CLEC-1 Restrains Acute Inflammatory Response and Recruitment of Neutrophils following Tissue Injury.

The inflammatory response is a key mechanism for the elimination of injurious agents but must be tightly controlled to prevent additional tissue damage and progression to persistent inflammation. C-type lectin receptors expressed mostly by myeloid cells play a crucial role in the regulation of inflammation by recognizing molecular patterns released by injured tissues. We recently showed that the C-type lectin receptor CLEC-1 is able to recognize necrotic cells. However, its role in the acute inflammatory response following tissue damage had not yet been investigated. We show in this study, in a mouse model of liver injury induced by acetaminophen intoxication, that Clec1a deficiency enhances the acute immune response with increased expression of Il1b, Tnfa, and Cxcl2 and higher infiltration of activated neutrophils into the injured organ. Furthermore, we demonstrate that Clec1a deficiency exacerbates tissue damage via CXCL2-dependent neutrophil infiltration. In contrast, we observed that the lack of CLEC-1 limits CCL2 expression and the accumulation, beyond the peak of injury, of monocyte-derived macrophages. Mechanistically, we found that Clec1a-deficient dendritic cells increase the expression of Il1b, Tnfa, and Cxcl2 in response to necrotic cells, but decrease the expression of Ccl2. Interestingly, treatment with an anti-human CLEC-1 antagonist mAb recapitulates the exacerbation of acute immunopathology observed by genetic loss of Clec1a in a preclinical humanized mouse model. To conclude, our results demonstrate that CLEC-1 is a death receptor limiting the acute inflammatory response following injury and represents a therapeutic target to modulate immunity.

CLEC-1 is a death sensor that limits antigen cross-presentation by dendritic cells and represents a target for cancer immunotherapy.

Tumors exploit numerous immune checkpoints, including those deployed by myeloid cells to curtail antitumor immunity. Here, we show that the C-type lectin receptor CLEC-1 expressed by myeloid cells senses dead cells killed by programmed necrosis. Moreover, we identified Tripartite Motif Containing 21 (TRIM21) as an endogenous ligand overexpressed in various cancers. We observed that the combination of CLEC-1 blockade with chemotherapy prolonged mouse survival in tumor models. Loss of CLEC-1 reduced the accumulation of immunosuppressive myeloid cells in tumors and invigorated the activation state of dendritic cells (DCs), thereby increasing T cell responses. Mechanistically, we found that the absence of CLEC-1 increased the cross-presentation of dead cell-associated antigens by conventional type-1 DCs. We identified antihuman CLEC-1 antagonist antibodies able to enhance antitumor immunity in CLEC-1 humanized mice. Together, our results demonstrate that CLEC-1 acts as an immune checkpoint in myeloid cells and support CLEC-1 as a novel target for cancer immunotherapy.

Instagram's Influence on Radiology Today: Reviewing the Evolving Educational Journey from a Hospital to National Societies.

We define social media as an interactive online platform that allows users to communicate and exchange knowledge. Educational and medical profiles have slowly emerged on different social media platforms, helping to teach about and publicize diverse aspects of medicine. Radiology is one of the specialties that could potentially benefit the most from social media, as the radiologist tends to have little outside-the-hospital representation. Progressively, audiovisual content has been gaining ground on social networks: Facebook, Twitter, Instagram, Youtube, TikTok, etc. Instagram appears to be ideally suited for radiology given its image-based nature. In addition, Instagram can also be used as a tool to help radiologists share and discuss radiological images, improve communication with clinicians and patients, advertise themselves and their specialty, and humanize their profession. Nevertheless, legal matters and privacy issues should always be taken into account when using these tools. In this overview, we describe the development of social networks and communication tools in our own radiology department, focusing especially on our Instagram account, as it has had a wide impact on our hospital and radiology residents around the country. We will also provide a summary of the various social media platforms used for radiology education along with their pros and cons, including useful tips for safe and efficient use.

C-Type Lectin-Like Receptors: Head or Tail in Cell Death Immunity.

C-type lectin-like receptors (CLRs) represent a family of transmembrane pattern recognition receptors, expressed primarily by myeloid cells. They recognize not only pathogen moieties for host defense, but also modified self-antigens such as damage-associated molecular patterns released from dead cells. Upon ligation, CLR signaling leads to the production of inflammatory mediators to shape amplitude, duration and outcome of the immune response. Thus, following excessive injury, dysregulation of these receptors leads to the development of inflammatory diseases. Herein, we will focus on four CLRs of the "Dectin family," shown to decode the immunogenicity of cell death. CLEC9A on dendritic cells links F-actin exposed by dying cells to favor cross-presentation of dead-cell associated antigens to CD8+ T cells. Nevertheless, CLEC9A exerts also feedback mechanisms to temper neutrophil recruitment and prevent additional tissue damage. MINCLE expressed by macrophages binds nuclear SAP130 released by necrotic cells to potentiate pro-inflammatory responses. However, the consequent inflammation can exacerbate pathogenesis of inflammatory diseases. Moreover, in a tumor microenvironment, MINCLE induces macrophage-induced immune suppression and cancer progression. Similarly, triggering of LOX-1 by oxidized LDL, amplifies pro-inflammatory response but promotes tumor immune escape and metastasis. Finally, CLEC12A that recognizes monosodium urate crystals formed during cell death, inhibits activating signals to prevent detrimental inflammation. Interestingly, CLEC12A also sustains type-I IFN response to finely tune immune responses in case of viral-induced collateral damage. Therefore, CLRs acting in concert as sensors of injury, could be used in a targeted way to treat numerous diseases such as allergies, obesity, tumors, and autoimmunity.

Curcumin enhances LXRα in an AMP-activated protein kinase-dependent manner in human macrophages.

Liver X receptor alpha (LXRα) is a nuclear receptor involved in cholesterol homeostasis. Curcumin, a traditional Chinese derivative from the rhizomes of Curcuma longa and a well-known AMP-activated protein kinase (AMPK) activator, possess hypocholesterolemic activity, however, the possible link between AMPK and cholesterol is unknown. In this study, we have investigated whether curcumin regulates metabolic changes in cholesterol metabolism via LXRα in THP-1 human macrophages, the cells implicated in atheroma plaques formation. Results showed that curcumin induced AMPK phosphorylation, increased LXRα mRNA and protein expression. Curcumin up-regulated mRNA expression of genes involved in cholesterol transport and metabolism as ATP-binding cassette (ABC) transporters ABCA1 and ABCG1, and the sterol response element binding protein 1c (SREBP1c). On the other hand, this increased LXRα mRNA and protein expression was reverted when AMPK was inhibited by its chemical inhibitor, compound C. Transfection with AMPK α1 and α2 siRNA decreased the LXRα mRNA expression and its target genes. Curcumin treatment inhibited cell migration and was also able to promote reverse cholesterol transport in THP-1 cells. This enhanced reverse cholesterol transport might be related to the up-regulating of ABCA1 and ABCG1 mRNA expression by activating AMPK-LXRα signaling in THP-1 cells. This study describes a possible mechanism for understanding the hypocholesterolemic effects of curcumin and expand knowledge about the LXRα regulation by AMPK.

Grapefruit Flavonoid Naringenin Regulates the Expression of LXRα in THP-1 Macrophages by Modulating AMP-Activated Protein Kinase.

The present work investigates the modulation of grapefruit flavonoid naringenin over liver X receptor alpha (LXRα) and its target genes in THP-1 macrophages, focusing on AMP-activated protein kinase (AMPK) implication. Naringenin induced LXRα at mRNA and protein levels besides influencing the expression of LXRα target genes ABCA1, ABCG1 (ATP-binding cassette A1 and G1), and SREBP1c (sterol response element binding protein 1c) in THP-1 macrophages. The increased LXRα mRNA and protein expression was reverted when AMPK was inhibited by its chemical inhibitor, compound C or by transfection with AMPK α1 and α2 siRNA. Naringenin treatments were also able to promote reverse cholesterol transport in THP-1 cells, which is in line with the increase in the ABCA1 and ABCG1 expression found. Treatments with this flavonoid also inhibited cell migration in THP-1 cells. In conclusion, LXRα and its target genes are up-regulated by naringenin in an AMPK dependent manner in human macrophages. The enhancement in the expression of genes involved in cholesterol efflux may reveal a new mechanism by which this polyphenol can prevent atherosclerosis and foam cell progression.

"Explora": atender a los alumnos con más curiosidad, motivación o capacidad sin excluir a nadie / "Explora": Assisting students with more curiosity, motivation, or ability without excluding anyone

Durante el curso 2014/2015, la Consejería de Educación del Gobierno de La Rioja puso en marcha en ocho colegios de esta Comunidad Autónoma, de manera experimental, el programa "Explora" para la atención al alumnado de capacidad intelectual elevada. Se planearon tanto talleres presenciales como online. La implementación de los presenciales (objetivos, contenidos, actividades, selección de alumnado, sesiones, etc.) fue diseñada por los propios centros docentes, estructurándose su funcionamiento de manera tradicional. Sin embargo, los cuatro talleres online (matemáticas, lenguaje, informática e inteligencia emocional) se desarrollaron siguiendo el enfoque deportivo (Sports Approach) de Joan Freeman. En el presente artículo se muestra la fundamentación, desarrollo y evaluación de estos talleres online. Se realizó una evaluación cualitativa y cuantitativa cuyos resultados son muy alentadores: se confirmó la buena aceptación del programa por parte de los participantes y se comprobó su adecuación para la selección del alumnado de elevada capacidad

In the academic year 2014/2015, the Education Department of the Government of La Rioja launched in eight schools in this region, on an experimental basis, the program "Explora" for the attention to students with high intellectual capacity. Both face-to-face and online workshops were planned. The implementation of face-to-face workshops (goals, contents, activities, student selection, sessions, etc.) was designed by the own educational centers in a traditional way. However, the four online workshops (maths, language, computing, and emotional intelligence) were developed following the Sports Approach by Joan Freeman. This paper shows the foundation, development, and evaluation of these online workshops. A qualitative and quantitative evaluation was carried out, with very encouraging results: big acceptance of the program by participants was confirmed along with the program appropriateness for the selection of students with high intellectual capacity

Platelet-activating factor and hydrogen peroxide exert a dual modulatory effect on the transcription of LXRα and its target genes in human neutrophils.

Liver X receptors (LXRs) are ligand-activated nuclear receptors involved mainly in the regulation of cholesterol metabolism in many organs, including liver and intestine, as well as in macrophages and neutrophils. Besides, both anti-inflammatory and pro-inflammatory properties have been ascribed to LXRs. The effect of the inflammatory condition on the expression of LXRα and its target genes has not been previously addressed in human neutrophils. We have described that platelet-activating factor (PAF) and hydrogen peroxide (H2O2) are potent pro-inflammatory mediators that link the haemostatic and innate immune systems. In this work we report that H2O2 at low doses (1 pM-1µM) exerts an inhibitory effect on TO901317-induced mRNA expression of LXRα and of its target genes encoding the ATP-binding cassette (ABC) transporters ABCA1 and ABCG1, and the sterol regulatory element-binding protein 1c (SREBP1c). However, an opposite behaviour, i.e., a transcription-enhancing effect, was found at higher H2O2 doses (100-500µM) on most of these genes. A similar dual effect was observed when the pro-inflammatory molecule PAF was used. Interestingly, H2O2 production separately elicited by 10nM PAF or 1µM H2O2 was similarly low, and analogously, H2O2 production levels elicited by 5µM PAF or 100µM H2O2 were similarly high when they were compared. On the other hand, low doses of PAF or H2O2 induced phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERK 1/2) and NF-κB activation, However, PAF or H2O2 at high doses did not produce changes in NF-κB activation levels. In summary, our results show that H2O2, either exogenous or PAF-induced, exerts a dual regulation on mRNA expression of LXRα and its target genes.

7-Keto-cholesterol and 25-hydroxy-1 cholesterol rapidly enhance ROS production in human neutrophils.

PURPOSE: Oxysterols are cholesterol-oxygenated derivatives generated in the organism and also present in foods because of cholesterol oxidation during processing and storage. They are the natural ligands of liver X receptors (LXRs) and are generally recognized as hypocholesterolemic and anti-inflammatory molecules although this latter property is still controversial. Most oxysterol studies have been performed in macrophages, whereas the effects of oxysterols in neutrophils are poorly known. In this study, human neutrophils were exposed to two different oxysterols, 7-keto-cholesterol (7-k-chol) and 25-hydroxy-cholesterol (25-OH-chol), and their possible participation in inflammatory process was evaluated. METHODS: Human neutrophils were incubated with 7-k-chol and 25-OH-chol, and ROS production, translocation of the NADPH oxidase cytosolic components, hemoxygenase-1 (HO-1) expression and lysozyme secretion were analyzed. RESULTS: An increase in ROS production was observed within a short period of time (minutes) with both molecules. These oxysterols also stimulated the cellular membrane translocation of the NADPH oxidase cytosolic components, p47phox and p67phox. On the other hand, HO-1 expression, a cytoprotector enzyme, is inhibited in human neutrophils upon oxysterols treatment. Moreover, both oxysterols were associated with high lysozyme enzyme secretion at 5 and 18 h of incubation. CONCLUSIONS: The present paper describes for the first time that two oxysterols (7-k-chol and 25-OH-chol) enhance the ROS production within a short period of time in human neutrophils, stimulate the translocation of the cytosolic components of NADPH oxidase to the cellular membrane and increase lysozyme secretion. These data suggest that both oxysterols are able to activate pro-inflammatory effects in human neutrophils which contrasts with the role assigned to the oxysterols when they act through LXR at long time of incubation.

Oleic acid modulates mRNA expression of liver X receptor (LXR) and its target genes ABCA1 and SREBP1c in human neutrophils.

PURPOSE: Regulation of liver X receptors (LXRs) is essential for cholesterol homeostasis and inflammation. The present study was conducted to determine whether oleic acid (OA) could regulate mRNA expression of LXRα and LXRα-regulated genes and to assess the potential promotion of oxidative stress by OA in neutrophils. METHODS: Human neutrophils were treated with OA at different doses and LXR target gene expression, oxidative stress production, lipid efflux and inflammation state were analyzed. RESULTS: We describe that mRNA synthesis of both LXRα and ABCA1 (a reverse cholesterol transporter) was induced by OA in human neutrophils. This fatty acid enhanced the effects of LXR ligands on ABCA1 and LXR expression, but it decreased the mRNA levels of sterol regulatory element-binding protein 1c (a transcription factor that regulates the synthesis of triglycerides). Although OA elicited a slight oxidative stress in the short term (15-30 min) in neutrophils, it is unlikely that this is relevant for the modulation of transcription in our experimental conditions, which involve longer incubation time (i.e., 6 h). Of physiological importance is our finding that OA depresses intracellular lipid levels and that markers of inflammation, such as ERK1/2 and p38 mitogen-activated protein kinase phosphorylation, were decreased by OA treatment. In addition, 200 µM OA reduced the migration of human neutrophils, another marker of the inflammatory state. However, OA did not affect lipid peroxidation induced by pro-oxidant agents. CONCLUSIONS: This work presents for the first time evidence that human neutrophils are highly sensitive to OA and provides novel data in support of a protective role of this monounsaturated acid against the activation of neutrophils during inflammation.

Platelet-activating factor downregulates the expression of liver X receptor-α and its target genes in human neutrophils.

Liver X receptors (LXRs) are ligand-activated members of the nuclear receptor superfamily that regulate the expression of genes involved in lipid metabolism and inflammation, although their role in inflammation and immunity is less well known. It has been reported that oxysterols/LXRs may act as anti-inflammatory molecules, although opposite actions have also been reported. In this study, we investigated the effect of platelet-activating factor (PAF), a proinflammatory molecule, on LXRα signalling in human neutrophils. We found that PAF exerted an inhibitory effect on mRNA expression of TO901317-induced LXRα, ATP-binding cassette transporter A1, ATP-binding cassette transporter G1, and sterol response element binding protein 1c. This negative action was mediated by the PAF receptor, and was dependent on the release of reactive oxygen species elicited by PAF, as it was enhanced by pro-oxidant treatment and reversed by antioxidants. Current data also support the idea that PAF induces phosphorylation of the LXRα molecule in an extracellular signal-regulated kinase 1/2-mediated fashion. These results suggest that a possible mechanism by which PAF exerts its proinflammatory effect is through the downregulation of LXRα and its related genes, which supports the notion that LXRα ligands exert a modulatory role in the neutrophil-mediated inflammatory response.

Reproducibility of percutaneous nephrolithotomy in the Galdakao-modified supine Valdivia position.

To demonstrate that percutaneous nephrolithotomy (PCNL) in the Galdakao-modified supine Valdivia position can be safely and effectively reproduced by different surgeons. A multicentre retrospective cross-sectional case study on 317 patients was conducted. The centres enrolled were four hospitals from the Spanish National Health System and provided data for consecutive PCNL from January 2008 to December 2010. The patients were divided into two groups: the Galdakao group (134; operated on by the master PCNL surgeon) and the other surgeons group (183; operated on by the other surgeons). The results of the technique were analysed relative to success and complications. Finally, a multivariate analysis introducing the covariates age, gender, BMI, ASA and type of stone was performed (backward stepwise logistic regression). The univariate analysis did not reveal differences in age, gender and ASA scores (p > 0.05) between the Galdakao group and the other surgeons group. The success rate was 80.6 % in the Galdakao group and 72.7 % in the other surgeons group (p = 0.01), and the complication rate was 16.4 and 26.2 %, respectively (p = 0.03). Complications were categorised based on the Clavien classification, and no differences were discovered between the groups (p = 0.19). The logistic regression confirmed only the surgeon and the stone type as independent predictive variables. PCNL in the Galdakao-modified supine Valdivia position is feasible for the use by different urologic surgeons. The results depend on the surgeon's experience, but with specific training and, maybe, selecting the simplest cases at the beginning, it is possible to achieve competitive results.

