The mouse metallomic landscape of aging and metabolism

Redox-sensitive δ65Cu isotopic fractionation in the tissue of the scleractinian coral Stylophora pistillata: a biomarker of holobiont photophysiology following volcanic ash exposure

Volcanic ash is a significant source of micronutrients including iron (Fe), copper (Cu), and zinc (Zn) in oligotrophic tropical waters. These bioactive metals enhance primary productivity, influencing local and global biogeochemical cycles. This study explores how volcanic ash exposure affects trace metal uptake and photophysiological response, and how redox-sensitive metal stable isotope measurements in the tissues of the scleractinian coral Stylophora pistillata can provide crucial information on coral health. Controlled coral culture experiments were conducted in which coral nubbins were exposed to varying intensity and duration of volcanic ash. Throughout the experiment, coral symbionts showed enhanced photosynthetic performance irrespective of intensity or duration of ash exposure. Stable isotopes, such as δ65Cu and δ56Fe, in the coral tissue are marked by systematic variations, not associated with intensity or duration of ash exposure. Instead, we suggest biologically modulated redox-sensitive fractionation associated with ash exposure, linked to the coral host's oxidative stress state. This is evidenced by significant correlations between δ65Cu in coral hosts and photophysiology, with lighter Cu isotope ratios associated with higher photosynthetic performances. Hence, we propose that δ65Cu, and more generally redox-sensitive isotopic ratios (i.e. δ56Fe), in coral hosts serves as an indicator of the physiological state of symbiotic corals.

Zonated Copper-Driven Breast Cancer Progression Countered by a Copper-Depleting Nanoagent for Immune and Metabolic Reprogramming

While studies of various carcinomas have reported aberrant metal metabolism, much remains unknown regarding their spatial accumulation and regulatory impacts in tumors. Here, elevated copper levels are detected in breast cancer tumors from patients and animal models, specifically exhibiting a zonate spatial pattern. Spatially resolved multiomics analyses reveal that copper zonation drives a tumor metabolic preference for oxidative phosphorylation (OXPHOS) over glycolysis and promotes tumor metastatic and immune-desert phenotypes. Then, a copper-depleting nanoagent is developed based on copper chelator tetrathiomolybdate (TM)-loaded hybridized bacterial outer membrane vesicles (hOMVs) from both Akkermansia muciniphila bacteria and CD326-targeting peptide-engineered Escherichia coli (TM@CD326hOMV). Systemic administration of TM@CD326hOMV reduces the labile copper level in tumors and inhibits both tumor growth and metastatic phenotypes, specifically through metabolic reprograming of OXPHOS toward glycolysis and restoration of antitumor immunity responses involving natural killer cells, CD4+ T cells, and cytotoxic CD8+ T cells in tumors. Assessing survival in murine breast cancer models, a combination of TM@CD326hOMV and a checkpoint blockade agent outperforms monotherapies. Notably, a copper-rich diet undermines the therapeutic efficacy of TM@CD326hOMV. Beyond demonstrating an effective nanoagent for treating breast cancer, this study deepens the understanding of how the pattern of copper accumulation in tumors affects pathophysiology and immunity.

Rare biochemical & genetic conditions: clues for broader mechanistic insights

Rare disorders often represent a molecular deviation from hi-fidelity genomic integrity networks and are often perceived as too difficult or unimportant for further mechanistic studies. Here, we synthesize evidence demonstrating how valuable knowledge of biochemical pathways related to rare disorders can be for biomedicine. To this end, we describe several rare congenital lipid, protein, organic acid, and glycan metabolism disorders and discuss how rare phenotypes (such as "extreme responders") and case reports (such as the lenalidomide cases) have provided clues for drug discovery or repurposing. We also discuss how rare disorders such as Gaucher disease and ultra-rare genetic syndromes can provide insights into cancer and mTOR-driven metabolism, respectively. Our discussion highlights the continued value of biochemical pathways and studies in understanding human pathophysiology and drug discovery even in the genomics era.

Recent advancements in the application of multi-elemental profiling and ionomics in cardiovascular diseases

BACKGROUND

Trace elements and minerals are crucial for human growth and health, whose imbalance is associated with a variety of diseases. Recently, multi-elemental profiling and ionomics have been rapidly developed and widely used to study the distribution, variation, and interactions of various elements in diverse physiological and pathological conditions. By utilizing high-throughput elemental analytical techniques and bioinformatics approaches, researchers can uncover the relationship between the metabolism and balance of different elements and numerous human diseases.

METHODS

The presented work reviews recent advances in multi-elemental and ionomic profiling of human biological samples for several major types of cardiovascular diseases.

RESULTS

Research indicates distinct and dynamic patterns of ion contents in these diseases. Accumulation of copper and environmental toxic metals as well as deficiencies in zinc and selenium appear to be the most significant risk factors for the majority of cardiovascular diseases, suggesting that an imbalance in these elements may play a role in the development of these illnesses. Furthermore, each type of cardiovascular disease exhibits a relatively unique distribution of ions in biofluid and hair samples from patients, potentially serving as indicators for the specific disease.

