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1.
Polymers (Basel) ; 16(10)2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38794526

RESUMO

In this paper, the solid-state shear milling (S3M) strategy featuring a very strong three-dimensional shear stress field was adopted to prepare the high-performance polyoxymethylene (POM)/molybdenum disulfide (MoS2) functional nanocomposite. The transmission electron microscope and Raman measurement results confirmed that the bulk MoS2 particle was successfully exfoliated into few-layer MoS2 nanoplatelets by the above simple S3M physical method. The polarized optical microscope (PLM) observation indicated the pan-milled nanoscale MoS2 particles presented a better dispersion performance in the POM matrix. The results of the tribological test indicated that the incorporation of MoS2 could substantially improve the wear resistance performance of POM. Moreover, the pan-milled exfoliated MoS2 nanosheets could further substantially decrease the friction coefficient of POM. Scanning electron microscope observations on the worn scar revealed the tribological mechanism of the POM/MoS2 nanocomposite prepared by solid-state shear milling. The tensile test results showed that the pan-milled POM/MoS2 nanocomposite has much higher elongation at break than the conventionally melt-compounded material. The solid-state shear milling strategy shows a promising prospect in the preparation of functional nanocomposite with excellent comprehensive performance at a large scale.

2.
Nanoscale ; 16(1): 373-383, 2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38063775

RESUMO

With the expansion of global energy problems and the deepening of research on oxygen reduction reaction (ORR) in alkaline media, the development of low cost and high electrocatalytic performance catalysts has become a research hotspot. In this study, a hexagonal Pd-C-MnOOH composite catalyst was prepared by using the triblock copolymer P123 as the reducing agent and protective agent, sucrose as the carbon source and self-made MnOOH as the carrier under hydrothermal conditions. When the Pd load is 20% and the C/MnOOH ratio is 1 : 1, the 20% Pd-C-MnOOH-1 : 1 catalyst obtained by the one-step method has the highest ORR activity and stability in the alkaline system. At 1600 rpm, the limiting diffusion current density and half-wave potential of the 20% Pd-C-MnOOH-1 : 1 electrocatalyst are -4.78 mA cm-2 and 0.84 V, respectively, which are better than those of the commercial 20%Pd/C catalyst. According to the Koutecky-Levich (K-L) equation and the linear fitting results, the electron transfer number of the 20%Pd-C-MnOOH-1 : 1 electrocatalyst for the oxygen reduction reaction is 3.8, which is similar to that of a 4-electron process. After 1000 cycles, the limiting diffusion current density of the 20%Pd-C-MnOOH-1 : 1 catalyst is -4.61 mA cm-2, which only decreases by 3.7%, indicating that the 20%Pd-C-MnOOH-1 : 1 catalyst has good stability. The reason for the improvement of the ORR performance of the Pd-C-MnOOH composite catalyst is the improvement of the conductivity of the carbon layer formed by original carbonization, the regular hexagonal highly active Pd particles and the synergistic catalytic effect between Pd and MnOOH. The method of introducing triblock copolymers in the synthesis of oxides and metal-oxide composite catalysts is expected to be extended to other electrocatalysis fields.

3.
Analyst ; 148(20): 5002-5011, 2023 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-37728433

RESUMO

Human angiotensin-converting enzyme 2 (hACE2) is the primary receptor for cellular entry of SARS-CoV-2 into human host cells. hACE2 is heavily glycosylated and glycans on the receptor may play a role in viral binding. Thus, comprehensive characterization of hACE2 glycosylation could aid our understanding of interactions between the receptor and SARS-CoV-2 spike (S) protein, as well as provide a basis for the development of therapeutic drugs targeting this crucial interaction. Herein, 138 N-glycan compositions were identified, most of which are complex-type N-glycans, from seven N-glycosites of hACE2. Among them, 67% contain at least one sialic acid residue. At the level of glycopeptides, the overall quantification of sialylated glycan isomers observed on the sites N322 and N546 have a higher degree of NeuAc (α2-3)Gal (over 80.3%) than that of other N-glycosites (35.6-71.0%). In terms of O-glycans, 69 glycan compositions from 12 O-glycosites were identified, and especially, the C-terminus of hACE2 is heavily O-glycosylated. The terminal sialic acid linkage type of H1N1S1 and H1N1S2 are covered highly with α2,3-sialic acid. These findings could aid the investigation of the interaction between SARS-CoV-2 and human host cells.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Enzima de Conversão de Angiotensina 2/metabolismo , Glicosilação , Ácido N-Acetilneuramínico , Polissacarídeos/química , Ligação Proteica , SARS-CoV-2/metabolismo
4.
Nat Commun ; 13(1): 7539, 2022 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-36477196

