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BACKGROUND: Histone modifications play a critical role in chromatin remodelling and regulate gene expression in health and disease. Histone methyltransferases EZH1, EZH2, and demethylases UTX, JMJD3, and UTY catalyse trimethylation of lysine 27 on histone H3 (H3K27me3). This study was designed to investigate whether H3K27me3 triggers hyperglycemia-induced oxidative and inflammatory transcriptional programs in the endothelium. METHODS: We studied human aortic endothelial cells exposed to high glucose (HAEC) or isolated from individuals with diabetes (D-HAEC). RT-qPCR, immunoblotting, chromatin immunoprecipitation (ChIP-qPCR), and confocal microscopy were performed to investigate the role of H3K27me3. We determined superoxide anion (O2-) production by ESR spectroscopy, NF-κB binding activity, and monocyte adhesion. Silencing/overexpression and pharmacological inhibition of chromatin modifying enzymes were used to modulate H3K27me3 levels. Furthermore, isometric tension studies and immunohistochemistry were performed in aorta from wild-type and db/db mice. RESULTS: Incubation of HAEC to high glucose showed that upregulation of EZH2 coupled to reduced demethylase UTX and JMJD3 was responsible for the increased H3K27me3. ChIP-qPCR revealed that repressive H3K27me3 binding to superoxide dismutase and transcription factor JunD promoters is involved in glucose-induced O2- generation. Indeed, loss of JunD transcriptional inhibition favours NOX4 expression. Furthermore, H3K27me3-driven oxidative stress increased NF-κB p65 activity and downstream inflammatory genes. Interestingly, EZH2 inhibitor GSK126 rescued these endothelial derangements by reducing H3K27me3. We also found that H3K27me3 epigenetic signature alters transcriptional programs in D-HAEC and aortas from db/db mice. CONCLUSIONS: EZH2-mediated H3K27me3 represents a key epigenetic driver of hyperglycemia-induced endothelial dysfunction. Targeting EZH2 may attenuate oxidative stress and inflammation and, hence, prevent vascular disease in diabetes.
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Diabetes Mellitus , Hiperglucemia , Ratones , Animales , Humanos , Histonas , FN-kappa B/metabolismo , Células Endoteliales/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Metilación , Diabetes Mellitus/metabolismo , Hiperglucemia/genética , Hiperglucemia/metabolismo , Endotelio , Glucosa/toxicidad , Glucosa/metabolismoRESUMEN
Autoimmune neuroinflammatory diseases are a group of disorders resulting from abnormal immune responses in the nervous system, causing inflammation and tissue damage. The interleukin (IL) family of cytokines, especially IL-1, IL-6, and IL-17, plays a critical role in the pathogenesis of these diseases. IL-1 is involved in the activation of immune cells, production of pro-inflammatory cytokines, and promotion of blood-brain barrier breakdown. IL-6 is essential for the differentiation of T cells into Th17 cells and has been implicated in the initiation and progression of neuroinflammation. IL-17 is a potent pro-inflammatory cytokine produced by Th17 cells that plays a crucial role in recruiting immune cells to sites of inflammation. This review summarizes the current understanding of the roles of different interleukins in autoimmune neuroinflammatory diseases, including multiple sclerosis, amyotrophic lateral sclerosis, Alzheimer's disease, neuromyelitis optica, and autoimmune encephalitis, and discusses the potential of targeting ILs as a therapeutic strategy against these diseases. We also highlight the need for further research to better understand the roles of ILs in autoimmune neuroinflammatory diseases and to identify new targets for treating these debilitating diseases.
