Introduction: Methylamines (MAs) are important brain metabolites that are known to exhibit neuroprotective effects. However, their role in the cholinergic system has not been well explored. In the present study, we investigated the effect of 4 MAs (sarcosine; dimethylglycine, DMG; betaine; and trimethylamine N-oxide, TMAO) on the structure and function integrity of acetylcholinesterase (AChE), an important enzyme in the cholinergic system responsible for the hydrolysis of the neurotransmitter acetylcholine (ACh) to choline and acetate.

Methods: The findings were generated from the systematic functional activity assay of AChE in the presence of MAs and further characterization using in silico, biophysical, and cellular approaches.

Results: We discovered that betaine and DMG are competitive inhibitors of AChE and could also reverse the cytotoxic effect of Aβ in cells, which is a key characteristic of AChE inhibitors. We also observed that betaine and DMG enhance the efficacy of donepezil, rivastigmine, and galantamine which are currently used drugs for the treatment of dementia.

Conclusions: As Betaine and DMG are FDA-approved supplements, the results implicate that they could be employed independently for the treatment of dementia. The use of AChE inhibitors is not sufficient to control different symptoms of dementia as the pathophysiology of dementia is multifactorial. Therefore, the use of a combinatorial therapy of AChE inhibitors and Betaine/DMG mixtures represents a newer approach.

Acute lymphoblastic leukemia (ALL) is an aggressive malignancy distinguished by an inferior survival rate, especially Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL), which comprises about 20-30% of all ALL cases. It is caused by the BCR-ABL protein, which is produced in cells that contain the Philadelphia (Ph) chromosome and stimulates the bone marrow to produce an excessive number of lymphoblasts. The ABL1 kinase domain has recently garnered significant attention as a promising molecular target for the development of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) treatment. In this research work, a study of the cytotoxic properties of phthalimido-1, 3-thiazole derivatives against the BCR-ABL protein PDB code 4WA9 was carried out using a combination of different computational chemistry methods, including a molecular docking/dynamics study and ADM-T evaluation. Five top hits were identified based on their free energy scores, namely, 4WA9-L18, 4WA9-L19, 4WA9-L20, 4WA9-L21, and 4WA9-L22, which demonstrated better binding affinity (from -7.8 to -8.3 kcal/mol). Furthermore, MD studies support the molecular docking results and validate the stability of the studied complexes under physiological conditions. These results confirm that the hits selected are verifiable inhibitors of the BCR-ABL protein, implying a good correlation between in silico and in vitro studies. Moreover, in silico ADME-TOX studies were used to predict the pharmacokinetic, pharmacodynamic, and toxicological properties of the studied hits. These findings support the future role of phthalimido-1,3-thiazole derivatives against the ALL disease and may help to find a new therapeutic combination of drugs to treat relapsed acute lymphoblastic leukemia and improve overall survival.

Diseases associated with the accumulation of ordered protein aggregates, amyloid fibrils, once thought to be rare, are predicted to soon become epidemics. However, there are still no effective drugs without serious side effects for the degradation of amyloid plaques, which is currently considered a promising therapeutic strategy. We tested the proteolytic enzyme cathepsin B, involved in the cellular immune response, as a potential amyloid-degrading agent.

Our investigation focused on model lysozyme amyloid fibrils that accumulate in systemic non-neuropathic hereditary amyloidosis. Various microscopic, biochemical, and spectroscopic approaches were used to study the properties of amyloids and their degradation products. We showed that cathepsin B-mediated proteolysis of amyloid-forming proteins led to fibril fragmentation. In some amyloid fragments, the loss of an ordered structure was also observed. The identified effects can be attributed to the disruption of intra- and intermolecular hydrogen bonds in the fibril core. At the same time, with the stepwise addition of cathepsin B (as opposed to a one-step enzyme addition at the same concentration), we observed a lower number of “fluffed” fragments, although the efficiency of amyloid degradation remained practically unchanged. Cathepsin B deactivation did not lead to fibril reassembly (as is the case with other amyloid-degrading factors) for at least 5 days. Despite the observed cathepsin B-induced degradation of amyloids, cell viability was not increased in its presence, indicating an equally high cytotoxicity of intact amyloids and of their degradation products.

The results of our study show that the visible destruction of amyloid fibrils does not always lead to a decrease in their cytotoxicity. However, the transformation of amyloids into smaller and less stable aggregates with an altered structure (as effected by cathepsin B) is an important step in the development of effective and safe anti-amyloid agents.

