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Germline histone H3.3 amino acid substitutions, including H3.3G34R/V, cause severe neurodevelopmental syndromes. To understand how these mutations impact brain development, we generated H3.3G34R/V/W knock-in mice and identified strikingly distinct developmental defects for each mutation. H3.3G34R-mutants exhibited progressive microcephaly and neurodegeneration, with abnormal accumulation of disease-associated microglia and concurrent neuronal depletion. G34R severely decreased H3K36me2 on the mutant H3.3 tail, impairing recruitment of DNA methyltransferase DNMT3A and its redistribution on chromatin. These changes were concurrent with sustained expression of complement and other innate immune genes possibly through loss of non-CG (CH) methylation and silencing of neuronal gene promoters through aberrant CG methylation. Complement expression in G34R brains may lead to neuroinflammation possibly accounting for progressive neurodegeneration. Our study reveals that H3.3G34-substitutions have differential impact on the epigenome, which underlie the diverse phenotypes observed, and uncovers potential roles for H3K36me2 and DNMT3A-dependent CH-methylation in modulating synaptic pruning and neuroinflammation in post-natal brains.
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ADN Metiltransferasa 3A , Histonas , Animales , Ratones , ADN (Citosina-5-)-Metiltransferasas/genética , Metilación de ADN/genética , Metilasas de Modificación del ADN/genética , Histonas/metabolismo , Enfermedades NeuroinflamatoriasRESUMEN
Histone H3.3 glycine 34 to arginine/valine (G34R/V) mutations drive deadly gliomas and show exquisite regional and temporal specificity, suggesting a developmental context permissive to their effects. Here we show that 50% of G34R/V tumors (n = 95) bear activating PDGFRA mutations that display strong selection pressure at recurrence. Although considered gliomas, G34R/V tumors actually arise in GSX2/DLX-expressing interneuron progenitors, where G34R/V mutations impair neuronal differentiation. The lineage of origin may facilitate PDGFRA co-option through a chromatin loop connecting PDGFRA to GSX2 regulatory elements, promoting PDGFRA overexpression and mutation. At the single-cell level, G34R/V tumors harbor dual neuronal/astroglial identity and lack oligodendroglial programs, actively repressed by GSX2/DLX-mediated cell fate specification. G34R/V may become dispensable for tumor maintenance, whereas mutant-PDGFRA is potently oncogenic. Collectively, our results open novel research avenues in deadly tumors. G34R/V gliomas are neuronal malignancies where interneuron progenitors are stalled in differentiation by G34R/V mutations and malignant gliogenesis is promoted by co-option of a potentially targetable pathway, PDGFRA signaling.
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Neoplasias Encefálicas/genética , Carcinogénesis/genética , Glioma/genética , Histonas/genética , Interneuronas/metabolismo , Mutación/genética , Células-Madre Neurales/metabolismo , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/genética , Animales , Astrocitos/metabolismo , Astrocitos/patología , Neoplasias Encefálicas/patología , Carcinogénesis/patología , Linaje de la Célula , Reprogramación Celular/genética , Cromatina/metabolismo , Embrión de Mamíferos/metabolismo , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Silenciador del Gen , Glioma/patología , Histonas/metabolismo , Lisina/metabolismo , Ratones Endogámicos C57BL , Modelos Biológicos , Clasificación del Tumor , Oligodendroglía/metabolismo , Regiones Promotoras Genéticas/genética , Prosencéfalo/embriología , Receptor alfa de Factor de Crecimiento Derivado de Plaquetas/metabolismo , Transcripción Genética , Transcriptoma/genéticaRESUMEN
Sirtuins (SIRTs) belong to the family of nicotine adenine dinucleotide (NAD+)-dependent class III histone deacetylases, which come into play in the regulation of epigenetic processes through the deacetylation of histones and other substrates. The human genome encodes for seven homologs (SIRT1-7), which are localized into the nucleus, cytoplasm, and mitochondria, with different enzymatic activities and regulatory mechanisms. Indeed, SIRTs are involved in different physio-pathological processes responsible for the onset of several human illnesses, such as cardiovascular and neurodegenerative diseases, obesity and diabetes, age-related disorders, and cancer. Nowadays, it is well-known that Citrus fruits, typical of the Mediterranean diet, are an important source of bioactive compounds, such as polyphenols. Among these, flavonoids are recognized as potential agents endowed with a wide range of beneficial properties, including antioxidant, anti-inflammatory, hypolipidemic, and antitumoral ones. On these bases, we offer a comprehensive overview on biological effects exerted by Citrus flavonoids via targeting SIRTs, which acted as modulator of several signaling pathways. According to the reported studies, Citrus flavonoids appear to be promising SIRT modulators in many different pathologies, a role which might be potentially evaluated in future therapies, along with encouraging the study of those SIRT members which still lack proper evidence on their support.
