while employing FTIR spectroscopy and XPS to characterize the adsorption mechanisms. The spectra analysis revealed the enrichment of highly aromatic and hydrophobic components, indicating that the degree of straw decomposition and humification were further intensified during incubation. Additionally, the existence of goethite (SG) accelerated the humification of OM. Sorption experiments revealed that the straw humification increased Cd adsorption capacity. Notably, SG exhibited significantly higher adsorption performance compared to the organic matter without minerals (RS) and the existence of kaolinite (SK). Further analysis using FT-IR spectroscopy and XPS verified that the primary mechanisms involved in Cd immobilization were complexion with -OH and -COOH, as well as the formation of Cd-π binds with aromatic C=C on the surface of solid OMs. These findings will facilitate understanding the interactions of the rice straw decomposing with soil minerals and its remediation effect on Cd-contaminated farmland.

Can cadmium-contaminated rice be used to produce food additive sodium erythorbate?

Cadmium (Cd) in rice is a significant concern for its quality and safety. Currently, there is a crucial need to develop cost-effective and efficient ways to remove Cd or re-utilize Cd-contaminated rice. The food additive sodium erythorbate is produced via 2-ketogluconic acid (2KGA) fermentation by Pseudomonas plecoglossicida and lactonization using starch-rich raw materials, such as rice. We aimed to determine whether cadmium-contaminated rice can be used to produce sodium erythorbate. To achieve this aim, the migration of cadmium during the production of sodium erythorbate from Cd-contaminated rice was studied. Five rice varieties with different Cd contents from 0.10 to 0.68 mg/kg were used as raw materials. The results indicated the presence of Cd in rice and CaCO3 did not have a notable impact on the fermentation performance of 2KGA. The acidification of 2KGA fermentation broth, the addition of K4Fe(CN)6·3H2O and ZnSO4, and 2KGA purification using cation exchange effectively removed >98% of the Cd in the fermentation broth, but the 2KGA yield remained high at approximately 94%. The sodium erythorbate synthesized from Cd-contaminated rice was of high quality and free from Cd, meeting the requirements of the Chinese National Standard, GB 1886.28-2016. The study provided a safe and effective strategy for comprehensively utilizing Cd-contaminated rice to produce high value-added food additive.

Cadmium toxicity on endoplasmic reticulum functioning.

Cadmium (Cd) is a heavy metal pollutant widely distributed in the environment due to industrial activities, mining, and agricultural practices. Cadmium-induced Toxicity exerts profound effects on ER functioning through multiple mechanisms, leading to cellular dysfunction and pathological consequences. Cadmium disrupts protein folding and activates the unfolded protein response (UPR). Cd exposure leads to the accumulation of misfolded proteins, triggering UPR pathways mediated by critical ER transmembrane sensors: IRE1, PERK, and ATF6. The subsequent UPR aims to restore ER homeostasis but can also induce apoptosis under severe stress conditions. Cd disrupts ER calcium homeostasis by inhibiting the SERCA pump, further exacerbating ER stress. The generation of reactive oxygen species (ROS also plays a critical role in Cd toxicity, damaging ER-resident proteins and amplifying UPR activation). Cadmium also affects the lipid metabolism. This review examines the mechanisms by which Cd toxicity impairs ER functioning, disruption of protein folding and quality control mechanisms, and dysregulation of calcium signaling and lipid metabolism. The subsequent cellular consequences, including oxidative stress, apoptosis, and inflammation, are discussed in the context of Cd-induced pathogenesis of diseases such as Cancer and neurodegenerative and cardiovascular disorders. Finally, potential therapeutic strategies must be explored to mitigate the adverse effects of Cd on ER functioning and human health.

Pretreatment with aqueous Moringa oleifera Lam. leaf extract prevents cadmium-induced hepatotoxicity by improving cellular antioxidant machinery and reducing cadmium accumulation.