RESUMO

Large-scale intact glycopeptide identification has been advanced by software tools. However, tools for quantitative analysis remain lagging behind, which hinders exploring the differential site-specific glycosylation. Here, we report pGlycoQuant, a generic tool for both primary and tandem mass spectrometry-based intact glycopeptide quantitation. pGlycoQuant advances in glycopeptide matching through applying a deep learning model that reduces missing values by 19-89% compared with Byologic, MSFragger-Glyco, Skyline, and Proteome Discoverer, as well as a Match In Run algorithm for more glycopeptide coverage, greatly expanding the quantitative function of several widely used search engines, including pGlyco 2.0, pGlyco3, Byonic and MSFragger-Glyco. Further application of pGlycoQuant to the N-glycoproteomic study in three different metastatic HCC cell lines quantifies 6435 intact N-glycopeptides and, together with in vitro molecular biology experiments, illustrates site 979-core fucosylation of L1CAM as a potential regulator of HCC metastasis. We expected further applications of the freely available pGlycoQuant in glycoproteomic studies.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Biologia Molecular
5.
Cells ; 11(21)2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36359916

RESUMO

The metabolism disorders are a common convergence of Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM). The characteristics of AD are senile plaques and neurofibrillary tangles (NFTs) composed by deposits of amyloid-ß (Aß) and phosphorylated tau, respectively. Advanced glycation end-products (AGEs) are a stable modification of proteins by non-enzymatic reactions, which could result in the protein dysfunction. AGEs are associated with some disease developments, such as diabetes mellitus and AD, but the effects of the glycated γ2 subunit of AMPK on its activity and the roles in AD onset are unknown. METHODS: We studied the effect of glycated γ2 subunit of AMPK on its activity in N2a cells. In 3 × Tg mice, we administrated L-arginine once every two days for 45 days and evaluated the glycation level of γ2 subunit and function of AMPK and alternation of pathologies. RESULTS: The glycation level of γ2 subunit was significantly elevated in 3 × Tg mice as compared with control mice, meanwhile, the level of pT172-AMPK was obviously lower in 3 × Tg mice than that in control mice. Moreover, we found that arginine protects the γ2 subunit of AMPK from glycation, preserves AMPK function, and improves pathologies and cognitive deficits in 3 × Tg mice. CONCLUSIONS: Arginine treatment decreases glycated γ2 subunit of AMPK and increases p-AMPK levels in 3 × Tg mice, suggesting that reduced glycation of the γ2 subunit could ameliorate AMPK function and become a new target for AD therapy in the future.


Assuntos
Doença de Alzheimer , Diabetes Mellitus Tipo 2 , Animais , Camundongos , Doença de Alzheimer/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Arginina , Placa Amiloide/metabolismo
6.
Nat Commun ; 13(1): 4291, 2022 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-35879296

RESUMO

Whether amino acids act on cellular insulin signaling remains unclear, given that increased circulating amino acid levels are associated with the onset of type 2 diabetes (T2D). Here, we report that phenylalanine modifies insulin receptor beta (IRß) and inactivates insulin signaling and glucose uptake. Mice fed phenylalanine-rich chow or phenylalanine-producing aspartame or overexpressing human phenylalanyl-tRNA synthetase (hFARS) develop insulin resistance and T2D symptoms. Mechanistically, FARS phenylalanylate lysine 1057/1079 of IRß (F-K1057/1079), inactivating IRß and preventing insulin from promoting glucose uptake by cells. SIRT1 reverse F-K1057/1079 and counteract the insulin-inactivating effects of hFARS and phenylalanine. F-K1057/1079 and SIRT1 levels in white blood cells from T2D patients are positively and negatively correlated with T2D onset, respectively. Blocking F-K1057/1079 with phenylalaninol sensitizes insulin signaling and relieves T2D symptoms in hFARS-transgenic and db/db mice. These findings shed light on the activation of insulin signaling and T2D progression through inhibition of phenylalanylation.


