Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 423
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 178(1): 176-189.e15, 2019 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-31155231

RESUMO

RLR-mediated type I IFN production plays a pivotal role in elevating host immunity for viral clearance and cancer immune surveillance. Here, we report that glycolysis, which is inactivated during RLR activation, serves as a barrier to impede type I IFN production upon RLR activation. RLR-triggered MAVS-RIG-I recognition hijacks hexokinase binding to MAVS, leading to the impairment of hexokinase mitochondria localization and activation. Lactate serves as a key metabolite responsible for glycolysis-mediated RLR signaling inhibition by directly binding to MAVS transmembrane (TM) domain and preventing MAVS aggregation. Notably, lactate restoration reverses increased IFN production caused by lactate deficiency. Using pharmacological and genetic approaches, we show that lactate reduction by lactate dehydrogenase A (LDHA) inactivation heightens type I IFN production to protect mice from viral infection. Our study establishes a critical role of glycolysis-derived lactate in limiting RLR signaling and identifies MAVS as a direct sensor of lactate, which functions to connect energy metabolism and innate immunity.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteína DEAD-box 58/antagonistas & inibidores , Proteína DEAD-box 58/metabolismo , Ácido Láctico/farmacologia , Receptores de Superfície Celular/antagonistas & inibidores , Receptores de Superfície Celular/metabolismo , Animais , Feminino , Glicólise , Células HEK293 , Humanos , Interferon beta/metabolismo , L-Lactato Desidrogenase/genética , L-Lactato Desidrogenase/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Células RAW 264.7 , Receptores Imunológicos , Transdução de Sinais/efeitos dos fármacos , Transfecção
2.
Mol Cell ; 81(18): 3803-3819.e7, 2021 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-34547240

RESUMO

Mitochondrial dynamics regulated by mitochondrial fusion and fission maintain mitochondrial functions, whose alterations underline various human diseases. Here, we show that inositol is a critical metabolite directly restricting AMPK-dependent mitochondrial fission independently of its classical mode as a precursor for phosphoinositide generation. Inositol decline by IMPA1/2 deficiency elicits AMPK activation and mitochondrial fission without affecting ATP level, whereas inositol accumulation prevents AMPK-dependent mitochondrial fission. Metabolic stress or mitochondrial damage causes inositol decline in cells and mice to elicit AMPK-dependent mitochondrial fission. Inositol directly binds to AMPKγ and competes with AMP for AMPKγ binding, leading to restriction of AMPK activation and mitochondrial fission. Our study suggests that the AMP/inositol ratio is a critical determinant for AMPK activation and establishes a model in which AMPK activation requires inositol decline to release AMPKγ for AMP binding. Hence, AMPK is an inositol sensor, whose inactivation by inositol serves as a mechanism to restrict mitochondrial fission.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Inositol/metabolismo , Dinâmica Mitocondrial/fisiologia , Proteínas Quinases Ativadas por AMP/fisiologia , Animais , Linhagem Celular , Humanos , Inositol/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias/metabolismo , Células PC-3 , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Estresse Fisiológico/fisiologia
3.
Proc Natl Acad Sci U S A ; 121(10): e2309656121, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38408254

RESUMO

Inner ear hair cells are characterized by the F-actin-based stereocilia that are arranged into a staircase-like pattern on the apical surface of each hair cell. The tips of shorter-row stereocilia are connected with the shafts of their neighboring taller-row stereocilia through extracellular links named tip links, which gate mechano-electrical transduction (MET) channels in hair cells. Cadherin 23 (CDH23) forms the upper part of tip links, and its cytoplasmic tail is inserted into the so-called upper tip-link density (UTLD) that contains other proteins such as harmonin. The Cdh23 gene is composed of 69 exons, and we show here that exon 68 is subjected to hair cell-specific alternative splicing. Tip-link formation is not affected in genetically modified mutant mice lacking Cdh23 exon 68. Instead, the stability of tip links is compromised in the mutants, which also suffer from progressive and noise-induced hearing loss. Moreover, we show that the cytoplasmic tail of CDH23(+68) but not CDH23(-68) cooperates with harmonin in phase separation-mediated condensate formation. In conclusion, our work provides evidence that inclusion of Cdh23 exon 68 is critical for the stability of tip links through regulating condensate formation of UTLD components.


