Metallomics最新文献

A method for quantitative speciation analysis of residual gadolinium in skin following gadolinium-based contrast agent exposure was developed for the first time. Polyethersulfone was identified as a suitable filter material for these compounds, allowing complete recovery of spiked contrast agents. In contrast, decreasing recoveries with increasing charge of the compound were observed for regenerated cellulose and cellulose triacetate as filter materials. The developed method entailed the utilization of bead beating for tissue homogenization, and the release of yttrium from ceramic beads was shown to result in the gadolinium transmetalation of a linear gadolinium-based contrast agent. A three-step centrifugation of homogenized skin samples, followed by filtration, was performed to extract hydrophilic species for analysis. In combination with using the respective europium chelates as internal standards, this approach enabled the complete recovery of macrocyclic contrast agents from spiked tissue. Quantitative speciation analysis of the biological extracts was conducted by means of anion exchange chromatography hyphenated to inductively coupled plasma-mass spectrometry. This analytical strategy applied to rat skin tissue after repeated administration of macrocyclic contrast agents showed that about a quarter of the residual gadolinium in skin tissue was present in the aqueous extract one month after the last injection. The majority of this water-soluble gadolinium was confirmed by speciation analysis to be the intact administered contrast agent. The presented methodological framework can serve as a first step towards exhaustive speciation analysis of residual gadolinium in skin matrix.

Raman spectroscopy is a label-free, chemically selective technique increasingly employed to probe intracellular biochemical changes associated with drug exposure. Herein, Raman microspectroscopy was applied to evaluate the in vitro responses of MCF-7 (cancerous) and MCF-12A (noncancerous) breast cells to a series of cytotoxic copper(II) (Cu(II)), manganese(II) (Mn(II)), and silver(I) (Ag(I)) complexes containing dicarboxylate and 1,10-phenathroline ligands. Their spectral responses were analysed using principal component analysis (PCA), establishing distinct molecular fingerprints for each metal complex, reflecting divergent mechanisms of action (MOAs). The Cu(II) complexes produced signatures consistent with canonical apoptosis, including reduced DNA backbone vibrations at ∼785 cm⁻¹ and protein conformational changes at ∼1660 cm⁻¹. The Mn(II) complexes demonstrated features of oxidative stress (∼1450 and 1180 cm⁻¹) and spectral features associated with autophagy (∼718 cm⁻¹), in addition to signatures of an apoptotic response like those observed by the Cu(II) analogues, supporting a multimodal mechanism. In contrast, Ag(I) complexes elicited distinct biochemical alterations suggestive of non-canonical pathways, including markers linked to cholesterol metabolism at ∼703 cm⁻¹ and steroid-related activity indicated by multiple features > 1600 cm⁻¹. These spectral distinctions shed light on the role of different types of metal centres in modulating downstream cellular responses and underscore Raman spectroscopy's utility in resolving subtle yet functionally relevant biochemical differences across this series of complexes. Collectively, these findings provide novel insights into the MOAs of this class of complex and support the broader application of Raman spectroscopy to inform future design and evaluation of metal-based cytotoxic agents.

Preservation and embedding procedures can substantially influence elemental distributions measured by X-ray fluorescence imaging (XFI), particularly for mobile endogenous elements. While effects of formalin fixation have been widely studied, comparatively little is known regarding methacrylate embedding. Here, larval zebrafish (Danio rerio) exposed to methylmercury-l-cysteinate (MeHg-l-Cys) were preserved either by JB-4 methacrylate embedding or using cryosectioning/air-drying, called herein cryopreservation, then were sectioned and analyzed using quantitative XFI. Mercury distributions were largely unaffected by preservation method, whereas endogenous elements including potassium, calcium, copper, sulfur, selenium, and zinc showed varying degrees of depletion or redistribution following methacrylate embedding, with potassium showing particularly strong depletion. Despite these changes, methacrylate embedding provided improved anatomical preservation relative to cryopreservation. These results demonstrate that methacrylate embedding is suitable for studies focused primarily on mercury localization, while cryopreservation remains highly preferable when accurate preservation of endogenous elemental distributions is required.

From bacteria to humans, the highly conserved Cu- and Zn-containing superoxide dismutase (Cu/Zn SOD) plays a pivotal role in free radical biology. By using Cu to disproportionate superoxide at rates that approach diffusion limits, Cu/Zn SODs are premier antioxidants. Interestingly, during eukaryotic evolution, several derivatives of the Cu/Zn SOD polypeptide appeared, where the Cu and/or Zn sites were lost and in some cases, Cu/Zn SOD-like sequences were replicated or fused to other protein domains. Such variations of Cu/Zn SOD include the CCS Cu chaperone, fungal Cu-only SODs, and animal CSRP (Cu-only SOD repeat proteins). Here we review the unique biophysical properties and biological functions of these Cu/Zn SOD-like proteins. CCS appeared early in eukaryotic evolution, where a primordial Cu/Zn SOD lost its Cu site and was fused to other Cu-binding domains, creating a dual Cu/molecular chaperone for intracellular Cu/Zn SOD. In the Opisthokont supergroup of eukaryotes that formed fungi and animals, a Cu/Zn SOD lost its Zn binding capacity and structural loop VII, forming Cu-only SODs of fungi and tandemly amplified Cu-only SODs in animal CSRP. Cu-only SODs and Cu-binding CSRPs are efficient SODs, and with lowered Cu-binding affinities, they have evolved to function exclusively outside the cell. Cu-only SODs promote virulence of pathogenic fungi, and recent studies have implicated a role for amphibian CSRP in tissue regeneration, a process involving reactive oxygen species. We have just begun to understand how nature has diversified the Cu/Zn SOD template to create new molecules for metal and free radical biology.

