Renal damage induced by cadmium and its possible therapy by mitochondrial transplantation

Farnesol attenuates cadmium-induced kidney injury by mitigating oxidative stress, inflammation and necroptosis and upregulating cytoglobin and PPARγ in rats

Heavy metals are environmental pollutants that can harm animals and humans even at low concentrations. Cadmium (Cd) is known for its serious health effects on different organs and its toxicity is associated with oxidative stress (OS) and inflammation. Farnesol (FAR), a sesquiterpene alcohol found in many vegetables and fruits, possesses promising anti-inflammatory and antioxidant activities. This study evaluated the effect of FAR on Cd-induced kidney injury, pinpointing its effect of the redox status, inflammation, fibrosis and necroptosis. Rats in this study received FAR for 14 days and Cd on day 7. Elevated serum creatinine, urea and uric acid, and several kidney histopathological alterations were observed in Cd-administered rats. Cd increased MDA, decreased antioxidants, downregulated PPARγ and upregulated NF-κB p65, IL-6, TNF-α, and IL-1β. Necroptosis mediators (RIP1, RIP3, MLKL, and caspase-8) and α-SMA were upregulated, and collagen deposition was increased in Cd-administered rats. FAR ameliorated kidney injury markers and tissue damage, attenuated OS, suppressed NF-κB and inflammatory mediators, and enhanced antioxidants. In addition, FAR suppressed RIP1, RIP3, MLKL, caspase-8, and α-SMA, and enhanced kidney cytoglobin and PPARγ. In conclusion, FAR protects against Cd nephrotoxicity by suppressing OS, inflammatory response and necroptosis, effects associated with enhanced antioxidants, cytoglobin, and PPARγ.

Unravelling the impact of epigenetic mechanisms on offspring growth, production, reproduction and disease susceptibility

Epigenetic mechanisms, such as DNA methylation, histone modifications and non-coding RNA molecules, play a critical role in gene expression and regulation in livestock species, influencing development, reproduction and disease resistance. DNA methylation patterns silence gene expression by blocking transcription factor binding, while histone modifications alter chromatin structure and affect DNA accessibility. Livestock-specific histone modifications contribute to gene expression and genome stability. Non-coding RNAs, including miRNAs, piRNAs, siRNAs, snoRNAs, lncRNAs and circRNAs, regulate gene expression post-transcriptionally. Transgenerational epigenetic inheritance occurs in livestock, with environmental factors impacting epigenetic modifications and phenotypic traits across generations. Epigenetic regulation revealed significant effect on gene expression profiling that can be exploited for various targeted traits like muscle hypertrophy, puberty onset, growth, metabolism, disease resistance and milk production in livestock and poultry breeds. Epigenetic regulation of imprinted genes affects cattle growth and metabolism while epigenetic modifications play a role in disease resistance and mastitis in dairy cattle, as well as milk protein gene regulation during lactation. Nutri-epigenomics research also reveals the influence of maternal nutrition on offspring's epigenetic regulation of metabolic homeostasis in cattle, sheep, goat and poultry. Integrating cyto-genomics approaches enhances understanding of epigenetic mechanisms in livestock breeding, providing insights into chromosomal structure, rearrangements and their impact on gene regulation and phenotypic traits. This review presents potential research areas to enhance production potential and deepen our understanding of epigenetic changes in livestock, offering opportunities for genetic improvement, reproductive management, disease control and milk production in diverse livestock species.

Heavy metals altered the xenobiotic metabolism of rats by targeting the GST enzyme: An in vitro and in silico study

Among all the heavy metals, Pb, Cd, and As are the most harmful pollutants in the environment. They reach into the organisms via various levels of food chains i.e. air and water. Glutathione-s-transferase (GST, E.C. 2.5.1.18), a key enzyme of xenobiotics metabolism, plays an important role in the removal of several toxicants. The present study aimed to evaluate any inhibitory action of these heavy metals on the GST enzyme isolated from the hepatic tissues of rats. A 10 % (w/v) homogenate of rat liver was prepared in cold and centrifuged at 4 °C at 9000xg for 30 min. The supernatant was collected and kept frozen at -20 °C or used fresh for carrying out different experiments. The activity of GST was monitored spectrophotometrically at 340 nm using 220 μg of soluble protein with varying equal substrate concentrations (0.125-2 mM) in phosphate buffer (50 mM, pH 6.5). To assess the impact of heavy metals on the enzyme activity, different concentrations of Cd (0-0.6 mM) and Pb (0-2 mM) were added to the reaction mixture followed by monitoring the residual activity. The optimum temperature and pH of rat liver GST were found to be 37 °C and 6.5, respectively. The Km value for GST was 0.69 mM and the Vmax was found to be 78.67 U/mg. The Cd and Pb significantly altered the kinetic behaviour of the enzyme. The Vmax and Kcat/Km parameters of GST were recorded to be decreased after interaction with Cd and Pb individually and showed a mixed type of inhibition pattern suggesting that these inhibitors may have a greater binding affinity either for the free enzyme or the substrate-enzyme complex. These metals showed a time-dependent enzyme inhibition profile. Cd was found to be the most potent inhibitor when compared to other treated metals; the order of inhibitory effect of metal ions was Cd>Pb>As. The in silico ion docking analysis for determining the probable interactions of Cd and Pb with fragmented GST validated that Cd exhibited higher inhibition potential for the enzyme as compared to Pb. The results of the present study indicated that exposure of both the Cd and Pb may cause significant inhibition of hepatic GST; the former with higher inhibitory potential than the later. However, As proved to be least effective against the enzyme under the aforesaid experimental conditions.