Assuntos
Surdez , Perda Auditiva , Camundongos , Animais , Perda Auditiva/genética , Perda Auditiva/metabolismo , Células Ciliadas Auditivas/fisiologia , Surdez/genética , Células Ciliadas Auditivas Internas/metabolismo , Caderinas/metabolismo , Éxons/genética
4.
Hum Mol Genet ; 32(10): 1622-1633, 2023 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-36617157

RESUMO

As the auditory and balance receptor cells in the inner ear, hair cells are responsible for converting mechanical stimuli into electrical signals, a process referred to as mechano-electrical transduction. Hair cell development and function are tightly regulated, and hair cell deficits are the main reasons for hearing loss and balance disorders. TMCC2 is an endoplasmic reticulum (ER)-residing transmembrane protein whose physiological function largely remains unknown. In the present work, we show that Tmcc2 is specifically expressed in the auditory hair cells of mouse inner ear. Tmcc2 knockout mice were then established to investigate its physiological role in hearing. Auditory brainstem responses measurements show that Tmcc2 knockout mice suffer from congenital hearing loss. Further investigations reveal progressive auditory hair cell loss in the Tmcc2 knockout mice. The general morphology and function of ER are unaffected in Tmcc2 knockout hair cells. However, increased ER stress was observed in Tmcc2 knockout mice and knockdown cells, suggesting that loss of TMCC2 leads to auditory hair cell death through elevated ER stress.


Assuntos
Surdez , Perda Auditiva , Animais , Camundongos , Surdez/metabolismo , Estresse do Retículo Endoplasmático/genética , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas Internas , Audição , Perda Auditiva/metabolismo , Camundongos Knockout
5.
PLoS Pathog ; 19(1): e1011089, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36638143

RESUMO

Primary effusion lymphoma (PEL) caused by Kaposi sarcoma-associated herpesvirus (KSHV) is an aggressive malignancy with poor prognosis even under chemotherapy. Currently, there is no specific treatment for PEL therefore requiring new therapies. Both histone deacetylases (HDACs) and bromodomain-containing protein 4 (BRD4) have been found as therapeutic targets for PEL through inducing viral lytic reactivation. However, the strategy of dual targeting with one agent and potential synergistic effects have never been explored. In the current study, we first demonstrated the synergistic effect of concurrently targeting HDACs and BRD4 on KSHV reactivation by using SAHA or entinostat (HDACs inhibitors) and (+)-JQ1 (BRD4 inhibitor), which indicated dual blockage of HDACs/BRD4 is a viable therapeutic approach. We were then able to rationally design and synthesize a series of new small-molecule inhibitors targeting HDACs and BRD4 with a balanced activity profile by generating a hybrid of the key binding motifs between (+)-JQ1 and entinostat or SAHA. Upon two iterative screenings of optimized compounds, a pair of epimers, 009P1 and 009P2, were identified to better inhibit the growth of KSHV positive lymphomas compared to (+)-JQ1 or SAHA alone at low nanomolar concentrations, but not KSHV negative control cells or normal cells. Mechanistic studies of 009P1 and 009P2 demonstrated significantly enhanced viral reactivation, cell cycle arrest and apoptosis in KSHV+ lymphomas through dually targeting HDACs and BRD4 signaling activities. Importantly, in vivo preclinical studies showed that 009P1 and 009P2 dramatically suppressed KSHV+ lymphoma progression with oral bioavailability and minimal visible toxicity. These data together provide a novel strategy for the development of agents for inducing lytic activation-based therapies against these viruses-associated malignancies.


