Escribir para aprender : ensayo de una alternativa en la enseñanza universitaria de las ciencias

Many professors of scientific disciplines are unsatisfied by a teaching strategy which consists mainly of formal lectures and laboratory exercises. We describe in this paper the implementation of a possible alternative based on the principles of the educational approach termed "Writing to Learn". This is a preliminary essay applied to a full-year course on "Chordates" in the Biological Sciences Degree from the University of Málaga. The students employ a "journal notebook" in which they record various writing exercises and an ongoing written dialogue about the course material. The objective is using writing as a tool to help students master a subject matter, developing analysis and synthesis skills as well as making students more active participants in the learning process

Wt1-expressing progenitors contribute to multiple tissues in the developing lung

Lungs develop from paired endodermal outgrowths surrounded by a mesodermal mesenchyme. Part of this mesenchyme arises from epithelial-mesenchymal transition of the mesothelium that lines the pulmonary buds. Previous studies have shown that this mesothelium-derived mesenchyme contributes to the smooth muscle of the pulmonary vessels, but its significance for lung morphogenesis and its developmental fate are still little known. We have studied this issue using the transgenic mouse model mWt1/IRES/GFP-Cre (Wt1cre) crossed with the Rosa26R-EYFP reporter mouse. In the developing lungs, Wt1, the Wilms' tumor suppressor gene, is specifically expressed in the embryonic mesothelium. In the embryos obtained from the crossbreeding, the Wt1-expressing cell lineage produces the yellow fluorescent protein (YFP), allowing for colocalization with differentiation markers. Wt1cre-YFP cells were very abundant from the origin of the lung buds to postnatal stages, contributing significantly to pulmonary endothelial and smooth muscle cells, bronchial musculature, tracheal and bronchial cartilage, as well as CD34+ fibroblast-like interstitial cells. Thus Wt1cre-YFP mesenchymal cells show the very same differentiation potential as the splanchnopleural mesenchyme surrounding the lung buds. FSP1+ fibroblast-like cells were always YFP−; they expressed the common leukocyte antigen CD45 and were apparently recruited from circulating progenitors. We have also found defects in pulmonary development in Wt1−/− embryos, which showed abnormally fused lung lobes, round-shaped and reduced pleural cavities, and diaphragmatic hernia. Our results suggest a novel role for the embryonic mesothelium-derived cells in lung morphogenesis and involve the Wilms' tumor suppressor gene in the development of this organ.This work was supported by grants BFU2011-25304 (Ministerio de Economía y Competitividad), P11-CTS-7564 (Junta de Andalucía), and RD12/00190/0022 (TerCel network, ISCIII). E. Cano is recipient of a MINECO fellowship (BES-2009-014847)

Peritoneal repairing cells: a type of bone marrow derived progenitor cells involved in mesothelial regeneration

The peritoneal mesothelium exhibits a high regenerative ability. Peritoneal regeneration is concomitant with the appearance, in the coelomic cavity, of a free-floating population of cells whose origin and functions are still under discussion. We have isolated and characterized this cell population and we have studied the process of mesothelial regeneration through flow cytometry and confocal microscopy in a murine model lethally irradiated and reconstituted with GFP-expressing bone marrow cells. In unoperated control mice, most free cells positive for mesothelin, a mesothelial marker, are green fluorescent protein (GFP). However, 24 hrs after peritoneal damage, free mesothelin+/ GFP+ cells appear in peritoneal lavages. Cultured lavage peritoneal cells show colocalization of GFP with mesothelial (mesothelin, cytokeratin) and fibroblastic markers. Immunohistochemical staining of the peritoneal wall also revealed colocalization of GFP with mesothelial markers and with procollagen-1 and smooth muscle α-actin. This was observed in the injured area as well as in the surrounding not-injured peritoneal surfaces. These cells, which we herein call peritoneal repairing cells (PRC), are very abundant 1 week after surgery covering both the damaged peritoneal wall and the surrounding uninjured area. However, they become very scarce 1 month later, when the mesothelium has completely healed. We suggest that PRC constitute a type of monocyte-derived cells, closely related with the tissue-repairing cells known as ‘fibrocytes’ and specifically involved in peritoneal reparation. Thus, our results constitute a synthesis of the different scenarios hitherto proposed about peritoneal regeneration, particularly recruitment of circulating progenitor cells and adhesion of free-floating coelomic cells.This work was supported by grants BFU2008–02384 and SAF2008–1883, (Ministerio de Ciencia e Innovación), RD06/0010/0015 (TerCel network, ISCIII), P06-CTS-01614, P08-CTS-03618 (Junta de AndalucÌa) and LSHM-CT-2005–018630 (VI framework, UE)

Peritoneal repairing cells: A type of bone marrow derived progenitor cells involved in mesothelial regeneration

