Functional significance of zinc-related signaling pathways in immune cells

Zinc alleviates thermal stress-induced damage to the integrity and barrier function of cultured chicken embryonic primary jejunal epithelial cells via the MAPK and PI3K/AKT/mTOR signaling pathways

Zinc (Zn) could alleviate the adverse effect of high temperature (HT) on intestinal integrity and barrier function of broilers, but the underlying mechanisms remain unclear. We aimed to investigate the possible protective mechanisms of Zn on primary cultured broiler jejunal epithelial cells exposed to thermal stress (TS). In Exp.1, jejunal epithelial cells were exposed to 40℃ (normal temperature, NT) and 44℃ (HT) for 1, 2, 4, 6, or 8 h. Cells incubated for 8 h had the lowest transepithelial resistance (TEER) and the highest phenol red permeability under HT. In Exp.2, the cells were preincubated with different Zn sources (Zn sulfate as iZn and Zn proteinate with the moderate chelation strength as oZn) and Zn supplemental levels (50 and 100 µmol/L) under NT for 24 h, and then continuously incubated under HT for another 8 h. TS increased phenol red permeability, lactate dehydrogenase (LDH) activity and p-PKC/PKC level, and decreased TEER, cell proliferation, mRNA levels of claudin-1, occludin, zona occludens-1 (ZO-1), PI3K, AKT and mTOR, protein levels of claudin-1, ZO-1 and junctional adhesion molecule-A (JAM-A), and the levels of p-ERK/ERK, p-PI3K/PI3K and p-AKT/AKT. Under HT, oZn was more effective than iZn in increasing TEER, occludin, ZO-1, PI3K, and AKT mRNA levels, ZO-1 protein level, and p-AKT/AKT level; supplementation with 50 μmol Zn/L was more effective than 100 μmol Zn/L in increasing cell proliferation, JAM-A, PI3K, AKT, and PKC mRNA levels, JAM-A protein level, and the levels of p-ERK/ERK and p-PI3K/PI3K; furthermore, supplementation with 50 μmol Zn/L as oZn had the lowest LDH activity, and the highest ERK, JNK-1, and mTOR mRNA levels. Therefore, supplemental Zn, especially 50 μmol Zn/L as oZn, could alleviate the TS-induced integrity and barrier function damage of broiler jejunal epithelial cells possibly by promoting cell proliferation and tight junction protein expression via the MAPK and PI3K/AKT/mTOR signaling pathways.

Advances in Organic Fluorescent Probes for Intracellular Zn2+ Detection and Bioimaging

Zinc ions (Zn2+) play a key role in maintaining and regulating protein structures and functions. To better understand the intracellular Zn2+ homeostasis and signaling role, various fluorescent sensors have been developed that allow the monitoring of Zn2+ concentrations and bioimaging in live cells in real time. This review highlights the recent development of organic fluorescent probes for the detection and imaging of intracellular Zn2+, including the design and construction of the probes, fluorescent response mechanisms, and their applications to intracellular Zn2+ detection and imaging on-site. Finally, the current challenges and prospects are discussed.

Protective effect of zinc gluconate on intestinal mucosal barrier injury in antibiotics and LPS-induced mice

Objective

The aim of the study is to investigate the function and mechanism of Zinc Gluconate (ZG) on intestinal mucosal barrier damage in antibiotics and Lipopolysaccharide (LPS)-induced mice.

Methods

We established a composite mouse model by inducing intestinal mucosal barrier damage using antibiotics and LPS. The animals were divided into five groups: Control (normal and model) and experimental (low, medium, and high-dose ZG treatments). We evaluated the intestinal mucosal barrier using various methods, including monitoring body weight and fecal changes, assessing pathological damage and ultrastructure of the mouse ileum, analyzing expression levels of tight junction (TJ)-related proteins and genes, confirming the TLR4/NF-κB signaling pathway, and examining the structure of the intestinal flora.

Results

In mice, the dual induction of antibiotics and LPS led to weight loss, fecal abnormalities, disruption of ileocecal mucosal structure, increased intestinal barrier permeability, and disorganization of the microbiota structure. ZG restored body weight, alleviated diarrheal symptoms and pathological damage, and maintained the structural integrity of intestinal epithelial cells (IECs). Additionally, ZG reduced intestinal mucosal permeability by upregulating TJ-associated proteins (ZO-1, Occludin, Claudin-1, and JAM-A) and downregulating MLCK, thereby repairing intestinal mucosal barrier damage induced by dual induction of antibiotics and LPS. Moreover, ZG suppressed the TLR4/NF-κB signaling pathway, demonstrating anti-inflammatory properties and preserving barrier integrity. Furthermore, ZG restored gut microbiota diversity and richness, evidenced by increased Shannon and Observed features indices, and decreased Simpson's index. ZG also modulated the relative abundance of beneficial human gut bacteria (Bacteroidetes, Firmicutes, Verrucomicrobia, Parabacteroides, Lactobacillus, and Akkermansia) and harmful bacteria (Proteobacteria and Enterobacter), repairing the damage induced by dual administration of antibiotics and LPS.

Conclusion

ZG attenuates the dual induction of antibiotics and LPS-induced intestinal barrier damage and also protects the intestinal barrier function in mice.

The Protective Effect of the Crosstalk between Zinc Hair Concentration and Lymphocyte Count-Preliminary Report

BACKGROUND

An imbalance between pro- and anti-inflammatory mechanisms is indicated in the pathophysiology of atherosclerotic plaque. The coronary artery and carotid disease, despite sharing similar risk factors, are developed separately. The aim of this study was to analyze possible mechanisms between trace element hair-scalp concentrations and whole blood counts that favor atherosclerotic plaque progression in certain locations.

METHODS

There were 65 (36 (55%) males and 29 (45%) females) patients with a median age of 68 (61-73) years enrolled in a prospective, preliminary, multicenter analysis. The study group was composed of 13 patients with stable coronary artery disease (CAD group) referred for surgical revascularization due to multivessel coronary disease, 34 patients with carotid artery disease (carotid group) admitted for vascular procedure, and 18 patients in a control group (control group).

RESULTS

There was a significant difference between the CAD and carotid groups regarding lymphocyte (p = 0.004) counts. The biochemical comparison between the coronary and carotid groups revealed significant differences regarding chromium (Cr) (p = 0.002), copper (Cu) (p < 0.001), and zinc (Zn) (p < 0.001) concentrations. Spearman Rank Order Correlations between lymphocyte counts and trace elements in the analyzed groups were performed, revealing a strong correlation with zinc (R = 0.733, p < 0.001) in the control group (non-CAD, non-carotid).

CONCLUSION

Significant differences in hair-scalp concentrations related to atherosclerosis location were observed in our analysis. The interplay between zinc concentration and lymphocyte count may play a pivotal role in cardiovascular disease development.

Zinc Ionophore Pyrithione Mimics CD28 Costimulatory Signal in CD3 Activated T Cells

Zinc is an essential trace element that plays a crucial role in T cell immunity. During T cell activation, zinc is not only structurally important, but zinc signals can also act as a second messenger. This research investigates zinc signals in T cell activation and their function in T helper cell 1 differentiation. For this purpose, peripheral blood mononuclear cells were activated via the T cell receptor-CD3 complex, and via CD28 as a costimulatory signal. Fast and long-term changes in intracellular zinc and calcium were monitored by flow cytometry. Further, interferon (IFN)-γ was analyzed to investigate the differentiation into T helper 1 cells. We show that fast zinc fluxes are induced via CD3. Also, the intracellular zinc concentration dramatically increases 72 h after anti-CD3 and anti-CD28 stimulation, which goes along with the high release of IFN-γ. Interestingly, we found that zinc signals can function as a costimulatory signal for T helper cell 1 differentiation when T cells are activated only via CD3. These results demonstrate the importance of zinc signaling alongside calcium signaling in T cell differentiation.

