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1.
Environ Sci Technol ; 58(24): 10786-10795, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38838217

RESUMO

Storage lipids are an important compartment in the bioaccumulation of neutral organic compounds. Reliable models for predicting storage lipid-water and storage lipid-air partition coefficients (Kislip/w and Kislip/a), as well as their temperature dependence, are considered useful. Polyparameter linear free energy relationships (PP-LFERs) are accurate, general, and mechanistically clear models for predicting partitioning-related physicochemical quantities. About a decade ago, PP-LFERs were calibrated for Kislip/w at the physiological temperature of 37 °C. However, to date, a comprehensive collection and sufficiently reliable PP-LFERs for Kislip/w and Kislip/a at the most common standard temperature of 25 °C are still lacking. In this study, experimentally based Kislip/w and/or Kislip/a values at 25 °C for 278 compounds were extensively collected or converted from the literature. Subsequently, PP-LFERs were calibrated for Kislip/w and Kislip/a at 25 °C, performing well over 10 orders of magnitude with root-mean-square errors of 0.17-0.21 log units for compounds with reliable descriptors. Furthermore, standard internal energy changes of transfer from water or air to storage lipids for 158 compounds were derived and used to calibrate PP-LFERs for estimating the temperature dependence of Kislip/w or Kislip/a. Additionally, using PP-LFERs, low-density polyethylene was confirmed to be a better storage lipid analogue than silicone and polyoxymethylene in the equilibrium passive sampling of nonpolar and H-bond acceptor polar compounds.


Assuntos
Lipídeos , Compostos Orgânicos , Compostos Orgânicos/química , Lipídeos/química , Temperatura , Termodinâmica , Água/química
2.
Pestic Biochem Physiol ; 200: 105824, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38582588

RESUMO

The slowpoke channel responds to the intracellular calcium concentration and the depolarization of the cell membrane. It plays an important role in maintaining the resting potential and regulating the homeostasis of neurons, but it can also regulate circadian rhythm, sperm capacitation, ethanol tolerance, and other physiological processes in insects. This renders it a potentially useful target for the development of pest control strategies. There are relatively few studies on the slowpoke channels in lepidopteran pests, and their pharmacological properties are still unclear. So, in this study, the slowpoke gene of Plutella xylostella (Pxslo) was heterologous expressed in HEK293T cells, and the I-V curve of the slowpoke channel was measured by whole cell patch clamp recordings. Results showed that the slowpoke channel could be activated at -20 mV with 150 µM Ca2+. The subsequent comparison of the electrophysiological characteristics of the alternative splicing site E and G deletions showed that the deletion of the E site enhances the response of the slowpoke channel to depolarization, while the deletion of the G site weakens the response of the slowpoke channel to depolarization. Meanwhile, the nonspecific inhibitors TEA and 4-AP of the Kv channels, and four pesticides were tested and all showed an inhibition effect on the PxSlo channel at 10 or 100 µM, suggesting that these pesticides also target the slowpoke channel. This study enriches our understanding of the slowpoke channel in Lepidopteran insects and can aid in the development of relevant pest management strategies.


Assuntos
Mariposas , Praguicidas , Animais , Masculino , Humanos , Mariposas/genética , Mariposas/metabolismo , Células HEK293 , Sementes , Praguicidas/metabolismo
3.
J Am Chem Soc ; 145(33): 18329-18339, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37608781

