Metallothionein Expression Research Articles

Effect of Vitamin E and Selenium (Se) Supplementation on Biochemical Parameters and Expression of Metallothionein (MT-2) in Heavy Metals Exposed Buffaloes

Background: Farm animals may serve as bio-indicators of environmental pollution. Environmental heavy metals may disrupt the normal physiological and biochemical profile of the animals. The present study was planned to reduce the stress caused by heavy metal pollution by oral feeding of vitamin E and Selenium in heavy metals exposed buffaloes.Methods: Twenty buffaloes were selected on the basis of blood levels of heavy metals and divided into exposed and non-exposed groups. Exposed animals (n=10) were orally supplemented with 20 ml/day of Cargill E care Se® containing vitamin E, 100mg/ml and Se 0.5mg/ml for 30 days. Antioxidants, biochemical parameters and the expression of metallothionein-2 were analyzed after supplementation on 0, 15 and 30 days.Result: The levels of heavy metal were found to be elevated even after 30 days of supplementation. No significant alterations were observed in activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) after 30 days of supplementation. There was significantly (p less than 0.05) higher activity of blood glutathione and plasma Vitamin E. In supplemented group, plasma glucose, total cholesterol, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactic dehydrogenase (LDH), creatine kinase (CK) and total Immunoglobulin were found to be significantly reduced in supplemented group. Expression of metal binding protein, metallothionein-2 was found to be elevated in exposed animals despite supplementation with Vitamin E and Se for 30 days.

Regulatory T cells induce polarization of pro-repair macrophages by secreting sFGL2 into the endometriotic milieu

An increased number of highly active regulatory T cells (Tregs) and macrophages has been found in peritoneal fluid from women with endometriosis. Here, we show that the level of Tregs-derived soluble fibrinogen-like protein 2 (sFGL2) increases in the peritoneal fluid of women with endometriosis. Higher expression of FGL2 and its receptor CD32B is observed in eutopic endometrium and ectopic tissues. The production of sFGL2 in Tregs may be enhanced by several cytokines. sFGL2 selectively induces pro-repair macrophage polarization mainly through the activation of the SHP2-ERK1/2-STAT3 signaling pathway, and the suppression of the NF-κB signaling pathway. Furthermore, sFGL2 induces a much higher level of metallothionein (MT) expression that in turn facilitates pro-repair macrophages polarization. sFGL2-induced pro-repair macrophages promote Th2 and Tregs differentiation, creating a positive feedback loop. These findings suggest that sFGL2 secreted by Tregs skews macrophages toward a pro-repair phenotype via SHP2-ERK1/2-STAT3 signaling pathway, which is involved in the progression of endometriosis.

Growth performance, tissue precipitation, metallothionein and cytokine transcript expression and economics in response to different dietary zinc sources in growing rabbits.

The impact of different dietary zinc sources on the growth, serum metabolites, tissue zinc content, economics and relative expression of cytokine and metallothionein genes was evaluated in this study. A total of 120 35-day-old male New Zealand White (NZW) rabbits were randomly distributed into four dietary experimental groups with 10 replicates per group and 3 animals per replicate. The control group was fed basal diet with a Zn-free vitamin-mineral premix; the other three groups received control basal diet supplemented with 50mg/kg level with zinc oxide (ZnO; as inorganic source), Zn-methionine (Zn-Met; as organic source) and zinc oxide nanoparticles (nano-ZnO). The results indicated that Zn-Met and nano-ZnO groups significantly improved body weight, daily weight gain (DWG), feed conversion ratio (FCR) and nutrient digestibility, as well as decreased mortality, compared to ZnO and control groups. Zn-Met and nano-ZnO significantly reduced serum total cholesterol but did not affect serum proteins and liver function. Nano-ZnO supplemented group also recorded the highest value of serum alkaline phosphatase (ALP), insulin-like growth factor (IGF-1) and lysozymes compared to other groups. Nano-ZnO supplementation had increased hepatic Zn and Cu content and decreased faecal Zn content. Also nano-ZnO group recorded higher expression levels of genes encoding for metallothionein I and metallothionein II, interleukin-2 and interferon-γ in the liver of rabbits. The findings of this study demonstrated zinc nanoparticles, and organic zinc supplementation had improved growth performance and health status of growing rabbits than inorganic zinc oxide.

