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Molecules (Basel, Switzerland) May 2024is a common pathogenic microorganism in humans and animals. Type II NADH oxidoreductase (NDH-2) is the only NADH:quinone oxidoreductase present in this organism and...
BACKGROUND
is a common pathogenic microorganism in humans and animals. Type II NADH oxidoreductase (NDH-2) is the only NADH:quinone oxidoreductase present in this organism and represents a promising target for the development of anti-staphylococcal drugs. Recently, myricetin, a natural flavonoid from vegetables and fruits, was found to be a potential inhibitor of NDH-2 of . The objective of this study was to evaluate the inhibitory properties of myricetin against NDH-2 and its impact on the growth and expression of virulence factors in .
RESULTS
A screening method was established to identify effective inhibitors of NDH-2, based on heterologously expressed NDH-2. Myricetin was found to be an effective inhibitor of NDH-2 with a half maximal inhibitory concentration (IC) of 2 μM. In silico predictions and enzyme inhibition kinetics further characterized myricetin as a competitive inhibitor of NDH-2 with respect to the substrate menadione (MK). The minimum inhibitory concentrations (MICs) of myricetin against strains ranged from 64 to 128 μg/mL. Time-kill assays showed that myricetin was a bactericidal agent against . In line with being a competitive inhibitor of the NDH-2 substrate MK, the anti-staphylococcal activity of myricetin was antagonized by MK-4. In addition, myricetin was found to inhibit the gene expression of enterotoxin SeA and reduce the hemolytic activity induced by culture on rabbit erythrocytes in a dose-dependent manner.
CONCLUSIONS
Myricetin was newly discovered to be a competitive inhibitor of NDH-2 in relation to the substrate MK. This discovery offers a fresh perspective on the anti-staphylococcal activity of myricetin.
Topics: Flavonoids; Staphylococcus aureus; Microbial Sensitivity Tests; Anti-Bacterial Agents; NADH Dehydrogenase; Enzyme Inhibitors; Animals; Bacterial Proteins; Humans; Virulence Factors
PubMed: 38792214
DOI: 10.3390/molecules29102354 -
Molecules (Basel, Switzerland) May 2024The electron-electron, or zero-field interaction (ZFI) in the electron paramagnetic resonance (EPR) of high-spin transition ions in metalloproteins and coordination...
The electron-electron, or zero-field interaction (ZFI) in the electron paramagnetic resonance (EPR) of high-spin transition ions in metalloproteins and coordination complexes, is commonly described by a simple spin Hamiltonian that is second-order in the spin : H=D[Sz2-SS+1/3+E(Sx2-Sy2). Symmetry considerations, however, allow for fourth-order terms when ≥ 2. In metalloprotein EPR studies, these terms have rarely been explored. Metal ions can cluster via non-metal bridges, as, for example, in iron-sulfur clusters, in which exchange interaction can result in higher system spin, and this would allow for sixth- and higher-order ZFI terms. For metalloproteins, these have thus far been completely ignored. Single-molecule magnets (SMMs) are multi-metal ion high spin complexes, in which the ZFI usually has a negative sign, thus affording a ground state level pair with maximal spin quantum number = ±, giving rise to unusual magnetic properties at low temperatures. The description of EPR from SMMs is commonly cast in terms of the 'giant-spin model', which assumes a magnetically isolated system spin, and in which fourth-order, and recently, even sixth-order ZFI terms have been found to be required. A special version of the giant-spin model, adopted for scaling-up to system spins of order ≈ 10-10, has been applied to the ubiquitous iron-storage protein ferritin, which has an internal core containing Fe ions whose individual high spins couple in a way to create a superparamagnet at ambient temperature with very high system spin reminiscent to that of ferromagnetic nanoparticles. This scaled giant-spin model is critically evaluated; limitations and future possibilities are explicitly formulated.
PubMed: 38792115
DOI: 10.3390/molecules29102254 -
International Journal of Molecular... May 2024Chronic environmental exposure to toxic heavy metals, which often occurs as a mixture through occupational and industrial sources, has been implicated in various...