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Flavonoides , Sirtuinas , Humanos , Flavonoides/farmacología , Histonas/metabolismo , Antioxidantes , Sirtuinas/metabolismo , Transducción de SeñalRESUMEN
A Mediterranean-style diet is highly encouraged thanks to its healthy food pattern, which includes valuable nutraceuticals such as polyphenols. Among these, flavonoids are associated with relevant biological properties through which they prevent or fight the onset of several human pathologies. Globally, the enhanced incidence of overweight and obese people has caused a dramatic increase in comorbidities, raising the need to provide better therapies. Therefore, the development of sophisticated animal models of metabolic dysregulation has allowed for a deepening of knowledge on this subject. Recent advances in using zebrafish (Danio rerio) as model for metabolic disease have yielded fundamental insights into the potential anti-obesity effects of flavonoids. Chronic low-grade inflammation and immune system activation seem to characterize the pathogenesis of obesity; thus, their reduction might improve the lipid profile of obese patients or prevent the development of associated metabolic illnesses. In this review, we highlight the beneficial role of flavonoids on obesity and related diseases linked to their anti-inflammatory properties. In light of the summarized studies, we suggest that anti-inflammatory therapies could have a relevant place in the prevention and treatment of obesity and metabolic disorders.
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Flavonoides , Pez Cebra , Animales , Humanos , Pez Cebra/metabolismo , Flavonoides/farmacología , Flavonoides/uso terapéutico , Flavonoides/metabolismo , Obesidad/metabolismo , Inflamación/complicaciones , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Antiinflamatorios/metabolismoRESUMEN
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by an increased level of ß-amyloid (Aß) protein deposition in the brain, yet the exact etiology remains elusive. Nowadays, treatments only target symptoms, thus the search for novel strategies is constantly stimulated, and looking to natural substances from the plant kingdom. The aim of this study was to investigate the neuroprotective effects of a spice blend composed of cinnamon bark and two different turmeric root extracts (CCSB) in Aß-exposed THP-1 cells as a model of neuroinflammation. In abiotic assays, CCSB demonstrated an antioxidant capacity up to three times stronger than Trolox in the ORAC assay, and it reduced reactive oxygen species (ROS) induced by the amyloid fragment in THP-1 cells by up to 39.7%. Moreover, CCSB lowered the Aß stimulated secretion of the pro-inflammatory cytokines IL-1ß and IL-6 by up to 24.9% and 43.4%, respectively, along with their gene expression by up to 25.2% and 43.1%, respectively. The mechanism involved the mitogen-activated protein kinases ERK, JNK and p38, whose phosphorylation was reduced by up to 51.5%, 73.7%, and 58.2%, respectively. In addition, phosphorylation of p65, one of the five components forming NF-κB, was reduced by up to 86.1%. Our results suggest that CCSB can counteract the neuroinflammatory stimulus induced by Aß-exposure in THP-1 cells, and therefore can be considered a potential candidate for AD management.
