Percorrer por autor "Palmeirim, Isabel"
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- Comprehensive analysis of fibroblast growth factor receptor expression patterns during chick forelimb developmentPublication . Sheeba, Caroline J.; Andrade, Raquel P.; Duprez, Delphine; Palmeirim, IsabelSpecific interactions between fibroblast growth factors (Fgf1-22) and their tyrosine kinase receptors (FgfR1-4) activate different signalling pathways that are responsible for the biological processes in which Fgf signalling is implicated during embryonic development. In the chick, several Fgf ligands (Fgf2, 4,8, 9, 10, 12, 13 and 18) and the four FgfRs (FgfR 1, 2, 3 and 4) have been reported to be expressed in the developing limb. The precise spatial and temporal expression of these transcripts is important to guide the limb bud to develop into a wing/leg. In this paper, we present a detailed and systematic analysis of the expression patterns of FgfR1, 2, 3 and 4 throughout chick wing development, by in situ hybridisation on whole mounts and sections. Moreover, we characterize for the first time the different isoforms of FGFR1-3 by analysing their differential expression in limb ectoderm and mesodermal tissues, using RT-PCR and in situ hybridisation on sections. Finally, isoform-specific sequences for FgfR1IIIb, FgfR1IIIc, FgfR3IIIb and FgfR3IIIc were determined and deposited in GenBank with the following accession numbers: GU053725, GU065444, GU053726, GU065445, respectively.
- Establishment of an induced pluripotent cell line (ABCRIi001-A) from an elderly female for ageing researchPublication . Esteves, Filipa; Vilhena Catarino Brito, David; Rajado, Ana Teresa; Silva, Nádia; Apolónio, Joana; Roberto, Vânia; Andrade, Raquel; Calado, Sofia; Faleiro, Maria Leonor; Albuquerque Andrade de Matos, Carlos Adriano; Marques, Nuno; Marreiros, Ana; Nzwalo, Hipólito; Pais, Sandra; Palmeirim, Isabel; Simãoa, Sónia; Joaquim, Natércia; Miranda, Rui; Pêgas, António; Raposo, Daniela Marques; Sardo, Ana; Araújo, Inês; Nóbrega, Clévio; Castelo-Branco, Pedro; Bragança, JoséHuman induced pluripotent stem cells (hiPSCs) hold promises to model and understand human diseases, including those associated with ageing. Here, we describe ABCRIi001-A, a hiPSC line generated from peripheral blood mononuclear cells (PBMCs) of a 79-year-old female enrolled in a study for development of an ageing score (ALFA Score). PBMCs were reprogrammed using three Sendai virus-based reprogramming vectors (hKOS, hc-Myc, and hKlf4). ABCRIi001-A showed normal morphology and karyotype, viral clearance, absence of genomic aberrations, and their pluripotency was confirmed by expression of pluripotency-related markers and their ability to differentiate into the three germ layers. ABCRIi001-A is valuable for ageing-related studies.
- Getting a handle on embryo limb development: Molecular interactions driving limb outgrowth and patterningPublication . Sheeba, C.J.; Andrade, Raquel P.; Palmeirim, IsabelDevelopment of the vertebrate embryo involves multiple segmentation processes to generate a functional, articulated organism. Cell proliferation, differentiation and patterning involve spatially and temporally regulated gene expression and signal transduction mechanisms. The developing vertebrate limb is an excellent model to study such fine-tuned regulations, whereby cells proliferate and are differentially sculptured along the proximal-distal, anterior-posterior and dorsal-ventral axes to form a functional limb. Complementary experimental approaches in different organisms have enhanced our knowledge on the molecular events underlying limb development. Herein, we summarize the current knowledge of the main signaling mechanisms governing vertebrate limb initiation, outgrowth, specification of limb segments and termination. (C) 2015 Elsevier Ltd. All rights reserved.
