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Association of the cellular adhesive protein CD44 and the N-terminal (FERM) domain of cytoskeleton adaptors is critical for cell proliferation, migration, and signaling. Phosphorylation of the cytoplasmic domain (CTD) of CD44 acts as an important regulator of the protein association, but the structural transformation and dynamics mechanism remain enigmatic. In this study, extensive coarse-grained simulations were employed to explore the molecular details in the formation of CD44-FERM complex under S291 and S325 phosphorylation, a modification path known to exert reciprocal effects on the protein association. We find that phosphorylation of S291 inhibits complexation by causing the CTD of CD44 to adopt a more closed structure. In contrast, S325 phosphorylation liberates the CD44-CTD from the membrane surface and promotes the linkage with FERM. The phosphorylation-driven transformation is found to occur in a PIP2-dependent manner, with PIP2 effecting the relative stability of the closed and open conformation, and a replacement of PIP2 by POPS greatly abrogates this effect. The revealed interdependent regulation mechanism by phosphorylation and PIP2 in the association of CD44 and FERM further strengthens our understanding of the molecular basis of cellular signaling and migration.
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Citoesqueleto , Proteínas , Transducción de Señal , Conformación Molecular , Unión ProteicaRESUMEN
Transmissibility of SARS-CoV-2 initially relies on its trimeric Spike-RBDs to tether the ACE-2 on host cells, and enhanced self-association of ACE-2 engaged with Spike facilitates the viral infection. Two primary packing modes of Spike-ACE2 heteroproteins exist potentially due to discrepant amounts of RBDs loading on ACE-2, but the resultant self-association difference is inherently unclear. We used extensive coarse-grained dynamic simulations to characterize the self-association efficiency, the conformation relevance, and the molecular mechanism of ACE-2 with different RBD amounts. It was revealed that the ACE-2 hanging two/full RBDs (Mode-A) rapidly dimerized into the heteroprotein complex in a compact "linear" conformation, while the bare ACE-2 showed weakened self-association and a protein complex. The RBD-tethered ectodomains of ACE-2 presented a more upright conformation relative to the membrane, and the intermolecular ectodomains were predominantly packed by the neck domains, which was obligated to the rapid protein self-association in a compact pattern. Noted is the fact that the ACE-2 tethered by a single RBD (Mode-B) retained considerable self-association efficiency and clustering capability, which unravels the interrelation of ACE-2 colocalization and protein cross-linkage. The molecular perspectives in this study expound the self-association potency of ACE-2 with different RBD amounts and the viral activity implications, which can greatly enhance our comprehension of SARS-CoV-2 infection details.
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COVID-19 , Humanos , Análisis por Conglomerados , Dimerización , Simulación de Dinámica Molecular , Unión Proteica , SARS-CoV-2RESUMEN
The homodimerization of CD44 plays a key role in an intercellular-to-extracellular signal transduction and tumor progression. Acylated modification and specific membrane environments have been reported to mediate translocation and oligomerization of CD44; however, the underlying molecular mechanism remains elusive. In this study, extensive molecular dynamics simulations are performed to characterize the dimerization of palmitoylated CD44 variants in different bilayer environments. CD44 forms homodimer depending on the cysteines on the juxta-membrane domains, and the dimerization efficiency and packing configurations are defected by their palmitoylated modifications. In the phase-segregated (raft included) membrane, homodimerization of the palmitoylated CD44 is hardly observed, whereas PIP2 addition compensates to realize dimerization. However, the structure of CD44 homodimer formed in the phase-segregated bilayer turns susceptive and PIP2 addition allows for an extensive conformation of the cytoplasmic domain, a proposal prerequisite to access the cytoskeleton linker proteins. The results unravel a delicate competitive relationship between PIP2, lipid raft, and palmitoylation in mediating protein homodimerization, which helps to clarify the dynamic dimer conformations and involved cellular signaling of the CD44 likewise proteins.
