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1.
Nature ; 632(8024): 287-293, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39020170

RESUMO

Compressing the optical field to the atomic scale opens up possibilities for directly observing individual molecules, offering innovative imaging and research tools for both physical and life sciences. However, the diffraction limit imposes a fundamental constraint on how much the optical field can be compressed, based on the achievable photon momentum1,2. In contrast to dielectric structures, plasmonics offer superior field confinement by coupling the light field with the oscillations of free electrons in metals3-6. Nevertheless, plasmonics suffer from inherent ohmic loss, leading to heat generation, increased power consumption and limitations on the coherence time of plasmonic devices7,8. Here we propose and demonstrate singular dielectric nanolasers showing a mode volume that breaks the optical diffraction limit. Derived from Maxwell's equations, we discover that the electric-field singularity sustained in a dielectric bowtie nanoantenna originates from divergence of momentum. The singular dielectric nanolaser is constructed by integrating a dielectric bowtie nanoantenna into the centre of a twisted lattice nanocavity. The synergistic integration surpasses the diffraction limit, enabling the singular dielectric nanolaser to achieve an ultrasmall mode volume of about 0.0005 λ3 (λ, free-space wavelength), along with an exceptionally small feature size at the 1-nanometre scale. To fabricate the required dielectric bowtie nanoantenna with a single-nanometre gap, we develop a two-step process involving etching and atomic deposition. Our research showcases the ability to achieve atomic-scale field localization in laser devices, paving the way for ultra-precise measurements, super-resolution imaging, ultra-efficient computing and communication, and the exploration of light-matter interactions within the realm of extreme optical field localization.

2.
Nature ; 624(7991): 282-288, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38092911

RESUMO

Miniaturized lasers play a central role in the infrastructure of modern information society. The breakthrough in laser miniaturization beyond the wavelength scale has opened up new opportunities for a wide range of applications1-4, as well as for investigating light-matter interactions in extreme-optical-field localization and lasing-mode engineering5-19. An ultimate objective of microscale laser research is to develop reconfigurable coherent nanolaser arrays that can simultaneously enhance information capacity and functionality. However, the absence of a suitable physical mechanism for reconfiguring nanolaser cavities hinders the demonstration of nanolasers in either a single cavity or a fixed array. Here we propose and demonstrate moiré nanolaser arrays based on optical flatbands in twisted photonic graphene lattices, in which coherent nanolasing is realized from a single nanocavity to reconfigurable arrays of nanocavities. We observe synchronized nanolaser arrays exhibiting high spatial and spectral coherence, across a range of distinct patterns, including P, K and U shapes and the Chinese characters '' and '' ('China' in Chinese). Moreover, we obtain nanolaser arrays that emit with spatially varying relative phases, allowing us to manipulate emission directions. Our work lays the foundation for the development of reconfigurable active devices that have potential applications in communication, LiDAR (light detection and ranging), optical computing and imaging.

3.
Nature ; 593(7859): 418-423, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33727703

RESUMO

The COVID-19 pandemic is the third outbreak this century of a zoonotic disease caused by a coronavirus, following the emergence of severe acute respiratory syndrome (SARS) in 20031 and Middle East respiratory syndrome (MERS) in 20122. Treatment options for coronaviruses are limited. Here we show that clofazimine-an anti-leprosy drug with a favourable safety profile3-possesses inhibitory activity against several coronaviruses, and can antagonize the replication of SARS-CoV-2 and MERS-CoV in a range of in vitro systems. We found that this molecule, which has been approved by the US Food and Drug Administration, inhibits cell fusion mediated by the viral spike glycoprotein, as well as activity of the viral helicase. Prophylactic or therapeutic administration of clofazimine in a hamster model of SARS-CoV-2 pathogenesis led to reduced viral loads in the lung and viral shedding in faeces, and also alleviated the inflammation associated with viral infection. Combinations of clofazimine and remdesivir exhibited antiviral synergy in vitro and in vivo, and restricted viral shedding from the upper respiratory tract. Clofazimine, which is orally bioavailable and comparatively cheap to manufacture, is an attractive clinical candidate for the treatment of outpatients and-when combined with remdesivir-in therapy for hospitalized patients with COVID-19, particularly in contexts in which costs are an important factor or specialized medical facilities are limited. Our data provide evidence that clofazimine may have a role in the control of the current pandemic of COVID-19 and-possibly more importantly-in dealing with coronavirus diseases that may emerge in the future.


