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Professor Bruce Ames demonstrated that nutritional recommendations should be adjusted in order to 'tune-up' metabolism and reduce mitochondria decay, a hallmark of aging and many disease processes. A major subset of tunable nutrients are the minerals, which despite being integral to every aspect of metabolism are often deficient in the typical Western diet. Mitochondria are particularly rich in minerals, where they function as essential cofactors for mitochondrial physiology and overall cellular health. Yet substantial knowledge gaps remain in our understanding of the form and function of these minerals needed for metabolic harmony. Some of the minerals have known activities in the mitochondria but with incomplete regulatory detail, whereas other minerals have no established mitochondrial function at all. A comprehensive metallome of the mitochondria is needed to fully understand the patterns and relationships of minerals within metabolic processes and cellular development. This brief overview serves to highlight the current progress towards understanding mineral homeostasis in the mitochondria and to encourage more research activity in key areas. Future work may likely reveal that adjusting the amounts of specific nutritional minerals has longevity benefits for human health.

Background: When consumed as whole grain, wheat has a high nutrient density that contributes to a healthy diet. However, products labeled as whole wheat can still contain a substantial amount of non-whole grain wheat, leading to confusion for consumers trying to maximize their whole grain intake. A biomarker of whole grain is needed to reveal the whole grain status within wheat-based foods.Objective: Wheat germ agglutinin (WGA), a lectin found predominantly in the germ tissue of wheat kernels, was evaluated as a biomarker of whole grain in commercial wheat products. Methods: The levels of WGA within wheat flour and pasta were assessed by an immunoblot method and compared to a whole grain standard. WGA content was also compared to other biomarkers including starch, minerals, phytate, and total protein content.Results: WGA content tightly correlated with the percentage of whole grain in pre-made mixtures of whole wheat and refined (white) flours. Several commercial flours labeled as whole wheat were then tested for WGA content and found to contain up to 40% less WGA compared to a whole grain standard. Several commercial pasta products labeled as whole wheat were also tested for WGA content and found to contain up to 90% less WGA compared to a whole grain standard. The discrepancies in WGA content were unlikely due to wheat varietial differences alone, as the WGA content measured in common varieties used in domestic wheat flour production varied less than 25%. Other wheat constituents including starch, mineral, phytate, and total protein were less consistent and did not discriminate between the commercial whole wheat flours and pasta products. Conclusions: The WGA content within wheat flour and pasta correlated with the levels of whole grain and identified discrepancies when tested in commercial wheat products compared to a whole wheat standard. WGA is a unique biomarker that could help identify which wheat products have the greatest amount of whole grain wheat.

Lysosome function is compromised during aging and in many disease states. Interventions that promote lysosomal activity and acidification are thus of prime interest as treatments for longevity and health. Intracellular pH can be controlled by the exchange of protons for inorganic ions, and in cells from microbes to man, when potassium is restricted in the growth medium, the cytoplasm becomes acidified. Here we use a yeast model to show that potassium limited-cells exhibit hallmarks of increased acidity in the vacuole, the analog of the lysosome, and live long by a mechanism that requires the vacuolar machinery. The emerging picture is one in which potassium restriction shores up vacuolar acidity and function, conferring health benefits early in life and extending viability into old age. Against the backdrop of well-studied protein and carbohydrate restrictions that extend lifespan and healthspan, our work establishes a novel pro-longevity paradigm of inorganic nutrient limitation.

In the USA, western Washington (WWA) and the Alaska (AK) Interior are two regions where maritime and continental climates, high latitude and cropping systems necessitate early maturing spring wheat (Triticum aestivum L.). Both regions aim to increase the production of hard spring bread wheat for human consumption to support regional agriculture and food systems. The Nordic region of Europe has a history of breeding for early maturing spring wheat and also experiences long daylengths with mixed maritime and continental climates. Nordic wheat also carries wildtype (wt) NAM-B1, an allele associated with accelerated senescence and increased grain protein and micronutrient content, at a higher frequency than global germplasm. Time to senescence, yield, protein and mineral content were evaluated on 42 accessions of Nordic hard red spring wheat containing wt NAM-B1 over 2 years on experimental stations in WWA and the AK Interior. Significant variation was found by location and accession for time to senescence, suggesting potential parental lines for breeding programmes targeting early maturity. Additionally, multiple regression analysis showed that decreased time to senescence correlated negatively with grain yield and positively with grain protein, iron and zinc content. Breeding for early maturity in these regions will need to account for this potential trade-off in yield. Nordic wt NAM-B1 accessions with early senescence yet with yields similar to regional checks are reported. Collaboration among alternative wheat regions can aid in germplasm exchange and varietal development as shown here for the early maturing trait.