The study was funded by the Russian Science Foundation (grant No. 23-74-10092).

Amyloid fibrils have attracted attention as protein aggregates accompanying the development of severe pathologies, including neurodegenerative diseases and systemic and local amyloidoses. Physiological amyloids essential for cell and tissue function have also been identified. These ordered aggregates represent morphologically similar fibers composed of stacked β-strands. This suggests a predisposition to amyloid formation of native proteins enriched with b-structure, particularly those with a β-barrel structure with β-strands arranged in a cylindrical β-sheet. Despite the growing number of β-barrel proteins known to possess amyloidogenic properties, the mechanism underlying the transition of these proteins from the native monomeric/oligomeric to the fibrillar state is not fully understood. We analyzed the structural features of β-barrel proteins that determine their high amyloidogenicity using bovine odorant-binding protein (bOBP) as an example. The structural reorganization at the early stages of fibrillogenesis and the efficiency of this process for bOBP and its variants were analyzed using spectroscopic, microscopic methods, and bioinformatic analysis.

We showed that the ordered aggregation of bOBP can be facilitated by the destabilization of its structure to form a highly structured monomeric intermediate state with a retained β-barrel scaffold but a melted short α2-helix and β9-strand in the C-terminal fragment of the protein, which is amyloidogenic. Further, the C-terminus fixation via the disulfide bridge in monomeric bOBP variant (bOBP-Gly121+/W64C/H155C) inhibited its fibrillogenesis, which was overcome by the reducing agent addition or in monomeric variant (bOBP/Gly121+) without a disulfide bond.

Our findings indicate that the C-domain of OBPs is crucial for fibrillogenesis initiation. We suggest that the loss of ordered structure in the C-terminal fragment of the molecule, coupled with the disassembly of the bOBP dimer or detachment of this fragment from the β-barrel of monomeric OBPs, demasks amyloidogenic regions of the molecule for intermolecular interactions.

This work was supported by the Russian Science Foundation (NO. 24-24-00247).

Introduction

In the present state, a novel amnesic and AD-like dementia pathology emerges in the ageing brains, namely Limbic-predominant age-related TDP-43 encephalopathy (LATE). The disease is represented by aberrant splitting, clumping, phosphorylation, and massive accumulations of TDP-43 within the cytoplasm of cells involving neurons and glia. The abnormal regulation of TDP-43 is responsible for the mediated alteration of signaling events, such as deprived synaptic transmission, progressive neuronal degeneration, and motor deviations. Therefore, TDP-43 is a central player for LATE-associated CNS pathologies.

Material and Methods

Autopsy studies have revealed the characteristic misfolding of TDP-43 proteins in aged brains, illuminating the prevalence and distribution of TDP-43 in LATE. Additionally, recent research underscores the crucial role of impaired immune cells as key players in the neurodegeneration and the pathogenesis of TDP-43 proteinopathy. The systematic analysis of TDP-43 in LATE comprised 25 research findings with sample sizes ranging from 10 to 500 individuals.

Results

The objective of this review is to provide an extensive overview of the symptoms, neuropathological signs, proteinopathy, and approaches to diagnose LATE, with a focus on the way immune cell failure plays a role in its growth.

Discussion

This work aims to help comprehend LATE better by looking at how immune dysregulation and TDP-43 proteinopathy interact with each other. This will allow for new treatments that focus on immune pathways to help manage dementia.

Tartary buckwheat is one of the world's minor cereal crops; it contains all 18 essential amino acids. Frozen baked goods made from raw materials such as tartary buckwheat have attracted increasing attention. Due to the strong carbohydrate metabolism function of Lactobacillus plantarum (Lp), the fermentation ability of Lactobacillus fermentum (Lf), and the ability of Weissella confuse (Wc) to produce a large amount of extracellular polysaccharides (EPSs) with certain anti-freeze properties during fermentation, the mixed fermentation of sourdough prepared by these strains will have a higher improvement effect on product quality. In this study, using HPLC, SDS-PAGE, and other methods, the growth of exogenous lactic acid bacteria in sourdough, major metabolic products (such as organic acids and sugars), and protein distribution, among other things, were investigated. The sourdough was then applied to produce frozen dough bread, and the quality characteristics of the bread products were characterized. The results showed that with the Lf+Wc mixed strain, the bacterial count reached 9.18 (lg(CFU/g))(based on the mass of sourdough) after 12 h of fermentation, with a large amount of fructose (11.82 mmol/kg) and EPS (3.132 g/kg) produced. Compared with other groups, it had a moderate acid production rate, lower proteinase activity, and a slower protein degradation rate. Furthermore, when the Lf+Wc group was applied to frozen dough bread, the degree of quality decline after 13 weeks of frozen storage was smaller, with a baking loss rate decreasing by only 5.3%. In addition, the GC-MS spectrometry analysis of flavor components found that after 13 weeks of frozen storage, there was an increase in eight volatile compounds (Lf+Wc frozen dough bread). In conclusion, Lf and Wc have good synergistic effects, with a fast sugar metabolism rate and the ability to produce a large amount of EPSs with anti-freeze properties, which also explains why the final frozen dough product has the best anti-freeze performance.

