Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Ethnopharmacol ; 270: 113776, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33421597

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: After cerebral ischemia/reperfusion injury, pro-inflammatory M1 and anti-inflammatory M2 phenotypes of microglia are involved in neuroinflammation, in which activation of NLRP3 inflammasome and subsequent pyroptosis play essential roles. Salvianolic Acids for Injection (SAFI) is Chinese medicine injection which composed of multiple phenolic acids extracted from Radix Salviae Miltiorrhizae, and has been reported to generate neuroprotective effects after cerebral ischemic insult in clinical and animal studies. AIM OF THE STUDY: The present study was designed to investigate whether SAFI exerts neuroprotective effects by switching microglial phenotype and inhibiting NLRP3 inflammasome/pyroptosis axis in microglia. MATERIALS AND METHODS: The middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats and oxygen-glucose deprivation/reoxygenation (OGD/R) model in co-cultured primary neurons and primary microglia were utilized. The neuroprotective effect of SAFI was evaluated through measuring neurological deficit scores, neuropathological changes, inflammatory factors, cell phenotype markers, and related proteins of NLRP3 inflammasome/pyroptosis axis. RESULTS: The results showed that SAFI treatment was able to: (1) produce a significant increase in neurological deficit scores and decrease in infarct volumes, and alleviate histological injury and neuronal apoptosis in cerebral cortex in MCAO/R model; (2) increase neuronal viability and reduce neuronal apoptosis in the OGD model; (3) reshape microglial polarization patterns from M1-like phenotype to M2-like phenotype; (4) inhibit the activation of the NLRP3 inflammasome and the expression of proteins related to NLRP3 inflammasome/pyroptosis axis in vivo and in vitro. CONCLUSION: These findings indicate that SAFI exert neuroprotective effect, probably via reducing neuronal apoptosis, switching microglial phenotype from M1 towards M2, and inhibiting NLRP3 inflammasome/pyroptosis axis in microglia.

2.
BMJ Glob Health ; 5(11)2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33184065

RESUMO

INTRODUCTION: The COVID-19 pandemic caused a healthcare crisis in China and continues to wreak havoc across the world. This paper evaluated COVID-19's impact on national and regional healthcare service utilisation and expenditure in China. METHODS: Using a big data approach, we collected data from 300 million bank card transactions to measure individual healthcare expenditure and utilisation in mainland China. Since the outbreak coincided with the 2020 Chinese Spring Festival holiday, a difference-in-difference (DID) method was employed to compare changes in healthcare utilisation before, during and after the Spring Festival in 2020 and 2019. We also tracked healthcare utilisation before, during and after the outbreak. RESULTS: Healthcare utilisation declined overall, especially during the post-festival period in 2020. Total healthcare expenditure and utilisation declined by 37.8% and 40.8%, respectively, while per capita expenditure increased by 3.3%. In a subgroup analysis, we found that the outbreak had a greater impact on healthcare utilisation in cities at higher risk of COVID-19, with stricter lockdown measures and those located in the western region. The DID results suggest that, compared with low-risk cities, the pandemic induced a 14.8%, 26.4% and 27.5% reduction in total healthcare expenditure in medium-risk and high-risk cities, and in cities located in Hubei province during the post-festival period in 2020 relative to 2019, an 8.6%, 15.9% and 24.4% reduction in utilisation services; and a 7.3% and 18.4% reduction in per capita expenditure in medium-risk and high-risk cities, respectively. By the last week of April 2020, as the outbreak came under control, healthcare utilisation gradually recovered, but only to 79.9%-89.3% of its pre-outbreak levels. CONCLUSION: The COVID-19 pandemic had a significantly negative effect on healthcare utilisation in China, evident by a dramatic decline in healthcare expenditure. While the utilisation level has gradually increased post-outbreak, it has yet to return to normal levels.


Assuntos
Infecções por Coronavirus/epidemiologia , Gastos em Saúde/estatística & dados numéricos , Acesso aos Serviços de Saúde , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Pneumonia Viral/epidemiologia , Betacoronavirus , China/epidemiologia , Humanos , Pandemias
3.
Autophagy ; : 1-18, 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32876514

