Stress related epigenetic changes may explain opportunistic success in biological invasions in Antipode mussels

Different environmental factors could induce epigenetic changes, which are likely involved in the biological invasion process. Some of these factors are driven by humans as, for example, the pollution and deliberate or accidental introductions and others are due to natural conditions such as salinity. In this study, we have analysed the relationship between different stress factors: time in the new location, pollution and salinity with the methylation changes that could be involved in the invasive species tolerance to new environments. For this purpose, we have analysed two different mussels’ species, reciprocally introduced in antipode areas: the Mediterranean blue mussel Mytilus galloprovincialis and the New Zealand pygmy mussel Xenostrobus securis, widely recognized invaders outside their native distribution ranges. The demetylathion was higher in more stressed population, supporting the idea of epigenetic is involved in plasticity process. These results can open a new management protocols, using the epigenetic signals as potential pollution monitoring tool. We could use these epigenetic marks to recognise the invasive status in a population and determine potential biopollutants

Assessing the human immune system through blood transcriptomics

Blood is the pipeline of the immune system. Assessing changes in transcript abundance in blood on a genome-wide scale affords a comprehensive view of the status of the immune system in health and disease. This review summarizes the work that has used this approach to identify therapeutic targets and biomarker signatures in the field of autoimmunity and infectious disease. Recent technological and methodological advances that will carry the blood transcriptome research field forward are also discussed

Surviving Sepsis Campaign: international guidelines for management of severe sepsis and septic shock, 2012

OBJECTIVE: To provide an update to the "Surviving Sepsis Campaign Guidelines for Management of Severe Sepsis and Septic Shock," last published in 2008. DESIGN: A consensus committee of 68 international experts representing 30 international organizations was convened. Nominal groups were assembled at key international meetings (for those committee members attending the conference). A formal conflict of interest policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independent of any industry funding. A stand-alone meeting was held for all subgroup heads, co- and vice-chairs, and selected individuals. Teleconferences and electronic-based discussion among subgroups and among the entire committee served as an integral part of the development. METHODS: The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence from high (A) to very low (D) and to determine the strength of recommendations as strong (1) or weak (2). The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized. Recommendations were classified into three groups: (1) those directly targeting severe sepsis; (2) those targeting general care of the critically ill patient and considered high priority in severe sepsis; and (3) pediatric considerations. RESULTS: Key recommendations and suggestions, listed by category, include: early quantitative resuscitation of the septic patient during the first 6 h after recognition (1C); blood cultures before antibiotic therapy (1C); imaging studies performed promptly to confirm a potential source of infection (UG); administration of broad-spectrum antimicrobials therapy within 1 h of the recognition of septic shock (1B) and severe sepsis without septic shock (1C) as the goal of therapy; reassessment of antimicrobial therapy daily for de-escalation, when appropriate (1B); infection source control with attention to the balance of risks and benefits of the chosen method within 12 h of diagnosis (1C); initial fluid resuscitation with crystalloid (1B) and consideration of the addition of albumin in patients who continue to require substantial amounts of crystalloid to maintain adequate mean arterial pressure (2C) and the avoidance of hetastarch formulations (1B); initial fluid challenge in patients with sepsis-induced tissue hypoperfusion and suspicion of hypovolemia to achieve a minimum of 30 mL/kg of crystalloids (more rapid administration and greater amounts of fluid may be needed in some patients (1C); fluid challenge technique continued as long as hemodynamic improvement is based on either dynamic or static variables (UG); norepinephrine as the first-choice vasopressor to maintain mean arterial pressure ≥65 mmHg (1B); epinephrine when an additional agent is needed to maintain adequate blood pressure (2B); vasopressin (0.03 U/min) can be added to norepinephrine to either raise mean arterial pressure to target or to decrease norepinephrine dose but should not be used as the initial vasopressor (UG); dopamine is not recommended except in highly selected circumstances (2C); dobutamine infusion administered or added to vasopressor in the presence of (a) myocardial dysfunction as suggested by elevated cardiac filling pressures and low cardiac output, or (b) ongoing signs of hypoperfusion despite achieving adequate intravascular volume and adequate mean arterial pressure (1C); avoiding use of intravenous hydrocortisone in adult septic shock patients if adequate fluid resuscitation and vasopressor therapy are able to restore hemodynamic stability (2C); hemoglobin target of 7-9 g/dL in the absence of tissue hypoperfusion, ischemic coronary artery disease, or acute hemorrhage (1B); low tidal volume (1A) and limitation of inspiratory plateau pressure (1B) for acute respiratory distress syndrome (ARDS); application of at least a minimal amount of positive end-expiratory pressure (PEEP) in ARDS (1B); higher rather than lower level of PEEP for patients with sepsis-induced moderate or severe ARDS (2C); recruitment maneuvers in sepsis patients with severe refractory hypoxemia due to ARDS (2C); prone positioning in sepsis-induced ARDS patients with a PaO (2)/FiO (2) ratio of ≤100 mm Hg in facilities that have experience with such practices (2C); head-of-bed elevation in mechanically ventilated patients unless contraindicated (1B); a conservative fluid strategy for patients with established ARDS who do not have evidence of tissue hypoperfusion (1C); protocols for weaning and sedation (1A); minimizing use of either intermittent bolus sedation or continuous infusion sedation targeting specific titration endpoints (1B); avoidance of neuromuscular blockers if possible in the septic patient without ARDS (1C); a short course of neuromuscular blocker (no longer than 48 h) for patients with early ARDS and a PaO (2)/FI O (2) 180 mg/dL, targeting an upper blood glucose ≤180 mg/dL (1A); equivalency of continuous veno-venous hemofiltration or intermittent hemodialysis (2B); prophylaxis for deep vein thrombosis (1B); use of stress ulcer prophylaxis to prevent upper gastrointestinal bleeding in patients with bleeding risk factors (1B); oral or enteral (if necessary) feedings, as tolerated, rather than either complete fasting or provision of only intravenous glucose within the first 48 h after a diagnosis of severe sepsis/septic shock (2C); and addressing goals of care, including treatment plans and end-of-life planning (as appropriate) (1B), as early as feasible, but within 72 h of intensive care unit admission (2C). Recommendations specific to pediatric severe sepsis include: therapy with face mask oxygen, high flow nasal cannula oxygen, or nasopharyngeal continuous PEEP in the presence of respiratory distress and hypoxemia (2C), use of physical examination therapeutic endpoints such as capillary refill (2C); for septic shock associated with hypovolemia, the use of crystalloids or albumin to deliver a bolus of 20 mL/kg of crystalloids (or albumin equivalent) over 5-10 min (2C); more common use of inotropes and vasodilators for low cardiac output septic shock associated with elevated systemic vascular resistance (2C); and use of hydrocortisone only in children with suspected or proven "absolute"' adrenal insufficiency (2C). CONCLUSIONS: Strong agreement existed among a large cohort of international experts regarding many level 1 recommendations for the best care of patients with severe sepsis. Although a significant number of aspects of care have relatively weak support, evidence-based recommendations regarding the acute management of sepsis and septic shock are the foundation of improved outcomes for this important group of critically ill patients

