Biometals最新文献

{"title":"Fine-tuning alkyl chain length in copper(II) complexes: effects on DNA binding and catalytic cleavage","authors":"Maiara I. N. dos Santos,&nbsp;Matheus S. S. Paqui,&nbsp;Giliandro Farias,&nbsp;Edinara Luiz,&nbsp;Ronny R. Ribeiro,&nbsp;Hernan Terenzi,&nbsp;Fernando R. Xavier","doi":"10.1007/s10534-026-00840-8","DOIUrl":"10.1007/s10534-026-00840-8","url":null,"abstract":"<div><p>Metal complexes are well known for their DNA cleavage activity. Copper is a metal that stands out for this purpose because it is able to perform cleavage through oxidative mechanisms using the Haber–Weiss cycle. We report two unprecedented copper(II) complexes (<b>2</b> and <b>3</b>) with long-chain ligands and compare the results with those of a previously reported complex (<b>1</b>), which we use as a reference in our studies. They were all properly characterized using a set of physicochemical methods, including elemental analysis, electron paramagnetic resonance, spectroscopic and electrochemical analysis. Density functional theory (DFT) modeling revealed a pseudo-octahedral environment where the ligands are <i>trans</i> to each other. The interaction of <b>1</b>, <b>2</b>, and <b>3</b> with salmon sperm DNA was monitored spectrophotometrically, and the binding constants (K_b) were 4.24 × 10⁴ L mol⁻¹, 1.92 × 10⁴ L mol⁻¹, and 1.15 × 10⁴ L mol⁻¹, respectively. The interactions were supported by docking studies conducted with the CCDC GOLD® docking suite. Finally, all complexes exhibited DNA binding and cleavage properties, but <b>2</b> stood out as the most active one (<b>2</b>, <i>k</i>_obs = 0.88 ± 0.09 h⁻¹ &gt; <b>1</b>, <i>k</i>_obs = 0.54 ± 0.06 h⁻¹ &gt; <b>3</b>, <i>k</i>_obs = 0.50 ± 0.03 h⁻¹). These results support the idea that fine-tuning the length of the alkyl chain can enhance DNA-targeting activity and contribute to the development of efficient strategies for catalytic cleavage of nucleic acids.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1903 - 1919"},"PeriodicalIF":4.0,"publicationDate":"2026-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10534-026-00840-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148269921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of essential and toxic trace element imbalances in hypothyroid patients with and without levothyroxine therapy: a case–control study","authors":"Asseel Ammar,&nbsp;Falah S. Al-Fartusie","doi":"10.1007/s10534-026-00838-2","DOIUrl":"10.1007/s10534-026-00838-2","url":null,"abstract":"<div><p>Hypothyroidism is a common endocrine disorder associated with widespread disturbances in essential and toxic trace elements. This study aimed to evaluate the serum levels of selected trace and toxic elements in Iraqi hypothyroid patients, both newly diagnosed and under levothyroxine therapy, to identify potential metabolic imbalances on trace element homeostasis. A total of 120 participants were enrolled and divided into three groups: healthy controls, untreated hypothyroid patients, and levothyroxine-treated hypothyroid patients. Serum concentrations of (Cu, Zn, Mg, Ni, Mn, Co, Cr, Al, Fe, Pb, and Cd) were measured using atomic absorption spectrophotometry. Results showed that the untreated patients had significantly lower levels of (Zn: 70.3 ± 9.1 vs 101.1 ± 14.6, Mg: 1.09 ± 0.23 vs 1.57 ± 0.21, Mn: 0.018 ± 0.003 vs 0.186 ± 0.028, Cr: 0.138 ± 0.041 vs 0.167 ± 0.024 and Fe: 73.50 ± 14.70 vs 104.13 ± 16.98, respectively, p &lt; 0.05) compared to controls, while levothyroxine therapy restored Cr and Fe only. In contrast, other elements including Cu, Ni, Al, Pb and Cd remained elevated in both treated and untreated patients (p &lt; 0.05). Correlation analyses revealed antagonistic and synergistic relationships among essential and toxic elements, suggesting complex interactions influencing thyroid function. These findings indicate that trace element dysregulation persists despite hormonal therapy and highlight the importance of monitoring both essential and toxic metals to optimize hypothyroidism management and prevent ongoing metabolic disturbances.