Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
iScience ; 27(4): 109515, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38591010

RESUMO

Transient anoxia causes amnesia and neuronal death. This is attributed to enhanced glutamate release and modeled as anoxia-induced long-term potentiation (aLTP). aLTP is mediated by glutamate receptors and nitric oxide (·NO) and occludes stimulation-induced LTP. We identified a signaling cascade downstream of ·NO leading to glutamate release and a glutamate-·NO loop regeneratively boosting aLTP. aLTP in entothelial ·NO synthase (eNOS)-knockout mice and blocking neuronal NOS (nNOS) activity suggested that both nNOS and eNOS contribute to aLTP. Immunostaining result showed that eNOS is predominantly expressed in vascular endothelia. Transient anoxia induced a long-lasting Ca2+ elevation in astrocytes that mirrored aLTP. Blocking astrocyte metabolism or depletion of the NMDA receptor ligand D-serine abolished eNOS-dependent aLTP, suggesting that astrocytic Ca2+ elevation stimulates D-serine release from endfeet to endothelia, thereby releasing ·NO synthesized by eNOS. Thus, the neuro-glial-endothelial axis is involved in long-term enhancement of glutamate release after transient anoxia.

2.
Eur J Gastroenterol Hepatol ; 35(10): 1143-1148, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37577787

RESUMO

OBJECTIVES: Small bowel (SB) endoscopic healing has not been well explored in patients with Crohn's disease (CD). This study aimed to assess the clinical utility of SB endoscopic mucosal and histological healing in patients with CD. METHODS: In total, 99 patients with CD in clinical-serological remission were retrospectively followed after they underwent colonoscopy and double-balloon enteroscopy. Time until clinical relapse (CD activity index of >150 with an increase of >70 points) and serological relapse (abnormal elevation of C-reactive protein levels) constituted the primary endpoints. RESULTS: Of the 99 patients, 75 (74.7%) exhibited colonoscopic healing and 43 (43.4%) exhibited SB endoscopic healing. Clinical relapse, serological relapse, hospitalization, and surgery occurred in 8 (18.6%), 11 (25.6%), 11 (25.6%), and 2 (4.6%) patients, respectively. Of the 43 patients who exhibited SB endoscopic healing, 21 (48.8%) achieved histological healing. Clinical relapse, serological relapse, hospitalization, and surgery occurred in 4 (19.0%), 7 (33.3%), 7 (33.3%), and 1 (4.8%) patient, respectively. There was no statistically significant difference in the number of patients who relapsed, were hospitalized, or underwent surgery between those who exhibited histological healing and those who did not. CONCLUSION: A substantial number of patients who were in clinical-serological remission did not undergo SB endoscopic healing, and the lesions increased their risk of clinical relapse. Thus, endoscopic healing may be of greater clinical value than histological healing when evaluating the remission of patients with CD.


Assuntos
Doença de Crohn , Humanos , Doença de Crohn/patologia , Estudos Retrospectivos , Intestino Delgado/patologia , Colonoscopia , Indução de Remissão , Recidiva , Índice de Gravidade de Doença
3.
Elife ; 112022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35471147

RESUMO

Elevation of soluble wild-type (WT) tau occurs in synaptic compartments in Alzheimer's disease. We addressed whether tau elevation affects synaptic transmission at the calyx of Held in slices from mice brainstem. Whole-cell loading of WT human tau (h-tau) in presynaptic terminals at 10-20 µM caused microtubule (MT) assembly and activity-dependent rundown of excitatory neurotransmission. Capacitance measurements revealed that the primary target of WT h-tau is vesicle endocytosis. Blocking MT assembly using nocodazole prevented tau-induced impairments of endocytosis and neurotransmission. Immunofluorescence imaging analyses revealed that MT assembly by WT h-tau loading was associated with an increased MT-bound fraction of the endocytic protein dynamin. A synthetic dodecapeptide corresponding to dynamin 1-pleckstrin-homology domain inhibited MT-dynamin interaction and rescued tau-induced impairments of endocytosis and neurotransmission. We conclude that elevation of presynaptic WT tau induces de novo assembly of MTs, thereby sequestering free dynamins. As a result, endocytosis and subsequent vesicle replenishment are impaired, causing activity-dependent rundown of neurotransmission.