RESUMO

We have approached the synthesis of colloidal InAs nanocrystals (NCs) using amino-As and ligands that are different from the commonly employed oleylamine (OA). We found that carboxylic and phosphonic acids led only to oxides, whereas tri-n-octylphosphine, dioctylamine, or trioctylamine (TOA), when employed as the sole ligands, yielded InAs NCs with irregular sizes and a broad size distribution. Instead, various combinations of TOA and OA delivered InAs NCs with good control over the size distribution, and the TOA:OA volume ratio of 4:1 generated InAs tetrapods with arm length of 5-6 nm. Contrary to tetrapods of II-VI materials, which have a zinc-blende core and wurtzite arms, these NCs are entirely zinc-blende, with arms growing along the ⟨111⟩ directions. They feature a narrow excitonic peak at ∼950 nm in absorption and a weak photoluminescence emission at 1050 nm. Our calculations indicated that the bandgap of the InAs tetrapods is mainly governed by the size of their core and not by their arm lengths when these are longer than ∼3 nm. Nuclear magnetic resonance analyses revealed that InAs tetrapods are mostly passivated by OA with only a minor fraction of TOA. Molecular dynamics simulations showed that OA strongly binds to the (111) facets whereas TOA weakly binds to the edges and corners of the NCs and their combined use (at high TOA:OA volume ratios) promotes growth along the ⟨111⟩ directions, eventually forming tetrapods. Our work highlights the use of mixtures of ligands as a means of improving control over InAs NCs size and size distribution.

4.
Haematologica ; 108(9): 2410-2421, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-36924252

RESUMO

Hematopoietic stem cells (HSC) maintain lifetime whole blood hematopoiesis through self-renewal and differentiation. In order to sustain HSC stemness, most HSC reside in a quiescence state, which is affected by diverse cellular stress and intracellular signal transduction. How HSC accommodate those challenges to preserve lifetime capacity remains elusive. Here we show that Pax transactivation domain-interacting protein (PTIP) is required for preserving HSC quiescence via regulating lysosomal activity. Using a genetic knockout mouse model to specifically delete Ptip in HSC, we find that loss of Ptip promotes HSC exiting quiescence, and results in functional exhaustion of HSC. Mechanistically, Ptip loss increases lysosomal degradative activity of HSC. Restraining lysosomal activity restores the quiescence and repopulation potency of Ptip-/- HSC. Additionally, PTIP interacts with SMAD2/3 and mediates transforming growth factor-ß signaling-induced HSC quiescence. Overall, our work uncovers a key role of PTIP in sustaining HSC quiescence via regulating lysosomal activity.


Assuntos
Proteínas de Ligação a DNA , Hematopoese , Células-Tronco Hematopoéticas , Animais , Camundongos , Hematopoese/genética , Hematopoese/fisiologia , Células-Tronco Hematopoéticas/metabolismo , Transdução de Sinais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-37000634

RESUMO

An actinobacterium strain, designated BH-MK-02T, was isolated from the soil of Lilium brownii. The taxonomic position was determined using a polyphasic approach. Strain BH-MK-02T grew well on International Streptomyces Project series media and formed well-developed, branched substrate hyphae and aerial mycelium that differentiated into straight spore chains with a wrinkled surface. The diagnostic diamino acid was ll-diaminopimelic acid. The major menaquinones were MK-9(H4), MK-9(H6) and MK-9(H8). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannosides, phosphatidylglycerol and unidentified lipid spots. The predominant fatty acids were anteiso-C15 : 0, iso-C16 : 0, C16 : 0 and C16 : 1 ω7c/C16 : 1 ω6c. The phenotypic characteristics of strain BH-MK-02T indicated that it belonged to the genus Streptomyces. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain BH-MK-02T was most closely related to Streptomyces aureus CGMCC 4.1833T (99.7 %). However, the average nucleotide identity and digital DNA-DNA hybridization values between the whole-genome sequences of strain BH-MK-02T and S. aureus CGMCC 4.1833T were 78.1 and 23.2 %, respectively, below the 96.7 and 70 % cut-off points respectively recommended for delineating Streptomyces species. Furthermore, the novel isolate could be distinguished from S. aureus CGMCC 4.1833T by morphological, physiological and biochemical characteristics. Based on all these data, strain BH-MK-02T (=MCCC 1K06237T=JCM 34789T) clearly represents a novel species within the genus Streptomyces, for which the name Streptomyces longhuiensis sp. nov. is proposed.


