Human Embryonic Stem Cells: A Model System for Delineating the Molecular Basis of Human Embryogenesis and Aging-related Diseases

Abstract

The recent development of techniques to culture human embryonic stem cells (hESC) has allowed the study of reproductive (pregnancy) hormones involved in the growth and development of the early embryo. Until the advent of hESC culture techniques, no model system existed that could readily assess the requirement for pregnancy hormones in the growth and development of the human embryo. Hormonal manipulation of developing embryoes in utero was technically cumbersome and complicated by competing in vivo maternal hormonal signals. This chapter describes recent experimental studies, utilizing hESC, aimed at identifying physiologically relevant signals that promote cell division, differentiation and apoptosis during early embryogenesis and summarizes our current knowledge of how reproductive hormones direct growth and development during embryogenesis. It also describes the potential for using hESC, embryoid bodies (EBs) and neuroectodermal rosettes to gain insights into how reproductive endocrine dyscrasia associated with menopause/andropause drives aberrant cell cycle signalling mechanisms leading to age-related diseases including neurodegeneration and associated cognitive decline.