Assuntos
Herpesvirus Humano 8 , Linfoma de Efusão Primária , Sarcoma de Kaposi , Humanos , Fatores de Transcrição/metabolismo , Proteínas Nucleares/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Herpesvirus Humano 8/fisiologia , Linhagem Celular Tumoral , Proteínas de Ciclo Celular/metabolismo
6.
FASEB J ; 38(15): e23860, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-39093051

RESUMO

Inner ear sensory hair cells are characterized by their apical F-actin-based cell protrusions named stereocilia. In each hair cell, several rows of stereocilia with different height are organized into a staircase-like pattern. The height of stereocilia is tightly regulated by two protein complexes, namely row-1 and row-2 tip complex, that localize at the tips of tallest-row and shorter-row stereocilia, respectively. Previously, we and others identified BAI1-associated protein 2-like 2 (BAIAP2L2) as a component of row-2 complex that play an important role in maintaining shorter-row stereocilia. In the present work we show that BAIAP2L1, an ortholog of BAIAP2L2, localizes at the tips of tallest-row stereocilia in a way dependent on known row-1 complex proteins EPS8 and MYO15A. Interestingly, unlike BAIAP2L2 whose stereocilia-tip localization requires calcium, the localization of BAIAP2L1 on the tips of tallest-row stereocilia is calcium-independent. Therefore, our data suggest that BAIAP2L1 and BAIAP2L2 localize at the tips of different stereociliary rows and might regulate the development and/or maintenance of stereocilia differently. However, loss of BAIAP2L1 does not affect the row-1 protein complex, and the auditory and balance function of Baiap2l1 knockout mice are largely normal. We hypothesize that other orthologous protein(s) such as BAIAP2 might compensate for the loss of BAIAP2L1 in the hair cells.


Assuntos
Estereocílios , Animais , Camundongos , Cálcio/metabolismo , Células Ciliadas Auditivas/metabolismo , Células Ciliadas Auditivas Internas/metabolismo , Camundongos Knockout , Miosinas/metabolismo , Miosinas/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas do Tecido Nervoso/genética , Estereocílios/metabolismo
7.
J Neurosci ; 43(18): 3219-3231, 2023 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-37001993

RESUMO

The mechanoelectrical transduction (MET) protein complex in the inner-ear hair cells is essential for hearing and balance perception. Calcium and integrin-binding protein 2 (CIB2) has been reported to be a component of MET complex, and loss of CIB2 completely abolishes MET currents in auditory hair cells, causing profound congenital hearing loss. However, loss of CIB2 does not affect MET currents in vestibular hair cells (VHCs) as well as general balance function. Here, we show that CIB2 and CIB3 act redundantly to regulate MET in VHCs, as MET currents are completely abolished in the VHCs of Cib2/Cib3 double knock-out mice of either sex. Furthermore, we show that Cib2 and Cib3 transcripts have complementary expression patterns in the vestibular maculae, and that they play different roles in stereocilia maintenance in VHCs. Cib2 transcripts are highly expressed in the striolar region, and knock-out of Cib2 affects stereocilia maintenance in striolar VHCs. In contrast, Cib3 transcripts are highly expressed in the extrastriolar region, and knock-out of Cib3 mainly affects stereocilia maintenance in extrastriolar VHCs. Simultaneous knock-out of Cib2 and Cib3 affects stereocilia maintenance in all VHCs and leads to severe balance deficits. Taken together, our present work reveals that CIB2 and CIB3 are important for stereocilia maintenance as well as MET in mouse VHCs.SIGNIFICANCE STATEMENT Calcium and integrin-binding protein 2 (CIB2) is an important component of mechanoelectrical transduction (MET) complex, and loss of CIB2 completely abolishes MET in auditory hair cells. However, MET is unaffected in Cib2 knock-out vestibular hair cells (VHCs). In the present work, we show that CIB3 could compensate for the loss of CIB2 in VHCs, and Cib2/Cib3 double knock-out completely abolishes MET in VHCs. Interestingly, CIB2 and CIB3 could also regulate VHC stereocilia maintenance in a nonredundant way. Cib2 and Cib3 transcripts are highly expressed in the striolar and extrastriolar regions, respectively. Stereocilia maintenance and balance function are differently affected in Cib2 or Cib3 knock-out mice. In conclusion, our data suggest that CIB2 and CIB3 are important for stereocilia maintenance and MET in mouse VHCs.


