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Many receptors signal upon phosphorylation of tyrosine-based motifs in their cytosolic tail, with intrinsic disorder as a common feature. Studies on CD3ζ and CD3ε tails, which are disordered and polybasic, suggested regulation of phosphorylation through accessibility of tyrosines, governed by electrostatic interactions with membrane anionic lipids. We noticed characteristics of intrinsic disorder and previously unappreciated features in tyrosine-based motif-bearing cytosolic tails of many, especially, inhibitory receptors. They are neutral or acidic polyampholytes, with acidic and basic residues linearly segregated. To explore roles of these electrostatic features, we studied inhibitory killer-cell immunoglobulin-like receptor (KIR). Its cytosolic tail is a disordered neutrally charged polyampholyte, wherein juxtamembrane and membrane distal stretches are basic, and the intervening stretch is acidic. Despite lacking net charge, it interacted electrostatically with the plasma membrane. The juxtamembrane stretch was crucial for overall binding, which sequestered tyrosines in the lipid bilayer and restrained their constitutive phosphorylation. Human leukocyte antigen-C ligand binding to KIR released its tail from the plasma membrane to initiate signaling. Tail release occurred independently of KIR polymerization, clustering, or tyrosine phosphorylation, but required acidic residues of the acidic stretch. Tail interaction with the plasma membrane dictated signaling strength of KIR. These results revealed an electrostatic protein-lipid interaction that is unusual in being governed by segregated clusters of acidic and basic residues in polyampholytic disordered region of protein. In contrast to previously known, segregated distribution of oppositely charged residues made both binding and unbinding modules inherent to receptor tail, which could make the interaction an independent signaling switch.
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Receptores KIR , Transdução de Sinais , Humanos , Eletricidade Estática , Membrana Celular , Fosforilação , Lipídeos de Membrana , Tirosina/químicaRESUMO
Timely detection and repair of envelope damage are paramount for bacterial survival. The Regulator of Capsule Synthesis (Rcs) stress response can transduce the stress signals across the multilayered gram-negative cell envelope to regulate gene expression in the cytoplasm. Previous studies defined the overall pathway, which begins with the sensory lipoprotein RcsF interacting with several outer membrane proteins (OMPs). RcsF can also interact with the periplasmic domain of the negative regulator IgaA, derepressing the downstream RcsCDB phosphorelay. However, how the RcsF/IgaA interaction is regulated at the molecular level to activate the signaling in response to stress remains poorly understood. In this study, we used a site-saturated mutant library of rcsF to carry out several independent genetic screens to interrogate the mechanism of signal transduction from RcsF to IgaA. We analyzed several distinct classes of rcsF signaling mutants, and determined the region of RcsF that is critically important for signal transduction. This region is bifunctional as it is important for RcsF interaction with both IgaA and OMPs. The mutant analysis provides strong evidence for conformational changes in the RcsF/OMP complex mediating signal transduction to IgaA, and the first direct evidence that OMPs play an important regulatory role in Rcs signaling.
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Proteínas da Membrana Bacteriana Externa , Proteínas de Escherichia coli , Escherichia coli , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/metabolismo , Membrana Celular/genética , Membrana Celular/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Transdução de Sinais/genéticaRESUMO
Enhancing maize kernel oil is vital for improving the bioavailability of fat-soluble vitamins. Here, we combined favourable alleles of dgat1-2 and fatb into parental lines of four multi-nutrient-rich maize hybrids (APTQH1, APTQH4, APTQH5 and APTQH7) using marker-assisted selection (MAS). Parental lines possessed favourable alleles of crtRB1, lcyE, vte4 and opaque2 genes. Gene-specific markers enabled successful foreground selection in BC1F1, BC2F1 and BC2F2, while background selection using genome-wide microsatellite markers (127-132) achieved 93% recurrent parent genome recovery. Resulting inbreds exhibited significantly higher oil (6.93%) and oleic acid (OA, 40.49%) and lower palmitic acid (PA, 14.23%) compared to original inbreds with elevated provitamin A (11.77 ppm), vitamin E (16.01 ppm), lysine (0.331%) and tryptophan (0.085%). Oil content significantly increased from 4.80% in original hybrids to 6.73% in reconstituted hybrids, making them high-oil maize hybrids. These hybrids displayed 35.70% increment in oil content and 51.56% increase in OA with 36.32% reduction in PA compared to original hybrids, while maintaining higher provitamin A (two-fold), vitamin E (nine-fold), lysine (two-fold) and tryptophan (two-fold) compared to normal hybrids. Lipid health indices showed improved atherogenicity, thrombogenicity, cholesterolaemic, oxidability, peroxidizability and nutritive values in MAS-derived genotypes over original versions. Besides, the MAS-derived inbreds and hybrids exhibited comparable grain yield and phenotypic characteristics to the original versions. The maize hybrids developed in the study possessed high-yielding ability with high kernel oil and OA, low PA, better fatty acid health and nutritional properties, higher multi-vitamins and balanced amino acids, which hold immense significance to address malnutrition and rising demand for oil sustainably in a fast-track manner.