Clays and Wound Healing

Aluminosilicates, such as montmorillonite, kaolinite, halloysite, and diatomite, have a uniform bidimensional structure, a high surface-to-volume ratio, inherent stiffness, a dual charge distribution, chemical inertness, biocompatibility, abundant active groups on the surface, such as silanol (Si-OH) and/or aluminol (Al-OH) groups. These compounds are on the list of U.S. Food and Drug Administration-approved active compounds and excipients and are used for various medicinal products, such as wound healing agents, antidiarrheals, and cosmetics. This review summarizes the wound healing mechanisms related to the material characteristics and the chemical components. Numerous wound dressings with different active components and multiple forms have been studied. Then, medicinal mineral resources for use in hemostatic materials can be developed.

Coccomyxa subellipsoidea KJ Components Enhance the Expression of Metallothioneins and Th17 Cytokines during Human T Cell Activation

Coccomyxa subellipsoidea KJ (C-KJ) is a green alga with unique immunoregulatory characteristics. Here, we investigated the mechanism underlying the modification of T cell function by C-KJ components. The water-soluble extract of C-KJ was fractionated into protein (P) and sugar (S) fractions acidic (AS), basic (BS), and neutral (NS). These fractions were used for the treatment of peripheral blood mononuclear cells stimulated with toxic shock syndrome toxin-1. Transcriptome analysis revealed that both P and AS enhanced the expression of the genes encoding metallothionein (MT) family proteins, inflammatory factors, and T helper (Th) 17 cytokine and suppressed that of those encoding Th2 cytokines in stimulated T cells. The kinetics of MT1 and MT2A gene expression showed a transient increase in MT1 and maintenance of MT2A mRNA after T cell stimulation in the presence of AS. The kinetics of Th17-related cytokine secretion in the early period were comparable to those of MT2A mRNA. Furthermore, our findings revealed that static, a STAT-3 inhibitor, significantly suppressed MT2A gene expression. These findings suggest that the expression of MTs is involved in the immune regulatory function of C-KJ components, which is partially regulated by Th17 responses, and may help develop innovative immunoregulatory drugs or functional foods.

Photoactivatable Engineering of CRISPR/Cas9-Inducible DNAzyme Probe for In Situ Imaging of Nuclear Zinc Ions

DNAzyme-based fluorescent probes for imaging metal ions in living cells have received much attention recently. However, employing in situ metal ions imaging within subcellular organelles, such as nucleus, remains a significant challenge. We developed a three-stranded DNAzyme probe (TSDP) that contained a 20-base-pair (20-bp) recognition site of a CRISPR/Cas9, which blocks the DNAzyme activity. When Cas9, with its specialized nuclear localization function, forms an active complex with sgRNA within the cell nucleus, it cleaves the TSDP at the recognition site, resulting in the in situ formation of catalytic DNAzyme structure. With this design, the CRISPR/Cas9-inducible imaging of nuclear Zn2+ is demonstrated in living cells. Moreover, the superiority of CRISPR-DNAzyme for spatiotemporal control imaging was demonstrated by integrating it with photoactivation strategy and Boolean logic gate for dynamic monitoring nuclear Zn2+ in both HeLa cells and mice. Collectively, this conceptual design expands the DNAzyme toolbox for visualizing nuclear metal ions and thus provides new analytical methods for nuclear metal-associated biology.

Zinc homeostasis and redox alterations in obesity

Impairment of both cellular zinc and redox homeostasis is a feature of several chronic diseases, including obesity. A significant two-way interaction exists between redox metabolism and the relatively redox-inert zinc ion. Redox metabolism critically influences zinc homeostasis and controls its cellular availability for various cellular functions by regulating zinc exchange from/to zinc-binding proteins. Zinc can regulate redox metabolism and exhibits multiple pro-antioxidant properties. On the other hand, even minor disturbances in zinc status and zinc homeostasis affect systemic and cellular redox homeostasis. At the cellular level, zinc homeostasis is regulated by a multi-layered machinery consisting of zinc-binding molecules, zinc sensors, and two selective families of zinc transporters, the Zinc Transporter (ZnT) and Zrt, Irt-like protein (ZIP). In the present review, we summarize the current state of knowledge on the role of the mutual interaction between zinc and redox homeostasis in physiology and pathophysiology, pointing to the role of zinc in the alterations responsible for redox stress in obesity. Since zinc transporters primarily control zinc homeostasis, we describe how changes in the expression and activity of these zinc-regulating proteins are associated with obesity.

Trace Mineral Nutrition in Confinement Dairy Cattle

Veterinarians are often called upon to diagnose health-related issues on the farm that may be related to trace mineral deficiencies or toxicities. Trace mineral feeding rates are often not available due to the proprietary nature of the trace mineral premixes provided by nutritional consultants. The veterinarian needs to be aware of the common clinical signs of trace mineral deficiencies and toxicities, interactions between trace minerals that may result in deficiencies, clinical samples that are necessary for the proper diagnosis, and the recommended normal ranges of each trace mineral depending on the age of the animal.

Antiviral activity of zinc against hepatitis viruses: current status and future prospects

Viral hepatitis is a major public health concern globally. World health organization aims at eliminating viral hepatitis as a public health threat by 2030. Among the hepatitis causing viruses, hepatitis B and C are primarily transmitted via contaminated blood. Hepatitis A and E, which gets transmitted primarily via the feco-oral route, are the leading cause of acute viral hepatitis. Although vaccines are available against some of these viruses, new cases continue to be reported. There is an urgent need to devise a potent yet economical antiviral strategy against the hepatitis-causing viruses (denoted as hepatitis viruses) for achieving global elimination of viral hepatitis. Although zinc was known to mankind for a long time (since before Christ era), it was identified as an element in 1746 and its importance for human health was discovered in 1963 by the pioneering work of Dr. Ananda S. Prasad. A series of follow up studies involving zinc supplementation as a therapy demonstrated zinc as an essential element for humans, leading to establishment of a recommended dietary allowance (RDA) of 15 milligram zinc [United States RDA for zinc]. Being an essential component of many cellular enzymes and transcription factors, zinc is vital for growth and homeostasis of most living organisms, including human. Importantly, several studies indicate potent antiviral activity of zinc. Multiple studies have demonstrated antiviral activity of zinc against viruses that cause hepatitis. This article provides a comprehensive overview of the findings on antiviral activity of zinc against hepatitis viruses, discusses the mechanisms underlying the antiviral properties of zinc and summarizes the prospects of harnessing the therapeutic benefit of zinc supplementation therapy in reducing the disease burden due to viral hepatitis.

Effect of zinc supplementation as an adjuvant to corticosteroid treatment in patients with oral lichen planus: A systematic review

Background

Oral lichen planus (OLP) and one of its main presentations, desquamative gingivitis, are common diseases with no definite treatment. Zinc deficiency has a critical role in the pathogenesis of oral mucosal diseases. The current study systematically reviewed the effect of zinc in addition to topical corticosteroids in the treatment of OLP.

Methods

English articles in PubMed, Web of Sciences, Embase, and Scopus were searched until August 2022. The differences in symptoms were analyzed, including pain, burning sensation, and lesion sizes in patients with lichen planus receiving zinc supplementation as an adjuvant to corticosteroid treatment.

Results

A total of 148 articles related to the searched keywords were found. Eventually, two clinical trials were selected. The total population of studied individuals included 60 patients. Due to the high heterogeneity between the studies, meta-analysis was not possible. Administering zinc, in addition to corticosteroids, did not improve the symptoms compared to corticosteroid monotherapy.

