Assessment of sulforaphane-induced protective mechanisms against cadmium toxicity in human mesenchymal stem cells

Associations of Blood Cadmium Levels With Osteoarthritis Among US Adults in NHANES 2013-2018

BACKGROUND

Osteoarthritis (OA) is a global public health problem, and limited information is available on the effects of Cd on OA. The purpose of this study is to explore the relationship between Cd and OA.

METHOD

Weighted multivariable logistic regression model, trend test, restricted cubic spline, and stratified analysis were used to study the association between BCd and OA.

RESULTS

In the two regression models of weighted multivariable logistic regression analysis, the correlation between BCd and OA was positive. Compared with the lowest quartile of BCd exposure, the highest quartile had a 2.03-fold (95% confidence interval, 1.67 to 2.47), displaying a dose-response relationship (P for trend <0.00001). The restrictive cubic spline shows a positive linear relationship between BCd and OA.

CONCLUSION

There was a positive linear relationship between BCd and OA and a dose-response relationship.

Sulforaphane Exposure Prevents Cadmium-Induced Toxicity and Mitochondrial Dysfunction in the Nematode Caenorhabditis elegans by Regulating the Insulin/Insulin-like Growth Factor Signaling (IIS) Pathway

Cadmium (Cd) is a heavy metal that is highly toxic to humans and animals. Its adverse effects have been widely associated with mitochondrial alterations. However, there are not many treatments that target mitochondria. This study aimed to evaluate the impact of sulforaphane (SFN) pre-exposure against cadmium chloride (CdCl2)-induced toxicity and mitochondrial alterations in the nematode Caenorhabditis elegans (C. elegans), by exploring the role of the insulin/insulin-like growth factor signaling pathway (IIS). The results revealed that prior exposure to SFN protected against CdCl2-induced mortality and increased lifespan, body length, and mobility while reducing lipofuscin levels. Furthermore, SFN prevented mitochondrial alterations by increasing mitochondrial membrane potential (Δψm) and restoring mitochondrial oxygen consumption rate, thereby decreasing mitochondrial reactive oxygen species (ROS) production. The improvement in mitochondrial function was associated with increased mitochondrial mass and the involvement of the daf-16 and skn-1c genes of the IIS signaling pathway. In conclusion, exposure to SFN before exposure to CdCl2 mitigates toxic effects and mitochondrial alterations, possibly by increasing mitochondrial mass, which may be related to the regulation of the IIS pathway. These discoveries open new possibilities for developing therapies to reduce the damage caused by Cd toxicity and oxidative stress in biological systems, highlighting antioxidants with mitochondrial action as promising tools.

Fabrication of myristic acid-potato starch complex nanostructures and assessment of their cytotoxic behavior

BACKGROUND

Lipids and carbohydrates perform essential functions in foods. In recent decades, food scientists have studied the effects of carbohydrate-lipid interactions on the functional properties of food. However, the ways in which carbohydrate-lipid complex-derived materials affect the biological system are unknown. In this study, a myristic acid-potato starch complex was created using a simple cooking approach. The complex was employed as a precursor for the fabrication of myristic acid-potato starch complex-based nanostructured materials (MPS-NMs) through a liquid-liquid extraction approach. A study was conducted on the structural and cytotoxic features of the fabricated MPS-NMs.

RESULTS

Transmission electron microscopy images confirmed the formation of spherical nanostructures, 3-60 nm in size. After 24 h exposure, the chloroform fraction-based and n-hexane fraction-based MPS-NMs increased cell death by ~90% and ~ 82%, respectively. Chloroform fraction-based MPS-NMs (CMPS-NMs) triggers apoptotic cell death in human mesenchymal stem cells (hMSCs). n-Hexane fraction-based MPS-NMs (HMPS-NMs) treated cells have red color-intact nuclei, attributed to necrotic cell death. The CMPS-NMs and HMPS-NMs significantly decreased the mitochondria membrane potential and increased the intracellular reactive oxygen species (ROS) levels. We observed significant downregulation in flavin-containing monooxygenase (FMO), Ataxia Telangiectasia Mutated (ATM), and uridine diphosphate glucuronosyltransferases (UGT) gene expression levels in the exposed cells of CMPS-NMs and HMPS- NMs. In addition, we found upregulation of glutathione-disulfide reductase (GSR) and glutathione S-transferase A4 (GSTA4) genes in CMPS-NMs, and HMPS-NMs exposure.

