Co-chaperones are limiting in a depleted chaperone network

To probe the limiting nodes in the chaperoning network which maintains cellular proteostasis, we expressed a dominant negative mutant of heat shock factor 1 (dnHSF1), the regulator of the cytoplasmic proteotoxic stress response. Microarray analysis of non-stressed dnHSF1 cells showed a two- or more fold decrease in the transcript level of 10 genes, amongst which are the (co-)chaperone genes HSP90AA1, HSPA6, DNAJB1 and HSPB1. Glucocorticoid signaling, which requires the Hsp70 and the Hsp90 folding machines, was severely impaired by dnHSF1, but fully rescued by expression of DNAJA1 or DNAJB1, and partially by ST13. Expression of DNAJB6, DNAJB8, HSPA1A, HSPB1, HSPB8, or STIP1 had no effect while HSP90AA1 even inhibited. PTGES3 (p23) inhibited only in control cells. Our results suggest that the DNAJ co-chaperones in particular become limiting in a depleted chaperoning network. Our results also suggest a difference between the transcriptomes of cells lacking HSF1 and cells expressing dnHSF1

Endogenous retrovirus-K promoter: a landing strip for inflammatory transcription factors?

Humans are symbiotic organisms; our genome is populated with a substantial number of endogenous retroviruses (ERVs), some remarkably intact, while others are remnants of their former selves. Current research indicates that not all ERVs remain silent passengers within our genomes; re-activation of ERVs is often associated with inflammatory diseases. ERVK is the most recently endogenized and transcriptionally active ERV in humans, and as such may potentially contribute to the pathology of inflammatory disease. Here, we showcase the transcriptional regulation of ERVK. Expression of ERVs is regulated in part by epigenetic mechanisms, but also depends on transcriptional regulatory elements present within retroviral long terminal repeats (LTRs). These LTRs are responsive to both viral and cellular transcription factors; and we are just beginning to appreciate the full complexity of transcription factor interaction with the viral promoter. In this review, an exploration into the inflammatory transcription factor sites within the ERVK LTR will highlight the possible mechanisms by which ERVK is induced in inflammatory diseases

Regional Practice Variation and Outcomes in the Standard Versus Accelerated Initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) Trial: A Post Hoc Secondary Analysis

OBJECTIVES: Among patients with severe acute kidney injury (AKI) admitted to the ICU in high-income countries, regional practice variations for fluid balance (FB) management, timing, and choice of renal replacement therapy (RRT) modality may be significant. DESIGN: Secondary post hoc analysis of the STandard vs. Accelerated initiation of Renal Replacement Therapy in Acute Kidney Injury (STARRT-AKI) trial (ClinicalTrials.gov number NCT02568722). SETTING: One hundred-fifty-three ICUs in 13 countries. PATIENTS: Altogether 2693 critically ill patients with AKI, of whom 994 were North American, 1143 European, and 556 from Australia and New Zealand (ANZ). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Total mean FB to a maximum of 14 days was +7199 mL in North America, +5641 mL in Europe, and +2211 mL in ANZ (p < 0.001). The median time to RRT initiation among patients allocated to the standard strategy was longest in Europe compared with North America and ANZ (p < 0.001; p < 0.001). Continuous RRT was the initial RRT modality in 60.8% of patients in North America and 56.8% of patients in Europe, compared with 96.4% of patients in ANZ (p < 0.001). After adjustment for predefined baseline characteristics, compared with North American and European patients, those in ANZ were more likely to survive to ICU (p < 0.001) and hospital discharge (p < 0.001) and to 90 days (for ANZ vs. Europe: risk difference [RD], -11.3%; 95% CI, -17.7% to -4.8%; p < 0.001 and for ANZ vs. North America: RD, -10.3%; 95% CI, -17.5% to -3.1%; p = 0.007). CONCLUSIONS: Among STARRT-AKI trial centers, significant regional practice variation exists regarding FB, timing of initiation of RRT, and initial use of continuous RRT. After adjustment, such practice variation was associated with lower ICU and hospital stay and 90-day mortality among ANZ patients compared with other regions

Faut-il proposer la ventilation non ionvasive aux patients en insuffisance respiratoire aigue pour lesquels l’intubation n’est plus une option thérapeutique

Paris SRLF 2012. 18-20 janvier.SO87.info:eu-repo/semantics/publishe

Effect of Cyclosporine in Nonshockable Out-of-Hospital Cardiac Arrest: The CYRUS Randomized Clinical Trial