Conclusion

Considering the limited number of studies and lack of sufficient evidence, it is not currently possible to reach a definite conclusion regarding the effects of zinc on OLP.

An Overview of Scaffolds and Biomaterials for Skin Expansion and Soft Tissue Regeneration: Insights on Zinc and Magnesium as New Potential Key Elements

The utilization of materials in medical implants, serving as substitutes for non-functional biological structures, supporting damaged tissues, or reinforcing active organs, holds significant importance in modern healthcare, positively impacting the quality of life for millions of individuals worldwide. However, certain implants may only be required temporarily to aid in the healing process of diseased or injured tissues and tissue expansion. Biodegradable metals, including zinc (Zn), magnesium (Mg), iron, and others, present a new paradigm in the realm of implant materials. Ongoing research focuses on developing optimized materials that meet medical standards, encompassing controllable corrosion rates, sustained mechanical stability, and favorable biocompatibility. Achieving these objectives involves refining alloy compositions and tailoring processing techniques to carefully control microstructures and mechanical properties. Among the materials under investigation, Mg- and Zn-based biodegradable materials and their alloys demonstrate the ability to provide necessary support during tissue regeneration while gradually degrading over time. Furthermore, as essential elements in the human body, Mg and Zn offer additional benefits, including promoting wound healing, facilitating cell growth, and participating in gene generation while interacting with various vital biological functions. This review provides an overview of the physiological function and significance for human health of Mg and Zn and their usage as implants in tissue regeneration using tissue scaffolds. The scaffold qualities, such as biodegradation, mechanical characteristics, and biocompatibility, are also discussed.

Effects of Different Dietary Zinc (Zn) Sources on Growth Performance, Zn Metabolism, and Intestinal Health of Grass Carp

This research was conducted to investigate the effects of four dietary zinc (Zn) sources on growth performance, Zn metabolism, antioxidant capacity, endoplasmic reticulum (ER) stress, and tight junctions in the intestine of grass carp Ctenopharyngodon idella. Four Zn sources consisted of Zn dioxide nanoparticles (ZnO NPs), Zn sulfate heptahydrate (ZnSO4·7H2O), Zn lactate (Zn-Lac), and Zn glycine chelate (Zn-Gly), respectively. Grass carp with an initial body weight of 3.54 g/fish were fed one of four experimental diets for 8 weeks. Compared to inorganic Zn (ZnSO4·7H2O), grass carp fed the ZnO NPs and Zn-Gly diets exhibited better growth performance. Furthermore, grass carp fed the organic Zn (Zn-Lac and Zn-Gly) diets displayed enhanced Zn transport activity, improved intestinal histology, and increased intestinal tight junction-related genes expression compared to other groups. In comparison to other Zn sources, dietary ZnO NPs caused increased Zn deposition and damaged antioxidation capacity by suppressing antioxidant enzymatic activities and related gene expression in the intestine. Grass cap fed the ZnO NPs diet also exhibited lower mRNA abundance of endoplasmic reticulum (ER) stress- and tight junction-associated genes. According to the above findings, it can be concluded that dietary organic Zn addition (Zn-Lac and Zn-Gly) is more beneficial for intestinal health in grass carp compared to inorganic and nanoform Zn sources. These findings provide valuable insights into the application of organic Zn sources, specifically Zn-Lac and Zn-Gly, in the diets for grass carp and potentially for other fish species.

Nutraceuticals as Modulators of Immune Function: A Review of Potential Therapeutic Effects

Dietary supplementation with nutraceuticals can promote optimal immune system activation, modulating different pathways that enhance immune defenses. Therefore, the immunity-boosting effects of nutraceuticals encompass not only immunomodulatory but also antioxidant, antitumor, antiviral, antibacterial, and antifungal properties, with therapeutic effects against diverse pathological conditions. However, the complexity of the pathways that regulate the immune system, numerous mechanisms of action, and heterogeneity of the immunodeficiencies, and subjects treated make their application in the clinical field difficult. Some nutraceuticals appear to safely improve immune system function, particularly by preventing viral and bacterial infections in specific groups, such as children, the elderly, and athletes, as well as in frail patients, such as those affected by autoimmune diseases, chronic diseases, or cancer. Several nutraceuticals, such as vitamins, mineral salts, polyunsaturated omega-3 fatty acids, many types of phytocompounds, and probiotic strains, have the most consolidated evidence in humans. In most cases, further large and long-term randomized clinical trials are needed to confirm the available preliminary positive data.

Preparation of quinoa bran dietary fiber-based zinc complex and investigation of its antioxidant capacity in vitro

In order to improve the economic utilization of quinoa bran and develop a safe and highly available zinc ion biological supplement. In this study, a four-factor, three-level response surface optimization of quinoa bran soluble dietary fiber (SDF) complexation of zinc was studied. The effect used four factors on the chelation rate was investigated: (A) mass ratio of SDF to ZnSO₄.7H₂O, (B) chelation temperature, (C) chelation time, and (D) pH. Based on the results of the single-factor test, the four-factor three-level response surface method was used to optimize the reaction conditions. The optimal reaction conditions were observed as mentioned here: the mass ratio of quinoa bran SDF to ZnSO₄.7H₂O was 1, the reaction temperature was 65°C, the reaction time was 120 min, and the pH of the reaction system was 8.0. The average chelation rate was 25.18%, and zinc content is 465.2 μg/g under optimal conditions. The hydration method rendered a fluffy quinoa bran SDF structure. The intramolecular functional groups were less stable which made the formation of the lone pairs of electrons feasible to complex with the added divalent zinc ions to form a quinoa bran soluble dietary fiber-zinc complex [SDF-Zn(II)]. The SDF-Zn(II) chelate had higher 2,2-diphenylpicrylhydrazyl (DPPH), ABTS⁺, hydroxyl radical scavenging ability, and total antioxidant capacity. Therefore, metal ion chelation in dietary fiber is of biological importance.

Application of Silk-Fibroin-Based Hydrogels in Tissue Engineering

Silk fibroin (SF) is an excellent protein-based biomaterial produced by the degumming and purification of silk from cocoons of the Bombyx mori through alkali or enzymatic treatments. SF exhibits excellent biological properties, such as mechanical properties, biocompatibility, biodegradability, bioabsorbability, low immunogenicity, and tunability, making it a versatile material widely applied in biological fields, particularly in tissue engineering. In tissue engineering, SF is often fabricated into hydrogel form, with the advantages of added materials. SF hydrogels have mostly been studied for their use in tissue regeneration by enhancing cell activity at the tissue defect site or counteracting tissue-damage-related factors. This review focuses on SF hydrogels, firstly summarizing the fabrication and properties of SF and SF hydrogels and then detailing the regenerative effects of SF hydrogels as scaffolds in cartilage, bone, skin, cornea, teeth, and eardrum in recent years.

The tricarboxylic acid (TCA) cycle: a malleable metabolic network to counter cellular stress

The tricarboxylic acid (TCA) cycle is a primordial metabolic pathway that is conserved from bacteria to humans. Although this network is often viewed primarily as an energy producing engine fueling ATP synthesis via oxidative phosphorylation, mounting evidence reveals that this metabolic hub orchestrates a wide variety of pivotal biological processes. It plays an important part in combatting cellular stress by modulating NADH/NADPH homeostasis, scavenging ROS (reactive oxygen species), producing ATP by substrate-level phosphorylation, signaling and supplying metabolites to quell a range of cellular disruptions. This review elaborates on how the reprogramming of this network prompted by such abiotic stress as metal toxicity, oxidative tension, nutrient challenge and antibiotic insult is critical for countering these conditions in mostly microbial systems. The cross-talk between the stressors and the participants of TCA cycle that results in changes in metabolite and nucleotide concentrations aimed at combatting the abiotic challenge is presented. The fine-tuning of metabolites mediated by disparate enzymes associated with this metabolic hub is discussed. The modulation of enzymatic activities aimed at generating metabolic moieties dedicated to respond to the cellular perturbation is explained. This ancient metabolic network has to be recognized for its ability to execute a plethora of physiological functions beyond its well-established traditional roles.

