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1.
Reprod Health ; 21(1): 82, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849864

RESUMO

This study assesses the impact of a voucher project that targeted vulnerable and poor pregnant women in Uganda. Highly subsidised vouchers gave access to a package of safe delivery services consisting of four antenatal visits, safe delivery, one postnatal visit, the treatment and management of selected pregnancy-related medical conditions and complications, and emergency transport. Vouchers were sold during the project's operational period from 2016 to 2019. This study covers 8 out of 25 project-benefiting districts in Uganda and a total of 1,881 pregnancies, including both beneficiary and non-beneficiary mothers. Using a matching design, the results show a positive effect on the survival of new-born babies. The difference in the survival rate between the control group and the treatment group is 5.4% points, indicating that the voucher project reduced infant mortality by more than 65 per cent.


Assuntos
Saúde Reprodutiva , Humanos , Feminino , Uganda , Gravidez , Recém-Nascido , Adulto , Mortalidade Infantil , Acessibilidade aos Serviços de Saúde , Serviços de Saúde Materna , Cuidado Pré-Natal , Lactente , Financiamento Governamental
2.
Life (Basel) ; 12(2)2022 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-35207580

RESUMO

Cardiac hypertrophy is an important and independent risk factor for the development of cardiac myopathy that may lead to heart failure. The mechanisms underlying the development of cardiac hypertrophy are yet not well understood. To increase the knowledge about mechanisms and regulatory pathways involved in the progression of cardiac hypertrophy, we have developed a human induced pluripotent stem cell (hiPSC)-based in vitro model of cardiac hypertrophy and performed extensive characterization using a multi-omics approach. In a series of experiments, hiPSC-derived cardiomyocytes were stimulated with Endothelin-1 for 8, 24, 48, and 72 h, and their transcriptome and secreted proteome were analyzed. The transcriptomic data show many enriched canonical pathways related to cardiac hypertrophy already at the earliest time point, e.g., cardiac hypertrophy signaling. An integrated transcriptome-secretome analysis enabled the identification of multimodal biomarkers that may prove highly relevant for monitoring early cardiac hypertrophy progression. Taken together, the results from this study demonstrate that our in vitro model displays a hypertrophic response on both transcriptomic- and secreted-proteomic levels. The results also shed novel insights into the underlying mechanisms of cardiac hypertrophy, and novel putative early cardiac hypertrophy biomarkers have been identified that warrant further investigation to assess their potential clinical relevance.

3.
Eur Radiol ; 32(4): 2404-2413, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34786614

RESUMO

OBJECTIVES: To evaluate the effects of center experience and a variety of patient- and procedure-related factors on patient radiation exposure during prostatic artery embolization (PAE) in three Scandinavian centers with different PAE protocols and levels of experience. Understanding factors that influence radiation exposure is crucial in effective patient selection and procedural planning. METHODS: Data were collected retrospectively for 352 consecutive PAE procedures from January 2015 to June 2020 at the three centers. Dose area product (DAP (Gy·cm2)) was selected as the primary outcome measure of radiation exposure. Multiple patient- and procedure-related explanatory variables were collected and correlated with the outcome variable. A multiple linear regression model was built to determine significant predictors of increased or decreased radiation exposure as reflected by DAP. RESULTS: There was considerable variation in DAP between the centers. Intended unilateral PAE (p = 0.03) and each 10 additional patients treated (p = 0.02) were significant predictors of decreased DAP. Conversely, increased patient body mass index (BMI, p < 0.001), fluoroscopy time (p < 0.001), and number of digital subtraction angiography (DSA) acquisitions (p < 0.001) were significant predictors of increased DAP. CONCLUSIONS: To minimize patient radiation exposure during PAE radiologists may, in collaboration with clinicians, consider unilateral embolization, pre-interventional CTA for procedure planning, using predominantly anteroposterior (AP) projections, and limiting the use of cone-beam CT (CBCT) and fluoroscopy. KEY POINTS: • Growing center experience and intended unilateral embolization decrease patient radiation exposure during prostatic artery embolization. • Patient BMI, fluoroscopy time, and number of DSA acquisitions are associated with increased DAP during procedures. • Large variation in radiation exposure between the centers may reflect the use of CTA before and CBCT during the procedure.


