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1.
Cell ; 162(5): 961-73, 2015 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-26317465

RESUMEN

DNA-demethylating agents have shown clinical anti-tumor efficacy via an unknown mechanism of action. Using a combination of experimental and bioinformatics analyses in colorectal cancer cells, we demonstrate that low-dose 5-AZA-CdR targets colorectal cancer-initiating cells (CICs) by inducing viral mimicry. This is associated with induction of dsRNAs derived at least in part from endogenous retroviral elements, activation of the MDA5/MAVS RNA recognition pathway, and downstream activation of IRF7. Indeed, disruption of virus recognition pathways, by individually knocking down MDA5, MAVS, or IRF7, inhibits the ability of 5-AZA-CdR to target colorectal CICs and significantly decreases 5-AZA-CdR long-term growth effects. Moreover, transfection of dsRNA into CICs can mimic the effects of 5-AZA-CdR. Together, our results represent a major shift in understanding the anti-tumor mechanisms of DNA-demethylating agents and highlight the MDA5/MAVS/IRF7 pathway as a potentially druggable target against CICs.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacología , Azacitidina/análogos & derivados , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/inmunología , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Azacitidina/farmacología , Células Cultivadas , ARN Helicasas DEAD-box/metabolismo , Metilación de ADN/efectos de los fármacos , Decitabina , Retrovirus Endógenos/metabolismo , Humanos , Factor 7 Regulador del Interferón/metabolismo , Helicasa Inducida por Interferón IFIH1 , Ratones , ARN Bicatenario/metabolismo , Receptores de Ácido Retinoico/metabolismo , Transducción de Señal
2.
Hum Mol Genet ; 33(10): 872-883, 2024 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-38340007

RESUMEN

Facioscapulohumeral muscular dystrophy (FSHD) is a progressive myopathy caused by the aberrant increased expression of the DUX4 retrogene in skeletal muscle cells. The DUX4 gene encodes a transcription factor that functions in zygotic genome activation and then is silenced in most adult somatic tissues. DUX4 expression in FSHD disrupts normal muscle cell function; however, the downstream pathogenic mechanisms are still unclear. Histologically, FSHD affected muscles show a characteristic dystrophic phenotype that is often accompanied by a pronounced immune cell infiltration, but the role of the immune system in FSHD is not understood. Previously, we used ACTA1;FLExDUX4 FSHD-like mouse models varying in severity as discovery tools to identify increased Interleukin 6 and microRNA-206 levels as serum biomarkers for FSHD disease severity. In this study, we use the ACTA1;FLExDUX4 chronic FSHD-like mouse model to provide insight into the immune response to DUX4 expression in skeletal muscles. We demonstrate that these FSHD-like muscles are enriched with the chemoattractant eotaxin and the cytotoxic eosinophil peroxidase, and exhibit muscle eosinophilia. We further identified muscle fibers with positive staining for eosinophil peroxidase in human FSHD muscle. Our data supports that skeletal muscle eosinophilia is a hallmark of FSHD pathology.


Asunto(s)
Modelos Animales de Enfermedad , Eosinofilia , Proteínas de Homeodominio , Músculo Esquelético , Distrofia Muscular Facioescapulohumeral , Distrofia Muscular Facioescapulohumeral/genética , Distrofia Muscular Facioescapulohumeral/metabolismo , Distrofia Muscular Facioescapulohumeral/patología , Animales , Ratones , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Músculo Esquelético/metabolismo , Músculo Esquelético/patología , Humanos , Eosinofilia/genética , Eosinofilia/patología , Eosinofilia/inmunología , Quimiocina CCL11/genética , Quimiocina CCL11/metabolismo , Enfermedad Crónica , MicroARNs/genética , MicroARNs/metabolismo
3.
Hum Mol Genet ; 33(8): 698-708, 2024 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-38268317

RESUMEN

Identifying the aberrant expression of DUX4 in skeletal muscle as the cause of facioscapulohumeral dystrophy (FSHD) has led to rational therapeutic development and clinical trials. Several studies support the use of MRI characteristics and the expression of DUX4-regulated genes in muscle biopsies as biomarkers of FSHD disease activity and progression. We performed lower-extremity MRI and muscle biopsies in the mid-portion of the tibialis anterior (TA) muscles bilaterally in FSHD subjects and validated our prior reports of the strong association between MRI characteristics and expression of genes regulated by DUX4 and other gene categories associated with FSHD disease activity. We further show that measurements of normalized fat content in the entire TA muscle strongly predict molecular signatures in the mid-portion of the TA, indicating that regional biopsies can accurately measure progression in the whole muscle and providing a strong basis for inclusion of MRI and molecular biomarkers in clinical trial design. An unanticipated finding was the strong correlations of molecular signatures in the bilateral comparisons, including markers of B-cells and other immune cell populations, suggesting that a systemic immune cell infiltration of skeletal muscle might have a role in disease progression.