CONCLUSION

Multi-elemental profiling and ionomics not only enhance our understanding of the association between elemental dyshomeostasis and the development of cardiovascular diseases but also facilitate the discovery of novel diagnostic and prognostic markers for these conditions.

Unveiling the hidden impact of long-term metal-rich volcanic pollution on male reproductive functions using isotope metallomics

Volcanic eruptions release particles in a range of sizes that can chronically affect the health of communities within tens of kilometers of the volcano. Many years after an eruption, resuspension of volcanic ash can exacerbate the health impact of primary eruptive events. So far, our global understanding of the health effects triggered by chronic exposure to volcanic particles at the whole-body scale is limited. Recently, it has been shown that mice chronically exposed to metal-rich volcanic ash deposits present metallome deregulations associated with pathophysiological changes. These deregulations preferentially impact the reproductive functions, questioning about the impact of ash on fertility. This work aims to further assess the mechanisms driving the ash-related fertility disorders and develop predictive biomarkers. For that, elemental concentrations and Cu-Zn-Fe isotope measurements coupled to metabolomic, proteomic and transcriptomic analyses were measured in blood, liver and two organs of the male reproductive system (testis, seminal vesicle). The samples were collected on wild-type and mice exposed over two months to volcanic ash. Mice exposed to ash are characterized by (i) significant metallomic deregulations, (ii) higher oxidative stress correlating with isotopic variations of redox-sensitive elements and (iii) testicular and hepatic alterations, marked by gains in organ mass, hepatic lipid accumulation and circulating bile acids overload, all of which might exacerbate testicular defects. Together, these results demonstrate that prolonged exposure to metal-rich ash is a threat for male reproduction and that investigating redox-sensitive isotopes might help identifying early signs of oxidative stress-related testicular injuries, with future implications for hepato-testicular disease prevention.

Metalloproteomic analysis of hemophilic arthropathy synovial tissue: insights into metal overload and pathogenesis

BACKGROUND

Hemophilic arthropathy (HA) is a joint disease characterized by local iron overload stemming from erythrocyte rupture and closely linked to synovial lesions. However, the precise molecular characteristics of clinical HA synovial samples remain to be defined.

OBJECTIVES

To gain insight into HA synovial tissue lesions, we utilized a metalloprotein strategy to compare the metal and protein spectra of HA with those of osteoarthritis and rheumatoid arthritis.

METHODS

We collected synovial samples from patients with HA, osteoarthritis, and rheumatoid arthritis. Tissue metal and protein profiles were obtained by metallomics and proteomics, respectively. Finally, metalloproteomics strategies compared metal content, proteins, metalloproteins, and the life processes involved.

RESULTS

Our metallomics analysis revealed an explicit increase in heavy metal content, particularly arsenic and mercury, in HA synovial samples. Through proteomics, we delineated specific metalloproteins and identified correlations between metals and pathways.

CONCLUSION

These findings yield valuable insights into the pathogenesis of HA and offer potential therapeutic targets for conditions characterized by iron overload.

Reliable and precise Zn isotopic analysis of biological matrices using a fully automated dual-column purification procedure

A fully automated dual-column purification procedure for Zn from biological samples, designed for subsequent Zn isotopic analysis, is presented that utilizes the prepFAST MC™ system (Elemental Scientific), DGA resin (TrisKem International), and TK201 resin (TrisKem International). The procedure developed enables the unattended processing of 20 samples per day and is characterized by low and reproduceable blanks (< 1.5 ng), no carry-over or memory effect, high reusability (> 50 times), high Zn yields 100.1% ± 5.3% (2 SD, N = 22), and strong robustness to matrix variations across biological samples (bone, liver, hair, blood). Additionally, Zn isotopic analysis using MC-ICP-MS showed no significant on-column fractionation. The measured δ66Zn/64ZnIRMM values for NIST SRM 1400 (0.67‰ ± 0.07‰, U, k = 2), NIST SRM 1486 (0.91‰ ± 0.06‰, U, k = 2), NIST SRM 1577c (- 0.45‰ ± 0.05‰, U, k = 2), ERM-DB001 (- 0.35‰ ± 0.05‰, U, k = 2), GBW09101 (- 0.32‰ ± 0.08‰, U, k = 2), and SeroNorm whole blood L-3 (-0.15 ‰ ± 0.05 ‰, U, k = 2) are consistent with published values. The procedure developed makes Zn, an analytically challenging isotope system, more accessible, feasible, and reliable for a broader range of users while enabling high sample throughput.

