Zinc deficiency alters lipid metabolism in LDL receptor deficient mice treated with rosiglitazone

Imbalanced and Unchecked: The Role of Metal Dyshomeostasis in Driving COPD Progression

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory condition characterized by persistent inflammation and oxidative stress, which ultimately leads to progressive restriction of airflow. Extensive research findings have cogently suggested that the dysregulation of essential transition metal ions, notably iron, copper, and zinc, stands as a critical nexus in the perpetuation of inflammatory processes and oxidative damage within the lungs of COPD patients. Unraveling the intricate interplay between metal homeostasis, oxidative stress, and inflammatory signaling is of paramount importance in unraveling the intricacies of COPD pathogenesis. This comprehensive review aims to examine the current literature on the sources, regulation, and mechanisms by which metal dyshomeostasis contributes to COPD progression. We specifically focus on iron, copper, and zinc, given their well-characterized roles in orchestrating cytokine production, immune cell function, antioxidant depletion, and matrix remodeling. Despite the limited number of clinical trials investigating metal modulation in COPD, the advent of emerging methodologies tailored to monitor metal fluxes and gauge responses to chelation and supplementation hold great promise in unlocking the potential of metal-based interventions. We conclude that targeted restoration of metal homeostasis represents a promising frontier for ameliorating pathological processes driving COPD progression.

Cardiovascular Diseases in Obesity: What is the Role of Magnesium?

An excess of adipose tissue, a characteristic of obesity, has been associated with endocrine-metabolic alterations that contribute to dyslipidemias, which are characterized by an increase in the plasma concentrations of triacylglycerols, total cholesterol, and LDL-c along with a reduction in HDL-c. Some nutrients such as the mineral magnesium play important roles in lipid metabolism. Magnesium regulates the activity of HMG-CoA reductase, increasing the activity of lipoprotein lipase and lecithin-cholesterol acyltransferase. The objective of this review is to present important aspects about the contribution of obesity to the manifestation of cardiovascular risk, to bring the main physiological functions of magnesium, as well as the role of the nutrient in the protection against cardiovascular diseases. Studies have shown that individuals with obesity have low intracellular concentrations of magnesium, which can compromise the nutrient's physiological functions. Thus, this mineral appears to play an important role in protecting against cardiovascular diseases; however, changes in the nutrient metabolism in obesity may compromise the functions of this element. Further studies are needed to clarify this.

The effects of Zinc-Methionine on glucose metabolism and insulin resistance during late pregnancy in ewes

This study investigated the effects of dietary supplements of Zinc-Methionine (Zn-Met) on the zinc concentration of the blood and indices such as insulin resistance and glucose tolerance in late-pregnancy ewes to provide a practical solution to prevent metabolic diseases associated with energy status. In this research, 18 Makouei pregnant ewes were selected and randomized into 3 experimental groups: Group 1: Basal diet containing 10.3 mg Zn/kgDM and no zinc supplementation = CTR (Control); Group 2: Basal diet supplemented with low-dose zinc equivalent to the pregnancy requirements (30 mg Zn/kgDM) = LZN; Group 3: Basal diet supplemented with high-dose zinc (300 mg Zn/kgDM) = HZN. Blood samples for insulin resistance and glucose tolerance indices were collected according to standard methods. The results of this study indicated that supplementation of high-dose Zn-Met decreased (P < 0.05) blood glucose and tended (P < 0.1) to reduce the beta-hydroxybutyrate (BHB) concentrations. After intravenous injection of glucose and insulin, none of the glucose tolerance and insulin resistance indices were significant among groups (P > 0.05). However, the intravenous glucose tolerance test (IGTT) showed that the area under the curve (AUC) of serum glucose in the HZN group was numerically lower than that of the LZN and CTR groups. Furthermore, the numerically higher clearance rate (CR) of glucose and more negative glucose AUC following intravenous administration of insulin in Zinc-supplemented groups suggested that the ewes had greater insulin response than control group. The results showed a decrease in blood glucose concentration due to higher zinc intake after insulin injection and supported the evidence for improving insulin sensitivity. In addition, our results showed that ewes receiving zinc supplementation experienced a more favorable state of BHB or NEFA values. In conclusion, Zn-Met supplementation was found to have promising effects in improving energy metabolism in late pregnant ewes. However, further studies are needed to understand the mechanisms involved in regulating lipolysis and energy metabolism.

Dietary and Physiological Effects of Zinc on the Immune System

Evidence for the importance of zinc for all immune cells and for mounting an efficient and balanced immune response to various environmental stressors has been accumulating in recent years. This article describes the role of zinc in fundamental biological processes and summarizes our current knowledge of zinc's effect on hematopoiesis, including differentiation into immune cell subtypes. In addition, the important role of zinc during activation and function of immune cells is detailed and associated with the specific immune responses to bacteria, parasites, and viruses. The association of zinc with autoimmune reactions and cancers as diseases with increased or decreased immune responses is also discussed. This article provides a broad overview of the manifold roles that zinc, or its deficiency, plays in physiology and during various diseases. Consequently, we discuss why zinc supplementation should be considered, especially for people at risk of deficiency. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Zinc Increases ABCA1 by Attenuating Its Clearance Through the Modulation of Calmodulin Activity

Aim: We previously revealed that Ca⁺⁺-activated calmodulin binds to ABCA1 by the region near the PEST sequence and retards its calpain-mediated degradation to increase HDL biogenesis. Calmodulin activity is reportedly modulated also by other nutritional divalent cations; thus, we attempted to determine whether Zn⁺⁺ is involved in the regulation of ABCA1 stability through the modulation of calmodulin activity.