Asunto(s)
Distrofia Muscular Facioescapulohumeral , Humanos , Distrofia Muscular Facioescapulohumeral/diagnóstico por imagen , Distrofia Muscular Facioescapulohumeral/genética , Distrofia Muscular Facioescapulohumeral/metabolismo , Proteínas de Homeodominio/genética , Ensayos Clínicos como Asunto , Músculo Esquelético/metabolismo , Imagen por Resonancia Magnética , Biomarcadores/metabolismo , Progresión de la Enfermedad
4.
Cell ; 147(6): 1283-94, 2011 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-22153073

RESUMEN

Key regulatory genes, suppressed by Polycomb and H3K27me3, become active during normal differentiation and induced reprogramming. Using the well-characterized enhancer/promoter pair of MYOD1 as a model, we have identified a critical role for enhancers in reprogramming. We observed an unexpected nucleosome-depleted region (NDR) at the H3K4me1-enriched enhancer at which transcriptional regulators initially bind, leading to subsequent changes in the chromatin at the cognate promoter. Exogenous Myod1 activates its own transcription by binding first at the enhancer, leading to an NDR and transcription-permissive chromatin at the associated MYOD1 promoter. Exogenous OCT4 also binds first to the permissive MYOD1 enhancer but has a different effect on the cognate promoter, where the monovalent H3K27me3 marks are converted to the bivalent state characteristic of stem cells. Genome-wide, a high percentage of Polycomb targets are associated with putative enhancers in permissive states, suggesting that they may provide a widespread avenue for the initiation of cell-fate reprogramming.


Asunto(s)
Elementos de Facilitación Genéticos , Proteínas Represoras/metabolismo , Animales , Línea Celular , Epigenómica , Fibroblastos/metabolismo , Humanos , Ratones , Proteína MioD/genética , Nucleosomas/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Proteínas del Grupo Polycomb , Regiones Promotoras Genéticas
5.
Nature ; 586(7827): 151-155, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32968275

RESUMEN

CpG methylation by de novo DNA methyltransferases (DNMTs) 3A and 3B is essential for mammalian development and differentiation and is frequently dysregulated in cancer1. These two DNMTs preferentially bind to nucleosomes, yet cannot methylate the DNA wrapped around the nucleosome core2, and they favour the methylation of linker DNA at positioned nucleosomes3,4. Here we present the cryo-electron microscopy structure of a ternary complex of catalytically competent DNMT3A2, the catalytically inactive accessory subunit DNMT3B3 and a nucleosome core particle flanked by linker DNA. The catalytic-like domain of the accessory DNMT3B3 binds to the acidic patch of the nucleosome core, which orients the binding of DNMT3A2 to the linker DNA. The steric constraints of this arrangement suggest that nucleosomal DNA must be moved relative to the nucleosome core for de novo methylation to occur.


Asunto(s)
Microscopía por Crioelectrón , ADN (Citosina-5-)-Metiltransferasas/química , ADN (Citosina-5-)-Metiltransferasas/metabolismo , Nucleosomas/metabolismo , Animales , Biocatálisis , Ensamble y Desensamble de Cromatina , ADN/química , ADN/metabolismo , Metilación de ADN , ADN Metiltransferasa 3A , Histonas/química , Histonas/genética , Histonas/metabolismo , Humanos , Modelos Moleculares , Nucleosomas/química , Unión Proteica , Dominios Proteicos , Xenopus/genética , ADN Metiltransferasa 3B
6.
Nature ; 588(7838): 436-441, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33328667

RESUMEN

Rivers support some of Earth's richest biodiversity1 and provide essential ecosystem services to society2, but they are often fragmented by barriers to free flow3. In Europe, attempts to quantify river connectivity have been hampered by the absence of a harmonized barrier database. Here we show that there are at least 1.2 million instream barriers in 36 European countries (with a mean density of 0.74 barriers per kilometre), 68 per cent of which are structures less than two metres in height that are often overlooked. Standardized walkover surveys along 2,715 kilometres of stream length for 147 rivers indicate that existing records underestimate barrier numbers by about 61 per cent. The highest barrier densities occur in the heavily modified rivers of central Europe and the lowest barrier densities occur in the most remote, sparsely populated alpine areas. Across Europe, the main predictors of barrier density are agricultural pressure, density of river-road crossings, extent of surface water and elevation. Relatively unfragmented rivers are still found in the Balkans, the Baltic states and parts of Scandinavia and southern Europe, but these require urgent protection from proposed dam developments. Our findings could inform the implementation of the EU Biodiversity Strategy, which aims to reconnect 25,000 kilometres of Europe's rivers by 2030, but achieving this will require a paradigm shift in river restoration that recognizes the widespread impacts caused by small barriers.


