RESUMO
Drosophila female germline stem cells (GSCs) are found inside the cellular niche at the tip of the ovary. They undergo asymmetric divisions to renew the stem cell lineage and to produce sibling cystoblasts that will in turn enter differentiation. GSCs and cystoblasts contain spectrosomes, membranous structures essential for orientation of the mitotic spindle and that, particularly in GSCs, change shape depending on the cell cycle phase. Using live imaging and a fusion protein of GFP and the spectrosome component Par-1, we follow the complete spectrosome cycle throughout GSC division and quantify the relative duration of the different spectrosome shapes. We also determine that the Par-1 kinase shuttles between the spectrosome and the cytoplasm during mitosis and observe the continuous addition of new material to the GSC and cystoblast spectrosomes. Next, we use the Fly-FUCCI tool to define, in live and fixed tissues, that GSCs have a shorter G1 compared with the G2 phase. The observation of centrosomes in dividing GSCs allowed us to determine that centrosomes separate very early in G1, before centriole duplication. Furthermore, we show that the anterior centrosome associates with the spectrosome only during mitosis and that, upon mitotic spindle assembly, it translocates to the cell cortex, where it remains anchored until centrosome separation. Finally, we demonstrate that the asymmetric division of GSCs is not an intrinsic property of these cells, as the spectrosome of GSC-like cells located outside of the niche can divide symmetrically. Thus, GSCs display unique properties during division, a behaviour influenced by the surrounding niche.
Assuntos
Divisão Celular Assimétrica/fisiologia , Centrossomo/fisiologia , Drosophila/fisiologia , Células Germinativas/fisiologia , Ovário/fisiologia , Células-Tronco/fisiologia , Animais , Diferenciação Celular/fisiologia , Centrossomo/metabolismo , Drosophila/metabolismo , Proteínas de Drosophila/metabolismo , Proteínas de Drosophila/fisiologia , Feminino , Fase G1/fisiologia , Fase G2/fisiologia , Células Germinativas/metabolismo , Mitose/fisiologia , Ovário/metabolismo , Fuso Acromático/fisiologia , Células-Tronco/metabolismoRESUMO
South American (SA) societies are highly vulnerable to droughts and pluvials, but lack of long-term climate observations severely limits our understanding of the global processes driving climatic variability in the region. The number and quality of SA climate-sensitive tree ring chronologies have significantly increased in recent decades, now providing a robust network of 286 records for characterizing hydroclimate variability since 1400 CE. We combine this network with a self-calibrated Palmer Drought Severity Index (scPDSI) dataset to derive the South American Drought Atlas (SADA) over the continent south of 12°S. The gridded annual reconstruction of austral summer scPDSI is the most spatially complete estimate of SA hydroclimate to date, and well matches past historical dry/wet events. Relating the SADA to the Australia-New Zealand Drought Atlas, sea surface temperatures and atmospheric pressure fields, we determine that the El Niño-Southern Oscillation (ENSO) and the Southern Annular Mode (SAM) are strongly associated with spatially extended droughts and pluvials over the SADA domain during the past several centuries. SADA also exhibits more extended severe droughts and extreme pluvials since the mid-20th century. Extensive droughts are consistent with the observed 20th-century trend toward positive SAM anomalies concomitant with the weakening of midlatitude Westerlies, while low-level moisture transport intensified by global warming has favored extreme rainfall across the subtropics. The SADA thus provides a long-term context for observed hydroclimatic changes and for 21st-century Intergovernmental Panel on Climate Change (IPCC) projections that suggest SA will experience more frequent/severe droughts and rainfall events as a consequence of increasing greenhouse gas emissions.
