Stresses induced by the deficiency or excess of trace mineral elements, such as manganese (Mn), represent a common limiting factor for the production of crops like Brassica napus. To identify key genes involved in Mn allocation in B. napus and elucidate the underlying mechanisms, a member of the metal tolerance protein (MTP) family obtained in the previous screening of cDNA library of B. napus under Mn stress was selected as the research subject. Based on the sequence information and phylogenetic analysis, it was named as BnMTP10. It belongs to the Mn-cation diffusion facilitator (CDF) subfamily. Expression of BnMTP10 in yeast significantly improved the tolerance of transformants to excessive Mn and iron (Fe) and reduced the accumulation of Mn and Fe. However, the yeast transformants exhibited no significant changes in tolerance to excess cadmium, boron, aluminum, zinc, or copper. The qRT-PCR results demonstrated that the flowers of B. napus had the highest expression of BnMTP10, followed by roots and leaves. Subcellular localization studies revealed that BnMTP10 was localized in the endoplasmic reticulum (ER). Compared with wild-type plants, transgenic Arabidopsis overexpressing BnMTP10 exhibited enhanced tolerance to excessive Mn stress but showed no significant difference under Fe stress. Correspondingly, under excessive Mn stress, the Mn content in the roots of transgenic Arabidopsis increased significantly. However, under excessive Fe stress, the Fe content in transgenic Arabidopsis did not alter significantly. According to the results, we hypothesize that BnMTP10 may alleviate excessive Mn stress in plants by mediating Mn transport to the ER. This study facilitated our understanding of efficient mineral nutrients, and provided theoretical foundations and gene resources for breeding B. napus.
Brassica napus/genetics* ; Manganese/metabolism* ; Plants, Genetically Modified/genetics* ; Plant Proteins/physiology* ; Arabidopsis/metabolism* ; Gene Expression Regulation, Plant ; Phylogeny ; Cation Transport Proteins/metabolism* ; Stress, Physiological

It has been confirmed that exposure to various metal pollutants can induce neurotoxicity, which is closely associated with the occurrence and development of neurological disorders. Ferroptosis is a form of cell death in response to metal pollutant exposure and it is closely related to oxidative stress, iron metabolism and lipid peroxidation. Recent studies have revealed that ferroptosis plays a significant role in the neurotoxicity induced by metals such as lead, cadmium, manganese, nickel, and antimony. Lead exposure triggers ferroptosis through oxidative stress, iron metabolism disorder and inflammation. Cadmium can induce ferroptosis through iron metabolism, oxidative stress and ferroptosis related signaling pathways. Manganese can promote ferroptosis through mitochondrial dysfunction, iron metabolism disorder and oxidative stress. Nickel can promote ferroptosis by influencing mitochondrial function, disrupting iron homeostasis and facilitating lipid peroxidation in the central nervous system. Antimony exposure can induce glutathione depletion by activating iron autophagy, resulting in excessive intracellular iron deposition and ultimately causing ferroptosis. This article reviews the effects of metal pollutants on ferroptosis-related indicators and discusses the specific mechanisms by which each metal triggers ferroptosis. It provides a reference for identifying targets for preventing neurotoxicity and for developing treatment strategies for neurological disorders.
Ferroptosis/drug effects* ; Humans ; Iron/metabolism* ; Oxidative Stress/drug effects* ; Neurotoxicity Syndromes/metabolism* ; Cadmium/adverse effects* ; Animals ; Lipid Peroxidation/drug effects* ; Metals/metabolism* ; Lead/adverse effects* ; Environmental Pollutants/toxicity* ; Manganese/adverse effects* ; Nickel/adverse effects* ; Mitochondria/drug effects* ; Signal Transduction/drug effects*