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Enfermedad de Alzheimer , Curcumina , Fármacos Neuroprotectores , Humanos , Proteínas Quinasas Activadas por Mitógenos , FN-kappa B/metabolismo , Curcumina/farmacología , Cinnamomum zeylanicum , Células THP-1 , Curcuma/metabolismo , Especias , Péptidos beta-Amiloides , Fármacos Neuroprotectores/farmacologíaRESUMEN
The recent growth and spread of smart sensor technologies make these connected devices suitable for diagnostic and monitoring in different fields. In particular, these sensors are useful in diagnostics for control of diseases or during rehabilitation. They are also extensively used in the monitoring field, both by non-expert and expert users, to monitor health status and progress during a sports activity. For athletes, these devices could be used to control and enhance their performance. This development has led to the realization of miniaturized sensors that are wearable during different sporting activities without interfering with the movements of the athlete. The use of these sensors, during training or racing, opens new frontiers for the understanding of motions and causes of injuries. This pilot study introduced a motion analysis system to monitor Alpine ski activities during training sessions. Through five inertial measurement units (IMUs), placed on five points of the athletes, it is possible to compute the angle of each joint and evaluate the ski run. Comparing the IMU data, firstly, with a video and then proposing them to an expert coach, it is possible to observe from the data the same mistakes visible in the camera. The aim of this work is to find a tool to support ski coaches during training sessions. Since the evaluation of athletes is now mainly developed with the support of video, we evaluate the use of IMUs to support the evaluation of the coach with more precise data.
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Esquí , Atletas , Fenómenos Biomecánicos , Humanos , Movimiento , Proyectos PilotoRESUMEN
It is known that plant phenolic compounds exert anti-inflammatory activity through both anti-oxidant effects and modulation of pivotal pro-inflammatory factors. Recently, Olea europaea has been studied as a natural source of bioactive molecules; however, few studies have focused on the biological effect of oleacein (OLC), the most abundant secoiridoid. Therefore, the aim of this study was to investigate the potential anti-oxidant activity of OLC, as well as to study its anti-inflammatory effect in lipopolysaccharide (LPS)-stimulated THP-1-derived macrophages. LPS brought a dramatic increase of both release and gene expression of pro-inflammatory cytokines (IL-6, IL-1ß and TNF-α), as well as a decrease of anti-inflammatory ones (IL-10), the effects of which are reverted by OLC. Moreover, it reduced the levels of COX-2, NO and PGE2 elicited by LPS exposure in THP-1 macrophages. Interestingly, OLC modulated inflammatory signaling pathways through the inhibition of CD14/TLR4/CD14/MyD88 axis and the activation of NF-κB. Finally, OLC showed relevant anti-oxidant capability, assessed by abiotic assays, and reduced the intracellular amount of ROS generated by LPS exposure in THP-1 macrophages. Overall, these results suggest that the anti-oxidant activity and anti-inflammatory effect of OLC may cooperate in its protective effect against inflammatory stressors, thus being a possible alternative pharmacological strategy aimed at reducing the inflammatory process.
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Aldehídos/farmacología , Inflamación/tratamiento farmacológico , Lipopolisacáridos/efectos adversos , Macrófagos/efectos de los fármacos , Factor 88 de Diferenciación Mieloide/antagonistas & inhibidores , FN-kappa B/antagonistas & inhibidores , Fenoles/farmacología , Receptor Toll-Like 4/antagonistas & inhibidores , Antiinflamatorios/farmacología , Citocinas/metabolismo , Humanos , Inflamación/inducido químicamente , Inflamación/metabolismo , Inflamación/patología , Macrófagos/inmunología , Macrófagos/metabolismo , Macrófagos/patología , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Transducción de Señal , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismoRESUMEN
Citrus fruits (CF) are among the most widely cultivated fruit crops throughout the world and their production is constantly increasing along with consumers' demand. Therefore, huge amounts of waste are annually generated through CF processing, causing high costs for their disposal, as well as environmental and human health damage, if inappropriately performed. According to the most recent indications of an economic, environmental and pharmaceutical nature, CF processing residues must be transformed from a waste to be disposed to a valuable resource to be reused. Based on a circular economy model, CF residues (i.e., seeds, exhausted peel, pressed pulp, secondary juice and leaves) have increasingly been re-evaluated to also obtain, but not limited to, valuable compounds to be employed in the food, packaging, cosmetic and pharmaceutical industries. However, the use of CF by-products is still limited because of their underestimated nutritional and economic value, hence more awareness and knowledge are needed to overcome traditional approaches for their disposal. This review summarizes recent evidence on the pharmacological potential of CF waste to support the switch towards a more environmentally sustainable society.