Iron-mediated post-transcriptional regulation in Toxoplasma gondii

Iron is required to support almost all life; however, levels must be carefully regulated to maintain homeostasis. Although the obligate parasite Toxoplasma gondii requires iron, how it responds upon iron limitation has not been investigated. Here, we show that iron depletion triggers significant transcriptional changes in the parasite, including in iron-dependent pathways. We find that a subset of T. gondii transcripts contain stem-loop structures, which have been associated with post-transcriptional iron-mediated regulation in other cellular systems. We validate one of these (found in the 3' UTR of TGME49_261720) using a reporter cell line. We show that the presence of the stem-loop-containing UTR is sufficient to confer accumulation at the transcript and protein levels under low iron. This response is dose and time-dependent and is specific for iron. The accumulation of transcript is likely driven by an increased reporter mRNA stability under low iron. Interestingly, we find iron-mediated changes in mRNA stability in around 400 genes. To examine the potential mechanism of this stability, we tested aconitase interaction with mRNA in low iron and found 43 enriched transcripts, but no specific interaction with our reporter UTR. However, the endogenous UTR led to maintenance of protein levels and increased survival of the parasite under low iron. Our data demonstrate the existence of iron-mediated post-transcriptional regulation in Toxoplasma for the first time; and suggests iron-mediated regulation may be important to the parasite in low iron environments.

Unveiling the Origin of Copper Accumulation in Plasma with Aging

Aging is intricately linked to various diseases including cancers, neurodegenerative disorders, and metabolic irregularities. Copper (Cu) overexposure has been found to be linked to many diseases during aging, particularly neurodegenerative diseases. Meanwhile, as an essential element, Cu has been implicated in key processes associated with aging, raising questions about its role in age-related health issues. This study delves into the mechanisms behind the copper imbalance during aging. By analyzing blood copper concentrations of healthy individuals (including data from healthy subjects (26 ≤ age ≤ 90, n = 62) and publicly available data from the National Health and Nutrition Examination Survey (18 ≤ age < 80, n = 1624)) and employing C57BL/6N male mice models (n = 22), we reveal a consistent age-related increase in copper levels, particularly in plasma. Utilizing stable copper isotopic analysis, copper-associated protein analysis, and metabolomic analysis, we trace the sources of Cu imbalance associated with aging. Our findings reveal that aged mice had a higher copper concentrations and an enrichment of light copper isotope (63Cu) in plasma compared to controls. Additionally, copper reductases and copper transporters are upregulated in the intestine tract, associated with the AMPK and mTOR signaling pathways. We suggest that aged mice have an abnormally high copper intake requirement, probably due to deregulated nutrient sensing, leading to increased expression levels of copper reductases and copper transporters for extra copper absorption in the intestines. This research provides a copper-centric perspective on the connection between deregulated nutrient sensing and aging, thus shedding light on the aspect of aging and copper overexposure.

New vision for TCM quality control: Elemental fingerprints and key ingredient combination strategy for identification and evaluation of TCMs

The quality control of Traditional Chinese Medicine (TCM) is crucial for ensuring its efficacy and safety. Traditional methods, however, have limitations in fully capturing the natural essence of TCM, thus hindering the comprehensive exhibition of its authenticity. Addressing this challenge requires the establishment of a scientific and reasonable quality control system, which poses significant complexities due to the TCM unique attributes. Our research team conducted in-depth exploration of the elemental fingerprints of TCM, amassing a robust theoretical and practical foundation. In this review, we presented a comprehensive review of the core value, advanced technologies, and classic cases of elemental fingerprints. We introduced a novel perspective that integrated inorganic and organic components, overcoming traditional paradigms. The review analysis highlighted unique role of elemental fingerprints in revealing the scientific connotation of TCM. Furthermore, we proposed an innovative strategy for identifying key components, which effectively addressed the limitations of traditional methods and elevated the overall evaluation standards for TCM. This strategy was supported by emerging technologies such as artificial intelligence, metallomics, and hyperspectral imaging. Looking ahead, the application prospects of the combined strategy of elemental fingerprints and key components were promising. It not only provided a solid foundation for the formulation of TCM quality control strategies but also introduced new methodologies and tools to the field of regulatory science and scientific oversight of TCM.

Discovering geroprotectors through the explainable artificial intelligence-based platform AgeXtend

Aging involves metabolic changes that lead to reduced cellular fitness, yet the role of many metabolites in aging is unclear. Understanding the mechanisms of known geroprotective molecules reveals insights into metabolic networks regulating aging and aids in identifying additional geroprotectors. Here we present AgeXtend, an artificial intelligence (AI)-based multimodal geroprotector prediction platform that leverages bioactivity data of known geroprotectors. AgeXtend encompasses modules that predict geroprotective potential, assess toxicity and identify target proteins and potential mechanisms. We found that AgeXtend accurately identified the pro-longevity effects of known geroprotectors excluded from training data, such as metformin and taurine. Using AgeXtend, we screened ~1.1 billion compounds and identified numerous potential geroprotectors, which we validated using yeast and Caenorhabditis elegans lifespan assays, as well as exploring microbiome-derived metabolites. Finally, we evaluated endogenous metabolites predicted as senomodulators using senescence assays in human fibroblasts, highlighting AgeXtend's potential to reveal unidentified geroprotectors and provide insights into aging mechanisms.