Assuntos
Embolização Terapêutica , Hiperplasia Prostática , Exposição à Radiação , Angiografia Digital/métodos , Artérias/diagnóstico por imagem , Embolização Terapêutica/métodos , Fluoroscopia , Humanos , Masculino , Próstata/irrigação sanguínea , Próstata/diagnóstico por imagem , Hiperplasia Prostática/diagnóstico por imagem , Hiperplasia Prostática/terapia , Doses de Radiação , Estudos Retrospectivos
4.
J Biotechnol ; 326: 1-10, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33285150

RESUMO

A common approach for analyzing large-scale molecular data is to cluster objects sharing similar characteristics. This assumes that genes with highly similar expression profiles are likely participating in a common molecular process. Biological systems are extremely complex and challenging to understand, with proteins having multiple functions that sometimes need to be activated or expressed in a time-dependent manner. Thus, the strategies applied for clustering of these molecules into groups are of key importance for translation of data to biologically interpretable findings. Here we implemented a multi-assignment clustering (MAsC) approach that allows molecules to be assigned to multiple clusters, rather than single ones as in commonly used clustering techniques. When applied to high-throughput transcriptomics data, MAsC increased power of the downstream pathway analysis and allowed identification of pathways with high biological relevance to the experimental setting and the biological systems studied. Multi-assignment clustering also reduced noise in the clustering partition by excluding genes with a low correlation to all of the resulting clusters. Together, these findings suggest that our methodology facilitates translation of large-scale molecular data into biological knowledge. The method is made available as an R package on GitLab (https://gitlab.com/wolftower/masc).


Assuntos
Algoritmos , Aprendizado de Máquina , Análise por Conglomerados , Perfilação da Expressão Gênica
5.
Biol Open ; 9(9)2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32878883

RESUMO

Cardiac hypertrophy is an important and independent risk factor for the development of heart failure. To better understand the mechanisms and regulatory pathways involved in cardiac hypertrophy, there is a need for improved in vitro models. In this study, we investigated how hypertrophic stimulation affected human induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs). The cells were stimulated with endothelin-1 (ET-1) for 8, 24, 48, 72, or 96 h. Parameters including cell size, ANP-, proBNP-, and lactate concentration were analyzed. Moreover, transcriptional profiling using RNA-sequencing was performed to identify differentially expressed genes following ET-1 stimulation. The results show that the CMs increase in size by approximately 13% when exposed to ET-1 in parallel to increases in ANP and proBNP protein and mRNA levels. Furthermore, the lactate concentration in the media was increased indicating that the CMs consume more glucose, a hallmark of cardiac hypertrophy. Using RNA-seq, a hypertrophic gene expression pattern was also observed in the stimulated CMs. Taken together, these results show that hiPSC-derived CMs stimulated with ET-1 display a hypertrophic response. The results from this study also provide new molecular insights about the underlying mechanisms of cardiac hypertrophy and may help accelerate the development of new drugs against this condition.


Assuntos
Cardiomegalia/patologia , Miócitos Cardíacos/citologia , Biomarcadores , Diferenciação Celular , Tamanho Celular , Células Cultivadas , Biologia Computacional/métodos , Citometria de Fluxo , Imunofluorescência , Perfilação da Expressão Gênica , Ontologia Genética , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Miócitos Cardíacos/patologia , Transcriptoma
6.
ACS Omega ; 5(10): 4816-4827, 2020 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-32201767

RESUMO

Human pluripotent stem cell-derived hepatocytes (hPSC-HEP) display many properties of mature hepatocytes, including expression of important genes of the drug metabolizing machinery, glycogen storage, and production of multiple serum proteins. To this date, hPSC-HEP do not, however, fully recapitulate the complete functionality of in vivo mature hepatocytes. In this study, we applied versatile bioinformatic algorithms, including functional annotation and pathway enrichment analyses, transcription factor binding-site enrichment, and similarity and correlation analyses, to datasets collected from different stages during hPSC-HEP differentiation and compared these to developmental stages and tissues from fetal and adult human liver. Our results demonstrate a high level of similarity between the in vitro differentiation of hPSC-HEP and in vivo hepatogenesis. Importantly, the transcriptional correlation of hPSC-HEP with adult liver (AL) tissues was higher than with fetal liver (FL) tissues (0.83 and 0.70, respectively). Functional data revealed mature features of hPSC-HEP including cytochrome P450 enzymes activities and albumin secretion. Moreover, hPSC-HEP showed expression of many genes involved in drug absorption, distribution, metabolism, and excretion. Despite the high similarities observed, we identified differences of specific pathways and regulatory players by analyzing the gene expression between hPSC-HEP and AL. These findings will aid future intervention and improvement of in vitro hepatocyte differentiation protocol in order to generate hepatocytes displaying the complete functionality of mature hepatocytes. Finally, on the transcriptional level, our results show stronger correlation and higher similarity of hPSC-HEP to AL than to FL. In addition, potential targets for further functional improvement of hPSC-HEP were also identified.