Asunto(s)
Ecosistema , Ríos , Agricultura/estadística & datos numéricos , Altitud , Biodiversidad , Conjuntos de Datos como Asunto , Restauración y Remediación Ambiental/métodos , Restauración y Remediación Ambiental/tendencias , Europa (Continente) , Actividades Humanas , Humanos , Modelos Logísticos , Aprendizaje Automático , Densidad de Población , Centrales Eléctricas/provisión & distribución
7.
Nucleic Acids Res ; 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38874474

RESUMEN

Long terminal repeats (LTRs), which often contain promoter and enhancer sequences of intact endogenous retroviruses (ERVs), are known to be co-opted as cis-regulatory elements for fine-tuning host-coding gene expression. Since LTRs are mainly silenced by the deposition of repressive epigenetic marks, substantial activation of LTRs has been found in human cells after treatment with epigenetic inhibitors. Although the LTR12C family makes up the majority of ERVs activated by epigenetic inhibitors, how these epigenetically and transcriptionally activated LTR12C elements can regulate the host-coding gene expression remains unclear due to genome-wide alteration of transcriptional changes after epigenetic inhibitor treatments. Here, we specifically transactivated >600 LTR12C elements by using single guide RNA-based dCas9-SunTag-VP64, a site-specific targeting CRISPR activation (CRISPRa) system, with minimal off-target events. Interestingly, most of the transactivated LTR12C elements acquired the H3K27ac-marked enhancer feature, while only 20% were co-marked with promoter-associated H3K4me3 modifications. The enrichment of the H3K4me3 signal was intricately associated with downstream regions of LTR12C, such as internal regions of intact ERV9 or other types of retrotransposons. Here, we leverage an optimized CRISPRa system to identify two distinct epigenetic signatures that define LTR12C transcriptional activation, which modulate the expression of proximal protein-coding genes.

8.
Hum Mol Genet ; 32(11): 1864-1874, 2023 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-36728804

RESUMEN

Human DUX4 and its mouse ortholog Dux are normally expressed in the early embryo-the 4-cell or 2-cell cleavage stage embryo, respectively-and activate a portion of the first wave of zygotic gene expression. DUX4 is epigenetically suppressed in nearly all somatic tissue, whereas facioscapulohumeral dystrophy (FSHD)-causing mutations result in its aberrant expression in skeletal muscle, transcriptional activation of the early embryonic program and subsequent muscle pathology. Although DUX4 and Dux both activate an early totipotent transcriptional program, divergence of their DNA binding domains limits the use of DUX4 expressed in mice as a preclinical model for FSHD. In this study, we identify the porcine DUXC messenger ribonucleic acid expressed in early development and show that both pig DUXC and human DUX4 robustly activate a highly similar early embryonic program in pig muscle cells. These results support further investigation of pig preclinical models for FSHD.


Asunto(s)
Distrofia Muscular Facioescapulohumeral , Humanos , Animales , Ratones , Porcinos , Distrofia Muscular Facioescapulohumeral/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Células Musculares/metabolismo , Músculo Esquelético/metabolismo
9.
Circ Res ; 132(11): e188-e205, 2023 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-37139790

