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1.
Opt Express ; 32(3): 3184-3193, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38297545

RESUMO

In this paper, we propose a method for simultaneously recovering multiple radio wave signals based on nitrogen-vacancy (NV) centers in diamond combining optically detected magnetic resonance (ODMR) spectrum. A controlled magnetic field gradient applied to the laser excitation area on the surface of diamond widens the detectable ODMR bandwidth to 200 MHz. Three different frequency-modulated (FM) signals with distinct carrier frequencies falling within the resonance frequency range are received and demodulated in real-time. Subsequently, the FM signal reception capability of this system is further investigated by measuring baseband signal frequencies ranging from 0.1 Hz to 200 Hz and adjusting the carrier power within a dynamic range from -10 dBm to 30 dBm. This proposal, which accomplishes multi-channel demodulation using a compact and single device, has potential applications in fields such as wireless communication, radar and navigation.

2.
Opt Express ; 32(10): 17336-17344, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38858919

RESUMO

The ensemble of nitrogen-vacancy (NV) centers is widely used in quantum information transmission, high-precision magnetic field, and temperature sensing due to their advantages of long-lived state and the ability to be pumped by optical cycling. In this study, we investigate the zero-phonon line behavior of the two charge states of NV centers by measuring the photoluminescence of the NV center at 1.6 K-300 K. The results demonstrate a positional redshift, an increase in line width, and a decrease in fluorescence intensity for the ZPL of NV0 and NV- as the temperature increased. In the range of 10 K to 140 K, the peak shift with high concentrations of NV- revealed an anomaly of bandgap reforming. The peak position undergoes a blueshift and then a redshift as temperature increases. Furthermore, the transformation between NV0 and NV- with temperature changes has been obtained in diamonds with different nitrogen concentrations. This study explored the ZPL characteristics of NV centers in various temperatures, and the findings are significant for the development of high-resolution temperature sensing and high-precision magnetic field sensing in ensemble NV centers.

3.
Opt Express ; 32(7): 10829-10840, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38570946

RESUMO

Imaging of electronic device surface or sub-surface electromagnetic fields under operating conditions is important for device design and diagnosis. In this study, we proposed a method to characterize specific magnetic field properties of electromagnetic devices at micron-scale using a solid-state quantum sensor, namely diamond nitrogen-vacancy (NV) centers. By employing a wide-field magnetic field measurement technique based on NV centers, we rapidly obtain the first-order magnetic field distribution of anomalous regions. Furthermore, we approximate the second-order magnetic field (magnetic gradient tensor) using the differential gradient method. To visualize the electromagnetic anomalous regions boundary, we utilize the tensor invariants of the magnetic gradient tensor components, along with their nonlinear combinations. The identification error rate of the anomalous regions is within 12.5%. Additionally, the electromagnetic field of anomalous regions is simulated showing the measurement accuracy. Our study shows that the experimental results are very similar to the theoretical simulation of the electromagnetic field (error: 7%). This work is essential for advancing electromagnetic field characterization of electronic devices and the advancement of quantum magnetic sensor applications.