Factores secretados por células óseas inducen acumulación de calcio intracelular y AMP cíclico y activación de ERK 1/2 en células de cáncer de próstata; evaluación por técnicas de fluorescencia en células vivas

Objetivos: Analizar en células tumorales de próstata los efectos causados por el secretoma de células óseas sobre la proliferación y sobre vías de señalización intracelular relacionadas con la progresión del cáncer de próstata. Materiales y métodos: Se caracterizaron los efectos de factores secretados presentes en medios condicionados de pre-osteoblastos MC3T3-E1 y osteocitos MLO-Y4 sobre la proliferación de células de adenocarcinoma de próstata metastásicas PC-3 mediante tinción por azul de tripano. Se observó por técnicas de fluorescencia en células vivas los efectos de los medios condicionados por células MC3T3-E1 y MLO-Y4 en moléculas de señalización intracelular implicadas en la progresión tumoral de células de adenocarcinoma de próstata PC-3. Se estudió la acumulación de calcio intracelular utilizando el indicador de calcio fluorescente Fluo-4AM y la generación de AMP cíclico, y la activación de la quinasa ERK 1/2 por Transferencia de Energía de Resonancia Fluorescente (FRET) usando los biosensores EPAC y ERK-NES, respectivamente. Resultados: La estimulación de células PC-3 con medios condicionados de pre-osteoblastos MC3T3-E1 y osteocitos MLO-Y4 indujo aumento en la proliferación de las células de adenocarcinoma PC-3. Los medios condicionados por células óseas causaron también aumento transitorio en la acumulación de calcio intracelular y de la generación de AMP cíclico e incrementaron la activación de la quinasa ERK 1/2. Conclusiones: Las células óseas secretan factores activadores de la proliferación y de vías de señalización que favorecen la progresión tumoral de células de cáncer de próstata, sugiriendo que la comunicación cruzada entre estos tipos celulares puede favorecer el desarrollo de nichos metástasicos de cáncer de próstata en el hueso