Endomucin (EMCN) contributes to both cell adhesion and signaling processes, thereby participating in the modulation of immune responses within the vasculature. In this study, we uncover how EMCN modulates the tumor immune microenvironment in clear-cell renal cell carcinoma (ccRCC).

The Cancer Genome Atlas (TCGA) was used to obtain clinicopathological and expression data on KIRC. The prognostic significance of EMCN expression in ccRCC was assessed through univariate analysis. DNMIVD was used to investigate the methylation status of EMCN in tumor and normal adjacent tissue (NAT). TCGExplorer was utilized to employ GSEA to identify pathways enriched by the high or low expression of EMCN. Hallmark Gene sets from MSigDB were utilized. The immune microenvironment was evaluated using the Tumor IMmune Esti-mation Resource (TIMER 2.0).

High EMCN expression was associated with heightened overall survival and better survival (HR: 0.60, 95% CI: 0.52-0.68, P < .0001) in the TCGA ccRCC cohort. The promoter region of EMCN was hypermethylated in tumor tissue, in contrast to normal adjacent tissue, with an increased beta value of 0.13715 (P < 0.001) associated with decreased expression of EMCN in tumor tissue compared to NAT. The top three enriched GSEA terms when EMCN was highly expressed were hallmark_TGF_beta_signaling, KRAS_signalling_up, and Apical_junction. In contrast, when the expression of EMCN was low, E2F_targets, Oxidative_phosphorylation, and MYC_targets_v2 were the top terms. EMCN expression was positively correlated with resting memory CD4+T cells (ρ = 0.217, P = 2.68e-6), naïve B cells (ρ = 0.273, P = 2.43e-9), plasma B cells (ρ = 0.158, P = 6.73e-4), M1 macrophages (ρ = 0.167, P = 3.05e-4), Monocytes (ρ = 0.29, P = 2.17e-10), resting NK cells (ρ = 0.208, P = 6.39e-6), activated mast cells (ρ = 0.373, P = 1.05e-16), and M2 macrophages (ρ = 0.127, P = 6.45e-3). It correlated negatively with Tregs (ρ = -0.349, P = 1.23e-14), activated memory CD4+ T cells (ρ = -0.17, P = 2.42e-4), follicular helper T cells (ρ = -0.209, P = 6.20e-06), neutrophils (ρ = -0.101, P = 3.07e-2), M0 macrophages (ρ = -0.333, P = 2.15e-13), and memory B cells (ρ = -0.217, P = 2.53e-6).

Pyrrolizidine alkaloids (PAs) are heterocyclic organic compounds of natural origin synthesized by either plants or microorganisms. They are found in species applied in the pharmaceutical industry for their beneficial biological activities to cure disease; thus, a thorough knowledge of their pharmacokinetics and toxicity is of great importance as they are notorious for their acute hepatotoxicity and carcinogenicity in humans and animals. Therefore, this study evaluated the drug-likeness of 15 phytotoxic pyrrolizidine alkaloids that were reportedly isolated from 11 plant species via in silico prediction of their pharmacokinetic and toxicity profiles. Using Swiss ADME, pkCSM, and PreADMET webserver tools, Lipinski's properties and topological polar surface area (TPSA) were predicted for drug-likeness, alongside their pharmacokinetic profiles and toxicity on various organ endpoints. The drug-likeness prediction showed that all the compounds obeyed Lipinski’s rule of five (LRo5). None of the compounds inhibited hERG I and hERG II, indicating their non-cardiotoxic nature. In addition, 20% of the compounds elicited AMES toxicity; 53.33% caused liver injury; and none was sensitive to the skin. Furthermore, 13.33% showed high Caco-2 permeability and all displayed good skin permeability, implying their suitability for transdermal drug delivery. Moreover, P-glycoprotein was effluxed by 80% of the compounds and none exhibited inhibition; 86.66% of the compounds readily crossed the blood–brain barrier, 6.66% penetrated the central nervous system, none was a substrate to cytochrome p450 isoenzymes, 6.66% inhibited cytochrome p450 isoenzymes, 53.33% and 26.66% would cause cancer in mice and rats, respectively, and 20% showed high tolerated doses in humans. All demonstrated high intestinal absorption and 46.66% demonstrated good water solubility while a significant number showed a moderate volume of distribution, were free-flowing in plasma, and demonstrated moderate bioavailability. This study identified Jacoline and monocrotaline as drug-like, non-toxic, and highly bioavailable pyrrolizidine alkaloids with strong potential for further assessment, optimization, and development.

