Transcriptional memory emerges from cooperative histone modifications

Background
Transcriptional regulation in cells makes use of diverse mechanisms to ensure that functional states can be maintained and adapted to variable environments; among them are chromatin-related mechanisms. While mathematical models of transcription factor networks controlling development are well established, models of transcriptional regulation by chromatin states are rather rare despite they appear to be a powerful regulatory mechanism.
Results
We here introduce a mathematical model of transcriptional regulation governed by histone modifications. This model describes binding of protein complexes to chromatin which are capable of reading and writing histone marks. Molecular interactions between these complexes and DNA or histones create a regulatory switch of transcriptional activity possessing a regulatory memory. The regulatory states of the switch depend on the activity of histone (de-) methylases, the structure of the DNA-binding regions of the complexes, and the number of histones contributing to binding. 
We apply our model to transcriptional regulation by trithorax- and polycomb- complex binding. By analyzing data on pluripotent and lineage-committed cells we verify basic model assumptions and provide evidence for a positive effect of the length of the modified regions on the stability of the induced regulatory states and thus on the transcriptional memory.
Conclusions
Our results provide new insights into epigenetic modes of transcriptional regulation. Moreover, they implicate well-founded hypotheses on cooperative histone modifications, proliferation induced epigenetic changes and higher order folding of chromatin which await experimental validation. Our approach represents a basic step towards multi-scale models of transcriptional control during development and lineage specification. 
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Une étude pilote sur le congé parental de pères au Tirol

La présente étude porte sur les pères en congé parental au Tirol. Les auteurs constatent que les réflexions systématiques à propos des pères en congé sont rares. Les auteurs tentent de répondre à la question suivante : le congé parental a-t-il des implications sur l'attachement père-enfant ? L'étude pilote porte sur un échantillon de 15 dyades père-enfant. La description et l'analyse du comportement d'interaction père-enfant ont été effectuées à l'aide du Child Adult Relationship Index (CARE-Index) élaboré par Crittenden (1988, 2000).A pilot study of fathers on parental leave in Tirol The current study examines fathers in parental leave in Tirol. The authors have come to realise that systematic reflections concerning fathers on leave of their work are rare. The authors attempt to answer the following question: does parental leave have implications on child/father attachment? The pilot study examines a small sample of 15 father/child couples. The description and analysis of father/child interactions was elaborated with the Child Adult Relationship Index (CARE-Index) designed by Crittenden (1988, 2000).Un proyecto piloto sobre el permiso parental en Tirol El estudio trata de los padres en permiso parental en Tirol. Los autores constatan que son muy pocas las reflexiones systématicas sobre los padres en permiso. ¿Tiene el permiso parental implicaciones sobre el apego padre-hijo? Los autores tratan de responder a esta pregunta en un estudio piloto con una muestra de 15 dyadas padre-hijo. La descripción y el analisis del comportamiento de la interaccion padre-hijo han sido realisadas con la ayuda del Child Adult Relationship Index (CARE-Index) elaborado por Crittenden (1988, 2000)

Relationship between the Clinical Frailty Scale and short-term mortality in patients ≥ 80 years old acutely admitted to the ICU: a prospective cohort study.

BACKGROUND: The Clinical Frailty Scale (CFS) is frequently used to measure frailty in critically ill adults. There is wide variation in the approach to analysing the relationship between the CFS score and mortality after admission to the ICU. This study aimed to evaluate the influence of modelling approach on the association between the CFS score and short-term mortality and quantify the prognostic value of frailty in this context. METHODS: We analysed data from two multicentre prospective cohort studies which enrolled intensive care unit patients ≥ 80 years old in 26 countries. The primary outcome was mortality within 30-days from admission to the ICU. Logistic regression models for both ICU and 30-day mortality included the CFS score as either a categorical, continuous or dichotomous variable and were adjusted for patient's age, sex, reason for admission to the ICU, and admission Sequential Organ Failure Assessment score. RESULTS: The median age in the sample of 7487 consecutive patients was 84 years (IQR 81-87). The highest fraction of new prognostic information from frailty in the context of 30-day mortality was observed when the CFS score was treated as either a categorical variable using all original levels of frailty or a nonlinear continuous variable and was equal to 9% using these modelling approaches (p < 0.001). The relationship between the CFS score and mortality was nonlinear (p < 0.01). CONCLUSION: Knowledge about a patient's frailty status adds a substantial amount of new prognostic information at the moment of admission to the ICU. Arbitrary simplification of the CFS score into fewer groups than originally intended leads to a loss of information and should be avoided. Trial registration NCT03134807 (VIP1), NCT03370692 (VIP2)

Restrictive cardiomyopathy in inherited ATTR amyloidosis (TTR-Ser23Asn) in a patient of German-Italian extraction

