Organelle age landscape in skin

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Project Description

Epidermal stem cells (EpSCs) and hair follicle stem cells (HFSCs) are responsible for maintaining the homeostasis in skin. In the interfollicular epidermis (IFE), the EpSCs keep the balance between self-renewal and differentiation. In the hair follicle (HF), the HFSCs maintain the characteristic cycling of the hair that alternates phases of rest, growth and retraction. In both cases, asymmetric cell division (ACD) is a key processes in charge of maintaining the balance between self-renewal and differentiation. Based on the snap-label chemistry, our lab has described the importance of organelle inheritance during ACD. Specifically, in EpSCs we have recently found that the old peroxisomes are mainly inherited by the cell that will remain in the basal layer and become a new stem cell. Moreover, despite of the fact that cells that divide asymmetrically inherit mostly old peroxisomes, we were able to observe a heterogeneity in the organelle age within the basal cells in both, IFE and HF. With this project we aim to go a step further into the understanding of the importance of organelle inheritance in stemness potential. Using the snap-label in vivo, we observe subpopulations of epidermal cells that can be classified based on their organelle age. Using confocal microscopy and image analysis, we will build a map of the organelle age of different populations in the epidermis. The information that we will obtain from this map, will be used to correlate organelle age and cell fate. Using this experimental set up we plan to characterize the organelle age landscape of the skin in homeostasis, regeneration and aging.