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1.
Environ Res ; 255: 119173, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38763280

RESUMO

The rapid development of modern society has led to an increasing severity in the generation of new pollutants and the significant emission of old pollutants, exerting considerable pressure on the ecological environment and posing a serious threat to both biological survival and human health. The skeletal system, as a vital supportive structure and functional unit in organisms, is pivotal in maintaining body shape, safeguarding internal organs, storing minerals, and facilitating blood cell production. Although previous studies have uncovered the toxic effects of pollutants on vertebrate skeletal systems, there is a lack of comprehensive literature reviews in this field. Hence, this paper systematically summarizes the toxic effects and mechanisms of environmental pollutants on the skeletons of vertebrates based on the evolutionary context from fish to mammals. Our findings reveal that current research mainly focuses on fish and mammals, and the identified impact mechanisms mainly involve the regulation of bone signaling pathways, oxidative stress response, endocrine system disorders, and immune system dysfunction. This study aims to provide a comprehensive and systematic understanding of research on skeletal toxicity, while also promoting further research and development in related fields.


Assuntos
Poluentes Ambientais , Peixes , Mamíferos , Animais , Poluentes Ambientais/toxicidade , Osso e Ossos/efeitos dos fármacos , Evolução Biológica , Vertebrados
2.
PLoS Genet ; 16(4): e1008771, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32348314

RESUMO

Some long noncoding RNAs (lncRNAs) are specifically expressed in brain cells, implying their neural and behavioural functions. However, how lncRNAs contribute to neural regulatory networks governing the precise behaviour of animals is less explored. Here, we report the regulatory mechanism of the nuclear-enriched lncRNA PAHAL for dopamine biosynthesis and behavioural adjustment in migratory locusts (Locusta migratoria), a species with extreme behavioral plasticity. PAHAL is transcribed from the sense (coding) strand of the gene encoding phenylalanine hydroxylase (PAH), which is responsible for the synthesis of dopamine from phenylalanine. PAHAL positively regulates PAH expression resulting in dopamine production in the brain. In addition, PAHAL modulates locust behavioral aggregation in a population density-dependent manner. Mechanistically, PAHAL mediates PAH transcriptional activation by recruiting serine/arginine-rich splicing factor 2 (SRSF2), a transcription/splicing factor, to the PAH proximal promoter. The co-activation effect of PAHAL requires the interaction of the PAHAL/SRSF2 complex with the promoter-associated nascent RNA of PAH. Thus, the data support a model of feedback modulation of animal behavioural plasticity by an lncRNA. In this model, the lncRNA mediates neurotransmitter metabolism through orchestrating a local transcriptional loop.


Assuntos
Comportamento Animal , Dopamina/biossíntese , Retroalimentação Fisiológica , RNA Longo não Codificante/metabolismo , Animais , Encéfalo/metabolismo , Dopamina/genética , Gafanhotos , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Fenilalanina Hidroxilase/genética , Fenilalanina Hidroxilase/metabolismo , Regiões Promotoras Genéticas , RNA Longo não Codificante/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Ativação Transcricional
3.
Physiol Plant ; 174(2): e13655, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35243634

RESUMO

Connected ramets of colonal plants often suffer from different environmental conditions such as light, nutrient, and stress. Colonal Bermudagrass (Cynodon dactylon [L.] Pers.) can form interconnected ramets and this connection facilitates the tolerance to abiotic stress, which is a kind of physiological integration. However, how bermudagrass responds to heterogeneously distributed salt stress needs to be further elucidated. Here, we demonstrated that severance of stolons aggravated the damage of salt-stressed ramets, displaying higher relative electrolytic leakage (EL), lower content of chlorophyll, higher accumulation of Na+ , and serious oxidative damages. This finding implied the positive effects of the physiological integration of bermudagrass on salt tolerance. The unstressed ramets connected with the stressed one were mildly injured, implying the supporting and sacrifice function of the unstressed ramets. Physiological integration did not mediate the translocation of Na+ among ramets, but induced a higher expression of salt overly sensitive (SOS) genes in the stressed ramets, consequently reducing the accumulation of Na+ in leaves and roots. In addition, physiological integration upregulated the genes expression and enzymes activity of catalase (CAT) and peroxidase (POD) in both stressed and unstressed ramets. This granted a stronger antioxidant ability of the whole clonal plants under salt stress. Enhanced Na+ transfer and increased reactive oxygen species (ROS) scavenging are mechanisms that likely contribute to the physiological integration leading to the salt tolerance of bermudagrass.