Assuntos
Doença de Alzheimer , Vesículas Sinápticas , Doença de Alzheimer/metabolismo , Animais , Dinamina I/genética , Dinamina I/metabolismo , Dinaminas/metabolismo , Endocitose , Camundongos , Microtúbulos/metabolismo , Sinapses/metabolismo , Transmissão Sináptica , Vesículas Sinápticas/metabolismo
4.
ACS Synth Biol ; 11(4): 1658-1668, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35324156

RESUMO

Two fundamentally different approaches are routinely used for protein engineering: user-defined mutagenesis and random mutagenesis, each with its own strengths and weaknesses. Here, we invent a unique mutagenesis protocol, which combines the advantages of user-defined mutagenesis and random mutagenesis. The new method, termed the reverse Kunkel method, allows the user to create random mutations at multiple specified regions in a one-pot reaction. We demonstrated the reverse Kunkel method by mimicking the somatic hypermutation in antibodies that introduces random mutations concentrated in complementarity-determining regions. Coupling with the phage display and yeast display selections, we successfully generated dramatically improved antibodies against a model protein and a neurotransmitter peptide in terms of affinity and immunostaining performance. The reverse Kunkel method is especially suitable for engineering proteins whose activities are determined by multiple variable regions, such as antibodies and adeno-associated virus capsids, or whose functional domains are composed of several discontinuous sequences, such as Cas9 and Cas12a.


Assuntos
Técnicas de Visualização da Superfície Celular , Engenharia de Proteínas , Anticorpos/genética , Mutagênese , Biblioteca de Peptídeos , Engenharia de Proteínas/métodos
5.
J Orthop Surg Res ; 17(1): 79, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-35123546

RESUMO

BACKGROUND: Medial opening wedge high tibial osteotomy (MOWHTO) changes the knee joint inclination in the coronal plane, which can be compensated by the ankle joint. Once there is a decompensated knee joint obliquity, it can induce excessive shear force on the articular cartilage. This study aimed to investigate the capacity of the compensation by analyzing the correlation of the knee-ankle joint line angle (KAJA) and the knee joint line obliquity (KJLO). PATIENTS AND METHODS: Ninety-six patients undergoing MOWHTO were included. We measured potential predictors including preoperative or postoperative body mass index (BMI), weight-bearing line (WBL) ratio/correction amount, knee-ankle joint line angle(KAJA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibia angle (MPTA), ankle joint line obliquity (AJLO), mechanical hip-knee-ankle angle (mHKA) and joint line convergence angle (JLCA). The correlations of these predictors and postoperative KJLO were determined using Pearson correlation coefficient. The contribution of significant predictors was further analyzed using multiple linear regression. Finally, the cutoff value of the most contributing factor resulting in decompensated KJLO was derived with receiver operating characteristic (ROC) curve analysis. RESULTS: Preoperative AJLO, JLCA, MPTA, mHKA and KJLO and postoperative KAJA and MPTA correlated with postoperative KJLO. After multiple linear regression, only preoperative AJLO and JLCA and postoperative KAJA still showed significant contribution to postoperative KJLO. Postoperative KAJA made the greatest contribution. The cutoff value of postoperative KAJA was at 9.6° after ROC analysis. The incidence rate of high-grade KJLO was 69.6% when postoperative KAJA exceeded 9.6°. CONCLUSIONS: Postoperative KAJA is a significant contributor to high-grade KJLO after MOWHTO. The incidence was increased at angles greater than 9.6°. The results suggest that KAJA should be carefully assessed during preoperative planning or intraoperative evaluation. Postoperative KAJA < 9.6° can lower the rate of early high-degree KJLO.


Assuntos
Articulação do Tornozelo , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Osteoartrite do Joelho/cirurgia , Osteotomia/métodos , Tíbia/cirurgia , Tornozelo , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/cirurgia , Humanos , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/etiologia , Estudos Retrospectivos , Tíbia/diagnóstico por imagem
6.
ACS Synth Biol ; 10(8): 2087-2095, 2021 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-34342970