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Enfermedades Autoinmunes , Enfermedades Neuroinflamatorias , Humanos , Interleucina-17 , Interleucina-6 , Interleucinas , Inflamación/tratamiento farmacológico , Citocinas , Células Th17 , Interleucina-1/uso terapéuticoRESUMEN
This study aimed to investigate the effect of the sympatholytic drug moxonidine on atherosclerosis. The effects of moxonidine on oxidised low-density lipoprotein (LDL) uptake, inflammatory gene expression and cellular migration were investigated in vitro in cultured vascular smooth muscle cells (VSMCs). The effect of moxonidine on atherosclerosis was measured by examining aortic arch Sudan IV staining and quantifying the intima-to-media ratio of the left common carotid artery in apolipoprotein E-deficient (ApoE-/-) mice infused with angiotensin II. The levels of circulating lipid hydroperoxides in mouse plasma were measured by ferrous oxidation-xylenol orange assay. Moxonidine administration increased oxidised LDL uptake by VSMCs via activation of α2 adrenoceptors. Moxonidine increased the expression of LDL receptors and the lipid efflux transporter ABCG1. Moxonidine inhibited mRNA expression of inflammatory genes and increased VSMC migration. Moxonidine administration to ApoE-/- mice (18 mg/kg/day) decreased atherosclerosis formation in the aortic arch and left common carotid artery, associated with increased plasma lipid hydroperoxide levels. In conclusion, moxonidine inhibited atherosclerosis in ApoE-/- mice, which was accompanied by an increase in oxidised LDL uptake by VSMCs, VSMC migration, ABCG1 expression in VSMCs and lipid hydroperoxide levels in the plasma.
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Aterosclerosis , Imidazoles , Lipoproteínas LDL , Músculo Liso Vascular , Animales , Ratones , Apolipoproteínas E/metabolismo , Aterosclerosis/metabolismo , Proliferación Celular , Células Cultivadas , Peróxidos Lipídicos/metabolismo , Lipoproteínas LDL/metabolismo , Ratones Endogámicos C57BL , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Imidazoles/farmacologíaRESUMEN
RATIONALE: Hyperglycemia -induced reactive oxygen species are key mediators of cardiac dysfunction. JunD (Jund proto-oncogene subunit), a member of the AP-1 (activator protein-1) family of transcription factors, is emerging as a major gatekeeper against oxidative stress. However, its contribution to redox state and inflammation in the diabetic heart remains to be elucidated. OBJECTIVE: The present study investigates the role of JunD in hyperglycemia-induced and reactive oxygen species-driven myocardial dysfunction. METHODS AND RESULTS: JunD mRNA and protein expression were reduced in the myocardium of mice with streptozotocin-induced diabetes mellitus as compared to controls. JunD downregulation was associated with oxidative stress and left ventricular dysfunction assessed by electron spin resonance spectroscopy as well as conventional and 2-dimensional speckle-tracking echocardiography. Furthermore, myocardial expression of free radical scavenger superoxide dismutase 1 and aldehyde dehydrogenase 2 was reduced, whereas the NOX2 (NADPH [nicotinamide adenine dinucleotide phosphatase] oxidase subunit 2) and NOX4 (NADPH [nicotinamide adenine dinucleotide phosphatase] oxidase subunit 4) were upregulated. The redox changes were associated with increased NF-κB (nuclear factor kappa B) binding activity and expression of inflammatory mediators. Interestingly, mice with cardiac-specific overexpression of JunD via the α MHC (α- myosin heavy chain) promoter (α MHC JunDtg) were protected against hyperglycemia-induced cardiac dysfunction. We also showed that JunD was epigenetically regulated by promoter hypermethylation, post-translational modification of histone marks, and translational repression by miRNA (microRNA)-673/menin. Reduced JunD mRNA and protein expression were confirmed in left ventricular specimens obtained from patients with type 2 diabetes mellitus as compared to nondiabetic subjects. CONCLUSIONS: Here, we show that a complex epigenetic machinery involving DNA methylation, histone modifications, and microRNAs mediates hyperglycemia-induced JunD downregulation and myocardial dysfunction in experimental and human diabetes mellitus. Our results pave the way for tissue-specific therapeutic modulation of JunD to prevent diabetic cardiomyopathy.