CONCLUSION

The cooking process may lead to the formation of nanostructured material in food systems. Chloroform fraction-based MPS-NMs and HMPS-NMs may contribute to cell metabolic disorders. © 2023 Society of Chemical Industry.

Sources, transfers and the fate of heavy metals in soil-wheat systems: The case of lead (Pb)/zinc (Zn) smelting region

Heavy metals (HMs) from smelters pose severe challenges to the environmental soil quality of surrounding farmlands, and threaten human health through the food chain. This study explored the environmental effects of smelting activities on farmland soil, and additionally assessed the enrichment, transfer and health risk of HMs in soil-wheat systems. Multiple characterization results were combined to demonstrate that HMs from smelter waste were transferred to the surrounding soil. It was determined that the enrichment of HMs in soil-wheat systems is mainly controlled by the total HM concentration and pH in soil. Furthermore, the priority pollutant in soil-wheat systems was found to be Cd, and Cd affected the transfer of Cu, Mn and Pb from soil to wheat roots. Interestingly, the -OH stretching, C-H stretching, N-H amide and C-O bending were involved in detoxifying HMs in wheat. The mean values of non-carcinogenic and carcinogenic risks by consuming wheat grain were 9.1, 1.4E-02 (adults) and 11.3, 3.3E-03 (children), respectively, indicating a noteworthy health risk. This study highlighted the critical issues arising from Pb/Zn smelting activities on agricultural soils. Notwithstanding, to ensure food security, the affected regions could opt to follow up on the type of crops grown.

Exploring the Potential Enhancing Effects of Trans-Zeatin and Silymarin on the Productivity and Antioxidant Defense Capacity of Cadmium-Stressed Wheat

Simple Summary

Wheat experiments have provided insight into tolerance to cadmium (Cd) stress, the way in which wheat alters its morpho-physio-biochemical and antioxidant system responses when trans-Zeatin + silymarin (applied as seed priming + leaf spray) treatment is offered against Cd stress. This integrative treatment effectively enhanced growth, productivity, photosynthetic efficiency, leaf integrity, and antioxidant systems in the Cd-stressed wheat plants. This treatment reduced the Cd contamination (healthy grains) and increased growth and productivity by increasing osmo-regulatory compounds along with different antioxidant activities, which serve as potent defenses to protect plants from Cd stress by increasing tolerance to Cd stress in wheat.

Abstract

Pot trials were performed to explore the impacts of seed priming (SPr) plus leaf treatment (LTr) with trans-zeatin-type cytokinin (tZck; 0.05 mM) and silymarin (Sim; 0.5 mM) on growth, yield, physio-biochemical responses, and antioxidant defense systems in Cd-stressed wheat. tZck + Sim applied as SPr + LTr was more effective than individual treatments, and the impacts were more pronounced under stress conditions. Cd stress (0.6 mM) severely declined growth and yield traits, and photosynthesis efficiency (pigment contents, instantaneous carboxylation efficiency, and photochemical activity) compared to the control. These negative impacts coincided with increased levels of Cd²⁺, O₂^•− (superoxide), H₂O₂ (hydrogen peroxide), MDA (malondialdehyde), and EL (electrolyte leakage). Non-enzymatic and enzymatic antioxidant activities, and tZck and Sim contents were also increased. However, tZck + Sim increased photosynthesis efficiency, and further boosted antioxidant activities, and contents of tZck and Sim, while minimizing Cd²⁺ levels in roots, leaves, and grains. The levels of O₂^•−, H₂O₂, MDA, and EL were also minimized, reflecting positively on growth and productivity. tZck + Sim applied as SPr + LTr was highly effective in promoting antioxidants and photosynthesis machineries, minimizing oxidative stress biomarkers and Cd²⁺ levels, boosting tolerance to Cd stress, and improving wheat productivity under Cd stress.

