NF-κB, AP-1, Zinc-deficiency and aging

Zinc and aging: a narrative review of the effects on hematopoiesis and its link with diseases

There has been a global increase in the older population in recent decades and, as age advances, complex metabolic and epigenetic changes occur in the organism, and these may trigger some health complications commonly found among this population. Additionally, several changes occur in older people that can reduce the dietary intake or the process of nutrient absorption. In this way, tissues with high nutrient requirements are more affected. Hematopoiesis is the process of formation, development, and maturation of blood cells and is a process with a high turnover. This high demand makes the integrity of the hematopoietic process susceptible to various factors that impair physiological function, such as aging and micronutrient bioavailability. Among these micronutrients, Zinc is considered an important micronutrient, playing diverse roles across various tissues and cell types. Some of the alterations in hematopoiesis that appear as a consequence of aging and due to insufficient micronutrient intake are well described in the literature; however, not much is known about how zinc deficiency contributes towards the development of diseases seen in aging. Considering the importance of zinc to act on several biological processes, this narrative review discusses several studies related to the physiological requirements, deficiency, or excess of zinc, including studies in experimental models and humans, and aimed to shed light on the relationship between zinc and the regulation of hematopoietic tissue, exploring possible links between this mineral with common disorders that appear during aging.

Effect of Sempervivum tectorum Extract on Some Biomarkers of Reproductive Function and Levels of Some Trace Elements in Male Rats Exposed to Aluminum

Aluminum, a contentious trace element found in the environment, has been demonstrated to have harmful effects on both humans and animals. In contrast, Sempervivum tectorum, an evergreen plant, has been found to offer numerous beneficial effects for both humans and animals. Therefore, this study aims to assess the protective effect of S. tectorum on certain reproductive biomarkers in male rats exposed to aluminum. Thirty-five Wistar rats were randomly divided into five groups: NTC (no-treatment control) received distilled water; NC (negative control) received drinking water containing 1 mg/L aluminum sulfate (AS); E1 received 1 mg/L AS along with an 8% S. tectorum extract; PC (positive control) received only 8% S. tectorum extract; E2 received 1 mg/L AS for three months followed by 8% extract for one month. The study analyzed testosterone, LH, FSH, body weight, and the histological structure of the testis, epididymis, and prostate, as well as the levels of zinc, manganese, copper, and iron in these organs. Significant decreases in body weight, testis, and epididymis size were observed in the aluminum-exposed groups compared to the control, whereas these decreases were not significant in the S. tectorum-treated groups compared to the control. Aluminum exposure led to significant decreases in testosterone and LH levels, with FSH levels showing a nonsignificant decrease in males, which were mitigated significantly by the administration of the plant extract. Histological analysis revealed alterations in the testis, epididymis, and prostate of the AS-exposed groups, including necrosis of seminiferous tubule epithelium and Leydig cells in the testis, and basal epithelial necrosis in the epididymis and prostate. Aluminum levels increased in all organs studied, while levels of zinc, copper, iron, and manganese decreased, showing a negative and significant correlation with aluminum levels. The aqueous extract of S. tectorum demonstrated a protective effect on certain studied biomarkers in male rats affected by aluminum exposure.

Association between serum copper, zinc, and selenium concentrations and depressive symptoms in the US adult population, NHANES (2011-2016)

BACKGROUND

Evidence suggests that alterations in serum trace element concentrations are closely associated with mental illness. However, ​studies on the relationship between serum copper, zinc, and selenium concentrations and depressive symptoms are limited and with controversial results. We aimed to investigate the association between serum concentrations of these trace elements and depressive symptoms in US adults.

METHODS

Data from the National Health and Nutrition Examination Survey (NHANES) (2011-2016) were used in this cross-sectional study. The Patient Health Questionnaire-9 Items (PHQ-9) was employed to assess depressive symptoms. Multiple logistic regression was performed to determine the relationship between the serum concentrations of copper, zinc, and selenium and depressive symptoms.

RESULTS

A total of 4552 adults were included. Subjects with depressive symptoms had higher serum copper concentrations (123.88 ± 1.87) than those without depressive symptoms (116.99 ± 0.86) (p < 0.001). In Model 2, weighted logistic regression analysis showed that the second (Q2) quartile of zinc concentrations (odds ratio [OR] = 1.534, 95% confident interval [CI]: 1.018 to 2.313) were significantly associated with an increased risk of depressive symptoms. Subgroup analysis revealed that the third (Q3) and fourth (Q4) quartiles of copper concentrations (Q3: OR = 2.699, 95% CI: 1.285 to 5.667; Q4: OR = 2.490, 95% CI: 1.026 to 6.046) were also positively associated with depressive symptoms in obese individuals after controlling for all confounders. However, no significant relationship between serum selenium concentrations and depressive symptoms was observed.

CONCLUSIONS

Obese US adults with high serum copper concentrations, as well as US adults in general with low serum zinc concentrations, were susceptible to depressive symptoms. Nevertheless, the causal mechanisms underlying these relationships need to be further explored.

Association between serum zinc levels and suicidal ideation in US adults: A population-based cross-sectional study

BACKGROUND

Evidence suggests that the homeostatic disruption of zinc, copper, and selenium might contribute to the pathophysiology of mental disorders. However, the specific relationship between the serum levels of these trace elements with suicidal ideation remains poorly understood. This study aimed to investigated the association among suicidal ideation on serum levels of zinc, copper, and selenium.

METHODS

The cross-sectional study was conducted using data from a nationally representative sample of the National Health and Nutrition Examination Survey (NHANES) 2011-2016. Suicidal ideation was assessed using Item #9 of the Patient Health Questionnaire-9 Items. Multivariate regression models and restricted cubic splines were performed and E-value was calculated.

RESULTS

A total of 4561 participants aged 20 years and older were analyzed, of whom 4.08 % had suicidal ideation. The serum zinc levels were lower in the suicidal ideation group than in the non-suicidal ideation group (P = 0.021). In Crude Model, the serum zinc levels were associated with a higher suicidal ideation risk in the second quartile compared with the highest quartile [odds ratio (OR) = 2.63; 95 % confidence interval (CI): 1.53-4.53]. The association persisted (OR = 2.35; 95 % CI: 1.20-4.58) after full adjustment, with E-value 2.44. A nonlinear relationship was observed between serum zinc levels and suicidal ideation (P = 0.028). No relationship was observed between suicidal ideation and serum copper or selenium levels (all P > 0.05).

CONCLUSIONS

Decreased serum zinc levels may increase susceptibility to suicidal ideation. Future studies are needed to validate the findings of this study.

Zinc: From Biological Functions to Therapeutic Potential

The trace element zinc (Zn) displays a wide range of biological functions. Zn ions control intercellular communication and intracellular events that maintain normal physiological processes. These effects are achieved through the modulation of several Zn-dependent proteins, including transcription factors and enzymes of key cell signaling pathways, namely those involved in proliferation, apoptosis, and antioxidant defenses. Efficient homeostatic systems carefully regulate intracellular Zn concentrations. However, perturbed Zn homeostasis has been implicated in the pathogenesis of several chronic human diseases, such as cancer, diabetes, depression, Wilson's disease, Alzheimer's disease, and other age-related diseases. This review focuses on Zn's roles in cell proliferation, survival/death, and DNA repair mechanisms, outlines some biological Zn targets, and addresses the therapeutic potential of Zn supplementation in some human diseases.