OBJECTIVE: To investigate the protective effects of curcumin(CUR) and its mechanism on a rat model of neurotoxicity induced by manganese chloride (MnCl₂), which mimics mangnism. METHODS: Sixty male SD rats were randomly divided into 5 groups, with 12 rats in each group. Control group received 0.9% saline solution intraperitoneally (ip) plus double distilled water (dd) H₂O intragastrically (ig), MnCl₂ group received 15 mg/kg MnCl₂(Mn²⁺ 6.48 mg/kg) intraperitoneally plus dd H₂O intragastrically, CUR group received 0.9% saline solution intraperitoneally plus 300 mg/kg CUR intragastrically, MnCl₂+ CUR1 group received 15 mg/kg MnCl₂ intraperitoneally plus 100 mg/kg curcumin intragastrically, MnCl₂+ CUR2 group received 15 mg/kg MnCl₂ intraperitoneally plus 300 mg/kg CUR intragastrically, 5 days/week, 4 weeks. Open-field and rotarod tests were used to detect animals' exploratory behavior, anxiety, depression, movement and balance ability. Morris water maze (MWM) experiment was used to detect animals' learning and memory ability. ICP-MS was used to investigate the Mn contents in striata. The rats per group were perfused in situ, their brains striata were removed by brains model and fixed for transmission electron microscope (TEM), histopathological and immunohistochemistry (ICH) analyses. The other 6 rats per group were sacrificed. Their brains striata were removed and protein expression levels of transcription factor EB (TFEB), mammalian target of rapamycin (mTOR), p-mTOR, Beclin, P62, microtubule-associated protein light chain-3 (LC3) were detected by Western blotting. Terminal deoxynucleotidyl transterase-mediated dUTP nick end labeling (TUNEL) staining was used to determine neurocyte apoptosis of rat striatum. RESULTS: After exposure to MnCl₂ for four weeks, MnCl₂-treated rats showed depressive-like behavior in open-field test, the impairments of movement coordination and balance in rotarod test and the diminishment of spatial learning and memory in MWM (P < 0.05). The striatal TH⁺ neurocyte significantly decreased, eosinophilic cells, aggregative α-Syn level and TUNEL-positive neurocyte significantly increased in the striatum of MnCl₂ group compared with control group (P < 0.05). Chromatin condensation, mitochondria tumefaction and autophagosomes were observed in rat striatal neurocytes of MnCl₂ group by TEM. TFEB nuclear translocation and autophagy occurred in the striatum of MnCl₂ group. Further, the depressive behavior, movement and balance ability, spatial learning and memory ability of MnCl₂+ CUR2 group were significantly improved compared with MnCl₂ group (P < 0.05). TH+ neurocyte significantly increased, the eosinophilic cells, aggregative α-Syn level significantly decreased in the striatum of MnCl₂+ CUR2 group compared with MnCl₂ group. Further, compared with MnCl₂ group, chromatin condensation, mitochondria tumefaction was alleviated and autophagosomes increased, TFEB-nuclear translocation, autophagy was enhanced and TUNEL-positive neurocyte reduced significantly in the striatum of MnCl₂+ CUR2 group (P < 0.05). CONCLUSION Curcumin alleviated the MnCl₂-induced neurotoxicity and α-Syn aggregation probably by promoting TFEB nuclear translocation and enhancing autophagy.
Animals ; Autophagy ; Chromatin ; Curcumin/pharmacology* ; Male ; Mammals ; Manganese/toxicity* ; Rats ; Rats, Sprague-Dawley ; Saline Solution/pharmacology* ; TOR Serine-Threonine Kinases

China ; Manganese/toxicity* ; Stainless Steel

Manganese is an element essential for living organisms. Development of industrial technologies and exploitation of mineral resources have led to the release of large amount of Mn(Ⅱ) into the environment, posing a serious threat to human health. Bioremediation can remove the Mn(Ⅱ) from the environment rapidly and effectively without generating secondary pollution, thus received increasing attention. This review summarized the diversity and distribution of Mn(Ⅱ) removal microorganisms and the associated mechanisms, followed by discussing the effect of environmental factors on microbial Mn(Ⅱ) removal. Finally, the challenges and prospects for bioremediation of Mn(Ⅱ) polluted wastewater were proposed.
Biodegradation, Environmental ; Humans ; Manganese ; Oxidation-Reduction ; Waste Water

