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1.
Proc Natl Acad Sci U S A ; 120(36): e2302145120, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37639592

RESUMO

How to illuminate dark matter has become the foremost open question in fundamental science nowadays, which is of great significance in understanding the laws of nature. Exploring exotic interactions beyond the standard model is one of the essential approaches to searching for dark matter particles. Although it has been explored in a variety of lab-scale and tabletop-scale setups over the past years, no such interactions have been observed, and improving the sensitivity significantly becomes of paramount importance, but challenging. Here, we formulate the conception of a spin-mechanical quantum chip compatible with scalable on-chip detectors. Utilizing the prototype chip realized by the integration of a mechanical resonator and a diamond with single nitrogen vacancy at the microscale, the constraints of spin-velocity-dependent interactions have been improved by two orders of magnitude, where there is no evidence for new bosons in the force range below 100 nm, i.e., in the rest-mass window of 2-10 electronvolts. Based on the proof-of-principle experiment, this promising chip can be scaled up to meet the requirements of searching for exotic interactions at preeminent sensitivity. Low-cost and high-yield chip-scale setups will accelerate the process of dark matter exploration, providing a path toward on-chip fundamental physics experiments.

2.
Nano Lett ; 24(26): 7868-7878, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38912706

RESUMO

Wound infections, especially those caused by pathogenic bacteria, present a considerable public health concern due to associated complications and poor therapeutic outcomes. Herein, we developed antibacterial nanoparticles, namely, PGTP, by coordinating guanidine derivatives with a porphyrin-based sonosensitizer. The synthesized PGTP nanoparticles, characterized by their strong positive charge, effectively disrupted the bacterial biosynthesis process through charge interference, demonstrating efficacy against both Gram-negative and Gram-positive bacteria. Additionally, PGTP nanoparticles generated reactive oxygen species under ultrasound stimulation, resulting in the disruption of biofilm integrity and efficient elimination of pathogens. RNA-seq analysis unveiled the detailed mechanism of wound healing, revealing that PGTP nanoparticles, when coupled with ultrasound, impair bacterial metabolism by interfering with the synthesis and transcription of amino acids. This study presents a novel approach to combatting wound infections through ultrasound-driven charge-interfering therapy, facilitated by advanced antibacterial nanomaterials.


Assuntos
Antibacterianos , Biofilmes , Nanopartículas , Infecção dos Ferimentos , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/uso terapêutico , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia , Nanopartículas/química , Nanopartículas/uso terapêutico , Biofilmes/efeitos dos fármacos , Animais , Camundongos , Ondas Ultrassônicas , Espécies Reativas de Oxigênio/metabolismo , Cicatrização/efeitos dos fármacos , Humanos , Porfirinas/química , Porfirinas/farmacologia , Porfirinas/uso terapêutico , Terapia por Ultrassom/métodos , Bactérias Gram-Positivas/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos
3.
Mol Biol Evol ; 40(8)2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37541261

RESUMO

Centromeres (CEN) are the chromosomal regions that play a crucial role in maintaining genomic stability. The underlying highly repetitive DNA sequences can evolve quickly in most eukaryotes, and promote karyotype evolution. Despite their variability, it is not fully understood how these widely variable sequences ensure the homeostasis of centromere function. In this study, we investigated the genetics and epigenetics of CEN in a population of wheat lines from global breeding programs. We captured a high degree of sequences, positioning, and epigenetic variations in the large and complex wheat CEN. We found that most CENH3-associated repeats are Cereba element of retrotransposons and exhibit phylogenetic homogenization across different wheat lines, but the less-associated repeat sequences diverge on their own way in each wheat line, implying specific mechanisms for selecting certain repeat types as functional core CEN. Furthermore, we observed that CENH3 nucleosome structures display looser wrapping of DNA termini on complex centromeric repeats, including the repositioned CEN. We also found that strict CENH3 nucleosome positioning and intrinsic DNA features play a role in determining centromere identity among different lines. Specific non-B form DNAs were substantially associated with CENH3 nucleosomes for the repositioned centromeres. These findings suggest that multiple mechanisms were involved in the adaptation of CENH3 nucleosomes that can stabilize CEN. Ultimately, we proposed a remarkable epigenetic plasticity of centromere chromatin within the diverse genomic context, and the high robustness is crucial for maintaining centromere function and genome stability in wheat 10+ lines as a result of past breeding selections.