Cadmium acute exposure induces metabolic and transcriptomic perturbations in human mature adipocytes

Obesity is considered as a major public health concern with strong economic and social burdens. Exposure to pollutants such as heavy metals can contribute to the development of obesity and its associated metabolic disorders, including type 2 diabetes and cardiovascular diseases. Adipose tissue is an endocrine and paracrine organ that plays a key role in the development of these diseases and is one of the main target of heavy metal accumulation. In this study, we determined by inductively coupled plasma mass spectrometry cadmium concentrations in human subcutaneous and visceral adipose tissues, ranging between 2.5nM and 2.5µM. We found a positive correlation between cadmium levels and age, sex and smoking status and a negative correlation between Cd and body mass index. Based on cadmium adipose tissue concentrations found in humans, we investigated the effects of cadmium exposure, at concentrations between 1nM and 10µM, on adipose-derived human mesenchymal stem cells differentiated into mature adipocytes in vitro. Transcriptomic analysis highlighted that such exposure altered the expression of genes involved in trace element homeostasis and heavy metal detoxification, such as Solute Carrier Family transporters and metallothioneins. This effect correlated with zinc level alteration in cells and cellular media. Interestingly, dysregulation of zinc homeostasis and transporters has been particularly associated with the development of obesity and type 2 diabetes. Moreover, we found that cadmium exposure induces the pro-inflammatory state of the adipocytes by enhancing the expression of genes such as IL-6, IL-1B and CCL2, cytokines also induced in obesity. Finally, cadmium modulates various adipocyte functions such as the insulin response signaling pathway and lipid homeostasis. Collectively, our data identified some of the cellular mechanisms by which cadmium alters adipocyte functions, thus highlighting new facets of its potential contribution to the progression of metabolic disorders.

Up-regulation of Arl4a gene expression by broccoli aqueous extract is associated with improved spermatogenesis in mouse testes

INTRODUCTION

Broccoli (Brassica oleracea) is well known for its properties as an anticancer, antioxidant, and scavenger of free radicals. However, its benefits in enhancing spermatogenesis have not been well established.

OBJECTIVE

To study broccoli aqueous extract effects on sperm factors and the expression of genes Catsper1, Catsper2, Arl4a, Sox5, and Sox9 in sperm factors in mice.

MATERIAL AND METHODS

Male mice were divided randomly into six groups: (1) Control; (2) cadmium (3 mg/kg of mouse body weight); (3) orally treated with 200 μl broccoli aqueous extract (1 g ml-1); (4) orally treated with 400 μl of broccoli aqueous extract; (5) orally treated with 200 broccoli aqueous extract plus cadmium, and (6) orally treated with 400 μl of broccoli aqueous extract plus cadmium. We analyzed the sperms factors and Catsper1, Catsper2, Arl4a, Sox5, and Sox9 gene expression.

RESULTS

An obvious improvement in sperm count and a slight enhancement in sperm motility were observed in mice treated with broccoli extract alone or with cadmium. Sperm viability was reduced by broccoli extract except for the 200 μl dose with cadmium, which significantly increased it. Interestingly, Arl4a gene expression increased in the 400 μl broccoli-treated group. Likewise, the Arl4a mRNA level in mice treated with cadmium and 200 μl of broccoli extract was higher than in the cadmium-treated mice. Furthermore, broccoli extract enhanced the mRNA level of Catsper2 and Sox5 genes in mice treated with 200 μl and 400 μl broccoli extract plus cadmium compared with the group treated solely with cadmium.

