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1.
Theranostics ; 14(7): 2835-2855, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38773970

RESUMO

Rationale: The large-scale genomic analysis classifies glioblastoma (GBM) into three major subtypes, including classical (CL), proneural (PN), and mesenchymal (MES) subtypes. Each of these subtypes exhibits a varying degree of sensitivity to the temozolomide (TMZ) treatment, while the prognosis corresponds to the molecular and genetic characteristics of the tumor cell type. Tumors with MES features are predominantly characterized by the NF1 deletion/alteration, leading to sustained activation of the RAS and PI3K-AKT signaling pathways in GBM and tend to acquire drug resistance, resulting in the worst prognosis compared to other subtypes (PN and CL). Here, we used the CRISPR/Cas9 library screening technique to detect TMZ-related gene targets that might play roles in acquiring drug resistance, using overexpressed KRAS-G12C mutant GBM cell lines. The study identified a key therapeutic strategy to address the chemoresistance against the MES subtype of GBM. Methods: The CRISPR-Cas9 library screening was used to discover genes associated with TMZ resistance in the U87-KRAS (U87-MG which is overexpressed KRAS-G12C mutant) cells. The patient-derived GBM primary cell line TBD0220 was used for experimental validations in vivo and in vitro. Chromatin isolation by RNA purification (ChIRP) and chromatin immunoprecipitation (ChIP) assays were used to elucidate the silencing mechanism of tumor suppressor genes in the MES-GBM subtype. The small-molecule inhibitor EPIC-0412 was obtained through high-throughput screening. Transmission electron microscopy (TEM) was used to characterize the exosomes (Exos) secreted by GBM cells after TMZ treatment. Blood-derived Exos-based targeted delivery of siRNA, TMZ, and EPIC-0412 was optimized to tailor personalized therapy in vivo. Results: Using the genome-wide CRISPR-Cas9 library screening, we found that the ERBIN gene could be epigenetically regulated in the U87-KRAS cells. ERBIN overexpression inhibited the RAS signaling and downstream proliferation and invasion effects of GBM tumor cells. EPIC-0412 treatment inhibited tumor proliferation and EMT progression by upregulating the ERBIN expression both in vitro and in vivo. Genome-wide CRISPR-Cas9 screening also identified RASGRP1(Ras guanine nucleotide-releasing protein 1) and VPS28(Vacuolar protein sorting-associated protein 28) genes as synthetically lethal in response to TMZ treatment in the U87-KRAS cells. We found that RASGRP1 activated the RAS-mediated DDR pathway by promoting the RAS-GTP transformation. VPS28 promoted the Exos secretion and decreased intracellular TMZ concentration in GBM cells. The targeted Exos delivery system encapsulating drugs and siRNAs together showed a powerful therapeutic effect against GBM in vivo. Conclusions: We demonstrate a new mechanism by which ERBIN is epigenetically silenced by the RAS signaling in the MES subtype of GBM. Restoration of the ERBIN expression with EPIC-0412 significantly inhibits the RAS signaling downstream. RASGRP1 and VPS28 genes are associated with the promotion of TMZ resistance through RAS-GDP to RAS-GTP transformation and TMZ efflux, as well. A quadruple combination therapy based on a targeted Exos delivery system demonstrated significantly reduced tumor burden in vivo. Therefore, our study provides new insights and therapeutic approaches for regulating tumor progression and TMZ resistance in the MES-GBM subtype.


Assuntos
Sistemas CRISPR-Cas , Resistencia a Medicamentos Antineoplásicos , Exossomos , Glioblastoma , Temozolomida , Glioblastoma/genética , Glioblastoma/patologia , Glioblastoma/tratamento farmacológico , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Humanos , Resistencia a Medicamentos Antineoplásicos/genética , Sistemas CRISPR-Cas/genética , Linhagem Celular Tumoral , Animais , Exossomos/metabolismo , Exossomos/genética , Camundongos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/tratamento farmacológico , Carcinogênese/genética , Carcinogênese/efeitos dos fármacos , Camundongos Nus , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Pest Manag Sci ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38742692

