Regulation of mRNA translation by a photoriboswitch.

Optogenetic tools have revolutionized the study of receptor-mediated processes, but such tools are lacking for RNA-controlled systems. In particular, light-activated regulatory RNAs are needed for spatiotemporal control of gene expression. To fill this gap, we used in vitro selection to isolate a novel riboswitch that selectively binds the trans isoform of a stiff-stilbene (amino-tSS)-a rapidly and reversibly photoisomerizing small molecule. Structural probing revealed that the RNA binds amino-tSS about 100-times stronger than the cis photoisoform (amino-cSS). In vitro and in vivo functional analysis showed that the riboswitch, termed Werewolf-1 (Were-1), inhibits translation of a downstream open reading frame when bound to amino-tSS. Photoisomerization of the ligand with a sub-millisecond pulse of light induced the protein expression. In contrast, amino-cSS supported protein expression, which was inhibited upon photoisomerization to amino-tSS. Reversible photoregulation of gene expression using a genetically encoded RNA will likely facilitate high-resolution spatiotemporal analysis of complex RNA processes

Influence of cryorolling on properties of L-PBF 316l stainless steel tested at 298K and 77K

The goal of the present work is to evaluate mechanical properties and to analyse the microstructure of 316L stainless steel produced by Laser Powder Bed Fusion (L-PBF) follow by rolling with different thickness reduction under ambient and cryogenic conditions. The samples before rolling were heat treated. The static tensile test was realized at ambient and cryogenic (77K) conditions. The L-PBF powder metal production technology approved that is a key technology in the additive manufacturing (AM) area, especially for metal powder materials. Mechanical properties tested at 298K and 77K shows that the application of various thermo-deformation rolling conditions increases of strength properties. Achieved mechanical properties are comparable to conventional bulk materials. The strength properties after the rolling under ambient and cryogenic conditions were significantly increased

Alphabetisierung - bloß berufliche Notwendigkeit oder mehr?

Anstrengungen zur Verringerung der unzureichend gegebenen Elementarbildung jener Bevölkerungsgruppe, auf die hierzulande die Bezeichnung „AnalphabetInnen“ zutrifft, werden derzeit – so wie Bildungsbemühungen generell – fast durchwegs unter dem Gesichtspunkt des gesellschaftlichen Tausch- bzw. Marktwerts argumentiert. Sie gelten als eine Investition in die „Ressource Mensch“ – auf einen darüber hinausgehenden humanitären oder politischen Wert wird nur selten Bezug genommen. Auch wenn die Bedeutung der Kulturtechniken im Rahmen der ökonomischen Verwertung menschlicher Arbeitskraft selbstverständlich nicht ignoriert werden kann, bedeutet die Befähigung der Menschen zur schriftlichen Kommunikation weit mehr als ihre Zurichtung zu verwertbarem Humankapital. Literalität ist ein grundsätzlicher Aspekt der „Menschwerdung“ des Menschen, sie erst ermöglicht dem einzelnen Individuum eine Teilhabe am kulturellen und gesellschaftlichen Leben, darüber hinaus und darauf aufbauend aber auch die fortschreitende Emanzipation des Menschengeschlechts insgesamt. Die Teilhabemöglichkeit an der menschlichen Gemeinschaft ist nicht bloß ein Vorteil unter vielen anderen, der auf der gleichen Ebene wie die Möglichkeit, seine Arbeitskraft lukrativ verkaufen zu können, angesiedelt ist. Es geht dabei um wesentlich mehr – in letzter Konsequenz um die Überwindung der die Gesellschaft in allen Aspekten bestimmenden Verwertungsprämisse. (DIPF/Orig.

Critical care workers have lower seroprevalence of SARS-CoV-2 IgG compared with non-patient facing staff in first wave of COVID19

With the first 2020 surge of the COVID-19 pandemic, many health care workers (HCW) were re-deployed to critical care environments to support intensive care teams to look after high numbers of patients with severe COVID-19. There was considerable anxiety of increased risk of COVID19 for staff working in these environments. Using a multiplex platform to assess serum IgG responses to SARS-CoV-2 N, S and RBD proteins, and detailed symptom reporting, we screened over 500 HCW (25% of the total workforce) in a quaternary level hospital to explore the relationship between workplace and evidence of exposure to SARS-CoV-2. Whilst 45% of the cohort reported symptoms that they consider may have represented COVID-19, overall seroprevalence was 14% with anosmia and fever being the most discriminating symptoms for seropositive status. There was a significant difference in seropositive status between staff working in clinical and non-clinical roles (9% patient facing critical care, 15% patient facing non-critical care, 22% nonpatient facing). In the seropositive cohort, symptom severity increased with age for men and not for women. In contrast, there was no relationship between symptom severity and age or sex in the seronegative cohort reporting possible COVID-19 symptoms. Of the 12 staff screened PCR positive (10 symptomatic), 3 showed no evidence of seroconversion in convalescence. Conclusion The current approach to Personal Protective Equipment (PPE) appears highly effective in protecting staff from patient acquired infection in the critical care environment including protecting staff managing interhospital transfers of COVID-19 patients. The relationship between seroconversion and disease severity in different demographics warrants further investigation. Longitudinally paired virological and serological surveillance, with symptom reporting are urgently required to better understand the role of antibody in the outcome of HCW exposure during subsequent waves of COVID-19 in health care environments

High fat, high sucrose diet causes cardiac mitochondrial dysfunction due in part to oxidative post-translational modification of mitochondrial complex II

Abstract not availableAaron L. Sverdlov, Aly Elezaby, Jessica B. Behring, Markus M. Bachschmid, Ivan Luptak, Vivian H. Tu, Deborah A. Siwik, Edward J. Miller, Marc Liesa, Orian S. Shirihai, David R. Pimentel, Richard A. Cohen, Wilson S. Colucc

Decreased ATP production and myocardial contractile reserve in metabolic heart disease

Available online 01 February 2018Metabolic syndrome is a cluster of obesity-related metabolic abnormalities that lead to metabolic heart disease (MHD) with left ventricular pump dysfunction. Although MHD is thought to be associated with myocardial energetic deficiency, two key questions have not been answered. First, it is not known whether there is a sufficient energy deficit to contribute to pump dysfunction. Second, the basis for the energy deficit is not clear. To address these questions, mice were fed a high fat, high sucrose (HFHS) 'Western' diet to recapitulate the MHD phenotype. In isolated beating hearts, we used 31P NMR spectroscopy with magnetization transfer to determine a) the concentrations of high energy phosphates ([ATP], [ADP], [PCr]), b) the free energy of ATP hydrolysis (∆G~ATP), c) the rate of ATP production and d) flux through the creatine kinase (CK) reaction. At the lowest workload, the diastolic pressure-volume relationship was shifted upward in HFHS hearts, indicative of diastolic dysfunction, whereas systolic function was preserved. At this workload, the rate of ATP synthesis was decreased in HFHS hearts, and was associated with decreases in both [PCr] and ∆G~ATP. Higher work demands unmasked the inability of HFHS hearts to increase systolic function and led to a further decrease in ∆G~ATP to a level that is not sufficient to maintain normal function of sarcoplasmic Ca2+-ATPase (SERCA). While [ATP] was preserved at all work demands in HFHS hearts, the progressive increase in [ADP] led to a decrease in ∆G~ATP with increased work demands. Surprisingly, CK flux, CK activity and total creatine were normal in HFHS hearts. These findings differ from dilated cardiomyopathy, in which the energetic deficiency is associated with decreases in CK flux, CK activity and total creatine. Thus, in HFHS-fed mice with MHD there is a distinct metabolic phenotype of the heart characterized by a decrease in ATP production that leads to a functionally-important energetic deficiency and an elevation of [ADP], with preservation of CK flux.Ivan Luptak, Aaron L. Sverdlov, Marcello Panagia, Fuzhong Qin, David R. Pimentel, Dominique Croteau, Deborah A. Siwik, Joanne S. Ingwall, Markus M. Bachschmid, James A. Balschi, Wilson S. Colucc

Mitochondrial reactive oxygen species mediate cardiac structural, functional, and mitochondrial consequences of diet-induced metabolic heart disease