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Cardiomiopatías Diabéticas/genética , Epigénesis Genética , Hiperglucemia/complicaciones , Proteínas Proto-Oncogénicas c-jun/genética , Animales , Metilación de ADN , Cardiomiopatías Diabéticas/etiología , Cardiomiopatías Diabéticas/metabolismo , Código de Histonas , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , MicroARNs/metabolismo , Miocardio/metabolismo , NADPH Oxidasa 2/genética , NADPH Oxidasa 2/metabolismo , NADPH Oxidasa 4/genética , NADPH Oxidasa 4/metabolismo , FN-kappa B/genética , FN-kappa B/metabolismo , Proto-Oncogenes Mas , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-jun/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Superóxido Dismutasa-1/genética , Superóxido Dismutasa-1/metabolismoRESUMEN
The current study explored the effects of natural compounds, berbamine, bergapten, and carveol on paclitaxel-associated neuroinflammatory pain. Berbamine, an alkaloid obtained from BerberisamurensisRuprhas been previously researched for anticancer and anti-inflammatory potential. Bergapten is 5-methoxsalenpsoralen previously investigated in cancer, vitiligo, and psoriasis. Carveol obtained from caraway is a component of essential oil. The neuropathic pain model was induced by administering 2 mg/kg of paclitaxel (PTX) every other day for a week. After the final PTX injection, a behavioral analysis was conducted, and subsequently, tissue was collected for molecular analysis. Berbamine, bergapten, and carveol treatment attenuated thermal hypersensitivity, improved latency of falling, normalized the changes in body weight, and increased the threshold for pain sensation. The drugs increased the protective glutathione (GSH) and glutathione S-transferase (GST) levels in the sciatic nerve and spinal cord while lowering inducible nitric oxide synthase (iNOS) and lipid peroxidase (LPO). Hematoxylin and eosin (H and E) and immunohistochemistry (IHC) examinations confirmed that the medication reversed the abnormal alterations. The aforementioned natural substances inhibited cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-α), and nuclear factor kappa B (NF-κb) overexpression, as evidenced by enzyme-linked immunosorbant assay (ELISA) and Western blot and hence provide neuroprotection in chronic constriction damage.
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Dolor Crónico , Neuralgia , Fármacos Neuroprotectores , 5-Metoxipsoraleno/uso terapéutico , Dolor Crónico/tratamiento farmacológico , Humanos , FN-kappa B/metabolismo , Neuralgia/inducido químicamente , Neuralgia/tratamiento farmacológico , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/uso terapéutico , Óxido Nítrico Sintasa de Tipo II/metabolismo , Paclitaxel/efectos adversos , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Seafood products have been one of the main drivers behind the popularity of high-pressure processing (HPP) in the food industry owing to a high demand for fresh ready-to-eat seafood products and food safety. This review provides an overview of the advanced knowledge available on the use of HPP for production of wholesome and highly nutritive clean label fish and shellfish products. Out of 653 explored items, 65 articles published during 2016-2021 were used. Analysis of the literature showed that most of the earlier work evaluated the HPP effect on physicochemical and sensorial properties, and limited information is available on nutritional aspects. HPP has several applications in the seafood industry. Application of HPP (400-600 MPa) eliminates common seafood pathogens, such as Vibrio and Listeria spp., and slows the growth of spoilage microorganisms. Use of cold water as a pressure medium induces minimal changes in sensory and nutritional properties and helps in the development of clean label seafood products. This technology (200-350 MPa) is also useful to shuck oysters, lobsters, crabs, mussels, clams, and scallops to increase recovery of the edible meat. High-pressure helps to preserve organoleptic and functional properties for an extended time during refrigerated storage. Overall, HPP helps seafood manufacturers to maintain a balance between safety, quality, processing efficiency, and regulatory compliance. Further research is required to understand the mechanisms of pressure-induced modifications and clean label strategies to minimize these modifications.
