33 research outputs found

    З історії меценатства в Катеринославі

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    The role of the melanocortin (MC) system in feeding behavior is well established. Food intake is potently suppressed by central infusion of the MC 3/4 receptor agonist α-melanocyte stimulating hormone (α-MSH), whereas the MC 3/4 receptor inverse-agonist Agouti Related Peptide (AGRP) has the opposite effect. MC receptors are widely expressed in both hypothalamic and extra-hypothalamic brain regions, including nuclei involved in food reward and motivation, such as the nucleus accumbens (NAc) and the ventral tegmental area. This suggests that MCs modulate motivational aspects of food intake. To test this hypothesis, rats were injected intracerebroventricularly with α-MSH or AGRP and their motivation for sucrose was tested under a progressive ratio schedule of reinforcement. Food motivated behavior was dose-dependently decreased by α-MSH. Conversely, AGRP increased responding for sucrose, an effect that was blocked by pretreatment with the dopamine receptor antagonist α-flupenthixol. In contrast to progressive ratio responding, free intake of sucrose remained unaltered upon α-MSH or AGRP infusion. In addition, we investigated whether the effects of α-MSH and AGRP on food motivation were mediated by the NAc shell. In situ hybridization of MC3 and MC4 receptor expression confirmed that the MC4 receptor was expressed throughout the NAc, and injection of α-MSH and AGRP into the NAc shell caused a decrease and an increase in motivation for sucrose, respectively. These data show that the motivation for palatable food is modulated by MC4 receptors in the NAc shell, and demonstrate cross-talk between the MC and dopamine system in the modulation of food motivation

    Viral mediated neuropeptide Y expression in the rat paraventricular nucleus results in obesity

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    OBJECTIVE: Chronic central administration of neuropeptide Y (NPY) has dramatic effects on energy balance; however, the exact role of the hypothalamic paraventricular nucleus (PVN) in this is unknown. The aim of this study was to further unravel the contribution of NPY signaling in the PVN to energy balance. RESEARCH METHODS AND PROCEDURES: Recombinant adeno-associated viral particles containing NPY (rAAV-NPY) were injected in the rat brain with coordinates targeted at the PVN. For three weeks, body weight, food intake, endocrine parameters, body temperature, and locomotor activity were measured. Furthermore, effects on insulin sensitivity and expression of NPY, agouti-related protein (AgRP), and pro-opiomelanocortin in the arcuate nucleus were studied. RESULTS: Food intake was increased specifically in the light period, and dark phase body temperature and locomotor activity were reduced. This resulted in obesity characterized by increased fat mass; elevated plasma insulin, leptin, and adiponectin; decreased AgRP expression in the arcuate nucleus; and decreased insulin sensitivity; whereas plasma corticosterone was unaffected. DISCUSSION: These data suggest that increased NPY expression targeted at the PVN is sufficient to induce obesity. Interestingly, plasma concentrations of leptin and insulin were elevated before a rise in food intake, which suggests that NPY in the PVN influences leptin and insulin secretion independently from food intake. This strengthens the role of the PVN in regulation of energy balance by NP

    Intratracheal administration of solutions in mice; development and validation of an optimized method with improved efficacy, reproducibility and accuracy

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    Animal models are still vital in the field of respiratory disease research. To improve the accuracy and consistency of the dose of specific compounds administered specifically in the respiratory tract, it is important to optimize and to compare the technique to currently available techniques. In this study, an optimized intubation-mediated intratracheal administration (IMIT) technique is described and compared to oropharyngeal aspiration (OA). Adult female Balb/c mice were treated with Evans Blue using IMIT or OA and sacrificed after a short recovery to observe the distribution of solutions throughout the lungs. Additionally, mice were treated with increasing doses of lipopolysaccharide (LPS) or saline to compare efficacy of both techniques. Inflammatory cell numbers in bronchoalveolar lavage were quantified 24 h post-administration. Evans Blue staining revealed a more homogeneous distribution and less variability among animals treated using IMIT as compared to OA. Higher inflammatory cell numbers were observed in IMIT mice compared to OA mice after exposure to vehicle or the lowest LPS concentration. This study shows that the optimized IMIT is superior to OA with regards to efficacy, reproducibility and accuracy. This IMIT method can be deployed to refine 3R animal welfare aspects of the experimental design and improve the reproducibility of respiratory disease mouse models