Zinc Deficiency Induces Inflammation and Apoptosis via Oxidative Stress in the Kidneys of Mice

Zinc (Zn) is an essential element that regulates not only cellular immunity but also antioxidant and anti-inflammatory agents. The present study investigated the effect of Zn deficiency on renal cell apoptosis and its mechanism. A Zn-deficient kidney model in mice was created by a Zn-deficient diet. Mice were fed diets with different Zn levels for 41 days as follows: normal-Zn group (NG, 34 mg Zn/kg), low-Zn group (LG, 2 mg Zn/kg), and high-Zn group (HG, 100 mg Zn/kg). H&E staining showed that inflammatory cells and many erythrocytes exuded in the renal tissue space of the low-Zn group, and TUNEL staining indicated massive death of kidney cells in the low-Zn group. In the low-Zn group, the levels of oxygen free radicals (ROS) were significantly increased, the antioxidants were significantly decreased, and the total antioxidant capacity was decreased. Moreover, RT-qPCR and ELISA results showed that inflammatory factors (TNF-α, IL-1β, and IL-6) were significantly increased in the low-Zn group. In addition, the levels of p-IκBα, p-NF-κB p65, p-ERK, p-JNK, and p-p38 were significantly increased in the low-Zn group, indicating that zinc deficiency activates NF-κB and MAPK signalling as well as increases its expression. RT-qPCR analysis of apoptosis-related genes, including Bcl-2 Bax, Caspa8, Caspa6, and Caspa3, demonstrated that the expression levels of proapoptotic genes in mouse kidneys were significantly increased. Importantly, the in vitro results were consistent with the in vivo results. Together, these data suggested that zinc deficiency induces renal oxidative stress to activate NF-κB and MAPK signalling, thereby inducing renal cell apoptosis.

Dietary zinc restriction affects the expression of genes related to immunity and stress response in the small intestine of pigs

Zinc (Zn) is an essential mineral and its deficiency manifests in non-specific clinical signs that require long time to develop. The response of swine intestine to Zn restriction was evaluated to identify early changes that can be indicative of Zn deficiency. Twenty-seven pigs (body weight = 77⋅5 ± 2⋅5 kg) were assigned to one of three diets: diet without added Zn (Zn-restricted diet, ZnR), and ZnR-supplemented with either 50 (Zn50) or 100 mg of Zn/kg of diet (Zn100) of Zn supplied by ZnCl₂. After 32 d consuming the diets, serum Zn concentration in ZnR pigs was below the range of 0⋅59-1⋅37 μg/ml considered sufficient, thereby confirming subclinical Zn deficiency. Pigs showed no obvious health or growth changes. RNA-seq analysis followed by qPCR showed decreased expression of metallothionein-1 (MT1) (P < 0⋅05) and increased expression of Zn transporter ZIP4 (P < 0⋅05) in jejunum and ileum of ZnR pigs compared with Zn-supplemented pigs. Ingenuity pathway analysis revealed that Zn50 and Zn100 induced changes in genes related to nucleotide excision repair and integrin signalling pathways. The top gene network in the ZnR group compared with Zn100 was related to lipid and drug metabolism; and compared with Zn50, was related to cellular proliferation, assembly and organisation. Dietary Zn concentrations resulted in differences in genes related to immune pathways. Our analysis showed that small intestine presents changes associated with Zn deficiency after 32 d of Zn restriction, suggesting that the intestine could be a sentinel organ for Zn deficiency.

Rebalancing the unbalanced aged immune system - A special focus on zinc

Nowadays, aging is understood as a dynamic and multifaceted dysregulation process that spares almost no human organ or cell. The immune system being among the most affected, it has been shown predominantly that its integrity determines the tightrope walk between the difference of escaping or suffering from age-related diseases. Next to drug-based anti-aging strategies, micronutrient intervention may represent an emerging but less radical way to slow immune aging. While a sufficient supply of a variety of micronutrients is undeniably important, adequate intake of the trace element zinc appears to tower over others in terms of reaching old age. Inconveniently, zinc deficiency prevalence among the elderly is high, which in turn contributes to increased susceptibility to infection, decreased anti-tumor immunity as well as attenuated response to vaccination. Driven by this research, this review aims to provide a comprehensive and up-to-date overview of the various rebalancing capabilities of zinc in the unbalanced immune system of the elderly. This includes an in-depth and cell type-centered discussion on the role of zinc in immunosenescence and inflammaging. We further address upcoming translational aspects e.g. how zinc deficiency promotes the flourishing of certain pathogenic taxa of the gut microbiome and how zinc supply counteracts such alterations in a manner that may contribute to longevity. In the light of the ongoing COVID-19 pandemic, we also briefly review current knowledge on the interdependency between age, zinc status, and respiratory infections. Based on two concrete examples and considering the latest findings in the field we conclude our remarks by outlining tremendous parallels between suboptimal zinc status and accelerated aging on the one hand and an optimized zinc status and successful aging on the other hand.

Zinc homeostasis in immunity and its association with preterm births

Preterm birth is among the most common adverse pregnancy outcomes and is the leading cause of neonatal mortality and morbidity. While trace elements are essential for humans, their specific roles in the prenatal period remain unexplored. Zinc, a ubiquitous element plays a pivotal role in protein synthesis, cell division, nucleic acid metabolism, apoptosis, ageing, reproduction, immunological as well as antioxidant defense mechanism. Although zinc quantities are very small in body tissue, it is involved in every conceivable biochemical pathway which is critical for the performance of various functions necessary to sustain life. Owing to the multifactorial role of zinc, it is not possible to attribute a certain zinc dependent mechanism in pre-term births. Although the effect of zinc deficiency on immunity, its impact on maternal function and health as well as its role in the developing foetus is well documented, much less attention has been given to the understanding of micronutrient zinc homeostasis in immunity and its association with preterm births. Despite extensive research, the pathway by which zinc regulates pregnancy outcomes as well as the function of immune cells in controlling the delivery status (term/ preterm) is still obscure. The present review aims to focus on the understanding of relationship of micronutrient zinc homeostasis in immunity and its association with preterm births.

Immune system aging and the aging-related diseases in the COVIID-19 era

The interest in the process of aging, and specifically in how aging affects the working of our immune system, has recently enormously grown among both specialists (immunologists and gerontologists) and representatives of other disciplines of health sciences. An obvious reason for this interest is the current pandemics of COVID-19, known to affect the elderly more than younger people. In this paper current knowledge about mechanisms and complex facets of human immune system aging is presented, stemming from the knowledge about the working of various parts of the immune system, and leading to understanding of immunological mechanisms of chronic, inflammatory, aging-related diseases and of COVID-19.