Calcium-based renal calculi demonstrated significant heterogeneity in the structure, density, mineral composition, and material hardness not elucidated by routine clinical testing. Mineral density distributions within calcium oxalate stones revealed differential areas of low (590±80 mg/cc), medium (840±140 mg/cc), and high (1100±200 mg/cc) densities. Apatite stones also contained regions of low (700±200 mg/cc), medium (1100±200 mg/cc), and high (1400±140 mg/cc) densities within layers extending from single or multiple nucleation sites. Despite having lower average mineral density, calcium oxalate (CaOx) stones demonstrated higher material hardness compared to apatite stones, suggesting other chemical components might be involved in determining stone hardness properties. Carbon concentrated sites were identified between morphologic layers in CaOx stones and in stratified layers of apatite stones. Elemental analyses revealed numerous additional trace elements in both stone types. Despite the widespread assumption that stone mineral density is an indicator of susceptibility to lithotripsy, calcium stone mineral density estimates do not directly correlate with actual ex vivo stone hardness. Underlying stone heterogeneity in both structure and mineral density could explain why historical approaches have failed in accurately predicting response of stones to lithotripsy.

Before initiating a mass zinc fortification program, this study assessed the prevalence of and risk factors for low zinc status among Cameroonian women and children. In a nationally representative survey, we randomly selected 30 clusters in each of 3 strata (North, South, and Yaounde/Douala) and 10 households per cluster, each with a woman aged 15-49 y and a child aged 12-59 mo (n = 1002 households). Twenty-four-hour dietary recalls (with duplicates in a subset) and anthropometric measurements were conducted, and non-fasting blood was collected to measure plasma zinc concentration (PZC) and markers of inflammation. PZC was adjusted for methodologic factors (time of collection and processing, and presence of inflammation). The prevalence of stunting was 33% (32% South; 46% North; 13% Yaounde/Douala). Among women, 82% had low adjusted PZC (

The loss of NPC1 protein function is the predominant cause of Niemann-Pick type C1 disease (NP-C1), a systemic and neurodegenerative disorder characterized by late-endosomal/lysosomal accumulation of cholesterol and other lipids. Limited evidence from post-mortem human tissues, an Npc1(-/-) mouse model, and cell culture studies also suggest failure of metal homeostasis in NP-C1. To investigate these findings, we performed a comprehensive transition metal analysis of cerebrospinal fluid (CSF), plasma and tissue samples from human NP-C1 patients and an Npc1(-/-) mouse model. NPC1 deficiency in the Npc1(-/-) mouse model resulted in a perturbation of transition metal homeostasis in the plasma and key organs (brain, liver, spleen, heart, lungs, and kidneys). Analysis of human patient CSF, plasma and post-mortem brain tissues also indicated disrupted metal homeostasis. There was a disparity in the direction of metal changes between the human and the Npc1(-/-) mouse samples, which may reflect species-specific metal metabolism. Nevertheless, common to both species is brain zinc accumulation. Furthermore, treatment with the glucosylceramide synthase inhibitor miglustat, the only drug shown in a controlled clinical trial to have some efficacy for NP-C1, did not correct the alterations in CSF and plasma transition metal and ceruloplasmin (CP) metabolism in NP-C1 patients. These findings highlight the importance of NPC1 function in metal homeostasis, and indicate that metal-targeting therapy may be of value as a treatment for NP-C.

