Adipogenesis of skeletal muscle fibro/adipogenic progenitors is affected by the WNT5a/GSK3/β-catenin axis

Fibro/Adipogenic Progenitors (FAPs) are muscle-interstitial progenitors mediating pro-myogenic signals that are critical for muscle homeostasis and regeneration. In myopathies, the autocrine/paracrine constraints controlling FAP adipogenesis are released causing fat infiltrates. Here, by combining pharmacological screening, high-dimensional mass cytometry and in silico network modeling with the integration of single-cell/bulk RNA sequencing data, we highlighted the canonical WNT/GSK/β-catenin signaling as a crucial pathway modulating FAP adipogenesis triggered by insulin signaling. Consistently, pharmacological blockade of GSK3, by the LY2090314 inhibitor, stabilizes β-catenin and represses PPARγ expression abrogating FAP adipogenesis ex vivo while limiting fatty degeneration in vivo. Furthermore, GSK3 inhibition improves the FAP pro-myogenic role by efficiently stimulating, via follistatin secretion, muscle satellite cell (MuSC) differentiation into mature myotubes. Combining, publicly available single-cell RNAseq datasets, we characterize FAPs as the main source of WNT ligands inferring their potential in mediating autocrine/paracrine responses in the muscle niche. Lastly, we identify WNT5a, whose expression is impaired in dystrophic FAPs, as a crucial WNT ligand able to restrain the detrimental adipogenic differentiation drift of these cells through the positive modulation of the β-catenin signaling

Inter and intra-tumor heterogeneity of paediatric type diffuse high-grade gliomas revealed by single-cell mass cytometry

Paediatric-type diffuse high-grade gliomas (PDHGG) are aggressive tumors affecting children and young adults, with no effective treatment. These highly heterogeneous malignancies arise in different sites of the Central Nervous System (CNS), carrying distinctive molecular alterations and clinical outcomes (inter-tumor heterogeneity). Moreover, deep cellular and molecular profiling studies highlighted the coexistence of genetically and phenotypically different subpopulations within the same tumor mass (intra-tumor heterogeneity). Despite the recent advances made in the field, the marked heterogeneity of PDHGGs still impedes the development of effective targeted therapies and the identification of suitable biomarkers. In order to fill the existing gap, we used mass cytometry to dissect PDHGG inter- and intra-heterogeneity. This is one of the most advanced technologies of the “-omics” era that, using antibodies conjugated to heavy metals, allows the simultaneous measurement of more than 40 markers at single-cell level. To this end, we analyzed eight PDHGG patient-derived cell lines from different locational and molecular subgroups. By using a panel of 15 antibodies, directly conjugated to metals or specifically customized to detect important histone variants, significant differences were highlighted in the expression of the considered antigens. The single-cell multiparametric approach realized has deepened our understanding of PDHGG, confirming a high degree of intra- and inter-tumoral heterogeneity and identifying some antigens that could represent useful biomarkers for the specific PDHGG locational or molecular subgroups

A GNR e as Operações de Apoio à Paz: Legitimidade e limites de actuação

O presente trabalho de investigação aplicada está subordinado ao tema: ―A GNR e as Operações de Apoio à Paz: Legitimidade e Limites de Actuação‖. As operações de apoio à paz são uma realidade do mundo actual e a participação da GNR nestas operações tem sido uma constante. Neste sentido, a legitimidade desta participação tem sido ao longo dos anos questionada, tese esta que é debatida neste trabalho. Para além da legitimidade, são também aqui debatidos quais são os limites de actuação desta força militar em operações deste tipo. Neste contexto, desenvolve-se um estudo através da pergunta de partida: "De que forma a participação nas OAP é importante para a GNR? E para o País?." Os principais objectivos do trabalho são responder às perguntas supra mencionadas, verificar a legitimidade da participação da GNR neste tipo de operações, compreender o conceito das regras de empenhamento e a sua criação e, finalmente , identificar a importância destas regras para a decisão de um comandante. O trabalho iniciou-se com uma fase exploratória, procedendo-se em seguida à pesquisa com particular incidência em livros, legislação e textos relacionados com o tema, tendo sido tam bém utilizada a internet como fontes de informação sobre as operações de apoio à paz. A investigação de campo baseou-se na análise de conteúdo das entrevistas efectuadas, o que permitiu responder às perguntas de investigação através da verificação das hipó teses formuladas. Após a análise dos dados, conclui-se que a GNR tem legitimidade para participar nestas operações, o que está contemplado na sua lei orgânica, e que, em simultâneo, estas participações revelam elevada importância não só para a GNR como para o País. No entanto, para que exista uma melhor preparação das forças que executam estas missões será necessário que o novo Centro de Treino e Aprontamento para Forças de Missões Internacionais entre em funcionamento com uma estrutura diferente da planeada. O presente trabalho foi realizado entre Janeiro e Março de 2009.Abstract This investigation project was developed under the theme: ―The GNR (Portuguese Republican National Guard) and the Peace Operations: Legitimacy and Action Limits. The peace-support operations are a reality in our contemporary world and the GNR's participation in these operations has been a constant. Considering this, the legitimacy of such participations has been questioned over the years, fact that led to the thesis discussed along this work. In addition to legitimacy, the limits of military force in such operations are also debated. In this context, this project was based on two former question s: "What is the meaning of the GNR participation in the peace operations? And for the country?". The main goals of the project are answering the questions above, confirming the legitimacy of GNR's participation in such operations, understanding the rules of engagement and its creation and, at last, identifying the rules importance for a commander’s decision. The project began with an exploratory phase, followed by a research work supported by books, legislation and texts on the subject as well as the Internet as sources of information on peace-support operations. The field research was developed by analysing the conducted interviews, which allowed the research to answer the questions while checking the assumptions previously made. After analyzing the data, it is concluded that the GNR is entitled to participate in these operations, which is included in its organic law, and, simultaneously, these actions reveal high importance not only for the GNR but for the country also. Nevertheless, in order to get a better preparation of the forces that will carry out these missions, changes in structure and functioning of the new Training Centre are needed. This work was developed from January to March 2009

