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1.
Proc Natl Acad Sci U S A ; 120(44): e2306465120, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37871214

RESUMO

Nucleic acid vaccines have shown promising results in the clinic against infectious diseases and cancers. To robustly improve the vaccine efficacy and safety, we developed an approach to increase the intracellular stability of nucleic acids by transiently inhibiting lysosomal function in targeted tissues using sucrose. To achieve efficient and localized delivery of sucrose in animals, we designed a biomimetic lipid nanoparticle (LNP) to target the delivery of sucrose into mouse muscle cells. Using this approach, viral antigen expression in mouse muscle after DNA vaccination was substantially increased and prolonged without inducing local or systemic inflammation or toxicity. The same change in antigen expression would be achieved if the vaccine dose could be increased by 3,000 folds, which is experimentally and clinically impractical due to material restrictions and severe toxicity that will be induced by such a high dose of nucleic acids. The increase in antigen expression augmented the infiltration and activation of antigen-presenting cells, significantly improved vaccine-elicited humoral and T cell responses, and fully protected mice against the viral challenge at a low dose of vaccine. Based on these observations, we conclude that transient inhibition of lysosome function in target tissue by sucrose LNPs is a safe and potent approach to substantially improve nucleic acid-based vaccines.


Assuntos
Nanopartículas , Ácidos Nucleicos , Vacinas de DNA , Vacinas , Animais , Camundongos , Vacinas Baseadas em Ácido Nucleico , Lisossomos , Sacarose
2.
J Nutr ; 154(7): 2006-2013, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38718924

RESUMO

BACKGROUND: In lactating women, iodine metabolism is regulated and maintained by the kidneys and mammary glands. Limited research exists on how iodine absorbed by lactating women is distributed between the kidneys and breasts. OBJECTIVES: This study aimed to accurately evaluate the total iodine intake (TII), urinary iodine excretion (UIE), and breast milk iodine excretion (BMIE) in lactating women and explore the relationship between TII and total iodine excretion (TIE). METHODS: A 7-d iodine metabolism study was conducted on 41 lactating women with a mean age of 30 y in Yuncheng and Gaoqing, China, from December 2021 to August 2023. TII and TIE were calculated by measuring the iodine content in food, water, 24-h urine, feces, and breast milk. The urinary iodine excretion rate (UIER), breast milk iodine excretion rate (BMIER), and partitioning of iodine excretion between urine and breast milk were determined. RESULTS: Iodine metabolism studies were performed for 285 d. The median TII and TIE values were 255 and 263 µg/d, respectively. With an increase in TII, UIER, and BMIER, the UIE and BMIE to TII ratio exhibited a downward trend. The median UIER, BMIER, and proportion of iodine excreted in urine and breast milk were 51.5%, 38.5%, 52%, and 37%, respectively. When the TII was <120 µg/d, the BMIER decreased with the increase of the TII (ß: -0.90; 95% confidence interval: -1.08, -0.72). CONCLUSIONS: When maternal iodine intake is low, the proportion in breast milk increases, ensuring sufficient iodine nutrition for infants. In addition, the UIE of lactating women with adequate iodine concentrations is higher than their BMIE. This study was registered at clinicaltrials.gov as NCT04492657.


Assuntos
Iodo , Lactação , Leite Humano , Adulto , Feminino , Humanos , China , Iodo/urina , Iodo/metabolismo , Lactação/metabolismo , Leite Humano/química , Leite Humano/metabolismo , Estudos de Coortes
3.
J Transl Med ; 21(1): 388, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37322475

RESUMO

BACKGROUND: Uveitis and posterior scleritis are sight-threatening diseases with undefined pathogenesis and accurate diagnosis remains challenging. METHODS: Two plasma-derived extracellular vesicle (EV) subpopulations, small and large EVs, obtained from patients with ankylosing spondylitis-related uveitis, Behcet's disease uveitis, Vogt-Koyanagi-Harada syndrome, and posterior scleritis were subjected to proteomics analysis alongside plasma using SWATH-MS. A comprehensive bioinformatics analysis was performed on the proteomic profiles of sEVs, lEVs, and plasma. Candidate biomarkers were validated in a new cohort using ELISA. Pearson correlation analysis was performed to analyze the relationship between clinical parameters and proteomic data. Connectivity map database was used to predict therapeutic agents. RESULTS: In total, 3,668 proteins were identified and over 3000 proteins were quantified from 278 samples. When comparing diseased group to healthy control, the proteomic profiles of the two EV subgroups were more correlated with disease than plasma. Comprehensive bioinformatics analysis highlighted potential pathogenic mechanisms for these diseases. Potential biomarker panels for four diseases were identified and validated. We found a negative correlation between plasma endothelin-converting enzyme 1 level and mean retinal thickness. Potential therapeutic drugs were proposed, and their targets were identified. CONCLUSIONS: This study provides a proteomic landscape of plasma and EVs involved in ankylosing spondylitis-related uveitis, Behcet's disease uveitis, Vogt-Koyanagi-Harada syndrome, and posterior scleritis, offers insights into disease pathogenesis, identifies valuable biomarker candidates, and proposes promising therapeutic agents.


