Role of the Wilms' tumor suppressor gene Wt1 in pancreatic development

The Wilms tumor suppressor gene (Wt1) encodes a transcription factor involved in the development of a number of organs, but the role played by Wt1 in pancreatic development is unknown. The pancreas contains a population of pancreatic stellate cells (PSC) very important for pancreatic physiology. We described elsewhere that hepatic stellate cells originate from the WT1‐expressing liver mesothelium. Thus, we checked if the origin of PSCs was similar. WT1 expression is restricted to the pancreatic mesothelium. Between embryonic day (E) 10.5 and E15.5, this mesothelium gives rise to mesenchymal cells that contribute to a major part of the PSC and other cell types including endothelial cells. Most WT1 systemic mutants show abnormal localization of the dorsal pancreas within the mesentery and intestinal malrotation by E14.0. Embryos with conditional deletion of WT1 between E9.5 and E12.5 showed normal dorsal pancreatic bud and intestine, but the number of acini in the ventral bud was reduced approximately 30% by E16.5. Proliferation of acinar cells was reduced in WT1 systemic mutants, but pancreatic differentiation was not impaired. Thus, mesothelial‐derived cells constitute an important subpopulation of pancreatic mesodermal cells. WT1 expression is not essential for pancreas development, although it influences intestinal rotation and correct localization of the dorsal pancreas within the mesogastrium

A population of hematopoietic stem cells derives from GATA4-expressing progenitors located in the placenta and lateral mesoderm of mice

GATA transcription factors are expressed in the mesoderm and endoderm during development. GATA1-3, but not GATA4, are critically involved in hematopoiesis. An enhancer (G2) of the mouse Gata4 gene directs its expression throughout the lateral mesoderm and the allantois, beginning at embryonic day 7.5, becoming restricted to the septum transversum by embryonic day 10.5, and disappearing by midgestation. We have studied the developmental fate of the G2-Gata4 cell lineage using a G2-Gata4Cre;R26REYFP mouse line. We found a substantial number of YFP+ hematopoietic cells of lymphoid, myeloid and erythroid lineages in embryos. Fetal CD41+ /cKit+ /CD34+ and Lin– /cKit+ /CD31+ YFP+ hematopoietic progenitors were much more abundant in the placenta than in the aorta-gonad-mesonephros area. They were clonogenic in the MethoCult assay and fully reconstituted hematopoiesis in myeloablated mice. YFP+ cells represented about 20% of the hematopoietic system of adult mice. Adult YFP+ hematopoietic stem cells constituted a long-term repopulating, transplantable population. Thus, a lineage of adult hematopoietic stem cells is characterized by the expression of GATA4 in their embryonic progenitors and probably by its extraembryonic (placental) origin, although GATA4 appeared not to be required for hematopoietic stem cell differentiation. Both lineages basically showed similar physiological behavior in normal mice, but clinically relevant properties of this particular hematopoietic stem cell population should be checked in physiopathological conditions.España Ministerio de Ecomomía BFU2014-52299-PEspaña Instituto de Salud Carlos III RD12/0019-002

Extracardiac septum transversum/proepicardial endothelial cells pattern embryonic coronary arterio–venous connections

Recent reports suggest that mammalian embryonic coronary endothelium (CoE) originates from the sinus venosus and ventricular endocardium. However, the contribution of extracardiac cells to CoE is thought to be minor and nonsignificant for coronary formation. Using classic (Wt1(Cre)) and previously undescribed (G2-Gata4(Cre)) transgenic mouse models for the study of coronary vascular development, we show that extracardiac septum transversum/proepicardium (ST/PE)-derived endothelial cells are required for the formation of ventricular coronary arterio-venous vascular connections. Our results indicate that at least 20% of embryonic coronary arterial and capillary endothelial cells derive from the ST/PE compartment. Moreover, we show that conditional deletion of the ST/PE lineage-specific Wilms' tumor suppressor gene (Wt1) in the ST/PE of G2-Gata4(Cre) mice and in the endothelium of Tie2(Cre) mice disrupts embryonic coronary transmural patterning, leading to embryonic death. Taken together, our results demonstrate that ST/PE-derived endothelial cells contribute significantly to and are required for proper coronary vascular morphogenesi

The Wilms' tumor suppressor gene regulates pancreas homeostasis and repair.