Potential implications of natural compounds on aging and metabolic regulation

Aging is generally accompanied by a progressive loss of metabolic homeostasis. Targeting metabolic processes is an attractive strategy for healthy-aging. Numerous natural compounds have demonstrated strong anti-aging effects. This review summarizes recent findings on metabolic pathways involved in aging and explores the anti-aging effects of natural compounds by modulating these pathways. The potential anti-aging effects of natural extracts rich in biologically active compounds are also discussed. Regulating the metabolism of carbohydrates, proteins, lipids, and nicotinamide adenine dinucleotide is an important strategy for delaying aging. Furthermore, phenolic compounds, terpenoids, alkaloids, and nucleotide compounds have shown particularly promising effects on aging, especially with respect to metabolism regulation. Moreover, metabolomics is a valuable tool for uncovering potential targets against aging. Future research should focus on identifying novel natural compounds that regulate human metabolism and should delve deeper into the mechanisms of metabolic regulation using metabolomics methods, aiming to delay aging and extend lifespan.

Toxicity study of mineral medicine haematitum

ETHNOPHARMACOLOGICAL RELEVANCE

Haematitum, a time-honored mineral-based Chinese medicine, has been used medicinally in China for over 2000 years. It is now included in the Chinese Pharmacopoeia and used clinically for treating digestive and respiratory diseases. The Chinese Materia Medica records that it is toxic and should not be taken for a long period, but there are few research reports on the toxicity of Haematitum and its potential toxicity mechanisms.

AIM OF THE STUDY

This study aimed to evaluate the toxicity of Haematitum and calcined Haematitum, including organ toxicity, neurotoxicity, and reproductive toxicity. Further, it is also necessary to explore the mechanism of Haematitum toxicity and to provide a reference for the safe clinical use of the drug.

MATERIALS AND METHODS

The samples of Haematitum and calcined Haematitum decoctions were prepared. KM mice were treated with samples by gavage for 10 days, and lung damage and apoptosis were assessed by HE staining and TUNEL staining of lung tissues respectively. Metabolomics analysis was performed by HPLC-MS. Metallomics analysis was performed by ICP-MS. In addition, C. elegans was used as a model for 48 h exposure to examine the neurotoxicity and reproductive toxicity-related indices of Haematitum, including locomotor behaviors, growth and development, reproductive behaviors, AChE activities, sensory behaviors, apoptosis, and ROS levels.

RESULTS

The use of large doses of Haematitum decoction caused lung damage in mice. Neither calcined Haematitum decoction nor Haematitum decoction at clinically used doses showed organ damage. Metabolomics results showed that disorders in lipid metabolic pathways such as sphingolipid metabolism and glycerophospholipid metabolism may be important factors in Haematitum-induced pulmonary toxicity. High doses of Haematitum decoction caused neurological damage to C. elegans, while low doses of Haematitum decoction and calcined Haematitum decoction showed no significant neurotoxicity. Decoction of Haematitum and calcined Haematitum did not show reproductive toxicity to C. elegans. Toxicity was also not observed in the control group of iron (Ⅱ) and iron (Ⅲ) ions in equal amounts with high doses of Haematitum.

CONCLUSIONS

Haematitum is relatively safe for routine doses and short-term use. Calcination can significantly reduce Haematitum toxicity, and this study provides a reference for safe clinical use.

Integrative Omics Uncovers Low Tumorous Magnesium Content as A Driver Factor of Colorectal Cancer

Magnesium (Mg) deficiency is associated with increased risk and malignancy in colorectal cancer (CRC), yet the underlying mechanisms remain elusive. Here, we used genomic, proteomic, and phosphoproteomic data to elucidate the impact of Mg deficiency on CRC. Genomic analysis identified 160 genes with higher mutation frequencies in Low-Mg tumors, including key driver genes such as KMT2C and ERBB3. Unexpectedly, initiation driver genes of CRC, such as TP53 and APC, displayed higher mutation frequencies in High-Mg tumors. Additionally, proteomic and phosphoproteomic data indicated that low Mg content in tumors may activate epithelial-mesenchymal transition (EMT) by modulating inflammation or remodeling the phosphoproteome of cancer cells. Notably, we observed a negative correlation between the phosphorylation of DBN1 at S142 (DBN1S142p) and Mg content. A mutation in S142 to D (DBN1S142D) mimicking DBN1S142p up-regulated MMP2 and enhanced cell migration, while treatment with MgCl2 reduced DBN1S142p, thereby reversing this phenotype. Mechanistically, Mg2+ attenuated the DBN1-ACTN4 interaction by decreasing DBN1S142p, which in turn enhanced the binding of ACTN4 to F-actin and promoted F-actin polymerization, ultimately reducing MMP2 expression. These findings shed new light on the crucial role of Mg deficiency in CRC progression and suggest that Mg supplementation may be a promising preventive and therapeutic strategy for CRC.

Metabolic Derangement of Essential Transition Metals and Potential Antioxidant Therapies

Essential transition metals have key roles in oxygen transport, neurotransmitter synthesis, nucleic acid repair, cellular structure maintenance and stability, oxidative phosphorylation, and metabolism. The balance between metal deficiency and excess is typically ensured by several extracellular and intracellular mechanisms involved in uptake, distribution, and excretion. However, provoked by either intrinsic or extrinsic factors, excess iron, zinc, copper, or manganese can lead to cellular damage upon chronic or acute exposure, frequently attributed to oxidative stress. Intracellularly, mitochondria are the organelles that require the tightest control concerning reactive oxygen species production, which inevitably leaves them to be one of the most vulnerable targets of metal toxicity. Current therapies to counteract metal overload are focused on chelators, which often cause secondary effects decreasing patients' quality of life. New therapeutic options based on synthetic or natural antioxidants have proven positive effects against metal intoxication. In this review, we briefly address the cellular metabolism of transition metals, consequences of their overload, and current therapies, followed by their potential role in inducing oxidative stress and remedies thereof.