CONCLUSION

The higher sperm count in broccoli-treated mice opens the way for the development of pharmaceutical products for infertile men.

Cadmium toxicity: A role in bone cell function and teeth development

Cadmium (Cd) is a widespread environmental contaminant that causes severe bone metabolism disease, such as osteoporosis, osteoarthritis, and osteomalacia. The present review aimed to explore the molecular mechanisms of Cd-induced bone injury starting from bone cell function and teeth development. Cd inhibits the differentiation of bone marrow mesenchymal stem cells (BMSCs) into osteoblasts, and directly causes BMSC apoptosis. In the case of osteoporosis, Cd mainly affects the activation of osteoclasts and promotes bone resorption. Cd-induces osteoblast injury and oxidative stress, which causes DNA damage, mitochondrial dysfunction, and endoplasmic reticulum stress, resulting in apoptosis. In addition, the development of osteoarthritis (OA) might be related to Cd-induced chondrocyte damage. The high expression of metallothionein (MT) might reduce Cd toxicity toward osteocytes. The toxicity of Cd toward teeth mainly focuses on enamel development and dental caries. Understanding the effect of Cd on bone cell function and teeth development could contribute to revealing the mechanisms of Cd-induced bone damage. This review explores Cd-induced bone disease from cellular and molecular levels, and provides new directions for removing this heavy metal from the environment.

Broccoli extract increases drug-mediated cytotoxicity towards cancer stem cells of head and neck squamous cell carcinoma

Background

Head and neck squamous cell carcinomas (HNSCC) are malignant neoplasms with poor prognosis. Treatment-resistant cancer stem cell (CSC) is one reason for treatment failure. Considerable attention has been focused on sulforaphane (SF), a phytochemical from broccoli possessing anticancer properties. We investigated whether SF could enhance the chemotherapeutic effects of cisplatin (CIS) and 5-fluorouracil (5-FU) against HNSCC–CSCs, and its mechanisms of action.

Methods

CD44⁺/CD271⁺ FACS-isolated CSCs from SCC12 and SCC38 human cell lines were treated with SF alone or combined with CIS or 5-FU. Cell viability, colony- and sphere-forming ability, apoptosis, CSC-related gene and protein expression and in vivo tumour growth were assessed. Safety of SF was tested on non-cancerous stem cells and in vivo.

Results

SF reduced HNSCC–CSC viability in a time- and dose-dependent manner. Combining SF increased the cytotoxicity of CIS twofold and 5-FU tenfold, with no effects on non-cancerous stem cell viability and functions. SF-combined treatments inhibited CSC colony and sphere formation, and tumour progression in vivo. Potential mechanisms of action included the stimulation of caspase-dependent apoptotic pathway, inhibition of SHH pathway and decreased expression of SOX2 and OCT4.

Conclusions

Combining SF allowed lower doses of CIS or 5-FU while enhancing these drug cytotoxicities against HNSCC–CSCs, with minimal effects on healthy cells.

N-acetylcysteine dual and antagonistic effect on cadmium cytotoxicity in human leukemia cells

Although cadmium (Cd²⁺) is unable to form reactive oxygen species (ROS) directly, many of its adverse effects are connected to increased ROS generation resulting in cell death. In support of this supposition, a large number of studies have shown protective effects of antioxidants such as N-acetylcysteine (NAC) against cadmium induced cytotoxicity. Here, we describe the cytotoxic effects of Cd²⁺ on human leukemia U937 and K562 cells that were not mediated by oxidative stress. Surprisingly, we observed that addition of low concentrations of NAC can drastically potentiate cadmium cytotoxicity solely via ROS production. However, all adverse effects of the metal were prevented by NAC at high concentrations. Detailed analysis indicated that the protective effect of NAC was mediated by its ability to form stable complex with cadmium [Cd(NAC)₂]. In conclusion, NAC exhibits dual and antagonistic effects on Cd²⁺ cytotoxicity in human leukemia cells.