Co-exposure to multiple heavy metals and metalloid induces dose dependent modulation in antioxidative, inflammatory, DNA damage and apoptic pathways progressing to renal dysfunction in mice

Humans are exposed to a cocktail of heavy metal toxicants at the same time in the environment rather than single metal. The kidney is often a site of early damage due to high renal contact to these pollutants. This study was done to examine the cumulative toxic effect of multiple elements prevalent in the environment. To explore the effect of subchronic exposure to heavy metal mixture male and female Swiss albino mice were randomly divided into 14 groups and given varying doses [MPL (maximum permissible limit), 1X, 5X, 10X, 50X, or 100X] of the multiple metals and metalloid mixtures via drinking water for 8 weeks. It was determined that metal treatment caused increased metal load in renal tissue. The kidney function deteriorated in response to 10X, 50X, 100X concentration of the dosing mixture was found associated to oxidative stress, glomerular damage, necrosis, cell death and further exacerbation of the inflammation.

Sodium p-perfluorinated noneoxybenzen sulfonate (OBS) induced neurotoxicity in zebrafish through mitochondrial dysfunction

Sodium p-perfluorous nonenoxybenzene sulfonate (OBS)-one of the main alternatives to perfluorooctane sulfonate-has been increasingly detected in both aquatic environments and human bodies. Therefore, the pathogenic risks of OBS exposure warrant attention, especially its central nervous system toxicity mechanism under long-term exposure. In this study, the effects and mechanisms of OBS on the zebrafish brain at 40 days post exposure were examined. The results demonstrated that at 3.2 μg/L, OBS had no significant effect on the zebrafish brain, but 32 μg/L OBS caused depression or poor social behavior in zebrafish and reduced both their memory and survival ability. These changes were accompanied by histological damage and cell apoptosis. Furthermore, OBS caused the accumulation of excessive reactive oxygen species in the fish brain, leading to oxidative stress and subsequently cell apoptosis. Moreover, an imbalance of both inflammatory factors (IL-6, IL-1β, IL-10, TNF-α, and NF-κB) and neurotransmitters (GABA and Glu) led to neuroinflammation. Additionally, 32 μg/L OBS induced decreases in mitochondrial membrane potential and Na+-K+-ATPase activity, leading to both mitochondrial structural damage and the emergence of mitochondrial autophagosomes, partly explaining the neurotoxicity of OBS. These results help to analyze the target sites and molecular mechanisms of OBS neurotoxicity and provide a basis for the scientific evaluation of its health risks to humans.

Antioxidative and anti-cytogenotoxic potential of Lysiphyllum strychnifolium (Craib) A. Schmitz extracts against cadmium-induced toxicity in human embryonic kidney (HEK293) and dermal fibroblast (HDF) cells

Exposure to cadmium (Cd) results in bioaccumulation and irreversible damage; this encourages an investigation of alternatives to address Cd toxicity, using natural compounds. Lysiphyllum strychnifolium, a well-known Thai medicinal plant, was investigated for its phytochemical compounds and corresponding bioactivities, including antioxidant and anti-cytogenotoxic effects against Cd toxicity in HEK293 renal and HDF dermal cell models. The crude extract of L. strychnifolium (LsCrude) was partitioned into four fractions, using sequential polarity solvents (hexane, dichloromethane, ethyl acetate, and water, denoted as LsH, LsD, LsE, and LsW, respectively). The extraction yields were 1.79 %, 5.08 %, 8.53 %, and 70.25 % (w/w), respectively. Phytochemical screening revealed the presence of tannins, alkaloids, and flavonoids in LsCrude and its fractions, except for LsH. LsE exhibited the highest concentrations of phenolics (286.83 ± 6.83 mg GAE/g extract) and flavonoids (86.36 ± 1.29 mg QE/g extract). Subsequent 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging and ferric-reducing ability of plasma (FRAP) reducing powder assays demonstrated the high antioxidant capacity of LsCrude and its fractions. The lowest IC50 value (9.11 ± 0.43 μg/mL) in the DPPH assay corresponded to LsW, whereas the highest total FRAP value (6.06 ± 0.70 mg QE Eq./g dry mass) corresponded to LsE. MTT and alkaline comet assays revealed the lack of toxicity of the extracts, which were considered safe. Upon exposure to Cd at the CC50 level, HEK293 cells treated with LsE suppressed Cd-induced damage. HDF cells treated with LsCrude, LsD, or LsE attenuated Cd-induced damage. In the pre-treatment, LsD protected the HDF cells against Cd-mediated cytogenotoxicity. These anti-cytogenotoxic potentials are likely due to the antioxidant properties of the phytochemicals. Our findings highlight the cyto-geno-protective properties of L. strychnifolium stem extracts against Cd toxicity in HEK293 and HDF cells, and provide a novel approach for combating oxidative stress and DNA damage caused by environmental pollutants.