RESUMO

Due to its highly immunogenic nature and the great engineerability, filamentous phage has shown promising antitumor activities in preclinical studies. Previous designs of antitumor phage mainly focused on tumor targeting using a cancer-specific moiety displayed on the minor capsid protein, pIII. In this work, we developed a new therapeutic platform of filamentous phage, in which the major capsid protein pVIII was utilized for displaying an antitumor cytokine. We showcased that a 16.1-kD cytokine GM-CSF could be efficiently presented on the M13 phage particle using the 8 + 8 type display system through a highly tolerable pVIII variant P8(1a). We verified that the GM-CSF phage was a potent activator for STAT5 signaling in murine macrophage. The GM-CSF phage significantly reduced the tumor size by more than 50% as compared to the unmodified phage in a murine colorectal cancer model. Immunological profiling of the tumor-infiltrating leukocytes revealed that an increase of CD4+ lymphocytes in the GM-CSF phage treatment group. Furthermore, the combined therapy of the GM-CSF phage and radiation greatly improved the therapeutic potency with a 100% survival rate and a 25% complete remission rate. We observed that the IFN-γ expression was dramatically up-regulated by the combined therapy in multiple types of tumor-infiltrating immune cells. Overall, we created a novel vehicle for cytokine therapy using the pVIII filamentous phage display. This new platform can be multiplexed with other phage engineering approaches, such as displaying targeting ligands on pIII or encapsulating therapeutic genes inside phage capsids, to create multifunctional nanoparticles for cancer therapy.


Assuntos
Bacteriófago M13 , Técnicas de Visualização da Superfície Celular , Neoplasias Colorretais , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Neoplasias Experimentais , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Neoplasias Experimentais/imunologia , Neoplasias Experimentais/patologia , Neoplasias Experimentais/terapia
7.
Proc Natl Acad Sci U S A ; 117(52): 33586-33596, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33376223

RESUMO

Current proteomic studies clarified canonical synaptic proteins that are common to many types of synapses. However, proteins of diversified functions in a subset of synapses are largely hidden because of their low abundance or structural similarities to abundant proteins. To overcome this limitation, we have developed an "ultra-definition" (UD) subcellular proteomic workflow. Using purified synaptic vesicle (SV) fraction from rat brain, we identified 1,466 proteins, three times more than reported previously. This refined proteome includes all canonical SV proteins, as well as numerous proteins of low abundance, many of which were hitherto undetected. Comparison of UD quantifications between SV and synaptosomal fractions has enabled us to distinguish SV-resident proteins from potential SV-visitor proteins. We found 134 SV residents, of which 86 are present in an average copy number per SV of less than one, including vesicular transporters of nonubiquitous neurotransmitters in the brain. We provide a fully annotated resource of all categorized SV-resident and potential SV-visitor proteins, which can be utilized to drive novel functional studies, as we characterized here Aak1 as a regulator of synaptic transmission. Moreover, proteins in the SV fraction are associated with more than 200 distinct brain diseases. Remarkably, a majority of these proteins was found in the low-abundance proteome range, highlighting its pathological significance. Our deep SV proteome will provide a fundamental resource for a variety of future investigations on the function of synapses in health and disease.


Assuntos
Encéfalo/metabolismo , Mamíferos/metabolismo , Proteoma/metabolismo , Vesículas Sinápticas/metabolismo , Sequência de Aminoácidos , Animais , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/metabolismo , Peptídeos/metabolismo , Proteoma/química , Proteômica , Ratos Sprague-Dawley , Transmissão Sináptica , Vesículas Sinápticas/ultraestrutura , Sinaptossomos/metabolismo
8.
J Neurosci ; 40(21): 4103-4115, 2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32327530

RESUMO

Volatile anesthetics are widely used for surgery, but neuronal mechanisms of anesthesia remain unidentified. At the calyx of Held in brainstem slices from rats of either sex, isoflurane at clinical doses attenuated EPSCs by decreasing the release probability and the number of readily releasable vesicles. In presynaptic recordings of Ca2+ currents and exocytic capacitance changes, isoflurane attenuated exocytosis by inhibiting Ca2+ currents evoked by a short presynaptic depolarization, whereas it inhibited exocytosis evoked by a prolonged depolarization via directly blocking exocytic machinery downstream of Ca2+ influx. Since the length of presynaptic depolarization can simulate the frequency of synaptic inputs, isoflurane anesthesia is likely mediated by distinct dual mechanisms, depending on input frequencies. In simultaneous presynaptic and postsynaptic action potential recordings, isoflurane impaired the fidelity of repetitive spike transmission, more strongly at higher frequencies. Furthermore, in the cerebrum of adult mice, isoflurane inhibited monosynaptic corticocortical spike transmission, preferentially at a higher frequency. We conclude that dual presynaptic mechanisms operate for the anesthetic action of isoflurane, of which direct inhibition of exocytic machinery plays a low-pass filtering role in spike transmission at central excitatory synapses.SIGNIFICANCE STATEMENT Synaptic mechanisms of general anesthesia remain unidentified. In rat brainstem slices, isoflurane inhibits excitatory transmitter release by blocking presynaptic Ca2+ channels and exocytic machinery, with the latter mechanism predominating in its inhibitory effect on high-frequency transmission. Both in slice and in vivo, isoflurane preferentially inhibits spike transmission induced by high-frequency presynaptic inputs. This low-pass filtering action of isoflurane likely plays a significant role in general anesthesia.


