Unraveling the evolutionary origin of the complex Nuclear Receptor Element (cNRE), a cis-regulatory module required for preferential expression in the atrial chamber.

Cardiac function requires appropriate proteins in each chamber. Atria requires slow myosin to act as reservoirs, while ventricles demand fast myosin for swift pumping. Myosins are thus under chamber-biased cis-regulation, with myosin gene expression imbalances leading to congenital heart dysfunction. To identify regulatory inputs leading to cardiac chamber-biased expression, we computationally and molecularly dissected the quail Slow Myosin Heavy Chain III (SMyHC III) promoter that drives preferential expression to the atria. We show that SMyHC III gene states are orchestrated by a complex Nuclear Receptor Element (cNRE) of 32 base pairs. Using transgenesis in zebrafish and mice, we demonstrate that preferential atrial expression is achieved by a combinatorial regulatory input composed of atrial activation motifs and ventricular repression motifs. Using comparative genomics, we show that the cNRE might have emerged from an endogenous viral element through infection of an ancestral host germline, revealing an evolutionary pathway to cardiac chamber-specific expression.

Analysis of Notch signaling-dependent gene expression in developing airways reveals diversity of Clara cells.

Clara cells (CCs) are a morphologically and operationally heterogeneous population of Secretoglobin Scgb1a1-expressing secretory cells that are crucial for airway homeostasis and post-injury repair. Analysis of the extent and origin of CC diversity are limited by knowledge of genes expressed in these cells and their precursors. To identify novel putative markers of CCs and explore the origins of CC diversity, we characterized global changes in gene expression in embryonic lungs in which CCs do not form due to conditional disruption of Notch signaling (Rbpjk(CNULL)). Microarray profiling, Real Time PCR (qRT-PCR), and RNA in situ hybridization (ISH) identified eleven genes downregulated in the E18.5 airways of Rbpjk(cnull) compared to controls, nearly half not previously known to mark CCs. ISH revealed that several genes had overlapping but distinct domains of expression of in the normal developing lung (E18.5). Notably, Reg3g, Chad, Gabrp and Lrrc26 were enriched in proximal airways, Hp in the distal airways and Upk3a in clusters of cells surrounding Neuroepithelial Bodies (NEBs). Seven of the eleven genes, including Reg3g, Hp, and Upk3a, were expressed in the adult lung in CCs in a pattern similar to that observed in the developing airways. qRT-PCR-based analysis of gene expression of CCs isolated from different airway regions of B1-EGFP reporter mice corroborated the spatial enrichment in gene expression observed by ISH. Our study identifies candidate markers for CC-precursors and CCs and supports the idea that the diversification of the CC phenotype occurs already during embryonic development.

Neuroepithelial body microenvironment is a niche for a distinct subset of Clara-like precursors in the developing airways.

Clara cells of mammalian airways have multiple functions and are morphologically heterogeneous. Although Notch signaling is essential for the development of these cells, it is unclear how Notch influences Clara cell specification and if diversity is established among Clara cell precursors. Here we identify expression of the secretoglobin Scgb3a2 and Notch activation as early events in a program of secretory cell fate determination in developing murine airways. We show that Scgb3a2 expression in vivo is Notch-dependent at early stages and ectopically induced by constitutive Notch1 activation, and also that in vitro Notch signaling together with the pan-airway transcription factor Ttf1 (Nkx2.1) synergistically regulate secretoglobin gene transcription. Furthermore, we identified a subpopulation of secretory precursors juxtaposed to presumptive neuroepithelial bodies (NEBs), distinguished by their strong Scgb3a2 and uroplakin 3a (Upk3a) signals and reduced Ccsp (Scgb1a1) expression. Genetic ablation of Ascl1 prevented NEB formation and selectively interfered with the formation of this subpopulation of cells. Lineage labeling of Upk3a-expressing cells during development showed that these cells remain largely uncommitted during embryonic development and contribute to Clara and ciliated cells in the adult lung. Together, our findings suggest a role for Notch in the induction of a Clara cell-specific program of gene expression, and reveals that the NEB microenvironment in the developing airways is a niche for a distinct subset of Clara-like precursors.

Activation dynamics and signaling properties of Notch3 receptor in the developing pulmonary artery.

