eprintid: 18691
rev_number: 20
eprint_status: archive
userid: 602
dir: disk0/00/01/86/91
datestamp: 2009-12-22 10:58:40
lastmod: 2015-07-24 14:57:23
status_changed: 2009-12-22 10:58:40
type: thesis
metadata_visibility: show
item_issues_count: 0
creators_name: Abeyewickreme, A.
creators_id: AABEY66
title: The effect of bone morphogenetic protein 4 on haematopoietic stem cells
ispublished: unpub
subjects: 21600
divisions: D13
abstract: Bone morphogenetic protein-4 (BMP4) is highly expressed at sites of haematopoietic stem cell (HSC) formation. During HSC formation in humans, BMP4 is strongly expressed by
cells underlying the ventral floor of the dorsal aorta. BMP4 in combination with other
factors has been shown to play a role in haematopoietic differentiation. The genes Runx1,
Scl, Gata2 and Lmo2 are vital to the development of the haematopoietic system, and
deletion of these genes produces an embryonic lethal phenotype due to the absence of
blood formation. This study investigated whether BMP4 alone upregulates the expression
of these genes. The role of BMP4 was explored during HSC development in an embryonic
stem (ES) cell differentiation model and at later developmental stages using ex vivo foetal
liver and bone marrow serum free cultures. Differentiating ES cells cultured in serum-free
medium were found to express BMP4 and the BMP receptor endogenously. To establish a
model for exogenous BMP4 addition in isolation, lentiviral vectors were used to deliver
short hairpin RNA (shRNA) for sustained RNAi knockdown of endogenous Bmp4
expression during ES cell differentiation. Differentiating shRNA treated ES cells were
cultured and the expression of Runx1, Scl, Gata2 and Lmo2 was measured over time by
real time reverse transcription PCR. With the addition of exogenous BMP4 alone,
expression of Runx1, Scl, Gata2 and Lmo2 was unchanged at days 2 and 4 but increased at
day 6 of differentiation. This demonstrates that BMP4 up regulates the expression of these
genes which are critical to the development of the haematopoietic system. The use of
lentiviral shRNA knockdown provides a model for the control of endogenous growth
factors in future investigations of growth factors in ES cell differentiation.
date: 2009-10
vfaculties: VFPHS
oa_status: green
thesis_class: doctoral_open
language: eng
thesis_view: UCL_Thesis
dart: DART-Europe
primo: open
primo_central: open_green
lyricists_name: Abeyewickreme, A
lyricists_id: AABEY66
full_text_status: public
pages: 304
institution: UCL (University College London)
department: UCL Institute of Child Health
thesis_type: Doctoral
citation:        Abeyewickreme, A.;      (2009)    The effect of bone morphogenetic protein 4 on haematopoietic stem cells.                   Doctoral thesis , UCL (University College London).     Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/18691/1/18691.pdf