Efectos de la estimulación mecánica en la comunicación entre células óseas

La fuerza mecánica es importante para el modelado, el remodelado y la regeneración ósea; estimula a los osteocitos provocando una alteración en la producción y secreción de moléculas de señalización que regulan la actividad de los osteoblastos y los osteoclastos. El objetivo del presente estudio fue evaluar el efecto del medio condicionado de células osteocíticas de ratón estimuladas mecánicamente sobre la capacidad proliferativa y migratoria de células mesenquimales y células óseas. Para ello, se analizó la proliferación y migración de las células preosteoblásticas de ratón, células mesenquimales preadiposas humanas y macrófagos de ratón en presencia del medio condicionado de las células osteocíticas, tras 6 y 24 horas después de ser sometidas a un estrés mecánico de 10 dinas/cm2 por flujo de fluido (FF) durante 10 minutos. Se encontró que la migración de células preosteoblásticas aumentó significativamente en presencia de medios condicionados de células osteocíticas con respecto al grupo control estático (SC) (SC=12,63±5,44; FF6h=23,03±11,57; FF24h=29,72±15,76; p<0,0001). De la misma manera, las células preadiposas también incrementaron significativamente su migración en presencia de dichos medios condicionados (SC=11,48±4,75; FF6h=18,43±9,94; FF24h=18,80±10,03; p≤0,0007). Sin embargo, la migración de los macrófagos disminuyó en presencia del medio condicionado recogido a las 24 horas con respecto al grupo control estático (SC=69±22,71; FF24h=26,57±5,47; p<0,0001). Estos efectos se asociaron con la disminución de la expresión proteica de ciertas quimioquinas, como la proteína quimiotáctica de monocitos de tipo I (SC=0,25±0,06; FF24h=0,09±0,005; p=0,0262), la proteína del grupo I de alta movilidad (SC=0,25±0,04; FF24h=0,15±0,05; p=0,0159) y la proteína reguladora de la activación de linfocitos T y monocitos (SC=3,29±0,88; FF6h=1,33±1,09; FF24h=0,97±0,66; p≤0,0314), por parte de los osteocitos en presencia de estímulo mecánico con respecto al grupo control estático. En conclusión, este estudio in vitro demuestra que la mecanotransducción de los osteocitos potencia el reclutamiento de osteoblastos y células mesenquimales preadiposas mientras que reduce la migración de los macrófagos

Comparación de las acciones osteogénicas de la proteína relacionada con la parathormona (PTHrP) en modelos de ratón diabético y con déficit del factor de crecimiento similar a la insulina tipo I (IGF-I)

Trabajo becado con una Beca de Investigación en Biología Molecular FEIOMM 2011. La diabetes mellitus (DM) es una patología metabólica caracterizada por hiperglucemia crónica debida al déficit de producción y/o acción de la insulina. La DM, sobre todo la tipo 1, se asocia comúnmente a osteopenia/osteoporosis y al aumento de riesgo de fracturas. El factor de crecimiento similar a la insulina tipo I (IGF-I), un factor abundante en la matriz ósea que ejerce un papel importante en el desarrollo y mantenimiento de la masa ósea, disminuye en la DM. La proteína relacionada con la parathormona (PTHrP), un modulador del crecimiento y la función osteoblástica, actúa sobre los osteoprogenitores promoviendo la diferenciación osteoblástica y la regeneración ósea. Su expresión disminuye en situación diabética. En este trabajo, hemos evaluado y comparado las acciones osteogénicas de la PTHrP en modelos murinos de DM tipo 1 y deficiente en IGF-I. Los ratones diabéticos por inyección de estreptozotocina presentan una disminución de la masa ósea en los huesos largos, asociada al incremento de proteínas oxidadas y a la disminución de expresión de genes relacionados con la vía Wnt y de la proteína β-catenina, además de mostrar alteraciones en el hueso trabecular vertebral. En el modelo de ratón con déficit de IGF-I, nuestros resultados indican una situación de osteopenia tanto en el fémur (asociado a una inhibición de la vía Wnt) como en la columna (L1-L5). Nuestros hallazgos demuestran que la administración de PTHrP, predominantemente a través de su dominio N-terminal, modula la vía de Wnt canónica en relación a sus acciones osteogénicas en situación diabética y, también en parte, en ausencia de IGF-I

Genetic regulation of RNA splicing in human pancreatic islets

Background: Non‑coding genetic variants that influence gene transcription in pancreatic islets play a major role in the susceptibility to type 2 diabetes (T2D), and likely also contribute to type 1 diabetes (T1D) risk. For many loci, however, the mechanisms through which non‑coding variants influence diabetes susceptibility are unknown. Results: We examine splicing QTLs (sQTLs) in pancreatic islets from 399 human donors and observe that genetic variation has a widespread influence on splicing of genes with established roles in islet biology and diabetes. In parallel, we profile expression QTLs (eQTLs) and use transcriptome‑wide association as well as genetic co‑localization studies to assign islet sQTLs or eQTLs to T2D and T1D susceptibility signals, many of which lack candidate effector genes. This analysis reveals biologically plausible mechanisms, including the association of T2D with an sQTL that creates a nonsense isoform in ERO1B, a regulator of ER‑stress and proinsulin biosynthesis. The expanded list of T2D risk effector genes reveals overrepresented pathways, including regulators of G‑protein‑mediated cAMP production. The analysis of sQTLs also reveals candidate effector genes for T1D susceptibility such as DCLRE1B, a senescence regulator, and lncRNA MEG3. Conclusions: These data expose widespread effects of common genetic variants on RNA splicing in pancreatic islets. The results support a role for splicing variation in diabetes susceptibility, and offer a new set of genetic targets with potential therapeutic benefit