Assuntos
Histonas , Nucleossomos , Histonas/genética , Triticum/genética , Filogenia , Melhoramento Vegetal , Centrômero/genética
4.
Anal Chem ; 96(15): 5940-5950, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38562013

RESUMO

Peptide-based supramolecules exhibit great potential in various fields due to their improved target recognition ability and versatile functions. However, they still suffer from numerous challenges for the biopharmaceutical analysis, including poor self-assembly ability, undesirable ligand-antibody binding rates, and formidable target binding barriers caused by ligand crowding. To tackle these issues, a "polyvalent recognition" strategy employing the CD20 mimotope peptide derivative NBD-FFVLR-GS-WPRWLEN (acting on the CDR domains of rituximab) was proposed to develop supramolecular nanofibers for target antibody recognition. These nanofibers exhibited rapid self-assembly within only 1 min and robust stability. Their binding affinity (179 nM) for rituximab surpassed that of the monomeric peptide (7 µM) by over 38-fold, highlighting that high ligand density and potential polyvalent recognition can efficiently overcome the target binding barriers of traditional supramolecules. Moreover, these nanofibers exhibited an amazing "instantaneous capture" rate (within 15 s), a high recovery (93 ± 3%), and good specificity for the target antibody. High-efficiency enrichment of rituximab was achieved from cell culture medium with good recovery and reproducibility. Intriguingly, these peptide nanofibers combined with bottom-up proteomics were successful in tracking the deamidation of asparagine 55 (from 10 to 16%) on the rituximab heavy chain after 21 day incubation in human serum. In summary, this study may open up an avenue for the development of versatile mimotope peptide supramolecules for biorecognition and bioanalysis of biopharmaceuticals.


Assuntos
Produtos Biológicos , Nanofibras , Humanos , Rituximab , Nanofibras/química , Ligantes , Reprodutibilidade dos Testes , Peptídeos/química
5.
BMC Cardiovasc Disord ; 24(1): 222, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38654152

RESUMO

The most common mechanical complications of acute myocardial infarction include free-wall rupture, ventricular septal rupture (VSR), papillary muscle rupture and pseudoaneurysm. It is rare for a patient to experience more than one mechanical complication simultaneously. Here, we present a case of ST-segment elevation myocardial infarction (STEMI) complicated with three mechanical complications, including ventricular apical wall rupture, ventricular aneurysm formation and ventricular septal dissection (VSD) with VSR. Cardiac auscultation revealed rhythmic S1 and S2 with a grade 3 holosystolic murmur at the left sternal border. Electrocardiogram indicated anterior ventricular STEMI. Serological tests showed a significant elevated troponin I. Bedside echocardiography revealed ventricular apical wall rupture, apical left ventricle aneurysm and VSD with VSR near the apex. This case demonstrates that several rare mechanical complications can occur simultaneously secondary to STEMI and highlights the importance of bedside echocardiography in the early diagnosis of mechanical complications.