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Óleo de Milho , Ácidos Graxos , Zea mays , Zea mays/genética , Zea mays/metabolismo , Óleo de Milho/metabolismo , Óleo de Milho/genética , Ácidos Graxos/metabolismo , Genômica/métodos , Vitamina E/metabolismo , Ácido Oleico/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Sementes/genética , Sementes/metabolismo , Sementes/química , Ácido Palmítico/metabolismo , Provitaminas/metabolismo , Alelos , Melhoramento Vegetal/métodos , Repetições de Microssatélites/genéticaRESUMO
BACKGROUND: Treatment of drug-resistant tuberculosis with bedaquiline-pretomanid-linezolid regimen has demonstrated good treatment efficacy. Given linezolid's toxicity profile, prudence suggests reconsidering its dose and duration. We determined the effectiveness and safety of structured dose reduction of linezolid with bedaquiline and pretomanid in adults with pre-extensively drug-resistant (pre-XDR) or treatment-intolerant/nonresponsive multidrug-resistant (MDRTI/NR) pulmonary tuberculosis. METHOD: Adults with pre-XDR or MDRTI/NR pulmonary tuberculosis were enrolled in a multicenter, parallel-group, randomized clinical trial in India. Patients were randomized to 26 weeks of bedaquiline, pretomanid, and daily linezolid, at 600â mg for 26 weeks (arm 1); 600â mg for 9 weeks followed by 300â mg for 17 weeks (arm 2); or 600â mg for 13 weeks followed by 300â mg for 13 weeks (arm 3). Study end points included sustained cure, bacteriological failure, toxicity, and death. RESULTS: Of 403 patients enrolled, 255 (63%) were <30 years old, 273 (68%) had prior tuberculosis episodes, and 238 (59%) were malnourished. At the end of treatment, after excluding those with negative baseline cultures, cure was seen in 120 (93%), 117 (94%), and 115 (93%) in arms 1, 2, and 3 respectively. Myelosuppression seen in 85 patients each in arms 1 and 2 and 77 patients in arm 3, not significantly different. Peripheral neuropathy was noticed in 66 patients (30, 17, and 19 in arms 1, 2, and 3) at 10-26 weeks (P = .02). The linezolid dose was reduced because of toxicity in 13, 2, and 4 patients in arms 1, 2, and 3, respectively. CONCLUSIONS: In adults with pre-XDR or MDRTI/NR pulmonary tuberculosis, structured linezolid dose reduction to 300â mg/d is as effective as the standard 600-mg dose but with fewer cases of peripheral neuropathy when given with bedaquiline and pretomanid. CLINICAL TRIALS REGISTRATION: Clinical Trial Registry of India (CTRI/2021/03/032189).
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The ß-barrel assembly machinery (Bam) complex facilitates the assembly of outer membrane proteins (OMPs) in gram-negative bacteria. The Bam complex is conserved and essential for bacterial viability and consists of five subunits, BamA-E. BamA is the transmembrane component, and its ß-barrel domain opens laterally to allow folding and insertion of incoming OMPs. The remaining components are regulatory, among which only BamD is essential. Previous studies suggested that BamB regulates BamA directly, while BamE and BamC serve as BamD regulators. However, specific molecular details of their functions remain unknown. Our previous research demonstrated that BamE plays a specialized role in assembling the complex between the lipoprotein RcsF and its OMP partners, required for the Regulator of Capsule Synthesis (Rcs) stress response. Here, we used RcsF/OmpA as a model substrate to investigate BamE function. Our results challenge the current view that BamE only serves as a BamD regulator. We show that BamE also directly interacts with BamA. BamE interaction with both BamA and BamD is important for function. Our genetic and biochemical analysis shows that BamE stabilizes the Bam complex and promotes bidirectional signaling interaction between BamA and BamD. This BamE function becomes essential when direct BamA/BamD communication is impeded.
