Abstract
BackgroundExpression of the LIM-homeobox gene Lhx2 in murine hematopoietic cells allows for the generation of hematopoietic stem cell (HSC)-like cell lines. To address the molecular basis of Lhx2 function, we generated HSC-like cell lines where Lhx2 expression is regulated by a tet-on system and hence dependent on the presence of doxycyclin (dox). These cell lines efficiently down-regulate Lhx2 expression upon dox withdrawal leading to a rapid differentiation into various myeloid cell types.ResultsGlobal gene expression of these cell lines cultured in dox was compared to different time points after dox withdrawal using microarray technology. We identified 267 differentially expressed genes. The majority of the genes overlapping with HSC-specific databases were those down-regulated after turning off Lhx2 expression and a majority of the genes overlapping with those defined as late progenitor-specific genes were the up-regulated genes, suggesting that these cell lines represent a relevant model system for normal HSCs also at the level of global gene expression. Moreover, in situ hybridisations of several genes down-regulated after dox withdrawal showed overlapping expression patterns with Lhx2 in various tissues during embryonic development.ConclusionGlobal gene expression analysis of HSC-like cell lines with inducible Lhx2 expression has identified genes putatively linked to self-renewal / differentiation of HSCs, and function of Lhx2 in organ development and stem / progenitor cells of non-hematopoietic origin.
Highlights
Expression of the LIM-homeobox gene Lhx2 in murine hematopoietic cells allows for the generation of hematopoietic stem cell (HSC)-like cell lines
Generation of hematopoietic progenitor cell (HPC) lines from the embryonic stem (ES) cells with inducible Lhx2 expression Previously, when generating HPC lines, we used ES cells transduced with retroviral vectors containing Lhx2 cDNA that were subsequently differentiated in vitro into embryoid bodies (EBs)
The HPC lines were established by expanding progenitor cells expressing Lhx2 present in colonies showing a distinct morphology that appeared in the clonal assays of EB cells [18,23]
Summary
Expression of the LIM-homeobox gene Lhx in murine hematopoietic cells allows for the generation of hematopoietic stem cell (HSC)-like cell lines. To address the molecular basis of Lhx function, we generated HSC-like cell lines where Lhx expression is regulated by a tet-on system and dependent on the presence of doxycyclin (dox) These cell lines efficiently downregulate Lhx expression upon dox withdrawal leading to a rapid differentiation into various myeloid cell types. A small number of hematopoietic stem cells (HSCs) are responsible for the continuous production of mature blood cells throughout life. This process is based on the capability of the HSC to replenish itself through a process called self-renewal [1,2,3], and to differentiate into all hematopoietic lineages. Elucidation of the mechanisms responsible for the expansion of the hematopoietic system during embryonic development might offer insights into the mechanisms of self-renewal in the hematopoietic system
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
