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Oxidative stress has been considered to be closely related to spaceflight-induced bone loss; however, mechanism is elusive and there are no effective countermeasures. Using cultured rat calvarial osteoblasts exposed to microgravity simulated by a random positioning machine, this study addressed the hypotheses that microgravity-induced shortening of primary cilia leads to oxidative stress and that primary cilium protection prevents oxidative stress and osteogenesis loss. Microgravity was found to induce oxidative stress (as represented by increased levels of reactive oxygen species (ROS) and malondialdehyde production, and decreased activities of antioxidant enzymes), which was perfectly replicated in osteoblasts growing in NG with abrogated primary cilia (created by transfection of an interfering RNA), suggesting the possibility that shortening of primary cilia leads to oxidative stress. Oxidative stress was accompanied by mitochondrial dysfunction (represented by increased mitochondrial ROS and decreased mitochondrial membrane potential) and intracellular Ca2+ overload, and the latter was found to be caused by increased activity of Ca2+ channel transient receptor potential vanilloid 4 (TRPV4), as also evidenced by TRPV4 agonist GSK1016790A-elicited Ca2+ influx. Supplementation of HC-067047, a specific antagonist of TRPV4, attenuated microgravity-induced mitochondrial dysfunction, oxidative stress, and osteogenesis loss. Although TRPV4 was found localized in primary cilia and expressed at low levels in NG, microgravity-induced shortening of primary cilia led to increased TRPV4 levels and Ca2+ influx. When primary cilia were protected by miR-129-3p overexpression or supplementation with a natural flavonoid moslosooflavone, microgravity-induced increased TRPV4 expression, mitochondrial dysfunction, oxidative stress, and osteogenesis loss were all prevented. Our data revealed a new mechanism that primary cilia function as a controller for TRPV4 expression. Microgravity-induced injury on primary cilia leads to increased expression and overactive channel of TRPV4, causing intracellular Ca2+ overload and oxidative stress, and primary cilium protection could be an effective countermeasure against microgravity-induced oxidative stress and loss of osteogenic potential of osteoblasts.
Assuntos
Cílios , Osteoblastos , Osteogênese , Estresse Oxidativo , Canais de Cátion TRPV , Ausência de Peso , Animais , Ratos , Cílios/metabolismo , Osteoblastos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Canais de Cátion TRPV/agonistas , Canais de Cátion TRPV/antagonistas & inibidores , Canais de Cátion TRPV/metabolismo , Células Cultivadas , Morfolinas/farmacologia , Pirróis/farmacologia , GravitaçãoRESUMO
A mild and high efficient method to prepare indolizines by two-component reaction with the acid as the catalyst was developed. In this reaction, a new ring efficiently formed in one-step reaction. A wide range of substrates could be applied and the desired products were obtained in 8-95% yields under metal-free conditions. Different indolizine derivatives (compounds 3a-3n) were synthesized by general conditions and microwave irradiation conditions, and compound 3a gave the best results with an isolated yield of 95% and 82%, respectively. The structures of synthesized compounds were characterized by spectral analysis, and compound 3m was confirmed by single crystal X-ray analysis. UV-vis absorption and fluorescence properties of these compounds were correlated with substituent groups on indolizine rings.
Assuntos
Indolizinas , Pirazóis , Catálise , Estrutura Molecular , Espectrometria de FluorescênciaRESUMO
In present work, three-dimensional (3D) reduced graphene hydrogels (RGHs) are prepared through an efficient and facile strategy by employing three types of carbohydrates (glucose, fructose and sucrose) as reducing agents in aqueous solution of graphene oxide (GO) with ammonia. The formation of RGHs could be confirmed by X-ray powder diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The structures and porosity were characterized by field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and N2 sorption experiments. Benefiting from the abundant porous architectures as fast ionic channels for electrochemical energy storage, the prepared RGHs exhibited a high specific capacitance up to 153.5, 145.0 and 150.3 F g−1 at 0.3 A g−1 for FRGHs (fructose), GRGHs (glucose) and SRGHs (sucrose), which can be maintained for 61.4, 61.5 and 46.9% as the discharging current density was increased up to 20 A g−1. Moreover, it also showed that the electrode based on RGHs has good electrochemical stability and high degree of reversibility in the charge/discharge cycling test.
