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Since Asian sea bass is one of the economically most important fish, aquaculture conditions are constantly optimized. Evidence from feeding studies combined with the current understanding of the importance of zinc for growth and immune defense suggest that zinc supplementation may be a possible approach to optimize aquacultures of Asian sea bass. To investigate the effects of zinc deficiency and zinc supplementation, cells from Asian sea bass were incubated in culture medium with different zinc contents. The expression of genes, important for zinc homeostasis, redox metabolism, and growth hormones was analyzed using RT-PCR. Zinc deficiency induced the expression of certain zinc transporters (ZIP14, ZIP10, ZIP6, ZIP4, ZnT4, ZnT9) as well as of SOD1, IGF I and IGF II, while expression of ZnT1 and metallothionein (MT) was reduced. Zinc supplementation decreased the expression of ZIP10, while expression of ZnT1 and MT were elevated. No differences in the effects of zinc supplementation with zinc sulfate compared to supplementation with zinc amino acid complexes were observed. Thus, extracellular zinc conditions may govern the cellular zinc homeostasis, the redox metabolism and growth hormone expression in cells from Asian sea bass as reported for other fish species. Our data indicate that supplementing aquacultures with zinc may be recommended to avoid detriments of zinc deficiency.
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Zinc supplementation prior to heat shock increases HSP70 (heat shock protein 70) expression, which has cytoprotective effects in tissue cells during inflammation. Effects of zinc deficiency in this regard have been discussed controversially. Whether zinc modulates the expression of HSP70 in the human immune system as well and thus affects cell survival during heat stress is so far largely unknown. Therefore, we investigated the effect of alterations in the cellular zinc status on HSP70 expression and on cellular survival in human monocytes and lymphocytes. Three cell lines (Jurkat, THP-1, and Ramos) and enriched primary human monocytes and lymphocytes from young subjects were subjected to zinc deficiency or supplementation and subsequently heat shock at 42 °C. HSP70 mRNA expression was analyzed by real-time PCR, whereas HSP70 protein expression was analyzed by western blotting. In all cells other than Ramos cells, zinc supplementation and deficiency augmented heat shock-induced HSP70 expression. Further experiments in primary monocytes and lymphocytes indicated that this may be explained by the enhanced phosphorylation of HSF1 (Heat shock factor 1) at Ser326, which plays a significant role in HSP70 induction, as observed in zinc deficient and supplemented cells. While zinc supplementation had negligible effects on cell viability, acute zinc deficiency further increased cell death, induced by heat shock. Our results emphasize the importance of an optimal cellular zinc status. Moreover, we present a possible mechanism behind zinc's influence on HSP70 expression in human leukocytes. Our data form the basis for further in vivo and ex vivo studies to investigate how the zinc status may affect cellular damage in transient high temperature situations.
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Proteínas de Unión al ADN , Zinc , Proteínas de Unión al ADN/genética , Suplementos Dietéticos , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP70 de Choque Térmico/metabolismo , Factores de Transcripción del Choque Térmico/genética , Factores de Transcripción del Choque Térmico/metabolismo , Respuesta al Choque Térmico , Humanos , Linfocitos/metabolismo , Fosforilación , Serina/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Zinc/metabolismo , Zinc/farmacologíaRESUMEN
BACKGROUND: Aging is accompanied by a dramatic decline in the interleukin (IL)-2 production capacity of human immune cells, thus making seniors more susceptible to a variety of age-related diseases. A common cause of impaired cytokine production in advanced age is a deficiency of the essential micronutrient zinc. Nevertheless, the molecular mechanisms underlying a zinc deficiency-induced decrease in IL-2 production have not yet been satisfactorily elucidated. Recent animal and in vitro data suggested that the transcription factor cAMP-responsive element modulator (CREM) [Formula: see text] plays a critical role in T cells´ disturbed IL-2 production in suboptimal zinc conditions. However, its role in the human aging process and the possibility of influencing this detrimental process by short-term zinc supplementation have not yet been evaluated. RESULTS: Comparing peripheral lymphocytes of 23 young and 31 elderly subjects with either high, intermediate, or deficient zinc status, we observed zinc-dependent regulation of the IL-2 production mediated by the transcription factor CREM [Formula: see text]. For the first time in humans, we report a mutual relationship between low zinc levels, high CREM [Formula: see text] expression, subsequent impaired IL-2 production, and vice versa. Remarkably, an average of only 6 days of in vivo zinc supplementation to zinc-deficient seniors was sufficient to rapidly improve zinc status, reverse CREM [Formula: see text] overexpression, and counteract subsequent low IL-2 production rates. CONCLUSIONS: Our ex vivo and in vivo data identify zinc deficiency-mediated CREM [Formula: see text] overexpression as a key cellular mechanism underlying impaired IL-2 production in the elderly and point toward the use of zinc as a rapidly immune-enhancing add-on nutraceutical in geriatric therapy. During the aging process, there is a progressive decrease in zinc status, which in turn leads to overexpression of the transcription factor CREM[Formula: see text] in peripheral lymphocytes. CREMα is a negative regulator of the IL-2 gene, the overexpression of which dramatically limits adequate IL-2 production. This deleterious mechanism can be counteracted by short-term oral zinc administration, which can adjust IL-2 production in old, zinc-deficient individuals to a level similar to that of young adults.