Cadmium (Cd) is a highly harmful pollutant that poses a serious threat to human health. The liver is the primary organ for Cd accumulation, and Cd-induced hepatotoxicity has been shown to be strongly correlated with an oxidative imbalance in hepatocytes. Our previous studies in the eukaryotic model organism Saccharomyces cerevisiae revealed that not only co-treatment but also pretreatment with aqueous Moringa oleifera Lam. leaf extract (AMOLE) effectively mitigated Cd toxicity by reducing intracellular Cd accumulation and Cd-mediated oxidative stress. In this study, we therefore investigated the preventive effect of AMOLE against Cd toxicity in human HepG2 hepatocytes. The results showed that, similar to the case of the yeast model, pretreatment with AMOLE prior to Cd exposure also significantly inhibited Cd-induced oxidative stress in HepG2 cells. Untargeted LC-MS/MS-based metabolomic analysis of AMOLE revealed that its major phytochemical constituents were organic acids, particularly phenolic acids and carboxylic acids. Additionally, DPPH-HPTLC fingerprints suggested that quercetin and other flavonoids possibly contribute to the antioxidant activities of AMOLE. Based on our findings, it appears that pretreatment with AMOLE prevented Cd-induced hepatotoxicity via three possible mechanisms: i) direct elimination of free radicals by AMOLE antioxidant compounds; ii) upregulation of antioxidant defensive machinery (GPx1, and HO-1) via Nrf2 signaling cascade to improve cellular antioxidant capacity; and iii) reduction of intracellular Cd accumulation, probably by suppressing Cd uptake. These data strongly suggest the high potential of AMOLE for clinical utility in the prevention of Cd toxicity.

Synergistic mitigation of cadmium stress in rice (Oryza sativa L.) through combined selenium, calcium, and magnesium supplementation.

Rice is susceptible to cadmium (Cd) accumulation, which poses a threat to human health. Traditional methods for mitigating moderately contaminated soils can be impractical or prohibitively expensive, necessitating innovative approaches to reduce Cd uptake in rice. Nutrient management has emerged as a promising solution by leveraging the antagonistic interactions between nutrients and cadmium. However, the research on the synergistic effects of multiple nutrients on Cd toxicity in rice is limited. To address this limitation, pot experiments was utilized to investigate the combined effects of selenium (Se), calcium (Ca), and magnesium (Mg) denoted as (SeCM) on Cd uptake and translocation in rice. The synergistic application of SeCM reduced grain Cd levels by 55.0%, surpassing the individual effects of Se (42.1%) and CM (40.5%), and bringing Cd content below the safe consumption limits. SeCM treatment exhibited multiple beneficial effects: it decreased malondialdehyde (MDA) levels, enhanced catalase (CAT), peroxidase (POD) and glutathione (GSH) enzyme activities, limited Cd translocation from roots to shoots, promoted iron plaque formation, and reduced Cd transfer from soil to iron plaque and subsequently to rice grains. Correlation analysis revealed strong negative relationships between rice Cd content, Cd translocation factors, and the translocation factors of selenium, calcium, and magnesium. These findings suggest that selenium, calcium, and magnesium collaboratively mitigate Cd toxicity through antagonistic and competitive interactions. These nutrients enhance the uptake of beneficial elements, while competitively inhibiting the translocation and accumulation of Cd in rice plants. SeCM application offers a promising strategy for producing nutrient-rich, and Cd-safe rice in contaminated soils.

The effect of cadmium on soil and plants, and the influence of Serendipita indica (Piriformospora indica) in mitigating cadmium stress.

Due to environmental pollution, the risk of cadmium stress for crops is soaring, so researchers are exploring inexpensive solutions to enhance cultivated crops in contaminated soil. Using microorganisms to reduce cadmium risk has been one of the most effective strategies in recent decades. Serendipita indica (Piriformospora indica) is one of the best endophyte fungi that, in addition to reducing heavy metal stress for crops, can significantly reduce the threat of other abiotic stresses. As part of this research, cadmium in soil has been investigated, as well as its effects on plants' morphophysiological and biochemical characteristics. The present review has also attempted to identify the role of Serendipita indica in improving the growth and performance of crops, as well as its possible effect on reducing the risk of cadmium. The results showed that Serendipita indica enhance the growth and productivity of plants in contaminated environments by improving soil quality, reducing cadmium absorption, improving the activity of antioxidant enzymes and secondary metabolites, raising water and mineral absorption, and altering morphophysiological structures.

Ammonium mitigates cadmium toxicity by activating the bZIP20-APX2/CATA transcriptional module in rice seedlings in an ABA-dependent manner.