Assuntos
Diabetes Mellitus Tipo 2 , Resistência à Insulina , Animais , Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Humanos , Insulina , Resistência à Insulina/fisiologia , Camundongos , Fenilalanina , Sirtuína 1/genética
7.
Front Pharmacol ; 13: 877806, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35529440

RESUMO

Alzheimer's disease (AD) is the most common cause of neurodegenerative dementia and one of the top medical concerns worldwide. Currently, the approved drugs to treat AD are effective only in treating the symptoms, but do not cure or prevent AD. Although the exact causes of AD are not understood, it is recognized that tau aggregation in neurons plays a key role. Chuanxiong Rhizoma (CR) has been widely reported as effective for brain diseases such as dementia. Thus, we explored the protections of CR in AD by a tau pathogenesis-based network pharmacology approach. According to ultra-HPLC with triple quadrupole mass spectrometry data and Lipinski's rule of five, 18 bioactive phytochemicals of CR were screened out. They were shown corresponding to 127 tau pathogenesis-related targets, among which VEGFA, IL1B, CTNNB1, JUN, ESR1, STAT3, APP, BCL2L1, PTGS2, and PPARG were identified as the core ones. We further analyzed the specific actions of CR-active phytochemicals on tau pathogenesis from the aspects of tau aggregation and tau-mediated toxicities. It was shown that neocnidilide, ferulic acid, coniferyl ferulate, levistilide A, Z-ligustilide, butylidenephthalide, and caffeic acid can be effective in reversing tau hyperphosphorylation. Neocnidilide, senkyunolide A, butylphthalide, butylidenephthalide, Z-ligustilide, and L-tryptophan may be effective in promoting lysosome-associated degradation of tau, and levistilide A, neocnidilide, ferulic acid, L-tryptophan, senkyunolide A, Z-ligustilide, and butylidenephthalide may antagonize tau-mediated impairments of intracellular transport, axon and synaptic damages, and neuron death (especially apoptosis). The present study suggests that acting on tau aggregation and tau-mediated toxicities is part of the therapeutic mechanism of CR against AD.

8.
Front Mol Biosci ; 9: 899192, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35573732

RESUMO

Glycosylation inhibition has great potential in cancer treatment. However, the corresponding cellular response, protein expression and glycosylation changes remain unclear. As a cell-permeable small-molecule inhibitor with reduced cellular toxicity, N-linked glycosylation inhibitor-1 (NGI-1) has become a great approach to regulate glycosylation in mammalian cells. Here for the first time, we applied a nascent proteomic method to investigate the effect of NGI-1 in hepatocellular carcinoma (HCC) cell line. Besides, hydrophilic interaction liquid chromatography (HILIC) was adopted for the enrichment of glycosylated peptides. Glycoproteomic analysis revealed the abundance of glycopeptides from LAMP2, NICA, and CEIP2 was significantly changed during NGI-1 treatment. Moreover, the alterations of LAMP2 site-specific intact N-glycopeptides were comprehensively assessed. NGI-1 treatment also led to the inhibition of Cathepsin D maturation and the induction of autophagy. In summary, we provided evidence that NGI-1 repressed the expression of glycosylated LAMP2 accompanied with the occurrence of lysosomal defects and autophagy.

9.
Molecules ; 27(5)2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35268705

RESUMO

Trichosanthin (TCS) is a traditional Chinese herbal medicine used to treat some gynecological diseases. Its effective component has diverse biological functions, including antineoplastic activity. The human trophoblast cell line BeWo was chosen as an experimental model for in vitro testing of a drug screen for anticancer properties of TCS. The MTT method was used in this study to get a primary screen result. The result showed that 100 mM had the best IC50 value. Proteomics analysis was then performed for further investigation of the drug effect of TCS on the BeWo cell line. In this differential proteomic expression analysis, the total proteins extracted from the BeWo cell line and their protein expression level after the drug treatment were compared by 2DE. Then, 24 unique three-fold differentially expressed proteins (DEPs) were successfully identified by MALDI-TOF/TOF MS. Label-free proteomics was run as a complemental method for the same experimental procedure. There are two proteins that were identified in both the 2DE and label-free methods. Among those identified proteins, bioinformatics analysis showed the importance of pathway and signal transduction and gives us the potential possibility for the disease treatment hypothesis.