- Investigação clínica da iniciativa do investigador em Portugal: identificação de problemas e propostas para melhoriaPublication . Ferreira, João Pedro; Leite-Moreira, Adelino; Da Costa-Pereira, Altamiro; Soares, António José; Robalo-Cordeiro, Carlos; Jerónimo, Cármen; Gavina, Cristina; J. Pinto, Fausto; Schmitt, Fernando; Saraiva, Francisca; Vasques-Nóvoa, Francisco; Canhão, Helena; Cyrne-Carvalho, Henrique; Palmeirim, Isabel; Pimenta, Joana; Cabral da Fonseca, João Eurico; Firmino-Machado, João; Correia Pinto, Jorge; Gonçalves, Lino; Castelo Branco, Miguel; Sousa, Nuno; Fontes de Carvalho, Ricardo; Machado Luciano, Teresa; Gil Oliveira, Tiago; Resende Oliveira, CatarinaPortugal tem um problema cronico de subfinanciamento da investigacao cientifica. Apesar do investimento nacional ter vindo a aumentar nos ultimos anos, este ainda e manifestamente insuficiente.1 A Fundacao para a Ciencia e Tecnologia (FCT) financia anualmente projetos de investigacao em todas as areas cientificas, limitando o valor maximo a euro250 000 por projeto. Todavia, a area cientifica na qual a investigacao clinica esta incluida - "Clinical Medicine, Immunology and estudos multicentricos epidemiologicos e de coorte da iniciativa do investigador, area onde o financiamento e hoje em dia tencial de retorno do investimento em ensaios clinicos e enorme. Em Portugal, por cada euro1 investido em ensaios clinicos 1) o reconhecimento do papel estrategico da investigacao clinica na melhoria dos cuidados de saude e na economia nacional e baixo; 2) a investigacao clinica nao e considerada como prioridade no Plano Nacional de Saude;, e 3) a atividade de EC da iniciativa do investigador e subfinanciada. O presente documento foca-se no ultimo ponto (i.e., subfinanciamento
- Joint interpretation of AER/FGF and ZPA/SHH over time and space underlies hairy2 expression in the chick limbPublication . Sheeba, Caroline J.; Andrade, Raquel P.; Palmeirim, IsabelEmbryo development requires precise orchestration of cell proliferation and differentiation in both time and space. A molecular clock operating through gene expression oscillations was first described in the presomitic mesoderm (PSM) underlying periodic somite formation. Cycles of HES gene expression have been further identified in other progenitor cells, including the chick distal limb mesenchyme, embryonic neural progenitors and both mesenchymal and embryonic stem cells. In the limb, hairy2 is expressed in the distal mesenchyme, adjacent to the FGF source (AER) and along the ZPA-derived SHH gradient, the two major regulators of limb development. Here we report that hairy2 expression depends on joint AER/FGF and ZPA/SHH signaling. FGF plays an instructive role on hairy2, mediated by Erk and Akt pathway activation, while SHH acts by creating a permissive state defined by Gli3-A/Gli3-R>1. Moreover, we show that AER/FGF and ZPA/SHH present distinct temporal and spatial signaling properties in the distal limb mesenchyme: SHH acts at a long-term, long-range on hairy2, while FGF has a shortterm, short-range action. Our work establishes limb hairy2 expression as an output of integrated FGF and SHH signaling in time and space, providing novel clues for understanding the regulatory mechanisms underlying HES oscillations in multiple systems, including embryonic stem cell pluripotency. (C) 2012. Published by The Company of Biologists Ltd.
- Mechanisms of vertebrate embryo segmentation: Common themes in trunk and limb developmentPublication . Sheeba, C.J.; Andrade, Raquel P.; Palmeirim, IsabelVarious ultradian rhythms ensure proper temporal regulations during embryo development. The embryo molecular clock, which was first identified in the presomitic mesoderm (PSM) underlying periodic somite formation, is one among them. Somites are the earliest manifestation of the segmented vertebrate body and they are formed with strict temporal precision. The tetrapod limb is also a segmented structure and the formation of limb bone elements have also been associated with a molecular clock, operating in the distal limb mesenchyme. In both the PSM and the distal limb mesenchyme, the molecular clock (MC) is influenced by FGF, SHH and RA, which are also the key regulators of the development of these tissues. While somitogenesis has been continuously scrutinized to understand the mechanisms of the MC, the limb bud has served as an outstanding paradigm to study how a cohort of undifferentiated cells is organized into functional 3D structures. The fact that both the trunk and limb development are shaped by the MC and by common signaling molecules has prompted the exciting possibility of establishing parallelisms between somitogenesis and limb development. Systematically correlating various parameters during trunk and limb development will help us to appreciate the common principles underlying segmented structure formation and allow the rise of new questions in order to fill the gaps in our present understanding. In this review we have established the parallelisms between somitogenesis and limb development at the level of gene expression patterns and their regulation. Finally, we have also discussed the most evident new avenues this exercise could open to the scientific community. (C) 2016 Elsevier Ltd. All rights reserved.
- Monocarboxylate transporters (MCTs) in gliomas: expression and exploitation as therapeutic targetsPublication . Miranda-Goncalves, Vera; Honavar, Mrinalini; Pinheiro, Celine; Martinho, Olga; Pires, Manuel M.; Pinheiro, Celia; Cordeiro, Michelle; Bebiano, Gil; Costa, Paulo; Palmeirim, Isabel; Reis, Rui M.; Baltazar, FatimaBackground. Gliomas exhibit high glycolytic rates, and monocarboxylate transporters (MCTs) play a major role in the maintenance of the glycolytic metabolism through the proton-linked transmembrane transport of lactate. However, their role in gliomas is poorly studied. Thus, we aimed to characterize the expression of MCT1, MCT4, and their chaperone CD 147 and to assess the therapeutic impact of MCT inhibition in gliomas. Methods. MCTs and CD 147 expressions were characterized by immunohistochemistry in nonneoplastic brain and glioma samples. The effect of CHC (MCT inhibitor) and MCT1 silencing was assessed in in vitro and in vivo glioblastoma models. Results. MCT1, MCT4, and CD 147 were overexpressed in the plasma membrane of glioblastomas, compared with diffuse astrocytomas and nonneoplastic brain. CHC decreased glycolytic metabolism, migration, and invasion and induced cell death in U251 cells (more glycolytic) but only affected proliferation in SW1088 (more oxidative). The effectiveness of CHC in glioma cells appears to be dependent on MCT membrane expression. MCT1 downregulation showed similar effects on different glioma cells, supporting CHC as an MCT1 inhibitor. There was a synergistic effect when combining CHC with temozolomide treatment in U251 cells. In the CAM in vivo model, CHC decreased the size of tumors and the number of blood vessels formed. Conclusions. This is the most comprehensive study reporting the expression of MCTs and CD 147 in gliomas. The MCT1 inhibitor CHC exhibited anti-tumoral and anti-angiogenic activity in gliomas and, of importance, enhanced the effect of temozolomide. Thus, our results suggest that development of therapeutic approaches targeting MCT1 may be a promising strategy in glioblastoma treatment.