Chronic environmental exposure to toxic heavy metals, which often occurs as a mixture through occupational and industrial sources, has been implicated in various neurological disorders, including Parkinsonism. Vanadium pentoxide (VO) typically presents along with manganese (Mn), especially in welding rods and high-capacity batteries, including electric vehicle batteries; however, the neurotoxic effects of vanadium (V) and Mn co-exposure are largely unknown. In this study, we investigated the neurotoxic impact of MnCl, VO and MnCl-VO co-exposure in an animal model. C57BL/6 mice were intranasally administered either de-ionized water (vehicle), MnCl (252 µg) alone, VO (182 µg) alone, or a mixture of MnCl (252 µg) and VO (182 µg) three times a week for up to one month. Following exposure, we performed behavioral, neurochemical, and histological studies. Our results revealed dramatic decreases in olfactory bulb (OB) weight and levels of tyrosine hydroxylase, dopamine, and 3,4-dihydroxyphenylacetic acid in the treatment groups compared to the control group, with the Mn/V co-treatment group producing the most significant changes. Interestingly, increased levels of α-synuclein expression were observed in the substantia nigra (SN) of treated animals. Additionally, treatment groups exhibited locomotor deficits and olfactory dysfunction, with the co-treatment group producing the most severe deficits. The treatment groups exhibited increased levels of the oxidative stress marker 4-hydroxynonenal in the striatum and SN, as well as the upregulation of the pro-apoptotic protein PKCδ and accumulation of glomerular astroglia in the OB. The co-exposure of animals to Mn/V resulted in higher levels of these metals compared to other treatment groups. Taken together, our results suggest that co-exposure to Mn/V can adversely affect the olfactory and nigral systems. These results highlight the possible role of environmental metal mixtures in the etiology of Parkinsonism.
Topics: Animals; Mice; Manganese; Mice, Inbred C57BL; Vanadium; Manganese Compounds; Male; Olfactory Bulb; Dopamine; Vanadium Compounds; Oxidative Stress; Parkinsonian Disorders; alpha-Synuclein; Chlorides; Tyrosine 3-Monooxygenase; Aldehydes; Substantia Nigra; Disease Models, Animal; 3,4-Dihydroxyphenylacetic Acid
PubMed: 38791326
DOI: 10.3390/ijms25105285 -
International Journal of Molecular... May 2024Heme biosynthesis is a highly conserved pathway from bacteria to higher animals. Heme, which serves as a prosthetic group for various enzymes involved in multiple...
Heme biosynthesis is a highly conserved pathway from bacteria to higher animals. Heme, which serves as a prosthetic group for various enzymes involved in multiple biochemical processes, is essential in almost all species, making heme homeostasis vital for life. However, studies on the biological functions of heme in filamentous fungi are scarce. In this study, we investigated the role of heme in . A mutant lacking the rate-limiting enzymes in heme synthesis, coproporphyrinogen III oxidase (Cpo) or ferrochelatase (Fc), was constructed using a homologous recombination strategy. The results showed that the absence of these enzymes was lethal to , but the growth defect could be rescued by the addition of hemin, so we carried out further studies with the help of hemin. The results demonstrated that heme was required for the activity of FgCyp51, and its absence increased the sensitivity to tebuconazole and led to the upregulation of in . Additionally, heme plays an indispensable role in the life cycle of , which is essential for vegetative growth, conidiation, external stress response (especially oxidative stress), lipid accumulation, fatty acid β-oxidation, autophagy, and virulence.
Topics: Fusarium; Heme; Fungal Proteins; Stress, Physiological; Oxidative Stress; Triazoles; Gene Expression Regulation, Fungal; Fungicides, Industrial; Ferrochelatase
PubMed: 38791308
DOI: 10.3390/ijms25105268 -
Genes May 2024Pa0665 in shares homologous sequences with that of the essential A-type iron-sulfur (Fe-S) cluster insertion protein ErpA in . However, its essentiality in and its...
Pa0665 in shares homologous sequences with that of the essential A-type iron-sulfur (Fe-S) cluster insertion protein ErpA in . However, its essentiality in and its complementation with has not been experimentally examined. To fulfill this task, we constructed plasmid-based -mutant / using a three-step protocol. The mutant displayed growth defects at 42 °C, which were complemented by expressing . Microscopic observations indicated a petite cell phenotype for / at 42 °C, correlated with the downregulation of the gene. RNA sequencing revealed significant transcriptional changes in genes associated with the oxidative phosphorylation (OXPHOS) system, aligning with reduced ATP levels in / under 42 °C. Additionally, the -mutant showed heightened sensitivity to HO at 42 °C. Overall, our study demonstrates the essential role of for OXPHOS function and is complemented by . We propose that the plasmid-based -allele is useful for genetic analysis of essential genes of interest in .
Topics: Pseudomonas aeruginosa; Oxidative Phosphorylation; Bacterial Proteins; Mutation; Escherichia coli; Iron-Sulfur Proteins; Gene Expression Regulation, Bacterial
PubMed: 38790219
DOI: 10.3390/genes15050590 -
Journal of Parkinson's Disease 2024Parkinson's disease (PD) is the second most common neurodegenerative disorder, with genetic factors accounting for about 15% of cases. There is a significant challenge...
