HEMATOPOIETIC REPROG · Molecular dissection of transcription factor mediated hematopoietic cell rogramming
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2005-04-01 → 2007-03-31
- EU contribution
- €137,582
- Participants
- 1
- Scheme
- EIF
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - HEMATOPOIETIC REPROG (Molecular dissection of transcription factor mediated hematopoietic cell programming)
The specialisation of cells, also called differentiation, is dependent on the activation of genes. Transcription factors are proteins that activate genes and thereby drive and regulate differentiation. Since a few years, it was reported that by introducing an 'inappropriate' transcription factor a given cell could be converted into another type of cell. This process is called trans-differentiation or cellular reprogramming. Both differentiation and reprogramming of cells are still poorly understood on the molecular level. Better and more reliable models explaining these processes would not only be desirable from an academic viewpoint, but could also fuel research in the field of regenerative medicine, i.e. the conversion of one type of tissue into another, referred to as 'tissue regeneration'. Hematopoiesis, the formation of blood cells, was an excellent system to study the role of transcription factors in cellular reprogramming. Work in our laboratory showed that B-lineage cells could be converted into macrophages by introduction of the transcription factor C/EBPa. In order to study this reprogramming phenomenon in molecular detail we created B cells that contained an inducible form of C/EBPa (C/EBPa-ER). While these cells remained regular B cells, treatment with a hormone led to activation of C/EBPa and subsequent reprogramming of cells into macrophages. By using DNA-microarrays, this system allowed us to conduct a large-scale investigation of all genes that were activated or deactivated during this process. With bioinformatic analyses we identified regulative networks of genes that played a role in cellular reprogramming. These studies greatly extended our knowledge as to how blood cells differentiated and how cellular identity was established by differential gene activation.
Data: CORDIS, © European Union
Project objective
Hematopoietic differentiation proceeds through a series of binary decisions where lymphoid and myeloid precursors are specified first, followed by more restricted bi- and monopotent progenitors. Each step involves extinction of the original gene expression program and establishment of a novel gene expression program. This is thought to be accomplished by both antagonistic and synergistic transcription factor interactions that establish cell type specific transcription factor combinations. Recent work from t he host laboratory demonstrated that enforced expression in B cells of either the C/EBPa or C/EBPb transcription factor reprograms these cells into macrophages by a series of paralell and sequential events that require endogenous PU.1. The proposed researc h project aims at dissecting the process of trans-differentiation in this system through analysing the changes that occur both at the level of gene expression and of transcription factor occupacy of target gene promoters. For these studies I will use B cel ls infected with an inducible form of C/EBP which will permit to observe the changes in gene expression over time, using Affymetrix-microarrays and quantitave PCR. To identify C/EBP and PU.1 target genes in B cells and macrophages I will use a ChIP-on-chi p" approach. Results obtained should lead to a better understanding of the lymphoid and myeloid cell branching process and the molecular events accompanying reprogramming of one differentiated cell type into another."
Original text from CORDIS.
Participants
- CENTER FOR GENOMIC REGULATION · BARCELONACoordinatorSpain
Links
Data: CORDIS, © European Union