Assuntos
Lilium , Streptomyces , Ácidos Graxos/química , Fosfolipídeos/química , Lilium/genética , Análise de Sequência de DNA , Filogenia , RNA Ribossômico 16S/genética , Solo , Staphylococcus aureus/genética , Composição de Bases , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , China
6.
Nano Lett ; 22(21): 8567-8573, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36288498

RESUMO

We show how, in the synthesis of yellow-emissive Bi-doped Cs2Ag1-xNaxInCl6 double perovskite nanocrystals (NCs), preventing the transient formation of Ag0 particles increases the photoluminescence quantum yield (PLQY) of the NCs from ∼30% to ∼60%. Calculations indicate that the presence of even a single Ag0 species on the surface of a NC introduces deep trap states. The PL efficiency of these NCs is further increased to ∼70% by partial replacement of Na+ with K+ ions, up to a 7% K content, due to a lattice expansion that promotes a more favorable ligands packing on the NC surface, hence better surface passivation. A further increase in K+ lowers the PLQY, due to both the activation of nonradiative quenching channels and a lower oscillator strength of the BiCl6→AgCl6 transition (through which PL emission occurs). The work indicates how a deeper understanding of parameters influencing carrier trapping/relaxation can boost the PLQY of double perovskites NCs.

7.
Angew Chem Int Ed Engl ; 62(5): e202215455, 2023 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-36445794

RESUMO

Remote functionalization involving a fascinating chain-walking process has emerged as a powerful strategy for the rapid access to value-added functional molecules from readily available feedstocks. However, the scope of current methods is predominantly limited to mono- and di-substituted alkenes. The remote functionalization of multi- and heteroatom-substituted alkenes is challenging, and the use of alkynes in the chain walking is unexplored. We herein report a rhodium catalyzed remote borylation of internal alkynes, offering an unprecedented reaction mode of alkynes for the preparation of synthetically valuable 1,n-diboronates. The regioselective distal migratory hydroboration of sterically hindered tri- and tetra-substituted vinylboronates is also demonstrated to furnish various multi-boronic esters. Synthetic utilities are highlighted through the selective manipulation of the two boryl groups in products such as the regioselective cross coupling, oxidation, and amination.

8.
Angew Chem Int Ed Engl ; 62(49): e202314006, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-37847644

RESUMO

Mixed-valence (MV) dimers have been extensively investigated, however, the structure and properties of purely organic MV trimers based on open-shell polycyclic aromatic hydrocarbons remain elusive. Herein, unprecedented MV BN-doped corannulene radical cations [BN-Cor1]3 ⋅⋅2+ ⋅ 2[BArylF 4 ]- and [BN-Cor2]3 ⋅⋅2+ ⋅ 2[BArylF 4 ]- were synthesized via chemical oxidation, and their structures were unambiguously confirmed by single-crystal X-ray diffraction. These uncommon radical cations consist of three corannulene cores and two [BArylF 4 ]- anions, and three corannulene motifs [BN-Cor1]3 ⋅⋅2+ and [BN-Cor2]3 ⋅⋅2+ in the unit cell exhibit a trimer structure with a slipped π-stacking configuration. Detailed structural analyses further revealed that the corannulene cores exhibit an infinite layered self-assembly configuration, allowing their potential applications as building blocks for molecular conductors. The detection of a forbidden transition (Δms =±2) by electron paramagnetic resonance (EPR) spectroscopy further confirmed the existence of two unpaired electrons in the π-trimers and the MV characteristic of these two species. Variable-temperature EPR and conductivity measurements suggested that the BN-doped π-trimers exhibited antiferromagnetic coupling and conductivity properties.