Iron overload occurs frequently in thalassemia and other disorders that require regular blood transfusions. Excess iron is toxic owing to the generation of free radicals that lead to oxidation of biomolecules and tissue damage. In order to identify compounds that reduce oxidative injury from iron, we evaluated alpha-lipoic acid (LA), a multifunctional antioxidant, in iron-overloaded primary human fibroblasts (IMR-90). Oxidant stress was measured using dichlorodihydrofluorescein diacetate that is converted to the fluorescent dichlorofluorescein (DCF) upon oxidation. Exposure to ferric ammonium citrate (FAC) increased the iron-content of IMR-90 cells and caused a rise in oxidant appearance. The addition of LA improved the cellular redox status and attenuated the iron-mediated rise in oxidants in a dose-dependent manner. The R- and RS-enantiomers of LA demonstrated similar antioxidant activity. N-tert-butyl hydroxylamine (NtBHA) treated cells also exhibited a decrease in DCF fluorescence, but at a much higher concentration compared with LA. The combination acetyl-L-carnitine (ALCAR) and LA exhibited superior antioxidant effect at all dose levels. We conclude that LA is highly effective in reversing oxidative stress arising from iron overload and that its antioxidant efficacy is further enhanced in combination with ALCAR.

Chemotherapeutics used to treat prostate cancer are often from a class of drugs that target microtubule networks, such as paclitaxel. A previous report indicated that supplemental zinc sensitized prostate cancer cells to paclitaxel-induced apoptosis, suggesting that increased zinc levels might enhance paclitaxel efficacy. The effect of zinc deficiency on paclitaxel activity is not known though, so we tested this in two prostate cancer cell lines maintained under moderately zinc-deficient conditions. LNCaP and PC3 cell lines were used as models of early and late-stage prostate cancer, respectively. Cells cultured in reduced zinc levels did not demonstrate altered cell viability, growth rates, or intracellular zinc content. Additionally, zinc deficiency alone had no apparent effect on cell cycle kinetics or apoptosis levels. However, the IC50 for paclitaxel-induced cell cycle arrest increased in LNCaP cells from zinc-deficient compared to zinc-replete conditions. Consequently, paclitaxel-induced apoptosis was reduced in LNCaP cells from zinc-deficient compared to zinc-replete conditions. In PC3 cells, the effects of paclitaxel were independent of zinc status. Reduced extracellular zinc levels were shown to affect paclitaxel activity in a prostate cancer cell line. Given the prevalence of zinc deficiency, determining how chemotherapeutic action is modulated by zinc adequacy may have clinical importance.

Age-related macular degeneration (AMD) is the leading cause of severe visual impairment in the elderly in developed countries. AMD patients have elevated levels of iron within the retinal pigment epithelia (RPE), which may lead to oxidative damage to mitochondria, disruption of retinal metabolism, and vision impairment or loss. As a possible model for iron-induced AMD, we investigated the effects of excess iron in cultured human fetal RPE cells on oxidant levels and mitochondrial cytochrome c oxidase (complex IV) function and tested for protection by N-tert-butyl hydroxylamine (Nt-BHA), a known mitochondrial antioxidant. RPE exposure to ferric ammonium citrate resulted in a time- and dose-dependent increase in intracellular iron, which increased oxidant production and decreased glutathione (GSH) levels and mitochondrial complex IV activity. NtBHA addition to iron-overloaded RPE cells led to a reduction of intracellular iron content, oxidative stress, and partial restoration of complex IV activity and GSH content. NtBHA might be useful in AMD due to its potential to reduce oxidative stress, mitochondrial damage, and age-related iron accumulation, which may damage normal RPE function and lead to loss of vision.

A coordinated network of zinc transporters and binding proteins tightly regulate cellular zinc levels. Canonical responses to zinc availability are thought to be mediated by changes in gene expression of key zinc transporters. We investigated the temporal relationships of actual zinc uptake with patterns of gene expression in membrane-bound zinc transporters in the human immortalized T lymphocyte Jurkat cell line. Cellular zinc levels were elevated or reduced with exogenous zinc sulfate or N,N,N',N-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), respectively. Excess zinc resulted in a rapid 44 % decrease in the rate of zinc uptake within 10 min. After 120 min, the expression of metallothionein (positive control) increased, as well as the zinc exporter, ZnT1; however, the expression of zinc importers did not change during this time period. Zinc chelation with TPEN resulted in a rapid twofold increase in the rate of zinc uptake within 10 min. After 120 min, the expression of ZnT1 decreased, while again the expression of zinc importers did not change. Overall, zinc transporter gene expression kinetics did not match actual changes in cellular zinc uptake with exogenous zinc or TPEN treatments. This suggests zinc transporter regulation may be the initial response to changes in zinc within Jurkat cells.