Assuntos
Cynodon , Estresse Salino , Clorofila/metabolismo , Cynodon/genética , Cynodon/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estresse Fisiológico
4.
Chem Biodivers ; 19(12): e202200452, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36328963

RESUMO

Orostachys cartilaginous is a traditional herbal medicine and its cell cultures contain large amounts of polysaccharides. To utilize the cultured O. cartilaginous cells, this study purified the crude polysaccharides of O. cartilaginous cells by macroporous resin absorption and optimized the purification process in the experiment of orthogonal design with four factors (sample concentration and volume, and eluent concentration and volume) and three levels; the antibacterial and anti-cancer effects of the purified polysaccharides (OTP) were further examined. The results showed that polysaccharide purity reached 95 % in the optimized group, i. e., 1.6 mg/mL of sample (crude polysaccharides) concentration, 3.0 bed volume (BV) of sample volume, 65 % eluent (ethanol) concentration, and 3.0 BV of eluent volume. In the antibacterial experiment, the growth of three bacterial species, i. e., Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis was inhibited by OTP, whereas that of Escherichia coli was not affected; the largest diameter of the inhibitory zone was found on B. subtilis; the extracellular alkaline phosphatase activity and the electrical conductivity, nucleic acid, and protein levels of B. subtilis increased after OTP treatment, indicating that the inhibition of B. subtilis growth was caused by the leakage of cell contents. In the anti-cancer experiment, OTP decreased the cell viabilities of the tested human cancer cells, i. e., AGS (gastric cancer), HCT116 (colon cancer), HepG2 (liver cancer), and HeLa (cervical cancer), and the highest inhibitory effect was on HCT116. OTP promoted HCT116 apoptosis and affected the expression of apoptosis-related proteins, i. e., the expression of B-cell lymphoma-2 decreased and that of bcl-2 associated X protein, cytochrome c, caspase 9 and caspase 3 increased. The findings of the present study suggest that O. cartilaginous cell cultures have a potential application in food or drug production.


Assuntos
Plantas Medicinais , Humanos , Antibacterianos/farmacologia , Etanol , Polissacarídeos/farmacologia , Técnicas de Cultura de Células
5.
J Obstet Gynaecol Res ; 47(6): 1946-1957, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33827148

RESUMO

AIM: Platinum-based chemotherapy is the standard treatment for ovarian cancer. However, tumor cells' resistance to platinum drugs often occurs. This paper provides a review of Forkhead box O (FOXO) protein's role in platinum resistance of ovarian cancer which hopefully may provide some further guidance for the treatment of platinum-resistant ovarian cancer. METHODS: We reviewed a 128 published papers from authoritative and professional journals on FOXO and platinum-resistant ovarian cancer, and adopts qualitative analyses and interpretation based on the literature. RESULTS: Ovarian cancer often has abnormal activation of cellular pathways, the most important of which is the PI3K/AKT pathway. FOXOs act as crucial downstream factor of the PI3K/Akt pathway and are negatively regulated by it. DNA damage response and apoptosis including the relationship between FOXOs and ATM-Chk2-p53 are essential for platinum resistance of ovarian cancer. Through gene expression analysis in platinum-resistant ovarian cancer cell model, it was found that FoxO-1 is decreased in platinum-resistant ovarian cancer, so studying the role of FOXO in the pathway on platinum-induced apoptosis may further guide the treatment of platinum-resistant ovarian cancer. CONCLUSIONS: There are many drug resistance mechanisms in ovarian cancer, wherein the decrease in cancer cells apoptosis is one of the important causes. Constituted by a series of transcription factors evolving conservatively and mainly working in inhibiting cancer, FOXO proteins play various roles in cells' antitumor response. More and more evidence suggests that we need to re-understand the role that FOXOs have played in cancer development and treatment.