Assuntos
Antivirais/farmacologia , Clofazimina/farmacologia , Coronavirus/classificação , Coronavirus/efeitos dos fármacos , SARS-CoV-2/efeitos dos fármacos , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Monofosfato de Adenosina/uso terapêutico , Alanina/análogos & derivados , Alanina/farmacologia , Alanina/uso terapêutico , Animais , Anti-Inflamatórios/farmacocinética , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Antivirais/farmacocinética , Antivirais/uso terapêutico , Disponibilidade Biológica , Fusão Celular , Linhagem Celular , Clofazimina/farmacocinética , Clofazimina/uso terapêutico , Coronavirus/crescimento & desenvolvimento , Coronavirus/patogenicidade , Cricetinae , DNA Helicases/antagonistas & inibidores , Sinergismo Farmacológico , Feminino , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Masculino , Mesocricetus , Profilaxia Pré-Exposição , SARS-CoV-2/crescimento & desenvolvimento , Especificidade da Espécie , Glicoproteína da Espícula de Coronavírus/antagonistas & inibidores , Transcrição Gênica/efeitos dos fármacos , Transcrição Gênica/genética
4.
Proc Natl Acad Sci U S A ; 121(45): e2415213121, 2024 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-39475655

RESUMO

Environmental concerns from plastic waste are driving interest in alternative monomers from bio-based sources. Pseudoaromatic dicarboxylic acids are promising alternatives with chemical structures similar to widely used petroleum-based aromatic dicarboxylic acids. However, their use in polyester synthesis has been limited due to production challenges. Here, we report the fermentative production of five pseudoaromatic dicarboxylic acids, including 2-pyrone-4,6-dicarboxylic acid (PDC) and pyridine dicarboxylic acids (PDCAs: 2,3-, 2,4-, 2,5-, and 2,6-PDCA), from glucose using five engineered Corynebacterium glutamicum strains. A platform C. glutamicum chassis strain was constructed by modulating the expression of nine genes involved in the synthesis and degradation pathways of precursor protocatechuate (PCA) and the glucose-uptake system. Comparative transcriptome analysis of the engineered strain against wild-type C. glutamicum identified iolE (NCgl0160) as a target for PDC production. Optimized fed-batch fermentation conditions enabled the final engineered strain to produce 76.17 ± 1.24 g/L of PDC. Using this platform strain, we constructed 2,3-, 2,4-, and 2,5-PDCA-producing strains by modulating the expression of key enzymes. Additionally, we demonstrated a previously uncharacterized pathway for 2,3-PDCA biosynthesis. The engineered strains produced 2.79 ± 0.005 g/L of 2,3-PDCA, 494.26 ± 2.61 mg/L of 2,4-PDCA, and 1.42 ± 0.02 g/L of 2,5-PDCA through fed-batch fermentation. To complete the portfolio, we introduced the 2,6-PDCA biosynthetic pathway to an L-aspartate pathway-enhanced C. glutamicum strain, producing 15.01 ± 0.03 g/L of 2,6-PDCA in fed-batch fermentation. The metabolic engineering strategies developed here will be useful for the production of pseudoaromatic chemicals.


Assuntos
Corynebacterium glutamicum , Ácidos Dicarboxílicos , Engenharia Metabólica , Piridinas , Pironas , Corynebacterium glutamicum/metabolismo , Corynebacterium glutamicum/genética , Engenharia Metabólica/métodos , Ácidos Dicarboxílicos/metabolismo , Piridinas/metabolismo , Pironas/metabolismo , Fermentação , Glucose/metabolismo
5.
Proc Natl Acad Sci U S A ; 120(1): e2209990120, 2023 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-36577069

RESUMO

Microglia play a critical role in the clearance of myelin debris, thereby ensuring functional recovery from neural injury. Here, using mouse model of demyelination following two-point LPC injection, we show that the microglial autophagic-lysosomal pathway becomes overactivated in response to severe demyelination, leading to lipid droplet accumulation and a dysfunctional and pro-inflammatory microglial state, and finally failed myelin debris clearance and spatial learning deficits. Data from genetic approaches and pharmacological modulations, via microglial Atg5 deficient mice and intraventricular BAF A1 administration, respectively, demonstrate that staged suppression of excessive autophagic-lysosomal activation in microglia, but not sustained inhibition, results in better myelin debris degradation and exerts protective effects against demyelination. Combined multi-omics results in vitro further showed that enhanced lipid metabolism, especially the activation of the linoleic acid pathway, underlies this protective effect. Supplementation with conjugated linoleic acid (CLA), both in vivo and in vitro, could mimic these effects, including attenuating inflammation and restoring microglial pro-regenerative properties, finally resulting in better recovery from demyelination injuries and improved spatial learning function, by activating the peroxisome proliferator-activated receptor (PPAR-γ) pathway. Therefore, we propose that pharmacological inhibition targeting microglial autophagic-lysosomal overactivation or supplementation with CLA could represent a potential therapeutic strategy in demyelinated disorders.