International audienceIMPORTANCE: Experimental evidence suggests that cyclosporine prevents postcardiac arrest syndrome by attenuating the systemic ischemia reperfusion response. OBJECTIVE: To determine whether early administration of cyclosporine at the time of resuscitation in patients with out-of-hospital cardiac arrest (OHCA) would prevent multiple organ failure. DESIGN, SETTING, AND PARTICIPANTS: A multicenter, single-blind, randomized clinical trial was conducted from June 22, 2010, to March 13, 2013 (Cyclosporine A in Out-of-Hospital Cardiac Arrest Resuscitation [CYRUS]). Sixteen intensive care units in 7 university-affiliated hospitals and 9 general hospitals in France participated. A total of 6758 patients who experienced nonshockable OHCA (ie, asystole or pulseless electrical activity) were assessed for eligibility. Analyses were performed according to the intention-to-treat analysis. INTERVENTIONS: Patients received an intravenous bolus injection of cyclosporine, 2.5 mg/kg, at the onset of advanced cardiovascular life support (cyclosporine group) or no additional intervention (control group). MAIN OUTCOMES AND MEASURES: The primary end point was the Sequential Organ Failure Assessment (SOFA) score, assessed 24 hours after hospital admission, which ranges from 0 to 24 (with higher scores indicating more severe organ failure). Secondary end points included survival at 24 hours, hospital discharge, and favorable neurologic outcome at discharge. RESULTS: Of the 6758 patients screened, 794 were included in intention-to-treat analysis (cyclosporine, 400; control, 394). The median (interquartile range [IQR]) ages were 63.0 (54.0-71.8) years for the cyclosporine group and 66.0 (57.0-74.0) years for the control group. The cohorts included 293 men (73.3%) in the treatment group and 288 men (73.1%) in the control group. At 24 hours after hospital admission, the SOFA score was not significantly different between the cyclosporine (median, 10.0; IQR, 7.0-13.0) and the control (median, 11.0; IQR, 7.0-15.0) groups. Survival was not significantly different between the 98 (24.5%) cyclosporine vs 101 (25.6%) control patients at hospital admission (adjusted odds ratio [aOR], 0.94; 95% CI, 0.66-1.34), at 24 hours for 67 (16.8%) vs 62 (15.7%) patients (aOR, 1.08; 95% CI, 0.71-1.63), and at hospital discharge for 10 (2.5%) vs 5 (1.3%) patients (aOR, 2.00; 95% CI, 0.61-6.52). Favorable neurologic outcome at discharge was comparable between the cyclosporine and control groups: 7 (1.8%) vs 5 (1.3%) patients (aOR, 1.39; 95% CI, 0.39-4.91). CONCLUSION AND RELEVANCE: In patients presenting with nonshockable cardiac rhythm after OHCA, cyclosporine does not prevent early multiple organ failure. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01595958; EudraCT Identifier: 2009-015725-37

Essential Role of Chromatin Assembly Factor-1–mediated Rapid Nucleosome Assembly for DNA Replication and Cell Division in Vertebrate Cells

Chromatin assembly factor-1 (CAF-1), a complex consisting of p150, p60, and p48 subunits, is highly conserved from yeast to humans and facilitates nucleosome assembly of newly replicated DNA in vitro. To investigate roles of CAF-1 in vertebrates, we generated two conditional DT40 mutants, respectively, devoid of CAF-1p150 and p60. Depletion of each of these CAF-1 subunits led to delayed S-phase progression concomitant with slow DNA synthesis, followed by accumulation in late S/G(2) phase and aberrant mitosis associated with extra centrosomes, and then the final consequence was cell death. We demonstrated that CAF-1 is necessary for rapid nucleosome formation during DNA replication in vivo as well as in vitro. Loss of CAF-1 was not associated with the apparent induction of phosphorylations of S-checkpoint kinases Chk1 and Chk2. To elucidate the precise role of domain(s) in CAF-1p150, functional dissection analyses including rescue assays were preformed. Results showed that the binding abilities of CAF-1p150 with CAF-1p60 and DNA polymerase sliding clamp proliferating cell nuclear antigen (PCNA) but not with heterochromatin protein HP1-γ are required for cell viability. These observations highlighted the essential role of CAF-1–dependent nucleosome assembly in DNA replication and cell proliferation through its interaction with PCNA