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1.
Cell ; 183(2): 490-502.e18, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33002410

RESUMO

The non-receptor protein tyrosine phosphatase (PTP) SHP2, encoded by PTPN11, plays an essential role in RAS-mitogen-activated protein kinase (MAPK) signaling during normal development. It has been perplexing as to why both enzymatically activating and inactivating mutations in PTPN11 result in human developmental disorders with overlapping clinical manifestations. Here, we uncover a common liquid-liquid phase separation (LLPS) behavior shared by these disease-associated SHP2 mutants. SHP2 LLPS is mediated by the conserved well-folded PTP domain through multivalent electrostatic interactions and regulated by an intrinsic autoinhibitory mechanism through conformational changes. SHP2 allosteric inhibitors can attenuate LLPS of SHP2 mutants, which boosts SHP2 PTP activity. Moreover, disease-associated SHP2 mutants can recruit and activate wild-type (WT) SHP2 in LLPS to promote MAPK activation. These results not only suggest that LLPS serves as a gain-of-function mechanism involved in the pathogenesis of SHP2-associated human diseases but also provide evidence that PTP may be regulated by LLPS that can be therapeutically targeted.


Assuntos
Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Células A549 , Animais , Criança , Pré-Escolar , Feminino , Mutação com Ganho de Função/genética , Células HEK293 , Células Endoteliais da Veia Umbilical Humana , Humanos , Sistema de Sinalização das MAP Quinases/fisiologia , Masculino , Camundongos , Células-Tronco Embrionárias Murinas , Mutação/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Transdução de Sinais , Domínios de Homologia de src/genética
2.
Proc Natl Acad Sci U S A ; 118(20)2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-33972418

RESUMO

Heterozygous point mutations of α-synuclein (α-syn) have been linked to the early onset and rapid progression of familial Parkinson's diseases (fPD). However, the interplay between hereditary mutant and wild-type (WT) α-syn and its role in the exacerbated pathology of α-syn in fPD progression are poorly understood. Here, we find that WT mice inoculated with the human E46K mutant α-syn fibril (hE46K) strain develop early-onset motor deficit and morphologically different α-syn aggregation compared with those inoculated with the human WT fibril (hWT) strain. By using cryo-electron microscopy, we reveal at the near-atomic level that the hE46K strain induces both human and mouse WT α-syn monomers to form the fibril structure of the hE46K strain. Moreover, the induced hWT strain inherits most of the pathological traits of the hE46K strain as well. Our work suggests that the structural and pathological features of mutant strains could be propagated by the WT α-syn in such a way that the mutant pathology would be amplified in fPD.


Assuntos
Amiloide/genética , Mutação de Sentido Incorreto , Doenças do Sistema Nervoso/genética , Doença de Parkinson/genética , Agregação Patológica de Proteínas/genética , alfa-Sinucleína/genética , Amiloide/metabolismo , Amiloide/ultraestrutura , Animais , Microscopia Crioeletrônica , Modelos Animais de Doenças , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia de Força Atômica , Microscopia Confocal , Atividade Motora/genética , Atividade Motora/fisiologia , Doenças do Sistema Nervoso/metabolismo , Doença de Parkinson/metabolismo , Agregação Patológica de Proteínas/metabolismo , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo
3.
Proc Natl Acad Sci U S A ; 118(26)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34172566

RESUMO

The spread of pathological α-synuclein (α-syn) is a crucial event in the progression of Parkinson's disease (PD). Cell surface receptors such as lymphocyte activation gene 3 (LAG3) and amyloid precursor-like protein 1 (APLP1) can preferentially bind α-syn in the amyloid over monomeric state to initiate cell-to-cell transmission. However, the molecular mechanism underlying this selective binding is unknown. Here, we perform an array of biophysical experiments and reveal that LAG3 D1 and APLP1 E1 domains commonly use an alkaline surface to bind the acidic C terminus, especially residues 118 to 140, of α-syn. The formation of amyloid fibrils not only can disrupt the intramolecular interactions between the C terminus and the amyloid-forming core of α-syn but can also condense the C terminus on fibril surface, which remarkably increase the binding affinity of α-syn to the receptors. Based on this mechanism, we find that phosphorylation at serine 129 (pS129), a hallmark modification of pathological α-syn, can further enhance the interaction between α-syn fibrils and the receptors. This finding is further confirmed by the higher efficiency of pS129 fibrils in cellular internalization, seeding, and inducing PD-like α-syn pathology in transgenic mice. Our work illuminates the mechanistic understanding on the spread of pathological α-syn and provides structural information for therapeutic targeting on the interaction of α-syn fibrils and receptors as a potential treatment for PD.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Amiloide/metabolismo , Antígenos CD/metabolismo , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , alfa-Sinucleína/metabolismo , Animais , Linhagem Celular Tumoral , Endocitose , Humanos , Camundongos , Degeneração Neural/patologia , Neurônios/metabolismo , Fosforilação , Fosfosserina/metabolismo , Ligação Proteica , Eletricidade Estática , alfa-Sinucleína/química , alfa-Sinucleína/toxicidade , Proteína do Gene 3 de Ativação de Linfócitos
4.
Proc Natl Acad Sci U S A ; 117(49): 31123-31133, 2020 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-33229560

