Treatment with p33 Curtails Morbidity and Mortality in a Histone-Induced Murine Shock Model.

Collateral damage caused by extracellular histones has an immediate impact on morbidity and mortality in many disease models. A significant increase in the levels of extracellular histones is seen in critically ill patients with trauma and sepsis. We showed that histones are released from necrotic cells in patients with invasive skin infections. Under in vitro conditions, endogenous p33, an endothelial surface protein also known as the gC1q receptor, interacts with histones released from damaged endothelial cells. Functional analyses have revealed that recombinantly expressed p33 completely neutralizes the harmful features of histones, i.e. hemolysis of erythrocytes, lysis of endothelial cells and platelet aggregation. We also noted that mice treated with a sublethal dose of histones developed severe signs of hemolysis, thrombocytopenia and lung tissue damage already 10 min after inoculation. These complications were fully counteracted when p33 was administered together with the histones. Moreover, application of p33 significantly improved survival in mice receiving an otherwise lethal dose of histones. Together, our data suggest that treatment with p33 is a promising therapeutic approach in severe infectious diseases. © 2014 S. Karger AG, Basel

Hybrid Metal-Organic Framework-Cellulose Materials Retaining High Porosity: ZIF-8@Cellulose Nanofibrils

Metal-organic frameworks have attracted a great deal of attention for future applications in numerous areas, including gas adsorption. However, in order for them to reach their full potential a substrate to provide an anchor may be needed. Ideally, this substrate should be environmentally friendly and renewable. Cellulose nanofibrils show potential in this area. Here we present a hybrid material created from the self-assembly of zeolitic imidazolate framework (ZIF-8) nanocrystals on cellulose nanofibrils (CNF) in aqueous medium. The CNF/ZIF-8 was freeze dried and formed free standing materials suitable for gas adsorption. A BET area of 1014 m2 g−1 was achieved for the CNF/ZIF-8 hybrid materials ZIF-8@cellulose which is comparable with reported values for free standing ZIF-8 materials, 1600 m2 g−1, considering the dilution with cellulose, and a considerable enhancement compared to CNF on its own, 32 m2 g−1

Composites with surface-grafted cellulose nanocrystals (CNC)

Hydroxyazetidinium salts were used to surface-modify cellulose nanocrystals (CNC) by grafting the salts onto the sulphate ester groups on the CNC surfaces. The grafting was confirmed by ζ-potential measurements and by the thermal degradation behaviour of the modified CNC. The thermal stability (onset of degradation) of the CNC was improved by the surface modification (almost 100\ua0\ub0C). Composites containing surface-modified or unmodified CNC (0.1, 1.0 and 10\ua0wt%) with an ethylene-based copolymer as matrix were produced by compression moulding. The thermal stability of the composites was not, however, markedly improved by the surface grafting onto the CNC. It is suggested that this is due to a degrafting mechanism, associated with the alkaline character of the system, taking place at high temperatures. Model experiments indicated, however, that this did not occur at the conditions under which the composites were produced. Furthermore, in the case of a reference based on pH-neutralised polymeric system and modified CNC, an upward shift in the onset of thermal degradation of the composite was observed. The addition of the CNC to the polymer matrix had a strong influence of the mechanical performance. For example, the tensile modulus increased approximately three times for some systems when adding 10\ua0wt% CNC. The surface grafting of the hydroxyazetidinium salts appeared mainly to affect, in a positive sense, the yield behaviour and ductility of the composites. The results of the mechanical testing are discussed in terms of interactions between the grafted units and the matrix material and between the grafted groups

The fungal peptide toxin Candidalysin activates the NLRP3 inflammasome and causes cytolysis in mononuclear phagocytes