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1871 - 1889"},"PeriodicalIF":4.0,"publicationDate":"2026-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148256834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Serum zinc, copper status and Cu/Zn ratio in overweight and obesity: associations with oxidative stress, adipokines, and cardiometabolic traits in adult women","authors":"Luis César Vázquez-Vázquez,&nbsp;Ana Nava-Cabrera,&nbsp;Jacqueline Soto-Sánchez,&nbsp;Armando Ramírez-Cruz,&nbsp;Miguel Cruz,&nbsp;Patricia Elizabeth Cossío-Torres,&nbsp;Esther Layseca-Espinosa,&nbsp;Miguel Vazquez-Moreno,&nbsp;Héctor Hernández-Mendoza,&nbsp;María Judith Rios-Lugo","doi":"10.1007/s10534-026-00839-1","DOIUrl":"10.1007/s10534-026-00839-1","url":null,"abstract":"<div><p>Obesity is more prevalent in women worldwide and has been associated with low-grade inflammation, oxidative stress, and alterations in the homeostasis of trace elements, such as zinc (Zn) and copper (Cu). The aim of this study was to evaluate the association between nutritional status and cardiometabolic traits, inflammatory biomarkers, oxidative stress markers, and serum concentrations of Zn and Cu in adult women. In this observational cross-sectional study, anthropometric data and cardiometabolic traits from 123 adult women in Mexico City were analyzed. Inflammatory biomarkers (leptin and resistin) were quantified by enzyme-linked immunosorbent assay (ELISA). Oxidative stress markers were evaluated by serum total antioxidant capacity (sTAC) using the DPPH radical scavenging method (2,2-diphenyl-1-picrylhydrazyl) and lipid peroxidation via thiobarbituric acid reactive substances (TBARS). Serum Zn and Cu concentrations were quantified by inductively coupled plasma mass spectrometry (ICP-MS). Overweight and obesity were associated with increased lipid peroxidation (<i>p</i> = 0.013) and the Cu/Zn ratio (<i>p</i> = 0.021) and negatively associated with sTAC (<i>p</i> = 0.030) and Zn concentrations (<i>p</i> = 0.003). A positive association was observed between serum Cu concentrations and total cholesterol (TC; <i>p</i> = <i>0.045</i>). Leptin and resistin concentrations were higher in the overweight and obesity groups. In conclusion, our findings suggest that higher body weight in Mexican adult women is associated with a deregulated redox status and trace elements homeostasis, particularly reduced Zn levels and an increased Cu/Zn ratio. Additionally, the observed association between serum Cu concentrations and TC may highlight a potential mechanism linking adiposity, oxidative stress, and lipid metabolism.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1891 - 1902"},"PeriodicalIF":4.0,"publicationDate":"2026-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148248330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrating pharmacologically important flora into phytoremediation: The role of bacillus strains in mitigating chromium toxicity and enhancing rhizostabilization","authors":"Manoj Srinivas Ravi,&nbsp;Indra Arulselvi Padikasan","doi":"10.1007/s10534-026-00836-4","DOIUrl":"10.1007/s10534-026-00836-4","url":null,"abstract":"<div><p>Plant Growth Promoting Rhizobacteria (PGPR) offer a cost-effective, eco-friendly solution for Cr(VI) bioremediation. This study evaluates the medicinal plants <i>Justicia adhatoda</i> and <i>Solanum trilobatum</i> as novel candidates for Cr(VI) bioremediation. We investigated the ameliorative effects of two PGPR, <i>Bacillus altitudinis</i> M1 (BaM1) and <i>Bacillus flexus</i> M2 (BfM2), isolated from tannery effluent contaminated soil. Both strains significantly improved plants’ biomass in soil containing 300 mg/kg Cr(VI). Inoculation of the PGPR markedly mitigated physiological stress, significantly lowering concentrations of proline, hydrogen peroxide (H₂O₂), and malondialdehyde (MDA) compared to Cr(VI)-only treatments by enhancing the plants phytostabilization potential.While Cr(VI) stress initially triggered a robust antioxidant response, PGPR application attenuated the oxidative pressure, where superoxide dismutase (SOD) and catalase (CAT) activities decreased by up to 66.74% in <i>S. trilobatum</i> and 56.97% in <i>J. adhatoda</i>, respectively. PGPR application significantly reduced Cr(VI) translocation to aerial tissues of both medicinal species, shifting the plants’ strategy toward superior rhizostabilization. This minimizes metal mobility and supports the long-term bioremediation capacity of the medicinal plant–microbe consortium. Our findings establish this approach as a highly efficient, sustainable, and novel strategy for the restoration of Cr(VI) contaminated industrial environments.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1847 - 1870"},"PeriodicalIF":4.0,"publicationDate":"2026-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148249016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of ion release, cytotoxicity, and potential systemic toxicity of titanium dental alloy","authors":"Gihan Hosny,&nbsp;Abdulaziz M. Eljamal,&nbsp;Sabah G. El-Banna,&nbsp;Sara A. Alsakhawy","doi":"10.1007/s10534-026-00830-w","DOIUrl":"10.1007/s10534-026-00830-w","url":null,"abstract":"<div><p>Titanium (Ti-6Al-4 V) alloys are widely utilized in dental and orthopedic implants for their strength, corrosion resistance, and biocompatibility. However, the oral environment’s corrosive conditions can promote ion release, raising concerns regarding potential long-term public health risks. In this investigation, samples of titanium alloy were submerged in artificial saliva for six months to simulate long-term oral exposure. The concentrations of corrosion derived metal ions were subsequently determined using Inductively Coupled Plasma Mass Spectrometry. Cytotoxicity, inflammatory, and apoptotic responses were assessed in fibroblast cell lines. Additionally, an in vivo study in male mice assessed systemic oxidative stress, antioxidant defense mechanisms, and liver and kidney function. Titanium alloy released ions treated cells showed a marked decline in fibroblast viability and a significant elevation (p &lt; 0.05) in pro-apoptotic and inflammatory markers, including Bax, TNF-α, and IL-6, compared with untreated cells. In vivo findings demonstrated significant increases in TBARS and DNA fragmentation, accompanied by a depletion of antioxidant enzymes, particularly in renal tissues. Biochemical evaluation of serum samples demonstrated significant changes in lipid profiles and marked impairments in liver and kidney function. Histopathological assessments confirmed these findings, showing inflammatory infiltration and degenerative changes in hepatic and renal tissues. Overall, ions released from the titanium alloy induced pronounced cytotoxicity accompanied by increased oxidative imbalance and inflammatory reactions, emphasizing the need for developing safer biomaterials and implementing long-term patient monitoring to mitigate chronic complications.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1783 - 1799"},"PeriodicalIF":4.0,"publicationDate":"2026-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148154838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vanadium(IV)-chlorodipicolinate alleviates hepatic steatosis via the AMPK/PGC-1α/CPT1a axis","authors":"Rulong Chen,&nbsp;Yufan Liu,&nbsp;Yuanli Wang,&nbsp;Fang Zhang,&nbsp;Jinkui Ma,&nbsp;Wei Cui,&nbsp;Wenjun Ding","doi":"10.1007/s10534-026-00811-z","DOIUrl":"10.1007/s10534-026-00811-z","url":null,"abstract":"<div><p>Non-alcoholic fatty liver disease (NAFLD) is closely associated with type 2 diabetes mellitus, which is characterized by hepatic steatosis. Vanadium compounds have the potential to prevent hyperlipidemia. However, whether vanadium compound supplementation could rescue hepatic