BACKGROUND
Parkinson's disease (PD) is the second most common neurodegenerative disorder, with genetic factors accounting for about 15% of cases. There is a significant challenge in tracking disease progression and treatment response, crucial for developing new therapies. Traditional methods like imaging, clinical monitoring, and biomarker analysis have not conclusively tracked disease progression or treatment response in PD. Our previous research indicated that PD patients with increased dopamine transporter (DAT) and tyrosine hydroxylase (TH) in peripheral blood mononuclear cells (PBMCs) might show disease progression and respond to levodopa treatment.
OBJECTIVE
This study evaluates whether DAT- and TH-expressing PBMCs can monitor motor progression in a PD patient with a heterozygous TH mutation.
METHODS
We conducted a longitudinal follow-up of a 46-year-old female PD patient with a TH mutation, assessing her clinical features over 18 months through DaT scans and PBMC immunophenotyping. This was compared with idiopathic PD patients (130 subjects) and healthy controls (80 age/sex-matched individuals).
RESULTS
We found an increase in DAT+ immune cells concurrent with worsening motor scores (UPDRS-III). Following levodopa therapy, unlike idiopathic PD patients, TH+ immune cell levels in this patient remained high even as her motor scores improved.
CONCLUSIONS
Longitudinal immunophenotyping in this PD patient suggests DAT+ and TH+ PBMCs as potential biomarkers for tracking PD progression and treatment efficacy, supporting further exploration of this approach in PD research.
Topics: Humans; Parkinson Disease; Female; Middle Aged; Disease Progression; Dopamine Plasma Membrane Transport Proteins; Leukocytes, Mononuclear; Tyrosine 3-Monooxygenase; Immunophenotyping; Mutation; Longitudinal Studies; Follow-Up Studies
PubMed: 38788089
DOI: 10.3233/JPD-240030 -
Aging May 2024Bone formation and homeostasis are greatly dependent on the osteogenic differentiation of human bone marrow stem cells (BMSCs). Therefore, revealing the mechanisms...
BACKGROUND
Bone formation and homeostasis are greatly dependent on the osteogenic differentiation of human bone marrow stem cells (BMSCs). Therefore, revealing the mechanisms underlying osteogenic differentiation of BMSCs will provide new candidate therapeutic targets for osteoporosis.
METHODS
The osteogenic differentiation of BMSCs was measured by analyzing ALP activity and expression levels of osteogenic markers. Cellular Fe and ROS levels and cell viability were applied to evaluate the ferroptosis of BMSCs. qRT-PCR, Western blotting, and co-immunoprecipitation assays were harnessed to study the molecular mechanism.
RESULTS
The mRNA level of CRYAB was decreased in the plasma of osteoporosis patients. Overexpression of CRYAB increased the expression of osteogenic markers including OCN, OPN, RUNX2, and COLI, and also augmented the ALP activity in BMSCs, on the contrary, knockdown of CRYAB had opposite effects. IP-MS technology identified CRYAB-interacted proteins and further found that CRYAB interacted with ferritin heavy chain 1 (FTH1) and maintained the stability of FTH1 via the proteasome mechanism. Mechanically, we unraveled that CRYAB regulated FTH1 protein stability in a lactylation-dependent manner. Knockdown of FTH1 suppressed the osteogenic differentiation of BMSCs, and increased the cellular Fe and ROS levels, and eventually promoted ferroptosis. Rescue experiments revealed that CRYAB suppressed ferroptosis and promoted osteogenic differentiation of BMSCs via regulating FTH1. The mRNA level of FTH1 was decreased in the plasma of osteoporosis patients.
CONCLUSIONS
Downregulation of CRYAB boosted FTH1 degradation and increased cellular Fe and ROS levels, and finally improved the ferroptosis and lessened the osteogenic differentiation of BMSCs.
Topics: Humans; Osteogenesis; Ferroptosis; Cell Differentiation; Osteoporosis; Mesenchymal Stem Cells; alpha-Crystallin B Chain; Ferritins; Protein Stability; Reactive Oxygen Species; Cells, Cultured; Bone Marrow Cells; Female; Oxidoreductases
PubMed: 38787373
DOI: 10.18632/aging.205851 -
Marine Drugs May 2024The development of antitumor drugs and therapy requires new approaches and molecules, and products of natural origin provide intriguing alternatives for antitumor...