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Alimentos Marinos , Mariscos , Animales , Peces , Inocuidad de los Alimentos , CarneRESUMEN
Atherosclerosis is a disease of large and medium arteries that can lead to life-threatening cerebrovascular and cardiovascular consequences such as heart failure and stroke and is a major contributor to cardiovascular-related mortality worldwide. Atherosclerosis development is a complex process that involves specific structural, functional and transcriptional changes in different vascular cell populations at different stages of the disease. The application of single-cell RNA sequencing (scRNA-seq) analysis has discovered not only disease-related cell-specific transcriptomic profiles but also novel subpopulations of cells once thought as homogenous cell populations. Vascular cells undergo specific transcriptional changes during the entire course of the disease. Epigenetics is the instruction-set-architecture in living cells that defines and maintains the cellular identity by regulating the cellular transcriptome. Although different cells contain the same genetic material, they have different epigenomic signatures. The epigenome is plastic, dynamic and highly responsive to environmental stimuli. Modifications to the epigenome are driven by an array of epigenetic enzymes generally referred to as writers, erasers and readers that define cellular fate and destiny. The reversibility of these modifications raises hope for finding novel therapeutic targets for modifiable pathological conditions including atherosclerosis where the involvement of epigenetics is increasingly appreciated. This article provides a critical review of the up-to-date research in the field of epigenetics mainly focusing on in vivo settings in the context of the cellular role of individual vascular cell types in the development of atherosclerosis.
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Aterosclerosis/etiología , Células Endoteliales/metabolismo , Epigénesis Genética , Miocitos del Músculo Liso/metabolismo , Placa Aterosclerótica/etiología , Animales , Aterosclerosis/metabolismo , Aterosclerosis/terapia , Metilación de ADN , Fibroblastos/metabolismo , Código de Histonas , Humanos , Linfocitos/metabolismo , Macrófagos/metabolismo , Terapia Molecular Dirigida , Análisis de la Célula IndividualRESUMEN
BACKGROUND: Intensive care unit (ICU) staff have faced unprecedented challenges during the coronavirus disease 2019 (COVID-19) pandemic, which could significantly affect their mental health and well-being. The present study aimed to investigate perceived stress and post-traumatic stress disorder (PTSD) symptoms reported by ICU staff working directly with COVID-19 patients. METHODS: The Perceived Stress Scale was used to assess perceived stress, the PTSD Diagnostic Scale for the Diagnostic and Statistical Manual of Mental Disorders (5th edition) was used to determine PTSD symptoms, and a sociodemographic questionnaire was used to record different sociodemographic variables. RESULTS: Altogether, 124 participants (57.2% of whom were men) were included in the analysis. The majority of participants perceived working in the ICU with COVID-19 patients as moderately to severely stressful. Moreover, 71.4% of doctors and 74.4% of nurses experienced moderate-to-severe perceived stress. The staff with previous ICU experience were less likely to have a probable diagnosis of PTSD than those without previous ICU experience. CONCLUSIONS: Assessing perceived stress levels and PTSD among ICU staff may enhance our understanding of COVID-19-induced mental health challenges. Specific strategies to enhance ICU staff's mental well-being during the COVID-19 pandemic should be employed and monitored regularly. Interventions aimed at alleviating sources of anxiety in a high-stress environment may reduce the likelihood of developing PTSD.