Ejection of damaged mitochondria and their removal by macrophages ensure efficient thermogenesis in brown adipose tissue

Recent findings have demonstrated that mitochondria can be transferred between cells to control metabolic homeostasis. Although the mitochondria of brown adipocytes comprise a large component of the cell volume and undergo reorganization to sustain thermogenesis, it remains unclear whether an intercellular mitochondrial transfer occurs in brown adipose tissue (BAT) and regulates adaptive thermogenesis. Herein, we demonstrated that thermogenically stressed brown adipocytes release extracellular vesicles (EVs) that contain oxidatively damaged mitochondrial parts to avoid failure of the thermogenic program. When re-uptaken by parental brown adipocytes, mitochondria-derived EVs reduced peroxisome proliferator-activated receptor-γ signaling and the levels of mitochondrial proteins, including UCP1. Their removal via the phagocytic activity of BAT-resident macrophages is instrumental in preserving BAT physiology. Depletion of macrophages in vivo causes the abnormal accumulation of extracellular mitochondrial vesicles in BAT, impairing the thermogenic response to cold exposure. These findings reveal a homeostatic role of tissue-resident macrophages in the mitochondrial quality control of BAT

Ejection of damaged mitochondria and their removal by macrophages ensure efficient thermogenesis in brown adipose tissue.

Recent findings have demonstrated that mitochondria can be transferred between cells to control metabolic homeostasis. Although the mitochondria of brown adipocytes comprise a large component of the cell volume and undergo reorganization to sustain thermogenesis, it remains unclear whether an intercellular mitochondrial transfer occurs in brown adipose tissue (BAT) and regulates adaptive thermogenesis. Herein, we demonstrated that thermogenically stressed brown adipocytes release extracellular vesicles (EVs) that contain oxidatively damaged mitochondrial parts to avoid failure of the thermogenic program. When re-uptaken by parental brown adipocytes, mitochondria-derived EVs reduced peroxisome proliferator-activated receptor-γ signaling and the levels of mitochondrial proteins, including UCP1. Their removal via the phagocytic activity of BAT-resident macrophages is instrumental in preserving BAT physiology. Depletion of macrophages in vivo causes the abnormal accumulation of extracellular mitochondrial vesicles in BAT, impairing the thermogenic response to cold exposure. These findings reveal a homeostatic role of tissue-resident macrophages in the mitochondrial quality control of BAT.This work was partially supported by the European Foundation for the Study of Diabetes (EFSD/Lilly, 2017 and EFSD/Boehringer Ingelheim European Research Programme on ‘‘Multi-System Challenges in Diabetes’’) and the Italian Ministry of Health (GR-2018-12367588) to D.L.-B.; Associazione Italiana per la Ricerca sul Cancro (AIRC) under IG 2019 - ID. 23562 project to K.A.; MIUR ‘‘Progetto Eccellenza’’ to Dipartimento di Scienze Farmacologiche e Biomolecolari, Universita` degli Studi di Milano, and NUTRAGE (CNR FOE 2019, DSB.AD004.271) to A.S; Italian Foundation of Multiple Sclerosis (grant 2017/R/8), the Italian Ministry of Health (grant GR-2016-02362380) and the MAI Award grant to V. Chiurchiu; National Institutes of Health (NIH) common fund (DP5 OD028125) and the Burroughs Wellcome Fund (1019648) to J.R.B.; NIH K01DK125608 to F.S.; R01DK102898 and R01DK122808 to Y.- H.T.; and NIH RO1 DK121805 and AHA 19TPA34910079 to B.Z. A.H. was supported by RTI2018-095497-B-I00 from MICINN, HR17_00527 from La Caixa Foundation, and TNE-18CVD04 from the Leducq Foundation. M.S-D was supported by a fellowship PRE2019-08746 from the Ministerio de Ciencia e Innovacio´ n. M.R. was partially supported by a fellowship from AIRC (IG 2019 - ID. 23562) and by the Italian Ministry of Health (SG-2019-12368589). V.C. is part of the PhD Program in Evolutionary Biology and Ecology, Department of Biology, University of Rome Tor Vergata.S