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1.
Nucleic Acids Res ; 52(7): 3971-3988, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38300787

RESUMO

The RAVER1 protein serves as a co-factor in guiding the polypyrimidine tract-binding protein (PTBP)-dependent control of alternative splicing (AS). Whether RAVER1 solely acts in concert with PTBPs and how it affects cancer cell fate remained elusive. Here, we provide the first comprehensive investigation of RAVER1-controlled AS in cancer cell models. This reveals a pro-oncogenic role of RAVER1 in modulating tumor growth and epithelial-mesenchymal-transition (EMT). Splicing analyses and protein-association studies indicate that RAVER1 guides AS in association with other splicing regulators, including PTBPs and SRSFs. In cancer cells, one major function of RAVER1 is the stimulation of proliferation and restriction of apoptosis. This involves the modulation of AS events within the miR/RISC pathway. Disturbance of RAVER1 impairs miR/RISC activity resulting in severely deregulated gene expression, which promotes lethal TGFB-driven EMT. Among others, RAVER1-modulated splicing events affect the insertion of protein interaction modules in factors guiding miR/RISC-dependent gene silencing. Most prominently, in all three human TNRC6 proteins, RAVER1 controls AS of GW-enriched motifs, which are essential for AGO2-binding and the formation of active miR/RISC complexes. We propose, that RAVER1 is a key modulator of AS events in the miR/RISC pathway ensuring proper abundance and composition of miR/RISC effectors. This ensures balanced expression of TGFB signaling effectors and limits TGFB induced lethal EMT.


Assuntos
Processamento Alternativo , Transição Epitelial-Mesenquimal , MicroRNAs , Transição Epitelial-Mesenquimal/genética , Humanos , MicroRNAs/metabolismo , MicroRNAs/genética , Linhagem Celular Tumoral , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Ligação a RNA/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Regulação Neoplásica da Expressão Gênica , Proliferação de Células/genética , Apoptose/genética , Fator de Crescimento Transformador beta/metabolismo , Animais
2.
Nature ; 572(7769): 355-357, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31413376

RESUMO

The Juno mission1 has provided an accurate determination of Jupiter's gravitational field2, which has been used to obtain information about the planet's composition and internal structure. Several models of Jupiter's structure that fit the probe's data suggest that the planet has a diluted core, with a total heavy-element mass ranging from ten to a few tens of Earth masses (about 5 to 15 per cent of the Jovian mass), and that  heavy elements (elements other than hydrogen and helium) are distributed within a region extending to nearly half of Jupiter's radius3,4. Planet-formation models indicate that most heavy elements are accreted during the early stages of a planet's formation to create a relatively compact core5-7 and that almost no solids are accreted during subsequent runaway gas accretion8-10. Jupiter's diluted core, combined with its possible high heavy-element enrichment, thus challenges standard planet-formation theory. A possible explanation is erosion of the initially compact heavy-element core, but the efficiency of such erosion is uncertain and depends on both the immiscibility of heavy materials in metallic hydrogen and on convective mixing as the planet evolves11,12. Another mechanism that can explain this structure is planetesimal enrichment and vaporization13-15 during the formation process, although relevant models typically cannot produce an extended diluted core. Here we show that a sufficiently energetic head-on collision (giant impact) between a large planetary embryo and the proto-Jupiter could have shattered its primordial compact core and mixed the heavy elements with the inner envelope. Models of such a scenario lead to an internal structure that is consistent with a diluted core, persisting over billions of years. We suggest that collisions were common in the young Solar system and that a similar event may have also occurred for Saturn, contributing to the structural differences between Jupiter and Saturn16-18.

3.
BMC Med Educ ; 24(1): 116, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38321407

RESUMO

BACKGROUND: Dermatology teaching is fundamental for the promotion of young colleagues in our specialty. However, traditional teaching methods are being scrutinized by students of the 'Generation Y and Z', which can pose new challenges for teaching institutions. We therefore aimed to assess the motivational impact and reception of a newly created four-week curriculum containing modernized teaching methods integrated into clinical routine. METHODS: In this single-center study, 67 medical students completed this curriculum composed of weekly learning objectives including knowledge of morphological terms, 10 common dermatoses, communication and presentation skills. The participants provided information on their level of interest in dermatology each week as well as positive and negative aspects of the curriculum. RESULTS: During the curriculum a significant median increase in interest in dermatology was reported with no differences between the genders. Low initial interest could be improved, high initial interest maintained. Participants with an interest in scientific work (20.9%) were more motivated during the curriculum. The variety, quality of teaching and structure were the main aspects rated positively. Suggestions for improvement included the need for more teaching by senior doctors, transfer of responsibility, and a working environment updated to the latest technology standards. CONCLUSION: The presented curriculum was well received by the participants and allowed to better define learning preferences of new generations which can be helpful to modernize traditional teaching methods. Interest in scientific work could be a factor to identify students with a particularly strong interest in dermatology.