Mitotherapy inhibits against tenofovir induced nephrotoxicity on rat renal proximal tubular cells

Tenofovir, as nucleotide reverse transcriptase inhibitors (NRTIs), is used to prevent and cure HIV/AIDS. Ample evidence confirmed that the nephrotoxicity of tenofovir has been linked to mitochondrial dysfunction. It seems that transplantation with healthy mitochondria instead of damaged mitochondria may be a beneficial approach to therapy. Therefore, it decided to investigate the impact of mitotherapy on tenofovir against renal proximal tubular cells (RPTCs) toxicity by measurement of oxidative stress and cytotoxicity biomarkers and restoring of mitochondrial function on isolated mitochondria. EC50 of tenofovir was achieved at 40 μM following 2 h incubation in Earle's solution (pH = 7.4; 37 °C). Freshly isolated mitochondria (80 μg/ml) were added to damage RPTCs affected by tenofovir in treated groups. One Way ANOVA analysis showed that healthy mitochondrial transplantation decreased oxidative stress biomarkers following tenofovir toxicity in RPTCs. Our data revealed that mitotherapy makes cell survival possible in RPTCs affected by tenofovir. In addition, it supposed that a novel and ideal strategy for the treatment of chemicals-induced nephrotoxicity.

m6A-methylated Lonp1 drives mitochondrial proteostasis stress to induce testicular pyroptosis upon environmental cadmium exposure

Cadmium (Cd) is a widely distributed typical environmental pollutant and one of the most toxic heavy metals. It is well-known that environmental Cd causes testicular damage by inducing classic types of cell death such as cell apoptosis and necrosis. However, as a new type of cell death, the role and mechanism of pyroptosis in Cd-induced testicular injury remain unclear. In the current study, we used environmental Cd to generate a murine model with testicular injury and AIM2-dependent pyroptosis. Based on the model, we found that increased cytoplasmic mitochondrial DNA (mtDNA), activated mitochondrial proteostasis stress occurred in Cd-exposed testes. We used ethidium bromide to generate mtDNA-deficient testicular germ cells and further confirmed that increased cytoplasmic mtDNA promoted AIM2-dependent pyroptosis in Cd-exposed cells. Uracil-DNA glycosylase UNG1 overexpression indicated that environmental Cd blocked UNG-dependent repairment of damaged mtDNA to drive the process in which mtDNA releases to cytoplasm in the cells. Interestingly, we found that environmental Cd activated mitochondrial proteostasis stress by up-regulating protein expression of LONP1 in testes. Testicular specific LONP1-knockdown significantly reversed Cd-induced UNG1 protein degradation and AIM2-dependent pyroptosis in mouse testes. In addition, environmental Cd significantly enhanced the m6A modification of Lonp1 mRNA and its stability in testicular germ cells. Knockdown of IGF2BP1, a reader of m6A modification, reversed Cd-induced upregulation of LONP1 protein expression and pyroptosis activation in testicular germ cells. Collectively, environmental Cd induces m6A modification of Lonp1 mRNA to activate mitochondrial proteostasis stress, increase cytoplasmic mtDNA content, and trigger AIM2-dependent pyroptosis in mouse testes. These findings suggest that mitochondrial proteostasis stress is a potential target for the prevention of testicular injury.

Metals on the Menu-Analyzing the Presence, Importance, and Consequences

Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets.

Overexpression of Lias Gene Alleviates Cadmium-Induced Kidney Injury in Mice Involving Multiple Effects: Metabolism, Oxidative Stress, and Inflammation

Oxidative stress is an important mechanism underlying toxicity induced by cadmium (Cd) exposure. However, there are significant differences of the antioxidant baseline in different populations. This means that different human has different intensity of oxidative stress in vivo after exposure to toxicants. LiasH/H mouse is a specific model which is created by genetically modifying the Lias 3'-untranslated region (3'-UTR). LiasH/H mice express high levels of LA and have high endogenous antioxidant capacity which is approximately 150% higher than wild-type C57BL/6 J mice (WT, Lias+/+). But more importantly, they have dual roles of metal chelator and antioxidant. Here, we applied this mouse model to evaluate the effect of endogenous antioxidant levels in the body on alleviating Cd-induced renal injury including Cd metabolism, oxidative stress, and inflammation. In the experiment, mice drank water containing Cd (50 mg/L), for 12 weeks. Many biomarkers of Cd metabolism, oxidative stress, inflammation, and major pathological changes in the kidney were examined. The results showed overexpression of the Lias gene decreased Cd burden in the body of mice, mitigated oxidative stress, attenuated the inflammatory response, and subsequent alleviated cadmium-induced kidney injury in mice.

Cadmium Exposure: Mechanisms and Pathways of Toxicity and Implications for Human Health

Cadmium (Cd), a prevalent environmental contaminant, exerts widespread toxic effects on human health through various biochemical and molecular mechanisms. This review encapsulates the primary pathways through which Cd inflicts damage, including oxidative stress induction, disruption of Ca2+ signaling, interference with cellular signaling pathways, and epigenetic modifications. By detailing the absorption, distribution, metabolism, and excretion (ADME) of Cd, alongside its interactions with cellular components such as mitochondria and DNA, this paper highlights the extensive damage caused by Cd2+ at the cellular and tissue levels. The role of Cd in inducing oxidative stress-a pivotal mechanism behind its toxicity-is discussed with emphasis on how it disrupts the balance between oxidants and antioxidants, leading to cellular damage and apoptosis. Additionally, the review covers Cd's impact on signaling pathways like Mitogen-Activated Protein Kinase (MAPK), Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB), and Tumor Protein 53 (p53) pathways, illustrating how its interference with these pathways contributes to pathological conditions and carcinogenesis. The epigenetic effects of Cd, including DNA methylation and histone modifications, are also explored to explain its long-term impact on gene expression and disease manifestation. This comprehensive analysis not only elucidates the mechanisms of Cd toxicity but also underscores the critical need for enhanced strategies to mitigate its public health implications.

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.