The Wilms' tumor suppressor gene (Wt1) encodes a zinc finger transcription factor that plays an essential role in the development of kidneys, gonads, spleen, adrenals and heart. Recent findings suggest that WT1 could also be playing physiological roles in adults. Systemic deletion of WT1 in mice provokes a severe deterioration of the exocrine pancreas, with mesothelial disruption, E-cadherin downregulation, disorganization of acinar architecture and accumulation of ascitic transudate. Despite this extensive damage, pancreatic stellate cells do not become activated and lose their canonical markers. We observed that pharmacological induction of pancreatitis in normal mice provokes de novo expression of WT1 in pancreatic stellate cells, concomitant with their activation. When pancreatitis was induced in mice after WT1 ablation, pancreatic stellate cells expressed WT1 and became activated, leading to a partial rescue of the acinar structure and the quiescent pancreatic stellate cell population after recovery from pancreatitis. We propose that WT1 modulates through the RALDH2/retinoic acid axis the restabilization of a part of the pancreatic stellate cell population and, indirectly, the repair of the pancreatic architecture, since quiescent pancreatic stellate cells are required for pancreas stability and repair. Thus, we suggest that WT1 plays novel and essential roles for the homeostasis of the adult pancreas and, through its upregulation in pancreatic stellate cells after a damage, for pancreatic regeneration. Due to the growing importance of the pancreatic stellate cells in physiological and pathophysiological conditions, these novel roles can be of translational relevance

“If we’re here, it’s only because we have no money…” discrimination and violence in Mexican maternity wards

Abstract Background Structural and gender violence in Mexico take on various forms, obstetric violence among them. The objective of our study consisted in analyzing experiences of structural and gender discrimination against women during childbirth care at two public hospitals in Mexico. Methods We conducted a cross-sectional mixed methods study including a survey of closed questions administered to all women who received health care for vaginal or cesarean childbirth at two public hospitals from May 7 to June 7, 2012 (N = 512). Those who reported some form of abuse on the part of health-care professionals were then invited to complete a semi-structured interview (20 women agreed to participate). In addition, three focus groups were organized with health-care professionals from both institutions (31 participants): two were composed of nurses and one of obstetrician-gynecologists (OB-GYNs). This work deals with the qualitative component of the study. Results The narratives of the health-care professionals interviewed contained expressions of health discrimination relating to certain characteristics of their clients, namely poverty, ignorance, failure to understand instructions and being women. The women, on the other hand, perceived themselves as belonging to a low social class and, as a result, behaved passively with staff throughout their hospital stay. They reported both physical and psychological abuse during care. The first included having their legs manipulated roughly, being strapped to the bed, and being subjected to multiple and careless pelvic examinations. Psychological abuse included reprimands, insults, disrespectful remarks, neglect and scowling gestures when requesting assistance. Conclusions The results of our study bear implications for the doctor-client relationship and for the health system in general. They suggest a need to dismantle medical practice – particularly with regard to obstetrics and gynecology - as it has been historically learned and internalized in Mexico. It is imperative to design public policies and strategies based on targeted interventions for dismantling the multiple forms of structural and gender violence replicated daily by actors in the health system

El abuso contra las mujeres durante la atención del parto en hospitales públicos en México