Methods: The effects of Zn⁺⁺ on ABCA1 expression was investigated in J774 mouse macrophage cell-line cells and HepG2 human hepatoma cell-line cells.

Results: Zn⁺⁺ increased ABCA1 expression, not by increasing the mRNA but by attenuating its decay rate, more prominently in the presence of cAMP. Accordingly, it enhanced cell cholesterol release with extracellular apolipo-protein A-I. Calmodulin binding to ABCA1 was increased by Zn⁺⁺ and Ca⁺⁺. Zn⁺⁺ suppressed calpain-mediated hydrolysis of the peptide of ABCA1 cytosolic loop, including the PEST sequence and the calmodulin-binding site, in a calmodulin-dependent fashion, in the presence of the minimum amount of Ca⁺⁺ to activate calpain, but not calmodulin. Calpain activity was not directly inhibited by Zn⁺⁺ at the concentration for enhancing calmodulin binding to ABCA1.

Conclusion: Nutritional divalent cation Zn⁺⁺ is involved in the regulation of ABCA1 activity and biogenesis of HDL through the modulation of calmodulin activity. The results were consistent with previous clinical findings that Zn⁺⁺ increased plasma HDL in the conditions of sympathetic activation, such as type 2 diabetes and chronic hemodialysis.

Role of Zinc in Zinc-α2-Glycoprotein Metabolism in Obesity: a Review of Literature

Excessive adipose tissue promotes the manifestation of endocrine disorders such as reduction of the secretion of zinc-α2-glycoprotein (ZAG), an adipokine with anti-inflammatory and lipid-mobilizing activity. The molecular structure of this adipokine includes binding sites for zinc, a trace element with important antioxidant and immunological proprieties that also participates in energy metabolism and stimulates the function of ZAG. The objective of this review is to highlight current data on the metabolism of ZAG in obesity and the role of zinc in this process. The identified studies show that subjects with obesity have low serum concentrations of zinc and ZAG, as well as low expression of the genes encoding this protein. Thus, zinc appears to be an important regulator of the homeostasis of ZAG in the body; however, alterations in the metabolism of zinc in obesity appear to compromise the functions of ZAG. Therefore, further studies are needed to clarify the relationship between zinc and ZAG metabolism and its repercussions in obesity.

High-precision isotopic analysis of serum and whole blood Cu, Fe and Zn to assess possible homeostasis alterations due to bariatric surgery

Bariatric surgery is an effective procedure to achieve weight loss in obese patients. However, homeostasis of essential metals may be disrupted as the main absorption site is bypassed. In this study, we determined Cu, Fe and Zn isotopic compositions in paired serum and whole blood samples of patients who underwent Roux-en-Y gastric bypass (RYGB) surgery for evaluation of longitudinal changes and their potential relation to mineral element concentrations and relevant clinical parameters used for monitoring the patient's condition. Samples from eight patients were collected pre-surgery and at 3, 6 and 12 months post-surgery. Multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS) was used for high-precision isotope ratio measurements. Alterations in metal homeostasis related to bariatric surgery were reflected in the serum and whole blood Cu, Fe and Zn isotopic compositions. The serum and whole blood Cu became isotopically lighter (lower δ⁶⁵Cu values) after bariatric surgery, reaching statistical significance at 6 months post-surgery (p < 0.05). The difference between the serum and the whole blood Zn isotopic composition increased after surgery, reaching significance from 6 months post-surgery onwards (p < 0.05). Those changes in Cu, Fe and Zn isotopic compositions were not accompanied by similar changes in their respective concentrations, making isotopic analysis more sensitive to physiological changes than elemental content. Furthermore, the Zn isotopic composition correlates with blood glycaemic and lipid parameters, while the Fe isotopic composition correlates with glycaemic parameters. Graphical Abstract.

Effect of Zinc Supplementation on Lipid Profile in Obese People: A Systematic Review

Background:

Many studies have investigated the influence of minerals on the control of changes in lipid metabolism in obese individuals. The objective of this study was to describe, in a systematic review, the clinical trial outcomes of zinc supplementation and lipid profiles of obese participants.

Methods:

This review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. A survey was conducted for selecting clinical trials related to the effects of zinc supplementation on lipid profiles in obese people, using the following databases: PubMed, SciVerse ScienceDirect and Cochrane.

Results:

After the selection process, five articles were identified as eligible for this review and it was observed that the clinical trials included adults and children of both sexes, in three different countries, and with zinc supplementation doses ranging from 20 to 100 mg/day. None of the studies observed changes in High-Density Lipoprotein (HDL-c) with zinc supplementation. On the other hand, three studies observed a positive effect of zinc supplementation on triglycerides, and two found an effect on Low-Density Lipoprotein (LDL-c) and total cholesterol.

Conclusion:

The results of this systematic review provide evidence on the benefits of zinc supplementation on lipid profiles in obese individuals. However, new intervention studies are needed to elucidate the function of the nutrient in protection against disorders related to lipid metabolism, as well as the standardization of the type, dose, and time of zinc supplementation.

