The Effect of High Fat Diet on Marrow Adipocytes from C57BL/6J (B6) Mice

In mice models, the administration of a high fat diet (HFD) is an accelerating factor for metabolic syndrome, impaired glucose tolerance, and early type 2 diabetes mellitus (T2DM) (1)https://knowledgeconnection.mainehealth.org/lambrew-retreat-2021/1049/thumbnail.jp

Phagocytic Activity Is Impaired in Type 2 Diabetes Mellitus and Increases after Metabolic Improvement

OBJECTIVE: 1) To evaluate whether peripheral blood mononuclear cells (PBMCs) from type 2 diabetic patients present an impairment of phagocytic activity; 2) To determine whether the eventual impairment in phagocytic activity is related to glycemic control and can be reversed by improving blood glucose levels. METHODS: 21 type 2 diabetic patients and 21 healthy volunteers were prospectively recruited for a case-control study. In addition, those patients in whom HbA1c was higher than 8% (n = 12) were hospitalized in order to complete a 5-day intensification treatment of blood glucose. Phagocytic activity was assessed by using a modified flow cytometry procedure developed in our laboratory based on DNA/RNA viable staining to discriminate erythrocytes and debris. This method is simple, highly sensitive and reproducible and it takes advantage of classic methods that are widely used in flow cytometry. RESULTS: Type 2 diabetic patients showed a lower percentage of activated macrophages in comparison with non-diabetic subjects (54.00±18.93 vs 68.53±12.77%; p = 0.006) Significant negative correlations between phagocytic activity and fasting glucose (r = -0.619, p = 0.004) and HbA1c (r = -0.506, p = 0.019) were detected. In addition, multiple linear regression analyses showed that either fasting plasma glucose or HbA1c were independently associated with phagocytic activity. Furthermore, in the subset of patients who underwent metabolic optimization a significant increase in phagocytic activity was observed (p = 0.029). CONCLUSIONS: Glycemic control is related to phagocytic activity in type 2 diabetes. Our results suggest that improvement in phagocytic activity can be added to the beneficial effects of metabolic optimization

The natural triterpene maslinic acid induces apoptosis in HT29 colon cancer cells by a JNK-p53-dependent mechanism

[Background] Maslinic acid, a pentacyclic triterpene found in the protective wax-like coating of the leaves and fruit of Olea europaea L., is a promising agent for the prevention of colon cancer. We have shown elsewhere that maslinic acid inhibits cell proliferation to a significant extent and activates mitochondrial apoptosis in colon cancer cells. In our latest work we have investigated further this compound's apoptotic molecular mechanism. [Methods] We used HT29 adenocarcinoma cells. Changes genotoxicity were analyzed by single-cell gel electrophoresis (comet assay). The cell cycle was determined by flow cytometry. Finally, changes in protein expression were examined by western blotting. Student's t-test was used for statistical comparison. [Results] HT29 cells treated with maslinic acid showed significant increases in genotoxicity and cell-cycle arrest during the G0/G1 phase after 72 hours' treatment and an apoptotic sub-G0/G1 peak after 96 hours. Nevertheless, the molecular mechanism for this cytotoxic effect of maslinic acid has never been properly explored. We show here that the anti-tumoral activity of maslinic acid might proceed via p53-mediated apoptosis by acting upon the main signaling components that lead to an increase in p53 activity and the induction of the rest of the factors that participate in the apoptotic pathway. We found that in HT29 cells maslinic acid activated the expression of c-Jun NH2-terminal kinase (JNK), thus inducing p53. Treatment of tumor cells with maslinic acid also resulted in an increase in the expression of Bid and Bax, repression of Bcl-2, release of cytochrome-c and an increase in the expression of caspases -9, -3, and -7. Moreover, maslinic acid produced belated caspase-8 activity, thus amplifying the initial mitochondrial apoptotic signaling. [Conclusion] All these results suggest that maslinic acid induces apoptosis in human HT29 colon-cancer cells through the JNK-Bid-mediated mitochondrial apoptotic pathway via the activation of p53. Thus we propose a plausible sequential molecular mechanism for the expression of the different proteins responsible for the intrinsic mitochondrial apoptotic pathway. Further studies with other cell lines will be needed to confirm the general nature of these findings.This study was supported by grants BIO157 from the Andalucian regional government; SAF2008-00164 and ISCIII-RTICC (RD06/0020/0046) grants from the Spanish national government and & European Regional Development Fund (ERDF) "Una manera de hacer Europa" and by AGAUR-Generalitat de Catalunya grant 2009SGR1308, 2009 CTP 00026 and Icrea Academia award 2010 granted to M. Cascante)

Pathogenic Acinetobacter species have a functional type I secretion system and contact-dependent inhibition systems

