Estudo dos parasitas gastrointestinais do sacarrabos (Herpestes ichneumon) e outros carnívoros silvestres coabitantes, com relevância em Portugal

Dissertação de Mestrado Integrado em Medicina VeterináriaO sacarrabos (Herpestes ichneumon) é um carnívoro silvestre, da família Herpestidae, diurno, pouco gregário e cuja distribuição se limita exclusivamente à Península Ibérica e a parte do norte de África. Poucos são os estudos efetuados neste mangusto, principalmente no que diz respeito à sua fauna parasitológica. Foi então realizado um estudo no âmbito dos parasitas gastrointestinais deste carnívoro, de forma a clarificar o papel que este tem na transmissão de certas parasitoses, tanto como hospedeiro definitivo ou como hospedeiro reservatório. Adicionalmente, pretendeu-se o estudo da fauna parasitológica de outros carnívoros silvestres coabitantes (raposa, texugo e fuinha), também comuns na Península Ibérica. Foram extraídas amostras fecais de 358 intestinos congelados de vários carnívoros silvestres, recolhidos através de um Projeto centralizado na Universidade de Aveiro: sacarrabos (n = 345), raposa (n = 9), texugo (n = 3) e fuinha (n = 1) que provinham de vários pontos de Portugal, na sua maioria na zona sul. Estas foram analisadas usando métodos coprológicos de flutuação, sedimentação, McMaster e esfregaço fecal com coloração de Ziehl-Neelsen. Foi isolada Giardia sp. de uma amostra de sacarrabos (1/345) e também da única amostra de fuinha (1/1), sendo este o primeiro relato deste protozoário no mangusto ibérico. Foi igualmente verificado, numa amostra de sacarrabos (1/345), um nemátode da superfamília Metastrongyloidea, cujo género foi impossível de identificar. Toxocara canis, Toxascaris leonina, Uncinaria sp. e Passalurus sp. foram isolados em quatro raposas (4/9). Quanto ao principal carnívoro em estudo, o sacarrabos, verificou-se que a prevalência de parasitas é bastante baixa neste carnívoro (0,6%). Causas comportamentais, alimentares e geográficas foram apontadas para justificar esta prevalência, não descartando, contudo, o modo de armazenamento das amostras pré-processamento (congelação). Mais uma vez, foi verificada a importância parasitária e zoonótica que as raposas representam tanto a nível silvático como doméstico, assim como a importância do sacarrabos e da fuinha como potenciais hospedeiros reservatórios e perpetuadores, a nível animal e humano, de Giardia sp.. Futuros estudos parasitológicos, com amostras frescas, poderão confirmar este tipo de prevalência, assim como estudos que incidam sobre a base vegetal da dieta e as características fisiológicas deste carnívoro.ABSTRACT - STUDY OF GASTROINTESTINAL PARASITES IN THE EGYPTIAN MONGOOSE (Herpestes ichneumon) AND OTHER CO-INHABITANT WILD CARNIVORES, WITH RELEVANCE IN PORTUGAL - The Egyptian mongoose (Herpestes ichneumon) is a wild carnivore, from the Herpestidae family, diurnal, with few gregarious habits, and whose geographical distribution is limited to the Iberian Peninsula and part of North Africa. Few are the revisions conducted in this mongoose, especially the ones that concern its parasitological fauna. A parasitological study was conducted on the gastrointestinal parasites of this carnivore, to clarify its role on the transmission of some parasitic diseases, as a definitive host or a reservoir host. Moreover, other wild carnivores (red fox, eurasian badger and stone marten), common in the Iberian Peninsula, were also studied. Fecal samples from 358 frozen intestines of various wild carnivores, collected through a Project centralized at the Aveiro University, were collected: Egyptian mongoose (n = 345), red fox (n = 9), eurasian badger (n = 3) and stone marten (n = 1) that originated from several spots in Portugal, mainly from the south. The samples were analyzed by flotation, sedimentation and McMaster procedures and fecal smears stained by Ziehl-Neelsen technique. Giardia sp. was isolated from a single sample of Egyptian mongoose (1/345) and also from the only sample of stone marten (1/1), this being the first report of this protozoan in the mongoose. Another sample of Egyptian mongoose demonstrated the presence of a nematode, from the superfamily Metastrongyloidea, but the genus could not be identified. Toxocara canis, Toxascaris leonina, Uncinaria sp. and Passalurus sp. were isolated from four red foxes (4/9). Concerning the main carnivore in this study, a low parasitological prevalence (0,6%) was verified. Behavioral, dietary and geographical causes were indicated to justify this prevalence, without ruling out the storage method used for the samples (freezing) prior to their treatment. Once again, the parasitological and zoonotic importance of red foxes on both sylvatic and domestic levels was confirmed. The same was established for the Egyptian mongoose and the stone marten regarding the protozoan Giardia sp.. Future parasitological studies with fresh samples may be needed to confirm this kind of prevalence, as well as studies addressing the plant-based part of the diet and the physiology of this carnivore

