Search Results (88)

Laboratory data from in-cell tests at and near open circuit potentials (OCV) and ex-situ H₂O₂ vapor exposure tests are used to develop a fluoride emission rate (FER) model for a state-of-the-art 12-µm thin, low equivalent weight, long-chain perfluorosulfonic acid (PFSA) ionomer membrane that is mechanically reinforced with expanded PTFE and chemically stabilized with 2 mol% cerium as an anti-oxidant. The anode FER at OCV linearly correlates with O₂ crossover from the cathode and the high yield of H₂O₂ at anode potentials, as observed in rotating ring disk electrode (RRDE) studies. The cathode FER may be linked to the energetic formation of reactive hydroxyl radicals (·OH) from the decomposition of H₂O₂ produced as an intermediate in the two-electron ORR pathway at high cathode potentials. Both anode and cathode FERs are significantly enhanced at low relative humidity and high temperatures. The modeled FER is strongly influenced by the gradients in water activity and cerium concentration that develops in operating fuel cells. Membrane stability maps are constructed to illustrate the relationship between the cell voltage, temperature, and relative humidity for FER thresholds that define H₂ crossover failure by chemical degradation over a specified lifetime. Full article

Background/Objectives: The low permeability of the blood-brain barrier (BBB) represents a significant challenge to effective systemic chemotherapy for primary and metastatic brain cancers. Kinin receptors play a crucial role in modulating BBB permeability, and their agonist analogs have been explored in preclinical animal models to enhance drug delivery to the brain. In this study, we investigated whether des-Arg⁹-bradykinin (DBK), a physiological agonist of kinin B₁ receptor (B1R), acts as a brain drug delivery adjuvant by promoting the transient opening of the BBB. Methods: Human brain microvascular endothelial cells (HBMECs) were treated with DBK in the culture medium and in conditioned media from glioblastoma cell lines, namely T98G (CMT98G) and U87MG (CMU87). Immunofluorescence, RT-qPCR, in-cell Western assay, and proximity ligation assay (PLA) were performed to analyze BBB components, kinin receptors and TLR4, a receptor associated with the kinin pathway and inflammation. The effect of DBK on enhancing paracellular molecule transport was evaluated using Evans blue dye (EB) quantification in a cell culture insert assay and in an in vivo model, where mice with and without brain tumors were treated with DBK. To assess the functional impact of the transient BBB opening induced by DBK, the chemotherapeutic drug doxorubicin (DOX) was administered. Results: Treatment with DBK facilitates the presence of EB in the brain parenchyma by transiently disrupting the BBB, as further evidenced by the increased paracellular passage of the dye in an in vitro assay. B1R activation by DBK induces transient BBB opening lasting less than 48 h, enhancing the bioavailability of the DOX within the brain parenchyma and glioma tumor mass. The interaction between B1R and TLR4 is disrupted by the secreted factors released by glioblastoma cells, as conditioned media from T98G and U87 reduce TLR4 staining in endothelial cells without affecting B1R expression. Conclusions: These results further support the potential of B1R activation as a strategy to enhance targeted drug delivery to the brain. Full article

We report two conjugates of gem-diethyl pyrroline nitroxide radicals with D-mannosamine as potential metabolic organic radical contrast agents, mORCAs, circumventing the need for biorthogonal reactions. In-cell EPR spectroscopy, using Jurkat cells and analogous conjugate, based on a pyrrolidine nitroxide radical, shows an efficient incorporation of highly immobilized nitroxides, with a correlation time of τ_cor = 20 ns. In vivo MRI experiments in mice show that the paramagnetic nitroxide radical shortens the T₁ and T₂ relaxation times of protons in water located in the kidney and brain by only up to ~10% after 3 d. Ex vivo EPR spectroscopic analyses indicate that the contrast agents in mouse tissues are primarily localized in the kidney, lung, liver, heart, and blood, which primarily contain immobilized nitroxide radicals with τ_cor = 4–9 ns. The spin concentrations in tissues remain low (1–3 nmol g⁻¹) at 24 h after the third mORCA injection, approximately one to two orders of magnitude lower than those of ORCAFluor and BASP-ORCA (measured at ~24 h post-injection). These low spin concentrations explain the small proton T₁ and T₂ relaxation changes observed in in vivo MRI. Full article