Assuntos
Neoplasias Ovarianas , Fosfatidilinositol 3-Quinases , Apoptose , Feminino , Fatores de Transcrição Forkhead/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Ovarianas/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
6.
BMC Med Genet ; 21(1): 49, 2020 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-32143588

RESUMO

BACKGROUND: This study wants to know the genetic cause of preeclampsia (PE) which is a leading cause of maternal and perinatal death, but the underlying molecular mechanisms that cause PE remain poorly understood. Many single nucleotide polymorphisms have been identified by genome-wide association studies and were found to be associated with PE; however, few studies have used whole-exome sequencing (WES) to identify PE variants. METHODS: Five patients with severe early-onset preeclampsia (EOPE) were recruited, and WES was performed on each patient. Sanger sequencing was used to confirm the potential causative genetic variant. RESULTS: After a stringent bioinformatics analysis, a rare variant in the GOT1 gene, c.44C > G:p.P15R, was found in one patient. Bioinformatics analysis showed that the variant site is highly conserved across several species and was predicted to be a pathogenic variant according to several online mutational function prediction software packages. Further structural biology homology modeling suggested that P15R would change the electric environment of enzymatic center, and might affect the binding affinity of substrate or product. CONCLUSION: We demonstrated for the first time that the variant in GOT1 may be associated with EOPE, the results of this study provide researchers and clinicians with a better understanding of the molecular mechanisms that underlie maternal severe EOPE.


Assuntos
Aspartato Aminotransferase Citoplasmática/genética , Polimorfismo de Nucleotídeo Único , Pré-Eclâmpsia/genética , Adulto , Idade de Início , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Idade Gestacional , Humanos , Pré-Eclâmpsia/epidemiologia , Pré-Eclâmpsia/patologia , Gravidez , Índice de Gravidade de Doença , Sequenciamento do Exoma
7.
Opt Lett ; 45(23): 6450-6453, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-33258834

RESUMO

Highly efficient tandem organic light-emitting diodes (TOLEDs) were achieved based on a non-doped charge generation unit (CGU) consisting of LiF/Al/C60/4,4',4"-tris(N-3-methylphenyl-N-phenyl-amino) triphenylamine (m-MTDATA) and ultrathin emitting layers. The current-voltage characteristics of the CGU devices and electron-only devices and the capacitance-voltage characteristics of the CGU-based capacitance devices were characterized to explore the charge generation and injection mechanisms. The charge generation process occurs at the interface of C60/m-MTDATA through electron transferring from the highest occupied molecular orbital of m-MTDATA to the lowest unoccupied molecular orbital of C60. It is found that the thinner C60 layer contributes to efficient electron injection. Under the optimal structure, the blue TOLEDs exhibit a maximum current efficiency (CEmax) of 43.3 cd/A. The CEmax and maximum external quantum efficiency (EQEmax) of the white TOLEDs reach 84.6 cd/A and 26.7%, respectively.

8.
Water Sci Technol ; 81(9): 1797-1827, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32666937

RESUMO

Industrial development has led to generation of large volumes of wastewater containing heavy metals, which need to be removed before the wastewater is released into the environment. Chemical and electrochemical methods are traditionally applied to treat this type of wastewater. These conventional methods have several shortcomings, such as secondary pollution and cost. Bioprocesses are gradually gaining popularity because of their high selectivities, low costs, and reduced environmental pollution. Removal of heavy metals by sulfate-reducing bacteria (SRB) is an economical and effective alternative to conventional methods. The limitations of and advances in SRB activity have not been comprehensively reviewed. In this paper, recent advances from laboratory studies in heavy metal removal by SRB were reported. Firstly, the mechanism of heavy metal removal by SRB is introduced. Then, the factors affecting microbial activity and metal removal efficiency are elucidated and discussed in detail. In addition, recent advances in selection of an electron donor, enhancement of SRB activity, and improvement of SRB tolerance to heavy metals are reviewed. Furthermore, key points for future studies of the SRB process are proposed.