4.
Ecotoxicol Environ Saf ; 270: 115892, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38157798

RESUMO

Polyhalogenated carbazoles (PHCZs) are emerging environmental pollutants, yet limited information is available on their embryotoxicity and neurotoxicity. Therefore, the current work was performed to investigate the adverse effects of 3,6-dibromocarbazole (3,6-DBCZ), a typical PHCZs homolog, on the early life stages of zebrafish larvae. It revealed that the 96-hour post-fertilization (hpf) median lethal concentration (LC50) value of 3,6-DBCZ in zebrafish larvae was determined to be 0.7988 mg/L. Besides, 3,6-DBCZ reduced survival rates at concentrations ≥ 1 mg/L and decreased hatching rates at ≥ 0.25 mg/L at 48 hpf. In behavior tests, it inhibited locomotor activities and reduced the frequency of recorded acceleration states in response to optesthesia (a sudden bright light stimulus) at concentrations ≥ 160 µg/L. Meanwhile, 3,6-DBCZ exposure decreased the frequency of recorded acceleration states in the startle response (tapping mode) at concentrations ≥ 6.4 µg/L. Pathologically, with the transgenic zebrafish model (hb9-eGFP), we observed a strikingly decreased axon length and number in motor neurons after 3,6-DBCZ treatment, which may be ascribed to the activation of the AhR signaling pathway, as evidenced by the molecular docking analysis and Microscale thermophoresis (MST) assay suggested that 3,6-DBCZ binding to AhR-ARNT2 compound proteins. Through interaction with AhR-ARNT, a striking reduction of the anti-oxidative stress (sod1/2, nqo1, nrf2) and neurodevelopment-related genes (elavl3, gfap, mbp, syn2a) were observed after 3,6-DBCZ challenge, accompanied by a marked increased inflammatory genes (TNFß, IL1ß, IL6). Collectively, our findings reveal a previously unrecognized adverse effect of 3,6-DBCZ on zebrafish neurodevelopment and locomotor behaviors, potentially mediated through the activation of the AhR pathway. Furthermore, it provides direct evidence for the toxic concentrations of 3,6-DBCZ and the potential target signaling in zebrafish larvae, which may be beneficial for the risk assessment of the aquatic ecosystems.


Assuntos
Poluentes Químicos da Água , Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Simulação de Acoplamento Molecular , Ecossistema , Proteínas de Peixe-Zebra/metabolismo , Estresse Oxidativo , Larva , Embrião não Mamífero , Poluentes Químicos da Água/metabolismo
5.
Phys Chem Chem Phys ; 22(35): 19795-19801, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32844830

RESUMO

Understanding oxygen adsorption and dissociation on the five-fold coordinated titanium (Ti5c) site of the rutile TiO2 surface is important in clarifying chemical reaction processes. Accordingly, three different configurations of molecularly adsorbed O2, including parallel side-on, inclined side-on and end-on configurations, and their dissociation were directly observed with atomic resolution at 78 K by atomic force microscopy. Our results experimentally demonstrated that the three adsorbed O2 configurations could be changed by electric field stimulation. The initial configurations of the adsorbed O2 and transition of O2 configurations were related to their coverage. On the other hand, the tunneling current stimulation could dissociate these O2 species, indicating that they are precursors for the O adatom (Oad). It is proposed that the effect of electric field stimulation contributes to the transition of these three adsorbed O2 configurations, and the effect of the tunneling current is the main factor for the dissociation of the adsorbed O2. In addition, based on the atomic contrast and height histograms of Oad, different charge states of Oad were observed, which could coexist on the surface region. The present study demonstrates an intuitional observation of O2 adsorption and dissociation on the Ti5c site, and thus is expected to be useful to understand the surface reactions on the oxide surface.

6.
J Am Chem Soc ; 140(46): 15668-15674, 2018 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-30403344

RESUMO

For the first time, the charge states of adsorbed oxygen adatoms on the rutile TiO2(110)-1×1 surface are successfully measured and deliberately manipulated by a combination of noncontact atomic force microscopy and Kelvin probe force microscopy at 78 K under ultrahigh vacuum and interpreted by extensive density functional theory modeling. Several kinds of single and double oxygen adatom species are clearly distinguished and assigned to three different charge states: Oad-/2Oad-, Oad2-/2Oad2-, and Oad--Oad2-, i.e., formal charges of either one or two electrons per atom. Because of the strong atomic-scale image contrast, these states are clearly resolved. The observations are supported by measurements of the short-range force and local contact potential difference as a function of the tip-sample distance as well as simulations. Comparison with the simulations suggests subatomic resolution by allowing us to resolve the rotated oxygen p orbitals. In addition, we manage to reversibly switch the charge states of the oxygen adatoms between the Oad- and Oad2- states, both individually and next to another oxygen, by modulating the frequency shift at constant positive voltage during both charging and discharging processes, i.e., by the tip-induced electric field of one orientation. This work provides a novel route for the investigation of the charge state of the adsorbates and opens up novel prospects for studying transition-metal-oxide-based catalytic reactions.

