66 research outputs found

    Prostaglandin profiling reveals a role for haematopoietic prostaglandin D synthase in adipose tissue macrophage polarisation in mice and humans.

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    BACKGROUND/OBJECTIVES: Obesity has been associated with both changes in adipose tissue lipid metabolism and inflammation. A key class of lipid-derived signalling molecules involved in inflammation are the prostaglandins. In this study, we aimed to determine how obesity affects the levels of prostaglandins within white adipose tissue (WAT) and determine which cells within adipose tissue produce them. To avoid the effects of cellular stress on prostaglandin levels, we developed a multivariate statistical approach in which metabolite concentrations and transcriptomic data were integrated, allowing the assignment of metabolites to cell types. SUBJECTS/METHODS: Eicosanoids were measured by liquid chromatography-tandem mass spectrometry and mRNA levels using real-time PCR. Eicosanoid levels and transcriptomic data were combined using principal component analysis and hierarchical clustering in order to associate metabolites with cell types. Samples were obtained from C57Bl/6 mice aged 16 weeks. We studied the ob/ob genetically obese mouse model and diet-induced obesity model. We extended our results in mice to a cohort of morbidly obese humans undergoing bariatric surgery. RESULTS: Using our modelling approach, we determined that prostglandin Dâ‚‚ (PGDâ‚‚) in adipose tissue was predominantly produced in macrophages by the haematopoietic isoform of prostaglandin D synthase (H-Pgds). Analysis of sub-fractionated WAT confirmed that H-Pgds was expressed in adipose tissue macrophages (ATMs). Furthermore, H-Pgds expression in ATMs isolated from lean and obese mice was consistent with it affecting macrophage polarisation. Functionally, we demonstrated that H-PGDS-produced PGDâ‚‚ polarised macrophages toward an M2, anti-inflammatory state. In line with a potential anti-inflammatory role, we found that H-PGDS expression in ATMs was positively correlated with both peripheral insulin and adipose tissue insulin sensitivity in humans. CONCLUSIONS: In this study, we have developed a method to determine the cellular source of metabolites within an organ and used it to identify a new role for PGDâ‚‚ in the control of ATM polarisation.HQL-79 was a kind gift of Professor Yoshihiro Urade. Professor Vidal-Puig was funded by the BHF, MRC and BBSRC. Dr Virtue was funded by the BBSRC and the BHF. Dr Eiden, Dr Masoodi and Dr Griffin were funded by the MRC. Dr Mok was funded by the Wellcome Trust.This is the final published version. It first appeared at http://www.nature.com/ijo/journal/vaop/ncurrent/full/ijo201534a.htm

    A Functional and Structural Investigation of the Human Fronto-Basal Volitional Saccade Network

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    Almost all cortical areas are connected to the subcortical basal ganglia (BG) through parallel recurrent inhibitory and excitatory loops, exerting volitional control over automatic behavior. As this model is largely based on non-human primate research, we used high resolution functional MRI and diffusion tensor imaging (DTI) to investigate the functional and structural organization of the human (pre)frontal cortico-basal network controlling eye movements. Participants performed saccades in darkness, pro- and antisaccades and observed stimuli during fixation. We observed several bilateral functional subdivisions along the precentral sulcus around the human frontal eye fields (FEF): a medial and lateral zone activating for saccades in darkness, a more fronto-medial zone preferentially active for ipsilateral antisaccades, and a large anterior strip along the precentral sulcus activating for visual stimulus presentation during fixation. The supplementary eye fields (SEF) were identified along the medial wall containing all aforementioned functions. In the striatum, the BG area receiving almost all cortical input, all saccade related activation was observed in the putamen, previously considered a skeletomotor striatal subdivision. Activation elicited by the cue instructing pro or antisaccade trials was clearest in the medial FEF and right putamen. DTI fiber tracking revealed that the subdivisions of the human FEF complex are mainly connected to the putamen, in agreement with the fMRI findings. The present findings demonstrate that the human FEF has functional subdivisions somewhat comparable to non-human primates. However, the connections to and activation in the human striatum preferentially involve the putamen, not the caudate nucleus as is reported for monkeys. This could imply that fronto-striatal projections for the oculomotor system are fundamentally different between humans and monkeys. Alternatively, there could be a bias in published reports of monkey studies favoring the caudate nucleus over the putamen in the search for oculomotor functions

    Tumor cell survival pathways activated by photodynamic therapy: a molecular basis for pharmacological inhibition strategies

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    Um estudo sobre a formação de treinadores de esporte de alto rendimento de modalidades olímpicas no Rio Grande do Sul

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    Este estudo tem por objetivo estabelecer o perfil de formação dos treinadores de esportes olímpicos que atuam com atletas e equipes de alto rendimento no Rio Grande do Sul. A pesquisa é de natureza qualitativa, realizada por meio de entrevistas semiestruturadas. Foram entrevistados 13 treinadores. Os resultados indicaram que os treinadores de esporte de alto rendimento do Rio Grande do Sul consideram, como principais meios para a obtenção de conhecimentos: a experiência como atleta, a graduação em educação física, a pós-graduação em educação física e esporte, os cursos de formação de treinadores e as participações em competições. Apesar da experiência como atleta ter uma importância no processo de formação do treinador, ela não parece ser fundamental. A formação do treinador deve ser continuada e é importante destacar que os treinadores ficaram divididos entre existir ou não uma aproximação do conhecimento produzido pela universidade com a prática do treinador.This study aims to establish the training profile of Olympic sports coaches who work with athletes and high-performance teams in Rio Grande do Sul. The research is of a qualitative nature, carried out through semi-structured interviews. Thirteen trainers were interviewed. The results indicated that high-performance sports coaches in Rio Grande do Sul consider as main means to obtain knowledge: athlete experience, graduation and post-graduation in physical education and sport, coaching training courses and wokshops and participation in competitions. Although the experience as an athlete has an importance in the training process of the coach, it does not seem to be fundamental. The training of the coach must be continued and it is important to emphasize that the coaches were divided between whether or not there is an approximation of the knowledge produced by the university with the practice of the coach
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