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Proteínas de Escherichia coli , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Proteínas da Membrana Bacteriana Externa/metabolismo , Lipoproteínas/genética , Lipoproteínas/metabolismoRESUMO
The beamline optics and endstations at branch B of the Versatile Soft X-ray (VerSoX) beamline B07 at Diamond Light Source are described. B07-B provides medium-flux X-rays in the range 45-2200â eV from a bending magnet source, giving access to local electronic structure for atoms of all elements from Li to Y. It has an endstation for high-throughput X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine-structure (NEXAFS) measurements under ultrahigh-vacuum (UHV) conditions. B07-B has a second endstation dedicated to NEXAFS at pressures from UHV to ambient pressure (1â atm). The combination of these endstations permits studies of a wide range of interfaces and materials. The beamline and endstation designs are discussed in detail, as well as their performance and the commissioning process.
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MAIN CONCLUSION: Silicon application mitigates phosphate deficiency in barley through an interplay with auxin and nitric oxide, enhancing growth, photosynthesis, and redox balance, highlighting the potential of silicon as a fertilizer for overcoming nutritional stresses. Silicon (Si) is reported to attenuate nutritional stresses in plants, but studies on the effect of Si application to plants grown under phosphate (Pi) deficiency are still very scarce, especially in barley. Therefore, the present work was undertaken to investigate the potential role of Si in mitigating the adverse impacts of Pi deficiency in barley Hordeum vulgare L. (var. BH902). Further, the involvement of two key regulatory signaling molecules--auxin and nitric oxide (NO)--in Si-induced tolerance against Pi deficiency in barley was tested. Morphological attributes, photosynthetic parameters, oxidative stress markers (O2·-, H2O2, and MDA), antioxidant system (enzymatic--APX, CAT, SOD, GR, DHAR, MDHAR as well as non-enzymatic--AsA and GSH), NO content, and proline metabolism were the key traits that were assessed under different treatments. The P deficiency distinctly declined growth of barley seedlings, which was due to enhancement in oxidative stress leading to inhibition of photosynthesis. These results were also in parallel with an enhancement in antioxidant activity, particularly SOD and CAT, and endogenous proline level and its biosynthetic enzyme (P5CS). The addition of Si exhibited beneficial effects on barley plants grown in Pi-deficient medium as reflected in increased growth, photosynthetic activity, and redox balance through the regulation of antioxidant machinery particularly ascorbate-glutathione cycle. We noticed that auxin and NO were also found to be independently participating in Si-mediated improvement of growth and other parameters in barley roots under Pi deficiency. Data of gene expression analysis for PHOSPHATE TRANSPORTER1 (HvPHT1) indicate that Si helps in increasing Pi uptake as per the need of Pi-deficient barley seedlings, and also auxin and NO both appear to help Si in accomplishing this task probably by inducing lateral root formation. These results are suggestive of possible application of Si as a fertilizer to correct the negative effects of nutritional stresses in plants. Further research at genetic level to understand Si-induced mechanisms for mitigating Pi deficiency can be helpful in the development of new varieties with improved tolerance against Pi deficiency, especially for cultivation in areas with Pi-deficient soils.