Introduction: To analyze the abuse exhibited by health personnel towards women in obstetrics rooms during attendance at birth in a public hospital in Mexico. Material and Methods: Qualitative study conducted as part of a more extensive research study using a mixed methodological approach that was performed in two public hospitals in the state of Morelos, Mexico, during May and June 2012. A total of 16 women were interviewed; the interviews were stopped after reaching the theoretical saturation point. The interviews were transcribed and processed with the Atlas ti v.7.2 software. Results: The results shows expressions of abuse against women in the delivery room in the four explored dimensions: neglect of the patient during medical examination, lack of information regarding procedures, verbal abuse and physical abuse. The most reported forms of physical abuse were: the roughness and frequency of pelvic examinations, episiotomy and episiorrhaphy without anesthesia, cannulation of the blood stream and epidural anesthesia, shoving legs, hitting with the hand or using any part of the body to cause physical harm to women; the women also reported verbal abuse with sexist comments referring to aspects of the erotic life of women. Conclusions: It is necessary to move forward on proposals favoring the dismantling of abuse in delivery rooms, is also essential to integrate obstetric abuse within the framework of human rights and health rights so that institutions consider women as citizens and subjects of rightIntroducción: Analizar las experiencias de abuso que experimentan las mujeres en las salas de obstetricia en el proceso de atención del parto por parte del personal de salud en un hospital público de México. Material y Métodos: Estudio cualitativo realizado un hospital público del estado de Morelos, México, durante mayo y junio de 2012. Se estableció contacto con todas las mujeres en puerperio inmediato y que se encontraban en condiciones de responder un cuestionario, a las mujeres que reportaron algún tipo de abuso se les invitó a participar en una entrevista semiestructurada, en total se entrevistaron a 16 mujeres. El estudio fue aprobado por la Comisión de Investigación y el Comité de Ética del Instituto Nacional de Salud Pública. A cada mujer se le pidió su consentimiento informado oral. Resultados: El estudio muestra las expresiones del abuso contra las mujeres en la sala de parto en las cuatro dimensiones exploradas: abandono de la mujer, ausencia de información, abuso verbal y abuso físico. Las dos formas de abuso físico más reportadas fueron a) brusquedad y frecuencia con la que se realizan procedimientos rutinarios: tacto, episiotomía y episiorrafia sin anestesia, canalización de vías vasculares y anestesia epidural; y b) aventones de piernas, golpes con la mano o utilización de alguna parte del cuerpo para causar daño físico a la mujer; además reportaron abuso verbal a partir de expresiones y manifestaciones de burla, sometimiento y amenazas, comentarios denigrantes y sexistas, que hacen alusión a aspectos de la vida erótica de la mujer. Asimismo la ausencia de información y del consentimiento informado para realizar algunas maniobras y abandono de la mujer durante el proceso del trabajo de parto fueron referidos en las entrevistas. Conclusión: Es necesario avanzar en propuestas que favorezcan la desarticulación del abuso en las salas de obstetricia, para ello se requiere profundizar en la comprensión de la formación de los profesionales de la salud y del funcionamiento de las instituciones. Asimismo, se hace imprescindible ubicar el abuso obstétrico dentro del marco de los derechos humanos y derechos en salud para que dentro de las instituciones se visualice a las mujeres como ciudadanas sujetas de derecho y no sólo usuarias receptoras de servicios

Conditional deletion of WT1 in the septum transversum mesenchyme causes congenital diaphragmatic hernia in mice

Congenital diaphragmatic hernia (CDH) is a severe birth defect. Wt1-null mouse embryos develop CDH but the mechanisms regulated by WT1 are unknown. We have generated a murine model with conditional deletion of WT1 in the lateral plate mesoderm, using the G2 enhancer of the Gata4 gene as a driver. 80% of G2-Gata4;Wt1 embryos developed typical Bochdalek-type CDH. We show that the posthepatic mesenchymal plate coelomic epithelium gives rise to a mesenchyme that populates the pleuroperitoneal folds isolating the pleural cavities before the migration of the somitic myoblasts. This process fails when Wt1 is deleted from this area. Mutant embryos show Raldh2 downregulation in the lateral mesoderm, but not in the intermediate mesoderm. The mutant phenotype was partially rescued by retinoic acid treatment of the pregnant females. Replacement of intermediate by lateral mesoderm recapitulates the evolutionary origin of the diaphragm in mammals. CDH might thus be viewed as an evolutionary atavism.This study was funded by grants BFU2014-52299-P (Spanish Ministry of Economy), ISCIII-RD12/0019-0022 (ISCIII-TERCEL), and P11-CTS-07564 (Junta de Andalucía). AR is the recipient of the grant PI14-00804 funded by Instituto de Salud Carlos III and cofounded by FEDER funding,Peer Reviewe