Mitochondrial administration alleviates lead- and cadmium-induced toxicity in rat renal cells

The role of heavy metals such as lead (Pb) and cadmium (Cd) in the etiology of many diseases has been proven. Also, these heavy metals can affect the normal mitochondrial function. Mitochondrial administration therapy is one of the methods used by researchers to help improve mitochondrial defects and diseases. The use of isolated mitochondria as a therapeutic approach has been investigated in in vivo and in vitro studies. Accordingly, in this study, the effects of mitochondrial administration on the improvement of toxicity caused by Pb and Cd in renal proximal tubular cells (RPTC) have been investigated. The results showed that treatment to Pb and Cd caused an increase in the level of free radicals, lipid peroxidation (LPO) content, mitochondrial and lysosomal membrane damage, and also a decrease in the reduced glutathione content in RPTC. In addition, reports have shown an increase in oxidized glutathione content and changes in energy (ATP) levels. Following, the results have shown the protective role of mitochondrial administration in improving the toxicity caused by Pb and Cd in RPTC. Furthermore, the mitochondrial internalization into RPT cells is mediated through actin-dependent endocytosis. So, it could be suggested that the treatment of Pb- and Cd-induced cytotoxicity in RPTC could be carried out through mitochondria administration.

EIF4A3 modulated circ_000999 promotes epithelial-mesenchymal transition in cadmium-induced malignant transformation through the miR-205-5p/ZEB1 axis

Cadmium (Cd) is an accumulative toxic metal which poses a serious threat to human health, even in trace amounts. One of the most important steps in the pathophysiology of lung cancer (LC) is the epithelial-mesenchymal transition (EMT). In this investigation, a cell malignant transformation model was established by exposing human bronchial epithelial cells (16HBE) to a low dose of Cd for 30 weeks, after which a highly expressed circular RNA (circ_000999) was identified. Cd-induced EMT was clearly observed in rat lungs and 16HBE cells, which was further enhanced following circ_000999-overexpression. Furthermore, upregulated EIF4A3 interacted with the parental gene AGTPBP1 to promote high expression of circ_000999. Subsequent experiments confirmed that circ_000999 could regulate the EMT process by competitively binding miR-205-5p and inhibiting its activity, consequently upregulating expression of zinc finger E-box binding protein 1 (ZEB1). Importantly, the circ_000999 expression level in LC tissues was significantly increased, exhibiting a strong correlation with EMT indicators. Overall, these findings provide a new objective and research direction for reversing lung EMT and subsequent treatment and prevention of LC.

A state-of-the-science review of using mitochondrial DNA copy number as a biomarker for environmental exposure

Mitochondria are bioenergetic, biosynthetic, and signaling organelles in eukaryotes, and contain their own genomes, mitochondrial DNA (mtDNA), to supply energy to cells by generating ATP via oxidative phosphorylation. Therefore, the threat to mitochondria' integrity and health resulting from environmental exposure could induce adverse health effects in organisms. In this review, we summarized the association between mtDNA copy number (mtDNAcn), and environmental exposures as reported in the literature. We conducted a literature search in the Web of Science using [Mitochondrial DNA copy number] and [Exposure] as two keywords and employed three selection criteria for the final inclusion of 97 papers for review. The consensus of data was that mtDNAcn could be used as a plausible biomarker for cumulative exposures to environmental chemical and physical agents. In order to furtherly expand the application of mtDNAcn in ecological and environmental health research, we suggested a series of algorithms aiming to standardize the calculation of mtDNAcn based on the PCR results in this review. We also discussed the pitfalls of using whole blood/plasma samples for mtDNAcn measurements and regard buccal cells a plausible and practical alternative. Finally, we recognized the importance of better understanding the mechanistic analysis and regulatory mechanism of mtDNAcn, in particular the signals release and regulation pathways. We believe that the development of using mtDNAcn as an exposure biomarker will revolutionize the evaluation of chronic sub-lethal toxicity of chemicals to organisms in ecological and environmental health research that has not yet been implemented.

Bioaccumulation of Potentially Toxic Elements in Commercially Important Food Fish Species from Lower Gangetic Stretch: Food Security and Human Health Risk Assessment

Ganga river is the inhabitant of more than 190 fish species and important river system of India. Potentially toxic elements (PTEs) in the Gangetic riverine ecosystem are a hot environmental issue. A detailed evaluation of PTEs bioaccumulation in Gangetic fishes is required to safeguard human health. The present study investigated the bioaccumulation of PTEs (Cd, Co, Cr, Cu, Li, Ni, Pb, Se, Zn, and Mn) within 12 economic fish species (n = 72) collected from the lower Gangetic stretch. The mean concentrations of PTEs followed the order Zn > Cu > Mn > Ni > Se > Cr > Pb > Co ~ Li > Cd. Li and Se bioaccumulation were studied first time from Gangetic fishes. Results demonstrated that all the selected PTEs were below the maximum permissible limit recommended by reference standards except for Zn in L. catla and L. rohita. For all PTEs, the metal pollution index (MPI), hazard quotient (THQ), and hazard index (HI) were < 1, indicating that these PTEs do not pose a health risk to the public through the dietary intake of fish in this study area. All studied fish were acceptable in terms of carcinogenic risk (CR) from exposure to Cd, Cr, and Pb. Multivariate statistical analysis suggests that inter-correlated metals have similar dispersion properties and bioaccumulation homology within the body. This study provides a scientific basis for food safety assessment and continuous monitoring of PTEs in Gangetic fishes is suggested in the future to safeguard human health.