RESUMO

BACKGROUND: Bombyx mori nuclear polyhedrosis virus (BmNPV), as a typical baculovirus, is the primary pathogen that infects the silkworm B. mori, a lepidopteran species. Owing to the high biological safety of BmNPV in infecting insects, it is commonly utilized as a biological insecticide for pest control. Apoptosis is important in the interaction between the host and pathogenic microorganisms. MicroRNAs (miRNAs) influence immune responses and promote stability of the immune system via apoptosis. Therefore, the study of apoptosis-related miRNA in silkworms during virus infection can not only provide support for standardizing the prevention and control of diseases and insect pests, but also reduce the economic losses to sericulture caused by the misuse of biological pesticides. RESULTS: Through transcriptome sequencing, we identified a miRNA, miR-31-5p, and demonstrated that it can inhibit apoptosis in silkworm cells and promote the proliferation of BmNPV in BmE-SWU1 cells. We identified a target gene of miR-31-5p, B. mori cytochrome P450 9e2 (BmCYP9e2), and demonstrated that it can promote apoptosis in silkworm cells and inhibit the proliferation of BmNPV. Moreover, we constructed transgenic silkworm strains with miR-31-5p knockout and confirmed that they can inhibit the proliferation of BmNPV. CONCLUSION: These data indicate that miR-31-5p may exert functions of inhibiting apoptosis and promoting virus proliferation by regulating BmCYP9e2. The findings demonstrate how miRNAs influence host cell apoptosis and how they are involved in the host immune system response to viruses, providing important insights into the applications of biological insecticides for pest control. © 2024 Society of Chemical Industry.

3.
Int J Biol Macromol ; 268(Pt 2): 131819, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38688334

RESUMO

The Notch signaling pathway is important in cell cycle regulation and cell proliferation. The transcriptional repressor Suppressor of Hairless [Su(H)] is a molecular switch for downstream target genes of the Notch signaling pathway but the regulatory mechanism of the Su(H) gene in the cell cycle is unclear. We determined the function of the Notch signaling pathway and Bombyx mori Su(H) [BmSu(H)] in the regulation of the silkworm cell cycle. Inhibition of Notch signaling promoted the replication of DNA in silkworm gland cells and expression of the BmSu(H) gene was significantly reduced. Overexpression of the BmSu(H) gene inhibited DNA replication and cell proliferation of silkworm cells, whereas knockout of the BmSu(H) gene promoted DNA replication and cell proliferation. Knockout of the BmSu(H) in silkworms improved the efficiency of silk gland cell endoreplication and increased important economic traits. We demonstrated that BmSu(H) protein can directly bind to the promoters of BmCyclinA, BmCyclinE and BmCDK1 genes, inhibiting or promoting their transcription at the cell and individual level. This study identified molecular targets for genetic improvement of the silkworm and also provided insights into the regulatory mechanism of the cell cycle.


Assuntos
Bombyx , Ciclo Celular , Proteínas de Insetos , Animais , Bombyx/genética , Bombyx/metabolismo , Ciclo Celular/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Receptores Notch/metabolismo , Receptores Notch/genética , Transdução de Sinais , Seda/genética , Proliferação de Células/genética , Replicação do DNA , Regiões Promotoras Genéticas/genética , Endorreduplicação , Regulação da Expressão Gênica , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo
5.
MedComm (2020) ; 5(5): e549, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38685971

RESUMO

Toll-like receptors (TLRs) are inflammatory triggers and belong to a family of pattern recognition receptors (PRRs) that are central to the regulation of host protective adaptive immune responses. Activation of TLRs in innate immune myeloid cells directs lymphocytes to produce the most appropriate effector responses to eliminate infection and maintain homeostasis of the body's internal environment. Inappropriate TLR stimulation can lead to the development of general autoimmune diseases as well as chronic and acute inflammation, and even cancer. Therefore, TLRs are expected to be targets for therapeutic treatment of inflammation-related diseases, autoimmune diseases, microbial infections, and human cancers. This review summarizes the recent discoveries in the molecular and structural biology of TLRs. The role of different TLR signaling pathways in inflammatory diseases, autoimmune diseases such as diabetes, cardiovascular diseases, respiratory diseases, digestive diseases, and even cancers (oral, gastric, breast, colorectal) is highlighted and summarizes new drugs and related clinical treatments in clinical trials, providing an overview of the potential and prospects of TLRs for the treatment of TLR-related diseases.