RESUMO

PDPK1 (3-phosphoinositide dependent protein kinase 1) is a phosphorylation-regulated kinase that plays a central role in activating multiple signaling pathways and cellular processes. Here, this study shows that PDPK1 turns on macroautophagy/autophagy as a SUMOylation-regulated kinase. In vivo data demonstrate that the SUMO modification of PDPK1 is a physiological feature in the brain and that it can be induced by viral infections. The SUMOylated PDPK1 regulates its own phosphorylation and subsequent activation of the AKT1 (AKT serine/threonine kinase 1)-MTOR (mechanistic target of rapamycin kinase) pathway. However, SUMOylation of PDPK1 is inhibited by binding to PIK3C3 (phosphatidylinositol 3-kinase catalytic subunit type 3). The nonSUMOylated PDPK1 then tethers LC3 to the endoplasmic reticulum to initiate autophagy, and it acts as a key component in forming the autophagic vacuole. Collectively, this study reveals the intricate molecular regulation of PDPK1 by post-translational modification in controlling autophagosome biogenesis, and it highlights the role of PDPK1 as a sensor of cellular stress and regulator of autophagosome biogenesis. Abbreviations: AKT1: AKT serine/threonine kinase 1; ATG14: autophagy related 14; Co-IP: co-immunoprecipitation; ER: endoplasmic reticulum; hpi: hours post-infection; mAb: monoclonal antibody; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MOI: multiplicity of infection; MTOR: mechanistic target of rapamycin kinase; pAb: polyclonal antibody; PDPK1: 3-phosphoinositide dependent protein kinase 1; PI3K: phosphoinositide 3-kinase; PIK3C3: phosphatidylinositol 3-kinase catalytic, subunit type 3; RPS6KB1: ribosomal protein S6 kinase B1; SGK: serum/glucocorticoid regulated kinase; SQSTM1: sequestosome 1; SUMO: small ubiquitin like modifier; UBE2I/UBC9: ubiquitin conjugating enzyme E2 I; UVRAG: UV radiation resistance associated.

4.
Exp Physiol ; 2020 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-32964508

RESUMO

NEW FINDINGS: What is the central question of this study? Does Dnmt3a plays a critical role in regulating diabetic muscle atrophy? What is the main finding and its importance? Muscle atrophy is one of the major long-term complications of diabetes mellitus. However, little is known about the molecular mechanism involved. In this paper, we demonstrated that Dnmt3a overexpression effectively improves the diabetic muscle health in mice and documented the underlying mechanisms. Dnmt3a may become a promising target to prevent muscle atrophy in patients with diabetes. ABSTRACT: Background : Muscle atrophy is one of the major long-term complications of diabetes mellitus (DM), which strongly affects the mobility of patients. DNA methyltransferases (DNMTs) mediated epigenetic processes play critical roles in the locomotor system, but little is known about their functions in diabetic muscle atrophy. Here we investigated the function of Dnmt3a in diabetic muscle atrophy and explored the mechanisms involved. METHODS: Adeno-associated virus AAV2 overexpressing Dnmt3a or its vector control was injected into the tibialis anterior muscle of streptozotocin-induced diabetic mice. Muscle mass and muscle cross-section area were used to evaluate muscle atrophy. In vitro, adeno-associated virus AAV2 overexpressing Dnmt3a or its vector control was transfected into C2C12 myoblasts. Horse serum was used to induce differentiation and palmitate was used to stimulate C2C12 myoblasts. The expressions of myogenic regulatory factors were examined by real-time PCR and western blot analysis Results : Overexpression of Dnmt3a attenuated muscle atrophy in diabetic mice and promoted myotube formation of C2C12 myoblasts. Overexpression of Dnmt3a restored the expressions of myogenic regulatory factors Atrogin-1, MuRF1, Pax7, MyoD1 and Myogenin, both in vivo and in vitro. Moreover, overexpression of Dnmt3a activated the phosphorylation of Akt by inhibiting the activation of Pten Conclusion : This study demonstrates that overexpression of Dnmt3a prevents diabetic muscle atrophy by modulating PTEN/Akt pathway. This article is protected by copyright. All rights reserved.

5.
J Virol ; 94(24)2020 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-32967959

RESUMO

Selective autophagy regulates the degradation of cytoplasmic cargos, such as damaged organelles, invading pathogens, and aggregated proteins. Furthermore, autophagy is capable of degrading avibirnavirus, but the mechanism responsible for this process is unclear. Here, we show that autophagy cargo receptor p62 regulates the degradation of the avibirnavirus capsid protein VP2. Binding of p62 to VP2 enhances autophagic induction and promotes autophagic degradation of viral protein VP2. Further study showed that the interaction of p62 with viral protein VP2 is dependent on ubiquitination at the K411 site of VP2 and the ubiquitin-associated domain of p62. Mutation analysis showed that the K411R mutation of viral protein VP2 prohibits its p62-mediated degradation. Consistent with this finding, p62 lacking the ubiquitin-associated domain or the LC3-interacting region no longer promoted the degradation of VP2. Virus production revealed that the knockout of p62 but not the overexpression of p62 promotes the replication of avibirnavirus. Collectively, our findings suggest that p62 mediates selective autophagic degradation of avibirnavirus protein VP2 in a ubiquitin-dependent manner and is an inhibitor of avibirnavirus replication.IMPORTANCE Avibirnavirus causes severe immunosuppression and mortality in young chickens. VP2, the capsid protein of avibirnavirus, is responsible for virus assembly, maturation, and replication. Previous study showed that avibirnavirus particles could be engulfed into the autophagosome and degradation of virus particles took apart. Selective autophagy is a highly specific and regulated degradation pathway for the clearance of damaged or unwanted cytosolic components and superfluous organelles as well as invading microbes. However, whether and how selective autophagy removes avibirnavirus capsids is largely unknown. Here, we have shown that selective autophagy specifically clears ubiquitinated avibirnavirus protein VP2 by p62 recognition and that p62 is an inhibitor of avibirnavirus replication, highlighting the role of p62 as a potential drug target for mediating the removal of ubiquitinated virus components from cells.