Assuntos
Clima , Aquecimento Global , Árvores/crescimento & desenvolvimento , Secas , Mapeamento Geográfico , Modelos Estatísticos , Chuva , América do SulRESUMO
Alzheimer's disease (AD) is a chronic neurodegenerative disease and the most frequent cause of progressive dementia in senior adults. It is characterized by memory loss and cognitive impairment secondary to cholinergic dysfunction and N-methyl-D-aspartate (NMDA)-mediated neurotoxicity. Intracellular neurofibrillary tangles, extracellular plaques composed of amyloid-ß (Aß), and selective neurodegeneration are the anatomopathological hallmarks of this disease. The dysregulation of calcium may be present in all the stages of AD, and it is associated with other pathophysiological mechanisms, such as mitochondrial failure, oxidative stress, and chronic neuroinflammation. Although the cytosolic calcium alterations in AD are not completely elucidated, some calcium-permeable channels, transporters, pumps, and receptors have been shown to be involved at the neuronal and glial levels. In particular, the relationship between glutamatergic NMDA receptor (NMDAR) activity and amyloidosis has been widely documented. Other pathophysiological mechanisms involved in calcium dyshomeostasis include the activation of L-type voltage-dependent calcium channels, transient receptor potential channels, and ryanodine receptors, among many others. This review aims to update the calcium-dysregulation mechanisms in AD and discuss targets and molecules with therapeutic potential based on their modulation.
Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Humanos , Doença de Alzheimer/patologia , Cálcio/metabolismo , Peptídeos beta-Amiloides/metabolismo , Cálcio da Dieta , Canais de Cálcio Tipo LRESUMO
Despite the effectiveness of plasma exchange (PEX) and immunosuppressants in the treatment of acquired thrombotic thrombocytopenic purpura (aTTP), a number of patients still die as a result of the disease. Whether caplacizumab could rescue these patients remains still unsettled. The objective of this study was to characterise mortality patterns and prognostic factors in the first episode of aTTP.We queried the Spanish TTP Registry for patients with a diagnosis of aTTP in their presenting episode who fulfilled complete clinical and follow-up data (n = 102). The patients were diagnosed between 2004 and 2018, and all were treated with daily PEX and corticosteroids. Clinical and laboratory data were analysed at diagnosis and during the treatment course.Eight patients (7.7%) died between 12 h and 36 days after presentation, and could be classified into three patterns: death before treatment, early death driven by acute cardiac or neurologic events, and late death due to unremitted aTTP. Stupor or coma at diagnosis and platelet count < 20 × 109 /L by the 6th treatment day were independently associated with increased risk of death.Stupor or coma at diagnosis and lack of response to PEX by the 6th day in patients experiencing the first episode of aTTP are strong predictors of mortality. These patients could be rescued by novel agents aimed at halting the microvascular thrombosis until adequate immunosuppression is achieved.
Assuntos
Corticosteroides/uso terapêutico , Troca Plasmática , Púrpura Trombocitopênica Trombótica/mortalidade , Púrpura Trombocitopênica Trombótica/terapia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Púrpura Trombocitopênica Trombótica/diagnóstico , Anticorpos de Domínio Único/uso terapêuticoRESUMO
Objective: Systemic lupus erythematosus (SLE) is associated to boosted atherosclerosis development and a higher cardiovascular disease risk. This study aimed to delineate the role of anti-double stranded DNA (anti-dsDNA) antibodies on the molecular profile and the activity of immune and vascular cells, as well as on their enhanced cardiovascular risk. Approach and Results: Eighty SLE patients were included. Extensive clinical/analytical evaluation was performed, including cardiovascular disease parameters (endothelial function, proatherogenic dyslipidemia, and carotid intima-media thickness). Gene and protein expression profiles were evaluated in monocytes from patients diagnosed positive or negative for anti-dsDNA antibodies by using NanoString and cytokine arrays, respectively. NETosis and circulating inflammatory profile was assessed in both neutrophils and plasma. Positivity and persistence of anti-dsDNA antibodies in SLE patients were associated to endothelial dysfunction, proatherogenic dyslipidemia, and accelerated atherosclerosis. In parallel, anti-dsDNA antibodies were linked to the aberrant activation of innate immune cells, so that anti-dsDNA(+) SLE monocytes showed distinctive gene and protein expression/activity profiles, and neutrophils were more prone to suffer NETosis in comparison with anti-dsDNA(−) patients. Anti-dsDNA(+) patients further displayed altered levels of numerous circulating mediators related to inflammation, NETosis, and cardiovascular risk. In vitro, Ig-dsDNA promoted NETosis on neutrophils, apoptosis on monocytes, modulated the expression of inflammation and thrombosis-related molecules, and induced endothelial activation, at least partially, by FcR (Fc receptor)-binding mechanisms. Conclusions: Anti-dsDNA antibodies increase the cardiovascular risk of SLE patients by altering key molecular processes that drive a distinctive and coordinated immune and vascular activation, representing a potential tool in the management of this comorbidity.