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

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

Tim-3 deficiency aggravates cadmium nephrotoxicity via regulation of NF-κB signaling and mitochondrial damage

Kidney is the target organ of serious cadmium injury. Kidney damage caused by cadmium exposure is greatly influenced by the inflammatory response and mitochondrial damage. T cell immunoglobulin domain and mucin domain 3 (Tim-3) is an essential protein that functions as a negative immunological checkpoint to regulate inflammatory responses. Mice were given cadmium treatments at various dosages (0, 1.5, 3, 4.5 mg/kg) and times (0, 3, 5, 7 days) to assess the effects of cadmium on kidney damage. We found that the optimal way to induce kidney injury in mice was to inject 4.5 mg/kg of cadmium intraperitoneally for five days. It is interesting that giving mice 4.5 mg/kg of cadmium intravenously for seven days drastically lowered their survival rate. After cadmium exposure, Tim-3 knockout mice exhibited higher blood concentrations of urea nitrogen and creatinine compared to control mice. Tim-3 impacted the expression of oxidative stress-associated genes such as UDP glucuronosyltransferase family 1 member A9 (Ugt1a9), oxidative stress-induced growth inhibitor 2 (Osgin2), and S100 calcium binding protein A8 (S100a8), according to RNA-seq and real-time RT-PCR data. Tim-3 deficiency also resulted in activated nuclear factor-kappa B (NF-κB) signaling pathway. The NF-κB inhibitor 2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide (TPCA-1) significantly alleviated cell apoptosis, oxidative stress response, and renal tubule inflammation in Tim-3 knockout mice exposed to cadmium. Furthermore, cadmium caused obvious B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) translocation from cytoplasm to mitochondria, which can be inhibited by TPCA-1. In conclusion, Tim-3 prevented mitochondrial damage and NF-κB signaling activation, hence providing protection against cadmium nephrotoxicity.

Mechanism of cadmium-induced nephrotoxicity

Heavy metals are found naturally in our environment and have many uses and applications in daily life. However, high concentrations of metals may be a result of pollution due to industrialization. In particular, cadmium (Cd), a white metal abundantly distributed in the terrestrial crust, is found in mines together with zinc, which accumulates after volcanic eruption or is found naturally in the sea and earth. High levels of Cd have been associated with disease. In the human body, Cd accumulates in two ways: via inhalation or consumption, mainly of plants or fish contaminated with high concentrations. Several international organizations have been working to establish the limit values of heavy metals in food, water, and the environment to avoid their toxic effects. Increased Cd levels may induce kidney, liver, or neurological diseases. Cd mainly accumulates in the kidney, causing renal disease in people exposed to moderate to high levels, which leads to the development of end-stage chronic kidney disease or death. The aim of this review is to provide an overview of Cd-induced nephrotoxicity, the mechanisms of Cd damage, and the current treatments used to reduce the toxic effects of Cd exposure.

Biomonitoring of Oxidative-Stress-Related Genotoxic Damage in Patients with End-Stage Renal Disease

Chronic kidney disease (CKD), a common progressive renal failure characterized by the permanent loss of functional nephrons can rapidly progress to end-stage renal disease, which is known to be an irreversible renal failure. In the therapy of ESRD, there are controversial suggestions about the use of regular dialysis, since it is claimed to increase oxidative stress, which may increase mortality in patients. In ESRD, oxidative-stress-related DNA damage is expected to occur, along with increased inflammation. Many factors, including heavy metals, have been suggested to exacerbate the damage in kidneys; therefore, it is important to reveal the relationship between these factors in ESRD patients. There are very few studies showing the role of oxidative-stress-related genotoxic events in the progression of ESRD patients. Within the scope of this study, genotoxic damage was evaluated using the comet assay and 8-OHdG measurement in patients with ESRD who were undergoing hemodialysis. The biochemical changes, the levels of heavy metals (aluminum, arsenic, cadmium, lead, and mercury) in the blood, and the oxidative biomarkers, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) levels were evaluated, and their relationship with genotoxic damages was revealed. Genotoxicity, oxidative stress, and heavy-metal levels, except mercury, increased significantly in all renal patients. DNA damage, 8OHdG, and MDA significantly increased, and GSH significantly decreased in patients undergoing dialysis, compared with those not having dialysis. The duration and the severity of disease was positively correlated with increased aluminum levels and moderate positively correlated with increased DNA damage and cadmium levels. In conclusion, this study revealed that the oxidative-stress-related DNA damage, and also the levels of Al and Cd, increased in ESRD patients. It is assumed that these changes may play an important role in the progression of renal damage. Approaches for reducing oxidative-stress-related DNA damage and heavy-metal load in ESRD patients are recommended.

Molecular Mechanisms of Oxidative Stress in Acute Kidney Injury: Targeting the Loci by Resveratrol

Reactive oxygen species are a group of cellular molecules that stand as double-edged swords, their good and bad being discriminated by a precise balance. Several metabolic reactions in the biological system generate these molecules that interact with cellular atoms to regulate functions ranging from cell homeostasis to cell death. A prooxidative state of the cell concomitant with decreased clearance of such molecules leads to oxidative stress, which contributes as a prime pathophysiological mechanism in various diseases including renal disorders, such as acute kidney injury. However, targeting the generation of oxidative stress in renal disorders by an antioxidant, resveratrol, is gaining considerable therapeutic importance and is known to improve the condition in preclinical studies. This review aims to discuss molecular mechanisms of oxidative stress in acute kidney injury and its amelioration by resveratrol. The major sources of data were PubMed and Google Scholar, with studies from the last five years primarily included, with significant earlier data also considered. Mitochondrial dysfunction, various enzymatic reactions, and protein misfolding are the major sources of reactive oxygen species in acute kidney injury, and interrupting these loci of generation or intersection with other cellular components by resveratrol can mitigate the severity of the condition.

