Biomedical subjects

Rachel Eiges

Publications and source records attributed to Rachel Eiges.

4 recordsLinked to original sources

PubMed2006

Human embryonic stem cells as a powerful tool for studying human embryogenesis.

Human embryonic stem cells (HESC) are pluripotent stem cell lines derived from the inner cell mass (ICM) of human blastocyst-stage embryos. They are characterized by their unlimited capacity to self-renew in culture. In addition, they have a broad developmental potential, as demonstrated by their ability to form practically any cell type in vivo and in vitro. These two features have made HESC extremely important in basic and applied research. In addition, they may serve as a powerful tool for studying human development. HESC can recapitulate embryogenesis by expressing developmentally regulated genes and by activating molecular pathways as they occur in vivo. Moreover, they can be used to analyze the effect of specific mutations on particular developmental events and may enable us to identify critical factors that play a role in the processes of cell commitment, differentiation, and adult cell reprogramming. Thus, modeling human embryogenesis by the use of HESC may allow new insights into developmental processes, which would otherwise be inaccessible for research.

Cell Differentiation↗

PubMed2006

Genetic manipulation of human embryonic stem cells by transfection.

One of the great advantages of embryonic stem (ES) cells over other cell types is their accessibility to genetic manipulation. They can easily undergo genetic modifications while remaining pluripotent, and can be selectively propagated, allowing the clonal expansion of genetically altered cells in culture. Since the first isolation of ES cells in mice, many effective techniques have been developed for gene delivery and manipulation of ES cells. These include transfection, electroporation, and infection protocols, as well as different approaches for inserting, deleting, or changing the expression of genes. These methods proved to be extremely useful in mouse ES cells, for monitoring and directing differentiation, discovering unknown genes and studying their function, and are now being initiated in human ES (hES) cells. This chapter describes the different approaches and methodologies that have been applied for the genetic manipulation of hES cells and their applications. Specifically, two detailed protocols that can be used to generate clones of genetically modified hES cells by transfection will be described, with special emphasis on the important technical details that are required for this purpose.

Animals↗

PubMed2004

Temporal gene expression during differentiation of human embryonic stem cells and embryoid bodies.

BACKGROUND: The aim of this study was to characterize human embryonic stem (ES) cells at the molecular level by performing large-scale complementary DNA (cDNA) analysis using DNA micro-arrays. METHODS: The transcription profile of human ES cells was determined by comparing it to 2, 10 and 30-day old embryoid bodies (EBs) using Affymetrix Genechip human micro-arrays (U133). RESULTS: According to this analysis we demonstrate that two human ES cell lines are more close to each other than to their differentiated derivatives. We also show the spectrum of cytokine receptors that they express, and demonstrate the presence of five genes that are highly specific to human ES cells and to germ cells. Moreover, by profiling different stages in the differentiation of human embryoid bodies, we illustrate the clustering of five sets of temporally expressed genes, which could be related to the sequential stages of embryonic development. Among them are known genes that are involved in early pattern formation. CONCLUSIONS: The present study provides a molecular basis for the identity of human ES cells and demonstrates that during their in vitro differentiation they express embryonic specific genes in a stage specific manner.

Cell Differentiation↗

PubMed2002

A molecular view on pluripotent stem cells.

Pluripotent stem cells are undifferentiated cells that are capable of differentiating to all three embryonic germ layers and their differentiated derivatives. They are transiently found during embryogenesis, in preimplantation embryos and fetal gonads, or as established cell lines. These unique cell types are distinguished by their wide developmental potential and by their ability to be propagated in culture indefinitely, without loosing their undifferentiated phenotype. This short review intends to give a general overview on the pluripotent nature of embryo-derived stem cells with a focus on human embryonic stem cells.

Animals↗