6.
Exp Neurol ; 332: 113399, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32652099

RESUMO

After cerebral ischemia/reperfusion injury, pro-inflammatory M1-like and anti-inflammatory M2-like phenotypes of microglia are involved in neuroinflammation, in which NLRP3 inflammasome plays an essential role. Kv1.3 channel has been recognized as neuro-immunomodulatory target, but it is not clear as to its role in the neuroinflammation after cerebral ischemic injury. The current study aimed to investigate the issue. Middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats and oxygen-glucose deprivation/ reoxygenation (OGD/R) in primary microglia were utilized to mimic disease state of ischemic stroke. Treatment with PAP-1, a Kv1.3 channel blocker, produced a significant improvement in neurological deficit scores and a decrease in infarct volume in MCAO/R model. An increased number of M2-like phenotypic microglia and a reduced number of M1-like phenotypic microglia were observed by immunofluorescent staining in the in vivo model, which was further validated by flow cytometry in vitro. Western blot showed that PAP-1 treatment profoundly reduced cleavage of caspase-1 and IL-1ß in vivo and in vitro. Furthermore, PAP-1 administration reduced the number of NLRP3+/Iba1+ cells and NLRP3 protein levels in vivo, while reduced mRNA and protein expression levels of NLRP3 in vitro. Reduced mRNA expression levels of IL-1ß in vitro and protein level of IL-1ß in vivo were also observed. Taken together, our findings suggested that Kv1.3 channel blockade effectively alleviated cerebral ischemic injury, possibly by reshaping microglial phenotypic response from M1 towards M2, compromising the activation of NLRP3 inflammasome in microglia, and inhibiting release of IL-1ß.

7.
J Obstet Gynaecol Res ; 46(8): 1298-1309, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32558037

RESUMO

AIM: Pre-eclampsia (PE) is the usual complication during pregnancy. Long noncoding RNAs are essential regulatory factors in many diseases. Nevertheless, the role of LINC00511 in the development of PE has not been fully elucidated. METHODS: The expression of LINC00511, homeobox protein A7 (HOXA7) and miR-31-5p was determined by quantitative real-time polymerase chain reaction. The levels of HOXA7 protein and autophagy-related proteins were measured by western blot analysis. Besides, cell proliferation was evaluated using cell counting kit 8 and colony formation assays. The apoptosis and invasion of cells were detected via flow cytometry and transwell assay, respectively. Further, the interaction between miR-31-5p and LINC00511 or HOXA7 was confirmed by dual-luciferase reporter assay. RESULTS: The LINC00511 and HOXA7 expression levels were decreased in placental tissues of PE patients, and the expression levels of both were positively correlated. LINC00511 knockdown suppressed proliferation, invasion and autophagy, while enhanced apoptosis in trophoblast cells. Meanwhile, the elevated HOXA7 expression promoted proliferation, invasion, autophagy, and inhibited the apoptosis of trophoblast cells. Besides, overexpression of HOXA7 also could reverse the effect of LINC00511 knockdown on the biological function of trophoblast cells. Further experiments confirmed that miR-31-5p could be sponged by LINC00511 and could target HOXA7. Also, miR-31-5p mimic could invert the promoting effect of LINC00511 overexpression on the biological function of trophoblast cells. CONCLUSION: LINC00511 expression was crucial for maintaining the normal function of trophoblast cells, and the decreased its expression might promote the progress of PE, which might provide some theoretical strategies for reducing the development of PE.