The amelioration of cadmium (Cd2+) toxicity in plants by ammonium (NH4+) has been widely investigated. However, the molecular mechanisms underpinning this amelioration have remained ambiguous. Here, we found that NH4+ significantly reduces Cd2+ accumulation and enhances antioxidant capacity by increasing ABA accumulation, which, in turn, improves Cd2+ tolerance in rice seedlings. A combination of qPCR, yeast-one-hybrid and dual-luciferase assays, and CUT&RUN-qPCR methods demonstrates that OsbZIP20 directly binds to the promoters of OsAPX2 and OsCATA, activating their transcription, and we show that the process requires phosphorylation modification of OsbZIP20 by OsSAPK9. Under Cd2+ stress, Osbzip20 and Ossapk9 mutants show reduced peroxidase and catalase activities, higher H2O2 accumulation, and reduced Cd2+ tolerance. In sum, our results elucidate a novel mechanism by which NH4+ enhances Cd2+ resistance, through ABA-SAPK9-bZIP20-APX2/CATA, offering a new strategy for improving Cd2+ resistance in rice.

Hydrogen sulfide alleviates cadmium stress in germinating carrot seeds by promoting the accumulation of proline.

Carrot (Daucus carota L.), a widely cultivated economically vegetable from the Apiaceae family, is grown globally. However, carrots can be adversely impacted by cadmium (Cd) pollution in the soil due to its propensity to accumulate in the fleshy root, thus impeding carrot growth and posing health hazards to consumers. Given the potential of hydrogen sulfide (H2S) to improve plant resistance against Cd stress, we treated germinating carrot seeds with varying concentrations of sodium hydrosulfide (NaHS), aiming to alleviate the toxic impacts of Cd stress on carrot seed germination. The results revealed that carrot seeds treated with a concentration of 0.25 mM NaHS displayed better seed germination-associated characteristics compared to seeds treated with NaHS concentrations of 0.1 mM and 0.5 mM. Further investigation revealed a rise in the expression levels of L-cysteine desulfhydrase and D-cysteine desulfhydrase, along with enhanced activity of L-cysteine desulfhydrase and D-cysteine desulfhydrase among the NaHS treatment group, thereby leading to H2S accumulation. Moreover, NaHS treatment triggered the expression of pyrroline-5-carboxylate synthase and pyrroline-5-carboxylate reductase and promoted the accumulation of endogenous proline, while the contents of soluble sugar and soluble protein increased correspondingly. Interestingly, since the application of exogenous proline did not influence the accumulation of endogenous H2S, suggesting that H2S served as the upstream regulator of proline. Histochemical staining and biochemical indices revealed that NaHS treatment led to elevated antioxidant enzyme activity, alongside a suppression of superoxide anion and hydrogen peroxide generation. Furthermore, high performance liquid chromatography analysis revealed that NaHS treatment reduced Cd2+ uptake, thereby promoting germination rate, seed vitality, and hypocotyl length of carrot seeds under Cd stress. Overall, our findings shed light on the application of NaHS to enhance carrot resistance against Cd stress and lay a foundation for exploring the regulatory role of H2S in plants responding to Cd stress.

Exploring the mechanisms of organic fertilizers on Cd bioavailability in rice fields: Environmental behavior and effect factors.

The problem of paddy Cadmium (Cd) contamination is currently the focus of global research. Earlier researches have confirmed that utilization of organic fertilizers regulates Cd chemical fraction distribution by increases organic bound Cd. However, environmental behaviours of organic fertilizers in paddy are still lack exploration. Here, we critical reviewed previous publications and proposed a novel research concept to help us better understand it. Three potential impact pathways of utilization of organic fertilizers on the bioavailability of Cd are presented: (i) use of organic fertilizers changes soil physicochemical properties, which directly affects Cd bioavailability by changing chemical form of Cd(II); (ii) use of organic fertilizers increases soil nutrient content, which indirectly regulates Cd supply and bioaccumulation through ion adsorption and competition for ion-transport channels between nutrients and Cd; and (iii) use of organic fertilizers increases activity of microorganisms and efflux of rice root exudates, which indirectly affects Cd bioavailability of through complexation and sequestration of these organic materials with Cd. Meanwhile, dissolved organic matter (DOM) in the rhizosphere of rice is believed to be the key to revealing the effects of organic fertilizers on Cd. DOM is capable of adsorption and complexation-chelation reactions with Cd and the fractionation of Cd(II) is regulated by DOM. Molecular mass, chemical composition, major functional groups and reaction sequence of DOM determine the formation and solubilization of DOM-Cd complexes.