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Citrus/química , Industria de Procesamiento de Alimentos , Fitoquímicos/farmacología , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Humanos , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/farmacología , Fitoquímicos/química , ResiduosRESUMEN
Acute myeloid leukemia (AML) is a hematologic neoplasm, characterized by a blockage of differentiation and an unconstrained proliferation of immature myeloid cells. Recently, the survival of leukemia patients has increased thanks to the use of differentiating agents, though these may cause serious side effects. Hence, the search for safer differentiating compounds is necessary. Our aim was to assess the pro-differentiating effects of a flavonoid-rich extract of bergamot juice (BJe) in human monocytic leukemia THP-1 cells, an in vitro AML model. For the first time, we showed that treatment with BJe induced differentiation of THP-1 cells, changes in cell morphology and increased expression of differentiation-associated surface antigens CD68, CD11b and CD14. Moreover, BJe enhanced protein levels of autophagy-associated markers, such as Beclin-1 and LC3, as well as induced the phosphorylation of the MAPKs JNK, ERK and p38, hence suggesting a potential mechanism underlying its antiproliferative effects. Indeed, parallel experiments highlighted that BJe was able to hamper THP-1 cell growth. In conclusion, our study suggests that BJe induces the differentiation of THP-1 cells and reduces their proliferation, highlighting its potential in differentiation therapy of AML.
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Autofagia , Diferenciación Celular , Citrus , Flavonoides , Extractos Vegetales , Humanos , Citrus/química , Flavonoides/farmacología , Diferenciación Celular/efectos de los fármacos , Células THP-1 , Extractos Vegetales/farmacología , Extractos Vegetales/química , Autofagia/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Jugos de Frutas y Vegetales/análisis , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/patología , Leucemia Mieloide Aguda/metabolismoRESUMEN
Chronic inflammation is the result of an acute inflammatory response that fails to eliminate the pathogenic agent or heal the tissue injury. The consequence of this failure lays the foundations to the onset of several chronic ailments, including skin disorders, respiratory and neurodegenerative diseases, metabolic syndrome, and, eventually, cancer. In this context, the long-term use of synthetic anti-inflammatory drugs to treat chronic illnesses cannot be tolerated by patients owing to the severe side effects. Based on this, the need for novel agents endowed with anti-inflammatory effects prompted to search potential candidates also within the plant kingdom, being recognized as a source of molecules currently employed in several therapeutical areas. Indeed, the ever-growing evidence on the anti-inflammatory properties of dietary polyphenols traced the route towards the study of flavonoid-rich sources, such as Citrus bergamia (bergamot) and its derivatives. Interestingly, the recent paradigm of the circular economy has promoted the valorization of Citrus fruit waste and, in regard to bergamot, it brought to light new evidence corroborating the anti-inflammatory potential of bergamot byproducts, thus increasing the scientific knowledge in this field. Therefore, this review aims to gather the latest literature supporting the beneficial role of both bergamot derivatives and waste products in different models of inflammatory-based diseases, thus highlighting the great potentiality of a waste re-evaluation perspective.