7.
Int J Mol Sci ; 21(2)2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31940797

RESUMO

There is a strong anticipated future for human induced pluripotent stem cell-derived hepatocytes (hiPS-HEP), but so far, their use has been limited due to insufficient functionality. We investigated the potential of hiPS-HEP as an in vitro model for metabolic diseases by combining transcriptomics with multiple functional assays. The transcriptomics analysis revealed that 86% of the genes were expressed at similar levels in hiPS-HEP as in human primary hepatocytes (hphep). Adult characteristics of the hiPS-HEP were confirmed by the presence of important hepatocyte features, e.g., Albumin secretion and expression of major drug metabolizing genes. Normal energy metabolism is crucial for modeling metabolic diseases, and both transcriptomics data and functional assays showed that hiPS-HEP were similar to hphep regarding uptake of glucose, low-density lipoproteins (LDL), and fatty acids. Importantly, the inflammatory state of the hiPS-HEP was low under standard conditions, but in response to lipid accumulation and ER stress the inflammation marker tumor necrosis factor α (TNFα) was upregulated. Furthermore, hiPS-HEP could be co-cultured with primary hepatic stellate cells both in 2D and in 3D spheroids, paving the way for using these co-cultures for modeling non-alcoholic steatohepatitis (NASH). Taken together, hiPS-HEP have the potential to serve as an in vitro model for metabolic diseases. Furthermore, differently expressed genes identified in this study can serve as targets for future improvements of the hiPS-HEP.


Assuntos
Hepatócitos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Doenças Metabólicas/metabolismo , Transcriptoma , Idoso , Diferenciação Celular , Linhagem Celular , Células Cultivadas , Estresse do Retículo Endoplasmático , Metabolismo Energético , Ácidos Graxos/metabolismo , Feminino , Glucose/metabolismo , Hepatócitos/citologia , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Lipoproteínas LDL/metabolismo , Masculino , Doenças Metabólicas/genética , Pessoa de Meia-Idade , Cultura Primária de Células/métodos , Esferoides Celulares/citologia , Esferoides Celulares/metabolismo
8.
Sci Rep ; 9(1): 4658, 2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30874605

RESUMO

Neurodegenerative diseases such as Alzheimer's disease are characterized by the progressive spreading and accumulation of hyper-phosphorylated tau protein in the brain. Anti-tau antibodies have been shown to reduce tau pathology in in vivo models and antibody-mediated clearance of tau exerted by microglia has been proposed as a contributing factor. By subjecting primary microglia cultured in vitro to anti-phospho-tau antibodies in complex with pathological tau, we show that microglia internalise and degrade tau in a manner that is dependent on FcγR interaction and functional lysosomes. It has recently been discussed if anti-tau antibody effector-functions are required for induction of tau clearance. Using antibodies with compromised FcγR binding and non-compromised control antibodies we show that antibody effector functions are required for induction of microglial clearance of tau. Understanding the inflammatory consequences of targeting microglia using therapeutic antibodies is important when developing these molecules for clinical use. Using RNA sequencing, we show that treatment with anti-tau antibodies increases transcription of mRNA encoding pro-inflammatory markers, but that the mRNA expression profile of antibody-treated cells differ from the profile of LPS activated microglia. We further demonstrate that microglia activation alone is not sufficient to induce significant tau clearance.