Usos da memória como recurso de contextualização no jornalismo digital

This article aims to discuss aspects of the production of the so-called contextual journalism linked to the notion of memory, in order to understand how it is triggered in the construction of journalistic contents that seek to offer, in a perspective of contextualization, better circumstances for understanding the facts and information reported. To this purpose, reports from the Nexo Jornal and UOL Tab websites are taken as objects of analysis. A first understanding provided by such approach is that memory can be present in journalism in different ways, highlighting here how it, in the activation of facts and circumstances of the past, can shed light on the present of everyday life. Journalism, so to speak, uses memory at the same time that it contributes to shaping it.O presente artigo tem o objetivo de discutir aspectos da produção do chamado jornalismo contextual articulado à noção de memória, a fim de compreender como esta é acionada na construção dos conteúdos jornalísticos que buscam oferecer, em uma perspectiva de contextualização, melhores circunstâncias de compreensão dos fatos e informações abordados. Para tal, toma-se como objetos de análise reportagens dos portais Nexo Jornal e do UOL Tab. Um primeiro entendimento propiciado por tal abordagem é de que a memória pode se fazer presente no jornalismo de diferentes modos, destacando aqui como esta, no acionamento de fatos e circunstâncias do passado, pode jogar luzes no presente da vida cotidiana. O jornalismo, por assim dizer, se vale da memória ao mesmo tempo em que contribui para configurá-la

ACVR1 function in health and disease

Activin A receptor type I (ACVR1) encodes for a bone morphogenetic protein type I receptor of the TGFβ receptor superfamily. It is involved in a wide variety of biological processes, including bone, heart, cartilage, nervous, and reproductive system development and regulation. Moreover, ACVR1 has been extensively studied for its causal role in fibrodysplasia ossificans progressiva (FOP), a rare genetic disorder characterised by progressive heterotopic ossification. ACVR1 is linked to different pathologies, including cardiac malformations and alterations in the reproductive system. More recently, ACVR1 has been experimentally validated as a cancer driver gene in diffuse intrinsic pontine glioma (DIPG), a malignant childhood brainstem glioma, and its function is being studied in other cancer types. Here, we review ACVR1 receptor function and signalling in physiological and pathological processes and its regulation according to cell type and mutational status. Learning from different functions and alterations linked to ACVR1 is a key step in the development of interdisciplinary research towards the identification of novel treatments for these pathologies

Interplay between BMPs and Reactive Oxygen Species in Cell Signaling and Pathology

The integration of cell extrinsic and intrinsic signals is required to maintain appropriate cell physiology and homeostasis. Bone morphogenetic proteins (BMPs) are cytokines that belong to the transforming growth factor-β (TGF-β) superfamily, which play a key role in embryogenesis, organogenesis and regulation of whole-body homeostasis. BMPs interact with membrane receptors that transduce information to the nucleus through SMAD-dependent and independent pathways, including PI3K-AKT and MAPKs. Reactive oxygen species (ROS) are intracellular molecules derived from the partial reduction of oxygen. ROS are highly reactive and govern cellular processes by their capacity to regulate signaling pathways (e.g., NF-κB, MAPKs, KEAP1-NRF2 and PI3K-AKT). Emerging evidence indicates that BMPs and ROS interplay in a number of ways. BMPs stimulate ROS production by inducing NOX expression, while ROS regulate the expression of several BMPs. Moreover, BMPs and ROS influence common signaling pathways, including PI3K/AKT and MAPK. Additionally, dysregulation of BMPs and ROS occurs in several pathologies, including vascular and musculoskeletal diseases, obesity, diabetes and kidney injury. Here, we review the current knowledge on the integration between BMP and ROS signals and its potential applications in the development of new therapeutic strategies

Glucose Restriction Promotes Osteocyte Specification by Activating a PGC-1α-Dependent Transcriptional Program