Assuntos
Doenças Desmielinizantes , Microglia , Camundongos , Animais , Microglia/metabolismo , Ácido Linoleico/metabolismo , Autofagia , Doenças Desmielinizantes/metabolismo , Regeneração
6.
J Biol Chem ; 300(10): 107778, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39270821

RESUMO

Propofol is a widely used anesthetic and sedative that acts as a positive allosteric modulator of gamma-aminobutyric acid type A (GABAA) receptors. Several potential propofol binding sites that may mediate this effect have been identified using propofol-analogue photoaffinity labeling. Ortho-propofol diazirine (o-PD) labels ß-H267, a pore-lining residue, whereas AziPm labels residues ß-M286, ß-M227, and α-I239 in the two membrane-facing interfaces [ß(+)/α(-) and α(+)/ß(-)] between α and ß subunits. This study used photoaffinity labeling of α1ß3 GABAA receptors to reconcile the apparently conflicting results obtained with AziPm and o-PD labeling, focusing on whether ß3-H267 identifies specific propofol binding site(s). The results show that propofol, but not AziPm protects ß3-H267 from labeling by o-PD, whereas both propofol and o-PD protect against AziPm labeling of ß3-M286, ß3-M227, and α1I239. These data indicate that there are three distinct classes of propofol binding sites, with AziPm binding to two of the classes and o-PD to all three. Analysis of binding stoichiometry using native mass spectrometry in ß3 homomeric receptors, demonstrated a minimum of five AziPm labeled residues and three o-PD labeled residues per pentamer, suggesting that there are two distinct propofol binding sites per ß-subunit. The native mass spectrometry data, coupled with photolabeling performed in the presence of zinc, indicate that the binding site(s) identified by o-PD are adjacent to, but not within the channel pore, since the pore at the 17' H267 residue can accommodate only one propofol molecule. These data validate the existence of three classes of specific propofol binding sites on α1ß3 GABAA receptors.

7.
BMC Genomics ; 25(1): 525, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38807041

RESUMO

BACKGROUND: The Rh blood group system is characterized by its complexity and polymorphism, encompassing 56 different antigens. Accurately predicting the presence of the C antigen using genotyping methods has been challenging. The objective of this study was to evaluate the accuracy of various genotyping methods for predicting the Rh C and to identify a suitable method for the Chinese Han population. METHODS: In total, 317 donors, consisting 223 D+ (including 20 with the Del phenotype) and 94 D- were randomly selected. For RHC genotyping, 48C and 109bp insertion were detected on the Real-time PCR platform and -292 substitution was analyzed via restriction fragment length polymorphism (RFLP). Moreover, the promoter region of the RHCE gene was sequenced to search for other nucleotide substitutions between RHC and RHc. Agreement between prediction methods was evaluated using the Kappa statistic, and comparisons between methods were conducted via the χ2 test. RESULTS: The analysis revealed that the 48C allele, 109bp insertion, a specific pattern observed in RFLP results, and wild-type alleles of seven single nucleotide polymorphisms (SNPs) were in strong agreement with the Rh C, with Kappa coefficients exceeding 0.8. However, there were instances of false positives or false negatives (0.6% false negative rate for 109bp insertion and 5.4-8.2% false positive rates for other methods). The 109bp insertion method exhibited the highest accuracy in predicting the Rh C, at 99.4%, compared to other methods (P values≤0.001). Although no statistical differences were found among other methods for predicting Rh C (P values>0.05), the accuracies in descending order were 48C (94.6%) > rs586178 (92.7%) > rs4649082, rs2375313, rs2281179, rs2072933, rs2072932, and RFLP (92.4%) > rs2072931 (91.8%). CONCLUSIONS: None of the methods examined can independently and accurately predict the Rh C. However, the 109bp insertion test demonstrated the highest accuracy for predicting the Rh C in the Chinese Han population. Utilizing the 109bp insertion test in combination with other methods may enhance the accuracy of Rh C prediction.