Objective: To explore the changes of γ-GCS mRNA expression and GSH-PX in serum of workers exposed to manganese in order to provide scientific basis for early diagnosis of manganese poisoning. Methods: In June 2017, a total of 180 workers from a motorcycle manufacturer were selected by stratified random sampling, including 115 welders as the exposure group and 65 administrative office workers as the Control Group, the exposure group was divided into high exposure group (43 persons) and low exposure group (72 persons) according to whether the exposure group exceeded the standard limit. The levels of γ-gcs Mrna expression and GSH-Px activity in serum were determined by Occupational Health Survey, and the differences of γ-gcs Mrna expression and GSH-Px activity among different groups were analyzed. Results: Compared with the control group, the serum GSH-Px activity was lower and the serum γ-GCS mRNA expression level was higher in the exposed group (F=370.52, 275.95, P<0.01) . Compared with the control group, there was significant difference in γ-GCS mRNA expression level and GSH-Px activity (F=0.475、1.06, P<0.01; F=48.53、111.70, P<0.01) . The concentrations of manganese in air, welding dust and urine were positively correlated with the level of γ-GCS mRNA (r=0.71, 0.50, 0.31, P<0.01) The serum GSH-Px activity was negatively correlated with the concentrations of manganese in air, welding dust and urine (r=-0.80, -0.52, -0.30, P< 0.01) , There was no correlation between Serum γ-GSH-Px activity and age and years of exposure (P>0.05) . Conclusion: Serum γ-GCS mRNA expression level and GSH-Px activity level can be used as early biomarkers of manganese poisoning. The concentrations of manganese in workplace air, welding dust and urine manganese in workers are the influencing factors.
Air Pollutants, Occupational ; Dust ; Humans ; Ions ; Manganese ; Manganese Poisoning ; Occupational Exposure/analysis* ; RNA, Messenger/genetics* ; Welding

Objective: To quantitatively evaluate the content differences of trace elements in workers with occupational exposure to lead. Methods: In January 2021, relevant literatures on the contents of trace elements in workers with occupational exposure to lead published from 1990 to 2020 were searched through CNKI, Wanfang, VIP, PubMed, web of science and Embase. Screened and extracted the literatures, and evaluated the quality of the included literatures with Newcastle Ottawa Scale. Meta analysis was performed with Review Manager 5.3 software, and standardized mean difference (SMD) and its 95% confidence interval were used as effect indicators. Results: A total of 20 literatures were included, and the quality scores were 5-7. The results of Meta-analysis showed that compared with the control group, the contents of blood zinc (SMD=-1.01, 95%CI: -1.53, -0.49) , hair zinc (SMD=-0.17, 95%CI: -0.33, -0.01) , hair copper (SMD=-0.50, 95%CI: -1.01, 0) , hair iron (SMD=-3.91, 95%CI: -5.80, -2.03) and hair manganese (SMD=-1.09, 95%CI: -2.02, -0.15) in occupational lead exposure group were significantly lower (P<0.05) . Compared with the control group, the content of cobalt in hair of occupational lead exposure group (SMD=1.41, 95%CI: 0.72, 2.10) was higher, and the difference was statistically significant (P<0.05) . There was no significant difference in the contents of blood chromium, blood copper, blood iron, blood manganese, blood selenium and hair nickel between the two groups (P>0.05) . Conclusion: Workers with occupational exposure to lead have abnormal trace elements.
Copper ; Humans ; Iron ; Lead ; Manganese ; Occupational Exposure ; Trace Elements ; Zinc