Assuntos
Lisossomos/metabolismo , Microglia/metabolismo , Receptores de IgG/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/metabolismo , Animais , Anticorpos/metabolismo , Encéfalo/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Neurônios/metabolismo , Fosforilação , Cultura Primária de Células , Receptores de IgG/imunologia , Proteínas tau/imunologia
9.
Alzheimers Dement (N Y) ; 4: 521-534, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30386817

RESUMO

INTRODUCTION: The abnormal hyperphosphorylation of the microtubule-associated protein tau plays a crucial role in neurodegeneration in Alzheimer's disease (AD) and other tauopathies. METHODS: Highly specific and selective anti-pS396-tau antibodies have been generated using peptide immunization with screening against pathologic hyperphosphorylated tau from rTg4510 mouse and AD brains and selection in in vitro and in vivo tau seeding assays. RESULTS: The antibody C10.2 bound specifically to pS396-tau with an IC50 of 104 pM and detected preferentially hyperphosphorylated tau aggregates from AD brain with an IC50 of 1.2 nM. C10.2 significantly reduced tau seeding of P301L human tau in HEK293 cells, murine cortical neurons, and mice. AD brain extracts depleted with C10.2 were not able to seed tau in vitro and in vivo, demonstrating that C10.2 specifically recognized pathologic seeding-competent tau. DISCUSSION: Targeting pS396-tau with an antibody like C10.2 may provide therapeutic benefit in AD and other tauopathies.

10.
Toxicol Sci ; 163(1): 182-195, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29385562

RESUMO

Anthracyclines, such as doxorubicin, are highly efficient chemotherapeutic agents against a variety of cancers. However, anthracyclines are also among the most cardiotoxic therapeutic drugs presently on the market. Chemotherapeutic-induced cardiomyopathy is one of the leading causes of disease and mortality in cancer survivors. The exact mechanisms responsible for doxorubicin-induced cardiomyopathy are not completely known, but the fact that the cardiotoxicity is dose-dependent and that there is a variation in time-to-onset of toxicity, and gender- and age differences suggests that several mechanisms may be involved. In this study, we investigated doxorubicin-induced cardiotoxicity in human pluripotent stem cell-derived cardiomyocytes using proteomics. In addition, different sources of omics data (protein, mRNA, and microRNA) from the same experimental setup were further combined and analyzed using newly developed methods to identify differential expression in data of various origin and types. Subsequently, the results were integrated in order to generate a combined visualization of the findings. In our experimental model system, we exposed cardiomyocytes derived from human pluripotent stem cells to doxorubicin for up to 2 days, followed by a wash-out period of additionally 12 days. Besides an effect on the cell morphology and cardiomyocyte functionality, the data show a strong effect of doxorubicin on all molecular levels investigated. Differential expression patterns that show a linkage between the proteome, transcriptome, and the regulatory microRNA network, were identified. These findings help to increase the understanding of the mechanisms behind anthracycline-induced cardiotoxicity and suggest putative biomarkers for this condition.


Assuntos
Antibióticos Antineoplásicos/toxicidade , Doxorrubicina/toxicidade , Miócitos Cardíacos/efeitos dos fármacos , Células-Tronco Pluripotentes/citologia , Proteínas/metabolismo , Transcriptoma/efeitos dos fármacos , Biomarcadores/metabolismo , Cardiotoxicidade , Células Cultivadas , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
11.
Physiol Genomics ; 49(8): 430-446, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28698227

RESUMO

Hepatocytes derived from human pluripotent stem cells (hPSC-HEP) have the potential to replace presently used hepatocyte sources applied in liver disease treatment and models of drug discovery and development. Established hepatocyte differentiation protocols are effective and generate hepatocytes, which recapitulate some key features of their in vivo counterparts. However, generating mature hPSC-HEP remains a challenge. In this study, we applied transcriptomics to investigate the progress of in vitro hepatic differentiation of hPSCs at the developmental stages, definitive endoderm, hepatoblasts, early hPSC-HEP, and mature hPSC-HEP, to identify functional targets that enhance efficient hepatocyte differentiation. Using functional annotation, pathway and protein interaction network analyses, we observed the grouping of differentially expressed genes in specific clusters representing typical developmental stages of hepatic differentiation. In addition, we identified hub proteins and modules that were involved in the cell cycle process at early differentiation stages. We also identified hub proteins that differed in expression levels between hPSC-HEP and the liver tissue controls. Moreover, we identified a module of genes that were expressed at higher levels in the liver tissue samples than in the hPSC-HEP. Considering that hub proteins and modules generally are essential and have important roles in the protein-protein interactions, further investigation of these genes and their regulators may contribute to a better understanding of the differentiation process. This may suggest novel target pathways and molecules for improvement of hPSC-HEP functionality, having the potential to finally bring this technology to a wider use.


