N-Methyl-d-aspartate receptors (NMDARs) play a crucial role in excitatory neurotransmission, with numerous pathogenic variants identified in the GluN subunits, including their ligand-binding domains (LBDs). The prevailing hypothesis postulates that the endoplasmic reticulum (ER) quality control machinery verifies the agonist occupancy of NMDARs, but this was tested in a limited number of studies. Using microscopy and electrophysiology in the human embryonic kidney 293 (HEK293) cells, we found that surface expression of GluN1/GluN2A receptors containing a set of alanine substitutions within the LBDs correlated with the measured EC50 values for glycine (GluN1 subunit mutations) while not correlating with the measured EC50 values for l-glutamate (GluN2A subunit mutations). The mutant cycle of GluN1-S688 residue, including the pathogenic GluN1-S688Y and GluN1-S688P variants, showed a correlation between relative surface expression of the GluN1/GluN2A receptors and the measured EC50 values for glycine, as well as with the calculated ΔGbinding values for glycine obtained from molecular dynamics simulations. In contrast, the mutant cycle of GluN2A-S511 residue did not show any correlation between the relative surface expression of the GluN1/GluN2A receptors and the measured EC50 values for l-glutamate or calculated ΔGbinding values for l-glutamate. Coexpression of both mutated GluN1 and GluN2A subunits led to additive or synergistic alterations in the surface number of GluN1/GluN2A receptors. The synchronized ER release by ARIAD technology confirmed the altered early trafficking of GluN1/GluN2A receptors containing the mutated LBDs. The microscopical analysis from embryonal rat hippocampal neurons (both sexes) corroborated our conclusions from the HEK293 cells.
- MeSH
- Glycine metabolism MeSH
- HEK293 Cells MeSH
- Hippocampus cytology metabolism MeSH
- Rats MeSH
- Glutamic Acid metabolism MeSH
- Humans MeSH
- Ligands MeSH
- Mutation genetics MeSH
- Protein Domains MeSH
- Nerve Tissue Proteins MeSH
- Receptors, N-Methyl-D-Aspartate * metabolism genetics chemistry MeSH
- Protein Transport physiology genetics MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Humans MeSH
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Cardiorespiratory signals have long been treated as "noise" in functional magnetic resonance imaging (fMRI) research, with the goal of minimizing their impact to isolate neural activity. However, there is a growing recognition that these signals, once seen as confounding variables, provide valuable insights into brain function and overall health. This shift reflects the dynamic interaction between the cardiovascular, respiratory, and neural systems, which together support brain activity. In this review, we explore the role of cardiorespiratory dynamics-such as heart rate variability (HRV), respiratory sinus arrhythmia (RSA), and changes in blood flow, oxygenation, and carbon dioxide levels-embedded within fMRI signals. These physiological signals reflect critical aspects of neurovascular coupling and are influenced by factors such as physiological stress, breathing patterns, and age-related changes. We also discuss the complexities of distinguishing these signals from neuronal activity in fMRI data, given their significant contribution to signal variability and interactions with cerebrospinal fluid (CSF). Recognizing the influence of these cardiorespiratory dynamics is crucial for improving the interpretation of fMRI data, shedding light on heart-brain and respiratory-brain connections, and enhancing our understanding of circulation, oxygen delivery, and waste elimination within the brain.
Spontaneous tumor regression is a recognized phenomenon across various cancer types. Recent research emphasizes the alterations in autoantibodies against carbonic anhydrase I (CA I) (anti-CA I) levels as potential prognostic markers for various malignancies. Particularly, autoantibodies targeting CA I and II appear to induce cellular damage by inhibiting their respective protein's catalytic functions. Our study illuminates the profound impact of anti-CA I autoantibodies from patient serum on the esterase activity of human CA I, exhibiting inhibitory effects akin to the acetazolamide inhibitor. Concurrently, our newly synthesized mouse monoclonal IgG antibody, mAb 2B8, against human CA I showcased a potent inhibitory action. An in-depth exploration into mAb 2B8's binding dynamics with its target enzyme was undertaken. Leveraging epitope extraction and phage display library techniques, we identified the amino acid sequence DFWTYP (positions 191-196 of CA I) as crucial for mAb 2B8's interaction. In 3-D structural analysis, this sequence is spatially adjacent to a previously identified epitope (DFWTYP) that interacts with patient-derived autoantibodies. Critically, mAb 2B8 demonstrated an ability to infiltrate eukaryotic cells, engaging specifically with its intracytoplasmic target. This positions mAb 2B8 as a promising model for future studies aimed at tumor cell eradication.