7.
Nanotechnology ; 29(10): 105504, 2018 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-29313525

RESUMO

We have carried out high-speed imaging of the topography and local contact potential difference (LCPD) on rutile TiO2(110) in O2 gas by atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM). We succeeded in KPFM/AFM imaging with atomic resolution at 1 frame min-1 and observed the adsorbate on a hydroxylated TiO2(110) surface. The observed adsorbate is considered to be oxygen adatoms (Oa), hydroperoxyls (HO2), or terminal hydroxyls (OHt). After adsorption, changes in the topography and the LCPD of the adsorbate were observed. This phenomenon is thought to be caused by the charge transfer of the adsorbate. This technique has the potential to observe catalytic behavior with atomic resolution.

8.
Phys Chem Chem Phys ; 20(44): 28331-28337, 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30398504

RESUMO

Clarifying the atomic configuration of step edges on a rutile TiO2 surface is crucial for understanding its fundamental reactivity, and the direct observation of atomic step edges is still a challenge. AFM is a powerful tool for investigating surface structures with true atomic resolution, and it provides the opportunity to resolve the real structure of step edges with improved techniques. In this work, we successfully imaged the atomic configuration of 001 and 1-11 step edges on the surface of rutile TiO2(110)-(1 × 1), and we present the direct observation of oxygen vacancies along the 1-11 step edges, indicating that one 1-11 step edge site corresponds to one oxygen vacancy using AFM. We also made use of the simultaneous AFM/STM measurements to explore the electronic structure of step edges, which enhanced the evidence of oxygen vacancies existing along the 1-11 step edges and further demonstrated that the 001 step edge was terminated by an O row. The effect of the reduced 1-11 step edges was explored by probing the O2 adsorption and the nucleation behavior of gold clusters. It was found that oxygen vacancies along the 1-11 step edges could contribute to O2 dissociative adsorption and there was no obvious difference compared with the oxygen vacancies on the flat terrace. The reduced step edge and terrace likewise acted as nucleation and growth sites for gold atoms/nanoparticles, in line with previous reports. The present study provides a complete characterization of the atomic configuration of the step edges on the TiO2(110) surface and plays an important role in investigating the surface chemistry of metal oxides.

9.
Nanotechnology ; 28(10): 105704, 2017 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-28164861

RESUMO

We propose a new multi-image method for obtaining the frequency shift, tunneling current and local contact potential difference (LCPD) on a TiO2(110) surface with atomic resolution. The tunneling current image reveals rarely observed surface oxygen atoms contrary to the conventional results. We analyze how the surface and subsurface defects affect the distribution of the LCPD. In addition, the subsurface defects are observed clearly in the tunneling current image, in contrast to a topographic image. To clarify the origin of the atomic contrast, we perform site-dependent spectroscopy as a function of the tip-sample distance. The multi-image method is expected to be widely used to investigate the charge transfer phenomena between the nanoparticles and surface sites, and it is useful for elucidating the mechanisms of catalytic reactions.

10.
J Appl Toxicol ; 35(11): 1271-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26096086

RESUMO

Bisphenol A (BPA), an endocrine-disrupting chemical (EDC), is known to induce male reproductive toxicity in rodents. However, its toxic effects on the germ cells are still poorly understood. It has been proposed that Ca(2+) homeostasis and Ca(2+) sensors, including calmodulin (CaM) and calmodulin-dependent protein kinase II (CaMKII), play critical roles in spermatogenesis. Therefore, in the present study, we aimed to investigate whether a perturbation in Ca(2+)-CaM-CaMKII signaling was involved in the BPA-induced injury to mouse spermatocyte GC-2spd (ts) (GC-2) cells. Our results showed that BPA (range from 0.2 to 20 µM) induced obvious GC-2 cell injury, including decreased cell viability, the release of mitochondrial cytochrome c and the activation of caspase-3. However, these processes could be partially abrogated by pretreatment with a Ca(2+) chelator (BAPTA/AM), a CaM antagonist (W7) or a CaMKII inhibitor (KN93). These results, taken together, indicate that BPA exposure contributes to male germ cell injury, which may be partially mediated through a perturbation in Ca(2+)/CaM/CaMKII signaling and the mitochondrial apoptotic process.


