An in vitro mechanism study on the proliferation and pluripotency of human embryonic stems cells in response to magnesium degradation.

Magnesium (Mg) is a promising biodegradable metallic material for applications in cellular/tissue engineering and biomedical implants/devices. To advance clinical translation of Mg-based biomaterials, we investigated the effects and mechanisms of Mg degradation on the proliferation and pluripotency of human embryonic stem cells (hESCs). We used hESCs as the in vitro model system to study cellular responses to Mg degradation because they are sensitive to toxicants and capable of differentiating into any cell types of interest for regenerative medicine.

Effects of magnesium on growth and proliferation of human embryonic stem cells.

The effects of magnesium on the growth and proliferation of human embryonic stem cells (hESCs) was explored to advance magnesium as an implant biomaterial. When magnesium ions from magnesium salt were added to the culture media at 10, 100, 250, 500, 750, and 1000 ppm (0.4, 4, 10, 20, 30, 40 mM) the rate of increase in viable cell coverage over time was higher for the larger doses of magnesium salt.

Genetic manipulation of human induced pluripotent stem cells.

Human induced pluripotent stem cells (HIPSC) have tremendous value as a source of autologous cells for cellular transplantation in the treatment of degenerative diseases. The protocols described here address methods for large-scale genetic modification of HIPSCs. The first is an optimized method for transfecting HIPSCs cultured in feeder-free conditions.

Feline neural progenitor cells II: use of novel plasmid vector and hybrid promoter to drive expression of glial cell line-derived neurotrophic factor transgene.

Sustained transgene expression is required for the success of cell transplant-based gene therapy. Most widely used are lentiviral-based vectors which integrate into the host genome and thereby maintain sustained transgene expression. This requires integration into the nuclear genome, and potential risks include activation of oncogenes and inactivation of tumor suppressor genes.

Derivation of neural progenitors and retinal pigment epithelium from common marmoset and human pluripotent stem cells.

Embryonic and induced pluripotent stem cells (IPSCs) derived from mammalian species are valuable tools for modeling human disease, including retinal degenerative eye diseases that result in visual loss. Restoration of vision has focused on transplantation of neural progenitor cells (NPCs) and retinal pigmented epithelium (RPE) to the retina. Here we used transgenic common marmoset (Callithrix jacchus) and human pluripotent stem cells carrying the enhanced green fluorescent protein (eGFP) reporter as a model system for retinal differentiation.

Altered patterns of differentiation in karyotypically abnormal human embryonic stem cells.

Upon prolonged culture, human embryonic stem (hES) cells undergo adaptation, exhibiting decreased population doubling times and increased cloning efficiencies, often associated with karyotypic changes. To test whether culture adaptation influences the patterns of differentiation of hES cells, we compared the expression of genes indicative of distinct embryonic lineages in the embryoid bodies produced from two early passage, karyotypically normal hES cell lines, and two late passage, karyotypically abnormal hES cell lines. One of the abnormal lines was a subline of one of the normal early passage lines.

Generation of insulin-producing cells from pluripotent stem cells: from the selection of cell sources to the optimization of protocols.

The pancreas arises from Pdx1-expressing progenitors in developing foregut endoderm in early embryo. Expression of Ngn3 and NeuroD1 commits the cells to form endocrine pancreas, and to differentiate into subsets of cells that constitute islets of Langerhans. β-cells in the islets transcribe gene-encoding insulin, and subsequently process and secrete insulin, in response to circulating glucose.

Efficient transduction of feline neural progenitor cells for delivery of glial cell line-derived neurotrophic factor using a feline immunodeficiency virus-based lentiviral construct.

Work has shown that stem cell transplantation can rescue or replace neurons in models of retinal degenerative disease. Neural progenitor cells (NPCs) modified to overexpress neurotrophic factors are one means of providing sustained delivery of therapeutic gene products in vivo. To develop a nonrodent animal model of this therapeutic strategy, we previously derived NPCs from the fetal cat brain (cNPCs).

Stem cell therapy to treat diabetes mellitus.

Transplantation of pancreatic islets offers a direct treatment for type 1 diabetes and in some cases, insulin-dependent type 2 diabetes. However, its widespread use is hampered by a shortage of donor organs. Many extant studies have focused on deriving beta-cell progenitors from pancreas and pluripotent stem cells.

PAX4 enhances beta-cell differentiation of human embryonic stem cells.

Background: Human embryonic stem cells (HESC) readily differentiate into an apparently haphazard array of cell types, corresponding to all three germ layers, when their culture conditions are altered, for example by growth in suspension as aggregates known as embryoid bodies (EBs). However, this diversity of differentiation means that the efficiency of producing any one particular cell type is inevitably low. Although pancreatic differentiation has been reported from HESC, practicable applications for the use of beta-cells derived from HESC to treat diabetes will only be possible once techniques are developed to promote efficient differentiation along the pancreatic lineages.

mGluR5 is involved in dendrite differentiation and excitatory synaptic transmission in NTERA2 human embryonic carcinoma cell-derived neurons.

The pluripotent human embryonic carcinoma cell line NTERA2 readily differentiates into neurons when exposed to retinoic acid in vitro. These neurons show characteristic morphology with long processes and they express neuronal markers TUJ-1 and NeuN. NTERA2-derived neurons can regulate Ca2+ signalling through ionotropic glutamate (iGluR) and muscarinic receptors (mAChRs).

Transient and stable transgene expression in human embryonic stem cells.

Plasmid vectors remain a valuable yet capricious tool for the genetic manipulation of human embryonic stem (hES) cells. We have compared the efficacy of four promoters to mediate transient and stable transfection in hES and human embryonal carcinoma cell lines with the reporter enhanced green fluorescent protein (eGFP). In transient assays, the two mammalian promoters, UbiquitinC and Rosa26 (pUbiC and pR26), the human cytomegalovirus major immediate early promoter (HCMV-MIE; pCMV), and the HCMV-MIE/chicken beta-actin/rabbit beta-globin hybrid promoter (pCAGG) gave variable results that depended upon the cell line transfected but in an unpredictable way: each promoter supported strong transient expression in at least one cell line.

Human embryonic stem cells: possibilities for human cell transplantation.

Human embryonic stem (ES) cells serve as a potentially unlimited renewable source for cell transplantation targeted to treat several diseases. One advantage of embryonic stem (ES) cells over other stem cells under research is their apparently indefinite self-renewal capacity if cultured appropriately, and their ready differentiation into various cell phenotypes of all three germ layers. To date, a number of studies have reported the derivation of specific functional derivatives from human ES cells in vitro.