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Lipoilación , Microdominios de Membrana , Membrana Celular/metabolismo , Dimerización , Microdominios de Membrana/metabolismo , Simulación de Dinámica Molecular , Proteínas/metabolismoRESUMEN
As plant-specific transcription regulators, YABBYs are involved in plant growth, development and stress responses. However, little information is available about genome-wide screening and identification of OsYABBY-interacting proteins. In this study, phylogenetic relationship, gene structure, protein structure and gene expression profile of eight OsYABBYs were carried out, all of which indicated that OsYABBYs were involved in different developmental processes and had functional differentiation. More importantly, PPI (protein-protein interaction) analysis and molecular docking simulation predicted that WUSCHEL-related homeobox (WOX) proteins might be interacting proteins of OsYABBYs. Yeast two-hybrid (Y2H) and luciferase complementation imaging assays (LCI) further confirmed that OsYABBYs (except for OsYABBY7) could interact with OsWOX3A in vitro and in vivo. In addition, OsYABBY3 and OsYABBY5 also could interact with OsWUS. Taken together, our results provided valuable information for further elucidating OsYABBYs regulation mechanism in improving rice performance.
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Oryza , Oryza/genética , Simulación del Acoplamiento Molecular , Filogenia , Bioensayo , Genes Homeobox , Saccharomyces cerevisiaeRESUMEN
AIMS: To investigate the potential of imDCs with high expression of HO-1 in preventing or delaying the onset of Type 1 diabetes mellitus (T1DM) in non-obese diabetic (NOD) mice. MATERIALS AND METHODS: The phenotypic features of DCs in each group were assessed using flow cytometry. Western blot analysis was used to confirm the high expression of HO-1 in imDCs induced with CoPP. Additionally, flow cytometry was used to evaluate the suppressive capacity of CoPP-induced imDCs on splenic lymphocyte proliferation. Finally, the preventive effect of CoPP-induced imDCs was tested in NOD mice. KEY FINDINGS: Compared to imDCs, CoPP-induced imDCs exhibited a reduced mean fluorescence intensity (MFI) of the co-stimulatory molecule CD80 on their surface (P < 0.05) and significantly increased HO-1 protein expression (P < 0.05). Following LPS stimulation, the MFI of co-stimulatory molecules CD80 and CD86 on the surface of CoPP-induced imDCs remained at a lower level (P < 0.05). Furthermore, there was a reduced proliferation rate of lymphocytes stimulated with anti-CD3/28 antibodies. The adoptive transfer of CoPP-imDCs significantly reduced the incidence of T1DM (16.66 % vs. control group: 66.67 %, P = 0.004). Furthermore, at 15 weeks of age, the insulitis score was also decreased in the CoPP-induced imDC treatment group (P < 0.05). There were no significant differences in serum insulin levels among all groups. SIGNIFICANCE: ImDCs induced with CoPP and exhibiting high expression of HO-1 demonstrate a robust ability to inhibit immune responses and effectively reduce the onset of diabetes in NOD mice. This finding suggests that CoPP-induced imDCs could potentially serve as a promising treatment strategy for T1DM.
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Diabetes Mellitus Tipo 1 , Animales , Ratones , Traslado Adoptivo , Células Cultivadas , Células Dendríticas , Diabetes Mellitus Tipo 1/prevención & control , Diabetes Mellitus Tipo 1/metabolismo , Hemo-Oxigenasa 1/metabolismo , Ratones Endogámicos NODRESUMEN
The effectiveness of silicon (Si) and silicon-based materials in catalyzing photoelectrochemistry (PEC) CO2 reduction is limited by poor visible light absorption. In this study, we prepared two-dimensional (2D) silicon-based photonic crystals (SiPCs) with circular dielectric pillars arranged in a square array to amplify the absorption of light within the wavelength of approximately 450 nm. By investigating five sets of n + p SiPCs with varying dielectric pillar sizes and periodicity while maintaining consistent filling ratios, our findings showed improved photocurrent densities and a notable shift in product selectivity towards CH4 (around 25% Faradaic Efficiency). Additionally, we integrated platinum nanoparticles, which further enhanced the photocurrent without impacting the enhanced light absorption effect of SiPCs. These results not only validate the crucial role of SiPCs in enhancing light absorption and improving PEC performance but also suggest a promising approach towards efficient and selective PEC CO2 reduction.