Assuntos
Aneurisma Cardíaco , Ruptura Cardíaca Pós-Infarto , Infarto do Miocárdio com Supradesnível do Segmento ST , Ruptura do Septo Ventricular , Idoso , Humanos , Eletrocardiografia , Aneurisma Cardíaco/diagnóstico por imagem , Aneurisma Cardíaco/etiologia , Aneurisma Cardíaco/complicações , Aneurisma Cardíaco/fisiopatologia , Ruptura Cardíaca Pós-Infarto/etiologia , Ruptura Cardíaca Pós-Infarto/diagnóstico por imagem , Ruptura Cardíaca Pós-Infarto/diagnóstico , Testes Imediatos , Valor Preditivo dos Testes , Infarto do Miocárdio com Supradesnível do Segmento ST/etiologia , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico , Infarto do Miocárdio com Supradesnível do Segmento ST/complicações , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Infarto do Miocárdio com Supradesnível do Segmento ST/fisiopatologia , Infarto do Miocárdio com Supradesnível do Segmento ST/diagnóstico por imagem , Resultado do Tratamento , Ruptura do Septo Ventricular/etiologia , Ruptura do Septo Ventricular/diagnóstico por imagem , Ruptura do Septo Ventricular/fisiopatologia , Ruptura do Septo Ventricular/diagnóstico , Ruptura do Septo Ventricular/cirurgia , Feminino
6.
J Nanobiotechnology ; 22(1): 372, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38918811

RESUMO

Hemangioma of infancy is the most common vascular tumor during infancy and childhood. Despite the proven efficacy of propranolol treatment, certain patients still encounter resistance or face recurrence. The need for frequent daily medication also poses challenges to patient adherence. Bleomycin (BLM) has demonstrated effectiveness against vascular anomalies, yet its use is limited by dose-related complications. Addressing this, this study proposes a novel approach for treating hemangiomas using BLM-loaded hyaluronic acid (HA)-based microneedle (MN) patches. BLM is encapsulated during the synthesis of polylactic acid (PLA) microspheres (MPs). The successful preparation of PLA MPs and MN patches is confirmed through scanning electron microscopy (SEM) images. The HA microneedles dissolve rapidly upon skin insertion, releasing BLM@PLA MPs. These MPs gradually degrade within 28 days, providing a sustained release of BLM. Comprehensive safety assessments, including cell viability, hemolysis ratio, and intradermal reactions in rabbits, validate the safety of MN patches. The BLM@PLA-MNs exhibit an effective inhibitory efficiency against hemangioma formation in a murine hemangioma model. Of significant importance, RNA-seq analysis reveals that BLM@PLA-MNs exert their inhibitory effect on hemangiomas by regulating the P53 pathway. In summary, BLM@PLA-MNs emerge as a promising clinical candidate for the effective treatment of hemangiomas.


Assuntos
Bleomicina , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos , Hemangioma , Ácido Hialurônico , Agulhas , Poliésteres , Bleomicina/farmacologia , Animais , Camundongos , Coelhos , Hemangioma/tratamento farmacológico , Ácido Hialurônico/química , Preparações de Ação Retardada/química , Sistemas de Liberação de Medicamentos/métodos , Poliésteres/química , Humanos , Microesferas , Antibióticos Antineoplásicos/farmacologia , Antibióticos Antineoplásicos/uso terapêutico , Antibióticos Antineoplásicos/administração & dosagem , Antibióticos Antineoplásicos/farmacocinética , Liberação Controlada de Fármacos
7.
Anal Chem ; 95(6): 3532-3543, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36744576

RESUMO

Phospholipid-based materials exhibit great application potential in the fields of chemistry, biology, and pharmaceutical sciences. In this study, an inside-out oriented choline phosphate molecule, 2-{2-(methacryloyloxy)ethyldimethylammonium}ethyl n-butyl phosphate (MBP), was proposed and verified as a novel ligand of C-reactive protein (CRP) to enrich the functionality of these materials. Compared with phosphorylcholine (PC)-CRP interactions, the binding between MBP and CRP was not affected by the reverse position of phosphate and choline groups and even found more abundant binding sites. Thus, high-density MBP-grafted biomimetic magnetic nanomaterials (MBP-MNPs) were fabricated by reversible addition-fragmentation chain transfer polymerization based on thiol-ene click chemistry. The novel materials exhibited multifunctional applications for CRP including purification and ultrasensitive detection. On the one hand, higher specificity, recovery (90%), purity (95%), and static binding capacity (198.14 mg/g) for CRP were achieved on the novel materials in comparison with traditional PC-based materials, and the enriched CRP from patient serum can maintain its structural integrity and bioactivity. On the other hand, the CRP detection method combining G-quadruplex and thioflavin T developed with MBP-MNPs showed a lower detection limit (10 pM) and wider linear range (0.1-50 nM) than most PC-functionalized analytical platforms. Therefore, the inside-out oriented choline phosphate can not only precisely recognize CRP but also be combined with biomimetic nanomaterials to provide high application potential.