Assuntos
Anticorpos Antinucleares/sangue , Doenças Cardiovasculares/imunologia , DNA/imunologia , Células Endoteliais/imunologia , Imunoglobulina G/sangue , Leucócitos/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Adulto , Apoptose , Biomarcadores/sangue , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/genética , Células Cultivadas , Técnicas de Cocultura , Estudos Transversais , Citocinas/genética , Citocinas/metabolismo , Células Endoteliais/metabolismo , Armadilhas Extracelulares/metabolismo , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Leucócitos/metabolismo , Lipídeos/sangue , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/diagnóstico , Lúpus Eritematoso Sistêmico/genética , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Monócitos/metabolismo , Neutrófilos/imunologia , Neutrófilos/metabolismo , Estresse Oxidativo , Estudos Retrospectivos , Medição de Risco , Transdução de SinaisRESUMO
OBJETIVO: Analizar la asociación de la concentración de con-taminantes atmosféricos y los indicadores epidemiológicos de Covid-19 en la Zona Metropolitana del Valle de México (ZMVM). Material y métodos. Se diseñó un estudio epidemiológico ecológico. Se utilizaron modelos lineales tipo Poisson para variables de conteo y modelos lineales de efectos aleatorios en variables continuas para cuantificar la asociación entre los contaminantes atmosféricos y los indicadores de Covid-19. Los datos obtenidos fueron del 28 de febrero de 2020 al 30 de junio de 2021. La exposición a contaminantes se estratificó por estaciones climáticas. RESULTADOS: Los contaminantes que tuvieron asociación significativa con indicadores de morbilidad y mortalidad fueron CO, NOX, O3 y PM10. En la estación seca fría el CO y el NOX tuvieron efecto sobre los casos diarios confirmados y las defunciones diarias. Las PM10 se asociaron con efecto en los indicadores de casos diarios confirmados, incidencia diaria, porcentaje de hospitalizados y la tasa de letalidad. CONCLUSIONES: Los resultados sugieren una asociación entre el comportamiento epidemiológico de Covid-19 y la exposición a CO, NOX, O3 y PM10, en la que se encontró un mayor efecto en la estación seca-fría en la ZMVM.
Assuntos
Poluentes Atmosféricos , COVID-19 , COVID-19/epidemiologia , Humanos , México/epidemiologia , Morbidade , Estudos RetrospectivosRESUMO
Alzheimer's disease (AD) is a frequent and disabling neurodegenerative disorder, in which astrocytes participate in several pathophysiological processes including neuroinflammation, excitotoxicity, oxidative stress and lipid metabolism (along with a critical role in apolipoprotein E function). Current evidence shows that astrocytes have both neuroprotective and neurotoxic effects depending on the disease stage and microenvironmental factors. Furthermore, astrocytes appear to be affected by the presence of amyloid-beta (Aß), with alterations in calcium levels, gliotransmission and proinflammatory activity via RAGE-NF-κB pathway. In addition, astrocytes play an important role in the metabolism of tau and clearance of Aß through the glymphatic system. In this review, we will discuss novel pharmacological and non-pharmacological treatments focused on astrocytes as therapeutic targets for AD. These interventions include effects on anti-inflammatory/antioxidant systems, glutamate activity, lipid metabolism, neurovascular coupling and glymphatic system, calcium dysregulation, and in the release of peptides which affects glial and neuronal function. According to the AD stage, these therapies may be of benefit in either preventing or delaying the progression of the disease.
Assuntos
Doença de Alzheimer , Humanos , Doença de Alzheimer/terapia , Doença de Alzheimer/metabolismo , Astrócitos/metabolismo , Cálcio/metabolismo , Peptídeos beta-Amiloides/metabolismo , Neurônios/metabolismoRESUMO
Laminin, a non-collagenous glycoprotein present in the brain extracellular matrix, helps to maintain blood-brain barrier (BBB) integrity and regulation. Neuroinflammation can compromise laminin structure and function, increasing BBB permeability. The aim of this paper is to determine if neuroinflammation-induced laminin functional changes may serve as a potential biomarker of alterations in the BBB. The 38 publications included evaluated neuroinflammation, BBB disruption, and laminin, and were assessed for quality and risk of bias (protocol registered in PROSPERO; CRD42020212547). We found that laminin may be a good indicator of BBB overall structural integrity, although changes in expression are dependent on the pathologic or experimental model used. In ischemic stroke, permanent vascular damage correlates with increased laminin expression (ß and γ subunits), while transient damage correlates with reduced laminin expression (α subunits). Laminin was reduced in traumatic brain injury and cerebral hemorrhage studies but increased in multiple sclerosis and status epilepticus studies. Despite these observations, there is limited knowledge about the role played by different subunits or isoforms (such as 411 or 511) of laminin in maintaining structural architecture of the BBB under neuroinflammation. Further studies may clarify this aspect and the possibility of using laminin as a biomarker in different pathologies, which have alterations in BBB function in common.