Metallic Orthodontic Materials Induce Gene Expression and Protein Synthesis of Metallothioneins.

Background: Due to the long-term contact with metallic elements of orthodontic appliances, the potential influence of released metal ions on living organisms and the type of induced changes was investigated. Materials and Methods: Twenty-four young domestic pigs classified in two groups (experimental and control) were chosen as the object of this study. In the experimental group of animals, two metal plates consisting of orthodontic bands representing the mass of orthodontic appliance were mounted on the internal side of the cheek for six months. The liver, lung, and brain samples were taken post mortem from animals of both groups. The gene expression of two isoforms of metallothionein (MT-1 and MT-2) were investigated using the qPCR technique. Protein expression was confirmed by the Western blot and ELISA techniques. Results: The differences in metallothionein concentrations were observed in the lung and brain in the group of experimental animals, but not in the liver. The expression of MT-1 and MT-2 genes in the experimental vs. control group (respectively) was as follows: lung MT-1 1.04 vs. 1.11, MT-2 0.96 vs. 1.05, liver MT-1 0.89 vs. 0.91 vs. 1.12, MT-2 0.91 vs. 1.05, brain MT-1 1.24 vs. 1.20, and MT-2 0.955 vs. 0.945. These results were confirmed by gene activity, which was tested by qPCR. This increased the activity of metallothionein genes in the lungs and brain as a consequence of the release of metal ions into these tissues. The possible effects of detected change in metallothionein-2 gene expression could be the alteration of physiological functions of lung tissue. Conclusions: The effect of long-term exposure to metal orthodontic appliances on metallothioneins gene expression, as well as the induction of protein synthesis was proved.

Metallothioneins alter macrophage phenotype and represent novel therapeutic targets for acetaminophen-induced liver injury.

Acetaminophen (APAP) intoxication is the foremost cause of drug-induced liver failure in developed countries. The only pharmacologic treatment option, N-acetylcysteine (NAC), is not effective for patients who are admitted too late and/or who have excessive liver damage, emphasizing the need for alternative treatment options. APAP intoxication results in hepatocyte death and release of danger signals, which further contribute to liver injury, in part by hepatic monocyte/macrophage infiltration and activation. Metallothionein (MT) 1 and 2 have important danger signaling functions and might represent novel therapeutic targets in APAP overdose. Therefore, we evaluated hepatic MT expression and the effect of anti-MT antibodies on the transcriptional profile of the hepatic macrophage population and liver injury following APAP overdose in mice. Hepatic MT expression was significantly induced in APAP-intoxicated mice and abundantly present in human livers. APAP intoxication in mice resulted in increased serum transaminase levels, extended necrotic regions on liver histology and induced expression of proinflammatory markers, which was significantly less pronounced in mice treated with anti-MT antibodies. Anti-MT antibody therapy attenuated proinflammatory macrophage polarization, as demonstrated by RNA sequencing analyses of isolated liver macrophages and in LPS-stimulated bone marrow-derived macrophages. Importantly, NAC and anti-MT antibodies were equally effective whereas administration of anti-MT antibody in combination with NAC exceeded the efficiency of both monotherapies in APAP-induced liver injury (AILI). We conclude that the neutralization of secreted MTs using a monoclonal antibody is a novel therapeutic strategy as mono- or add-on therapy for AILI. In addition, we provide evidence suggesting that MTs in the extracellular environment are involved in macrophage polarization.