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AIMS: Impairments of retinal vessel diameter are associated with major adverse cardiovascular (CV) events. Promoter DNA methylation is a repressor of the mitochondrial adaptor p66Shc gene transcription, a key driver of ageing-induced reactive oxygen species. The study aimed to investigate whether high-intensity interval training (HIIT) affects retinal microvascular phenotype as well as p66Shc expression and oxidative stress in ageing subjects with increased CV risk from the EXAMIN AGE cohort. METHODS AND RESULTS: Eighty-four sedentary subjects (mean age 59.4 ± 7.0 years) with ≥2 CV risk factors were randomized into either a 12-week HIIT or standard physical activity recommendations. Retinal arteriolar and venular diameters were measured by use of a retinal vessel analyser. As a marker of oxidative stress plasma 3-nitrotyrosine (3-NT) level was determined by ELISA. Gene expression of p66Shc and DNA methylation were assessed in mononuclear cells by RT-qPCR and methylated-DNA capture (MethylMiner Enrichment Kit) coupled with qPCR, respectively. High-intensity interval training reduced body mass index, fat mass, low-density lipoprotein and increased muscle mass, as well as maximal oxygen uptake (VO2max). Moreover, HIIT restored microvascular phenotype by inducing retinal arteriolar widening (pre: 175 ± 14 µm vs. post: 181 ± 13 µm, P = 0.001) and venular narrowing (pre: 222 ± 14 µm vs. post: 220 ± 14 µm, P = 0.007). After HIIT, restoration of p66Shc promoter methylation (P = 0.034) reduced p66Shc gene expression (P = 0.037) and, in turn, blunted 3-NT plasma levels (P = 0.002). CONCLUSION: High-intensity interval training rescues microvascular dysfunction in ageing subjects at increased CV risk. Exercise-induced reprogramming of DNA methylation of p66Shc gene may represent a putative mechanistic link whereby exercise protects against age-related oxidative stress. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT02796976 (https://clinicaltrials.gov/ct2/show/NCT02796976).
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Entrenamiento de Intervalos de Alta Intensidad , Metilación de ADN , Fenotipo , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src/genéticaRESUMEN
Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder characterized by bone marrow failure, exocrine pancreatic insufficiency, and skeletal abnormalities, caused by loss-of-function mutations in the SBDS gene, a factor involved in ribosome biogenesis. By analyzing osteoblasts from SDS patients (SDS-OBs), we show that SDS-OBs displayed reduced SBDS gene expression and reduced/undetectable SBDS protein compared to osteoblasts from healthy subjects (H-OBs). SDS-OBs cultured in an osteogenic medium displayed a lower mineralization capacity compared to H-OBs. Whole transcriptome analysis showed significant differences in the gene expression of SDS-OBs vs. H-OBs, particularly in the ossification pathway. SDS-OBs expressed lower levels of the main genes responsible for osteoblastogenesis. Of all downregulated genes, Western blot analyses confirmed lower levels of alkaline phosphatase and collagen type I in SDS-OBs than in H-OBs. Interestingly, SDS-OBs showed higher protein levels of p53, an inhibitor of osteogenesis, compared to H-OBs. Silencing of Tp53 was associated with higher collagen type I and alkaline phosphatase protein levels and an increase in SDS-OB mineralization capacity. In conclusion, our results show that the reduced capacity of SDS-OBs to mineralize is mediated, at least in part, by the high levels of p53 and highlight an important role of SBDS in osteoblast functions.
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Calcificación Fisiológica , Osteoblastos/metabolismo , Síndrome de Shwachman-Diamond/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Células Cultivadas , Femenino , Humanos , Masculino , Osteoblastos/patología , Proteínas/genética , Proteínas/metabolismo , Síndrome de Shwachman-Diamond/genética , Síndrome de Shwachman-Diamond/patología , Proteína p53 Supresora de Tumor/genéticaRESUMEN
Epidemiological data about determinants of influenza A virus (IAV) in the Pakistani population is scarce. We aimed to conduct a prospective hospital-based active surveillance study from October 2015 to May 2016 to identify potential risk factors associated with IAV infection among patients with influenza-like illness (ILI) and severe acute respiratory illness (SARI). Surveillance was conducted in Lahore General Hospital, selected as a sentinel site in Lahore District, Pakistan. Nasal/throat samples were collected along with epidemiological and clinical data from enrolled patients. Real-time reverse-transcription polymerase chain reaction (rRT-PCR) was performed to identify IAV and its subtypes (H1N1pdm09, H3N2). Data were analyzed to determine risk factors and risk markers associated with IAV infections. A total of 311 suspected ILI and SARI cases were enrolled in the study, and among these 50 were IAV-positive. Of these 50 confirmed cases of IAV, 14 were subtyped as H1N1pdm09 and 15 were H3N2; the remaining 21 were untyped. A final multivariable model identified four independent risk factors/markers for IAV infection: exposure history to ILI patients within last 7 days and gender being male were identified as risk factors of IAV infection, while use of antibiotics prior to hospital consultation and presence of fever were identified as risk markers. We concluded that adopting nonpharmaceutical interventions like hand hygiene, masks, social distancing, and where possible, avoiding identified risk factors could decrease the risk of IAV infection and may prevent imminent outbreaks of IAV in the community.