Assuntos
Síndrome de Behçet , Vesículas Extracelulares , Esclerite , Espondilite Anquilosante , Uveíte , Síndrome Uveomeningoencefálica , Humanos , Síndrome de Behçet/diagnóstico , Síndrome de Behçet/complicações , Síndrome Uveomeningoencefálica/diagnóstico , Síndrome Uveomeningoencefálica/complicações , Esclerite/etiologia , Espondilite Anquilosante/complicações , Proteômica , Uveíte/complicações
4.
Clin Exp Rheumatol ; 41(4): 902-909, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36826789

RESUMO

OBJECTIVES: Takayasu's arteritis (TAK) is a progressive autoimmune vasculitis that mainly affects the aorta and its major branches. While recent studies have identified proinflammatory T cells, including Th1 and Th17 cells, as the dominant infiltrates in the arterial adventitia, mechanisms underpinning the maintenance of such vasculogenic T cells remain obscure. METHODS: 75 patients with TAK and 30 age-matched healthy controls were enrolled in this study. CD4 T cells from TAK patients were activated with anti-CD3/CD28 beads to mimic vasculogenic T cells. The survival of T cells was detected by quantifying Annexin-V+7-AAD+ fractions. Expression and activity of AMP-activated protein kinase (AMPK) were determined using phosflow cytometry and immunoblots. Specific inhibitors and shRNA were applied to block the function of AMPK and Notch1, while erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were used to reflect the disease activity of TAK patients. RESULTS: T cells from TAK patients undergo spontaneous differentiation into vasculogenic proinflammatory T cells with prolonged survival capacity. Mechanistic explorations uncover AMPK hyperactivity in such T cells from TAK patients, promoting mitochondrial metabolism and their survival. Such AMPK hyperactivity results from the robust Notch1 activity in TAK T cells. Accordingly, T cell-intrinsic phosphor-AMPK reflects the disease activity in clinical TAK patients. CONCLUSIONS: AMPK hyperactivity is essential for maintaining the vasculogenic proinflammatory T cells in TAK patients, serving as a promising therapeutic target for TAK management.


Assuntos
Arterite de Células Gigantes , Arterite de Takayasu , Humanos , Proteínas Quinases Ativadas por AMP/uso terapêutico , Proteína C-Reativa/metabolismo , Diferenciação Celular , Linfócitos T/imunologia
5.
BMC Ophthalmol ; 22(1): 174, 2022 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-35436862

RESUMO

BACKGROUND: To analyse demographic, clinical features, treatment and therapeutic outcomes of pediatric uveitis and scleritis patients. SUBJECTS: The clinical records of pediatric uveitis and scleritis cases between January 2012 and December 2020 at a tertiary uveitis service center in Tianjin Medical University Eye Hospital (TMUEH) were reviewed. RESULTS: In total, 209 patients (337 eyes) were included, 49.3% were male. The median onset age was 9.0 (IQR, 7.0-12.0) years. Chronic uveitis and scleritis accounted for 86.1%. Panuveitis (29.2%), anterior uveitis(29.2%), and intermediate uveitis (22.0%) were the most common presentations. The most common diagnoses were idiopathic (71.3%), JIA (8.1%), and infectious uveitis (4.8%). At baseline, 40.7% patients received oral corticosteroid therapy; during follow-up, corticosteroids (66.0%), disease-modifying antirheumatic drugs (61.2%), and biologic agents (35.4%) were the mainstay. Posterior synechia (26.1%) and cataracts (25.5%) were the most common complications. In acute cases, the median best corrected visual acuity (BCVA) was 0.99 (IQR, 0.5-1.0) at baseline and 0 (IQR, 0-0) at last follow-up; in chronic cases, the median BCVA improved from 1.09 (IQR, 0.5-2.0) to 0.27 (IQR, 0-0.5), with anterior chamber cell grade significantly declining. Ten eyes underwent cataract surgery during regular follow-up and achieved satisfactory long-term visual outcomes and decreased burden of immunosuppressants. The incidence of steroid-induced ocular hypertension was 41.0%, and children with frequent instillation of eyedrops were at high risk. CONCLUSIONS: Most cases were of chronic uveitis and scleritis requiring long-term systemic immunosuppressive therapies in pediatric uveitis and scleritis in China. Good management of complications is important for long-term prognosis.


