Cannabinoid CB₂ Receptor Modulation by the Transcription Factor NRF2 is Specific in Microglial Cells

Nuclear factor erythroid 2-related factor 2 (NRF2) is a pleiotropic transcription factor that has neuroprotective and anti-inflammatory effects, regulating more than 250 genes. As NRF2, cannabinoid receptor type 2 (CB2) is also implicated in the preservation of neurons against glia-driven inflammation. To this concern, little is known about the regulation pathways implicated in CB2 receptor expression. In this study, we analyze whether NRF2 could modulate the transcription of CB2 in neuronal and microglial cells. Bioinformatics analysis revealed an antioxidant response element in the promoter sequence of the CB2 receptor gene. Further analysis by chemical and genetic manipulations of this transcription factor demonstrated that NRF2 is not able to modulate the expression of CB2 in neurons. On the other hand, at the level of microglia, the expression of CB2 is NRF2-dependent. These results are related to the differential levels of expression of both genes regarding the brain cell type. Since modulation of CB2 receptor signaling may represent a promising therapeutic target with minimal psychotropic effects that can be used to modulate endocannabinoid-based therapeutic approaches and to reduce neurodegeneration, our findings will contribute to disclose the potential of CB2 as a novel target for treating different pathologies.This work was supported by the Spanish Ministry of Economy and Competitiveness (Grants Refs. SAF2016-76520-R to ILB and BFU2016-75973-R to MDG)

Phenolic composition of artichoke waste and its antioxidant capacity on differentiated Caco-2 cells

Artichoke waste represents a huge amount of discarded material. This study presents the by-products (bracts, exterior leaves, and stalks) of the “Blanca de Tudela” artichoke variety as a potential source of phenolic compounds with promising antioxidant properties. Artichoke residues were subjected to different extraction processes, and the antioxidant capacity and phenolic composition of the extracts were analyzed by spectrophotometric methods and high performance liquid chromatography (HPLC) analyses, respectively. The most abundant polyphenols in artichoke waste were chlorogenic acid, luteolin-7-O-rutinoside, and luteolin-7-O-glucoside. Minor quantities of cynarin, luteolin, apigenin-7-O-glucoside, apigenin-7-O-rutinoside, and naringenin-7-O-glucoside were also found. The antioxidant activity of the obtained extracts determined by ABTS [2, 2’-azinobis (3-ethylbenzothiazoline-6-sulphonic acid)], DPPH (2, 2-diphenyl-1-pycrilhydracyl), and FRAP (Ferric Ion Reducing Antioxidant Power) was highly correlated with the total concentration of phenolic compounds. Chlorogenic acid, luteolin-7-O-glucoside, and luteolin-7-O-rutinoside, the most abundant compounds in 60% methanol extracts, are the components most responsible for the antioxidant activity of the artichoke waste extracts. The extract with the best antioxidant capacity was selected to assay its antioxidant potential on a model intestinal barrier. This action of the hydroxycinnamic acids on intestinal cells (Caco-2) was confirmed. In summary, artichoke waste may be considered a very interesting ingredient for food functionalization and for therapeutic purposes

Grape stem extracts with potential anticancer and antioxidant properties

The application of plant extracts for therapeutic purposes has been used in traditional medicine because plants contain bioactive compounds with beneficial properties for health. Currently, the use of these compounds that are rich in polyphenols for the treatment and prevention of diseases such as cancer, diabetes, and cardiovascular diseases, many of them related to oxidative stress, is gaining certain relevance. Polyphenols have been shown to have antimutagenic, antioxidant, and anti-inflammatory properties. Therefore, the objective of the present work was to study the potential effect of grape stem extracts (GSE), rich in phenolic compounds, in the treatment of cancer, as well as their role in the prevention of this disease associated with its antioxidant power. For that purpose, three cancer lines (Caco-2, MCF-7, and MDA-MB-231) were used, and the results showed that grape stem extracts were capable of showing an antiproliferative effect in these cells through apoptosis cell death associated with a modification of the mitochondrial potential and reactive oxygen species (ROS) levels. Additionally, grape stem extracts showed an antioxidant effect on differentiated intestinal cells that could protect the intestine from diseases related to oxidative stress. Therefore, grape extracts contain bioactive principles with important biological properties and could be used as bio-functional food ingredients to prevent diseases or even to improve certain aspects of human health