We describe a method tailored to the in-cell selection of protease inhibitors. In this method, a target protease is co-expressed with a selective substrate, the product of which kills host cells. Therefore, the method can be applied to identify potential inhibitors based on cell host survival when inhibition of the target protease occurs. The TEV protease was chosen for this proof-of-concept experiment. The genetically encoded selective substrate is a single polypeptide chain composed of three parts: (1) a ccdB protein, which can cause host cell death when it accumulates inside the cell; (2) a protease cleavage sequence that can be changed according to the target protease, in this case the TEV substrate ENLYFQ↓G (↓-predicted cleavage site); and (3) the ssrA sequence (AANDENYALAA), which drives the polypeptide to degradation by the ClpX/ClpP complex inside host E. coli cells. In our experiment, co-expression of the active TEV protease and this selective substrate (ccdB-ENLYFQG-ssrA) caused the death of a significant host cell population, while control assays with an inactive mutant TEV Asp81Asn did not. Details of the methodology used are given, providing the basis for the application of similar systems for other proteases of interest. Full article

Dengue virus (DV) infection poses a severe life-threatening risk in certain cases. This is mainly due to endothelial dysregulation, which causes plasma leakage and hemorrhage. However, the etiology of DV-induced endothelial dysregulation remains incompletely understood. To identify the potential mechanisms of endothelial dysregulation caused by DV, the effects of conditioned media from Dengue virus (CMDV) on the mechanics and transcriptional profile of the endothelial cells were examined using permeability assays, atomic force microscopy, In-Cell Western blot and in silico transcriptomics. Exposure of HMEC-1 cells to the CMDV increased endothelial permeability and cellular stiffness. It also induced the expression of the key proteins associated with endothelial-to-mesenchymal transition (EndMT). These data support the notion that the DV promotes endothelial dysfunction by triggering transcriptional programs that compromise the endothelial barrier function. Understanding the molecular mechanisms underlying DV-induced endothelial dysregulation is crucial for developing targeted therapeutic strategies to mitigate the severe outcomes associated with dengue infection. Full article

The term incel is a neologism combining “involuntary” and “celibate”, describing men who experience involuntary absence from sexual and romantic relationships. Incels frequently espouse conspiratorial and misogynistic ideologies, often engaging in verbal aggression. The present study aimed at qualitatively exploring the emotional experiences and beliefs articulated within an online incel community, contributing to the formation of its collective identity. A thread (453 comments) sampled from an Italian “incel” forum was analyzed by two independent raters, using thematic analysis. Four themes emerged: (a) “non-persons (i.e., women) are not like us” revealed perceived gender inequality and misogynistic beliefs, (b) “without experiences in adolescence you are ruined” reflected the belief that early romantic and sexual experiences are crucial for later relationship satisfaction, (c) “I have no life” captured expressions of profound distress and life dissatisfaction, and (d) “only ours is true suffering” highlighted a sense of unique victimhood. Incel group identity was shaped by gender role stress, primarily stemming from the perceived failure to meet socially constructed expectations of hegemonic masculinity. Suffering emerged as the dominant emotional experience, seemingly exacerbated by feelings of hopelessness regarding romantic and sexual prospects. The perceived subordinate status of men and male suffering were exploited to rationalize and perpetuate misogyny. The observed incels’ openness in discussing experiences of suffering and trauma may present an opportunity for the development of preventive interventions aimed at increasing help-seeking behavior in this population. Full article

