Myocardial infarction ´through the window´: dual dynamics for cardiac fibroblasts activation

Activated cardiac fibroblasts (CFs) are responsible for the healing of the heart tissue after a myocardial infarction (MI). Based on high throughput technologies, several groups have recently demonstrated their heterogeneity and a unique role of each subpopulation of CFs during the ventricular remodelling process. This is relevant towards the discovery of personalized treatments to control the initial post-MI healing scar that will contribute to preserve ventricular function and prevent the onset of heart failure. However, little is known about the moment that CFs are activated, and which genes are potentially involved in this process. Using a mouse model for MI and single cell RNA-Seq, we demonstrate that the activation of Reparative Cardiac Fibroblasts (RCFs), the CFs responsible for the healing scar, happens within the first week after MI. Interestingly, our data reveals that all CFs show high expression of the top markers genes for RCF in a specific moment, but only few of them finally evolve to an RCF transcriptomic identity. Furthermore, we describe two different molecular dynamics that could give rise to this activation and, in consequence, the appearance of definitive RCFs. Using Spatial Transcriptomics, we localized the genes related to each dynamic in different anatomical regions of the infarcted heart, but, remarkably, only one persists seven days after MI. These results highlight the existence of a specific “window of activation” of RCFs at the beginning of the ventricular remodelling process. This potential ´therapeutical window´ could allow us to regulate the size of the healing scar and, in consequence, the poor prognosis for patients that have suffered an ischemic event.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Application of single cell transcriptomics to characterize the progression of hematopoietic cells to myeloid malignancies

Hematopoiesis is the process by which blood cells are formed. It has been a broadly studied system since the second half of the 20th century. Attention was drawn to this process after the discovery, in 1951, of the protective role that bone marrow intravenous infusion had against radiation. In the mid-1950s, it was subsequently discovered that this protection was caused by transplanted stem cells contained in the bone marrow. Multipotency of the hematopoietic stem cells (HSCs) was further proven during the 1960s, with the development of clonal in vivo repopulation assays. Following clonal in vitro assays, together with the study of cell surface markers and flow sorting, have configured the current view of the hematopoietic system, as a tree-like hierarchy with the HSCs at the top and mature cells at the bottom (Figure 1.1) [1, 2]. Hematopoiesis is active throughout life and it maintains the pool of mature blood cells, which constitute one of the human tissues with highest turnover. Broadly speaking, specialized blood cells can carry out four main functions: 1) The innate immune system, composed, among others, by macrophages, dendritic cells and granulocytes, constitutes the first defense against infection 2) The adaptive immune system, composed by B and T lymphocytes, carries out a delayed and specialized response against pathogens. 3) Red blood cells transport oxygen to every cell 4) Platelets take care of wound healing

Application of single cell transcriptomics to characterize the progression of hematopoietic cells to myeloid malignancies

Hematopoiesis is the process by which blood cells are formed. It has been a broadly studied system since the second half of the 20th century. Attention was drawn to this process after the discovery, in 1951, of the protective role that bone marrow intravenous infusion had against radiation. In the mid-1950s, it was subsequently discovered that this protection was caused by transplanted stem cells contained in the bone marrow. Multipotency of the hematopoietic stem cells (HSCs) was further proven during the 1960s, with the development of clonal in vivo repopulation assays. Following clonal in vitro assays, together with the study of cell surface markers and flow sorting, have configured the current view of the hematopoietic system, as a tree-like hierarchy with the HSCs at the top and mature cells at the bottom (Figure 1.1) [1, 2]. Hematopoiesis is active throughout life and it maintains the pool of mature blood cells, which constitute one of the human tissues with highest turnover. Broadly speaking, specialized blood cells can carry out four main functions: 1) The innate immune system, composed, among others, by macrophages, dendritic cells and granulocytes, constitutes the first defense against infection 2) The adaptive immune system, composed by B and T lymphocytes, carries out a delayed and specialized response against pathogens. 3) Red blood cells transport oxygen to every cell 4) Platelets take care of wound healing

Multimodal communication in academic oral presentations by L2 Spanish students

Presenting in a second language (L2) is perhaps the greatest challenge for international students in a foreign academic context. In this study, we examine the multimodal (verbal and non-verbal) oral performances of two L2 and two L1 groups of Spanish students enrolled in a university Applied Linguistics course. To determine the specific demands and challenges that each group faces, we conducted a questionnaire with 16 participants and carried out an audiovisual discourse analysis of the presentations based on a multimodal framework applied to the use of academic Spanish. It was discovered in the analysis of the data that multimodal competence, the ability to make use of and combine verbal and non-verbal modes of communication to construct and communicate meaning, can compensate for L2 students’ linguistic deficiencies. The article concludes with guidelines to support the development of multimodal competence of L2 students.Hacer una presentación académica oral en una L2 es quizás uno de los mayores retos a los que se enfrentan los estudiantes internacionales en un contexto académico. En este estudio, examinamos la actuación oral multimodal (verbal y no verbal) de cuatro grupos de estudiantes, dos con español como L2 y dos como L1, matriculados en un curso universitario de Lingüística Aplicada, dos con español como L2 y dos como L1. Con el objetivo de establecer las diferencias entre los grupos y explorar sus dificultades, administramos un cuestionario a los 16 participantes y realizamos un análisis discursivo y audiovisual de las presentaciones, basado en un marco multimodal aplicado al uso del español académico. Entre los resultados obtenidos encontramos que la competencia multimodal, entendida como la habilidad de usar y combinar diversos modos verbales y no verbales para construir y comunicar significado, puede compensar las carencias lingüísticas del alumnado de español L2. El artículo finaliza con algunas recomendaciones para el desarrollo de la competencia multimodal de los estudiantes de movilidad internacional