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1.
Angew Chem Int Ed Engl ; : e202409004, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38837495

RESUMEN

Previous N-glycosylation approaches have predominately involved acidic conditions, facing challenges of low stereoselectivity and limited scope. Herein, we introduce a radical activation strategy that enables versatile and stereoselective N-glycosylation using readily accessible glycosyl sulfinate as a donor under basic conditions and exhibits exceptional tolerance towards various N-aglycones containing alkyl, aryl, heteroaryl and nucleobase functionalities. Preliminary mechanistic studies indicate a pivotal role of iodide, which orchestrates the formation of a glycosyl radical from the glycosyl sulfinate and subsequent generation of the key intermediate, a configurationally well-defined glycosyl iodide, which is subsequently attacked by an N-aglycone in a stereospecific SN2 manner to give the desired N-glycosides. An alternative route involving the coupling of a glycosyl radical and a nitrogen-centered radical is also proposed, affording the exclusive 1,2-trans product. This novel approach promises to broaden the synthetic landscape of N-glycosides, offering a powerful tool for the construction of complex glycosidic structures under mild conditions.

2.
RSC Adv ; 14(7): 4607-4613, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38318614

RESUMEN

Enhancing the oxygen reduction reaction (ORR) activity and stability of the fuel cell cathode electrocatalysts and reducing their costs are critical. In response to this need, Fe, B, and N co-doped hollow mesoporous carbon materials were prepared by a simple chemical doping one-step pyrolysis method using ZIF-8 as a precursor. The results showed that the optimized catalyst displayed a higher limiting current density (6.154 mA cm-2) and half-wave potential (0.859 V), which showed significant enhancement compared with the Pt/C catalyst (5.487 mA cm-2 and 0.853 V). Moreover, the optimized catalyst had outstanding long-term stability with a current density retention higher than 91% after 36 000 s of stability testing. This work provides a facile strategy for the design of outstanding ORR performance of non-precious metal oxygen reduction catalysts.

3.
Front Mol Biosci ; 10: 1263962, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38155957

RESUMEN

Introduction: Qi-Xian Decoction (QXD), a traditional Chinese medicine (TCM) formula consisting of eight herbs, has been clinically used to treat asthma. However, the underlying mechanisms have not been completely elucidated. This study aimed to combine metabolomics and network pharmacology to reveal the mechanism of action of QXD in asthma treatment. Methods: An ovalbumin (OVA)-induced asthma mouse model was constructed to evaluate the therapeutic effects of QXD. Serum metabolomics and network pharmacology were combined to study the mechanism of anti-asthma action as well as the potential target, and related biological functions were validated. Results: The QXD treatment has demonstrated significant protective effects in OVA-induced asthmatic mice, as evidenced by its ability to inhibit inflammation, IgE, mucus overproduction, and airway hyperreactivity (AHR). Metabolomic analysis has revealed a total of 140 differential metabolites associated with QXD treatment. In addition, network pharmacology has identified 126 genes that are linked to the effects of QXD, including TNF, IL-6, IL1ß, STAT3, MMP9, EGFR, JUN, CCL2, TLR4, MAPK3 and MAPK8. Through comprehensive gene-metabolite interaction network analysis, seven key metabolites have been identified and associated with the potential anti-asthmatic effect of QXD, with palmitic acid (PA) being the most notable among them. In vitro validation studies have confirmed the gene-metabolite interaction involving PA, IL-6, and MAPK8. Furthermore, our research has demonstrated that QXD treatment can effectively inhibit PA-promoted IL-6 expression in MH-S cells and reduce PA concentration in OVA-induced asthmatic mice. Conclusion: The regulation of metabolic pathways by QXD was found to be associated with its anti-asthmatic action, which provides insight into the mechanism of QXD in treating asthma.