Assuntos
Proteína C-Reativa , Fosforilcolina , Humanos , Fosforilcolina/química , Proteína C-Reativa/análise , Biomimética , Fenômenos Magnéticos , Fosfatos
8.
Dermatol Surg ; 49(11): 1017-1022, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37669082

RESUMO

BACKGROUND: Cutaneous erythema is one of the most common signs of arteriovenous malformations (AVMs) in the head and neck region, influencing aesthetic appearance. Surgical resection of AVMs may lead to cicatrization of the skin or aggravation of the lesion. Laser treatment, although effective in improving superficial vascular lesions, cannot prevent deep AVMs from further development. OBJECTIVE: The authors propose an absolute ethanol embolization therapy that can effectively and safely eradicate the nidus with a favorable aesthetic outcome. METHODS: The authors conducted a retrospective observational study of 14 AVM patients with distinct cutaneous erythema in the head and neck region undergoing embolotherapy in a single primary care center. Symptoms before and after treatment, complications, and degree of devascularization were recorded and assessed. Changes in cutaneous redness were evaluated using a previously reported quantitative measurement. RESULTS: Complete symptomatic relief was observed in 5 patients, and major improvement was observed in 9 patients. The mean Δ a * value of the color change had a significant reduction of 6.50 ± 4.04, p < .001, indicating a remarkable remission of cutaneous erythema. CONCLUSION: Ethanol embolization is an effective and safe treatment for head and neck AVMs with excellent aesthetic outcomes and might become a potential treatment method for other superficial vascular anomalies.


Assuntos
Malformações Arteriovenosas , Embolização Terapêutica , Humanos , Etanol/uso terapêutico , Resultado do Tratamento , Malformações Arteriovenosas/cirurgia , Embolização Terapêutica/efeitos adversos , Embolização Terapêutica/métodos , Eritema/etiologia , Eritema/terapia , Estudos Retrospectivos
9.
Ann Plast Surg ; 90(5S Suppl 2): S177-S182, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36752531

RESUMO

ABSTRACT: Extracranial arteriovenous malformation (AVM) is a high-flow congenital vascular malformation, where direct communication between the arteries and veins impedes perfusion of capillary beds and causes disfigurement of the affected tissue. Surgery and endovascular therapy are currently the main treatment for extracranial AVMs. Nevertheless, management of complex cases is sometimes challenging because of severe complications such as refractory ulceration, life-threatening bleeding, and even cardiac insufficiency. Here, we reviewed the development and potential treatment for extracranial AVMs and shared our single-center experiences of diagnosis and treatment of this challenging disease.


Assuntos
Malformações Arteriovenosas , Embolização Terapêutica , Humanos , Malformações Arteriovenosas/diagnóstico , Malformações Arteriovenosas/cirurgia , Veias
10.
Nano Lett ; 22(9): 3545-3549, 2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35439014

RESUMO

A negatively charged boron vacancy (VB-) color center in hexagonal boron nitride has recently been proposed as a promising quantum sensor due to its excellent properties. However, the spin level structure of the VB- color center is still unclear, especially for the excited state. Here we measured and confirmed the excited-state spin transitions of VB- using an optically detected magnetic resonance (ODMR) technique. The zero-field splitting of the excited state is 2.06 GHz, the transverse splitting is 93.1 MHz, and the g factor is 2.04. Moreover, negative peaks in fluorescence intensity and ODMR contrast at the level anticrossing point were observed, and they further confirmed that the spin transitions we measured came from the excited state. Our work deepens the understanding of the excited-state structure of VB- and promotes VB--based quantum sensing applications.