Profiling inflammatory cytokines following zinc supplementation: a systematic review and meta-analysis of controlled trials

Chronic inflammation has been considered as the main cause of chronic diseases. Zn has anti-inflammatory effects by decreasing the expression of inflammatory markers. The present systematic review and meta-analysis study aims to evaluate the impact of Zn supplementation on inflammation. PubMed (Medline), Scopus, Web of Science, and Embase databases were searched up to 10 December 2020. Controlled trials which have investigated the effects of Zn supplementation on serum/plasma levels of inflammatory cytokines in subjects aged >15 years were included. A pooled meta-analysis was performed using a random effect model. Sensitivity analysis was performed to determine the robustness of the observed effect sizes. A total of twelve studies was included in meta-analysis. Zn could decrease IL-6 levels (standardised mean difference (SMD) = -0·76 pg/ml; 95 % CI -1·28, -0·24; P = 0·004). There was no significant change in TNF-α (SMD = 0·42 pg/ml; 95 % CI -0·31, 1·16; P = 0·257) and IL-2 levels (SMD = 1·64 pg/ml; 95 % CI -1·31, 4·59; P = 0·277) following Zn supplementation. However, Zn could increase IL-2 significantly after the deletion of one arm in sensitivity analysis (SMD = 2·96 pg/ml; 95 % CI 2·03, 3·88; P < 0·05). Conclusively, Zn supplementation can decrease the IL-6 level. Zn increased IL-2 level after the sensitivity analysis. Zn supplementation has not ameliorative effects on TNF-α.

Deciphering the antitumoral potential of the bioactive metabolites from medicinal mushroom Inonotus obliquus

ETHNOPHARMACOLOGICAL RELEVANCE

The crude extracts of the medicinal mushroom Inonotus obliquus have been used as an effective traditional medicine to treat malicious tumors, gastritis, gastric ulcers, and other inflammatory conditions in Russia and most Baltic countries.

AIM OF THIS REVIEW

Deciphering the antitumoral potential of the bioactive metabolites from I. obliquus and addressing its possibility to be used as effective agents for tumor treatment, restoration of compromised immunity and protection of gastrointestinal damage caused by chemotherapy.

MATERIALS AND METHODS

We analysed the current achievements and dilemma in tumor chemo- or immunotherapy. In this context, we searched the published literatures on I. obliquus covering from 1990 to 2020, and summarized the activities of antitumor, antioxidation, and immunomodulation by the polysaccharides, triterpenoids, small phenolic compounds, and hispidin polyphenols. By comparing the merits and shortcomings of current and traditional methodology for tumor treatment, we further addressed feasibility for the use of I. obliquus as an effective natural drug for tumor treatment and prevention.

RESULTS

The diverse bioactive metabolites confer I. obliquus great potential to inhibit tumor growth and metastasis. Its antitumor activities are achieved either through suppressing multiple oncogenic signals including but not limited to the activation of NF-κB and FAK, and the expression of RhoA/MMP-9 via ERK1/2 and PI3K/Akt signaling pathway. The antitumor activities can also be achieved by inhibiting tyrosinase activity via PAK1-dependent signaling pathway or altering lysosomal membrane permeabilization through blocking tubulin polymerization and/or disturbing energy metabolism through LKB1/AMPK pathway. In addition, the metabolites from I. obliquus also harbour the potentials to reverse MDR either through selective inhibition on P-gp/ABCB1 or MRP1/ABCC1 proteins or the induction of G2/M checkpoint arrest in tumor cells of chemoresistant phenotypes mediated by Nox/ROS/NF-kB/STAT3 signaling pathway. In addition to the eminent effects in tumor inhibition, the metabolites in I. obliquus also exhibit immunomodulatory potential to restore the compromised immunity and protect against ulcerative damage of GI tract caused by chemotherapy.

CONCLUSIONS

I. obliquus possesses the potential to reduce incidence of tumorigenesis in healthy people. For those whose complete remission has been achieved by chemotherapy, administration of the fungus will inhibit the activation of upstream oncogenic signals and thereby prevent metastasis; for those who are in the process of chemotherapy administration of the fungus will not only chemosensitize the tumor cells and thereby increasing the chemotherapeutic effects, but also help to restore the compromised immunity and protect against ulcerative GI tract damage and other side-effects induced by chemotherapy.

Proteodynamics and aging of eukaryotic cells

All aspects of each protein existence in the eukaryotic cells, starting from the pre-translation events, through translation, multiple different post-translational modifications, functional life and eventual proteostatic removal after loss of functionality and changes in physico-chemical properties, can be collectively called the proteodynamics. With aging, passing of time as well as accumulating effects of exposures, interactions and wearing-off lead to problems at each of the above mentioned stages, eventually leading to general malfunction of the proteome. This work briefly reviews and summarizes current knowledge concerning this important topic.

Zinc Modulates Several Transcription-Factor Regulated Pathways in Mouse Skeletal Muscle Cells

Zinc is an essential metal ion involved in many biological processes. Studies have shown that zinc can activate several molecules in the insulin signalling pathway and the concomitant uptake of glucose in skeletal muscle cells. However, there is limited information on other potential pathways that zinc can activate in skeletal muscle. Accordingly, this study aimed to identify other zinc-activating pathways in skeletal muscle cells to further delineate the role of this metal ion in cellular processes. Mouse C2C12 skeletal muscle cells were treated with insulin (10 nM), zinc (20 µM), and the zinc chelator TPEN (various concentrations) over 60 min. Western blots were performed for the zinc-activation of pAkt, pErk, and pCreb. A Cignal 45-Reporter Array that targets 45 signalling pathways was utilised to test the ability of zinc to activate pathways that have not yet been described. Zinc and insulin activated pAkt over 60 min as expected. Moreover, the treatment of C2C12 skeletal muscle cells with TPEN reduced the ability of zinc to activate pAkt and pErk. Zinc also activated several associated novel transcription factor pathways including Nrf1/Nrf2, ATF6, CREB, EGR1, STAT1, AP-1, PPAR, and TCF/LEF, and pCREB protein over 120 min of zinc treatment. These studies have shown that zinc’s activity extends beyond that of insulin signalling and plays a role in modulating novel transcription factor activated pathways. Further studies to determine the exact role of zinc in the activation of transcription factor pathways will provide novel insights into this metal ion actions.

Parthenolide Inhibits Angiogenesis in Esophageal Squamous Cell Carcinoma Through Suppression of VEGF

Background

Parthenolide (PT), the effective active ingredient of the medicinal plant, feverfew (Tanacetum parthenium), has been used as an anti-inflammatory drug due to its involvement in the inhibition of the NF-кB pathway. Moreover, recent studies have demonstrated the anti-tumor effect of PT in several cancers. However, the effect of PT on esophageal carcinoma remains unclear to date. In this study, we examined the inhibitory effects of PT and its underlying mechanism of action in human esophageal squamous cell carcinoma (ESCC) cells – Eca109 and KYSE-510.

Methods

The proliferation ability of Eca109 and KYSE-510 treated with PT was detected using the Cell Counting Kit-8 and colony forming assay. The Transwell assay and the wound healing assay were used to analyze the cell invasion and migration ability, respectively. The tube formation assay was used to investigate the effect of PT on tube formation of endothelial cells. The expression level of NF-кB, AP-1 and VEGF was analyzed by Western blot.