RESUMEN

BACKGROUND: Transverse tubules (t-tubules) form gradually in the developing heart, critically enabling maturation of cardiomyocyte Ca2+ homeostasis. The membrane bending and scaffolding protein BIN1 (bridging integrator 1) has been implicated in this process. However, it is unclear which of the various reported BIN1 isoforms are involved, and whether BIN1 function is regulated by its putative binding partners MTM1 (myotubularin), a phosphoinositide 3'-phosphatase, and DNM2 (dynamin-2), a GTPase believed to mediate membrane fission. METHODS: We investigated the roles of BIN1, MTM1, and DNM2 in t-tubule formation in developing mouse cardiomyocytes, and in gene-modified HL-1 and human-induced pluripotent stem cell-derived cardiomyocytes. T-tubules and proteins of interest were imaged by confocal and Airyscan microscopy, and expression patterns were examined by RT-qPCR and Western blotting. Ca2+ release was recorded using Fluo-4. RESULTS: We observed that in the postnatal mouse heart, BIN1 localizes along Z-lines from early developmental stages, consistent with roles in initial budding and scaffolding of t-tubules. T-tubule proliferation and organization were linked to a progressive and parallel increase in 4 detected BIN1 isoforms. All isoforms were observed to induce tubulation in cardiomyocytes but produced t-tubules with differing geometries. BIN1-induced tubulations contained the L-type Ca2+ channel, were colocalized with caveolin-3 and the ryanodine receptor, and effectively triggered Ca2+ release. BIN1 upregulation during development was paralleled by increasing expression of MTM1. Despite no direct binding between MTM1 and murine cardiac BIN1 isoforms, which lack exon 11, high MTM1 levels were necessary for BIN1-induced tubulation, indicating a central role of phosphoinositide homeostasis. In contrast, the developing heart exhibited declining levels of DNM2. Indeed, we observed that high levels of DNM2 are inhibitory for t-tubule formation, although this protein colocalizes with BIN1 along Z-lines, and binds all 4 isoforms. CONCLUSIONS: These findings indicate that BIN1, MTM1, and DNM2 have balanced and collaborative roles in controlling t-tubule growth in cardiomyocytes.


Asunto(s)
Dinamina II , Miocitos Cardíacos , Animales , Humanos , Ratones , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Dinamina II/genética , Dinamina II/metabolismo , Miocitos Cardíacos/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Proteínas Nucleares/metabolismo , Isoformas de Proteínas/metabolismo , Proteínas Tirosina Fosfatasas no Receptoras/genética , Proteínas Tirosina Fosfatasas no Receptoras/metabolismo , Proteínas Supresoras de Tumor/metabolismo
10.
Arterioscler Thromb Vasc Biol ; 44(7): 1502-1511, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38813700

RESUMEN

Atherosclerosis is a complex inflammatory disease in which the adaptive immune response plays an important role. While the overall impact of T and B cells in atherosclerosis is relatively well established, we are only beginning to understand how bidirectional T-cell/B-cell interactions can exert prominent atheroprotective and proatherogenic functions. In this review, we will focus on these T-cell/B-cell interactions and how we could use them to therapeutically target the adaptive immune response in atherosclerosis.


Asunto(s)
Inmunidad Adaptativa , Aterosclerosis , Linfocitos B , Comunicación Celular , Linfocitos T , Humanos , Aterosclerosis/inmunología , Aterosclerosis/patología , Aterosclerosis/metabolismo , Animales , Linfocitos T/inmunología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Transducción de Señal
11.
Nucleic Acids Res ; 51(12): 5997-6005, 2023 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-37094063

RESUMEN

CpG methylation generally occurs on both DNA strands and is essential for mammalian development and differentiation. Until recently, hemimethylation, in which only one strand is methylated, was considered to be simply a transitory state generated during DNA synthesis. The discovery that a subset of CCCTC-binding factor (CTCF) binding sites is heritably hemimethylated suggests that hemimethylation might have an unknown biological function. Here we show that the binding of CTCF is profoundly altered by which DNA strand is methylated and by the specific CTCF binding motif. CpG methylation on the motif strand can inhibit CTCF binding by up to 7-fold, whereas methylation on the opposite strand can stimulate binding by up to 4-fold. Thus, hemimethylation can alter binding by up to 28-fold in a strand-specific manner. The mechanism for sensing methylation on the opposite strand requires two critical residues, V454 and S364, within CTCF zinc fingers 7 and 4. Similar to methylation, CpG hydroxymethylation on the motif strand can inhibit CTCF binding by up to 4-fold. However, hydroxymethylation on the opposite strand removes the stimulatory effect. Strand-specific methylation states may therefore provide a mechanism to explain the transient and dynamic nature of CTCF-mediated chromatin interactions.