Mitochondrial transplantation attenuates toxicity in rat renal proximal tubular cells caused by Favipiravir

OBJECTIVES

Exogenous mitochondria transplantation or mitotherapy can be used to swap out unhealthy mitochondria for functioning ones. Treatment of mitochondrial diseases using this approach may be beneficial.

METHODS

In this study, we looked at the effect of transplanting newly isolated mitochondria on the toxicity that favipiravir (FAV) causes in renal proximal tubular cells (RPTCs). In this study, parameters such as lactate dehydrogenase (LDH) leakiness, reactive oxygen species (ROSs) production, damage to the lysosome membrane, reduced glutathione (GSH) content, extracellular oxidized glutathione (GSSG) content, GSH/GSSG ratio, ATP level, mitochondrial membrane potential (MMP) collapse, Bcl-2 content, and caspase-3 activity were used to assess the protective effects of mitochondrial transplantation against FAV-induced mitochondrial toxicity.

KEY FINDINGS

The statistical analysis showed that the cytotoxicity, ROS production, MMP collapse, lysosomal damage, GSSG levels, and caspase-3 activity brought on by FAV in RPTCs were reduced by transplanting the healthy mitochondria. In addition, it led to an increase in ATP level, GSH content, Bcl-2 content, and GSH/GSSG ratio in RPTCs.

CONCLUSIONS

A recent study found that mitochondrial transplantation is a powerful therapeutic approach for treating nephrotoxicity brought on by xenobiotics.

Cadmium-chelating ability of the siderophore DHBS secreted by Leclercia adecarboxylata FCH-CR2 and its action mechanism

As one of the most accumulative toxic heavy metals, cadmium (Cd) poses a major threat to human health. Bacterial siderophores, as small molecules with metal-absorbing ability, have great potential activity for Cd-reduction. In this study, the siderophore-producing bacterialstrain FCH-CR2 was isolated from a high-Cd contaminated soil using the CAS method. Leclercia adecarboxylata was identified through 16S rRNA sequence, homology analysis, colony morphology, physiological and biochemical tests. A siderophore, catechol type 2,3-dihydroxy-N-benzoyl-l-serine (DHBS) secreted by FCH-CR2, was purified using RP-HPLC and identified by LC-MS/MS. Intraperitoneal injection of DHBS significantly increased fecal Cd levels, and reduced Cd accumulation in organs. In density flooding theory (DFT) analysis, DHBS may bind to Cd via the hydroxyl site on the benzene ring. Besides, the isothermal titration calorimetry (ITC) assay revealed that the formation of Cd-DHBS is a spontaneous and endothermic reaction with ΔG = -21.4 kJ/mol and ΔH = 1.51 ± 0.142 kJ/mol.

Mitochondrial transplantation strategies in multifaceted induction of cancer cell death

Otto Warburg hypothesized that some cancer cells reprogram their metabolism, favoring glucose metabolism by anaerobic glycolysis (Warburg effect) instead of oxidative phosphorylation, mainly because the mitochondria of these cells were damaged or dysfunctional. It should be noted that mitochondrial apoptosis is decreased because of the dysfunctional mitochondria. Strategies like mitochondrial transplantation therapy, where functional mitochondria are transplanted to cancer cells, could increase cell death, such as apoptosis, because the intrinsic apoptosis mechanisms would be reactivated. In addition, mitochondrial transplantation is associated with the redox state, which could promote synergy with common anticancer treatments such as ionizing radiation, chemotherapy, or radiotherapy, increasing cell death due to the presence or decrease of oxidative stress. On the other hand, mitochondrial transfer, a natural process for sharing mitochondrial between cells, induces an increase in chemoresistance and invasiveness in cancer cells that receive mitochondria from cells of the tumor microenvironment (TME), which indicates an antitumor therapeutic target. This review focuses on understanding mitochondrial transplantation as a therapeutic outcome induced by a procedure in aspects including oxidative stress, metabolism shifting, mitochondrial function, auto-/mitophagy, invasiveness, and chemoresistance. It also explores how these mechanisms, such as apoptosis, necroptosis, and parthanatos, impact cell death pathways. Finally, it discusses the chemoresistance and invasiveness in cancer cells associated with mitochondria transfer, indicating an antitumor therapeutic target.

Grape seed proanthocyanidins regulate mitophagy of endothelial cells and promote wound healing in mice through p-JNK/FOXO3a/ROS signal pathway

Skin wound healing is a dynamic and complex process that involves multiple physiological and cellular events. Grape seed proanthocyanidins (GSP) have strong anti-oxidation and elimination of oxygen free radicals, and have been shown to significantly promote wound healing, but the underlying mechanism remains unclear. Studies have indicated that reactive oxygen species (ROS) acts as an upstream signal to induce mitophagy, suggesting that GSP can regulate mitophagy through the signal pathway. This study aimed to investigate whether GSP regulates mitophagy by down-regulating oxidative stress to promote wound healing. In vivo, GSP treatment accelerated wound healing, granulation tissue formation, collagen deposition, and angiogenesis in mice. Moreover, GSP down-regulated ROS levels and promoted the expression of antioxidant proteins by up-regulating the expression of p-JNK/FOXO3a protein, thereby regulating the expression of mitophagy-related proteins. In vitro, 4 μg/mL GSP showed no apparent toxic effects on cells and effectively reduce the oxidative stress damage of cells induced by H2O2. Western blot and superoxide anion fluorescence probe further confirmed that GSP effectively reduced Dihydroethidium content and up-regulated the expression of antioxidant proteins by activation of p-JNK/FOXO3a protein expression, thereby regulating mitophagy. Taken together, the findings from in vitro and in vivo experiments provide new insights into the promotion of wound healing by GSP.