Environmental biomonitoring by snails

Background: Bio-indicator systems are vital in terms of monitoring of pollutants around the world. The impact of environmental change can be monitored by employing the responsive behaviour of snails. Heavy metal and organic pollutants affects snail reproduction, mortality, and normal metabolic activities. Various changes like a discontinuity in food intake, growth rate, twitching, and quenching of tentacles, are the biomarkers of the snails for biomonitoring. Different snails can bio-monitor eco-toxicological urban pollution, oil pollutant, terrestrial pollution, pesticide pollutants, mercury contamination, ammonia, chlorinated paraffin in soil, ethanol in water, ocean acidification pollutions. These animals can also make bio-sense about diverse environment spheres, which include the biosphere, lithosphere, anthroposphere, cryosphere, and hydrosphere. Methods: We examined the scientific literature and related articles listed in Pub-med, Google Scholar reporting on biomonitoring potential and biomarkers expression of various snail species and consequently explore the value of snails in the respective field by discussing various outcomes of a number of studies on the pollution biomonitoring and biosensing capabilities. Results: Several terrestrial, freshwater and sea snail species are characterized by the high sense of biomonitoring and biosensing potential. Various biomarkers such as expression of heat shock proteins and metallothioneins in the body are found to be the essential in-vivo biomarkers for pollution biomonitoring. Conclusion: It is observed that snails offer an environment friendly approach for the environmental bio monitoring by expressing their numerous physiological, biochemical, genetical and histological biomarkers in their body. Thus, it proved to be a critical bio monitoring tool and early warning indicators.

Dietary exposure to methyl mercury chloride induces alterations in hematology, biochemical parameters, and mRNA expression of antioxidant enzymes and metallothionein in Nile tilapia.

Methyl mercury chloride "MMC" (CH3ClHg) is an ubiquitous environmental toxicant that causes a variety of adverse effects. In the present study, we investigated the effects of sub-chronic toxicity of MMC on Nile tilapia (Oreochromis niloticus) through the evaluation of growth performance and hematological, biochemical, and oxidative stress biomarkers. From 150 healthy fish, five equally sized treatment groups were created: a control (CT) group fed with a basal diet and four MMC treatment groups exposed to 0.5, 1, 1.5, and 2 mg of MMC per kg of basal diet for 60 days. MMC exposure significantly reduced the growth performance and survival of O. niloticus and decreased red blood cell count and hemoglobin concentration. Treated fish exhibited normocytic normochromic anemia in addition to leucopenia, lymphopenia, granulocytopenia, and monocytopenia. Moreover, MMC exposure significantly affected liver function, including a reduction in the total protein levels while increasing cholesterol and triglyceride levels. It also markedly increased the production of stress biomarkers such as glucose and cortisol levels. Furthermore, MMC significantly elevated the levels of hepatic enzymes, induced tissue damage, and caused inflammation, as indicated by the upregulation of mRNA expression of hepatic metallothionein. Finally, MMC exposure induced oxidative stress by altering the antioxidant status of the liver and downregulating the mRNA expression of superoxide dismutase, glutathione peroxidase, and glutathione S-reductase. In conclusion, MMC toxicity induced hematological and biochemical alterations, leading to an enhanced state of oxidative stress in O. niloticus.

CT23 knockdown attenuating malignant behaviors of hepatocellular carcinoma cell is associated with upregulation of metallothionein 1.

The cancer-testis antigen 23 (CT23) gene has been reported in association with the pathogenesis and progressof hepatocellular carcinoma (HCC). However, the alterations of gene expression profiling induced by CT23 knockdown in HCC cells remains largely unknown. In this study, theRNA interfering (RNAi) method was used to silence CT23 expression in BEL-7404 cells. Microarray analysis was performed on mRNAextracted from the CT23 knockdown cells and the control cells to determine the alterations of gene expression profiles. The result showed a total of 1051 genes expressed differentially (two-fold change), including 470 genes upregulated and 581 gene downregulated in the CT23 knockdown cells. A bioinformaticanalysis showed that the functional differentially expressed genes (DEGs) were linked to cell proliferation, migration, and apoptosis, and metallothionein 1 (MT1) attainedthe maximum enrichment scores in functional annotation, classification, and pathway analysis of DEGs. Furthermore, Western blot analysis and cell behaviors assays verified that CT23 modulates cell proliferation, migration, and apoptosis by regulating MT1 expression in HCC cells and non-neoplastic hepatocytes. In summary, downregulated CT23 gene in BEL-7404 cells might change the expressions of carcinogenesis and progression related genes in HCC by upregulating MT1 expression, which would provide insight intosearching for a novel therapeutic target for HCC.

DNA methylation and gene expression alterations in zebrafish embryos exposed to cadmium.