Asunto(s)
Factor de Unión a CCCTC , Metilación de ADN , Proteínas Represoras , Animales , Sitios de Unión , Factor de Unión a CCCTC/metabolismo , Cromatina , Islas de CpG , ADN/metabolismo , Mamíferos/genética , Proteínas Represoras/metabolismo
12.
J Physiol ; 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38686538

RESUMEN

Mechanical load is a potent regulator of cardiac structure and function. Although high workload during heart failure is associated with disruption of cardiomyocyte t-tubules and Ca2+ homeostasis, it remains unclear whether changes in preload and afterload may promote adaptive t-tubule remodelling. We examined this issue by first investigating isolated effects of stepwise increases in load in cultured rat papillary muscles. Both preload and afterload increases produced a biphasic response, with the highest t-tubule densities observed at moderate loads, whereas excessively low and high loads resulted in low t-tubule levels. To determine the baseline position of the heart on this bell-shaped curve, mice were subjected to mildly elevated preload or afterload (1 week of aortic shunt or banding). Both interventions resulted in compensated cardiac function linked to increased t-tubule density, consistent with ascension up the rising limb of the curve. Similar t-tubule proliferation was observed in human patients with moderately increased preload or afterload (mitral valve regurgitation, aortic stenosis). T-tubule growth was associated with larger Ca2+ transients, linked to upregulation of L-type Ca2+ channels, Na+-Ca2+ exchanger, mechanosensors and regulators of t-tubule structure. By contrast, marked elevation of cardiac load in rodents and patients advanced the heart down the declining limb of the t-tubule-load relationship. This bell-shaped relationship was lost in the absence of electrical stimulation, indicating a key role of systolic stress in controlling t-tubule plasticity. In conclusion, modest augmentation of workload promotes compensatory increases in t-tubule density and Ca2+ cycling, whereas this adaptation is reversed in overloaded hearts during heart failure progression. KEY POINTS: Excised papillary muscle experiments demonstrated a bell-shaped relationship between cardiomyocyte t-tubule density and workload (preload or afterload), which was only present when muscles were electrically stimulated. The in vivo heart at baseline is positioned on the rising phase of this curve because moderate increases in preload (mice with brief aortic shunt surgery, patients with mitral valve regurgitation) resulted in t-tubule growth. Moderate increases in afterload (mice and patients with mild aortic banding/stenosis) similarly increased t-tubule density. T-tubule proliferation was associated with larger Ca2+ transients, with upregulation of the L-type Ca2+ channel, Na+-Ca2+ exchanger, mechanosensors and regulators of t-tubule structure. By contrast, marked elevation of cardiac load in rodents and patients placed the heart on the declining phase of the t-tubule-load relationship, promoting heart failure progression. The dependence of t-tubule structure on preload and afterload thus enables both compensatory and maladaptive remodelling, in rodents and humans.

13.
Int J Cancer ; 154(10): 1794-1801, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38312102

RESUMEN

DNA methyltransferase inhibitors (DNMTi) have demonstrated benefit in reversing resistance to systemic therapies for several cancer types. In a phase II trial of guadecitabine and irinotecan compared to regorafenib or TAS-102 in pts with advanced mCRC refractory to irinotecan. Patients with mCRC refractory to irinotecan were randomized 2:1 to guadecitabine and irinotecan (Arm A) vs standard of care regorafenib or TAS-102 (Arm B) on a 28-day cycle. Between January 15, 2016 and October 24, 2018, 104 pts were randomized at four international sites, with 96 pts undergoing treatment, 62 in Arm A and 34 in Arm B. Median overall survival was 7.15 months for Arm A and 7.66 months for Arm B (HR 0.93, 95% CI: 0.58-1.47, P = .75). The Kaplan-Meier rates of progression free survival at 4 months were 32% in Arm A and 26% in Arm B. Common ≥Grade 3 treatment related adverse events in Arm A were neutropenia (42%), anemia (18%), diarrhea (11%), compared to Arm B pts with neutropenia (12%), anemia (12%). Guadecitabine and irinotecan had similar OS compared to standard of care TAS-102 or regorafenib, with evidence of target modulation. Clinical trial information: NCT01896856.


Asunto(s)
Anemia , Azacitidina/análogos & derivados , Neoplasias del Colon , Neoplasias Colorrectales , Neutropenia , Compuestos de Fenilurea , Piridinas , Pirrolidinas , Neoplasias del Recto , Timina , Trifluridina , Humanos , Irinotecán/uso terapéutico , Neoplasias Colorrectales/patología , Resultado del Tratamiento , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Recto/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Anemia/tratamiento farmacológico , Combinación de Medicamentos
14.
Psychol Med ; 54(8): 1810-1823, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38288603