The Activation of cGAS-STING in Acute Kidney Injury

The activation of the cGAS-STING pathway is associated with many sterile inflammatory and inflammatory conditions, including acute kidney injury. As a cytoplasmic DNA sensor, sensitization of the cGAS-STING pathway can ignite the innate immune response in vivo and trigger a series of biological effects. In recent years, there is increasing evidence showing that the cGAS-STING pathway plays a vital role in acute kidney injury, a non-inflammatory disease induced by activation of innate immune cells, and closely related to intracellular reactive oxygen species, mitochondrial DNA, and the cGAS-STING pathway. This review provides a prospect of the cGAS-STING pathway and its relationship to acute kidney injury.

Cadmium (Cd) and 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) co-exposure induces acute kidney injury through oxidative stress and RIPK3-dependent necroptosis

Environmental pollution is complex, and co-exposure can accurately reflect the true environmental conditions that are important for assessment of human health. Cadmium (Cd) is a widespread toxicant that can cause acute kidney injury (AKI), while its combined effect with 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) is not fully understood. Thus, we used an in vivo model where C57BL/6J mice were treated with low dietary intake of Cd (5 mg/kg/day) and/or BDE-47 (1 mg/kg/day) for 28 days to examine AKI, and in vitro experiments to investigate the possible mechanism. Results showed that Cd or BDE-47 caused pathological kidney damage, accompanied by elevated urea nitrogen (BUN) and urinary creatinine, as well as increased interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), and reduced IL-10 in kidney tissues. In vitro Cd or BDE-47 exposure decreased cell viability and induced cell swelling and blebbing of human embryonic kidney 293 (HEK-293) and renal tubular epithelial cell lines (HKCs), and changes in co-exposure was larger than that in Cd and BDE-47 treatment. Oxidative stress indicators of the reactive oxygen species (ROS) and malondialdehyde (MDA) were elevated, while the antioxidant superoxide dismutase (SOD) was decreased. Necrosis occurred with increased lactate dehydrogenase (LDH) release and propidium iodide (PI) staining, which was attenuated by the ROS scavenger N-acetyl-L-cysteine (NAC). Furthermore, necroptotic genes of receptor-interacting protein kinase-3 (RIPK3), classical mixed lineage kinase domain-like protein-dependent (MLKL), IL-1β and TNF-α were up-regulated, whereas RIPK1 was down-regulated, which was attenuated by the RIPK3 inhibitor GSK872. These findings demonstrate that Cd or BDE-47 alone produces kidney toxicities, and co-exposure poses an additive effect, resulting in AKI via inducing oxidative stress and regulating RIPK3-dependent necroptosis, which offers a further mechanistic understanding for kidney damage, and the combined effect of environmental pollutants should be noticed.

Co-exposure to environmentally relevant concentrations of cadmium and polystyrene nanoplastics induced oxidative stress, ferroptosis and excessive mitophagy in mice kidney

Nanoplastics (NPs) are defined as a group of emerging pollutants. However, the adverse effect of NPs and/or heavy metals on mammals is still largely unclear. Therefore, we performed a 35-day chronic toxicity experiment with mice to observe the impacts of exposure to Cadmium (Cd) and/or polystyrene nanoplastics (PSNPs). This study revealed that combined exposure to Cd and PSNPs added to the mice's growth toxicity and kidney damage. Moreover, Cd and PSNPs co-exposure obviously increased the MDA level and expressions of 4-HNE and 8-OHDG while decreasing the activity of antioxidase in kidneys via inhibiting the Nrf2 pathway and its downstream genes and proteins expression. More importantly, the results suggested for the first time that Cd and PSNPs co-exposure synergistically increased iron concentration in kidneys, and induced ferroptosis through regulating expression levels of SLC7A11, GPX4, PTGS2, HMGB1, FTH1 and FTL. Simultaneously, Cd and PSNPs co-exposure further increased the expression levels of Pink, Parkin, ATG5, Beclin1, and LC3 while significantly reducing the P62 expression level. In brief, this study found that combined exposure to Cd and PSNPs synergistically caused oxidative stress, ferroptosis and excessive mitophagy ultimately aggravating kidney damage in mice, which provided new insight into the combined toxic effect between heavy metals and PSNPs on mammals.

Heavy metal toxicity in poultry: a comprehensive review

Arsenic (As), lead (Pb), cadmium (Cd), and mercury (Hg) have been recognized as most toxic heavy metals that are continuously released into the environment, both from natural sources and from anthropogenic production of fertilizers, industrial activities, and waste disposal. Therefore, As, Cd, Hg, and Pb are found in increasing concentrations in bodies of water, fodder, feed, and in the tissues of livestock, including poultry, in the surroundings of industrial areas, leading to metabolic, structural, and functional abnormalities in various organs in all animals. In poultry, bioaccumulation of As, Pb, Cd, and Hg occurs in many organs (mainly in the kidneys, liver, reproductive organs, and lungs) as a result of continuous exposure to heavy metals. Consumption of Cd lowers the efficiency of feed conversion, egg production, and growth in poultry. Chronic exposure to As, Pb, Cd, and Hg at low doses can change the microscopic structure of tissues (mainly in the brain, liver, kidneys, and reproductive organs) as a result of the increased content of these heavy metals in these tissues. Histopathological changes occurring in the kidneys, liver, and reproductive organs are reflected in their negative impact on enzyme activity and serum biochemical parameters. Metal toxicity is determined by route of exposure, length of exposure, and absorbed dosage, whether chronic and acute. This review presents a discussion of bioaccumulation of As, Cd, Pb, and Hg in poultry and the associated histopathological changes and toxic concentrations in different tissues.

