High Doses Of Cd Research Articles

Exploring the effects of metallic toxicity on the seed germination and initial growth of Lavandula stoechas L. and Myrtus communis L.: Towards promoting the dissemination of aromatic plants in contaminated lands

The high accumulation of heavy metals (HMs) in soils is becoming a major ecological concern worldwide that negatively impacts all living organisms. Therefore, sustainable solutions are urgently needed to withstand these challenging circumstances and to maintain natural ecosystem functionality. Among the relevant solutions is to select well-adapted plant species and embed them in revegetation operations for degraded areas. In this study, the effects of different concentrations (0, 200, 400, and 600 mg L–1) of cadmium (Cd), chromium (Cr), nickel (Ni), and lead (Pd) on the seed germination capacity and initial growth performance of two valuable aromatic plants (Lavandula stoechas L. and Myrtus communis L.) were tested. The germination of seeds was greatest in the control treatment (0 mg L–1), while amplifying HM stress restricted germination. The results obtained showed that seeds of L. stoechas were unable to germinate in the presence of high doses of Cd (400 and 600 mg L–1) and Ni (600 mg mg L–1), and subsequently featuring increasing tolerance thresholds in the following order: Pb > Cr > Ni > Cd. Regardless of the HM used, M. communis seeds germinated at all concentrations, and germination increased in the following pattern of HM resistance: Cd > Ni > Cr > Pb. Seedlings of L. stoechas displayed better resistance to Ni and Pb, while M. communis seedlings were most strongly affected by Ni. Overall, the hypocotyl was typically more susceptible to different metal elements than the radicle. The ability of seeds to effectively emerge in a broad range of HM solutions indicates that both species can further establish and propagate in contaminated soils.

Nanoplastics increase algal absorption and toxicity of Cd through alterations in cell wall structure and composition

Nanoplastics (NPs) may act as carriers of heavy metals and cause complex toxicity to aquatic organisms, while the exact role of NPs in the joint toxicity remains unclear. Here, we investigated the joint toxicity of polystyrene NPs (PS-NPs) and Cd to freshwater algae (Chlorella vulgaris). It was found that PS-NPs (1 mg L−1) could hardly enter algal cells and slightly inhibit algal growth (p < 0.01). The effect of PS-NPs as carriers on the joint toxicity of PS-NPs and heavy metals could be neglected because of the limited adsorption of Cd by PS-NPs, while the PS-NPs altered the cell wall structure and composition, which resulted in the increased algal absorption and toxicity of Cd. Compared to the low dose Cd (0.4 mg L−1) treatment alone, the extracellular and intracellular Cd contents in the cotreatment were significantly increased by 27.3 % and 18.0 %, respectively, due to the increased contents of cell wall polysaccharides (pectin and hemicellulose in particular) by the PS-NPs. Furthermore, after the high dose Cd (2 mg L−1) exposure, the inhibited polysaccharide biosynthesis and the loosen cell wall structure weakened the tolerance of cell wall to abiotic stress, facilitating the entry of PS-NPs into the algal cells and inducing the higher toxicity. These results elucidate the mechanism by which NPs enhance heavy metal toxicity to algae, providing a novel insight into environmental risks of NPs.

The effect of zinc application on growth and alleviating shoot concentration of cadmium in durum wheat plant growth under conditions of salt and cadmium stress

A study was conducted in a greenhouse to investigate the effect of the combination of cadmium (Cd) and salinity (NaCl) stress in zinc (Zn) deficiency on growth, Cd accumulation in durum wheat (Triticum turgidum L. durum, cv. Balcali-2000), and micro (Zn, Fe, Cu, Mn) minerals differing in salt tolerance. The negative effects of Cd and NaCl stress on plant growth and Cd accumulation detected to alleviate Cd uptake on wheat growth increasing zinc application. The results revealed that Cd, NaCl and their combined stresses reduced shoots dry matter and Cd concentration in shoots increased compared to control pots. In increasing Cd and NaCl treatments, increasing Zn application significantly decreased the Cd concentration in shoot. In particularly, the decrease in Cd concentration was more noticeable with the improvement of Zn nutrition of plants at low doses of NaCl and Cd. The effect of increasing zinc treatments on reducing Cd accumulation decreased to slightly at high doses of Cd and NaCl. According to the results it can be suggested that Zn application to soils with low Cd content and medium salinity can be reduce Cd uptake by durum wheat.