RESUMEN

BACKGROUND: Incidence of first-episode psychosis (FEP) varies substantially across geographic regions. Phenotypes of subclinical psychosis (SP), such as psychotic-like experiences (PLEs) and schizotypy, present several similarities with psychosis. We aimed to examine whether SP measures varied across different sites and whether this variation was comparable with FEP incidence within the same areas. We further examined contribution of environmental and genetic factors to SP. METHODS: We used data from 1497 controls recruited in 16 different sites across 6 countries. Factor scores for several psychopathological dimensions of schizotypy and PLEs were obtained using multidimensional item response theory models. Variation of these scores was assessed using multi-level regression analysis to estimate individual and between-sites variance adjusting for age, sex, education, migrant, employment and relational status, childhood adversity, and cannabis use. In the final model we added local FEP incidence as a second-level variable. Association with genetic liability was examined separately. RESULTS: Schizotypy showed a large between-sites variation with up to 15% of variance attributable to site-level characteristics. Adding local FEP incidence to the model considerably reduced the between-sites unexplained schizotypy variance. PLEs did not show as much variation. Overall, SP was associated with younger age, migrant, unmarried, unemployed and less educated individuals, cannabis use, and childhood adversity. Both phenotypes were associated with genetic liability to schizophrenia. CONCLUSIONS: Schizotypy showed substantial between-sites variation, being more represented in areas where FEP incidence is higher. This supports the hypothesis that shared contextual factors shape the between-sites variation of psychosis across the spectrum.


Asunto(s)
Trastornos Psicóticos , Trastorno de la Personalidad Esquizotípica , Humanos , Trastornos Psicóticos/epidemiología , Masculino , Femenino , Europa (Continente)/epidemiología , Adulto , Brasil/epidemiología , Adulto Joven , Adolescente , Trastorno de la Personalidad Esquizotípica/epidemiología , Incidencia , Persona de Mediana Edad , Fenotipo
15.
Diabet Med ; 41(6): e15279, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38185936

RESUMEN

AIMS: Evidence is accumulating of the therapeutic benefits of mesenchymal stromal cells (MSCs) in diabetes-related conditions. We have identified a novel population of stromal cells within islets of Langerhans - islet stellate cells (ISCs) - which have a similar morphology to MSCs. In this study we characterize mouse ISCs and compare their morphology and function to MSCs to determine whether ISCs may also have therapeutic potential in diabetes. METHODS: ISCs isolated from mouse islets were compared to mouse bone marrow MSCs by analysis of cell morphology; expression of cell-surface markers and extracellular matrix (ECM) components; proliferation; apoptosis; paracrine activity; and differentiation into adipocytes, chondrocytes and osteocytes. We also assessed the effects of co-culture with ISCs or MSCs on the insulin secretory capacity of islet beta cells. RESULTS: Although morphological similar, ISCs were functionally distinct from MSCs. Thus, ISCs were less proliferative and more apoptotic; they had different expression levels of important paracrine factors; and they were less efficient at differentiation down multiple lineages. Co-culture of mouse islets with ISCs enhanced glucose induced insulin secretion more effectively than co-culture with MSCs. CONCLUSIONS: ISCs are a specific sub-type of islet-derived stromal cells that possess biological behaviors distinct from MSCs. The enhanced beneficial effects of ISCs on islet beta cell function suggests that they may offer a therapeutic target for enhancing beta cell functional survival in diabetes.


Asunto(s)
Diferenciación Celular , Técnicas de Cocultivo , Células Secretoras de Insulina , Islotes Pancreáticos , Células Madre Mesenquimatosas , Animales , Ratones , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/fisiología , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/fisiología , Células Secretoras de Insulina/citología , Diferenciación Celular/fisiología , Islotes Pancreáticos/citología , Islotes Pancreáticos/metabolismo , Células Estrelladas Pancreáticas/metabolismo , Células Estrelladas Pancreáticas/fisiología , Proliferación Celular/fisiología , Insulina/metabolismo , Células Cultivadas , Secreción de Insulina/fisiología , Ratones Endogámicos C57BL , Masculino , Apoptosis/fisiología
16.
Mol Psychiatry ; 28(5): 2095-2106, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37062770