Assuntos
Antineoplásicos , Tricosantina , Antineoplásicos/farmacologia , Linhagem Celular , Humanos , Proteínas , Proteômica/métodos , Tricosantina/farmacologia
10.
EMBO Mol Med ; 14(2): e14713, 2022 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-34978375

RESUMO

The prevalence of intracranial aneurysm (IA) is increasing, and the consequences of its rupture are severe. This study aimed to reveal specific, sensitive, and non-invasive biomarkers for diagnosis and classification of ruptured and unruptured IA, to benefit the development of novel treatment strategies and therapeutics altering the course of the disease. We first assembled an extensive candidate biomarker bank of IA, comprising up to 717 proteins, based on altered proteins discovered in the current tissue and serum proteomic analysis, as well as from previous studies. Mass spectrometry assays for hundreds of biomarkers were efficiently designed using our proposed deep learning-based method, termed DeepPRM. A total of 113 potential markers were further quantitated in serum cohort I (n = 212) & II (n = 32). Combined with a machine-learning-based pipeline, we built two sets of biomarker combinations (P6 & P8) to accurately distinguish IA from healthy controls (accuracy: 87.50%) or classify IA rupture patients (accuracy: 91.67%) upon evaluation in the external validation set (n = 32). This extensive circulating biomarker development study provides valuable knowledge about IA biomarkers.


Assuntos
Aneurisma Roto , Aneurisma Intracraniano , Aneurisma Roto/diagnóstico , Aneurisma Roto/metabolismo , Biomarcadores , Humanos , Aneurisma Intracraniano/diagnóstico , Aneurisma Intracraniano/metabolismo , Proteômica , Medição de Risco
11.
Phenomics ; 2(4): 230-241, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36939752

RESUMO

Asparagine-linked glycosylation protein 1 homolog (ALG1) participates in the initial stage of protein N-glycosylation and N-glycosylation has been implicated in the process of hepatocellular carcinoma (HCC) progression. However, whether ALG1 plays a role in human HCC remains unknown. In this study, the expression profile of ALG1 in tumorous and corresponding adjacent non-tumor tissues was analyzed. The relationship of ALG1 expression with clinical features and prognosis of HCC patients was also evaluated using immuno-histochemical method. Here we found ALG1 decreased in HCC tissues compared with adjacent normal liver tissues, which predicted an unfavorable prognosis. Combined with RNA interference, nascent proteome and glycoproteome were determined systematically in Huh7 cell line. Bioinformatics analysis indicated that the differentially expressed proteins participating in the response of ALG1 knockdown were most significantly associated with cell-cell adhesion. Functional studies confirmed that knockdown of ALG1 reduced cell adhesion capacity, and promoted cell migration. Furthermore, down-regulation of H8N2 (on N-glycosite N651) and H5N4S2F1 (on N-glycosite N692) from N-cadherin was identified as a feature of ALG1 knockdown. Our findings revealed that ALG1 controlled the expression of glycosylated N-cadherin and played a role in HCC migration, with implications for prognosis. Supplementary Information: The online version contains supplementary material available at 10.1007/s43657-022-00050-5.

12.
Aging (Albany NY) ; 13(20): 23620-23636, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34644262

RESUMO

Amyloid-ß (Aß) accumulating is considered as a causative factor for formation of senile plaque in Alzheimer's disease (AD), but its mechanism is still elusive. The Nicotinamide mononucleotide adenylyltransferase 2 (Nmnat2), a key redox cofactor for energy metabolism, is reduced in AD. Accumulative evidence has shown that the decrease of α-secretase activity, a disintegrin and metalloprotease domain 10 (ADAM10), is responsible for the increase of Aß productions in AD patient's brain. Here, we observe that the activity of α-secretase ADAM10 and levels of Nmnat2 are significantly decreased, meanwhile there is a simultaneous elevation of Aß in Tg2576 mice. Over-expression of Nmnat2 increases the mRNA expression of α-secretase ADAM10 and its activity and inhibits Aß production in N2a/APPswe cells, which can be abolished by Compound C, an AMPK antagonist, suggesting that AMPK is involved in over-expression of Nmnat2 against Aß production. The further assays demonstrate that Nmnat2 activates AMPK by up-regulating the ratio of NAD+/NADH, moreover AMPK agonist AICAR can also increase ADAM10 activity and reduces Aß1-40/1-42. Taken together, Nmnat2 suppresses Aß production and up-regulates ADAM10 in AMPK activity-dependent manner, suggesting that Nmnat2 may serve as a new potential target in arresting AD.