Epicardial cell lineages and the origin of the coronary endothelium

The embryonic epicardium generates a population of epicardial‐derived mesenchymal cells (EPDC) whose contribution to the coronary endothelium is minor or, according to some reports, negligible. We have compared four murine cell‐tracing models related to the EPDC in order to elucidate this contribution. Cre recombinase was expressed under control of the promoters of the Wilms' tumor suppressor (Wt1), the cardiac troponin (cTnT), and the GATA5 genes, activating expression of the R26REYFP reporter. We have also used the G2 enhancer of the GATA4 gene as a driver due to its activation in the proepicardium. Recombination was found in most of the epicardium/EPDC in all cases. The contribution of these lineages to the cardiac endothelium was analyzed using confocal microscopy and flow cytometry. G2‐GATA4 lineage cells are the most frequent in the endothelium, probably due to the recruitment of circulating endothelial progenitors. The contribution of the WT1 cell lineage increases along gestation due to further endothelial expression of WT1. GATA5 and cTnT lineages represent 4% of the cardiac endothelial cells throughout the gestation, probably standing for the actual EPDC contribution to the coronary endothelium. These results suggest caution when using a sole cell‐tracing model to study the fate of the EPDC.This work was supported by the Spanish Ministry of Science, Innovation and Universities under grants BFU2017‐83907‐P and BFU2017‐82497‐P; Instituto de Salud Carlos III‐TERCEL network under grant RD16/0011/0034 and RD16/0011/0030; and Consejería de Salud, Junta de Andalucía under grant PC0066‐2017. AJLG is the recipient of a i‐PFIS contract from Instituto de Salud Carlos III (IFI18/00042).Peer reviewe

Estrategia para la promoción del buen trato en la atención obstétrica en México

Objective: Describe the design and implementation of an intervention to confront the abuse of women during childbirth care in Mexico. Material and methods: Two methodological actions were made. The fi rst consisted of a review of conventional literature and gray literature of Latin America and the Caribbean, this review aimed to identify previous experiences in design of interventions to address abuse against women during childbirth care. The search covered the period between January 1, 1990 to October 31, 2014. The second action consisted of the design and implementation of an intervention within health workers in several states of Mexico. Results: Literature review. Seven articles were identifi ed in the category of interventions made in Latin America. The intervention’s design is a methodological theoretical supported in: a) gender perspective b) violence against women based in the ecological model, c) health promotion d) peace education and e) rapprochement counselling. Several health workers among 22 states of Mexico have been trained for this approach. Conclusions: The intervention designed and implemented in Mexico is relevant because it is the fi rst effort of the Ministry of Health to address the abuse and disrespect in obstetric care among public health services. It is necessary to carry out an assessment to ascertain the scope and limitations as well as the next steps.Objetivo: Describir el diseño e implantación de una intervención para enfrentar el abuso hacia las mujeres en la atención del parto en México. Material y métodos: Se efectuaron dos acciones metodológicas: 1) revisión de la literatura para América Latina y El Caribe para identifi car experiencias en el diseño de intervenciones acerca del abuso en las salas de parto. La búsqueda cubrió el periodo del 1o de enero de 1990 al 31 de octubre 2014. 2) diseño e implantación de la intervención con personal de salud. Resultados: Revisión de la literatura. Se identifi caron siete artículos. El diseño de la intervención tiene un sustento teórico metodológico en a) perspectiva de género; b) violencia con base en el modelo ecológico; c) promoción de salud; d) educación para la paz y e) terapia de reencuentro. Se ha capacitado al personal de salud de 22 entidades federativas. Conclusión: Esta intervención implantada en México constituye una estrategia de la Secretaría de Salud para enfrentar el abuso y falta de respeto en la atención obstétrica en los servicios públicos de salu