RESUMO

Membraneless organelles contain a wide spectrum of molecular chaperones, indicating their important roles in modulating the metastable conformation and biological function of membraneless organelles. Here we report that class I and II Hsp40 (DNAJ) proteins possess a high ability of phase separation rendered by the flexible G/F-rich region. Different Hsp40 proteins localize in different membraneless organelles. Specifically, human Hdj1 (DNAJB1), a class II Hsp40 protein, condenses in ubiquitin (Ub)-rich nuclear bodies, while Hdj2 (DNAJA1), a class I Hsp40 protein, condenses in nucleoli. Upon stress, both Hsp40 proteins incorporate into stress granules (SGs). Mutations of the G/F-rich region not only markedly impaired Hdj1 phase separation and SG involvement and disrupted the synergistic phase separation and colocalization of Hdj1 and fused in sarcoma (FUS) in cells. Being cophase separated with FUS, Hdj1 stabilized the liquid phase of FUS against proceeding into amyloid aggregation in vitro and alleviated abnormal FUS aggregation in cells. Moreover, Hdj1 uses different domains to chaperone FUS phase separation and amyloid aggregation. This paper suggests that phase separation is an intrinsic property of Hsp40 proteins, which enables efficient incorporation and function of Hsp40 in membraneless organelles and may further mediate the buildup of chaperone network in membraneless organelles.


Assuntos
Proteínas de Choque Térmico HSP40/genética , Chaperonas Moleculares/genética , Membrana Celular/genética , Humanos , Membranas , Organelas/genética , Ligação Proteica/genética , Proteína FUS de Ligação a RNA/genética , Ubiquitina/genética
5.
Proc Natl Acad Sci U S A ; 117(33): 20305-20315, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32737160

RESUMO

Posttranslational modifications (PTMs) of α-synuclein (α-syn), e.g., phosphorylation, play an important role in modulating α-syn pathology in Parkinson's disease (PD) and α-synucleinopathies. Accumulation of phosphorylated α-syn fibrils in Lewy bodies and Lewy neurites is the histological hallmark of these diseases. However, it is unclear how phosphorylation relates to α-syn pathology. Here, by combining chemical synthesis and bacterial expression, we obtained homogeneous α-syn fibrils with site-specific phosphorylation at Y39, which exhibits enhanced neuronal pathology in rat primary cortical neurons. We determined the cryo-electron microscopy (cryo-EM) structure of the pY39 α-syn fibril, which reveals a fold of α-syn with pY39 in the center of the fibril core forming an electrostatic interaction network with eight charged residues in the N-terminal region of α-syn. This structure composed of residues 1 to 100 represents the largest α-syn fibril core determined so far. This work provides structural understanding on the pathology of the pY39 α-syn fibril and highlights the importance of PTMs in defining the polymorphism and pathology of amyloid fibrils in neurodegenerative diseases.