4.
Cells ; 12(12)2023 06 19.
Artículo en Inglés | MEDLINE | ID: mdl-37371137

RESUMEN

Pathological cardiac hypertrophy is one of the notable causes of heart failure. Circular RNAs (circRNAs) have been studied in association with cardiac hypertrophy; however, the mechanisms by which circRNAs regulate cardiac hypertrophy remain unclear. In this study, we identified a new circRNA, named circCacna1c, in cardiac hypertrophy. Adult male C57BL/6 mice and H9c2 cells were treated with isoprenaline hydrochloride (ISO) to establish a hypertrophy model. We found that circCacna1c was upregulated in ISO-induced hypertrophic heart tissue and H9c2 cells. Western blot and quantitative real-time polymerase chain reaction showed that silencing circCacna1c inhibited hypertrophic gene expression in ISO-induced H9c2 cells. Mechanistically, circCacna1c competitively bound to miR-29b-2-5p in a dual-luciferase reporter assay, which was downregulated in ISO-induced hypertrophic heart tissue and H9c2 cells. MiR-29b-2-5p inhibited the nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1 (NFATc1) to control hypertrophic gene expression. After silencing circCacna1c, the expression of miR-29b-2-5p increased, which reduced hypertrophic gene expression by inhibiting NFATc1 expression. Together, these experiments indicate that circCacna1c promotes ISO-induced pathological hypertrophy through the miR-29b-2-5p/NFATc1 axis.


Asunto(s)
Cardiomegalia , MicroARNs , ARN Circular , Animales , Masculino , Ratones , Cardiomegalia/inducido químicamente , Cardiomegalia/genética , Cardiomegalia/metabolismo , Ratones Endogámicos C57BL , MicroARNs/genética , MicroARNs/metabolismo , ARN Circular/genética , ARN Circular/metabolismo , Factores de Transcripción
5.
Cell Death Dis ; 14(4): 272, 2023 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-37072408

RESUMEN

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast neoplasms with a higher risk of recurrence and metastasis than non-TNBC. Nevertheless, the factors responsible for the differences in the malignant behavior between TNBC and non-TNBC are not fully explored. Proline rich 15 (PRR15) is a protein involved in the progression of several tumor types, but its mechanisms are still controversial. Therefore, this study aimed to investigate the biological role and clinical applications of PRR15 on TNBC. PRR15 gene was differentially expressed between TNBC and non-TNBC patients, previously described as an oncogenic factor in breast cancer. However, our results showed a decreased expression of PRR15 that portended a favorable prognosis in TNBC rather than non-TNBC. PRR15 knockdown facilitated the proliferation, migration, and invasive ability of TNBC cells in vitro and in vivo, which was abolished by PRR15 restoration, without remarkable effects on non-TNBC. High-throughput drug sensitivity revealed that PI3K/Akt signaling was involved in the aggressive properties of PRR15 silencing, which was confirmed by the PI3K/Akt signaling activation in the tumors of PRR15Low patients, and PI3K inhibitor reversed the metastatic capacity of TNBC in mice. The reduced PRR15 expression in TNBC patients was positively correlated with more aggressive clinicopathological characteristics, enhanced metastasis, and poor disease-free survival. Collectively, PRR15 down-regulation promotes malignant progression through the PI3K/Akt signaling in TNBC rather than in non-TNBC, affects the response of TNBC cells to antitumor agents, and is a promising indicator of disease outcomes in TNBC.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Humanos , Animales , Ratones , Neoplasias de la Mama Triple Negativas/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proliferación Celular , Transducción de Señal , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Movimiento Celular/genética
6.
Int Immunopharmacol ; 114: 109535, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36527880

RESUMEN

Programmed death molecule ligand 1 (PD-L1) expression in urothelial carcinoma is a predictive marker used to guide immunotherapy. As expression of PD-L1 may be heterogeneous in the tumor tissue space, it cannot be accurately determined by immunohistochemical analysis. In this study, we examined PD-L1 protein levels in preoperative urine samples from bladder cancer patients, evaluated the prevalence of PD-L1 in urine, examined the usefulness of urine as a surrogate for PD-L1 expression in tumors, and compared PD-L1 expression in postoperative pathological sections. We found that PD-L1 in urine and tumor tissue correlated well and that it may be able to some extent serve as a surrogate for tissues in bladder cancer and thus predict risk of recurrence in muscle-invasive bladder cancer (MIBC) patients. Our findings reveal the clinical relevance of urine PD-L1 as a noninvasive prognostic indicator for immunotherapy and offer clinical translational suggestions for eventual development of a prognostic model for immunotherapy for bladder cancer.