Adaptive Asymmetric Least Squares baseline estimation for analytical instruments

Automated signal processing in analytical instrumentation is today required for the analysis of highly complex biomedical samples. Baseline estimation techniques are often used to correct long term instrument contamination or degradation. They are essential for accurate peak area integration. Some methods approach the baseline estimation iteratively, trying to ignore peaks which do not belong to the baseline. The proposed method in this work consists of a modification of the Asymmetric Least Squares (ALS) baseline removal technique developed by Eilers and Boelens. The ALS technique suffers from bias in the presence of intense peaks (in relation to the noise level). This is typical of diverse instrumental techniques such as Gas Chromatography-Mass Spectrometry (GC-MS) or Gas Chromatography-Ion Mobility Spectrometry (GC-IMS). In this work, we propose a modification (named psalsa) to the asymmetry weights of the original ALS method in order to better reject large peaks above the baseline. Our method will be compared to several versions of the ALS algorithm using synthetic and real GC signals. Results show that our proposal improves previous versions being more robust to parameter variations and providing more accurate peak areas

Breast cancer–secreted factors perturb murine bone growth in regions prone to metastasis

Breast cancer frequently metastasizes to bone, causing osteolytic lesions. However, how factors secreted by primary tumors affect the bone microenvironment before the osteolytic phase of metastatic tumor growth remains unclear. Understanding these changes is critical as they may regulate metastatic dissemination and progression. To mimic premetastatic bone adaptation, immunocompromised mice were injected with MDA-MB-231–conditioned medium [tumor-conditioned media (TCM)]. Subsequently, the bones of these mice were subjected to multiscale, correlative analysis including RNA sequencing, histology, micro–computed tomography, x-ray scattering analysis, and Raman imaging. In contrast to overt metastasis causing osteolysis, TCM treatment induced new bone formation that was characterized by increased mineral apposition rate relative to control bones, altered bone quality with less matrix and more carbonate substitution, and the deposition of disoriented mineral near the growth plate. Our study suggests that breast cancer–secreted factors may promote perturbed bone growth before metastasis, which could affect initial seeding of tumor cells

An early myeloma bone disease model in skeletally mature mice as a platform for biomaterial characterization of the extracellular matrix

Multiple myeloma (MM) bone disease is characterized by osteolytic bone tissue destruction resulting in bone pain, fractures, vertebral collapse, and spinal cord compression in patients. Upon initial diagnosis of MM, almost 80% of patients suffer from bone disease. Earlier diagnosis and intervention in MM bone disease would potentially improve treatment outcome and patient survival. New preclinical models are needed for developing novel diagnostic markers of bone structural changes as early as possible in the disease course. Here, we report a proof-of-concept, syngeneic, intrafemoral MOPC315.BM MM murine model in skeletally mature BALB/c mice for detection and characterization of very early changes in the extracellular matrix (ECM) of MM-injected animals. Bioluminescence imaging (BLI) in vivo confirmed myeloma engraftment in 100% of the animals with high osteoclast activity within 21 days after tumor cell inoculation. Early signs of aggressive bone turnover were observed on the outer bone surfaces by high-resolution microcomputed tomography (microCT). Synchrotron phase contrast-enhanced microcomputer tomography (PCE-CT) revealed very local microarchitecture differences highlighting numerous active sites of erosion and new bone at the micrometer scale. Correlative backscattered electron imaging (BSE) and confocal laser scanning microscopy allowed direct comparison of mineralized and nonmineralized matrix changes in the cortical bone. The osteocyte lacunar-canalicular network (OLCN) architecture was disorganized, and irregular-shaped osteocyte lacunae were observed in MM-injected bones after 21 days. Our model provides a potential platform to further evaluate pathological MM bone lesion development at the micro- and ultrastructural levels. These promising results make it possible to combine material science and pharmacological investigations that may improve early detection and treatment of MM bone disease

PAX4 preserves endoplasmic reticulum integrity preventing beta cell degeneration in a mouse model of type 1 diabetes mellitus