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SCOPE: Zinc is suggested to be necessary for functional signaling induced by certain growth factors. The granulocyte-macrophage colony-stimulating factor (GM-CSF) is a key factor for differentiation and activation of myeloid cells. This report analyses the impact of different zinc concentrations on GM-CSF-induced signaling in mature polymorphonuclear leukocytes (PMN). METHODS AND RESULTS: As measured by flow cytometry, zinc increases surface GM-CSF receptor (GM-CSFR) in PMN, whereas monocytes respond with decreased GM-CSFR surface expression. Since total cellular GM-CSFR expression remains unaffected, the observed zinc-induced GM-CSFR surface dynamics may be explained by receptor redistribution. In PMN, zinc enhanced phosphorylation of mitogen-activated protein kinases (MAPK) in a dose-dependent manner as found in western blot. Zinc-induced MAPK phosphorylation is additionally augmented by moderate GM-CSF stimulation. CONCLUSION: The present study demonstrates the opposing influence of zinc on GM-CSFR surface expression in monocytes and PMN. Zinc and GM-CSF, use in optimized concentrations, augment MAPK signaling, and increase expression of MAPK-induced myeloid cell leukemia-1 (Mcl-1) in PMN. Thus, this study concludes that zinc strengthens growth factor-induced signaling. Hence, the study provides a basis for further in vivo studies, focusing on the therapeutic value of zinc in patients with a disturbed GM-CSF signaling.
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Factor Estimulante de Colonias de Granulocitos y Macrófagos , Neutrófilos , Factor Estimulante de Colonias de Granulocitos y Macrófagos/farmacología , Humanos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Neutrófilos/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/análisis , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/metabolismo , Transducción de Señal , Zinc/metabolismo , Zinc/farmacologíaRESUMEN
SCOPE: T cell activation requires a metabolic reprogramming from oxidative phosphorylation to aerobic glycolysis to rapidly provide substrates for biosynthesis. An individual's zinc status plays an important role in balancing the activation of T cells and is required for a proper function of immune cells. Furthermore, zinc plays an important role during effector T cell polarization to T helper cell subsets or regulatory T cells, with effector T cells relying on glycolysis and regulatory T cells on oxidative phosphorylation. Therefore, the study aims to analyze if zinc also impacts on T cell activation on the level of intracellular metabolism. METHODS AND RESULTS: Mixed lymphocyte culture and anti-CD3/CD28 stimulation is used as in vitro models for T cell activation to investigate the effect of zinc supplementation and deprivation on metabolic switching. Promoted glucose uptake, insulin receptor expression, and signaling in both zinc conditions are observed, whereas key metabolic enzymes are stimulated mainly by zinc deprivation. Alterations in cytokine production suggest an immune-activating effect of zinc deprivation and a balancing effect of zinc supplementation. CONCLUSION: The results suggest a supportive effect of both zinc supplementation and deprivation on the metabolic switch during T cell activation, adding another level of immune regulation by zinc.