RESUMEN

ABTRACT: Studies conducted in psychotic disorders have shown that DNA-methylation (DNAm) is sensitive to the impact of Childhood Adversity (CA). However, whether it mediates the association between CA and psychosis is yet to be explored. Epigenome wide association studies (EWAS) using the Illumina Infinium-Methylation EPIC array in peripheral blood tissue from 366 First-episode of psychosis and 517 healthy controls was performed. Adversity scores were created for abuse, neglect and composite adversity with the Childhood Trauma Questionnaire (CTQ). Regressions examining (I) CTQ scores with psychosis; (II) with DNAm EWAS level and (III) between DNAm and caseness, adjusted for a variety of confounders were conducted. Divide-Aggregate Composite-null Test for the composite null-hypothesis of no mediation effect was conducted. Enrichment analyses were conducted with missMethyl package and the KEGG database. Our results show that CA was associated with psychosis (Composite: OR = 1.68; p = <0.001; abuse: OR = 2.16; p < 0.001; neglect: OR = 2.27; p = <0.001). None of the CpG sites significantly mediated the adversity-psychosis association after Bonferroni correction (p < 8.1 × 10-8). However, 28, 34 and 29 differentially methylated probes associated with 21, 27, 20 genes passed a less stringent discovery threshold (p < 5 × 10-5) for composite, abuse and neglect respectively, with a lack of overlap between abuse and neglect. These included genes previously associated to psychosis in EWAS studies, such as PANK1, SPEG TBKBP1, TSNARE1 or H2R. Downstream gene ontology analyses did not reveal any biological pathways that survived false discovery rate correction. Although at a non-significant level, DNAm changes in genes previously associated with schizophrenia in EWAS studies may mediate the CA-psychosis association. These results and associated involved processes such as mitochondrial or histaminergic disfunction, immunity or neural signalling requires replication in well powered samples. The lack of overlap between mediating genes associated with abuse and neglect suggests differential biological trajectories linking CA subtypes and psychosis.


Asunto(s)
Experiencias Adversas de la Infancia , Pruebas Psicológicas , Trastornos Psicóticos , Autoinforme , Humanos , Niño , Metilación de ADN/genética , Epigenoma , Trastornos Psicóticos/genética
17.
Epilepsia ; 65(6): 1605-1619, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38634858

RESUMEN

OBJECTIVE: Determination of the real-world performance of a health care system in the treatment of status epilepticus (SE). METHODS: Prospective, multicenter population-based study of SE in Auckland, New Zealand (NZ) over 1 year, with data recorded in the EpiNet database. Focus on treatment patterns and determinants of SE duration and 30-day mortality. The incidence, etiology, ethnic discrepancies, and seizure characteristics of this cohort have been published previously. RESULTS: A total of 365 patients were included in this treatment cohort; 326 patients (89.3%) were brought to hospital because of SE, whereas 39 patients (10.7%) developed SE during a hospital admission for another reason. Overall, 190 (52.1%) had a known history of epilepsy and 254 (70.0%) presented with SE with prominent motor activity. The mean Status Epilepticus Severity Score (STESS) was 2.15 and the mean SE duration of all patients was 44 min. SE self-terminated without any treatment in 84 patients (22.7%). Earlier administration of appropriately dosed benzodiazepine in the pre-hospital setting was a major determinant of SE duration. Univariate analysis demonstrated that mortality was significantly higher in older patients, patients with longer durations of SE, higher STESS, and patients who developed SE in hospital, but these did not maintain significance with multivariate analysis. There was no difference in the performance of the health care system in the treatment of SE across ethnic groups. SIGNIFICANCE: When SE was defined as 10 continuous minutes of seizure, overall mortality was lower than expected and many patients had self-limited presentations for which no treatment was required. Although there were disparities in the incidence of SE across ethnic groups there was no difference in treatment or outcome. The finding highlights the benefit of a health care system designed to deliver universal health care.


Asunto(s)
Anticonvulsivantes , Estado Epiléptico , Humanos , Estado Epiléptico/epidemiología , Estado Epiléptico/terapia , Estado Epiléptico/mortalidad , Estado Epiléptico/tratamiento farmacológico , Masculino , Femenino , Nueva Zelanda/epidemiología , Persona de Mediana Edad , Adulto , Anciano , Estudios Prospectivos , Anticonvulsivantes/uso terapéutico , Adolescente , Adulto Joven , Resultado del Tratamiento , Estudios de Cohortes , Anciano de 80 o más Años , Niño , Preescolar
18.
Circ Res ; 131(12): 1004-1017, 2022 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-36321446