The damage caused by Cd toxicity to photosynthesis, cellular ultrastructure, antioxidant metabolism, and gene expression in young cacao plants are mitigated by high Mn doses in soil.

Manganese (Mn) is one of the essential mineral micronutrients most demanded by cacao. Cadmium (Cd) is highly toxic to plants and other living beings. There are indications that Mn can interact with Cd and mitigate its toxicity. The objective of this study was to evaluate the action of Mn on the toxic effect of Cd in young plants of the CCN 51 cacao genotype, subjected to different doses of Mn, Cd, and Mn+Cd in soil, through physiological, biochemical, molecular, and micromorphological and ultrastructural changes. High soil Mn doses favored the maintenance and performance of adequate photosynthetic processes in cacao. However, high doses of Cd and Mn+Cd in soil promoted damage to photosynthesis, alterations in oxidative metabolism, and the uptake, transport, and accumulation of Cd in roots and leaves. In addition, high Cd concentrations in roots and leaf tissues caused irreversible damage to the cell ultrastructure, compromising cell function and leading to programmed cell death. However, there was a mitigation of Cd toxicity when cacao was grown in soils with low Cd doses and in the presence of Mn. Thus, damage to the root and leaf tissues of cacao caused by Cd uptake from contaminated soils can be attenuated or mitigated by the presence of high Mn doses in soil.

Effects of Cadmium Toxicity on Chemical Contents and Leaf Yield of Three Sun-Cured Tobacco Varieties

ABSTRACT Tobacco plants grown in cadmium (Cd)-contaminated soils accumulate high concentration of Cd in leaves and the Cd in leaves can readily be transferred to the human body through smoking of cigarettes. This study was conducted to investigate the effects of four soil Cd concentrations (0, 5, 10, and 20 mg kg−1) on leaf Cd, zinc (Zn), and nitrogen (N) concentrations and nicotine, reducing sugar and phenolic compounds of sun-cured Canik 190/5, Xanthi 81, and Birlik 124 varieties grown in a semi-arid condition of Turkey. Increasing doses of Cd did not significantly decrease leaf yield of tobacco cultivars, while significant (p < .05) increase and decrease were recorded in leaf Cd and Zn concentrations, respectively. The highest leaf Cd concentration was accumulated in Birlik 124 (60.5 mg kg−1), and the lowest in Canik 190/5 (55.35 mg kg−1) variety. Nicotine concentration of Xanthi 81 and Birlik 124 cultivars in the highest Cd dose (Cd20) increased compared to the nicotine in control application, while nicotine concentration of Canik 190/5 cultivars decreased in Cd20 dose. The results revealed that all three tobacco varieties were able to accumulate Cd in their leaves under high soil Cd levels. The effects of Cd on N uptake and nicotine, reducing sugar and phenolic compounds were different among the tobacco varieties. The result may be associated with differences in responses of tobacco cultivars to soil Cd concentration.

Effects of postnatal exposure to cadmium on male sexual incentive motivation and copulatory behavior: Estrogen and androgen receptors expression in adult brain rat

There are numerous evidence showing that cadmium (Cd) is an endocrine disruptor that exerts multiple toxic effects at different reproductive levels, including male sexual behavior (MSB). The effect of early exposure to Cd on sexual incentive motivation (SIM) and MSB in adult stage, and the immunoreactivity of receptors for hormones such as estrogens and androgens in brain regions that are relevant for the SIM and MSB display, have not been studied until now. The present study evaluated the effects of 0.5 and 1 mg/kg CdCl2 from day 1–56 of postnatal life on SIM and MSB in adults rats, as well as serum testosterone concentrations, Cd concentration in blood, testis, and brain areas, and the immunoreactivity in estrogen receptors (ER-α and -β), and androgen receptor (AR) in the olfactory bulbs (OB), medial preoptic area (mPOA), and medial amygdala (MeA). Our results showed that both doses of Cd decreased SIM and MSB, accompanied by low serum concentrations of testosterone. Also, there was a significant reduction in immunoreactivity of ER-α and AR in mPOA, and a significant reduction in AR in MeA on male rats treated with Cd 1 mg/kg. These results show that exposure to high doses of Cd in early postnatal life could alter the correct integration of hormonal signals in the brain areas that regulate and display SIM and MSB in adult male rats.