Assuntos
Dermatologia , Educação de Graduação em Medicina , Estudantes de Medicina , Humanos , Masculino , Feminino , Dermatologia/educação , Educação de Graduação em Medicina/métodos , Currículo , Aprendizagem , Ensino
4.
J Neurosci ; 42(40): 7673-7688, 2022 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-36333098

RESUMO

As the CNS-resident macrophages and member of the myeloid lineage, microglia fulfill manifold functions important for brain development and homeostasis. In the context of neurodegenerative diseases, they have been implicated in degenerative and regenerative processes. The discovery of distinct activation patterns, including increased phagocytosis, indicated a damaging role of myeloid cells in multiple system atrophy (MSA), a devastating, rapidly progressing atypical parkinsonian disorder. Here, we analyzed the gene expression profile of microglia in a mouse model of MSA (MBP29-hα-syn) and identified a disease-associated expression profile and upregulation of the colony-stimulating factor 1 (Csf1). Thus, we hypothesized that CSF1 receptor-mediated depletion of myeloid cells using PLX5622 modifies the disease progression and neuropathological phenotype in this mouse model. Intriguingly, sex-balanced analysis of myeloid cell depletion in MBP29-hα-syn mice revealed a two-faced outcome comprising an improved survival rate accompanied by a delayed onset of neurological symptoms in contrast to severely impaired motor functions. Furthermore, PLX5622 reversed gene expression profiles related to myeloid cell activation but reduced gene expression associated with transsynaptic signaling and signal release. While transcriptional changes were accompanied by a reduction of dopaminergic neurons in the SNpc, striatal neuritic density was increased upon myeloid cell depletion in MBP29-hα-syn mice. Together, our findings provide insight into the complex, two-faced role of myeloid cells in the context of MSA emphasizing the importance to carefully balance the beneficial and adverse effects of CSF1R inhibition in different models of neurodegenerative disorders before its clinical translation.SIGNIFICANCE STATEMENT Myeloid cells have been implicated as detrimental in the disease pathogenesis of multiple system atrophy. However, long-term CSF1R-dependent depletion of these cells in a mouse model of multiple system atrophy demonstrates a two-faced effect involving an improved survival associated with a delayed onset of disease and reduced inflammation which was contrasted by severely impaired motor functions, synaptic signaling, and neuronal circuitries. Thus, this study unraveled a complex role of myeloid cells in multiple system atrophy, which indicates important functions beyond the previously described disease-associated, destructive phenotype and emphasized the need of further investigation to carefully and individually fine-tune immunologic processes in different neurodegenerative diseases.


Assuntos
Atrofia de Múltiplos Sistemas , Animais , Camundongos , Atrofia de Múltiplos Sistemas/genética , Longevidade , Compostos Orgânicos/farmacologia , Microglia/metabolismo , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/genética , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/metabolismo , Modelos Animais de Doenças , Células Mieloides/metabolismo , Receptores de Fator Estimulador de Colônias
5.
Exp Dermatol ; 32(7): 1143-1155, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37114406

RESUMO

The translatability of research is highly dependent on models that recapitulate human tissues and organs. Here, we describe a procedure for the generation of human epidermis organotypic cultures (HEOCs) from primary keratinocytes isolated from foreskin and adult skin as well as from an immortalized keratinocyte cell line (KerTr). We tested several media conditions to develop a defined HEOC growing and expansion media. We characterized the HEOCs and show that in optimal culture conditions they express the proliferation marker Ki67, the basement membrane protein collagen 17 (col17) and the epidermal differentiation markers keratin 15 (K15), keratin 14 (K14), keratin 5 (K5), keratin 10 (K10), keratin 1 (K1), transglutaminase 1 (TGM1), transglutaminase 3 (TGM3) and filaggrin (FLG). Thus, they recapitulate the human epidermis and are stratified from the basal layer to the stratum corneum. These HEOC can be generated reproducibly on a large scale, making it an invaluable model for screening therapeutic compounds and also for the study of pathologies affecting the epidermis.


Assuntos
Epiderme , Sistemas Microfisiológicos , Adulto , Humanos , Diferenciação Celular , Epiderme/metabolismo , Células Epidérmicas/metabolismo , Queratinócitos/metabolismo , Queratinas/metabolismo , Transglutaminases/metabolismo
6.
J Dtsch Dermatol Ges ; 21(3): 239-243, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36892188

RESUMO

Colchicine, which was already used by the ancient Egyptians, has recently experienced a renaissance in various medical disciplines, including dermatology. However, due to the potentially significant side effects of systemic use, many clinicians are cautious in their use of colchicine. This review provides a practical overview of the data on the established and emerging use of systemic and topical colchicine in dermatologic diseases.