Bioaccumulation of Atmospherically Deposited Cadmium in Soybean: Three-Year Field Experiment Combined with Cadmium Isotopes.

Atmospheric deposition plays a significant role in introducing cadmium (Cd) into agroecological systems; however, accurately determining its accumulation in crops through foliar and root uptake presents challenges. This study investigated the bioaccumulation of atmospherically deposited Cd in soybean using a three-year fully factorial atmospheric exposure experiment incorporating Cd isotope analysis. Results shown that atmospheric deposition accounted for 1-13% of soil Cd pools, yet contributed 11-72% of Cd to soybean tissues during the growing seasons. Over the course of soil exposure to atmospheric deposition ranging from 1 to 3 years, no notable variations were observed in Cd concentrations in soil solutions and soybean tissues, nor in isotope ratios. Newly deposited Cd was a major source in soybean plants, and the bioavailability of deposited Cd rapidly aged in soils. Atmospheric Cd enriched in lighter isotopes induced negative isotope shifts in soybean plants. By employing an optimized isotope mixing model in conjunction with a mass balance approach, foliar Cd uptake contributed 13-51%, 16-45%, and 21-56% to stem, leaf, and seed, respectively. This study highlights substantial contribution of foliar uptake of atmospheric deposition to Cd levels in soybean and controlling foliar uptake as a potential strategy in agroecological systems experiencing high atmospheric Cd deposition.

Revisiting cadmium-induced toxicity in the male reproductive system: an update.

Heavy metals like cadmium (Cd) are one of the main environmental pollutants, with no biological role in the human body. Cd has been well-documented to have disastrous effects on both plants and animals. It is known to accumulate in kidneys, lungs, liver, and testes and is thought to affect these organs' function over time, which is linked to a very long biological half-life and a very poor rate of elimination. According to recent researches, the testes are extremely vulnerable to cadmium. The disruption of the blood-testis barrier, seminiferous tubules, Sertoli cells, and Leydig cells caused by cadmium leads to the loss of sperm through various mechanisms, such as oxidative stress, spermatogenic cell death, testicular swelling, dysfunction in androgen-producing cells, interference with gene regulation, disruption of ionic homeostasis, and damage to the vascular endothelium. Additionally, through epigenetic control, cadmium disrupts the function of germ cells and somatic cells, resulting in infertile or subfertile males. A full grasp of the mechanisms underlying testicular toxicity caused by Cd is very important to develop suitable strategies to ameliorate male fertility. Therefore, this review article outlines cadmium's impact on growth and functions of the testicles, reviews therapeutic approaches and protective mechanisms, considers recent research findings, and identifies future research directions.

Health Hazards Associated with Dietary Exposure of Female Rat to Cadmium-Contaminated Cooked Rice: Biochemical, Hormonal, and Histopathological Analysis.

The actual exposure, bioavailability, and body burden of dietary cadmium (Cd) vary with the food matrix. Here, we evaluated the health hazards of 45-day long-term exposure of growing Sprague-Dawley (SD) female rats to a natural and endogenous Cd-contaminated brown and white cooked rice dietary model. Cd was found mainly in the duodenum, kidney, and liver; the cecum and colon also contained substantial amounts of Cd in rats fed Cd-contaminated cooked white rice (cWR-test) but not Cd-contaminated cooked brown rice (cBR-test). Damage due to Cd exposure was reflected in liver dysfunction, altered estradiol levels, and distinctive pathologies in organ systems, although urinary Cd (U-Cd) excretion and blood Cd (B-Cd) were not detectable, suggesting that these are not the most accurate or appropriate biomarkers for evaluating dietary Cd exposure. Brown rice, despite being higher in Cd, can reduce Cd absorption and distribution in organs and increase the volume of Cd-containing feces, even achieving slightly higher excretion and lower apparent absorption rates of Cd than white rice, thereby reducing Cd damage to the body. The beneficial components of brown rice such as more dietary fiber, rice bran oil and polyphenol were speculated therefore to confer a degree of protection or repair. Nevertheless, the high apparent absorption levels observed here (> 5%) and signs of significant physical damage indicate that more stringent Cd intake guidelines and measures are needed to minimize Cd levels in rice.