An unexplored attributing molecular mechanism of Cd toxicity is interference with the epigenetic machinery, such as DNA methylation, processes that are crucial for early fetal development. In order to investigate the effects of Cd on the expression of metallothionein (MT) and Dnmts transcripts, markers of DNA methylation, and signaling pathway gene expression, zebrafish embryos were exposed during 24 hours post-fertilization (starting at maximum 8-cell stage) to 0.0089, 0.089, and 0.89 μM Cd. The results showed that the Cd accumulation in zebrafish embryo reached a stable level after 12 hpf, and the Cd accumulation at individual time points was significantly different among different concentration groups. MT mRNA fold was significantly positive with the Cd content in embryos. We observed that the expression level of DNA methyltransferase (Dnmts) in the 0.089 μM Cd exposure group was significantly up-regulated. Dnmt1 expression was significantly up-regulated in the 0.89 μM Cd exposure group, and Dnmt3s expression and global methylation levels were significantly down-regulated. Cd up-regulated ErbB-3 gene expression, down-regulated ErbB-4 gene expression, and neutralized ErbB-1 gene expression. Cd activated Ca2+, MAPK-JUK, p38 MAP kinase, PI3K-AKT, and VEGF signaling pathway genes, indicating these pathway genes related to Cd exposure level. The results are helpful to clarify the molecular mechanism of DNA methylation in zebrafish embryo under metal pressure and further interference with the epigenetic machinery.

Accumulation and Depuration of Cd and its Effect on the Expressions of Metallothionein and Apoptotic Genes in Litopenaeus vannamei.

We investigated cadmium (Cd) accumulation in muscles, gills and hepatopancreas of Litopenaeus vannamei following 48h exposure to 5.25mg/L, and depuration of Cd in these tissues on 1, 5 and 15 d post exposure. We also detected the expressions of metallothionein (MT), caspase-3 and p53 in hepatopancreas of shrimp exposed to 0, 5.25 and 10.5mg/L Cd (the 24h median lethal concentration, 24h LC50) at 0, 3, 12, 24 and 48h. Cd accumulated with high concentration in hepatopancreas, and low concentration in muscles. Cd depurated fast in hepatopancreas and gills. MT expression increased in a time-dependent manner after Cd exposure. The p53 and caspase-3 increased at 12 and 24h in 10.5mg/L group. In conclusion, the accumulation and depuration of Cd in three tissues were tissues-specific. The changes of the expressions of MT, p53 and caspase-3, were stress response of L. vannamei under Cd exposure.

Levels of Zinc Transporters mRNA Depending on Zinc Status and HIV-1 Tat Induced Inflammation in Muscle (Rhabdomyosarcoma) and Monocyte (THP-1) Cell Lines.

Monocytes and muscles demonstrate functionally contrasting behavior under conditions of zinc deficiency with relation to zinc storage system (muscle retain zinc in contrast to monocytes). We aimed to understand the effects of zinc status and HIV-1 Tat mediated inflammation on expression of zinc transporters in these types of cells. Expression of zinc transporters [ZnTs, ZIPs, and metallothionein (MT)] was quantified by qRT-PCR in RD, THP-1 cells separately and in co-cultured THP-1-RD cells. ZnT1 protein expression levels were confirmed by Western blot. Significant increase of MT and ZnT1 mRNA in response to zinc supplementation and decrease during zinc deficiency indicates significance of the genes encoding transporters in maintaining zinc homeostasis in these tissues. In the RD cells ZIP10 exhibited inverse relation to zinc status whereas no correlation was found in the THP-1 cells. Tat-induced inflammation resulted in the significant elevation of MT, IL6, ZIP7, ZIP8, ZIP9 transcripts in the co-cultured RD cells, whereas THP-1 cells demonstrated increased IL-1β levels and reduced levels of ZIP7 and ZIP14. Zinc status and HIV-1Tat induced inflammation appear to influence differential expression of MT, ZnTs, and ZIPs in the muscle and monocyte cells.