Assuntos
Colchicina , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Colchicina/uso terapêutico , Colchicina/farmacologia
7.
Clin Exp Allergy ; 52(5): 670-683, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35073608

RESUMO

BACKGROUND: Inconsistent data exist regarding the influence of parasitic infection on the prevalence of allergic sensitization and disorders. OBJECTIVE: To investigate the impact of geohelminth and protozoan infections on sensitization patterns and allergic symptoms of children living in low-income communities in Gqeberha, South Africa. METHODS: In a cross-sectional study, 587 schoolchildren aged 8-12 years were recruited in June 2016 and screened for reactivity to common allergens by skin prick tests (SPTs) and for parasitic infections by stool examination. Additionally, questionnaires were completed to record allergic symptoms the children may have experienced. RESULTS: Positive SPTs were found in 237/587 children (40.4%), and about one-third of whom were polysensitized. Sensitizations were most frequently detected against the house dust mites (HDM) Dermatophagoides spp. (31.9%) and Blomia tropicalis (21.0%). Infections with geohelminths (Ascaris lumbricoides, Trichuris trichiura) were found in 26.8% and protozoan infections (Giardia intestinalis, Cryptosporidia spp.) in 13.9% of study participants. Mixed logistic regression analyses revealed negative associations between parasite infection and sensitization to Blomia tropicalis (OR: 0.54, 95% CI 0.33-0.89) and to Dermatophagoides spp. (OR 0.65, 95% CI 0.43-0.96), and between protozoan infection and allergic sensitization to any aeroallergen, although these associations were not significant when adjusted for false discovery. Geohelminth infection and intensity of geohelminth infection were both associated with reduced risk of polysensitization (OR 0.41, 95% CI 0.21-0.86), and this association remained significant with adjustment for false discovery. Reported respiratory symptoms were associated with HDM sensitization (ORs from 1.54 to 2.48), but not with parasite infection. CONCLUSIONS AND CLINICAL RELEVANCE: Our data suggest that geohelminth infection and high geohelminth infection intensity are associated with a reduced risk of polysensitization.


Assuntos
Alérgenos , Hipersensibilidade , Animais , Criança , Estudos Transversais , Humanos , Pyroglyphidae , Testes Cutâneos , África do Sul/epidemiologia
8.
Nucleic Acids Res ; 48(15): 8576-8590, 2020 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-32761127

RESUMO

The IGF2 mRNA-binding protein 1 (IGF2BP1) is a non-catalytic post-transcriptional enhancer of tumor growth upregulated and associated with adverse prognosis in solid cancers. However, conserved effector pathway(s) and the feasibility of targeting IGF2BP1 in cancer remained elusive. We reveal that IGF2BP1 is a post-transcriptional enhancer of the E2F-driven hallmark in solid cancers. IGF2BP1 promotes G1/S cell cycle transition by stabilizing mRNAs encoding positive regulators of this checkpoint like E2F1. This IGF2BP1-driven shortening of the G1 cell cycle phase relies on 3'UTR-, miRNA- and m6A-dependent regulation and suggests enhancement of cell cycle progression by m6A-modifications across cancers. In addition to E2F transcription factors, IGF2BP1 also stabilizes E2F-driven transcripts directly indicating post-transcriptional 'super'-enhancer role of the protein in E2F-driven gene expression in cancer. The small molecule BTYNB disrupts this enhancer function by impairing IGF2BP1-RNA association. Consistently, BTYNB interferes with E2F-driven gene expression and tumor growth in experimental mouse tumor models.


Assuntos
Fatores de Transcrição E2F/genética , Neoplasias/genética , Proteínas de Ligação a RNA/genética , Regiões 3' não Traduzidas/genética , Animais , Linhagem Celular Tumoral , Fator de Transcrição E2F1/genética , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Camundongos , Neoplasias/patologia , Proteínas de Ligação a RNA/efeitos dos fármacos , Bibliotecas de Moléculas Pequenas/farmacologia
9.
Am J Physiol Gastrointest Liver Physiol ; 320(1): G66-G80, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33174454