Translational toxicology of metal(loid) species: linking their bioinorganic chemistry in the bloodstream to organ damage onset

The quantification of arsenic, mercury, cadmium and lead in the human bloodstream is routinely used today to assess exposure to these toxic metal(loid)s, but the interpretation of the obtained data in terms of their cumulative health relevance remains problematic. Seemingly unrelated to this, epidemiological studies strongly suggest that the simultaneous chronic exposure to these environmental pollutants is associated with the etiology of autism, type 2 diabetes, irritable bowel disease and other diseases. This from a public health point of view undesirable situation urgently requires research initiatives to establish functional connections between human exposure to multiple toxic metal(loid) species and adverse health effects. One way to establish causal exposure-response relationships is a molecular toxicology approach, which requires one to unravel the biomolecular mechanisms that unfold after individual toxic metal(loid)s enter the bloodstream/organ nexus as these interactions ultimately determine which metabolites impinge on target organs and thus provide mechanistic links to diseases of unknown etiology. In an attempt to underscore the importance of the toxicological chemistry of metal(loid)s in the bloodstream, this review summarizes recent progress into relevant bioinorganic processes that are implicated in the etiology of adverse organ-based health effects and possibly diseases. A better understanding of these bioinorganic processes will not only help to improve the regulatory framework to better protect humans from the adverse effects of toxic metal(loid) species, but also represents an important starting point for the development of treatments to ameliorate pollution-induced adverse health effects on human populations, including pregnant women, the fetus and children.

Multipollutant reciprocal neurological hazard from smoke particulate matter and heavy metals cadmium and lead in brain nerve terminals

Heavy metals, Cd2+ and Pb2+, and carbonaceous air pollution particulate matter are hazardous neurotoxicants. Here, a capability of water-suspended smoke particulate matter preparations obtained from poplar wood (WPs) and polypropylene fibers (medical facemasks) (MPs) to influence Cd2+/Pb2+-induced neurotoxicity, and vice versa, was monitored using biological system, i.e. isolated presynaptic rat cortex nerve terminals. Combined application of Pb2+ and WPs/MPs to nerve terminals in an acute manner revealed that smoke preparations did not change a Pb2+-induced increase in the extracellular levels of excitatory neurotransmitter L-[14C]glutamate and inhibitory one [3H]GABA, thereby demonstrating additive result and no interference of neurotoxic effects of Pb2+ and particulate matter. Whereas, both smoke preparations decreased a Cd2+-induced increase in the extracellular level of L-[14C]glutamate and [3H]GABA in nerve terminals. In fluorimetric measurements, the metals and smoke preparations demonstrated additive effects on the membrane potential of nerve terminals causing membrane depolarisation. WPs/MPs-induced reduction of spontaneous ROS generation was mitigated by Cd2+ and Pb2+. Therefore, a potential variety of multipollutant heavy metal-/airborne particulate-induced effects on key presynaptic processes was revealed. Multipollutant reciprocal neurological hazard through disturbance of the excitation-inhibition balance, membrane potential and ROS generation was evidenced. This multipollutant approach and data contribute to up-to-date environmental quality/health risk estimation.

Long-term suboptimal dietary trace element supply does not affect trace element homeostasis in murine cerebellum

The ageing process is associated with alterations of systemic trace element (TE) homeostasis increasing the risk, e.g. neurodegenerative diseases. Here, the impact of long-term modulation of dietary intake of copper, iron, selenium, and zinc was investigated in murine cerebellum. Four- and 40-wk-old mice of both sexes were supplied with different amounts of those TEs for 26 wk. In an adequate supply group, TE concentrations were in accordance with recommendations for laboratory mice while suboptimally supplied animals received only limited amounts of copper, iron, selenium, and zinc. An additional age-adjusted group was fed selenium and zinc in amounts exceeding recommendations. Cerebellar TE concentrations were measured by inductively coupled plasma-tandem mass spectrometry. Furthermore, the expression of genes involved in TE transport, DNA damage response, and DNA repair as well as selected markers of genomic stability [8-oxoguanine, incision efficiency toward 8-oxoguanine, 5-hydroxyuracil, and apurinic/apyrimidinic sites and global DNA (hydroxy)methylation] were analysed. Ageing resulted in a mild increase of iron and copper concentrations in the cerebellum, which was most pronounced in the suboptimally supplied groups. Thus, TE changes in the cerebellum were predominantly driven by age and less by nutritional intervention. Interestingly, deviation from adequate TE supply resulted in higher manganese concentrations of female mice even though the manganese supply itself was not modulated. Parameters of genomic stability were neither affected by age, sex, nor diet. Overall, this study revealed that suboptimal dietary TE supply does not substantially affect TE homeostasis in the murine cerebellum.