Enhancing the potential for cadmium phytoremediation by introducing Perilla frutescens genes in tobacco.

To improve the potential of cadmium phytoremediation, distant hybridization between tobacco (Nicotiana tabacum L. var. 78-04), a high-biomass crop, and Perilla frutescens var. frutescens, a wild Cd-hyperaccumulator, was carried out, developing a new variety N. tabacum L. var. ZSY. Seedlings at the six-leaf stage were grown in hydroponics and treated with 0 (control), 10µM, 180µM, and 360µM CdCl2 for 7days; then, the differences in Cd tolerance and accumulation and physiological and metabolic responses were evaluated among "ZSY" and its parents. At high Cd dose, the growth of "ZSY," such as fresh weight, plant height, and root length, was evidently better than "78-04." In contrast to P. frutescens and "78-04," "ZSY" could accumulate more Cd in shoots than roots. Under the same treatment, "ZSY" accumulated greater amounts of Cd in both shoots (195-1523mgkg-1) and roots (140-1281mgkg-1) than "78-04" (shoots: 35-89mgkg-1, roots: 39-252mgkg-1), followed by P. frutescens (shoots: 156-454mgkg-1, roots: 103-761mgkg-1). BCF and TF values of "ZSY" reached 38-195 and 1.2-1.4, which were far higher than those of "78-04" (BCF: 2.2-35.3, TF: 0.35-0.9). Perilla frutescens was found with BCF and TF of 11-156 and 0.5-1.5. Cd stress obviously promoted the production of ROS and MDA in seedlings but reduced chlorophyll contents, especially in "78-04." As a response to Cd stress, "ZSY" had higher SOD and CAT activities when compared to P. frutescens and "78-04," while "78-04" produced more POD and proline than those of P. frutescens and "ZSY." Cd stress could affect the production and accumulation of alkaloids and phenolic compounds in root (endodermis and cortex) and mesophyll. At high Cd doses, P. frutescens and "ZSY" had more alkaloids in tissues than "78-04." Phenolic compounds in "78-04" were more obviously inhibited compared with P. frutescens and "ZSY." These secondary metabolites may play an important role in eliminating oxidative damage and enhancing Cd tolerance and accumulation in "ZSY" and P. frutescens. Results indicated that distant hybridization could be one of effective methods for introducing excellent genes from metal-hyperaccumulators into high biomass species, creating plants with superior phytoremediation potential.

Cadmium exposure induces histological damage and cytotoxicity in the cardiovascular system of mice.

Epidemiological studies have reported an association between chronic cadmium (Cd) exposure and increased cardiovascular risk; however, their causal relationship remains unclear. The aim of this study is to explore the effects of Cd exposure on the cardiac and arterial systems in mice. According to the concentration of cadmium chloride in drinking water, male mice were randomly divided into control and low-dose and high-dose Cd exposure groups. The intervention duration was 12 weeks. In cardiac tissues, Cd exposure led to focal necrosis, myofibril disarray, perivascular and interstitial fibrosis, and disorganized sarcomere structures. Cd also induced the apoptosis of cardiomyocytes and increased the expression levels of matrix metalloproteinase (MMP)-2 and MMP-14 in cardiac tissues. In the arterial tissues, Cd exposure damaged the intimal and medial layers of the aorta. Cd further reduced the viability of aortic smooth muscle cells in vitro. This study provides evidence for the Cd-induced damage of the cardiovascular system, which may contribute to various cardiovascular diseases.

The Changes of Tolerance, Accumulation and Oxidative Stress Response to Cadmium in Tobacco Caused by Introducing Datura stramonium L. Genes