RESUMO

Human hepatic bile acid transporter Na+/taurocholate cotransporting polypeptide (NTCP) represents the liver-specific entry receptor for the hepatitis B and D viruses (HBV/HDV). Chronic hepatitis B and D affect several million people worldwide, but treatment options are limited. Recently, HBV/HDV entry inhibitors targeting NTCP have emerged as promising novel drug candidates. Nevertheless, the exact molecular mechanism that NTCP uses to mediate virus binding and entry into hepatocytes is still not completely understood. It is already known that human NTCP mRNA expression is downregulated under cholestasis. Furthermore, incubation of rat hepatocytes with the secondary bile acid taurolithocholic acid (TLC) triggers internalization of the rat Ntcp protein from the plasma membrane. In the present study, the long-term inhibitory effect of TLC on transport function, HBV/HDV receptor function, and membrane expression of human NTCP were analyzed in HepG2 and human embryonic kidney (HEK293) cells stably overexpressing NTCP. Even after short-pulse preincubation, TLC had a significant long-lasting inhibitory effect on the transport function of NTCP, but the NTCP protein was still present at the plasma membrane. Furthermore, binding of the HBV/HDV myr-preS1 peptide and susceptibility for in vitro HDV infection were significantly reduced by TLC preincubation. We hypothesize that TLC rapidly accumulates in hepatocytes and mediates long-lasting trans-inhibition of the transport and receptor function of NTCP via a particular TLC-binding site at an intracellularly accessible domain of NTCP. Physiologically, this trans-inhibition might protect hepatocytes from toxic overload of bile acids. Pharmacologically, it provides an interesting novel NTCP target site for potential long-acting HBV/HDV entry inhibitors.NEW & NOTEWORTHY The hepatic bile acid transporter NTCP is a high-affinity receptor for hepatitis B and D viruses. This study shows that TLC rapidly accumulates in NTCP-expressing hepatoma cells and mediates long-lasting trans-inhibition of NTCP's transporter and receptor function via an intracellularly accessible domain, without substantially affecting its membrane expression. This domain is a promising novel NTCP target site for pharmacological long-acting HBV/HDV entry inhibitors.


Assuntos
Vírus da Hepatite B/efeitos dos fármacos , Hepatite B/tratamento farmacológico , Hepatite D/tratamento farmacológico , Hepatócitos/efeitos dos fármacos , Transportadores de Ânions Orgânicos Dependentes de Sódio/farmacologia , Simportadores/farmacologia , Animais , Ácidos e Sais Biliares/metabolismo , Hepatite B/metabolismo , Hepatócitos/metabolismo , Ratos , Receptores Virais/efeitos dos fármacos , Receptores Virais/metabolismo
10.
RNA Biol ; 18(3): 391-403, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32876513

RESUMO

Epithelial-to-mesenchymal transition (EMT) is a hallmark of aggressive, mesenchymal-like high-grade serous ovarian carcinoma (HGSOC). The SRC kinase is a key driver of cancer-associated EMT promoting adherens junction (AJ) disassembly by phosphorylation-driven internalization and degradation of AJ proteins. Here, we show that the IGF2 mRNA-binding protein 1 (IGF2BP1) is up-regulated in mesenchymal-like HGSOC and promotes SRC activation by a previously unknown protein-ligand-induced, but RNA-independent mechanism. IGF2BP1-driven invasive growth of ovarian cancer cells essentially relies on the SRC-dependent disassembly of AJs. Concomitantly, IGF2BP1 enhances ERK2 expression in an RNA-binding dependent manner. Together this reveals a post-transcriptional mechanism of interconnected stimulation of SRC/ERK signalling in ovarian cancer cells. The IGF2BP1-SRC/ERK2 axis is targetable by the SRC-inhibitor saracatinib and MEK-inhibitor selumetinib. However, due to IGF2BP1-directed stimulation, only combinatorial treatment effectively overcomes the IGF2BP1-promoted invasive growth in 3D culture conditions as well as intraperitoneal mouse models. In conclusion, we reveal an unexpected role of IGF2BP1 in enhancing SRC/MAPK-driven invasive growth of ovarian cancer cells. This provides a rationale for the therapeutic benefit of combinatorial SRC/MEK inhibition in mesenchymal-like HGSOC.


Assuntos
Regulação Neoplásica da Expressão Gênica , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Neoplasias Ovarianas/etiologia , Neoplasias Ovarianas/metabolismo , Proteínas de Ligação a RNA/genética , Transdução de Sinais , Quinases da Família src/metabolismo , Junções Aderentes/genética , Junções Aderentes/metabolismo , Animais , Biomarcadores Tumorais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Transição Epitelial-Mesenquimal/genética , Feminino , Humanos , Camundongos , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Inibidores de Proteínas Quinases/farmacologia , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Domínios de Homologia de src , Quinases da Família src/antagonistas & inibidores
11.
Nucleic Acids Res ; 47(1): 375-390, 2019 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-30371874

RESUMO

The oncofetal mRNA-binding protein IGF2BP1 and the transcriptional regulator SRF modulate gene expression in cancer. In cancer cells, we demonstrate that IGF2BP1 promotes the expression of SRF in a conserved and N6-methyladenosine (m6A)-dependent manner by impairing the miRNA-directed decay of the SRF mRNA. This results in enhanced SRF-dependent transcriptional activity and promotes tumor cell growth and invasion. At the post-transcriptional level, IGF2BP1 sustains the expression of various SRF-target genes. The majority of these SRF/IGF2BP1-enhanced genes, including PDLIM7 and FOXK1, show conserved upregulation with SRF and IGF2BP1 synthesis in cancer. PDLIM7 and FOXK1 promote tumor cell growth and were reported to enhance cell invasion. Consistently, 35 SRF/IGF2BP1-dependent genes showing conserved association with SRF and IGF2BP1 expression indicate a poor overall survival probability in ovarian, liver and lung cancer. In conclusion, these findings identify the SRF/IGF2BP1-, miRNome- and m6A-dependent control of gene expression as a conserved oncogenic driver network in cancer.