Assuntos
Células Ciliadas Vestibulares , Animais , Camundongos , Cálcio/metabolismo , Células Ciliadas Vestibulares/metabolismo , Integrinas , Camundongos Knockout , Estereocílios/metabolismo
8.
J Cell Sci ; 135(16)2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35892293

RESUMO

Stereocilia are F-actin-based protrusions on the apical surface of inner-ear hair cells and are indispensable for hearing and balance perception. The stereocilia of each hair cell are organized into rows of increasing heights, forming a staircase-like pattern. The development and maintenance of stereocilia are tightly regulated, and deficits in these processes lead to stereocilia disorganization and hearing loss. Previously, we showed that the F-BAR protein FCHSD2 is localized along the stereocilia of cochlear hair cells and cooperates with CDC42 to regulate F-actin polymerization and cell protrusion formation in cultured COS-7 cells. In the present work, Fchsd2 knockout mice were established to investigate the role of FCHSD2 in hearing. Our data show that stereocilia maintenance is severely affected in cochlear hair cells of Fchsd2 knockout mice, which leads to progressive hearing loss. Moreover, Fchsd2 knockout mice show increased acoustic vulnerability. Noise exposure causes robust stereocilia degeneration as well as enhanced hearing threshold elevation in Fchsd2 knockout mice. Lastly, Fchsd2/Cdc42 double knockout mice show more severe stereocilia deficits and hearing loss, suggesting that FCHSD2 and CDC42 cooperatively regulate stereocilia maintenance.


Assuntos
Proteínas de Transporte , Perda Auditiva , Proteínas de Membrana , Estereocílios , Animais , Camundongos , Actinas/metabolismo , Proteínas de Transporte/metabolismo , Células Ciliadas Auditivas/metabolismo , Perda Auditiva/metabolismo , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estereocílios/metabolismo
9.
Small ; : e2407147, 2024 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-39444083

RESUMO

Adopting a ternary strategy is an effective approach to enhance the power conversion efficiency (PCE) in organic solar cells (OSCs). Previous research on highly efficient ternary systems has predominantly focused on those based on highly crystalline dual small molecule acceptors. However, limited attention has been given to ternary systems utilizing dual polymer donors. Herein, by incorporating the fluorine and alkylsilyl substitution, a new polymer donor named PX1 is developed, which demonstrates strong crystallinity and excellent miscibility with polymer PM6. Moreover, PX1 broadens and enhances the absorption properties of the PM6:L8-BO blends, and its molecular orbital energy level is situated between those of PM6 and L8-BO, highlighting its suitability as a third component. Introducing 20% PX1 into the PM6:L8-BO system resulted in a high PCE of 18.82%. PX1 effectively suppresses charge recombination and reduces energy losses, while also serving as a morphology modulator that enhances the crystallization and improves the molecular packing order of the active layer by shortening the π-π stacking distance and extending crystalline coherence length. These factors collectively contribute to the performance improvements in ternary devices. This study demonstrates that employing a dual polymer donor strategy is a promising approach for achieving high-performance ternary OSCs.