Assuntos
Doença de Parkinson , alfa-Sinucleína/química , Amiloide/química , Amiloide/metabolismo , Animais , Células Cultivadas , Microscopia Crioeletrônica , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Modelos Moleculares , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação , Conformação Proteica , Ratos , Ratos Sprague-Dawley , alfa-Sinucleína/síntese química , alfa-Sinucleína/metabolismo
6.
J Environ Sci (China) ; 129: 1-15, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36804226

RESUMO

Due to the combined effect of sluices and sea tide, the sluice-controlled coastal plain river would be characterized by both trophic state and salinity gradients, affecting the spatiotemporal optical properties of dissolved organic matter (DOM). In this study, we investigated the spatiotemporal variation of water quality parameters and optical properties of DOM in the Haihe River, a representative sluice-controlled coastal plain river in Tianjin, China. A significant salinity gradient and four trophic states were observed in the water body of the Haihe River. Two humic- and one protein-like substances were identified from the DOM by the three-dimensional fluorescence spectra combined with the parallel factor (PARAFAC) analysis. Pearson's correlation analysis and redundancy analysis (RDA) showed that the salinity significantly affected the abundance of chromophoric DOM (CDOM) but did not cause significant changes in the fluorescence optical characteristics. In addition, the effect of Trophic state index (TSI) on the CDOM abundance was greater than that on the fluorescence intensity of fluorescent dissolved organic matter (FDOM). In the water body with both salinity and trophic state gradients, TSI posed a greater influence than salinity on the CDOM abundance. Our results fill the research gap in spatiotemporal DOM characteristics and water quality variation in water bodies with both salinity and trophic state gradients. These results are beneficial for clarifying the joint influence of saline intrusion and sluices on the DOM characteristics and water quality in sluice-controlled coastal plain rivers.


Assuntos
Matéria Orgânica Dissolvida , Rios , Salinidade , Qualidade da Água , China , Espectrometria de Fluorescência
7.
Zhongguo Zhong Yao Za Zhi ; 48(19): 5152-5161, 2023 Oct.
Artigo em Zh | MEDLINE | ID: mdl-38114105

RESUMO

During the storage process, Chinese medicinal materials are susceptible to insect infestation due to their own nature and external storage factors. Infestation by insects can have varying impacts on the materials. In mild cases, it affects the appearance and reduces consumer purchasing power, while in severe cases, it affects the quality, reduces medicinal value, and introduces impurities such as insect bodies, excrement, and secretions, resulting in significant contamination of the medicinal materials. This study reviewed the rele-vant factors influencing insect infestation in Chinese medicinal materials and the compositional changes that occur after infestation and summarized maintenance measures for preventing insect infestation. Additionally, it provided an overview of detection techniques applicable to identifying insect infestation during the storage of Chinese medicinal materials. During the storage process, insect infestation is the result of the combined effects of biological factors(source, species, and population density of insects), intrinsic factors(moisture, chemical composition, and metabolism), and environmental factors(temperature, relative humidity, and oxygen content). After infestation, there are significant changes in the content of constituents in the medicinal materials. By implementing strict pre-storage inspections, regular maintenance after storage, and appropriate storage and maintenance methods, the occurrence of insect infestation can be reduced, and the preservation rate of Chinese medicinal materials can be improved. The storage and maintenance of Chinese medicinal materials are critical for ensuring their quality. Through scientifically standardized storage and strict adherence to operational management standards, the risk of insect infestation can be minimized, thus guaranteeing the quality of Chinese medicinal materials.


Assuntos
Contaminação de Medicamentos , Insetos , Animais , Contaminação de Medicamentos/prevenção & controle , Preservação Biológica , Temperatura
8.
PLoS Pathog ; 16(4): e1008409, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32287326

RESUMO

The continual emergence of novel influenza A strains from non-human hosts requires constant vigilance and the need for ongoing research to identify strains that may pose a human public health risk. Since 1999, canine H3 influenza A viruses (CIVs) have caused many thousands or millions of respiratory infections in dogs in the United States. While no human infections with CIVs have been reported to date, these viruses could pose a zoonotic risk. In these studies, the National Institutes of Allergy and Infectious Diseases (NIAID) Centers of Excellence for Influenza Research and Surveillance (CEIRS) network collaboratively demonstrated that CIVs replicated in some primary human cells and transmitted effectively in mammalian models. While people born after 1970 had little or no pre-existing humoral immunity against CIVs, the viruses were sensitive to existing antivirals and we identified a panel of H3 cross-reactive human monoclonal antibodies (hmAbs) that could have prophylactic and/or therapeutic value. Our data predict these CIVs posed a low risk to humans. Importantly, we showed that the CEIRS network could work together to provide basic research information important for characterizing emerging influenza viruses, although there were valuable lessons learned.