9.
Artigo em Inglês | MEDLINE | ID: mdl-35471105

RESUMO

Two novel strains of actinobacteria, ZYC-3T and BH-SS-21T, were isolated from Hunan Province, PR China. The fermentation broth of BH-SS-21T inhibited the rapid spread of ginger blast, unlike that of ZYC-3T. The taxonomic characteristics of ZYC-3T and BH-SS-21T were defined using a polyphasic approach. The analysis of the full-length 16S rRNA gene sequence revealed that ZYC-3T and BH-SS-21T represented members of the genus Streptomyces. ZYC-3T had less than 98.7% sequence similarities to all species of the genus Streptomyces, while BH-SS-21T exhibited 99.97, 98.95, 98.83, 98.82, 98.75 and less than 98.7% sequence similarities to 'Streptomyces dioscori' A217, Streptomyces ederensis JCM 4958T, Streptomyces glomeroaurantiacus NBRC 15418T, Streptomyces aurantiacus NBRC 13017T, Streptomyces umbrinus JCM 4521T and other species with validly published names in the genus Streptomyces. However, the digital DNA-DNA relatedness and average nucleotide identity values between ZYC-3T, BH-SS-21T, and their closely related strains were significantly lower than the recommended threshold values. Also, phenotypic, chemotaxonomic and genetic features distinguished ZYC-3T and BH-SS-21T from their reference strains. On the basis of their genotypic and phenotypic characteristics, strains ZYC-3T and BH-SS-21T were classified as representing novel species of the genus Streptomyces under the names Streptomyces liliifuscus sp. nov. ZYC-3T (=CICC 25040T=JCM 34560T=MCCC 1K04978T) and Streptomyces liliiviolaceus sp. nov. BH-SS-21T (=MCCC 1K06236T=JCM 34767T), respectively.


Assuntos
Lilium , Peste , Streptomyces , Zingiber officinale , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Zingiber officinale/genética , Lilium/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo , Microbiologia do Solo
10.
Arch Insect Biochem Physiol ; 105(1): e21720, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32557681

RESUMO

The large-conductance calcium-activated potassium channel (BKCa ) plays an important role in the regulation of insect neural circuits and locomotion, and thus is a potential target of insecticides. In this study, iberiotoxin, an inhibitor of BKCa , was found to prolong the anesthetic time of ethyl acetate on Plutella xylostella larvae. Therefore, the coding sequence of slowpoke gene coding the alpha subunit of BKCa was cloned to investigate the function of this channel in P. xylostella, and the gene expression profile in the developmental stages and tissues was also characterized. The total length of pxslo DNA was more than 19.9 kb, which harbored four alternative splicing sites (ASP-A, ASP-C, ASP-E, and ASP-G), and the coding sequence of pxslo with the highest frequency of splicing (GenBank ID: MN938456) was 3,405 base pair. The characterized PxSlo protein contained conserved domains previously identified in other insects. Quantitative reverse transcription-polymerase chain reaction analysis showed that pxslo was expressed in all the developmental stages of P. xylostella, with the highest level in adults. In the larval stage, pxslo was mainly expressed in the head and epidermis, while a limited protein was expressed in the midgut. In the adult stage, pxslo was highly expressed in the head, followed by in the ovarian tubule, and was not expressed in the testis or wings. These results suggest that BKCa plays an important physiological role in P. xylostella and provides useful information for the functional study and screening of BKCa inhibitors.


Assuntos
Proteínas de Insetos/genética , Canais de Potássio Ativados por Cálcio de Condutância Alta/genética , Mariposas/genética , Transcriptoma , Sequência de Aminoácidos , Animais , Proteínas de Insetos/química , Proteínas de Insetos/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Alta/química , Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Mariposas/crescimento & desenvolvimento , Mariposas/metabolismo , Óvulo/crescimento & desenvolvimento , Pupa/genética , Pupa/crescimento & desenvolvimento , Alinhamento de Sequência
11.
Biotechnol Lett ; 42(4): 641-655, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31965394