- MeSH
- Autoantibodies * immunology metabolism MeSH
- Epitopes immunology chemistry MeSH
- Carbonic Anhydrase I * metabolism antagonists & inhibitors MeSH
- Humans MeSH
- Antibodies, Monoclonal * immunology MeSH
- Mice MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Despite covering <5% of Earth's terrestrial area, peatlands are crucial for global carbon storage and are hot spots of methane cycling. This study examined the dynamics of aerobic and anaerobic methane oxidation in two undisturbed peatlands: a fen and a spruce swamp forest. Using microcosm incubations, we investigated the effect of ammonium addition, at a level similar to current N pollution processes, on aerobic methane oxidation. Our findings revealed higher methane consumption rates in fen compared to swamp peat, but no effect of ammonium amendment on methane consumption was found. Members of Methylocystis and Methylocella were the predominant methanotrophs in both peatlands. Furthermore, we explored the role of ferric iron and sulfate as electron acceptors for the anaerobic oxidation of methane (AOM). AOM occurred without the addition of an external electron acceptor in the fen, but not in the swamp peat. AOM was stimulated by sulfate and ferric iron addition in the swamp peat and inhibited by ferric iron in the fen. Our findings suggest that aerobic methane oxidizers are not N-limited in these peatlands and that there is an intrinsic potential for AOM in these environments, partially facilitated by ferric iron and sulfate acting as electron acceptors.
Troponiny T a I jsou důležitými biomarkery kardiálního poškození, ke stanovení hladin se v současnosti používají vysoce senzitivní diagnostické soupravy. V dospělé populaci má troponin stěžejní význam v diagnostice akutního koronárního syndromu. V pediatrii jsou důvody vyšetření troponinu odlišné, nejčastější indikací je akutní myokarditida infekční i neinfekční etiologie. Hladina troponinu vylučuje nebo do značné míry potvrzuje toto onemocnění a koreluje se závažností, nepredikuje ale pozdní dysfunkci myokardu. Přesto troponin, spolu s natriuretickými peptidy, lze využít při sledování kardiomyopatií k predikci komplikací a prognózy. U vrozených srdečních vad se troponin nejčastěji využívá v hodnocení pooperačního průběhu. V souvislosti s diagnostikou ischemie myokardu má u dětí troponin význam při suspekci na patologii koronárních arterií u Kawasakiho choroby, postkovidového syndromu, vrozených anomálií nebo při stavech po chirurgické koronární intervenci. Dalšími možnými indikacemi vyšetření troponinu jsou trauma hrudníku, úraz elektrickým proudem, sepse, renální selhání, intoxikace oxidem uhelnatým, arytmie, kardiotoxická léčba či endokrinní a neuromuskulární choroby. Vždy je nutné znát normy pro danou diagnostickou soupravu a typ troponinu, posouzení dynamiky hodnot v čase a korelace s klinickým vyšetřením a dalšími diagnostickými metodami.
Troponins T and I are important biomarkers of cardiac damage, the levels of which are currently determined by highly sensitive diagnostic kits. In the adult population, troponin is of central importance in the diagnosis of acute coronary syndrome. In pediatrics, the reasons for troponin testing are different, with acute myocarditis of infectious or non-infectious aetiology being the most common indication. Troponin levels can rule out or to a great degree confirm this disease and correlate with its severity; the levels, however, can not reliably predict late myocardial dysfunction. Still, troponin, along with natriuretic peptides, can be used in the monitoring of cardiomyopathies to predict complications and prognosis. In congenital heart disease, troponin is most commonly used to evaluate the postoperative course. In the context of diagnosing myocardial ischemia in children, troponin is important when coronary artery pathology is suspected in Kawasaki disease, post-COVID syndrome, congenital anomalies, or after surgical coronary interventions. Other possible indications for troponin testing include chest trauma, electric shock, sepsis, renal failure, carbon monoxide intoxication, arrhythmias, cardiotoxic therapy, or endocrine and neuromuscular diseases. It is always necessary to know the normal values for the used diagnostic kit and the type of troponin, to assess the dynamics of values over time and to correlate the laboratory results with clinical examination and other diagnostic methods.