Assuntos
Metais Pesados , Sulfatos , Bactérias , Biodegradação Ambiental , Águas Residuárias
9.
Mol Pain ; 15: 1744806919826789, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30632435

RESUMO

Accumulating evidence shows that inhibition of glycogen synthase kinase-3beta (GSK-3ß) ameliorates cognitive impairments caused by a diverse array of diseases. Our previous work showed that spared nerve injury (SNI) that induces neuropathic pain causes short-term memory deficits. Here, we reported that GSK-3ß activity was enhanced in hippocampus and reduced in spinal dorsal horn following SNI, and the changes persisted for at least 45 days. Repetitive applications of selective GSK-3ß inhibitors (SB216763, 5 mg/kg, intraperitoneally, three times or AR-A014418, 400 ng/kg, intrathecally, seven times) prevented short-term memory deficits but did not affect neuropathic pain induced by SNI. Surprisingly, we found that the repetitive SB216763 or AR-A014418 induced a persistent pain hypersensitivity in sham animals. Mechanistically, both ß-catenin and brain-derived neurotrophic factor (BDNF) were upregulated in spinal dorsal horn but downregulated in hippocampus following SNI. Injections of SB216763 prevented the BDNF downregulation in hippocampus but enhanced its upregulation in spinal dorsal horn in SNI rats. In sham rats, SB216763 upregulated both ß-catenin and BDNF in spinal dorsal horn but affect neither of them in hippocampus. Finally, intravenous injection of interleukin-1beta that induces pain hypersensitivity and memory deficits mimicked the SNI-induced the differential regulation of GSK-3ß/ß-catenin/BDNF in spinal dorsal horn and in hippocampus. Accordingly, the prolonged opposite changes of GSK-3ß activity in hippocampus and in spinal dorsal horn induced by SNI may contribute to memory deficits and neuropathic pain by differential regulation of BDNF in the two regions. GSK-3ß inhibitors that treat cognitive disorders may result in a long-lasting pain hypersensitivity.


Assuntos
Glicogênio Sintase Quinase 3 beta/metabolismo , Hipocampo/metabolismo , Hiperalgesia/patologia , Interleucina-1beta/farmacologia , Transtornos da Memória/patologia , Corno Dorsal da Medula Espinal/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/uso terapêutico , Regulação da Expressão Gênica/efeitos dos fármacos , Hiperalgesia/etiologia , Indóis/uso terapêutico , Masculino , Maleimidas/uso terapêutico , Transtornos da Memória/etiologia , Transtornos da Memória/prevenção & controle , Proteínas do Tecido Nervoso/metabolismo , Medição da Dor , Traumatismos dos Nervos Periféricos/complicações , Ratos , Ratos Sprague-Dawley , Tiazóis/uso terapêutico , Fatores de Tempo , Ureia/análogos & derivados , Ureia/uso terapêutico , beta Catenina/metabolismo
10.
J Org Chem ; 84(22): 14936-14942, 2019 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-31608635

RESUMO

A new protocol has been developed for the use of allylic amines as allylating agents in the chiral α-amino acid/palladium-catalyzed asymmetric allylation of α-branched ß-ketoesters, providing highly enantioselective access to all-carbon quaternary stereocenters. Notably, the formation of a primary amine, a secondary amine, or ammonia as a byproduct has little influence on the enantioselectivity for the catalytic asymmetric synthesis of structurally diverse α,α-disubstituted ß-ketoesters.

11.
Sleep Breath ; 23(2): 455-462, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30145676

RESUMO

PURPOSE: Post-stroke cognitive impairment (PSCI) is common among stroke survivors, although its risk factors are not well understood. Here, we assessed cognitive function in patients within 14 days after minor stroke and investigated the risk factors of PSCI, including sleep-related factors. METHODS: Patients with minor acute ischemic stroke (n = 86) were continuously recruited from November 2015 to October 2016. Demographic and clinical data were collected, and cognitive assessment and polysomnography were performed. Based on their cognitive performance, stroke patients were divided into PSCI and no PSCI groups. Age-, sex-, and education-matched participants (n = 36) were included as a healthy control (HC) group. RESULTS: Stroke patients showed impairments in multiple cognitive domains relative to HC participants (p < 0.01). Among stroke patients, the prevalence of PSCI and obstructive sleep apnea was 81.4 and 74.4%, respectively. Impairments in attention and working memory (87.1%) and executive function (84.3%) were the most common among stroke patients. Compared with no PSCI patients, PSCI patients showed a higher prevalence of obstructive sleep apnea (50.0 vs. 80.0%, p = 0.030) and shorter total sleep time (435.1 ± 104.0 vs. 347.3 ± 98.1 min, p = 0.002). Logistic regression analysis showed that education duration, total sleep time, and lowest SaO2 were independent risk factors for PSCI. CONCLUSIONS: The prevalence of PSCI is high after minor ischemic stroke. In particular, attention and working memory and executive function are most commonly impaired. Although the risk factors for PSCI are numerous, shorter total sleep time and degree of hypoxia at night warrant further attention.