Modulatory effect of fructooligosaccharide against triphenyltin-induced oxidative stress and immune suppression in goldfish (Carassius auratus)

Triphenyltin (TPT) is a widely used pesticide that is highly toxic to a variety of organisms, including humans, and is a potential contributor to environmental pollution. The present study was conducted to evaluate the oxidative stress and immunotoxicity induced by TPT in goldfish (Carassius auratus) and the protective effects of fructooligosaccharide (FOS). Goldfish (mean weight of 13.3 ± 0.2 g) were randomly divided into six groups with three replicates: (G1) the control group, (G2) the 10 ng/L TPT group, (G3) the 0.4% FOS group, (G4) the 10 ng/L TPT + 0.4% FOS group, (G5) the 0.8% FOS group, and (G6) the 10 ng/L TPT + 0.8% FOS group. The results showed that 10 ng/L TPT induced oxidative stress and significantly decreased the activities of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), in the liver and the gene expression of SOD, GPx, metallothionein (MT), and peroxiredoxin-4 (Prdx-4). The concentration of malondialdehyde (MDA) and the gene expression of cytochrome P450 (CYP) and glutathione S-transferase (GST) in the liver were significantly increased in the TPT-treated group. Exposure to 10 ng/L TPT in water induced immune suppression and significantly decreased the activities of immune enzymes, such as lysozyme, myeloperoxidase (MPO), alternative complement (ACH50), acid phosphatase (ACP) and alkaline phosphatase (AKP), in the serum. TPT could stimulate the fish to generate large amounts of proinflammatory cytokines, including increased tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1β (IL-1β), and nitric oxide (NO) levels and TNF-α, IL-6, IL-1β, and NF-κB mRNA expression. However, TPT-induced toxicity was significantly ameliorated in the groups treated with FOS, and FOS partly prevented alterations in the activities of antioxidant enzymes and the expression of antioxidant- and ROS scavenger-related genes. In addition, TPT-induced immune toxicity was significantly ameliorated in the groups treated with FOS. FOS markedly suppressed TNF-α, IL-6, IL-1β, and NO production and TNF-α, IL-6, and IL-1β mRNA expression in the TPT-treated groups. The study indicated that TPT-induced oxidative stress may play a critical role in inhibiting immunity. However, FOS administration attenuates TPT-induced oxidative stress and immune suppression in goldfish.

Immunoexpression and Prognostic Significance of Multidrug Resistance Markers in Feline Mammary Carcinomas

Feline mammary carcinomas (FMCs) are commonly characterized by high clinical aggressiveness and poor prognosis. FMCs share many features with the corresponding human disease, allowing the comparative investigation of tumour biology and therapeutic strategies, including multidrug resistance (MDR) mechanisms. Although transporting/binding proteins, including permeability glycoprotein (P-gp), lung resistance protein (LRP) and metallothionein (MT), are frequently associated with tumour aggressiveness and unresponsiveness to chemotherapy in human breast cancer, they have not been analysed in FMCs. We investigated the immunoexpression of P-gp, LRP and MT in FMCs and their correlation with clinicopathological parameters and overall survival (OS) time in 46 FMCs, with a median follow-up period of 289 days. These markers were co-expressed in 85% of tumours. P-gp was expressed in 93.4% of FMCs and was positively associated with tumour grade (P=0.049). While unequivocally observed in all FMCs, LRP immunoexpression did not correlate with any clinicopathological parameters or OS. Expression of MT was significant in triple-negative basal- and normal-like molecular subtypes of FMCs (P=0.023). The concurrent expression of MDR proteins indicates the potential existence of chemotherapy resistance-related mechanisms in FMCs. The positive association between P-gp and MT immunoexpression and aggressive phenotypes could open new therapeutic and translational strategies for FMCs.

Multi-elemental composition and toxicity of bottom sediments from Panama Canal watershed

The Panama Canal is a milestone in the history of interoceanic communication. Despite its importance, environmental data regarding this important ecosystem is scarce. The aim of this work was to quantify trace-element levels in bottom sediments from 11 sites along the Canal watershed using ICP-MS, and in the case of mercury, employing a direct Hg Analyzer. These data were associated with the biological activity of aqueous sediment extracts tested on wild type and mutant strains of Caenorhabditis elegans, measuring physiological and molecular markers. The levels of trace elements in bottom sediments decreased in the order Sr > V > Ba > Cr > Li > Sc > Ce > Ni > Y > Co > Ga > Pb > Rb > Nd > La > Gd > Dy > Sm > Pr > Er > Hf > Yb > U > Th > Eu > Ho > Be > Tb > Tm > Ta > Hg. The Pollution factor and Pollution Load Index showed that 36% of the sites presented strong sediment pollution by V, Li, Pb, and Sr. Moreover, the Comprehensive Ecological Risk Index based on Cr and Ni levels was exceeded in all stations. Toxicity tests revealed that sediment extracts, despite not being highly lethal against C. elegans, did significantly reduce its mobility and activated toxicity mechanisms associated with the expression of metallothionein and oxidative stress-related genes. These last three endpoints were statistically related to Cr, Ta and Ba concentrations in sediments, respectively. Data suggest elements present in sediments from Panama Canal may be impacting benthonic organisms, and therefore, stronger management regulations should be considered in order to ensure its sustainability.

