2010 - 2014
Dates of Study: Oct 2010 - Sept 2014
PhD Supervisor: Prof Fiona Watt
Studentship Sponsor: The Medical Research Council
Thesis Title: Remodelling adult mouse skin by epidermal b-catenin activation
Outreach: Kai was a regular volunteer at the Stem Cell Institute's 'Cambridge Science Festival' stand in 2010, 2012, 2013 and 2014 (co-organiser of the activities in 2013). Kai was also Co-organiser of the 4th Open Academy Davos (Switzerland) in 2010 and 2011.
In June 2014, Kai began his Postdoc career under Hans Clevers' supervision at the Hubrecht Institute for Developmetal Biology
Adult mouse tail epidermal whole-mount labelled with antibodies to keratin 14 (red) and the androgen receptor (green).
Published as cover of the book Skin and its diseases: a subject from the Cold Spring Harbor perspectives in medicine / edited by Anthony E. Oro, Stanford University School of Medicine and Fiona M. Watt, Kings College London.
Genetics lineage tracing of BLIMP1-expressing cells and their progeny (labelled with green fluorescent protein, GFP) in a whole-mount preparation of adult mouse tail epidermis. Differentiated sebocytes are labelled in red and polymerized actin is labelled in blue. The image shows GFP-positive cells in the hair follicle bulge but not in the sebaceous gland.
Published as the cover of the October 2014 issue of Stem Cell Reports, an ISSCR/Cell Press journal
During my PhD, I studied the role of a molecular signalling cascade, the so-called Wnt/β-catenin signalling pathway, in adult mammalian skin. This pathway is required for hair follicle growth and is frequently perturbed in skin diseases such as baldness and cancer. My doctoral research contributed to the better understanding of the impact of this signalling pathway on the communication between the two main layers of mammalian skin (epidermis and dermis). I was also able to show that the epidermal subcompartments (i.e. interfollicular epidermis, sebaceous gland and hair follicle) respond differentially to Wnt/β-catenin signalling during experimental induction of hair growth and tumour formation. In conclusion, my studies revealed a previously unknown plasticity of adult skin tissue.
- Kretzschmar K et al. (2014). BLIMP1 is required for postnatal epidermal homeostasis but does not define a sebaceous gland progenitor under steady state conditions. Stem Cell Reports 3, 620-633 (cover shot).
- Kretzschmar K et al. (2014). Markers of epidermal stem cell subpopulations in adult mammalian skin. Cold Spring Harbor Perspectives in Medicine 4 (doi:10.1101/cshperspect.a013631).
- Driskell RR et al. (2013). Distinct fibroblast lineages determine dermal architecture during skin development and regeneration. Nature 504, 277-281 (cover shot). (* denotes equal contribution).
- Lesko MH et al. (2013). Sox2 modulates the function of two distinct skin cell lineages. Developmental Biology 382, 15-26. (* denotes equal contribution).
- Cottle DL et al. (2013). c-MYC-induced sebaceous gland differentiation is controlled by an androgen receptor/p53 axis. Cell Reports 3, 427-441.
- Kretzschmar K et al. (2012). Lineage tracing. Cell 148, 33-45.
- Driskell RR et al. (2012). Clonal growth of dermal papilla cells in hydrogels reveals intrinsic differences between Sox2-positive and -negative cells in vitro and in vivo. Journal of Investigative Dermatology 132, 1084-1093. (* denotes equal contribution).
- Collins CA et al. (2011). Reprogramming adult dermis to a neonatal state through epidermal activation of β-catenin. Development 138, 5189-5199.