Molecular mechanism of behavior; Molecular physiology; Specialized functions of cellsMecanismo molecular del comportamiento; Fisiología molecular; Funciones especializadas de las célulasMecanisme molecular del comportament; Fisiologia molecular; Funcions especialitzades de les cèl·lulesOsteocytes, the most abundant of bone cells, differentiate while they remain buried within the bone matrix. This encasement limits their access to nutrients and likely affects their differentiation, a process that remains poorly defined. Here, we show that restriction in glucose supply promotes the osteocyte transcriptional program while also being associated with increased mitochondrial DNA levels. Glucose deprivation triggered the activation of the AMPK/PGC-1 pathway. AMPK and SIRT1 activators or PGC-1α overexpression are sufficient to enhance osteocyte gene expression in IDG-SW3 cells, murine primary osteoblasts, osteocytes, and organotypic/ex vivo bone cultures. Conversely, osteoblasts and osteocytes deficient in Ppargc1a and b were refractory to the effects of glucose restriction. Finally, conditional ablation of both genes in osteoblasts and osteocytes generate osteopenia and reduce osteocytic gene expression in mice. Altogether, we uncovered a role for PGC-1 in the regulation of osteocyte gene expressio

NRF2 function in osteocytes is required for bone homeostasis and drives osteocytic gene expression

Osteocytes, the most abundant bone cell type, are derived from osteoblasts through a process in which they are embedded in an osteoid. We previously showed that nutrient restriction promotes the osteocyte transcriptional program and is associated with increased mitochondrial biogenesis. Here, we show that increased mitochondrial biogenesis increase reactive oxygen species (ROS) levels and consequently, NRF2 activity during osteocytogenesis. NRF2 activity promotes osteocyte-specific expression of Dmp1, Mepe, and Sost in IDG-SW3 cells, primary osteocytes, and osteoblasts, and in murine models with Nfe2l2 deficiency in osteocytes or osteoblasts. Moreover, ablation of Nfe2l2 in osteocytes or osteoblasts generates osteopenia and increases osteoclast numbers with marked sexual dimorphism. Finally, treatment with dimethyl fumarate prevented the deleterious effects of ovariectomy in trabecular bone masses of mice and restored osteocytic gene expression. Altogether, we uncovered the role of NRF2 activity in osteocytes during the regulation of osteocyte gene expression and maintenance of bone homeostasis

Nanoclay-reinforced HA/alginate scaffolds as cell carriers and SDF-1 delivery-platforms for bone tissue engineering

Bone tissue engineering has come on the scene to overcome the difficulties of the current treatment strategies. By combining biomaterials, active agents and growth factors, cells and nanomaterials, tissue engineering makes it possible to create new structures that enhance bone regeneration. Herein, hyaluronic acid and alginate were used to create biologically active hydrogels, and montmorillonite nanoclay was used to reinforce and stabilize them. The developed scaffolds were found to be biocompatible and osteogenic with mMSCs in vitro, especially those reinforced with the nanoclay, and allowed mineralization even in the absence of differentiation media. Moreover, an in vivo investigation was performed to establish the potential of the hydrogels to mend bone and act as cell-carriers and delivery platforms for SDF-1. Scaffolds embedded with SDF-1 exhibited the highest percentages of bone regeneration as well as of angiogenesis, which confirms the suitability of the scaffolds for bone. Although there are a number of obstacles to triumph over, these bioengineered structures showed potential as future bone regeneration treatments

Glucose Restriction Promotes Osteocyte Specification by Activating a PGC-1α-Dependent Transcriptional Program

Osteocytes, the most abundant of bone cells, differentiate while they remain buried within the bone matrix. This encasement limits their access to nutrients and likely affects their differentiation, a process that remains poorly defined. Here, we show that restriction in glucose supply promotes the osteocyte transcriptional program while also being associated with increased mitochondrial DNA levels. Glucose deprivation triggered the activation of the AMPK/PGC-1 pathway. AMPK and SIRT1 activators or PGC-1α overexpression are sufficient to enhance osteocyte gene expression in IDG-SW3 cells, murine primary osteoblasts, osteocytes, and organotypic/ ex vivo bone cultures. Conversely, osteoblasts and osteocytes deficient in Ppargc1a and b were refractory to the effects of glucose restriction. Finally, conditional ablation of both genes in osteoblasts and osteocytes generate osteopenia and reduce osteocytic gene expression in mice. Altogether, we uncovered a role for PGC-1 in the regulation of osteocyte gene expression. Molecular Mechanism of Behavior; Molecular Physiology; Specialized Functions of Cell

Glucose Restriction Promotes Osteocyte Specification by Activating a PGC-1α-Dependent Transcriptional Program.