9.
Aging (Albany NY) ; 12(1): 628-649, 2020 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-31907339

RESUMO

Trimethylamine-N-oxide (TMAO) is a gut microbial metabolite that promotes Alzheimer's disease (AD) progression. Given that probiotics can alleviate AD symptoms by inhibiting the synthesis of TMAO, here we investigated the correlation between TMAO and cognitive deterioration by measuring TMAO levels in the plasma of choline-treated APP/PS1 mice (an AD mouse model) with and without probiotic treatments. We found that declines in L. plantarum in the gut were associated with cognitive impairment. Moreover, 12-weeks of treatment with memantine plus L. plantarum ameliorated cognitive deterioration, decreased Αß levels in the hippocampus, and protected neuronal integrity and plasticity. These effects were accompanied by reductions in TMAO synthesis and neuroinflammation. These experiments demonstrate that L. plantarum augments the beneficial therapeutic effects of memantine treatment in APP/PS1 mice by remodeling the intestinal microbiota, inhibiting the synthesis of TMAO, and reducing clusterin levels. Our results thus highlight intestinal microbiota as a potential therapeutic target to decrease the risk of AD.


Assuntos
Doença de Alzheimer/complicações , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/terapia , Lactobacillus plantarum , Memantina/farmacologia , Doença de Alzheimer/etiologia , Doença de Alzheimer/metabolismo , Animais , Animais Geneticamente Modificados , Biomarcadores , Colina/administração & dosagem , Suplementos Nutricionais , Modelos Animais de Doenças , Microbioma Gastrointestinal , Masculino , Metagenômica/métodos , Camundongos , Probióticos , Células Piramidais/metabolismo
10.
Virol Sin ; 35(2): 171-180, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31777011

RESUMO

Long noncoding RNAs (lncRNAs) participate in regulating many biological processes. However, their roles in influenza A virus (IAV) pathogenicity are largely unknown. Here, we analyzed the expression profiles of lncRNAs and mRNAs in H3N2-infected cells and mock-infected cells by high-throughput sequencing. The results showed that 6129 lncRNAs and 50,031 mRNA transcripts in A549 cells displayed differential expression after H3N2 infection compared with mock infection. Among the differentially expressed lncRNAs, 4963 were upregulated, and 1166 were downregulated. Functional annotation and enrichment analysis using gene ontology and Kyoto Encyclopedia of Genes and Genomes databases (KEGG) suggested that target genes of the differentially expressed lncRNAs were enriched in some biological processes, such as cellular metabolism and autophagy. The up- or downregulated lncRNAs were selected and further verified by quantitative real-time polymerase chain reaction (RT-qPCR) and reverse transcription PCR (RT-PCR). To the best of our knowledge, this is the first report of a comparative expression analysis of lncRNAs in A549 cells infected with H3N2. Our results support the need for further analyses of the functions of differentially expressed lncRNAs during H3N2 infection.

11.
Autophagy ; 16(9): 1697-1710, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-31885313

RESUMO

Macroautophagy/autophagy is a host natural defense response. Viruses have developed various strategies to subvert autophagy during their life cycle. Recently, we revealed that autophagy was activated by binding of Avibirnavirus to cells. In the present study, we report the inhibition of autophagy initiated by PIK3C3/VPS34 via the PDPK1-dependent AKT-MTOR pathway. Autophagy detection revealed that viral protein VP3 triggered inhibition of autophagy at the early stage of Avibirnavirus replication. Subsequent interaction analysis showed that the CC1 domain of VP3 disassociated PIK3C3-BECN1 complex by direct interaction with BECN1 and blocked autophagosome formation, while the CC3 domain of VP3 disrupted PIK3C3-PDPK1 complex via directly binding to PIK3C3 and inhibited both formation and maturation of autophagosome. Furthermore, we found that PDPK1 activated AKT-MTOR pathway for suppressing autophagy via binding to AKT. Finally, we proved that CC3 domain was critical for role of VP3 in regulating replication of Avibirnavirus through autophagy. Taken together, our study identified that Avibirnavirus VP3 links PIK3C3-PDPK1 complex to AKT-MTOR pathway and inhibits autophagy, a critical step for controlling virus replication. ABBREVIATIONS: ATG14/Barkor: autophagy related 14; BECN1: beclin 1; CC: coiled-coil; ER: endoplasmic reticulum; hpi: hours post-infection; IBDV: infectious bursal disease virus; IP: co-immunoprecipitation; mAb: monoclonal antibody; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MOI: multiplicity of infection; MTOR: mechanistic target of rapamycin kinase; PDPK1: 3-phosphoinositid-dependent protein kinase-1; PIK3C3/VPS34: phosphatidylinositol 3-kinase catalytic subunit type 3; PtdIns3K: phosphatidylinositol 3-kinase; PtdIns3P: phosphatidylinositol-3-phosphate; SQSTM1: sequestosome 1; vBCL2: viral BCL2 apoptosis regulator.