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Citrus , Inflamación , Humanos , Inflamación/tratamiento farmacológico , Flavonoides , Conocimiento , Antiinflamatorios/farmacologíaRESUMEN
Human exposure to bisphenol A (BPA) occurs through the ingestion of contaminated food and water, thus leading to endothelial dysfunction, the first signal of atherosclerosis. Vitis vinifera L. (grape) juice is well known for its health-promoting properties, due to its numerous bioactive compounds among which are polyphenols. The aim of this study was to evaluate the protective effect of a red grape juice extract (RGJe) against the endothelial damage induced by BPA in human umbilical vein endothelial cells (HUVECs) as an in vitro model of endothelial dysfunction. Our results showed that RGJe treatment counteracted BPA-induced cell death and apoptosis in HUVECs, blocking caspase 3 and modulating p53, Bax, and Bcl-2. Moreover, RGJe demonstrated antioxidant properties in abiotic tests and in vitro, where it reduced BPA-induced reactive oxygen species as well as restored mitochondrial membrane potential, DNA integrity, and nitric oxide levels. Furthermore, RGJe reduced the increase of chemokines (IL-8, IL-1ß, and MCP-1) and adhesion molecules (VCAM-1, ICAM-1, and E-selectin), caused by BPA exposure, involved in the primary phase of atheromatous plaque formation. Overall, our results suggest that RGJe prevents BPA-induced vascular damage modulating specific intracellular mechanisms, along with protecting cells, owing to its antioxidant capability.
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BACKGROUND: Autoimmune diseases are chronic disorders in which the immune system does not recognize and attacks one self's healthy components. In this context, although natural remedies might represent a promising therapeutic strategy, evidence regarding Citrus flavonoids is still controversial. OBJECTIVE: To summarize and critically discuss the clinical evidence on the effects of Citrus flavonoids on managing autoimmune diseases. METHOD: A systematic review of articles has been carried out independently by two authors using MEDLINE, Scopus and ISI Web of Science databases. Search terms comprised keywords related to Citrus flavonoids and autoimmune diseases. The last search was performed on the 16th of March, 2021. No language restrictions were applied. Systematic review and study selection were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Before starting the review, the authors defined the types of articles to be included. Three reviewers independently carried out the extraction of papers. RESULTS: Ten clinical studies fulfilled the eligibility criteria and were included in the final review. CONCLUSION: The studies discussed in this review are heterogeneous. Indeed, some studies suggest using Citrus flavonoids in the frame of autoimmune disorders, whereas others discourage it. Hence, this systematic review highlights the need for further large-scale clinical studies to define the exact role of Citrus flavonoids in managing autoimmune diseases (PROSPERO number CRD42021234903).
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Enfermedades Autoinmunes , Citrus , Enfermedades Autoinmunes/tratamiento farmacológicoRESUMEN
The NeoChord procedure is an echo-guided trans-ventricular beating-heart mitral valve repair technique to treat degenerative mitral regurgitation (MR) due to prolapse and/or flail. The aim of this study is to analyze echocardiographic images to find pre-operative parameters to predict procedural success (≤moderate MR) at 3-year follow-up. Seventy-two consecutive patients with severe MR underwent the NeoChord procedure between 2015 and 2021. MV pre-operative morphological parameters were assessed using 3D transesophageal echocardiography with dedicated software (QLAB, Philips). Three patients died during their hospitalization. The remaining 69 patients were retrospectively analyzed. At follow-up, MR > moderate was found in 17 patients (24.6%). In the univariate analysis, end-systolic annulus area (12.5 ± 2.5 vs. 14.1 ± 2.6 cm2; p = 0.038), end-systolic annulus circumference (13.2 ± 1.2 vs. 14 ± 1.3 cm; p = 0.042), indexed left atrial volume (59 ± 17 vs. 76 ± 7 mL/m2; p = 0.041), and AF (25% vs. 53%; p = 0.042) were lower in the 52 patients with ≤ MR compared to those with > moderate MR. Annular dysfunction parameters were the best predictors of procedural success: 3D early-systolic annulus area (AUC 0.74; p = 0.004), 3D early-systolic annulus circumference (AUC 0.75; p = 0.003), and 3D annulus area fractional change (AUC 0.73; p = 0.035). Patient selection relying on 3D dynamic and static MA dimensions may improve the maintenance of procedural success at follow-up.