Silicon nanoparticles enhanced the growth and reduced the cadmium accumulation in grains of wheat (Triticum aestivum L.)

The application of silicon (Si) under heavy metal stress is well known, but the use of Si nanoparticles (NPs) under metal stress in not well documented. Thus, the experiments were performed to investigate the impacts of soil and foliar applied Si NPs on wheat (Triticum aestivum L.) growth and cadmium (Cd) accumulation in grains under Cd toxicity. The plants were grown under natural environmental conditions and were harvested after physiological maturity (124 days after sowing). The results demonstrated that Si NPs significantly improved, relative to the control, the dry biomass of shoots, roots, spikes and grains by 24-69%, 14-59%, 34-87%, and 31-96% in foliar spray and by 10-51%, 11-49%, 25-69%, and 27-74% in soil applied Si NPs, respectively. The Si NPs enhanced the leaf gas exchange attributes and chlorophyll a and b concentrations, whereas diminished the oxidative stress in leaves which was indicated by the reduced electrolyte leakage and enhancement in superoxide dismutase and peroxidase activities in leaf under Si NPs treatments over the control. When compared with the control, the foliar spray of Si NPs reduced the Cd contents in shoots, roots, and grains by 16-58%, 19-64%, and 20-82%, respectively, whereas soil applied Si NPs reduced the Cd concentrations in shoots, roots, and grains by 11-53%, 10-59%, and 22-83%, respectively. In comparison with the control, Si concentrations significantly (p ≤ 0.05) increased in the shoots and roots in both foliar and soil supplementation of Si NPs. Our results suggested that Si NPs could improve the yield of wheat and more importantly, reduce the Cd concentrations in the grains. Thus, the use of Si NPs might be a feasible approach in controlling Cd entry into the human body via crops.

Sulforaphane Protect Against Cadmium-Induced Oxidative Damage in mouse Leydigs Cells by Activating Nrf2/ARE Signaling Pathway

Cadmium (Cd) is harmful for humans and animals, especially for the reproductive system. However, the mechanism of its toxicity has not been elucidated, and how to alleviate its toxicity is very important. This study aimed to explore the role and mechanism of action of sulforaphane (SFN) in protecting mouse Leydigs (TM3) cells from cadmium (Cd)-induced damage. The half-maximal inhibitory concentration (IC₅₀) of Cd and the safe doses of SFN were determined using a methyl thiazolyl tetrazolium (MTT) assay. The testosterone secretion from TM3 cells was measured using the enzyme-linked immunosorbent assay. The intracellular oxidative stress was evaluated using corresponding kits. The cell apoptosis was detected using flow cytometry. The mRNA expression of genes associated with NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling was detected using reverse transcription–polymerase chain reaction, including Nrf2, heme oxygenase I (HO-1), glutathione peroxidase (GSH-Px), NAD(P)H:quinone acceptor oxidoreductase 1 (NQO1), and γ-glutamylcysteine synthetase (γ-GCS). The protein expression of Nrf2, GSH-Px, HO-1, γ-GCS, and NQO1 was detected using Western blot analysis. The results showed that the IC₅₀ of Cd to TM3 cells was 51.4 µmol/L. SFN reduced the release of lactate dehydrogenase from Cd-exposed cells. Cd + SFN 2.5 treatment significantly elevated testosterone concentration compared with the Cd group (p < 0.05). SFN significantly increased total superoxide dismutase (T-SOD) and GSH-Px activity and GSH content in Cd-treated cells (p < 0.05; p < 0.01), inhibited the production of malondialdehyde or reactive oxygen species caused by Cd (p < 0.05; p < 0.01), and reduced the apoptotic rate of Cd-induced TM3 cells (p < 0.01). SFN upregulated the mRNA expression of Nrf2, GSH-Px, HO-1, NQO1, and γ-GCS in Cd-treated cells, indicating the protective effect of SFN against Cd-induced oxidative stress or cell apoptosis by activating the Nrf2/ARE signaling pathway.