Clearance of invading microbes requires phagocytes of the innate immune system. However, successful pathogens have evolved sophisticated strategies to evade immune killing. The opportunistic human fungal pathogen Candida albicans is efficiently phagocytosed by macrophages, but causes inflammasome activation, host cytolysis, and escapes after hypha formation. Previous studies suggest that macrophage lysis by C. albicans results from early inflammasome-dependent cell death (pyroptosis), late damage due to glucose depletion and membrane piercing by growing hyphae. Here we show that Candidalysin, a cytolytic peptide toxin encoded by the hypha-associated gene ECE1, is both a central trigger for NLRP3 inflammasome-dependent caspase-1 activation via potassium efflux and a key driver of inflammasome-independent cytolysis of macrophages and dendritic cells upon infection with C. albicans. This suggests that Candidalysin-induced cell damage is a third mechanism of C. albicans-mediated mononuclear phagocyte cell death in addition to damage caused by pyroptosis and the growth of glucose-consuming hyphae

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Host modulation of excessive innate immune responses

A fundamental role of the innate immune system is to elicit a proper response against both invading pathogens and tissue damage or danger signals. Although the innate immune system often is successful in eliminating danger, an excessive host-response can result in severe tissue injury. Factors that contribute to the elimination of the microbe are the same factors that cause tissue injury. Therefore, innate immune response has to be carefully balanced to avoid excessive inflammation with systemic consequences. The first part of this thesis is focused on molecular interactions between host-defense peptides and p33 (globular C1q receptor), a protein that can modulate cell injury. We show in vitro how recombinant p33 binds and neutralizes cytotoxic effects of the host-defense peptides human beta defensin 3 and LL-37. Moreover, treatment with p33 was also shown to modulate the sepsis-like pathogenesis caused by extracellular histones and rescue mice in a histone-induced shock model. Extracellular histones are released into tissue and circulation after cell necrosis or neutrophil extracellular trap formation. They are found in patients with severe inflammatory diseases and contribute to disease progression. However, for the first time, we have shown that extracellular histones contribute to resolving local inflammation. Low concentrations of extracellular histones contribute to innate immunity by inducing chemokine production and leukocyte recruitment which might be beneficial for the host. The final part of this thesis describes a novel defense mechanism of microvesicles against the gram-positive bacterium Streptococcus pyogenes. We show that procoagulant microvesicles are released after stimulation of pheripheral blood mononuclear cells with M1 protein from S. pyogenes. These microvesicles bind to the surface of bacteria, induce clotting and thereby prevent bacterial dissemination in vivo. In conclusion, this thesis describes new mechanisms involved in host defense as well as mechanisms involved in the modulation of excessive immune responses

Implementing ICBT : An interview study of internet therapists' experiences of implementation.

Internetbaserad kognitiv beteendeterapi (IKBT) för olika former av psykisk ohälsa har presenterats som ett alternativ till traditionell samtalsbehandling baserat på forskning från det senaste decenniet. Trots klinisk relevans och flera fördelar för patienter och behandlare går implementeringen långsamt i flera europeiska länder. Syftet med den föreliggande studien var att undersöka behandlares erfarenheter av att implementera IKBT i sina verksamheter. Intervjuer genomfördes med åtta behandlare hos en svensk offentlig vårdgivare, varefter en tematisk analys gjordes. Fyra huvudteman arbetades fram: En ny metod, En ny roll, Premisser och Lärande. Behandlarna har en övergripande samstämmighet och förståelse kring IKBT och dess användning, vilket är en viktig aspekt av implementeringen. Behandlarna beskriver dock också att kollegor som inte arbetar med behandling, men har en roll i implementeringen, ibland har bristande kunskap och negativa fördomar som förhindrar arbetet. Vidare berättar behandlarna att organiserat samarbete mellan aktiva behandlare bortprioriteras i den kliniska vardagen. Resultaten från analysen diskuteras med utgångspunkt i Normalization Process Theory. Vidare forskning kan utforska upplevelsen hos IKBT-utbildade behandlare som inte börjat arbeta med IKBT och hos icke-behandlande kollegor på arbetsplatser där metoden implementeras.Internet-based Cognitive Behavioral Therapy (ICBT) for different kinds of mental health issues has been presented as an alternative to traditional face-to-face treatment based on research from the last decade. Despite clinical relevance and several advantages for both patients and therapists the implementation of the method is progressing slowly in many European countries. The purpose of this study was to examine therapists’ experiences of implementing ICBT in their everyday work. Interviews were conducted with eight therapists in a Swedish public health care setting, after which a thematic analysis was made. Four main themes were defined: A new method, A new role, Premises and Learning. The therapists have an overarching mutual comprehension of ICBT and its use, which is an important aspect of the implementation. The therapists explained that colleagues that don't work with ICBT, but still have a role in the implementation, sometimes lack knowledge and have negative preconceptions which obstruct the work. Furthermore, therapists talked about organized collaboration between active therapists not being prioritized in the everyday clinical work. Results from the analysis are discussed by applying Normalization Process Theory to the findings. Further research could examine the experiences of ICBT-trained therapists who have not yet started working with ICBT and of colleagues who do not work with treatment in workplaces where ICBT is being implemented

Phagocytosis of Necrotic Debris at Sites of Injury and Inflammation

Clearance of cellular debris is required to maintain the homeostasis of multicellular organisms. It is intrinsic to processes such as tissue growth and remodeling, regeneration and resolution of injury and inflammation. Most of the removal of effete and damaged cells is performed by macrophages and neutrophils through phagocytosis, a complex phenomenon involving ingestion and degradation of the disposable particles. The study of the clearance of cellular debris has been strongly biased toward the removal of apoptotic bodies; as a result, the mechanisms underlying the removal of necrotic cells have remained relatively unexplored. Here, we will review the incipient but growing knowledge of the phagocytosis of necrotic debris, from their recognition and engagement to their internalization and disposal. Critical insights into these events were gained recently through the development of new in vitro and in vivo models, along with advances in live-cell and intravital microscopy. This review addresses the classes of "find-me" and "eat-me" signals presented by necrotic cells and their cognate receptors in phagocytes, which in most cases differ from the extensively characterized counterparts in apoptotic cell engulfment. The roles of damage-associated molecular patterns, chemokines, lipid mediators, and complement components in recruiting and activating phagocytes are reviewed. Lastly, the physiological importance of necrotic cell removal is emphasized, highlighting the key role of impaired debris clearance in autoimmunity.status: publishe

Candida albicans Hyphal Expansion Causes Phagosomal Membrane Damage and Luminal Alkalinization

C. albicans is the most common cause of nosocomial fungal infection, and over 3 million people acquire life-threatening invasive fungal infections every year. Even if antifungal drugs exist, almost half of these patients will die. Despite this, fungi remain underestimated as pathogens. Our study uses quantitative biophysical approaches to demonstrate that yeast-to-hypha transition occurs within the nutrient-deprived, acidic phagosome and that alkalinization is a consequence, as opposed to the cause, of hyphal growth.Macrophages rely on phagosomal acidity to destroy engulfed microorganisms. To survive this hostile response, opportunistic fungi such as Candida albicans developed strategies to evade the acidic environment. C. albicans is polymorphic and able to convert from yeast to hyphae, and this transition is required to subvert the microbicidal activity of the phagosome. However, the phagosomal lumen, which is acidic and nutrient deprived, is believed to inhibit the yeast-to-hypha transition. To account for this apparent paradox, it was recently proposed that C. albicans produces ammonia that alkalinizes the phagosome, thus facilitating yeast-to-hypha transition. We reexamined the mechanism underlying phagosomal alkalinization by applying dual-wavelength ratiometric pH measurements. The phagosomal membrane was found to be highly permeable to ammonia, which is therefore unlikely to account for the pH elevation. Instead, we find that yeast-to-hypha transition begins within acidic phagosomes and that alkalinization is a consequence of proton leakage induced by excessive membrane distension caused by the expanding hypha