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BACKGROUND: Point mutations in histone variant H3.3 (H3.3K27M, H3.3G34R) and the H3.3-specific ATRX/DAXX chaperone complex are frequent events in pediatric gliomas. These H3.3 point mutations affect many chromatin modifications but the exact oncogenic mechanisms are currently unclear. Histone H3.3 is known to localize to nuclear compartments known as promyelocytic leukemia (PML) nuclear bodies, which are frequently mutated and confirmed as oncogenic drivers in acute promyelocytic leukemia. RESULTS: We find that the pediatric glioma-associated H3.3 point mutations disrupt the formation of PML nuclear bodies and this prevents differentiation down glial lineages. Similar to leukemias driven by PML mutations, H3.3-mutated glioma cells are sensitive to drugs that target PML bodies. We also find that point mutations in IDH1/2-which are common events in adult gliomas and myeloid leukemias-also disrupt the formation of PML bodies. CONCLUSIONS: We identify PML as a contributor to oncogenesis in a subset of gliomas and show that targeting PML bodies is effective in treating these H3.3-mutated pediatric gliomas.
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Neoplasias Encefálicas , Glioma , Histonas , Adulto , Niño , Humanos , Neoplasias Encefálicas/genética , Glioma/genética , Histonas/genética , Mutación , Cuerpos Nucleares de la Leucemia Promielocítica/genética , Cuerpos Nucleares de la Leucemia Promielocítica/patologíaRESUMEN
BACKGROUND: Long-term right ventricular pacing (VP) has been related to negative left ventricular remodeling and heart failure (HF), but there is a lack of evidence regarding the prognostic impact on transcatheter aortic valve replacement (TAVR) patients. OBJECTIVES: The aim of the PACE-TAVI registry is to evaluate the association of high percentage of VP with adverse outcomes in patients with pacemaker implantation after TAVR. METHODS: PACE-TAVI is an international multicenter registry of all consecutive TAVR patients who underwent permanent pacemaker implantation for conduction disturbances in the first 30 days after the procedure. Patients were divided into 2 subgroups according to the percentage of VP (<40% vs ≥40%) at pacemaker interrogation. The primary endpoint was the composite of cardiovascular mortality or hospitalization for HF. RESULTS: A total of 377 patients were enrolled, 158 with VP <40% and 219 with VP ≥40%. After multivariable adjustment, VP ≥40% was associated with a higher incidence of the primary endpoint (HR: 2.76; 95% CI: 1.39-5.51; P = 0.004), first HF hospitalization (HR: 3.37; 95% CI: 1.50-7.54; P = 0.003), and cardiovascular death (HR: 3.77; 95% CI: 1.02-13.88; P = 0.04), while the incidence of all-cause death was not significantly different (HR: 2.17; 95% CI: 0.80-5.90; P = 0.13). Patients with VP ≥ 40% showed a higher New York Heart Association functional class both at 1 year (P = 0.009) and at last available follow-up (P = 0.04) and a nonsignificant reduction of left ventricular ejection fraction (P = 0.18) on 1-year echocardiography, while patients with VP <40% showed significant improvement (P = 0.009). CONCLUSIONS: In TAVR patients undergoing permanent pacemaker implantation, a high percentage of right VP at follow-up is associated with an increased risk for cardiovascular death and HF hospitalization. These findings suggest the opportunity to minimize right VP through dedicated algorithms in post-TAVR patients without complete atrioventricular block and to evaluate a more physiological VP modality in patients with persistent complete atrioventricular block.