Metal-binding amino acid ligands commonly found in metalloproteins differentially fractionate copper isotopes

Copper (Cu) is a cofactor in numerous key proteins and, thus, an essential element for life. In biological systems, Cu isotope abundances shift with metabolic and homeostatic state. However, the mechanisms underpinning these isotopic shifts remain poorly understood, hampering use of Cu isotopes as biomarkers. Computational predictions suggest that isotope fractionation occurs when proteins bind Cu, with the magnitude of this effect dependent on the identity and arrangement of the coordinating amino acids. This study sought to constrain equilibrium isotope fractionation values for Cu bound by common amino acids at protein metal-binding sites. Free and bound metal ions were separated via Donnan dialysis using a cation-permeable membrane. Isotope ratios of pre- and post-dialysis solutions were measured by MC-ICP-MS following purification. Sulfur ligands (cysteine) preferentially bound the light isotope (63Cu) relative to water (Δ65Cucomplex-free = - 0.48 ± 0.18‰) while oxygen ligands favored the heavy isotope (65Cu; + 0.26 ± 0.04‰ for glutamate and + 0.16 ± 0.10‰ for aspartate). Binding by nitrogen ligands (histidine) imparted no isotope effect (- 0.01 ± 0.04‰). This experimental work unequivocally demonstrates that amino acids differentially fractionate Cu isotopes and supports the hypothesis that metalloprotein biosynthesis affects the distribution of transition metal isotopes in biological systems.

Calcium's Role and Signaling in Aging Muscle, Cellular Senescence, and Mineral Interactions

Calcium research, since its pivotal discovery in the early 1800s through the heating of limestone, has led to the identification of its multi-functional roles. These include its functions as a reducing agent in chemical processes, structural properties in shells and bones, and significant role in cells relating to this review: cellular signaling. Calcium signaling involves the movement of calcium ions within or between cells, which can affect the electrochemical gradients between intra- and extracellular membranes, ligand binding, enzyme activity, and other mechanisms that determine cell fate. Calcium signaling in muscle, as elucidated by the sliding filament model, plays a significant role in muscle contraction. However, as organisms age, alterations occur within muscle tissue. These changes include sarcopenia, loss of neuromuscular junctions, and changes in mineral concentration, all of which have implications for calcium's role. Additionally, a field of study that has gained recent attention, cellular senescence, is associated with aging and disturbed calcium homeostasis, and is thought to affect sarcopenia progression. Changes seen in calcium upon aging may also be influenced by its crosstalk with other minerals such as iron and zinc. This review investigates the role of calcium signaling in aging muscle and cellular senescence. We also aim to elucidate the interactions among calcium, iron, and zinc across various cells and conditions, ultimately deepening our understanding of calcium signaling in muscle aging.

Contribution to Knowledge on Bioapatites: Does Mg Level Reflect the Organic Matter and Water Contents of Enamel?

The matter constituting the enamels of four types of organisms was studied. The variability of the ions was presented in molar units. It was proven that the changes in water contents of the enamel are significantly positively related to changes in Mg; inversely, there is also a strong connection with changes in Ca and P, the main components of bioapatite. The variability in the organic matter has the same strong and positive characteristics and is also coupled with changes in Mg contents. Amelogenins in organic matter, which synthesize enamel rods, likely have a role in adjusting the amount of Mg, thus establishing the amount of organic matter and water in the whole enamel; this adjustment occurs through an unknown mechanism. Ca, P, Mg, and Cl ions, as well as organic matter and water, participate in the main circulation cycle of bioapatites. The selection of variations in the composition of bioapatite occurs only along particular trajectories, where the energy of transformation linearly depends on the following factors: changes in the crystallographic d parameter; the increase in the volume, V, of the crystallographic cell; the momentum transfer, which is indirectly expressed by ΔsinΘ value. To our knowledge, these findings are novel in the literature. The obtained results indicate the different chemical and crystallographic affinities of the enamels of selected animals to the human ones. This is essential when animal bioapatites are transformed into dentistic or medical substitutes for the hard tissues. Moreover, the role of Mg is shown to control the amount of water in the apatite and in detecting organic matter in the enamels.

Machine learning-aided metallomic profiling in serum and urine of thyroid cancer patients and its environmental implications

The incidence rate of thyroid cancer has been growing worldwide. Thyroid health is closely related with multiple trace metals, and the nutrients are essential in maintaining thyroid function while the contaminants can disturb thyroid morphology and homeostasis. In this study, we conducted metallomic analysis in thyroid cancer patients (n = 40) and control subjects (n = 40) recruited in Shenzhen, China with a high incidence of thyroid cancer. We found significant alterations in serumal and urinary metallomic profiling (including Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Cd, I, Ba, Tl, and Pb) and elemental correlative patterns between thyroid cancer patients and controls. Additionally, we also measured the serum Cu isotopic composition and found a multifaceted disturbance in Cu metabolism in thyroid disease patients. Based on the metallome variations, we built and assessed the thyroid cancer-predictive performance of seven machine learning algorithms. Among them, the Random Forest model performed the best with the accuracy of 1.000, 0.858, and 0.813 on the training, 5-fold cross-validation, and test set, respectively. The high performance of machine learning has demonstrated the great promise of metallomic analysis in the identification of thyroid cancer. Then, the Shapley Additive exPlanations approach was used to further interpret the variable contributions of the model and it showed that serum Pb contributed the most in the identification process. To the best of our knowledge, this is the first study that combines machine learning and metallome data for cancer identification, and it supports the indication of environmental heavy metal-related thyroid cancer etiology.