Assuntos
MicroRNAs/genética , Proteínas de Ligação a RNA/genética , Fator de Resposta Sérica/genética , Adenosina/análogos & derivados , Adenosina/genética , Animais , Linhagem Celular Tumoral , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
12.
Molecules ; 26(6)2021 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-33806853

RESUMO

The characterization of terpene-based eutectic solvent systems is performed to describe their solid-liquid phase transitions. Physical properties are measured experimentally and compared to computed correlations for deep eutectic solvents (DES) and the percentage relative error er for the density, surface tension, and refractive index is obtained. The thermodynamic parameters, including the degradation, glass transition and crystallization temperatures, are measured using DSC and TGA. Based on these data, the solid-liquid equilibrium phase diagrams are calculated for the ideal case and predictions are made using the semi-predictive UNIFAC and the predictive COSMO RS models, the latter with two different parametrization levels. For each system, the ideal, experimental, and predicted eutectic points are obtained. The deviation from ideality is observed experimentally and using the thermodynamic models for Thymol:Borneol and Thymol:Camphor. In contrast, a negative deviation is observed only experimentally for Menthol:Borneol and Menthol:Camphor. Moreover, the chemical interactions are analyzed using FTIR and 1H-NMR to study the intermolecular hydrogen bonding in the systems.

13.
Anal Bioanal Chem ; 412(18): 4447-4459, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32388578

RESUMO

Industry 4.0 is all about interconnectivity, sensor-enhanced process control, and data-driven systems. Process analytical technology (PAT) such as online nuclear magnetic resonance (NMR) spectroscopy is gaining in importance, as it increasingly contributes to automation and digitalization in production. In many cases up to now, however, a classical evaluation of process data and their transformation into knowledge is not possible or not economical due to the insufficiently large datasets available. When developing an automated method applicable in process control, sometimes only the basic data of a limited number of batch tests from typical product and process development campaigns are available. However, these datasets are not large enough for training machine-supported procedures. In this work, to overcome this limitation, a new procedure was developed, which allows physically motivated multiplication of the available reference data in order to obtain a sufficiently large dataset for training machine learning algorithms. The underlying example chemical synthesis was measured and analyzed with both application-relevant low-field NMR and high-field NMR spectroscopy as reference method. Artificial neural networks (ANNs) have the potential to infer valuable process information already from relatively limited input data. However, in order to predict the concentration at complex conditions (many reactants and wide concentration ranges), larger ANNs and, therefore, a larger training dataset are required. We demonstrate that a moderately complex problem with four reactants can be addressed using ANNs in combination with the presented PAT method (low-field NMR) and with the proposed approach to generate meaningful training data. Graphical abstract.

14.
J Phys Chem A ; 124(20): 4171-4181, 2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32336096

RESUMO

The prediction of solvation free energies is essential for a variety of applications. Solvation free energies of neutral systems can be predicted quite accurately. The accuracy of predictions for solvation free energies of ionic solutes dissolved in neutral solvents, however, has been reported to be worse by at least 1 order of magnitude. In this study, the performance of three approaches for solvation free energy prediction of several hundred ions dissolved in neutral solvents is evaluated. The applied methods are COSMO-RS, cluster continuum model (CCM) together with COSMO-RS, and COSMO-RS-ES. It is emphasized that the reference data for model evaluation are subject to large uncertainties stemming from the impossibility to measure the so-called elusive absolute free energies of solvation of a single ion. Consequently, such uncertainty must be considered during the evaluation of prediction methods. Therefore, a straightforward approach to account for the underlying uncertainty is applied here. Hereby, it is revealed that the true performance of the method is better than what is often reported. The average absolute deviation (AAD) of COSMO-RS is calculated to be 2.3 kcal mol-1, while applying the CCM and COSMO-RS-ES each results in AADs of 2.0 kcal mol-1. This accuracy allows for qualitative assessment of solvation free energy-dependent quantities, such as reaction rate constants.

15.
Nucleic Acids Res ; 46(12): 6285-6303, 2018 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-29660014

RESUMO

The oncofetal IGF2 mRNA binding proteins (IGF2BPs) are upregulated in most cancers but their paralogue-specific roles in tumor cells remain poorly understood. In a panel of five cancer-derived cell lines, IGF2BP1 shows highly conserved oncogenic potential. Consistently, the deletion of IGF2BP1 impairs the growth and metastasis of ovarian cancer-derived cells in nude mice. Gene expression analyses in ovarian cancer-derived cells reveal that the knockdown of IGF2BPs is associated with the downregulation of mRNAs that are prone to miRNA regulation. All three IGF2BPs preferentially associate upstream of miRNA binding sites (MBSs) in the 3'UTR of mRNAs. The downregulation of mRNAs co-regulated by miRNAs and IGF2BP1 is abrogated at low miRNA abundance or when miRNAs are depleted. IGF2BP1 associates with these target mRNAs in RISC-free complexes and its deletion enhances their association with AGO2. The knockdown of most miRNA-regulated target mRNAs of IGF2BP1 impairs tumor cell properties. In four primary cancers, elevated synthesis of these target mRNAs is largely associated with upregulated IGF2BP1 mRNA levels. In ovarian cancer, the enhanced expression of IGF2BP1 and most of its miRNA-controlled target mRNAs is associated with poor prognosis. In conclusion, these findings indicate that IGF2BP1 enhances an aggressive tumor cell phenotype by antagonizing miRNA-impaired gene expression.


Assuntos
Regulação Neoplásica da Expressão Gênica , MicroRNAs/metabolismo , Neoplasias/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/fisiologia , Animais , Linhagem Celular Tumoral , Regulação para Baixo , Feminino , Deleção de Genes , Humanos , Camundongos Nus , MicroRNAs/antagonistas & inibidores , Neoplasias/metabolismo , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Fenótipo , Estabilidade de RNA , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Sirtuína 1/genética , Sirtuína 1/metabolismo
16.
Int J Mol Sci ; 22(1)2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33375004

RESUMO

BACKGROUND: The muscarinic receptor antagonist trospium chloride (TCl) is used for pharmacotherapy of the overactive bladder syndrome. TCl is a hydrophilic positively charged drug. Therefore, it has low permeability through biomembranes and requires drug transporters for distribution and excretion. In humans, the organic cation transporters OCT1 and OCT2 and the multidrug and toxin extrusion MATE1 and MATE2-K carriers showed TCl transport. However, their individual role for distribution and excretion of TCl is unclear. Knockout mouse models lacking mOct1/mOct2 or mMate1 might help to clarify their role for the overall pharmacokinetics of TCl. METHOD: In preparation of such experiments, TCl transport was analyzed in HEK293 cells stably transfected with the mouse carriers mOct1, mOct2, mMate1, and mMate2, respectively. RESULTS: Mouse mOct1, mOct2, and mMate1 showed significant TCl transport with Km values of 58.7, 78.5, and 29.3 µM, respectively. In contrast, mMate2 did not transport TCl but showed MPP+ transport with Km of 60.0 µM that was inhibited by the drugs topotecan, acyclovir, and levofloxacin. CONCLUSION: TCl transport behavior as well as expression pattern were quite similar for the mouse carriers mOct1, mOct2, and mMate1 compared to their human counterparts.


Assuntos
Benzilatos/metabolismo , Proteínas da Membrana Plasmática de Transporte de Catecolaminas/metabolismo , Nortropanos/metabolismo , Proteínas de Transporte de Cátions Orgânicos/metabolismo , Transportador 2 de Cátion Orgânico/metabolismo , Animais , Benzilatos/farmacocinética , Transporte Biológico , Proteínas da Membrana Plasmática de Transporte de Catecolaminas/genética , Células HEK293 , Humanos , Cinética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Antagonistas Muscarínicos/metabolismo , Antagonistas Muscarínicos/farmacocinética , Nortropanos/farmacocinética , Proteínas de Transporte de Cátions Orgânicos/genética , Transportador 2 de Cátion Orgânico/genética
17.
Biol Chem ; 400(10): 1371-1384, 2019 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-31256060

RESUMO

The solute carrier family SLC10 consists of seven members, including the bile acid transporters Na+/taurocholate co-transporting polypeptide (NTCP) and apical sodium-dependent bile acid transporter (ASBT), the steroid sulfate transporter SOAT as well as four orphan carriers (SLC10A3, SLC10A4, SLC10A5 and SLC10A7). Previously, homodimerization of NTCP, ASBT and SOAT was described and there is increasing evidence that carrier oligomerization is an important regulatory factor for protein sorting and transport function. In the present study, homo- and heterodimerization were systematically analyzed among all SLC10 carriers (except for SLC10A3) using the yeast-two-hybrid membrane protein system. Strong homodimerization occurred for NTCP/NTCP, ASBT/ASBT and SLC10A7/SLC10A7. Heterodimerization was observed for most of the SLC10 carrier combinations. Heterodimerization of NTCP was additionally investigated by co-localization of NTCP-GFP and NTCP-mScarlet with respective SLC10 carrier constructs. NTCP co-localized with SLC10A4, SLC10A5, SOAT and SLC10A7. This co-localization was most pronounced for SLC10A4 and was additionally confirmed by co-immunoprecipitation. Interestingly, SLC10 carrier co-expression decreased the taurocholate transport function of NTCP for most of the analyzed constructs, indicating that SLC10 carrier heterodimerization is of functional relevance. In conclusion, homo- and heterodimerization is a common feature of the SLC10 carriers. The relevance of this finding for regulation and transport function of the SLC10 carriers in vivo needs further investigation.


Assuntos
Transportadores de Ânions Orgânicos Dependentes de Sódio/química , Animais , Transporte Biológico , Dimerização , Humanos , Transportadores de Ânions Orgânicos Dependentes de Sódio/metabolismo , Sódio/metabolismo
18.
Neurosurg Focus ; 46(1): E6, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30611164

RESUMO

OBJECTIVEInfection of the cervical spine is a rare disease but is associated with significant risk of neurological deterioration, morbidity, and a poor response to nonsurgical management. The ideal treatment for cervical spondylodiscitis (CSD) remains unclear.METHODSHospital records of patients who underwent acute surgical management for CSD were reviewed. Information about preoperative neurological status, surgical treatment, peri- and postoperative processes, antibiotic treatment, repeated procedure, and neurological status at follow-up examination were analyzed.RESULTSA total of 30 consecutive patients (17 male and 13 female) were included in this retrospective study. The mean age at procedures was 68.1 years (range 50-82 years), with mean of 6 coexisting comorbidities. Preoperatively neck pain was noted in 21 patients (70.0%), arm pain in 12 (40.0%), a paresis in 12 (40.0%), sensory deficit in 8 (26.7%), tetraparesis in 6 (20%), a septicemia in 4 (13.3%). Preoperative MRI scan revealed a CSD in one-level fusion in 21 patients (70.0%), in two-level fusions in 7 patients (23.3%), and in three-level fusions in 2 patients (6.7%). In 16 patients an antibiotic treatment was initiated prior to surgical treatment. Anterior cervical discectomy and fusion with cervical plating (ACDF+CP) was performed in 17 patients and anterior cervical corpectomy and fusion (ACCF) in 12 patients. Additional posterior decompression was performed in one case of ACDF+CP and additional posterior fixation in ten cases of ACCF procedures. Three patients died due to multiple organ failure (10%). Revision surgery was performed in 6 patients (20.7%) within the first 2 weeks postoperatively. All patients received antibiotic treatment for 6 weeks. At the first follow-up (mean 3 month) no recurrent infection was detected on blood workup and MRI scans. At final follow-up (mean 18 month), all patients reported improvement of neck pain, all but one patients were free of radicular pain and had no sensory deficits, and all patients showed improvement of motor strength. One patient with preoperative tetraparesis was able to ambulate.CONCLUSIONSCSD is a disease that is associated with severe neurological deterioration. Anterior cervical surgery with radical debridement and appropriate antibiotic treatment achieves complete healing. Anterior cervical plating with the use of polyetheretherketone cages has no negative effect of the healing process. Posterior fixation is recommended following ACCF procedures.


Assuntos
Vértebras Cervicais/cirurgia , Discite/cirurgia , Cervicalgia/cirurgia , Espondilose/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Descompressão Cirúrgica/métodos , Discotomia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fusão Vertebral/métodos , Resultado do Tratamento
19.
J Hepatol ; 68(6): 1114-1122, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29428874

RESUMO

BACKGROUND & AIMS: All known hepatitis B virus (HBV) genotypes occur in humans and hominoid Old World non-human primates (NHPs). The divergent woolly monkey HBV (WMHBV) forms another orthohepadnavirus species. The evolutionary origins of HBV are unclear. METHODS: We analysed sera from 124 Brazilian monkeys collected during 2012-2016 for hepadnaviruses using molecular and serological tools, and conducted evolutionary analyses. RESULTS: We identified a novel orthohepadnavirus species in capuchin monkeys (capuchin monkey hepatitis B virus [CMHBV]). We found CMHBV-specific antibodies in five animals and high CMHBV concentrations in one animal. Non-inflammatory, probably chronic infection was consistent with an intact preCore domain, low genetic variability, core deletions in deep sequencing, and no elevated liver enzymes. Cross-reactivity of antisera against surface antigens suggested antigenic relatedness of HBV, CMHBV, and WMHBV. Infection-determining CMHBV surface peptides bound to the human HBV receptor (human sodium taurocholate co-transporting polypeptide), but preferentially interacted with the capuchin monkey receptor homologue. CMHBV and WMHBV pseudotypes infected human hepatoma cells via the human sodium taurocholate co-transporting polypeptide, and were poorly neutralised by HBV vaccine-derived antibodies, suggesting that cross-species infections may be possible. Ancestral state reconstructions and sequence distance comparisons associated HBV with humans, whereas primate hepadnaviruses as a whole were projected to NHP ancestors. Co-phylogenetic analyses yielded evidence for co-speciation of hepadnaviruses and New World NHP. Bayesian hypothesis testing yielded strong support for an association of the HBV stem lineage with hominoid ancestors. Neither CMHBV nor WMHBV was likely the ancestor of the divergent human HBV genotypes F/H found in American natives. CONCLUSIONS: Our data suggest ancestral co-speciation of hepadnaviruses and NHP, and an Old World origin of the divergent HBV genotypes F/H. The identification of a novel primate hepadnavirus offers new perspectives for urgently needed animal models of chronic hepatitis B. LAY SUMMARY: The origins of HBV are unclear. The new orthohepadnavirus species from Brazilian capuchin monkeys resembled HBV in elicited infection patterns and could infect human liver cells using the same receptor as HBV. Evolutionary analyses suggested that primate HBV-related viruses might have emerged in African ancestors of New World monkeys millions of years ago. HBV was associated with hominoid primates, including humans and apes, suggesting evolutionary origins of HBV before the formation of modern humans. HBV genotypes found in American natives were divergent from those found in American monkeys, and likely introduced along prehistoric human migration. Our results elucidate the evolutionary origins and dispersal of primate HBV, identify a new orthohepadnavirus reservoir, and enable new perspectives for animal models of hepatitis B.


Assuntos
Cebus/virologia , Evolução Molecular , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Orthohepadnavirus/genética , Orthohepadnavirus/isolamento & purificação , Sequência de Aminoácidos , Animais , Teorema de Bayes , Brasil , Especiação Genética , Genoma Viral , Hepatite B/veterinária , Hepatite B/virologia , Antígenos da Hepatite B/química , Antígenos da Hepatite B/genética , Antígenos da Hepatite B/imunologia , Vírus da Hepatite B/classificação , Interações entre Hospedeiro e Microrganismos/genética , Humanos , Modelos Genéticos , Doenças dos Macacos/virologia , Transportadores de Ânions Orgânicos Dependentes de Sódio/fisiologia , Orthohepadnavirus/classificação , Filogenia , Primatas/virologia , Receptores Virais/fisiologia , Simportadores/fisiologia , Internalização do Vírus
20.
Nucleic Acids Res ; 44(8): 3845-64, 2016 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-26917013

RESUMO

The tumor-suppressive let-7 microRNA family targets various oncogene-encoding mRNAs. We identify the let-7 targets HMGA2, LIN28B and IGF2BP1 to form a let-7 antagonizing self-promoting oncogenic triangle. Surprisingly, 3'-end processing of IGF2BP1 mRNAs is unaltered in aggressive cancers and tumor-derived cells although IGF2BP1 synthesis was proposed to escape let-7 attack by APA-dependent (alternative polyadenylation) 3' UTR shortening. However, the expression of the triangle factors is inversely correlated with let-7 levels and promoted by LIN28B impairing let-7 biogenesis. Moreover, IGF2BP1 enhances the expression of all triangle factors by recruiting the respective mRNAs in mRNPs lacking AGO proteins and let-7 miRNAs. This indicates that the downregulation of let-7, largely facilitated by LIN28B upregulation, and the protection of let-7 target mRNAs by IGF2BP1-directed shielding in mRNPs synergize in enhancing the expression of triangle factors. The oncogenic potential of this triangle was confirmed in ovarian cancer (OC)-derived ES-2 cells transduced with let-7 targeting decoys. In these, the depletion of HMGA2 only diminishes tumor cell growth under permissive conditions. The depletion of LIN28B and more prominently IGF2BP1 severely impairs tumor cell viability, self-renewal and 2D as well as 3D migration. In conclusion, this suggests the targeting of the HMGA2-LIN28B-IGF2BP1 triangle as a promising strategy in cancer treatment.


Assuntos
Regulação Neoplásica da Expressão Gênica , Proteína HMGA2/genética , MicroRNAs/metabolismo , Proteínas de Ligação a RNA/genética , Linhagem Celular Tumoral , Movimento Celular , Feminino , Células HEK293 , Proteína HMGA2/antagonistas & inibidores , Proteína HMGA2/metabolismo , Humanos , MicroRNAs/antagonistas & inibidores , Proteínas Oncogênicas/genética , Proteínas Oncogênicas/metabolismo , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/fisiopatologia , Isoformas de RNA/metabolismo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas/metabolismo
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