Results

We demonstrated that PT attenuates the proliferation and migration ability of ESCC cells in vitro and also inhibits tumor growth in the mouse xenograft model. In addition, PT exhibited anti-angiogenesis activity by weakening the proliferation, invasion and tube formation of endothelial cells in vitro and reduced microvessel density in the xenograft tumors. Further studies revealed that PT reduced the expression level of NF-кB, AP-1 and VEGF in ESCC cells.

Conclusion

Collectively, the results of our study demonstrated that PT exerts anti-tumor and anti-angiogenesis effects possibly by inhibiting the NF-кB/AP-1/VEGF signaling pathway on esophageal carcinoma and might serve as a promising therapeutic agent for ESCC.

Association of NF-κB and AP-1 with MMP-9 Overexpression in 2-Chloroethanol Exposed Rat Astrocytes

Subacute poisoning of 1,2-dichloroethane (1,2-DCE) has become a serious occupational problem in China, and brain edema is its main pathological consequence, but little is known about the underlying mechanisms. As the metabolite of 1,2-DCE, 2-chloroethanol (2-CE) is more reactive, and might play an important role in the toxic effects of 1,2-DCE. In our previous studies, we found that matrix metalloproteinases-9 (MMP-9) expression was enhanced in mouse brains upon treatment with 1,2-DCE, and in rat astrocytes exposed to 2-CE. In the present study, we analyzed the association of nuclear factor kappa B (NF-κB) and activator protein-1 (AP-1) with MMP-9 overexpression in astrocytes treated with 2-CE. MMP-9, p65, c-Jun, and c-Fos were significantly upregulated by 2-CE treatment, which also enhanced phosphorylation of c-Jun, c-Fos and inhibitor of κBα (IκBα), and nuclear translocation of p65. Furthermore, inhibition of IκBα phosphorylation and AP-1 activity with the specific inhibitors could attenuate MMP-9 overexpression in the cells. On the other hand, inhibition of p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway suppressed the activation of both NF-κB and AP-1 in 2-CE-treated astrocytes. In conclusion, MMP-9 overexpression induced by 2-CE in astrocytes could be mediated at least in part through the p38 signaling pathway via activation of both NF-κB and AP-1. This study might provide novel clues for clarifying the mechanisms underlying 1,2-DCE associated cerebral edema.

Proteodynamics in aging human T cells - The need for its comprehensive study to understand the fine regulation of T lymphocyte functions

Cellular life depends mostly on the creation, modification, interactions and destruction of proteins. This is true for every cell, including human T lymphocytes. One way these cells can ascertain the fidelity and at least partial functionality of their proteomes under constant attack of irreversible modulations (e.g., ROS- or glycation-dependent) is proteostasis. However, with cellular aging proteostasis progressively fails and proteostenosis (decreased amounts and functionalities of remaining proteins) occurs. There are several mechanisms involved in the modulation and protection of the proteome in the T cells which include mainly multiple layers of vesicle-bound and cytoplasmic proteases (e.g., lysosomal and proteasomal ones) acting mostly by degradation of obsolete and age-modified proteins. Recently it was shown that another not yet so widely known system consisting of obligatorily calcium-dependent cysteine proteases, the calpains and their inhibitor, the calpastatin serves in T cells as a dual switch, either activating or inactivating different proteins depending on intracellular conditions. Thus the proteolytic elimination of altered proteins as well as modulation of activity of those remaining leads to dynamic change of proteome composition and function (proteodynamics) in aging lymphocytes, so far in an almost unknown way. Aging T cell proteodynamics requires further comprehensive analysis of the resulting lysoproteomic patterns and their changes.

Low zinc environment induces stress signaling, senescence and mixed cell death modalities in colon cancer cells

Currently it is not clear what type of the final cellular response (i.e. cell death modality or senescence) is induced upon chronic intracellular zinc depletion in colon cancer cells. To address this question, isogenic colon cancer lines SW480 and SW620 exposed to low zinc environment were studied over the period of 6 weeks. Low zinc environment reduced total as well as free intracellular zinc content in both cell lines. Decreased intracellular zinc content resulted in changes in cellular proliferation, cell cycle distribution and activation of stress signaling. In addition, colonocytes with low zinc content displayed increased levels of oxidative stress, changes in mitochondrial activity but in the absence of significant DNA damage. Towards the end of treatment (4th-6th week), exposed cells started to change morphologically, and typical markers of senescence as well as cell death appeared. Of two examined colon cancer cell lines, SW480 cells proved to activate predominantly senescent phenotype, with frequent form of demise being necrosis and mixed cell death modality but not apoptosis. Conversely, SW620 cells activated mostly cell death, with relatively equal distribution of apoptosis and mixed types, while senescent phenotypes and necrosis were present only in a small fraction of cell populations. Addition of zinc at the beginning of 4th week of treatment significantly suppressed cell death phenotypes in both cell lines but had no significant effect on senescence. In conclusion, presented results demonstrate variability of responses to chronic zinc depletion in colon cancer as modeled in vitro.

Zinc delays the progression of obesity-related glomerulopathy in mice via down-regulating P38 MAPK-mediated inflammation

OBJECTIVE

Obesity, particularly child obesity, is one of the most common public health problems in the world and raises the risk of end-stage renal disease. Zinc (Zn) is essential for multiple organs in terms of normal structure and function; however, effects of Zn deficiency or supplementation among young individuals with obesity have not been well studied.

METHODS

Weaned mice were fed high-fat diets (HFD) with varied contents of Zn (Zn deficient, adequate, and supplemented) for 3 or 6 months. This study examined associations between renal pathogenesis and dietary Zn levels, specifically assessing inflammatory pathways by utilizing P38 MAPK inhibitor SB203580.

RESULTS

HFD feeding induced typical syndromes of obesity-related renal disorders, which worsened by Zn marginal deficiency. The progression of obesity-related renal disorders was delayed by Zn supplementation. HFD induced renal inflammation, reflected by increased P38 MAPK phosphorylation along with increases of inflammatory cytokines MCP-1, IL-1β, IL-6, and TNF-α. P38 MAPK inhibition prevented renal pathological changes in mice fed with HFD and HFD/Zn deficiency.

CONCLUSIONS

P38 MAPK mediated the renal inflammatory responses, which played a central role in the pathogenesis of HFD-induced renal disorders. Zn could delay the progression of obesity-related kidney disease by down-regulating P38 MAPK-mediated inflammation.

Cellular Defense and Sensory Cell Survival Require Distinct Functions of ebi in Drosophila

The innate immune response and stress-induced apoptosis are well-established signaling pathways related to cellular defense. NF-κB and AP-1 are redox-sensitive transcription factors that play important roles in those pathways. Here we show that Ebi, a Drosophila homolog of the mammalian co-repressor molecule transducin β-like 1 (TBL1), variously regulates the expression of specific genes that are targets of redox-sensitive transcription factors. In response to different stimuli, Ebi activated gene expression to support the acute immune response in fat bodies, whereas Ebi repressed genes that are involved in apoptosis in photoreceptor cells. Thus, Ebi seems to act as a regulatory switch for genes that are activated or repressed in response to different external stimuli. Our results offer clear in vivo evidence that the Ebi-containing co-repressor complex acts in a distinct manner to regulate transcription that is required for modulating the output of various processes during Drosophila development.