- A morphometric characterization of early CHICK embryo elongationPublication . Maia-Fernandes, Ana C; Pais de Azevedo, Tomás; Martins, Nísia Borralho; Ventura Ramalhete, Sara Maria; Martins, G. G.; Palmeirim, Isabel; dos Santos Duarte, Guilhermina Isabel; Marreiros, Ana; Martel, Paulo; Andrade, RaquelThe chicken embryo has long been a pivotal model system to understand the cellular and molecular mechanisms driving amniote embryo development. Its easy access for in vivo experimentation, together with the development of ex ovo culture techniques, has made it a choice model system for elaborate experimental manipulations. Temporal progression of chick embryo development is classically categorized using the Hamburger and Hamilton staging system (Hamburger, V., & Hamilton, 1951). However, this offers limited temporal resolution when comparing embryos within the same developmental stage and may further be hindered by experimental conditions that directly impact the morphological structures used for stage identification. Here, we performed timelapse imaging of early chick embryonic stages HH4 to HH10 and obtained quantitative elongation data of multiple embryonic portions, yielding two valuable and freely accessible data resources for the chick research community. We identified length measurements capable of describing developmental time, thus enabling the alignment of independent embryos with temporal resolution. Notably, the head-fold (C-HF) showed a strong time correlation, even though it elongates above the primary embryonic axis. A morphometric characterization of HH stages further showed that C-HF length can discriminate HH stages of development, albeit with limited resolution. Finally, we present ChEEQ: Chicken Embryo Elongation Quantification (https://colab.research.google.co m/github/EmbryoClock/ChickElong/blob/main/ChEEQ/ChEEQ.ipynb), a new morphometric tool describing HH4-HH10 embryo elongation, that allows the comparison of user-input data with our reference dataset and is capable of inferring quantitative alterations to embryo developmental time using length measurements alone. Together, these resources open new avenues for investigating vertebrate embryo elongation and quantitatively assessing the effects of experimental interventions on development.
- Patterning in time and space: HoxB cluster gene expression in the developing chick embryoPublication . Gouveia, Analuce; Marcelino, Hugo M.; Gonçalves, Lisa; Palmeirim, Isabel; Andrade, Raquel P.The developing embryo is a paradigmatic model to study molecular mechanisms of time control in Biology. Hox genes are key players in the specification of tissue identity during embryo development and their expression is under strict temporal regulation. However, the molecular mechanisms underlying timely Hox activation in the early embryo remain unknown. This is hindered by the lack of a rigorous temporal framework of sequential Hox expression within a single cluster. Herein, a thorough characterization of HoxB cluster gene expression was performed over time and space in the early chick embryo. Clear temporal collinearity of HoxB cluster gene expression activation was observed. Spatial collinearity of HoxB expression was evidenced in different stages of development and in multiple tissues. Using embryo explant cultures we showed that HoxB2 is cyclically expressed in the rostral presomitic mesoderm with the same periodicity as somite formation, suggesting a link between timely tissue specification and somite formation. We foresee that the molecular framework herein provided will facilitate experimental approaches aimed at identifying the regulatory mechanisms underlying Hox expression in Time and Space.
- rdml: A Mathematica package for parsing and importing Real-Time qPCR dataPublication . Magno, Ramiro; Duarte, Isabel; Andrade, Raquel P.; Palmeirim, IsabelObjective The purpose and objective of the research presented is to provide a package for easy importing of Real-Time PCR data markup language (RDML) data to Mathematica. Results Real-Time qPCR is the most widely used experimental method for the accurate quantification of gene expression. To enable the straightforward archiving and sharing of qPCR data and its associated experimental information, an XML-based data standard was developed—the Real-Time PCR data markup language (RDML)—devised by the RDML consortium. Here, we present rdml, a package to parse and import RDML data into Mathematica, allowing the quick loading and extraction of relevant data, thus promoting the re-analysis, meta-analysis or experimental re-validation of gene expression data deposited in RDML format.