Assuntos
Anestésicos Inalatórios/administração & dosagem , Tronco Encefálico/efeitos dos fármacos , Isoflurano/administração & dosagem , Neurônios/efeitos dos fármacos , Terminações Pré-Sinápticas/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Animais , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Exocitose/efeitos dos fármacos , Feminino , Masculino , Camundongos , Técnicas de Patch-Clamp , Ratos , Ratos Wistar
9.
J Neurosci ; 40(1): 131-142, 2020 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-31767677

RESUMO

Cytoskeletal filaments such as microtubules (MTs) and filamentous actin (F-actin) dynamically support cell structure and functions. In central presynaptic terminals, F-actin is expressed along the release edge and reportedly plays diverse functional roles, but whether axonal MTs extend deep into terminals and play any physiological role remains controversial. At the calyx of Held in rats of either sex, confocal and high-resolution microscopy revealed that MTs enter deep into presynaptic terminal swellings and partially colocalize with a subset of synaptic vesicles (SVs). Electrophysiological analysis demonstrated that depolymerization of MTs specifically prolonged the slow-recovery time component of EPSCs from short-term depression induced by a train of high-frequency stimulation, whereas depolymerization of F-actin specifically prolonged the fast-recovery component. In simultaneous presynaptic and postsynaptic action potential recordings, depolymerization of MTs or F-actin significantly impaired the fidelity of high-frequency neurotransmission. We conclude that MTs and F-actin differentially contribute to slow and fast SV replenishment, thereby maintaining high-frequency neurotransmission.SIGNIFICANCE STATEMENT The presence and functional role of MTs in the presynaptic terminal are controversial. Here, we demonstrate that MTs are present near SVs in calyceal presynaptic terminals and that MT depolymerization specifically prolongs the slow-recovery component of EPSCs from short-term depression. In contrast, F-actin depolymerization specifically prolongs fast-recovery component. Depolymerization of MT or F-actin has no direct effect on SV exocytosis/endocytosis or basal transmission, but significantly impairs the fidelity of high-frequency transmission, suggesting that presynaptic cytoskeletal filaments play essential roles in SV replenishment for the maintenance of high-frequency neurotransmission.


Assuntos
Citoesqueleto de Actina/fisiologia , Exocitose/fisiologia , Microtúbulos/fisiologia , Transmissão Sináptica/fisiologia , Vesículas Sinápticas/fisiologia , Actinas/fisiologia , Animais , Vias Auditivas/fisiologia , Tronco Encefálico/citologia , Tronco Encefálico/fisiologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Potenciais Pós-Sinápticos Excitadores/fisiologia , Feminino , Masculino , Terminações Pré-Sinápticas/fisiologia , Ratos , Ratos Wistar , Transmissão Sináptica/efeitos dos fármacos , Tiazolidinas/farmacologia , Corpo Trapezoide/fisiologia , Vimblastina/farmacologia
10.
J Zhejiang Univ Sci B ; 20(9): 776-780, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31379147

RESUMO

Laryngeal squamous cell carcinoma (LSCC) is the most common type of head and neck squamous cell carcinoma (HNSCC) worldwide. Protein phosphatase 2A (PP2A) dysfunction has been widely reported in a broad range of malignancies due to its distinctive role in miscellaneous cellular processes. However, it is poorly understood whether aberrant alterations of PP2A are involved in the network of oncogenic events in LSCC. Here, we detected a panel of PP2A-associated proteins using western blot in both laryngeal squamous cell carcinoma tissues and paired adjacent normal tissues from patients (Data S1). We found that phospho-PP2A/C (Y307), α4, cancerous inhibitor of protein phosphatase 2A (CIP2A), Akt, ezrin, phospho-ezrin (T567), 14-3-3, and focal adhesion kinase (FAK) showed increased expression levels in carcinoma tissues relative to normal tissues, while phospho-Akt (T308) showed decreased levels. Our study, thus, provides a rationale for targeting PP2A to develop novel therapies and proposes a combination of interrelated biomarkers for the diagnostic evaluation and prognosis prediction in LSCC.


Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Laríngeas/metabolismo , Laringe/metabolismo , Proteína Fosfatase 2/metabolismo , Autoantígenos/metabolismo , Carcinoma de Células Escamosas/genética , Estudos de Casos e Controles , Proteínas do Citoesqueleto/metabolismo , Quinase 1 de Adesão Focal/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Neoplasias Laríngeas/genética , Proteínas de Membrana/metabolismo , Fosforilação , Proteína Fosfatase 2/genética
11.
Protein Sci ; 28(9): 1703-1712, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31306516

RESUMO

APEX2, an engineered ascorbate peroxidase for high activity, is a powerful tool for proximity labeling applications. Owing to its lack of disulfides and the calcium-independent activity, APEX2 can be applied intracellularly for targeted electron microscopy imaging or interactome mapping when fusing to a protein of interest. However, APEX2 fusion is often deleterious to the protein expression, which seriously hampers its wide utility. This problem is especially compelling when APEX2 is fused to structurally delicate proteins, such as multi-pass membrane proteins. In this study, we found that a cysteine-free single mutant C32S of APEX2 dramatically improved the expression of fusion proteins in mammalian cells without compromising the enzyme activity. We fused APEX2 and APEX2C32S to four multi-transmembrane solute carriers (SLCs), SLC1A5, SLC6A5, SLC6A14, and SLC7A1, and compared their expressions in stable HEK293T cell lines. Except the SLC6A5 fusions expressing at decent levels for both APEX2 (70%) and APEX2C32S (73%), other three SLC proteins showed significantly better expression when fusing to APEX2C32S (69 ± 13%) than APEX2 (29 ± 15%). Immunofluorescence and western blot experiments showed correct plasma membrane localization and strong proximity labeling efficiency in all four SLC-APEX2C32S cells. Enzyme kinetic experiments revealed that APEX2 and APEX2C32S have comparable activities in terms of oxidizing guaiacol. Overall, we believe APEX2C32S is a superior fusion tag to APEX2 for proximity labeling applications, especially when mismatched disulfide bonding or poor expression is a concern.


Assuntos
DNA Liase (Sítios Apurínicos ou Apirimidínicos)/genética , Endonucleases/genética , Enzimas Multifuncionais/genética , Mutação , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Carreadoras de Solutos/genética , Membrana Celular/metabolismo , Cisteína/genética , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/metabolismo , Endonucleases/metabolismo , Expressão Gênica , Células HEK293 , Humanos , Enzimas Multifuncionais/metabolismo , Engenharia de Proteínas , Proteínas Carreadoras de Solutos/metabolismo
12.
J Zhejiang Univ Sci B ; 20(5): 391-398, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31090265

RESUMO

Sirtuin 1 (SIRT1) is a protein deacetylase, which regulates various physiological activities by deacetylating different protein substrates. An increasing number of studies have revealed critical roles of SIRT1 in different aspects of cancers including metabolism, proliferation, genomic instability, and chemotherapy resistance. Depending on the protein targets in a certain oncogenic context, SIRT1 may play a unique role in each individual blood cancer subtype. Our previous work showed that activation of SIRT1 in primitive leukemia cells of acute myeloid leukemia (AML) and chronic myelogenous leukemia (CML) promotes disease maintenance. On the other hand, an SIRT1 agonist was shown to disrupt maintenance of myelodysplastic syndrome (MDS) stem cells and holds promise as a potential therapeutic approach. Herein, we present a concise summary of the different functions of SIRT1 in hematologic malignancies.


Assuntos
Resistencia a Medicamentos Antineoplásicos , Neoplasias Hematológicas/metabolismo , Sirtuína 1/metabolismo , Proliferação de Células , Sobrevivência Celular , Perfilação da Expressão Gênica , Regulação Leucêmica da Expressão Gênica , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Leucemia Mieloide Aguda/metabolismo , Linfoma/metabolismo , Síndromes Mielodisplásicas/metabolismo , Fenótipo , Microambiente Tumoral
13.
J Clin Med ; 8(2)2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30764571