Zinc Binding to MG53 Protein Facilitates Repair of Injury to Cell Membranes

Zinc is an essential trace element that participates in a wide range of biological functions, including wound healing. Although Zn(2+) deficiency has been linked to compromised wound healing and tissue repair in human diseases, the molecular mechanisms underlying Zn(2+)-mediated tissue repair remain unknown. Our previous studies established that MG53, a TRIM (tripartite motif) family protein, is an essential component of the cell membrane repair machinery. Domain homology analysis revealed that MG53 contains two Zn(2+)-binding motifs. Here, we show that Zn(2+) binding to MG53 is indispensable to assembly of the cell membrane repair machinery. Live cell imaging illustrated that Zn(2+) entry from extracellular space is essential for translocation of MG53-containing vesicles to the acute membrane injury sites for formation of a repair patch. The effect of Zn(2+) on membrane repair is abolished in mg53(-/-) muscle fibers, suggesting that MG53 functions as a potential target for Zn(2+) during membrane repair. Mutagenesis studies suggested that both RING and B-box motifs of MG53 constitute Zn(2+)-binding domains that contribute to MG53-mediated membrane repair. Overall, this study establishes a base for Zn(2+) interaction with MG53 in protection against injury to the cell membrane.

Zinc homeostasis and immunosenescence

For more than 50 years, zinc is known to be an essential trace element, having a regulatory role in the immune system. Deficiency in zinc thus compromises proper immune function, like it is observed in the elderly population. Here mild zinc deficiency is a common condition, documented by a decline of serum or plasma zinc levels with age. This leads to a dysregulation mainly in the adaptive immunity that can result in an increased production of pro-inflammatory cytokines, known as a status called inflamm-aging. T cell activation as well as polarization of T helper (Th) cells into their different subpopulations (Th1, Th2, Th17, regulatory T cells (Treg)) is highly influenced by zinc homeostasis. In the elderly a shift of the Th cell balance towards Th2 response is observed, a non-specific pre-activation of T cells is displayed, as well as a decreased response to vaccination is seen. Moreover, an impaired function of innate immune cells indicate a predominance of zinc deficiency in the elderly that may contribute to immunosenescence. This review summarizes current findings about zinc deficiency and supplementation in elderly individuals.

The antagonism of aluminum against fluoride-induced oxidative stress and c-Fos overexpression in rat testes

Sodium fluoride (NaF) has been found to interfere with the reproductive system of animals. However, the cellular mechanisms underlying the reproductive toxicity of fluoride are unclear. The present study aims to define a possible mechanism of NaF-induced reproductive toxicity with respect to mineral, oxidative stress and c-Fos expression and the role of aluminum (Al) in intervening the toxic effect of NaF on rat testes. Fifty-six male Wistar rats were treated with normal saline, 1.0, 2.0, and 3.0 mg NaF/kg body weight (bw)/day, and each NaF concentration plus Al ion (0.1 mg Al(3+)/kg bw/day). After 90 days, no significant changes in the contents of Fe and Cu were observed in any of the NaF-treated groups compared with those of the control group. There were, however, significant decreases in the contents of Ca in the 1.0 mg NaF group, Zn in all NaF-treated groups and Mg in the 3.0 mg NaF group. The levels of malondialdehyde (MDA) in the 1.0 mg NaF group and hydrogen peroxide (H2O2) in the 2.0 mg NaF group significantly increased, whereas the activity of nitric oxide synthase (NOS) significantly decreased in the 1.0 mg NaF group. Meanwhile, the protein expression of c-Fos increased significantly in the 1.0 and 2.0 mg NaF groups compared with the control group. Conversely, these changes were partially attenuated in rats simultaneously administered Al. The present study suggested that NaF could decrease the contents of Ca, Fe and Mg and enhance oxidative stress leading to c-Fos overexpression, and some deleterious effects were more prominent at lower NaF intake. Furthermore, Al within the research concentration could minimize reproductive toxicity caused by fluoride.

Titanium particles up-regulate the activity of matrix metalloproteinase-2 in human synovial cells

PURPOSE

Wear debris particle-induced osteolysis and subsequent aseptic loosening is one of the major causes of failure of total joint replacement. The purpose of this study was to investigate the effect of titanium implant material and inflammatory cytokines on human synovial cells and the development to osteolysis and aseptic loosening.

METHODS

This study investigated the effect of titanium implant material on the ECM-degraded MMP-2 in human synovial cells and analyzed the contribution of synovial cells in osteolysis and aseptic loosening.

RESULTS

When human synovial cells are exposed to titanium materials, MMP-2 activity is induced by 1.72 ± 0.14-fold with Ti disc and 3.95 ± 0.10-fold with Ti particles, compared with that of the controls, respectively. Inflammatory cytokines TNFα and IL-1β are also shown to induce MMP-2 activity by 3.65 ± 0.28-fold and 6.76 ± 0.28-fold, respectively. A combination of Ti particles and cytokines induces MMP-2 activities to a higher level (10.54 ± 0.45-fold). Inhibitors of various signal pathways involved in MMP-2 reverse Ti particle-induced MMP-2 activities.

CONCLUSIONS

Synovial cells surrounding the bone-prosthesis interface may contribute to production of MMP-2, and NFκB inhibitors may be explored as potential therapeutics to alleviate wear debris-induced osteolysis and aseptic loosening.

Interleukin-13 inhibits cytokines synthesis by blocking nuclear factor-κB and c-Jun N-terminal kinase in human mesangial cells

Objective

Monocytes/macrophages, proinflammatory cytokines and chemokines are important in the pathogenesis of glomerulonephritis. Interleukin (IL) -13 has been shown to exert potent anti-inflammatory properties. This study was designed to investigate the effect of IL-13 on the expression of proinflammatory cytokines, chemokines and profibrogenic cytokines and the involved molecular mechanism in cultured human mesangial cells (HMCs).

Methods

The expressions of proinflammatory cytokines, chemokines and profibrogenic cytokines were determined by ribonuclease protection assay (RPA). Activity of nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) was examined by electrophoretic mobility shift assay (EMSA). NF-κB subunit p65 nuclear transportation and c-Jun N-terminal kinase (JNK) activity were assayed by immunoblot.

Results

Recombinant IL-13 inhibited tumor necrosis factor-α (TNF-α), IL-1α, IL-1β, monocyte chemoattractant protein-1 (MCP-1), IL-8, and transforming growth factor-β1 (TGF-β1) mRNA expressions in a dose-dependent manner. Lipopolysacchorides (LPS) dramatically increased NF-κB DNA binding activity of HMCs, which was inhibited by IL-13 in a dose-dependent manner. LPS-activated NF-κB contained p50 and p65 dimers, but not c-Rel subunit. IL-13 blocked LPS-induced NF-κB subunit p65. LPS stimulated JNK/AP-1 activation, which was inhibited by IL-13 in a dose-dependent manner.