11.
Pharm Biol ; 61(1): 1222-1233, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37565668

RESUMO

CONTEXT: Diabetic nephropathy (DN) is the main cause of end-stage renal disease. Modified Shen-Yan-Fang-Shuai formula (M-SYFSF) has excellent clinical efficacy in treating diabetic kidney disease. However, the potential mechanism of M-SYFSF remains unknown. OBJECTIVE: To investigate the mechanism of M-SYFSF against DN by network pharmacological analysis and biological experiments. MATERIALS AND METHODS: Utilizing a web-based pharmacology database, the potential mechanisms of M-SYFSF against DN were identified. In vivo experiments, male SD rats were injected with streptozotocin (50 mg/kg) and got uninephrectomy to construct a model of DN. M-SYFSF (11.34 g/kg/d) was gavaged once per day for 12 weeks after model establishment. In vitro experiments, human proximal tubular cells (HK-2) were performed with advanced glycation end-products (AGEs) (100 µg/mL), then intervened with M-SYFSF freeze-dried powder. Pathological staining, WB, IHC, ELISA were conducted to explore the mechanism of M-SYFSF against DN. RESULTS: Network pharmacological analysis showed that MAPK pathway was the potential pathway. Results showed that compared with the Model group, M-SYFSF significantly reduced 24h urine albumin, UACR, and serum creatinine levels (54.90 ± 26.67 vs. 111.78 ± 4.28, 8.87 ± 1.69 vs. 53.94 ± 16.01, 11.56 ± 1.70 vs. 118.70 ± 49.57, respectively), and improved renal pathological changes. Furthermore, the intervention of M-SYFSF reduced the expression of pro-inflammatory cytokines and inhibited the activation of MAPK pathway in AGEs-treated HK-2 cells. DISCUSSION AND CONCLUSION: M-SYFSF is likely to reduce inflammation in DN by inhibiting the MAPK pathway. It provides a theoretical basis for the clinical application of M-SYFSF in the treatment of DN.


Assuntos
Diabetes Mellitus Experimental , Nefropatias Diabéticas , Medicamentos de Ervas Chinesas , Ratos , Masculino , Humanos , Animais , Nefropatias Diabéticas/metabolismo , Farmacologia em Rede , Ratos Sprague-Dawley , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Produtos Finais de Glicação Avançada/metabolismo
12.
Plant Biotechnol J ; 20(11): 2051-2063, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35722725

RESUMO

Centromeres are the genomic regions that organize and regulate chromosome behaviours during cell cycle, and their variations are associated with genome instability, karyotype evolution and speciation in eukaryotes. The highly repetitive and epigenetic nature of centromeres were documented during the past half century. With the aid of rapid expansion in genomic biotechnology tools, the complete sequence and structural organization of several plant and human centromeres were revealed recently. Here, we systematically summarize the current knowledge of centromere biology with regard to the DNA compositions and the histone H3 variant (CENH3)-dependent centromere establishment and identity. We discuss the roles of centromere to ensure cell division and to maintain the three-dimensional (3D) genomic architecture in different species. We further highlight the potential applications of manipulating centromeres to generate haploids or to induce polyploids offspring in plant for breeding programs, and of targeting centromeres with CRISPR/Cas for chromosome engineering and speciation. Finally, we also assess the challenges and strategies for de novo design and synthesis of centromeres in plant artificial chromosomes. The biotechnology applications of plant centromeres will be of great potential for the genetic improvement of crops and precise synthetic breeding in the future.