Assuntos
Isquemia Encefálica/complicações , Disfunção Cognitiva/etiologia , Apneia Obstrutiva do Sono/etiologia , Acidente Vascular Cerebral/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Atenção , Função Executiva , Feminino , Humanos , Hipóxia/etiologia , Masculino , Memória de Curto Prazo , Pessoa de Meia-Idade , Testes Neuropsicológicos , Polissonografia , Estudos Prospectivos , Fatores de Risco
12.
Sheng Li Xue Bao ; 71(6): 883-893, 2019 Dec 25.
Artigo em Zh | MEDLINE | ID: mdl-31879744

RESUMO

In this study, we improved the culture method of mouse hippocampal primary microglia to obtain hippocampal ramified microglia with high activity and purity, which were resemble to the resting status of normal microglia in healthy brain in vivo. Hippocampal tissue was excised from 2-4-week-old SPF C57BL/6J mice and cut into pieces after PBS perfusion, and then manually dissociated into the single-cell suspension by using Miltenyi Biotec's Adult Brain Dissociation Kit. The tissue fragments such as myelin in the supernatant were removed by debris removal solution in the kit. The cell suspension was incubated with CD11b immunomagnetic beads for 15 min at 4 °C. To obtain high-purity microglia, we used two consecutive cell-sorting steps by magnetic activated cell sorting (MACS). After centrifugation, the cells were resuspended and seeded in a 24-well culture plate. The primary microglia were cultured with complete medium (CM) or TIC medium (a serum-free medium with TGF-ß, IL-34 and cholesterol as the main nutritional components) for 4 days, and then were used for further experiments. The results showed that: (1) The cell viability was (56.03 ± 2.10)% by manual dissociation of hippocampus; (2) Compared with immunopanning, two-step MACS sorting allowed for efficient enrichment of microglia with higher purity of (86.20 ± 0.68)%; (3) After being incubated in TIC medium for 4 d, microglia exhibited branching, quiescent morphology; (4) The results from qRT-PCR assay showed that the levels of TNF-α, IL-1ß and CCL2 mRNA in TIC cultured-microglia were similar to freshly isolated microglia, while those were much higher in CM cultured-microglia after incubation for 4 d and 7 d (P < 0.05). Taken together, compared to the conventional approaches, this modified protocol of mouse hippocampal primary microglia culture by using MACS and TIC medium enables the increased yield and purity of microglia in the quiescent state, which is similar to normal ramified microglia in healthy brain in vivo.


Assuntos
Técnicas de Cultura de Células , Separação Celular , Hipocampo , Magnetismo , Microglia , Animais , Técnicas de Cultura de Células/métodos , Separação Celular/métodos , Células Cultivadas , Camundongos , Camundongos Endogâmicos C57BL , Microglia/citologia
13.
Pestic Biochem Physiol ; 152: 90-97, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30497717