6.
Inorg Chem ; 63(19): 8925-8937, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38683480

RESUMO

The development of efficient urea oxidation reaction (UOR) catalysts helps UOR replace the oxygen evolution reaction (OER) in hydrogen production from water electrolysis. Here, we prepared Fe-doped Ni2P/NiSe2 composite catalyst (Fe-Ni2P/NiSe2-12) by using phosphating-selenizating and acid etching to increase the intrinsic activity and active areas. Spectral characterization and theoretical calculations demonstrated that electrons flowed through the Ni-P-Fe-interface-Ni-Se-Fe, thus conferring high UOR activity to Fe-Ni2P/NiSe2-12, which only needed 1.39 V vs RHE to produce the current density of 100 mA cm-2. Remarkably, this potential was 164 mV lower than that required for the OER under the same conditions. Furthermore, EIS demonstrated that UOR driven by the Fe-Ni2P/NiSe2-12 exhibited faster interfacial reactions, charge transfer, and current response compared to OER. Consequently, the Fe-Ni2P/NiSe2-12 catalyst can effectively prevent competition with OER and NSOR, making it suitable for efficient hydrogen production in UOR-assisted water electrolysis. Notably, when water electrolysis is operated at a current density of 40 mA cm-2, this UOR-assisted system can achieve a decrease of 140 mV in the potential compared to traditional water electrolysis. This study presents a novel strategy for UOR-assisted water splitting for energy-saving hydrogen production.

7.
Int J Biol Macromol ; 264(Pt 2): 130842, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38484820

RESUMO

Bombyx mori nucleopolyhedrovirus (BmNPV) is a pathogen that causes significant losses to the silkworm industry. Numerous antiviral genes and proteins have been identified by studying silkworm resistance to BmNPV. However, the molecular mechanism of silkworm resistance to BmNPV is unclear. We analyzed the differences between the susceptible strain 871 and a near-isogenic resistant strain 871C. The survival of strain 871C was significantly greater than that of 871 after oral and subcutaneous exposure to BmNPV. Strain 871C exhibited a nearly 10,000-fold higher LD50 for BmNPV compared to 871. BmNPV proliferation was significantly inhibited in all tested tissues of strain 871C using HE strain and fluorescence analysis. Strain 871C exhibited cellular resistance to BmNPV rather than peritrophic membrane or serum resistance. Strain 871C suppressed the expression of the viral early gene Bm60. This led to the inhibition of BmNPV DNA replication and late structural gene transcription based on the cascade regulation of baculovirus gene expression. Bm60 could also interact with the viral DNA binding protein and alkaline nuclease, as well as host proteins Methylcrotonoyl-CoA carboxylase subunit alpha, mucin-2-like protein, and 30 K-8. Overexpression of 30 K-8 significantly inhibited BmNPV proliferation. These results increase understanding of the molecular mechanism behind silkworm resistance to BmNPV and suggest targets for the breeding of resistant silkworm strains and the controlling pest of Lepidoptera.


Assuntos
Bombyx , Nucleopoliedrovírus , Animais , Bombyx/metabolismo , Nucleopoliedrovírus/fisiologia , Genes Virais , Proliferação de Células , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo
8.
Inorg Chem ; 63(8): 3702-3711, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38335057

RESUMO

A long-term goal of rechargeable zinc-air batteries (ZABs) has always been to design bifunctional electrocatalysts that are robust, effective, and affordable for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). It has become a feasible method to construct metal/metal oxide interfaces to achieve superior electrocatalytic performance for ORR and OER by enhanced charge transfer. In this study, Co/Co3O4 heterojunctions were successfully prepared and encased in porous N-doped mesoporous carbon (Co/Co3O4@NC) via a simple condensation-carbonization-etching method. The extensive specific surface area of Co/Co3O4@NC facilitates effective interaction between the electrolyte and the catalyst, thereby enabling sufficient exposure of active sites for the ORR and the OER, consequently enhancing the rate of transport of active species. The well-designed Co/Co3O4@NC delivers superior ORR catalytic activity with a half-wave potential of 0.82 V (vs RHE) and a low overpotential of 347 mV at 10 mA cm-2 for OER in alkaline solution. The power density of Co/Co3O4@NC-based alkaline aqueous ZAB (156.5 mW cm-2) is superior to the commercial Pt/C + IrO2-based alkaline aqueous ZAB, and the cycling stability of ZAB is up to 220 h. In addition, Co/Co3O4@NC-based ZAB shows a high power density (50.1 mW cm-2). The construction of metal/metal oxide heterojunction encased in N-doped mesoporous carbon provides a novel route for the design of bifunctional electrocatalysts for high-performance ZABs.