Assuntos
Proteína ADAM10 , Proteínas Quinases Ativadas por AMP , Secretases da Proteína Precursora do Amiloide , Amiloide , Proteínas de Membrana , Nicotinamida-Nucleotídeo Adenililtransferase , Proteína ADAM10/genética , Proteína ADAM10/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Amiloide/genética , Amiloide/metabolismo , Secretases da Proteína Precursora do Amiloide/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Linhagem Celular , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Nicotinamida-Nucleotídeo Adenililtransferase/genética , Nicotinamida-Nucleotídeo Adenililtransferase/metabolismo , Regulação para Cima/genética
13.
Front Chem ; 9: 698297, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249867

RESUMO

In recent years, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) plays an essential role in the analysis of polymers. To acquire a more reliable strategy for polymer profiling, we characterized four representative polymers including polyethylene glycol 6000, polyvinylpyrrolidone K12, polymer polyol KPOP-5040, and polyether polyol DL-4000. The preparation methods of these four polymer samples have been optimized from six aspects, including matrix, cationization reagent, solvent, mixing ratio of cationization reagent to polymer, mixing ratio of matrix to polymer, and laser intensity. After investigating the effects of seven commonly used matrices on the ionization efficiency of four polymers, trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene] malononitrile (DCTB) was found to be the only matrix suitable for the analysis of all the four polymers. Our experimental results suggested that different polymers showed a certain preference for different cationization reagents. For example, the polymer polyol KPOP-5040 was suitable for sodium iodide as the cationization reagent, while polyvinylpyrrolidone K12 was more suitable for silver trifluoroacetate (AgTFA). For the choice of solvent, tetrahydrofuran is a reagent with rapid evaporation and a wide range of dissolution which can achieve the best results for the analysis of four polymers. The optimized method was successfully applied to the identification of DSPE-PEG-NH2 with different polymerized degrees. This MALDI-TOF strategy potentially provided the supplementary function through the polymer's application in biomedical and visible probing.

14.
Anal Chem ; 93(16): 6403-6413, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33856767

RESUMO

Nascent proteome is crucial in directly revealing how the expression of a gene is regulated on a translation level. In the nascent protein identification, puromycin capture is one of the pivotal methods, but it is still facing the challenge in the deep profiling of nascent proteomes due to the low abundance of most nascent proteins. Here, we describe the synthesis of puromycin-modified silica microspheres (PMSs) as the sorbent of dispersive solid-phase microextraction and the establishment of the PMS-based nascent proteomics (PMSNP) method for efficient capture and analysis of nascent proteins. The modification efficiency of puromycin groups on silica microspheres reached 91.8% through the click reaction. After the optimization and simplification of PMSNP, more than 3500 and 3900 nascent proteins were rapidly identified in HeLa cells and mouse brains within 13.5 h, respectively. The PMSNP method was successfully applied to explore changes in the translation process in a biological stress model, namely, the lipopolysaccharide-stimulated HeLa cells. Biological functional analyses revealed the unique characters of the nascent proteomes and exhibited the superiority of the PMSNP in the identification of low abundance and secreted nascent proteins, thus demonstrating the sensitivity and immediacy of the PMSNP method.


Assuntos
Microesferas , Proteoma , Proteômica , Puromicina , Células HeLa , Humanos , Proteoma/análise , Dióxido de Silício
15.
J Colloid Interface Sci ; 595: 107-117, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33819686

RESUMO

A perfect PtCu nanocube with partial hollow structure was prepared by hydrothermal reaction and its electrocatalytic methanol oxidation reaction (MOR) was studied. The appropriate concentration of shape-control additives KI and triblock pluronic copolymers, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO19-PPO69-PEO19) (P123) play crucial roles in the final product morphology. The PtCu nanocubes can be perfectly in situ immobilizedonto graphene under the action of P123 while the structure and cubic morphologyremain unchanged. The electrochemical tests suggest that the obtained PtCu nanocube (PtCu-NCb) exhibits better MOR activity and stability than PtCu hexagon nanosheet (PtCu-NSt), PtCu nanoellipsoid (PtCu-NEs) and commercial Pt/C in alkaline medium. When in situ immobilized onto graphene, the MOR catalytic activity and stability of PtCu cubes are further improved. The markedly enhanced electrocatalytic activity and durability maybe attributed to the special cubic morphology with partial hollow structure enclosed by highly efficient facet and the probably the synergistic effect of PtCu and intermediate state CuI decorated on the surface and graphene.

