Phosphorylation of CARMA1: the link(er) to NF-kappaB activation.

Antigen receptor-induced NF-kappaB activation depends on receptor-proximal and -distal signaling events. Two papers in this issue of Immunity demonstrate that PKC-dependent phosphorylation of CARMA1 is the critical molecular link that controls the activation of the IKK signalosome and NF-kappaB.

Tissue-specific opposing functions of the inflammasome adaptor ASC in the regulation of epithelial skin carcinogenesis.

A chronic inflammatory microenvironment favors tumor progression through molecular mechanisms that are still incompletely defined. In inflammation-induced skin cancers, IL-1 receptor- or caspase-1-deficient mice, or mice specifically deficient for the inflammasome adaptor protein ASC (apoptosis-associated speck-like protein containing a CARD) in myeloid cells, had reduced tumor incidence, pointing to a role for IL-1 signaling and inflammasome activation in tumor development. However, mice fully deficient for ASC were not protected, and mice specifically deficient for ASC in keratinocytes developed more tumors than controls, suggesting that, in contrast to its proinflammatory role in myeloid cells, ASC acts as a tumor-suppressor in keratinocytes. Accordingly, ASC protein expression was lost in human cutaneous squamous cell carcinoma, but not in psoriatic skin lesions. Stimulation of primary mouse keratinocytes or the human keratinocyte cell line HaCaT with UVB induced an ASC-dependent phosphorylation of p53 and expression of p53 target genes. In HaCaT cells, ASC interacted with p53 at the endogenous level upon UVB irradiation. Thus, ASC in different tissues may influence tumor growth in opposite directions: it has a proinflammatory role in infiltrating cells that favors tumor development, but it also limits keratinocyte proliferation in response to noxious stimuli, possibly through p53 activation, which helps suppressing tumors.

Molecular characterization of the Carma1-related protein card9

ABSTRACT : Fungal infections have become a major source of diseases in immuncompromised patients, but are quite benign in healthy individuals. As fungi are eukaryotes, and share many biological processes with humans, many antifungal drugs can cause toxicity in the patients. Therefore, the characterization of signaling pathways specific to the anti-fungal immune response is relevant for the better understanding of the disease and the development of new therapeutic approaches. Dectin-1 is the major mammalian pattern recognition receptor for the fungal component zymosan. Dectin-1 is an innate non-Toll-like receptor containing immunoreceptor tyrosine-based activation motifs (ITAMs). Card9, Bc110 and Maltl are proteins that have been shown to play a key role in the Dectin-l-induced signaliñg pathway by controlling Dectin-l-mediated cell activation, cytokine production and innate anti-fungal immunity in mice. Here we investigate the role of the Card9-Bc110-Maltl complex in humans using the monocytic cell line THP-1. We show that Card9 interacts with Bc110 through a CARD-CARD interaction and that interaction of Card9 with Bc110 is required for NF-xB activation. We further demonstrate that Card9 is phosphorylated in its C-terminal part on serine residues. The phosphorylation status of Card9 can influence its ability to active NF-xB, since mutation of the phosphorylation sites increases its ability to activate NF-xB. We find that Card9 is expressed in myeloid derived cells, such as the human monocytic cell lines THP1 and U937, and in human monocyte-enriched PBLs and monocyte-derived DCs. Our findings demonstrate that Card9 is implicated in anti-fungal responses, since silencing of Card9 as well as of Bc110 and Maltl diminishes the capacity of THP1 cells to produce TNF-a in response to zymosan. Interestingly, activation of the NF-xB and MAPK pathway remained normal and levels of TNF-a mRNA produced were also not affected in THP 1 cells silenced for the expression of Card9, Bc110 or Malt1. Using a Malt1 inhibitor, we provide evidence that the proteolytic activity of Malt1 is needed for zymosan-induced TNF-a production in THP 1 cells and bone marrow-derived macrophages of mice, but further experiments are required to confirm these findings and identify the substrate(s) of Malt1. In conclusion, our results reveal an important role for Card9 in the innate immune response of human macrophages to fungi. RÉSUMÉ : Les infections fongiques sont une source majeure de maladie chez les patients immunodéprimés, alors qu'elles sont plutôt bénignes chez les individus sains. Comme les champignons sont des eucaryotes et partagent beaucoup de processus biologiques avec les humains, les médicaments antifongiques peuvent être source de toxicité chez les patients. Il est donc important de mieux caractériser les voies de signalisation intracellulaire des réponses anti-fongiques pour pouvoir développer de nouvelles approches thérapeutiques. La protéine Dectin-1 est le récepteur principal du composé fongique zymosan. Les protéines Card9, Bc110 et Maltl ont été décrites comme jouant un rôle primordial dans les signaux d'activation induits par Dectin-l, en contrôlant l'activité cellulaire, la production de cytokines et la défense anti-fongique dans les souris. Dans cette étude, nous investiguons le rôle du complexe Card9-Bc110-Maltl dans la lignée monocytaire humaine THP1. Nous montrons que Card9 interagit avec Bc110 par une interaction CARD-CARD et que cette interaction est requise pour activer le facteur de transcription NF-xB. Nous observons que Card9 est phosphorylé dans sa partie C-terminale sur des résidus serine et que l'état de phosphorylation de Card9 influence sa capacité à activer NF-xB. En effet, sa capacité à activer NF-xB est augmentée, après mutation des sites de phosphorylation. La génération d'un anticorps spécifique dirigé contre Card9 nous a permis de démontrer que Card9 est exprimé dans des cellules myéloïdes comme les lignées cellulaires monocytiques THP-1 et U-937, ainsi que dans les cellules dendritiques humaines. Nos résultats démontrent que Card9 est impliqué dans la réponse immunitaire antifongique puisque la réduction de l'expression de Card9 ainsi que de Bc110 et de Malt1 diminue la capacité des THP-1 à produire du TNF-a en réponse au zymosan. Par contre, les voies de signalisation NF-xB et MAPK ainsi que les niveaux de mRNA de TNF-a produits en réponse au zymosan ne sont pas affectés dans ces cellules. En utilisant un inhibiteur de Malt1, nous montrons que l'activité protéolytique de Malt1 est nécessaire pour la production de TNF-a induite par le zymosan dans les cellules THP-1 ainsi que dans les macrophages de souris, mais d'autres expériences seront nécessaires pour confirmer cette observation et identifier le(s) substrat(s) de Malt1 responsables de cet effet. En conclusion, nos résultats révèlent un rôle important de la protéine Card9 dans la réponse immunitaire innée antifongique dans les macrophages humains.

Percutaneous coronary interventions prior to coronary artery bypass surgery.

BACKGROUND AND AIM OF THE STUDY: Percutaneous coronary interventions (PCI) are frequently performed before coronary artery bypass graft (CABG) surgery. This study sought to evaluate postoperative outcomes, and incidence of recurrent target ischemia in vessels with prior PCI in patients who had PCI prior to CABG compared to only CABG patients. METHODS: A review included CABG patients operated from 2000 to 2012. PCI prior to CABG patients were compared with patients having had CABG on native coronary arteries. Demographic and risk factors, including hospital morbidity, mortality, and recurrent target vessel ischemia at follow-up (FU), were compared. Major end-points were statistical differences of postoperative morbidity and reintervention rates due to symptomatic graft failure or target vessel ischemia during FU. RESULTS: Twenty-four percent of 1669 isolated CABG patients had PCI prior to CABG, with an increasing percentage during recent years. Demographics, risk factors, comorbidities and mortality rates were similar. Incidence of postoperative hemorrhage (OR 1.9; 95% CI 1.1-3.2; p = 0.02), perioperative myocardial infarction rate (p = 0.02), neurological deficits (OR 3.5; 95% CI 1.2-9.7; p = 0.02) and re-intervention rate for symptomatic graft or target vessel occlusion were higher in pretreated patients (OR 1.8; 95% CI 1.1-3.0; p = 0.01). CONCLUSIONS: PCI prior to CABG increases the risk for postoperative morbidity. Increased postoperative hemorrhage could be attributed to ongoing double anti-platelet therapy. doi: 10.1111/jocs.12514 (J Card Surg 2015;30:313-318).

Risk Behavior and Reciprocity of Organ Donation Attitudes in Young Men.

BACKGROUND: Lack of donor organs remains a major obstacle in organ transplantation. Our aim was to evaluate (1) the association between engaging in high-risk recreational activities and attitudes toward organ donation and (2) the degree of reciprocity between organ acceptance and donation willingness in young men. METHODS: A 17-item, close-ended survey was offered to male conscripts ages 18 to 26 years in all Swiss military conscription centers. Predictors of organ donation attitudes were assessed in bivariate analyses and multiple logistic regression. Reciprocity of the intentions to accept and to donate organs was assessed by means of donor card status. RESULTS: In 1559 responses analyzed, neither motorcycling nor practicing extreme sports reached significant association with donor card holder status. Family communication about organ donation, student, or academic profession and living in a Latin linguistic region were predictors of positive organ donation attitudes, whereas residence in a German-speaking region and practicing any religion predicted reluctance. Significantly more respondents were willing to accept than to donate organs, especially among those without family communication concerning organ donation. CONCLUSIONS: For the first time, it was shown that high-risk recreational activities do not influence organ donation attitudes. Second, a considerable discrepancy in organ donation reciprocity was identified. We propose that increasing this reciprocity could eventually increase organ donation rates.