Subcongenic analysis of a quantitative trait locus affecting body weight and glucose metabolism in zinc transporter 7 (znt7)-knockout mice

Background

A genome-wide mapping study using male F₂zinc transporter 7-knockout mice (znt7-KO) and their wild type littermates in a mixed 129P1/ReJ (129P1) and C57BL/6J (B6) background identified a quantitative trait locus (QTL) on chromosome 7, which had a synergistic effect on body weight gain and fat deposit with the znt7-null mutation.

Results

The genetic segment for body weight on mouse chromosome 7 was investigated by newly created subcongenic znt7-KO mouse strains carrying different lengths of genomic segments of chromosome 7 from the 129P1 donor strain in the B6 background. We mapped the sub-QTL for body weight in the proximal region of the previously mapped QTL, ranging from 47.4 to 64.4 megabases (Mb) on chromosome 7. The 129P1 donor allele conferred lower body weight gain and better glucose handling during intraperitoneal glucose challenge than the B6 allele control. We identified four candidate genes, including Htatip2, E030018B13Rik, Nipa1, and Atp10a, in this sub-QTL using quantitative RT-PCR and cSNP detection (single nucleotide polymorphisms in the protein coding region).

Conclusions

This study dissected the genetic determinates of body weight and glucose metabolism in znt7-KO mice. The study demonstrated that a 17-Mb long 129P1 genomic region on mouse chromosome 7 conferred weight reduction and improved glucose tolerance in znt7-KO male mice. Among the four candidate genes identified, Htatip2 is the most likely candidate gene involved in the control of body weight based on its function in regulation of lipid metabolism. The candidate genes discovered in this study lay a foundation for future studies of their roles in development of metabolic diseases, such as obesity and type 2 diabetes.

Electronic supplementary material

The online version of this article (10.1186/s12863-019-0715-2) contains supplementary material, which is available to authorized users.

Lipidome of plasma lipoproteins and liver is zinc- modulated in High fat diet treated mice

Zinc (Zn) and Zn-transcription Factors regulate the metabolic pathways of lipids and glucose, consequently nutritional zinc deficiency or excess, activates stress pathways and deranges the hepatic metabolism of lipids. High fat diet (HFD) also leads to lipids' profile disorders as well as to intracellular free radicals (FR) accumulation and finally to metabolic stress-syndrome. Study of nutritional Zn effects on the lipidome of plasma lipoproteins and liver, in HFD-mice, was the aim of the present research. Three Zn enriched HF-Diets as follows, 3 mg/kg feed (Zn deficient diet), 30 mg/kg feed (Zn sufficient diet), 300mgZn /kg feed (Zn excess diet) (Mucedola s.r.l Italy-55% cal) were applied respectively to three groups of male wild type (wt) mice (Hybrid F1/F1),C57Bl/6xCBA, one month old, for 10 weeks. Accordingly, mice body weight rate and ¹H-NMR spectrum analysis of liver extracts and plasma HDL and non-HDL lipoproteins were evaluated at the end of the experimental period. It is concluded that Zn sufficient diet (30 mg/Kg Feed) creates a highly protective lipidomic profile on plasma and liver lipoproteins of HFD-mice, related to significantly increased antiatherogenic indicators in lipids' composition, compared to mice in nutritional Zn deficiency or excess.

Association between the consumption of antioxidant nutrients with lipid alterations and cardiometabolic risk in adolescents

ABSTRACT Objective This study aimed at validating the associations between the consumption of antioxidant nutrients as well as lipid alterations and cardiometabolic risks in adolescents. Methods This cross-sectional study included 327 adolescents aged 14-19 years. Sociodemographic and dietary information, anthropometric and blood pressure measurements, and biochemical data were obtained. Cardiometabolic risk was calculated by aggregating the risk factors, which were expressed as the sum of Z-scores. Poisson regression was performed to estimate the prevalence ratios. Results In boys, low intake of zinc was associated with elevated total cholesterol and triglyceride levels, whereas it was associated with low high-density lipoprotein cholesterol levels and high low-density lipoprotein cholesterol and total cholesterol levels in girls, thus indicating a cardiometabolic risk. Furthermore, low intake of copper was associated with high triglyceride levels and cardiometabolic risk in girls. The high prevalence ratios of high low-density lipoprotein cholesterol and total cholesterol levels and cardiometabolic risk were higher in those with low intake of vitamin A. Among girls, associations were also observed between lower intake of vitamin A and high triglyceride levels. Low intake of vitamin C among boys was associated with elevated high low-density lipoprotein cholesterol and triglyceride levels. Among girls, the intake of this vitamin was associated with lower low high-density lipoprotein cholesterol levels. In girls, low intake of vitamin E was associated with low low high-density lipoprotein cholesterol levels and high total cholesterol levels. Conclusion The associations between antioxidant micronutrients as well as lipid alterations and cardiometabolic risk emphasize the importance of encouraging the consumption of foods that are rich in these nutrients to modulate lipid alterations and cardiometabolic risk.

