The beta 2-Adrenoceptor Agonist Formoterol Improves Structural and Functional Regenerative Capacity of Skeletal Muscles From Aged Rat at the Early Stages of Postinjury

Skeletal muscles from old rats fail to completely regenerate following injury. This study investigated whether pharmacological stimulation of beta 2-adrenoceptors in aged muscles following injury could improve their regenerative capacity, focusing on myofiber size recovery. Young and aged rats were treated with a subcutaneous injection of beta 2-adrenergic agonist formoterol (2 mu g/kg/d) up to 10 and 21 days after soleus muscle injury. Formoterol-treated muscles from old rats evaluated at 10 and 21 days postinjury showed reduced inflammation and connective tissue but a similar number of regenerating myofibers of greater caliber when compared with their injured controls. Formoterol minimized the decrease in tetanic force and increased protein synthesis and mammalian target of rapamycin phosphorylation in old muscles at 10 days postinjury. Our results suggest that formoterol improves structural and functional regenerative capacity of regenerating skeletal muscles from aged rats by increasing protein synthesis via mammalian target of rapamycin activation. Furthermore, formoterol may have therapeutic benefits in recovery following muscle damage in senescent individuals.

BAY 41-2272, a soluble guanylate cyclase agonist, activates human mononuclear phagocytes

BACKGROUND AND PURPOSE Phagocyte function is critical for host defense against infections. Defects in phagocytic function lead to several primary immunodeficiencies characterized by early onset of recurrent and severe infections. In this work, we further investigated the effects of BAY 41-2272, a soluble guanylate cyclase (sGC) agonist, on the activation of human peripheral blood monocytes (PBM) and THP-1 cells. EXPERIMENTAL APPROACH THP-1 cells and PBM viability was evaluated by methylthiazoletetrazolium assay; reactive oxygen species production by lucigenin chemiluminescence; gene and protein expression of NAPDH oxidase components by qRT-PCR and Western blot analysis, respectively; phagocytosis and microbicidal activity by co-incubation, respectively, with zymosan and Escherichia coli; and cytokine release by elisa. KEY RESULTS BAY 41-2272, compared with the untreated group, increased spreading of monocytes by at least 35%, superoxide production by at least 50%, and gp91PHOX and p67PHOX gene expression 20 to 40 times, in both PBM and THP-1 cells. BAY 41-2272 also augmented phagocytosis of zymosan particles threefold compared with control, doubled microbicidal activity against E. coli and enhanced the release of TNF-a and IL-12p70 by both PBM and THP-1 cells. Finally, by inhibiting sGC with ODQ, we showed that BAY 41-2272-induced superoxide production and phagocytosis is not dependent exclusively on sGC activation. CONCLUSIONS AND IMPLICATIONS In addition to its ability to induce vasorelaxation and its potential application for therapy of vascular diseases, BAY 41-2272 was shown to activate human mononuclear phagocytes. Hence, it is a novel pro-inflammatory drug that may be useful for controlling infections in the immunocompromised host.

Apoptosis rate and transcriptional response of pancreatic islets exposed to the PPAR gamma agonist Pioglitazone

To explore the molecular pathways underlying thiazolidinediones effects on pancreatic islets in conditions mimicking normo- and hyperglycemia, apoptosis rate and transcriptional response to Pioglitazone at both physiological and supraphysiological glucose concentrations were evaluated. Adult rat islets were cultured at physiological (5.6 mM) and supraphysiological (23 mM) glucose concentrations in presence of 10 μM Pioglitazone or vehicle. RNA expression profiling was evaluated with the PancChip 13k cDNA microarray after 24-h, and expression results for some selected genes were validated by qRT-PCR. The effects of Pioglitazone were investigated regarding apoptosis rate after 24-, 48- and 72-h. At 5.6 mM glucose, 101 genes were modulated by Pioglitazone, while 1,235 genes were affected at 23 mM glucose. Gene networks related to lipid metabolism were identified as altered by Pioglitazone at both glucose concentrations. At 23 mM glucose, cell cycle and cell death pathways were significantly regulated as well. At 5.6 mM glucose, Pioglitazone elicited a transient reduction in islets apoptosis rate while at 23 mM, Bcl2 expression was reduced and apoptosis rate was increased by Pioglitazone. Our data demonstrate that the effect of Pioglitazone on gene expression profile and apoptosis rate depends on the glucose concentration. The modulation of genes related to cell death and the increased apoptosis rate observed at supraphysiological glucose concentration raise concerns about Pioglitazone’s direct effects in conditions of hyperglycemia and reinforce the necessity of additional studies designed to evaluate TZDs effects on the preservation of β-cell function in situations where glucotoxicity might be more relevant than lipotoxicity.