16.
Front Pharmacol ; 12: 758049, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34992531

RESUMO

Presently, the treatment options for ischemic stroke (IS) are limited due to the complicated pathological process of the disease. Chuanxiong Rhizome (CR), also known as Conioselinum anthriscoides "Chuanxiong" (rhizome), is the most widely used traditional Chinese medicine for treating stroke. This study aimed to uncover the key phytochemicals and biological functions of CR against IS through a network pharmacology approach combining with IS pathophysiology analysis. We employed permanent unilateral common carotid artery ligation to construct a mouse model of global cerebral ischemia and found that cerebral ischemia injuries were improved after 7 days of gavage treatment of CR (1,300 mg/kg/day). CR exerts protective effects on neurons mainly by acting on targets related to synaptic structure, synaptic function, neuronal survival and neuronal growth. A total of 18 phytochemicals from CR based on UHPLC-MS/MS that corresponded to 85 anti-IS targets. Coniferyl ferulate, neocnidilide and ferulic acid were identified as the key phytochemicals of CR against IS. Its brain protective effects involve anti-inflammatory, anti-oxidative stress, and anti-cell death activities and improves blood circulation. Additionally, the two most important synergistic effects of CR phytochemicals in treating IS are prevention of infection and regulation of blood pressure. In brain samples of Sham mice, L-tryptophan and vanillin were detected, while L-tryptophan, gallic acid, vanillin and cryptochlorogenic acid were detected in IS mice by UHPLC-MS/MS. Our findings provide a pathophysiology relevant pharmacological basis for further researches on IS therapeutic drugs.

17.
Anal Chim Acta ; 1140: 60-68, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-33218490

RESUMO

A powerful and fast glycopeptide/glycan enrichment method is critical for the efficiency and throughput of mass spectrometry (MS)-based glycoproteomic and glycomic analyses, especially for large-scale sample analysis. Here, we report an ultrafast and effective method for both intact N-glycopeptide and N-glycan enrichment and apply it to human serum samples. In this method, a natural hydrophilic material, bacterial cellulose (BC), was adopted and fully optimized for enrichment. This method offers the following advantages: (i) The enrichment material has natural hydrophilicity and is low-cost, biocompatible, biodegradable and easily accessible; (ii) the whole enrichment procedure is remarkably simple and fast. It takes only 10 min for intact glycopeptides/glycans to be easily purified from mixtures; (iii) the specificity of this method is over 94% for both glycan and glycopeptide enrichment; and (iv) the outstanding specificity of this technique enables high isolation efficiency for the enrichment of both intact glycopeptides and glycans. A total of 36 N-glycans and 31 N-glycopeptides were identified from human immunoglobulin G (IgG). The glycan and glycopeptide absorption capacity of BC was as high as 333 µg/mg and 250 µg/mg (IgG/BC) respectively. The selectivity for glycan and glycopeptide enrichment reached 1:100 (IgG/bovine serum albumin (BSA), molar ratio) and 1:200 (maltoheptaose (DP7)/BSA, molar ratio), respectively. Furthermore, a total of 159 N-glycans and 523 N-glycopeptides were identified in human serum by using this method. Overall, the BC-based enrichment method we present here provides an ultrafast and highly efficient method for the enrichment of both N-glycopeptides and N-glycans in complex samples and shows great potential in large-scale glycoproteomic and glycomic analyses.


Assuntos
Celulose , Glicopeptídeos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Espectrometria de Massas , Polissacarídeos
18.
Mol Neurobiol ; 57(12): 5011-5025, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32820462

RESUMO

Alzheimer's disease (AD) is the most common neurodegenerative disease, but its underlying mechanism is still unclear and the identities of drugs for AD also lack. Tau acetylation has become potentially important post-translational modification of tau. Levels of tau acetylation are significantly enhanced in AD patients and transgenic mouse models of AD, but the underlying mechanism and roles of tau hyperacetylation in AD onset maintain elusive. In the current study, we found that tau acetylation is obviously enhanced and the activities of AMP-activated protein kinase (AMPK) and sirtuin1 (Sirt1) are significantly decreased in APP/PS1 and streptozotocin (STZ) mice and high glucose (HG)-treated cells. Moreover, we demonstrated that activation of AMPK reduces the level of tau acetylation and ameliorates memory impairment, and its mechanism is associated with activation of Sirt1. Taken together, AMPK might be a crucial upstream molecular to regulate acetylation of tau and become a new target for AD therapy in the future.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Transtornos da Memória/metabolismo , Sirtuína 1/metabolismo , Proteínas tau/metabolismo , Acetilação , Peptídeos beta-Amiloides/metabolismo , Animais , Regulação para Baixo , Células HEK293 , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fosforilação , Fosfotreonina/metabolismo , Presenilina-1/metabolismo , Estreptozocina , Regulação para Cima
19.
J Cell Mol Med ; 24(16): 9176-9188, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32648620