The distribution of inorganic elements in brown rice has been vigorously investigated for many years using the most advanced instruments of each era. The present study was a challenge to gain new insights into the distribution of various inorganic elements in brown rice by autoradiography using radioisotopes: 22Na, 45Ca, 54Mn, 55Fe, 60Co, 63Ni, 65 Zn, 90Sr, 203 Hg, and 210 Pb. Autoradiography of tissue sections using the Imaging Plate (IP) fully exploited its advantage of high-throughput imaging, enabling three-dimensional reconstruction that encompassed the entire brown rice grain. Consequently, characteristic distribution patterns of individual elements in the peripheral layer, endosperm, and embryo were identified following radiotracer supplementation to the culture solution. For instance, 63Ni was uniformly distributed within the endosperm during the early stages of development but progressively accumulated in the outer layers and embryo as growth advanced; such a pattern was not observed for 54Mn or 55Fe. To minimize the cost of the experiment, a direct injection method into the node was developed. This approach successfully visualized 203 Hg, demonstrating that its entry into the embryonic tissue is severely restricted irrespective of the developmental stage of the rice grain.

Introduction: Zinc is an essential trace element with antioxidant and signaling functions critical to cardiac physiology. This study investigated the role of zinc in myocardial ischemia-reperfusion (IR)-induced cardiac damage using a rat model, and whether zinc deficiency induced by intermittent hypoxia (IH) exacerbates cardiac injury.

Methods: Regional IR was performed in isolated rat hearts, and zinc concentrations were measured in coronary effluents. Plasma zinc status was assessed following 14- or 35-day IH exposure (1-min cycles alternating 21% and 5% FiO₂, 8 h/day). The cardioprotective effects of intracoronary zinc administration with the ionophore pyrithione were evaluated based on arrhythmias, infarct size, and contractile recovery.

Results: Myocardial IR induced significant zinc release upon reperfusion (615.7 ± 78.2 nM vs. 374.5 ± 40.3 nM pre-reperfusion, P < 0.01). Zinc administration during reperfusion reduced arrhythmia duration (358.0 ± 61.7 sec vs. 559.9 ± 31.6 sec, P < 0.01) and improved myocardial recovery. IH exposure led to reduced plasma zinc levels (10.3 ± 0.5 µM vs. 13.0 ± 1.2 µM, P = 0.057) and significantly increased infarct size following IR (43.9 ± 4.2% vs. 29.2 ± 4.3%, P < 0.05). Zinc-pyrithione treatment during reperfusion abolished the deleterious effects of IH on infarct size.

Discussion: IH-induced zinc deficiency exacerbates cardiac vulnerability to IR injury, while zinc restoration through targeted administration mitigates this damage. Zinc's protective effects may involve antioxidant action, calcium homeostasis, and signaling modulation.

Conclusion: Zinc plays a critical role in limiting IR-induced cardiac damage. Zinc supplementation during reperfusion may offer therapeutic benefit, particularly in conditions associated with chronic IH, such as obstructive sleep apnea.

The title novel cage complexes were prepared using two-stage nucleophilic substitution of their dichloromacrobicyclic precursor and characterized using elemental analysis, MALDI-TOF mass, UV-vis, 1H and 13C{1H} NMR spectra, and single-crystal XRD experiments. Their chemical compositions suggest an existence of 3D-shaped molecules in either neutral or zwitter-ionic forms and molecular drawings were evaluated basing on most likely hydrogen bonds in the crystals. Effect of proton intramolecular transfer on peculiarities of charge distribution was theoretically studied using XRD structures of two forms of a para-amino-meta-carboxyl-terminated complex. Molecular geometries, charge distributions and electrostatic potentials for them were quantum-chemically calculated. Solution circular dichroism (CD) data suggest that the nature and position of terminal biorelevant groups strongly affect their supramolecular interactions with globular proteins, inducing a metal-centered chirality. Intensities of CD outputs on formation of protein-clathrochelate assemblies and positions of their maxima are also affected by the nature of protein host. Four novel iron(II) clathrochelates possess a cytotoxicity against several cancer cell lines in the comparable low-micromolar concentration range. Maximal cytotoxicities against the cancer HeLa, MCF-7, Caco-2, A549, Hep-2, and PC-3 cells, and relatively low cytotoxities against the normal MRC-5 cells were found for heterodifunctionalized meta(para)-amine-para-carboxyl-terminated isomers (being affected by their structural isomerism) and for mono-meta(para)-carboxylochloroclathrochelates. Cell death in cancer HeLa and Hep-2 lines almost equiprobably includes both necrosis and apoptosis. Low-micromolecular concentration of a meta-amine-para-carboxyl-terminated iron(II) clathrochelate affected a cell cycle of Hep-2 cells causing an increase in the fraction inclined in its S-phase. Pathway of their death and cycle phase distribution shift were studied.