12.
Int J Equity Health ; 18(1): 178, 2019 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-31752984

RESUMO

BACKGROUND: Exposure to natural outdoor environments (NOE) has been shown to be beneficial to older adults' health and functioning, yet this assertion has rarely been tested in China. We investigated the relationships between exposure to NOE and older adults' self-rated health in Shanghai, China and examined whether these relationships varied by sex, age, education and hukou status. METHOD: This cross-sectional study used micro-data sample of the 2010 Shanghai population census, including 7962 older adults nested within 3345 neighbourhoods. Self-rated health was the outcome variable. Four NOE exposure indicators were calculated for each neighbourhood: the amount of surrounding greenness/blueness and proximity to large green/blue spaces. Multilevel logistic regression was employed to explore the association between natural outdoor environment exposure and self-rated health, adjusting for individual-level and neighbourhood-level covariates. Stratified analyses were used to examine variations by sex, age, education and hukou status. RESULTS: Older adults living in neighbourhoods with higher surrounding greenness and higher proximity to both green spaces and blue spaces were more likely to report good health. Residential surrounding blueness was not significantly related to self-rated health. Females, those aged 60-69 years, those who had elementary school or junior high school education and those with non-local hukou benefit more from residential surrounding greenness, and those aged 70-79 years and who had elementary school or junior high school education benefit more from residential proximity to blue spaces. CONCLUSIONS: Higher residential greenness and proximity to both green spaces and blue spaces were associated with better self-rated health, particularly for females, younger older adults, the low educated and non-local hukou holders. Our findings suggest that urban green spaces and urban blue spaces have different effects on health among Chinese older adults and that the assessment of exposure matters to the investigation of NOE-health relationships.


Assuntos
Planejamento Ambiental/estatística & dados numéricos , Nível de Saúde , Características de Residência/estatística & dados numéricos , Idoso , China , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
13.
Am J Transl Res ; 11(9): 6249-6261, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31632591

RESUMO

We aimed to investigate the value of cholestasis-related miRNAs in the diagnosis of intra-hepatic cholestasis of pregnancy (ICP) as well as the molecular mechanisms underlying the role of these miRNAs in the pathogenesis of ICP. In this study, electron microscopy was utilized to observe the exosomes present in the urine samples collected from both ICP patients and healthy pregnant women. Real-time PCR and area under curve (AUC) analysis were performed to predict the values of several miRNAs in the diagnosis of ICP. Bioinformatics analysis and luciferase assays were conducted to identify the target genes of miR-21, miR-29a and miR-590-3p, whose regulatory relationships were then established using real-time PCR, immunohistochemistry (IHC) assay and Western Blot. In the exosomes isolated from urine samples, several miRNAs, including miR-21, miR-29a and miR-590-3p, were differentially expressed between ICP patients and healthy pregnant women. In addition, the gene of intercellular adhesion molecule 1 (ICAM1) was identified as a shared target of miR-21, miR-29a and miR-590-3p, all of which inhibited ICAM1 expression. Therefore, up-regulated expression of miR-21, miR-29a and miR-590-3p in urinary exosomes reduced the expression of ICAM1, which in turn increased the incidence of ICP.

14.
Mol Med Rep ; 20(4): 3113-3122, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31432171

RESUMO

The aim of the present study was to determine the function of microRNA­16 (miR­16) in myocardial hypoxia/reoxygenation (H/R)­induced cardiomyocyte injury and the possible mechanism underlying its involvement. An H/R model was constructed using H9c2(2­1) cells in vitro. The results of reverse transcription­quantitative PCR demonstrated that the expression levels of miR­16 were significantly upregulated in H9c2(2­1) cells in the H/R group compared with the sham group (1.53±0.09 vs. 1.0±0.08; P=0.0019). Cell Counting Kit­8 assays revealed that the relative proliferative ability of H9c2(2­1) cells was significantly decreased in the H/R + negative control (NC) group compared with the sham group (0.53±0.05 vs. 1.0±0.08; P=0.00005). Upregulation of miR­16 using miR­16 mimics further decreased the proliferative ability of cells (0.31±0.03 vs. 0.53±0.05; P=0.0097), whereas downregulation of miR­16 using an miR­16 inhibitor increased the proliferative ability of cells compared with the H/R+NC group (0.89±0.08 vs. 0.53±0.05; P=0.000385). Flow cytometric analysis found that the apoptotic rate of H9c2(2­1) cells was increased significantly following H/R compared with the sham group (25.86±2.62% vs. 9.29±0.82%, P=0.000014). Upregulation of miR­16 further increased the apoptotic rate (38.62±2.04% vs. 25.86±2.62%; P=0.000099), whereas downregulation of miR­16 decreased the apoptotic rate compared with the H/R+NC group (15.14±0.92% vs. 25.86±2.62%; P=0.000343). miR­16 directly bound to the 3'­untranslated region of cytokine­induced apoptosis inhibitor 1 (CIAPIN1) and negatively modulated CIAPIN1 expression. Overexpression of CIAPIN1 reversed the changes in the expression of apoptosis­associated proteins caused by H/R. Western blot analysis revealed that the levels of phospho­(p­)nuclear factor­κB (NF­κB) and p­NF­κB inhibitor α (IκBα) were upregulated following H/R (1.82±0.11 vs. 1.0±0.08; P=0.000152; and 1.77±0.07 vs. 1.0±0.00; P=0.000024, respectively), and these changes were further enhanced when miR­16 expression levels were increased (3.10±0.14 vs. 1.82±0.11; P=0.000006; and 2.19±0.10 vs. 1.77±0.07; P=0.0017, respectively). Downregulation of miR­16 exhibited the opposite effect on p­NF­κB and p­IκBα expression levels. The present study illustrates that downregulation of miR­16 may protect against H/R­induced injury partially by targeting CIAPIN1 and the NF­κB signaling pathway.