Assuntos
Esclerite , Uveíte , Criança , Demografia , Feminino , Humanos , Masculino , Estudos Retrospectivos , Esclerite/diagnóstico , Esclerite/tratamento farmacológico , Esclerite/epidemiologia , Centros de Atenção Terciária , Uveíte/diagnóstico , Uveíte/tratamento farmacológico , Uveíte/epidemiologia , Acuidade Visual
6.
Acta Biochim Biophys Sin (Shanghai) ; 54(5): 725-735, 2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35920198

RESUMO

APOBEC3G (A3G) is a member of cytosine deaminase family with a variety of innate immune functions. It displays activities against retrovirus and retrotransposon by inhibition of virus infectivity factor (Vif)-deficient HIV-1 replication. The interaction between A3G N-terminal domain and Vif directs the cellular Cullin 5 E3-ubiquitin ligase complex to ubiquitinate A3G, and leads to A3G proteasomal degradation, which is a potential target for anti-HIV drug. Currently, there are very few reports about stable small molecules targeting the interaction between A3G and Vif. In this study, we screened two series of small molecules containing carbamyl sulfamide bond or disulfide bond as bridges of two different aromatic rings. Five asymmetrical disulfides were successfully identified against interaction between A3G and Vif with the IC 50 values close to or smaller than 1 µM, especially, not through covalently binding with A3G or Vif. They restore the A3G expression in the presence of Vif by inhibiting Vif-induced A3G ubiquitination and degradation. This study opens a way to the discovery of new anti-HIV drugs.


Assuntos
Infecções por HIV , Produtos do Gene vif do Vírus da Imunodeficiência Humana , Desaminase APOBEC-3G , Linhagem Celular , Citidina Desaminase/química , Citidina Desaminase/metabolismo , Dissulfetos , Infecções por HIV/tratamento farmacológico , Humanos , Produtos do Gene vif do Vírus da Imunodeficiência Humana/metabolismo
7.
J Neurochem ; 157(3): 574-585, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33289070

RESUMO

Nuclear factor (NF)-κB-mediated neuroinflammation is an important mechanism of intracerebral hemorrhage (ICH)-induced neurotoxicity. Silent information regulator 1 (SIRT1) plays a multi-protective effect in a variety of diseases by deacetylating and inhibiting NF-κB/p65. However, the role of SIRT1 in brain damage following ICH remains unclear. We hypothesized that SIRT1 can protect against ICH-induced brain damage by inhibiting neuroinflammation through deacetylating NF-κB/p65. The ICH model was induced in vivo (with collagenase) and in vitro (with hemoglobin). Resveratrol and Ex527 were administered to activate or inhibit SIRT1, respectively. Western blot, immunohistochemistry, and immunofluorescence assays were performed to detect the expression of SIRT1 and p65. Enzyme-linked immunosorbent assays (ELISAs) were used to explore tumor necrosis factor (TNF)-α and interleukin (IL)-1ß release. The neurological score, brain water content, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and brain hemoglobin content were determined to evaluate the neuroprotective effect of SIRT1. SIRT1 expression was decreased, whereas the level of acetylated p65 (Ac-p65) was elevated after ICH in vivo. Moreover, hemoglobin treatment decreased the expression of SIRT1 in vitro. Activation of SIRT1 by resveratrol had a neuroprotective effect, along with decreased levels of Ac-p65, IL-1ß, TNF-α, and apoptosis after ICH. The effect of resveratrol was abolished by the SIRT1 inhibitor Ex527. Our results are consistent with the hypothesis that SIRT1 exerts a neuroprotective effect after ICH by deacetylating p65 to inhibit the NF-κB-dependent inflammatory response.


Assuntos
Hemorragia Cerebral/tratamento farmacológico , Fármacos Neuroprotetores , Sirtuína 1/genética , Fator de Transcrição RelA/efeitos dos fármacos , Acetilação , Animais , Apoptose/efeitos dos fármacos , Hemorragia Cerebral/induzido quimicamente , Colagenases , Encefalite/tratamento farmacológico , Encefalite/patologia , Hemoglobinas , Injeções Intraventriculares , Interleucina-1beta/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/efeitos dos fármacos , Cultura Primária de Células , Resveratrol/uso terapêutico , Sirtuína 1/efeitos dos fármacos , Fator de Transcrição RelA/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
8.
J Appl Toxicol ; 41(8): 1286-1303, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33355407