10.
J Org Chem ; 89(16): 11671-11681, 2024 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-39096319

RESUMO

2-Alkyl chromanone scaffold has become prominent in pharmaceuticals and natural compounds. Consequently, devising robust strategies for synthesizing 2-alkyl chromanones remains crucial. Here, multicomponent reactions were employed to synthesize 2-alkyl chromanones containing an oxazole moiety using 3-formylchromones, amines, and N-propargylamides as reactants. This method utilizes readily available feedstocks with a catalytic amount of Zn(OTf)2 and exhibits an impressive substrate scope compared to existing methods. Importantly, the synthesized compounds demonstrated highly selective anticancer activity against the DU145 cell line.


Assuntos
Antineoplásicos , Cromonas , Ácidos de Lewis , Antineoplásicos/química , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Humanos , Cromonas/química , Cromonas/farmacologia , Cromonas/síntese química , Linhagem Celular Tumoral , Ácidos de Lewis/química , Estrutura Molecular , Ensaios de Seleção de Medicamentos Antitumorais , Proliferação de Células/efeitos dos fármacos , Catálise , Relação Estrutura-Atividade
11.
Mol Divers ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38647989

RESUMO

The pyridine moiety is a crucial structural component in various pharmaceuticals. While the direct ortho- and para-functionalization of pyridines is relatively straightforward, the meta-selective C-H functionalization remains a significant challenge. This review highlights dearomatization strategies as a key area of interest in expanding the application of meta-C-H functionalization of pyridines. Dearomatization enables the meta-functionalization through various catalytic methods that directly generate dearomatization products, and some products can be rearomatized back to pyridine derivatives. Furthermore, this article also covers the dearomatization of multiple positions of pyridine in the synthesis of polycyclic compounds. It offers a comprehensive overview of the latest advancements in dearomatization at different positions of pyridine, aiming to provide a valuable resource for researchers in this field. It also highlights the advantages and limitations of existing technologies, aiming to inform a broader audience about this important field and foster its future development.

12.
J Nanobiotechnology ; 22(1): 494, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39160572

RESUMO

BACKGROUND: Sclerotinia sclerotiorum is a highly destructive phytopathogenic fungus that poses a significant threat to a wide array of crops. The current constraints in genetic manipulation techniques impede a thorough comprehension of its pathogenic mechanisms and the development of effective control strategies. RESULTS: Herein, we present a highly efficient genetic transformation system for S. sclerotiorum, leveraging the use of fusiform nanoparticles, which are synthesized with FeCl3 and 2,6-diaminopyrimidine (DAP). These nanoparticles, with an average longitude length of 59.00 nm and a positively charged surface, facilitate the direct delivery of exogenous DNA into the mycelial cells of S. sclerotiorum, as well as successful integration with stable expression. Notably, this system circumvents fungal protoplast preparation and tedious recovery processes, streamlining the transformation process considerably. Furthermore, we successfully employed this system to generate S. sclerotiorum strains with silenced oxaloacetate acetylhydrolase-encoding gene Ss-oah1. CONCLUSIONS: Our findings demonstrate the feasibility of using nanoparticle-mediated delivery as a rapid and reliable tool for genetic modification in S. sclerotiorum. Given its simplicity and high efficiency, it has the potential to significantly propel genetic research in filamentous fungi, offering new avenues for elucidating the intricacies of pathogenicity and developing innovative disease management strategies.


Assuntos
Ascomicetos , Nanopartículas , Transformação Genética , Ascomicetos/genética , Nanopartículas/química , Pirimidinas , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo
13.
Gerontology ; 70(6): 572-584, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38461811