Assuntos
Técnicas de Genotipagem , Polimorfismo de Nucleotídeo Único , Sistema do Grupo Sanguíneo Rh-Hr , Humanos , Alelos , China , População do Leste Asiático , Frequência do Gene , Genótipo , Técnicas de Genotipagem/métodos , Polimorfismo de Fragmento de Restrição , Regiões Promotoras Genéticas , Sistema do Grupo Sanguíneo Rh-Hr/genética
8.
Mol Pain ; : 17448069241260349, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38795338

RESUMO

Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disease characterized by chronic visceral pain with a complex etiology and challenging treatment. Although accumulating evidence supports the involvement of central nervous system sensitization in the development of visceral pain, the precise molecular mechanisms remain incompletely understood. In this study, we highlight the critical regulatory role of lysine-specific demethylase 6B (KDM6B) in the anterior cingulate cortex (ACC) in chronic visceral pain. To simulate clinical IBS conditions, we utilized the neonatal maternal deprivation (NMD) mouse model. Our results demonstrated that NMD induced chronic visceral pain and anxiety-like behaviors in mice. Notably, the protein expression level of KDM6B significantly increased in the ACC of NMD mice, leading to a reduction in the expression level of H32K7me3. Immunofluorescence staining revealed that KDM6B primarily co-localizes with neurons in the ACC, with minimal presence in microglia and astrocytes. Injecting GSK-J4 (a KDM6B-specific inhibitor) into ACC of NMD mice, resulted in a significant alleviation in chronic visceral pain and anxiety-like behaviors, as well as a remarkable reduction in NR2B expression level. ChIP assay further indicated that KDM6B regulates NR2B expression by influencing the demethylation of H3K27me3. In summary, our findings underscore the critical role of KDM6B in regulating chronic visceral pain and anxiety-like behaviors in NMD mice. These insights provide a basis for further understanding the molecular pathways involved in IBS and may pave the way for targeted therapeutic interventions.

9.
BMC Immunol ; 25(1): 16, 2024 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-38347480

RESUMO

OBJECTIVE: The study aimed to explore the mechanism of artemisinin in treating primary Sjögren's syndrome (pSS) based on network pharmacology and experimental validation. METHODS: Relevant targets of the artemisinin and pSS-related targets were integrated by public databases online. An artemisinin-pSS network was constructed by Cytoscape. The genes of artemisinin regulating pSS were imported into STRING database to construct a protein-protein interaction (PPI) network in order to predict the key targets. The enrichment analyses were performed to predict the crucial mechanism and pathway of artemisinin against pSS. The active component of artemisinin underwent molecular docking with the key proteins. Artemisinin was administered intragastrically to SS-like NOD/Ltj mice to validate the efficacy and critical mechanisms. RESULTS: Network Pharmacology analysis revealed that artemisinin corresponded to 412 targets, and pSS related to 1495 genes. There were 40 intersection genes between artemisinin and pSS. KEGG indicated that therapeutic effects of artemisinin on pSS involves IL-17 signaling pathway, HIF-1 signaling pathway, apoptosis signaling pathway, Th17 cell differentiation, PI3K-Akt signaling pathway, and MAPK signaling pathway. Molecular docking results further showed that the artemisinin molecule had higher binding energy by combining with the key nodes in IL-17 signaling pathway. In vivo experiments suggested artemisinin can restored salivary gland secretory function and improve the level of glandular damage of NOD/Ltj mice. It contributed to the increase of regulatory T cells (Tregs) and the downregulated secretion of IL-17 in NOD/Ltj model. CONCLUSION: The treatment of pSS with artemisinin is closely related to modulating the balance of Tregs and Th17 cells via T cell differentiation.


Assuntos
Artemisininas , Síndrome de Sjogren , Camundongos , Animais , Camundongos Endogâmicos NOD , Interleucina-17 , Simulação de Acoplamento Molecular , Farmacologia em Rede , Fosfatidilinositol 3-Quinases , Síndrome de Sjogren/tratamento farmacológico , Artemisininas/farmacologia , Artemisininas/uso terapêutico
10.
Anal Chem ; 96(8): 3335-3344, 2024 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-38363654

RESUMO

Metabolomics has emerged as a powerful tool in biomedical research to understand the pathophysiological processes and metabolic biomarkers of diseases. Nevertheless, it is a significant challenge in metabolomics to identify the reliable core metabolites that are closely associated with the occurrence or progression of diseases. Here, we proposed a new research framework by integrating detection-based metabolomics with computational network biology for function-guided and network-based identification of core metabolites, namely, FNICM. The proposed FNICM methodology is successfully utilized to uncover ulcerative colitis (UC)-related core metabolites based on the significantly perturbed metabolic subnetwork. First, seed metabolites were screened out using prior biological knowledge and targeted metabolomics. Second, by leveraging network topology, the perturbations of the detected seed metabolites were propagated to other undetected ones. Ultimately, 35 core metabolites were identified by controllability analysis and were further hierarchized into six levels based on confidence level and their potential significance. The specificity and generalizability of the discovered core metabolites, used as UC's diagnostic markers, were further validated using published data sets of UC patients. More importantly, we demonstrated the broad applicability and practicality of the FNICM framework in different contexts by applying it to multiple clinical data sets, including inflammatory bowel disease, colorectal cancer, and acute coronary syndrome. In addition, FNICM was also demonstrated as a practicality methodology to identify core metabolites correlated with the therapeutic effects of Clematis saponins. Overall, the FNICM methodology is a new framework for identifying reliable core metabolites for disease diagnosis and drug treatment from a systemic and a holistic perspective.