Metals and metalloids play essential roles in cancer biology, influencing redox balance, epigenetic regulation, immune responses, and cell death throughout tumour development, progression, and resistance to therapy. Despite this broad biological relevance, the systematic clinical integration of metallomics into oncology remains in its early stages. This review introduces the Cancer Metallome Continuum, a framework illustrating how metallomic reprogramming evolves from cancer initiation through progression to therapy-resistant states, and evaluates the analytical, systems-level, and translational approaches needed to test it. In early stages of cancer, toxic metals such as As, Cd, hexavalent chromium [Cr(VI)], and Ni induce oxidative stress, epigenetic modifications, and DNA repair defects. During progression, dyshomeostasis of essential metals creates tumour-specific dependencies. For example, Fe accumulation can support tumour growth, while tumour cells concurrently engage antiferroptotic programs; Cu contributes to angiogenesis and kinase signalling, and Zn transporter networks regulate apoptosis and immune responses. Under treatment pressure, tumours adapt by rewiring metal transporters, upregulating metallothionein buffering, and suppressing metal-dependent cell death pathways, including ferroptosis and cuproptosis. Translational advances include selenium-based prognostic panels with replicated evidence in breast cancer (SCAN-B) and colorectal cancer (CORSA), Cu-chelation trials, and spatially resolved metallodrug imaging. The strongest human evidence currently supports Se-based prognostic panels (replicated across breast and colorectal cancer cohorts) and the feasibility of biomarker-guided Cu depletion (a Phase II single-arm trial), while spatial integration and artificial intelligence/machine learning applications remain at the proof-of-concept or emerging stages. Clinical translation will require tighter control of preanalytical variability, prospective multicentre validation, and standardized reporting.

The ability to acquire iron drives microbial fitness in marine environments where iron solubility is extremely low. Iron uptake via the siderophore aerobactin plays an important role in Vibrio fischeri colonization in the light organ of the Hawaiian bobtail squid. To date, the contribution of aerobactin to this mutualistic relationship has not been demonstrated quantitatively. Here we report a revised total synthesis of aerobactin, characterize its stability and iron-binding properties, and demonstrate its importance to Vibrio-squid mutualism. Synthetic aerobactin was characterized by nuclear magnetic resonance (NMR) and high-resolution mass spectrometry and iron binding was measured via the Chrome Azurol S (CAS) assay. Stability experiments in artificial seawater showed that aerobactin degrades slowly, with a half-life on the order of weeks. The activity of synthetic aerobactin was then demonstrated by growth recovery experiments with wild-type V. fischeri ES114 and mutant strains deficient in aerobactin biosynthesis (ΔiucABCD), its outer-membrane aerobactin receptor (ΔiutA), and in the inner-membrane importer (ΔfhuCDB). Available iron was controlled in cell culture experiments by the addition of 2,2'-bipyridine (BPY) or citrate to experimental growth media, with bathocuproine disulfonic acid (BCDS) included as a membrane-impermeable, and poor iron-sequestering control. Exogenous aerobactin restored growth in iron-limited environments in a concentration-dependent manner, particularly in the biosynthesis-deficient mutant. Additionally, we report that BPY inhibits V. fischeri ES114 growth with a broad MIC range (128-256 μM) that highlights its capacity to disrupt the intracellular iron pool. Together, these findings support the use of AB-FeCit as the optimal media system for testing siderophore-dependent growth in V. fischeri and link synthetic aerobactin and iron availability to bacterial growth in a model marine mutualism.

Iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) are essential micronutrients for plant growth and development, but their low bioavailability in soil limits crop growth and yield. The ZIP (ZRT/IRT-like protein) family plays critical roles in the uptake and distribution of these divalent metal ions. Here, we performed a genome-wide identification of the ZIP family in tomato (Solanum lycopersicum) and analyzed their expression profiles under various metal deficiencies. A total of 14 SlZIP genes were identified and classified into three clades based on phylogenetic analysis. Conserved motif and gene structure analyses revealed that SlZIP genes within the same clade share similar exon/intron organization and protein motifs. The 14 SlZIP genes are unevenly distributed across eight chromosomes of tomato, and their promoters contain multiple iron- and copper-deficiency-responsive cis-elements. To further explore the potential functions of these SlZIP genes, we quantified their expression levels in tomato roots under metal-deficient conditions and found that SlIRT1, SlIRT2, and SlZIP4 were significantly induced by Fe deficiency, while SlZIP2 and SlZIP11 were specifically induced by Cu deficiency, and SlZIP13 and SlZIP14 by Mn deficiency. These results provide a comprehensive resource for the tomato ZIP family and lay a foundation for future functional studies of SlZIP genes in metal uptake and transport in tomato.