RESUMO

The specific cytotoxic effects of nanoparticles on tumor cells may be used in future antitumor clinical applications. Gold nanoparticles (AuNPs) have been reported to produce potent cytotoxic effects; however, the precise mechanism is unclear. In this study, AuNPs were synthesized; the average size of the particles was 62.2 ± 6 nm with smooth surface and multiple shapes, which were determined using transmission electron microscopy and field emission scanning electron microscopy. The selected area electron diffraction patterns suggested that the synthesized AuNPs were crystalline. The X-ray photoelectron spectroscopy (XPS) spectrum of the synthesized AuNPs has presented an intense peak at 100 eV, signifying the entire composition of Au in the developed AuNPs. This synthesized AuNPs showed the most potent efficacy in prostate cancer cells, regardless of whether or not they were androgen dependent. Secretome determinations using two-dimensional difference in-gel electrophoresis (2D-DIGE), followed by enzyme-linked immunosorbent assay and quantitative reverse transcriptase-polymerase chain reaction validations, have identified a series of secretory proteins that were dysregulated by AuNP treatment in prostate cancer cells, many of which are highly involved in cytokine-chemokine functions, including CXCL3, interleukin-10, CCL2, and matrix metalloproteinase 9 (MMP9). Further research on molecular mechanism has indicated that AuNPs can trigger the secretion of anticancer factors and myeloid cell-polarizing factors from tumor cells through MMP9 inhibition. These results have clearly signified the cytotoxic potential of AuNPs for treating prostate cancer and may provide a novel direction for prostate cancer therapy in the future.


Assuntos
Nanopartículas Metálicas/uso terapêutico , Neoplasias da Próstata/tratamento farmacológico , Secretoma/efeitos dos fármacos , Linhagem Celular Tumoral , Citotoxinas/uso terapêutico , Eletroforese em Gel Bidimensional , Ouro , Humanos , Masculino , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Espectroscopia Fotoeletrônica , Espectrofotometria Atômica
9.
BJU Int ; 125(6): 801-809, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-30958622

RESUMO

OBJECTIVES: To explore characteristics of urinary stone composition in China, and determine the effects of gender, age, body mass index (BMI), stone location, and geographical region on stone composition. PATIENTS AND METHODS: We prospectively used Fourier-transform infrared spectroscopy to analyse stones from consecutive patients presenting with new-onset urolithiasis at 46 hospitals in seven geographical areas of China, between 1 June 2010 and 31 May 2015. Chi-squared tests and logistic regression analyses were used to determine associations between stone composition and gender, age, BMI, stone location, and geographical region. RESULTS: The most common stone constituents were: calcium oxalate (CaOx; 65.9%), carbapatite (15.6%), urate (12.4%), struvite (2.7%), and brushite (1.7%). CaOx and urate stones occurred more frequently in males, whereas carbapatite and struvite were more common in females (P < 0.01). CaOx and carbapatite were more common in those aged 30-50 and 20-40 years than in other groups. Brushite and struvite were most common amongst those aged <20 and >70 years. The detection rate of urate increased with age, whilst cystine decreased with age. Obese patients were more likely to have urate stones than carbapatite or brushite stones (P < 0.01). CaOx, carbapatite, brushite, and cystine stones were more frequently found in the kidney than other types, whereas urate and struvite were more frequent in the bladder (P < 0.01). Stone composition varied by geographical region. CONCLUSIONS: The most common stone composition was CaOx, followed by carbapatite, urate, struvite, and brushite. Stone composition differed significantly in patients grouped by gender, age, BMI, stone location, and geographical region.


Assuntos
Cálculos Urinários/química , Cálculos Urinários/epidemiologia , Adolescente , Adulto , Idoso , Apatitas , Índice de Massa Corporal , Oxalato de Cálcio , Criança , Pré-Escolar , China/epidemiologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Espectroscopia de Infravermelho com Transformada de Fourier , Adulto Jovem
10.
World J Urol ; 38(9): 2295-2300, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31720763