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The growing trend for women to postpone childbearing has resulted in a dramatic increase in the incidence of aneuploid pregnancies. Despite the importance to human reproductive health, the events precipitating female age-related meiotic errors are poorly understood. To gain new insight into the molecular basis of age-related chromosome missegregation in human oocytes, we combined the transcriptome profiles of twenty single oocytes (derived from females divided into two groups according to age <35 and ≥35 years) with their chromosome status obtained by array comparative genomic hybridization (aCGH). Furthermore, we compared the transcription profile of the single oocyte with the surrounding cumulus cells (CCs). RNA-seq data showed differences in gene expression between young and old oocytes. Dysregulated genes play a role in important biological processes such as gene transcription regulation, cytoskeleton organization, pathways related to RNA maturation and translation. The comparison of the transcription profile of the oocyte and the corresponding CCs highlighted the differential expression of genes belonging to the G protein-coupled receptor superfamily. Finally, we detected the loss of a X chromosome in two oocytes derived from women belonging to the ≥35 years age group. These aneuploidies may be caused by the detriment of REEP4, an endoplasmic reticulum protein, in women aged ≥35 years. Here we gained new insight into the complex regulatory circuit between the oocyte and the surrounding CCs and uncovered a new putative molecular basis of age-related chromosome missegregation in human oocytes.
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Cromosomas/genética , Oocitos/fisiología , Transcriptoma/genética , Adulto , Aneuploidia , Células Cultivadas , Hibridación Genómica Comparativa/métodos , Células del Cúmulo/fisiología , Femenino , Perfilación de la Expresión Génica/métodos , Regulación de la Expresión Génica/genética , Humanos , Masculino , Análisis por Micromatrices/métodos , Embarazo , Adulto JovenRESUMEN
OBJECTIVE: There are growing concerns towards the quality of medical education in Pakistan. To help strengthen accreditation processes, this study identifies the challenges towards quality assurance of Basic Medical Education in Pakistan. METHODS: A qualitative case study was carried out from March to August 2018. Participants included inspectors from various disciplines in both public and private medical colleges, and medical educationists from Pakistan. Semi-structured interviews were conducted with 12 inspectors, while focus group discussion included 10 medical educationists. All the interviews were audio recorded and transcribed verbatim. Thematic analysis was conducted to capture the intricacies of meaning within the data. RESULTS: Data identified 14 sub-themes grouped under three major themes. Challenges towards quality assurance included mounting political influence, commercialism in medical education, weak regulatory capacity of accrediting body, violation of rules, lack of valid accreditation standards and skilled inspectors. CONCLUSION: Quality assurance of Basic Medical Education in Pakistan involves various systemic, resource and personnel related challenges. The accrediting body needs to bring major reforms in its accreditation system and strengthen its regulatory and technical educational capacity to ensure the quality of medical education in nearly 168 medical and dental colleges of the country.