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

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

Nutriepigenomics in Environmental-Associated Oxidative Stress

Complex molecular mechanisms define our responses to environmental stimuli. Beyond the DNA sequence itself, epigenetic machinery orchestrates changes in gene expression induced by diet, physical activity, stress and pollution, among others. Importantly, nutrition has a strong impact on epigenetic players and, consequently, sustains a promising role in the regulation of cellular responses such as oxidative stress. As oxidative stress is a natural physiological process where the presence of reactive oxygen-derived species and nitrogen-derived species overcomes the uptake strategy of antioxidant defenses, it plays an essential role in epigenetic changes induced by environmental pollutants and culminates in signaling the disruption of redox control. In this review, we present an update on epigenetic mechanisms induced by environmental factors that lead to oxidative stress and potentially to pathogenesis and disease progression in humans. In addition, we introduce the microenvironment factors (physical contacts, nutrients, extracellular vesicle-mediated communication) that influence the epigenetic regulation of cellular responses. Understanding the mechanisms by which nutrients influence the epigenome, and thus global transcription, is crucial for future early diagnostic and therapeutic efforts in the field of environmental medicine.

Nuclear factor-kappaB mediates the survival of rat kidney cells after cadmium exposure via promoting autophagy and inhibiting apoptosis

Cadmium (Cd) is a heavy metal pollutant in the environment, and the kidney is one of the target organs after Cd exposure. Previous studies have shown that apoptosis and autophagy disorders are the main mechanisms of Cd-induced nephrotoxicity in rats. As a transcription factor that balances cell survival and death, nuclear factor-kappaB (NF-κB) protein plays dual regulatory effects on apoptosis and autophagy in multiple renal diseases. However, the regulatory mechanisms of NF-κB in Cd-induced kidney injury remain unclear. Therefore, the normal rat kidney cell line (NRK-52E cells) was applied to investigate the above questions in this study. Here, we found that Cd promotes the nuclear translocation and activation of NF-κB in a concentration-dependent manner, and activated NF-κB mediates NRK-52E cells survival after Cd exposure. Next, our study elaborated the mechanisms of NF-κB in antagonizing Cd-induced renal cytotoxicity. Inhibition of NF-κB by inhibitor BAY 11-7082 (BAY) and NF-κB p65 siRNA (siNF-κB p65) exacerbate Cd-induced apoptosis and autophagy inhibition, and then aggravate Cd-induced NRK-52E cells injury. Activation of NF-κB by activator phorbol-12-myristate-13-acetate (PMA) alleviates Cd-induced apoptosis and autophagy inhibition, and then attenuates Cd-induced NRK-52E cells injury. In conclusion, Cd exposure promotes the activation of NF-κB, and activated NF-κB mediates the survival of NRK-52E cells after Cd exposure via promoting autophagy and inhibiting apoptosis.

Multi-Omics Uncover the Mechanism of Wheat under Heavy Metal Stress

Environmental pollution of heavy metals has received growing attention in recent years. Heavy metals such as cadmium, lead and mercury can cause physiological and morphological disturbances which adversely affect the growth and quality of crops. Wheat (Triticum aestivum L.) can accumulate high contents of heavy metals in its edible parts. Understanding wheat response to heavy metal stress and its management in decreasing heavy metal uptake and accumulation may help to improve its growth and grain quality. Very recently, emerging advances in heavy metal toxicity and phytoremediation methods to reduce heavy metal pollution have been made in wheat. Especially, the molecular mechanisms of wheat under heavy metal stress are increasingly being recognized. In this review, we focus on the recently described epigenomics, transcriptomics, proteomics, metabolomics, ionomics and multi-omics combination, as well as functional genes uncovering heavy metal stress in wheat. The findings in this review provide some insights into challenges and future recommendations for wheat under heavy metal stress.

Roles of Mitochondrial DNA Damage in Kidney Diseases: A New Biomarker

The kidney is a mitochondria-rich organ, and kidney diseases are recognized as mitochondria-related pathologies. Intact mitochondrial DNA (mtDNA) maintains normal mitochondrial function. Mitochondrial dysfunction caused by mtDNA damage, including impaired mtDNA replication, mtDNA mutation, mtDNA leakage, and mtDNA methylation, is involved in the progression of kidney diseases. Herein, we review the roles of mtDNA damage in different setting of kidney diseases, including acute kidney injury (AKI) and chronic kidney disease (CKD). In a variety of kidney diseases, mtDNA damage is closely associated with loss of kidney function. The level of mtDNA in peripheral serum and urine also reflects the status of kidney injury. Alleviating mtDNA damage can promote the recovery of mitochondrial function by exogenous drug treatment and thus reduce kidney injury. In short, we conclude that mtDNA damage may serve as a novel biomarker for assessing kidney injury in different causes of renal dysfunction, which provides a new theoretical basis for mtDNA-targeted intervention as a therapeutic option for kidney diseases.