RESUMO

Itol A, a novel isoryanodane diterpene derived from Itoa orientalis Hemsl., has potent activities against insect pests. This study was conducted to determine the contact toxicity and biochemical effects of itol A on the Nilaparvata lugens. After macropterous females of N. lugens were exposed to itol A from 0.5 to 24 h, the mortality and poisoning symptoms were measured. Effects of itol A on the major enzymes activity and oxidative stress level were assessed in dose-response (with LD10-LD70 at 24 h) and time-course (with LD50 at 0.5-24 h) experiments for the potential toxicity mechanisms. Based on the results, the mortality of N. lugens showed significant dose- and time-dependent effects, with the 24-h LD50 value was 0.58 µg/insect. The symptoms of excitation, convulsion and paralysis were also observed. However, acetylcholinesterases (AChE) activity was not altered after itol A treatment compared to control. Na+/K+-ATPases, Ca2+-ATPases, Ca2+/Mg2+-ATPases, glutathione S-transferases (GSTs), cytochrome P450 monooxygenases (P450s), superoxide dismutases (SOD) and catalases (CAT) activities were significantly reduced in dose-response and time-course experiments. While acid phosphatases (ACP) and glutathione peroxidases (GPX) activities were significantly increased. We further revealed that itol A exposure resulted in the decrease of GSH/GSSG (reduced to oxidized glutathione) ratio and the increase of hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels in both experiments. The results indicated that the inhibition of Na+/K+-ATPases, Ca2+-ATPases, Ca2+/Mg2+-ATPases, GSTs, P450s, SOD and CAT activities and the induction of oxidative stress was one of the potential biochemical mechanisms of itol A against N. lugens.


Assuntos
Diterpenos/toxicidade , Inibidores Enzimáticos/toxicidade , Hemípteros/efeitos dos fármacos , Inseticidas/toxicidade , Fosfatase Ácida/antagonistas & inibidores , Adenosina Trifosfatases/antagonistas & inibidores , Animais , Diterpenos/química , Inibidores Enzimáticos/química , Feminino , Glutationa/metabolismo , Glutationa Transferase/antagonistas & inibidores , Hemípteros/metabolismo , Inseticidas/química , Dose Letal Mediana , Malondialdeído/metabolismo , Oxirredutases/antagonistas & inibidores , Salicaceae
14.
Chemistry ; 22(37): 13041-5, 2016 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-27339655

RESUMO

A new strategy has been established for the kinetic resolution of racemic allylic alcohols through a palladium/sulfonyl-hydrazide-catalyzed asymmetric OH-substitution under mild conditions. In the presence of 1 mol % [Pd(allyl)Cl]2 , 4 mol % (S)-SegPhos, and 10 mol % 2,5-dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than 400 through an asymmetric allylic alkylation of monosubstituted hydrazines under air at room temperature. Importantly, this kinetic resolution process provided various allylic alcohols and allylic hydrazine derivatives with high enantiopurity.

15.
Org Biomol Chem ; 13(19): 5367-71, 2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25880785

RESUMO

A range of primary allylic amines were resolved with selectivity factors of up to 491 through [Pd(allyl)Cl]2/(S)-BINAP-catalyzed and mesitylsulfonyl hydrazide-accelerated asymmetric allylic alkylation of malononitriles involving enantioselective C-N bond cleavage under aerobic conditions. Moreover, the reaction proved useful for the asymmetric synthesis of α-branched allyl-substituted malononitriles with high enantiopurity.


Assuntos
Compostos Alílicos/química , Aminas/química , Nitrilas/química , Paládio/química , Alquilação , Catálise , Hidrazinas/química , Cinética , Solventes/química , Estereoisomerismo
16.
Nature ; 462(7272): 467-72, 2009 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-19940917

RESUMO

FocA is a representative member of the formate-nitrite transporter family, which transports short-chain acids in bacteria, archaea, fungi, algae and parasites. The structure and transport mechanism of the formate-nitrite transporter family remain unknown. Here we report the crystal structure of Escherichia coli FocA at 2.25 A resolution. FocA forms a symmetric pentamer, with each protomer consisting of six transmembrane segments. Despite a lack of sequence homology, the overall structure of the FocA protomer closely resembles that of aquaporin and strongly argues that FocA is a channel, rather than a transporter. Structural analysis identifies potentially important channel residues, defines the channel path and reveals two constriction sites. Unlike aquaporin, FocA is impermeable to water but allows the passage of formate. A structural and biochemical investigation provides mechanistic insights into the channel activity of FocA.