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Glucólisis , Receptor de Insulina , Glucosa/metabolismo , Activación de Linfocitos , Receptor de Insulina/metabolismo , Zinc/farmacologíaRESUMEN
Zinc has been suggested to play a role in carcinogenesis and tumor progression. Serum zinc levels of lung cancer patients are for example lower than in healthy individuals. The activation and expression of the epidermal growth factor receptor (EGFR), which plays a role in tumor biology, are presumably influenced by zinc. EGFR activation influences cell adhesion and immune escape. This study provides insights into the impacts of zinc on the EGFR activation and expression of downstream proteins such as E-cadherin and PD-L1 in the alveolar carcinoma cell line A549. To model chronic changes in zinc homeostasis, A549 cells were cultured in media with different zinc contents. EGFR surface expression of unstimulated and stimulated A549 cells was determined by flow cytometry. EGFR phosphorylation as well as the protein expression of E-cadherin and PD-L1 were analyzed by Western blot. In our hands, chronic zinc deficiency led to increased EGFR surface expression, decreased E-cadherin protein expression and increased PD-L1 protein expression. Zinc supplementation decreased EGFR surface expression and PD-L1 protein expression. In summary, zinc-deficient A549 cells may display a more malignant phenotype. Thus, future clinical research should further focus on the possible benefits of restoring disturbed zinc homeostasis, especially in lung cancer patients.
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Zinc/metabolismo , Células A549 , Antígeno B7-H1/metabolismo , Cadherinas/metabolismo , Línea Celular Tumoral , Receptores ErbB/metabolismo , Regulación Neoplásica de la Expresión Génica/fisiología , Humanos , Neoplasias Pulmonares/metabolismo , Transducción de Señal/fisiologíaRESUMEN
The importance of Zn for human health becomes obvious during Zn deficiency. Even mild insufficiencies of Zn cause alterations in haematopoiesis and immune functions, resulting in a proinflammatory phenotype and a disturbed redox metabolism. Although immune system malfunction has the most obvious effect, the functions of several tissue cell types are disturbed if Zn supply is limiting. Adhesion molecules and tight junction proteins decrease, while cell death increases, generating barrier dysfunction and possibly organ failure. Taken together, Zn deficiency both weakens the resistance of the human body towards pathogens and at the same time increases the danger of an overactive immune response that may cause tissue damage. The case numbers of Corona Virus Disease 19 (COVID-19) are still increasing, which is causing enormous problems for health systems and economies. There is an urgent need to reduce both the number of severe cases and the resulting deaths. While therapeutic options are still under investigation, and first vaccines have been approved, cost-effective ways to reduce the likelihood of or even prevent infection, and the transition from mild symptoms to more serious detrimental disease, are highly desirable. Nutritional supplementation might be an effective option to achieve these aims. In this review, we discuss known Zn deficiency effects in the context of an infection with Severe Acute Respiratory Syndrome-Coronavirus-2 and its currently known pathogenic mechanisms and elaborate on how severe pre-existing Zn deficiency may pre-dispose patients to a severe progression of COVID-19. First published clinical data on the association of Zn homoeostasis with COVID-19 and registered studies in progress are listed.
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COVID-19 , Zinc , COVID-19/epidemiología , COVID-19/patología , Progresión de la Enfermedad , Humanos , Gravedad del Paciente , Medición de Riesgo , Factores de Riesgo , Zinc/deficienciaRESUMEN
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.
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Sistema Inmunológico , Zinc , Dieta , HumanosRESUMEN
The significance of zinc for an efficient immune response is well accepted. During zinc deficiency, an increase in the myeloid to lymphoid immune cells ratio was observed. This results in a disturbed balance of pro- and anti-inflammatory processes as well as defects in tolerance during infections. Consequently, instead of efficiently defending the body against invading pathogens, damage of host cells is frequently observed. This explains the increased susceptibility to infections and their severe progression observed for zinc deficient individuals as well as the association of autoimmune diseases with low serum zinc levels. Together with the advances in techniques for investigating cellular development, communication and intracellular metabolism, our understanding of the mechanisms underlying the benefits of zinc for human health and the detriments of zinc deficiency has much improved. As analyses of the zinc status and effects of zinc supplementation were more frequently included into clinical studies, our knowledge of the association of zinc deficiency to a variety of diseases was strongly improved. Still there are several areas in zinc biology that require further in-depth investigation such as the interaction with other nutritional elements, the direct association between zinc transportation, membrane-structure, receptors, and signaling as well as its role in cell degeneration. This article will describe our current understanding of the role of zinc during the immune response focusing on the most recent findings and underlying mechanisms. Research questions that need to be addressed in the future will be discussed as well.