RESUMO

OBJECTIVES: In the plant transformation process, marker genes play a vital role in identifying transformed cells from non-transformed cells. However, once transgenic plants have been obtained, the presence of marker genes may provoke public concern about environmental or biosafety issues. In our previous study, a double T-DNA vector system has been developed to obtain marker-free transgenic plants, but the T-DNA left border (LB) and right border (RB) of the vector showed an RB-LB-RB-LB pattern and led to high linkage integration between the selectable marker gene (SMG) and the gene of interest (GOI). To improve this double T-DNA vector system, we inverted the first T-DNA direction such that a LB-RB-RB-LB pattern resulted to avoid transcriptional read-through at the LB and the subsequent linkage transfer of the SMG and GOI. RESULTS: We separately inserted the green fluorescent protein (GFP) gene as the GOI and the neomycin phosphotransferase II (NPTII) gene as the SMG in both optimized and original vectors and carried out Agrobacterium-mediated tobacco transformation. Statistical analysis revealed that the linkage frequency was 25.6% in T0 plants transformed with the optimized vector, which is a 42.1% decrease compared with that of the original vector (44.2%). The frequency of obtaining marker-free transgenic plants was 66.7% in T1 plants transformed with the optimized vector, showing a 33.4% increase compared with that of the original vector (50.0%). CONCLUSION: Our results demonstrate that the optimized double T-DNA binary vector system is a more effective, economical and time-saving approach for obtaining marker-free transgenic plants.


Assuntos
Agrobacterium tumefaciens/fisiologia , DNA Bacteriano/genética , Nicotiana/crescimento & desenvolvimento , Agrobacterium tumefaciens/genética , Regulação da Expressão Gênica de Plantas , Vetores Genéticos , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Canamicina Quinase/genética , Canamicina Quinase/metabolismo , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/microbiologia , Nicotiana/genética , Nicotiana/microbiologia , Transformação Genética
12.
Int J Mol Sci ; 20(2)2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-30669419

RESUMO

Baculoviruses have already been used for insect pest control, but the slow killing speed limits their further promotion and application. Here we provide a strategy for improving baculovirus insecticidal activity using Helicoverpa armigera nucleopolyhedrovirus (HearNPV) to express double-stranded RNAs (dsRNAs) targeting cotton bollworm (Helicoverpa armigera) juvenile hormone (JH)-related genes. Droplet-feeding bioassays show that the 50% lethal concentration (LC50) values of recombinant baculoviruses expressing the dsRNA of JH acid methyl transferase gene (HaJHAMT) and the JH acid binding protein gene (HaJHBP) were 1.24 × 104 polyhedral inclusion bodies (PIB)/mL and 2.26 × 104 PIB/mL, respectively. Both were much lower than the control value (8.12 × 104 PIB/mL). Meanwhile, the LT50 of recombinant baculovirus expressing dsRNA of HaJHBP was only 54.2% of the control value, which means that larval death was accelerated. Furthermore, the mRNA level of target genes was reduced in recombinant baculovirus-treated cotton bollworm larvae. Transcription of several key genes involved in hormone signaling pathways-for example, ecdysone receptor gene (HaEcR)-was also altered. This study establishes a new strategy for pest management by interfering with insect hormone-related gene expression via baculoviruses, and the engineered baculoviruses have great potential application in cotton production.


Assuntos
Baculoviridae/fisiologia , Genes de Insetos , Interações Hospedeiro-Patógeno/genética , Insetos/genética , Insetos/virologia , Hormônios Juvenis/genética , RNA de Cadeia Dupla/genética , Animais , Sobrevivência Celular , Expressão Gênica , Genes Reporter , Vetores Genéticos/genética , Larva , Interferência de RNA
13.
Tumour Biol ; 35(10): 10443-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25053591

RESUMO

Hypoxia is a widespread phenomenon present in many human solid tumors and is associated with a poor prognosis and therapy resistance. Here, we tested the feasibility of melittin, a major component of bee venom, on radiosensitization of hypoxic head and neck squamous cell carcinoma (HNSCC). CNE-2 and KB cells were treated with melittin and radiation response was determined. Cell viability, cytotoxicity and apoptosis induction were examined by CCK-8 assay, colony formation assay, and flow cytometry. Expression of hypoxia-inducible factor 1-alpha (HIF-1α) and vascular endothelial growth factor (VEGF) proteins were assessed using western blotting. Additionally, we also examined the effect of melittin on tumor growth and radiosensitivity in vivo using a xenograft model of HNSCC. Treatment with melittin resulted in cell growth inhibition, induction of cell apoptosis, and reduction of HIF-1α and VEGF expression, which has been linked to hypoxia cell radioresistance. In addition, intraperitoneal injection of melittin significantly reduced the growth of HNSCC tumors in CNE-2 tumor-bearing mice. These data suggest that melittin enhances radiosensitivity of HNSCC under hypoxia condition, and this is associated with the suppression of HIF-1α expression. Melittin appears to be a potential radiotherapy sensitization agent due to its significant antihypoxia activity.