Assuntos
Proteínas Reguladoras de Apoptose/biossíntese , Regulação para Baixo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , NF-kappa B/metabolismo , Transdução de Sinais , Animais , Linhagem Celular , Humanos , MicroRNAs , Traumatismo por Reperfusão Miocárdica/patologia , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Miócitos Cardíacos/patologia , Ratos
15.
Neoplasia ; 21(10): 974-988, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31442917

RESUMO

We recently described a positive feedback loop connecting c-MYC, NAMPT, DBC1 and SIRT1 that contributes to unrestricted cancer cell proliferation. Here we determine the relevance of the loop for serrated route intestinal tumorigenesis using genetically well-defined BrafV600E and K-rasG12D mouse models. In both models we show that c-MYC and SIRT1 protein expression increased through progression from hyperplasia to invasive carcinomas and metastases. It correlated with high NAMPT expression and was directly associated to activation of the oncogenic drivers. Assessing functional and molecular consequences of pharmacological interference with factors of the loop, we found that inhibition of NAMPT resulted in apoptosis and reduced clonogenic growth in human BRAF-mutant colorectal cancer cell lines and patient-derived tumoroids. Blocking SIRT1 activity was only effective when combined with a PI3K inhibitor, whereas the latter antagonized the effects of NAMPT inhibition. Interfering with the positive feedback loop was associated with down-regulation of c-MYC and temporary de-repression of TP53, explaining the anti-proliferative and pro-apoptotic effects. In conclusion we show that the c-MYC-NAMPT-DBC1-SIRT1 positive feedback loop contributes to murine serrated tumor progression. Targeting the feedback loop exerted a unique, dual therapeutic effect of oncoprotein inhibition and tumor suppressor activation. It may therefore represent a promissing target for serrated colorectal cancer, and presumably for other cancer types with deregulated c-MYC.


Assuntos
Transformação Celular Neoplásica , Citocinas/metabolismo , Neoplasias Intestinais/etiologia , Neoplasias Intestinais/metabolismo , Nicotinamida Fosforribosiltransferase/metabolismo , Oncogenes , Proteínas Proto-Oncogênicas c-myc/metabolismo , Sirtuína 1/metabolismo , Animais , Apoptose/genética , Biomarcadores , Biópsia , Linhagem Celular Tumoral , Proliferação de Células , Resistencia a Medicamentos Antineoplásicos/genética , Imuno-Histoquímica , Neoplasias Intestinais/tratamento farmacológico , Neoplasias Intestinais/patologia , Camundongos , Mutação , Metástase Neoplásica , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Proteínas Proto-Oncogênicas B-raf/genética , Transdução de Sinais , Sirtuína 1/antagonistas & inibidores
16.
Vet Microbiol ; 231: 238-245, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30955816

RESUMO

Circular RNAs (circRNAs) play critical roles in various diseases. However, whether and how circular RNA regulates influenza A virus (IAV) infection is unknown. Here, we studied the role of circular RNA GATA Zinc Finger Domain Containing 2A (circ-GATAD2A) in the replication of IAV H1N1 in A549 cells. Circ-GATAD2A was formed upon H1N1 infection. Knockdown of circ-GATAD2A in A549 cells enhanced autophagy and inhibited H1N1 replication. By contrast, overexpression of circ-GATAD2A impaired autophagy and promoted H1N1 replication. Similarly, knockout of vacuolar protein sorting 34 (VPS34) blocked autophagy and increased H1N1 replication. However, the expression of circ-GATAD2A could not further enhance H1N1 replication in VPS34 knockout cells. Collectively, these data indicated that circ-GATAD2A promotes the replication of H1N1 by inhibiting autophagy.