RESUMO

Uremic toxins accumulated in chronic kidney disease (CKD) increases the risk of cognitive impairment. Indoxyl sulfate (IS) is a well-known protein-bound uremic toxin that is correlated with several systemic diseases, but no studies on human brain cells are available. We investigated the effect of IS on primary human astrocytes through next-generation sequencing and cell experiment confirmation to explore the mechanism of IS-associated brain damage. Total RNAs extracted from IS-treated and control astrocytes were evaluated by performing functional and pathway enrichment analysis. The toxicities of IS in the astrocytes were investigated in terms of cell viability through flow cytometry; the signal pathway was then investigated through immunoblotting. IS stimulated the release of reactive oxygen species, increased nuclear factor (erythroid-derived 2)-like 2 levels, and reduced mitochondrial membrane potential. IS triggered astrocyte apoptosis by inhibiting the mitogen-activated protein kinase (MAPK) pathway, including extracellular-signal-regulated kinase (ERK), MAPK/ERK kinase, c-Jun N-terminal kinase, and p38. The decreased ERK phosphorylation was mediated by the upregulated dual-specificity phosphatase 1, 5, 8, and 16. In conclusion, IS can induce neurotoxicity in patients with CKD and the pathogenesis involves cell apoptosis through oxidative stress induction and MAPK pathway inhibition in human astrocytes.

14.
J Org Chem ; 83(21): 13103-13110, 2018 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-30260649

RESUMO

A novel rearrangement reaction based on the structure of N-fluoro- N-alkyl benzenesulfonamide was developed. The reaction proceeded readily at 50 °C in formic acid and generated a variety of benzenesulfonamides and aldehydes or ketones simultaneously. The reaction mechanism is believed to be a concerted mechanism that consist of 1,2-aryl migration with the departure of fluorine anion via an SN2 mechanism. This rearrangement reaction features an interesting reaction mechanism, mild reaction conditions, simple operations, and a broad substrate scope.

15.
Int J Mol Med ; 42(5): 2489-2502, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30226555

RESUMO

Atherosclerotic cardiovascular disease and acute myocardial infarction are the leading causes of mortality worldwide, and apoptosis is the major pathway of cardiomyocyte death under hypoxic conditions. Although studies have reported changes in the expression of certain pro­apoptotic and anti­apoptotic genes in hypoxic cardiomyocytes, genetic regulations are complex in human cardiomyocytes and there is much that remains to be fully elucidated. The present study aimed to identify differentially expressed genes in hypoxic human AC16 cardiomyocytes using next­generation sequencing and bioinformatics. A total of 24 genes (15 upregulated and 9 downregulated) with potential micro (mi)RNA­mRNA interactions were identified in the miRmap database. Utilising the Gene Expression Omnibus database of cardiac microvascular endothelial cells, tensin 1, B­cell lymphoma 2­interacting protein 3 like, and stanniocalcin 1 were found to be upregulated, and transferrin receptor and methyltransferase like 7A were found to be downregulated in response to hypoxia. Considering the results from miRmap, TargetScan and miRDB together, two potential miRNA­mRNA interactions were identified: hsa­miRNA (miR)­129­5p/CDC42EP3 and hsa­miR­330­3p/HELZ. These findings contribute important insights into possible novel diagnostic or therapeutic strategies for targeting cardiomyocytes under acute hypoxic stress in conditions, including acute myocardial infarction. The results of the present study also introduce an important novel approach in investigating acute hypoxic pathophysiology.


Assuntos
Regulação da Expressão Gênica , Hipóxia/genética , Miócitos Cardíacos/metabolismo , Hipóxia Celular , Biologia Computacional , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , MicroRNAs/genética , RNA Mensageiro/genética , Transcriptoma
16.
Cell Death Dis ; 8(11): e3167, 2017 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-29120412

RESUMO

MicroRNAs (miRNAs) have been suggested to repress transcription via binding the 3'-untranslated regions of mRNAs. However, the involvement and details of miRNA-mediated epigenetic regulation, particularly in targeting genomic DNA and mediating epigenetic regulation, remain largely uninvestigated. In the present study, transcription factor CCAAT/enhancer binding protein delta (CEBPD) was responsive to the anticancer drug bortezomib, a clinical and highly selective drug for leukemia treatment, and contributed to bortezomib-induced cell death. Interestingly, following the identification of CEBPD-induced miRNAs, we found that miR-744, miR-3154 and miR-3162 could target CpG islands in the 5'-flanking region of the CEBPD gene. We previously demonstrated that the Yin Yang 1 (YY1)/polycomb group (PcG) protein/DNA methyltransferase (DNMT) complex is important for CCAAT/enhancer binding protein delta (CEBPD) gene inactivation; we further found that Argonaute 2 (Ago2) interacts with YY1 and binds to the CEBPD promoter. The miRNA/Ago2/YY1/PcG group protein/DNMT complex linked the inactivation of CEBPD and genes adjacent to its 5'-flanking region, including protein kinase DNA-activated catalytic polypeptide (PRKDC), minichromosome maintenance-deficient 4 (MCM4) and ubiquitin-conjugating enzyme E2 variant 2 (UBE2V2), upon bortezomib treatment. Moreover, we revealed that miRNA binding is necessary for YY1/PcG group protein/DNMT complex-mediated epigenetic gene silencing and is associated with bortezomib-induced methylation on genomic DNA. The present study successfully characterized the interactions of the miRNA/Ago2/YY1/PcG group protein/DNMT complex and provided new insights for miRNA-mediated epigenetic regulation in bortezomib-induced leukemic cell arrest and cell death.