Assuntos
Centrômero , Melhoramento Vegetal , Humanos , Centrômero/genética , Cromossomos de Plantas/genética , Plantas/genética , Epigenômica , Biotecnologia
13.
Phys Rev Lett ; 129(21): 215901, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36461959

RESUMO

High quality nanomechanical oscillators are promising platforms for quantum entanglement and quantum technology with phonons. Realizing coherent transfer of phonons between distant oscillators is a key challenge in phononic quantum information processing. Here, we report on the realization of robust unidirectional adiabatic pumping of phonons in a parametrically coupled nanomechanical system engineered as a one-dimensional phononic topological insulator. By exploiting three nearly degenerate local modes-two edge states and an interface state between them-and the dynamic modulation of their mutual couplings, we achieve nonreciprocal adiabatic transfer of phononic excitations from one edge to the other with near unit fidelity. We further demonstrate the robustness of such adiabatic transfer of phonons in the presence of various noises in the control signals. Our experiment paves the way toward nonreciprocal phonon dynamics via adiabatic pumping and is valuable for phononic quantum information processing.

14.
Phys Rev Lett ; 129(1): 010502, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35841558

RESUMO

Superconducting qubits provide a promising path toward building large-scale quantum computers. The simple and robust transmon qubit has been the leading platform, achieving multiple milestones. However, fault-tolerant quantum computing calls for qubit operations at error rates significantly lower than those exhibited in the state of the art. Consequently, alternative superconducting qubits with better error protection have attracted increasing interest. Among them, fluxonium is a particularly promising candidate, featuring large anharmonicity and long coherence times. Here, we engineer a fluxonium-based quantum processor that integrates high qubit coherence, fast frequency tunability, and individual-qubit addressability for reset, readout, and gates. With simple and fast gate schemes, we achieve an average single-qubit gate fidelity of 99.97% and a two-qubit gate fidelity of up to 99.72%. This performance is comparable to the highest values reported in the literature of superconducting circuits. Thus our work, within the realm of superconducting qubits, reveals an alternative qubit platform that is competitive with the transmon system.

15.
Plant Dis ; 105(11): 3705-3714, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33779256

RESUMO

The characterization of leaf rust (caused by Puccinia triticina) and stripe rust (caused by Puccinia striiformis f. sp. tritici) resistance genes is the basis for breeding resistant wheat varieties and managing epidemics of these diseases in wheat. A cross between the susceptible wheat variety 'Apav#1' and resistant variety 'Neimai 836' was used to develop a mapping population containing 148 F5 recombinant inbred lines (RILs). Leaf rust phenotyping was done in field trials at Ciudad Obregón, Mexico, in 2017 and 2018, and stripe rust data were generated at Toluca, Mexico, in 2017 and in Mianyang, Ezhou, and Gansu, China, in 2019. Inclusive complete interval mapping (ICIM) was used to create a genetic map and identify significant resistance quantitative trait loci (QTL) with 2,350 polymorphic markers from a 15K wheat single-nucleotide polymorphism (SNP) array and simple-sequence repeats (SSRs). The pleiotropic multipathogen resistance gene Lr46/Yr29 and four QTL were identified, including two new loci, QLr.hzau-3BL and QYr.hzau-5AL, which explained 3 to 16% of the phenotypic variation in resistance to leaf rust and 7 to 14% of that to stripe rust. The flanking SNP markers for the two loci were converted to Kompetitive Allele-Specific PCR (KASP) markers and used to genotype a collection of 153 wheat lines, indicating the Chinese origin of the loci. Our results suggest that Neimai 836, which has been used as a parent for many wheat varieties in China, could be a useful source of high-level resistance to both leaf rust and stripe rust.


Assuntos
Basidiomycota , Triticum , Mapeamento Cromossômico , Resistência à Doença/genética , Doenças das Plantas/genética , Triticum/genética
16.
Angew Chem Int Ed Engl ; 60(5): 2393-2397, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33079440

RESUMO

Highly fluorogenic tetrazine bioorthogonal probes emitting at near-infrared wavelengths are in strong demand for biomedical imaging applications. Herein, we have developed a strategy for forming a palette of novel Huaxi-Fluor probes in situ, whose fluorescence increases hundreds of times upon forming the bioorthogonal reaction product, pyridazine. The resulting probes show large Stokes shifts and high quantum yields. Manipulating the conjugate length and pull-push strength in the fluorophore skeleton allows the emission wavelength to be fine-tuned from 556 to 728 nm. The highly photo-stable and biocompatible probes are suitable for visualizing organelles in live cells without a washing step and for imaging of tumors in live small animals to depths of 500 µm by two-photon excitation.