Assuntos
Doenças Transmissíveis Emergentes/veterinária , Doenças do Cão/virologia , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza A Subtipo H3N8/isolamento & purificação , Vírus da Influenza A/isolamento & purificação , Zoonoses/virologia , Animais , Doenças Transmissíveis Emergentes/transmissão , Doenças Transmissíveis Emergentes/virologia , Doenças do Cão/transmissão , Cães , Furões , Cobaias , Humanos , Vírus da Influenza A Subtipo H3N2/classificação , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N8/classificação , Vírus da Influenza A Subtipo H3N8/genética , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Humana/transmissão , Influenza Humana/virologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Estados Unidos , Zoonoses/transmissão
9.
Appl Microbiol Biotechnol ; 106(7): 2619-2636, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35291023

RESUMO

Perylenequinones (PQ) are natural polyketides used as anti-microbial, -cancers, and -viral photodynamic therapy agents. Herein, the effects of L-arginine (Arg) on PQ biosynthesis of Shiraia sp. Slf14(w) and the underlying molecular mechanism were investigated. The total content of PQ reached 817.64 ± 72.53 mg/L under optimal conditions of Arg addition, indicating a 30.52-fold improvement over controls. Comparative transcriptome analysis demonstrated that Arg supplement promoted PQ precursors biosynthesis of Slf14(w) by upregulating the expression of critical genes associated with the glycolysis pathway, and acetyl-CoA and malonyl-CoA synthesis. By downregulating the expression of genes related to the glyoxylate cycle pathway and succinate dehydrogenase, more acetyl-CoA flow into the formation of PQ. Arg supplement upregulated the putative biosynthetic gene clusters for PQ and activated the transporter proteins (MFS and ABC) for exudation of PQ. Further studies showed that Arg increased the gene transcription levels of nitric oxide synthase (NOS) and nitrate reductase (NR), and activated NOS and NR, thus promoting the formation of nitric oxide (NO). A supplement of NO donor sodium nitroprusside (SNP) also confirmed that NO triggered promoted biosynthesis and efflux of PQ. PQ production stimulated by Arg or/and SNP can be significantly inhibited upon the addition of NO scavenger carboxy-PTIO, NOS inhibitor Nω-nitro-L-arginine, or soluble guanylate cyclase inhibitor NS-2028. These results showed that Arg-derived NO, as a signaling molecule, is involved in the biosynthesis and regulation of PQ in Slf14(W) through the NO-cGMP-PKG signaling pathway. Our results provide a valuable strategy for large-scale PQ production and contribute to further understanding of NO signaling in the fungal metabolite biosynthesis. KEY POINTS: • PQ production of Shiraia sp. Slf14(w) was significantly improved by L-arginine addition. • Arginine-derived NO was firstly reported to be involved in the biosynthesis and regulation of PQ. • The NO-cGMP-PKG signaling pathway was proposed for the first time to participate in PQ biosynthesis.


Assuntos
Ascomicetos , Acetilcoenzima A/metabolismo , Arginina/metabolismo , Ascomicetos/metabolismo , GMP Cíclico/metabolismo , Óxido Nítrico/metabolismo , Nitroprussiato , Perileno/análogos & derivados , Quinonas , Transdução de Sinais
10.
Molecules ; 27(20)2022 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-36296619

RESUMO

Trichosanthes anguina L. (family Cucurbitaceae) is a monoecious and diclinous plant that can be consumed as a vegetable and has anti-inflammatory and antioxidant effects. The chemical composition and content of volatile compounds in female and male buds of T. anguina were explored by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) technology combined with multivariate statistical analysis. The results showed that the content of the volatile compounds was different between female and male buds. 2,2,6-trimethyl-6-vinyltetrahydro-2H-pyran-3-ol and 2,2,6-trimethyl-6-vinyldihydro-2H-pyran-3(4H)-one were the main volatile compounds in both female and male buds. Based on the multivariate statistical analysis of orthogonal projections to latent structures discriminant analysis (OPLS-DA) and t-test, the content of seven compounds was significantly different between female and male buds. The content of three compounds in male buds was higher than that in female, i.e., (E)-4,8-dimethyl-1,3,7-nonatriene, 1,5,9,9-tetramethyl-1,4,7-cycloundecatriene, and (E)-caryophyllene. Conversely, the content of (Z)-4-hexen-1-ol, (Z)-3-hexenyl benzoate, (Z)-3-hexenyl salicylate, and 2-hexen-1-ol in female buds was higher than that in male buds. This is the first report on the difference in the volatile compounds between female and male buds of T. anguina, which enriches the basic research on the monoecious and diclinous plant and provides a reference for the study of plant sex differentiation.