Imbalance of Essential Metals in Traumatic Brain Injury and Its Possible Link with Disorders of Consciousness

Dysfunction of the complex cerebral networks underlying wakefulness and awareness is responsible for Disorders of Consciousness (DoC). Traumatic Brain Injury (TBI) is a common cause of DoC, and it is responsible for a multi-dimensional pathological cascade that affects the proper functioning of the brainstem and brain consciousness pathways. Iron (Fe), Zinc (Zn), and Copper (Cu) have a role in the neurophysiology of both the ascending reticular activating system, a multi-neurotransmitter network located in the brainstem that is crucial for consciousness, and several brain regions. We aimed to summarize the role of these essential metals in TBI and its possible link with consciousness alterations. We found that TBI alters many neuronal molecular mechanisms involving essential metals, causing neurodegeneration, neural apoptosis, synaptic dysfunction, oxidative stress, and inflammation. This final pattern resembles that described for Alzheimer's disease (AD) and other neurological and psychiatric diseases. Furthermore, we found that amantadine, zolpidem, and transcranial direct current stimulation (tDCS)-the most used treatments for DoC recovery-seem to have an effect on essential metals-related pathways and that Zn might be a promising new therapeutic approach. This review summarizes the neurophysiology of essential metals in the brain structures of consciousness and focuses on the mechanisms underlying their imbalance following TBI, suggesting their possible role in DoC. The scenario supports further studies aimed at getting a deeper insight into metals' role in DoC, in order to evaluate metal-based drugs, such as metal complexes and metal chelating agents, as potential therapeutic options.

Zinc Modulates the Priming of T Helper 1, T Helper 17, and T Regulatory Cells in Allogeneic and Autologous in vitro Models

Introduction

Zinc is essential for the growth and differentiation of immune cells. Zinc insufficiency affects immune system function, thereby increasing infection susceptibility, autoimmunity, and allergies. Here, we aimed to determine the effects of zinc supplementation on T cell subpopulations, regulatory T (Tregs), T helper 1 (Th1), and T helper 17 (Th17) cells, in mixed lymphocyte cultures (MLC).

Methods

Allogeneic immune reactions were imitative using mixed lymphocyte cultures, followed by incubation with zinc to further monitor their effects. Cells were analyzed by flow cytometry. Production of Interferon-gamma (IFNγ), Interleukin-17 A (IL17A), and IL10 were analyzed by enzyme-linked immunosorbent assay. Th1 cell-specific Tbet, Th17 cell-specific RORC2, and Tregs-specific Foxp3 expression levels were determined by quantitative real-time PCR.

Results

Zinc supplementation at a physiological dose significantly increased CD4+ Foxp3+ Tregs and CD25+ Foxp3+ Tregs numbers and slightly decreased CD4+ RORC2+ and CD25+ RORC2+ Th17 cell numbers. A significant reduction in IFNγ production was observed in both restimulated T cells with autologous peripheral blood mononuclear cell (PBMC) and allogeneic PBMC compared to that in untreated T cells. Zinc significantly reduced IL17 expression, but the increase in IL10 expression was insignificant. In zinc-supplemented MLC, a non-significant decrease in Th1 or Th17 cell-specific transcription factors expression was observed, whereas there was a significant increase in Tregs-specific transcription factor expression.

Conclusion

Zinc can stabilize Tregs participating in adverse immune reactions or in an in vitro transplantation model.

The Important Role of Zinc in Neurological Diseases

Zinc is one of the most abundant metal ions in the central nervous system (CNS), where it plays a crucial role in both physiological and pathological brain functions. Zinc promotes antioxidant effects, neurogenesis, and immune system responses. From neonatal brain development to the preservation and control of adult brain function, zinc is a vital homeostatic component of the CNS. Molecularly, zinc regulates gene expression with transcription factors and activates dozens of enzymes involved in neuronal metabolism. During development and in adulthood, zinc acts as a regulator of synaptic activity and neuronal plasticity at the cellular level. There are several neurological diseases that may be affected by changes in zinc status, and these include stroke, neurodegenerative diseases, traumatic brain injuries, and depression. Accordingly, zinc deficiency may result in declines in cognition and learning and an increase in oxidative stress, while zinc accumulation may lead to neurotoxicity and neuronal cell death. In this review, we explore the mechanisms of brain zinc balance, the role of zinc in neurological diseases, and strategies affecting zinc for the prevention and treatment of these diseases.

Immunoregulation in Diabetic Wound Repair with a Photoenhanced Glycyrrhizic Acid Hydrogel Scaffold

M1 macrophage accumulation and excessive inflammation are commonly encountered issues in diabetic wounds and can fail in the healing process. Hence, hydrogel dressings with immunoregulatory capacity have great promise in the clinical practice of diabetic wound healing. However, current immunoregulatory hydrogels are always needed for complex interventions and high-cost treatments, such as cytokines and cell therapies. In this study, a novel glycyrrhizic acid (GA)-based hybrid hydrogel dressing with intrinsic immunoregulatory properties is developed to promote rapid diabetic wound healing. This hybrid hydrogel consists of interpenetrating polymer networks composed of inorganic Zn²⁺ -induced self-assembled GA and photo-crosslinked methyl acrylated silk fibroin (SF), realizing both excellent injectability and mechanical strength. Notably, the SF/GA/Zn hybrid hydrogel can regulate macrophage responses in the inflammatory microenvironment, circumventing the use of any additives. The immunomodulatory properties of the hydrogel can be harnessed for safe and efficient therapeutics that accelerate the three phases of wound repair and serve as a promising dressing for the management of diabetic wounds.

Zinc and Respiratory Viral Infections: Important Trace Element in Anti-viral Response and Immune Regulation

Influenza viruses, respiratory syncytial virus (RSV), and SARS-COV2 are among the most dangerous respiratory viruses. Zinc is one of the essential micronutrients and is very important in the immune system. The aim of this narrative review is to review the most interesting findings about the importance of zinc in the anti-viral immune response in the respiratory tract and defense against influenza, RSV, and SARS-COV2 infections. The most interesting findings on the role of zinc in regulating immunity in the respiratory tract and the relationship between zinc and acute respiratory distress syndrome (ARDS) are reviewed, as well. Besides, current findings regarding the relationship between zinc and the effectiveness of respiratory viruses' vaccines are reviewed. The results of reviewed studies have shown that zinc and some zinc-dependent proteins are involved in anti-viral defense and immune regulation in the respiratory tract. It seems that zinc can reduce the viral titer following influenza infection. Zinc may reduce RSV burden in the lungs. Zinc can be effective in reducing the duration of viral pneumonia symptoms. Zinc may enhance the effectiveness of hydroxychloroquine in reducing mortality rate in COVID-19 patients. Besides, zinc has a positive effect in preventing ARDS and ventilator-induced lung damage. The relationship between zinc levels and the effectiveness of respiratory viruses' vaccines, especially influenza vaccines, is still unclear, and the findings are somewhat contradictory. In conclusion, zinc has anti-viral properties and is important in defending against respiratory viral infections and regulating the immune response in the respiratory tract.

Regulation of NLRP3 inflammasome by zinc supplementation in Behçet's disease patients: A double-blind, randomized placebo-controlled clinical trial

BACKGROUND

Overproduction of NLRP3 inflammasome complex is one of the causes of Behcet's disease's (BD) auto-inflammatory nature. The aim of current study was to examine the effect of zinc supplementation on NLRP3 inflammasome expression; as well as clinical manifestations of BD.