Roles of ROS, Nrf2, and autophagy in cadmium-carcinogenesis and its prevention by sulforaphane

Environmental and occupational exposures to cadmium increase the risk of various cancers, including lung cancer. The carcinogenic mechanism of cadmium, including its prevention remains to be investigated. Using fluorescence and electron spin resonance spin trapping, the present study shows that in immortalized lung cells (BEAS-2BR cells), exposure cadmium generated reactive oxygen species (ROS). Through ROS generation, cadmium increased the protein level of TNF-α, which activated NF-κB and its target protein COX-2, creating an inflammatory microenvironment. As measured by anchorage-independent colony formation assay, cadmium induced malignant cell transformation. Inhibition of ROS by antioxidants inhibited transformation, showing that ROS were important in the mechanism of this process. The inflammatory microenvironment created by cadmium may also contribute to the mechanism of the transformation. Using tandem fluorescence protein mCherry-GFP-LC3 construct, the present study shows that cadmium-transformed cells had a property of autophagy deficiency, resulting in accumulation of autophagosomes and increased p62. This protein upregulated Nrf2, which also upregulated p62 through positive feed-back mechanism. Constitutive Nrf2 activation increased its downstream anti-apoptotic proteins, Bcl-2 and Bcl-xl, resulting in apoptosis resistance. In untransformed BEAS-2BR cells, sulforaphane, a natural compound, increased autophagy, activated Nrf2, and decreased ROS. In cadmium-transformed BEAS-2BR cells, sulforaphane restored autophagy, decreased Nrf2, and decreased apoptosis resistance. In untransformed cells, this sulforaphane induced inducible Nrf2 to decrease ROS and possibly malignant cell transformation. In cadmium-transformed cells, it decreased constitutive Nrf2 and reduced apoptosis resistance. The dual roles of sulforaphane make this natural compound a valuable agent for prevention against cadmium-induced carcinogenesis.

Protective Mechanism of Sulforaphane on Cadmium-Induced Sertoli Cell Injury in Mice Testis via Nrf2/ARE Signaling Pathway

The present study evaluated the mechanism underlying the protective effect of sulforaphane (SFN) on cadmium (Cd)-induced Sertoli cell (TM4 cells) injury in mice. The apoptosis rate of cells in each group was detected by flow cytometry. It was determined the effect of SFN on the expression of downstream molecular targets of Nrf2/ARE axis and on the lipid peroxide content. The related genes involved in the nuclear factor E2-related factor 2(Nrf2)/antioxidant response element (ARE) signaling pathway were evaluated by RT-PCR; for example, the mRNA expression levels of Nrf2, heme oxygenase-1 (HO-1), glutathione peroxidase (GSH-Px), quinone oxidoreductase 1 (NQO1), and γ-glutamylcysteine synthetase (γ-GCS), while the protein expression levels were assessed by Western blot. Our results showed that the mRNA and protein expression levels of Nrf2, HO-1, NQO1, GSH-Px, and γ-GCS were increased in various degree when the Sertoli cells were to added different concentrations of SFN. Our results also showed that SFN reduced the apoptosis rate, increased the activity of T-SOD, inhibited the increase of the MDA content caused by Cd. Meanwhile, SFN could increase the mRNA and protein expression levels of Nrf2, HO-1 and NQO1 and reduced the mRNA and protein expression levels of GSH-Px and γ-GCS caused by Cd in Sertoli cells (p < 0.01). Taken together, SFN could improve the antioxidant capacity of Sertoli cells, and exert a protective effect on the oxidative damage and apoptosis of Cd-induced Sertoli cells through the activation of Nrf2/ARE signal transduction pathway.