3D Co-culture of hiPSC-Derived Cardiomyocytes With Cardiac Fibroblasts Improves Tissue-Like Features of Cardiac Spheroids.

Both cardiomyocytes and cardiac fibroblasts (CF) play essential roles in cardiac development, function, and remodeling. Properties of 3D co-cultures are incompletely understood. Hence, 3D co-culture of cardiomyocytes and CF was characterized, and selected features compared with single-type and 2D culture conditions.

Functional domains of the FgfrL1 receptor.

FgfrL1 is a novel growth factor receptor that is primarily expressed in musculoskeletal tissues and the kidney. FgfrL1-deficient mice have a malformed diaphragm and no kidneys. Such animals die immediately after birth because they are not able to inflate their lungs.

Del Nido cardioplegia in the setting of minimally invasive aortic valve surgery.

The purpose of this study is to report our experience with del Nido cardioplegia (DNC) in the setting of minimally invasive aortic valve surgery. Forty-six consecutive patients underwent minimally invasive aortic valve replacement (AVR) through a "J" ministernotomy: twenty-five patients received the DNC (Group 1) and 21 patients received standard blood cardioplegia (SBC) (Group 2). The rate of ventricular fibrillation at unclamping was significantly lower in the DNC group (12% vs 52%, p=0.

Development and Characterization of a Scaffold-Free 3D Spheroid Model of Induced Pluripotent Stem Cell-Derived Human Cardiomyocytes.

Cardiomyocytes (CMs) are terminally differentiated cells in the adult heart, and ischemia and cardiotoxic compounds can lead to cell death and irreversible decline of cardiac function. As testing platforms, isolated organs and primary cells from rodents have been the standard in research and toxicology, but there is a need for better models that more faithfully recapitulate native human biology. Hence, a new in vitro model comprising the advantages of 3D cell culture and the availability of induced pluripotent stem cells (iPSCs) of human origin was developed and characterized.

Electrical coupling and propagation in engineered ventricular myocardium with heterogeneous expression of connexin43.

Rationale: Spatial heterogeneity in connexin (Cx) expression has been implicated in arrhythmogenesis.

Objective: This study was performed to quantify the relation between the degree of heterogeneity in Cx43 expression and disturbances in electric propagation.

Methods And Results: Cell pairs and strands composed of mixtures of Cx43(-/-) (Cx43KO) or GFP-expressing Cx43(+/+) (WT(GFP)) murine ventricular myocytes were patterned using microlithographic techniques.

Connexin43 ablation in foetal atrial myocytes decreases electrical coupling, partner connexins, and sodium current.

Aims: Remodelling and regional gradients in expression of connexins (Cx) are thought to contribute to atrial electrical dysfunction and atrial fibrillation. We assessed the effect of interaction between Cx43, Cx40, and Cx45 on atrial cell-to-cell coupling and inward Na current (I(Na)) in engineered pairs of atrial myocytes derived from wild-type mice (Cx43(+/+)) and mice with genetic ablation of Cx43 (Cx43(-/-)).

Methods And Results: Cell pairs were engineered by microcontact printing from atrial Cx43(+/+) and Cx43(-/-) murine myocytes (1 day before birth, 3-5 days in culture).

Relative contributions of connexins 40 and 43 to atrial impulse propagation in synthetic strands of neonatal and fetal murine cardiomyocytes.

Atrial tissue expresses both connexin 40 (Cx40) and 43 (Cx43) proteins. To assess the relative roles of Cx40 and Cx43 in atrial electrical propagation, we synthesized cultured strands of atrial myocytes derived from mice with genetic deficiency in Cx40 or Cx43 expression and measured propagation velocity (PV) by high-resolution optical mapping of voltage-sensitive dye fluorescence. The amount of Cx40 and/or Cx43 in gap junctions was measured by immunohistochemistry and total or sarcolemmal Cx43 or Cx40 protein by immunoblotting.

The complete mitochondrial DNA sequence of the green alga Oltmannsiellopsis viridis: evolutionary trends of the mitochondrial genome in the Ulvophyceae.

The mitochondrial genome displays a highly plastic architecture in the green algal division comprising the classes Prasinophyceae, Trebouxiophyceae, Ulvophyceae, and Chlorophyceae (Chlorophyta). The compact mitochondrial DNAs (mtDNAs) of Nephroselmis (Prasinophyceae) and Prototheca (Trebouxiophyceae) encode about 60 genes and have been ascribed an 'ancestral' pattern of evolution, whereas those of chlorophycean green algae are much more reduced in gene content and size. Although the mtDNA of the early-diverging ulvophyte Pseudendoclonium contains 57 conserved genes, it differs from 'ancestral' chlorophyte mtDNAs by its unusually large size (96 kb) and long intergenic spacers.

Electrical propagation in synthetic ventricular myocyte strands from germline connexin43 knockout mice.

To characterize the role of connexin43 (Cx43) as a determinant of cardiac propagation, we synthesized strands and pairs of ventricular myocytes from germline Cx43-/- mice. The amount of Cx43, Cx45, and Cx40 in gap junctions was analyzed by immunohistochemistry and confocal microscopy. Intercellular electrical conductance, gj, was measured by the dual-voltage clamp technique (DVC), and electrical propagation was assessed by multisite optical mapping of transmembrane potential using a voltage-sensitive dye.

Endothelial protective effects of preconditioning.

The consequences of cardiac ischemia-reperfusion are not limited to myocytes but also extend to the coronary endothelium, where they are characterized by decreased nitric oxide (NO)-dependent relaxations. Given the essential role of the endothelium and NO in the regulation of vascular tone as well as platelet and leukocyte function, protection of coronary endothelial cells is an important therapeutic target. In this context, several studies have shown that both early and delayed preconditioning may prevent endothelial dysfunction after index ischemia-reperfusion.