Assuntos
Autofagia/genética , Fatores de Transcrição GATA/genética , Interações entre Hospedeiro e Microrganismos/genética , Vírus da Influenza A Subtipo H1N1/fisiologia , RNA/genética , Replicação Viral , Células A549 , Classe III de Fosfatidilinositol 3-Quinases/genética , Técnicas de Silenciamento de Genes , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Influenza Humana/virologia , RNA Circular , Regulação para Cima
17.
J Virol ; 93(10)2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30842328

RESUMO

SUMOylation is a posttranslational modification that has crucial roles in diverse cellular biological pathways and in various viral life cycles. In this study, we found that the VP1 protein, the RNA-dependent RNA polymerase of avibirnavirus infectious bursal disease virus (IBDV), regulates virus replication by SUMOylation during infection. Our data demonstrated that the polymerase VP1 is efficiently modified by small ubiquitin-like modifier 1 (SUMO1) in avibirnavirus-infected cell lines. Mutation analysis showed that residues 404I and 406I within SUMO interaction motif 3 of VP1 constitute the critical site for SUMO1 modification. Protein stability assays showed that SUMO1 modification enhanced significantly the stability of polymerase VP1 by inhibiting K48-linked ubiquitination. A reverse genetic approach showed that only IBDV with I404C/T and I406C/F mutations of VP1 could be rescued successfully with decreased replication ability. Our data demonstrated that SUMO1 modification is essential to sustain the stability of polymerase VP1 during IBDV replication and provides a potential target for designing antiviral drugs targeting IBDV.IMPORTANCE SUMOylation is an extensively discussed posttranslational modification in diverse cellular biological pathways. However, there is limited understanding about SUMOylation of viral proteins of IBDV during infection. In the present study, we revealed a SUMO1 modification of VP1 protein, the RNA-dependent RNA polymerase of avibirnavirus infectious bursal disease virus (IBDV). The required site of VP1 SUMOylation comprised residues 404I and 406I of SUMO interaction motif 3, which was essential for maintaining its stability by inhibiting K48-linked ubiquitination. We also showed that IBDV with SUMOylation-deficient VP1 had decreased replication ability. These data demonstrated that the SUMOylation of IBDV VP1 played an important role in maintaining IBDV replication.


Assuntos
Vírus da Doença Infecciosa da Bursa/metabolismo , Proteína SUMO-1/metabolismo , Proteínas Estruturais Virais/metabolismo , Avibirnavirus/metabolismo , Avibirnavirus/patogenicidade , Células HEK293 , Interações Hospedeiro-Patógeno , Humanos , Vírus da Doença Infecciosa da Bursa/patogenicidade , Vírus da Doença Infecciosa da Bursa/fisiologia , Processamento de Proteína Pós-Traducional , RNA Replicase/genética , Proteína SUMO-1/fisiologia , Sumoilação , Ubiquitinação , Proteínas Virais/metabolismo , Proteínas Estruturais Virais/genética , Replicação Viral/fisiologia
18.
Colloids Surf B Biointerfaces ; 173: 504-511, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30340178

RESUMO

Thermosensitive glucose-functionalized glycopolymers grafted gold nanoparticles (Glyco@GNPs) with good colloidal stability and thermosensitive in aqueous solution were fabricated by reversible addition-fragmentation chain transfer (RAFT) mediated one-pot synthesis. The formation of core-shell morphology with about a 60 nm gold core in diameter and a glycopolymer shell of about 80 nm in thickness was indicated by transmission electron microscopy (TEM). The recognition ability of the Glyco@GNPs toward lectin concannavalin A (Con A) was verified by ultraviolet-visible spectroscopy and dynamic light scattering (DLS). The good cytocompatibility of the glycopolymers and Glyco@GNPs was proven by MTT assay on L-929 cells. Glyco@GNPs could effectively inhibit hepatoma cells SMMC-7721 growth after recognizing Con A was also proved by MTT assay and flow cytometry assay.


Assuntos
Técnicas de Química Sintética , Concanavalina A/análise , Glucose/química , Glicoconjugados/química , Ouro/química , Nanopartículas Metálicas/química , Animais , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Concanavalina A/química , Fibroblastos/efeitos dos fármacos , Glicoconjugados/farmacologia , Hepatócitos/efeitos dos fármacos , Temperatura Alta , Humanos , Nanopartículas Metálicas/ultraestrutura , Metacrilatos/química , Camundongos , Polimerização , Soluções , Compostos de Vinila/química , Água/química
19.
J Virol ; 93(3)2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30429342