Effect of Zinc Supplementation on Maintenance Hemodialysis Patients: A Systematic Review and Meta-Analysis of 15 Randomized Controlled Trials

We aimed to examine the effects of zinc supplementation on nutritional status, lipid profile, and antioxidant and anti-inflammatory therapies in maintenance hemodialysis (MHD) patients. We performed a systematic review and meta-analysis of randomized, controlled clinical trials of zinc supplementation. Metaregression analyses were utilized to determine the cause of discrepancy. Begg and Egger tests were performed to assess publication bias. Subgroup analysis was utilized to investigate the effects of zinc supplementation in certain conditions. In the crude pooled results, we found that zinc supplementation resulted in higher serum zinc levels (weighted mean difference [WMD] = 28.489; P < 0.001), higher dietary protein intake (WMD = 8.012; P < 0.001), higher superoxide dismutase levels (WMD = 357.568; P = 0.001), and lower levels of C-reactive protein (WMD = −8.618; P = 0.015) and malondialdehyde (WMD = −1.275; P < 0.001). The results showed no differences in lipid profile. In the metaregression analysis, we found that serum zinc levels correlated positively with intervention time (β = 0.272; P = 0.042) and varied greatly by ethnicity (P = 0.023). Results from Begg and Egger tests showed that there was no significant bias in our meta-analysis (P > 0.1). Results of subgroup analysis supported the above results. Our analysis shows that zinc supplementation may benefit the nutritional status of MHD patients and show a time-effect relationship.

Association of trace metal elements with lipid profiles in type 2 diabetes mellitus patients: a cross sectional study

BACKGROUND

It is well known that dyslipidemia and chronic hyperglycemia increase the onset of diabetes and diabetic complication. The aim of this study is to see the association of trace metals elements and lipid profile among type 2 diabetes mellitus patients.

METHODS

The study was conducted on 214 type 2 diabetic patients at Jimma University Specialized Hospital, Jimma, Ethiopia. All the eligible study participants responded to the structured interviewer administered questionnaire and fasting venous blood was drawn for biochemical analysis. Trace metal elements (zinc(Zn⁺²), magnesium(Mg⁺²), chromium(Cr⁺³), calcium(Ca⁺²), phosphorus(Po₄^-3), manganese(Mn⁺²), copper(Cu⁺²), and iron(Fe⁺³)) and lipid profiles (total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein (HDL-C), and triglycerides (TG)) were measured by atomic absorption spectrophotometry and enzymatic determination method respectively. Data were analyzed by SPSS version 24 software for windows. Bonferroni correction for multiple statistical comparisons was used and a p-value less than 0.01 were accepted as a level of significance.

RESULT

The mean age of study participants was 42.95(±12.6) with an average of 5.83(±3.1) years being diagnosed with diabetes mellitus. The BMI of female (27.1(±4.9)) was significantly higher than male (25.21(±4.2)). BMI shows positive and significant (p < 0.01) association with lipid profiles (TC, LDL-C, and TG) among type 2 diabetic patients in the liner regression model. In addition, WH-R was positively associated with TG. In Pearson partial correlation adjusted for sex and age, Za⁺² shown to have statistically significant and negative correlations with TC, LDL-C and with TG. Mg⁺² and Cr⁺² negatively and significantly correlated with the lipid profile TC and LDL-C. Ca⁺² negatively correlated with TC and TG. Po^-3₄ positively correlated with HDL-C; iron negatively correlated with TC. However, in the liner regression model, only calcium positively and significantly (Beta = -0.21, p < 0.01) associated with TG.

CONCLUSION

In the current study, a negative correlation was observed between trace metal elements (Zn⁺², Mg⁺², Cr⁺³, Ca⁺² and Fe⁺³) and lipid profile (TC, LDL-C and TG) among type 2 diabetes mellitus patients. In addition, Ca⁺² observed to be associated with TG. Future studies are highly advised to uncover the bidirectional association between trace metal element and dyslipidemia in diabetic patients.

Dietary zinc addition influenced zinc and lipid deposition in the fore- and mid-intestine of juvenile yellow catfishPelteobagrus fulvidraco

The present study explored the mechanisms of dietary Zn influencing Zn and lipid deposition in the fore- and mid- intestine in yellow catfishPelteobagrus fulvidraco, and investigated whether the mechanism was intestinal-region dependent. For this purpose, yellow catfish were fed three diets containing Zn levels of 8·83, 19·20 and 146·65 mg Zn/kg, respectively. Growth performance, intestinal TAG and Zn contents as well as activities and mRNA expression of enzymes and genes involved in Zn transport and lipid metabolism in the fore- and mid-intestine were analysed. Dietary Zn increased Zn accumulation as well as activities of Cu-, Zn-superoxide dismutase and ATPase in the fore- and mid-intestine. In the fore-intestine, dietary Zn up-regulated mRNA levels of ZnT1, ZnT5, ZnT7, metallothionein (MT) and metal response element-binding transcription factor-1 (MTF-1), but down-regulated mRNA levels of ZIP4 and ZIP5. In the mid-intestine, dietary Zn up-regulated mRNA levels of ZnT1, ZnT5, ZnT7, MT and MTF-1, but down-regulated mRNA levels of ZIP4 and ZIP5. Dietary Zn reduced TAG content, down-regulated activities of 6-phosphogluconate dehydrogenase (6PGD), glucose-6-phosphate dehydrogenase (G6PD), malic enzyme (ME) and fatty acid synthase (FAS) activities, and reduced mRNA levels of 6PGD, G6PD, FAS, PPARγand sterol-regulator element-binding protein (SREBP-1), but up-regulated mRNA levels of carnitine palmitoyltransferase IA, hormone-sensitive lipase (HSLa), adipose TAG lipase (ATGL) and PPARαin the fore-intestine. In the mid-intestine, dietary Zn reduced TAG content, activities of G6PD, ME, isocitrate dehydrogenase and FAS, down-regulated mRNA levels of 6PGD, G6PD, FAS, acetyl-CoA carboxylase a, PPARγand SREBP-1, but up-regulated mRNA expression of HSLa, ATGL and PPARγ. The reduction in TAG content following Zn addition was attributable to reduced lipogenesis and increased lipolysis, and similar regulatory mechanisms were observed between the fore- and mid-intestine.

