Parallel assessment of globin lentiviral transfer in induced pluripotent stem cells and adult hematopoietic stem cells derived from the same transplanted β-thalassemia patient.

A patient with β(E)/β(0) -thalassemia major was converted to transfusion-independence 4.5 years ago by lentiviral gene transfer in hematopoietic stem cells while showing a myeloid-biased cell clone. Induced pluripotent stem cells (iPSCs) are a potential alternative source of hematopoietic stem cells.

Modeling human hematopoietic cell development from pluripotent stem cells.

Understanding the steps and cues that allow hematopoietic cells to be generated during development holds great clinical as well as biological interest. Analysis of these events in mice has provided many important insights into the processes involved, but features that might be unique to humans remain challenging to elucidate because they cannot be studied directly in vivo. Human embryonic stem or induced pluripotent stem cells offer attractive in vitro alternatives to analyze the process.

Functional assays for human embryonic stem cell pluripotency.

Realizing the potential that human embryonic stem cells (hESCs) hold, both for the advancement of biomedical science and the development of new treatments for many human disorders, will be greatly facilitated by the introduction of standardized methods for assessing and altering the biological properties of these cells. The 7-day in vitro alkaline phosphatase colony-forming cell (AP(+)-CFC) assay currently offers the most sensitive and specific method to quantify the frequency of undifferentiated cells present in a culture. In this regard, it is superior to any phenotypic assessment protocol.

Enhanced generation of hematopoietic cells from human hepatocarcinoma cell-stimulated human embryonic and induced pluripotent stem cells.

Objective: Human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) constitute unique sources of pluripotent cells, although the molecular mechanisms involved in their differentiation into specific lineages are just beginning to be defined. Here we evaluated the ability of MEDII (medium conditioned by HepG2 cells, a human hepatocarcinoma cell line) to selectively enhance generation of mesodermal derivatives, including hematopoietic cells, from hESCs and hiPSCs.

Materials And Methods: Test cells were exposed to MEDII prior to being placed in conditions that promote embryoid body (EB) formation.

Alkaline phosphatase-positive colony formation is a sensitive, specific, and quantitative indicator of undifferentiated human embryonic stem cells.

Human embryonic stem cells (hESCs) can be maintained in vitro as immortal pluripotent cells but remain responsive to many differentiation-inducing signals. Investigation of the initial critical events involved in differentiation induction would be greatly facilitated if a specific, robust, and quantitative assay for pluripotent hESCs with self-renewal potential were available. Here we describe the results of a series of experiments to determine whether the formation of adherent alkaline phosphatase-positive (AP(+)) colonies under conditions optimized for propagating undifferentiated hESCs would meet this need.

CECR2, a protein involved in neurulation, forms a novel chromatin remodeling complex with SNF2L.

Chromatin remodeling complexes play critical roles in development. Here we describe a transcription factor, CECR2, which is involved in neurulation and chromatin remodeling. CECR2 shows complex alternative splicing, but all variants contain DDT and bromodomain motifs.

Three duplicons form a novel chimeric transcription unit in the pericentromeric region of chromosome 22q11.

Pericentromeric regions of human chromosomes are preferential sites for the integration of duplicated DNA, or "duplicons", which often contain gene fragments. Although pericentromeric regions appear to be genomic junkyards, they could also be the birthplace of new genes with novel functions. We have characterized a chimeric transcription unit (cat eye syndrome critical region gene 7, CECR7) formed from three duplicons in the pericentromeric region of chromosome 22q.