Assessment of Adverse Effects of Lead, Nickel and Cadmium on Biochemical Parameters, Antioxidants Status and Metallothionein Expression in Buffaloes Slaughtered at Local Abattoir

Background: With the pace of industrialization, heavy metal level has been increasing in animals thereby causing deleterious effects, which emanate as public health concern, associated with their accumulation in food chain. The present study was undertaken to assess the systemic damage caused by heavy metals in buffaloes. Methods: The assessment of adverse effects of the lead (Pb), nickel (Ni) and cadmium (Cd), in blood was determined by monitoring the levels of biochemical parameters, antioxidants and expression of metallothionein in buffaloes. Blood and tissue (liver, kidney, pancreas and ovary) samples (n=50) were collected from local abattoir to estimate the levels of lead, nickel and cadmium using atomic absorption spectrophotometry. Antioxidants and biochemical parameters were estimated using standard procedures and while the expression of metallothionein-2 was analyzed using real-time PCR.Result: After determining the concentration of heavy metals in samples the buffaloes were classified as heavy metal exposed and non-exposed groups. The plasma level of heavy metals were found to be significantly (p less than 0.05) higher than the permissible limit in exposed buffaloes. In tissues, heavy metals levels were within the permissible limits. Malondialdehyde level in each of lead, nickel and cadmium exposed groups was significantly (p less than 0.05) higher than the non-exposed, control group. The antioxidant activity of superoxide dismutase, catalase and glutathione was found to be increased significantly (p less than 0.05) in exposed groups. Also, plasma glucose, cholesterol, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactic dehydrogenase (LDH), creatine kinase (CK), urea and creatinine levels were found to be significantly higher (p less than 0.05) in the blood of the animal model used for the study. The fold change expression of MT-2 in blood was found to be at maximum level in cadmium and minimum in nickel exposed buffaloes. It can be concluded from the results of the experiment that heavy metals affect major organs (liver, kidney and muscle etc.) as evident by altered intracellular expression of MT-2, antioxidants and biochemical parameters.

Anti-oxidants in astrocytes as target of neuroprotection for Parkinson's disease

Recently, it has been reported that dysfunction of astrocytes is involved vulnerability of neuronal cells in several neurological disorders. Glutathione (GSH) is the most abundant intrinsic antioxidant in the central nervous system, and its substrate cysteine is readily becomes the oxidized dimeric cystine. Since neurons lack a cystine transport system, neuronal GSH synthesis depends on cystine uptake via the cystine/glutamate exchange transporter (xCT), GSH synthesis and release in/from surrounding astrocytes. The expression and release of the zinc-binding protein metallothionein (MT) in astrocytes, which is a strong antioxidant, is induced and exerts neuroprotective in the case of dopaminergic neuronal damage. In addition, the transcription factor Nrf2 induces expression of MT-1 and GSH related molecules. We previously revealed that several antiepileptic drugs, serotonin 5-HT1A receptor agonists, plant-derived chemicals (phytochemicals) increased xCT expression, Nrf2 activation, GSH or MT expression and release in/from astrocytes, and exerted a neuroprotective effect against dopaminergic neurodegeneration in Parkinson's disease model. Our serial studies on neuroprotection via antioxidant defense mechanism of astrocytes have found three target molecular systems of astrocytes for neuroprotection: (1) xCT-GSH synthetic system, (2) Nrf2 system and (3) 5-HT1A receptor-Nrf2-MT system, 5-HT1A-S100β system. In this article, possible neuroprotective strategy for Parkinson's disease has been reviewed targeting antioxidative molecules in astrocytes.