Notch3 signaling is fundamental for arterial specification of systemic vascular smooth muscle cells (VSMCs). However, the developmental role and signaling properties of the Notch3 receptor in the mouse pulmonary artery remain unknown. Here, we demonstrate that Notch3 is expressed selectively in pulmonary artery VSMCs, is activated from late fetal to early postnatal life, and is required to maintain the morphological characteristics and smooth muscle gene expression profile of the pulmonary artery after birth. Using a conditional knock-out mouse model, we show that Notch3 receptor activation in VSMCs is Jagged1-dependent. In vitro VSMC lentivirus-mediated Jagged1 knockdown, confocal localization analysis, and co-culture experiments revealed that Notch3 activation is cell-autonomous and occurs through the physical engagement of Notch3 and VSMC-derived Jagged1 in the interior of the same cell. Although the current models of mammalian Notch signaling involve a two-cell system composed of a signal-receiving cell that expresses a Notch receptor on its surface and a neighboring signal-sending cell that provides membrane-bound activating ligand, our data suggest that pulmonary artery VSMC Notch3 activation is cell-autonomous. This unique mechanism of Notch activation may play an important role in the maturation of the pulmonary artery during the transition to air breathing.

Controle pressórico de pacientes submetidos à cirurgia cardíaca / Blood pressure control in patients submitted to cardiac surgery / Control presórico de la presión de pacientes sometidos a cirugía cardíaca

As alterações nos níveis tensionais são comumente encontradas nos pacientes submetidos à cirurgia cardíaca. Este estudo teve como objetivo analisar os níveis pressóricos dos pacientes no perioperatório de cirurgia cardíaca. Pesquisa descritiva e documental, a amostra foi 176 prontuários dos pacientes submetidos à cirurgia cardíaca em 2007 no Hospital do Coração de Sobral-CE. Quanto ao perfil foi predominante os pacientes do sexo masculino, casados, residindo em municípios distantes do serviço de saúde e população com mais de quarenta anos. A cirurgia de revascularização do miocárdio foi realizada em mais da metade dos pacientes. Houve oscilações nos valores de pressão arterial, porém a normotensão predominou em todas as fases da cirurgia cardíaca, alterações mais importantes ocorreram no pós-operatório. Devido às alterações na pressão arterial nos pacientes submetidos à cirurgia cardíaca, a equipe de enfermagem deve estar cada vez mais habilitada e apta para a monitorização desse parâmetro.

Changes in blood pressure levels are commonly found in patients submitted to cardiac surgery. This study aimed to analyze the bloodpressure of patients in the perioperative period of cardiac surgery. This is a descriptive and documentary research, the sample was 176was composed of records of patients undergoing cardiac surgery in 2007 at the Heart Hospital of Sobral-CE. The profile was predominantlymade of males, married, living in cities far from the health service and the population over forty years of age. The coronary artery bypassgrafting was performed in more than half of the patients. There were fluctuations in blood pressure values, but the normotension predominatedin all phases of cardiac surgery, major changes occurred in the postoperative period. Due to changes in blood pressure in patientsundergoing cardiac surgery, the nursing staff should be increasingly empowered and capable of monitoring this parameter.

Las alteraciones en los niveles de tensión se encuentran comúnmente en los pacientes sometidos a cirugía cardíaca. Este estudio tuvocomo objetivo analizar los niveles presóricos de los pacientes en el perioperatorio de cirugía cardiaca. Investigación descriptiva y documental,la muestra fue de 176 historiales médicos de pacientes sometidos a cirugía cardíaca en el año 2007 en el Hospital del Corazónde Sobral-CE. El perfil predominante punteó pacientes de sexo masculino, casados, que viven en municipios lejanos de los servicios desalud y población de más de cuarenta años de edad. La cirugía de revascularización de miocardio fue realizada en más de la mitad de lospacientes. Hubo oscilaciones en los valores de presión arterial, pero la normotensión predominó en todas las fases de la cirugía cardiaca,alteraciones más importantes ocurrieron en el postoperatorio. Debido a las alteraciones en la presión arterial en los pacientes sometidosa cirugía cardiaca, el equipo de enfermería debe estar cada vez más capacitado y apto para la monitorización de este parámetro.