The peritoneal mesothelium exhibits a high regenerative ability. Peritoneal regeneration is concomitant with the appearance, in the coelomic cavity, of a free-floating population of cells whose origin and functions are still under discussion. We have isolated and characterized this cell population and we have studied the process of mesothelial regeneration through flow cytometry and confocal microscopy in a murine model lethally irradiated and reconstituted with GFP-expressing bone marrow cells. In unoperated control mice, most free cells positive for mesothelin, a mesothelial marker, are green fluorescent protein (GFP). However, 24 hrs after peritoneal damage, free mesothelin+/ GFP+ cells appear in peritoneal lavages. Cultured lavage peritoneal cells show colocalization of GFP with mesothelial (mesothelin, cytokeratin) and fibroblastic markers. Immunohistochemical staining of the peritoneal wall also revealed colocalization of GFP with mesothelial markers and with procollagen-1 and smooth muscle α-actin. This was observed in the injured area as well as in the surrounding not-injured peritoneal surfaces. These cells, which we herein call peritoneal repairing cells (PRC), are very abundant 1 week after surgery covering both the damaged peritoneal wall and the surrounding uninjured area. However, they become very scarce 1 month later, when the mesothelium has completely healed. We suggest that PRC constitute a type of monocyte-derived cells, closely related with the tissue-repairing cells known as 'fibrocytes' and specifically involved in peritoneal reparation. Thus, our results constitute a synthesis of the different scenarios hitherto proposed about peritoneal regeneration, particularly recruitment of circulating progenitor cells and adhesion of free-floating coelomic cells. © 2011 The Authors Journal of Cellular and Molecular Medicine © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.(Ministerio de Ciencia e Innovación), RD06/0010/0015 (TerCel network, ISCIII), P06-CTS-01614, P08-CTS-03618 (Junta de AndalucÌa) and LSHM-CT-2005–018630 (VI framework, UE)Peer Reviewe

The embryonic epicardium: an essential element of cardiac development

The epicardium has recently been identified as an active and essential element of cardiac development. Recent reports have unveiled a variety of functions performed by the embryonic epicardium, as well as the cellular and molecular mechanisms regulating them. However, despite its developmental importance, a number of unsolved issues related to embryonic epicardial biology persist. In this review, we will summarize our current knowledge about (i) the ontogeny and evolution of the epicardium, including a discussion on the evolutionary origins of the proepicardium (the epicardial primordium), (ii) the nature of epicardial–myocardial interactions during development, known to be essential for myocardial growth and maturation, and (iii) the contribution of epicardially derived cells to the vascular and connective tissue of the heart. We will finish with a note on the relationships existing between the primordia of the viscera and their coelomic epithelial lining. We would like to suggest that at least a part of the properties of the embryonic epicardium are shared by many other coelomic cell types, such that the role of epicardium in cardiac development is a particular example of a more general mechanism for the contribution of coelomic and coelomic-derived cells to the morphogenesis of organs such as the liver, kidneys, gonads or spleen.This work was supported by grants BFU2008–02384, BFU2009–07929 and SAF2008–1883, (Ministerio de Ciencia e Innovación), RD06/0010/0015 (TerCel network, ISCIII), RD96/0014/1009 (RECAVA network, ISCIII), P08-CTS-03618 (Junta de AndalucÌa) and LSHM-CT-2005–018630 (VI framework, UE)

Exploring and challenging the network of angiogenesis

Angiogenesis is one of the hallmarks of cancer and, as such, one of the alternative general targets for anticancer therapy. Since angiogenesis is a complex process involving a high number of interconnected components, a network approach would be a convenient systemic way to analyse responses to directed drug attacks. Herein we show that, although the angiogenic network is easily broken by short combinations of directed attacks, it still remains essentially functional by keeping the global patterns and local efficiency essentially unaltered after these attacks. This is a clear sign of its high robustness and resilience and stresses the need of directed, combined attacks for an effective blockade of the process. The results of this theoretical study could be relevant for the design of new antiangiogenic therapies and the selection of their targets

Escribir para aprender : ensayo de una alternativa en la enseñanza universitaria de las ciencias

Many professors of scientific disciplines are unsatisfied by a teaching strategy which consists mainly of formal lectures and laboratory exercises. We describe in this paper the implementation of a possible alternative based on the principles of the educational approach termed "Writing to Learn". This is a preliminary essay applied to a full-year course on "Chordates" in the Biological Sciences Degree from the University of Málaga. The students employ a "journal notebook" in which they record various writing exercises and an ongoing written dialogue about the course material. The objective is using writing as a tool to help students master a subject matter, developing analysis and synthesis skills as well as making students more active participants in the learning process

Mesothelial-mesenchymal transitions in embryogenesis

Most animals develop coelomic cavities lined by an epithelial cell layer called the mesothelium. Embryonic mesothelial cells have the ability to transform into mesenchymal cells which populate many developing organs contributing to their connective and vascular tissues, and also to organ-specific cell types. Furthermore, embryonic mesothelium and mesothelial-derived cells produce essential signals for visceral morphogenesis. We review the most relevant literature about the mechanisms regulating the embryonic mesothelial-mesenchymal transition, the developmental fate of the mesothelial-derived cells and other functions of the embryonic mesothelium, such as its contribution to the establishment of left-right visceral asymmetries or its role in limb morphogenesis