Assuntos
Barreira Hematoencefálica , Laminina , Biomarcadores/metabolismo , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Humanos , Laminina/metabolismo , Doenças NeuroinflamatóriasRESUMO
Neurodegenerative diseases are characterized by increased permeability of the blood-brain barrier (BBB) due to alterations in cellular and structural components of the neurovascular unit, particularly in association with neuroinflammation. A previous screening study of peptide ligands to identify molecular alterations of the BBB in neuroinflammation by phage-display, revealed that phage clone 88 presented specific binding affinity to endothelial cells under inflammatory conditions in vivo and in vitro. Here, we aimed to identify the possible target receptor of the peptide ligand 88 expressed under inflammatory conditions. A cross-link test between phage-peptide-88 with IL-1ß-stimulated human hCMEC cells, followed by mass spectrometry analysis, was used to identify the target of peptide-88. We modeled the epitope-receptor molecular interaction between peptide-88 and its target by using docking simulations. Three proteins were selected as potential target candidates and tested in enzyme-linked immunosorbent assays with peptide-88: fibronectin, laminin subunit α5 and laminin subunit ß-1. Among them, only laminin subunit ß-1 presented measurable interaction with peptide-88. Peptide-88 showed specific interaction with laminin subunit ß-1, highlighting its importance as a potential biomarker of the laminin changes that may occur at the BBB endothelial cells under pathological inflammation conditions.
Assuntos
Barreira Hematoencefálica , Células Endoteliais/metabolismo , Inflamação/metabolismo , Laminina/metabolismo , Animais , Bacteriófago M13 , Biomarcadores , Células Cultivadas , Reagentes de Ligações Cruzadas , Fibronectinas/metabolismo , Ontologia Genética , Humanos , Interleucina-1beta/farmacologia , Modelos Moleculares , Simulação de Acoplamento Molecular , Biblioteca de Peptídeos , Ligação Proteica , Conformação Proteica , Mapeamento de Interação de Proteínas , RatosRESUMO
BACKGROUND: The enzyme-linked immunosorbent assay (ELISA), is the most widely used and reliable clinical routine method for the detection of important protein markers in healthcare. Improving ELISAs is crucial for detecting biomolecules relates to health disorders and facilitating diagnosis at the early diseases stages. Several methods have been developed to improve the ELISA sensitivity through immobilization of antibodies on the microtiter plates. We have developed a highly sensitive ELISA strategy based on the preparation of acetylated chitosan surfaces in order to improve the antibodies orientation. RESULTS: Chitin surfaces were obtained by mixing small quantities of chitosan and acetic anhydride in each well of a microtiter plate. Anti-c-myc 9E10 low affinity antibody fused to ChBD was cloned and expressed in CHO cells obtaining the anti-c-myc-ChBD antibody. We found that anti c-myc-ChBD binds specifically to the chitin surfaces in comparison with anti-c-myc 9E10, which did not. Chitin surface was used to develop a sandwich ELISA to detect the chimeric human protein c-myc-GST-IL8 cloned and expressed in Escherichia coli. The ELISA assays developed on chitin surfaces were 6-fold more sensitive than those performed on standard surface with significant differences (p<0,0001). CONCLUSIONS: As shown here, acetylated chitosan surfaces improve the antibody orientation on the substrate and constitute a suitable method to replace the standard surfaces given the stability over time and the low cost of its preparation.