In-cell touch and display integrated panels, along with their integrated readout systems, are widely adopted in mobile devices for their cost-effectiveness and compact design. This paper proposes an analog Gaussian-shaped filter and a current mode compensation technique for dot-matrix Touch Screen Panel (TSP) readout systems. Specifically, this article presents a noise management strategy for both intrinsic and external noise, offering simulation guidelines for determining intrinsic circuit noise levels in relation to scan time and enhancing external noise immunity through the Gaussian-shaped filter response. The system achieved an intrinsic SNR of 66 dB with a 200 kHz TSP driving frequency and a 160 μs scan time, while the 4-bit quantized Gaussian coefficients filter provided 33 dB noise suppression for out-of-band noise. The compensation error in the dot-matrix capacitance compensation was measured at 1.24 pF, which corresponds to a 0.078% deviation. The simulated power consumption of the proposed readout system is 24 mW, with a layout area of 1.017 mm² for the 10-channel readout front-end. Full article

Based on the established neuroprotective properties of indole-based compounds and their significant potential as multi-targeted therapeutic agents, a series of synthetic indole–phenolic compounds was evaluated as multifunctional neuroprotectors. Each compound demonstrated metal-chelating properties, particularly in sequestering copper ions, with quantitative analysis revealing approximately 40% chelating activity across all the compounds. In cellular models, these hybrid compounds exhibited strong antioxidant and cytoprotective effects, countering reactive oxygen species (ROS) generated by the Aβ(25–35) peptide and its oxidative byproduct, hydrogen peroxide, as demonstrated by quantitative analysis showing on average a 25% increase in cell viability and a reduction in ROS levels to basal states. Further analysis using thioflavin T fluorescence assays, circular dichroism, and computational studies indicated that the synthesized derivatives effectively promoted the self-disaggregation of the Aβ(25–35) fragment. Taken together, these findings suggest a unique profile of neuroprotective actions for indole–phenolic derivatives, combining chelating, antioxidant, and anti-aggregation properties, which position them as promising compounds for the development of multifunctional agents in Alzheimer’s disease therapy. The methods used provide reliable in vitro data, although further in vivo validation and assessment of blood–brain barrier penetration are needed to confirm therapeutic efficacy and safety. Full article

Fragment-based drug discovery is a powerful approach in drug discovery, applicable to a wide range of targets. This method enables the discovery of potent compounds that can modulate target functions, starting from fragment compounds that bind weakly to the targets. While biochemical, biophysical, and cell-based assays are commonly used to identify fragments, ¹⁹F-NMR spectroscopy has emerged as a powerful tool for exploring interactions between biomolecules and ligands. Because fluorine atoms are not naturally present in biological systems, ¹⁹F-NMR serves as a sensitive method for fragment screening against diverse targets. Herein, we reviewed the applications of ¹⁹F-NMR in fragment screening, highlighting its effectiveness in identifying fragments that bind weakly to various targets such as proteins and RNA. The accumulated evidence suggests that ¹⁹F-NMR will continue to be a crucial tool in drug discovery. Full article

Background and objective: Cannabinoids are commonly used as adjuvant cancer drugs to overcome numerous adverse side effects for patients. The aim of this study was to identify the target genes that show a synergistic anti-tumor role in combination with the cannabinoid WIN55212-2 in vitro and in vivo. Methods: A human kinome RNAi library was used to screen the targeted gene that silencing plus WIN55212-2 treatment synergistically inhibited cancer cell growth in an INCELL Analyzer 2000. Cell viability, cell phase arrest and apoptosis were evaluated by MTT and flow cytometry assay. In vivo combined anti-tumor effects and regulatory mechanisms were detected in immunocompromised and immunocompetent mice. Results: Using RNAi screening, we identified the tyrosine receptor kinase AXL as a potential gene whose silencing plus WIN55212-2 treatment synergistically inhibited the proliferation of cancer cells in an INCELL Analyzer 2000. Subsequently, we demonstrated that inhibition of AXL by TP-0903 potentiated the inhibitory role of WIN55212-2 on cellular viability, colony formation and 3D tumor sphere in HCT-8 cells. Meanwhile, TP-0903 plus WIN55212-2 treatment promoted the apoptosis of HCT-8 cells. We then investigated the synergistic anti-tumor effect of TP-0903 and WIN55212-2 using colon cancer cell xenografts in immunocompromised and immunocompetent mice. The in vivo study demonstrated that combined administration of TP-0903 plus WIN55212-2 effectively reduced tumor volume and microvessel density and promoted apoptotic cells of tumor tissues in HCT-8 exogenous mice compared to either TP-0903 or WIN55212-2 treatment alone. Moreover, in addition to tumor suppression, the combination therapy of TP-0903 and WIN55212-2 induced the infiltration of cytotoxic CD8⁺ T cells and significantly reduced mTOR and STAT3 activation in tumor tissues of C57BL/6J mice bearing MC-38 cells. Conclusions: This study demonstrated that targeting AXL could sensitize cannabinoids to cancer therapy by interfering with tumor cells and tumor-infiltrating CD8⁺ T cells. Full article

The control of metabolic networks is incompletely understood, even for glycolysis in highly studied model organisms. Direct real-time observations of metabolic pathways can be achieved in cellular systems with ¹³C NMR using dissolution Dynamic Nuclear Polarization (dDNP NMR). The method relies on a short-lived boost of NMR sensitivity using a redistribution of nuclear spin states to increase the alignment of the magnetic moments by more than four orders of magnitude. This temporary boost in sensitivity allows detection of metabolism with sub-second time resolution. Here, we hypothesized that dDNP NMR would be able to investigate molecular phenotypes that are not easily accessible with more conventional methods. The use of dDNP NMR allows real-time insight into carbohydrate metabolism in a Gram-positive bacterium (Lactoccocus lactis), and comparison to other bacterial, yeast and mammalian cells shows differences in the kinetic barriers of glycolysis across the kingdoms of life. Nevertheless, the accumulation of non-toxic precursors for biomass at kinetic barriers is found to be shared across the kingdoms of life. We further find that the visualization of glycolysis using dDNP NMR reveals kinetic characteristics in transgenic strains that are not evident when monitoring the overall glycolytic rate only. Finally, dDNP NMR reveals that resting Lactococcus lactis cells use the influx of carbohydrate substrate to produce acetoin rather than lactate during the start of glycolysis. This metabolic regime can be emulated using suitably designed substrate mixtures to enhance the formation of the C4 product acetoin more than 400-fold. Overall, we find that dDNP NMR provides analytical capabilities that may help to clarify the intertwined mechanistic determinants of metabolism and the optimal usage of biotechnologically important bacteria. Full article

Background: Intracellular tracking is commonly used in trafficking research. Until today, the respective techniques have remained complex, and complicated, mostly transgenic target protein changes are necessary, often requiring expensive equipment and expert knowledge. Methods: We present a novel method, which we term “cell-sonar”, that enables the user to track expression changes of specific protein markers that serve as points of interaction. Our study provides comparable analyses of expression changes of these marker proteins by in-cell Western analyses in two otherwise isogenic cell lines that only differ in the overexpression of the tracked target protein. Using the overexpressed human adult muscle-type nicotinic acetylcholine receptor as an example, we demonstrate that cell-sonar can cover multiple intracellular compartments such as the endoplasmic reticulum, the pathway between it and the Golgi apparatus, and the endocytic pathway. Results: We provide evidence for receptor maturation in the Golgi and storage in recycling endosomes, rather than the fate of increased insertion into the plasma membrane. Additionally, we demonstrate with the implementation of nicotine that the receptor’s destiny is exasperated up to secondary degradation. Conclusions: Cell-sonar is an affordable, easy-to-implement, and cheap method that can be adapted to a broad variety of proteins and cellular pathways of interest to researchers. Full article