RESUMO

INTRODUCTION: Although the relationship between the number of teeth and frailty has been extensively studied, the mediating role of nutrition status in the association between the number of teeth and frailty remains to be clarified. METHODS: A number of 6,664 participants lived in the communities of West China were analyzed in our study. Physical frailty was determined based on the phenotype established by Fried. Nutrition status was evaluated using the Mini Nutrition Assessment-Short Form (MNA-SF) scale. Multiple linear regression was employed to evaluate the direct relationships between the number of teeth, nutrition, and frailty. Mediation models and structural equation model (SEM) pathway analysis were used to test the mediating role of nutrition status in the relationship between the number of teeth and frailty. RESULTS: Among the 6,664 participants aged over 50 years old, the prevalence of frailty was 6.2%. Multiple linear regression analysis showed a significant total relationship between the number of teeth (ß = -0.359, 95% CI: -0.473 to -0.244, p < 0.001) and frailty. After adjusting for MNA-SF scores, the relationship between the number of teeth and frailty remained significant (ß = -0.327, 95% CI: -0.443 to -0.211, p < 0.001), indicating a partial mediating effect of nutrition. Mediation analysis verified that nutrition partially mediated the relationship between the number of teeth and frailty (indirect effect estimate = -0.0121, bootstrap 95% CI: -0.0151 to -0.0092; direct effect estimate = -0.0874, bootstrap 95% CI: -0.1086 to -0.0678) in the fully adjusted model. This mediating effect occurred through influencing weight loss, low level of physical activity, and debility. SEM framework pathway analysis confirmed the association between the number of teeth, nutrition, and frailty. CONCLUSIONS: Our findings demonstrated that frailty was correlated with the number of teeth and poorer nutritional status, with nutrition partially mediating the correlation between the number of teeth and frailty. Our results supported early nutritional evaluation and intervention in oral health to decrease the risk of frailty.


Assuntos
Idoso Fragilizado , Fragilidade , Estado Nutricional , Humanos , Masculino , Feminino , Estudos Transversais , Idoso , Pessoa de Meia-Idade , Fragilidade/epidemiologia , China/epidemiologia , Idoso Fragilizado/estatística & dados numéricos , Avaliação Geriátrica/métodos , Avaliação Nutricional , Perda de Dente/epidemiologia , Idoso de 80 Anos ou mais , Modelos Lineares , Prevalência
14.
Sensors (Basel) ; 24(18)2024 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-39338859

RESUMO

The point cloud is one of the measurement results of local measurement and is widely used because of its high measurement accuracy, high data density, and low environmental impact. However, since point cloud data from a single measurement are generally small in spatial extent, it is necessary to accurately globalize the local point cloud to measure large components. In this paper, the method of using an iGPS (indoor Global Positioning System) as an external measurement device to realize high-accuracy globalization of local point cloud data is proposed. Two calibration models are also discussed for different application scenarios. Verification experiments prove that the average calibration errors of these two calibration models are 0.12 mm and 0.17 mm, respectively. The proposed method can maintain calibration precision in a large spatial range (about 10 m × 10 m × 5 m), which is of high value for engineering applications.

15.
Sensors (Basel) ; 24(6)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38544010

RESUMO

In the field of aerospace, large and heavy cabin segments present a significant challenge in assembling space engines. The substantial inertial force of cabin segments' mass often leads to unexpected motion during docking, resulting in segment collisions, making it challenging to ensure the accuracy and quality of engine segment docking. While traditional manual docking leverages workers' expertise, the intensity of the labor and low productivity are impractical for real-world applications. Human-robot collaboration can effectively integrate the advantages of humans and robots. Parallel robots, known for their high precision and load-bearing capacity, are extensively used in precision assembly under heavy load conditions. Therefore, human-parallel-robot collaboration is an excellent solution for such problems. In this paper, a framework is proposed that is easy to realize in production, using human-parallel-robot collaboration technology for cabin segment docking. A fractional-order variable damping admittance control and an inverse dynamics robust controller are proposed to enhance the robot's compliance, responsiveness, and trajectory tracking accuracy during collaborative assembly. This allows operators to dynamically adjust the robot's motion in real-time, counterbalancing inertial forces and preventing collisions between segments. Segment docking assembly experiments are performed using the Stewart platform in this study. The results show that the proposed method allows the robot to swiftly respond to interaction forces, maintaining compliance and stable motion accuracy even under unknown interaction forces.