RESUMO

PURPOSE: To provide a comprehensive analysis about safety and efficacy of fluoroscopy-free total ultrasound-guided percutaneous nephrolithotomy (TUPN) versus ultrasound with fluoroscopy-guided percutaneous nephrolithotomy (UFPN). PATIENTS AND METHODS: 3-dimensional ultrasound-guided PCNL was retrospectively analyzed in 377 patients from 2015 to 2017. TUPN was performed in 185 patients and UFPN was finished in 192 patients. In TUPN group, the entire procedures of puncture and dilation were real-time monitored by three-dimensional ultrasound alone. Conversely, in UFPN group, the puncture was performed under the guidance of real-time ultrasound, while the dilation was monitored by fluoroscopy. Preoperative demographic data, intraoperative parameters and postoperative complications were compared. RESULTS: Groups were comparable in baseline characteristics. Fifty percent of patients were Guy's score III-IV and over half of the patients were mild or none of hydronephrosis. All renal punctures were successfully performed. The primary successful rates of dilation were more than 95% in both groups (95.1% in TUPN and 95.8% in UFPN, p = 0.74). Two or more accesses were established in 33 patients (17.8%) in TUPN group and 25 patients (13%) in UFPN group (p = 0.20). Post-operative instant stone-free rates were 88.6% and 90.1%, TUPN versus UFPN, respectively, p = 0.65. Most of the complications were minor and there were no differences in Clavien-Dindo complications in both groups. Mean operating time and hospitalization were comparable. CONCLUSIONS: Our findings show that fluoroscopy-free total ultrasound-guided PCNL represents an alternatively safe and efficient approach for the treatment of renal stones. Further study will be required to evaluate fluoroscopy-free TUPN in various clinical settings.


Assuntos
Imageamento Tridimensional , Cálculos Renais/cirurgia , Nefrolitotomia Percutânea/métodos , Cirurgia Assistida por Computador , Ultrassonografia de Intervenção , Adulto , Idoso , Feminino , Fluoroscopia/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
11.
J Biol Chem ; 293(23): 8947-8955, 2018 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-29666187

RESUMO

Tumor angiogenesis is mainly regulated by vascular endothelial growth factor (VEGF) produced by cancer cells. It is active on the endothelium via VEGF receptor 2 (VEGFR-2). G-quadruplexes are DNA secondary structures formed by guanine-rich sequences, for example, within gene promoters where they may contribute to transcriptional activity. The proximal promoter of VEGFR-2 contains a G-quadruplex, which has been suggested to interact with small molecules that inhibit VEGFR-2 expression and thereby tumor angiogenesis. However, its structure is not known. Here, we determined its NMR solution structure, which is composed of three stacked G-tetrads containing three syn guanines. The first guanine (G1) is positioned within the central G-tetrad. We also observed that a noncanonical, V-shaped loop spans three G-tetrad planes, including no bridging nucleotides. A long and diagonal loop, which includes six nucleotides, connects reversal double chains. With a melting temperature of 54.51 °C, the scaffold of this quadruplex is stabilized by one G-tetrad plane stacking with one nonstandard bp, G3-C8, whose bases interact with each other through only one hydrogen bond. In summary, the NMR solution structure of the G-quadruplex in the proximal promoter region of the VEGFR-2 gene reported here has uncovered its key features as a potential anticancer drug target.


Assuntos
Inibidores da Angiogênese/farmacologia , Desenho de Fármacos , Quadruplex G , Neoplasias/irrigação sanguínea , Neovascularização Patológica/tratamento farmacológico , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Inibidores da Angiogênese/química , Sequência de Bases , Quadruplex G/efeitos dos fármacos , Humanos , Modelos Moleculares , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neovascularização Patológica/genética , Regiões Promotoras Genéticas/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia
12.
Biochem Biophys Res Commun ; 516(4): 1242-1247, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31301771

RESUMO

The human adenovirus oncoprotein E4orf6 hijacks intracellular Cullin 5-based E3 ubiquitin ligases (CRL5s) to induce the degradation of host proteins, including p53, that impede efficient viral replication. The complex also relies on another viral protein, E1B55K, to recruit substrates for ubiquitination. However, the determinants of adenoviral E4orf6-CRL5 E3 ligase-mediated p53 degradation in the scaffolding protein Cullin5 remain rarely investigated. Here, we demonstrated that the viral protein E4orf6 triggered relocalization of the Cullin5 protein from the cytoplasm to the nucleus and induced activation of the CRL5 E3 ligase via facilitating neddylation. The expression of the deneddylase SENP8/Den1 was significantly downregulated by E4orf6. We then identified SENP8 as a natural restriction factor for E4orf6-induced p53 degradation. Furthermore, our results indicated that the NEDD8-conjugating E2 enzyme UBE2M was essential for E4orf6-mediated p53 degradation and that its dominant negative mutant UBE2M C111S dramatically blocked E4orf6 functions. The Nedd8-activating enzyme inhibitor MLN4924 decreased E4orf6-induced neddylation of the cullin5 protein and subsequently suppressed p53 degradation. Collectively, our findings illuminate the strategy by which this viral oncoprotein specifically utilizes the neddylation pathway to activate host CRL E3 ligases to degrade host restriction factors. Disrupting this post-translational modification is an attractive pharmacological intervention against human adenoviruses.