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Estenosis de la Válvula Aórtica , Bloqueo Atrioventricular , Marcapaso Artificial , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Bloqueo Atrioventricular/diagnóstico , Bloqueo Atrioventricular/etiología , Bloqueo Atrioventricular/terapia , Volumen Sistólico , Estimulación Cardíaca Artificial/efectos adversos , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Factores de Riesgo , Función Ventricular Izquierda , Resultado del Tratamiento , Marcapaso Artificial/efectos adversos , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugíaRESUMEN
Polycomb Repressive Complex 2 (PRC2)-mediated histone H3K27 tri-methylation (H3K27me3) recruits canonical PRC1 (cPRC1) to maintain heterochromatin. In early development, polycomb-regulated genes are connected through long-range 3D interactions which resolve upon differentiation. Here, we report that polycomb looping is controlled by H3K27me3 spreading and regulates target gene silencing and cell fate specification. Using glioma-derived H3 Lys-27-Met (H3K27M) mutations as tools to restrict H3K27me3 deposition, we show that H3K27me3 confinement concentrates the chromatin pool of cPRC1, resulting in heightened 3D interactions mirroring chromatin architecture of pluripotency, and stringent gene repression that maintains cells in progenitor states to facilitate tumor development. Conversely, H3K27me3 spread in pluripotent stem cells, following neural differentiation or loss of the H3K36 methyltransferase NSD1, dilutes cPRC1 concentration and dissolves polycomb loops. These results identify the regulatory principles and disease implications of polycomb looping and nominate histone modification-guided distribution of reader complexes as an important mechanism for nuclear compartment organization. Highlights: The confinement of H3K27me3 at PRC2 nucleation sites without its spreading correlates with increased 3D chromatin interactions.The H3K27M oncohistone concentrates canonical PRC1 that anchors chromatin loop interactions in gliomas, silencing developmental programs.Stem and progenitor cells require factors promoting H3K27me3 confinement, including H3K36me2, to maintain cPRC1 loop architecture.The cPRC1-H3K27me3 interaction is a targetable driver of aberrant self-renewal in tumor cells.
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Acute myeloid leukemia (AML) represents the most alarming hematological disease for adults. Several genetic modifications are known to be pivotal in AML; however, SIRT2 over-expression has attracted the scientific community's attention as an unfavorable prognostic marker. The plant kingdom is a treasure trove of bioactive principles, with flavonoids standing out among the others. On this line, the aim of this study was to investigate the anti-leukemic properties of the main flavanones of Citrus spp., exploring the potential implication of SIRT2. Naringenin (NAR), hesperetin (HSP), naringin (NRG), and neohesperidin (NHP) inhibited SIRT2 activity in the isolated recombinant enzyme, and more, the combination between NAR and HSP. In monocytic leukemic THP-1 cells, only NAR and HSP induced antiproliferative effects, altering the cell cycle. These effects may be ascribed to SIRT2 inhibition since these flavonoids reduced its gene expression and hampered the deacetylation of p53, known sirtuin substrate, and contextually modulated the expression of the downstream cell cycle regulators p21 and cyclin E1. Additionally, these two flavanones proved to interact with the SIRT2 inhibitory site, as shown by docking simulations. Our results suggest that both NAR and HSP may act as anti-leukemic agents, alone and in combination, via targeting the SIRT2/p53/p21/cyclin E1 pathway, thus encouraging deeper investigations.
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Novel targets are constantly sought to fight hematologic malignancies. In this regard, high levels of SIRT2 expression are associated with unfavorable prognosis of acute myeloid leukemia. The interest in the plant kingdom has allowed the identification of ever-new anti-leukemic agents. Citrus × bergamia (bergamot) was proved to possess anticancer properties, yet no evidence is available regarding leukemia. For the first time, we studied the potential anti-leukemic effect of a flavonoid-rich extract of bergamot juice (BJe) in THP-1 cells, investigating the underlying mechanisms. Our findings showed that BJe reduced THP-1 cell proliferation, without affecting that of primary PBMCs, blocking the cell cycle in S phase and inducing apoptosis. Triggering of both extrinsic and intrinsic apoptotic pathways was witnessed by cleavage of caspase-8 and -9, which in turn activated caspase-3 and PARP. Interestingly, the increased p53 acetylation in THP-1 cells underlies SIRT2 inhibition by BJe, that was proved also in the isolated enzyme. Moreover, BJe hampered SIRT2 also by lowering its gene expression. Finally, BJe reduced AKT phosphorylation, which we hypothesized being the joining link between SIRT2 and p53, that play a pivotal role in BJe-induced cell cycle arrest and apoptosis in THP-1 cells. Our results suggest BJe as a potential anti-leukemic agent, via targeting of the SIRT2/AKT/p53 pathway.