RESUMEN

BACKGROUND: Genome-wide association studies have discovered a link between genetic variants on human chromosome 15q26.1 and increased coronary artery disease (CAD) susceptibility; however, the underlying pathobiological mechanism is unclear. This genetic locus contains the FES (FES proto-oncogene, tyrosine kinase) gene encoding a cytoplasmic protein-tyrosine kinase involved in the regulation of cell behavior. We investigated the effect of the 15q26.1 variants on FES expression and whether FES plays a role in atherosclerosis. METHODS AND RESULTS: Analyses of isogenic monocytic cell lines generated by CRISPR (clustered regularly interspaced short palindromic repeats)-mediated genome editing showed that monocytes with an engineered 15q26.1 CAD risk genotype had reduced FES expression. Small-interfering-RNA-mediated knockdown of FES promoted migration of monocytes and vascular smooth muscle cells. A phosphoproteomics analysis showed that FES knockdown altered phosphorylation of a number of proteins known to regulate cell migration. Single-cell RNA-sequencing revealed that in human atherosclerotic plaques, cells that expressed FES were predominately monocytes/macrophages, although several other cell types including smooth muscle cells also expressed FES. There was an association between the 15q26.1 CAD risk genotype and greater numbers of monocytes/macrophage in human atherosclerotic plaques. An animal model study demonstrated that Fes knockout increased atherosclerotic plaque size and within-plaque content of monocytes/macrophages and smooth muscle cells, in apolipoprotein E-deficient mice fed a high fat diet. CONCLUSIONS: We provide substantial evidence that the CAD risk variants at the 15q26.1 locus reduce FES expression in monocytes and that FES depletion results in larger atherosclerotic plaques with more monocytes/macrophages and smooth muscle cells. This study is the first demonstration that FES plays a protective role against atherosclerosis and suggests that enhancing FES activity could be a potentially novel therapeutic approach for CAD intervention.


Asunto(s)
Aterosclerosis , Enfermedad de la Arteria Coronaria , Placa Aterosclerótica , Proteínas Proto-Oncogénicas c-fes , Animales , Humanos , Ratones , Arterias/metabolismo , Aterosclerosis/genética , Aterosclerosis/metabolismo , Enfermedad de la Arteria Coronaria/genética , Enfermedad de la Arteria Coronaria/metabolismo , Estudio de Asociación del Genoma Completo , Miocitos del Músculo Liso/metabolismo , Placa Aterosclerótica/genética , Placa Aterosclerótica/metabolismo , Proteínas Proto-Oncogénicas c-fes/genética , Proteínas Proto-Oncogénicas c-fes/metabolismo
19.
AIDS Behav ; 28(3): 854-867, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37751109

RESUMEN

Numerous contextual factors contribute to risky sexual decision-making among men who have sex with men (MSM), with experimental laboratory-based studies suggesting that alcohol consumption, sexual arousal, and partner familiarity have the potential to impact condom negotiations during sexual encounters. The purpose of the current study was to extend this line of inquiry outside of the laboratory and into the everyday lives of MSM. We collected six weeks of daily data on alcohol consumption and sexual behaviors from 257 moderate- and heavy-drinking MSM to examine the within- and between-subjects effects of alcohol consumption, average daily sexual arousal, and partner familiarity on condom negotiation processes during sexual encounters. We hypothesized that alcohol consumption, higher levels of average daily sexual arousal, and greater partner familiarity would all contribute to a reduced likelihood of condom negotiation prior to sexual activity, and that they would also affect the difficulty of negotiations. Contrary to hypotheses, none of these three predictors had significant within-subjects effects on condom negotiation outcomes. However, partner familiarity and average daily sexual arousal did exert significant between-subjects effects on the incidence of negotiation and negotiation difficulty. These findings have important implications for risk-reduction strategies in this population. They also highlight the challenges of reconciling results from experimental laboratory research and experience sampling conducted outside of the laboratory on sexual risk behavior.


Asunto(s)
Infecciones por VIH , Minorías Sexuales y de Género , Masculino , Humanos , Condones , Homosexualidad Masculina , Negociación , Excitación Sexual , Evaluación Ecológica Momentánea , Infecciones por VIH/epidemiología , Infecciones por VIH/prevención & control , Conducta Sexual , Etanol/farmacología , Consumo de Bebidas Alcohólicas/epidemiología , Parejas Sexuales
20.
J Chem Inf Model ; 64(2): 543-554, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38176097

RESUMEN

All-atom molecular dynamics (MD) simulations are an essential structural biology technique with increasing application to multimillion-atom systems, including viruses and cellular machinery. Classical MD simulations rely on parameter sets, such as the AMBER family of force fields (AMBERff), to accurately describe molecular motion. Here, we present an implementation of AMBERff for use in NAMD that overcomes previous limitations to enable high-performance, massively parallel simulations encompassing up to two billion atoms. Single-point potential energy comparisons and case studies on model systems demonstrate that the implementation produces results that are as accurate as running AMBERff in its native engine.

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