Assuntos
Colite Ulcerativa , Metabolômica , Humanos , Metabolômica/métodos , Biologia Computacional/métodos , Colite Ulcerativa/diagnóstico
11.
Biochem Biophys Res Commun ; 691: 149314, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38039831

RESUMO

P: -glycoprotein (P-gp/ABCB1) overexpression is one of the primary causes of multidrug resistance (MDR). Therefore, it is crucial to discover effective pharmaceuticals to combat multidrug resistance mediated by ABCB1. Pemigatinib is a selective the fibroblast growth factor receptor (FGFR) inhibitor that is used to treat a variety of solid tumors, Clinical Trials for Urothelial Carcinoma (NCT02872714) completed its research on Pemigatinib. This study aimed to determine whether Pemigatinib can reverse ABCB1-mediated multidrug resistance, as well as its mechanism of action. Pemigatinib substantially reversed ABCB1-mediated multidrug resistance, as determined by a CCK8 assay, and immunofluorescence experiments revealed that Pemigatinib had no effect on the intracellular localization of ABCB1. Pemigatinib was discovered to increase intracellular drug accumulation, thereby reversing multidrug resistance. In addition, Docking analysis revealed that Pemigatinib and ABCB1 have a high affinity for one another. This study concludes that Pemigatinib is capable of reversing the multidrug resistance mediated by ABCB1, offering ideas and references for the clinical application of Pemigatinib.


Assuntos
Antineoplásicos , Carcinoma de Células de Transição , Neoplasias da Bexiga Urinária , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/metabolismo , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , Resistência a Múltiplos Medicamentos , Subfamília B de Transportador de Cassetes de Ligação de ATP
12.
Am J Gastroenterol ; 119(4): 655-661, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37975609

RESUMO

INTRODUCTION: Whether 10-day short-course vonoprazan-amoxicillin dual therapy (VA-dual) is noninferior to the standard 14-day bismuth-based quadruple therapy (B-quadruple) against Helicobacter pylori eradication has not been determined. This trial aimed to compare the eradication rate, adverse events, and compliance of 10-day VA-dual regimen with standard 14-day B-quadruple regimen as first-line H. pylori treatment. METHODS: This prospective randomized clinical trial was performed at 3 institutions in eastern China. A total of 314 treatment-naive, H. pylori -infected patients were randomly assigned in a 1:1 ratio to either 10-day VA-dual group or 14-day B-quadruple group. Eradication success was determined by 13 C-urea breath test at least 4 weeks after treatment. Eradication rates, adverse events, and compliance were compared between groups. RESULTS: Eradication rates of VA-dual and B-quadruple groups were 86.0% and 89.2% ( P = 0.389), respectively, by intention-to-treat (ITT) analysis; 88.2% and 91.5% ( P = 0.338), respectively, by modified ITT analysis; and 90.8% and 91.3% ( P = 0.884), respectively, by per-protocol (PP) analysis. The efficacy of the VA-dual remained noninferior to B-quadruple therapy in all ITT, modified ITT, and PP analyses. The incidence of adverse events in the VA-dual group was significantly lower compared with that in the B-quadruple group ( P < 0.001). Poor compliance contributed to eradication failure in the VA-dual group ( P < 0.001), while not in the B-quadruple group ( P = 0.110). DISCUSSION: The 10-day VA-dual therapy provided satisfactory eradication rates of >90% (PP analysis) and lower rates of adverse events compared with standard 14-day B-quadruple therapy as first-line H. pylori therapy. TRAIL REGISTRATION NUMBER: ChiCTR2300070100.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Pirróis , Sulfonamidas , Humanos , Amoxicilina/uso terapêutico , Bismuto/uso terapêutico , Bismuto/efeitos adversos , Antibacterianos , Infecções por Helicobacter/tratamento farmacológico , Estudos Prospectivos , Quimioterapia Combinada , Adesão à Medicação , Resultado do Tratamento , Inibidores da Bomba de Prótons/efeitos adversos
13.
Chemistry ; 30(8): e202303519, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38018776