Thalassemia (THAL) patients have a genetic anemia causing incomplete erythropoiesis and iron overload, possibly leading to cardiomyopathy and diabetes. Plasma zinc (Zn) and Copper (Cu) deficiency are also observed in some patients with THAL, however, these effects are not as well characterized. It has been suggested that oxidative stress can be caused by increased labile plasma iron (LPI), and decreased serum Zn and Cu levels, however this is unproven. LPI can initiate peroxidation releasing malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE). Thus, we hypothesized that that a functional Zn or Cu deficiency can increase oxidative stress and that changes in the levels of key iron trafficking proteins, such as soluble transferrin receptor (sTfR) or hemopexin (HPX) would also affect oxidative stress. 39 subjects with informed consent were enrolled (29 patients with THAL and 10 healthy controls). LPI was measured using dihydrorhodamine 123. Both MDA and 4-HNE were measured using N-methyl-2-phenylindole. Iron trafficking proteins were measured by MRM mass spectrometry. Trace mineral levels were assessed by ICP spectroscopy. Plasma levels of the iron trafficking proteins, transferrin, HPX and haptoglobin (HAP) were all decreased in THAL patients (P

Zinc deficiency continues to be a major concern of international nutrition, yet there are still few sensitive and reliable biomarkers for identifying moderate zinc deficiency or monitoring changes ...

Iron accumulates as a function of age and is associated with the pathology of numerous age-related diseases. These changes may be caused by altered iron homeostasis at the cellular level, yet this is poorly understood. Therefore, changes in iron content in primary human fibroblasts were studied in culture models of cellular senescence. Total iron content increased exponentially during cellular senescence, reaching approximately 10-fold higher levels than young cells. Increasing intracellular iron levels through iron-citrate supplementation or decreasing intracellular iron levels using iron-selective chelators had little effect on cellular life span and markers of cellular senescence when used at subtoxic doses. However, accelerating cellular senescence with low-dose H(2)O(2) also accelerated senescence-associated iron accumulation. Delaying cellular senescence with N-tert-butyl-hydroxylamine (NtBHA) attenuated senescence-associated iron accumulation. Furthermore, H(2)O(2) or NtBHA had no effect on iron intracellular levels in immortalized fibroblasts. Thus, iron accumulation is not a cause, but a consequence of normal cellular senescence in vitro. Senescence-associated iron accumulation may contribute to the increased oxidative stress and cellular dysfunction seen in senescent cells.

Background The Cystic Fibrosis Transmembrane conductance Regulator (CFTR) is a chloride channel that primarily resides in airway epithelial cells. Decreased CFTR expression and/or function lead to impaired airway surface liquid (ASL) volume homeostasis, resulting in accumulation of mucus, reduced clearance of bacteria, and chronic infection and inflammation. Methods Expression of CFTR and the cigarette smoke metal content were assessed in lung samples of controls and COPD patients with established GOLD stage 4. CFTR protein and mRNA were quantified by immunohistochemistry and quantitative RT-PCR, respectively. Metals present in lung samples were quantified by ICP-AES. The effect of cigarette smoke on down-regulation of CFTR expression and function was assessed using primary human airway epithelial cells. The role of leading metal(s) found in lung samples of GOLD 4 COPD patients involved in the alteration of CFTR was confirmed by exposing human bronchial epithelial cells 16HBE14o- to metal-depleted cigarette smoke extracts. Results We found that CFTR expression is reduced in the lungs of GOLD 4 COPD patients, especially in bronchial epithelial cells. Assessment of metals present in lung samples revealed that cadmium and manganese were significantly higher in GOLD 4 COPD patients when compared to control smokers (GOLD 0). Primary human airway epithelial cells exposed to cigarette smoke resulted in decreased expression of CFTR protein and reduced airway surface liquid height. 16HBE14o-cells exposed to cigarette smoke also exhibited reduced levels of CFTR protein and mRNA. Removal and/or addition of metals to cigarette smoke extracts before exposure established their role in decrease of CFTR in airway epithelial cells. Conclusions CFTR expression is reduced in the lungs of patients with severe COPD. This effect is associated with the accumulation of cadmium and manganese suggesting a role for these metals in the pathogenesis of COPD.