Assuntos
Apoptose/efeitos dos fármacos , Bortezomib/farmacologia , Leucemia/fisiopatologia , MicroRNAs/metabolismo , Regiões 3' não Traduzidas , Antineoplásicos/farmacologia , Proteínas Argonautas/química , Proteínas Argonautas/metabolismo , Proteína delta de Ligação ao Facilitador CCAAT/genética , Proteína delta de Ligação ao Facilitador CCAAT/metabolismo , Linhagem Celular Tumoral , Ilhas de CpG , Metilação de DNA/efeitos dos fármacos , Proteína Quinase Ativada por DNA/genética , Proteína Quinase Ativada por DNA/metabolismo , Inativação Gênica , Humanos , Leucemia/metabolismo , Ligases/genética , Ligases/metabolismo , MicroRNAs/genética , Componente 4 do Complexo de Manutenção de Minicromossomo/genética , Componente 4 do Complexo de Manutenção de Minicromossomo/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Transcrição Gênica/efeitos dos fármacos , Enzimas de Conjugação de Ubiquitina , Fator de Transcrição YY1/química , Fator de Transcrição YY1/metabolismo
17.
PLoS One ; 11(10): e0164164, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27701470

RESUMO

Dysfunction of RBFOX3 has been identified in neurodevelopmental disorders such as autism spectrum disorder, cognitive impairments and epilepsy and a causal relationship with these diseases has been previously demonstrated with Rbfox3 homozygous knockout mice. Despite the importance of RBFOX3 during neurodevelopment, the function of RBFOX3 regarding neurogenesis and synaptogenesis remains unclear. To address this critical question, we profiled the developmental expression pattern of Rbfox3 in the brain of wild-type mice and analyzed brain volume, disease-relevant behaviors, neurogenesis, synaptic plasticity, and synaptogenesis in Rbfox3 homozygous knockout mice and their corresponding wild-type counterparts. Here we report that expression of Rbfox3 differs developmentally for distinct brain regions. Moreover, Rbfox3 homozygous knockout mice exhibited cold hyperalgesia and impaired cognitive abilities. Focusing on hippocampal phenotypes, we found Rbfox3 homozygous knockout mice displayed deficits in neurogenesis, which was correlated with cognitive impairments. Furthermore, RBFOX3 regulates the exons of genes with synapse-related function. Synaptic plasticity and density, which are related to cognitive behaviors, were altered in the hippocampal dentate gyrus of Rbfox3 homozygous knockout mice; synaptic plasticity decreased and the density of synapses increased. Taken together, our results demonstrate the important role of RBFOX3 during neural development and maturation. In addition, abnormalities in synaptic structure and function occur in Rbfox3 homozygous knockout mice. Our findings may offer mechanistic explanations for human brain diseases associated with dysfunctional RBFOX3.


Assuntos
Hipocampo/crescimento & desenvolvimento , Proteínas do Tecido Nervoso/genética , Transtornos do Neurodesenvolvimento/genética , Neurogênese , Proteínas Nucleares/genética , Sinapses/metabolismo , Animais , Proteínas de Ligação a DNA , Modelos Animais de Doenças , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Inativação de Genes , Humanos , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Transtornos do Neurodesenvolvimento/patologia , Plasticidade Neuronal , Proteínas Nucleares/metabolismo , Sinapses/patologia
18.
J Leukoc Biol ; 99(1): 131-41, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26342105