Screening Dietary Herbs for Health Intervention on Mass Cadmium Poisoning

Objective: Mass cadmium (Cd) poisoning is a serious health problem in many parts of the world. We propose that dietary intervention can be a practical solution to this problem. This study aimed to identify effective dietary products from traditional Chinese herbs that can detoxify Cd. Design: Five candidate herbal foods with detoxifying potential were selected and subjected to mouse toxicological tests. The chemical composition and dose-response effects of licorice on mouse hepatocytes were determined. Licorice was selected for further tests to examine its effects on growth, tissue Cd accumulation, and gut and liver fitness of mice. The expression of hepatic metallothionein (Mt) genes was quantified in vitro in hepatocytes and in vivo in liver tissues of mice. Results: The results showed that licorice dietary intervention was effective in reducing blood Cd by > 50% within 1 month. Cd was also substantially reduced in the heart and lung tissues, but increased 2.1-fold in the liver. The liver of Cd poisoned mice improved with licorice intervention. Licorice treatment significantly induced Cd accumulation and expression of the Mt1 gene in hepatic cells both in vitro and in vivo. Licorice intake substantially altered gut microbial structure and enriched Parabacteroides distasonis. Omics results showed that licorice improved gut metabolism, particularly the metabolic pathways for glycyrrhizin, bile acids, and amino acids. Conclusion: Dietary licorice effectively reduced mouse blood Cd and had a profound impact on liver and gut fitness. We conclude that herbal licorice can be used as a dietary intervention for mass Cd poisoning. Funding: This work was supported by the Hebei Provincial Science Fund or Distinguished Young Scholars (No. D2018503005), the National Key Research and Development Program of China (No.2018YFD0800306), and the National Natural Science Foundation of China (Nos. 41877414 and 31700228). Declaration of Interest: None to declare. Ethical Approval: The study was approved by the Animal Care and Use Committee of the Hebei Science and Technical Bureau, China

Zinc Supplementation Forms Influenced Zinc Absorption and Accumulation in Piglets.

Simple SummaryHigh levels of inorganic Zn were supplemented to meet the nutritional requirements of Zn in piglets, which results in the development of intestinal microbial resistance and environmental pollution. Previous research indicated that organic Zn sources had higher bioavailability than inorganic Zn. There is limited information on the comparison of dietary Zn source dissolved in water with other Zn supplementation forms in piglets. Therefore, the present study was designed to compare the effects of three Zn supplementation forms (Zn-Met in the feed, ZnSO4 in the feed, and ZnSO4 dissolved in drinking water) on growth performance, Zn accumulation, activities of Zn-containing enzymes, expression of MT, and Zn transporters in piglets. In conclusion, Zn-Met and ZnSO4 dissolved in drinking water had higher bioavailability in piglets.The study aimed at determining the effect of different zinc (Zn) supplementation forms on Zn accumulation, activities of Zn-containing enzymes, gene expression of metallothionein (MT), and Zn transporters in piglets. Eighteen piglets were randomly divided into three groups: (a) a basal diet supplemented with 150 mg/kg Zn from Zn methionine (Zn-Met) in the feed (Zn-Met group), (b) a basal diet supplemented with 150 mg/kg Zn from Zn sulfate (ZnSO4) in the feed (ZnSO4, feed group), and (c) a basal diet supplemented with the same dose of Zn as in ZnSO4,feed group but in water (ZnSO4, water group). The results showed that Zn-Met added in feed and ZnSO4 dissolved in drinking water significantly improved (p < 0.05) the Zn concentration in liver and jejunum and the apparent digestibility of Zn in comparison with the ZnSO4 added in feed. In addition, dietary Zn supplementation as Zn-Met significantly increased (p < 0.05) the activity of alkaline phosphatase (AKP) in the jejunum of piglets in comparison with the ZnSO4, feed group. Furthermore, the Zn-Met and ZnSO4, water groups showed an improved total superoxide dismutase activity (T-SOD) in the ileum as compared to the ZnSO4, feed group. Meanwhile, the qPCR and western blot results showed that Zn-Met and ZnSO4 dissolved in drinking water increased the expression of MT in the jejunum in comparison with the ZnSO4 added in the piglets’ feed. However, different Zn supplementation forms had no effect on the mRNA expressions of Zip4 and ZnT1 transporters. In conclusion, Zn-Met added in feed and ZnSO4 dissolved in drinking water had higher bioavailability in piglets.