Assuntos
Carcinoma de Células Escamosas/patologia , Neoplasias de Cabeça e Pescoço/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Meliteno/farmacologia , Radiossensibilizantes/farmacologia , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Carcinoma de Células Escamosas/metabolismo , Hipóxia Celular/efeitos dos fármacos , Hipóxia Celular/fisiologia , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Carcinoma de Células Escamosas de Cabeça e Pescoço , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Tumour Biol ; 35(3): 2565-74, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24170321

RESUMO

Currently, unresectable esophageal squamous cell carcinoma (ESCC) is primarily treated by chemoradiotherapy. However, the outcome has not improved significantly due to radioresistance of cancer cells. This study aimed to determine the radiosensitizing effect of LCL161, a novel second mitochondrial-derived activator of caspase (Smac) mimetic, in ESCC cells. ESCC cell lines were treated with LCL161 or radiation, alone or in combination. Cell proliferation was detected by MTT assay. Radiosensitization was evaluated by clonogenic survival assay. Cell apoptosis was detected by flow cytometry. The results showed that LCL161 potently sensitized ESCC cells to radiation with a sensitization enhancement ratio of 1.4-2.0. LCL161 increased radiation-induced DNA double-stranded breaks and promoted the apoptosis of ESCC cells, which could be abrogated by a pan-caspase inhibitor z-VAD-FMK. Furthermore, LCL161 decreased the level of cIAP1 in ESCC cells in a dose-dependent manner and synthesized with irradiation to promote the activation of caspase 8 and the upregulation of TNFα expression in ESCC cells. In conclusion, LCL161 acts as a strong radiosensitizer in human esophageal cancer cells by inhibiting the expression of cIAP1 and promoting the activation of caspase 8, leading to enhanced apoptosis.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias Esofágicas/metabolismo , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Radiossensibilizantes/farmacologia , Tiazóis/farmacologia , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose , Biomimética , Western Blotting , Linhagem Celular Tumoral , Ensaio de Imunoadsorção Enzimática , Carcinoma de Células Escamosas do Esôfago , Citometria de Fluxo , Imunofluorescência , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Mitocondriais/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ubiquitina-Proteína Ligases
15.
Tumour Biol ; 35(10): 9793-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24981247

RESUMO

Radiotherapy is the main therapy for inoperable and locally advanced esophageal squamous cell carcinoma (ESCC). However, radioresistance in ESCC remains a challenge. The aim of this study is to investigate the radiosensitizing effects of STAT3 inhibitor NSC74859 on ESCC and explore the underlying mechanisms. ECA109 and TE13 cells were exposed to hypoxia, and treated with NSC74859 or radiation, alone or in combination. Cell proliferation, survival, apoptosis, and double-stranded DNA breaks (DSBs) were examined. Nude mice model of ECA109 xenograft was treated with radiation and/or NSC74859. The levels of STAT3, p-STAT3, HIF-1α, and VEGF were detected by Western blot analysis. NSC74859 efficiently radiosensitized ESCC cells and xenografts in nude mice, and inhibited hypoxia-/radiation-induced activation of STAT3 and upregulation of HIF-1α and VEGF expression. NSC74859 confers radiosensitivity in ESCC via the inhibition of STAT3 activation and the downregulation of HIF-1α and VEGF expression. NSC74859 may become a promising radiosensitizer for ESCC radiotherapy.