The cadDX operon contributes to cadmium resistance, oxidative stress resistance, and virulence in zoonotic streptococci.

Mobile genetic elements (MGEs) enable bacteria to acquire novel genes and traits. However, the functions of cargo genes within MGEs remain poorly understood. The cadmium resistance operon cadDX is present in many gram-positive bacteria. Although cadDX has been reported to be involved in metal detoxification, its regulatory mechanisms and functions in bacterial pathogenesis are poorly understood. This study revealed that cadDX contributes to cadmium resistance, oxidative stress resistance, and virulence in Streptococcus suis, an important zoonotic pathogen in pigs and humans. CadX represses cadD expression by binding to the cadDX promoter. Notably, cadX responds to H2O2 stress through an additional promoter within the cadDX operon, mitigating the harmful effect of excessive cadD expression during oxidative stress. cadDX resides within an 11 K integrative and mobilizable element that can autonomously form circular structures. Moreover, cadDX is found in diverse MGEs, accounting for its widespread distribution across various bacteria, especially among pathogenic streptococci. Transferring cadDX into another zoonotic pathogen, Streptococcus agalactiae, results in similar phenotypes, including resistance to cadmium and oxidative stresses and increased virulence of S. agalactiae in mice. The new functions and regulatory mechanisms of cadDX shed light on the importance of the cadDX system in driving evolutionary adaptations and survival strategies across diverse gram-positive bacteria.

Overexpression of PsMYB62 from Potentilla sericea confers cadmium tolerance in tobacco.

Excessive cadmium (Cd) content in soil poses serious hazard to the survival and development of various organisms. Potentilla sericea, characterized by strong resistance and high utility value, is an excellent choice for urban ecological greening. Plant MYB transcription factors can participate in respondind to a variety of abiotic stresses such as heavy metals and salinity. In this study, PsMYB62 was transformed into tobacco by leaf disc infestation to obtain PsMYB62 overexpressing tobacco lines, and its mechanism in response to Cd stress was further investigated. The results showed that with Cd treatment, PsMYB62 overexpressing tobacco exhibited significantly higher net photosynthetic rate, stomatal conductance, transpiration rate, intercellular CO2 concentration, chlorophyll content, as well as enhanced activities of superoxide dismutase, peroxidase, catalase, and glutathione reductase enzymes, along with increased levels of reduced glutathione, proline, and soluble protein compared to the control. Conversely, levels of O2- and H2O2, and malondialdehyde were markedly lower than those in the control(P<0.05). Moreover, the aboveground Cd content was notably higher in the control than in the transgenic lines, whereas the control was much lower than the transgenic lines in the belowground fraction, with Cd subcellular distribution ratios ranking as follows: cell wall fraction > soluble fraction > organelle fraction (P<0.05). The expression of NtHMA3, NtYSL, NtPDR4 and NtPDR5B were much lower in transgenic lines compared to the control, while NtNAS3, NtSOD, and NtGSH2 exhibited significantly higher expression. Consequently, this study provides genetic resources for molecular breeding of Cd-tolerant plants through genetic engineering and lays a theoretical foundation for the remediation of heavy metal-contaminated soil.

Associations between metal/metalloid exposure during pregnancy and placental growth characteristics: Findings from the Hangzhou birth cohort study II.