RESUMO

Acute myeloid leukemia is the majority type presented in leukemia patients. Forcing malignant cells to undergo differentiation is 1 strategy for acute myeloid leukemia therapy. However, the failure of acute myeloid leukemia patients to achieve remission as a result of drug resistance remains a challenge. In this study, we found that the abundances of the proinflammatory cytokine IL-18 and its receptor (IL-18R) correlated with the occurrence of drug resistance in AML patients during standard treatment. Cyclooxygenase 2 (COX-2) has been suggested to have an antiapoptotic role in chemoresistant cancer cells. IL-18 treatment resulted in an increase in COX-2 expression through the post-transcriptional regulation of COX-2 mRNA in differentiated U937 cells and showed antiapoptotic activity in U937 and THP-1 cells. Two RNA-binding proteins, human antigen R and insulin-like growth factor mRNA-binding protein 3, mediated the stabilization of COX-2 mRNA. IL-18 induced the shuttling of human antigen R and insulin-like growth factor mRNA-binding protein 3 from the nucleus to the cytoplasm and facilitated their interaction; subsequently, this complex bound to the 3' untranslated region of COX-2 mRNA and affected its stability. We demonstrated further that JNK and/or ERK1/2 regulated human antigen R nucleocytoplasmic shuttling, mediating IL-18 stabilization of cyclooxygenase 2 mRNA.


Assuntos
Ciclo-Oxigenase 2/genética , Proteína Semelhante a ELAV 1/metabolismo , Interleucina-18/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Estabilidade de RNA , RNA Mensageiro/genética , Proteínas de Ligação a RNA/metabolismo , Linhagem Celular Tumoral , Humanos , Interleucina-18/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Ligação Proteica , Processamento Pós-Transcricional do RNA , Estabilidade de RNA/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ativação Transcricional
19.
Polymers (Basel) ; 8(11)2016 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-30974658

RESUMO

A series of novel p-type conjugated copolymers, PTTVBDT, PTTVBDT-TPD, and PTTVBDT-DPP, cooperating benzo[1,2-b:4,5-b']dithiophene (BDT) and terthiophene-vinylene (TTV) units with/without thieno[3,4-c]pyrrole-4,6-dione (TPD) or pyrrolo[3,4-c]pyrrole-1,4-dione (DPP) via Stille polymerization were synthesized and characterized. Copolymer PTTVBDT shows a low-lying HOMO energy level and ordered molecular-packing behavior. Furthermore, two terpolymers, PTTVBDT-TPD and PTTVBDT-DPP, display stronger absorption ability, alower-lying HOMO energy level, and preferred molecular orientation, due to the replacement TTV-monomer units with electron-deficient groups. Furthermore, bulk-heterojunction organic solar cells were fabricated using blends of the PTTVBDT-TPD, and PC61BM gave the best power conversion efficiency of 5.01% under the illumination of AM 1.5G, 100 mW·cm-2; the short circuit current (Jsc) was 11.65 mA·cm-2 which displayed a 43.8% improvement in comparison with the PTTVBDT/PC61BM device. These results demonstrate a valid strategy combining the two-dimensional molecular structure with random copolymerization strikes promising conjugated polymers to achieve highly efficient organic photovoltaics.

20.
Sci Rep ; 5: 17383, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26619789

RESUMO

RBFOX3 mutations are linked to epilepsy and cognitive impairments, but the underlying pathophysiology of these disorders is poorly understood. Here we report replication of human symptoms in a mouse model with disrupted Rbfox3. Rbfox3 knockout mice displayed increased seizure susceptibility and decreased anxiety-related behaviors. Focusing on hippocampal phenotypes, we found Rbfox3 knockout mice showed increased expression of plasticity genes Egr4 and Arc, and the synaptic transmission and plasticity were defective in the mutant perforant pathway. The mutant dentate granules cells exhibited an increased frequency, but normal amplitude, of excitatory synaptic events, and this change was associated with an increase in the neurotransmitter release probability and dendritic spine density. Together, our results demonstrate anatomical and functional abnormality in Rbfox3 knockout mice, and may provide mechanistic insights for RBFOX3-related human brain disorders.


Assuntos
Hipocampo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Transmissão Sináptica , Animais , Ansiedade/genética , Ansiedade/metabolismo , Ansiedade/patologia , Ansiedade/fisiopatologia , Transtornos Cognitivos/genética , Transtornos Cognitivos/metabolismo , Transtornos Cognitivos/patologia , Transtornos Cognitivos/fisiopatologia , Proteínas do Citoesqueleto/biossíntese , Proteínas do Citoesqueleto/genética , Proteínas de Ligação a DNA , Modelos Animais de Doenças , Fatores de Transcrição de Resposta de Crescimento Precoce/biossíntese , Fatores de Transcrição de Resposta de Crescimento Precoce/genética , Epilepsia/genética , Epilepsia/metabolismo , Epilepsia/fisiopatologia , Hipocampo/fisiopatologia , Humanos , Camundongos , Camundongos Knockout , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...