steatosis in NAFLD remains uncertain. We sought to investigate the molecular mechanisms by which vanadium(IV)-chlorodipicolinate (VOdipic-Cl) ameliorated hepatic steatosis in obesity. The therapeutic effect of VOdipic-Cl was evaluated using high-fat diet (HFD)-induced C57BL/6 mice and palmitic acid/oleic acid (PO)-treated L02 hepatocytes, respectively. Lipidomic analysis, RNA-sequencing (RNA-seq), Western blotting, and molecular dynamics simulation were employed to elucidate the molecular mechanism of VOdipic-Cl in regulating lipid metabolism in liver and hepatocytes. VOdipic-Cl treatment effectively reduced hepatic lipid accumulation and improved hepatic function in HFD-fed mice. Lipidomic analysis showed that the primary differential lipid metabolites were mainly associated with glycerophospholipid metabolism pathway. Transcriptomic analysis revealed that adenosine monophosphate-activated protein kinase (AMPK) signaling pathway was involved in the regulation of hepatic lipid metabolism by VOdipic-Cl treatment. Moreover, VOdipic-Cl-induced AMPK activation significantly restored hepatic mitochondrial homeostasis and reduced lipid accumulation through upregulating transcription factor peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and carnitine palmitoyltransferase 1 (CPT1) in hepatocytes, respectively. Our findings suggest that VOdipic-Cl triggers the activation of AMPK, leading to the upregulation of PGC-1α and CPT1 expression, ultimately improving mitochondrial homeostasis and decreasing lipid accumulation. Collectively, these molecular cascades contribute to the ameliorating effect of VOdipic-Cl on HFD-induced hepatic steatosis. This study also provides evidence supporting the potential utilization of VOdipic-Cl for the treatment of NAFLD.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1545 - 1560"},"PeriodicalIF":4.0,"publicationDate":"2026-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148142337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iron dysregulation in the central nervous system: implications for autism spectrum disorder","authors":"Geir Bjørklund,&nbsp;Hasmik Harutyunyan,&nbsp;Zaven Mkrtchyan,&nbsp;Ella Baghdasaryan,&nbsp;Tamara Avetisyan,&nbsp;Nagwa A. Meguid,&nbsp;Fatma Hussein,&nbsp;Konstantin Yenkoyan","doi":"10.1007/s10534-026-00833-7","DOIUrl":"10.1007/s10534-026-00833-7","url":null,"abstract":"<div><p>Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition characterized by deficits in social interaction, impaired communication, and restricted, repetitive behaviors. Its pathophysiology involves a complex interplay of genetic, epigenetic, metabolic, and environmental factors. Among these, iron metabolism has emerged as a critical component due to its essential role in brain maturation. Iron supports oxygen transport, mitochondrial ATP production, neurotransmitter synthesis, DNA replication, myelination, and enzyme regulation processes vital for neurodevelopment. Dysregulation of iron homeostasis, both iron deficiency and iron overload, has been frequently observed in individuals with ASD and may contribute to core neurobehavioral symptoms through mechanisms involving neuroinflammation, oxidative stress, mitochondrial dysfunction, and altered synaptic plasticity. Genetic variants affecting iron-regulatory proteins such as transferrin receptor, ferritin, ferroportin, and ceruloplasmin highlight the link between iron imbalance and ASD. Iron deficiency during critical windows of brain development may impair cognitive and behavioral maturation, whereas excessive iron accumulation may trigger glial activation, lipid peroxidation, and ferroptotic death of neurons. Therapeutic strategies differ across developmental stages: normalizing maternal iron status in pregnancy, correcting early-life deficiencies through supplementation of iron-fortified foods, and applying chelation therapies to prevent iron overload. This review integrates molecular, developmental, and clinical evidence to highlight the role of iron dysregulation in ASD with a focus on iron imbalance at different stages of neurodevelopment. Understanding the key mechanisms of iron dysregulation may grant new opportunities to restore iron homeostasis at specific time windows, supporting healthy neurodevelopment.