Pathogenic Acinetobacter species, including Acinetobacter baumannii and Acinetobacter nosocomialis, are opportunistic human pathogens of increasing relevance worldwide. Although their mechanisms of drug resistance are well studied, the virulence factors that governAcinetobacter pathogenesis are incompletely characterized. Here we define the complete secretome of A. nosocomialis strain M2 in minimal medium and demonstrate that pathogenicAcinetobacter species produce both a functional type I secretion system (T1SS) and a contact-dependent inhibition (CDI) system. Using bioinformatics, quantitative proteomics, and mutational analyses, we show that Acinetobacter uses its T1SS for exporting two putative T1SS effectors, an Repeatsin-Toxin (RTX)-serralysin-like toxin, and the biofilm-associated protein (Bap). Moreover, we found that mutation of any component of the T1SS system abrogated type VI secretion activity under nutrient-limited conditions, indicating a previously unrecognized cross-talk between these two systems. We also demonstrate that the Acinetobacter T1SS is required for biofilm formation. Last, we show that both A. nosocomialis and A. baumannii produce functioning CDI systems that mediate growth inhibition of sister cells lacking the cognate immunity protein. The Acinetobacter CDI systems are widely distributed across pathogenicAcinetobacter species, with manyA. baumannii isolates harboring two distinct CDI systems. Collectively, these data demonstrate the power of differential, quantitative proteomics approaches to study secreted proteins, define the role of previously uncharacterized protein export systems, and observe cross-talk between secretion systems in the pathobiology of medically relevant Acinetobacter speciesSubprograma Sara Borrell from the Instituto de Salud Carlos IIISubdirección General de Evaluación y Fomento de la InvestigaciónMinisterio de Economía y Competitividad de España CD14/0001

Novel Phenazine 5,10-Dioxides Release •OH in Simulated Hypoxia and Induce Reduction of Tumour Volume In Vivo

Phenazine 5,10-dioxides (PDOs) are a new class of bioreductive cytotoxins, which could act towards tumours containing hypoxic regions. The PDOs selective-hypoxic bioreduction was probed in vitro; however, the mechanism of action has not been completely explained. Besides, PDOs in vivo antitumour activities have not been demonstrated hitherto. We study the mechanism of hypoxic/normoxic cytotoxicity of PDO representative members. Electron spin resonance is used to confirm •OH production, alkaline comet assay to determine genotoxicity, and gel electrophoresis and flow cytometry to analyze DNA fragmentation and cell cycle distribution. Chemically induced rat breast tumours are employed to evaluate in vivo activities. For the most selective cytotoxin, 7(8)-bromo-2-hydroxyphenazine 5,10-dioxide (PDO1), exclusive hypoxic •OH production is evidenced, while for the unselective ones, •OH is produced in both conditions (normoxia and simulated hypoxia). In normoxia (Caco-2 cells), PDO1 induces cell-cycle arrest and DNA fragmentation but does not significantly induce apoptosis neither at IC50 nor IC80. No difference in the comet-assay scores are observed in normoxia and simulated hypoxia being the unselective 2-amino-7(8)-bromophenazine 5,10-dioxide (PDO2) the most genotoxic. The in vivo efficacy with the absence of systemic toxicity of PDO1 and PDO2 is checked out. Results from this study highlight the potential of PDOs as new therapeutics for cancer

Unveiling the Metabolic changes on muscle cell metabolism underlying p-phenylenediamine toxicity

Rhabdomyolysis is a disorder characterized by acute damage of the sarcolemma of the skeletal muscle leading to release of potentially toxic muscle cell components into the circulation, most notably creatine phosphokinase (CK) and myoglobulin, and is frequently accompanied by myoglobinuria. In the present work, we evaluated the toxicity of p-phenylenediamine (PPD), a main component of hair dyes which is reported to induce rhabdomyolysis. We studied the metabolic effect of this compound in vivo with Wistar rats and in vitro with C2C12 muscle cells. To this aim we have combined multi-omic experimental measurements with computational approaches using model-driven methods. The integrative study presented here has unveiled the metabolic disorders associated to PPD exposure that may underlay the aberrant metabolism observed in rhabdomyolys disease. Animals treated with lower doses of PPD (10 and 20 mg/kg) showed depressed activity and myoglobinuria after 10 h of treatment. We measured the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine kinase (CK) in rats after 24, 48, and 72 h of PPD exposure. At all times, treatment with PPD at higher doses (40 and 60 mg/kg) showed an increase of AST and ALT, and also an increase of lactate dehydrogenase (LDH) and CK after 24 h. Blood packed cell volume and hemoglobin levels, as well as organs weight at 48 and 72 h, were also measured. No significant differences were observed in these parameters under any condition. PPD induce cell cycle arrest in S phase and apoptosis (40% or early apoptotic cells) on mus musculus mouse C2C12 cells after 24 h of treatment. Incubation of mus musculus mouse C2C12 cells with [1,2-13C2]-glucose during 24 h, subsequent quantification of 13C isotopologues distribution in key metabolites of glucose metabolic network and a computational fluxomic analysis using in-house developed software (Isodyn) showed that PPD is inhibiting glycolysis, non-oxidative pentose phosphate pathway, glycogen turnover, and ATPAse reaction leading to a reduction in ATP synthesis. These findings unveil the glucose metabolism collapse, which is consistent with a decrease in cell viability observed in PPD-treated C2C12 cells and with the myoglubinuria and other effects observed in Wistar Rats treated with PPD. These findings shed new light on muscle dysfunction associated to PPD exposure, opening new avenues for cost-effective therapies in Rhabdomyolysis disease

