The self-association of amylogenic proteins to the fibril form is considered a pivotal factor in the pathogenesis of neurodegenerative diseases, including Parkinson’s disease (PD). PD causes unintended or uncontrollable movements in its common symptoms. α-synuclein is the major cause of PD development and thus has been the main target of numerous studies to suppress and sequester its expression or effectively degrade it. Nonetheless, to date, there are no efficient and proven ways to prevent pathological protein aggregation. Recent investigations proposed applying an external electric field to interrupt the fibrils. This method is a non-invasive approach that has a certain benefit over others. We performed molecular dynamics (MD) simulations by applying an electric field on highly toxic fibrils of α-synuclein to gain a molecular-level insight into fibril disruption mechanisms. The results revealed that the applied external electric field induces substantial changes in the conformation of the α-synuclein fibrils. Furthermore, we show the threshold value for electric field strength required to completely disrupt the α-synuclein fibrils by opening the hydrophobic core of the fibril. Thus, our findings might serve as a valuable foundation to better understand molecular-level mechanisms of the α-synuclein fibrils disaggregation process under an applied external electric field.

Superconserved receptors expressed in brain (SREB) are a family of orphan G protein–coupled receptors with 3 members in most vertebrates (GPR27 or SREB1, GPR85 or SREB2, and GPR173 or SREB3). They are associated with diverse physiological processes, ranging from glucose homeostasis to ovarian development. Despite a lack of confirmed ligands, our understanding of these receptors has increased based on interactions with putative SREB3 ligands such as phoenixin (PNX) and the development of synthetic SREB1 agonists (A8535 and PT-91). However, to date no studies have used these agonists in any complex vertebrate system. The objective of this study was to compare the in vitro transcriptomic responses to PNX-20, A8535, and PT-91 in the ovaries of 3 fishes with different SREB systems: (1) zebrafish (Danio rerio) that exhibit similar receptors to mammals, (2) mummichog (Fundulus heteroclitus) that lost a receptor but gained a fish-specific member, and (3) pufferfish (Dichotomyctere nigroviridis) that exhibit all 4 receptors. Agonist interactions with fish SREB1s were confirmed using in silico characterizations. Zebrafish exhibited the strongest transcriptome response, including agonist-induced changes in oxidative phosphorylation and cell adhesion pathways. Mummichog exhibited a less robust response, possibly related to receptor evolutionary divergence, while pufferfish exhibited an intermediate transcriptome response. Short-term agonist exposure did not alter ovarian steroid levels ([17]estradiol, 17-hydroxyprogesterone, cortisol, testosterone, or 11-ketotestosterone). Collectively, the data reveal previously unrecognized developmental, metabolic, neural, and vascular gene networks associated with SREB activation and suggest both receptor-specific signaling and functional overlap within this family.

Quinoxaline and oxadiazole are renowned heterocyclic structures valued for their diverse biological activities, making them prime candidates for developing chemotherapeutic drugs. This study explored the anti-cancer potential and mechanism of apoptosis induction in A549 (lung cancer), HaCaT (skin cancer), and HepG2 (liver cancer) cell lines using newly designed, synthesized, and characterized quinoxaline-oxadiazole hybrid derivatives. Characterization employed NMR and HRMS analysis. The anti-cancer activity of these compounds (8a-8j) was evaluated against the aforementioned cell lines using the SRB colorimetric test. Compounds 8c and 8d displayed exceptional cytotoxicity, particularly when compared to other tested compounds and across different cell lines. These hybrids were found to generate reactive oxygen species (ROS), disrupt cell proliferation pathways, induce apoptosis (programmed cell death), and interfere with structural tubulin proteins. Notably, the presence of specific halogen substituents significantly enhanced their cytotoxic efficacy. Furthermore, to understand how these molecules interact with cancer cells at the molecular level, docking simulations were performed for all compounds. These simulations targeted the HeLa Cell Tubulin microtubule protein, a crucial component of the cell cytoskeleton. Additionally, molecular dynamic simulations were employed to elucidate the binding mechanism between the ligands (hybrid derivatives) and the protein target.

