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MODULAZIONE DEI FENOMENI DI SENESCENZA CELLULARE DI ADIPOCITI E PREADIPOCITI IN VITRO
Get PDFL’invecchiamento è accompagnato da una complessa rete di processi biologici caratterizzati da uno stato infiammatorio cronico basale, a sua volta correlato allo sviluppo di patologie età-associate come: aterosclerosi, osteoartriti, Alzheimer, diabete di tipo 2. Una sempre più approfondita analisi del processo di senescenza tessutospecifico potrebbe consentire l’individuazione di target terapeutici utili a modulare il processo complessivo dell’invecchiamento stesso. L’invecchiamento è causa di declino delle funzionalità sistemiche e il tessuto adiposo è uno degli organi maggiormente colpiti in quanto subisce cambiamenti significativi che riguardano la quantità, la distribuzione, la composizione cellulare e l’attività endocrina, giocando un ruolo chiave nell’insorgenza di insulino-resistenza, di disfunzioni metaboliche e infiammazione sistemica. L’abbondanza del tessuto adiposo e le diverse funzioni da esso esercitate lo rendono un organo fondamentale per la comprensione della fisiologia dell’intero organismo. Tuttavia, i cambiamenti a cui è sottoposto durante il processo di invecchiamento sono solo in parte noti e oggetto di studio negli ultimi anni. È quindi fondamentale conoscere i processi molecolari che stanno alla base della fisiopatologia del tessuto adiposo e del suo invecchiamento in modo da poter individuare strategie terapeutiche per le malattie correlate all’invecchiamento. In questo studio, è stato messo a punto un modello cellulare di senescenza in vitro attraverso il trattamento con perossido di idrogeno (H2O2) in adipociti e preadipociti 3T3-L1 murini. Successivamente è stata valutata la potenziale attività senolitica della quercetina esaminandone l’effetto antiossidante e antinfiammatorio, cercando di individuarne il target molecolare.Aging is associated with pathological age-related processes as inflammatory low-grade state, atherosclerosis, Alzheimer's disease, type II diabetes and osteoarthritis diseases. A deep analysis of the tissue-specific senescence process could allow the identification of therapeutic targets to modulate the aging process itself. In this study, premature senescence model was developed in vitro through treatment with oxygen peroxide (H2O2) in murine 3T3-L1 preadipocytes before and after induction to mature adipocytes. H2O2 treated cells showed characteristic senescence-associated features including senescence-associated beta-galactosidase activity (SA-ß-gal), activation of reactive oxygen species (ROS) development of senescence-associated secretory phenotype (SASP), induction of cell cycle inhibitors P-21 as well as induction of pro-inflammatory transduction factor NFκB and a downregulation of deacetylase SIRT1. We found that stimulation with H2O2 results in an induction of miR-155-5p expression in preadipocytes and in mature adipocytes. The treatment with quercetin (20 μM) showed significant decrease in the number of ß-galactosidase positive cell along with the suppression of ROS, NFκB and SASP factor in both cell models. In addition, quercetin treatment also upregulated protein expression of SIRT1 and decreased miR-155-5p expression. These results suggest that quercetin acts as a potential senolytic agent in both preadipocytes and adipocytes cell models, inhibiting ROS production and proinflammatory miR-155-5p
Delirium after thiazide diuretic suspension can unmask diabetes insipidus.
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Relationship between neck circumference, insulin resistance and arterial stiffness in overweight and obese subjects.
No full textBackground Only a few studies have investigated the relationship between neck circumference and cardiometabolic risk. The aim of this study was to assess the relationships between neck circumference, waist circumference, metabolic variables and arterial stiffness in a group of overweight and obese subjects evaluating a possible independent role of neck circumference in determining arterial stiffness. Methods and results We studied 95 subjects (53 women) with an age range of 20-77 years and body mass index range from 25.69 to 47.04 kg/m2. In each subject we evaluated body mass index, waist, hip and neck circumference, systolic and diastolic blood pressure, insulin, fasting glucose, cholesterol, low-density lipoprotein and high-density lipoprotein cholesterol and triglycerides. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (PWVcf) and carotid-radial pulse wave velocity (PWVcr). Both PWVcf and PWVcr were higher in subjects with high values of neck circumference compared with subjects with normal values of neck circumference. Subjects with high values of neck circumference and abdominal obesity presented higher values of mean arterial pressure, PWVcr and homeostasis model assessment (HOMA) index and lower values of high-density lipoprotein than subjects with only abdominal obesity. Two models of stepwise multiple regression were performed in order to evaluate the combined effect of independent variables on arterial stiffness. In the first model PWVcf was considered a dependent variable, and age, gender, systolic blood pressure, triglycerides, high-density lipoprotein cholesterol, waist circumference, neck circumference, HOMA index and the use of anti-hypertensive medications were considered independent variables. Age, systolic blood pressure, triglycerides and waist circumference were significant predictors of PWVcf, explaining 65% of its variance. In the second model, in which PWVcr was considered a dependent variable, neck circumference and gender were significant predictors of PWVcr, explaining 24% of its variance. Conclusions These findings emphasise the need to measure not only waist but even neck circumference to better stratify and identify individuals at increased cardiometabolic risk, as upper-body subcutaneous fat is a novel, easily measured fat depot
Iron primes 3T3-L1 adipocytes to a TLR4-mediated inflammatory response.
No full textOBJECTIVE:Iron participates in several mechanisms involving inflammation and innate immunity, yet the dysregulation of its homeostasis is a major cause of metabolic syndrome. Adipocytes should play a major role in iron metabolism, as an impairment in iron turnover is closely related to insulin resistance, obesity, and type 2 diabetes. The aim of this study was to investigate the role of iron in an in vitro-inflamed adipocyte model.METHODS:Gene expression of tumor necrosis factor-α, interleukin-6, inflammatory chemokines (CCL3, CCL4, and CXCL12), and molecules involved in iron metabolism were evaluated in an in vitro mouse 3T3-L1 cell model. Cells underwent treatment with FeSO4 heptahydrate and lipopolysaccharide (LPS) stimulation. Toll-like receptor 4 (TLR4) membrane expression, lipid droplet immunohystochemistry, and lipolysis were also evaluated.RESULTS:Iron sulphate heptahydrate elicited gene expression of hepcidin, hemojuvelin, and ferroportin at different time courses. Additionally, it activated lipolysis but did not trigger any adipokine gene expression. When cells treated with physiological doses of iron were also stimulated with LPS, an enhancement in the LPS-induced gene expression of cytokines and chemokines was observed. The enhancement occurred with different patterns depending on different time courses and investigated genes, showing its maximal effect for IL-6 gene expression.CONCLUSIONS:FeSO4 heptahydrate at a relatively physiological dose, induced gene expression of iron modulatory proteins and also enhanced RNA transcripts of several inflammatory cytokines and chemokines through a priming/synergistic mechanism involving membrane TLR4.Copyright © 2015 Elsevier Inc. All rights reserved.KEYWORDS:Adipocyte: Lipopolysaccharide; Chemokine; Inflammation; Iron; Toll-like recepto
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Myosteatosis and myofibrosis: relationship with aging, inflammation and insulin resistance.
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