Mitochondrial reactive oxygen species (ROS) are associated with metabolic heart disease (MHD). However, the mechanism by which ROS cause MHD is unknown. We tested the hypothesis that mitochondrial ROS are a key mediator of MHD.Mice fed a high-fat high-sucrose (HFHS) diet develop MHD with cardiac diastolic and mitochondrial dysfunction that is associated with oxidative posttranslational modifications of cardiac mitochondrial proteins. Transgenic mice that express catalase in mitochondria and wild-type mice were fed an HFHS or control diet for 4 months. Cardiac mitochondria from HFHS-fed wild-type mice had a 3-fold greater rate of H2O2 production (P=0.001 versus control diet fed), a 30% decrease in complex II substrate-driven oxygen consumption (P=0.006), 21% to 23% decreases in complex I and II substrate-driven ATP synthesis (P=0.01), and a 62% decrease in complex II activity (P=0.002). In transgenic mice that express catalase in mitochondria, all HFHS diet-induced mitochondrial abnormalities were ameliorated, as were left ventricular hypertrophy and diastolic dysfunction. In HFHS-fed wild-type mice complex II substrate-driven ATP synthesis and activity were restored ex vivo by dithiothreitol (5 mmol/L), suggesting a role for reversible cysteine oxidative posttranslational modifications. In vitro site-directed mutation of complex II subunit B Cys100 or Cys103 to redox-insensitive serines prevented complex II dysfunction induced by ROS or high glucose/high palmitate in the medium.Mitochondrial ROS are pathogenic in MHD and contribute to mitochondrial dysfunction, at least in part, by causing oxidative posttranslational modifications of complex I and II proteins including reversible oxidative posttranslational modifications of complex II subunit B Cys100 and Cys103.Aaron L. Sverdlov, Aly Elezaby, Fuzhong Qin, Jessica B. Behring, Ivan Luptak, Timothy D. Calamaras, Deborah A. Siwik, Edward J. Miller, Marc Liesa, Orian S. Shirihai, David R. Pimentel, Richard A. Cohen, Markus M. Bachschmid, Wilson S. Colucc

Partial Liver Kinase B1 (LKB1) Deficiency Promotes Diastolic Dysfunction, De Novo Systolic Dysfunction, Apoptosis, and Mitochondrial Dysfunction with Dietary Metabolic Challenge

Background - Myocardial hypertrophy and dysfunction are key features of metabolic heart disease due to dietary excess. Metabolic heart disease manifests primarily as diastolic dysfunction but may progress to systolic dysfunction, although the mechanism is poorly understood. Liver kinase B1 (LKB1) is a key activator of AMP-activated protein kinase and possibly other signaling pathways that oppose myocardial hypertrophy and failure. We hypothesized that LKB1 is essential to the heart's ability to withstand the metabolic stress of dietary excess. Methods and Results - Mice heterozygous for cardiac LKB1 were fed a control diet or a high-fat, high-sucrose diet for 4 months. On the control diet, cardiac LKB1 hearts had normal structure and function. After 4 months of the high-fat, high-sucrose diet, there was left ventricular hypertrophy and diastolic dysfunction in wild-type mice. In cardiac LKB1 (versus wild-type) mice, high-fat, high-sucrose feeding caused more hypertrophy (619 versus 553 μm(2), P<0.05), the de novo appearance of systolic dysfunction (left ventricular ejection fraction; 41% versus 59%, P<0.01) with left ventricular dilation (3.6 versus 3.2 mm, P<0.05), and more severe diastolic dysfunction with progression to a restrictive filling pattern (E/A ratio; 5.5 versus 1.3, P=0.05). Myocardial dysfunction in hearts of cardiac LKB1 mice fed the high-fat, high-sucrose diet was associated with evidence of increased apoptosis and apoptotic signaling via caspase 3 and p53/PUMA (p53 upregulated modulator of apoptosis) and more severe mitochondrial dysfunction. Conclusions - Partial deficiency of cardiac LKB1 promotes the adverse effects of a high-fat, high-sucrose diet on the myocardium, leading to worsening of diastolic function and the de novo appearance of systolic dysfunction. LKB1 plays a key role in protecting the heart from the consequences of metabolic stress.Edward J. Miller, Timothy Calamaras, Aly Elezaby, Aaron Sverdlov, Fuzhong Qin, Ivan Luptak, Ke Wang, Xinxin Sun, Andrea Vijay, Dominique Croteau, Markus Bachschmid, Richard A. Cohen, Kenneth Walsh, Wilson S. Colucc

Strangeness enhancement at mid-rapidity in Pb-Pb collisions at 158 GeV/c

$K^{0}_{s}$, $\Lambda$, $\Xi$, $\Omega$ and negative particle yields and transverse mass spectra have been measured at central rapidity in Pb-Pb and p-Pb collisions at 158 $A$ GeV/$c$. The yields in Pb-Pb interactions % are presented as a function of the collision centrality and compared with those obtained from p-Pb collisions. Strangeness enhancement in Pb-Pb relative to p-Pb collisions increases with the strangeness content of the particle. Going from p-Pb to Pb-Pb, the strange particle yields increase faster than linearly with the number of participants $N_{part}$ up to $N_{part} \approx 100$, thereafter the increase becomes %linear with $N_{part}$. Yields are studied as a function of the number of nucleons participating in the collision $N_{part}$, which is estimated with the Glauber model. From p-Pb to Pb-Pb collisions the particle yields per participant increase substantially. The enhancement is more pronounced for multistrange particles, and exceeds an order of magnitude for the $\Omega$. For a number of participants, $N_{part}$, greater than $100$, however, all yields per participant appear to be constant