Serum Zinc Deficiency and its Relation to Liver Fibrosis in Chronic HCV: a Real-Life Egyptian Study

Zinc is essential for the activation of approximately 300 metallo-enzymes. Serum and hepatic zinc is decreased in chronic liver disease patients, and zinc depletion has been suggested to accelerate liver fibrosis. The study was designed to assess Zinc status in chronic HCV Egyptian patients and its relationship to fibrosis stage diagnosed by FibroScan. This was a cross-sectional study on 297 Egyptian patients with naïve chronic HCV. All patients underwent laboratory tests (including assessment of serum Zinc) and liver stiffness measurement (LSM) by Transient Elastography (FibroScan^®). The study included 170 (57.2%) females and 127 (42.8%) males with a mean age 52.4 ± 10.2 years. Most of the patients had zinc deficiency as the mean zinc level was 55.5 ± 30.7 μg/dl. The FibroScan scores showed that 97 patients had mild to moderate fibrosis (≤F2), while 200 patients had advanced to severe fibrosis (˃F2). Zinc level was significantly lower in patients with ˃F2 than those with ≤F2 (52 ± 30.7 vs 62.5 ± 29.7, p value: 0.005), as the zinc values decreased with the progression of liver fibrosis. Serum zinc level had a negative significant correlation with INR and negative significant correlation with FibroScan score but no correlation to bilirubin, ALT, AST, or albumin. Most of Egyptian chronic liver disease patients had zinc deficiency. Zinc level gets significantly lower with progression of fibrosis. Zinc supplementation is essential before and during antiviral therapy for HCV.

Effect of zinc deprivation on the lipid metabolism of budding yeast

Zinc is an essential micronutrient for all living cells. It serves as a structural and catalytic cofactor for numerous proteins, hence maintaining a proper level of cellular zinc is essential for normal functioning of the cell. Zinc homeostasis is sustained through various ways under severe zinc-deficient conditions. Zinc-dependent proteins play an important role in biological systems and limitation of zinc causes a drastic change in their expression. In budding yeast, a zinc-responsive transcription factor Zap1p controls the expression of genes required for uptake and mobilization of zinc under zinc-limiting conditions. It also regulates the polar lipid levels under zinc-limiting conditions to maintain membrane integrity. Deletion of ZAP1 causes an increase in triacylglyerol levels which is due to the increased biosynthesis of acetate that serves as a precursor for triacylglycerol biosynthesis. In this review, we expanded our recent work role of Zap1p in nonpolar lipid metabolism of budding yeast.

The prevention of diabetic cardiomyopathy by non-mitogenic acidic fibroblast growth factor is probably mediated by the suppression of oxidative stress and damage

BACKGROUND

Emerging evidence showed the beneficial effect of acidic fibroblast growth factor (aFGF) on heart diseases. The present study investigated whether non-mitogenic aFGF (nm-aFGF) can prevent diabetic cardiomyopathy and the underlying mechanisms, if any.

METHODOLOGY/PRINCIPAL FINDINGS

Type 1 diabetes was induced in mice by multiple intraperitoneal injections of low-dose streptozotocin. Hyperglycemic and age-matched control mice were treated with or without nm-aFGF at 10 µg/kg daily for 1 and 6 months. Blood pressure and cardiac function were assessed. Cardiac H9c2 cell, human microvascular endothelial cells, and rat cardiomyocytes were exposed to high glucose (25 mM) for mimicking an in vitro diabetic condition for mechanistic studies. Oxidative stress, DNA damage, cardiac hypertrophy and fibrosis were assessed by real-time qPCR, immunofluorescent staining, Western blotting, and pathological examination. Nm-aFGF significantly prevented diabetes-induced hypertension and cardiac dysfunction at 6 months. Mechanistic studies demonstrated that nm-aFGF showed the similar preventive effect as the native aFGF on high glucose-induced oxidative stress (increase generation of reactive oxygen species) and damage (cellular DNA oxidation), cell hypertrophy, and fibrotic response (increased mRNA expression of fibronectin) in three kinds of cells. These in vitro findings were recaptured by examining the heart of the diabetic mice with and without nm-aFGF.

CONCLUSIONS

These results suggest that nm-aFGF can prevent diabetic cardiomyopathy, probably through attenuation of cardiac oxidative stress, hypertrophy, and fibrosis.