Conclusion

IL-13 inhibits proinflammatory cytokines, chemokines, and profibrogenic cytokines synthesis by blocking NF-κB and JNK/AP-1 activation. These observations point to the importance of IL-13 in the modulation of inflammatory processes in the renal glomerulus.

Corneal wound healing is compromised by immunoproteasome deficiency

Recent studies have revealed roles for immunoproteasome in regulating cell processes essential for maintaining homeostasis and in responding to stress and injury. The current study investigates how the absence of immunoproteasome affects the corneal epithelium under normal and stressed conditions by comparing corneas from wildtype (WT) mice and those deficient in two immunoproteasome catalytic subunits (lmp7(-/-)/mecl-1(-/-), L7M1). Immunoproteasome expression was confirmed in WT epithelial cells and in cells of the immune system that were present in the cornea. More apoptotic cells were found in both corneal explant cultures and uninjured corneas of L7M1 compared to WT mice. Following mechanical debridement, L7M1 corneas displayed delayed wound healing, including delayed re-epithelialization and re-establishment of the epithelial barrier, as well as altered inflammatory cytokine production compared to WT mice. These results suggest that immunoproteasome plays an important role in corneal homeostasis and wound healing.

Systems genetics of the nuclear factor-κB signal transduction network. I. Detection of several quantitative trait loci potentially relevant to aging

A theory of aging holds that senescence is caused by a dysregulated nuclear factor kappa B (NF-κB) signal transduction network (STN). We adopted a systems genetics approach in our study of the NF-κB STN. Ingenuity Pathways Analysis (IPA) was used to identify gene/gene product interactions between NF-κB and the genes in our transcriptional profiling array. Principal components factor analysis (PCFA) was performed on a sub-network of 19 genes, including two initiators of the toll-like receptor (TLR) pathway, myeloid differentiation primary response gene (88) (MyD88) and TIR (Toll/interleukin-1 receptor)-domain-containing adapter-inducing interferon-β (TRIF). TLR pathways are either MyD88-dependent or TRIF-dependent. Therefore, we also performed PCFA on a subset excluding the MyD88 transcript, and on another subset excluding two TRIF transcripts. Using linkage analysis we found that each set gave rise to at least one factor with a logarithm of the odds (LOD) score greater than 3, two on chromosome 15 at 15q12 and 15q22.2, and another two on chromosome 17 at 17p13.3 and 17q25.3. We also found several suggestive signals (2<LOD score<3) at 1q32.1, 1q41, 2q34, 3q23, and 7p15.3. We are currently examining potential associations with single nucleotide polymorphisms within the 1-LOD intervals of our linkage signals.

Modulation of vascular endothelial cell senescence by integrin β4

Increasing evidence has demonstrated that the senescence of vascular endothelial cells (VECs) has critical roles in the pathogenesis of vascular dysfunction. Finding important factors that regulate VEC senescence will help provide novel therapeutic strategies for vascular disorders. Previously, we found that integrin β4 was involved in VEC senescence. However, the mechanism underlying VEC senescence mediated by integrin β4 remains poorly understand. In this study, we used a mouse in vivo model and showed that the level of integrin β4 in the endothelium of mouse thoracic aorta was increased during natural aging and atherosclerosis. Furthermore, we found that H-ras, caveolin-1, and AP-1 were implicated in the senescent signal pathway mediated by integrin β4 in human umbilical vein ECs (HUVECs). Knockdown of integrin β4 could attenuate HUVEC senescent features, including increased interleukin-8 (IL-8) release and decreased endothelial nitric oxide synthase (eNOS) and NO levels and mitochondrial membrane potential in vitro. Our findings provide new clues illustrating the mechanism of VEC senescence. Integrin β4 might be a potential target for therapy in cardiovascular diseases.

Responses of human gingival and periodontal fibroblasts to a low-zinc environment

Morphology, motility, proliferation rate and markers of oxidative stress in primary human gingival fibroblasts (GF) and periodontal ligamental fibroblasts (PDL-F) grown in zinc-deficient cultivation medium (ZDM), were studied over a 5-week culture period. A low-zinc environment effectively reduced the total, as well as the free, intracellular zinc content in both cell types, over the course of the experiment. Decreased intracellular zinc content resulted in altered cellular morphology, reduced motility, and rearrangement of actin and tubulin in the cytoskeleton. In addition, fibroblasts with low zinc content exhibited decreased proliferation, accompanied by changes in cell cycle distribution, expression of specific biochemical markers, increased oxidative stress and the activation of caspase-3. Supplementation of ZDM with exogenous zinc prevented the loss of intracellular zinc, while also restoring the morphology, cell proliferation and mitogenic signalling of the cultured cells. Moreover, such supplemented cells were protected against oxidative stress and cell death. Of the two primary cell cultures examined, GF were more sensitive to decreased intracellular zinc content, when compared to PDL-F. The results obtained suggest that the human primary cell cultures can be useful for the longer-term evaluation of the effects of nutritional factors originating from the environment.

Differential expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in anterior cruciate ligament and medial collateral ligament fibroblasts after a mechanical injury: involvement of the p65 subunit of NF-kappaB

The anterior cruciate ligament (ACL) is known to have a poor healing ability, especially in comparison with the medial collateral ligament, which can heal relatively well. In this study, we detected significant increases in the mRNA levels of multiple matrix metalloproteinases (MMPs) (MMP-1, -2, -7, -9, -11, -14, -17, -21, -23A, -24, -25, -27, and -28) and tissue inhibitors of metalloproteinases (TIMPs) (TIMP-1, -2, -3, and -4) in ACL fibroblasts after an in vitro injury with an equi-biaxial stretch chamber. However, only some MMPs (MMP-7, -9, -14, -21, and -24) showed increases in injured medial collateral ligament fibroblasts, and to a much lesser degree than that observed in the injured ACL fibroblasts. Zymography revealed a 6.3-fold increase of MMP-2 activity in injured ACL but not medial collateral ligament fibroblasts, which agrees with the global MMP activities assay. Bay-11 and curcumin can significantly decrease MMP-2 activities to 13% and 29% in injured ACL fibroblasts, respectively, which implies the involvement of p65 subunits of nuclear factor kappaB and AP-1 pathways. Furthermore, Bay-11 can decrease the global MMP activity released from injured ACL fibroblasts in a dose-dependent manner. In summary, the differential expression and activities of MMPs might help to explain the poor healing ability of ACL, and the p65 subunit of nuclear factor kappaB might be a potential target to facilitate the ACL repair.