Asunto(s)
Carcinoma de Células Transicionales , Neoplasias de la Vejiga Urinaria , Humanos , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Carcinoma de Células Transicionales/tratamiento farmacológico , Antígeno B7-H1/metabolismo , Pronóstico , Músculos/química , Músculos/metabolismo , Músculos/patología
7.
Mil Med Res ; 9(1): 71, 2022 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-36529792

RESUMEN

BACKGROUND: The cell cycle is at the center of cellular activities and is orchestrated by complex regulatory mechanisms, among which transcriptional regulation is one of the most important components. Alternative splicing dramatically expands the regulatory network by producing transcript isoforms of genes to exquisitely control the cell cycle. However, the patterns of transcript isoform expression in the cell cycle are unclear. Therapies targeting cell cycle checkpoints are commonly used as anticancer therapies, but none of them have been designed or evaluated at the alternative splicing transcript level. The utility of these transcripts as markers of cell cycle-related drug sensitivity is still unknown, and studies on the expression patterns of cell cycle-targeting drug-related transcripts are also rare. METHODS: To explore alternative splicing patterns during cell cycle progression, we performed sequential transcriptomic assays following cell cycle synchronization in colon cancer HCT116 and breast cancer MDA-MB-231 cell lines, using flow cytometry and reference cell cycle transcripts to confirm the cell cycle phases of samples, and we developed a new algorithm to describe the periodic patterns of transcripts fluctuating during the cell cycle. Genomics of Drug Sensitivity in Cancer (GDSC) drug sensitivity datasets and Cancer Cell Line Encyclopedia (CCLE) transcript datasets were used to assess the correlation of genes and their transcript isoforms with drug sensitivity. We identified transcripts associated with typical drugs targeting cell cycle by determining correlation coefficients. Cytotoxicity assays were used to confirm the effect of ENST00000257904 against cyclin dependent kinase 4/6 (CDK4/6) inhibitors. Finally, alternative splicing transcripts associated with mitotic (M) phase arrest were analyzed using an RNA synthesis inhibition assay and transcriptome analysis. RESULTS: We established high-resolution transcriptome datasets of synchronized cell cycle samples from colon cancer HCT116 and breast cancer MDA-MB-231 cells. The results of the cell cycle assessment showed that 43,326, 41,578 and 29,244 transcripts were found to be periodically expressed in HeLa, HCT116 and MDA-MB-231 cells, respectively, among which 1280 transcripts showed this expression pattern in all three cancer cell lines. Drug sensitivity assessments showed that a large number of these transcripts displayed a higher correlation with drug sensitivity than their corresponding genes. Cell cycle-related drug screening showed that the level of the CDK4 transcript ENST00000547281 was more significantly associated with the resistance of cells to CDK4/6 inhibitors than the level of the CDK4 reference transcript ENST00000257904. The transcriptional inhibition assay following M phase arrest further confirmed the M-phase-specific expression of the splicing transcripts. Combined with the cell cycle-related drug screening, the results also showed that a set of periodic transcripts, for example, ENST00000314392 (a dolichyl-phosphate mannosyltransferase polypeptide 2 isoform transcript), was more associated with drug sensitivity than the levels of their corresponding gene transcripts. CONCLUSIONS: In summary, we identified a panel of cell cycle-related periodic transcripts and found that the levels of transcripts of drug target genes showed different values for predicting drug sensitivity, providing novel insights into alternative splicing-related drug development and evaluation.


Asunto(s)
Antineoplásicos , Neoplasias de la Mama , Neoplasias del Colon , Humanos , Femenino , Línea Celular Tumoral , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Isoformas de Proteínas/genética , Isoformas de Proteínas/uso terapéutico , División Celular , Ciclo Celular , Neoplasias del Colon/tratamiento farmacológico
8.
RSC Adv ; 12(52): 33981-33987, 2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36505686

RESUMEN

Transition metal and nitrogen codoped carbon materials have emerged as one of the most promising candidates to replace noble metal-based oxygen reduction reaction (ORR) catalysts. However, the development of high-efficiency, stable and low-cost metal-nitrogen-carbon catalysts still remains a challenge. In this study, cobalt and nitrogen codoped carbon sheet catalysts were successfully prepared by a simple self-injected vapor phase growth and template method. The catalysts exhibited a multilevel pore structure with a large specific surface area and resulting physical characteristics. The catalysts have excellent onset and half-wave potentials during the ORR. Notably, the onset (E 0) and half-wave potential (E 1/2) in alkaline media for the Co-N-C-43.8 catalyst are 31 mV and 3 mV higher than those of a commercial Pt/C catalyst, respectively. Moreover, the durability of the Co-N-C-43.8 catalyst remains at a 93% current density after 10 000 s, while that of a commercial Pt/C catalyst only remains at 83%. Also, the Co-N-C-43.8 catalyst has little change in the current density after the addition of methanol. These results indicate that the Co,N-doped carbon sheet is a promising ORR catalyst.

