Early peroxisome proliferator-activated receptor gamma regulated genes involved in expansion of pancreatic beta cell mass.

BACKGROUND: The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion RESULTS: Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell. CONCLUSIONS: Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Increased dihydroceramide/ceramide ratio mediated by defective expression of degs1 impairs adipocyte differentiation and function.

Adipose tissue dysfunction is an important determinant of obesity-associated, lipid-induced metabolic complications. Ceramides are well-known mediators of lipid-induced insulin resistance in peripheral organs such as muscle. DEGS1 is the desaturase catalyzing the last step in the main ceramide biosynthetic pathway. Functional suppression of DEGS1 activity results in substantial changes in ceramide species likely to affect fundamental biological functions such as oxidative stress, cell survival, and proliferation. Here, we show that degs1 expression is specifically decreased in the adipose tissue of obese patients and murine models of genetic and nutritional obesity. Moreover, loss-of-function experiments using pharmacological or genetic ablation of DEGS1 in preadipocytes prevented adipogenesis and decreased lipid accumulation. This was associated with elevated oxidative stress, cellular death, and blockage of the cell cycle. These effects were coupled with increased dihydroceramide content. Finally, we validated in vivo that pharmacological inhibition of DEGS1 impairs adipocyte differentiation. These data identify DEGS1 as a new potential target to restore adipose tissue function and prevent obesity-associated metabolic disturbances.This work was funded by Medical Research Council, MDU MRC, FP7- ETHERPATHS and the British Heart Foundation (BHF). We declare no conflict of interest.This is the accepted manuscript. The final version is available from ADA at http://diabetes.diabetesjournals.org/content/early/2014/10/22/db14-0359.abstract

Leukocyte Overexpression of Intracellular NAMPT Attenuates Atherosclerosis by Regulating PPAR gamma-Dependent Monocyte Differentiation and Function

Objective-Extracellular nicotinamide phosphoribosyltransferase (eNAMPT) mediates inflammatory and potentially proatherogenic effects, whereas the role of intracellular NAMPT (iNAMPT), the rate limiting enzyme in the salvage pathway of nicotinamide adenine dinucleotide (NAD)(+) generation, in atherogenesis is largely unknown. Here we investigated the effects of iNAMPT overexpression in leukocytes on inflammation and atherosclerosis. Approach and Results-Low-density lipoprotein receptor-deficient mice with hematopoietic overexpression of human iNAMPT (iNAMPT(hi)), on a western type diet, showed attenuated plaque burden with features of lesion stabilization. This anti-atherogenic effect was caused by improved resistance of macrophages to apoptosis by attenuated chemokine (C-C motif) receptor 2-dependent monocyte chemotaxis and by skewing macrophage polarization toward an anti-inflammatory M2 phenotype. The iNAMPT(hi) phenotype was almost fully reversed by treatment with the NAMPT inhibitor FK866, indicating that iNAMPT catalytic activity is instrumental in the atheroprotection. Importantly, iNAMPT overexpression did not induce any increase in eNAMPT, and eNAMPT had no effect on chemokine (C-C motif) receptor 2 expression and promoted an inflammatory M1 phenotype in macrophages. The iNAMPT-mediated effects at least partly involved sirtuin 1-dependent molecular crosstalk of NAMPT and peroxisome proliferator-activated receptor.. Finally, iNAMPT and peroxisome proliferator-activated receptor. showed a strong correlation in human atherosclerotic, but not healthy arteries, hinting to a relevance of iNAMPT/peroxisome proliferator-activated receptor. pathway also in human carotid atherosclerosis. Conclusions-This study highlights the functional dichotomy of intracellular versus extracellular NAMPT, and unveils a critical role for the iNAMPT-peroxisome proliferator-activated receptor. axis in atherosclerosis

Chikungunya Outbreak in the Republic of the Congo, 2019—Epidemiological, Virological and Entomological Findings of a South-North Multidisciplinary Taskforce Investigation

The Republic of Congo (RoC) declared a chikungunya (CHIK) outbreak on 9 February 2019. We conducted a ONE-Human-Animal HEALTH epidemiological, virological and entomological investigation. Methods: We collected national surveillance and epidemiological data. CHIK diagnosis was based on RT-PCR and CHIKV-specific antibodies. Full CHIKV genome sequences were obtained by Sanger and MinION approaches and Bayesian tree phylogenetic analysis was performed. Mosquito larvae and 215 adult mosquitoes were collected in different villages of Kouilou and Pointe-Noire districts and estimates of Aedes (Ae.) mosquitos’ CHIKV-infectious bites obtained. We found two new CHIKV sequences of the East/Central/South African (ECSA) lineage, clustering with the recent enzootic sub-clade 2, showing the A226V mutation. The RoC 2019 CHIKV strain has two novel mutations, E2-T126M and E2-H351N. Phylogenetic suggests a common origin from 2016 Angola strain, from which it diverged around 1989 (95% HPD 1985–1994). The infectious bite pattern was similar for 2017, 2018 and early 2019. One Ae. albopictus pool was RT-PCR positive. The 2019 RoC CHIKV strain seems to be recently introduced or be endemic in sylvatic cycle. Distinct from the contemporary Indian CHIKV isolates and in contrast to the original Central-African strains (transmitted by Ae. aegypti), it carries the A226V mutation, indicating an independent adaptive mutation in response to vector replacement (Ae. albopictus vs Ae. aegypti)