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Inmunidad Innata/efectos de los fármacos , Inmunidad/inmunología , Zinc/inmunología , HumanosRESUMEN
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.
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Modulador del Elemento de Respuesta al AMP Cíclico/inmunología , Expresión Génica/genética , Silenciador del Gen , Interleucina-2/biosíntesis , Linfocitos T/inmunología , Zinc/deficiencia , Zinc/inmunología , Animales , Modulador del Elemento de Respuesta al AMP Cíclico/genética , Modelos Animales de Enfermedad , Expresión Génica/inmunología , Humanos , Técnicas In Vitro , Interleucina-2/genética , Interleucina-2/inmunología , PorcinosRESUMEN
During the current corona pandemic, new therapeutic options against this viral disease are urgently desired. Due to the rapid spread and immense number of affected individuals worldwide, cost-effective, globally available, and safe options with minimal side effects and simple application are extremely warranted. This review will therefore discuss the potential of zinc as preventive and therapeutic agent alone or in combination with other strategies, as zinc meets all the above described criteria. While a variety of data on the association of the individual zinc status with viral and respiratory tract infections are available, study evidence regarding COVID-19 is so far missing but can be assumed as was indicated by others and is detailed in this perspective, focusing on re-balancing of the immune response by zinc supplementation. Especially, the role of zinc in viral-induced vascular complications has barely been discussed, so far. Interestingly, most of the risk groups described for COVID-19 are at the same time groups that were associated with zinc deficiency. As zinc is essential to preserve natural tissue barriers such as the respiratory epithelium, preventing pathogen entry, for a balanced function of the immune system and the redox system, zinc deficiency can probably be added to the factors predisposing individuals to infection and detrimental progression of COVID-19. Finally, due to its direct antiviral properties, it can be assumed that zinc administration is beneficial for most of the population, especially those with suboptimal zinc status.
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Antivirales/inmunología , Betacoronavirus/fisiología , Infecciones por Coronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Suplementos Dietéticos , Pandemias/prevención & control , Neumonía Viral/inmunología , Neumonía Viral/prevención & control , Zinc/inmunología , Animales , Antivirales/farmacología , Antivirales/uso terapéutico , COVID-19 , Cilios/efectos de los fármacos , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/virología , Homeostasis/inmunología , Humanos , Neumonía Viral/tratamiento farmacológico , Neumonía Viral/virología , Mucosa Respiratoria/inmunología , SARS-CoV-2 , Internalización del Virus/efectos de los fármacos , Replicación Viral/efectos de los fármacos , Zinc/deficiencia , Zinc/farmacología , Zinc/uso terapéuticoRESUMEN
INTRODUCTION: Zinc is well known for its anti-inflammatory effects, including regulation of migration and activity of polymorphonuclear neutrophils (PMN). Zinc deficiency is associated with inflammatory diseases such as acute lung injury (ALI). As deregulated neutrophil recruitment and their hyper-activation are hallmarks of ALI, benefits of zinc supplementation on the development of lipopolysaccharides (LPS)-induced ALI were tested. METHODS: 64 C57Bl/6 mice, split into eight groups, were injected with 30 µg zinc 24 hours before exposure to aerosolised LPS for 4 hours. Zinc homoeostasis was characterised measuring serum and lung zinc concentrations as well as metallothionein-1 expression. Recruitment of neutrophils to alveolar, interstitial and intravascular space was assessed using flow cytometry. To determine the extent of lung damage, permeability and histological changes and the influx of protein into the bronchoalveolar lavage fluid were measured. Inflammatory status and PMN activity were evaluated via tumour necrosis factor α levels and formation of neutrophil extracellular traps. The effects of zinc supplementation prior to LPS stimulation on activation of primary human granulocytes and integrity of human lung cell monolayers were assessed as well. RESULTS: Injecting zinc 24 hours prior to LPS-induced ALI indeed significantly decreased the recruitment of neutrophils to the lungs and prevented their hyperactivity and thus lung damage was decreased. Results from in vitro investigations using human cells suggest the transferability of the finding to human disease, which remains to be tested in more detail. CONCLUSION: Zinc supplementation attenuated LPS-induced lung injury in a murine ALI model. Thus, the usage of zinc-based strategies should be considered to prevent detrimental consequences of respiratory infection and lung damage in risk groups.