Assuntos
Compostos Benzidrílicos/toxicidade , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Calmodulina/metabolismo , Fenóis/toxicidade , Espermatócitos/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Calmodulina/genética , Caspase 3/genética , Caspase 3/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citocromos c/genética , Citocromos c/metabolismo , Disruptores Endócrinos/toxicidade , Masculino , Camundongos , Mitocôndrias/efeitos dos fármacos , Transdução de Sinais , Espermatócitos/citologia
11.
Molecules ; 21(1): E46, 2015 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-26729079

RESUMO

This study was aimed to investigate whether vitamin A deficiency could alter P-GP expression and function in tissues of rats and whether such effects affected the drug distribution in vivo of vitamin A-deficient rats. We induced vitamin A-deficient rats by giving them a vitamin A-free diet for 12 weeks. Then, Abcb1/P-GP expression was evaluated by qRT-PCR and Western blot. qRT-PCR analysis revealed that Abcb1a mRNA levels were increased in hippocampus and liver. In kidney, it only showed an upward trend. Abcb1b mRNA levels were increased in hippocampus, but decreased in cerebral cortex, liver and kidney. Western blot results were in good accordance with the alterations of Abcb1b mRNA levels. P-GP function was investigated through tissue distribution and body fluid excretion of rhodamine 123 (Rho123), and the results proclaimed that P-GP activities were also in good accordance with P-GP expression in cerebral cortex, liver and kidney. The change of drug distribution was also investigated through the tissue distribution of vincristine, and the results showed a significantly upward trend in all indicated tissues of vitamin A-deficient rats. In conclusion, vitamin A deficiency may alter Abcb1/P-GP expression and function in rat tissues, and the alterations may increase drug activity/toxicity through the increase of tissue accumulation.


Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Vincristina/toxicidade , Deficiência de Vitamina A/induzido quimicamente , Animais , Córtex Cerebral/metabolismo , Modelos Animais de Doenças , Hipocampo/metabolismo , Rim/metabolismo , Fígado/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Vincristina/farmacocinética , Deficiência de Vitamina A/genética , Deficiência de Vitamina A/metabolismo
12.
Int J Cancer ; 134(7): 1539-48, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24114584

RESUMO

Cytochrome P450 2A13 (CYP2A13), mainly expressed in human respiratory tract, is highly efficient in the metabolic activation of aflatoxin (AF) B1 (AFB1) and is assumed to play a role in human lung tumorigenesis in airborne AFB1 exposure. To validate the assumption, we exposed human bronchial epithelial (BEAS-2B) cells stably expressing CYP2A13 (B-2A13), CYP1A2 (B-1A2) and CYP2A6 (B-2A6) to 0.1-10 nM AFB1 for 30-50 passages. B-2A13 cells showed increased sensitivity to 0.1 nM AFB1-induced neoplastic transformation and the formation of tumors in nude mice were observed at passage 30 (P30) while it occurred at P50 B-1A2 cells. B-2A6, similar to vector control, showed no neoplastic transformation in this condition. Additionally, AFB1-DNA adducts and 8-OHdG significantly increased in transformed P40 B-2A13, in parallel with the upregulation of p-ATR, p-BRCA1, Mre11, Rad50 and Rad51. However, the apoptosis of P40 cells was near normal, while the expression of Bax, C-Caspase 3 and C-PARP increased passage-dependently. Inhibition of ATR (ATR siRNA or NU6027) reversely increased the apoptosis of P40 B-2A13 cells in parallel with the upregulation of Bax, C-Caspase 3 and C-PARP, suggesting that ATR plays an important role in maintaining cell survival via antiapoptosis. Additionally, activation of ATR was necessary to neoplastic transformation since blockage of ATR in P40 cells inhibited DNA damage repair response and anchorage-independent growth. Our data demonstrated that CYP2A13 played a critical role in AFB1-induced neoplastic transformation. ATR-mediated the dysfunction of apoptosis and DNA damage repair might be involved. These results help establish a linkage between airborne AFB1 and human respiratory carcinoma.