- MeSH
- Biomarkers * analysis MeSH
- Child MeSH
- Cardiomyopathies diagnosis MeSH
- Cardiotoxicity MeSH
- Humans MeSH
- Myocarditis diagnosis MeSH
- Troponin I * analysis MeSH
- Troponin T * analysis MeSH
- Heart Defects, Congenital MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Publication type
- Review MeSH
The mangrove ecosystem is the world's fourth most productive ecosystem in terms of service value and offering rich biological resources. Microorganisms play vital roles in these ecological processes, thus researching the mangroves-microbiota is crucial for a deeper comprehension of mangroves dynamics. Amplicon sequencing that targeted V4 region of 16S rRNA gene was employed to profile the microbial diversities and community compositions of 19 soil samples, which were collected from the rhizosphere of 3 plant species (i.e., Avicennia marina, Ceriops tagal, and Rhizophora mucronata) in the mangrove forests of Lasbela coast, Pakistan. A total of 67 bacterial phyla were observed from three mangroves species, and these taxa were classified into 188 classes, 453 orders, 759 families, and 1327 genera. We found that Proteobacteria (34.9-38.4%) and Desulfobacteria (7.6-10.0%) were the dominant phyla followed by Chloroflexi (6.6-7.3%), Gemmatimonadota (5.4-6.8%), Bacteroidota (4.3-5.5%), Planctomycetota (4.4-4.9%) and Acidobacteriota (2.7-3.4%), Actinobacteriota (2.5-3.3%), and Crenarchaeota (2.5-3.3%). After considering the distribution of taxonomic groups, we prescribe that the distinctions in bacterial community composition and diversity are ascribed to the changes in physicochemical attributes of the soil samples (i.e., electrical conductivity (ECe), pH, total organic matter (OM), total organic carbon (OC), available phosphorus (P), and extractable potassium (CaCO3). The findings of this study indicated a high-level species diversity in Pakistani mangroves. The outcomes may also aid in the development of effective conservation policies for mangrove ecosystems, which have been hotspots for anthropogenic impacts in Pakistan. To our knowledge, this is the first microbial research from a Pakistani mangrove forest.
- MeSH
- Avicennia microbiology MeSH
- Bacteria * classification genetics isolation & purification MeSH
- Biodiversity * MeSH
- DNA, Bacterial genetics MeSH
- Phylogeny * MeSH
- Microbiota * MeSH
- Wetlands * MeSH
- Soil Microbiology * MeSH
- Rhizophoraceae microbiology MeSH
- Rhizosphere MeSH
- RNA, Ribosomal, 16S * genetics MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Pakistan MeSH
Microtubule dynamic is exceptionally sensitive to modulation by small-molecule ligands. Our previous work presented the preparation of microtubule-targeting estradiol dimer (ED) with anticancer activity. In the present study, we explore the effect of selected linkers on the biological activity of the dimer. The linkers were designed as five-atom chains with carbon, nitrogen or oxygen in their centre. In addition, the central nitrogen was modified by a benzyl group with hydroxy or methoxy substituents and one derivative possessed an extended linker length. Thirteen new dimers were subjected to cytotoxicity assay and cell cycle profiling. Dimers containing linker with benzyl moiety substituted with one or more methoxy groups and longer branched ones were found inactive, whereas other structures had comparable efficacy as the original ED (e.g. D1 with IC50 = 1.53 μM). Cell cycle analysis and immunofluorescence proved the interference of dimers with microtubule assembly and mitosis. The proposed in silico model and calculated binding free energy by the MM-PBSA method were closely correlated with in vitro tubulin assembly assay.