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Hordeum , Ácidos Indolacéticos , Óxido Nítrico , Estresse Oxidativo , Fosfatos , Fotossíntese , Raízes de Plantas , Silício , Hordeum/metabolismo , Hordeum/genética , Hordeum/efeitos dos fármacos , Hordeum/crescimento & desenvolvimento , Hordeum/fisiologia , Silício/farmacologia , Silício/metabolismo , Ácidos Indolacéticos/metabolismo , Fosfatos/deficiência , Fosfatos/metabolismo , Óxido Nítrico/metabolismo , Raízes de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Fotossíntese/efeitos dos fármacos , Antioxidantes/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Plântula/genética , Plântula/efeitos dos fármacos , Plântula/fisiologiaRESUMO
Bioconversion of abundant lactose-replete whey permeate to value-added chemicals holds promise for valorization of this expanding food processing waste. Efficient conversion of whey permeate-borne lactose requires adroit microbial engineering to direct carbon to the desired chemical. An engineered strain of Clostridium beijerinckii NCIMB 8052 (C. beijerinckii_mgsA+mgR) that produces 87% more butanol on lactose than the control strain was assessed for global transcriptomic changes. The results revealed broadly contrasting gene expression patterns in C. beijerinckii_mgsA+mgR relative to the control strain. These were characterized by widespread decreases in the abundance of mRNAs of Fe-S proteins in C. beijerinckii_mgsA+mgR, coupled with increased differential expression of lactose uptake and catabolic genes, iron uptake genes, two-component signal transduction and motility genes, and genes involved in the biosynthesis of vitamins B5 and B12, aromatic amino acids (particularly tryptophan), arginine, and pyrimidines. Conversely, the mRNA patterns suggest that the L-aspartate-dependent de novo biosynthesis of NAD as well as biosynthesis of lysine and asparagine and metabolism of glycine and threonine were likely down-regulated. Furthermore, genes involved in cysteine and methionine biosynthesis and metabolism, including cysteine desulfurase-a central player in Fe-S cluster biosynthesis-equally showed reductions in mRNA abundance. Genes involved in biosynthesis of capsular polysaccharides and stress response also showed reduced mRNA abundance in C. beijerinckii_mgsA+mgR. The results suggest that remodeling of cellular and metabolic networks in C. beijerinckii_mgsA+mgR to counter anticipated effects of methylglyoxal production from heterologous expression of methylglyoxal synthase led to enhanced growth and butanol production in C. beijerinckii_mgsA+mgR. IMPORTANCE: Biological production of commodity chemicals from abundant waste streams such as whey permeate represents an opportunity for decarbonizing chemical production. Whey permeate remains a vastly underutilized feedstock for bioproduction purposes. Thus, enhanced understanding of the cellular and metabolic repertoires of lactose-mediated production of chemicals such as butanol promises to identify new targets that can be fine tuned in recombinant and native microbial strains to engender stronger coupling of whey permeate-borne lactose to value-added chemicals. Our results highlight new genetic targets for future engineering of C. beijerinckii for improved butanol production on lactose and ultimately in whey permeate.
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Clostridium beijerinckii , Lactose , Transcriptoma , Clostridium beijerinckii/genética , Clostridium beijerinckii/metabolismo , Clostridium beijerinckii/enzimologia , Lactose/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clostridium/genética , Clostridium/metabolismo , Clostridium/enzimologia , Engenharia Metabólica , Butanóis/metabolismo , Soro do Leite/metabolismoRESUMO
We demonstrate a single-photon counting Raman spectroscope and benchmark it against conventional and surface-enhanced Raman spectroscopy. For direct comparison without ambiguity, we use the same solutions of Rhodamine 6G and a common optical setup with either a spectrometer or an acousto-optic tunable filter, whereas the surface enhancement is realized with immobilized Ag nanoparticles. Our results find that the single photon counting significantly elevates the detection sensitivity by up to eight orders of magnitude, arriving at a comparable level of surface-enhanced Raman spectroscopy. Another significant advantage is with the time-resolving measurement, where we demonstrate time-gated and time-correlated single-photon counting with sub-nanosecond resolution. It offers insights into the samples' transient responses and enables the isolation of Raman scattering from fluorescence signals.
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Doxorubicin (DOX) is an important drug for cancer treatment, but its clinical application is limited due to its toxicity and side effects. Therefore, detecting the concentration of DOX during treatment is crucial for enhancing efficacy and reducing side effects. In this study, the authors developed a biophotonic fiber sensor based on localized surface plasmon resonance (LSPR) with the multimode fiber (MMF)-four core fiber (FCF)-seven core fiber (SCF)-MMF-based direct-taper and anti-taper structures for the specific detection of DOX. Compared to other detection methods, it has the advantages of high sensitivity, low cost, and strong anti-interference ability. In this experiment, multi-walled carbon nanotubes (MWCNTs), cerium-oxide nanorods (CeO2-NRs), and gold nanoparticles (AuNPs) were immobilized on the probe surface to enhance the sensor's biocompatibility. MWCNTs and CeO2-NRs provided more binding sites for the fixation of AuNPs. By immobilizing AuNPs on the surface, the LSPR was stimulated by the evanescent field to detect DOX. The sensor surface was functionalized with DOX aptamers for specific detection, enhancing its specificity. The experiments demonstrated that within a linear detection range of 0-10 µM, the sensitivity of the sensor is 0.77 nm/µM, and the limit of detection (LoD) is 0.42 µM. Additionally, the probe's repeatability, reproducibility, stability, and selectivity were evaluated, indicating that the probe has high potential for detecting DOX during cancer treatment.