Mujeres, inclusión y educación

Esta publicación recoge las ponencias y conferencias presentadas en el X Foro por la vida. Mujeres, inclusión y educación, realizado los días 18, 19, 20 y 21 de septiembre de 2019. Dicho espacio de intercambio y diálogo académico se organizó desde la unidad de Bienestar Universitario de la Universidad Católica de Colombia, con la colaboración del semillero de investigación-grupo de discusión Inclusión, mujeres y universidad. Herramientas artísticas de investigación, con el n de apoyar algunos de los objetivos que este último se plantea: aportar al fomento y fortalecimiento de la cultura de la investigación interdisciplinaria a través del análisis crítico de la situación de inclusión de las mujeres en los espacios universitarios y en el ámbito académico de la educación superior; así como sensibilizar a la comunidad académica frente a las relaciones de inequidad entre hombres y mujeres en el ámbito universitario. Desde Bienestar Universitario consideramos un aporte muy valioso contar con estos espacios de encuentro y de diálogo en el contexto académico, y esperamos que esta publicación, que re eja una amplia diversidad de abordajes alrededor del tema de las mujeres, la inclusión y la educación, sea una forma más de llevar todas las re exiones y discusiones del Foro al resto de la comunidad de la Universidad Católica de Colombia, a otros espacios educativos y al público en general.INTRODUCCIÓN. CUERPOS DE LA MEMORIA Y RESISTENCIAS POLÍTICAS PARA EL CAMBIO SOCIAL. PAISAJES HÍBRIDOS MUJERES E IMAGINARIOS DE LUGAR DESDE UNA PROPUESTA. YO CUESTIONO, NOSOTRAS CUESTIONAMOS: VISIONES CRÍTICAS EN LA ERA DEL ESTERTOR PATRIARCALDE TRADUCCIÓN VISUAL. APLICACIÓN DE ENFOQUES ADMINISTRATIVOS EN LAS MIPYMES DE LA CAPITAL COLOMBIANA LIDERADAS POR MUJERES. BRECHA DE GÉNERO EN EL MERCADO LABORAL COLOMBIANO, UN PROBLEMA LATENTE. LAS MUJERES ANTE LA EDUCACIÓN SUPERIOR EN COLOMBIA: UNA APROXIMACIÓN GENERAL. LAS LUCHAS DE LA MUJER PARA DETENER EL ACOSO DENTRO DE LA UNIVERSIDAD. ¿PROTOCOLOS DE ATENCIÓN O RUTAS DE ACCIÓN?: UNA RESPUESTA INTEGRAL AL ACOSO SEXUAL EN LAS UNIVERSIDADES DESDE LOS MECANISMOS DE PROTECCIÓN INSTITUCIONAL. PROTECCIÓN Y PARTICIPACIÓN DE LA MUJER COMO GARANTÍA DE ACCESO A LA JUSTICIA. PERSPECTIVAS MÉXICO-COLOMBIA.1ª ed

Survivin, a key player in cancer progression, increases in obesity and protects adipose tissue stem cells from apoptosis

Adipose tissue (AT) has a central role in obesity-related metabolic imbalance through the dysregulated production of cytokines and adipokines. In addition to its known risk for cardiovascular disease and diabetes, obesity is also a major risk for cancer. We investigated the impact of obesity for the expression of survivin, an antiapoptotic protein upregulated by adipokines and a diagnostic biomarker of tumor onset and recurrence. In a cross-sectional study of 111 subjects classified by body mass index, circulating levels of survivin and gene expression in subcutaneous ATwere significantly higher in obese patients and positively correlated with leptin. Within AT, survivin was primarily detected in human adipocyte-derived stem cells (hASCs), the adipocyte precursors that determine AT expansion. Remarkably, survivin expression was significantly higher in hASCs isolated from obese patients that fromlean controls and was increased by proinflammatory M1 macrophage soluble factors including IL-1β. Analysis of survivin expression in hASCs revealed a complex regulation including epigenetic modifications and protein stability. Surprisingly, obese hASCs showed survivin promoter hypermethylation that correlated with a significant decrease in its mRA levels. Nonetheless, a lower level ofmir-203, which inhibits survivin protein translation, and higher protein stability, was found in obese hASCs compared with their lean counterparts. We discovered that survivin levels determine the susceptibility of hASCs to apoptotic stimuli (including leptin and hypoxia). Accordingly, hASCs from an obese setting were protected from apoptosis. Collectively, these data shed new light on the molecular mechanisms governing AT expansion in obesity through promotion of hASCs that are resistant to apoptosis, and point to survivin as a potential new molecular player in the communication between AT and tumor cells. Thus, inhibition of apoptosis targeting survivin might represent an effective strategy for both obesity and cancer therapy