Assuntos
Quitosana/metabolismo , Ensaio de Imunoadsorção Enzimática/métodos , Acetilação , Animais , Anticorpos/metabolismo , Células CHO , Quitina/metabolismo , Cricetulus , Proteínas de Ligação a DNA/imunologia , Escherichia coli/metabolismo , Humanos , Hibridomas , Interleucina-8/metabolismo , Sensibilidade e Especificidade , Fatores de Transcrição/imunologiaRESUMO
Cystic fibrosis (CF) is a multisystem disorder that reduces quality of life and survival in affected individuals. In newborns, the release of pancreatic enzymes into the blood raises the levels of immunoreactive trypsinogen (IRT), the main marker for CF screening, which is detected in dried blood samples on filter paper by immunoenzymatic assays. In Cuba, CF has an estimated incidence of 1/9862 live births and should be included in the national basic newborn screening (NBS) panel given its benefits in terms of nutrition, lung function and survival. The Immunoassay Center develops and produces diagnostic kits allowing the establishment of large-scale NBS programs for inherited metabolic disorders in Cuba and other Latin American countries. IRT-specific monoclonal antibodies (MAbs) obtained at the Immunoassay Center are essential for developing an affordable immunoassay for IRT to support CF NBS in our low-income country. An immunization scheme with trypsinogen-1 originated two IgG1-producing murine hybridomas. 4C9C9 and 4C9E11 MAbs recognized different determinants on both trypsin-1 and trypsin-2 molecules. Both antibodies identified conformational epitopes on the molecule of trypsin-1 and of its zymogen. As 4C9E11 MAb cross-reacted with proteins structurally and functionally related to trypsinogen, it was used as revealing antibody in a sandwich-type UMELISA® assay for IRT determination with 4C9C9 MAb for capture. This combination, aside from detecting several commercially available trypsins, adequately quantified IRT from dried blood samples on filter paper of newborns. The evaluation of the assay's accuracy yielded percentage recoveries ranging 93.3-109.2% for commercial controls. The properties of the studied MAbs demonstrate their suitability for being used in a sandwich-type UMELISA® assay for the CF NBS in Cuba.
Assuntos
Anticorpos Monoclonais Murinos/biossíntese , Fibrose Cística/diagnóstico , Tripsina/imunologia , Tripsinogênio/imunologia , Animais , Anticorpos Monoclonais Murinos/isolamento & purificação , Biomarcadores/sangue , Feminino , Humanos , Hibridomas , Imunoensaio , Recém-Nascido , Camundongos , Camundongos Endogâmicos BALB C , Triagem NeonatalRESUMO
BACKGROUND: Radiographic axial spondyloarthritis (r-axSpA) is a chronic inflammatory form of arthritis in which tumor necrosis factor (TNF)-α, a potent inducer of inflammatory response and a key regulator of innate immunity and of Th1 immune responses, plays a central role. NETosis is a mechanism of innate immune defense that is involved in diverse rheumatology diseases. Nevertheless, spontaneous NETosis generation in r-axSpA, its association to disease pathogenesis, and the NETosis involvement on anti-TNF-α therapy's effects has never been explored. METHODS: Thirty r-axSpA patients and 32 healthy donors (HDs) were evaluated. Neutrophil extracellular trap (NET) formation, mediators of signal-transduction cascade required for NETosis induction and cell-free NETosis-derived products were quantified. An additional cohort of 15 r-axSpA patients treated with infliximab (IFX) for six months were further analyzed. In vitro studies were designed to assess the effects of IFX in NETosis generation and the inflammatory profile triggered. RESULTS: Compared to HDs, neutrophils from r-axSpA patients displayed augmented spontaneous NET formation, elevated expression of NET-associated signaling components, nuclear peptidylarginine deiminase 4 translocation and increased citrullinated histone H3. Furthermore, patients exhibited altered circulating levels of cell-free NETosis-derived products (DNA, nucleosomes and elastase). Additional studies revealed that cell-free NETosis-derived products could be suitable biomarkers for distinguish r-axSpA patients from HDs. Correlation studies showed association between cell-free NETosis-derived products and clinical inflammatory parameters. Besides, nucleosomes displayed potential as a biomarker for discriminate patients according to disease activity. IFX therapy promoted a reduction in both NETosis generation and disease activity in r-axSpA patients. Mechanistic in vitro studies further unveiled the relevance of IFX in reducing NET release and normalizing the augmented inflammatory activities promoted by NETs in mononuclear cells. CONCLUSIONS: This study reveals that NETosis is enhanced in r-axSpA patients and identifies the NETosis-derived products as potential disease activity biomarkers. In addition, the data suggests the potential role of NET generation analysis for assessment of therapeutic effectiveness in r-axSpA.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Armadilhas Extracelulares/fisiologia , Infliximab/uso terapêutico , Espondilartrite/tratamento farmacológico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Adulto , Biomarcadores , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espanha , Espondilartrite/etiologiaRESUMO