Mycobacterium tuberculosis is the causative agent of tuberculosis (TB), a highly contagious disease affecting millions of individuals globally. The emergence of drug-resistance becomes a significant obstacle in the treatment of tuberculosis (TB). The Mycobacterium tuberculosis protein Rv1979c has been implicated in drug resistance, yet its function and potential inhibitors remain largely unexplored. In this study, we employed a comprehensive computational approach to unravel the role of Rv1979c and identify potential inhibitors from natural sources.

The investigation was initiated by revealing the three-dimensional structure of Rv1979c via the Threading/Fold recognition method. Subsequently, a functional analysis of its molecular mechanism using a variety of computational tools yielded valuable insights. In addition, we screened a diverse collection of 11,708 phytochemicals against the Rv1979c target to identify potential inhibitors followed by molecular dynamic simulation. This exhaustive screening and simulation led to the identification of several prospective phytochemical candidates with significant binding affinity to the protein, indicating their potential as Rv1979c inhibitors.

This interdisciplinary study combines computational biology and drug discovery techniques to cast light on the function of Rv1979c and reveal potential strategies for combating pathogenesis in M. tuberculosis. The findings provide a foundation for further experimental validation and the development of novel therapeutic agents to address the evolving challenges of TB drug resistance.

Bone tissue exhibits inherent regenerative capabilities. Nevertheless, the adjunct of specialized biomaterials often proves beneficial, if not essential, for enhancing this healing process. Among these, bone cements stand out as biofunctional materials. Magnesium phosphate cements (MPCs) are distinguished by rapid setting, high initial mechanical strength, advantageous resorption, and osteogenic properties. Yet, challenges such as pronounced brittleness, paste leachability, and injection difficulties persist. Addressing these issues, this study introduces a novel dual-setting MPC-based cement formula modified with poly(2-hydroxyethyl methacrylate) (HEMA), aiming to enhance performance and applicability.

The formulation comprised an MPC powder component of tri-magnesium phosphate combined with di-ammonium hydrogen phosphate at a 4:1 mass ratio, alongside liquid components of 2-hydroxyethyl methacrylate solutions. HEMA polymerization was triggered by APS+TEMED, starting hydrogel formation after premixing (2-4 min). Specimen preparation involved mixing the components at a 2.5 g/mL powder-to-liquid ratio to achieve a paste, which was subsequently cast into molds and cured (24h, 37°C, >90% humidity). Evaluations comprised setting time, SEM microstructure, XRD and FTIR analyses, mechanical strengths, porosity, and degradation rate. Further, cytocompatibility was assessed using human osteoblasts.

The integration of a hydrogel component was pivotal in modulating the cement's functional characteristics. Notably, the concentration of HEMA and the duration of premixing markedly influenced hydrogel agglomerate formation within the cement matrix. Enhanced mechanical strength was associated with extended premix times and HEMA concentrations. Conversely, shorter premix durations facilitated more rapid and efficient matrix degradation. Cytotoxic effects observed in cultured osteoblasts were attributed to the application of TEMED as a catalyst in the polymerization process. Despite the achievement of desirable functional and mechanical properties, further investigations should explore alternative hydrogel additives or modifications to the HEMA polymerization methodology.

Acknowledgment: This research was partially supported by the Gdańsk University of Technology by the DEC-3/2022/IDUB /III.4.3/Pu grant under the PLUTONIUM 'Excellence Initiative – Research University' program.