CHROMATIN IN SKIN · Deciphering the role of chromatin in epidermal stem cell biology
FP7 — People (Marie Curie Actions)
- Duration
- 2008-06-01 → 2010-05-31
- EU contribution
- €177,173
- Participants
- 1
- Scheme
- MC-IEF
Lines connect the coordinator with its partners.
Results in brief
Deciphering the role of chromatin in epidermal stem cell biology
The work performed in the duration of the IEF CHROMATIN IN SKIN has shown to be successful. Using a system to inactivate a large set of genes individually we have devised a strategy to infer functional and genetic interactions between chromatin-factors in a primary human adult stem cell system. This has led to profound insight into how stem cells regulate the genes required at different stages of maturation. Furthermore, using contemporary genome-wide localisation approaches an bioinformatics we have provided evidence explaining why this system is very robust and resistant to pertubation. First we developed methods to initiate primary human epidermal stem cell differentiation using distinct stimuli in culture. Second we optimised transfection protocols to allow silencing of the chromatin-factors of our interest. This, in combination with our quantitative read-out and our newly established conditions for induction of differentiation, enabled us to determine the role of a set of 332 chromatin related factors in epidermal differentiation and self-renewal. The resulting dataset of approximately 5 000 quantitative functional data-points was subjected to bioinformatics analysis based on logic and methodology used in conventional mRNA expression profiling studies. The rediscovery of two known epigenetic mechanisms implicated in epidermal self-renewal validated our approach. Strikingly, we found that these mechanisms are functionally connected. In addition, we could show that they form a functional network with two newly implicated chromatin complexes. Using Chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-seq) we found that this network targets several distinct downstream gene sets, reaffirming the robustness of this network.
Data: CORDIS, © European Union
Project objective
The skin is a multi-layered epithelium consisting of interfollicular epidermis (IFE), hair follicles (HF), sebaceous glands (SG) and apocrine (sweat) glands. Continuous shedding of terminally differentiated keratinocytes necessitates constant regeneration to ensure tissue homeostasis. This depends on the epidermal stem cell compartment located on top of the basement membrane. Several of the signaling pathways involved in this process are known (e.g. Myc, Wnt, Rac1, Notch, and EGFR) and under investigation. Commonly, the end-point of signaling pathways is regulation of transcription. In the cell, transcription takes place in a chromatin context and requires modification of the histones. However, the role of these modifications in epidermal stem cell maintenance and differentiation remains poorly understood. The proposed work aims to provide novel insights into the function of chromatin in these processes. Human epidermal stem cells are easily obtained and retain their ability to terminally differentiate in vitro upon certain stimuli, as determined by involucrin expression. Making use of sh/siRNA mediated knock-down, factors involved in regulation of chromatin will be tested for their role in epidermal stem cell differentiation. Interestingly, recent work of the Watt laboratory showed that Myc-induced differentiation involves histone acetylation. A second of research will be aimed at identifying the gene-expression programs underlying lineage commitment. Recent advances have been made in the Watt laboratory to differentiate human sebocytes into either IFE or SG. This system will be subjected to gene expression profiling to uncover the determinants of commitment to either lineage. In addition, RNAi based screens for chromatin factors involved in this process will be initiated. Finally the role of the identified chromatin factors in the formation of epidermal benign and neoplastic anomalies will be investigated using established in vivo murine-based approaches
Original text from CORDIS.
Participants
- CANCER RESEARCH UK LBG · LONDONCoordinatorUnited Kingdom
Links
Data: CORDIS, © European Union