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HDAC inhibitors can regulate gene expression by post-translational modification of histone as well as nonhistone proteins. Often studied at single loci, increased histone acetylation is the paradigmatic mechanism of action. However, little is known of the extent of genome-wide changes in cells stimulated by the hydroxamic acids, TSA and SAHA. In this article, we map vascular chromatin modifications including histone H3 acetylation of lysine 9 and 14 (H3K9/14ac) using chromatin immunoprecipitation (ChIP) coupled with massive parallel sequencing (ChIP-seq). Since acetylation-mediated gene expression is often associated with modification of other lysine residues, we also examined H3K4me3 and H3K9me3 as well as changes in CpG methylation (CpG-seq). RNA sequencing indicates the differential expression of â¼30% of genes, with almost equal numbers being up- and down-regulated. We observed broad deacetylation and gene expression changes conferred by TSA and SAHA mediated by the loss of EP300/CREBBP binding at multiple gene promoters. This study provides an important framework for HDAC inhibitor function in vascular biology and a comprehensive description of genome-wide deacetylation by pharmacological HDAC inhibition.
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Inhibidores de Histona Desacetilasas/farmacología , Histonas/metabolismo , Ácidos Hidroxámicos/farmacología , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Acetilación , Animales , Antiinflamatorios/farmacología , Aorta/citología , Células Cultivadas , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Endotelio Vascular/citología , Regulación de la Expresión Génica/efectos de los fármacos , Genoma Humano , Humanos , Masculino , Ratones Endogámicos C57BL , Regiones Promotoras Genéticas , Unión Proteica , Factores de Transcripción/metabolismo , Transcriptoma , VorinostatRESUMEN
Many epigenetic-based therapeutics, including drugs such as histone deacetylase inhibitors, are now used in the clinic or are undergoing advanced clinical trials. The study of chromatin-modifying proteins has benefited from the rapid advances in high-throughput sequencing methods, the organized efforts of major consortiums and by individual groups to profile human epigenomes in diverse tissues and cell types. However, while such initiatives have carefully characterized healthy human tissue, disease epigenomes and drug-epigenome interactions remain very poorly understood. Reviewed here is how high-throughput sequencing improves our understanding of chromatin regulator proteins and the potential implications for the study of human disease and drug development and discovery.
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Ensamble y Desensamble de Cromatina , Descubrimiento de Drogas/métodos , Inhibidores de Histona Desacetilasas/farmacología , Histona Desacetilasas/metabolismo , Histonas/metabolismo , Proteína Metiltransferasas/metabolismo , Procesamiento Proteico-Postraduccional , Animales , Humanos , Proteína Metiltransferasas/antagonistas & inhibidoresRESUMEN
BACKGROUND: Methyl-dependent regulation of transcription has expanded from a traditional focus on histones to encompass transcription factor modulation. While the Set7 lysine methyltransferase is associated with pro-inflammatory gene expression in vascular endothelial cells, genome-wide regulatory roles remain to be investigated. From initial characterization of Set7 as specific for methyl-lysine 4 of H3 histones (H3K4m1), biochemical activity toward non-histone substrates has revealed additional mechanisms of gene regulation. RESULTS: mRNA-Seq revealed transcriptional deregulation of over 8,000 genes in an endothelial model of Set7 knockdown. Gene ontology identified up-regulated pathways involved in developmental processes and extracellular matrix remodeling, whereas pathways regulating the inflammatory response as well as nitric oxide signaling were down-regulated. Chromatin maps derived from ChIP-Seq profiling of H3K4m1 identified several hundred loci with loss of H3K4m1 at gene regulatory elements associated with an unexpectedly subtle effect on gene expression. Transcription factor network analysis implicated six previously described Set7 substrates in mRNA-Seq changes, and we predict that Set7 post-translationally regulates other transcription factors associated with vascular endothelial gene expression through the presence of Set7 amino acid methylation motifs. CONCLUSION: We describe a role for Set7 in regulating developmental pathways and response to stimuli (inflammation/immune response) in human endothelial cells of vascular origin. Set7-dependent gene expression changes that occurred independent of H3K4m1 may involve transcription factor lysine methylation events. The method of mapping measured transcriptional changes to transcription factors to identify putative substrates with strong associations to functional changes is applicable to substrate prediction for other broad-substrate histone modifiers.