Dietary zinc deficiency exaggerates ethanol-induced liver injury in mice: involvement of intrahepatic and extrahepatic factors

Clinical studies have demonstrated that alcoholics have a lower dietary zinc intake compared to health controls. The present study was undertaken to determine the interaction between dietary zinc deficiency and ethanol consumption in the pathogenesis of alcoholic liver disease. C57BL/6N mice were subjected to 8-week feeding of 4 experimental liquid diets: (1) zinc adequate diet, (2) zinc adequate diet plus ethanol, (3) zinc deficient diet, and (4) zinc deficient diet plus ethanol. Ethanol exposure with adequate dietary zinc resulted in liver damage as indicated by elevated plasma alanine aminotransferase level and increased hepatic lipid accumulation and inflammatory cell infiltration. Dietary zinc deficiency alone increased hepatic lipid contents, but did not induce hepatic inflammation. Dietary zinc deficiency showed synergistic effects on ethanol-induced liver damage. Dietary zinc deficiency exaggerated ethanol effects on hepatic genes related to lipid metabolism and inflammatory response. Dietary zinc deficiency worsened ethanol-induced imbalance between hepatic pro-oxidant and antioxidant enzymes and hepatic expression of cell death receptors. Dietary zinc deficiency exaggerated ethanol-induced reduction of plasma leptin, although it did not affect ethanol-induced reduction of white adipose tissue mass. Dietary zinc deficiency also deteriorated ethanol-induced gut permeability increase and plasma endotoxin elevation. These results demonstrate, for the first time, that dietary zinc deficiency is a risk factor in alcoholic liver disease, and multiple intrahepatic and extrahepatic factors may mediate the detrimental effects of zinc deficiency.

Effects of high zinc levels on the lipid synthesis in rat hepatocytes

Zinc deficiency impairs the hepatic lipid metabolism. Previous studies were focused on the negative effects of zinc deficiency on the hepatic lipid metabolism. A few studies investigated the effects of high zinc levels on the lipid metabolism in hepatocytes. In this study, rat hepatocytes were cultured and treated with different and high concentrations of zinc to investigate the effects of high zinc levels on the lipid synthesis in hepatocytes in vitro. The levels of hepatocytes functional markers, including alkaline phosphatase, lactate dehydrogenase, and albumin, were significantly higher in the zinc treatment groups than in the control group (p < 0.05, p < 0.01). The mRNA and protein levels of sterol regulatory element-binding protein 1c (SREBP-1c) were significantly higher in the zinc treatment groups than in the control group (p < 0.05, p < 0.01). Furthermore, the mRNA expression levels of acetyl-CoA carboxylase 1 (ACC1) and fatty acid synthase (FAS) were significantly higher in the medium- and high-dose zinc treatment groups than in the control group (p < 0.01). The mRNA levels of stearoyl-CoA desaturase-1 (SCD-1) were significantly higher in the high-dose group (p < 0.01). These results indicate that high levels of zinc increase hepatocytes activity and SREBP-1c expression, which upregulate the expression of ACC1, FAS, and SCD-1, thereby improving the lipid metabolism in the hepatocytes.

Dietary zinc intake is inversely associated to metabolic syndrome in male but not in female urban adolescents

OBJECTIVE

To evaluate the relationship of copper and zinc dietary intakes with metabolic syndrome (MetS) in adolescents.

METHODS

The sample consisted of 1,311 adolescents aged 11-16 years, and MetS definition by de Ferranti et al. was used. Nutritional intakes, anthropometrical and biochemical markers were measured.

RESULTS

In males, highest quartile of zinc intake was inversely associated with MetS without and with adjustment by covariables. Without adjustment, highest quartile of copper intake was inversely associated (marginal significance) with MetS, but with adjustment, the relationship was not maintained. Likewise in male gender, elevated waist circumference was the only MetS component inversely associated with highest quartiles of zinc (without and with adjustment) and copper (significant in crude analysis and marginal significant in adjustment by covariables) intakes. In the girls, only waist circumference was significant and inversely associated with highest quartiles of zinc and copper intakes but the association did not remain significant after adjustments.

DISCUSSION

In the adolescents of this study, zinc intake could be more associated to a clustering of anthropometric, vascular, and metabolic alterations than to these alterations separately, and also it is inversely related to this clustering (MetS). However, studies in other populations are necessary to confirm and explain the finding of exclusive association zinc intake-MetS in male gender adolescents. Further research is required to explore biomarkers of physiological processes (antioxidant function, blood flow regulation, and epigenetic modulation dependent of zinc) in relation to zinc intake and MetS in pediatric and adult populations.

Zinc homeostasis in the metabolic syndrome and diabetes

Zinc (Zn) is an essential mineral that is required for various cellular functions. Zn dyshomeostasis always is related to certain disorders such as metabolic syndrome, diabetes and diabetic complications. The associations of Zn with metabolic syndrome, diabetes and diabetic complications, thus, stem from the multiple roles of Zn: (1) a constructive component of many important enzymes or proteins, (2) a requirement for insulin storage and secretion, (3) a direct or indirect antioxidant action, and (4) an insulin-like action. However, whether there is a clear cause-and-effect relationship of Zn with metabolic syndrome, diabetes, or diabetic complications remains unclear. In fact, it is known that Zn deficiency is a common phenomenon in diabetic patients. Chronic low intake of Zn was associated with the increased risk of diabetes and diabetes also impairs Zn metabolism. Theoretically Zn supplementation should prevent the metabolic syndrome, diabetes, and diabetic complications; however, limited available data are not always supportive of the above notion. Therefore, this review has tried to summarize these pieces of available information, possible mechanisms by which Zn prevents the metabolic syndrome, diabetes, and diabetic complications. In the final part, what are the current issues for Zn supplementation were also discussed.