Whether it is possible to create suitable plants for cadmium phytoremediation by introducing Datura stramonium L. genes into tobacco (Nicotiana tabacum L.) remains unclear. Hydroponic experiments were performed on N. tabacum L. var. MTLY, a newly developed hybrid variety, and the parents. Seedlings at the six-leaf stage were treated with 0 (control), 10 µM, 180 µM and 360 µM CdCl2 for 7 days, and their differences in Cd tolerance and accumulation and physiological and metabolic responses were evaluated. When subjected to 360 µM Cd, the growth of “MTLY”, in terms of the dry weight, plant height and root length, was obviously better than N. tabacum L. var. LY2 (female parent). In contrast to D. stramonium (male parent) and “LY2”, “MTLY” accumulated more Cd in shoots (127.6–3837.1 mg kg−1) and roots (121.6–1167.7 mg kg−1). Moreover, unlike “LY2”, “MTLY” could accumulate more Cd in its shoots than roots. Its bioconcentration factor (BCF) and translocation factor (TF) values reached 95.9–149.7 and 1.0–3.5, respectively, which were far greater than those of “LY2”. High-dose Cd stress significantly increased reactive oxygen species (ROS) and malondialdehyde (MDA) levels and decreased chlorophyll contents in tobacco seedlings, especially in “LY2”. Various enzymatic and non-enzymatic antioxidants in the three materials showed different responses to Cd stress. The change of the phenolic compounds and alkaloids in “MTLY” was basically similar to that in D. stramonium, but their levels were apparently higher than those in “LY2”. Results indicated that distant hybridization could be one of the effective methods for introducing metal-hyperaccumulator genes into a high biomass species, which contributed to enhancing the Cd tolerance, accumulation and detoxification in tobacco. This study has great significance in obtaining elite germplasm for phytoremediation. The exact mechanisms in molecules and genetics and the practical effectiveness in cadmium-contaminated soil remain to be further elucidated.

Proteomic analysis reveals differential responsive mechanisms in Solanum nigrum exposed to low and high dose of cadmium

Cadmium (Cd) contamination is becoming a widespread environmental problem. However, the differential responsive mechanisms of Cd hyperaccumulator Solanum nigrum to low or high dose of Cd are not well documented. In this study, phenotypic and physiological analysis firstly suggested that the seedlings of S. nigrum showed slight leaf chlorosis symptoms under 25 μM Cd and severe inhibition on growth and photosynthesis under 100 μM Cd. Further proteomic analysis identified 105 differentially expressed proteins (DEPs) in the Cd-treated leaves. Under low dose of Cd stress, 47 DEPs are mainly involved in primary metabolic processes, while under high dose of Cd stress, 92 DEPs are mainly involved in photosynthesis, energy metabolism, production of phytochelatin and reactive oxygen species (ROS). Protein-protein interaction (PPI) network analysis of DEPs support above differential responses in the leaves of S. nigrum to low and high dose of Cd treatments. This work provides the differential responsive mechanisms in S. nigrum to low and high dose of Cd, and the theoretical foundation for the application of hyperaccumulating plants in the phytoremediation of Cd-contaminated soils.

Combined toxicity of acetamiprid and cadmium to larval zebrafish (Danio rerio) based on metabolomic analysis

Emerging contaminants, such as neonicotinoid pesticide acetamiprid (Ace), are frequently detected in the water environment, which can interact with existing heavy metal cadmium (Cd) to produce unpredicted influence. Limited studies have evaluated the effects of multiple pollutant exposures on aquatic animals. Here, we characterized the joint toxicity of Ace and Cd exposure to zebrafish (Danio rerio). The results revealed that Cd and its combined exposure with Ace had an inhibitory effect on the growth of larval zebrafish and induced morphological defects. Combined exposure to high doses of Ace and Cd could significantly reduce the levels of TG, glucose, and pyruvate in larval zebrafish. Untargeted metabolomics revealed that Cd treatment (285) produced more differentially expressed metabolites (DEMs) than Ace treatment (115), and combined treatment produced the most DEMs (294). The KEGG pathway enrichment analysis showed that they could disrupt riboflavin metabolism, amino acid metabolism, and glycolipid metabolism in the larvae of D. rerio. ELISA showed that VB2, FMN, and FAD levels were significantly increased. In addition, gene expression analysis exhibited that the mRNA levels of essential genes related to glycolipid metabolism were substantially affected, such as PK, PEPckc, PPAR-α, and FABP6. Furthermore, targeted amino acid metabolomics confirmed that both single exposure to Cd and combined exposure to Ace and Cd altered the levels of amino acids in larvae, including ALA, ARG, MET, PRO, TYR, VAL, GLY, ORN, and PHE. Taken together, exposure to Ace and Cd, alone or in combination, exerted harmful effects on the individual development, riboflavin metabolism, glycolipid metabolism, and amino acid metabolism disorder of D. rerio. These findings highlighted that more attention should be paid to the compound toxicity of chemical mixtures to aquatic organisms.