9.
Int J Mol Sci ; 23(22)2022 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-36430822

RESUMEN

Chronic myeloid leukemia (CML) is a myeloproliferative disease characterized by a unique BCR-ABL fusion gene. Tyrosine kinase inhibitors (TKIs) were developed to target the BCR-ABL oncoprotein, inhibiting its abnormal kinase activity. TKI treatments have significantly improved CML patient outcomes. However, the patients can develop drug resistance and relapse after therapy discontinues largely due to intratumor heterogeneity. It is critical to understand the differences in therapeutic responses among subpopulations of cells. Single-cell RNA sequencing measures the transcriptome of individual cells, allowing us to differentiate and analyze individual cell populations. Here, we integrated a single-cell RNA sequencing profile of CML stem cells and network analysis to decipher the mechanisms of distinct TKI responses. Compared to normal hematopoietic stem cells, a set of genes that were concordantly differentially expressed in various types of stem cells of CML patients was revealed. Further transcription regulatory network analysis found that most of these genes were directly controlled by one or more transcript factors and the genes have more regulators in the cells of the patients who responded to the treatment. The molecular markers including a known drug-resistance gene and novel gene signatures for treatment response were also identified. Moreover, we combined protein-protein interaction network construction with a cancer drug database and uncovered the drugs that target the marker genes directly or indirectly via the protein interactions. The gene signatures and their interacted proteins identified by this work can be used for treatment response prediction and lead to new strategies for drug resistance monitoring and prevention. Our single-cell-based findings offered novel insights into the mechanisms underlying the therapeutic response of CML.


Asunto(s)
Leucemia Mielógena Crónica BCR-ABL Positiva , Transcriptoma , Humanos , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Resistencia a Antineoplásicos/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/patología , Proteínas de Fusión bcr-abl
10.
Curr Protein Pept Sci ; 23(7): 456-464, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35792131

RESUMEN

Prostate cancer (PCa) is the most frequent cancer of the male genitourinary system and the second most common cancer in men worldwide. PCa has become one of the leading diseases endangering men's health in Asia in recent years, with a large increase in morbidity and mortality. MTA1 (metastasis-associated antigen-1), a transcriptional coregulator involved in histone deacetylation and nucleosome remodeling, is a member of the MTA family. MTA1 is involved in cell signaling, chromosomal remodeling, and transcriptional activities, all of which are important for epithelial cell progression, invasion, and growth. MTA1 has been demonstrated to play a significant role in the formation, progression, and metastasis of PCa, and MTA1 expression is specifically linked to PCa bone metastases. Therefore, MTA1 may be a potential target for PCa prevention and treatment. Here, we reviewed the structure, function, and expression of MTA1 in PCa as well as drugs that target MTA1 to highlight a potential new treatment for PCa.


Asunto(s)
Histona Desacetilasas , Neoplasias de la Próstata , Humanos , Masculino , Histona Desacetilasas/metabolismo , Proteínas Represoras/genética , Transactivadores/metabolismo , Neoplasias de la Próstata/metabolismo , Transducción de Señal , Regulación Neoplásica de la Expresión Génica
11.
Sensors (Basel) ; 21(10)2021 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-34066299

RESUMEN

A complex permittivity characterization method for liquid samples has been proposed. The measurement is carried out based on a self-designed microwave sensor with a split ring resonator (SRR), the unload resonant frequency of which is 5.05 GHz. The liquid samples in capillary are placed in the resonant zone of the fabricated senor for high sensitivity measurement. The frequency shift of 58.7 MHz is achieved when the capillary is filled with ethanol, corresponding a sensitivity of 97.46 MHz/µL. The complex permittivity of methanol, ethanol, isopropanol (IPA) and deionized water at the resonant frequency are measured and calibrated by the first order Debye model. Then, the complex permittivity of different concentrations of aqueous solutions of these materials are measured by using the calibrated sensor system. The results show that the proposed sensor has high sensitivity and accuracy in measuring the complex permittivity of liquid samples with volumes as small as 0.13 µL. It provides a useful reference for the complex permittivity characterization of small amount of liquid chemical samples. In addition, the characterization of an important biological sample (inositol) is carried out by using the proposed sensor.