RESUMO

Three unusual ajmaline-macroline type bisindole alkaloids, alsmaphylines A-C, together with their postulated biogenetic precursors, were isolated from the stem barks and leaves of Alstonia macrophylla via the building blocks-based molecular network (BBMN) strategy. Alsmaphyline A represents a rare ajmaline-macroline type bisindole alkaloid with an S-shape polycyclic ring system. Alsmaphylines B and C are two novel ajmaline-macroline type bisindole alkaloids with N-1-C-21' linkages, and the former possesses an unconventional stacked conformation due to the presence of intramolecular noncovalent interactions. The chemical structures including absolute configurations of alsmaphylines A-C were established by comprehensive spectroscopic analyses, electronic circular dichroism (ECD) calculations, and single-crystal X-ray crystallography. In addition, a plausible biosynthetic pathway of these bisindole alkaloids as well as their ability to promote the protein synthesis on HT22 cells were discussed.


Assuntos
Alcaloides , Alstonia , Oxindóis , Alstonia/química , Ajmalina , Alcaloides Indólicos/química , Estrutura Molecular , Alcaloides/química
14.
Mol Psychiatry ; 28(3): 1383-1395, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36481932

RESUMO

In response to stressful events, the hypothalamic-pituitary-adrenal (HPA) axis is activated, and consequently glucocorticoids are released by the adrenal gland into the blood circulation. A large body of research has illustrated that excessive glucocorticoids in the hippocampus exerts negative feedback regulation of the HPA axis through glucocorticoid receptor (GR), which is critical for the homeostasis of the HPA axis. Maternal prenatal stress causes dysfunction of the HPA axis feedback mechanism in their offspring in adulthood. Here we report that telomerase reverse transcriptase (TERT) gene knockout causes hyperactivity of the HPA axis without hippocampal GR deficiency. We found that the level of TERT in the dentate gyrus (DG) of the hippocampus during the developmental stage determines the responses of the HPA axis to stressful events in adulthood through modulating the excitability of the dentate granular cells (DGCs) rather than the expression of GR. Our study also suggests that the prenatal high level of glucocorticoids exposure-induced hypomethylation at Chr13:73764526 in the first exon of mouse Tert gene accounted for TERT deficiency in the DG and HPA axis abnormality in the adult offspring. This study reveals a novel GR-independent mechanism underlying prenatal stress-associated HPA axis impairment, providing a new angle for understanding the mechanisms for maintaining HPA axis homeostasis.


Assuntos
Sistema Hipotálamo-Hipofisário , Receptores de Glucocorticoides , Feminino , Gravidez , Animais , Camundongos , Sistema Hipotálamo-Hipofisário/metabolismo , Receptores de Glucocorticoides/metabolismo , Glucocorticoides/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Homeostase
15.
Biomacromolecules ; 25(3): 1923-1932, 2024 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-38394470

RESUMO

Fatty acid cellulose esters (FACE) are common cellulose-based thermoplastics, and their thermoplasticity is determined by both the contents and the lengths of the side chains. Herein, various FACE were synthesized by the ball-milling esterification of cellulose and fatty acyl chlorides containing 10-18 carbons, and their structures and thermoplasticity were thoroughly studied. The results showed that FACE with high degrees of substitution (DS) and low melting flow temperatures (Tf) were achieved as the chain lengths of the fatty acyl chlorides were reduced. In particular, a cellulose decanoate with a DS of 1.85 and a Tf of 186 °C was achieved by feeding 3 mol of decanoyl chloride per mole anhydroglucose units of cellulose. However, cellulose stearate (DS = 1.53) synthesized by the same protocols cannot melt even at 250 °C. More interestingly, the fatty acyl chlorides with 10 and 12 carbons resulted in FACE with superior toughness (elongation at break up to 94.4%). In contrast, due to their potential crystallization of the fatty acyl groups with 14-18 carbons, the corresponding FACE showed higher tensile strength and Young's modulus than the others. This study provides some theoretical basis for the mechanochemical synthesis of thermoplastic FACE with designated properties.


Assuntos
Cloretos , Ésteres , Ésteres/química , Estudos de Viabilidade , Esterificação , Celulose/química
16.
Cancer Control ; 31: 10732748241284535, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39292867