Stabilization Characteristics of Exogenous Cd in Different Types of Soil

To clarify the characteristics of stabilization and availability of exogenous cadmium (Cd) in different types of soils, six main agricultural soils in Sichuan province, including acidic purple soil, neutral purple soil, calcareous purple soil, gray fluvo-aquic soil, typical yellow soil, and rinsed yellow soil, were used in this study. A soil culture experiment was conducted to explore the differences in stabilization time, chemical form, and effective Cd content between the six types of soils. Additionally, the effects of exogenous Cd on the growth and Cd accumulation of cabbage growing in different soils was discussed. The results showed the following: 1 with exogenous Cd treatment, the available Cd content of the six soils decreased sharply within 15 d after Cd addition and then tended to be flat. After 30 d, there was no significant difference. The available Cd contents of rinsed yellow soil and acidic purple soil were significantly higher than that of the other four soils, and the content of calcareous purple soil was significantly lower (1.01 mg·kg-1). 2 After stabilization, exchangeable Cd was the main Cd form in the six soils, up to 42.51%-56.07%. The relative proportions of other Cd forms differed greatly between different soils. The proportion of iron and manganese oxides in the rinsed yellow soil and typical yellow soil was higher, whereas organic complex Cd, residual Cd, and carbonate-bound Cd were higher in the gray fluvo-aquic soil, neutral purple soil, and calcareous purple soil, respectively. 3 The characteristics of availability and bioavailability of Cd among different soils were significantly different with different exogenous Cd doses. With the lowest Cd dose (0.5 mg·kg-1), compared with that in the control, there was no significant decrease in Cd content in the edible parts of the cabbage, but Cd accumulation in the edible parts differed. The Cd contents of edible parts of the cabbage growing in typical yellow soil and rinsed yellow soil were significantly higher than that of the other soils. With the highest Cd dose (2.0 mg·kg-1), the growths of cabbage growing in all six soils were significantly inhibited. The available Cd contents of rinsed yellow soil and acidic purple soil were significantly higher than that of the other four soils, which is consistent with the Cd content in the edible parts of the cabbage. The available Cd contents and the Cd content in the edible parts of the cabbage in calcareous purple soil were the lowest, and acidic soils, especially in rinsed yellow soil, had the highest.

Safflower (Carthamus tinctorius L.) Response to Cadmium Stress: Morpho-Physiological Traits and Mineral Concentrations.

Cadmium is a widely distributed heavy metal in agricultural soils that affects plant growth and productivity. In this context, the current study investigated the effects of different cadmium (Cd) doses (0, 25, 50, 75, and 100 mg L-1 of CdSO4) on the growth and physiological attributes of safflower (Carthamus tinctorius L.) including plant height (cm), root length (cm), fresh weight (g) of root, stem, and leaves, leaf number, macro and micro-nutrients, Se, and heavy metal (Cd, Cr, and Pb) content. The experiment was carried out in a completely randomized design (CRD) with four replicates. The results showed that Cd stress significantly negatively affected all growth indices, macro- and micro-nutrients, and heavy metal content. In addition, it increased the MDA and APX activities. The highest amounts of Fe, Mn, Ni, Pb, Zn, K, Na, Cd, Cr, and Cu were determined in plant roots, while the highest values of Ca and Mg were detected in plant stem tissues. High Cd doses decreased the content of Ca, K, Mg, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn in safflower plant tissues by 45.47%, 39.33%, 79.28%, 68.21%, 37.06%, 66.67%, 45.62%, 50.38%, 54.37%, 33.33% and 65.87%, respectively, as compared to the control treatments.

The Effect of Some Heavy Metals on the Growth of Garlic under In Vitro Conditions

Garlic (Allium sativum L.) is an important plant species because of its nutritional and medical value. One of the important advantages of plant tissue culture is in vitro selection. The tolerance of garlic to some heavy metals under in vitro conditions was studied. In vitro experiments were carried out in Murashige and Skoog (MS) nutrient medium supplemented with different doses of cadmium (Cd), cobalt (Co), nickel (Ni), aluminum (Al), copper (Cu), chromium (Cr), and lead (Pb) at 100 µm, 200 µm, 300 µm, 400 µm, and 500 µm. During experiments, plant length, number of leaves, leaf length, root number, and root length parameters were considered. In the findings, there was a decrease in both leaf and root development as doses of heavy metals increased. In addition, it has been found that the decrease in plant development at doses of 400 µm and 500 µm was higher compared with other doses. There was no root formation at high doses of Cd, Co, Ni, and Cu (400 µm and 500 µm). As a recommendation, further research should be conducted under in vivo conditions to evaluate the level of tolerance to heavy metals in garlic.