Assuntos
Trichosanthes , Compostos Orgânicos Voláteis , Microextração em Fase Sólida/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Antioxidantes/análise , Compostos Orgânicos Voláteis/análise , Piranos/análise
11.
Molecules ; 27(4)2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35209076

RESUMO

Herpetospermum pedunculosum (Ser.) C. B. Clarke (Family Cucurbitaceae) is a dioecious plant and has been used as a traditional Tibetan medicine for the treatment of hepatobiliary diseases. The component, content, and difference in volatile compounds in the female and male buds of H. pedunculosum were explored by using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) technology and multivariate statistical analysis. The results showed that isoamyl alcohol was the main compound in both female and male buds and its content in males was higher than that in females; 18 compounds were identified in female buds including 6 unique compounds such as (E)-4-hexenol and isoamyl acetate, and 32 compounds were identified in male buds, including 20 unique compounds such as (Z)-3-methylbutyraldehyde oxime and benzyl alcohol. (Z)-3-methylbutyraldehyde oxime and (E)-3-methylbutyraldehyde oxime were found in male buds, which only occurred in night-flowering plants. In total, 9 differential volatile compounds between female and male buds were screened out, including isoamyl alcohol, (Z)-3-methylbutanal oxime, and 1-nitropentane based on multivariate statistical analysis such as principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA). This is the first time to report the volatile components of H. pedunculosum, which not only find characteristic difference between female and male buds, but also point out the correlation between volatile compounds, floral odor, and plant physiology. This study enriches the basic theory of dioecious plants and has guiding significance for the production and development of H. pedunculosum germplasm resources.


Assuntos
Cucurbitaceae/química , Cromatografia Gasosa-Espectrometria de Massas , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/isolamento & purificação , Microextração em Fase Sólida , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/isolamento & purificação , Flores/química , Análise Multivariada
12.
Zhongguo Zhong Yao Za Zhi ; 47(2): 385-391, 2022 Jan.
Artigo em Zh | MEDLINE | ID: mdl-35178980

RESUMO

This study aimed to analyze aflatoxins content and fungal community distribution in the harvesting and processing of Platycladi Semen, and explore the key link that affects aflatoxins contamination. The related Platycladi Semen samples of different maturity periods(cone non-rupture period, early rupture, and complete rupture period) and different processing periods(before drying, during 2-d drying, during 7-d drying, before and after seed scale removal, before and after peeling, 1 d after color sorting, and 7 d after color sorting) were collected for identifying the fungal community composition on sample surface by ITS amplicon sequencing. Then the content of aflatoxins B_1, B_2, G_1 and G_2 was determined by HPLC-MS/MS. The results showed that during the harvesting of Platycladi Semen from cone non-rupture to complete rupture, aflatoxins were only detected in the seed scale and seed coat, with aflatoxin G_2 in the seed scale and aflatoxin B_1 in the seed coat. During the drying, with the prolongation of drying time, aflatoxins B_1 and G_2 were detected simultaneously in the seed scale, aflatoxin B_1 in the seed coat, and low-content aflatoxin B_1 in the seed kernel. During subsequent processing, the aflatoxin content in seed kernel during subsequent processing was slighted increased. As demonstrated by fungal detection, Aspergillus flavus was not present during the harvesting of Platycladi Semen, but present during the drying and processing. Its content in the seed coat during the drying process was relatively higher. In short, Platycladi Semen should be harvested as soon as possible after it becomes fully mature. Drying process is the key link of preventing aflatoxin contamination. It is advised to build a sunlight room or adopt similar settings, standardize the operations in other processes, and keep the surrounding environment clean to minimize aflatoxin contamination.