9.
medRxiv ; 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38370729

RESUMO

Intervention against falciparum malaria in high transmission regions remains challenging, with relaxation of control efforts typically followed by rapid resurgence. Resilience to intervention co-occurs with incomplete immunity, whereby children eventually become protected from severe disease but not infection and a large transmission reservoir results from high asymptomatic prevalence across all ages. Incomplete immunity relates to the vast antigenic variation of the parasite, with the major surface antigen of the blood stage of infection encoded by the multigene family known as var. Recent deep sampling of var sequences from individual isolates in northern Ghana showed that parasite population structure exhibited persistent features of high-transmission regions despite the considerable decrease in prevalence during transient intervention with indoor residual spraying (IRS). We ask whether despite such apparent limited impact, the transmission system had been brought close to a transition in both prevalence and resurgence ability. With a stochastic agent-based model, we investigate the existence of such a transition to pre-elimination with intervention intensity, and of molecular indicators informative of its approach. We show that resurgence ability decreases sharply and nonlinearly across a narrow region of intervention intensities in model simulations, and identify informative molecular indicators based on var gene sequences. Their application to the survey data indicates that the transmission system in northern Ghana was brought close to transition by IRS. These results suggest that sustaining and intensifying intervention would have pushed malaria dynamics to a slow-rebound regime with an increased probability of local parasite extinction.

10.
Neuro Oncol ; 26(1): 100-114, 2024 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-37651725

RESUMO

BACKGROUND: Temozolomide (TMZ) treatment efficacy in glioblastoma is determined by various mechanisms such as TMZ efflux, autophagy, base excision repair (BER) pathway, and the level of O6-methylguanine-DNA methyltransferase (MGMT). Here, we reported a novel small-molecular inhibitor (SMI) EPIC-1042 (C20H28N6) with the potential to decrease TMZ efflux and promote PARP1 degradation via autolysosomes in the early stage. METHODS: EPIC-1042 was obtained from receptor-based virtual screening. Co-immunoprecipitation and pull-down assays were applied to verify the blocking effect of EPIC-1042. Western blotting, co-immunoprecipitation, and immunofluorescence were used to elucidate the underlying mechanisms of EPIC-1042. In vivo experiments were performed to verify the efficacy of EPIC-1042 in sensitizing glioblastoma cells to TMZ. RESULTS: EPIC-1042 physically interrupted the interaction of PTRF/Cavin1 and caveolin-1, leading to reduced secretion of small extracellular vesicles (sEVs) to decrease TMZ efflux. It also induced PARP1 autophagic degradation via increased p62 expression that more p62 bound to PARP1 and specially promoted PARP1 translocation into autolysosomes for degradation in the early stage. Moreover, EPIC-1042 inhibited autophagy flux at last. The application of EPIC-1042 enhanced TMZ efficacy in glioblastoma in vivo. CONCLUSION: EPIC-1042 reinforced the effect of TMZ by preventing TMZ efflux, inducing PARP1 degradation via autolysosomes to perturb the BER pathway and recruitment of MGMT, and inhibiting autophagy flux in the later stage. Therefore, this study provided a novel therapeutic strategy using the combination of TMZ with EPIC-1042 for glioblastoma treatment.


Assuntos
Glioblastoma , Humanos , Temozolomida/farmacologia , Temozolomida/uso terapêutico , Glioblastoma/genética , Dacarbazina/uso terapêutico , Antineoplásicos Alquilantes/farmacologia , Antineoplásicos Alquilantes/uso terapêutico , Caveolina 1/metabolismo , Caveolina 1/farmacologia , Caveolina 1/uso terapêutico , Linhagem Celular Tumoral , Enzimas Reparadoras do DNA/genética , Metilases de Modificação do DNA/genética , Autofagia , Resistencia a Medicamentos Antineoplásicos , Poli(ADP-Ribose) Polimerase-1/metabolismo , Poli(ADP-Ribose) Polimerase-1/farmacologia , Poli(ADP-Ribose) Polimerase-1/uso terapêutico
11.
J Comput Assist Tomogr ; 47(6): 959-966, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37948372