Responses of Spring Barley to Zn- and Cd-Induced Stress: Morphometric Analysis and Cytotoxicity Assay.

Heavy metals such as cadmium (Cd) and zinc (Zn) could be dangerous and pollute the environment due to their high migration ability, robust bioavailability, and acute toxicity to soil biota and plants. Considering the above characteristics of these elements, the study's aim was to explore the individual and combined impact of Cd and Zn contamination of Haplic Chernozem on growing two-row spring barley (Hordeum vulgare L.). The accumulation and distribution of Cd and Zn in various parts of H. vulgare have also been studied, which showed that Cd accumulation by H. vulgare occurred more intensely than that by Zn up to eight times. Cadmium and Zn suppress plant growth up to two times, more effect was noted by the combined impact of Cd and Zn. The study of plant morphological characteristics revealed that growth suppression and structural changes in the root and leaf tissues increased in proportion to Cd and Zn concentrations. Detailed analysis of the localizations of Zn and Cd in various organelles of H. vulgare cells was performed. Heavy metals change the ultrastructure of prominent energy-producing organelles in leaf cells, especially chloroplasts and mitochondria. Overall, the current findings offer insights into phytotoxicity induced by Cd and Zn individual application as well as in combination with the H. vulgare plant. Zinc showed protective effects against high doses of Cd under the combined application. These antagonistic interactions reduce their accessibility to H. vulgare. The present work can be useful in restricting the entry of these elements into the food chain and preventing creating a threat to human health.

Anchoring of Nanocomposites Based on Novel Metal Nanocomplexes/Nanocarbonaceous Surfaces and Assessing Their In Vivo Anticancer Effects on Ehrlich Ascites Tumor.

Nanotechnology is the study of materials' unique properties at the nanoscale. Nanomedicine is the application of nanotechnology in medicine, which has been utilized to treat some common diseases, such as cancer. The aim of the present work is to synthesize the cadmium (Cd) nanocomplex using paracetamol as a ligand with a molar ratio of 1:2 M/L that was characterized by different physicochemical methods and to explore the effect of the synthesized Cd nanocomplex on the immune system and the redox status of the body and their anticancer effects on Ehrlich ascites carcinoma (EAC) induced in mice. Eighty female albino mice were separated into Group I: control; Group II: EAC; Group III: EAC treated with a low-dose Cd nanocomplex; and Group IV: EAC treated with a high-dose Cd nanocomplex. Interleukin-6 (IL-6), NLR family pyrin domain containing 3 (NLRP3), and 8-hydroxy 2-deoxyguanosine (8-OHdG) levels were assessed by enzyme-linked immunosorbent assay (ELISA). Peroxynitrite level and glutathione peroxidase activity were assessed by spectrophotometry. NRF2 mRNA expression, cadmium content, and liver and renal toxicity were estimated. Results: There was a significant increase in IL-6, NLRP3, 8-OHdG, peroxynitrite, and NRF2 mRNA expressions and in the glutathione peroxidase activity in EAC treated with low- and high-dose Cd nanocomplexes. However, the EAC treated with high-dose Cd nanocomplex group showed significant liver and renal toxicity. Conclusion: Cadmium nanocomplex has anticancer effects on EAC induced in mice via its effects on the immune system and redox status as well as pyroptosis and epigenetic instability of the body, while high doses of Cd nanocomplex can cause liver and renal toxicity.

Cerebellar injury induced by cadmium via disrupting the heat-shock response.