Assuntos
Aflatoxinas , Micobioma , Aflatoxinas/análise , Aspergillus flavus , Contaminação de Alimentos/prevenção & controle , Sêmen/química , Espectrometria de Massas em Tandem
13.
J Biol Chem ; 295(21): 7470-7480, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32291284

RESUMO

Amyloid aggregation of pathological proteins is closely associated with a variety of neurodegenerative diseases, and α-synuclein (α-syn) deposition and Tau tangles are considered hallmarks of Parkinson's disease and Alzheimer's disease, respectively. Intriguingly, α-syn and Tau have been found to co-deposit in the brains of individuals with dementia and parkinsonism, suggesting a potential role of cross-talk between these two proteins in neurodegenerative pathologies. Here we show that monomeric α-syn and the two variants of Tau, Tau23 and K19, synergistically promote amyloid fibrillation, leading to their co-aggregation in vitro NMR spectroscopy experiments revealed that α-syn uses its highly negatively charged C terminus to directly interact with Tau23 and K19. Deletion of the C terminus effectively abolished its binding to Tau23 and K19 as well as its synergistic effect on promoting their fibrillation. Moreover, an S129D substitution of α-syn, mimicking C-terminal phosphorylation of Ser129 in α-syn, which is commonly observed in the brains of Parkinson's disease patients with elevated α-syn phosphorylation levels, significantly enhanced the activity of α-syn in facilitating Tau23 and K19 aggregation. These results reveal the molecular basis underlying the direct interaction between α-syn and Tau. We proposed that this interplay might contribute to pathological aggregation of α-syn and Tau in neurodegenerative diseases.


Assuntos
Amiloide , Encéfalo/metabolismo , Doença de Parkinson , Agregados Proteicos , alfa-Sinucleína , Proteínas tau , Substituição de Aminoácidos , Amiloide/química , Amiloide/genética , Amiloide/metabolismo , Humanos , Mutação de Sentido Incorreto , Ressonância Magnética Nuclear Biomolecular , Doença de Parkinson/genética , Doença de Parkinson/metabolismo , alfa-Sinucleína/química , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Proteínas tau/química , Proteínas tau/genética , Proteínas tau/metabolismo
14.
Nanotechnology ; 32(38)2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34116524

RESUMO

In this work, we prepared NiCo alloy/C with rhombic dodecahedron structure and superior microwave absorption performance by using ZIF-67 as the raw material. The rhombic dodecahedron NiCo alloy/C was with rough particles on the surface was photographed by field emission scanning electron microscopy. By adjusting the doping amount of Ni and the temperature of pyrolysis, improved the impedance matching of NiCo alloy/C. Specifically, NiCo alloy/C exhibits a minimum reflection loss of -65.48 dB at 13.48 GHz, while the thickness is 1.63 mm. Defects introduced in the Ni doping process and the special rhombic dodecahedral structure can cause multiple loss mechanisms. Therefore, this NiCo alloy/C composite has the potential to be a potential microwave absorber material with lightweight and high microwave absorption properties.

15.
J Environ Sci (China) ; 104: 40-52, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33985743

RESUMO

The Yongding New River is essential for the water supplies of Tianjin. To date, there is no comprehensive report that assesses the year-round water quality of the Yongding New River Main stream. Moreover, little attention has been given to determining a combined weight for improving the traditional comprehensive water quality identification index (ICWQII) by the game theory. Seven water quality parameters were investigated monthly along the main stream of the Yongding New River from May 2018 to April 2019. Organic contaminants and nitrogen pollution were mainly caused by point sources pollution, and the total phosphorus mainly by non-point source pollution. Dramatic spatio-temporal variations of water quality parameters were jointly caused by different pollutant sources and hydrometeorological factors. In terms of this study, an improved comprehensive water quality identification index (ICWQII) based on entropy weight or variation coefficient and traditional CWQII underestimated the water qualities, and an ICWQII based on the superstandard multiple method overvalued the assessments. By contrast, water qualities assessments done with an ICWQII based on the game theory matched perfectly with the practical situation. The ICWQII based on game theory proposed in this study takes into account not only the degree of disorder and variation of water quality data, but also the influence of standard-exceeded pollution indicators, whose results are relatively reasonable. All findings and the ICWQII based on game theory can provide scientific support for decisions related to the water environment management of the Yongding New River and other waters.