Assuntos
Proteínas E4 de Adenovirus/metabolismo , Proteínas Culina/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Adenoviridae/metabolismo , Ciclopentanos/farmacologia , Regulação para Baixo , Endopeptidases/metabolismo , Regulação da Expressão Gênica , Células HEK293 , Humanos , Pirimidinas/farmacologia , Transdução de Sinais , Enzimas de Conjugação de Ubiquitina/metabolismo
13.
Angew Chem Int Ed Engl ; 57(41): 13475-13479, 2018 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-30151879

RESUMO

Aromatic-fused γ-pyrones are structural features of many bioactive natural products and valid scaffolds for medicinal chemistry. However, the enzymology of their formation has not been completely established. Now it is demonstrated that TxnO9, a CalC-like protein belonging to a START family, functions as an unexpected anthraquinone-γ-pyrone synthase involved in the biosynthesis of antitumor antibiotic trioxacarcin A (TXN-A). Structural analysis by NMR identified a likely substrate/product-binding mode and putative key active sites of TxnO9, which allowed an enzymatic mechanism to be proposed. Moreover, a subset of uncharacterized homologous proteins bearing an unexamined Lys-Thr dyad exhibit the same function. Therefore, the functional assignment and mechanistic investigation of this γ-pyrone synthase elucidated an undescribed step in TXN-A biosynthesis, and the discovery of this new branch of polyketide heterocyclases expands the functions of the START superfamily.


Assuntos
Aminoglicosídeos/biossíntese , Antraquinonas/química , Antibióticos Antineoplásicos/biossíntese , Ligases/metabolismo , Policetídeos/metabolismo , Pironas/química , Aminoglicosídeos/química , Antibióticos Antineoplásicos/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular
14.
J Biol Chem ; 290(7): 4010-21, 2015 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-25542899

RESUMO

APOBEC3G (A3G) is a DNA cytidine deaminase (CD) that demonstrates antiviral activity against human immunodeficiency virus 1 (HIV-1) and other pathogenic virus. It has an inactive N-terminal CD1 virus infectivity factor (Vif) protein binding domain (A3G-CD1) and an actively catalytic C-terminal CD2 deamination domain (A3G-CD2). Although many studies on the structure of A3G-CD2 and enzymatic properties of full-length A3G have been reported, the mechanism of how A3G interacts with HIV-1 single-stranded DNA (ssDNA) is still not well characterized. Here, we reported a crystal structure of a novel A3G-CD2 head-to-tail dimer (in which the N terminus of the monomer H (head) interacts with the C terminus of monomer T (tail)), where a continuous DNA binding groove was observed. By constructing the A3G-CD1 structural model, we found that its overall fold was almost identical to that of A3G-CD2. We mutated the residues located in or along the groove in monomer H and the residues in A3G-CD1 that correspond to those seated in or along the groove in monomer T. Then, by performing enzymatic assays, we confirmed the reported key elements and the residues in A3G necessary to the catalytic deamination. Moreover, we identified more than 10 residues in A3G essential to DNA binding and deamination reaction. Therefore, this dimer structure may represent a structural model of full-length A3G, which indicates a possible binding mode of A3G to HIV-1 ssDNA.


Assuntos
Citidina Desaminase/química , Citidina Desaminase/metabolismo , DNA de Cadeia Simples/metabolismo , Dobramento de Proteína , Multimerização Proteica , Desaminase APOBEC-3G , Catálise , Domínio Catalítico , Cristalografia por Raios X , Desaminação , Humanos , Modelos Moleculares , Ligação Proteica , Conformação Proteica
16.
J Neuroinflammation ; 12: 200, 2015 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-26527034

RESUMO

BACKGROUND: Subarachnoid hemorrhage (SAH) is a devastating neurological injury with high morbidity and mortality that is mainly caused by early brain injury (EBI). Progranulin (PGRN) is known to be involved in various biological functions, such as anti-inflammation and tissue repair. This study aimed to investigate the change of PGRN in the brain after SAH and its role on EBI. METHODS: The levels of PGRN, myeloperoxidase (MPO), interleukin1ß (IL-1ß), and tumor necrosis factor-α (TNF-α) were detected in the cerebrospinal fluid (CSF) from SAH patients by enzyme-linked immunosorbent assay (ELISA). In addition, PGRN levels were also detected in the cerebral cortex after experimental SAH in rats by western blotting and immunohistochemistry (IHC). Recombinant human PGRN (r-PGRN) or an equal volume of phosphate-buffered saline (PBS) was administrated at 30 min after SAH. All rats were subsequently sacrificed at 24 h after SAH. Neurological score and brain water content were assessed. For mechanistic studies, the changes of MPO, matrix metalloproteinase-9 (MMP-9), zonula occludens 1 (ZO-1), Bcl-2, and cleaved caspase-3 were examined by western blotting and the levels of pro-inflammatory cytokines (IL-1ß and TNF-α) were determined by ELISA. In addition, neuronal apoptosis and blood brain barrier (BBB) permeability were examined. RESULTS: The levels of PGRN significantly decreased, and the levels of MPO, IL-1ß, and TNF-α were markedly elevated in the CSF from SAH patients. In rats, PGRN levels in the brain also decreased after SAH. Administration of r-PGRN decreased brain water content and improved neurological scores at 24 h after SAH. These changes were associated with marked reductions in MPO, MMP-9, and proinflammation cytokine levels, as well as increased levels of Bcl-2 and ZO-1. In addition, neuronal apoptosis and BBB permeability were alleviated by r-PGRN. CONCLUSIONS: These results indicate that the levels of PGRN decreased after SAH and that r-PGRN alleviates EBI after SAH possibly via inhibition of neutrophil recruitment, providing a new target for the treatment of SAH.