PURPOSE: The aim of this study is to evaluate the effectiveness of MnO₂-diatom microbubbler (DM) on the surface of prosthetic materials as a mouthwash by comparing the biofilm removal effect with those previously used as a mouthwash in dental clinic.MATERIALS AND METHODS: DM was fabricated by doping manganese dioxide nanosheets to the diatom cylinder surface. Scanning electron microscopy (SEM) was used to observe the morphology of DM and to analyze the composition of doped MnO₂. Stereomicroscope was used to observe the reaction of DM in 3% hydrogen peroxide. Non-precious metal alloys, zirconia and resin specimens were prepared to evaluate the effect of biofilm removal on the surface of prosthetic materials. And then Streptococcus mutans and Porphyromonas gingivalis biofilms were formed on the specimens. When 3% hydrogen peroxide solution and DM were treated on the biofilms, the decontamination effect was compared with chlorhexidine gluconate and 3% hydrogen peroxide solution by crystal violet staining.RESULTS: Manganese dioxide was found on the surface of the diatom cylinder, and it was found to produce bubble of oxygen gas when added to 3% hydrogen peroxide. For all materials used in the experiments, biofilms of the DM-treated groups got effectively removed compared to the groups used with chlorhexidine gluconate or 3% hydrogen peroxide alone.CONCLUSION: MnO₂-diatom microbubbler can remove bacterial membranes on the surface of prosthetic materials more effectively than conventional mouthwashes.
Alloys ; Biofilms ; Chlorhexidine ; Decontamination ; Dental Clinics ; Dental Plaque ; Diatoms ; Gentian Violet ; Hydrogen Peroxide ; In Vitro Techniques ; Manganese ; Membranes ; Microscopy, Electron, Scanning ; Mouthwashes ; Oral Hygiene ; Oxygen ; Porphyromonas gingivalis ; Streptococcus mutans

An extracellular lipase from Aureobasidium pullulans was obtained and purified with a specific activity of 17.7 U/mg of protein using ultrafiltration and a DEAE-Sepharose Fast Flow column. Characterization of the lipase indicated that it is a novel finding from the species A. pullulans. The molecular weight of the lipase was 39.5 kDa, determined by sodium dodecyl sulfonate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme exhibited its optimum activity at 40 °C and pH of 7. It also showed a remarkable stability in some organic solutions (30%, v/v) including n-propanol, isopropanol, dimethyl sulfoxide (DMSO), and hexane. The catalytic activity of the lipase was enhanced by Ca²⁺ and was slightly inhibited by Mn²⁺ and Zn²⁺ at a concentration of 10 mmol/L. The lipase was activated by the anionic surfactant SDS and the non-ionic surfactants Tween 20, Tween 80, and Triton X-100, but it was drastically inhibited by the cationic surfactant cetyl trimethyl ammonium bromide (CTAB). Furthermore, the lipase was able to hydrolyze a wide variety of edible oils, such as peanut oil, corn oil, sunflower seed oil, sesame oil, and olive oil. Our study indicated that the lipase we obtained is a potential biocatalyst for industrial use.
Ascomycota/enzymology* ; Calcium ; Catalysis ; Corn Oil/metabolism* ; Detergents/chemistry* ; Enzyme Stability ; Fungal Proteins/chemistry* ; Glucans/chemistry* ; Hexanes/chemistry* ; Hydrogen-Ion Concentration ; Hydrolysis ; Industrial Microbiology ; Lipase/chemistry* ; Manganese/chemistry* ; Olive Oil/metabolism* ; Peanut Oil/metabolism* ; Sesame Oil/metabolism* ; Substrate Specificity ; Sunflower Oil/metabolism* ; Surface-Active Agents ; Temperature ; Zinc/chemistry*

Two manganese peroxidases (MnPs), MnP1 and MnP2, and a laccase, Lac1, were purified from Trametes polyzona KU-RNW027. Both MnPs showed high stability in organic solvents which triggered their activities. Metal ions activated both MnPs at certain concentrations. The two MnPs and Lac1, played important roles in dye degradation and pharmaceutical products deactivation in a redox mediator-free system. They completely degraded Remazol brilliant blue (25 mg/L) in 10–30 min and showed high degradation activities to Remazol navy blue and Remazol brilliant yellow, while Lac1 could remove 75% of Remazol red. These three purified enzymes effectively deactivated tetracycline, doxycycline, amoxicillin, and ciprofloxacin. Optimal reaction conditions were 50 °C and pH 4.5. The two MnPs were activated by organic solvents and metal ions, indicating the efficacy of using T. polyzona KU-RNW027 for bioremediation of aromatic compounds in environments polluted with organic solvents and metal ions with no need for redox mediator supplements.
Amoxicillin ; Biodegradation, Environmental ; Ciprofloxacin ; Doxycycline ; Hydrogen-Ion Concentration ; Ions ; Laccase ; Manganese ; Oxidation-Reduction ; Peroxidases ; Pharmaceutical Preparations ; Solvents ; Tetracycline ; Trametes