Origin of congenital coronary arterio-ventricular fistulae from anomalous epicardial and myocardial development.

Coronary Artery Fistulae (CAFs) are cardiac congenital anomalies consisting of an abnormal communication of a coronary artery with either a cardiac chamber or another cardiac vessel. In humans, these congenital anomalies can lead to complications such as myocardial hypertrophy, endocarditis, heart dilatation, and failure. Unfortunately, despite their clinical relevance, the aetiology of CAFs remains unknown. In this work, we have used two different species (mouse and avian embryos) to experimentally model CAFs morphogenesis. Both conditional Itga4 (alpha 4 integrin) epicardial deletion in mice and cryocauterisation of chick embryonic hearts disrupted epicardial development and ventricular wall growth, two essential events in coronary embryogenesis. Our results suggest that myocardial discontinuities in the embryonic ventricular wall promote the early contact of the endocardium with epicardial-derived coronary progenitors at the cardiac surface, leading to ventricular endocardial extrusion, precocious differentiation of coronary smooth muscle cells, and the formation of pouch-like aberrant coronary-like structures in direct connection with the ventricular lumen. The structure of these CAF-like anomalies was compared with histopathological data from a human CAF. Our results provide relevant information for the early diagnosis of these congenital anomalies and the molecular mechanisms that regulate their embryogenesis.The authors thank Dr. A. Rojas (CABIMER, Sevilla, Spain) and Prof. Thalia Papayannopoulou (University of Washington, WA, USA) for sharing with us the G2- Gata4-Cre and Itga4-floxed mouse lines, respectively. We also thank Vanessa Benhamo (Institut Imagine) for her expert support with HREM. Finally, we thank all members of “DeCA” laboratory (University of Málaga, Málaga, Spain), and the “Heart Morphogenesis” laboratory (Institut Imagine and Institut Pasteur, Paris, France) for their help and fruitful discussions on this paper. This work was supported by the Spanish Ministry of Science, R+D+i National Programme [grants RTI2018-095410-RBI00 and PID2021-122626-OB-I00], Spanish Ministry of Science-ISCIII [grant number RD16/0011/0030], and University of Málaga [grant number UMA18-FEDERJA-146] to [JMPP]; Consejería de Salud y Familias, Junta de Andalucía [grant number PIER-0084- 2019] to [JAGD]; University of Málaga [grant number I Plan Propio-UMA-A.4] to [ARV]; Spanish Ministry of Science, Innovation, and Universities (MCIU) (CIBER CV) [grant numbers PID2019-104776RB-I00 and CB16/11/00399] to [JLDLP].S

Development of Mural Cells: From In Vivo Understanding to In Vitro Recapitulation

Mural cells are indispensable for the development and maintenance of healthy mature vasculature, valuable for vascular therapies and as developmental models. However, their functional plasticity, developmental diversity, and multitude of differentiation pathways complicate in vitro generation. Fortunately, there is a vast pool of untapped knowledge from in vivo studies that can guide in vitro engineering. This review highlights the in vivo genesis of mural cells from progenitor populations to recruitment pathways to maturation and identity with an emphasis on how this knowledge is applicable to in vitro models of stem cell differentiation

Targeted Inactivation of Cerberus Like-2 Leads to Left Ventricular Cardiac Hyperplasia and Systolic Dysfunction in the Mouse

Previous analysis of the Cerberus like 2 knockout (Cerl2(-/-)) mouse revealed a significant mortality during the first day after birth, mostly due to cardiac defects apparently associated with randomization of the left-right axis. We have however, identified Cerl2-associated cardiac defects, particularly a large increase in the left ventricular myocardial wall in neonates that cannot be explained by laterality abnormalities. Therefore, in order to access the endogenous role of Cerl2 in cardiogenesis, we analyzed the embryonic and neonatal hearts of Cerl2 null mutants that did not display a laterality phenotype. Neonatal mutants obtained from the compound mouse line Cer2(-/-)Fundacao para a Ciencia e Tecnologia (FCT); IBB/CBME [PEst-OE/EQB/LA0023/2011]; FCT [SFRH/BD/62081/2009]info:eu-repo/semantics/publishedVersio

Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations

Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24−/− mouse model of HGPS. Challenge of Zmpste24−/− mice with the β-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24−/− cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24−/− progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death

The Variant rs1867277 in FOXE1 Gene Confers Thyroid Cancer Susceptibility through the Recruitment of USF1/USF2 Transcription Factors