Status of essential trace minerals and oxidative stress in viral hepatitis C patients with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) may be an important factor leading to altered trace mineral homeostasis, thereby accelerating the progression of hepatitis C virus (HCV) infection. Our aim was to determine whether NAFLD influenced the status of certain essential trace minerals and oxidative stress in chronic HCV-infected patients.

DESIGN AND METHODS

Blood biochemical parameters were determined in a group of 30 healthy, non-obese, non-diabetic participants (CNL group), and hepatitis C patients without NAFLD (HCV group, n = 30) and with NAFLD (HCV-NAFLD group, n = 32).

RESULTS

Concentrations of thiobarbituric acid reactive substances (TBARS; a measure of oxidative stress), C-reactive protein (CRP), ferritin, aminotransferases, lipid profiles, and insulin metabolism were markedly abnormal in both patient groups than in CNL subjects. Compared to patients in the HCV group, those with HCV-NAFLD group had lower high-density lipoprotein concentrations, higher low-density lipoprotein and homeostasis model assessment-insulin resistance (HOMA-IR) values, disrupted antioxidant enzyme activities, and elevated TBARS concentrations, as well as decreased plasma concentrations of trace minerals zinc (Zn) and selenium (Se) and increased copper (Cu). The alterations in mineral homeostasis were also linked to TBARS, CRP, ferritin, lipoproteins, and HOMA-IR values in the HCV-NAFLD group.

CONCLUSIONS

There is a progressive deterioration in the homeostasis of minerals (Zn, Se, and Cu) in HCV-NAFLD patients, which may reflect greater oxidative stress and inflammation. These results suggest that the disturbance in mineral metabolism by NAFLD has an impact on the effectiveness of treatment for chronic HCV infection.

Suboptimal dietary zinc intake promotes vascular inflammation and atherogenesis in a mouse model of atherosclerosis

SCOPE

Cardiovascular health is strongly influenced by diet. Zinc has antioxidant and anti-inflammatory properties but its long-term influence on vascular health at dietary intake levels relevant to the human population in developed countries has not been studied. We investigated the influence of suboptimal zinc intake in a Western-type diet on the development of vascular inflammation and arterial plaque in apoE knock-out (AEKO) mice.

METHODS AND RESULTS

Weanling AEKO and wild-type (WT) controls were given high saturated fat (21% w/w) and high cholesterol (0.15%) semi-synthetic diets containing 3 or 35 mg Zn/kg (AEKO and WT) or 8 mg Zn/kg (AEKO only) for over 6 months. AEKO mice on zinc intakes of 3 and 8 mg Zn/kg (suboptimal zinc) developed significantly (p < 0.05) more aortic plaque than AEKO mice consuming 35 mg Zn/kg (adequate zinc). Circulating levels of interleukin-1β, interleukin-6 and soluble vascular adhesion molecule-1 were significantly (p < 0.05) raised at the lowest zinc intake in AEKO mice, as compared to zinc-adequate controls. Plasma total cholesterol and total protein were also significantly (p < 0.05) increased at the lowest zinc intake.

CONCLUSION

We propose that suboptimal dietary zinc intake raises circulating pro-atherogenic lipoprotein levels that promote vascular inflammation and enhance arterial plaque formation.

The relationship between serum lipid profile and selected trace elements for adult men in mosul city

OBJECTIVES

To evaluate the correlations of the serum concentrations of copper, zinc, and manganese with lipid profile parameters of adult men in Mosul City, Iraq.

METHODS

The study included 51 apparently healthy adult men as a control group aged 34-62 years (group 1), and 31 hyperlipidemic patients aged 37-60 years (group 2). Trace elements copper, zinc and manganese were determined using atomic absorption spectrometry. Concentrations of total cholesterol, triglyceride and high density lipoprotein cholesterol were determined using enzymatic method. Indirect serum concentration of low-density lipoprotein cholesterol were calculated via the Friedewald formula. Data were evaluated as mean and standard deviation by analysis of variance (ANOVA) and t-test.

RESULTS

The results indicated that there is a significant lower level of serum zinc in hyperlipidemic patients compared with the control group, while copper and manganese showed no significant differences between the two groups. A significant negative correlation was found between serum zinc and total cholesterol, low-density lipoprotein cholesterol, triglyceride and low/high-density lipoprotein cholesterol ratio; while a significant positive correlation was found between serum zinc and high density lipoprotein cholesterol. In addition, a significant positive correlation between copper and triglyceride existed in the patient group, while the control group showed no such correlation.

CONCLUSION

Hyperlipidemia may possibly be related to a decrease in the level of serum zinc in hyperlipidemic adult men. The data also supports the concept that zinc supplementation might be useful in improving metabolic complications in subjects with hyperlipidemia.