BACKGROUND: Typically, web-based consumer health information is considered more beneficial for people with high levels of education and income. No evidence shows that equity-oriented information offers equal benefits to all. This is important for parents of low socioeconomic status (SES; low levels of education and income and usually a low level of literacy). OBJECTIVE: This study is based on a conceptual framework of information outcomes. In light of this, it aims to compare the perception of the outcomes of web-based parenting information in low-SES mothers with that of other mothers and explore the perspective of low-SES mothers on contextual factors and information needs and behavior associated with these outcomes. METHODS: A participatory mixed methods research was conducted in partnership with academic researchers and Naître et grandir (N&G) editors. N&G is a magazine, website, and newsletter that offers trustworthy parenting information on child development, education, health, and well-being in a format that is easy to read, listen, or watch. Quantitative component (QUAN) included a 3-year longitudinal observational web survey; participants were mothers of 0- to 8-year-old children. For each N&G newsletter, the participants' perception regarding the outcomes of specific N&G webpages was gathered using a content-validated Information Assessment Method (IAM) questionnaire. Differences between participants of low SES versus others were estimated. Qualitative component (QUAL) was interpretive; participants were low-SES mothers. The thematic analysis of interview transcripts identified participants' characteristics and different sources of information depending on information needs. Findings from the two components were integrated (QUAN+QUAL integration) through the conceptual framework and assimilated into the description of an ideal-typical mother of low SES (Kate). A narrative describes Kate's perception of the outcomes of web-based parenting information and her perspective on contextual factors, information needs, and behavior associated with these outcomes. RESULTS: QUAN-a total of 1889 participants completed 2447 IAM responses (50 from mothers of low SES and 2397 from other mothers). N&G information was more likely to help low-SES participants to better understand something, decrease worries, and increase self-confidence in decision making. QUAL-the 40 participants (21 N&G users and 19 nonusers) used 4 information sources in an iterative manner: websites, forums, relatives, and professionals. The integration of QUAN and QUAL findings provides a short narrative, Kate, which summarizes the main findings. CONCLUSIONS: This is the first study comparing perceptions of information outcomes in low-SES mothers with those of other mothers. Findings suggest that equity-oriented, web-based parenting information can offer equal benefits to all, including low-SES mothers. The short narrative, Kate, can be quickly read by decision policy makers, for example, web editors, and might encourage them to reach the underserved and provide and assess trustworthy web-based consumer health information in a format that is easy to read, listen, or watch.
Assuntos
Desenvolvimento Infantil , Internet/normas , Mães/psicologia , Poder Familiar/tendências , Classe Social , Criança , Pré-Escolar , Feminino , Humanos , Renda , Lactente , Recém-Nascido , Estudos Longitudinais , MasculinoRESUMO
In research on natural molecules with cytotoxic activity that can be used for the development of new anticancer agents, the cytotoxic activity of hexane, chloroform, and methanol extracts from the roots of Acacia schaffneri against colon, lung, and skin cancer cell lines was explored. The hexane extract showed the best activity with an average IC50 of 10.6 µg mL-1. From this extract, three diterpenoids, phyllocladan-16α,19-diol (1), phyllocladan-16α-ol (2), and phylloclad-16-en-3-ol (3), were isolated and characterized by their physical and spectroscopic properties. Diterpenoids 1 and 2 were tested against the same cancer cell lines, as well as their healthy counterparts, CCD841 CoN, MRC5, and VH10, respectively. Compound 1 showed moderate activity (IC50 values between 24 and 70 µg mL-1), although it showed a selective effect against cancer cell lines. Compound 2 was practically inactive. The cytotoxicity mechanism of 1 was analyzed by cell cycle, indicating that the compound induces G0/G1 cell cycle arrest. This effect might be generated by DNA alkylation damage. In addition, compound 1 decreased migration of HT29 cells.
