Generation of cardiomyocytes from human-induced pluripotent stem cells resembling atrial cells with ability to respond to adrenoceptor agonists.

Atrial fibrillation (AF) is the most common chronic arrhythmia presenting a heavy disease burden. We report a new approach for generating cardiomyocytes (CMs) resembling atrial cells from human-induced pluripotent stem cells (hiPSCs) using a combination of Gremlin 2 and retinoic acid treatment. More than 40% of myocytes showed rod-shaped morphology, expression of CM proteins (including ryanodine receptor 2, -actinin-2 and F-actin) and striated appearance, all of which were broadly similar to the characteristics of adult atrial myocytes (AMs).

Intermediate filament protein accumulation in motor neurons derived from giant axonal neuropathy iPSCs rescued by restoration of gigaxonin.

Giant axonal neuropathy (GAN) is a progressive neurodegenerative disease caused by autosomal recessive mutations in the GAN gene resulting in a loss of a ubiquitously expressed protein, gigaxonin. Gene replacement therapy is a promising strategy for treatment of the disease; however, the effectiveness and safety of gigaxonin reintroduction have not been tested in human GAN nerve cells. Here we report the derivation of induced pluripotent stem cells (iPSCs) from three GAN patients with different GAN mutations.

Reprogramming for cardiac regeneration.

Treatment of cardiovascular diseases remains challenging considering the limited regeneration capacity of the heart muscle. Developments of reprogramming strategies to create in vitro and in vivo cardiomyocytes have been the focus point of a considerable amount of research in the past decades. The choice of cells to employ, the state-of-the-art methods for different reprogramming strategies, and their promises and future challenges before clinical entry, are all discussed here.

Endothelial cells provide a niche for placental hematopoietic stem/progenitor cell expansion through broad transcriptomic modification.

Umbilical cord blood (UCB) is an attractive source of hematopoietic stem cells (HSCs). However, the number of HSCs in UCB is limited, and attempts to amplify them in vitro remain inefficient. Several publications have documented amplification of hematopoietic stem/progenitor cells (HSPCs) on endothelial or mesenchymal cells, but the lack of homogeneity in culture conditions and HSC definition impairs direct comparison of these results.

Adaptation of a commonly used, chemically defined medium for human embryonic stem cells to stable isotope labeling with amino acids in cell culture.

Metabolic labeling with stable isotopes is a prominent technique for comparative quantitative proteomics, and stable isotope labeling with amino acids in cell culture (SILAC) is the most commonly used approach. SILAC is, however, traditionally limited to simple tissue culture regimens and only rarely employed in the context of complex culturing conditions as those required for human embryonic stem cells (hESCs). Classic hESC culture is based on the use of mouse embryonic fibroblasts (MEFs) as a feeder layer, and as a result, possible xenogeneic contamination, contribution of unlabeled amino acids by the feeders, interlaboratory variability of MEF preparation, and the overall complexity of the culture system are all of concern in conjunction with SILAC.

Improved methods for reprogramming human dermal fibroblasts using fluorescence activated cell sorting.

Current methods to derive induced pluripotent stem cell (iPSC) lines from human dermal fibroblasts by viral infection rely on expensive and lengthy protocols. One major factor contributing to the time required to derive lines is the ability of researchers to identify fully reprogrammed unique candidate clones from a mixed cell population containing transformed or partially reprogrammed cells and fibroblasts at an early time point post infection. Failure to select high quality colonies early in the derivation process results in cell lines that require increased maintenance and unreliable experimental outcomes.