Immunohistochemical evidence for myofibroblastlike cells associated with liver injury induced by Aflatoxin B1 in rainbow trout (Oncorhynchus mykiss)

In mammalian species, profibrogenic cells are activated to become myofibroblasts in response to liver damage. Few studies have examined hepatic myofibroblasts and their role in liver damage in teleosts. The aim of the present study was to investigate the involvement of myofibroblast-like cells in rainbow trout (Oncorhynchus mykiss) with hepatic damage induced by aflatoxin B1 (AFB1). Histopathological and immunohistochemical analyses characterized alterations in the liver stroma during the carcinogenic process. Anti-human a-smoothmuscle actin (SMA) and anti-human desmin primary antibodies were used in immunohistochemistry. Only the anti-SMA reagent labelled cells in trout liver. In the livers of control fish, only smooth muscle in blood vessels and around bile ducts was labelled. In the livers from AFB1-treated fish, SMA-positive cells were present in the stroma surrounding neoplastic lesions and in areas of desmoplastic reaction. These observations indicate that in teleosts, as in mammals, the myofibroblast-like cell is involved in fibrosis associated with liver injury. Chronic liver injury induced in trout by aflatoxin may provide a useful model system for study of the evolution of such mechanisms.

Role of an indole-thiazolidine molecule PPAR pan-agonist and COX inhibitor on inflammation and microcirculatory damage in acute gastric lesions

The present study aimed to show the in vivo mechanisms of action of an indole-thiazolidine molecule peroxisome-proliferator activated receptor pan-agonist (PPAR pan) and cyclooxygenase (COX) inhibitor, LYSO-7, in an ethanol/HCl-induced (Et/HCl) gastric lesion model. Swiss male mice were treated with vehicle, LYSO-7 or Bezafibrate (p.o.) 1 hour before oral administration of Et/HCl (60%/0.03M). In another set of assays, animals were injected i.p. with an anti-granulocyte antibody, GW9962 or L-NG-nitroarginine methyl ester (L-NAME) before treatment. One hour after Et/HCl administration, neutrophils were quantified in the blood and bone marrow and the gastric microcirculatory network was studied in situ. The gastric tissue was used to quantify the percentage of damaged area, as well as myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) protein and PPARγ protein and gene expression. Acid secretion was evaluated by the pylorus ligation model. LYSO-7 or Bezafibrate treatment reduced the necrotic area. LYSO-7 treatment enhanced PPARγ gene and protein expression in the stomach, and impaired local neutrophil influx and stasis of the microcirculatory network caused by Et/HCl administration. The effect seemed to be due to PPARγ agonist activity, as the LYSO-7 effect was abolished in GW9962 pre-treated mice. The reversal of microcirculatory stasis, but not neutrophil influx, was mediated by nitric oxide (NO), as L-NAME pre-treatment abolished the LYSO-7-mediated reestablishment of microcirculatory blood flow. This effect may depend on enhanced eNOS protein expression in injured gastric tissue. The pH and concentration of H(+) in the stomach were not modified by LYSO-7 treatment. In addition, LYSO-7 may induce less toxicity, as 28 days of oral treatment did not induce weight loss, as detected in pioglitazone treated mice. Thus, we show that LYSO-7 may be an effective treatment for gastric lesions by controlling neutrophil influx and microcirculatory blood flow mediated by NO

Nivel B1: autonomía y trabajo de los estudiantes de primer año de EFL

[ES]El proceso de aprendizaje y adquisición de competencias para conseguir el tan solicitado nivel B1 requiere tanto la actividad presencial como el trabajo autónomo del alumno. De las 7 habilidades lingüísticas recogidas en el Marco Común Europeo de Referencia para las Lenguas vamos a escoger tres: la lectura (reading), la expresión escrita (writing and written interaction) y la expresión oral (speaking and spoken interaction) para presentar este método de instrucción en la Educación Superior. Detallaremos qué métodos se utilizan para conseguir ese progreso, si se adecuan al objetivo inicial y los resultados que pueden derivarse.