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Background: The diagnosis of allergic rhinitis is mainly based on the typical medical history, clinical manifestations, and corresponding allergen test results of the patients. However, there are often clinical inconsistencies among the 3. Objective: To study the clinical characteristics of patients with allergic rhinitis from both subjective and objective aspects to determine the correlations between the quantitative assessment outcomes of subjective and objective indicators. Methods: A total of 111 patients with allergic rhinitis who visited our outpatient clinic from June 2022 to December 2022 were selected. The 22-item sino-nasal outcome test (SNOT-22) and the visual analog scale (VAS) for the severity of the disease were used to score the subjective indicators of allergic rhinitis. The objective indicators of allergic rhinitis were evaluated by serum inhalant allergens immunoglobulin E test, nasal endoscopy modified Lund-Kennedy (MLK) scoring method, and acoustic rhinometry. Results: SNOT-22 score, total VAS score for symptoms, and the VAS score for nasal itching were positively correlated with the number of positive allergens (r = 0.266, P = 0.005, r = 0.576, P < 0.001, and r = 0.271, P = 0.004, respectively). No differences were found in all subjective indicators scores between the total immunoglobulin E positive and negative groups (P > 0.05). SNOT-22 score, total VAS score for symptoms, and the VAS score for nasal congestion were positively correlated with MLK total score of nasal endoscopy (r = 0.343, P < 0.001, r = 0.438, P < 0.001, and r = 0.225, P = 0.018, respectively). Parameters of acoustic rhinometry were not correlated with the subjective indicators scores of allergic rhinitis (P > 0.05). Conclusion: A multifaceted quantitative assessment of allergic rhinitis using a combination of subjective and objective methods can help physicians make an accurate diagnosis and create reasonable treatment plans.
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The intracellular viscosity is an important parameter of the microenvironment and SO2 is a vital gas signal molecule. At present, some dual-response fluorescence probes for simultaneous measurements of viscosity and SO2 derivatives (HSO3-/SO32-) possessed poor water solubility. In this work, we developed a water-soluble fluorescence probe CIJ (0.0864 g/100 mL of water at 20 °C) for simultaneous measurements of viscosity and SO2 derivatives. CIJ exhibited a sensitive fluorescence enhancement to environmental viscosity from 0.97 to 28.04 cP based on a twisted intramolecular charge transfer mechanism and was applied to effective measurement of viscosity in vitro and in vivo. CIJ could also respond to SO2 derivatives with a low detection limit (44 nM) and a fast response time (5 min) based on the nucleophilic addition reaction. Furthermore, CIJ was applied to monitor SO2 derivatives in ratiometric response manner in living cells.
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Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes , Humanos , Solubilidade , Viscosidade , Sulfitos , Células HeLa , Água , Dióxido de EnxofreRESUMO
A novel fluorescence resonance energy transfer (FRET)-based ratiometric emission fluorescent probe AT was designed and developed in which the imidazo[1,5-α]pyridine was served as a FRET donor and tricyanofuran (TCF) as the FRET acceptor to detect SO32-/HSO3- based on the Michael addition reaction. Probe AT had a high energy transfer efficiency (95%) and a large pseudo-Stokes shift (259 nm) in EtOH/PBS buffer (5/5, v/v). It also possessed good selectivity and quick response to SO32-/HSO3-. There was good linearity between the ratio of fluorescence intensity (F499/F645) and the concentrations of SO32-/HSO3- in the ranges of 1.5-7.5 µM and 9-20 µM, with calculated detection limits (LOD) of 55 nM. In addition, the probe could also detect the concentrations of SO32-/HSO3- in real samples such as environmental water and sugar, allowing the probe to be used in a variety of applications.
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Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes , Piridinas , Dióxido de Enxofre , ÁguaRESUMO
Two simple turn-on fluorescent probes, containing a benzothiazole and the 2,4-dinitrobenzenesulfonyl group, were designed for detecting H2S. Two probes exhibited good selectivity and high sensitivity, which were applied to detect the H2S in real water samples. Probe P2 with a positive charge had better solubility than probe P1 in water; therefore, probe P2 was successfully applied to detect both the endogenous and exogenous H2S in lysosomes of living HeLa cells.