    Corrigendum to ‘Small molecule-mediated inhibition of CD40-TRAF6 reduces adverse cardiac remodelling in pressure overload induced heart failure’ [Int. J. Cardiol., Volume 279, 15 March 2019, Pages 141-144](S0167527318325531)(10.1016/j.ijcard.2018.12.076)

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    The authors regret that after the publication of the above paper, the authors noted that the initials of the authors listed on the paper were not included on the paper. Specifically, Judith de Haan should have been be listed as Judith J. de Haan, Tom Seijkens should have been listed as Tom T.P. Seijkens, Claudia van Tiel should have been listed as Claudia M. van Tiel, Maike Brans should have been listed as Maike A.D. Brans, and Saskia de Jager should be listed as Saskia C.A. de Jager. The authors would like to apologise for any inconvenience caused

    Intratracheal administration of solutions in mice; development and validation of an optimized method with improved efficacy, reproducibility and accuracy

    Get PDF
    Animal models are still vital in the field of respiratory disease research. To improve the accuracy and consistency of the dose of specific compounds administered specifically in the respiratory tract, it is important to optimize and to compare the technique to currently available techniques. In this study, an optimized intubation-mediated intratracheal administration (IMIT) technique is described and compared to oropharyngeal aspiration (OA). Adult female Balb/c mice were treated with Evans Blue using IMIT or OA and sacrificed after a short recovery to observe the distribution of solutions throughout the lungs. Additionally, mice were treated with increasing doses of lipopolysaccharide (LPS) or saline to compare efficacy of both techniques. Inflammatory cell numbers in bronchoalveolar lavage were quantified 24 h post-administration. Evans Blue staining revealed a more homogeneous distribution and less variability among animals treated using IMIT as compared to OA. Higher inflammatory cell numbers were observed in IMIT mice compared to OA mice after exposure to vehicle or the lowest LPS concentration. This study shows that the optimized IMIT is superior to OA with regards to efficacy, reproducibility and accuracy. This IMIT method can be deployed to refine 3R animal welfare aspects of the experimental design and improve the reproducibility of respiratory disease mouse models

    Extracellular vesicle‐mediated protein delivery to the liver

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    Abstract Extracellular vesicles (EVs) are nanoscale particles that facilitate intercellular communication. They are regarded as a promising natural drug delivery system for transporting and delivering bioactive macromolecules to target cells. Recently, researchers have engineered EVs with FKBP12/FRB heterodimerization domains that interact with rapamycin to load and deliver exogenous proteins for both in vitro and in vivo applications. In this study, we examined the tissue distribution of EVs using near‐infrared fluorescent imaging. We evaluated the effectiveness of EV‐mediated delivery of Cre recombinase specifically to hepatocytes in the livers of Ai9 Cre‐loxP reporter mice. Intravenous injection resulted in more efficient Cre protein delivery to the liver than intraperitoneal injections. Depleting liver‐resident macrophages with clodronate‐encapsulated liposome pre‐treatment did not enhance EV‐mediated Cre delivery to hepatocytes. Moreover, we demonstrated that multiple intravenous injections of Cre‐EVs facilitated functional Cre delivery to hepatocytes. To the best of our knowledge, this is the first study to simultaneously investigate the tissue distribution of FKBP12/FRB‐engineered EVs and their subsequent intracellular protein delivery in Ai9 Cre‐loxP reporter mice. These insights can inform preclinical research and contribute to developing next‐generation EV‐based platforms for delivering therapeutic proteins or genome editing technologies targeting the liver
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