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Lesión Pulmonar Aguda/metabolismo , Lesión Pulmonar Aguda/prevención & control , Infiltración Neutrófila/efectos de los fármacos , Neutrófilos/fisiología , Zinc/farmacología , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/patología , Animales , Líquido del Lavado Bronquioalveolar/química , Proteínas de Transporte de Catión/genética , Línea Celular , Supervivencia Celular/efectos de los fármacos , Quimiocina CXCL1/metabolismo , Modelos Animales de Enfermedad , Expresión Génica/efectos de los fármacos , Factor Estimulante de Colonias de Granulocitos/genética , Homeostasis , Humanos , Selectina L/metabolismo , Lipopolisacáridos , Masculino , Metalotioneína/genética , Metalotioneína/metabolismo , Ratones , Ratones Endogámicos C57BL , ARN Mensajero , Receptores de Complemento 3b/metabolismo , Factor de Transcripción STAT3/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo , Zinc/metabolismo , Zinc/uso terapéuticoRESUMEN
A high number of illnesses and disorders are connected to zinc deficiency. Equally, T cell polarization and a balance between different T helper (Th) cell subsets are essential. Therefore, in this study, the influence of zinc deficiency on T cell polarization and on respective signaling pathways was investigated. We uncovered a significantly increased number of regulatory T cells (Treg) and Th17 cells in expanded T cells during zinc deficiency after 3 days of combined treatment with IL-2 and TGF-ß1 (Treg) or IL-6 and TGF-ß1 (Th17). No difference in Th1 and Th2 cell polarization between zinc-deficient and zinc-adequate status was prominent. On the molecular level, Smad signaling was significantly enhanced by stimulation with TGF-ß1/IL-6 during zinc deficiency compared to adequate zinc condition. This represents an explanation for the elevated Th17 cell numbers associated with autoimmune disease especially during zinc deficiency. Moreover, Treg cell numbers are increased during zinc deficiency as well. However, those cells might be nonfunctional since a lower expression of miR-146a was uncovered compared to normal zinc concentrations. In summary, an adequate zinc homeostasis is fundamental to slow down or probably stop the progression of autoimmune diseases and infections. Therefore, supplementing zinc might be a therapeutic approach to dampen autoimmune diseases connected to Th17 cells.
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Linfocitos T Reguladores/fisiología , Células Th17/patología , Zinc/deficiencia , Polaridad Celular , Células Cultivadas , Regulación de la Expresión Génica , Humanos , Células Jurkat , Leucocitos Mononucleares , MicroARNs/genética , Proteínas/metabolismo , Linfocitos T Reguladores/inmunología , Células Th17/inmunología , Zinc/metabolismoRESUMEN
Zinc is an essential trace element, highly important for a well functioning immune system. In case of zinc deficiency, proper immune functions are not ensured thus leading to various diseases. Weaning of pigs from the sow causes stress, increasing susceptibility to infections. Moreover, low feed intake during the first two weeks post-weaning, accompanied by low zinc intake, results in temporary zinc deficiency. Therefore, supporting the immune system by zinc supplementation might improve its function and thereby the pigs' health and well-being. In this study, the immune status of weaned pigs was analyzed under different conditions of zinc supplementation. More precisely, the daily porcine diet was either left unsupplemented (0â¯ppm), or was supplemented with low (100â¯ppm), or high (2500â¯ppm) amounts of additional zinc in the form of zinc oxide (ZnO) (Zn0, Zn100, and Zn2500, respectively). Porcine innate and adaptive immune cells of the different dietary groups were analyzed. Results revealed an improved innate immune capacity, represented by increased phagocytosis and slightly increased oxidative burst in cells from the Zn2500 pigs and Zn100 pigs, respectively. Apart from that, zinc supplementation improved adaptive immunity, as seen by increased numbers of CD3+ T cells as well as increased numbers of CD3+CD4+Foxp3+ regulatory T cells, elevated interleukin (IL)-2 production and decreased IL-10 production. Although not significant, supplementing 2500â¯ppm zinc slightly decreased killing activity of natural killer (NK) cells. Thus, the optimal concentration for zinc supplementation of weaned pigs two weeks post-weaning needs to be further studied, presumably establishing an optimal concentration between 100â¯ppm and 2500â¯ppm zinc. Genome comparisons indicate that the porcine genome is more closely related to the human genome than the murine genome is related to the human genome. Therefore, the pig seems to be a suitable organism to study human immunity and diseases. Results obtained in the current study might therefore be transferable to the human immune system.