KCNQ2 (Kv7.2) subunits contribute to the channels that carry the neuronal M-current, and variants in KCNQ2 cause epilepsies that range from self-limited neonatal seizures to developmental and epileptic encephalopathy (DEE). Structures of KCNQ2 bound to PIP ₂ and cannabidiol show a widened activation gate, yet it has remained unclear which point of the activated pore limits K ⁺ flux and how DEE variants at that point act. We simulated the KCNQ2 pore domain (PDB 8J01) in a POPC bilayer under an applied field of about 565 mV, restraining only the terminal residues of S5 and S6 so that G310 and S314 were free. The activated pore conducted K ⁺ at 4.3 pS (95% CI 2.5–6.9; 17 net filter crossings in 1.12 µs over four replicas), while the closed-state pore (PDB 7CR3) conducted none in 560 ns. Conduction proceeded by knock-on through a filter that was doubly occupied in 84–92% of frames. Along S6 the narrowest position of the activated pore was not the canonical gate residue S314 but the glycine of the Pro-Ala-Gly motif, G310: activation widens S314 by 3.7 Å but G310 by only 0.7 Å, and restraining G310 to its closed-state width in one replica abolished gate crossings. The DEE variant G310S reduced conduction about six-fold (G310S/wild-type ratio 0.16, 95% CI 0.02–0.66; p = 0.003). Its serine hydroxyls project into the constriction and halve the water column in the G310 plane (8.7 to 4.7 waters), an effect reproduced in CHARMM36m (9.9 to 4.3). The first coordination shell of a K ⁺ ion at the constriction was, however, conserved (6.3 vs 6.5 oxygens), because the serine hydroxyls replace the waters they displace. The hydroxyls did not retain the ion: contacts lasted tens of picoseconds, and ions were instead turned back at the serine ring, fewer reaching the gate plane (45 vs 79 excursions per microsecond) and fewer of those crossing it (5% vs 23%). In mixed tetramers carrying one or two variant subunits the effect on the water column was additive, each subunit removing about a quarter of it (f = 0.22 and 0.58 of the full effect). These results identify G310 as the flux-limiting constriction of the activated KCNQ2 pore in our simulations and point to a permeation defect as one component of G310S loss of function. Significance: Loss-of-function variants in the neuronal potassium channel KCNQ2 cause neonatal epilepsy that ranges from self-limited to severe, but for variants that line the pore it is usually not known whether they impair the opening of the channel or the movement of ions through it. Simulating the activated KCNQ2 pore under an applied voltage, we find that K ⁺ flux is limited by a glycine of the conserved Pro-Ala-Gly motif that the field’s standard gate metrics do not measure, and that the encephalopathy variant G310S slows permeation roughly six-fold at exactly this point. Its serine hydroxyls take the place of water in the ion’s first shell, yet they do not trap the ion: ions approaching the serine ring are turned back before they cross it. The effect grows in proportion to the number of variant subunits, the situation in the heterozygous channels of patients.

Introduction: Cancer remains one of the major causes of death worldwide. Tyrosine kinase inhibitors (TKIs) represent an important class of targeted anticancer agents because they block key oncogenic signaling pathways. Imatinib mesylate was among the first TKIs introduced in clinical oncology and has significantly improved the treatment of several malignancies. Nevertheless, its clinical use is associated with adverse effects, which highlights the need to develop modified derivatives with improved efficacy and reduced toxicity. Methods: In the present work, a new compound, imatinib aescinate, was prepared by dissolving imatinib and aescin separately in ethyl alcohol and combining the solutions under continuous stirring, followed by filtration and acetone-induced precipitation. For identification and structural characterization, the compound was analyzed using UV and FTIR spectroscopy, scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), thermogravimetric–differential thermal analysis (TGA/DTA), and HPLC. Antiproliferative activity was assessed in MCF-7 breast cancer cells using a CCK-8 cell viability assay (24 h), and wound closure was evaluated using a scratch assay. To understand potential molecular interactions, molecular dynamics simulations together with MM-PBSA binding energy calculations were also performed. Results: The synthesized compound exhibited greater antiproliferative activity against MCF-7 cells than either imatinib mesylate or aescin alone. The IC50 values determined from a 24 h CCK-8 assay were: imatinib aescinate 15.16 μM, aescin alone 23.55 μM, and imatinib mesylate 76.66 μM. Imatinib aescinate also inhibited MCF-7 wound closure in a concentration-dependent manner in the scratch assay. Computational analysis indicated stable binding of imatinib aescinate to the BCR-ABL tyrosine kinase (PDB ID: 2HYY). Molecular dynamics simulations suggested reduced conformational flexibility of the protein–ligand complex, and MM-PBSA calculations supported favorable binding energy. Discussion: Imatinib aescinate was approximately fivefold more potent than imatinib mesylate and 1.6-fold more potent than aescin, indicating enhanced antiproliferative activity. Its concentration-dependent inhibition of wound closure also suggests potential antimigratory effects, although reduced cell proliferation may contribute to this result. Computational findings supported stable and favorable binding to BCR-ABL; however, the underlying mechanism requires experimental confirmation. Further studies should evaluate kinase inhibition, toxicity, and in vivo efficacy. Conclusion: Overall, the results indicate that imatinib aescinate shows enhanced antiproliferative activity against MCF-7 cells compared with its individual components. Computational predictions suggest that the compound may interact with kinase targets; however, direct biochemical validation is required before definitive mechanistic conclusions can be drawn. These findings identify imatinib aescinate as a promising candidate for further preclinical investigation as a potential anticancer agent.