Amyloidosis occurs when certain soluble proteins are transformed into amyloid fibrils in the extracellular space. Most common are the light-chain amyloidoses; less common is the AA-amyloidosis, which follows chronic inflammatory diseases, and the amyloidoses of transthyretin (TTR) origin. We report on a women of Italian-German origin with the mutation TTR (Ser23Asn). Whole body scintigraphy using TC99m-DPD showed end stage hereditary amyloidosis caused by ATTR with predominant tracer retention in the myocardium. Myocardial biopsies revealed the presence of amyloid by Congo red staining. Further immunohistochemical analysis showed ATTR amyloidosis. DNA sequencing revealed a point mutation of the transthyretin gene leading to a single amino acid substitution. The only effective treatment in patients with manifest cardiac ATTR amyloidosis is combined heart and liver transplantation. Our patient was placed on a list for this procedure, but unfortunately she died during the standby procedure due to urosepsis

Dual Inhibition of GLUT1 and the ATR/CHK1 Kinase Axis Displays Synergistic Cytotoxicity in KRAS-Mutant Cancer Cells

The advent of molecularly targeted therapeutic agents has opened a new era in cancer therapy. However, many tumors rely on nondruggable cancer-driving lesions. In addition, long-lasting clinical benefits from single-agent therapies rarely occur, as most of the tumors acquire resistance over time. The identification of targeted combination regimens interfering with signaling through oncogenically rewired pathways provides a promising approach to enhance efficacy of single-agent-targeted treatments. Moreover, combination drug therapies might overcome the emergence of drug resistance. Here, we performed a focused flow cytometry-based drug synergy screen and identified a novel synergistic interaction between GLUT1-mediated glucose transport and the cell-cycle checkpoint kinases ATR and CHK1. Combined inhibition of CHK1/GLUT1 or ATR/GLUT1 robustly induced apoptosis, particularly in RAS-mutant cancer cells. Mechanistically, combined inhibition of ATR/CHK1 and GLUT1 arrested sensitive cells in S-phase and led to the accumulation of genotoxic damage, particularly in S-phase. In vivo, simultaneous inhibition of ATR and GLUT1 significantly reduced tumor volume gain in an autochthonous mouse model of KrasG12D-driven soft tissue sarcoma. Taken together, these findings pave the way for combined inhibition of GLUT1 and ATR/CHK1 as a therapeutic approach for KRAS-driven cancers. Significance: Dual targeting of the DNA damage response and glucose transport synergistically induces apoptosis in KRAS-mutant cancer, suggesting this combination treatment for clinical validation in KRAS-stratified tumor patients

Prognostic significance of NOD2/CARD15 variants in HLA-identical sibling hematopoietic stem cell transplantation: effect on long-term outcome is confirmed in 2 independent cohorts and may be modulated by the type of gastrointestinal decontamination

To assess the role of NOD2/CARD15 variants on the long-term outcome of allogeneic stem cell transplantation in a genetically homogeneous group, we extended our previous study (cohort I, n = 78) and typed DNA for NOD2/CARD15 single nucleotide polymorphisms (SNPs) from an additional 225 recipients and their HLA-identical sibling donors (cohort II) treated at four other European centers. Results of genotyping were compared with clinical outcome. The strong association of NOD2/CARD15 variants with transplantation-related mortality (TRM) was confirmed in univariate and multivariate analysis; TRM increased from 20% in cohort I/22% in cohort II in recipient/donor pairs without any NOD2/CARD15 variants to 47% in cohort I/32% in cohort II in the presence of one variant in either donor or recipient and further to 57% in cohort I/74% in cohort II in the presence of 2 or more variants (P < .002 in both cohorts). NOD2/CARD15 SNPs were not associated with relapse rate but had a strong impact on overall survival. In an analysis of center effects, the type of gastrointestinal decontamination was the only factor interfering with the prognostic significance of NOD2/CARD15 SNPs. Our data further support an interaction between gastrointestinal defense mechanisms, activation of the innate immune system, and specific transplant-related complications

The impact of frailty on survival in elderly intensive care patients with COVID-19: the COVIP study

Auteurs : COVIP study groupInternational audienceBackground The COVID-19 pandemic has led highly developed healthcare systems to the brink of collapse due to the large numbers of patients being admitted into hospitals. One of the potential prognostic indicators in patients with COVID-19 is frailty. The degree of frailty could be used to assist both the triage into intensive care, and decisions regarding treatment limitations. Our study sought to determine the interaction of frailty and age in elderly COVID-19 ICU patients. Methods A prospective multicentre study of COVID-19 patients ≥ 70 years admitted to intensive care in 138 ICUs from 28 countries was conducted. The primary endpoint was 30-day mortality. Frailty was assessed using the clinical frailty scale. Additionally, comorbidities, management strategies and treatment limitations were recorded. Results The study included 1346 patients (28% female) with a median age of 75 years (IQR 72–78, range 70–96), 16.3% were older than 80 years, and 21% of the patients were frail. The overall survival at 30 days was 59% (95% CI 56–62), with 66% (63–69) in fit, 53% (47–61) in vulnerable and 41% (35–47) in frail patients ( p < 0.001). In frail patients, there was no difference in 30-day survival between different age categories. Frailty was linked to an increased use of treatment limitations and less use of mechanical ventilation. In a model controlling for age, disease severity, sex, treatment limitations and comorbidities, frailty was independently associated with lower survival. Conclusion Frailty provides relevant prognostic information in elderly COVID-19 patients in addition to age and comorbidities. Trial registration Clinicaltrials.gov: NCT04321265 , registered 19 March 2020