Assuntos
Trabalho de Parto , Robótica , Humanos , Gravidez , Feminino , Movimento (Física) , Tecnologia
16.
Molecules ; 29(9)2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38731412

RESUMO

Skeleton editing has rapidly advanced as a synthetic methodology in recent years, significantly streamlining the synthesis process and gaining widespread acceptance in drug synthesis and development. This field encompasses diverse ring reactions, many of which exhibit immense potential in skeleton editing, facilitating the generation of novel ring skeletons. Notably, reactions that involve the cleavage of two distinct rings followed by the reformation of new rings through ring insertion play a pivotal role in the construction of novel ring skeletons. This article aims to compile and systematize this category of reactions, emphasizing the two primary reaction types and offering a thorough exploration of their associated complexities and challenges. Our endeavor is to furnish readers with comprehensive reaction strategies, igniting research interest and injecting fresh impetus into the advancement of this domain.


Assuntos
Compostos Heterocíclicos , Compostos Heterocíclicos/química , Compostos Heterocíclicos/síntese química , Estrutura Molecular , Técnicas de Química Sintética
17.
Molecules ; 29(2)2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38257377

RESUMO

A facile methodology for the construction of a complex heterocycle indazolo-fused quinoxalinone has been developed via an Ugi four-component reaction (U-4CR) followed by an intramolecular Ullmann reaction. The expeditious process features an operationally simple approach, time efficiency, and a broad substrate scope. Biological activity was evaluated and demonstrated that compound 6e inhibits human colon cancer cell HCT116 proliferation with an IC50 of 2.1 µM, suggesting potential applications for developing a drug lead in medicinal chemistry.


Assuntos
Neoplasias do Colo , Quinoxalinas , Humanos , Quinoxalinas/farmacologia , Proliferação de Células , Química Farmacêutica
18.
J Cell Physiol ; 238(5): 1095-1110, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36947695

RESUMO

As the sensory receptor cells in vertebrate inner ear and lateral lines, hair cells are characterized by the hair bundle that consists of one tubulin-based kinocilium and dozens of actin-based stereocilia on the apical surface of each hair cell. Hair cell development is tightly regulated, and deficits in this process usually lead to hearing loss and/or balance dysfunctions. RNA-binding motif protein 24 (RBM24) is an RNA-binding protein that is specifically expressed in the hair cells in the inner ear. Previously, we showed that RBM24 affects hair cell development in zebrafish by regulating messenger RNA (mRNA) stability. In the present work, we further investigate the role of RBM24 in hearing and balance using conditional knockout mice. Our results show that Rbm24 knockout results in severe hearing and balance deficits. Hair cell development is significantly affected in Rbm24 knockout cochlea, as the hair bundles are poorly developed and eventually degenerated. Hair bundle disorganization is also observed in Rbm24 knockout vestibular hair cells, although to a lesser extent. Consistently, significant hair cell loss is observed in the cochlea but not vestibule. RNAseq analysis identified several genes whose mRNA stability or pre-mRNA alternative splicing is affected by Rbm24 knockout. Among them are Cdh23, Pcdh15, and Myo7a, which have been shown to play important roles in stereocilia development as well as mechano-electrical transduction. Taken together, our present work suggests that RBM24 is required for mouse hair cell development through regulating pre-mRNA alternative splicing as well as mRNA stability.