RESUMO

OBJECTIVE: To retrospectively analyze the effect of hyperthermic intraperitoneal chemotherapy (HIPEC) on the progression free survival (PFS) of advanced gastric cancer (GC) and colorectal cancer (CRC). METHOD: We retrospectively collected all the HIPEC data of GC and CRC in the Chongqing University Cancer Hospital from August 2018 to April 2023. Data were extracted from inpatient records and outpatient examination records. The IBM SPSS statistics 23.0 software was used to analyze the data. We mainly compared the PFS of HIPEC cases with that of non-HIPEC cases (both from our center and from the literature). PFS was analyzed with the Kaplan-Meier method. Log Rank (Mantel Cox), Breslow (Generalized Wilcoxon), and Tarone-Ware were used for univariate analyses. RESULT: A total of 342 HIPEC cases were analyzed in this study. Stage IV GC and CRC accounted for 48.5% of the total number of cases. Abdominal pain and distension (47.4%) were the most common side effects from HIPEC. Serious complications were rare (1.8%, including bleeding, perforation, obstruction, and death). The PFS and disease-free survival (DFS) of abdominal malignancy treated with HIPEC were significantly associated with the TNM stage, but not HIPEC numbers nor HIPEC drugs. In stage IV HIPEC cases, adding adjuvant chemotherapy after HIPEC resulted in better PFS. In addition, the association between peritoneal carcinomatosis index (PCI) and PFS of stage IV HIPEC cases was close to significant. Compared with the 33 stage IV (with peritoneal metastases) GC cases without HIPEC in our center from the last 15 years, the PFS of the 56 stage Ⅳ GC cases with HIPEC was not improved significantly (median PFS: 6 ± 2.92 months vs 7 ± 1.63 months for with vs without HIPEC in stage IV GC, respectively; P ≥ 0.05). Compared with the 58 stage IV (with peritoneal metastases) CRC cases without HIPEC in our center from the last 15 years, the PFS of the 86 stage IV CRC cases with HIPEC was not improved significantly either (median PFS: 7 ± 1.68 months vs 7 ± 0.62 months for with vs without HIPEC in stage IV CRC, respectively; P ≥ 0.05). When comparing our HIPEC data with the non-HIPEC data reported by other scholars for the PFS of advanced GC and CRC, the negative results were similar. CONCLUSION: The PFS/DFS of HIPEC cases was associated with the TNM stage, but not with the HIPEC numbers or HIPEC drugs. PCI may be related to the PFS of stage IV HIPEC cases. Adding chemotherapy or targeted therapy after HIPEC may improve the PFS of stage IV cases. HIPEC did not significantly improve the PFS of stage IV GC or CRC cases in our center.


Assuntos
Neoplasias Colorretais , Quimioterapia Intraperitoneal Hipertérmica , Neoplasias Gástricas , Humanos , Estudos Retrospectivos , Masculino , Feminino , Quimioterapia Intraperitoneal Hipertérmica/métodos , Neoplasias Gástricas/terapia , Neoplasias Gástricas/patologia , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/tratamento farmacológico , Pessoa de Meia-Idade , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Idoso , Adulto , Intervalo Livre de Progressão
17.
Int J Legal Med ; 138(5): 2037-2047, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38802694

RESUMO

In forensic practice, determining the postmortem submersion interval (PMSI) and cause-of-death of cadavers in aquatic ecosystems has always been challenging task. Traditional approaches are not yet able to address these issues effectively and adequately. Our previous study proposed novel models to predict the PMSI and cause-of-death based on metabolites of blood from rats immersed in freshwater. However, with the advance of putrefaction, it is hardly to obtain blood samples beyond 3 days postmortem. To further assess the feasibility of PMSI estimation and drowning diagnosis in the later postmortem phase, gastrocnemius, the more degradation-resistant tissue, was collected from drowned rats and postmortem submersion model in freshwater immediately after death, and at 1 day, 3 days, 5 days, 7 days, and 10 days postmortem respectively. Then the samples were analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to investigate the dynamic changes of the metabolites. A total of 924 metabolites were identified. Similar chronological changes of gastrocnemius metabolites were observed in the drowning and postmortem submersion groups. The difference in metabolic profiles between drowning and postmortem submersion groups was only evident in the initial 1 day postmortem, which was faded as the PMSI extension. Nineteen metabolites representing temporally-dynamic patterns were selected as biomarkers for PMSI estimation. A regression model was built based on these biomarkers with random forest algorithm, which yielded a mean absolute error (± SE) of 5.856 (± 1.296) h on validation samples from an independent experiment. These findings added to our knowledge of chronological changes in muscle metabolites from submerged vertebrate remains during decomposition, which provided a new perspective for PMSI estimation.