Assuntos
Aquaporinas/química , Proteínas de Escherichia coli/química , Proteínas de Membrana Transportadoras/química , Aquaporinas/metabolismo , Cristalografia por Raios X , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Formiatos/metabolismo , Lipossomos/química , Lipossomos/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Modelos Moleculares , Mimetismo Molecular , Mutação , Permeabilidade , Estrutura Quaternária de Proteína , Relação Estrutura-Atividade , Água/análise , Água/metabolismo
17.
Int J Mol Sci ; 16(6): 12855-70, 2015 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-26057749

RESUMO

Tapiscia sinensis Oliv (Tapisciaceae) is an endangered species native to China famous for its androdioecious breeding system. However, there is a lack of genomic and transcriptome data on this species. In this study, the Tapiscia sinensis transcriptomes from two types of sex flower buds were sequenced. A total of 97,431,176 clean reads were assembled into 52,169 unigenes with an average length of 1116 bp. Through similarity comparison with known protein databases, 36,662 unigenes (70.27%) were annotated. A total of 10,002 (19.17%) unigenes were assigned to 124 pathways using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway database. Additionally, 10,371 simple sequence repeats (SSRs) were identified in 8608 unigenes, with 16,317 pairs of primers designed for applications. 150 pairs of primers were chosen for further validation, and the 68 pairs (45.5%) were able to produce clear polymorphic bands. Six polymorphic SSR markers were used to Bayesian clustering analysis of 51 T. sinensis individuals. This is the first report to provide transcriptome information and to develop large-scale SSR molecular markers for T. sinensis. This study provides a valuable resource for conservation genetics and functional genomics research on T. sinensis for future work.


Assuntos
Etiquetas de Sequências Expressas , Flores/genética , Magnoliopsida/genética , Repetições de Microssatélites , Transcriptoma , Sequência de Bases , Espécies em Perigo de Extinção , Flores/metabolismo , Marcadores Genéticos , Genoma de Planta , Magnoliopsida/metabolismo , Dados de Sequência Molecular
18.
Nucleic Acids Res ; 40(19): 9802-14, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22885301

RESUMO

Bloom (BLM) syndrome is an autosomal recessive disorder characterized by an increased risk for many types of cancers. Previous studies have shown that BLM protein forms a hexameric ring structure, but its oligomeric form in DNA unwinding is still not well clarified. In this work, we have used dynamic light scattering and various stopped-flow assays to study the active form and kinetic mechanism of BLM in DNA unwinding. It was found that BLM multimers were dissociated upon ATP hydrolysis. Steady-state and single-turnover kinetic studies revealed that BLM helicase always unwound duplex DNA in the monomeric form under conditions of varying enzyme and ATP concentrations as well as 3'-ssDNA tail lengths, with no sign of oligomerization being discerned. Measurements of ATPase activity further indicated that BLM helicase might still function as monomers in resolving highly structured DNAs such as Holliday junctions and D-loops. These results shed new light on the underlying mechanism of BLM-mediated DNA unwinding and on the molecular and functional basis for the phenotype of heterozygous carriers of BLM syndrome.


Assuntos
Adenosina Trifosfatases/metabolismo , DNA/metabolismo , RecQ Helicases/metabolismo , Trifosfato de Adenosina/metabolismo , Adenilil Imidodifosfato/farmacologia , DNA/química , Hidrólise , Cinética , Luz , Multimerização Proteica , RecQ Helicases/antagonistas & inibidores , RecQ Helicases/química , Espalhamento de Radiação
19.
Mol Immunol ; 170: 144-155, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38669759