Assuntos
Fígado/citologia , Fígado/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Técnicas de Cultura de Células , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem Celular , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Transcriptoma/genética
12.
PLoS One ; 12(6): e0179613, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28654683

RESUMO

The development of high-throughput biomolecular technologies has resulted in generation of vast omics data at an unprecedented rate. This is transforming biomedical research into a big data discipline, where the main challenges relate to the analysis and interpretation of data into new biological knowledge. The aim of this study was to develop a framework for biomedical big data analytics, and apply it for analyzing transcriptomics time series data from early differentiation of human pluripotent stem cells towards the mesoderm and cardiac lineages. To this end, transcriptome profiling by microarray was performed on differentiating human pluripotent stem cells sampled at eleven consecutive days. The gene expression data was analyzed using the five-stage analysis framework proposed in this study, including data preparation, exploratory data analysis, confirmatory analysis, biological knowledge discovery, and visualization of the results. Clustering analysis revealed several distinct expression profiles during differentiation. Genes with an early transient response were strongly related to embryonic- and mesendoderm development, for example CER1 and NODAL. Pluripotency genes, such as NANOG and SOX2, exhibited substantial downregulation shortly after onset of differentiation. Rapid induction of genes related to metal ion response, cardiac tissue development, and muscle contraction were observed around day five and six. Several transcription factors were identified as potential regulators of these processes, e.g. POU1F1, TCF4 and TBP for muscle contraction genes. Pathway analysis revealed temporal activity of several signaling pathways, for example the inhibition of WNT signaling on day 2 and its reactivation on day 4. This study provides a comprehensive characterization of biological events and key regulators of the early differentiation of human pluripotent stem cells towards the mesoderm and cardiac lineages. The proposed analysis framework can be used to structure data analysis in future research, both in stem cell differentiation, and more generally, in biomedical big data analytics.


Assuntos
Diferenciação Celular/fisiologia , Linhagem da Célula/fisiologia , Mesoderma/citologia , Células-Tronco Pluripotentes/citologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Humanos
13.
J Chromatogr A ; 1481: 73-81, 2017 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-28017561

RESUMO

Biomolecular and pharmaceutical downstream processing is dominated by chromatographic separation, which is associated with high product quality, low capacity and high costs. The separation can be optimized to minimize the costs while achieving a high purity. This paper presents an experimental validation of a discretized multi-level elution (DiME) trajectory, implemented on commercially available chromatography equipment. The tertiary protein separation of ribonuclease A, cytochrome C and lysozyme was used as a case study. A mechanistic model was calibrated using step and linear gradient experiments. The model was simulated together with the state sensitivities with respect to model parameters, which was used in the Levenberg-Marquardt algorithm to fit the model response to the experimental data. The model was used to solve the dynamic optimization problem of maximizing the yield of cytochrome C given a 95% purity requirement, 1000s processing time and 50 salt concentration levels in the elution trajectory. The model was spatially discretized using finite volumes and temporally discretized using direct collocation. The corresponding non-linear programming problem was solved with IPOPT. Once the optimal salt trajectory was found it was experimentally implemented on an ÄKTA Pure using an OPC interface. The optimal trajectory was analyzed in-line by UV absorbance measurements and off-line by analysis of collected fractions. The results presented in this study show the successful experimental realization of DiME trajectories and how to use model calibration, optimization and control to realize DiME trajectories for any chromatography separation problem.


Assuntos
Modelos Teóricos , Proteínas/isolamento & purificação , Adsorção , Algoritmos , Calibragem , Cromatografia , Simulação por Computador , Reprodutibilidade dos Testes , Sais/química
14.
Toxicol In Vitro ; 34: 26-34, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27033315

RESUMO

Anthracyclines, such as doxorubicin, are well-established, highly efficient anti-neoplastic drugs used for treatment of a variety of cancers, including solid tumors, leukemia, lymphomas, and breast cancer. The successful use of doxorubicin has, however, been hampered by severe cardiotoxic side-effects. In order to prevent or reverse negative side-effects of doxorubicin, it is important to find early biomarkers of heart injury and drug-induced cardiotoxicity. The high stability under extreme conditions, presence in various body fluids, and tissue-specificity, makes microRNAs very suitable as clinical biomarkers. The present study aimed towards evaluating the early and late effects of doxorubicin on the microRNA expression in cardiomyocytes derived from human pluripotent stem cells. We report on several microRNAs, including miR-34a, miR-34b, miR-187, miR-199a, miR-199b, miR-146a, miR-15b, miR-130a, miR-214, and miR-424, that are differentially expressed upon, and after, treatment with doxorubicin. Investigation of the biological relevance of the identified microRNAs revealed connections to cardiomyocyte function and cardiotoxicity, thus supporting the findings of these microRNAs as potential biomarkers for drug-induced cardiotoxicity.