Osteocytes, the most abundant of bone cells, differentiate while they remain buried within the bonematrix. This encasement limits their access to nutrients and likely affects their differentiation, a pro-cess that remains poorly defined. Here, we show that restriction in glucose supply promotes the oste-ocyte transcriptional program while also being associated with increased mitochondrial DNA levels.Glucose deprivation triggered the activation of the AMPK/PGC-1 pathway. AMPK and SIRT1 activa-tors or PGC-1aoverexpression are sufficient to enhance osteocyte gene expression in IDG-SW3 cells,murine primary osteoblasts, osteocytes, and organotypic/ex vivobone cultures. Conversely, osteo-blasts and osteocytes deficient inPpargc1aandbwere refractory to the effects of glucose restriction.Finally, conditional ablation of both genes in osteoblasts and osteocytes generate osteopenia andreduce osteocytic gene expression in mice. Altogether, we uncovered a role for PGC-1 in the regula-tion of osteocyte gene expression

Nanomechanical Phenotypes in Cardiac Myosin-Binding Protein C Mutants That Cause Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a disease of the myocardium caused by mutations in sarcomeric proteins with mechanical roles, such as the molecular motor myosin. Around half of the HCM-causing genetic variants target contraction modulator cardiac myosin-binding protein C (cMyBP-C), although the underlying pathogenic mechanisms remain unclear since many of these mutations cause no alterations in protein structure and stability. As an alternative pathomechanism, here we have examined whether pathogenic mutations perturb the nanomechanics of cMyBP-C, which would compromise its modulatory mechanical tethers across sliding actomyosin filaments. Using single-molecule atomic force spectroscopy, we have quantified mechanical folding and unfolding transitions in cMyBP-C domains targeted by HCM mutations that do not induce RNA splicing alterations or protein thermodynamic destabilization. Our results show that domains containing mutation R495W are mechanically weaker than wild-type at forces below 40 pN and that R502Q mutant domains fold faster than wild-type. None of these alterations are found in control, nonpathogenic variants, suggesting that nanomechanical phenotypes induced by pathogenic cMyBP-C mutations contribute to HCM development. We propose that mutation-induced nanomechanical alterations may be common in mechanical proteins involved in human pathologies.J.A.C. acknowledges funding from the Ministerio de Ciencia e Innovación (MCIN) through grants BIO2014– 54768-P, BIO2017–83640-P (AEI/FEDER, UE), EIN2019–102966, RYC-2014–16604, and BFU2017–90692­ REDT, the European Research Area Network on Cardiovascular Diseases (ERA-CVD/ISCIII, MINOTAUR, AC16/00045), and the Comunidad de Madrid (consortium Tec4Bio-CM, S2018/NMT-4443, FEDER). This work was supported by NIH grants RM1 GM33289 and HL117138 to J.A.S.; a Stanford Dean’s Postdoctoral Fellowship to D.P. and N.N.; and a Stanford Maternal and Child Health Research Institute (MCHRI) Postdoctoral Fellowship (1220552–140-DHPEU) to N.N. Financial support to D.D.S. comes from Eusko Jaurlaritza (Basque Government) through the project IT1254–19, and grants RYC-2016–19590 and PGC2018–099321-B-I00 from the MCIN (FEDER). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), MCIN, and the Pro CNIC Foundation and was a Severo Ochoa Center of Excellence (SEV-2015–0505). We acknowledge funding from ISCIII to the Centro de Investigación Biomédica en Red (CIBERCV), CB16/11/00425. C.S.C. is the recipient of an FPI-SO predoctoral fellowship, BES-2016–076638. M.R.P. was the recipient of a Ph.D. fellowship from the Italian Ministry of Education, Universities and Research (MIUR). C.P.L. was a recipient of a CNIC Master Fellowship. We thank N. Vicente for excellent technical support (through grant PEJ16/MED/TL-1593 from Consejería de Educación, Juventud y Deporte de la Comunidad de Madrid and the European Social Fund). We thank the Spectroscopy and Nuclear Magnetic Resonance Core Unit at CNIO for access to CD instrumentation and discussion about protein binding assays. We thank A. Thompson and S. Day for their insights. We thank all members of the Molecular Mechanics of the Cardiovascular System team for helpful discussions and the contribution of five anonymous reviewers.S