Thrombin induces endothelial arginase through AP-1 activation

Arterial thrombosis is a common disease leading to severe ischemia beyond the obstructing thrombus. Additionally, endothelial dysfunction at the site of thrombosis can be rescued by l-arginine supplementation or arginase blockade in several animal models. Exposure of rat aortic endothelial cells (RAECs) to thrombin upregulates arginase I mRNA and protein levels. In this study, we further investigated the molecular mechanism of thrombin-induced arginase changes in endothelial cells. Thrombin strikingly increased arginase I promoter and enzyme activity in primary cultured RAECs. Using different deletion and point mutations of the promoter, we demonstrated that the activating protein-1 (AP-1) consensus site located at -3,157 bp in the arginase I promoter was a thrombin-responsive element. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay further confirmed that upon thrombin stimulation, c-Jun and activating transcription factor-2 (ATF-2) bound to the AP-1 site, which initiated the transactivation. Moreover, loss-of-function studies using small interfering RNA confirmed that recruitment of these two transcription factors to the AP-1 site was required for thrombin-induced arginase upregulation. In the course of defining the signaling pathway leading to the activation of AP-1 by thrombin, we found thrombin-induced phosphorylation of stress-activated protein kinase/c-Jun-NH(2)-terminal kinase (SAPK/JNK or JNK1/2/3) and p38 mitogen-activated protein kinase, which were followed by the phosphorylation of both c-Jun and ATF-2. These findings reveal the basis for thrombin induction of endothelial arginase I and indicate that arginase inhibition may be an attractive therapeutic alternative in the setting of arterial thrombosis and its associated endothelial dysfunction.

The comparison of the effects of anesthetic doses of ketamine, propofol, and etomidate on ischemia-reperfusion injury in skeletal muscle

The fact that a considerable amount of clinical conditions suffering from ischemia-reperfusion injury (IRI) occur under general anesthesia has triggered researchers to focus on the effects of anesthetic drugs on IRI. Hence, the aim of this study was to compare the use of different anesthetic drugs in a skeletal IRI model. Tourniquet IRI method was performed and two experimental groups were established as sham-control and IRI group. Rats in each group were anesthetized either with thiopental, ketamine, propofol or etomidate. Malondialdehyde, superoxide dismutase, catalase, and glutathione peroxidase were measured in skeletal muscle via a spectrophotometer. Zinc, iron, copper, and selenium were evaluated by atomic absorption spectrophotometer. In rats anesthetized with thiopental (40 mg/kg, i.p.), malondialdehyde values in IRI group were higher and glutathion peroxidase levels were lower compared to sham-control group. However, superoxide dismutase and catalase activities were identical. On the other hand, while the level of zinc in IRI group attenuated, no differences in iron and copper values were determined. Rats anesthetized with ketamine (60 mg/kg), propofol (100 mg/kg), or etomidate (20 mg/kg) did not show increased malondialdehyde levels in comparison with control levels. While the drugs did not cause a distinction in the levels of superoxide dismutase, catalase, glutathion peroxidase, iron, and copper, zinc was in a lower level in IRI group compared to sham-control. In conclusion, ketamine, propofol, and etomidate, with anesthetic doses, denoted efficacious effects on IRI; hence the drugs might be preferred in certain operations with the risk of IRI.

The EVER proteins as a natural barrier against papillomaviruses: a new insight into the pathogenesis of human papillomavirus infections

Infections by human papillomaviruses (HPVs) are the most frequently occurring sexually transmitted diseases. The crucial role of genital oncogenic HPV in cervical carcinoma development is now well established. In contrast, the role of cutaneous HPV in skin cancer development remains a matter of debate. Cutaneous beta-HPV strains show an amazing ubiquity. The fact that a few oncogenic genotypes cause cancers in patients suffering from epidermodysplasia verruciformis is in sharp contrast to the unapparent course of infection in the general population. Our recent investigations revealed that a natural barrier exists in humans, which protects them against infection with these papillomaviruses. A central role in the function of this HPV-specific barrier is played by a complex of the zinc-transporting proteins EVER1, EVER2, and ZnT-1, which maintain cellular zinc homeostasis. Apparently, the deregulation of the cellular zinc balance emerges as an important step in the life cycles not only of cutaneous but also of genital HPVs, although the latter viruses have developed a mechanism by which they can break the barrier and impose a zinc imbalance. Herein, we present a previously unpublished list of the cellular partners of EVER proteins, which points to future directions concerning investigations of the mechanisms of action of the EVER/ZnT-1 complex. We also present a general overview of the pathogenesis of HPV infections, taking into account the latest discoveries regarding the role of cellular zinc homeostasis in the HPV life cycle. We propose a potential model for the mechanism of function of the anti-HPV barrier.

Distinctive modulation of inflammatory and metabolic parameters in relation to zinc nutritional status in adult overweight/obese subjects

Overweight and obesity are associated with low grade of inflammation and chronic inflammatory response characterized by abnormal production and activation of some pro-inflammatory signalling pathways. Taking into account that obesity is the direct result of an imbalance between energy intake and energy expenditure, the nutritional factors in the diet, with particular focus on zinc, may play a pivotal role in the development of obesity-associated comorbidities. Considering the potential interactions among zinc nutritional status, inflammation, overweight/obesity and insulin secretion, the aim of the present work was to clarify the influence of zinc dietary intake on some metabolic, inflammatory and zinc status parameters in adult overweight/obese subjects. We found a close interrelationship between nutritional zinc and obesity. In particular, subjects with a lower zinc dietary intake display a deeper inflammatory status, general impairment of the zinc status, an altered lipid profile and increased insulin production with respect to obese subjects with normal zinc dietary intake. Moreover, in the presence of low dietary zinc intake, the obese subjects are less capable to respond to oxidative stress and to inflammation leading to the development of obesity or to a worsening of already preexisting obesity status. In conclusion, a possible zinc supplementation in obese subjects with a deeper inflammatory status and more altered zinc profile may be suggested in order to limit or reduce the inflammation, taking also into account that zinc supplementation normalizes "inflammaging" as well as zinc profile leading to a correct intra- and extracellular zinc homeostasis.

Zinc replenishment reverses overexpression of the proinflammatory mediator S100A8 and esophageal preneoplasia in the rat

BACKGROUND & AIMS

Zinc deficiency is implicated in the pathogenesis of human esophageal cancer. In the rat esophagus, it induces cell proliferation, modulates genetic expression, and enhances carcinogenesis. Zinc-replenishment reverses proliferation and inhibits carcinogenesis. The zinc-deficient rat model allows the identification of biological differences affected by zinc during early esophageal carcinogenesis.

METHODS

We evaluated gene expression profiles of esophageal epithelia from zinc-deficient and replenished rats vs zinc-sufficient rats using microarray analysis. We characterized the role of the top-up-regulated gene S100A8 in esophageal hyperplasia/reversal and in chemically induced esophageal carcinogenesis in zinc-modulated animals by immunohistochemistry and real-time quantitative polymerase chain reaction.

