Molecular mechanisms regulating pluripotency and differentiation of human embryonic stem cells

[摘要] Dr James A. Thomson reached a milestone discovery in 1998, as he managed to isolate and in vitro expand embryonic stem cells originating from human blastocysts. Since then, human embryonic stem (hES) cells have served as excellent tools for the understanding of a plethora of events that take place during embryogenesis. A full and comprehensive analysis of the molecular mechanisms that regulate both pluripotency and differentiation procedures will ultimately allow these cells to be utilised for therapeutic purposes. The first part of the present thesis is dedicated to investigating the implication of ADP-Ribosylation Factor 6 (ARF6) in TGFβ signalling. ARF6 is a low molecular weight GTPase involved in various cellular functions. Our preliminary data indicate that ARF6 interacts with SMAD4. Building on that, we uncover novel interactions of ARF6 with proteins SMAD2/3 and the interconnection between nucleotide status and downstream signalling events. The connection between ARF6 and TGFβ signalling led us to hypothesize a role for the GTPase in hES cells. In that system, we characterise the effects of ARF6 activation or knockout on both Activin A and BMP4 signalling. In addition, we uncover a novel role for the GTPase during mesendoderm specification. In the last part of the thesis, we utilise a broad transcriptomic approach to reveal novel candidates that are implicated in early differentiation of hES cells to mesendoderm. The assay has been carried out using a novel culture system, based on the ability of Activin A to preserve pluripotency and BMP4 to initiate differentiation.

[发布机构] University:University of Birmingham;Department:School of Biosciences

[关键词] Q Science;QR Microbiology