Cadmium (Cd) is a food contaminant that poses serious threats to animal health, including birds. It is also an air pollutant with well-known neurotoxic effects on humans. However, knowledge on the neurotoxic effects of chronic Cd exposure on chicken is limited. Thus, this study assessed the neurotoxic effects of chronic Cd on chicken cerebellum. Chicks were exposed to 0 (control), 35 (low), and 70 (high) mg/kg of Cd for 90days, and the expression of genes related to the heat-shock response was investigated. The chickens showed clinical symptoms of ataxia, and histopathology revealed that Cd exposure decreased the number of Purkinje cells and induced degeneration of Purkinje cells with pyknosis, and some dendrites were missing. Moreover, Cd exposure increased the expression of heat-shock factors, HSF1, HSF2, and HSF3, and heat-shock proteins, HSP60, HSP70, HSP90, and HSP110. These changes indicate that HSPs improve the tolerance of the cerebellum to Cd. Conversely, the expressions of HSP10, HSP25, and HSP40 were decreased significantly, which indicated that Cd inhibits the expression of small heat-shock proteins. However, HSP27 and HSP47 were upregulated following low-dose Cd exposure, but downregulated under high-dose Cd exposure. This work sheds light on the toxic effects of Cd on the cerebellum, and it may provide evidence for health risks posed by Cd. Additionally, this work also identified a novel target of Cd exposure in that Cd induces cerebellar injury by disrupting the heat-shock response. Cd can be absorbed into chicken's cerebellum through the food chain, which eventually caused cerebellar injury. This study provided a new insight that chronic Cd-induced neurotoxicity in the cerebellum is associated with alterations in heat-shock response-related genes, which indicated that Cd through disturbing heat-shock response induced cerebellar injury.

White adipose tissue as a target for cadmium toxicity.

Cadmium (Cd) is a widespread heavy metal known as a toxic environmental pollutant. Cd exposure is threatening due to its bioaccumulation trait in living systems that exceeds 35 years without a beneficial biological role. Acute exposure to high Cd doses was reported to impact adipose tissue (AT) function adversely. The main aim of this study is to investigate the effect of low-dose chronic Cd exposure on the genes involved in adipose tissue (AT) functions. Adult male Sprague-Dawley rats were exposed to a low Cd dose (15 mg/kg B.W./day) for 10 weeks. Then, three AT depots-subcutaneous AT (SUB-AT), abdominal AT (AB-AT), and retroperitoneal AT (REtrop-AT) were excised for Cd accumulation measures and gene expression analysis. Adiponectin and leptin gene expression levels were investigated as markers for adipocytes function and homeostasis. Our results showed that Cd accumulated in all the tested adipose depots, but SUB-AT was found to be the depot to most accumulate Cd. Also, it was exhibited that chronic exposure to low Cd doses altered the gene expression of adipocytokines. The levels of adiponectin and leptin mRNA expression were downregulated in all tested AT-depots after Cd exposure. The significant adverse effect on SUB-AT compared to other depots indicates different responses based on AT depots location toward Cd exposure. Collectively, these results suggest a toxic effect of Cd that influenced adipocyte function.

JAK2/STAT3 Signaling Pathway and Klotho Gene in Cadmium-induced Neurotoxicity In Vitro and In Vivo.

Cadmium (Cd), a common heavy metal in the environment, is associated with cognitive impairment. In the present study, we carried out a preliminary inquiry to explore whether Cd causes neurotoxicity by regulating the JAK2/STAT3 signaling pathway and affecting the expression of klotho genes in vivo and in vitro, providing clues for the mechanism of Cd-induced cognitive dysfunction. The rat samples were injected with Cd chloride solution for 14weeks, and the memory function of the rats was detected. Different concentrations of Cd and JAK2/STAT3 signaling pathway inhibitors were used to treat PC12 cells and thus detect the apoptosis rate. The protein expression levels of JAK2, p-JAK2, STAT3, p-STAT3, and klotho in rat and PC12 cell were detected by ELISA and Western blot, respectively. With the increase in exposure dose, the memory function of rats was severely impaired. The expression of p-JAK2 and p-STAT3 proteins was significantly up-regulated, whereas that of klotho was significantly down-regulated both in vivo and in vitro (p < 0.05). In comparison with the high-dose Cd exposure group, after adding tyrphostin AG490 (AG490), the apoptosis rate of PC12 cells increased, whereas the phosphorylation levels of JAK2 and STAT3 in the cells decreased significantly (p < 0.05). Cd exposure may cause neurotoxicity by regulating the JAK2/STAT3 signaling pathway and down-regulating klotho protein expression, leading to cognitive dysfunction.

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.