RESUMO

OBJECTIVE: This study aimed to perform an assessment of brain microstructure in children with autism aged 2 to 5 years using relaxation times acquired by synthetic magnetic resonance imaging. MATERIALS AND METHODS: Thirty-four children with autism spectrum disorder (ASD) (ASD group) and 17 children with global developmental delay (GDD) (GDD group) were enrolled, and synthetic magnetic resonance imaging was performed to obtain T1 and T2 relaxation times. The differences in brain relaxation times between the 2 groups of children were compared, and the correlation between significantly changed T1/T2 and clinical neuropsychological scores in the ASD group was analyzed. RESULTS: Compared with the GDD group, shortened T1 relaxation times in the ASD group were distributed in the genu of corpus callosum (GCC) ( P = 0.003), splenium of corpus callosum ( P = 0.002), and right thalamus (TH) ( P = 0.014), whereas shortened T2 relaxation times in the ASD group were distributed in GCC ( P = 0.011), left parietal white matter ( P = 0.035), and bilateral TH (right, P = 0.014; left, P = 0.016). In the ASD group, the T2 of the left parietal white matter is positively correlated with gross motor (developmental quotient [DQ] 2) and personal-social behavior (DQ5), respectively ( r = 0.377, P = 0.028; r = 0.392, P = 0.022); the T2 of the GCC was positively correlated with DQ5 ( r = 0.404, P = 0.018); and the T2 of the left TH is positively correlated with DQ2 and DQ5, respectively ( r = 0.433, P = 0.009; r = 0.377, P = 0.028). All significantly changed relaxation values were not significantly correlated with Childhood Autism Rating Scale scores. CONCLUSIONS: The shortened relaxometry times in the brain of children with ASD may be associated with the increased myelin content and decreased water content in the brain of children with ASD in comparison with GDD, contributing the understanding of the pathophysiology of ASD. Therefore, the T1 and T2 relaxometry may be used as promising imaging markers for ASD diagnosis.


Assuntos
Transtorno do Espectro Autista , Encefalopatias , Substância Branca , Humanos , Pré-Escolar , Criança , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno do Espectro Autista/patologia , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Corpo Caloso/diagnóstico por imagem , Corpo Caloso/patologia
12.
Theranostics ; 13(15): 5305-5321, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37908718

RESUMO

Background: The CRISPR/Cas13a system offers the advantages of rapidity, precision, high sensitivity, and programmability as a molecular diagnostic tool for critical illnesses. One of the salient features of CRISPR/Cas13a-based bioassays is its ability to recognize and cleave the target RNA specifically. Simple and efficient approaches for RNA manipulation would enrich our knowledge of disease-linked gene expression patterns and provide insights into their involvement in the underlying pathomechanism. However, only a few studies reported the Cas13a-based reporter system for in vivo molecular diagnoses. Methods: A tiled crRNA pool targeting a particular RNA transcript was generated, and the optimally potential crRNA candidates were selected using bioinformatics modeling and in vitro biological validation methods. For in vivo imaging assessment of the anti-GBM effectiveness, we exploited a human GBM patient-derived xenograft model in nude mice. Results: The most efficient crRNA sequence with a substantial cleavage impact on the target RNA as well as a potent collateral cleavage effect, was selected. In the xenografted GBM rodent model, the Cas13a-based reporter system enabled us in vivo imaging of the tumor growth. Furthermore, systemic treatments using this approach slowed tumor progression and increased the overall survival time in mice. Conclusions: Our work demonstrated the clinical potential of a Cas13a-based in vivo imaging method for the targeted degradation of specific RNAs in glioma cells, and suggested the feasibility of a tailored approach like Cas13a for the modulation of diagnosis and treatment options in glioma.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Glioma , Humanos , Animais , Camundongos , Camundongos Nus , Medicina de Precisão , Sistemas CRISPR-Cas/genética , RNA , Glioma/diagnóstico , Glioma/genética , Glioma/terapia
13.
bioRxiv ; 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37986738