The ionome and proteome landscape of aging in laying hens and relation to egg white quality

The ionome is essential for maintaining body function and health status by participating in diverse key biological processes. Nevertheless, the distribution and utilization of ionome among different organs and how aging impacts the ionome leading to a decline in egg white quality remain unknown. Thus, we used inductively coupled plasma mass spectrometry (ICP-MS) to analyze 35 elements and their isotopic contents in eight organs of laying hens at 35, 72, and 100 weeks. Moreover, the magnum proteome, amino acids in egg white, and egg white quality were analyzed in laying hens at three different ages using 4D proteomics techniques, an amino acid analyzer, and an egg quality analyzer. Across the organs, we identified varying distribution patterns among macroelements (Mg24, Ca43/44, K39, and P31), transition metals (Zn64/66, Cu63/65, Fe56/57, and Mn55), and toxic elements (Pb208, Ba137, and Sr86). We observed an organ-specific aging pattern characterized by the accumulation of toxic elements (Pb208, Ba137, and Sr86) and calcification in the small intestine. Additionally, a decrease in the utilization of essential trace elements selenium (Se78/82) and manganese (Mn55) was noted in the oviduct. By analyzing ionome in tandem with egg quality, egg white amino acids, and proteome, we unveiled that the reduction of selenium and manganese concentrations in the magnum during the aging process affected amino acid metabolism, particularly tryptophan metabolism, thereby inhibiting the amino acid synthesis in the magnum. Furthermore, it accelerated the senescence of magnum cells through necroptosis activation, leading to a decline in the albumen secretion function of the magnum and subsequently reducing egg white quality. Overall, this study provides insights into the evolution of 35 elements and their isotopes across 8 organs of laying hens with age. It also reveals the elemental composition, interactions, and utilization patterns of these organs, as well as their correlation with egg white quality. The present study highlights the significance of ionome and offers a comprehensive perspective on the selection of ionome for regulating the aging of laying hens.

Zinc and iron dynamics in human islet amyloid polypeptide-induced diabetes mouse model

Metal homeostasis is tightly regulated in cells and organisms, and its disturbance is frequently observed in some diseases such as neurodegenerative diseases and metabolic disorders. Previous studies suggest that zinc and iron are necessary for the normal functions of pancreatic β cells. However, the distribution of elements in normal conditions and the pathophysiological significance of dysregulated elements in the islet in diabetic conditions have remained unclear. In this study, to investigate the dynamics of elements in the pancreatic islets of a diabetic mouse model expressing human islet amyloid polypeptide (hIAPP): hIAPP transgenic (hIAPP-Tg) mice, we performed imaging analysis of elements using synchrotron scanning X-ray fluorescence microscopy and quantitative analysis of elements using inductively coupled plasma mass spectrometry. We found that in the islets, zinc significantly decreased in the early stage of diabetes, while iron gradually decreased concurrently with the increase in blood glucose levels of hIAPP-Tg mice. Notably, when zinc and/or iron were decreased in the islets of hIAPP-Tg mice, dysregulation of glucose-stimulated mitochondrial respiration was observed. Our findings may contribute to clarifying the roles of zinc and iron in islet functions under pathophysiological diabetic conditions.

Recent advances in the application of ionomics in metabolic diseases

Trace elements and minerals play a significant role in human health and diseases. In recent years, ionomics has been rapidly and widely applied to explore the distribution, regulation, and crosstalk of different elements in various physiological and pathological processes. On the basis of multi-elemental analytical techniques and bioinformatics methods, it is possible to elucidate the relationship between the metabolism and homeostasis of diverse elements and common diseases. The current review aims to provide an overview of recent advances in the application of ionomics in metabolic disease research. We mainly focuses on the studies about ionomic or multi-elemental profiling of different biological samples for several major types of metabolic diseases, such as diabetes mellitus, obesity, and metabolic syndrome, which reveal distinct and dynamic patterns of ion contents and their potential benefits in the detection and prognosis of these illnesses. Accumulation of copper, selenium, and environmental toxic metals as well as deficiency of zinc and magnesium appear to be the most significant risk factors for the majority of metabolic diseases, suggesting that imbalance of these elements may be involved in the pathogenesis of these diseases. Moreover, each type of metabolic diseases has shown a relatively unique distribution of ions in biofluids and hair/nails from patients, which might serve as potential indicators for the respective disease. Overall, ionomics not only improves our understanding of the association between elemental dyshomeostasis and the development of metabolic disease but also assists in the identification of new potential diagnostic and prognostic markers in translational medicine.