Conjugation of Toll Like Receptor 7 agonist through conjugation to immunogenic proteins. Synthesis, characterization, formulation and pre-clinical evaluation

The next generation of vaccine adjuvant are represented by a wide ranging set of molecules called Toll like agonists (TLR’s). Although many of these molecules are complex structures extracted from microorganisms, small molecule TLR agonists have also been identified. However, delivery systems have not been optimized to allow their effective delivery in conjunction with antigens. Here we describe a novel approach in which a small molecule TLR agonist has been conjugated directly to antigens to ensure effective co delivery. We describe the conjugation of a relevant protein, a recombinant protective antigen from S.pneumoniae (RrgB), which is linked to a TLR7 agonist. Following thorough characterization to ensure there was no aggregation, the conjugate was evaluated in a murine infection model. Results showed that the conjugate extended animals’ survival after lethal challenge with S.pneumoniae. Comparable results were obtained with a 10 fold lower dose than that of the native unconjugated antigen. Notably, the animals immunized with the same dose of unconjugated TLR7 agonist and antigen showed no adjuvant effect. The increased immunogenicity was likely a consequence of the co-localization of TLR7 agonist and antigen by chemical binding and is was more effective than simple co-administration. Likely, this approach can be adopted to reduce the dose of antigen required to induce protective immunity, and potentially increase the safety of a broad variety of vaccine candidates

La grammaire et les interférences linguistiques dans l'apprentissage du français langue étrangère : le cas des apprenants italophones et sinophones de niveau B1.

Ce mémoire propose d’étudier le phénomène des interférences linguistiques qui se vérifient lors de l’apprentissage du français langue étrangère (FLE). Après avoir apporté quelques notions historico-théoriques de la grammaire et de la didactique, nous nous pencherons sur la question des interférences linguistiques à travers une étude de cas spécifique portant sur des apprenants italophones et sinophones de niveau B1 selon le Cadre Européen Commun de Référence pour les langues. Il s’agit de réfléchir, à travers cette analyse, au rôle de la grammaire dans un contexte d’enseignement/apprentissage de la langue française où l’origine de l’apprenant influence l’approche à la langue étrangère et est source d’interférences linguistiques. En dernier lieu, nous tirerons les conclusions de l’analyse sur le plan didactique.

MODELING THE DYNAMICS OF AIRWAY CONSTRICTION: EFFECTS OF AGONIST TRANSPORT AND BINDING

Recent advances have revealed that during exogenous airway challenge, airway diameters can not be adequately predicted by their initial diameters. Furthermore, airway diameters can also vary greatly in time on scales shorter than a breath. In order to better understand these phenomena, we developed a multiscale model which allows us to simulate aerosol challenge in the airways during ventilation. The model incorporates agonist-receptor binding kinetics to govern the temporal response of airway smooth muscle (ASM) contraction on individual airway segments, which together with airway wall mechanics, determines local airway caliber. Global agonist transport and deposition is coupled with pressure-driven flow, linking local airway constrictions with global flow dynamics. During the course of challenge, airway constriction alters the flow pattern, redistributing agonist to less constricted regions. This results in a negative feedback which may be a protective property of the normal lung. As a consequence, repetitive challenge can cause spatial constriction patterns to evolve in time, resulting in a loss of predictability of airway diameters. Additionally, the model offers new insight into several phenomena including the intra- and inter-breath dynamics of airway constriction throughout the tree structure.