- MeSH
- Apoptosis MeSH
- Ethinyl Estradiol * chemistry pharmacology MeSH
- G2 Phase Cell Cycle Checkpoints drug effects MeSH
- Microtubules MeSH
- Tubulin Modulators * chemistry pharmacology MeSH
- Cell Line, Tumor MeSH
- Antineoplastic Agents * chemistry pharmacology MeSH
- Triazoles * chemistry pharmacology MeSH
- Tubulin * metabolism MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The N2-fixing cyanobacterium Trichodesmium is an important player in the oceanic nitrogen and carbon cycles. Trichodesmium occurs both as single trichomes and as colonies containing hundreds of trichomes. In this review, we explore the benefits and disadvantages of colony formation, considering physical, chemical, and biological effects from nanometer to kilometer scale. Showing that all major life challenges are affected by colony formation, we claim that Trichodesmium's ecological success is tightly linked to its colonial lifestyle. Microbial interactions in the microbiome, chemical gradients within the colony, interactions with particles, and elevated mobility in the water column shape a highly dynamic microenvironment. We postulate that these dynamics are key to the resilience of Trichodesmium and other colony formers in our changing environment.
- MeSH
- Nitrogen Fixation MeSH
- Oceans and Seas MeSH
- Cyanobacteria * MeSH
- Social Behavior MeSH
- Trichodesmium * MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
- Geographicals
- Oceans and Seas MeSH
Stimuli-responsive copolymers are of great interest for targeted drug delivery. This study reports on a controllable post-polymerization quaternization with 2-bromomethyl-4-fluorophenylboronic acid of the poly(4-vinyl pyridine) (P4VP) block of a common poly(styrene)-b-poly(4-vinyl pyridine)-b-poly(ethylene oxide) (SVE) triblock terpolymer in order to achieve a selective responsivity to various diols. For this purpose, a reproducible method was established for P4VP block quaternization at a defined ratio, confirming the reaction yield by 11B, 1H NMR. Then, a reproducible self-assembly protocol is designed for preparing stable micelles from functionalized stimuli-responsive triblock terpolymers, which are characterized by light scattering and by cryogenic transmission electron microscopy. In addition, UV-Vis spectroscopy is used to monitor the boron-ester bonding and hydrolysis with alizarin as a model drug and to study encapsulation and release of this drug, induced by sensing with three geminal diols: fructose, galactose and ascorbic acid. The obtained results show that only the latter, with the vicinal diol group on sp2-hybridized carbons, was efficient for alizarin release. Therefore, the post-polymerization method for triblock terpolymer functionalization presented in this study allows for preparation of specific stimuli-responsive systems with a high potential for targeted drug delivery, especially for cancer treatment.
- Publication type
- Journal Article MeSH
Phosphate···π, also called anion···π, contacts occur between nucleobases and anionic phosphate oxygens (OP2) in r(GNRA) and r(UNNN) U-turn motifs (N = A,G,C,U; R = A,G). These contacts were investigated using state-of-the-art quantum-chemical methods (QM) to characterize their physicochemical properties and to serve as a reference to evaluate AMBER force field (AFF) performance. We found that phosphate···π interaction energies calculated with the AFF for dimethyl phosphate···nucleobase model systems are less stabilizing in comparison with double-hybrid DFT and that minimum contact distances are larger for all nucleobases. These distance stretches are also observed in large-scale AFF vs QM/MM computations and classical molecular dynamics (MD) simulations on several r(gcGNRAgc) tetraloop hairpins when compared to experimental data extracted from X-ray/cryo-EM structures (res. ≤ 2.5 Å) using the WebFR3D bioinformatic tool. MD simulations further revealed shifted OP2/nucleobase positions. We propose that discrepancies between the QM and AFF result from a combination of missing polarization in the AFF combined with too large AFF Lennard-Jones (LJ) radii of nucleobase carbon atoms in addition to an exaggerated short-range repulsion of the r-12 LJ repulsive term. We compared these results with earlier data gathered on lone pair···π contacts in CpG Z-steps occurring in r(UNCG) tetraloops. In both instances, charge transfer calculations do not support any significant n → π* donation effects. We also investigated thiophosphate···π contacts that showed reduced stabilizing interaction energies when compared to phosphate···π contacts. Thus, we challenge suggestions that the experimentally observed enhanced thermodynamic stability of phosphorothioated r(GNRA) tetraloops can be explained by larger London dispersion.
- MeSH
- Phosphates MeSH
- RNA * chemistry MeSH
- Molecular Dynamics Simulation * MeSH
- Thermodynamics MeSH
- Computational Biology MeSH
- Publication type
- Journal Article MeSH