Previous studies have suggested that metal/metalloid (hereafter referred to as metal) exposure may influence placental growth by affecting gene expression in the placenta. However, no epidemiological studies have been conducted to validate the relationships between metals exposure, placental gene expression, and placental growth at the population level. This study aims to investigate these relationships based on Hangzhou birth cohort study II (HBCS-II). Totally, 1025 participants were derived from HBCS-II. Thirteen metals levels in the placenta were measured using inductively coupled plasma mass spectrometry. Placental growth characteristics were assessed, including placental weight, chorionic disc area, placental eccentricity, and distance from cord insertion site to the nearest edge of placenta (DCIEP). The relationships between metals exposure and placental growth characteristics were examined using the elastic net model combined unpenalized linear regression model. Placental gene expression levels were analyzed through RNA sequencing and real-time polymerase chain reaction (RT-qPCR), and mediation analysis was conducted to investigate whether placental gene expression could mediate the relationship between metal exposure and placental growth. Notably, the results showed that a unite increase in Ln-transformed cadmium (Cd) levels was associated with a reduction of 16.4 g [95% confidence interval (CI): 31.2, -1.5] in placental weight, 13.9 cm2 (95%CI: 20.0, -7.8) in chorionic disc area, and 0.3 cm (95%CI: 0.55, -0.06) in DCIEP. Through RNA sequencing followed by validation, significant associations were observed between placental Cd level and increased expression of placental genes, including TNFAIP2, OLAH, FLT4, SH3PXD2A, LIMCH1, BCL6, SLCO2A1, and CPSF1. Additionally, increased placental TNFAIP2, OLAH, FLT4, SH3PXD2A and LIMCH1 expression was linked to reduced placental weight. Moreover, SH3PXD2A was associated with decreased chorionic disc area. Mediation analysis showed that placental Cd level was associated with a 12.0 g (95%CI: 23.8, -2.7) decrease in placental weight mediated through the upregulation of FTL4 gene expression. The study provides evidence of the association between placental Cd exposure and decreased placental weight, and the FLT4 gene may play a mediating role in this relationship. Future experiment studies should be performed to validate the results.

Cadmium-induced fetal erythropoiesis disturbances in mice.

Maternal anemia has been identified as a contributing factor to adverse reproductive outcomes associated with cadmium (Cd) exposure, a common heavy metal. Our recent findings suggest that inhibited erythroid differentiation and enucleation also play significant roles in the direct embryonic toxicity resulting from maternal Cd exposure. However, the effects of Cd exposure on lipid metabolism remodeling, which is essential for physiological erythropoiesis, remain poorly understood. In the present study, pregnant mice were administered low doses of CdCl2 via oral exposure from early to late gestation to mitigate Cd-induced maternal anemia. Compared to vehicle-treated controls, embryos from Cd-treated mice exhibited a slight decrease in weight, though without signs of atrophy. Consistent with our previous observations, fetal livers from Cd-exposed embryos demonstrated a dose-dependent inhibition of erythroid differentiation, as confirmed by ex vivo analysis. Notably, an intrinsic decrease in lipid peroxidation during erythroid differentiation was observed in the bone marrow and fetal livers of vehicle-treated mice, attributed to diminished lipid content. In contrast, this decrease in lipid peroxidation was absent in fetal liver erythroblasts from Cd-treated mice, where an increase in lipid peroxidation was instead noted. These findings elucidate a potential mechanism, lipid peroxidation, underlying Cd-induced embryonic toxicity.

ABA-regulated MAPK signaling pathway promotes hormesis in sugar beet under cadmium exposure.

Sugar beet (Beta vulgaris L.) shows potential as an energy crop for cadmium (Cd) phytoremediation. To elucidate its in vivo response strategy to Cd exposure, seedlings were treated with 1, 3, and 5 mmol/L CdCl2 (Cd-1, Cd-3, and Cd-5) for 6 h, using 0 mmol/L CdCl2 (Cd-0) as the control. The results showed that Cd-3 promoted a unique "hormesis" effect, leading to superior growth performance, increased levels of chlorophyll, soluble protein, and SOD activity, and reduced MDA content in sugar beet, compared to Cd-1, Cd-5, and even Cd-0. GO and KEGG enrichments and PPI networks of transcriptomic analysis revealed that the differentially expressed genes (DEGs) were primarily involved in lipid metabolism, cellular protein catabolism, and photosynthesis. Notably, the MAPK signaling pathway was significantly enriched only under Cd-3, with the up-regulation of ABA-related core gene BvPYL9 and an increase in ABA content after 6 h of Cd exposure. Furthermore, overexpression of BvPYL9 in Arabidopsis thaliana (OE-1 and OE-2) resulted in enhanced growth (fresh weight, dry weight, and root length), as well as higher ABA and soluble protein contents under different Cd treatments. Cd-induced transcriptional responses of BvPYL9 were also evident in OE-1 and OE-2, especially at 10 µmol/L, indicated by qRT-PCR. These findings suggest that ABA-mediated MAPK signaling pathway is activated in response to Cd toxicity, with BvPYL9 being a key factor in the cascade effects for the Cd-induced hormesis in sugar beet.