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Redes Reguladoras de Genes , Secuenciación de Nucleótidos de Alto Rendimiento , N-Metiltransferasa de Histona-Lisina/metabolismo , Línea Celular , Proliferación Celular , Supervivencia Celular , Cromatina/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , N-Metiltransferasa de Histona-Lisina/genética , Histonas/genética , Histonas/metabolismo , Humanos , Metilación , Interferencia de ARN , ARN Interferente Pequeño/metabolismo , Análisis de Secuencia de ADN , Factores de Transcripción/metabolismoRESUMEN
BACKGROUND: Disruption of 11p15 imprinting results in two fetal growth disorders with opposite phenotypes: the Beckwith-Wiedemann (BWS; MIM 130650) and the Silver-Russell (SRS; MIM 180860) syndromes. DNA methylation defects account for 60% of BWS and SRS cases and, in most cases, occur without any identified mutation in a cis-acting regulatory sequence or a trans-acting factor. METHODS: We investigated whether 11p15 cis-acting sequence variants account for primary DNA methylation defects in patients with SRS and BWS with loss of DNA methylation at ICR1 and ICR2, respectively. RESULTS: We identified a 4.5â kb haplotype that, upon maternal transmission, is associated with a risk of ICR2 loss of DNA methylation in patients with BWS. This novel region is located within the second intron of the KCNQ1 gene, 170â kb upstream of the ICR2 imprinting centre and encompasses two CTCF binding sites. We showed that, within the 4.5â kb region, two SNPs (rs11823023 and rs179436) affect CTCF occupancy at DNA motifs flanking the CTCF 20â bp core motif. CONCLUSIONS: This study shows that genetic variants confer a risk of DNA methylation defect with a parent-of-origin effect and highlights the crucial role of CTCF for the regulation of genomic imprinting of the CDKN1C/KCNQ1 domain.
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Síndrome de Beckwith-Wiedemann/genética , Canal de Potasio KCNQ1/genética , Sitios de Unión/genética , Factor de Unión a CCCTC , Metilación de ADN/genética , Femenino , Haplotipos/genética , Humanos , Intrones/genética , Canal de Potasio KCNQ1/metabolismo , Masculino , Mutación/genética , Proteínas Represoras/metabolismoRESUMEN
A significant proportion of the worldwide population is of the elderly people living with chronic diseases that result in high health-care cost. To provide continuous health monitoring with minimal health-care cost, Wireless Body Sensor Networks (WBSNs) has been recently emerged as a promising technology. Depending on nature of sensory data, WBSNs might require a high level of Quality of Service (QoS) both in terms of delay and reliability during data reporting phase. In this paper, we propose a data-centric routing for intra WBSNs that adapts the routing strategy in accordance with the nature of data, temperature rise issue of the implanted bio-medical sensors due to electromagnetic wave absorption, and high and dynamic path loss caused by postural movement of human body and in-body wireless communication. We consider the network models both with and without relay nodes in our simulations. Due to the multi-facet routing strategy, the proposed data-centric routing achieves better performance in terms of delay, reliability, temperature rise, and energy consumption when compared with other state-of-the-art.
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Temperatura Corporal , Monitoreo Ambulatorio/instrumentación , Tecnología Inalámbrica , Algoritmos , Radiación Electromagnética , Ingestión de Energía , Humanos , Modelos Teóricos , Reproducibilidad de los ResultadosRESUMEN
Wireless Body Sensor Networks (WBSNs) constitute a subset of Wireless Sensor Networks (WSNs) responsible for monitoring vital sign-related data of patients and accordingly route this data towards a sink. In routing sensed data towards sinks, WBSNs face some of the same routing challenges as general WSNs, but the unique requirements of WBSNs impose some more constraints that need to be addressed by the routing mechanisms. This paper identifies various issues and challenges in pursuit of effective routing in WBSNs. Furthermore, it provides a detailed literature review of the various existing routing protocols used in the WBSN domain by discussing their strengths and weaknesses.