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1339 - 1359"},"PeriodicalIF":4.0,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10534-026-00833-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148136394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the chemical and biological interplay in phenanthroline-containing copper complexes","authors":"Victoria Collazo,&nbsp;Marcos V. Palmeira-Mello,&nbsp;Bruno Rosa,&nbsp;Jerica M. Montilla-Suárez,&nbsp;Carlos Y. Fernández,&nbsp;Natalia Alvarez,&nbsp;Antonio J. Costa-Filho,&nbsp;Alzir A. Batista,&nbsp;Julia Torres,&nbsp;Gianella Facchin","doi":"10.1007/s10534-026-00831-9","DOIUrl":"10.1007/s10534-026-00831-9","url":null,"abstract":"<div><p>Copper complexes of 1,10-phenanthroline (phen) and related α-diimines present high potential as antitumor agents. Despite this, their selectivity toward cancer cells still needs improvement, and establishing clear structure–activity relationships for rational design remains elusive. To identify chemical factors that may underlie their biological behavior but remain poorly understood, we investigated the speciation equilibria of Cu-α-diimine-dipeptide systems by potentiometry and assessed how different factors influence their cytotoxic activity in human ovarian cancer cells (A2780 and A2780-cisR). The results indicate that both homoleptic Cu-α-diimine and heteroleptic Cu-α-diimine-dipeptide species are relevant even at the micromolar concentrations used in biological assays. Copper enhances the cytotoxicity of α-diimines in the order neo (2,9-dimethyl-1,10-phenanthroline) &gt; phen &gt; tmp (3,4,7,8-tetramethyl-1,10-phenanthroline), through the formation of complexes expected to predominate in the culture medium and by promoting cellular uptake. The copper-bound α-diimine in Cu-α-diimine-dipeptide systems proved to be a key factor in cytotoxicity, whereas the coordinated dipeptide modulates it only at short incubation times. Dipeptides can be considered models of biological ligands that interact with Cu-α-diimine species. Indeed, both dipeptides and albumin have minimal effects on the cytotoxicity of Cu-α-diimine systems. The mixed-ligand Cu-α-diimine-dipeptide complexes with neo are the most stable and predominate under simulated biological conditions. Thus, compared with phen and tmp, neo is expected to remain coordinated to copper in biological media, further enhancing its cytotoxicity.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1801 - 1818"},"PeriodicalIF":4.0,"publicationDate":"2026-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148100854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ascorbic and citric acids mitigate cadmium stress and reduce metal accumulation in spinach grown in alkaline calcareous soil","authors":"Saira Hameed,&nbsp;Muhammad Nadeem,&nbsp;Muhammad Ashar Ayub,&nbsp;Muhammad Shabaan,&nbsp;Usman Zulfiqar,&nbsp;Hossam S. El-Beltagi,&nbsp;Dilrabo Kodirova,&nbsp;Dilafruz Solieva,&nbsp;Abdumurod Sattarov,&nbsp;Mashael Daghash Alqahtani,&nbsp;Abdulrahman Alasmari","doi":"10.1007/s10534-026-00832-8","DOIUrl":"10.1007/s10534-026-00832-8","url":null,"abstract":"<div><p>Cadmium (Cd) is a toxic heavy metal released through various industrial processes, mining, batteries disposal and agro-chemicals application posing serious risks to agricultural production and food safety. Limited research has investigated the potential of organic chelators, such as ascorbic acid (AsA) and citric acid (CA), to mitigate Cd toxicity and reduce its bioaccumulation in plants. Current pot study was conducted to evaluate the effects of Cd stress on two spinach varieties, i.e., Green