Assuntos
Fabaceae/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Fracionamento Químico , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Extratos Vegetais/isolamento & purificaçãoRESUMO
KEY POINTS: Slow periodic activity can propagate with speeds around 0.1 m s-1 and be modulated by weak electric fields. Slow periodic activity in the longitudinal hippocampal slice can propagate without chemical synaptic transmission or gap junctions, but can generate electric fields which in turn activate neighbouring cells. Applying local extracellular electric fields with amplitude in the range of endogenous fields is sufficient to modulate or block the propagation of this activity both in the in silico and in the in vitro models. Results support the hypothesis that endogenous electric fields, previously thought to be too small to trigger neural activity, play a significant role in the self-propagation of slow periodic activity in the hippocampus. Experiments indicate that a neural network can give rise to sustained self-propagating waves by ephaptic coupling, suggesting a novel propagation mechanism for neural activity under normal physiological conditions. ABSTRACT: Slow oscillations are a standard feature observed in the cortex and the hippocampus during slow wave sleep. Slow oscillations are characterized by low-frequency periodic activity (<1 Hz) and are thought to be related to memory consolidation. These waves are assumed to be a reflection of the underlying neural activity, but it is not known if they can, by themselves, be self-sustained and propagate. Previous studies have shown that slow periodic activity can be reproduced in the in vitro preparation to mimic in vivo slow oscillations. Slow periodic activity can propagate with speeds around 0.1 m s-1 and be modulated by weak electric fields. In the present study, we show that slow periodic activity in the longitudinal hippocampal slice is a self-regenerating wave which can propagate with and without chemical or electrical synaptic transmission at the same speeds. We also show that applying local extracellular electric fields can modulate or even block the propagation of this wave in both in silico and in vitro models. Our results support the notion that ephaptic coupling plays a significant role in the propagation of the slow hippocampal periodic activity. Moreover, these results indicate that a neural network can give rise to sustained self-propagating waves by ephaptic coupling, suggesting a novel propagation mechanism for neural activity under normal physiological conditions.
Assuntos
Hipocampo/fisiologia , Modelos Neurológicos , Rede Nervosa , Animais , Eletrodos , Fenômenos Eletrofisiológicos , Feminino , Masculino , Camundongos Transgênicos , Neurônios/fisiologia , Transmissão SinápticaRESUMO
The extracellular matrix (ECM) is a pivotal component adult tissues and of many tissue-specific stem cell niches. It provides structural support and regulates niche signaling during tissue maintenance and regeneration. In many tissues, ECM remodeling depends on the regulation of MMP (matrix metalloproteinase) activity by inhibitory TIMP (tissue inhibitors of metalloproteinases) proteins. Here, we report that the only Drosophila timp gene is required for maintaining the normal organization and function of the germline stem cell niche in adult females. timp mutant ovaries show reduced levels of both Drosophila Collagen IV α chains. In addition, tissue stiffness and the cellular organization of the ovarian niche are affected in timp mutants. Finally, loss of timp impairs the ability of the germline stem cell niche to generate new cysts. Our results demonstrating a crucial role for timp in tissue organization and gamete production thus provide a link between the regulation of ECM metabolism and tissue homeostasis.
Assuntos
Matriz Extracelular/metabolismo , Ovário/metabolismo , Nicho de Células-Tronco/genética , Inibidores Teciduais de Metaloproteinases/genética , Animais , Colágeno Tipo IV/genética , Drosophila , Matriz Extracelular/genética , Feminino , Células Germinativas , Metaloproteinases da Matriz/genética , Ovário/crescimento & desenvolvimentoRESUMO
Epidemiological studies strongly suggest an association between high levels of dietary fat intake and an increased risk of developing breast cancer. Linoleic acid (LA) is an essential omega-6 PUFA and the major fatty acid in occidental diets. In breast cancer cells, LA induces expression of plasminogen activator inhibitor-1, proliferation, migration, and invasion. Fascin is an actin crosslinker globular protein that generates actin bundles made of parallel actin filaments, which mediate formation and stability of microspikes, stress fibers, membrane ruffles, and filopodia. However, the role of fascin in migration and invasion induced by LA in MDA-MB-231 breast cancer cells remains to be studied. We demonstrate here that LA induces an increase of fascin expression in MDA-MB-231 and MCF12A mammary epithelial cells. Particularly, LA induces the formation of filopodia and lamellipodia and the localization of fascin in these actin structures in MDA-MB-231 breast cancer cells. However, LA only induces formation of microspikes and the localization of fascin in these actin structures in mammary non-tumorigenic epithelial cells MCF12A. In addition, LA induces migration, invasion, and matrix metalloproteinase-9 secretion through a fascin-dependent pathway in MDA-MB-231 cells. In summary, our findings demonstrate that fascin is required for migration and invasion induced by LA in MDA-MB-231 breast cancer cells.