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Destete , Óxido de Zinc/farmacología , Zinc/farmacología , Inmunidad Adaptativa/efectos de los fármacos , Animales , Cobre/farmacología , Suplementos Dietéticos , Femenino , Interleucina-10/metabolismo , Interleucina-2/metabolismo , Masculino , Estallido Respiratorio/efectos de los fármacos , Porcinos , Linfocitos T ReguladoresRESUMEN
After the discovery of zinc deficiency in the 1960s, it soon became clear that zinc is essential for the function of the immune system. Zinc ions are involved in regulating intracellular signaling pathways in innate and adaptive immune cells. Zinc homeostasis is largely controlled via the expression and action of zinc "importers" (ZIP 1-14), zinc "exporters" (ZnT 1-10), and zinc-binding proteins. Anti-inflammatory and anti-oxidant properties of zinc have long been documented, however, underlying mechanisms are still not entirely clear. Here, we report molecular mechanisms underlying the development of a pro-inflammatory phenotype during zinc deficiency. Furthermore, we describe links between altered zinc homeostasis and disease development. Consequently, the benefits of zinc supplementation for a malfunctioning immune system become clear. This article will focus on underlying mechanisms responsible for the regulation of cellular signaling by alterations in zinc homeostasis. Effects of fast zinc flux, intermediate "zinc waves", and late homeostatic zinc signals will be discriminated. Description of zinc homeostasis-related effects on the activation of key signaling molecules, as well as on epigenetic modifications, are included to emphasize the role of zinc as a gatekeeper of immune function.
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Sistema Inmunológico/efectos de los fármacos , Zinc/deficiencia , Zinc/inmunología , Animales , Antiinflamatorios/farmacología , Antioxidantes/farmacología , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Suplementos Dietéticos , Epigénesis Genética , Homeostasis/efectos de los fármacos , Humanos , Inmunidad Innata/efectos de los fármacos , Células Asesinas Naturales/inmunología , Monoéster Fosfórico Hidrolasas/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Transducción de Señal , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Zinc/farmacologíaRESUMEN
SCOPE: Zinc is an essential trace element, regulating immune function. Its deficiency results in immune dysfunction and transplant rejection. In here, a benefit of zinc supplementation for the induction of tolerance was investigated, focusing on the TH 1-dominated allogeneic immune reaction. METHODS AND RESULTS: Allogeneic immune reaction was modeled by mixed lymphocyte culture (MLC). The effect of zinc supplementation was monitored via expression of cytokines and surface lineage markers using ELISA and flow cytometry. Epigenetic analyses were performed to investigate mechanisms underlying zinc-induced changes in regulatory T cell (Treg) activation. Results reveal that Tregs are induced when MLCs are treated with 50 µM zinc causing a decrease in IFNγ production. IL-2 and IL-10 expression were not affected. The teleology of this effect includes the inhibition of histone deacetylase Sirt-1-mediated Foxp3 deacetylation, resulting in its decreased degradation. CONCLUSION: In conclusion, zinc should be considered to prevent graft-versus-host disease (GVHD) as it is capable of stabilizing iTregs, resulting in increased numbers of this cell type while not suppressing the immune system.