Assuntos
Afogamento , Água Doce , Imersão , Metabolômica , Modelos Animais , Músculo Esquelético , Mudanças Depois da Morte , Animais , Músculo Esquelético/metabolismo , Afogamento/diagnóstico , Afogamento/metabolismo , Masculino , Cromatografia Líquida , Espectrometria de Massas em Tandem , Ratos , Ratos Sprague-Dawley , Biomarcadores/metabolismo
18.
Inorg Chem ; 63(31): 14345-14353, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-39033409

RESUMO

A biocompatible metal-organic framework (MOF), named HSTC-4, constructed using the flexible 4,4'-oxybis(benzoic acid) (OBA), was developed to enable efficient loading and controlled release of vitamin C (VC) through a combination of strategies involving ligand length, structure design, and metal selection. The kinetic product HSTC-4 demonstrates a propensity for transforming into the thermodynamically stable HSTC-5 under external stimuli, such as photoillumination and vacuum heating, as witnessed by single-crystal to single-crystal transformation. Density functional theory (DFT) calculations reveal that the VC guest molecules exhibit stronger binding affinity with HSTC-5 due to its narrower pores compared to HSTC-4, resulting in a slower release of VC from VC@HSTC-5. Furthermore, precise control over VC release can be achieved by introducing surface modifications involving SiO2 onto the structure of VC@HSCT-5, while simultaneously adjusting environmental factors such as pH and temperature conditions. Preliminary cell culture experiments and cytotoxicity assays highlight the biocompatibility of HSTC-5, suggesting that it is a promising platform for sustained drug delivery and diverse biomedical applications.


Assuntos
Ácido Ascórbico , Estruturas Metalorgânicas , Termodinâmica , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Ácido Ascórbico/química , Cinética , Humanos , Teoria da Densidade Funcional , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , Estrutura Molecular , Liberação Controlada de Fármacos
19.
Org Biomol Chem ; 2024 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-39434558

RESUMO

We described a chiral phosphoric acid (CPA) catalyzed asymmetric [3 + 3] cycloaddition of cinnamaldehyde-derived N-aryl nitrones with 2-indolylmethanols to prepare various indole-fused 1,2-oxazines in high yields (up to 96%) with excellent enantioselectivity (>99% ee). Control experiments indicate that hydrogen bonding plays important roles in controlling the enantioselectivity of products. This strategy provides an efficient pathway to construct enantioenriched indole-fused 1,2-oxazines from N-aryl nitrones with 2-indolylmethanols.

20.
BMC Infect Dis ; 24(1): 533, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38802753

RESUMO

BACKGROUND: Hepatitis B virus (HBV) infection can cause liver failure, while individuals with Acquired Immunodeficiency Virus Disease (AIDS) are highly susceptible to various opportunistic infections, which can occur concurrently. The treatment process is further complicated by the potential occurrence of immune reconstitution inflammatory syndrome (IRIS), which presents significant challenges and contributes to elevated mortality rates. CASE PRESENTATION: The 50-year-old male with a history of chronic hepatitis B and untreated human immunodeficiency virus (HIV) infection presented to the hospital with a mild cough and expectoration, revealing multi-drug resistant pulmonary tuberculosis (MDR-PTB), which was confirmed by XpertMTB/RIF PCR testing and tuberculosis culture of bronchoalveolar lavage fluid (BALF). The patient was treated with a regimen consisting of linezolid, moxifloxacin, cycloserine, pyrazinamide, and ethambutol for tuberculosis, as well as a combination of bictegravir/tenofovir alafenamide/emtricitabine (BIC/TAF/FTC) for HBV and HIV viral suppression. After three months of treatment, the patient discontinued all medications, leading to hepatitis B virus reactivation and subsequent liver failure. During the subsequent treatment for AIDS, HBV, and drug-resistant tuberculosis, the patient developed disseminated cryptococcal disease. The patient's condition worsened during treatment with liposomal amphotericin B and fluconazole, which was ultimately attributed to IRIS. Fortunately, the patient achieved successful recovery after appropriate management. CONCLUSION: Enhancing medical compliance is crucial for AIDS patients, particularly those co-infected with HBV, to prevent HBV reactivation and subsequent liver failure. Furthermore, conducting a comprehensive assessment of potential infections in patients before resuming antiviral therapy is essential to prevent the occurrence of IRIS. Early intervention plays a pivotal role in improving survival rates.


Assuntos
Criptococose , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose Pulmonar , Humanos , Masculino , Pessoa de Meia-Idade , Criptococose/tratamento farmacológico , Criptococose/microbiologia , Criptococose/complicações , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/complicações , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/complicações , Falência Hepática/virologia , Síndrome da Imunodeficiência Adquirida/complicações , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Hepatite B Crônica/complicações , Hepatite B Crônica/tratamento farmacológico , Coinfecção/tratamento farmacológico , Coinfecção/microbiologia , Coinfecção/virologia , Antituberculosos/uso terapêutico , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Infecções Oportunistas Relacionadas com a AIDS/microbiologia
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