METHODS

In this double-blind parallel placebo-controlled randomized clinical trial, 50 BD patients were randomly allocated into either zinc gluconate (30 mg/day elemental zinc) or placebo groups for 12 weeks. The mRNA expression of NLRP3 and caspase-1 in the leukocytes, serum level of zinc and IL-1β, anthropometric measures, and clinical manifestations of patients were collected at pre- and post-intervention phase. The Iranian Behçet's disease dynamic activity measure (IBDDAM) was scored to measure the treatment effect using the calculation of number needed to treat (NNT). Analysis of covariance was performed to obtain the corresponding effect sizes.

RESULTS

Zinc gluconate led to a significant improvement in genital ulcer (P = 0.019). Zinc supplementation decreased NLRP3 and caspase-1 genes expression compared with placebo group (baseline-adjusted P-value = 0.046 for NLRP3 and P-value = 0.003 for caspase-1), even after adjustment for the effect of confounding factors (baseline- and confounders-adjusted P-value = 0.032 for NLRP3 and P-value = 0.004 for caspase-1). Baseline and confounders adjusted effect size demonstrated that zinc was effective in reducing the serum level of IL-1β (P = 0.046). The NNT [95 %CI] for the rate of IBDDAM improvement was 3 [1.7-8.5].

CONCLUSIONS

Zinc gluconate supplementation (30 mg/day) for a 3-month period can be considered as an adjuvant therapy in alleviating inflammation and genital ulcer among BD patients.

Inadequate Vitamin C Intake and Intestinal Inflammation Are Associated with Multiple Micronutrient Deficiency in Young Children: Results from a Multi-Country Birth Cohort Study

Children living in resource-limited settings often suffer from multiple micronutrient deficiencies (MMD). However, there lacks evidence on the correlates of MMD in young children. We investigated the role of diets, water, sanitation and hygiene practice, enteric infections, and impaired gut health on MMD in children at 24 months of age using data from the multi-country MAL-ED birth cohort study. Co-existence of more than one micronutrient deficiency (e.g., anemia, iron, zinc, or retinol deficiency) was considered as MMD. We characterized intestinal inflammation by fecal concentrations of myeloperoxidase (MPO) and neopterin (NEO) measured in the non-diarrheal stool samples. Bayesian network analysis was applied to investigate the factors associated with MMD. A total of 1093 children were included in this analysis. Overall, 47.6% of the children had MMD, with the highest prevalence in Pakistan (90.1%) and lowest in Brazil (6.3%). MMD was inversely associated with the female sex [OR: 0.72, 95% CI: 0.54, 0.92]. A greater risk of MMD was associated with lower vitamin C intake [OR: 0.70, 95% CI: 0.48, 0.94] and increased fecal concentrations of MPO [OR: 1.31, 95% CI: 1.08, 1.51]. The study results imply the importance of effective strategies to ameliorate gut health and improve nutrient intake during the early years of life.

Organelle-Level Labile Zn2+ Mapping Based on Targetable Fluorescent Sensors

Although many Zn²⁺ fluorescent probes have been developed, there remains a lack of consensus on the labile Zn²⁺ concentrations ([Zn²⁺]) in several cellular compartments, as the fluorescence properties and zinc affinity of the fluorescent probes are greatly affected by the pH and redox environments specific to organelles. In this study, we developed two turn-on-type Zn²⁺ fluorescent probes, namely, ZnDA-2H and ZnDA-3H, with low pH sensitivity and suitable affinity (K_d = 5.0 and 0.16 nM) for detecting physiological labile Zn²⁺ in various cellular compartments, such as the cytosol, nucleus, ER, and mitochondria. Due to their sufficient membrane permeability, both probes were precisely localized to the target organelles in HeLa cells using HaloTag labeling technology. Using an in situ standard quantification method, we identified the [Zn²⁺] in the tested organelles, resulting in the subcellular [Zn²⁺] distribution as [Zn²⁺]_ER < [Zn²⁺]_mito < [Zn²⁺]_cyto ∼ [Zn²⁺]_nuc.

New Insights into Potential Beneficial Effects of Bioactive Compounds of Bee Products in Boosting Immunity to Fight COVID-19 Pandemic: Focus on Zinc and Polyphenols

The coronavirus disease 2019 (COVID-19) is an epidemic caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). Populations at risk as well as those who can develop serious complications are people with chronic diseases such as diabetes, hypertension, and the elderly. Severe symptoms of SARS-CoV-2 infection are associated with immune failure and dysfunction. The approach of strengthening immunity may be the right choice in order to save lives. This review aimed to provide an overview of current information revealing the importance of bee products in strengthening the immune system against COVID-19. We highlighted the immunomodulatory and the antiviral effects of zinc and polyphenols, which may actively contribute to improving symptoms and preventing complications caused by COVID-19 and can counteract viral infections. Thus, this review will pave the way for conducting advanced experimental research to evaluate zinc and polyphenols-rich bee products to prevent and reduce the severity of COVID-19 symptoms.

Zinc Intakes and Health Outcomes: An Umbrella Review

It is widely accepted that the zinc element is crucial in human beings. Zinc has gained more attention during the COVID-19 pandemic due to its utilization for the treatment and prevention of respiratory tract infections. However, some studies also pointed out that zinc intake might cause unwanted side effects and even be dangerous when overdosed. To reveal the relationship between zinc intake and health outcomes, we performed an umbrella review from human studies. In total, the umbrella review included 43 articles and identified 11 outcomes for dietary zinc intake and 86 outcomes for supplementary zinc intake. Dietary zinc intake in the highest dose would decrease the risk of overall and specific digestive tract cancers, depression, and type 2 diabetes mellitus (T2DM) in adults. Supplementary zinc consumption in adults was linked to an improvement of depression, antioxidant capacity and sperm quality, higher serum zinc concentration, and lower concentration of inflammatory markers. Zinc supplementation in children would reduce the incidence of diarrhea and pneumonia, improve zinc deficiency and boost growth. However, zinc might not decrease all-cause mortality in adults or the in-hospital mortality of COVID-19. And better maternal and neonatal outcomes may not derive from pregnant women who consumed higher or lower doses of zinc supplementation (&gt;20 mg/day and &lt;20 mg/day, respectively). Dose-response analyses revealed that a daily 5 mg increment of zinc would lower the risk of colorectal and esophageal cancer, whereas a large dose of zinc supplementation (daily 100 mg) showed no benefit in reducing prostate cancer risk.

Cytoplasmic zinc promotes IL-1β production by monocytes and macrophages through mTORC1-induced glycolysis in rheumatoid arthritis

[Figure: see text].

Mechanism of Zn2+ and Ca2+ Binding to Human S100A1

S100A1 is a member of the S100 family of small ubiquitous Ca²⁺-binding proteins, which participates in the regulation of cell differentiation, motility, and survival. It exists as homo- or heterodimers. S100A1 has also been shown to bind Zn²⁺, but the molecular mechanisms of this binding are not yet known. In this work, using ESI-MS and ITC, we demonstrate that S100A1 can coordinate 4 zinc ions per monomer, with two high affinity (K_D~4 and 770 nm) and two low affinity sites. Using competitive binding experiments between Ca²⁺ and Zn²⁺ and QM/MM molecular modeling we conclude that Zn²⁺ high affinity sites are located in the EF-hand motifs of S100A1. In addition, two lower affinity sites can bind Zn²⁺ even when the EF-hands are saturated by Ca²⁺, resulting in a 2Ca²⁺:S100A1:2Zn²⁺ conformer. Finally, we show that, in contrast to calcium, an excess of Zn²⁺ produces a destabilizing effect on S100A1 structure and leads to its aggregation. We also determined a higher affinity to Ca²⁺ (K_D~0.16 and 24 μm) than was previously reported for S100A1, which would allow this protein to function as a Ca²⁺/Zn²⁺-sensor both inside and outside cells, participating in diverse signaling pathways under normal and pathological conditions.