Elastin, a key structural protein essential for the elasticity of the skin and elastogenic tissues, degrades with age. Replenishing elastin holds promise for anti-aging cosmetics and the supplementation of elastic activities of the cardiovascular system. We employed RiboScreen^TM, a technology for identifying molecules that enhance the production of specific proteins, to target the production of tropoelastin. We make use of RiboScreen^TM in two crucial steps: first, to pinpoint a target ribosomal protein (TRP), which acts as a switch to increase the production of the protein of interest (POI), and second, to identify small molecules that activate this ribosomal protein switch. Using RiboScreen^TM, we identified ribosomal protein L40, henceforth eL40, as a TRP switch to boost tropoelastin production. Drug discovery identified a small-molecule hit that binds to eL40. In-cell treatment demonstrated activity of the eL40 ligand and delivered increased tropoelastin production levels in a dose-dependent manner. Thus, we demonstrate that RiboScreen^TM can successfully identify a small-molecule hit capable of selectively enhancing tropoelastin production. This compound has the potential to be developed for topical or systemic applications to promote skin rejuvenation and to supplement elastic functionality within the cardiovascular system. Full article

The signaling complex around voltage-gated sodium (Nav) channels includes accessory proteins and kinases crucial for regulating neuronal firing. Previous studies showed that one such kinase, WEE1—critical to the cell cycle—selectively modulates Nav1.2 channel activity through the accessory protein fibroblast growth factor 14 (FGF14). Here, we tested whether WEE1 exhibits crosstalk with the AKT/GSK3 kinase pathway for coordinated regulation of FGF14/Nav1.2 channel complex assembly and function. Using the in-cell split luciferase complementation assay (LCA), we found that the WEE1 inhibitor II and GSK3 inhibitor XIII reduce the FGF14/Nav1.2 complex formation, while the AKT inhibitor triciribine increases it. However, combining WEE1 inhibitor II with either one of the other two inhibitors abolished its effect on the FGF14/Nav1.2 complex formation. Whole-cell voltage-clamp recordings of sodium currents (I_Na) in HEK293 cells co-expressing Nav1.2 channels and FGF14-GFP showed that WEE1 inhibitor II significantly suppresses peak I_Na density, both alone and in the presence of triciribine or GSK3 inhibitor XIII, despite the latter inhibitor’s opposite effects on I_Na. Additionally, WEE1 inhibitor II slowed the tau of fast inactivation and caused depolarizing shifts in the voltage dependence of activation and inactivation. These phenotypes either prevailed or were additive when combined with triciribine but were outcompeted when both WEE1 inhibitor II and GSK3 inhibitor XIII were present. Concerted regulation by WEE1 inhibitor II, triciribine, and GSK3 inhibitor XIII was also observed in long-term inactivation and use dependency of Nav1.2 currents. Overall, these findings suggest a complex role for WEE1 kinase—in concert with the AKT/GSK3 pathway—in regulating the Nav1.2 channelosome. Full article

Hantaviruses are zoonotic agents responsible for causing Hantavirus Cardiopulmonary Syndrome (HCPS) in the Americas, with Brazil ranking first in number of confirmed HCPS cases in South America. In this study, we simulate the monthly spread of highly lethal hantavirus in natural hosts by conjugating a Kermack–McCormick SIR model with a cellular automata model (CA), therefore simultaneously evaluating both in-cell and between-cell infection dynamics in host populations, using recently compiled data on main host species abundances and confirmed deaths by hantavirus infection. For both host species, our models predict an increase in the area of infection, with 22 municipalities where no cases have been confirmed to date expected to have at least one case in the next decade, and a reduction in infection in 11 municipalities. Our findings support existing research and reveal new areas where hantavirus is likely to spread within recognized epicenters. Highlighting spatial-temporal trends and potential expansion, we emphasize the increased risk due to pervasive habitat fragmentation and agricultural expansion. Consistent prevention efforts and One Health actions are crucial, especially in newly identified high-risk municipalities. Full article