RESUMO

Ubiquitination is critical for several cellular physical processes. However, ubiquitin modification in virus replication is poorly understood. Therefore, the present study aimed to determine the presence and effect of ubiquitination on polymerase activity of viral protein 1 (VP1) of avibirnavirus. We report that the replication of avibirnavirus is regulated by ubiquitination of its VP1 protein, the RNA-dependent RNA polymerase of infectious bursal disease virus (IBDV). In vivo detection revealed the ubiquitination of VP1 protein in IBDV-infected target organs and different cells but not in purified IBDV particles. Further analysis of ubiquitination confirms that VP1 is modified by K63-linked ubiquitin chain. Point mutation screening showed that the ubiquitination site of VP1 was at the K751 residue in the C terminus. The K751 ubiquitination is independent of VP1's interaction with VP3 and eukaryotic initiation factor 4A II. Polymerase activity assays indicated that the K751 ubiquitination at the C terminus of VP1 enhanced its polymerase activity. The K751-to-R mutation of VP1 protein did not block the rescue of IBDV but decreased the replication ability of IBDV. Our data demonstrate that the ubiquitination of VP1 is crucial to regulate its polymerase activity and IBDV replication.IMPORTANCE Avibirnavirus protein VP1, the RNA-dependent RNA polymerase, is responsible for IBDV genome replication, gene expression, and assembly. However, little is known about its chemical modification relating to its polymerase activity. In this study, we revealed the molecular mechanism of ubiquitin modification of VP1 via a K63-linked ubiquitin chain during infection. Lysine (K) residue 751 at the C terminus of VP1 is the target site for ubiquitin, and its ubiquitination is independent of VP1's interaction with VP3 and eukaryotic initiation factor 4A II. The K751 ubiquitination promotes the polymerase activity of VP1 and unubiquitinated VP1 mutant IBDV significantly impairs virus replication. We conclude that VP1 is the ubiquitin-modified protein and reveal the mechanism by which VP1 promotes avibirnavirus replication.


Assuntos
Avibirnavirus/fisiologia , Infecções por Birnaviridae/virologia , Vírus da Doença Infecciosa da Bursa/fisiologia , RNA Replicase/metabolismo , Ubiquitinação , Proteínas Estruturais Virais/metabolismo , Replicação Viral , Animais , Avibirnavirus/classificação , Infecções por Birnaviridae/enzimologia , Células Cultivadas , Galinhas/virologia , Fibroblastos/metabolismo , Fibroblastos/virologia , Células HEK293 , Humanos , RNA Replicase/química , Ubiquitina/metabolismo , Proteínas Estruturais Virais/química
20.
J Mol Neurosci ; 66(4): 595-603, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30414017

RESUMO

To examine the effect of subcutaneous injection of insulin-like growth factor-1 (IGF-1) on the expression of the amyloid protein (Aß1-40), α-secretase (ADAM10), ß-secretase (BACE1), and γ-secretase (PS1) in APP/PS1 double transgenic mice. APP/PS1 double transgenic mice and wild-type mice were divided into wild-type group, wild-type therapy group, transgenome group, and transgenic therapy group. Subcutaneous injection of IGF-1 (50 µg/kg day) was administered once daily to the wild-type therapy group and transgenic therapy group for 8 weeks, respectively. The expression of the Aß1-40 in the cortex and hippocampus was detected by immunohistochemistry 8 weeks after administration. The levels of Aß1-40, DAM10, BACE1, and PS1 were analysed by Western blot. The expression of the Aß1-40 in the cortex of the gene therapy group was significantly lower than that of the transgenome group (p < 0.05). In APP/PS1 double transgenic mice, BACE1 expression was markedly higher in both the hippocampus (p < 0.001, p = 0.00009) and the cortex (p = 0.001), compared to that of the wild-type mice. The treatment of IGF-1 markedly reduced ADAM10 expression in the hippocampus in both transgenic mice and wild-type mice (p < 0.05), whereas the treatment mainly decreased BACE1 expression in transgenic mice but not in the wild-type mice (p < 0.05). No significant differences in PS1 levels were detected in all groups. IGF decreased Aß1-40 over-expression in the cortex and hippocampus and might inhibit the damage induced by Aß1-40 in APP/PS1 double transgenic mice. Our study suggests that IGF-1 should inhibit Aß production through α-secretase and ß-secretase but not γ-secretase.


Assuntos
Proteína ADAM10/genética , Doença de Alzheimer/tratamento farmacológico , Secretases da Proteína Precursora do Amiloide/genética , Peptídeos beta-Amiloides/genética , Ácido Aspártico Endopeptidases/genética , Fator de Crescimento Insulin-Like I/farmacologia , Proteínas de Membrana/genética , Fragmentos de Peptídeos/genética , Proteína ADAM10/metabolismo , Doença de Alzheimer/genética , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Ácido Aspártico Endopeptidases/metabolismo , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Fator de Crescimento Insulin-Like I/administração & dosagem , Fator de Crescimento Insulin-Like I/uso terapêutico , Proteínas de Membrana/metabolismo , Camundongos , Fragmentos de Peptídeos/metabolismo , Presenilina-1/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA