The cannabinoid ligand LH-21 reduces anxiety and improves glucose handling in diet-induced obese pre-diabetic mice

LH-21 is a triazol derivative that has been described as a low-permeant neutral CB1 antagonist, though its pharmacology is still unclear. It has been associated with anti-obesity actions in obese rats. However, its role in preventing type 2 diabetes (T2D) onset have not been studied yet. Given CB1 receptors remain as potential pharmacological targets to fight against obesity and T2D, we wanted to explore the metabolic impact of this compound in an animal model of obesity and pre-diabetes as well as the lack of relevant actions in related central processes such as anxiety. C57BL/6J mice were rendered obese and pre-diabetic by feeding a high-fat diet for 15 weeks and then treated with LH-21 or vehicle for two weeks. Food intake, body weight and glucose handling were assessed, together with other relevant parameters. Behavioural performance was evaluated by the open field test and the elevated plus maze. LH-21 did not affect food intake nor body weight but it improved glucose handling, displaying tissue-specific beneficial actions. Unexpectedly, LH-21 induced anxiolysis and reverted obesity-induced anxiety, apparently through GPR55 receptor. These results suggest that LH-21 can be a new candidate to fight against diabetes onset. Indeed, this compound shows potential in counteracting obesity-related anxiety.España, Ministerio de Sanidad 13/00309 to F.J.B.S. and PI13/00593 to B.R.GConsejería de Salud Junta de Andalucía C-0070-201

The diet-derived short chain fatty acid propionate improves beta-cell function in humans and stimulates insulin secretion from human islets in vitro

Aims: Diet-derived short chain fatty acids (SCFAs) improve glucose homeostasis in vivo, but the role of individual SCFAs and their mechanisms of action have not been defined. This study evaluated the effects of increasing colonic delivery of the SCFA propionate on β-cell function in humans and the direct effects of propionate on isolated human islets in vitro. Materials and Methods: For 24 weeks human subjects ingested an inulin-propionate ester that delivers propionate to the colon. Acute insulin, GLP-1 and non-esterified fatty acid (NEFA) levels were quantified pre- and post-supplementation in response to a mixed meal test. Expression of the SCFA receptor FFAR2 in human islets was determined by western blotting and immunohistochemistry. Dynamic insulin secretion from perifused human islets was quantified by radioimmunoassay and islet apoptosis was determined by quantification of caspase 3/7 activities. Results: Colonic propionate delivery in vivo was associated with improved β-cell function with increased insulin secretion that was independent of changes in GLP-1 levels. Human islet β-cells expressed FFAR2 and propionate potentiated dynamic glucose-stimulated insulin secretion in vitro, an effect that was dependent on signalling via protein kinase C. Propionate also protected human islets from apoptosis induced by the NEFA sodium palmitate and inflammatory cytokines. Conclusions: Our results indicate that propionate has beneficial effects on β-cell function in vivo, and in vitro analyses demonstrated that it has direct effects to potentiate glucose-stimulated insulin release and maintain β-cell mass through inhibition of apoptosis. These observations support ingestion of propiogenic dietary fibres to maintain healthy glucose homeostasis

High fat-fed GPR55 null mice display impaired glucose tolerance without concomitant changes in energy balance or insulin sensitivity but are less responsive to the effects of the cannabinoids rimonabant or Δ(9)-tetrahydrocannabivarin on weight gain

Background The insulin-sensitizing phytocannabinoid, Δ(9)-tetrahydrocannabivarin (THCV) can signal partly via G protein coupled receptor-55 (GPR55 behaving as either an agonist or an antagonist depending on the assay). The cannabinoid receptor type 1 (CB1R) inverse agonist rimonabant is also a GPR55 agonist under some conditions. Previous studies have shown varied effects of deletion of GPR55 on energy balance and glucose homeostasis in mice. The contribution of signalling via GPR55 to the metabolic effects of THCV and rimonabant has been little studied. Methods In a preliminary experiment, energy balance and glucose homeostasis were studied in GPR55 knockout and wild-type mice fed on both standard chow (to 20 weeks of age) and high fat diets (from 6 to 15 weeks of age). In the main experiment, all mice were fed on the high fat diet (from 6 to 14 weeks of age). In addition to replicating the preliminary experiment, the effects of once daily administration of THCV (15 mg.kg-1 po) and rimonabant (10 mg.kg-1 po) were compared in the two genotypes. Results There was no effect of genotype on absolute body weight or weight gain, body composition measured by either dual-energy X-ray absorptiometry or Nuclear Magnetic Resonance (NMR), fat pad weights, food intake, energy expenditure, locomotor activity, glucose tolerance or insulin tolerance in mice fed on chow. When the mice were fed a high fat diet, there was again no effect of genotype on these various aspects of energy balance. However, in both experiments, glucose tolerance was worse in the knockout than the wild-type mice. Genotype did not affect insulin tolerance in either experiment. Weight loss in rimonabant- and THCV-treated mice was lower in knockout than in wild-type mice, but surprisingly there was no detectable effect of genotype on the effects of the drugs on any aspect of glucose homeostasis after taking into account the effect of genotype in vehicle-treated mice. Conclusions Our two experiments differ from those reported by others in finding impaired glucose tolerance in GPR55 knockout mice in the absence of any effect on body weight, body composition, locomotor activity or energy expenditure. Nor could we detect any effect of genotype on insulin tolerance, so the possibility that GPR55 regulates glucose-stimulated insulin secretion merits further investigation. By contrast with the genotype effect in untreated mice, we found that THCV and rimonabant reduced weight gain, and this effect was in part mediated by GPR55

She\u27s So Bubbly

We introduce the Automatic Learning for the Rapid Classification of Events (ALeRCE) broker, an astronomical alert broker designed to provide a rapid and self-consistent classification of large etendue telescope alert streams, such as that provided by the Zwicky Transient Facility (ZTF) and, in the future, the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST). ALeRCE is a Chilean-led broker run by an interdisciplinary team of astronomers and engineers working to become intermediaries between survey and follow-up facilities. ALeRCE uses a pipeline that includes the real-time ingestion, aggregation, cross-matching, machine-learning (ML) classification, and visualization of the ZTF alert stream. We use two classifiers: a stamp-based classifier, designed for rapid classification, and a light curve–based classifier, which uses the multiband flux evolution to achieve a more refined classification. We describe in detail our pipeline, data products, tools, and services, which are made public for the community (see https://alerce.science). Since we began operating our real-time ML classification of the ZTF alert stream in early 2019, we have grown a large community of active users around the globe. We describe our results to date, including the real-time processing of 1.5 × 10⁸ alerts, the stamp classification of 3.4 × 10⁷ objects, the light-curve classification of 1.1 × 10⁶ objects, the report of 6162 supernova candidates, and different experiments using LSST-like alert streams. Finally, we discuss the challenges ahead in going from a single stream of alerts such as ZTF to a multistream ecosystem dominated by LSST

Los receptores CB1 y GPR55 en la fisiología del islote pancreático y en la fisiopatología de la diabetes tipo 2

A continuación, resumimos los resultados más significativos del trabajo realizado: i)Los CB1 modulan la actividad de las proteínas AKT, CREB y AMPK en islotes de ratones sanos y humanos, sugiriendo que podrían jugar un papel en la proliferación e incrementos de masa de los mismos. Esta modulación está disminuida en islotes de animales pre-diabéticos pudiendo colaborar al desarrollo de T2D. ii)Los receptores GPR55 manifiestan efectos especie-dependientes al modular AKT, CREB y AMPK en islotes de ratones sanos pero sólo AKT en humanos, proteína que podría ser responsable de los efectos biológicos de su ligando endógeno. iii)Los CB1 y GPR55 modulan la GSIS y la [Ca2+]i en islotes de ratones sanos y de humanos. A concentraciones bajas, LH-21 incrementa la GSIS y la [Ca2+]i modulando a GPR55 y no a CB1 como podría pensarse. De manera similar, Abn-CBD, potencia la secreción de insulina a través de mecanismos dependientes e independientes de GPR55. iv)Los CB1 y la vía de señalización de mTORC1 están funcionalmente conectados, modulando la GSIS en islotes de ratones sanos. La conexión CB1-mTOR desaparece en islotes de ratones pre-diabéticos, lo que sugiere que ésta contribuye a la fisiopatología de T2D. v)Los CB1, a baja glucosa, modulan el contenido de ROS en islotes de ratones sanos. Dicha modulación está alterada en islotes de ratones pre-diabéticos sugiriendo, también, que afecta al desarrollo de T2D. vi)Finalmente, LH-21 y Abn-CBD, de manera dependiente de GPR55, protegen de la apoptosis a los islotes de ratón y humanos, pudiendo así ser útiles para evitar la muerte celular producida durante T2D.La diabetes tipo 2 (T2D), es una enfermedad caracterizada por hiperglucemia, debida a una combinación entre resistencia a la insulina y una progresiva disfunción y pérdida de masa de las células β que impide compensarla liberando mayor insulina. La secreción de insulina estimulada por glucosa (GSIS) está modulada por la propia insulina y otros factores como los endocannabinoides. Estas sustancias, ejercen sus funciones reguladoras en las células β actuando principalmente sobre receptores cannabinoides CB1 (CB1) y otros relacionados como los GPR55. En esta tesis, hemos estudiado el papel modulador que CB1 y GPR55 ejercen en islotes pancreáticos (humanos, y de ratones sanos, pre-diabéticos (obtenidos tras el suministro prolongado de una dieta rica en grasa) y GPR55-/-), sobre las rutas de señalización de AKT, AMPK y CREB, que controlan la proliferación, supervivencia y masa de las células β, y que suelen alterarse en T2D. Para ello, los islotes se trataron con rimonabant ó LH-21, antagonistas de CB1, ó Abn-CBD, agonista de GPR55. Se han estudiado también los efectos moduladores de estos receptores sobre la GSIS y la [Ca2+]i tras tratamiento farmacológico, y cómo el antagonismo de CB1 afecta a la ruta de señalización de mTOR en islotes de ratones sanos y pre-diabéticos, y su efecto sobre la GSIS. Asimismo, se ha investigado el papel de CB1 en la generación de ROS en islotes de rata, ratones sanos y pre-diabéticos, y el jugado por GPR55 en la apoptosis en islotes de ratones sanos, GPR55-/- y de humanos

COVID 19 y suspensión de actividades, el caso mexicano

The COVID-19 pandemic has represented an enormous challenge due to the danger to the health of the world population, which each State has faced through the implementation of measures based on its internal regulations. In the case of the Mexican government, which initially slowly assumed responsibility for controlling this disease in its territory, it did so by exceeding the scope of the constitutional norm on which it is based, by establishing obligations directed at individuals, but without decreeing a state of exception, as it has been done in other countries where, through such decrees, the freedoms of transit and assembly have been restricted, guaranteeing essential activities and instructing the necessary measures in labor and economic matters. To limit human mobility and determine labor issues, the executive authority, before the required approvals, should have exercised power provided in article 29 of the Constitution, founding and motivating the suspension of the exercise of rights and specifying the affectation of labor rights, guaranteeing the stability of public finances, the financial system, sources of employment and the minimum to subsist of the Mexican people.La pandemia por COVID-19 ha significado un enorme reto por el grave peligro a la salud de la población mundial, que cada Estado ha enfrentado a través de la implementación de medidas basadas en su normatividad interna. En el caso del gobierno mexicano, quien asumió inicialmente de forma lenta la responsabilidad de controlar esta enfermedad en su territorio, lo hizo extralimitando los alcances de la norma constitucional en que las fundamenta, al establecer obligaciones dirigidas a particulares, pero sin decretar un estado de excepción, como sí se ha hecho en otros países donde, a través de tales decretos, se han restringido las libertades de tránsito y reunión, garantizando las actividades esenciales e instruyendo las medidas necesarias en materia laboral y económica. Para restringir la movilidad humana y determinar cuestiones laborales se debió ejercer por el ejecutivo, previa las aprobaciones necesarias, la facultad prevista en el artículo 29 constitucional fundando y motivando la suspensión del ejercicio de los derechos y precisando la afectación de los derechos laborales, garantizando la estabilidad de las finanzas públicas, del sistema financiero, las fuentes de empleo y el mínimo para subsistir del pueblo mexicano

Identifying signalling pathways regulated by GPRC5B in β-cells by CRISPR-Cas9-mediated genome editing

Background/Aims: CRISPR-Cas9, a RNA-guided targeted genome editing tool, has revolutionized genetic engineering by offering the ability to precisely modify DNA. GPRC5B is an orphan receptor belonging to the group C family of G protein-coupled receptors (GPCRs). In this study, we analysed the functional roles of the Gprc5b receptor in MIN6 β-cells using CRISPR-Cas9 and transient over-expression of Gprc5b. Methods: The optimal transfection reagent for use in MIN6 β-cells was determined by analysing efficiency of GFP plasmid delivery by cell sorting. A MIN6 β-cell line in which Gprc5b expression was knocked down (Gprc5b KD) was generated using CRISPR-Cas9 technology. Gprc5b receptor mRNA expression, proliferation, apoptosis, Cignal 45-Pathway Reporter Array signalling and western blot assays were carried out using Gpcr5b KD MIN6 β-cells that had been transiently transfected with different concentrations of mouse Gprc5b plasmid to over-express Gprc5b. Results: JetPRIME® was the best candidate for MIN6 β-cell transfection, providing approximately 30% transfection efficiency. CRISPR-Cas9 technology targeting Gprc5b led to stable knock-down of this receptor in MIN6 β-cells and its re-expression induced proliferation and potentiated cytokine- and palmitate-induced apoptosis. The Cignal 45 Reporter analysis indicated Gprc5b-dependent regulation of apoptotic and proliferative pathways, and western blotting confirmed activation of signalling via TGF-β and IFNγ. Conclusion: This study provides evidence of CRISPR-Cas9 technology being used to down-regulate Gprc5b expression in MIN6 β-cells. This strategy allowed us to identify signalling pathways linking GPRC5B receptor expression to β-cell proliferation and apoptosis

Dynamic Profiling of Insulin Secretion and ATP Generation in Isolated Human and Mouse Islets Reveals Differential Glucose Sensitivity

Background/Aims: Rodent islets are often used for basic science research but they do not always recapitulate signalling events in human islets. This study evaluated the glucose-dependent responses of human and mouse islets in terms of dynamic insulin secretion, metabolic coupling and the role of glucose transporters. Methods: Glucose-induced insulin secretion from isolated mouse and human islets was profiled by perifusion and islet ATP levels were measured by chemoluminescence assay. Glucose transporter expression was determined by qPCR and western blotting. Results: Human islets show a left-shifted glucose concentration-insulin secretion profile compared to mouse islets. These data are consistent with glucose transporter expression, with human islets expressing mainly GLUT1 and GLUT3, and GLUT2 being the predominant transporter in mouse islets. Using the GLUT1 inhibitor STF-31 we unveiled an important role for GLUT1 for differences in glucose-induced insulin secretion profiles observed between the two species. Conclusion: The high affinity of GLUT1/3 for glucose reflects the left-shifted glucose-induced insulin secretory response of human islets and the impairment of insulin secretion from human islets after STF-31 treatment indicates an important role for GLUT1 in human islet stimulus-secretion coupling. Our data provide further insight into key differences between insulin secretion regulation in mouse and human islets