Asunto(s)
Microondas , Agua
12.
Pathogens ; 10(3)2021 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-33806598

RESUMEN

Type I interferon (IFN) induction is a critical component of innate immune response to viral and bacterial infection, including S. aureus, but whether it activates the signaling in macrophages and the regulation mechanisms is less well understood. Here we show that S. aureus infection promoted the IFN-ß mRNA expression and stimulator of IFN genes (STING)/TANK-binding kinase 1 (TBK1)/interferon regulatory factor 3 (IRF3)-dependent production of IFN-ß. Infection with S. aureus induced caspase recruitment domain and membrane-associated guanylate kinase-like domain protein 3 (CARMA3) expression at both the mRNA and protein levels. The heat-killed bacteria failed to trigger IRF3 phosphorylation and upregulation of CARMA3 expression. However, overexpression of CARMA3 did not affect phosphorylation of TBK1 or IRF3 in RAW264.7 cells, J774A.1 macrophages, and mouse embryonic fibroblast (MEF) cells. In conclusion, S. aureus infection induces STING/TBK1/IRF3-mediated IFN-ß production in a CARMA3-independent manner.

13.
Pathogens ; 10(2)2021 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-33503864

RESUMEN

Mycobacterium tuberculosis (MTB) infection is characterized by granulomatous lung lesions and systemic inflammatory responses during active disease. Inflammasome activation is involved in regulation of inflammation. Inflammasomes are multiprotein complexes serving a platform for activation of caspase-1, which cleaves the proinflammatory cytokines such as interleukin-1ß (IL-1ß) and IL-18 into their active forms. These cytokines play an essential role in MTB control. MTB infection triggers activation of the nucleotide-binding domain, leucine-rich-repeat containing family, pyrin domain-containing 3 (NLRP3) and absent in melanoma 2 (AIM2) inflammasomes in vitro, but only AIM2 and apoptosis-associated speck-like protein containing a caspase-activation recruitment domain (ASC), rather than NLRP3 or caspase-1, favor host survival and restriction of mycobacterial replication in vivo. Interferons (IFNs) inhibits MTB-induced inflammasome activation and IL-1 signaling. In this review, we focus on activation and regulation of the NLRP3 and AIM2 inflammasomes after exposure to MTB, as well as the effect of inflammasome activation on host defense against the infection.

14.
ACS Appl Mater Interfaces ; 12(36): 40859-40869, 2020 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-32803950

RESUMEN

Transparent conductive film (TCF) is promising for optoelectronic instrument applications. However, designing a robust, stable, and flexible TCF that can shield electromagnetic waves and work in harsh conditions remains a challenge. Herein, a multifunctional and flexible TCF with effective electromagnetic interference shielding (EMI) performance and outstanding electro-photo-thermal effect is proposed by orderly coating Ti3C2Tx MXene and a silver nanowire (AgNW) hybrid conductive network using a simple and scalable solution-processed method. Typically, the air-plasma-treated polycarbonate (PC) film was sequentially spray-coated with MXene and AgNW to construct a highly conductive network, which was transferred and partly embedded into an ultrathin poly(vinyl alcohol) (PVA) film using spin coating coupled with hot pressing to enhance the interfacial adhesion. The peeled MXene/AgNW-PVA TCF exhibits an optimal optical and electrical performance of sheet resistance 18.3 Ω/sq and transmittance 52.3%. As a consequence, the TCF reveals an effective EMI shielding efficiency of 32 dB in X-band with strong interfacial adhesion and satisfactory flexibility. Moreover, the high electrical conductivity and localized surface plasmon resonance (LSPR) effect of hybrid conductive network endow the TCF with low-voltage-driven Joule heating performance and excellent photothermal effect, respectively, which can ensure the normal functioning under extreme cold condition. In view of the comprehensive performance, this work offers new solutions for next-generation transparent EMI shielding challenges.