Gold (Hybrid) and AARI Desi (Conventional), grown in sandy clay loam soil, and assessed the efficacy of foliar-applied AsA, CA, and their combination in alleviating Cd-induced stress. Stress was applied by irrigating the crop with Cd-contaminated water (1 mg L⁻¹) whereas organic acids, AsA and CA, were applied at 10 mM concentration as individual treatments and 5 mM + 5 mM as combined treatment. Cd stress significantly reduced root and shoot growth, physiological attributes, and biochemical parameters, while enhancing antioxidant enzyme activity and Cd accumulation in both varieties. Foliar applications of AsA, CA, and particularly combined application significantly improved plant growth and biomass, chlorophyll concentration, and biochemical traits, while markedly reducing Cd uptake in roots and leaves. The combined application of AsA and CA reduced the Cd concentration in shoots by 36% and in roots by 40% and increased shoot dry weight up to 43% and root dry weight up to 50% compared to cadmium stressed plants. Overall, the study demonstrates that AsA, either individually or in combination with CA, enhances the antioxidant defense and promotes metal chelation, thereby reducing oxidative damage and Cd bioaccumulation. This ultimately leads to improved growth and physiological performance of spinach under Cd stress.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1819 - 1833"},"PeriodicalIF":4.0,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148051752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The genes zntA and zntR encoding a P-type ATPase and its activator confer zinc and cadmium resistance in Chromobacterium violaceum","authors":"Carolina Panosso Schuindt,&nbsp;Bianca Bontempi Batista,&nbsp;Lucas Cesetti,&nbsp;Sergio Pereira Lima Neto,&nbsp;Thierry Soldati,&nbsp;José Freire da Silva Neto","doi":"10.1007/s10534-026-00828-4","DOIUrl":"10.1007/s10534-026-00828-4","url":null,"abstract":"<div><p>The transition metal zinc is an essential trace element for life but becomes toxic at high concentrations. In the opportunistic pathogen <i>Chromobacterium violaceum</i>, zinc acquisition is crucial for virulence, yet how this bacterium copes with zinc toxicity remains unknown. In this work, we demonstrate that <i>C. violaceum</i> senses and responds to excess zinc by activating the <i>zntA</i> gene, which encodes a P_1B-2-type ATPase, via the transcriptional regulator ZntR. Phenotypic analyses by growth curves, disk diffusion, and CFU assays revealed that both Δ<i>zntA</i> or Δ<i>zntR</i> mutant strains exhibited increased sensitivity to zinc and cadmium. The Δ<i>zntA</i> mutant showed increased zinc and cadmium accumulation, suggesting that ZntA functions as an efflux pump. The expression of <i>zntA</i> increased in the presence of zinc and cadmium in the wild-type strain, but not in the Δ<i>zntR</i> mutant strain, indicating that ZntR activates <i>zntA</i> under conditions of zinc or cadmium excess. The role of ZntA in vivo was analyzed using the social amoeba <i>Dictyostelium discoideum</i> as a host cell. Plaque assays indicated that the <i>C. violaceum</i> Δ<i>zntA</i> mutant strain was more susceptible than the <i>C. violaceum</i> wild-type strain to clearance by <i>D. discoideum</i> knockout strains with altered intracellular zinc allocation. Overall, our data reveal that the genes <i>zntA</i> and <i>zntR</i> encoding a P_1B-2-type ATPase and its transcriptional activator are key determinants of zinc and cadmium resistance in <i>C. violaceum</i>, ensuring bacterial survival under zinc-stress conditions encountered in the environment and the host.</p></div>","PeriodicalId":491,"journal":{"name":"Biometals","volume":"39 5","pages":"1747 - 1765"},"PeriodicalIF":4.0,"publicationDate":"2026-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10534-026-00828-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148003898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}