Assuntos
Aflatoxina B1/toxicidade , Hidrocarboneto de Aril Hidroxilases/genética , Brônquios/efeitos dos fármacos , Brônquios/enzimologia , Transformação Celular Neoplásica/efeitos dos fármacos , Aflatoxina B1/farmacocinética , Animais , Apoptose/efeitos dos fármacos , Hidrocarboneto de Aril Hidroxilases/metabolismo , Proteínas Mutadas de Ataxia Telangiectasia/genética , Brônquios/patologia , Caspase 3/genética , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Sistema Enzimático do Citocromo P-450/genética , Adutos de DNA/efeitos dos fármacos , Reparo do DNA , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/enzimologia , Células Epiteliais/patologia , Humanos , Camundongos , Camundongos Nus , Poli(ADP-Ribose) Polimerases/genética , Regulação para Cima/efeitos dos fármacos , Proteína X Associada a bcl-2/genética
13.
Bioorg Med Chem Lett ; 24(10): 2388-91, 2014 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24745970

RESUMO

In this study we report the synthesis and activity against bovine viral diarrhea virus (BVDV) of a novel series of bicycle δ-sultones containing γ-lactones. BVDV is responsible for major losses in cattle. Some of the synthesized δ-sultones showed pronounced anti-BVDV activity with EC50 values of 0.12-1.0µM and no significant cytotoxicity. Among them, the ortho bromosubstituted derivative 4f (EC50=0.12µM) showed better antiviral activity than other derivatives and was 10 fold more that of than positive control ribavirin (EC50=1.3µM). BVDV is also considered to be a valuable surrogate for the hepatitis C virus (HCV) in antiviral drug studies. The above results provided a novel candidate for the development of anti-HCV agents.


Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Vírus da Diarreia Viral Bovina/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Animais , Bovinos , Modelos Animais de Doenças , Desenho de Fármacos
14.
Chemotherapy ; 60(2): 135-142, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25766299

RESUMO

OBJECTIVE: The gut microbiome is essential for human health due to its effects on disease development, drug metabolism and the immune system. It may also play a role in the interaction with environmental toxicants. However, the effect of epoxiconazole, a fungicide active ingredient from the class of azoles developed to protect crops, on the abundance and composition of the gut microbiome has never been studied. We put forward the hypothesis that changes in gut microbiota may be early signs of toxicity induced by epoxiconazole. METHODS: In this study, female rats were fed with epoxiconazole-adulterated diets (0, 4 and 100 mg/kg/day) for 90 days. The gut microbiome was determined by 16S rRNA gene sequencing. Body and organ weight, and blood biochemistry were also measured after 90 days of oral epoxiconazole exposure. RESULTS: Interestingly, the abundance of gut Firmicutes decreased, and Bacteroidetes and Proteobacteria increased. At family level, Lachnospiraceae and Enterobacteriaceae were selectively enriched following epoxiconazole exposure. Our results indicate that epoxiconazole exposure may induce changes in the gut microbiome and potential liver toxicity. CONCLUSION: Changes in the gut microbiome may be used as early indicators for monitoring the health risk of the host.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/microbiologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Compostos de Epóxi/toxicidade , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/microbiologia , Microbiota/efeitos dos fármacos , Triazóis/toxicidade , Animais , Feminino , Trato Gastrointestinal/patologia , Microbiota/fisiologia , Ratos , Ratos Sprague-Dawley
15.
J Agric Food Chem ; 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38598840

RESUMO

Sarcoplasmic calcium-binding protein (Cra a 4) from Crassostrea angulata belongs to the EF-hand superfamily, and understanding of its structure-allergenicity relationship is still insufficient. In this study, chemical denaturants were used to destroy the structure of Cra a 4, showing that disruption of the structure reduced its IgG-/IgE-binding activity. To explore which critical amino acid site affects the allergenicity of Cra a 4, the mutants were obtained by site-directed mutations in the disulfide bonds site (C97), conformational epitopes (I105, D114), or Ca2+-binding region (D106, D110) and their IgG-/IgE-binding activity was reduced significantly using serological tests. Notably, C97A had the lowest immunoreactivity. In addition, two conformational epitopes of Cra 4 were verified. Meanwhile, the increase of the α-helical content, surface hydrophobicity, and surface electrostatic potential of C97A affected its allergenicity. Overall, the understanding of the structure-allergenicity relationship of Cra a 4 allowed the development of a hypoallergenic mutant.

