Epithelial Biology

Kristin Braun PhD

Research field

Our overall focus is to understand the genetic and extracellular mechanisms that regulate adult epithelial stem cells, both under homeostatic and pathological conditions (e.g. following tissue damage and during cancer formation). Currently, we are focusing our studies on epithelial stem cells in three organ systems: skin, liver and thymus. Specific areas of investigation include: (1) identification of novel putative stem or progenitor cell subpopulations and characterisation of their self-renewal, differentiation potential and global gene expression patterns, (2) assessing the effects of Polycomb group repressors in regulating epidermal and hepatic stem cells, and (3) developing methods for in vivo cell marking to assess the differential fate of epithelial stem cells.

Key research papers

1 Nijhof, J.G.W.*, Braun, K.M.*, Giangreco, A., van Pelt, C., Kawamoto, H., Boyd, R.L., Willemze, R., Mullenders, L.H.F., Watt, F.M, de Gruijl, F.R. and van Ewijk, W. The cell surface marker MTS24 identifies a novel population of follicular keratinocytes with characteristics of progenitor cells. 2006. Development. 133(15), 3027-3037.

2 Silva-Vargas, V.*, Lo Celso, C.*, Giangreco, A., Ofstad, T., Prowse, D.M., Braun, K.M. and Watt, F.M. b -catenin and Hedgehog signal strength specifies number and location of hair follicles in adult epidermis without recruitment of bulge stem cells. 2005. Dev. Cell. 9(1), 121-131.

3 Braun, K.M. , Niemann, C., Jensen, U.B., Sundberg, J.P., Silva-Vargas, V. and Watt, F.M. Manipulation of stem cell proliferation and lineage commitment: visualisation of label-retaining cells in wholemounts of mouse epidermis. 2003. Development. 130(21), 5241- 5255.

4 Braun, K.M ., Degen, J.L. and Sandgren, E.P. Hepatocyte transplantation in a model of toxin-induced liver disease: variable therapeutic effect during replacement of damaged parenchyma by donor cells. 2000. Nat. Med. 6(3), 320-326.