[Aims/hypothesis]: A strategy to enhance pancreatic islet functional beta cell mass (BCM) while restraining inflammation, through the manipulation of molecular and cellular targets, would provide a means to counteract the deteriorating glycaemic control associated with diabetes mellitus. The aims of the current study were to investigate the therapeutic potential of such a target, the islet-enriched and diabetes-linked transcription factor paired box 4 (PAX4), to restrain experimental autoimmune diabetes (EAD) in the RIP-B7.1 mouse model background and to characterise putative cellular mechanisms associated with preserved BCM. [Methods]: Two groups of RIP-B7.1 mice were genetically engineered to: (1) conditionally express either PAX4 (BPTL) or its diabetes-linked mutant variant R129W (mutBPTL) using doxycycline (DOX); and (2) constitutively express luciferase in beta cells through the use of RIP. Mice were treated or not with DOX, and EAD was induced by immunisation with a murine preproinsulin II cDNA expression plasmid. The development of hyperglycaemia was monitored for up to 4 weeks following immunisation and alterations in the BCM were assessed weekly by non-invasive in vivo bioluminescence intensity (BLI). In parallel, BCM, islet cell proliferation and apoptosis were evaluated by immunocytochemistry. Alterations in PAX4- and PAX4R129W-mediated islet gene expression were investigated by microarray profiling. PAX4 preservation of endoplasmic reticulum (ER) homeostasis was assessed using thapsigargin, electron microscopy and intracellular calcium measurements. [Results]: PAX4 overexpression blunted EAD, whereas the diabetes-linked mutant variant PAX4R129W did not convey protection. PAX4-expressing islets exhibited reduced insulitis and decreased beta cell apoptosis, correlating with diminished DNA damage and increased islet cell proliferation. Microarray profiling revealed that PAX4 but not PAX4R129W targeted expression of genes implicated in cell cycle and ER homeostasis. Consistent with the latter, islets overexpressing PAX4 were protected against thapsigargin-mediated ER-stress-related apoptosis. Luminal swelling associated with ER stress induced by thapsigargin was rescued in PAX4-overexpressing beta cells, correlating with preserved cytosolic calcium oscillations in response to glucose. In contrast, RNA interference mediated repression of PAX4-sensitised MIN6 cells to thapsigargin cell death. [Conclusions/interpretation]: The coordinated regulation of distinct cellular pathways particularly related to ER homeostasis by PAX4 not achieved by the mutant variant PAX4R129W alleviates beta cell degeneration and protects against diabetes mellitus. The raw data for the RNA microarray described herein are accessible in the Gene Expression Omnibus database under accession number GSE62846

Does Variation of the Inter-Domain Linker Sequence Modulate the Metal Binding Behaviour of Helix pomatia Cd-Metallothionein?

Snail metallothioneins (MTs) constitute an ideal model to study structure/function relationships in these metal-binding polypeptides. Helix pomatia harbours three MT isoforms: the highly specific CdMT and CuMT, and an unspecific Cd/CuMT, which represent paralogous proteins with extremely different metal binding preferences while sharing high sequence similarity. Preceding work allowed assessing that, although, the Cys residues are responsible for metal ion coordination, metal specificity or preference is achieved by diversification of the amino acids interspersed between them. The metal-specific MT polypeptides fold into unique, energetically-optimized complexes of defined metal content, when binding their cognate metalions, while they produce a mixture of complexes, none of them representing a clear energy minimum, with non-cognate metal ions. Another critical, and so far mostly unexplored, region is the stretch linking the individual MT domains, each of which represents an independent metal cluster. In this work, we have designed and analyzed two HpCdMT constructs with substituted linker segments, and determined their coordination behavior when exposed to both cognate and non-cognate metal ions. Results unequivocally show that neither length nor composition of the inter-domain linker alter the features of the Zn(II)- and Cd(II)-complexes, but surprisingly that they influence their ability to bind Cu(I), the non-cognate metal ion

Academic engagement: A diary study on the mediating role of academic support

© 2020 Elsevier Inc. Based on the Job Demands-Resources (JD-R) model, this diary study investigated the mediator role of academic resources in the relationship between personal resources and variables of well-being. The study postulates that the perceived level of academic support received by students during the day mediates the relationship between the levels of self-efficacy and curiosity, measured early in the day, and the level of academic engagement measured at the end of the day. Ninety-four undergraduates filled in a general questionnaire and subsequently completed a daily questionnaire, for 5 consecutive academic days (470 diary entries). The multilevel analysis showed a positive relationship between self-efficacy and curiosity and academic engagement. In addition, the results revealed a positive relationship between academic support and academic engagement. Finally, the results showed partial mediation of academic support in the relationship between self-efficacy and academic engagement and in the relationship between curiosity and academic engagement. The results can be used to improve teaching and learning programs in colleges and universities.This research was supported by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES (Brazil), through a scholarship granted to the first author (process n° 99999.004301/2015-03

An Analysis of the Relationship between Victimization and Violent Behavior at School

Previous studies have identified two subgroups of school violence victims: submissive and aggressive. Submissive victims are characterized by their withdrawal in violent situations, while aggressive victims combine hostile behavior with victimization. This study focuses on the second subgroup and aims to analyze possible factors influencing the transition from passive victimization to involvement in aggressive behaviors within the school context. To test these relationships, 1319 adolescents between 12 and 16 years of age were recruited from seven secondary schools in various Spanish provinces. Structural equation modeling techniques were used to analyze the data. Results supported Emler¿s theory, which posits that the victim¿s helplessness in situations of intimidation, along with disappointment resulting from a lack of expected protection from adult authority figures, may result in adolescents searching and developing an antisocial and non-conformist reputation that helps them defend themselves against future attacks. Practical implications of these results are further discussed.Departamento de Educación y Psicología SocialUniversidad Miguel HernándezUniversidad de ZaragozaPostprin