Assuntos
Processamento Alternativo , Células Ciliadas Auditivas , Precursores de RNA , Animais , Camundongos , Processamento Alternativo/genética , Caderinas/genética , Camundongos Knockout , Precursores de RNA/genética , Precursores de RNA/metabolismo , Estabilidade de RNA/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Peixe-Zebra , Células Ciliadas Auditivas/fisiologia
19.
Am J Transplant ; 23(7): 920-934, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37054890

RESUMO

End-stage organ failure often requires solid organ transplantation. Nevertheless, transplant rejection remains an unresolved issue. The induction of donor-specific tolerance is the ultimate goal in transplantation research. In this study, an allograft vascularized skin rejection model using BALB/c-C57/BL6 mice was established to evaluate the regulation of the poliovirus receptor signaling pathway using CD226 knockout or T cell immunoglobulin and ITIM domain (TIGIT)-crystallizable fragment (Fc) recombinant protein treatment. In the TIGIT-Fc-treated and CD226 knockout groups, graft survival time prolonged significantly, with a regulatory T cell proportion increase and M2-type macrophage polarization. Donor-reactive recipient T cells became hyporesponsive while responding normally after a third-party antigen challenge. In both groups, serum interleukin (IL)-1ß, IL-6, IL-12p70, IL-17A, tumor necrosis factor-α, interferon gamma, and monocyte chemoattractant protein-1 levels decreased, and the IL-10 level increased. In vitro, M2 markers, such as Arg1 and IL-10, were markedly increased by TIGIT-Fc, whereas iNOS, IL-1ß, IL-6, IL-12p70, tumor necrosis factor-α, and interferon gamma levels decreased. CD226-Fc exerted the opposite effect. TIGIT suppressed TH1 and TH17 differentiation by inhibiting macrophage SHP-1 phosphorylation and enhanced ERK1/2-MSK1 phosphorylation and nuclear translocation of CREB. In conclusion, CD226 and TIGIT competitively bind to poliovirus receptor with activating and inhibitory functions, respectively. Mechanistically, TIGIT promotes IL-10 transcription from macrophages by activating the ERK1/2-MSK1-CREB pathway and enhancing M2-type polarization. CD226/TIGIT-poliovirus receptor are crucial regulatory molecules of allograft rejection.


Assuntos
Antígenos de Diferenciação de Linfócitos T , Rejeição de Enxerto , Macrófagos , Receptores Imunológicos , Transplante de Pele , Animais , Camundongos , Antígenos de Diferenciação de Linfócitos T/metabolismo , Ligação Competitiva , Rejeição de Enxerto/etiologia , Interferon gama , Interleucina-10 , Interleucina-6 , Macrófagos/metabolismo , Fator de Necrose Tumoral alfa
20.
Small ; 19(21): e2300244, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36843276

RESUMO

Energy band structure of inorganic nano-sonosensitizers is usually optimized by surface decoration with noble metals or metal oxide semiconductors, aiming to enhance interfacial charge transfer, augment spin-flip and promote radical generation. To avoid potential biohazards of metallic elements, herein, metal-free graphitic carbon nitride quantum dots (g-C3 N4 QDs) are anchored onto hollow mesoporous TiO2 nanostructure to formulate TiO2 @g-C3 N4 heterojunction. The direct Z-scheme charge transfer significantly improves the separation/recombination dynamics of electron/hole (e- /h+ ) pairs upon ultrasound (US) stimulation, which promotes the yield of singlet oxygen (1 O2 ) and hydroxyl radicals (·OH). The conjugated g-C3 N4 QDs with peroxidase-mimic activity further react with the elevated endogenous H2 O2 and aggravate oxidative stress. After loading prodrug romidepsin (RMD) in TiO2 @g-C3 N4 , stimulus-responsive drug delivery can be realized by US irradiation. The disulfide bridge of the released RMD tends to be reduced by glutathione (GSH) into a monocyclic dithiol, which arrests cell cycle in G2/M phase and evokes apoptosis through enhanced histone acetylation. Importantly, reactive oxygen species accumulation accompanied by GSH depletion is devoted to deleterious redox dyshomeostasis, leading to augmented systemic oncotherapy by eliciting antitumor immunity. Collectively, this paradigm provides useful insights in optimizing the performance of TiO2 -based nano-sonosensitizers for tackling critical diseases.


Assuntos
Óxidos , Oxirredução , Ultrassonografia , Acetilação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA