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1.
Macromolecules ; 57(15): 7074-7086, 2024 Aug 13.
Artículo en Inglés | MEDLINE | ID: mdl-39156193

RESUMEN

Thanks to many promising properties, including biocompatibility and the ability to experience large deformations, poly(ethylene glycol) diacrylate (PEGDA) hydrogels are excellent candidate materials for a wide range of applications. Interestingly, the polymerization of PEGDA leads to a network microstructure that is fundamentally different from that of the "classic" polymeric gels. Specifically, PEGDA hydrogels comprise PEG chains that are interconnected by multifunctional densely grafted rod-like polyacrylates (PAs), which serve as cross-linkers. In this work, we derive a microstructurally motivated model that captures the essential features which enable deformation in PEGDA hydrogels: (1) entropic elasticity of PEG chains, (2) deformation of PA rods, and (3) PA-PA interactions. Expressions for the energy-density functions and the stress associated with each of the three contributions are derived. The model demonstrates the microstructural evolution of the network during loading and reveals the role of key microscopic quantities. To validate the model, we fabricate and compress PEGDA hydrogel discs. The model is in excellent agreement with our experimental findings for a broad range of PEGDA compositions. Interestingly, we show that the response of PEGDA hydrogels with short PEG chains and long PA rods is governed by PA-PA interactions, whereas networks with longer PEG chains are dominated by entropy. To enable design, we employ the model to investigate the influence of key microstructural quantities, such as the length of the PEG and the PA chains, on the macroscopic properties and response. The findings from this work pave the way to the efficient design of PEGDA hydrogels with tunable properties and behaviors, which will enable the optimization of their performance in various applications.

2.
Methods Mol Biol ; 2680: 29-54, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37428369

RESUMEN

In planarian flatworms, piRNAs and SMEDWI (Schmidtea mediterranea PIWI) proteins are both essential for the animals' impressive regenerative ability and for their survival. A knockdown of SMEDWI proteins disrupts the specification of the planarian germline and impairs stem cell differentiation, resulting in lethal phenotypes. As the molecular targets of PIWI proteins and thus their biological function are determined by PIWI-bound small RNAs, termed piRNAs (for PIWI-interacting RNAs), it is imperative to study the wealth of PIWI-bound piRNAs using next-generation sequencing-based techniques. Prior to sequencing, piRNAs bound to individual SMEDWI proteins must be isolated. To that end, we established an immunoprecipitation protocol that can be applied to all planarian SMEDWI proteins. Co-immunoprecipitated piRNAs are visualized by using qualitative radioactive 5'-end labeling, which detects even trace amounts of small RNAs. Next, isolated piRNAs are subjected to a library preparation protocol that has been optimized for the efficient capture of piRNAs, whose 3'-ends carry a 2'-O-methyl modification. Successfully prepared piRNA libraries are subjected to Illumina-based next-generation sequencing. Obtained data are analyzed as presented in the accompanying manuscript.


Asunto(s)
Planarias , Animales , ARN de Interacción con Piwi , ARN/genética , Interferencia de ARN , ARN Interferente Pequeño/genética , ARN Interferente Pequeño/metabolismo , Proteínas Argonautas/genética
3.
Methods Mol Biol ; 2680: 55-65, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37428370

RESUMEN

In planarian flatworms, the piRNA pathway is operated by three PIWI proteins, termed SMEDWI-1, SMEDWI-2, and SMEDWI-3 (SMEDWI = Schmidtea mediterranea PIWI). The interplay between these three PIWI proteins and their associated small noncoding RNAs, termed piRNAs, fuels the outstanding regenerative abilities of planarians, enables tissue homeostasis, and, ultimately, ensures animal survival. As the molecular targets of PIWI proteins are determined by the sequences of their co-bound piRNAs, it is imperative to identify these sequences by next-generation sequencing applications. Following sequencing, the genomic targets and the regulatory potential of the isolated piRNA populations need to be uncovered. To that end, here we present a bioinformatics analysis pipeline for processing and systematic characterization of planarian piRNAs. The pipeline includes steps for the removal of PCR duplicates based on unique molecular identifier (UMI) sequences, and it accounts for piRNA multimapping to different loci in the genome. Importantly, our protocol also includes a fully automated pipeline that is freely available at GitHub. Together with the piRNA isolation and library preparation protocol (see accompanying chapter), the presented computational pipeline enables researchers to explore the functional role of the piRNA pathway in flatworm biology.


Asunto(s)
Biología Computacional , Genoma , ARN de Interacción con Piwi , Planarias , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Biología Computacional/métodos , Genoma/genética , Estudio de Asociación del Genoma Completo , ARN de Interacción con Piwi/genética , Planarias/genética , Internet , Programas Informáticos
4.
Front Rehabil Sci ; 4: 1000838, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36873817

RESUMEN

Background: Patients with disabilities and those from diverse equity-deserving backgrounds have been disproportionately affected by the SARS COV-2 ("COVID-19") pandemic. Objective: To describe the significant needs and social determinants of health that affected a group of uninsured patients (from equity-deserving groups) with rehabilitation diagnoses during the early months of the COVID-19 pandemic. Design: Retrospective cohort study utilizing a telephone-based needs assessment from April to October, 2020. Setting: Free interdisciplinary rehabilitation clinic serving patients with physical disabilities from equity-deserving minority backgrounds. Participants: 51 uninsured, diverse patients with spinal cord injuries, brain injuries, amputations, strokes, and other diagnoses requiring interdisciplinary rehabilitation care. Methods: Using a non-structured approach, telephone-based needs assessments were collected monthly. Reported needs were summarized into themes and the frequencies of each theme were recorded. Results: From the total number of concerns, medical issues were reported with the highest frequency (46%), followed by equipment needs (30%) and mental health concerns (30%). Other frequently mentioned needs centered around themes of rent, employment, and supplies. Rent and employment were more frequently cited in earlier months, and equipment problems were more frequently cited in later months. A minority of patients reported they had no needs, some of whom had acquired insurance. Conclusions: Our objective was to describe the needs of a racially and ethnically diverse set of uninsured individuals with physical disabilities seen at a specialized interdisciplinary rehabilitation pro bono clinic during the early months of COVID-19. Medical issues, equipment needs, and mental health concerns were the top three needs. To optimally serve them, care providers must be aware of current and future needs for their underserved patients, especially if future lockdowns occur.

5.
Protein Sci ; 31(7): e4369, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35762708

RESUMEN

Proteins are under selection to maintain central functions and to accommodate needs that arise in ever-changing environments. The positive selection and neutral drift that preserve functions result in a diversity of protein variants. The amount of diversity differs between proteins: multifunctional or disease-related proteins tend to have fewer variants than proteins involved in some aspects of immunity. Our work focuses on the extensively studied protein Vitellogenin (Vg), which in honey bees (Apis mellifera) is multifunctional and highly expressed and plays roles in immunity. Yet, almost nothing is known about the natural variation in the coding sequences of this protein or how amino acid-altering variants might impact structure-function relationships. Here, we map out allelic variation in honey bee Vg using biological samples from 15 countries. The successful barcoded amplicon Nanopore sequencing of 543 bees revealed 121 protein variants, indicating a high level of diversity in Vg. We find that the distribution of non-synonymous single nucleotide polymorphisms (nsSNPs) differs between protein regions with different functions; domains involved in DNA and protein-protein interactions contain fewer nsSNPs than the protein's lipid binding cavities. We outline how the central functions of the protein can be maintained in different variants and how the variation pattern may inform about selection from pathogens and nutrition.


Asunto(s)
Vitelogeninas , Secuencia de Aminoácidos , Animales , Abejas/genética , Vitelogeninas/genética , Vitelogeninas/metabolismo
6.
Nat Commun ; 13(1): 2429, 2022 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-35508485

RESUMEN

Enhancer RNAs (eRNAs) are long non-coding RNAs that originate from enhancers. Although eRNA transcription is a canonical feature of activated enhancers, the molecular features required for eRNA function and the mechanism of how eRNAs impinge on target gene transcription have not been established. Thus, using eRNA-dependent RNA polymerase II (Pol II) pause release as a model, we here investigate the requirement of sequence, structure and length of eRNAs for their ability to stimulate Pol II pause release by detaching NELF from paused Pol II. We find eRNAs not to exert their function through common structural or sequence motifs. Instead, eRNAs that exhibit a length >200 nucleotides and that contain unpaired guanosines make multiple, allosteric contacts with NELF subunits -A and -E to trigger efficient NELF release. By revealing the molecular determinants of eRNA function, our study establishes eRNAs as an important player in Pol II pause release, and it provides new insight into the regulation of metazoan transcription.


Asunto(s)
ARN Polimerasa II , ARN Largo no Codificante , Animales , Elementos de Facilitación Genéticos , Regulación de la Expresión Génica , Regiones Promotoras Genéticas , ARN Polimerasa II/metabolismo , ARN Largo no Codificante/fisiología , Secuencias Reguladoras de Ácidos Nucleicos , Transcripción Genética
7.
Phys Rev Lett ; 128(9): 098101, 2022 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-35302814

RESUMEN

Spider silk is a protein material that exhibits extraordinary and nontrivial properties such as the ability to soften, decrease in length (i.e., supercontract), and twist upon exposure to high humidity. These behaviors stem from a unique microstructure in combination with a transition from glassy to rubbery as a result of humidity-driven diffusion of water. In this Letter we propose four length scales that govern the mechanical response of the silk during this transition. In addition, we develop a model that describes the microstructural evolution of the spider silk thread and explains the response due to the diffusion of water molecules. The merit of the model is demonstrated through an excellent agreement to experimental findings. The insights from this Letter can be used as a microstructural design guide to enable the development of new materials with unique spiderlike properties.


Asunto(s)
Humedad , Seda , Agua , Difusión , Seda/química , Agua/química
8.
J Cell Physiol ; 237(5): 2420-2433, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35014036

RESUMEN

In adult mammals, the kidney is the main source of circulating erythropoietin (Epo), the master regulator of erythropoiesis. In vivo data in mice demonstrated multiple subtypes of interstitial renal Epo-producing (REP) cells. To analyze the differentiation plasticity of fibroblastoid REP cells, we used a transgenic REP cell reporter mouse model to generate conditionally immortalized REP-derived (REPD) cell lines. Under nonpermissive conditions, REPD cells ceased from proliferation and acquired a stem cell-like state, with strongly enhanced hypoxia-inducible factor 2 (HIF-2α), stem cell antigen 1 (SCA-1), and CD133 expression, but also enhanced alpha-smooth muscle actin (αSMA) expression, indicating myofibroblastic signaling. These cells maintained the "on-off" nature of Epo expression observed in REP cells in vivo, whereas other HIF target genes showed a more permanent regulation. Like REP cells in vivo, REPD cells cultured in vitro generated long tunneling nanotubes (TNTs) that aligned with endothelial vascular structures, were densely packed with mitochondria and became more numerous under hypoxic conditions. Although inhibition of mitochondrial oxygen consumption blunted HIF signaling, removal of the TNTs did not affect or even enhance the expression of HIF target genes. Apart from pericytes, REPD cells readily differentiated into neuroglia but not adipogenic, chondrogenic, or osteogenic lineages, consistent with a neuronal origin of at least a subpopulation of REP cells. In summary, these results suggest an unprecedented combination of differentiation features of this unique cell type.


Asunto(s)
Eritropoyetina , Pericitos , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Línea Celular , Eritropoyesis , Eritropoyetina/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Riñón/metabolismo , Mamíferos/metabolismo , Ratones , Ratones Transgénicos , Pericitos/metabolismo
9.
BMC Public Health ; 22(1): 18, 2022 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-34991530

RESUMEN

BACKGROUND: Occupational accidents continue to be a significant public health challenge worldwide. Construction workers in particular are at high risk of occupational accidents, and thus it is of major importance to identify possible predictors of occupational accidents among construction workers. We aimed to investigate the association between self-reported work pace and physical work demands and occupational accidents among ageing male construction workers in Denmark. METHODS: Data on perceived work pace, physical work demands, and occupational accidents was acquired from questionnaires sent to ageing construction workers in Denmark in 2016 as part of the ALFA project (ALdring og Fysisk Arbejde; Ageing and Physical Work). A sample of 1270 Danish male construction workers above 50 years of age was included in the present study. Multiple logistic regression models were applied, with adjustments for age, smoking, body mass index, musculoskeletal disorders, occupation, work experience, and support at work. RESULTS: Of 1270 construction workers, 166 (13.1%) reported an occupational accident within the last 12 months. There was no significant association between perceived work pace and occupational accidents, but physical work demands were associated with higher odds for occupational accidents, with an odds ratio of 2.27 (95% confidence interval 1.26-4.10) for medium physical work demands and 2.62 (95% confidence interval 1.50-4.57) for high physical work demands. CONCLUSIONS: Ageing male construction workers with high physical work demands had statistically significant higher odds of having an occupational accident. By contrast, perceived work pace was not associated with occupational accidents in this large cross-sectional study.


Asunto(s)
Accidentes de Trabajo , Industria de la Construcción , Envejecimiento , Estudios Transversales , Dinamarca/epidemiología , Humanos , Masculino , Encuestas y Cuestionarios
10.
Scand J Public Health ; 50(3): 404-411, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-33645305

RESUMEN

AIMS: The link between perceived social support and mental health has received much attention from numerous scientific fields in recent years. Most studies, however, have examined associations only over relatively short follow-up periods using global measures of perceived social support and dichotomous negative indicators of mental health. We investigated the long-term association between perceived social support from friends, parents and teachers and multiple positive hedonic and eudemonic indicators of mental health, including hope, meaningfulness and subjective well-being. METHODS: This study used questionnaire data from 2004, 2007 and 2010 from the West Jutland Birth Cohort study with linked register data. The study population consisted of 3681 adolescents born in 1989. Multiple linear and ordered logistic regression were used to analyse the association between perceived social support at age 14/15 years and mental health indicators at age 20/21 years while controlling for possible confounders, including the Big Five personality traits and baseline symptoms of depression. RESULTS: The results show that perceived social support from friends in adolescence was positively associated with all indicators of mental health in early adulthood. Furthermore, perceived paternal social support was positively associated with meaningfulness and subjective well-being, while perceived social support from teachers was positively associated with meaningfulness. CONCLUSIONS: Overall, the results from this study indicate that perceived social support in adolescence, particularly support from friends, could promote positive mental health outcomes in early adulthood.


Asunto(s)
Amigos , Apoyo Social , Adolescente , Adulto , Estudios de Cohortes , Amigos/psicología , Humanos , Evaluación de Resultado en la Atención de Salud , Estudios Prospectivos , Adulto Joven
11.
BMC Public Health ; 21(1): 2044, 2021 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-34749681

RESUMEN

BACKGROUND: Transitioning from school to work is important in influencing people's trajectories throughout their life course. This study investigated the extent to which adverse childhood experiences (ACEs) were associated with differences in labour market trajectories for young adults in the context of a Nordic child care regime with low levels of child poverty. METHODS: Information on labour market participation, educational events, and public transfer records was recoded into seven state spaces for each month between ages 16 and 32 for a cohort of Danish adolescents born in a rural county in 1983 (N = 3373). Cluster analysis of the sequences using the optimal matching algorithm was used to identify groups with similar trajectories. Multinomial regression was used to assess the association between self-reported ACEs and cluster membership, taking gender and family of origin into account. RESULTS: 'In employment' was the state space in which the young adults spent the most time over their early life courses (mean: 85 out of 204 months; 42%). Cluster analysis identified three clusters. Cluster 3 was most distinct, where the mean time 'outside the labour market' was 149 months (73%), and only 17 months (8%) were spent 'in employment'. Cumulative ACEs increased the probability of being included in Cluster 3 (OR: 1.51). Experiencing parental divorce (OR: 3.05), witnessing a violent event (OR: 3.70), and being abused (OR: 5.64) were most strongly associated with Cluster 3 membership. CONCLUSIONS: Labour market trajectories among adolescents with a higher number of ACEs consisted of more time outside the labour market, compared to adolescents who had experienced fewer adversities. The lasting consequences of childhood adversity should be taken more into account in welfare policies, even in countries such as Denmark, with high social security levels and high-quality universal childcare.


Asunto(s)
Experiencias Adversas de la Infancia , Adolescente , Adulto , Niño , Pobreza Infantil , Estudios de Cohortes , Empleo , Humanos , Estudios Longitudinales , Adulto Joven
12.
Biomacromolecules ; 22(2): 993-1000, 2021 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-33481568

RESUMEN

Spider silk is a protein material that exhibits extraordinary and nontrivial properties such as the ability to soften and decrease its length by up to ∼60% upon exposure to high humidity. This process is commonly called supercontraction and is the result of a transition from a highly oriented glassy phase to a disoriented rubbery phase. In this work, we derive a microscopically motivated and energy-based model that captures the underlying mechanisms that give rise to supercontraction. We propose that the increase in relative humidity and the consequent wetting of a spider silk have two main consequences: (1) the dissociation of hydrogen bonds and (2) the swelling of the fiber. From a mechanical viewpoint, the first consequence leads to the formation of rubbery domains. This process is associated with an entropic gain and a loss of orientation of chains in the silk network, which motivates the contraction of the spider silk. The swelling of the fiber is accompanied by the extension of chains in order to accommodate the influx of water molecules. Supercontraction occurs when the first consequence is more dominant than the second. The model presented in this work allows us to qualitatively track the transition of the chains from glassy to rubbery states and determine the increase in entropy, the loss of orientation, and the swelling as the relative humidity increases. We also derive explicit expressions for the stiffness and the mechanical response of a spider silk under given relative humidity conditions. To illustrate the merit of this model, we show that the model is capable of capturing several experimental findings. The insights from this work can be used as a microstructural design guide to enable the development of new materials with unique spider-like properties.


Asunto(s)
Seda , Arañas , Animales , Humedad , Enlace de Hidrógeno , Estrés Mecánico , Agua
13.
EBioMedicine ; 60: 102987, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32942121

RESUMEN

BACKGROUND: Limited knowledge of stem cell therapies` mechanisms of action hampers their sustainable implementation into the clinic. Specifically, the interactions of transplanted stem cells with the host vasculature and its implications for their therapeutic efficacy are not elucidated. We tested whether adhesion receptors and chemokine receptors on stem cells can be functionally modulated, and consequently if such modulation may substantially affect therapeutically relevant stem cell interactions with the host endothelium. METHODS: We investigated the effects of cationic molecule polyethylenimine (PEI) treatment with or without nanoparticles on the functions of adhesion receptors and chemokine receptors of human bone marrow-derived Mesenchymal Stem Cells (MSC). Analyses included MSC functions in vitro, as well as homing and therapeutic efficacy in rodent models of central nervous system´s pathologies in vivo. FINDINGS: PEI treatment did not affect viability, immunomodulation or differentiation potential of MSC, but increased the CCR4 expression and functionally blocked their adhesion receptors, thus decreasing their adhesion capacity in vitro. Intravenously applied in a rat model of brain injury, the homing rate of PEI-MSC in the brain was highly increased with decreased numbers of adherent PEI-MSC in the lung vasculature. Moreover, in comparison to untreated MSC, PEI-MSC featured increased tumour directed migration in a mouse glioblastoma model, and superior therapeutic efficacy in a murine model of stroke. INTERPRETATION: Balanced stem cell adhesion and migration in different parts of the vasculature and tissues together with the local microenvironment impacts their therapeutic efficacy. FUNDING: Robert Bosch Stiftung, IZEPHA grant, EU grant 7 FP Health.


Asunto(s)
Adhesión Celular , Movimiento Celular , Endotelio/metabolismo , Células Madre/metabolismo , Animales , Biomarcadores , Diferenciación Celular , Línea Celular , Tratamiento Basado en Trasplante de Células y Tejidos , Células Cultivadas , Microambiente Celular , Modelos Animales de Enfermedad , Glioma/diagnóstico , Glioma/patología , Glioma/terapia , Humanos , Inmunofenotipificación , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratas , Trasplante de Células Madre , Ensayos Antitumor por Modelo de Xenoinjerto
14.
EBioMedicine ; 60: 102989, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32920368

RESUMEN

BACKGROUND: Stem cells` (SC) functional heterogeneity and its poorly understood aetiology impedes clinical development of cell-based therapies in regenerative medicine and oncology. Recent studies suggest a strong correlation between the SC migration potential and their therapeutic efficacy in humans. Designating SC migration as a denominator of functional SC heterogeneity, we sought to identify highly migrating subpopulations within different SC classes and evaluate their therapeutic properties in comparison to the parental non-selected cells. METHODS: We selected highly migrating subpopulations from mesenchymal and neural SC (sMSC and sNSC), characterized their features including but not limited to migratory potential, trophic factor release and transcriptomic signature. To assess lesion-targeted migration and therapeutic properties of isolated subpopulations in vivo, surgical transplantation and intranasal administration of MSCs in mouse models of glioblastoma and Alzheimer's disease respectively were performed. FINDINGS: Comparison of parental non-selected cells with isolated subpopulations revealed superior motility and migratory potential of sMSC and sNSC in vitro. We identified podoplanin as a major regulator of migratory features of sMSC/sNSC. Podoplanin engineering improved oncovirolytic activity of virus-loaded NSC on distantly located glioblastoma cells. Finally, sMSC displayed more targeted migration to the tumour site in a mouse glioblastoma model and remarkably higher potency to reduce pathological hallmarks and memory deficits in transgenic Alzheimer's disease mice. INTERPRETATION: Functional heterogeneity of SC is associated with their motility and migration potential which can serve as predictors of SC therapeutic efficacy. FUNDING: This work was supported in part by the Robert Bosch Stiftung (Stuttgart, Germany) and by the IZEPHA grant.


Asunto(s)
Movimiento Celular , Células Madre/fisiología , Enfermedad de Alzheimer/terapia , Animales , Biomarcadores , Supervivencia Celular , Rastreo Celular/métodos , Células Cultivadas , Modelos Animales de Enfermedad , Expresión Génica , Perfilación de la Expresión Génica , Humanos , Masculino , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/fisiología , Ratones , Ratones Transgénicos , Células-Madre Neurales/citología , Células-Madre Neurales/fisiología , Viroterapia Oncolítica , Trasplante de Células Madre , Células Madre/citología , Resultado del Tratamiento
15.
BMC Psychiatry ; 20(1): 218, 2020 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-32398111

RESUMEN

BACKGROUND: The System Usability Scale (SUS) is used to measure usability of internet-based Cognitive Behavioural Therapy (iCBT). However, whether the SUS is a valid instrument to measure usability in this context is unclear. The aim of this study is to assess the factor structure of the SUS, measuring usability of iCBT for depression in a sample of professionals. In addition, the psychometric properties (reliability, convergent validity) of the SUS were tested. METHODS: A sample of 242 professionals using iCBT for depression from 6 European countries completed the SUS. Confirmatory Factor Analysis (CFA) was conducted to test whether a one-factor, two-factor, tone-model or bi-direct model would fit the data best. Reliability was assessed using complementary statistical indices (e.g. omega). To assess convergent validity, the SUS total score was correlated with an adapted Client Satisfaction Questionnaire (CSQ-3). RESULTS: CFA supported the one-factor, two-factor and tone-model, but the bi-factor model fitted the data best (Comparative Fit Index = 0.992, Tucker Lewis Index = 0.985, Root Mean Square Error of Approximation = 0.055, Standardized Root Mean Square Residual = 0.042 (respectively χ2diff (9) = 69.82, p < 0.001; χ2diff (8) = 33.04, p < 0.001). Reliability of the SUS was good (ω = 0.91). The total SUS score correlated moderately with the CSQ-3 (CSQ1 rs = .49, p < 0.001; CSQ2 rs = .46, p < 0.001; CSQ3 rs = .38, p < 0.001), indicating convergent validity. CONCLUSIONS: Although the SUS seems to have a multidimensional structure, the best model showed that the total sumscore of the SUS appears to be a valid and interpretable measure to assess the usability of internet-based interventions when used by professionals in mental healthcare.


Asunto(s)
Depresión , Intervención basada en la Internet , Depresión/diagnóstico , Depresión/terapia , Europa (Continente) , Análisis Factorial , Humanos , Psicometría , Reproducibilidad de los Resultados , Encuestas y Cuestionarios
16.
Biol Chem ; 401(10): 1123-1141, 2020 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-32229649

RESUMEN

PIWI-interacting RNAs (piRNAs) are small regulatory RNAs that associate with members of the PIWI clade of the Argonaute superfamily of proteins. piRNAs are predominantly found in animal gonads. There they silence transposable elements (TEs), regulate gene expression and participate in DNA methylation, thus orchestrating proper germline development. Furthermore, PIWI proteins are also indispensable for the maintenance and differentiation capabilities of pluripotent stem cells in free-living invertebrate species with regenerative potential. Thus, PIWI proteins and piRNAs seem to constitute an essential molecular feature of somatic pluripotent stem cells and the germline. In keeping with this hypothesis, both PIWI proteins and piRNAs are enriched in neoblasts, the adult stem cells of planarian flatworms, and their presence is a prerequisite for the proper regeneration and perpetual tissue homeostasis of these animals. The piRNA pathway is required to maintain the unique biology of planarians because, in analogy to the animal germline, planarian piRNAs silence TEs and ensure stable genome inheritance. Moreover, planarian piRNAs also contribute to the degradation of numerous protein-coding transcripts, a function that may be critical for neoblast differentiation. This review gives an overview of the planarian piRNA pathway and of its crucial function in neoblast biology.


Asunto(s)
Planarias/metabolismo , ARN Interferente Pequeño/metabolismo , Animales , ARN Interferente Pequeño/genética
17.
Bioorg Chem ; 97: 103703, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32143017

RESUMEN

Three N-metallocenoylsphingosines with variance in the central metal (Fe, Co, Ru), the charge (neutral or cationic), and the arene ligands (Cp2, Cp*Ph) were synthesized from serine and metallocene carboxylic acids as substrate-analogous inhibitors of human acid ceramidase (AC). Their inhibitory potential was examined using the recombinant full length ASAH1 enzyme, expressed and secreted from High Five insect cells, and the fluorescent substrate Rbm14-12. All complexes inhibited AC, most strongly so ruthenium(II) complex 13a. Some antitumoral effects of the complexes, such as the interference with the microtubular and F-actin cytoskeleton of cancer cells, were correlated to their AC-inhibition, whereas others, e.g. their cytotoxicity and their induction of caspase-3/-7 activity in cancer cells, were not. All complexes accumulated preferentially in the lysosomes of cancer cells like their target AC, arrested the cells in G1 phase of the cell cycle, and displayed cytotoxicity with mostly single-digit micromolar IC50 values while inducing cancer cell apoptosis.


Asunto(s)
Ceramidasa Ácida/antagonistas & inhibidores , Antineoplásicos/química , Antineoplásicos/farmacología , Esfingosina/análogos & derivados , Esfingosina/farmacología , Ceramidasa Ácida/metabolismo , Animales , Antineoplásicos/síntesis química , Apoptosis/efectos de los fármacos , Línea Celular , Línea Celular Tumoral , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/enzimología , Neoplasias/metabolismo , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/química , Compuestos Organometálicos/farmacología , Esfingosina/síntesis química
18.
Sci Rep ; 10(1): 1577, 2020 01 31.
Artículo en Inglés | MEDLINE | ID: mdl-32005861

RESUMEN

The iron chelator Deferasirox (DFX) causes severe toxicity in patients for reasons that were previously unexplained. Here, using the kidney as a clinically relevant in vivo model for toxicity together with a broad range of experimental techniques, including live cell imaging and in vitro biophysical models, we show that DFX causes partial uncoupling and dramatic swelling of mitochondria, but without depolarization or opening of the mitochondrial permeability transition pore. This effect is explained by an increase in inner mitochondrial membrane (IMM) permeability to protons, but not small molecules. The movement of water into mitochondria is prevented by altering intracellular osmotic gradients. Other clinically used iron chelators do not produce mitochondrial swelling. Thus, DFX causes organ toxicity due to an off-target effect on the IMM, which has major adverse consequences for mitochondrial volume regulation.