RESUMO

The therapeutic hypothermia is an effective tool for TBI-associated brain impairment, but its side effects limit in clinical routine use. Hypothermia up-regulates RNA-binding motif protein 3 (RBM3), which is verified to protect synaptic plasticity. Here, we found that cognitive and LTP deficits, loss of spines, AD-like tau pathologies are displayed one month after TBI in mice. In contrast, the deficits of LTP and cognitive, loss of spines and tau abnormal phosphorylation at several sites are obviously reversed in TBI mice combined with hypothermia pre-treatment (HT). But, the neuroprotective role of HT disappears in TBI mouse models under condition of blocking RBM3 expression with RBM3 shRNA. In other hand, overexpressing RBM3 by AAV-RBM3 plasmid can mimic HT-like neuroprotection against TBI-induced chronic brain injuries, such as improving LTP and cognitive, loss of spines and tau hyperphosphorylation in TBI mouse models. Taken together, hypothermia pre-treatment reverses TBI-induced chronic AD-like pathology and behaviour deficits in RBM3 expression dependent manner, RBM3 may be a potential target for neurodegeneration diseases including Alzheimer disease.


Assuntos
Doença de Alzheimer/terapia , Comportamento Animal , Lesões Encefálicas Traumáticas/complicações , Hipotermia Induzida/métodos , Fármacos Neuroprotetores , Proteínas de Ligação a RNA/metabolismo , Tauopatias/terapia , Doença de Alzheimer/etiologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Ligação a RNA/genética , Tauopatias/etiologia , Tauopatias/metabolismo , Tauopatias/patologia
20.
Br J Cancer ; 123(6): 1012-1023, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32601462

RESUMO

BACKGROUND: The molecular signature underlying pancreatic ductal adenocarcinoma (PDAC) progression may include key proteins affecting the malignant phenotypes. Here, we aimed to identify the proteins implicated in PDAC with different tumour-node-metastasis (TNM) stages. METHODS: Eight-plex isobaric tags coupled with two-dimensional liquid chromatography-tandem mass spectrometry were used to analyse the proteome of PDAC tissues with different TNM stages. A loss-of-function study was performed to evaluate the oncogenic roles of WD repeat-containing protein 1 (WDR1) in PDAC. The molecular mechanism by which WDR1 promotes PDAC progression was studied by real-time qPCR, Western blotting, proximity ligation assay and co-immunoprecipitation. RESULTS: A total of 5036 proteins were identified, and 4708 proteins were quantified with high confidence. Compared with normal pancreatic tissues, 37 proteins were changed significantly in PDAC tissues of different stages. Moreover, 64 proteins were upregulated or downregulated in a stepwise manner as the TNM stages of PDAC increased, and 10 proteins were related to tumorigenesis. The functionally uncharacterised protein, WDR1, was highly expressed in PDAC and predicted a poor prognosis. WDR1 knockdown suppressed PDAC tumour growth and metastasis in vitro and in vivo. Moreover, WDR1 knockdown repressed the activity of the Wnt/ß-Catenin pathway; ectopic expression of a stabilised form of ß-Catenin restored the suppressive effects of WDR1 knockdown. Mechanistically, WDR1 interacted with USP7 to prevent ubiquitination-mediated degradation of ß-Catenin. CONCLUSION: Our study identifies several previous functional unknown proteins implicated in the progression of PDAC, and provides new insight into the oncogenic roles of WDR1 in PDAC development.


Assuntos
Carcinoma Ductal Pancreático/patologia , Proteínas dos Microfilamentos/fisiologia , Neoplasias Pancreáticas/patologia , beta Catenina/fisiologia , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Proteínas dos Microfilamentos/análise , Proteínas dos Microfilamentos/antagonistas & inibidores , Peptidase 7 Específica de Ubiquitina/fisiologia , Ubiquitinação , Via de Sinalização Wnt/fisiologia
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