15.
J Membr Biol ; 253(3): 271-286, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32405692

RESUMEN

Membrane proteins are the major component of plasma membranes, and they play crucial roles in all organisms. To understand the influence of the presence of KcsA channel on cell membrane electroporation induced by picosecond pulse trains (psPT), in this paper, the electroporation of KcsA membrane protein system and bare lipid bilayer system (POPC) with the applied psPT are simulated using molecular dynamics (MD) method. First, we find that the average pore formation time of the KcsA system is longer than the bare system with the applied psPT. In the KcsA system, water protrusions appear more slowly. Then, the system size effects of psPT in the MD simulations are investigated. When the system size decreases, the average pore formation time of small KcsA membrane protein system is shorter than the bare system with the applied psPT. It is found that the psPT makes the protein fluctuation of small system increase greatly; meanwhile the instability of protein disturbs the water and then affects the water protrusion appearance time. Furthermore, it shows that the protein fluctuation of constant electric field is smaller than that of psPT and no field, and protein fluctuation increases with the psPT repetition frequency increasing.


Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Canales de Potasio/química , Canales de Potasio/metabolismo , Electricidad , Electroporación , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Modelos Moleculares , Modelos Teóricos , Conformación Molecular , Relación Estructura-Actividad
16.
Phys Chem Chem Phys ; 22(17): 9316-9321, 2020 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-32309833

RESUMEN

Local oriented intense electric fields play a vital role in biochemical reactions such as enzyme catalysis. Many researchers have gradually applied external oriented electric fields to control specific chemical reactions. The rapidly developing intense field of terahertz technology can provide a strong enough oriented electric field with specific polarization direction on a sub-picosecond timescale, which matches the timescale and intensity requirements for affecting specific ultrafast chemical reactions. Inspired by this, this paper theoretically studied the full quantum model of the proton transfer process in DNA base pair hydrogen bonds induced by intense terahertz radiation (ITR) with a sub-picosecond-oriented electric field through simulation based on density functional theory (DFT) and the Schrodinger equation. The result shows that the ITR with an electric field intensity up to 10 GV m-1 in a specific polarization direction can precisely control the proton transfer process in the base pair hydrogen bonds. Based on flexible optical methods, the ITR is expected to go beyond the traditional techniques for applying strong electric fields to chemical systems through solid electrodes and become a catalyst for controlling chemical reactions or a scalpel to manipulate molecular structures.

17.
Biochim Biophys Acta Biomembr ; 1862(5): 183213, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32057755

RESUMEN

Picosecond pulse trains (psPTs) are emerging as a new characteristic diagnostic and therapeutic tool in biomedical fields. To specifically determine the stimulus provided to cells, in this article, we use a molecular dynamics (MD) model to show the molecular mechanisms of electroporation induced by symmetrical bipolar psPTs and predict a bipolar cancellation for the studied picosecond pulses. Electric field conditions that do not cause electroporation reveal that the interfacial water molecules continuously flip and redirect as the applied bipolar psPT reverses, and the molecules cannot keep moving in one direction or leave the lipid-water interface. Based on our simulation results, we determine the threshold for electroporation with symmetrical bipolar psPTs. For a fixed electric field intensity, a lower repetition frequency leads to more rapid electroporation. For a fixed repetition frequency, a higher electric field intensity leads to more rapid electroporation. We found that the water dipole relaxation time decreases as the electric field magnitude increases. Additionally, the influences of the symmetrical bipolar psPT intensity and frequency on the pore formation time are presented. Discrete nanoscale pores can form with the applied psPT at terahertz (THz) repetition frequency. When the psPT amplitude increases or the frequency decreases, the number of water bridges will increase. Moreover, for the first time, the molecular mechanism of bipolar cancellation for the studied picosecond pulse is discussed preliminarily. Our results indicate that the influence of the unipolar picosecond pulse on the interfacial water dipoles will accumulate in one direction, but the bipolar picosecond pulse does not cause this effect.