Emerging applications of high-precision Cu isotopic analysis by MC-ICP-MS

As a component of many minerals and an essential trace element in most aerobic organisms, the transition metal element Cu is important for studying reduction-oxidation (redox) interactions and metal cycling in the total environment (lithosphere, atmosphere, biosphere, hydrosphere, and anthroposphere). The "fractionation" or relative partitioning of the naturally occurring "heavy" (⁶⁵Cu) and "light" (⁶³Cu) isotope between two coexisting phases in a system occurs according to bonding environment and/or as a result of a slight difference in the rate at which these isotopes take part in physical processes and chemical reactions (in absence of equilibrium). Due to this behaviour, Cu isotopic analysis can be used to study a range of geochemical and biological processes that cannot be elucidated with Cu concentrations alone. The shift between Cu⁺ and Cu²⁺ is accompanied by a large degree of Cu isotope fractionation, enabling the Cu isotope to be applied as a vector in mineral exploration, tracer of origin, transport, and fate of metal contaminants in the environment, biomonitor, and diagnostic/prognostic marker of disease, among other applications. In this contribution, we (1) discuss the analytical protocols that are currently available to perform Cu isotopic analysis, (2) provide a compilation of published δ⁶⁵Cu values for matrix reference materials, (3) review Cu isotope fractionation mechanisms, (4) highlight emerging applications of Cu isotopic analysis, and (5) discuss future research avenues.

Magnesium stable isotope composition, but not concentration, responds to obesity and early insulin-resistant conditions in minipig

Hypomagnesemia is frequently associated with type 2 diabetes and generally correlates with unfavorable disease progression, but the magnesium status in pre-diabetic conditions remains unclear. Here, the magnesium metabolism is scrutinized in a minipig model of obesity and insulin resistance by measuring variations of the metallome—the set of inorganic elements—and the magnesium stable isotope composition in six organs of lean and obese minipigs raised on normal and Western-type diet, respectively. We found that metallomic variations are most generally insensitive to lean or obese phenotypes. The magnesium stable isotope composition of plasma, liver, kidney, and heart in lean minipigs are significantly heavier than in obese minipigs. For both lean and obese minipigs, the magnesium isotope composition of plasma and liver were negatively correlated to clinical phenotypes and plasma lipoproteins concentration as well as positively correlated to hyperinsulinemic-euglycemic clamp output. Because the magnesium isotope composition was not associated to insulin secretion, our results suggest that it is rather sensitive to whole body insulin sensitivity, opening perspectives to better comprehend the onset of insulin-resistant diabetic conditions.

Recent advances in the application of metallomics in diagnosis and prognosis of human cancer

Metals play a critical role in human health and diseases. In recent years, metallomics has been introduced and extensively applied to investigate the distribution, regulation, function, and crosstalk of metal(loid) ions in various physiological and pathological processes. Based on high-throughput multielemental analytical techniques and bioinformatics methods, it is possible to elucidate the correlation between the metabolism and homeostasis of diverse metals and complex diseases, in particular for cancer. This review aims to provide an overview of recent progress made in the application of metallomics in cancer research. We mainly focuses on the studies about metallomic profiling of different human biological samples for several major types of cancer, which reveal distinct and dynamic patterns of metal ion contents and the potential benefits of using such information in the detection and prognosis of these malignancies. Elevated levels of copper appear to be a significant risk factor for various cancers, and each type of cancer has a unique distribution of metals in biofluids, hair/nails, and tumor-affected tissues. Furthermore, associations between genetic variations in representative metalloprotein genes and cancer susceptibility have also been demonstrated. Overall, metallomics not only offers a better understanding of the relationship between metal dyshomeostasis and the development of cancer but also facilitates the discovery of new diagnostic and prognostic markers for cancer translational medicine.

Atp11b Deletion Affects the Gut Microbiota and Accelerates Brain Aging in Mice

The microbiota-gut-brain axis has attracted significant attention with respect to studying the mechanisms of brain aging; however, the specific connection between gut microbiota and aging remains unclear. The abnormal expression and mutation of proteins belonging to the P4-ATPase family, including Atp11b, results in a variety of neurological diseases. The results of our analysis demonstrate that there was a shift in the abundance of certain gut microbiota in Atp11b-knockout (KO) mice. Specifically, there was an increase in pro-inflammatory bacteria that accelerate aging and a decrease in probiotics that delay aging. Consequently, an enhanced oxidative stress response was observed, which was characterized by a reduction in the superoxide dismutase (SOD) activity and an increase in malondialdehyde (MDA) and reactive oxygen species (ROS) levels. In addition, our data demonstrate that there was a decrease in the number of cells in the dentate gyrus (DG) region of the hippocampus, and aggravation of aging-related pathological features such as senescence β-galactosidase (SA-β-Gal), p-HistoneH2AX (Ser139), and p16INK4. Moreover, KO mice show typical aging-associated behavior, such as memory impairment and slow pain perception. Taken together, we demonstrate a possible mechanism of aging induced by gut microbiota in Atp11b-KO mice, which provides a novel perspective for the treatment of aging through the microbiota-gut-brain axis.