Assuntos
Benzenossulfonatos/farmacologia , Carcinoma de Células Escamosas/metabolismo , Neoplasias Esofágicas/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Radiossensibilizantes/farmacologia , Ácidos Aminossalicílicos/farmacologia , Animais , Western Blotting , Linhagem Celular Tumoral , Regulação para Baixo , Carcinoma de Células Escamosas do Esôfago , Feminino , Citometria de Fluxo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/efeitos dos fármacos , Imuno-Histoquímica , Camundongos , Camundongos Nus , Fator de Transcrição STAT3/antagonistas & inibidores , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Tumour Biol ; 35(9): 8699-705, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24870598

RESUMO

Currently, unresectable esophageal squamous cell carcinoma (ESCC) is primarily treated by chemoradiotherapy. However, the outcome has not improved significantly because of radioresistance of cancer cells. This study aimed to determine the radiosensitizing effect of melittin, a novel component of bee venom, in ESCC. ESCC cell lines were irradiated with or without melittin. Cell proliferation was detected by Cell Counting Kit 8 assay. Radiosensitization was evaluated by clonogenic survival assay. Cell apoptosis was detected by flow cytometry. Results show that melittin potently sensitized ESCC cells to radiation with a sensitization enhancement ratio of 1.15-1.42. Radiosensitization was accompanied with enhanced apoptosis and regulated by apoptosis proteins. The results were confirmed by in vivo studies on tumor-bearing xenografts. In summary, these results provide support that melittin may be a potentially promising radiosensitizer in ESCC radiation therapy.


Assuntos
Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Carcinoma de Células Escamosas/terapia , Neoplasias Esofágicas/terapia , Meliteno/farmacologia , Animais , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Quimiorradioterapia/métodos , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/patologia , Citometria de Fluxo , Humanos , Immunoblotting , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Microscopia Confocal , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Radiossensibilizantes/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína X Associada a bcl-2/metabolismo
17.
Tumour Biol ; 35(6): 5149-58, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24492941

RESUMO

To date, no scientific consensus about the associations of DR4 C626G, A683C, A1322G, and G422A polymorphisms with cancer risk has been reached. Therefore, we conducted a meta-analysis to assess the associations. This meta-analysis involved 16 studies, of which 15 (4,261 cases and 4,598 controls) described C626G genotypes, 8 (2,898 cases and 3,135 controls) described A683C genotypes, 6 (1,564 cases and 1,673 controls) described A1322G genotypes, and 5 (584 cases and 607 controls) described A683C genotypes. We associated all the four polymorphisms with cancer risk. The C626G polymorphism was associated with slightly elevated cancer risk in recession model comparison [odds ratio (OR)=1.12, 95 % confidence interval (CI)=1.00-1.26, P heterogeneity=0.425]. In the subgroup analysis by cancer type, significantly elevated cancer risks were found among groups with lung cancer for heterozygote comparison (OR=1.76, 95 % CI=1.00-3.09, P heterogeneity=0.863). The A1322G polymorphism was associated with significantly elevated cancer risk in the different models (heterozygote comparison: OR=1.21, 95 % CI=1.00-1.46, P heterogeneity=0.347; dominant model: OR=1.21, 95 % CI=1.01-1.46, P heterogeneity=0.189; allele model comparison for G allele vs. A allele: OR=1.17, 95 % CI=1.02-1.35, P heterogeneity=0.173). The A683C and G422A polymorphisms were not associated with cancer risk in all genetic models. The C626G and A1322G polymorphisms are associated with increased cancer risk, but the A683C polymorphism is rarely associated with cancer risk.


Assuntos
Predisposição Genética para Doença , Neoplasias/genética , Polimorfismo Genético , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/genética , Genótipo , Humanos , Neoplasias/etiologia , Viés de Publicação , Risco
18.
J Pharmacol Sci ; 126(1): 56-65, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25168470