Assuntos
Poluentes Químicos da Água , Qualidade da Água , China , Monitoramento Ambiental , Teoria dos Jogos , Nitrogênio/análise , Fósforo/análise , Rios , Poluentes Químicos da Água/análise , Poluição da Água/análise
16.
Zhongguo Zhong Yao Za Zhi ; 46(1): 72-79, 2021 Jan.
Artigo em Zh | MEDLINE | ID: mdl-33645054

RESUMO

In the process of harvesting, production and processing, storage, and transportation, the traditional Chinese medicine Platycladi Semen is prone to mildew due to its own and environmental factors, which can nourish the production of toxic or pathogenic fungi, and even produce mycotoxins, which affects the safety of clinical medication. The 2020 edition of Chinese Pharmacopoeia limits the highest standard of aflatoxin content in Platycladi Semen. However, there are few studies on the fungal contamination of Platycladi Semen, and it is difficult to prevent and control it in a targeted manner. Therefore, based on the Illumina NovaSeq6000 platform, this article uses ITS sequence amplicon technology to analyze the distribution and diversity of fungi in 27 batches of commercially available Platycladi Semen in the Chinese market. A total of 10 phyla, 35 classes, 93 orders, 193 families, 336 genera, and 372 species of fungi were identified in China. Among them, Aspergillus, Alternaria spp. were dominant, 20 batches of samples were detected for A. flavus, 10 batches of samples were detected for A. nidulans, and all samples were detected for potential pathogenic fungi such as A. fumigatus and A. niger. According to diversity analysis, the diversity of the fungal communities in the samples from Gansu province was high, the samples in Shandong province contain the largest number of fungal species, and the samples in Guangxi province had the lo-west diversity and the least number of species. In most samples, pathogenic fungi such as A. fumigatus, A. niger, A. flavus, A. parasiticus were detected in varying degrees. This study systematically investigated the fungal contamination of Platycladi Semen from the markets in the last link of the its industrial chain, and clarified the distribution of Platycladi Semen fungi, especially toxin-producing fungi, and provided theoretical basis for the targeted prevention and control of fungal contamination in Platycladi Semen.


Assuntos
Aflatoxinas , Micobioma , Micotoxinas , China , Fungos/genética , Humanos , Micotoxinas/análise , Sêmen/química
17.
J Biol Chem ; 293(38): 14880-14890, 2018 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-30076220

RESUMO

αB-Crystallin (αBc) is a small heat shock protein that protects cells against abnormal protein aggregation and disease-related degeneration. αBc is also a major structural protein that forms polydisperse multimers that maintain the liquid-like property of the eye lens. However, the relationship and regulation of the two functions have yet to be explored. Here, by combining NMR spectroscopy and multiple biophysical approaches, we found that αBc uses a conserved ß4/ß8 surface of the central α-crystallin domain to bind α-synuclein and Tau proteins and prevent them from aggregating into pathological amyloids. We noted that this amyloid-binding surface can also bind the C-terminal IPI motif of αBc, which mediates αBc multimerization and weakens its chaperone activity. We further show that disruption of the IPI binding impairs αBc self-multimerization but enhances its chaperone activity. Our work discloses the structural mechanism underlying the regulation of αBc chaperone activity and self-multimerization and sheds light on the different functions of αBc in antagonizing neurodegeneration and maintaining eye lens liquidity.


Assuntos
Amiloide/metabolismo , Chaperonas Moleculares/metabolismo , Multimerização Proteica , Cadeia B de alfa-Cristalina/metabolismo , Ligação Competitiva , Fenômenos Biofísicos , Humanos , Chaperonas Moleculares/química , Ressonância Magnética Nuclear Biomolecular , Cadeia B de alfa-Cristalina/química , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismo
18.
Int J Mol Sci ; 20(1)2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30587819

RESUMO

The intrinsically disordered protein, Tau, is abundant in neurons and contributes to the regulation of the microtubule (MT) and actin network, while its intracellular abnormal aggregation is closely associated with Alzheimer's disease. Here, using in-cell Nuclear Magnetic Resonance (NMR) spectroscopy, we investigated the conformations of two different isoforms of Tau, Tau40 and k19, in mammalian cells. Combined with immunofluorescence imaging and western blot analyses, we found that the isotope-enriched Tau, which was delivered into the cultured mammalian cells by electroporation, is partially colocalized with MT and actin filaments (F-actin). We acquired the NMR spectrum of Tau in human embryonic kidney 293 (HEK-293T) cells, and compared it with the NMR spectra of Tau added with MT, F-actin, and a variety of crowding agents, respectively. We found that the NMR spectrum of Tau in complex with MT best recapitulates the in-cell NMR spectrum of Tau, suggesting that Tau predominantly binds to MT at its MT-binding repeats in HEK-293T cells. Moreover, we found that disease-associated phosphorylation of Tau was immediately eliminated once phosphorylated Tau was delivered into HEK-293T cells, implying a potential cellular protection mechanism under stressful conditions. Collectively, the results of our study reveal that Tau utilizes its MT-binding repeats to bind MT in mammalian cells and highlight the potential of using in-cell NMR to study protein structures at the residue level in mammalian cells.