Increased 30-day mortality in very old ICU patients with COVID-19 compared to patients with respiratory failure without COVID-19

Purpose The number of patients >= 80 years admitted into critical care is increasing. Coronavirus disease 2019 (COVID-19) added another challenge for clinical decisions for both admission and limitation of life-sustaining treatments (LLST). We aimed to compare the characteristics and mortality of very old critically ill patients with or without COVID-19 with a focus on LLST. Methods Patients 80 years or older with acute respiratory failure were recruited from the VIP2 and COVIP studies. Baseline patient characteristics, interventions in intensive care unit (ICU) and outcomes (30-day survival) were recorded. COVID patients were matched to non-COVID patients based on the following factors: age (+/- 2 years), Sequential Organ Failure Assessment (SOFA) score (+/- 2 points), clinical frailty scale (+/- 1 point), gender and region on a 1:2 ratio. Specific ICU procedures and LLST were compared between the cohorts by means of cumulative incidence curves taking into account the competing risk of discharge and death. Results 693 COVID patients were compared to 1393 non-COVID patients. COVID patients were younger, less frail, less severely ill with lower SOFA score, but were treated more often with invasive mechanical ventilation (MV) and had a lower 30-day survival. 404 COVID patients could be matched to 666 non-COVID patients. For COVID patients, withholding and withdrawing of LST were more frequent than for non-COVID and the 30-day survival was almost half compared to non-COVID patients. Conclusion Very old COVID patients have a different trajectory than non-COVID patients. Whether this finding is due to a decision policy with more active treatment limitation or to an inherent higher risk of death due to COVID-19 is unclear

The association of the Activities of Daily Living and the outcome of old intensive care patients suffering from COVID-19

Purpose: Critically ill old intensive care unit (ICU) patients suffering from Sars-CoV-2 disease (COVID-19) are at increased risk for adverse outcomes. This post hoc analysis investigates the association of the Activities of Daily Living (ADL) with the outcome in this vulnerable patient group. Methods: The COVIP study is a prospective international observational study that recruited ICU patients >= 70 years admitted with COVID-19 (NCT04321265). Several parameters including ADL (ADL; 0 = disability, 6 = no disability), Clinical Frailty Scale (CFS), SOFA score, intensive care treatment, ICU- and 3-month survival were recorded. A mixed-effects Weibull proportional hazard regression analyses for 3-month mortality adjusted for multiple confounders. Results: This pre-specified analysis included 2359 patients with a documented ADL and CFS. Most patients evidenced independence in their daily living before hospital admission (80% with ADL = 6). Patients with no frailty and no disability showed the lowest, patients with frailty (CFS >= 5) and disability (ADL < 6) the highest 3-month mortality (52 vs. 78%, p < 0.001). ADL was independently associated with 3-month mortality (ADL as a continuous variable: aHR 0.88 (95% CI 0.82-0.94, p < 0.001). Being "disable" resulted in a significant increased risk for 3-month mortality (aHR 1.53 (95% CI 1.19-1.97, p 0.001) even after adjustment for multiple confounders. Conclusion: Baseline Activities of Daily Living (ADL) on admission provides additional information for outcome prediction, although most critically ill old intensive care patients suffering from COVID-19 had no restriction in their ADL prior to ICU admission. Combining frailty and disability identifies a subgroup with particularly high mortality

Noninvasive ventilation in COVID-19 patients aged ≥ 70 years : a prospective multicentre cohort study

Background: Noninvasive ventilation (NIV) is a promising alternative to invasive mechanical ventilation (IMV) with a particular importance amidst the shortage of intensive care unit (ICU) beds during the COVID-19 pandemic. We aimed to evaluate the use of NIV in Europe and factors associated with outcomes of patients treated with NIV. Methods: This is a substudy of COVIP study-an international prospective observational study enrolling patients aged >= 70 years with confirmed COVID-19 treated in ICU. We enrolled patients in 156 ICUs across 15 European countries between March 2020 and April 2021.The primary endpoint was 30-day mortality. Results: Cohort included 3074 patients, most of whom were male (2197/3074, 71.4%) at the mean age of 75.7 years (SD 4.6). NIV frequency was 25.7% and varied from 1.1 to 62.0% between participating countries. Primary NIV failure, defined as need for endotracheal intubation or death within 30 days since ICU admission, occurred in 470/629 (74.7%) of patients. Factors associated with increased NIV failure risk were higher Sequential Organ Failure Assessment (SOFA) score (OR 3.73, 95% CI 2.36-5.90) and Clinical Frailty Scale (CFS) on admission (OR 1.46, 95% CI 1.06-2.00). Patients initially treated with NIV (n = 630) lived for 1.36 fewer days (95% CI - 2.27 to - 0.46 days) compared to primary IMV group (n = 1876). Conclusions: Frequency of NIV use varies across European countries. Higher severity of illness and more severe frailty were associated with a risk of NIV failure among critically ill older adults with COVID-19. Primary IMV was associated with better outcomes than primary NIV