Assuntos
Antibióticos Antineoplásicos/toxicidade , Cardiotoxicidade/genética , Doxorrubicina/toxicidade , MicroRNAs/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Biomarcadores/metabolismo , Cardiotoxicidade/etiologia , Células Cultivadas , Humanos , Miócitos Cardíacos/metabolismo
15.
Mol Cell Biochem ; 352(1-2): 47-55, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21298325

RESUMO

The liver is an important target for interleukin-6 (IL-6) action leading to an increased inflammatory response with impaired insulin signaling and action. The aims of this study are to address if insulin is anti-inflammatory and attenuates IL-6-induced inflammation in the human hepatoma cell line HepG2 and if this involves signal transducer and activator of transcription 3 (STAT3) signal transduction. It was found that insulin significantly reduced IL-6-induced gene transcription of serum amyloid 1 (SAA1), serum amyloid 2 (SAA2), haptoglobin, orosomucoid, and plasmin activator inhibitor-1 (PAI-1). However, the authors did not find any evidence that insulin inhibited IL-6 signal transduction, i.e., no effect of insulin was detected on STAT3 phosphorylation or its translocation to cell nucleus. The potential role of PKCδ was also analyzed but no evidence of its involvement was found. Taken together, these results suggest that the anti-inflammatory effect of insulin on IL-6 action is exerted at the level of the transcriptional activation of the genes. Further analysis revealed that insulin regulates nuclear localization of FOXO1, which is an important co-activator for STAT3 mediated transcription. Insulin induced nuclear exit and Thr24 phosphorylation of FOXO1, thus, inhibiting STAT3-mediated transcription.


Assuntos
Carcinoma Hepatocelular/metabolismo , Núcleo Celular/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Inflamação/prevenção & controle , Insulina/fisiologia , Interleucina-6/genética , Neoplasias Hepáticas/metabolismo , Transcrição Gênica/fisiologia , Sequência de Bases , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Primers do DNA , Proteína Forkhead Box O1 , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Hepáticas/patologia , Reação em Cadeia da Polimerase , Proteína Quinase C-delta/genética , RNA Interferente Pequeno/genética , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Transfecção
17.
Bioprocess Biosyst Eng ; 33(6): 711-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19921276

RESUMO

During dual-phase fermentations using Escherichia coli engineered for succinic acid production, the productivity and viable cell concentration decrease as the concentration of succinic acid increases. The effects of succinic acid on the fermentation kinetics, yield, and cell viability were investigated by resuspending cells in fresh media after selected fermentation times. The cellular succinic acid productivity could be restored, but cell viability continuously decreased throughout the fermentations by up to 80% and subsequently the volumetric productivity was reduced. Omitting complex nutrients in the resuspension media had no significant effect on cellular succinate productivity and yield, although the viable cell concentration and thus the volumetric productivity was reduced by approximately 20%. By resuspending the cells, the amount of succinate produced during a 100-h fermentation was increased by more than 60%. The results demonstrate that by product removal succinic acid productivity can be maintained at high levels for extended periods of time.


Assuntos
Meios de Cultura , Escherichia coli/enzimologia , Ácido Succínico/metabolismo , Anaerobiose , Técnicas Bacteriológicas , Escherichia coli/crescimento & desenvolvimento , Fermentação , Cinética , Ácido Succínico/isolamento & purificação , Ácido Succínico/farmacologia , Fatores de Tempo
18.
Biotechnol Prog ; 25(1): 116-23, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19198001