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In this study, a novel microcirculation chromatography with pulsed amperometric discovery (IC/PAD) system is established for the cyanide in business sewage. For business sewage with complicated substrates, the microstrewing means is leveraged for purification and decoration, and subsequently, the IC/PAD course is utilized to psychoanalyze and accuse the cyanide in the match. Under optimum plight, cyanide exhibits some kind of linearity in the frequency of 1.0-200.0 µg/L, and the perception termination and quantification check of cyanide in business sewage are 0.15 µg/L and 0.5 0 µg/L, respectively. The scold is between 88.6% and 1 08.5%. This mode is highly caring, tenacious and awesome, and calm to manage. It offers recent discrimination for the discovery of cyanide in business sewage. In this case, the insincere-frequent uninterrupted inundate analyzer is to decide business sewage with comprehensive distinction in ammonium propellant major. The spring is compared with the mensuration rise of Nessler's test spectrophotometry. The rise has shown that when the double-stroll regularity of extended overflow analyzer is a manner to simultaneously moderate lofty and blaze concentrations of ammonia packaging gas, there is no important contention compared with the mensuration inference of Nessler's test spectrophotometry. The analysis of the regularity has whole reagents, and harmless and strong transformation. This can optimally decrease the effort intenseness of testers and is valuable of preferment. Index Terms-DE oxidation, industrial wastewater, purification, fuzzy control, simulation.
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Purificación del Agua , Cianuros/análisis , Aguas del AlcantarilladoRESUMEN
Purpose: To investigate the effectiveness and safety of gonadotropin-releasing hormone analogue (GnRHa) in combination with recombinant human growth hormone (rhGH) in girls with central precocious puberty (CPP). Methods: Clinical data of 80 girls diagnosed with idiopathic central precocious puberty (ICPP) between January 2017 and June 2021 were retrospectively analyzed. Treatment strategy involved GnRHa alone (group A: n=34) and GnRHa+rhGH (group B: n=46). Children's heights (Ht), weights (Wt) and sex hormone levels were measured every 3 months after treatment and bone age (BA) every six months. Heights, growth velocity (GV), predicted adult height (PAH), weights, body mass index (BMI), sex hormone levels and bone age were compared between the two groups. Results: Children in group B showed greater height gain at the 12th, 24th and 30th months after treatment (p<0.05) than those in group A, had faster growth rates in the first and second year following treatment (p<0.05) and better PAH (p<0.05). No statistical differences in weight or BMI were found between the two groups before treatment or at any time after treatment (p>0.05). Levels of LH and FSH were lower in both groups after treatment with no statistical differences between groups (p>0.05). The gap between bone age and chronological age gradually decreased in both groups and no abnormal progression of bone age or other adverse side effects occurred. Conclusions: The combination of GnRHa with rhGH produced better height gains than GnRHa alone for patients with CPP. The gonadal axis was suppressed and progression of bone age delayed with good safety and efficacy.
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Hormona de Crecimiento Humana , Pubertad Precoz , Niño , Femenino , Adulto , Humanos , Lactante , Pubertad Precoz/tratamiento farmacológico , Pubertad Precoz/inducido químicamente , Hormona de Crecimiento Humana/uso terapéutico , Hormona Liberadora de Gonadotropina , Estudios Retrospectivos , Estatura , Hormonas Esteroides GonadalesRESUMEN
The development of nanozymes with enhanced catalytic activity has been drawing great interest. Lentinan with special structure may be used to prepare bimetallic nanomaterials to enhance their catalytic activity. Herein, lentinan stabilized PdPt3 dendritic nanoparticles (PdPt3-LNT NDs) were prepared through reduction of Na2PdCl4 and K2PtCl4 with a molar ratio of 1:3 using lentinan as a biological template. PdPt3-LNT NDs had dendritic shape with size of 10.76 ± 1.82 nm. PdPt3-LNT NDs had the hydrodynamic size about 25.7 nm and the zeta potential between -1.4 mV and - 4.9 mV at different pH. Furthermore, PdPt3-LNT NDs catalyzed 3,3',5,5'-tetramethylbenzidine (TMB) to produce oxidized TMB, suggesting their oxidase-like property. The catalytic activity of PdPt3-LNT NDs was the highest when pH was 4 and the temperature was 40 °C. The catalytic mechanism was the generation of reactive oxygen species- from O2 catalyzed by PdPt3-LNT NDs. More importantly, L-cysteine detection method was set up based on the oxidase-like property of PdPt3-LNT NDs. This method had wide linear range for 0-200 µM and low detection limit for 3.099 µM. Taken together, PdPt3-LNT NDs have good potential applications in bio-related detection in the future.