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Outcomes and patterns of use of Radium-223 in metastatic castration-resistant prostate cancer

IntroductionRadium-223 dichloride (Ra-223) is recommended as a treatment option for metastatic castration-resistant prostate cancer (mCRPC) patients with symptomatic bone metastases and no visceral disease, after docetaxel failure, or in patients who are not candidates to receive it. In this study, we aimed to ambispectively analyze overall survival (OS) and prognostic features in mCRPC in patients receiving Ra-223 as per clinical routine practice and identify the most suitable treatment sequence.Patients and methodsThis study is observational, multicentric, and ambispective. Eligibility criteria included mCRPC patients treated with Ra-223, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0–2, without visceral metastases, and no more than three cm involved lymph nodes.ResultsA total of 145 patients were included; the median age was 73.97 years, and a Gleason score of more than or equal to 7 in 61 (48%) patients; 73 (81%) had previously received docetaxel. The most important benefit was reached by those patients who received Ra-223 in the second-line setting, with a median OS of 17 months (95% CI, 12–21), and by patients who received six cycles of treatment, with a median OS of 19 months (95% CI, 14–21). An alkaline phosphatase (ALP) decrease was also identified as a prognosis marker. When performing the multivariate analysis, the time to develop castration-resistant disease longer than 24 months was the most important prognostic factor to predict the evolution of the patients receiving Ra-223. Ra-223 was well tolerated, with thrombocytopenia, anemia, and diarrhea being the main adverse events.ConclusionThere is a benefit for those patients who received Ra-223 in the second-line setting, regardless of prior use of docetaxel. In addition, a survival benefit for patients presenting with a decline in ALP was observed

Association of Lipidome Remodeling in the Adipocyte Membrane with Acquired Obesity in Humans

The authors describe a new approach to studying cellular lipid profiles and propose a compensatory mechanism that may help maintain the normal membrane function of adipocytes in the context of obesity

Guía de práctica clínica para el tratamiento farmacológico inicial de nefritis lúpica en el Seguro Social del Perú (EsSalud)

Background: This article summarizes the clinical practice guideline (CPG) for the initial pharmacological treatment of lupus nephritis in the Social Security of Peru (EsSalud). Objective: To provide evidence-based clinical recommendations for initial pharmacological treatment of non-refractory adults with class I to V lupus nephritis in EsSalud. Material and Methods: A guideline development group (GDG) was formed, which included specialist physicians and methodologists, who formulated clinical questions. Systematic searches were conducted for systematic reviews and - when deemed relevant - primary studies in PubMed during 2021. Evidence was selected to answer each of the clinical questions posed. The certainty of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. In periodic working meetings, the GEG used the GRADE methodology to review the evidence and formulate recommendations. The CPG was reviewed by external experts before its approval. Results: The CPG addressed 6 clinical questions, divided into 2 topics: initial treatment of the induction and maintenance phase. Based on these questions, 11 recommendations were formulated (all conditional), 22 points of good clinical practice, and 2 flow charts. Conclusion: Evidence-based recommendations were issued for the management of patients with this pathology.Introducción: El presente artículo resume la guía de práctica clínica (GPC) para el tratamiento farmacológico inicial nefritis lúpica en el Seguro Social del Perú (EsSalud). Objetivo: Proveer recomendaciones clínicas basadas en evidencia para tratamiento farmacológico inicial de adultos con nefritis lúpica clase I a V no refractarios en EsSalud. Material y Métodos: Se conformó un grupo elaborador de la guía (GEG) que incluyó médicos especialistas y metodólogos, el cual formuló preguntas clínicas. Se realizaron búsquedas sistemáticas de revisiones sistemáticas y –cuando fue considerado pertinente– estudios primarios en PubMed durante el 2021. Se seleccionó la evidencia para responder cada una de las preguntas clínicas planteadas. Se evaluó la certeza de evidencia usando la metodología Grading of Recommendations Assessment, Development, and Evaluation (GRADE). En reuniones de trabajo periódicas, el GEG usó la metodología GRADE para revisar la evidencia y formular las recomendaciones. La GPC fue revisada por expertos externos antes de su aprobación. Resultados: La GPC abordó 6 preguntas clínicas, divididas en 2 temas: tratamiento inicial de la fase de inducción y mantenimiento. En base a dichas preguntas se formularon 11 recomendaciones (todas condicionales), 22 puntos de buena práctica clínica, y 2 flujogramas. Conclusión: Se emitieron recomendaciones basadas en evidencia para el manejo de pacientes con esta patología

Studies of the mass composition of cosmic rays and proton-proton interaction cross-sections at ultra-high energies with the Pierre Auger Observatory

In this work, we present an estimate of the cosmic-ray mass composition from the distributions of the depth of the shower maximum (Xmax) measured by the fluorescence detector of the Pierre Auger Observatory. We discuss the sensitivity of the mass composition measurements to the uncertainties in the properties of the hadronic interactions, particularly in the predictions of the particle interaction cross-sections. For this purpose, we adjust the fractions of cosmic-ray mass groups to fit the data with Xmax distributions from air shower simulations. We modify the proton-proton cross-sections at ultra-high energies, and the corresponding air shower simulations with rescaled nucleus-air cross-sections are obtained via Glauber theory. We compare the energy-dependent composition of ultra-high-energy cosmic rays obtained for the different extrapolations of the proton-proton cross-sections from low-energy accelerator data