RESUMO

The var multigene family encodes the P. falciparum erythrocyte membrane protein 1 (PfEMP1), which is important in host-parasite interaction as a virulence factor and major surface antigen of the blood stages of the parasite, responsible for maintaining chronic infection. Whilst important in the biology of P. falciparum, these genes (50 to 60 genes per parasite genome) are routinely excluded from whole genome analyses due to their hyper-diversity, achieved primarily through recombination. The PfEMP1 head structure almost always consists of a DBLα-CIDR tandem. Categorised into different groups (upsA, upsB, upsC), different head structures have been associated with different ligand-binding affinities and disease severities. We study how conserved individual DBLα types are at the country, regional, and local scales in Sub-Saharan Africa. Using publicly-available sequence datasets and a novel ups classification algorithm, cUps, we performed an in silico exploration of DBLα conservation through time and space in Africa. In all three ups groups, the population structure of DBLα types in Africa consists of variants occurring at rare, low, moderate, and high frequencies. Non-rare variants were found to be temporally stable in a local area in endemic Ghana. When inspected across different geographical scales, we report different levels of conservation; while some DBLα types were consistently found in high frequencies in multiple African countries, others were conserved only locally, signifying local preservation of specific types. Underlying this population pattern is the composition of DBLα types within each isolate DBLα repertoire, revealed to also consist of a mix of types found at rare, low, moderate, and high frequencies in the population. We further discuss the adaptive forces and balancing selection, including host genetic factors, potentially shaping the evolution and diversity of DBLα types in Africa.

14.
Cancer Commun (Lond) ; 43(12): 1326-1353, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37920878

RESUMO

BACKGROUND: Metabolism reprogramming plays a vital role in glioblastoma (GBM) progression and recurrence by producing enough energy for highly proliferating tumor cells. In addition, metabolic reprogramming is crucial for tumor growth and immune-escape mechanisms. Epidermal growth factor receptor (EGFR) amplification and EGFR-vIII mutation are often detected in GBM cells, contributing to the malignant behavior. This study aimed to investigate the functional role of the EGFR pathway on fatty acid metabolism remodeling and energy generation. METHODS: Clinical GBM specimens were selected for single-cell RNA sequencing and untargeted metabolomics analysis. A metabolism-associated RTK-fatty acid-gene signature was constructed and verified. MK-2206 and MK-803 were utilized to block the RTK pathway and mevalonate pathway induced abnormal metabolism. Energy metabolism in GBM with activated EGFR pathway was monitored. The antitumor effect of Osimertinib and Atorvastatin assisted by temozolomide (TMZ) was analyzed by an intracranial tumor model in vivo. RESULTS: GBM with high EGFR expression had characteristics of lipid remodeling and maintaining high cholesterol levels, supported by the single-cell RNA sequencing and metabolomics of clinical GBM samples. Inhibition of the EGFR/AKT and mevalonate pathways could remodel energy metabolism by repressing the tricarboxylic acid cycle and modulating ATP production. Mechanistically, the EGFR/AKT pathway upregulated the expressions of acyl-CoA synthetase short-chain family member 3 (ACSS3), acyl-CoA synthetase long-chain family member 3 (ACSL3), and long-chain fatty acid elongation-related gene ELOVL fatty acid elongase 2 (ELOVL2) in an NF-κB-dependent manner. Moreover, inhibition of the mevalonate pathway reduced the EGFR level on the cell membranes, thereby affecting the signal transduction of the EGFR/AKT pathway. Therefore, targeting the EGFR/AKT and mevalonate pathways enhanced the antitumor effect of TMZ in GBM cells and animal models. CONCLUSIONS: Our findings not only uncovered the mechanism of metabolic reprogramming in EGFR-activated GBM but also provided a combinatorial therapeutic strategy for clinical GBM management.


Assuntos
Glioblastoma , Animais , Linhagem Celular Tumoral , Metabolismo Energético , Receptores ErbB/genética , Receptores ErbB/metabolismo , Ácidos Graxos , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Ligases/metabolismo , Ácido Mevalônico/antagonistas & inibidores , Ácido Mevalônico/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Temozolomida/farmacologia , Temozolomida/uso terapêutico
15.
Artigo em Inglês | MEDLINE | ID: mdl-37874182

RESUMO

Polymer-stabilized liquid crystals (PSLCs) are important electrically switchable materials due to their superior electro-optical properties. Nevertheless, it remains a formidable challenge to balance PSLCs' instant electro-optical performance and long-term durability due to their relatively low polymer content and the related sensitivity to external force. Herein, we demonstrate the possibility of regulating the polymer network structure in PSLCs via reversible addition-fragmentation chain transfer (RAFT) polymerization reactions of acrylate monomers with a chain transfer agent (CTA). By controlling the concentration of CTA and conditions of photopolymerization, the kinetics of the polymerization reaction can be modified. Compared to conventional free-radical (FR) polymerization, the reduced chain growth rate leads to sufficient chain relaxation, reorientation of liquid crystal (LC) directors, and alleviation of shrinkage stresses in the RAFT polymerization process. This in turn produces an ordered polymer network structure in the vertical direction and a uniform distribution in the horizontal plane. As a result, the PSLC network presents increased elasticity with a lower hysteresis effect and greatly improved durability. Our research offers insightful guidance for the fine-tuning of polymer network structures to prepare advanced LC/polymer composite structures with outstanding performances.