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Doxorrubicina , Ouro , Nanopartículas Metálicas , Ressonância de Plasmônio de Superfície , Doxorrubicina/farmacologia , Humanos , Ressonância de Plasmônio de Superfície/instrumentação , Ouro/química , Nanopartículas Metálicas/química , Neoplasias/tratamento farmacológico , Nanotubos de Carbono/química , Técnicas Biossensoriais/instrumentação , Fibras Ópticas , Desenho de Equipamento , Antibióticos Antineoplásicos/análise , Cério/química , Tecnologia de Fibra Óptica/instrumentaçãoRESUMO
In this paper, a highly sensitive sensor consisting of a silicon nanorod and symmetric rings (SNSR) is presented. Theoretically, three Fano resonances with high Q-factors are excited in the near-infrared range by breaking the symmetry structure based on quasi-bound states in the continuum (Q-BICs). The electromagnetic near-field analysis confirms that the resonances are mainly controlled by toroidal dipole (TD) resonance. The structure is optimized by adjusting different geometrical parameters, and the maximum Q-factor of the Fano resonances can reach 7427. To evaluate the sensing performance of the structure, the sensitivity and the figure of merit (FOM) are calculated by adjusting the environmental refractive index: the maximum sensitivity of 474â nm/RIU and the maximum FOM of 3306 RIU-1. The SNSR can be fabricated by semiconductor-compatible processes, which is experimentally evaluated for changes in transmission spectra at different solution concentrations. The results show that the sensitivity and the Q-factor of the designed metasurface can reach 295â nm/RIU and 850, while the FOM can reach 235 RIU-1. Therefore, the metasurface of SNSR is characterized by high sensitivity and multi-wavelength sensing, which are current research hotspots in the field of optics and can be applied to biomedical sensing and multi-target detection.
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Every year, millions of people suffer some form of illness associated with the consumption of contaminated food. Escherichia coli (E. coli), found in the intestines of humans and other animals, is commonly associated with various diseases, due to the existence of pathogenic strains. Strict monitoring of food products for human consumption is essential to ensure public health, but traditional cell culture-based methods are associated with long waiting times and high costs. New approaches must be developed to achieve cheap, fast, and on-site monitoring. Thus, in this work, we developed optical fiber sensors based on surface plasmon resonance. Gold and cysteamine-coated fibers were functionalized with anti-E. coli antibody and tested using E. coli suspensions with concentrations ranging from 1 cell/mL to 105 cells/mL. An average logarithmic sensitivity of 0.21 ± 0.01â nm/log(cells/mL) was obtained for three independent assays. An additional assay revealed that including molybdenum disulfide resulted in an increase of approximately 50% in sensitivity. Specificity and selectivity were also evaluated, and the sensors were used to analyze contaminated water samples, which verified their promising applicability in the aquaculture field.
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Técnicas Biossensoriais , Ressonância de Plasmônio de Superfície , Animais , Humanos , Ressonância de Plasmônio de Superfície/métodos , Escherichia coli , Fibras Ópticas , Técnicas Biossensoriais/métodos , ImunoensaioRESUMO
Spatial-mode projective measurements could achieve super-resolution in remote sensing and imaging, yet their performance is usually sensitive to the parameters of the target scenes. We propose and demonstrate a robust classifier of close-by light sources using optimized mode projection via nonlinear optics. Contrary to linear-optics based methods using the first few Hermite-Gaussian (HG) modes for the projection, here the projection modes are optimally tailored by shaping the pump wave to drive the nonlinear-optical process. This minimizes modulation losses and allows high flexibility in designing those modes for robust and efficient measurements. We test this classifier by discriminating one light source and two sources separated well within the Rayleigh limit without prior knowledge of the exact centroid or brightness. Our results show a classification fidelity of over 80% even when the centroid is misaligned by half the source separation, or when one source is four times stronger than the other.
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BACKGROUND: High-risk strains of HPV are known to cause cervical cancer. Multiple clinical studies have emphasized that smoking and drinking are critical risk factors for cervical cancer and its high-grade precursors. In this study, we investigated if smoking and/or drinking augment the molecular mechanisms of cervical carcinogenesis and defined a potential therapeutic approach for their attenuation. METHODS: The impact of benzo[a]pyrene (B[a]P) and/or ethanol (EtOH) exposure on cervical cancer cells was assessed by measuring changes in their cell migration and invasion characteristics. Expression of HPV16 E6/E7, NF-κB, cytokines, and inflammation mediators was determined using qRT-PCR, immunoblotting, ELISA, luciferase reporter assay, and confocal microscopy. Herein, we used curcumin (Cur), and PLGA nanoparticle formulation of curcumin (PLGA-Cur) and determined effectiveness of free Cur and PLGA-Cur formulation on smoking and drinking activated NF-κB/IL-6 mediated inflammatory signaling pathways using in vitro cervical cancer models. RESULTS: Treatments with B[a]P and/or EtOH altered the expression of HPV16 E6/E7 oncogenes and EMT markers in cervical cancer cells; it also enhanced migration and invasion. In addition, B[a]P and/or EtOH exposure promoted inflammation pathways through TNF-α and NF-κB signaling, leading to IL-6 upregulation and activation of VEGF. The molecular effects caused by B[a]P and/or EtOH exposure were effectively attenuated by curcumin (Cur)/PLGA-Cur treatment. CONCLUSIONS: These data suggest a molecular link between smoking, drinking, and HPV infectivity in cervical carcinogenesis. In addition, attenuation of these effects by treatment with Cur/PLGA-Cur treatment, implies the role of curcumin in cervical cancer prevention and treatment.
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Helicobacter pylori (H. pylori) seems to play causative roles in gastric cancers. H. pylori has also been detected in established gastric cancers. How the presence of H. pylori modulates immune response to the cancer is unclear. The cytotoxicity of natural killer (NK) cells, toward infected or malignant cells, is controlled by the repertoire of activating and inhibitory receptors expressed on their surface. Here, we studied H. pylori-induced changes in the expression of ligands, of activating and inhibitory receptors of NK cells, in the gastric adenocarcinoma AGS cells, and their impacts on NK cell responses. AGS cells lacked or had low surface expression of the class I major histocompatibility complex (MHC-I) molecules HLA-E and HLA-C-ligands of the major NK cell inhibitory receptors NKG2A and killer-cell Ig-like receptor (KIR), respectively. However, AGS cells had high surface expression of ligands of activating receptors DNAM-1 and CD2, and of the adhesion molecules LFA-1. Consistently, AGS cells were sensitive to killing by NK cells despite the expression of inhibitory KIR on NK cells. Furthermore, H. pylori enhanced HLA-C surface expression on AGS cells. H. pylori infection enhanced HLA-C protein synthesis, which could explain H. pylori-induced HLA-C surface expression. H. pylori infection enhanced HLA-C surface expression also in the hepatoma Huh7 and HepG2 cells. Furthermore, H. pylori-induced HLA-C surface expression on AGS cells promoted inhibition of NK cells by KIR, and thereby protected AGS cells from NK cell cytotoxicity. These results suggest that H. pylori enhances HLA-C expression in host cells and protects them from the cytotoxic attack of NK cells expressing HLA-C-specific inhibitory receptors.
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Adenocarcinoma , Infecções por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Humanos , Adenocarcinoma/genética , Adenocarcinoma/microbiologia , Adenocarcinoma/patologia , Infecções por Helicobacter/genética , Infecções por Helicobacter/patologia , Helicobacter pylori/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Antígenos HLA-C/genética , Antígenos HLA-C/metabolismo , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/patologia , Receptores Imunológicos/metabolismo , Receptores KIR/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologiaRESUMO
BACKGROUND: TSP1 (thrombospondin-1)-a well-known angiogenesis inhibitor-mediates differential effects via interacting with cell surface receptors including CD36 (cluster of differentiation) and CD47. However, the role of TSP1 in regulating lymphangiogenesis is not clear. Our previous study suggested the importance of cell-specific CD47 blockade in limiting atherosclerosis. Further, our experiments revealed CD47 as a dominant TSP1 receptor in lymphatic endothelial cells (LECs). As the lymphatic vasculature is functionally linked to atherosclerosis, we aimed to investigate the effects of LEC TSP1-CD47 signaling inhibition on lymphangiogenesis and atherosclerosis. METHODS: Murine atherosclerotic and nonatherosclerotic arteries were utilized to investigate TSP1 expression using Western blotting and immunostaining. LEC-specific knockout mice were used to determine the in vivo role of LEC Cd47 in lymphangiogenesis and atherosclerosis. Various in vitro cell-based assays, in vivo Matrigel plug implantation, molecular biological techniques, and immunohistological approaches were used to evaluate the underlying signaling mechanisms. RESULTS: Elevated TSP1 expression was observed in mouse atherosclerotic aortic tissue compared with nonatherosclerotic control tissue. TSP1 at pathological concentrations suppressed both in vitro and in vivo lymphangiogenesis. Mechanistically, TSP1 inhibited VEGF (vascular endothelial growth factor)-C-induced AKT and eNOS activation in LEC and attenuated NO (nitric oxide) production. Further, CD47 silencing in LEC prevented the effects of TSP1 on lymphangiogenic AKT-eNOS signaling and lymphangiogenesis. Atheroprone AAV (adeno-associated virus) 8-PCSK9-injected LEC-specific Cd47 knockout mice (Cd47ΔLEC) had reduced atherosclerosis in both aorta and aortic root compared with control mice (Cd47ΔWT). However, no differences in metabolic parameters including body weight, plasma total cholesterol levels, and fasting blood glucose were observed. Additional immunostaining experiments performed on aortic root cross-sections indicated higher lymphatic vessel density in Cd47ΔLEC mice in comparison to controls. CONCLUSIONS: These findings demonstrate that TSP1 inhibits lymphangiogenesis via activation of CD47 in LEC, and loss of LEC Cd47 attenuates atherosclerotic lesion formation. Collectively, these results identify LEC CD47 as a potential therapeutic target in atherosclerosis.
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Aterosclerose , Células Endoteliais , Animais , Camundongos , Aterosclerose/genética , Aterosclerose/prevenção & controle , Aterosclerose/metabolismo , Antígeno CD47/genética , Antígeno CD47/metabolismo , Células Endoteliais/metabolismo , Linfangiogênese , Camundongos Knockout , Pró-Proteína Convertase 9/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Trombospondina 1/genética , Trombospondina 1/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
In recent years, significant advancements in nanotechnology have improved the various disciplines of scientific fields. Nanomaterials, like, carbon-based (carbon nanotubes, graphene), metallic, metal oxides, conductive polymers, and 2D materials (MXenes) exhibit exceptional electrical conductivity, mechanical strength, flexibility, thermal property and chemical stability. These materials hold significant capability in transforming material science and biomedical engineering by enabling the creation of more efficient, miniaturized, and versatile devices. The indulgence of nanotechnology with conductive materials in biological fields promises a transformative innovation across various industries, from bioelectronics to environmental regulations. The conductivity of nanomaterials with a suitable size and shape exhibits unique characteristics, which provides a platform for realization in bioelectronics as biosensors, tissue engineering, wound healing, and drug delivery systems. It can be explored for state-of-the-art cardiac, skeletal, nerve, and bone scaffold fabrication while highlighting their proof-of-concept in the development of biosensing probes and medical imaging. This review paper highlights the significance and application of the conductive nanomaterials associated with conductivity and their contribution towards a new perspective in improving the healthcare system globally.
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Técnicas Biossensoriais , Condutividade Elétrica , Nanoestruturas , Engenharia Tecidual , Nanoestruturas/química , Humanos , Engenharia Tecidual/métodos , Técnicas Biossensoriais/métodos , Engenharia Biomédica/métodos , Sistemas de Liberação de Medicamentos , Nanotubos de Carbono/química , Animais , Nanotecnologia/métodos , Grafite/químicaRESUMO
Schizophrenia is a neuropsychiatric disorder characterized by various symptoms such as hallucinations, delusions, and disordered thinking. The etiology of this disease is unknown; however, it has been linked to many microdeletion syndromes that are likely to contribute to the pathology of schizophrenia. In this review we have comprehensively analyzed the role of various microdeletion syndromes, like 3q29, 15q13.3, and 22q11.2, which are known to be involved with schizophrenia. A variety of factors lead to schizophrenia phenotypes, but copy number variants that disrupt gene regulation and impair brain function and cognition are one of the causes that have been identified. Multiple case studies have shown that loss of one or more genes in the microdeletion regions lead to brain activity defects. In this article, we present a coherent paradigm that connects copy number variations (CNVs) to numerous neurological and behavioral abnormalities associated with schizophrenia. It would be helpful in understanding the different aspects of the microdeletions and how they contribute in the pathophysiology of schizophrenia.