RESUMO

The economical viability of biochemical succinic acid production is a result of many processing parameters including final succinic acid concentration, recovery of succinate, and the volumetric productivity. Maintaining volumetric productivities >2.5 g L(-1) h(-1) is important if production of succinic acid from renewable resources should be competitive. In this work, the effects of organic acids, osmolarity, and neutralizing agent (NH4OH, KOH, NaOH, K2CO3, and Na2CO3), and Na2CO3) on the fermentative succinic acid production by Escherichia coli AFP184 were investigated. The highest concentration of succinic acid, 77 g L(-1), was obtained with Na2CO3. In general, irrespective of the base used, succinic acid productivity per viable cell was significantly reduced as the concentration of the produced acid increased. Increased osmolarity resulting from base addition during succinate production only marginally affected the productivity per viable cell. Addition of the osmoprotectant glycine betaine to cultures resulted in an increased aerobic growth rate and anaerobic glucose consumption rate, but decreased succinic acid yield. When using NH4OH productivity completely ceased at a succinic acid concentration of approximately 40 g L(-1). Volumetric productivities remained at 2.5 g L(-1) h(-1) for up to 10 h longer when K- or Na-bases where used instead of NH4OH. The decrease in cellular succinic acid productivity observed during the anaerobic phase was found to be due to increased organic acid concentrations rather than medium osmolarity.


Assuntos
Ácidos/farmacologia , Álcalis/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Concentração Osmolar , Ácido Succínico/metabolismo , Hidróxido de Amônia , Carbonatos/farmacologia , Escherichia coli/crescimento & desenvolvimento , Fermentação , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Hidróxidos/farmacologia , Potássio/farmacologia , Compostos de Potássio/farmacologia , Hidróxido de Sódio/farmacologia
19.
Diabetes Metab Res Rev ; 24(8): 595-603, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18756581

RESUMO

Type 2 diabetes is the most common metabolic disorder today and has reached epidemic proportions in many countries. Insulin resistance and inflammation play a central role in the pathogenesis of type 2 diabetes and are present long before the onset of the disease. During this time, many of the complications associated with type 2 diabetes are initiated. Of major concern is the two- to fourfold increase in cardiovascular morbidity and mortality in this group compared to a nondiabetic population. Obesity, characterized by enlarged fat cells, and insulin resistance are, like type 2 diabetes, associated with impaired adipogenesis and a low-grade chronic inflammation that to a large extent emanates from the adipose tissue. Both these processes contribute to unfavourable alterations of the circulating levels of several bioactive molecules (adipokines) that are secreted from the adipose tissue, many of which have documented inhibitory effects on insulin sensitivity in the liver and peripheral tissues and, in addition, have negative effects on the cardiovascular system.Here we review current knowledge of the adipose tissue as an endocrine organ, the local and systemic effects of a chronic state of low-grade inflammation residing in the adipose tissue, and, in particular, the effects of inflammation and circulating adipokines on the vascular wall.


Assuntos
Adipocinas/fisiologia , Tecido Adiposo/irrigação sanguínea , Tecido Adiposo/fisiopatologia , Inflamação/fisiopatologia , Resistência à Insulina , Doenças Vasculares/fisiopatologia , Células 3T3 , Adipócitos/patologia , Adipócitos/fisiologia , Animais , Diabetes Mellitus Tipo 2/etiologia , Humanos , Macrófagos/fisiologia , Camundongos
20.
Arterioscler Thromb Vasc Biol ; 27(11): 2276-83, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17823366

RESUMO

The metabolic syndrome is associated with a dysregulated adipose tissue; in part a consequence of adipose cell enlargement and the associated infiltration of macrophages. Adipose cell enlargement leads to a proinflammatory state in the cells with reduced secretion of adiponectin and with increased secretion of several cytokines and chemokines including interleukin (IL)-6, IL-8, and MCP-1. MCP-1 has been shown to play an important role for the associated recruitment of macrophages into the adipose tissue. The increased release of cytokines leads to an impaired differentiation of the preadipocytes with reduced lipid accumulation and induction of adiponectin, thus promoting ectopic lipid storage. In particular tumor necrosis factor (TNF) alpha, but also IL-6, has been shown to induce these effects in preadipocytes and this is associated with an increased Wnt signaling maintaining the cells in an undifferentiated and proinflammatory state. The proinflammatory state in the adipose tissue also leads to a local insulin resistance including an impaired inhibitory effect of insulin on FFA release. The insulin resistance further supports the proinflammatory state because insulin, by itself, is both antilipolytic and antiinflammatory by antagonizing cytokine-induced activation of STAT signaling.


Assuntos
Tecido Adiposo/imunologia , Inflamação/fisiopatologia , Síndrome Metabólica/imunologia , Adipogenia/imunologia , Aterosclerose/imunologia , Citocinas/imunologia , Citocinas/metabolismo , Humanos , Insulina/fisiologia , Ativação de Macrófagos/imunologia , Síndrome Metabólica/fisiopatologia
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