Asunto(s)
Deferasirox/farmacología , Quelantes del Hierro/farmacología , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Membranas Mitocondriales/efectos de los fármacos , Animales , Línea Celular , Humanos , Riñón/efectos de los fármacos , Riñón/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica , Mitocondrias/ultraestructura , Membranas Mitocondriales/metabolismo , Permeabilidad/efectos de los fármacos
19.
Proc Natl Acad Sci U S A ; 117(6): 2894-2905, 2020 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-31988137

RESUMEN

The Mediator kinase module regulates eukaryotic transcription by phosphorylating transcription-related targets and by modulating the association of Mediator and RNA polymerase II. The activity of its catalytic core, cyclin-dependent kinase 8 (CDK8), is controlled by Cyclin C and regulatory subunit MED12, with its deregulation contributing to numerous malignancies. Here, we combine in vitro biochemistry, cross-linking coupled to mass spectrometry, and in vivo studies to describe the binding location of the N-terminal segment of MED12 on the CDK8/Cyclin C complex and to gain mechanistic insights into the activation of CDK8 by MED12. Our data demonstrate that the N-terminal portion of MED12 wraps around CDK8, whereby it positions an "activation helix" close to the T-loop of CDK8 for its activation. Intriguingly, mutations in the activation helix that are frequently found in cancers do not diminish the affinity of MED12 for CDK8, yet likely alter the exact positioning of the activation helix. Furthermore, we find the transcriptome-wide gene-expression changes in human cells that result from a mutation in the MED12 activation helix to correlate with deregulated genes in breast and colon cancer. Finally, functional assays in the presence of kinase inhibitors reveal that binding of MED12 remodels the active site of CDK8 and thereby precludes the inhibition of ternary CDK8 complexes by type II kinase inhibitors. Taken together, our results not only allow us to propose a revised model of how CDK8 activity is regulated by MED12, but also offer a path forward in developing small molecules that target CDK8 in its MED12-bound form.


Asunto(s)
Quinasa 8 Dependiente de Ciclina/metabolismo , Complejo Mediador/metabolismo , Dominio Catalítico , Ciclina C/genética , Ciclina C/metabolismo , Quinasa 8 Dependiente de Ciclina/química , Quinasa 8 Dependiente de Ciclina/genética , Activación Enzimática , Humanos , Complejo Mediador/genética , Unión Proteica , Conformación Proteica en Hélice alfa , Dominios Proteicos
20.
Scand J Public Health ; 48(5): 537-543, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31405331

RESUMEN

Aims: The aim of this study was to investigate whether coping strategies in adolescence (14-15 years of age) were associated with labour-market participation (LMP) in young adulthood (25-26 years of age) and whether the association differed by sex. Methods: A birth cohort from the former county of Ringkjoebing, Denmark, consisting of 2826 individuals, comprised the study population. In 2004, the study population completed a questionnaire from which information about coping and covariates were gathered. Coping strategies were measured using five sub-scales of the Brief COPE Scale, which were combined into two overall coping strategies: active coping and avoidant coping. Ten years later, the participants were followed for a 52-week period in a register on social benefits. Logistic regression was applied to data, with adjustment for covariates: sex, parents' socio-economic status (education and income) and self-rated health. Results: A total of 2203 (78%) participants were categorised as high LMP at follow-up. No significant associations were found between active coping in adolescence and LMP in 2014/2015. For avoidant coping, in the fully adjusted model, medium-level avoidant coping was associated with higher odds (odds ratio (OR)=1.02 (95% confidence interval (CI) 0.83-1.25) of high LMP. For low avoidant coping, the OR was 1.37 (95% 1.07-1.75). For both coping strategies, sex did not modify the association. Conclusions: Findings showed that avoidant coping was significantly associated with high LMP. Further research is needed to investigate coping in relation to specific problem areas.


Asunto(s)
Adaptación Psicológica , Empleo/estadística & datos numéricos , Adolescente , Adulto , Dinamarca , Femenino , Humanos , Masculino , Estudios Prospectivos , Adulto Joven
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