Maternal Serum Zinc Level and Pre-eclampsia Risk in African Women: a Systematic Review and Meta-analysis

Some studies have reported the association between maternal serum zinc (Zn) levels and pre-eclampsia. However, many studies have reported controversial results. Hence, this systematic review and meta-analysis was planned to generate summarized evidence on the association between maternal serum Zn levels and pre-eclampsia in African women. Four electronic databases such as PubMed, Hinari, Google Scholar, and African Journals Online were searched for studies published in English. Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument, and Newcastle-Ottawa Scale were used for data extraction and quality assessment of the included studies. The meta-regression analysis was performed by the Stata 14 software. The standardized mean difference (SMD) values of lipid profiles were computed to assess their association with pre-eclampsia at 95% CI. A total of 12 observational studies were included. The mean values of serum Zn level were significantly lower in pre-eclamptic women as compared with normotensive pregnant women (Zn = 59.40 ± 22.80 μg/dL and 80.24 ± 16.04 μg/dL), respectively. The pooled SMD of Zn was significantly reduced in pre-eclamptic women as compared with normotensive pregnant women with the SMD of -1.45 (95% CI -2.26, -0.65) at 95% CI. In this review, we found that the maternal Zn serum level was significantly reduced in pre-eclamptic women than normotensive pregnant women. This suggests that Zn could be involved in the etio-pathogenesis of pre-eclampsia. However, the specific functions of Zn in pre-eclampsia pathogenesis should be proved in large-scale clinical trial studies.

Medicinal Plants and Zinc: Impact on COVID-19 Pandemic

The world is currently grappling with the coronavirus disease (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The infection can cause fever, a dry cough, fatigue, severe pneumonia, respiratory distress syndrome, and in some cases death. There is currently no effective antiviral SARS-CoV-2 drug. To reduce the number of infections and deaths, it is critical to focus on strengthening immunity. This review aims to conduct a comprehensive search on the previous studies using Google Scholar, ScienceDirect, Medline, PubMed, and Scopus for the collection of research papers based on the role of zinc in the immune system, the antiviral activity of zinc, the effect of zinc supplementation in respiratory infections, the therapeutic approaches against viral infections based on medicinal plants, and the role of plants' bioactive molecules in fighting viral infections. In conclusion, we highlighted the pivotal role of zinc in antiviral immunity and we suggested the bioactive molecules derived from medicinal plants as a search matrix for the development of anti-SARS-CoV-2 drugs.

Zap70 Regulates TCR-Mediated Zip6 Activation at the Immunological Synapse

The essential microelement zinc plays immunoregulatory roles via its ability to influence signaling pathways. Zinc deficiency impairs overall immune function and resultantly increases susceptibility to infection. Thus, zinc is considered as an immune-boosting supplement for populations with hypozincemia at high-risk for infection. Besides its role as a structural cofactor of many proteins, zinc also acts as an intracellular messenger in immune cell signaling. T-cell activation instructs zinc influx from extracellular and subcellular sources through the Zip6 and Zip8 zinc transporters, respectively. Increased cytoplasmic zinc participates in the regulation of T-cell responses by modifying activation signaling. However, the mechanism underlying the activation-dependent movement of zinc ions by Zip transporters in T cells remains elusive. Here, we demonstrate that Zip6, one of the most abundantly expressed Zip transporters in T cells, is mainly localized to lipid rafts in human T cells and is recruited into the immunological synapse in response to TCR stimulation. This was demonstrated through confocal imaging of the interaction between CD4⁺ T cells and antigen-presenting cells. Further, immunoprecipitation assays show that TCR triggering induces tyrosine phosphorylation of Zip6, which has at least three putative tyrosine motifs in its long cytoplasmic region, and this phosphorylation is coupled with its physical interaction with Zap70. Silencing Zip6 reduces zinc influx from extracellular sources and suppresses T-cell responses, suggesting an interaction between Zip6-mediated zinc influx and TCR activation. These results provide new insights into the mechanism through which Zip6-mediated zinc influx occurs in a TCR activation-dependent manner in human CD4⁺ T cells.

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.

Assessment of the In Vivo Release and Biocompatibility of Novel Vesicles Containing Zinc in Rats

This paper is focused on the in vivo release and biocompatibility evaluation in rats of some novel systems entrapping zinc chloride in lipid vesicles. The particles were prepared by zinc chloride immobilization inside lipid vesicles made using phosphatidylcholine, stabilized with 0.5% chitosan solution, and dialyzed for 10 h to achieve a neutral pH. The submicrometric systems were physico-chemically characterized. White Wistar rats, assigned into four groups of six animals each, were treated orally with a single dose, as follows: Group I (control): deionized water 0.3 mL/100 g body weight; Group II (Zn): 2 mg/kg body weight (kbw) zinc chloride; Group III (LV-Zn): 2 mg/kbw zinc chloride in vesicles; Group IV (LVC-Zn): 2 mg/kbw zinc chloride in vesicles stabilized with chitosan. Haematological, biochemical, and immune parameters were assessed after 24 h and 7 days, and then liver fragments were collected for histopathological examination. The use of zinc submicrometric particles-especially those stabilized with chitosan-showed a delayed zinc release in rats. No substantial changes to blood parameters, plasma biochemical tests, serum complement activity, or peripheral neutrophils phagocytic capacity were noted; moreover, the tested substances did not induce liver architectural disturbances. The obtained systems provided a delayed release of zinc, and showed good biocompatibility in rats.

Immuno-pharmacokinetics of Meglumine Antimoniate in Patients With Cutaneous Leishmaniasis Caused by Leishmania (Viannia)

BACKGROUND

Control of cutaneous leishmaniasis (CL) relies on chemotherapy, yet gaps in our understanding of the determinants of therapeutic outcome impede optimization of antileishmanial drug regimens. Pharmacodynamic (PD) parameters of antimicrobials are based on the relationship between drug concentrations/exposure and microbial kill. However, viable Leishmania persist in a high proportion of individuals despite clinical resolution, indicating that determinants other than parasite clearance are involved in drug efficacy.

METHODS

In this study, the profiles of expression of neutrophils, monocytes, Th1 and Th17 gene signatures were characterized in peripheral blood mononuclear cells (PBMCs) during treatment with meglumine antimoniate (MA) and clinical cure of human CL caused by Leishmania (Viannia). We explored relationships of immune gene expression with plasma and intracellular antimony (Sb) concentrations.

RESULTS

Our findings show a rapid and orchestrated modulation of gene expression networks upon exposure to MA. We report nonlinear pharmacokinetic/pharmacodynamic (PK/PD) relationships of Sb and gene expression dynamics in PBMCs , concurring with a time lag in the detection of intracellular drug concentrations and with PK evidence of intracellular Sb accumulation.

CONCLUSIONS

Our results quantitatively portray the immune dynamics of therapeutic healing, and provide the knowledge base for optimization of antimonial drug treatments, guiding the selection and/or design of targeted drug delivery systems and strategies for targeted immunomodulation.

Regulatory Role of Zinc in Immune Cell Signaling

Zinc is an essential micronutrient with crucial roles in multiple facets of biological processes. Dysregulated zinc homeostasis impairs overall immune function and resultantly increases susceptibility to infection. Clinically, zinc supplementation is practiced for treatment of several infectious diseases, such as diarrhea and malaria. Recent focus on zinc as a beneficial element for immune system support has resulted in investigation of the immunomodulatory roles of zinc in a variety of immune cells. Besides its classical role as a cofactor that regulates the structural function of thousands of proteins, accumulating evidence suggests that zinc also acts, in a manner similar to calcium, as an ionic regulator of immune responses via participation as an intracellular messenger in signaling pathways. In this review, we focus on the role of zinc as a signaling molecule in major pathways such as those downstream of Toll-like receptors-, T cell receptor-, and cytokine-mediated signal transduction that regulate the activity and function of monocytes/macrophages and T cells, principal players in the innate and adaptive immune systems.

