Rapid renewing epithelia such as the epidermis and the intestinal epithelium are maintained by proliferation of undifferentiated stem cells located at specific locations. Recent experiments indicate that stem cells from adult organs might be able to populate tissues other than their tissue of origin. Such findings open the possibility that adult stem cells from different tissues might share common markers. We investigated this by two different approaches. In a first approach we compared the expression profiles from epidermal and intestinal epithelial cells at various stages of differentiation. We found that 108 of 1176 genes analyzed were expressed above background in either keratinocytes or enterocytes and, among these, only 16 genes were expressed in both cell types. Of these 16 genes expressed in both cell types, only five displayed the same shift in expression level during cellular differentiation. Interestingly, all five genes were downregulated during cellular differentiation and represented ubiquitously expressed genes. In the second approach we analyzed the expression of the CC chemokine receptor 6 (CCR6), which we have recently identified as an early differentiation marker of epidermal cells, in the intestine. This analysis demonstrates that the CCR6 protein is found in enterocytes at later stages of differentiation.
- CC chemokine receptor 6 (CCR6)
- Expression profiles