Assuntos
Encéfalo/metabolismo , Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Infiltração de Neutrófilos/imunologia , Hemorragia Subaracnóidea/metabolismo , Adulto , Idoso , Animais , Barreira Hematoencefálica/metabolismo , Western Blotting , Encéfalo/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Imuno-Histoquímica , Inflamação/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Masculino , Pessoa de Meia-Idade , Progranulinas , Ratos , Ratos Sprague-Dawley , Hemorragia Subaracnóidea/imunologia
17.
J Urol ; 193(2): 690-8, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25132238

RESUMO

PURPOSE: Spliced variant forms of androgen receptor were recently identified in castration resistant prostate cancer cell lines and clinical samples. We identified the cistrome and gene signature of androgen receptor splice variants in castration resistant prostate cancer cell lines and determined the clinical significance of androgen receptor splice variant regulated genes. MATERIALS AND METHODS: The castration resistant prostate cancer cell line 22Rv1, which expresses full-length androgen receptor and androgen receptor splice variants endogenously, was used as the research model. We established 22Rv1-ARFL(-)/ARV(+) and 22Rv1-ARFL(-)/ARV(-) through RNA interference. Chromatin immunoprecipitation coupled with next generation sequencing and microarray techniques were used to identify the cistrome and gene expression profiles of androgen receptor splice variants in the absence of androgen. RESULTS: Androgen receptor splice variant binding sites were identified in 22Rv1-ARFL(-)/ARV(+). A gene set was regulated uniquely by androgen receptor splice variants but not by full-length androgen receptor in the absence of androgen. Integrated analysis revealed that some genes were directly modulated by androgen receptor splice variants. Unsupervised clustering analysis showed that the androgen receptor splice variant gene signature differentiated benign from malignant prostate tissue as well as localized prostate cancer from metastatic castration resistant prostate cancer specimens. Some genes that were modulated uniquely by androgen receptor splice variants also correlated with histological grade and biochemical failure. CONCLUSIONS: Androgen receptor splice variants can bind to DNA independent of full-length androgen receptor in the absence of androgen and modulate a unique set of genes that is not regulated by full-length androgen receptor. The androgen receptor splice variant gene signature correlates with disease progression. It distinguishes primary cancer from castration resistant prostate cancer specimens and benign from malignant prostate specimens.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias de Próstata Resistentes à Castração/genética , Receptores Androgênicos/genética , Transcriptoma , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Isoformas de Proteínas , Células Tumorais Cultivadas
18.
Cell Mol Neurobiol ; 35(3): 407-416, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25423917

RESUMO

Subarachnoid hemorrhage (SAH) is one of the life-threatening diseases with high morbidity and mortality rates. Small ubiquitin-like modifier (SUMO)-specific proteases 3 (SENP3), a member of the SUMO-specific protease family, was identified as an isopeptidase that deconjugates SUMOylation (The covalent modification by SUMO) of modified protein substrates. It is reported that SUMO-2/3 conjugation, a member of SUMOylation, presented neuroprotection. The study aimed to evaluate the expression of SENP3 and to explore its role potential role in SAH. A total of 95 Sprague-Dawley rats were randomly divided into sham group and SAH groups at 6, 12, 24, 48 h, day 3, day 5, and day 7. SAH groups suffered experimental SAH by injection with 0.3 ml nonheparinized autoblood into the prechiasmatic cistern. SENP3 expression is surveyed by western blot analysis, real-time polymerase chain reaction, immunohistochemistry, and immunofluorescence. The levels of cleavage caspase-3 were determined by western blot and immunohistochemistry. SENP3 protein expression was significantly up-regulated after SAH which peaked at 24 h; however, the mRNA expression of SENP3 remained unchanged. Meanwhile, the level of cleaved caspase-3 was also increased after SAH. There is a highly positive correlation between cleavage caspase-3 and SENP3 in protein level. Immunofluorescent results showed that the expression of SENP3 was increased in neurons, rather than astrocytes nor microglia. Our findings indicated a possible role of SENP3 in the pathogenesis of early brain injury mediated by apoptosis following SAH.