Assuntos
Compostos Heterocíclicos com 1 Anel/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Humanos , Imagem Óptica/métodos
17.
J Chem Inf Model ; 60(10): 4985-4994, 2020 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-32786702

RESUMO

Microbe class I terpene cyclases (TPCs) are responsible for deriving numerous functionally and structurally diverse groups of terpenoid natural products. The conformational change of their active pockets from "open" state to "closed" state upon substrate binding has been clarified. However, the key structural basis relevant to this active pocket dynamics and its detailed molecular mechanism are still unclear. In this work, on the basis of the molecular dynamics (MD) on two microbe class I TPCs (SdS and bCinS), we propose that the active pocket dynamics is highly dependent on the residue orientation of two conserved structural bases R-D dyad and X-R-D triad, rather than the previously suggested flexibility of kink region. Actually, we considered that the flexibility of kink region is synchronous with the R residue orientation of the X-R-D triad, which could regulate the entrance size of active pocket and thus affect the substrate selectivity of active pocket by utilizing the promiscuity of the X-R-D triad. Furthermore, to better understand the function of the two structural bases, two intelligible models of "PPi catcher-locker" and "selector-PPi sensor-orienter" are proposed to, respectively, describe the R-D dyad and X-R-D triad and broadened to more microbe class I TPCs. These findings exhibit the dynamics of active pocket inaccessible in static crystal structures and provide useful structural basis knowledge for further design of microbe class I TPCs with different cyclization ability.


Assuntos
Simulação de Dinâmica Molecular , Terpenos , Cristalografia por Raios X , Ciclização
18.
Mol Med ; 25(1): 11, 2019 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-30925862

RESUMO

BACKGROUND: Endometrial carcinoma represents one of the most common cancer types of the female reproductive tract. If diagnosed at an early stage, the 5-year survival rate is promising. However, recurrence and chemoresistance remain problematic for at least 15% of the patients. In the present study, we aim to reveal the mechanism by which PGK1 regulates chemoresistance in endometrial carcinoma. METHODS: qPCR was performed to detect expression of PGK1 in clinical tissue samples of endometrial carcinoma. Specific shRNAs were employed to knockdown PGK1 expression in endometrial cancer cell lines. MTT assay was used to evaluate cell viability and cisplatin sensitivity of endometrial carcinoma cell lines. Western blot was performed to assess the effects of PGK1 knockdown on the expression levels of HSP90, DNA repair-associated proteins (c-JUN, FOSL1, and POLD1), and DNA methylation-related enzymes (DNMT1, DNMT3A and DNMT3B). Immunoprecipitation was performed to verify direct binding between PGK1 and HSP90. RESULTS: We first showed that PGK1 expression is elevated in tumor tissues of endometrial cancer, and high PGK1 levels are associated with clinical stages and metastasis. Knockdown of PGK1 inhibits proliferation of endometrial cancer cells, and enhances the inhibitory effect of cisplatin on cell viability. In addition, knockdown of PGK1 down-regulates the expression of DNA repair-related proteins, methylation-related enzymes, and total cellular methylation level. PGK1 was next shown to interact directly with HSP90 and exhibit pro-tumor effects by modulating the ATPase activity of HSP90. CONCLUSIONS: We propose that PGK1 mediates DNA repair and methylation through the HSP90/ERK pathway, and eventually enhances the chemoresistance to cisplatin. The results provide new insights on functions of PGK1 and HSP90, which might make them as promising targets for endometrial cancer chemotherapy.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Endometrioide/genética , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/fisiologia , Neoplasias do Endométrio/genética , Proteínas de Choque Térmico HSP90/metabolismo , Fosfoglicerato Quinase/genética , Animais , Carcinoma Endometrioide/metabolismo , Linhagem Celular Tumoral , Metilação de DNA , Reparo do DNA , Neoplasias do Endométrio/metabolismo , Endométrio/metabolismo , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Fosfoglicerato Quinase/metabolismo
19.
Anal Chem ; 91(3): 2480-2487, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30618242