Spatial expression of metallothionein, matrix metalloproteinase-1 and Ki-67 in human epidermal wounds treated with zinc and determined by quantitative immunohistochemistry: A randomised double-blind trial

Reepithelialisation is fundamental to wound healing, but our current understanding largely relies on cellular and animal studies. The aim of the present randomised double-blind three-arm controlled trial was to correlate genuine epidermal wound healing with key proteins and topical zinc treatment in humans. Sixty wounds were produced using deroofed suction blisters in 30 healthy volunteers and randomised to topical zinc sulphate (n = 20), placebo (n = 20), or control (n = 20) treatment for 4 days. All wounds with perilesional skin were processed for automatic immunostaining of paraffin tissue sections with monoclonal antibodies against Ki-67, metallothionein (MT) and matrix metalloproteinase (MMP)-1. Protein expression was quantified by automated digital image analysis. Epidermal Ki-67 and MT labelling indices were increased in keratinocytes in the neoepidermis (∼1.1 mm) and at the wound edge (0.5 mm) compared to normal skin. Increased MMP-1 immunostaining was restricted to the neoepidermis. MT was robustly upregulated in the upper dermis of the wounds. Zinc treatment enhanced MMP-1 expression beneath the neoepidermis via paracrine mechanisms and MT under the neoepidermis and in the nonepithelialised wound bed via direct actions of zinc as indicated by the induction of MT2A mRNA but not MMP-1 mRNA in cultured normal human dermal fibroblasts by zinc sulphate. The present human study demonstrates that quantitative immunohistochemistry can identify proteins involved in reepithelialisation and actions of external compounds. Increased dermal MT expression may contribute to the anti-inflammatory activities of zinc and increased MMP-1 levels to promote keratinocyte migration.

Moderate Hydrogen Peroxide Postconditioning Ameliorates Ischemia/Reperfusion Injury in Cardiomyocytes via STAT3-Induced Calcium, ROS, and ATP Homeostasis

Introduction: Moderate hydrogen peroxide postconditioning (H₂O₂PoC) activates signal transducer and activator of transcription 3 (STAT3) to alleviate mitochondrial calcium overload during cardiac ischemia/reperfusion (I/R). However, the initial time window of STAT3-induced calcium hemostasis, the production of reactive oxygen species (ROS) and adenosine triphosphate (ATP) in H₂O₂PoC, and its regulated mechanism remain unknown. This study aimed to investigate H₂O₂PoC-induced homeostasis of calcium, ROS and ATP, and the role of STAT3 in the regulation. Methods: Isolated rat cardiomyocytes were exposed to H₂O₂PoC and Janus kinase 2 (JAK2)/STAT3 inhibitor AG490 during I/R. Ca²⁺ transients, cell contraction, intracellular calcium concentration, ROS production, ATP contents, phosphorylation of STAT3, gene and protein expression of manganese superoxide dismutase (MnSOD), metallothionein 1 (MT1) and metallothionein 2 (MT2), as well as activities of mitochondrial complex I and complex II were detected. Results: Moderate H₂O₂PoC improved post-ischemic Ca²⁺ transients and cell contraction recovery as well as alleviated cytosolic and mitochondrial calcium overload, which were abrogated by AG490 in rat cardiomyocytes. Moderate H₂O₂PoC increased ROS production and rate of ROS production at early reperfusion in rat I/R cardiomyocytes, and this phenomenon was also abrogated by AG490. Notably, the expression of phosphorylated nuclear STAT3; gene and protein expression of MnSOD, MT1, and MT2; and activities of mitochondrial complex I and complex II were upregulated by moderate H₂O₂PoC but downregulated by AG490. Conclusion: These findings indicated that the cardioprotection of moderate H₂O₂PoC against cardiac I/R could be associated with activated STAT3 at early reperfusion to maintain calcium, ROS, and ATP homeostasis in rat cardiomyocytes.