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Sirtuina 1/antagonistas & inhibidores , Linfocitos T Reguladores/efectos de los fármacos , Zinc/farmacología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Citocinas , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Enfermedad Injerto contra Huésped/prevención & control , Inhibidores de Histona Desacetilasas/farmacología , Humanos , Sirtuina 1/metabolismo , Linfocitos T Reguladores/inmunología , Células TH1/efectos de los fármacosRESUMEN
Integrity of the immune system is particularly dependent on the availability of zinc. Recent data suggest that zinc is involved in the development of sepsis, a life-threatening systemic inflammation with high death rates, but with limited therapeutic options. Altered cell zinc transport mechanisms could contribute to the inflammatory effects of sepsis. Zip14, a zinc importer induced by proinflammatory stimuli, could influence zinc metabolism during sepsis and serve as a target for therapy. Using cecal ligation-and-puncture (CLP) to model polymicrobial sepsis, we narrowed the function of ZIP14 to regulation of zinc homeostasis in hepatocytes, while hepatic leukocytes were mostly responsible for driving inflammation, as shown by higher expression of IL-1ß, TNFα, S100A8, and matrix metalloproteinase-8. Using Zip14 knockout (KO) mice as a novel approach, we found that ablation of Zip14 produced a delay in development of leukocytosis, prevented zinc accumulation in the liver, altered the kinetics of hypozincemia, and drastically increased serum IL-6, TNFα, and IL-10 concentrations following CLP. Hence, this model revealed that the zinc transporter ZIP14 is a component of the pathway for zinc redistribution that contributes to zinc dyshomeostasis during polymicrobial sepsis. In contrast, using the identical CLP model, we found that supplemental dietary zinc reduced the severity of sepsis, as shown by amelioration of cytokines, calprotectins, and blood bacterial loads. We conclude that the zinc transporter ZIP14 influences aspects of the pathophysiology of nonlethal polymicrobial murine sepsis induced by CLP through zinc delivery. The results are promising for the use of zinc and its transporters as targets for future sepsis therapy.
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Antiinflamatorios/farmacología , Proteínas de Transporte de Catión/metabolismo , Suplementos Dietéticos , Hígado/efectos de los fármacos , Sepsis/prevención & control , Zinc/farmacología , Animales , Carga Bacteriana , Biomarcadores/sangre , Proteínas de Transporte de Catión/deficiencia , Proteínas de Transporte de Catión/genética , Ciego/microbiología , Ciego/cirugía , Citocinas/sangre , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Femenino , Hepatocitos/efectos de los fármacos , Hepatocitos/inmunología , Hepatocitos/metabolismo , Homeostasis , Mediadores de Inflamación/sangre , Leucocitos/efectos de los fármacos , Leucocitos/inmunología , Leucocitos/metabolismo , Ligadura , Hígado/inmunología , Hígado/metabolismo , Hígado/microbiología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Punciones , Sepsis/sangre , Sepsis/genética , Sepsis/inmunología , Sepsis/microbiología , Índice de Severidad de la Enfermedad , Factores de Tiempo , Zinc/metabolismoRESUMEN
The deprivation of zinc, caused by malnutrition or as a consequence of aging or disease, strongly affects immune cell functions, causing higher frequency of infections. Among other effects, an increased production of reactive oxygen species (ROS) and proinflammatory cytokines has been observed in zinc-deficient patients, but the underlying mechanisms were unknown. The aim of the current study was to define mechanisms explaining the increase in proinflammatory cytokine production during zinc deficiency, focusing on the role of epigenetic and redox-mediated mechanisms. Interleukin (IL)-1ß and tumor necrosis factor (TNF)α production was increased in HL-60 cells under zinc deficiency. Analyses of the chromatin structure demonstrated that the elevated cytokine production was due to increased accessibilities of IL-1ß and TNFα promoters in zinc-deficient cells. Moreover, the level of nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) oxidase-produced ROS was elevated under zinc deficiency, subsequently leading to p38 mitogen-activated protein kinase (MAPK) phosphorylation. The increased activation of p38 MAPK appeared to be necessary for posttranscriptional processes in IL-1ß and TNFα synthesis. These data demonstrate that IL-1ß and TNFα expression under zinc deficiency is regulated via epigenetic and redox-mediated mechanisms. Assuming an important role of zinc in proinflammatory cytokine regulation, this should encourage research in the use of zinc supplementation for treatment of inflammatory diseases.