Role of zinc in neonatal growth and brain growth: review and scoping review

This manuscript includes (1) a narrative review of Zinc as an essential nutrient for fetal and neonatal growth and brain growth and development and (2) a scoping review of studies assessing the effects of Zinc supplementation on survival, growth, brain growth, and neurodevelopment in neonates. Very preterm infants and small for gestational age infants are at risk for Zinc deficiency. Zinc deficiency can cause several complications including periorificial lesions, delayed wound healing, hair loss, diarrhea, immune deficiency, growth failure with stunting, and brain atrophy and dysfunction. Zinc is considered essential for oligodendrogenesis, neurogenesis, neuronal differentiation, white matter growth, and multiple biological and physiological roles in neurobiology. Data support the possibility that the critical period of Zinc delivery for brain growth in the mouse starts at 18 days of a 20-21-day pregnancy and extends during lactation and in human may start at 26 weeks of gestation and extend until at least 44 weeks of postmenstrual age. Studies are needed to better elucidate Zinc requirement in extremely low gestational age neonates to minimize morbidity, optimize growth, and brain growth, prevent periventricular leukomalacia and optimize neurodevelopment. IMPACT: Zinc is essential for growth and brain growth and development. In the USA, very preterm small for gestational age infants are at risk for Zinc deficiency. Data support the possibility that the critical period of Zinc delivery for brain growth in the mouse starts at 18 days of a 20-21-day pregnancy and extends during lactation and in human may start at 26 weeks' gestation and extend until at least 44 weeks of postmenstrual age. Several randomized trials of Zinc supplementation in neonates have shown improvement in growth when using high enough dose, for long duration in patients likely to or proven to have a Zinc deficiency. Studies are needed to better elucidate Zinc requirement in extremely low gestational age neonates to minimize morbidity, optimize growth and brain growth, prevent periventricular leukomalacia and optimize neurodevelopment.

Attenuating the Effects of Novel COVID-19 (SARS-CoV-2) Infection-Induced Cytokine Storm and the Implications

The COVID-19 pandemic constitutes an arduous global health challenge, and the increasing number of fatalities calls for the speedy pursuit of a remedy. This review emphasizes the changing aspects of the COVID-19 disease, featuring the cytokine storm's pathological processes. Furthermore, we briefly reviewed potential therapeutic agents that may modulate and alleviate cytokine storms. The literature exploration was made using PubMed, Embase, MEDLINE, Google scholar, and China National Knowledge Infrastructure databases to retrieve the most recent literature on the etiology, diagnostic markers, and the possible prophylactic and therapeutic options for the management of cytokine storm in patients hospitalized with COVID-19 disease. The causative agent, severe acute respiratory coronavirus-2 (SARS-CoV-2), continually threatens the efficiency of the immune system of the infected individuals. As the first responder, the innate immune system provides primary protection against COVID-19, affecting the disease's progression, clinical outcome, and prognosis. Evidence suggests that the fatalities associated with COVID-19 are primarily due to hyper-inflammation and an aberrant immune function. Accordingly, the magnitude of the release of pro-inflammatory cytokines such as interleukin (IL)-1, (IL-6), and tumor necrosis alpha (TNF-α) significantly differentiate between mild and severe cases of COVID-19. The early prediction of a cytokine storm is made possible by several serum chemistry and hematological markers. The prompt use of these markers for diagnosis and the aggressive prevention and management of a cytokine release syndrome is critical in determining the level of morbidity and fatality associated with COVID-19. The prophylaxis and the rapid treatment of cytokine storm by clinicians will significantly enhance the fight against the dreaded COVID-19 disease.

Interactions of zinc- and redox-signaling pathways

Zinc and cellular oxidants such as reactive oxygen species (ROS) each participate in a multitude of physiological functions. There is considerable overlap between the affected events, including signal transduction. While there is no obvious direct connection between zinc and ROS, mainly because the bivalent cation zinc does not change its oxidation state in biological systems, these are linked by their interaction with sulfur, forming the remarkable triad of zinc, ROS, and protein thiols. First, zinc binds to reduced thiols and can be released upon oxidation. Thereby, redox signals are translated into changes in the free zinc concentration, which can act as zinc signals. Second, zinc affects oxidation of thiols in several ways, directly as well as indirectly. A protein incorporating many of these interactions is metallothionein (MT), which is rich in cysteine and capable of binding up to seven zinc ions in its fully reduced state. Zinc binding is diminished after (partial) oxidation, while thiols show increased reactivity in the absence of bound metal ions. Adding still more complexity, the MT promoter is controlled by zinc (via metal regulatory transcription factor 1 (MTF-1)) as well as redox (via nuclear factor erythroid 2-related factor 2 (NRF2)). Many signaling cascades that are important for cell proliferation or apoptosis contain protein thiols, acting as centers for crosstalk between zinc- and redox-signaling. A prominent example for shared molecular targets for zinc and ROS are active site cysteine thiols in protein tyrosine phosphatases (PTP), their activity being downregulated by oxidation as well as zinc binding. Because zinc binding also protects PTP thiols form irreversible oxidation, there is a multi-faceted reciprocal interaction, illustrating that zinc- and redox-signaling are intricately linked on multiple levels.

Potential Role of Zinc in the COVID-19 Disease Process and its Probable Impact on Reproduction

COVID-19 (coronavirus disease 2019) is the current world health crisis, producing extensive morbidity and mortality across all age groups. Given the established roles of zinc in combating oxidative damage and viral infections, zinc is being trialed as a treatment modality against COVID-19. Zinc also has confirmed roles in both male and female reproduction. The possible depletion of zinc with the oxidative events of COVID-19 is especially relevant to the fertility of affected couples. This review aims to present the pathophysiology of COVID-19, especially in relation to reproductive function; the role of zinc in the COVID-19 disease process; and how zinc depletion in concert with cytokine storm and reactive oxygen species production could affect reproduction. It also highlights research areas to better the understanding of COVID-19 and its impact on fertility and potential ways to mitigate the impact.

Imaging Beta-Cell Function in the Pancreas of Non-Human Primates Using a Zinc-Sensitive MRI Contrast Agent

Non-invasive beta cell function measurements may provide valuable information for improving diabetes diagnostics and disease management as the integrity and function of pancreatic beta cells have been found to be compromised in Type-1 and Type-2 diabetes. Currently, available diabetes assays either lack functional information or spatial identification of beta cells. In this work, we introduce a method to assess the function of beta cells in the non-human primate pancreas non-invasively with MRI using a Gd-based zinc(II) sensor as a contrast agent, Gd-CP027. Additionally, we highlight the role of zinc(II) ions in the paracrine signaling of the endocrine pancreas via serological measurements of insulin and c-peptide. Non-human primates underwent MRI exams with simultaneous blood sampling during a Graded Glucose Infusion (GGI) with Gd-CP027 or with a non-zinc(II) sensitive contrast agent, gadofosveset. Contrast enhancement of the pancreas resulting from co-release of zinc(II) ion with insulin was observed focally when using the zinc(II)-specific agent, Gd-CP027, whereas little enhancement was detected when using gadofosveset. The contrast enhancement detected by Gd-CP027 increased in parallel with an increased dose of infused glucose. Serological measurements of C-peptide and insulin indicate that Gd-CP027, a high affinity zinc(II) contrast agent, potentiates their secretion only as a function of glucose stimulation. Taken in concert, this assay offers the possibility of detecting beta cell function in vivo non-invasively with MRI and underscores the role of zinc(II) in endocrine glucose metabolism.