16.
Nanoscale ; 15(28): 11777-11800, 2023 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-37404024

RESUMO

Transition metal nitrides (TMNs) have become excellent substitutes for precious metals such as Pt and Ir in the field of electrocatalysis because of their excellent electrocatalytic performance, high conductivity, good corrosion resistance and stability. As we all know, the commonly utilized carbon-based materials corrode easily during electrocatalysis, which will lead to catalyst falling off and agglomeration. Compared with carbon-based materials, TMNs have stronger corrosion resistance and higher stability. In the metal nitrides, a variety of chemical bonds (metal bond, ionic bond and covalent bond) coexist, among which the ionic bond between metal atoms and nitrogen atoms can make the d-band shrink and narrow, which leads to TMNs having characteristics similar to precious metals in the electrocatalytic process; thus, they can be used as a substitute for precious metal catalysts. In this paper, the synthesis method and catalytic principle of transition metal nitrides and their applications in the fields of hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are discussed, and the shortcomings of TMNs as a catalyst, the challenges faced in catalyst research and the developments and prospects for the future are pointed out.

17.
Small ; 19(45): e2301130, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37434036

RESUMO

Compared with the traditional electrolysis of water to produce hydrogen, urea-assisted electrolysis of water to produce hydrogen has significant advantages and has received extensive attention from researchers. Unfortunately, urea oxidation reaction (UOR) involves a complex six-electron transfer process leading to high overpotential, which forces researchers to develop high-performance UOR catalysts to drive the development of urea-assisted water splitting. Based on the UOR mechanism and extensive literature research, this review summarizes the strategies for preparing highly efficient UOR catalysts. First, the UOR mechanism is introduced and the characteristics of excellent UOR catalysts are pointed out. Aiming at this, the following modulation strategies are proposed to improve the catalytic performance based on summarizing various literature: 1) Accelerating the active phase formation to reduce initial potential; 2) Creating double active sites to trigger a new UOR mechanism; 3) Accelerating urea adsorption and promoting C─N bond cleavage to ensure the effective conduct of UOR; 4) Promoting the desorption of CO2 to improve stability and prevent catalyst poisoning; 5) Promoting electron transfer to overcome the inherent slow dynamics of UOR; 6) Increasing active sites or active surface area. Then, the application of UOR in electrochemical devices is summarized. Finally, the current deficiencies and future directions are discussed.

18.
medRxiv ; 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37292908

RESUMO

Here we introduce a new endpoint "census population size" to evaluate the epidemiology and control of Plasmodium falciparum infections, where the parasite, rather than the infected human host, is the unit of measurement. To calculate census population size, we rely on a definition of parasite variation known as multiplicity of infection (MOIvar), based on the hyper-diversity of the var multigene family. We present a Bayesian approach to estimate MOIvar from sequencing and counting the number of unique DBLα tags (or DBLα types) of var genes, and derive from it census population size by summation of MOIvar in the human population. We track changes in this parasite population size and structure through sequential malaria interventions by indoor residual spraying (IRS) and seasonal malaria chemoprevention (SMC) from 2012 to 2017 in an area of high-seasonal malaria transmission in northern Ghana. Following IRS, which reduced transmission intensity by > 90% and decreased parasite prevalence by ~40-50%, significant reductions in var diversity, MOIvar, and population size were observed in ~2,000 humans across all ages. These changes, consistent with the loss of diverse parasite genomes, were short lived and 32-months after IRS was discontinued and SMC was introduced, var diversity and population size rebounded in all age groups except for the younger children (1-5 years) targeted by SMC. Despite major perturbations from IRS and SMC interventions, the parasite population remained very large and retained the var population genetic characteristics of a high-transmission system (high var diversity; low var repertoire similarity) demonstrating the resilience of P. falciparum to short-term interventions in high-burden countries of sub-Saharan Africa.