Assuntos
Proteínas Serina-Treonina Quinases/metabolismo , Proteínas tau/química , Actinas/química , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Células HEK293 , Humanos , Microtúbulos/química , Ressonância Magnética Nuclear Biomolecular , Fosforilação , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas tau/genética , Proteínas tau/metabolismo
19.
Am J Emerg Med ; 35(4): 640-646, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27832977

RESUMO

BACKGROUND: We aimed to derive and validate a parsimonious and pragmatic clinical prediction rule using the concepts of Predisposition, Infection, Response, and Organ Dysfunction to predict in-hospital mortality; and to compare it with other prediction rules, as well as with conventional biomarkers for evaluating the mortality risk of patients with suspected sepsis in the emergency department (ED). METHODS: We conducted a pragmatic cohort study with consecutive ED patients aged 18 or older with documented diagnostic codes of infection and two sets of blood culture ordered by physicians between 2010 and 2012 in a tertiary teaching hospital. RESULTS: 7011 and 12,110 patients were included in the derivation cohort and the validation cohort for the final analysis. There were 479 deaths (7%) in the derivation cohort and 1145 deaths (9%) in the validation cohort. Independent predictors of death were absence of Chills (odds ratio: 2.28, 95% confidence interval: 1.75-2.97), Hypothermia (2.12, 1.57-2.85), Anemia (2.45, 1.97-3.04), wide Red cell Distribution Width (RDW) (3.27, 2.63-4.05) and history of Malignancy (2.00, 1.63-2.46). This novel clinical prediction rule (CHARM) performed well for stratifying patients into mortality risk groups (sensitivity: 99.4%, negative predictive value 99.7%, receiver operating characteristic area 0.77). The CHARM score also outperformed the other scores or biomarkers such as PIRO, SIRS, MEDS, CURB-65, C-reactive protein, procalcitonin and lactate (all p<.05). CONCLUSIONS: In patients with suspected sepsis, this parsimonious and pragmatic model could be utilized to stratify the mortality risk of patients in the early stage of sepsis.


Assuntos
Mortalidade Hospitalar , Sepse/mortalidade , Idoso , Idoso de 80 Anos ou mais , Anemia/epidemiologia , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Calcitonina/sangue , Calafrios/epidemiologia , Estudos de Coortes , Comorbidade , Técnicas de Apoio para a Decisão , Serviço Hospitalar de Emergência , Índices de Eritrócitos , Feminino , Humanos , Hipotermia/epidemiologia , Ácido Láctico/sangue , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Razão de Chances , Prognóstico , Curva ROC , Estudos Retrospectivos , Sepse/sangue , Sepse/epidemiologia , Centros de Atenção Terciária
20.
Front Immunol ; 15: 1343316, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38361933

RESUMO

Lung cancer (LC) produces some of the most malignant tumors in the world, with high morbidity and mortality. Tumor immune microenvironment (TIME), a component of the tumor microenvironment (TME), are critical in tumor development, immune escape, and drug resistance. The TIME is composed of various immune cells, immune cytokines, etc, which are important biological characteristics and determinants of tumor progression and outcomes. In this paper, we reviewed the recently published literature and discussed the potential uses of natural products in regulating TIME. We observed that a total of 37 natural compounds have been reported to exert anti-cancer effects by targeting the TIME. In different classes of natural products, terpenoids are the most frequently mentioned compounds. TAMs are one of the most investigated immune cells about therapies with natural products in TIME, with 9 natural products acting through it. 17 natural products exhibit anti-cancer properties in LC by modulating PD-1 and PD-L1 protein activity. These natural products have been extensively evaluated in animal and cellular LC models, but their clinical trials in LC patients are lacking. Based on the current review, we have revealed that the mechanisms of LC can be treated with natural products through TIME intervention, resulting in a new perspective and potential therapeutic drugs.


Assuntos
Neoplasias Pulmonares , Animais , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Microambiente Tumoral , Citocinas
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