Switch from antagonist to agonist after addition of a DOTA chelator to a somatostatin analog

Peptide receptor targeting has become an increasingly attractive method to target tumors diagnostically and radiotherapeutically. Peptides linked to a variety of chelators have been developed for this purpose. They have, however, rarely been tested for their agonistic or antagonistic properties. We report here on a somatostatin antagonist that switched to an agonist upon coupling to a DOTA chelator.

Agonist-biased signaling at the sst2A receptor: the multi-somatostatin analogs KE108 and SOM230 activate and antagonize distinct signaling pathways

Somatostatin analogs that activate the somatostatin subtype 2A (sst2A) receptor are used to treat neuroendocrine cancers because they inhibit tumor secretion and growth. Recently, new analogs capable of activating multiple somatostatin receptor subtypes have been developed to increase tumor responsiveness. We tested two such multi-somatostatin analogs for functional selectivity at the sst2A receptor: SOM230, which activates sst1, sst2, sst3, and sst5 receptors, and KE108, which activates all sst receptor subtypes. Both compounds are reported to act as full agonists at their target sst receptors. In sst2A-expressing HEK293 cells, somatostatin inhibited cAMP production, stimulated intracellular calcium accumulation, and increased ERK phosphorylation. SOM230 and KE108 were also potent inhibitors of cAMP accumulation, as expected. However, they antagonized somatostatin stimulation of intracellular calcium and behaved as partial agonists/antagonists for ERK phosphorylation. In pancreatic AR42J cells, which express sst2A receptors endogenously, SOM230 and KE108 were both full agonists for cAMP inhibition. However, although somatostatin increased intracellular calcium and ERK phosphorylation, SOM230 and KE108 again antagonized these effects. Distinct mechanisms were involved in sst2A receptor signaling in AR42J cells; pertussis toxin pretreatment blocked somatostatin inhibition of cAMP accumulation but not the stimulation of intracellular calcium and ERK phosphorylation. Our results demonstrate that SOM230 and KE108 behave as agonists for inhibition of adenylyl cyclase but antagonize somatostatin's actions on intracellular calcium and ERK phosphorylation. Thus, SOM230 and KE108 are not somatostatin mimics, and their functional selectivity at sst2A receptors must be considered in clinical applications where it may have important consequences for therapy.

The tumour-suppressive miR-29a/b1 cluster is regulated by CEBPA and blocked in human AML

CCAAT/enhancer-binding protein-alpha (CEBPA) is crucial for normal granulopoiesis and is frequently disrupted in acute myeloid leukaemia (AML). Increasing evidence suggests that CEBPA exerts its effects, in parts, by regulating specific microRNAs (miRNAs), as previously shown for miR-223. The aim of this study was to investigate the genome-wide pattern of miRNAs regulated by CEBPA in myeloid cells.

Dose escalation and pharmacokinetic study of AEZS-108 (AN-152), an LHRH agonist linked to doxorubicin, in women with LHRH receptor-positive tumors

Receptors for luteinizing hormone-releasing hormone (LHRH) can be utilized for targeted chemotherapy of cytotoxic LHRH analogs. The compound AEZS-108 (previously AN-152) consists of [D-Lys?]LHRH linked to doxorubicin. The objectives of this first study in humans with AESZ-108 were to determine the maximum tolerated dose and to characterize the dose-limiting toxicity, pharmacokinetics, preliminary efficacy, and hormonal effects.

Evaluation of 177Lu-DOTA-sst2 antagonist versus 177Lu-DOTA-sst2 agonist binding in human cancers in vitro

Somatostatin receptor targeting of neuroendocrine tumors using radiolabeled somatostatin agonists is today an established method to image and treat cancer patients. However, in a study using an animal tumor model, somatostatin receptor antagonists were shown to label sst(2)- and sst(3)-expressing tumors in vivo better than agonists, with comparable affinity even though they are not internalized into the tumor cell. In the present study, we evaluated the in vitro binding of the antagonist (177)Lu-DOTA-pNO(2)-Phe-c (DCys-Tyr-DTrp-Lys-Thr-Cys) DTyrNH(2) ((177)Lu-DOTA-BASS) or the (177)Lu-DOTATATE agonist to sst(2)-expressing human tumor samples.