RESULTS

The hyperplastic-deficient esophagus has a distinct expression signature with the proinflammation genes S100 calcium binding protein A8 (S100A8) and A9 (S100A9) up-regulated 57-fold and 5-fold, respectively. Zinc replenishment rapidly restored to control levels the expression of S100A8/A9 and 27 other genes and reversed the hyperplastic phenotype. With its receptor for advanced glycation end products (RAGE), colocalization and overexpression of S100A8 protein occurred in the deficient esophagus that overexpressed nuclear factor kappaBeta p65 and cyclooxygenase-2 (COX-2) protein. Zinc replenishment, but not a COX-2 inhibitor, reduced the overexpression of these 4 proteins. Additionally, esophageal S100A8/A9 messenger RNA levels were associated directly with the diverse tumorigenic outcome in zinc-deficient and zinc-replenished rats.

CONCLUSIONS

In vivo zinc regulates S100A8 expression and modulates the link between S100A8-RAGE interaction and downstream nuclear factor kappaBeta/COX-2 signaling. The finding that zinc regulates an inflammatory pathway in esophageal carcinogenesis may lead to prevention and therapy for this cancer.

Pro-inflammatory genetic background and zinc status in old atherosclerotic subjects

Inflammation and genetics are prominent mechanisms in the pathogenesis of atherosclerosis (AT) and its complications. In this review we discuss the possible impact on AT development of several genetic determinants involved in inflammation, oxidative stress and cytoprotection (IL-6, TNF-alpha, IL-10, CD14, TLR4, MT, HSP70). Genetic polymorphisms of these genes may affect a differential inflammatory response predisposing to AT. However, allelic polymorphisms of genes which increase the risk of AT frequently occur in the general population but, only adequate gene-environment-polymorphism interactions promote the onset of the disease. Zinc deficiency has been suggested as an environmental risk factor for AT. With advancing age, the incidence of zinc deficiency increases for several reasons. Among them, dietary intake, malabsorption and genetic background of inflammatory markers may be involved. A crucial contribution may also be played by increased oxidative stress which may lead to the appearance of dysfunctional proteins, including metallothioneins (MT) that are in turn involved in zinc homeostasis. The detection of candidate genes related to inflammation and promoting AT and their reciprocal influence/interaction with zinc status might allow earlier appropriate dietary interventions in genetically susceptible subjects.

Scurvy is still present in developed countries

INTRODUCTION

Scurvy, while uncommon, still occurs in developed countries despite the widespread availability of vitamins and fortified foods. A vitamin C deficiency prevalence of 10 to 14% in adults was reported in the National Health and Nutrition Examination Survey (NHANES) in 1994.

OBJECTIVE

We report the case of a 57-year-old male who presented with a combined vitamin C deficiency (scurvy) and a Zinc deficiency.

INTERVENTIONS

He came to the emergency department complaining of a painful swollen ecchymotic leg and dyspnea. Prescriptions for narcotics did not relieve his symptoms. When a detailed dietary history was obtained, we added scurvy to the differential diagnosis. An extensive evaluation excluded trauma, coagulopathies, neoplasia, and vasculitides.

MAIN RESULT

The combination of a classic skin biopsy and a low vitamin C level confirmed the diagnosis.

CONCLUSION

This presentation illustrates the necessity of including scurvy in the differential diagnosis of ecchymoses and demonstrates specific populations at risk: single adults and the elderly with deficient diets.

Involvement of NF-kappaB and AP-1 activation in icariin promoted cardiac differentiation of mouse embryonic stem cells

Icariin has been reported to facilitate the differentiation of mouse embryonic stem (ES) cells into cardiomyocytes; however, the mechanism on cardiomyogenic cell lineage differentiation has not been fully elucidated yet. In the present studies, an underlying signaling network including p38, extracellular signal-regulated kinase 1, 2 (ERK1, 2), nuclear factor-kappaB (NF-kappaB), activator protein-1 (AP-1) transcription factors c-jun and c-fos was assumed in icariin induced cardiomyogenesis. Icariin rapidly activated p38 and ERK1, 2 in embryoid bodies, treatment with p38 antagonist 4-(4-Fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole (SB203580) or ERK1, 2 inhibitor 1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio] butadiene (U0126) significantly abolished icariin induced cardiac commitment, MEF2C gene expression and nuclear translocation, as well as cardiac-specific protein alpha-actinin expression, indicating that p38 and ERK1, 2 are specifically involved in icariin stimulated cardiomyogenic cell lineage differentiation of ES cells. Further, IkappaBalpha phosphorylation and NF-kappaB p65 translocation to the nucleus appeared rapidly when embryoid bodies exposed to icariin, and the expression of IkappaBalpha or NF-kappaB p65 in cytoplasm was decreased concomitantly. Moreover, icariin increased c-jun and c-fos mRNA and protein expression. Either SB203580 or U0126 displayed inhibitory effect on icariin induced NF-kappaB and AP-1 activation. It could be concluded that p38 and ERK1, 2 are activated in a coordinated manner, which in turn contribute to NF-kappaB and AP-1 activation in icariin induced cardiomyogenic cell lineage differentiation of mouse ES cells.

In vitro and in vivo effects of zinc on cytokine signalling in human T cells

Aging is associated with changes in the immune response which are collectively called immunosenescence. The changes mainly affect the adaptive immune response and especially the T cell-mediated cellular immune response. There are a few data indicating that the cytokine signalling in T cells is altered with aging. Zinc has been specifically shown to have potent immunomodulatory effects. The aim of the present work was to study the IL-2 and IL-6 cytokine signalling and activation induced cell death (AICD) in T cells of elderly subjects of various ages and from various European countries. These experiments were performed in the frame of European Community financed project called ZINCAGE "Nutritional zinc, oxidative stress and immunosenescence: biochemical, genetic and lifestyle implications for healthy ageing", assembling 17 laboratories from 8 countries through Europe. The study was carried out in a total of 312 French and a group of 201 (26 from Italy, 63 from France, 57 from Greece, 24 from Poland and 30 from Germany) healthy non-institutionalized men and women older than 60 years of age, with available dietary data. Human peripheral blood mononuclear cells (PBMC) were obtained from heparinized blood and were stimulated in vitro by IL-2 or IL-6 for various periods and the phosphorylation of STAT3 and STAT5 was measured by FACScan. The activation induced cell death (AICD) was measured after anti-CD3 and CD28 restimulation for 48h by using the Annexin:FITC Apoptosis Kit. We found that there is an IL-2 signalling defect with aging up to 90 years of age which cannot be modulated by zinc. In contrast at 90 years and over the zinc could reverse the negative signalling effect of IL-2. There is also a signalling defect for STAT3 and STAT5 activation in T cells under IL-6 stimulation with aging and the zinc supplementation could potentiate only the STAT5 activation in the age-group 90 years and over. Studying signalling in PBL from different countries we detected less activation in T cells of subjects from France and the most changes occurred in T cells of subjects from Poland, suggesting no correlation with the plasma zinc status observed in these countries. In vivo zinc supplementation had no effect on IL-2 and IL-6-modulated STAT3 and STAT5 activation. Zinc added in vitro to these T cells even inhibited the stimulation either by IL-2 or by IL-6. Zinc supplementation improved the susceptibility of T cells to AICD in both age-groups, with more efficiency in later ages. Our results suggest that zinc can have a potent immunomodulatory effect via the modulation of cytokine signalling and AICD, however this effect depends on the function and the activation status of the T cells.