Assuntos
Córtex Cerebral/química , Córtex Cerebral/metabolismo , Endopeptidases/análise , Endopeptidases/biossíntese , Hemorragia Subaracnóidea/metabolismo , Animais , Córtex Cerebral/patologia , Regulação da Expressão Gênica , Masculino , Projetos Piloto , Ratos , Ratos Sprague-Dawley , Hemorragia Subaracnóidea/patologia
19.
Cell Mol Neurobiol ; 35(5): 723-31, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25744577

RESUMO

Convincing evidence indicates that apoptosis contributes to the unfavorable prognosis of subarachnoid hemorrhage (SAH), a significant cause of morbidity and case fatality throughout the world. Gelsolin (GSN) is a Ca(2+)-dependent actin filament severing, capping, and nucleating protein, as well as multifunctional regulator of cell structure and metabolism, including apoptosis. In the present study, we intended to investigate the expression pattern and cell distribution of GSN in rat brain after experimental SAH. GSN expression was examined in sham group and at 3, 6, 12 h, day 1 (1 day), 2, 3, 5, and 7 days after SAH by Western blot analysis as well as real-time polymerase chain reaction. Immunohistochemistry and immunofluorescence were performed to detect the localization of GSN. The level of GSN protein expression was significantly decreased in SAH group and reached a bottoming point on 1 day after SAH. GSN mRNA level was significantly decreased in SAH groups in comparison with the sham group, and reached a minimum value at 12 h after SAH. Immunohistochemistry showed that GSN was constitutively and obviously expressed in the cortex of the normal rat brain and significantly decreased in the rat cortex after SAH. In addition, immunofluorescence results revealed that GSN expression could be found in both neurons and microglias, as well as in glialfibrillary acidic protein-positive astrocytes. The decreased expression of GSN could mainly be found in neurons and astrocytes as well, and GSN-positive microglias showed different cell morphological characteristics. Interestingly, the protein and gene levels of GSN seemed to be constant in the rat hippocampus of sham and SAH groups. These findings suggested a potential role of GSN in the pathophysiology of the brain at the early stage of SAH.


Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Citoplasma/metabolismo , Gelsolina/metabolismo , Hemorragia Subaracnóidea/metabolismo , Hemorragia Subaracnóidea/patologia , Animais , Imunofluorescência , Gelsolina/genética , Regulação da Expressão Gênica , Hipocampo/metabolismo , Hipocampo/patologia , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Fatores de Tempo
20.
Neurochem Res ; 40(9): 1829-38, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26260377

RESUMO

Evidence has shown that the activation of the autophagy pathway after experimental subarachnoid hemorrhage (SAH) protects against neuronal damage. Tert-butylhydroquinone (tBHQ), a commonly used nuclear factor erythroid 2-related factor 2 (Nrf2) activator, was found to significantly enhance autophagy activation. The aim of this study was to explore the effect of tBHQ treatment on early stage brain injury at 24 h after SAH. The results showed that tBHQ treatment failed to stimulate an effective anti-oxidative effect at 24 h after the SAH operation, but succeeded in ameliorating early brain injury, including alleviated brain edema, BBB disruption, neuronal degeneration and neurological deficits. Further exploration found that tBHQ treatment significantly increased the expression of Beclin-1 and the ratio of microtubule-associated protein 1 light chain 3 (LC3)-II to LC3-I, suggesting that autophagy was enhanced after tBHQ treatment. Moreover, tBHQ treatment restored Bcl-2 and Bax expression and reduced caspase-3 cleavage, suggesting the protective effect of tBHQ treatment in ameliorating brain injury after SAH. Furthermore, tBHQ enhanced autophagy activation, decreased neuronal degeneration and improved the neurological score after SAH in Nrf2-deficient mice. Taken together, these findings suggest that tBHQ treatment exerts neuro-protective effects against EBI following SAH by enhancing Nrf2-independent autophagy. Therefore, tBHQ is a promising therapeutic agent against EBI following SAH.


Assuntos
Autofagia/efeitos dos fármacos , Lesões Encefálicas/prevenção & controle , Modelos Animais de Doenças , Hidroquinonas/farmacologia , Fator 2 Relacionado a NF-E2/fisiologia , Hemorragia Subaracnóidea/complicações , Animais , Barreira Hematoencefálica , Lesões Encefálicas/etiologia , Camundongos
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