Assuntos
Neoplasias da Mama/metabolismo , Proteínas de Transporte/metabolismo , Movimento Celular/efeitos dos fármacos , Ácido Linoleico/farmacologia , Proteínas dos Microfilamentos/metabolismo , Proteínas de Neoplasias/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Feminino , Humanos , Invasividade NeoplásicaRESUMO
OBJECTIVE: Antiphospholipid syndrome (APS) leukocytes exhibit an oxidative perturbation, directly linked to alterations in mitochondrial dynamics and metabolism. This disturbance is related to the patients' prothrombotic status and can be prevented by in vitro treatment with coenzyme Q10. Our aim was to investigate short-term effects of in vivo ubiquinol (reduced coenzyme Q10 [Qred]) supplementation on markers related to inflammation and thrombosis in APS through a prospective, randomized, crossover, placebo-controlled trial. APPROACH AND RESULTS: Thirty-six patients with APS were randomized to receive Qred (200 mg/d) or placebo for 1 month. Thirty-three patients with APS completed the intervention, which increased plasma coenzyme Q10. Qred improved endothelial function and decreased monocyte expression of prothrombotic and proinflammatory mediators, inhibited phosphorylation of thrombosis-related protein kinases, and decreased peroxides and percentage of monocytes with depolarized mitochondria; mitochondrial size was increased, and mitochondrial biogenesis-related genes were upregulated. Qred ameliorated extruded neutrophil extracellular traps in neutrophils and downregulated peroxides, intracellular elastase, and myeloperoxidase. Nanostring microRNA profiling revealed 20 microRNAs reduced in APS monocytes, and 16 of them, with a preponderance of cardiovascular disease-related target mRNAs, were upregulated. Monocytes gene profiling showed differential expression of 29 atherosclerosis-related genes, 23 of them changed by Qred. Interaction networks of genes and microRNAs were identified. Correlation studies demonstrated co-ordinated effects of Qred on thrombosis and endothelial function-associated molecules. CONCLUSIONS: Our results highlight the potential of Qred to modulate the overexpression of inflammatory and thrombotic risk markers in APS. Because of the absence of clinically significant side effects and its potential therapeutic benefits, Qred might act as safe adjunct to standard therapies in APS. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02218476.
Assuntos
Síndrome Antifosfolipídica/tratamento farmacológico , Síndrome Antifosfolipídica/fisiopatologia , Ubiquinona/análogos & derivados , Vitaminas/uso terapêutico , Estudos Cross-Over , Endotélio Vascular/fisiologia , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases , Inflamação/fisiopatologia , Masculino , Pessoa de Meia-Idade , Mitocôndrias/fisiologia , Monócitos/patologia , Oxirredução , Estudos Prospectivos , Ubiquinona/uso terapêuticoRESUMO
Alzheimer's disease (AD) is the leading cause of dementia worldwide. It compromises patients' daily activities owing to progressive cognitive deterioration, which has elevated direct and indirect costs. Although AD has several risk factors, aging is considered the most important. Unfortunately, clinical diagnosis is usually performed at an advanced disease stage when dementia is established, making implementation of successful therapeutic interventions difficult. Current biomarkers tend to be expensive, insufficient, or invasive, raising the need for novel, improved tools aimed at early disease detection. AD is characterized by brain atrophy due to neuronal and synaptic loss, extracellular amyloid plaques composed of amyloid-beta peptide (Aß), and neurofibrillary tangles of hyperphosphorylated tau protein. The visual system and central nervous system share many functional components. Thus, it is plausible that damage induced by Aß, tau, and neuroinflammation may be observed in visual components such as the retina, even at an early disease stage. This underscores the importance of implementing ophthalmological examinations, less invasive and expensive than other biomarkers, as useful measures to assess disease progression and severity in individuals with or at risk of AD. Here, we review functional and morphological changes of the retina and visual pathway in AD from pathophysiological and clinical perspectives.