16.
J Biomed Res ; : 1-14, 2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38808572

RESUMO

As a potential endocrine-disrupting chemical, bisphenol F (BPF) may cause nonalcoholic fatty liver disease (NAFLD)-like changes, but the mechanisms underpinning its pathogenesis as well as the intervention strategies remain poorly understood. Using the electron microscopy technology, along with LipidTOX Deep Red neutral and Bodipy 493/503 staining assays, we observed that BPF treatment elicited a striking accumulation of lipid droplets in HepG2 cells, accompanied by an increased total level of triglycerides. At the molecular level, the lipogenesis-associated mRNAs and proteins, including acetyl-CoA carboxylase, fatty acid synthase, stearoyl-CoA desaturase-1, peroxisome proliferator-activated receptor gamma, and CCAAT-enhancer-binding proteins, increased significantly via the AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) signaling regulation in both in vitro and in vivo studies. Furthermore, the immunofluorescence results also showed the robust lipogenesis induced by BPF, evident in its ability to promote the translocation of sterol regulatory element-binding protein-1c from the cytoplasm to the nuclei. To investigate the intervention strategies for BPF-induced NAFLD-like changes, we demonstrated that bellidifolin, isolated and purified from Swertia chirayita, significantly attenuated BPF-induced lipid droplet deposition in HepG2 cell and NAFLD-like changes in mice by blocking the expression of lipogenesis-associated proteins. Therefore, the present study elucidates the mechanisms underlying BPF-induced lipid accumulation in HepG2 cells, while also highlighting the potential of bellidifolin to mitigate BPF-induced NAFLD-like changes.

17.
Environ Pollut ; 346: 123356, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38266696

RESUMO

Bisphenol F (BPF), one of the major alternatives of Bisphenol A (BPA), is becoming extensively used in industrial production with great harm to human beings and environment. Recent studies have revealed that environmental exposure is crucial to the initiation and development of depression. Thereby, the aim the present study is to ascertain the correlationship between the BPF exposure and depression occurrence. In the current study, BPF strikingly triggered depression-like changes in mice through the sucrose preference test (SPT), tail suspension test (TST) and forced swim test (FST), accompanied by the perturbation of the kynurenine (KYN) metabolic pathway along the "liver-brain" axis. Mechanistically, the neurotransmitters from the tryptophan metabolic pathway were converted to the toxic KYN pathway after BPF treatment. With the ELISA assay, it revealed that the toxic KYN metabolites, including KYN and 3-hydroxykynurenine (3-HK), were strikingly increased in the mouse brains which was ascribed to the enhanced expression of the rate-limiting enzymes Indoleamine 2,3-dioxygenase (IDO1) and Kynurenine 3-monooxygenase (KMO) respectively. Interestingly, the increased brain KYN induced by BPF was also validated partially from the periphery, since the ELISA and western blotting results indicated the significantly increased KYN in the serum and L-type amino acid transporter 1 (LAT1) in the brain, the key transporter responsible for KYN and 3-HK crossing the blood-brain barrier. Intriguingly, the liver-derived KYN metabolic pathway was the important source of the peripheral KYN and 3-HK, as BPF substantially enhanced hepatic IDO1, Tryptophan, 2, 3-dioxygenase (TDO2), and KMO levels indicated by western blotting. This study is the first to delineate previously unrecognized BPF-induced depression by regulating the KYN metabolic pathway along the "liver-brain" axis; therefore, targeting LAT1 or hepatic KYN signaling may provide a potentially unique therapeutic intervention in BPF-induced depression.


Assuntos
Compostos Benzidrílicos , Cinurenina , Fenóis , Triptofano , Humanos , Camundongos , Animais , Cinurenina/metabolismo , Triptofano/metabolismo , Depressão/induzido quimicamente , Encéfalo/metabolismo , Fígado/metabolismo , Redes e Vias Metabólicas
18.
J Membr Biol ; 246(5): 391-7, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23575985