RESUMO

The specific sensing of an exact G-quadruplex structure by small molecules has never been reported. A fluorescent sensor based on the photoinduced electron transfer (PeT) mechanism provides possibilities for such specific, one-to-one recognition, indicated by fluorescence. We have rationally developed a PeT fluorescent sensor IZFL-2 by linking triarylimidazole and fluorescein moieties. IZFL-2 is a distinctive, smart sensor whose fluorescence is tunable by its molecular conformations. We then applied IZFL-2 to sensing G-quadruplexes and found that it could exactly distinguish the wild-type c-MYC G-quadruplex from other types of G-quadruplexes, as shown by the activation of its fluorescence. To understand this behavior, we performed various experiments, including fluorescence assays, absorption assays, and multiscale molecular dynamics simulations, to thoroughly investigate the optimal binding mode of IZFL-2 in the c-MYC G-quadruplex. Then, the corresponding HOMO-LUMO of IZFL-2 was analyzed, and the results demonstrated that the PeT process of IZFL-2 is suppressed only in the wild-type c-MYC G-quadruplex via specific loop interactions, which restores its fluorescence. To our knowledge, this smart molecule provides the first example of and new insights into the development of sensors specific for a particular G-quadruplex structure by utilizing intramolecular PeT-controlled fluorescence switching.


Assuntos
Corantes Fluorescentes/química , Quadruplex G , Proteínas Proto-Oncogênicas c-myc/genética , Sequência de Bases , Transporte de Elétrons , Simulação de Dinâmica Molecular , Mutação
20.
Behav Pharmacol ; 30(8): 700-711, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31703032

RESUMO

The brain renin-angiotensin system plays a vital role in the modulation of the neuroinflammatory responses and the progression of dopaminergic (DA) degeneration. Angiotensin II (Ang II) induces microglia activation via angiotensin II type 1 receptor (AT1R), which in turn affects the function of DA neurons. Endophilin A2 (EPA2) is involved in fast endophilin-mediated endocytosis and quickly endocytoses several G-protein-coupled receptor (GPCR), while AT1R belongs to GPCR family. Therefore, we speculated that EPA2 may modulate microglia activation via endocytosing AT1R. Biochanin A is an O-methylated isoflavone, classified as a kind of phytoestrogen due to its chemical structure that is similar to mammalian estrogens. In this study, we investigated the protective effects of biochanin A on Ang II-induced DA neurons damage in vivo, and molecular mechanisms. The results showed that biochanin A treatment for 7 days attenuated the behavioral dysfunction, inhibited the microglial activation, and prevented DA neuron damage in Ang II-induced rats. Furthermore, biochanin A increased EPA2 expression and decreased the expression of AT1R, gp91phox, p22 phox, NLRP3, ASC, Caspase-1, IL-1ß, IL-6, IL-18, and TNF-α. In summary, these results suggest that biochanin A exerts protective effects in Ang II-induced model rats, and the mechanisms may involve inhibition of inflammatory responses, an increase in EPA2 expression and a decrease in AT1R expression.


Assuntos
Aciltransferases/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Genisteína/farmacologia , Aciltransferases/genética , Angiotensina II/farmacologia , Animais , Neurônios Dopaminérgicos/fisiologia , Genisteína/metabolismo , Inflamação , Lipopolissacarídeos , Masculino , Microglia/metabolismo , Neuroimunomodulação/efeitos dos fármacos , Neuroimunomodulação/fisiologia , Óxido Nítrico/metabolismo , Fitoestrógenos/farmacologia , Substâncias Protetoras/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor Tipo 1 de Angiotensina/metabolismo , Receptores Acoplados a Proteínas G
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