Asunto(s)
Electroporación/métodos , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Membrana Celular/metabolismo , Membrana Celular/fisiología , Electricidad , Simulación de Dinámica Molecular , Fosfatidilcolinas/química , Fosfatidilcolinas/fisiología
18.
J Membr Biol ; 251(5-6): 681-693, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30094474

RESUMEN

In this paper, the membrane electroporation induced by the terahertz electric field is simulated by means of the molecular dynamics method. The influences of the waveform and frequency of the applied terahertz electric field on the electroporation and the unique features of the process of the electroporation with the applied terahertz electric field are given. It shows that whether the electroporation can happen depends on the waveform of the applied terahertz electric field when the magnitude is not large enough. No pore appears if the terahertz electric field direction periodically reverses, and dipole moments of the interfacial water and the bulk water keep reversing. The nm-scale single pore forms with the applied terahertz trapezoidal electric field. It is found that the average pore formation time is strongly influenced by the terahertz electric field frequency. An abnormal variation region that shows decline exists on the correlation curve of the average pore formation time and the trapezoidal electric field frequency, whereas the overall trend of the curve is increasing. The decrease of the water oriented polarization degree results in the increase of the electroporation time, and the abnormal variation region appearance may be related to the drastic change of average water hydrogen bond number that is resulted from the resonance of water hydrogen bond network and the applied electric field. Compared to the nanosecond electric pulse and constant electric field, the numbers of the water protrusions and the water bridges are smaller and the pore formation time is relatively longer with the applied terahertz electric field.


Asunto(s)
Campos Electromagnéticos , Electroporación/métodos , Membrana Dobles de Lípidos/química , Enlace de Hidrógeno , Simulación de Dinámica Molecular
19.
J Exp Zool B Mol Dev Evol ; 328(8): 772-780, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29044994

RESUMEN

r-spondin1 (rspo1) encodes a secreted protein that is involved in the determination and differentiation of the mammalian ovary. However, little information is yet available for teleosts. Here, we identified a homologue of rspo1 in Cynoglossus semilaevis. The full-length cDNA of rspo1 had a length of 2,703 bp with an open reading frame of 834 bp, encoding a protein with a length of 277 amino-acids. rspo1 expression was detected via qRT-PCR in various tissues, and significant sexually dimorphic expression was observed in the gonads. Furthermore, ISH located rspo1 in germ cells such as spermatogonia, spermatocytes, spermatids, spermatozoa, and oocytes, as well as in somatic cells of the gonads. Following knockdown of rspo1 in an ovarian cell line, the expressions of wnt4a, ß-catenin, foxl2, and StAR were highly affected; wnt4a and ß-catenin were significantly downregulated, whereas foxl2 and StAR were significantly upregulated. In summary, these data suggest that rspo1 may be involved in the regulation of ovarian development and differentiation through a conserved pathway, while the function of the gene in the testis remains elusive.


Asunto(s)
Peces Planos/metabolismo , Ovario/metabolismo , Testículo/metabolismo , Trombospondinas/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Evolución Biológica , ADN Complementario , Femenino , Regulación del Desarrollo de la Expresión Génica , Silenciador del Gen , Masculino , Interferencia de ARN , Diferenciación Sexual/genética , Diferenciación Sexual/fisiología , Trombospondinas/química , Trombospondinas/genética
20.
Gene ; 592(1): 215-220, 2016 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-27480167

RESUMEN

E3 ubiquitin ligases are a large gene family that plays a diversity of roles in spermatogenesis. In this study, the functional characterization of a neuralized E3 ubiquitin protein ligase 3 (neurl3) revealed its potential participation in spermatogenesis. Firstly, we found that neurl3 exhibited male-biased transcription and that its translation was predominant in testis germ cells. The knockdown of neurl3 by RNA interference caused increased transcription of spermatogenesis-related genes. These results corroborate previous studies indicating a role for neurl3 in spermatogenesis. Moreover, the levels of neurl3 transcription and testis protein ubiquitination were closely correlated. Based on these findings, we speculate that neurl3 modulates testis protein ubiquitination in a dosage-dependent manner and that this influences spermatogenesis.


Asunto(s)
Proteínas de Peces/metabolismo , Espermatogénesis , Testículo/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitinación , Animales , Proteínas de Peces/genética , Peces , Masculino , Ubiquitina-Proteína Ligasas/genética
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