Murine Models for the Investigation of Colonization Resistance and Innate Immune Responses in Campylobacter Jejuni Infections

Human infections with the food-borne pathogen Campylobacter jejuni are progressively increasing worldwide and constitute a significant socioeconomic burden to mankind. Intestinal campylobacteriosis in humans is characterized by bloody diarrhea, fever, abdominal pain, and severe malaise. Some individuals develop chronic post-infectious sequelae including neurological and autoimmune diseases such as reactive arthritis and Guillain-Barré syndrome. Studies unraveling the molecular mechanisms underlying campylobacteriosis and post-infectious sequelae have been hampered by the scarcity of appropriate experimental in vivo models. Particularly, conventional laboratory mice are protected from C. jejuni infection due to the physiological colonization resistance exerted by the murine gut microbiota composition. Additionally, as compared to humans, mice are up to 10,000 times more resistant to C. jejuni lipooligosaccharide (LOS) constituting a major pathogenicity factor responsible for the immunopathological host responses during campylobacteriosis. In this chapter, we summarize the recent progress that has been made in overcoming these fundamental obstacles in Campylobacter research in mice. Modification of the murine host-specific gut microbiota composition and sensitization of the mice to C. jejuni LOS by deletion of genes encoding interleukin-10 or a single IL-1 receptor-related molecule as well as by dietary zinc depletion have yielded reliable murine infection models resembling key features of human campylobacteriosis. These substantial improvements pave the way for a better understanding of the molecular mechanisms underlying pathogen-host interactions. The ongoing validation and standardization of these novel murine infection models will provide the basis for the development of innovative treatment and prevention strategies to combat human campylobacteriosis and collateral damages of C. jejuni infections.

Zinc, ω-3 polyunsaturated fatty acids and vitamin D: An essential combination for prevention and treatment of cancers

Zinc, ω-3 polyunsaturated fatty acids (PUFAs) and vitamin D are essential nutrients for health, maturation and general wellbeing. Extensive literature searches have revealed the widespread similarity in molecular biological properties of zinc, ω-3 PUFAs and vitamin D, and their similar anti-cancer properties, even though they have different modes of action. These three nutrients are separately essential for good health, especially in the aged. Zinc, ω-3 PUFAs and vitamin D are inexpensive and safe as they are fundamentally natural and have the properties of correcting and inhibiting undesirable actions without disturbing the normal functions of cells or their extracellular environment. This review of the anticancer properties of zinc, ω-3 PUFAs and vitamin D is made in the context of the hallmarks of cancer. The anticancer properties of zinc, ω-3 PUFAs and vitamin D can therefore be used beneficially through combined treatment or supplementation. It is proposed that sufficiency of zinc, ω-3 PUFAs and vitamin D is a necessary requirement during chemotherapy treatment and that clinical trials can have questionable integrity if this sufficiency is not checked and maintained during efficacy trials.

Zinc deficiency leads to reduced interleukin-2 production by active gene silencing due to enhanced CREMα expression in T cells

BACKGROUND & AIMS

The micronutrient zinc is essential for proper immune function. Consequently, zinc deficiency leads to impaired immune function, as seen in decreased secretion of interleukin (IL)-2 by T cells. Although this association has been known since the late 1980s, the underlying molecular mechanisms are still unknown. Zinc deficiency and reduced IL-2 levels are especially found in the elderly, which in turn are prone to chronic diseases. Here, we describe a new molecular link between zinc deficiency and reduced IL-2 expression in T cells.

METHODS

The effects of zinc deficiency were first investigated in vitro in the human T cell lines Jurkat and Hut-78 and complemented by in vivo data from zinc-supplemented pigs. A short- and long-term model for zinc deficiency was established. Zinc levels were detected by flow cytometry and expression profiles were investigated on the mRNA and protein level.

RESULTS

The expression of the transcription factor cAMP-responsive-element modulator α (CREMα) is increased during zinc deficiency in vitro, due to increased protein phosphatase 2A (PP2A) activity, resulting in decreased IL-2 production. Additionally, zinc supplementation in vivo reduced CREMα levels causing increased IL-2 expression. On epigenetic levels increased CREMα binding to the IL-2 promoter is mediated by histone deacetylase 1 (HDAC1). The HDAC1 activity is inhibited by zinc. Moreover, deacetylation of the activating histone mark H3K9 was increased under zinc deficiency, resulting in reduced IL-2 expression.

CONCLUSIONS

With the transcription factor CREMα a molecular link was uncovered, connecting zinc deficiency with reduced IL-2 production due to enhanced PP2A and HDAC1 activity.

Potentials of Musa Species Fruits against Oxidative Stress-Induced and Diet-Linked Chronic Diseases: In Vitro and In Vivo Implications of Micronutritional Factors and Dietary Secondary Metabolite Compounds

Nutritional quality and the well-being of the body system are directly linked aspects of human survival. From the unborn foetus to adulthood, the need for sustainable access to micronutrient-rich foods is pertinent and the global consumption of banana and plantain fruits, in effect, contributes to the alleviation of the scourge of malnutrition. This review is particularly aimed at evaluating the pharmacological dimensions through the biological mechanisms of Musa fruits in the body, which represent correlations with their constituent micronutrient factors and dietary polyphenolic constituents such as minerals, vitamin members, anthocyanins, lutein, α-,β- carotenes, neoxanthins and cryptoxanthins, epi- and gallo catechins, catecholamines, 3-carboxycoumarin, β-sitosterol, monoterpenoids, with series of analytical approaches for the various identified compounds being highlighted therein. Derivative value-products from the compartments (flesh and peel) of Musa fruits are equally highlighted, bringing forth the biomedicinal and nutritional relevance, including the potentials of Musa species in dietary diversification approaches.

Zinc: Roles in pancreatic physiology and disease

Zinc is an essential trace element. Deficiencies are frequently seen with gastrointestinal diseases, including chronic pancreatitis, nutritional deficiency, and reduced intestinal absorption. Additionally, reduced zinc levels have been linked to cellular changes associated with acute pancreatitis such as enhanced inflammation with increased macrophage activation and production of inflammatory cytokines such as IL-1β, impaired autophagy, and modulation of calcium homeostasis. Preliminary data suggest that zinc deficiency may lead to pancreatic injury in animal models. The purpose of this review is to explore the biologic effects of zinc deficiency that could impact pancreatic disease. MESH KEYWORDS: Malnutrition, inflammation, trace element.

Quantitative Imaging of Labile Zn2+ in the Golgi Apparatus Using a Localizable Small-Molecule Fluorescent Probe

Fluorescent Zn²⁺ probes used for the quantitative analysis of labile Zn²⁺ concentration ([Zn²⁺]) in target organelles are crucial for understanding the role of Zn²⁺ in biological processes. Although several fluorescent Zn²⁺ probes have been developed to date, there is still a lack of consensus concerning the [Zn²⁺] in intracellular organelles. In this study, we describe the development of ZnDA-1H, a small-molecule fluorescent probe for Zn²⁺, which exhibits less pH sensitivity, high Zn²⁺ selectivity, and large fluorescence enhancement upon binding to Zn²⁺. Through protein labeling technology, ZnDA-1H was precisely targeted in various intracellular organelles, such as the nucleus, mitochondria, endoplasmic reticulum, and Golgi apparatus. ZnDA-1H exhibited a reversible fluorescence response toward labile Zn²⁺ in these organelles in live cells. Using this probe, the [Zn²⁺] in the Golgi apparatus was estimated to be 25 ± 1 nM, suggesting that labile Zn²⁺ plays a physiological role in the secretory pathway.