RESUMO

OBJECTIVE: Dihydroartemisinin (DHA) plays a very important role in various diseases. However, the precise involvement of DHA in systemic lupus erythematosus (SLE), relation to the equilibrium between M1 and M2 cells, remains uncertain. Therefore, we aimed to investigate the role of DHA in SLE and its effect on the M1/M2 cells balance. METHODS: SLE mice model was established by pristane induction. Flow cytometry was employed to measure the abundance of M1 and M2 cells within the peripheral blood of individuals diagnosed with SLE. The concentrations of various cytokines, namely TNF-α, IL-1ß, IL-4, IL-6, and IL-10, within the serum of SLE patients or SLE mice were assessed via ELISA. Immunofluorescence staining was utilized to detect the deposition of IgG and complement C3 in renal tissues of the mice. We conducted immunohistochemistry analysis to assess the expression levels of Collagen-I, a collagen protein, and α-SMA, a fibrosis marker protein, in the renal tissues of mice. Hematoxylin-eosin staining, Masson's trichrome staining, and Periodic acid Schiff staining were used to examine histological alterations. In this study, we employed qPCR and western blot techniques to assess the expression levels of key molecular markers, namely CD80 and CD86 for M1 cells, as well as CD206 and Arg-1 for M2 cells, within kidney tissue. Additionally, we investigated the involvement of the MAPK signaling pathway. The Venny 2.1 online software tool was employed to identify shared drug-disease targets, and subsequently, the Cytoscape 3.9.2 software was utilized to construct the "disease-target-ingredient" network diagram. Protein-protein interactions of the target proteins were analyzed using the String database, and the network proteins underwent enrichment analysis for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways. RESULTS: The results showed that an increase in M1 cells and a decrease in M2 cells within the peripheral blood of individuals diagnosed with SLE. Further analysis revealed that prednisone (PDN) combined with DHA can alleviate kidney damage and regulate the balance of M1 and M2 cells in both glomerular mesangial cells (GMC) and kidney. The MAPK signaling pathway was found to be involved in SLE kidney damage and M1/M2 balance in the kidney. Furthermore, PDN and/or DHA were found to inhibit the MAPK signaling pathway in GMC and kidney. CONCLUSION: We demonstrated that PDN combined with DHA attenuates SLE by regulating M1/M2 balance through MAPK signaling pathway. These findings propose that the combination of PDN and DHA could serve as a promising therapeutic strategy for SLE, as it has the potential to mitigate kidney damage and reinstate the equilibrium of M1 and M2 cells.


Assuntos
Artemisininas , Lúpus Eritematoso Sistêmico , Sistema de Sinalização das MAP Quinases , Prednisona , Animais , Humanos , Camundongos , Artemisininas/farmacologia , Artemisininas/uso terapêutico , Citocinas/metabolismo , Modelos Animais de Doenças , Quimioterapia Combinada , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Prednisona/farmacologia , Prednisona/uso terapêutico
20.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 36(4): 425-429, 2024 Apr.
Artigo em Zh | MEDLINE | ID: mdl-38813640

RESUMO

AMP-activated protein kinase (AMPK) is a widely distributed and evolutionarily conserved serine/threonine protein kinase present in eukaryotic cells. In regulating cellular energy metabolism, AMPK plays an extremely important role as an energy metabolic kinase. When the body is in a low energy state, AMPK is activated in response to changes in intracellular adenine nucleotide levels and is bound to adenosine monophosphate (AMP) or adenosine diphosphate (ADP). Activated AMPK regulates various metabolic processes, including lipid and glucose metabolism and cellular autophagy. AMPK directly promotes autophagy by phosphorylating autophagy-related proteins in the mammalian target of rapamycin complex 1 (mTORC1), serine/threonine protein kinase-dysregulated 51-like kinase 1 (ULK1) and type III phosphatidylinositol 3-kinase-vacuolar protein-sorting 34 (PIK3C3-VPS34) complexes. AMPK also indirectly promotes autophagy by regulating the expression of downstream autophagy-related genes of transcription factors such as forkhead box O3 (FOXO3), lysosomal function transcription factor EB (TFEB) and bromodomain protein 4 (BRD4). AMPK also regulates mitochondrial autophagy, induces the division of damaged mitochondria and promotes the transfer of the autophagic response to damaged mitochondria. Another function of AMPK is to regulate mitochondrial health by stimulating mitochondrial biogenesis and participating in various aspects of mitochondrial homeostasis regulation. This review discusses the specific regulation of mitochondrial biology and internal environmental homeostasis by AMPK signaling channels as central to the cellular response to energy stress and regulation of mitochondria, highlighting the key role of AMPK in regulating cellular autophagy and mitochondrial autophagy, as well as advances in research on the regulation of mitochondrial homeostasis.


Assuntos
Proteínas Quinases Ativadas por AMP , Autofagia , Homeostase , Mitocôndrias , Transdução de Sinais , Autofagia/fisiologia , Proteínas Quinases Ativadas por AMP/metabolismo , Humanos , Mitocôndrias/metabolismo , Animais , Metabolismo Energético , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo
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