Home caregivers knowledge and practices of pressure ulcer: qualitative study / Saberes e práticas de cuidadores domiciliares sobre úlcera por pressão: estudo qualitativo / Saberes y prácticas de los cuidadores domiciliares de pacientes con úlcera de presión: un estudio cualitativo

The pressure ulcer (PU) emerges for mobility restrictions and patients with these limitations need a caretaker. The study is of exploratory-descriptive type, with qualitative approach which objectives were: to draw the home caretaker's profile; to evaluate the knowledge of these ones on PU; to identify the preventions completion by them and the factors that hinder and facilitate when caring, it was developed with seven caretakers. Data were collected through semi-structured interviews with seven caregivers of patients with pressure ulcers, being analyzed in accordance with the theme analysis approach. The study revealed that most of the caretakers were women and daughters with knowledge deficit about PU prevention. As an obstacle of caring was mentioned the weight and as facilitators love and affection. We concluded that as bedridden the patient requires caring related to PU prevention, nursing fits there to evaluate and to manage the patients' needs and the caretakers, which will contribute to the promotion of qualified attendance, and will make possible for the caretaker to be autonomous in the completion of the cares.

A úlcera por pressão (UP) surge por restrições de mobilidade e pacientes com estas limitações necessitam de cuidador. Estudo do tipo exploratório-descritivo, com abordagem qualitativa cujos objetivos foram: traçar o perfil do cuidador domiciliar; avaliar o conhecimento destes sobre UP; identificar as prevenções realizadas pelos mesmos e os fatores que dificultam e facilitam no cuidado, foi desenvolvido com sete cuidadores. Os dados foram coletados por meio de entrevista semi-estruturada com sete cuidadores de pacientes portadores de úlcera de pressão e analisados seguindo as diretrizes da análise temática. O estudo revelou que a maioria dos cuidadores eram mulheres e filhas com déficit de conhecimento sobre prevenção de UP. Como obstáculo do cuidado foi mencionado peso e como facilitadores o amor e carinho. Concluímos que como o paciente acamado requer cuidados relativos à prevenção da UP, cabe a enfermagem avaliar e gerenciar as necessidades dos pacientes e cuidadores, o que contribuirá para promoção da assistência qualificada, e possibilitará ao cuidador autonomia na realização dos cuidados.

La úlcera de presión (UP) surge para las restricciones de movilidad y pacientes con estas limitaciones necesitan de un cuidador. El estudio es de tipo exploratorio-descriptivo, con un abordaje cualitativo cuyos objetivos eran; trazar el perfil del cuidador domiciliar; evaluar el conocimiento de éstos en UP; identificar las prevenciones hechas por ellos y los factores que impiden y facilitan el cuidado, se desarrolló con siete cuidadores. Los datos fueron recolectados por medio de una entrevista semiestructurada con siete cuidadores de pacientes con úlceras por presión y analizados según las directrices del análisis temático. El estudio reveló que la mayoría de los cuidadores era mujeres e hijas con déficit de conocimiento sobre la prevención de UP. Como obstáculo del cuidado fue mencionado el peso y como facilitadores el amor y el afecto. Concluimos que un paciente postrado requiere cuidando relacionado a la prevención de UP, cabe a la enfermería evaluar y gestionar las necesidades de los pacientes y de los cuidadores que contribuirá a la promoción de asistencia calificada y posibilitará al cuidador autonomía en la realización de los cuidados.

ALDH1A2 (RALDH2) genetic variation in human congenital heart disease.