In order to identify genetic factors related to thyroid cancer susceptibility, we adopted a candidate gene approach. We studied tag- and putative functional SNPs in genes involved in thyroid cell differentiation and proliferation, and in genes found to be differentially expressed in thyroid carcinoma. A total of 768 SNPs in 97 genes were genotyped in a Spanish series of 615 cases and 525 controls, the former comprising the largest collection of patients with this pathology from a single population studied to date. SNPs in an LD block spanning the entire FOXE1 gene showed the strongest evidence of association with papillary thyroid carcinoma susceptibility. This association was validated in a second stage of the study that included an independent Italian series of 482 patients and 532 controls. The strongest association results were observed for rs1867277 (OR[per-allele] = 1.49; 95%CI = 1.30–1.70; P = 5.9×10−9). Functional assays of rs1867277 (NM_004473.3:c.−283G>A) within the FOXE1 5′ UTR suggested that this variant affects FOXE1 transcription. DNA-binding assays demonstrated that, exclusively, the sequence containing the A allele recruited the USF1/USF2 transcription factors, while both alleles formed a complex in which DREAM/CREB/αCREM participated. Transfection studies showed an allele-dependent transcriptional regulation of FOXE1. We propose a FOXE1 regulation model dependent on the rs1867277 genotype, indicating that this SNP is a causal variant in thyroid cancer susceptibility. Our results constitute the first functional explanation for an association identified by a GWAS and thereby elucidate a mechanism of thyroid cancer susceptibility. They also attest to the efficacy of candidate gene approaches in the GWAS era

Early Embryonic Vascular Patterning by Matrix-Mediated Paracrine Signalling: A Mathematical Model Study

During embryonic vasculogenesis, endothelial precursor cells of mesodermal origin known as angioblasts assemble into a characteristic network pattern. Although a considerable amount of markers and signals involved in this process have been identified, the mechanisms underlying the coalescence of angioblasts into this reticular pattern remain unclear. Various recent studies hypothesize that autocrine regulation of the chemoattractant vascular endothelial growth factor (VEGF) is responsible for the formation of vascular networks in vitro. However, the autocrine regulation hypothesis does not fit well with reported data on in vivo early vascular development. In this study, we propose a mathematical model based on the alternative assumption that endodermal VEGF signalling activity, having a paracrine effect on adjacent angioblasts, is mediated by its binding to the extracellular matrix (ECM). Detailed morphometric analysis of simulated networks and images obtained from in vivo quail embryos reveals the model mimics the vascular patterns with high accuracy. These results show that paracrine signalling can result in the formation of fine-grained cellular networks when mediated by angioblast-produced ECM. This lends additional support to the theory that patterning during early vascular development in the vertebrate embryo is regulated by paracrine signalling

Dynamic Epicardial Contribution to Cardiac Interstitial c-Kit and Sca1 Cellular Fractions.

Background: The cardiac interstitial cellular fraction is composed of multiple cell types. Some of these cells are known to express some well-known stem cell markers such as c-Kit and Sca1, but they are no longer accepted to be true cardiac stem cells. Although their existence in the cardiac interstitium has not been disputed, their dynamic throughout development, specific embryonic origin, and potential heterogeneity remain unknown. In this study, we hypothesized that both c-KitPOS and Sca1POS cardiac interstitial cell (CIC) subpopulations are related to the Wilms' tumor 1 (Wt1) epicardial lineage. Methods: In this study, we have used genetic cell lineage tracing methods, immunohistochemistry, and FACS techniques to characterize cardiac c-KitPOS and Sca1POS cells. Results: Our data show that approximately 50% of cardiac c-KitPOS cells are derived from the Wt1-lineage at E15.5. This subpopulation decreased along with embryonic development, disappearing from P7 onwards. We found that a large proportion of cardiac c-KitPOS cells express specific markers strongly suggesting they are blood-borne cells. On the contrary, the percentage of Sca1POS cells within the Wt1-lineage increases postnatally. In accordance with these findings, 90% of adult epicardial-derived endothelial cells and 60% of mEFSK4POS cardiac fibroblasts expressed Sca1. Conclusion: Our study revealed a minor contribution of the Wt1-epicardial lineage to c-KitPOS CIC from embryonic stages to adulthood. Remarkably, a major part of the adult epicardial-derived cell fraction is enriched in Sca1, suggesting that this subpopulation of CICs is heterogeneous from their embryonic origin. The study of this heterogeneity can be instrumental to the development of diagnostic and prognostic tests for the evaluation of cardiac homeostasis and cardiac interstitium response to pathologic stimuli

Evaluation of a bidimensional myoelectric control scheme for robotic prosthesis

[Resumen] En este artículo se presenta un esquema de control mioeléctrico bidimensional orientado al control de la orientación de prótesis robóticas. Tras preprocesar la señal EMG (rectificado y suavizado) obtenida a partir de cuatro canales, se han aplicado cuatro clasificadores distintos con el fin de discriminar entre movimientos de flexión, extensión, abducción y aducción de muñeca. Once participantes han evaluado el esquema y los resultados obtenidos muestran una gran robustez superando el 70% de acierto en todos los casos y alcanzando, en muchos casos, el 80%. Además, los resultados obtenidos sugieren que no hay diferencias entre género y estado físico de los participantes.[Abstract] In this paper, we present a bidimensional myoelectric control scheme oriented to the control of the orientation of a robotic hand prosthesis. After preprocessing the EMG signal (rectification and linear envelope) obtained from four channels, four different classifiers have been applied to discriminate between flexion, extension, adduction and abduction wrist movements. Eleven participants evaluated the control scheme showing results over a 70% accuracy, most of them surpassing an 80%. Moreover, the obtained results suggest that there are no differences in gender or physical condition.Universidad de Alicante; GRE16-2