RESUMO

The endocrine-disrupting chemical bisphenol A (BPA) is used to manufacture plastics including food containers, and it may leach into these containers. Consumption of BPA that has leached out of plastics may be harmful as recent research highlighted that BPA can induce alterations in the nervous system. In the present work, we studied the effects of BPA on Ca²âº channels in dorsal root ganglion (DRG) neurons. Using whole-cell patch-clamp recordings, we found that I(Ca) could be reduced by BPA in a concentration-dependent manner. Additionally, BPA shifted the activation curve of calcium currents toward a depolarizing direction and increased the slope factor of the curve. The inactivation curve for the currents was also assessed, and the curve shifted toward the depolarizing direction, although it was not significant. Moreover, inhibitory effects of BPA on the increments of intracellular Ca²âº concentrations ([Ca²âº](i)) induced by 50 mM KCl were observed in DRG neurons using a laser scanning confocal microscopy assay. Further work revealed that the PKA and PKC pathways may be involved in the inhibitory effects of BPA since the PKA antagonist GÖ-6983 and the PKC antagonist H-89 significantly alleviated the inhibitory effects of BPA on I(Ca). As such, the results of the present study provide direct evidence that BPA decreases I(Ca) and impairs calcium homeostasis, which may be involved in any toxic effects of BPA on DRG neurons.


Assuntos
Compostos Benzidrílicos/farmacologia , Cálcio/metabolismo , Sequestradores de Radicais Livres/farmacologia , Gânglios Espinais/metabolismo , Neurônios/metabolismo , Fenóis/farmacologia , Animais , Compostos Benzidrílicos/efeitos adversos , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Sequestradores de Radicais Livres/efeitos adversos , Gânglios Espinais/citologia , Indóis/farmacologia , Isoquinolinas/farmacologia , Masculino , Maleimidas/farmacologia , Neurônios/citologia , Fenóis/efeitos adversos , Proteína Quinase C/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Ratos , Ratos Sprague-Dawley , Sulfonamidas/farmacologia
19.
J Agric Food Chem ; 71(2): 1214-1223, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36602420

RESUMO

The structure of allergenic proteins provides important information about the binding of allergens to antibodies. In this study, the crystal structure of Scy p 4 with a resolution of 1.60 Å was obtained by X-ray diffraction. Epitope mapping of Scy p 4 revealed that linear epitopes are located on the surface of Scy p 4. Also, conformational epitopes are mostly located in the structural conservative region. Further structural comparison, surface electrostatic potential, and hydrogen bond force analysis showed that mutation of Asp70 and Asp18/20/70 would lead to calcium-binding capacity being lost and destruction of allergenicity. Furthermore, a comparative analysis of structure showed that sarcoplasmic-calcium-binding protein (SCP) had high sequence, secondary, and spatial structural identity in crustaceans, which may be an important factor leading to cross-reactivity among crustaceans. The structure of Scy p 4 provides a template for epitope evaluation and localization of SCPs, which will help to reveal cross-reactivity among species.


Assuntos
Alérgenos , Braquiúros , Animais , Alérgenos/química , Sequência de Aminoácidos , Proteínas de Ligação ao Cálcio/química , Imunoglobulina E , Braquiúros/genética , Epitopos/química
20.
J Agric Food Chem ; 71(24): 9508-9518, 2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37289596

RESUMO

As the main allergenic food, shrimp can trigger allergic reactions in various degrees. In this study, arginine kinase (AK) was identified as an allergen in Oratosquilla oratoria by LC-MS/MS. The open reading frame of AK was obtained, which included 356 amino acids, and recombinant AK (rAK) was expressed in Escherichia coli. The results of immunological analysis and circular dichroism showed that rAK displayed similar IgG-/IgE-binding activity and structure as native AK. Besides, five IgE linear epitopes of AK were verified by serological analysis, on the basis of which an epitope-deleted derivative was obtained and named as mAK-L. It has been shown that mAK-L displayed hypo-immunoreactivity compared to rAK, and the contents of secondary structures were different. In conclusion, these discoveries enrich the overall understanding of crustacean allergens and epitopes and set the foundations for food allergy diagnosis and immunotherapy.


Assuntos
Arginina Quinase , Hipersensibilidade Alimentar , Animais , Epitopos/química , Arginina Quinase/genética , Cromatografia Líquida , Espectrometria de Massas em Tandem , Crustáceos/metabolismo , Alérgenos/química , Imunoglobulina E
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