UNLABELLED
The development of antitumor drugs and therapy requires new approaches and molecules, and products of natural origin provide intriguing alternatives for antitumor research. Gastropodan hemocyanins-multimeric copper-containing glycoproteins have been used in therapeutic vaccines and antitumor agents in many cancer models.
MATERIALS AND METHODS
We established a murine model of melanoma by challenging C57BL/6 mice with a B16F10 cell line for solid tumor formation in experimental animals. The anticancer properties of hemocyanins isolated from the marine snail (RtH) and the terrestrial snail (HaH) were evaluated in this melanoma model using various schemes of therapy. Flow cytometry, ELISA, proliferation, and cytotoxicity assays, as well as histology investigations, were also performed.
RESULTS
Beneficial effects on tumor growth, tumor incidence, and survival of tumor-bearing C57BL/6 mice after administration of the RtH or HaH were observed. The generation of high titers of melanoma-specific IgM antibodies, pro-inflammatory cytokines, and tumor-specific CTLs, and high levels of tumor-infiltrated M1 macrophages enhanced the immune reaction and tumor suppression.
DISCUSSION
Both RtH and HaH exhibited promising properties for applications as antitumor therapeutic agents and future experiments with humans.
Topics: Animals; Mice, Inbred C57BL; Melanoma, Experimental; Mice; Hemocyanins; Cell Line, Tumor; Antineoplastic Agents; Immunotherapy; Mollusca; Disease Models, Animal; Cytokines; Snails; Cell Proliferation; Melanoma
PubMed: 38786612
DOI: 10.3390/md22050220 -
Biomolecules Apr 2024The principle of continuity posits that some central features of primordial biocatalytic mechanisms should still be present in the genetically dependent pathway of... (Review)
Review
The principle of continuity posits that some central features of primordial biocatalytic mechanisms should still be present in the genetically dependent pathway of protein synthesis, a crucial step in the emergence of life. Key bimolecular reactions of this process are catalyzed by DNA-dependent RNA polymerases, aminoacyl-tRNA synthetases, and ribosomes. Remarkably, none of these biocatalysts contribute chemically active groups to their respective reactions. Instead, structural and functional studies have demonstrated that nucleotidic α-phosphate and β-d-ribosyl 2' OH and 3' OH groups can help their own catalysis, a process which, consequently, has been called "substrate-assisted". Furthermore, upon binding, the substrates significantly lower the entropy of activation, exclude water from these catalysts' active sites, and are readily positioned for a reaction. This binding mode has been described as an "entropy trap". The combination of this effect with substrate-assisted catalysis results in reactions that are stereochemically and mechanistically simpler than the ones found in most modern enzymes. This observation is consistent with the way in which primordial catalysts could have operated; it may also explain why, thanks to their complementary reactivities, β-d-ribose and phosphate were naturally selected to be the central components of early coding polymers.
Topics: Protein Biosynthesis; Amino Acyl-tRNA Synthetases; Biocatalysis; Ribosomes; DNA-Directed RNA Polymerases
PubMed: 38785925
DOI: 10.3390/biom14050518 -
Biosensors May 2024Nitrites widely exist in human life and the natural environment, but excessive contents of nitrites will result in adverse effects on the environment and human health;...
Nitrites widely exist in human life and the natural environment, but excessive contents of nitrites will result in adverse effects on the environment and human health; hence, sensitive and stable nitrite detection systems are needed. In this study, we report the synthesis of TiC nanosheets functionalized with apoferritin (ApoF)-biomimetic platinum (Pt) nanoparticle (Pt@ApoF/TiC) composite materials, which were formed by using ApoF as a template and protein-inspired biomineralization. The formed nanohybrid exhibits excellent electrochemical sensing performance towards nitrite (NaNO). Specifically, the Pt@ApoF catalyzes the conversion of nitrites into nitrates, converting the chemical signal into an electrical signal. The prepared Pt@ApoF/TiC-based electrochemical NaNO biosensors demonstrate a wide detection range of 0.001-9 mM with a low detection limit of 0.425 μM. Additionally, the biosensors possess high selectivity and sensitivity while maintaining a relatively stable electrochemical sensing performance within 7 days, enabling the monitoring of NaNO in complex environments. The successful preparation of the Pt@ApoF/TiC nanohybrid materials provides a new approach for constructing efficient electrochemical biosensors, offering a simple and rapid method for detecting NaNO in complex environments.
Topics: Biosensing Techniques; Platinum; Nitrites; Electrochemical Techniques; Ferritins; Metal Nanoparticles; Titanium; Humans; Biomimetic Materials; Limit of Detection
PubMed: 38785732
DOI: 10.3390/bios14050258