Generating mESC-derived insulin-producing cell lines through an intermediate lineage-restricted progenitor line.

Generating surrogate insulin-producing cells from embryonic stem cells (ESCs) through in vitro replication of successive steps during pancreatic development has been challenging . Here we describe a novel reproducible protocol to establish homogeneous and scalable insulin-producing cell lines from mouse (m) ESCs via differentiation of the previously described lineage-restricted clonal mESC-derived E-RoSH cells. Unlike their parental mESCs, E-RoSH cells expressed high levels of mesodermal and endodermal genes. Nutrient depletion in the presence of nicotinamide inhibited proliferation of E-RoSH cells and induced differentiation into heterogeneous cultures comprising vascular-like structures that produced detectable levels of insulin and C-peptide in an equimolar ratio. Limiting dilution of these cultures resulted in the isolation of eight independent insulin-producing cell lines in five experiments. All these lines were cloned and shown to be amenable to repeated cycles of freeze and thaw and to replicate for months with a doubling time of 3-4 days. Under such conditions, the cultured cells exhibited genomic, structural, biochemical, and pharmacological properties of pancreatic beta cells, including storage of an equimolar ratio of insulin and C-peptide in granules and release of the contents of these organelles through a glucose-sensitive machinery. After transplantation, these cells reversed hyperglycemia in streptozotocin-treated SCID mice and did not form teratomas.

Establishing clonal cell lines with endothelial-like potential from CD9(hi), SSEA-1(-) cells in embryonic stem cell-derived embryoid bodies.

BACKGROUND: Differentiation of embryonic stem cells (ESCs) into specific cell types with minimal risk of teratoma formation could be efficiently directed by first reducing the differentiation potential of ESCs through the generation of clonal, self-renewing lineage-restricted stem cell lines. Efforts to isolate these stem cells are, however, mired in an impasse where the lack of purified lineage-restricted stem cells has hindered the identification of defining markers for these rare stem cells and, in turn, their isolation. METHODOLOGY/PRINCIPAL FINDINGS: We describe here a method for the isolation of clonal lineage-restricted cell lines with endothelial potential from ESCs through a combination of empirical and rational evidence-based methods. Using an empirical protocol that we have previously developed to generate embryo-derived RoSH lines with endothelial potential, we first generated E-RoSH lines from mouse ESC-derived embryoid bodies (EBs). Despite originating from different mouse strains, RoSH and E- RoSH lines have similar gene expression profiles (r(2) = 0.93) while that between E-RoSH and ESCs was 0.83. In silico gene expression analysis predicted that like RoSH cells, E-RoSH cells have an increased propensity to differentiate into vasculature. Unlike their parental ESCs, E-RoSH cells did not form teratomas and differentiate efficiently into endothelial-like cells in vivo and in vitro. Gene expression and FACS analysis revealed that RoSH and E-RoSH cells are CD9(hi), SSEA-1(-) while ESCs are CD9(lo), SSEA-1(+). Isolation of CD9(hi), SSEA-1(-) cells that constituted 1%-10% of EB-derived cultures generated an E-RoSH-like culture with an identical E-RoSH-like gene expression profile (r(2) = 0.95) and a propensity to differentiate into endothelial-like cells. CONCLUSIONS: By combining empirical and rational evidence-based methods, we identified definitive selectable surface antigens for the isolation and propagation of lineage-restricted stem cells with endothelial-like potential from mouse ESCs.