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AIMS: To assess the impact of secondary prevention medical therapies (statins, ACE-inhibitors/Angiotensin Receptor Blockers (ARB), beta-blockers (BB) and Dual Antiplatelet Therapy (DAPT)) on outcomes of patients with myocardial infarction with nonobstructive coronary artery disease (MINOCA). METHODS: Five adjusted observational studies encompassing 10,546 were included in this meta-analysis. All-cause death was the primary endpoint, while Major Adverse Cardiovascular Events (MACE) and acute myocardial infarction (AMI) were the secondary endpoints. RESULTS: After 24 months of follow up, statins (tested in 8093 patients) were associated with a reduced risk of all-cause death (HR 0.60:0.45-0.81, p ã0,001), while ACE-inhibitors/ARB (on 9666 patients) were not. Aggregate data from two studies (n = 9720, 7719 on beta-blockers, 6423 on DAPT) indicated that beta-blockers and DAPT (median follow-up 34.1 and 15.7 months, respectively) were both associated with a significant reduction of all-cause death (HR0.81:0.66-0.99, p = 0.04, and HR0.73:0.55-0.98, p = 0.03, for beta-blockers and DAPT, respectively). Among the investigated therapies, only ACE-inhibitors/ARBs entailed a reduced risk of MACE (HR0.65:0.44-0.94, p = 0.02, all CI 95%) over 36.5 months (four studies, n = 10,150). None of the investigated therapies was associated with a reduced risk of AMI. CONCLUSIONS: Data from adjusted observational studies suggest that beta-blockers, statins and DAPT are associated with a survival benefit among MINOCA patients. ACE-inhibitors/ARB entail a reduced risk of MACE while none of the investigated secondary prevention therapies is associated with a reduced risk of AMI. Randomized controlled trials are warranted to confirm these findings.
Asunto(s)
Enfermedad de la Arteria Coronaria , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Infarto del Miocardio , Antagonistas Adrenérgicos beta/uso terapéutico , Antagonistas de Receptores de Angiotensina , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , MINOCA , Infarto del Miocardio/tratamiento farmacológico , Infarto del Miocardio/prevención & control , Estudios Observacionales como Asunto , Inhibidores de Agregación Plaquetaria/uso terapéutico , Prevención Secundaria , Resultado del TratamientoRESUMEN
The plant kingdom has always been a treasure trove for valuable bioactive compounds, and Citrus fruits stand out among the others. Bergamottin (BRG) and 5-geranyloxy-7-methoxycoumarin (5-G-7-MOC) are two coumarins found in different Citrus species with well-acknowledged pharmacological properties. Previously, they have been claimed to be relevant in the anti-proliferative effects exerted by bergamot essential oil (BEO) in the SH-SY5Y human neuroblastoma cells. This study was designed to verify this assumption and to assess the mechanisms underlying the anti-proliferative effect of both compounds. Our results demonstrate that BRG and 5-G-7-MOC are able to reduce the proliferation of SH-SY5Y cells, inducing apoptosis and increasing cell population in sub-G0/G1 phase. Moreover, we demonstrated the pro-oxidant activity of the two coumarins that increased reactive oxygen species and impaired mitochondrial membrane potential. From a molecular point of view, BRG and 5-G-7-MOC were able to modulate apoptosis related factors at both protein and gene levels. Lastly, we evaluated the synergistic effect of their combination, finding that the highest synergy was observed at a concentration ratio similar to that occurring in the BEO, supporting our initial hypothesis. Taken together, our results deepen the knowledge regarding the effect of BRG and 5-G-7-MOC in SH-SY5Y cells, emphasizing the relevance of their cooperation in achieving this effect.