RESUMO

IAP antagonists increased the antitumor efficacy of X-irradiation in some types of cancers, but their effects on hypoxic cancer cells remain unclarified. We aims to investigate the radiosensitizing effect of an IAP inhibitor AT-406 on cervical cancer cell lines under both normoxia and hypoxia conditions. Hela and Siha cells were treated to investigate the effects of drug administration on cell proliferation, apoptosis, and radiosensitivity. Western blot analysis was used to determine the role of AT-406 in inhibition of IAPs. The pathway of apoptosis was characterized by caspases activity assay. AT-406 potently sensitized Hela cells but not Siha cells to radiation under normoxia. Notably, the radiosensitizing effect of AT-406 on hypoxic cells was more evident than on normoxic cells in both cell lines. Further mechanism studies by western blot showed that under normoxia AT-406 decreased the level of cIAP1 in Hela cells in a dose-dependent manner; while additional downregulation of XIAP expression was induced by AT-406 treatment under hypoxia in both cell lines. Finally, AT-406 works on both extrinsic death receptor and intrinsic mitochondrial apoptosis pathways to activate apoptosis. Totally, AT-406 acts as a strong radiosensitizer in human cervical cancer cells, especially in hypoxic condition.


Assuntos
Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Azocinas/farmacologia , Compostos Benzidrílicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Hipóxia/patologia , Proteínas Inibidoras de Apoptose/farmacologia , Tolerância a Radiação/efeitos dos fármacos , Radiossensibilizantes/farmacologia , Neoplasias do Colo do Útero/patologia , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Feminino , Células HeLa , Humanos , Proteínas Inibidoras de Apoptose/metabolismo , Mitocôndrias/patologia , Neoplasias do Colo do Útero/genética , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo
19.
Int Immunopharmacol ; 137: 112382, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-38875995

RESUMO

Hematopoietic stem and progenitor cells (HSPCs) can give rise to all kinds of immune cells including neutrophils. Neutrophils are the first line of defense in the innate immune system with a short lifespan, due to which it is well-accepted that neutrophils have no immune memory. However, recent reports showed that the changes in HSPCs induced by primary stimulation could last a long time, which contributes to enhancing response to subsequent infection by generating more monocytes or macrophages equipped with stronger anti-bacterial function. Here, we used the reinfection mice model to reveal that primary infection could improve neutrophil-mediated host defense by training neutrophil progenitors in mammals, providing a new idea to enhance neutrophil number and improve neutrophil functions, which is pretty pivotal for patients with compromised or disordered immunity.


Assuntos
Células-Tronco Hematopoéticas , Neutrófilos , Animais , Neutrófilos/imunologia , Camundongos , Células-Tronco Hematopoéticas/imunologia , Camundongos Endogâmicos C57BL , Imunidade Inata , Humanos , Reinfecção/imunologia , Modelos Animais de Doenças
20.
J Econ Entomol ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38748551

RESUMO

The globally prevalent pests, Diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae) and Beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae), pose significant threats to cruciferous vegetables. They have rapidly developed resistance to a wide range of insecticides, leading to significant yield losses and increased control expenses. In this study, we have established an efficient approach utilizing amplicon sequencing to detect the frequency of 15 target resistance mutant sites in 6 molecular targets, acetylcholinesterase 1 (ACE1), chitin synthase 1 (CHS1), the γ-aminobutyric acid receptor (GABAR), glutamate-gated chloride channel (GluCl), voltage-gated sodium channels (NaV), and ryanodine receptor (RyR) in P. xylostella and the frequency of 11 mutations in 5 molecular targets (except GluCl) in S. exigua in China. Our findings indicate that P. xylostella exhibits remarkably high frequency (over 88.67%) in pyrethroid resistance-related mutations T929I and L1014F of NaV. In S. exigua, the frequencies of L659F mutation were ranging from 41.92% to 74.89%. In addition, the organophosphorus resistance-related mutations A298S and G324A of ACE1 were detected at frequencies ranging from 34.29% to 75.66%, and these 2 mutations occurred simultaneously (from 29.22% to 65.79%) in P. xylostella. An interannual variation in mutation frequency from 2019 to 2021 was found for P. xylostella in HNCS. The frequency of A298S and G324A mutations steadily increased while the frequency of G4946E and I4790M mutations continuously decreased. These results unveil a worrisome scenario of multiple resistance sites in these 2 pests in China and provide valuable insights for the practical application of pesticides in the field.

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