Assuntos
Deleção Cromossômica , Variações do Número de Cópias de DNA , Esquizofrenia , Humanos , Esquizofrenia/genética , Variações do Número de Cópias de DNA/genética , Fenótipo , Cromossomos Humanos Par 15/genética , Predisposição Genética para Doença , Deficiência Intelectual/genética , Transtornos Cromossômicos/genética , Deficiências do Desenvolvimento , Cromossomos Humanos Par 3 , ConvulsõesRESUMO
Copper iodide, an environmentally friendly material abundant in nature, holds great significance for room temperature thermoelectric (TE) applications owing to its high Seebeck coefficient and optical transparency. However, to fully unlock its thermoelectric potential and match the performance of conventional TE materials, there is a need to further enhance its electrical conductivity. In this study, we have successfully synthesized nano-crystalline powders of both undoped and aluminium-doped CuI at room temperature using the chemical precipitation method in an ethanol medium. The concentration of aluminium dopant has been optimized to maximize TE performance. At 400 K, the highest TE power factor and figure of merit achieved are 79 µW m-1 K-2 and 0.08, respectively, for CuI doped with 0.1 mol% Al. This enhancement in TE properties can be attributed to the increased carrier density resulting from aluminium doping. The impact of aluminium doping on the temperature-dependent thermal conductivity has been investigated, and the findings are explained by the decay mechanism of optical phonons, supported by the anharmonic phonon coupling theory. Our work delves into the evolution of structural, thermal, optical, and TE properties of CuI upon aluminium (Al) doping. The results provide valuable insights into the future application of CuI in transparent thermoelectric and optoelectronic fields.
RESUMO
Dopamine receptors are therapeutic targets for the treatment of various neurological and psychiatric disorders, including Parkinson's and Alzheimer's. Previously, PF-06649751 (tavapadon), PF-2562 and PW0464 have been discovered as potent and selective G protein-biased D1/D5 receptor agonists with optimal pharmacokinetic properties. However, no selective D5R agonist has been reported yet. In this context, we designed and synthesized forty non-catecholamines-based pyrimidine derivatives and identified four pyrimidine derivatives as selective D5R partial agonists. Using cAMP-based GloSensor assay in transiently transfected HEK293T cells with human D1 or D5 receptors, we discovered that compound 5c (4-(4-bromophenyl)-6-(2,4,5-trimethoxyphenyl)pyrimidin-2-amine) exhibited modest D5R agonist activity. This leads us to explore various modifications of this scaffold to improve the D5 agonist potency and efficacy. Using molecular docking, and rational design followed by their evaluation at D1 and D5 receptors for agonist activity, we identified three new derivatives, 5j, 5h, and 5e. The most potent compound of this series 5j (4-(4-iodophenyl)-6-(2,4,5-trimethoxyphenyl)pyrimidin-2-amine), exhibited EC50 of 269.7 ± 6.6 nM. Mice microsomal stability studies revealed that 5j is quite stable (>70 % at 1 hr). Furthermore, pharmacokinetic analysis of 5j (20 mg/kg, p.o) in C57BL/6j mice showed that 5j is readily absorbed via oral route of dosing and also enters into the brain (plasma Tmax: 1 h, Cmax: 51.10 ± 13.51 ng/ml; Brain Tmax: 0.5 h, Cmax: 22.54 ± 4.08 ng/ml). We further determined the in-vivo effect of 5j on cognition in scopolamine-induced amnesia in C57BL/6j mice. We observed that 5j (10 mg/kg, p.o) alleviated scopolamine-induced impairment in short-term memory and social recognition, which were blocked by D1/D5 antagonist SCH23390 (0.1 mg/kg, i.p.). Furthermore, 5j did not exhibit any cytotoxicity (up to 10 µM) or in vivo acute toxicity up to 200 mg/kg (p.o). These results strongly suggest that 5j could be further developed for treating neurological disorders wherein the D5 receptors play pivotal roles.