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Lentinano , Nanopartículas , Cisteína , Lentinano/química , Oxidorreductasas , Especies Reactivas de OxígenoRESUMEN
Gold nanoparticles are a kind of good photothermal agents. However, gold nanoparticle photothermal agents have low photothermal conversion efficiency and low tumor inhibiting ability. To overcome these problems, polymyxin E (PE) biomineralized and doxorubicin-loaded gold nanoflowers (DOX-SH@AuNFs) nanodrug was synthesized by the green synthesis method using the biological antimicrobial peptide PE as a stabilizer and grower of crystal seed, and doxorubicin-thiol (DOX-SH) was further loaded on the gold nanoparticles through the Au-S bond. The final DOX-SH@AuNFs displayed a wide absorption band in the UV-Vis spectra, and their photothermal conversion efficiency was 33.9%. Furthermore, the inhibition rate of DOX-SH@AuNFs on A549 cells was as high as 80.1% under the irradiation of near-infrared light at 808 nm. The tumor inhibition rate of DOX-SH@AuNFs was as high as 87.81% in vivo experiments. The high tumor suppression rate was attributed to the high photothermal conversion ability of DOX-SH@AuNFs and the delivery of doxorubicin. Taken together, the method of preparing DOX-SH@AuNFs provides a new idea for the treatment of cancer by photothermal therapy and chemotherapy synergistic system.
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Hipertermia Inducida , Nanopartículas del Metal , Línea Celular Tumoral , Colistina , Doxorrubicina , Sistemas de Liberación de Medicamentos , Oro/química , Nanopartículas del Metal/química , Fototerapia , Terapia FototérmicaRESUMEN
Lactate is an energy substrate in adult brain especially when glucose is withdrawn or only lactate is present as main energy source. Besides, the most abundant lactate transporter in brain-monocarboxylate transporter 1 (MCT1)-was recognized recently. Despite this, MCT1 expressions in central nervous system (CNS) have not been clearly understood. Medial prefrontal cortex (mPFC), taking part in many higher executive functions in brain, is chosen here for observing MCT1 expressions in mice in 12 months. As results showed, MCT1 is gradually increased from an initial level at the 1st week to a high level at the 6th week and then gradually decreased to a low level at the 12th month. Besides, neuronal amounts change in a similar trend as MCT1 that neurons at the 6th week are more than that of at the 1st week and the 12th month. Also, MCT1 expressions are highly correlated with neuronal amounts, while MCT1 does not localize within neurons, instead localize around axons. On the other hand, MCT1 does localize to oligodendrocytes (OLs) without localizing to other glial cells (astrocytes and microglias). Importantly, the amounts of OLs change in a similar trend as MCT1, while the amounts of other glial cells do not change obviously in the mPFC in vivo in 12 months. These results demonstrate that the changeable expressions of MCT1 in the mPFC in vivo in 12 months may be mainly contributed by OLs and associate with the neuronal amounts. Above all, it infers that in vivo, MCT1 which is changeably expressed in OLs may further affect neuronal amounts in the mPFC in 12 months.
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Transportadores de Ácidos Monocarboxílicos/metabolismo , Neuronas/metabolismo , Oligodendroglía/metabolismo , Corteza Prefrontal/metabolismo , Simportadores/metabolismo , Animales , Astrocitos/metabolismo , Ácido Láctico/metabolismo , Ratones Endogámicos C57BLRESUMEN
Myelin destruction due to inflammatory damage of oligodendrocytes (OLs) in conjunction with axonal degeneration is one of the major histopathological hallmarks of multiple sclerosis (MS), a common autoimmune disorder affecting the central nervous system (CNS). Therapies over the last 20 years mainly focus on the immune system and, more specifically, on the modulation of immune cell behavior. It seems to be effective in MS with relapse, while it is of little benefit to progressive MS in which neurodegeneration following demyelination outweighs inflammation. Otherwise, remyelination, as a result of oligodendrocyte production from oligodendrocyte precursor cells (OPCs), is considered to be a potential target for the treatment of progressive MS. In this review, positive effects of remyelination on MS will be discussed in view of the critical role played by thyroid hormone (TH), focusing on the following points: (1) promising treatment of TH on MS that potentially targets to remyelination; (2) the active role of TH that is able to promote remyelination; (3) the regulative role of TH that works on endogenous stem and precursor cells; (4) the effect of TH on gene transcription; and (5) a working hypothesis which is developed that TH can alleviate MS by promoting remyelination, and the mechanism of which is its regulative role in gene transcription of OPCs.