19.
Lipids Health Dis ; 22(1): 74, 2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37337187

RESUMO

BACKGROUND: Stroke represents the second most prevalent contributor to global mortality. The Chinese Visceral Adiposity Index (CVAI) serves as an established metric for assessing visceral adiposity in the Chinese population, exhibiting prognostic capabilities. This investigation aimed to explore the association of CVAI and new-onset stroke among middle-aged and older Chinese populations. METHODS: The study employed data from the 2011 and 2018 China Health and Retirement Longitudinal Study (CHARLS) to assess the association of CVAI and the incidence of new-onset stroke. Utilizing a directed acyclic graph (DAG), 10 potential confounders were identified. Moreover, to explore the association between CVAI and new-onset stroke, three multifactor logistic regression models were constructed, accounting for the identified confounders and mitigating their influence on the findings. RESULTS: The study comprised 7070 participants, among whom 417 (5.9%) experienced new-onset strokes. After controlling for confounding variables, regression analysis suggested that the new-onset stroke's highest risk was linked to the fourth quartile (Q4) of the CVAI, with an odds ratio (OR) of 2.33 and a 95% confidence interval (CI) of 1.67-3.28. The decision tree analysis demonstrated a heightened probability of new-onset stroke among hypertensive individuals with a CVAI equal to or greater than 83, coupled with a C-reactive protein level no less than 1.1 mg/l. Age seemed to have a moderating influence on the CVAI and new-onset stroke association, exhibiting a more prominent interaction effect in participants under 60 years. CONCLUSIONS: In middle-aged and older Chinese populations, a linear relationship was discerned between CVAI and the probability of new-onset stroke. CVAI provides a predictive framework for stroke incidence in this demographic, laying the groundwork for more sophisticated risk prediction models that improve the precision and specificity of stroke risk evaluations.


Assuntos
Adiposidade , Acidente Vascular Cerebral , Humanos , População do Leste Asiático , Estudos Longitudinais , Povo Asiático , China/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Fatores de Risco , Obesidade Abdominal/complicações
20.
Pathol Oncol Res ; 29: 1610897, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37334172

RESUMO

Objective: This study aimed to develop a novel scoring system, named the integrated oxidative stress score (IOSS), based on oxidative stress indices to predict the prognosis in stage III gastric cancer. Methods: Retrospective analysis of stage III gastric cancer patients who were operated on between January 2014 and December 2016 were enrolled into this research. IOSS is a comprehensive index based on an achievable oxidative stress index, comprising albumin, blood urea nitrogen, and direct bilirubin. The patients were divided according to receiver operating characteristic curve into two groups of low IOSS (IOSS ≤ 2.00) and high IOSS (IOSS > 2.00). The grouping variable was performed by Chi-square test or Fisher's precision probability test. The continuous variables were evaluated by t-test. The disease free survival (DFS) and overall survival (OS) were performed by Kaplan-Meier and Log-Rank tests. Univariate Cox proportional hazards regression models and stepwise multivariate Cox proportional hazards regression analysis were determined to appraise the potential prognostic factors for DFS and OS. A nomogram of the potential prognostic factors by the multivariate analysis for DFS and OS was established with R software. In order to assess the accuracy of the nomogram in forecasting prognosis, the calibration curve and decision curve analysis were produced, contrasting the observed outcomes with the predicted outcomes. Results: The IOSS was significantly correlated with the DFS and OS, and was a potential prognostic factor in patients with stage III gastric cancer. Patients with low IOSS had longer survival (DFS: χ2 = 6.632, p = 0.010; OS: χ2 = 6.519, p = 0.011), and higher survival rates. According to the univariate and multivariate analyses, the IOSS was a potential prognostic factor. The nomograms were conducted on the potential prognostic factors to improve the correctness of survival prediction and evaluate the prognosis in stage III gastric cancer patients. The calibration curve indicated a good agreement in 1-, 3-, 5-year lifetime rates. The decision curve analysis indicated that the nomogram's predictive clinical utility for clinical decision was better than IOSS. Conclusion: IOSS is a nonspecific tumor predictor based on available oxidative stress index, and low IOSS is found to be a vigorous factor of better prognosis in stage III gastric cancer.


Assuntos
Neoplasias Gástricas , Humanos , Estudos Retrospectivos , Prognóstico , Nomogramas , Intervalo Livre de Doença
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