Reactions of the fluorescent sensor, Zinquin, with the zinc-proteome: adduct formation and ligand substitution

Zinquin (ZQ) is a commonly used sensor for cellular Zn(2+) status. It has been assumed that it measures accessible Zn(2+) concentrations in the nanomolar range. Instead, this report shows a consistent pattern across seven mammalian cell and tissue types that ZQ reacts with micromolar concentrations of Zn(2+) bound as Zn-proteins. The predominant class of products were ZQ-Zn-protein adducts that were characterized in vivo and in vitro by a fluorescence emission spectrum centered at about 470 nm, by their migration over Sephadex G-75 as protein not low molecular weight species, by the exclusion of reaction with lipid vesicles, and by their large aggregate concentration. In addition, variable, minor formation of Zn(ZQ)(2) with a fluorescence band at about 490 nm was observed in vivo in each case. Because incubation of isolated Zn-proteome with ZQ also generated similar amounts of Zn(ZQ)(2), it was concluded that this species had formed through direct ligand substitution in which ZQ had successfully competed for protein-bound Zn(2+). Parallel studies with the model Zn-proteins, alcohol dehydrogenase (ADH), and alkaline phosphatase (AP) revealed a similar picture of reactivity: ZQ(ACID) (Zinquin acid, (2-methyl-8-p-toluenesulfonamido-6-quinolyloxy)acetate)) able to bind to one Zn(2+) and extract the other in Zn(2)-ADH, whereas it removed one Zn(2+) from Zn(2)-AP and did not bind to the other. Zinquin ethyl ester (ethyl(2-methyl-8-p-toluenesulfonamido-6-quinolyloxy)acetate); ZQ(EE)) bound to both proteins without sequestering Zn(2+) from either one. In contrast to a closely related sensor, 6-methoxy-8-p-toluenesulfonamido-quinoline (TSQ), neither ZQ(ACID) nor ZQ(EE) associated with Zn-carbonic anhydrase. A survey of reactivity of these sensors with partially fractionated Zn-proteome confirmed that ZQ and TSQ bind to distinct, overlapping subsets of the Zn-proteome.

Multi-carbohydrase and phytase supplementation improves growth performance and liver insulin receptor sensitivity in broiler chickens fed diets containing full-fat rapeseed

The effect of a combination of carbohydrase and phytase enzymes on growth performance, insulin-like growth factor 1 gene expression, insulin status, and insulin receptor sensitivity in broiler chickens fed wheat-soybean meal diets containing 6% (starter) and 12% (grower-finisher) of full-fat rapeseed (canola type; low glucosinolate, low erucic acid) from 1 to 42 d of age was studied. A total of 510 one-day-old male broiler chickens were randomly assigned to 3 dietary treatments, with 17 pens per treatment and 10 birds per pen. The dietary treatments consisted of a control diet and P- and Ca-deficient diets supplemented with either phytase (500 U/kg) or a combination of phytase and a multi-carbohydrase enzyme (Superzyme OM). The diets were pelleted at 78 degrees C and were fed ad libitum throughout the starter (9 d), grower (18 d), and finisher (15 d) phases of the experiment. Over the entire trial, growth performance of birds fed the phytase-supplemented diet did not differ from birds fed the control diet. The use of phytase in combination with a multicarbohydrase enzyme improved (P = 0.007) the feed conversion ratio from 1.90 to 1.84. Insulin liver receptor sensitivity increased by 9.3 and 12.3% (P = 0.004) for the phytase- and the carbohydrase-phytase-supplemented diets, respectively. There was no effect of phytase alone or carbohydrase and phytase supplementation on total plasma cholesterol, high-density lipoprotein cholesterol, and blood glucose levels. However, low-density lipoprotein cholesterol decreased (P = 0.007) for the phytase-carbohydrase treatment. Gene expression of insulin-like growth factor 1 tended to decrease by 32% (P = 0.083) after phytase-carbohydrase supplementation. The combination of carbohydrase and phytase enzymes may serve as an attractive means of facilitating nutrient availability for digestion and thus enhance the feeding value of wheat-soybean meal-based diets containing full-fat rapeseed. However, the extent to which the effects of enzyme addition on insulin receptors are associated with growth performance of broiler chicken requires further research.

Zinc deficiency induces vascular pro-inflammatory parameters associated with NF-kappaB and PPAR signaling

OBJECTIVES

Marginal intake of dietary zinc can be associated with increased risk of cardiovascular diseases. In the current study we hypothesized that vascular dysfunction and associated inflammatory events are activated during a zinc deficient state.

DESIGN

We tested this hypothesis using both vascular endothelial cells and mice lacking the functional LDL-receptor gene.

RESULTS

Zinc deficiency increased oxidative stress and NF-kappaB DNA binding activity, and induced COX-2 and E-selectin gene expression, as well as monocyte adhesion in cultured endothelial cells. The NF-kappaB inhibitor CAPE significantly reduced the zinc deficiency-induced COX-2 expression, suggesting regulation through NF-kappaB signaling. PPAR can inhibit NF-kappaB signaling, and our previous data have shown that PPAR transactivation activity requires adequate zinc. Zinc deficiency down-regulated PPARalpha expression in cultured endothelial cells. Furthermore, the PPARgamma agonist rosiglitazone was unable to inhibit the adhesion of monocytes to endothelial cells during zinc deficiency, an event which could be reversed by zinc supplementation. Our in vivo data support the importance of PPAR dysregulation during zinc deficiency. For example, rosiglitazone induced inflammatory genes (e.g., MCP-1) only during zinc deficiency, and adequate zinc was required for rosiglitazone to down-regulate pro-inflammatory markers such as iNOS. In addition, rosiglitazone increased IkappaBalpha protein expression only in zinc adequate mice. Finally, plasma data from LDL-R-deficient mice suggest an overall pro-inflammatory environment during zinc deficiency and support the concept that zinc is required for proper anti-inflammatory or protective functions of PPAR.

CONCLUSIONS

These studies suggest that zinc nutrition can markedly modulate mechanisms of the pathology of inflammatory diseases such as atherosclerosis.