The one-stop clinic as the standard of out-patient care in a hospital urology department.

PURPOSE: To evaluate the performance of a 'one-stop' clinic in terms of proportion of discharges or inclusion in surgical waiting lists. MATERIALS AND METHODS: All patients were referred from primary care facilities (population 220,646) and from different departments in the hospital. Eight senior urologists, two registered nurses and two nurse attendants participated in the experience. Prior to the start of the project, referral protocols had been agreed with the primary care physicians involved. Compliance with the protocols was periodically tested. Eventually 5537 first visits (January-December 2009) where evaluable. RESULTS: Overall, the 'one-stop' format proved feasible in 74.2% of the patients (4108/5537). Patients, who successfully used the 'one-stop' format, were significantly younger than those who required additional consultations (43 vs 50 years old, respectively, Student 's t test < 0.001). For obvious reasons the 'one-stop' format was universally possible in male sterilization and penile phimosis patients. Similarly, the 'one-stop' policy was applied in most consultations due to male sexual dysfunction (75%) and urinary tract infection (73%). Other health problems, such as haematuria (62%) and renal colic (46%), required more than one visit so that care of the patient reverted to the traditional, outpatient care model. CONCLUSION: A 'one-stop' philosophy is feasible for a number of procedures in a urological outpatient clinic. The costs to implement such an approach would be limited to managerial expenditure.

The one-stop clinic as the standard of out-patient care in a hospital urology department

PURPOSE: To evaluate the performance of a 'one-stop' clinic in terms of proportion of discharges or inclusion in surgical waiting lists. MATERIALS AND METHODS: All patients were referred from primary care facilities (population 220.646) and from different departments in the hospital. Eight senior urologists, two registered nurses and two nurse attendants participated in the experience. Prior to the start of the project, referral protocols had been agreed with the primary care physicians involved. Compliance with the protocols was periodically tested. Eventually 5537 first visits (January-December 2009) where evaluable. RESULTS: Overall, the 'one-stop' format proved feasible in 74.2 percent of the patients (4108/5537). Patients, who successfully used the 'one-stop' format, were significantly younger than those who required additional consultations (43 vs 50 years old, respectively, Student's t test < 0.001). For obvious reasons the 'one-stop' format was universally possible in male sterilization and penile phimosis patients. Similarly, the 'one-stop' policy was applied in most consultations due to male sexual dysfunction (75 percent) and urinary tract infection (73 percent). Other health problems, such as haematuria (62 percent) and renal colic (46 percent), required more than one visit so that care of the patient reverted to the traditional, outpatient care model. CONCLUSION: A 'one-stop' philosophy is feasible for a number of procedures in a urological outpatient clinic. The costs to implement such an approach would be limited to managerial expenditure.

The broad-spectrum antitumor action of cyclosporin A is due to its tachykinin receptor antagonist pharmacological profile.

Cyclosporin A (CsA) is an immunosuppressive drug. In human cancer cells substance P (SP) and neurokinin-1 (NK-1) receptor antagonists, respectively, induce cell proliferation and inhibition. CsA is a tachykinin receptor antagonist that showed selectivity for both NK-1 and NK-2 receptors. CsA exerts antitumor action against gastric (AGS) and colon (HT29) carcinoma cell lines. However, the mechanisms involved in this action remain unknown, and it is unknown whether CsA exerts an antitumor action on other human cancer cell lines or not. To demonstrate that CsA exerts a broad-spectrum antitumor action, we carried out an in vitro study of the growth-inhibitory capacity of CsA against seven human cancer cell lines, namely GAMG glioma, SKN-BE(2) neuroblastoma, WERI-Rb-1 retinoblastoma, HEp-2 larynx carcinoma, CAPAN pancreas carcinoma, 23132/87 gastric carcinoma, and SW-403 colon carcinoma. A Coulter counter was used to determine viable cell numbers followed by application of the MTS colorimetric method. Micromolar concentrations of CsA inhibited the growth of these tumor cells, both with and without previous administration of nanomolar concentrations of SP; the inhibition occurred in a dose-dependent manner. Moreover, CsA blocks SP-induced mitogen stimulation of tumor cells, suggesting that the NK-1 receptor is involved in such action. Following administration of CsA apoptosis was observed in the above seven tumor cell lines. These findings suggest that the antitumor action of CsA is at least due to its NK-1 receptor antagonist pharmacological profile, since the involvement of NK-2 receptors in the mentioned action must not be discarded, and that CsA has a broad-spectrum antitumor action.