BACKGROUND: Signaling by the vitamin A-derived morphogen retinoic acid (RA) is required at multiple steps of cardiac development. Since conversion of retinaldehyde to RA by retinaldehyde dehydrogenase type II (ALDH1A2, a.k.a RALDH2) is critical for cardiac development, we screened patients with congenital heart disease (CHDs) for genetic variation at the ALDH1A2 locus. METHODS: One-hundred and thirty-three CHD patients were screened for genetic variation at the ALDH1A2 locus through bi-directional sequencing. In addition, six SNPs (rs2704188, rs1441815, rs3784259, rs1530293, rs1899430) at the same locus were studied using a TDT-based association approach in 101 CHD trios. Observed mutations were modeled through molecular mechanics (MM) simulations using the AMBER 9 package, Sander and Pmemd programs. Sequence conservation of observed mutations was evaluated through phylogenetic tree construction from ungapped alignments containing ALDH8 s, ALDH1Ls, ALDH1 s and ALDH2 s. Trees were generated by the Neighbor Joining method. Variations potentially affecting splicing mechanisms were cloned and functional assays were designed to test splicing alterations using the pSPL3 splicing assay. RESULTS: We describe in Tetralogy of Fallot (TOF) the mutations Ala151Ser and Ile157Thr that change non-polar to polar residues at exon 4. Exon 4 encodes part of the highly-conserved tetramerization domain, a structural motif required for ALDH oligomerization. Molecular mechanics simulation studies of the two mutations indicate that they hinder tetramerization. We determined that the SNP rs16939660, previously associated with spina bifida and observed in patients with TOF, does not affect splicing. Moreover, association studies performed with classical models and with the transmission disequilibrium test (TDT) design using single marker genotype, or haplotype information do not show differences between cases and controls. CONCLUSION: In summary, our screen indicates that ALDH1A2 genetic variation is present in TOF patients, suggesting a possible causal role for this gene in rare cases of human CHD, but does not support the hypothesis that variation at the ALDH1A2 locus is a significant modifier of the risk for CHD in humans.

Notch signaling controls the balance of ciliated and secretory cell fates in developing airways.

Although there is accumulated evidence of a role for Notch in the developing lung, it is still unclear how disruption of Notch signaling affects lung progenitor cell fate and differentiation events in the airway epithelium. To address this issue, we inactivated Notch signaling conditionally in the endoderm using a Shh-Cre deleter mouse line and mice carrying floxed alleles of the Pofut1 gene, which encodes an O-fucosyltransferase essential for Notch-ligand binding. We also took the same conditional approach to inactivate expression of Rbpjk, which encodes the transcriptional effector of canonical Notch signaling. Strikingly, these mutants showed an almost identical lung phenotype characterized by an absence of secretory Clara cells without evidence of cell death, and showed airways populated essentially by ciliated cells, with an increase in neuroendocrine cells. This phenotype could be further replicated in cultured wild-type lungs by disrupting Notch signaling with a gamma-secretase inhibitor. Our data suggest that Notch acts when commitment to a ciliated or non-ciliated cell fate occurs in proximal progenitors, silencing the ciliated program in the cells that will continue to expand and differentiate into secretory cells. This mechanism may be crucial to define the balance of differentiated cell profiles in different generations of the developing airways. It might also be relevant to mediate the metaplastic changes in the respiratory epithelium that occur in pathological conditions, such as asthma and chronic obstructive pulmonary disease.

The evolutionary origin of cardiac chambers.

Identification of cardiac mechanisms of retinoic acid (RA) signaling, description of homologous genetic circuits in Ciona intestinalis and consolidation of views on the secondary heart field have fundamental, but still unrecognized implications for vertebrate heart evolution. Utilizing concepts from evolution, development, zoology, and circulatory physiology, we evaluate the strengths of animal models and scenarios for the origin of vertebrate hearts. Analyzing chordates, lower and higher vertebrates, we propose a paradigm picturing vertebrate hearts as advanced circulatory pumps formed by segments, chambered or not, devoted to inflow or outflow. We suggest that chambers arose not as single units, but as components of a peristaltic pump divided by patterning events, contrasting with scenarios assuming that chambers developed one at a time. Recognizing RA signaling as a potential mechanism patterning cardiac segments, we propose to use it as a tool to scrutinize the phylogenetic origins of cardiac chambers within chordates. Finally, we integrate recent ideas on cardiac development such as the ballooning and secondary/anterior heart field paradigms, showing how inflow/outflow patterning may interact with developmental mechanisms suggested by these models.

Simulation of the effect of Na+ and Cl- on the velocity of a spreading depression wave using a simplified electrochemical model of synaptic terminals.

In the study of the spreading depression (SD) wave phenomenon and its dynamics, it is necessary to describe the ionic movements along the extracellular space, as well as between this and the intracellular space. In both cases, the ionic movement includes a double coupling involving the concentration and the potential gradients and hence must be described by electrodiffusion mechanisms. Based on this, the effects of the ionic composition on the characteristics of the wave propagation can be predicted. The influence of varying extracellular sodium and chloride concentrations on the velocity of propagation of the SD wave was investigated by simulation. The results achieved are close to the experimental measurement from the literature. These findings suggest the potentiality of the model proposed in supporting the interpretation of experimental data in neuronal tissues, particularly the SD.