The ether layer was carefully removed and the extraction was repeated two more times

lexes are not altered in the Grhl12/2 mice. GRHL1 is expressed in the same epidermal cells as DSG1, and in the Grhl12/ 2 animals the production of this cadherin is reduced, which leads to the thickening of innermost, keratin 5-positive cell layer. By study of other differentiation markers we demonstrated that the suprabasal keratinocytes in the skin of Grhl1-null mice exhibit severe deregulation of terminal differentiation program, which may lead to thickening of the epidermis and subacute impairment of epidermal barrier. In our subsequent experiments we investigated whether the Grhl12/2 mice display symptoms of skin barrier defects. In the mutant animals we observed elevated blood levels of a marker of response to barrier defects TSLP, an interleukin-7-like cytokine. When secreted by epithelial cells, this factor stimulates tissue infiltration with immune cells and facilitates their activation. Other markers of defective barrier are antimicrobial peptides S100A8 and S100A9. Genes coding for these Ca2+-dependent alarm factors belong to epidermal differentiation complex . In the unaffected epidermis the expression of S100A8 and S100A9 is low, but it is strongly stimulated upon induction of chronic inflammation. These proteins act as chemoattractants and their elevated secretion by keratinocytes induces dermal infiltration by immune cells. In addition, S100 proteins are increasingly recognized as major regulators of tumor promoting inflammatory GRHL1 in Skin Cancer microenvironment. Therefore we measured the levels of these markers in the epidermis of Grhl12/2 mice and we observed increased expression of S100A8 and S100A9. Moreover, the expressional microarray on whole skin of Grhl12/2 mice revealed upregulation of genes from the small proline-rich family which also belong to EDC PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19638617 Sprr2d, as well as Sprr2g, Sprr2e, Sprr2a, Sprr1a. SPRR proteins form scaffold for other proteins in the cornified envelope of epidermis and are highly upregulated in the skin of barrier-deficient mouse models. Furthermore, the upregulation of other genes associated with inflammation was also detected in this experiment, including the chemokines from chemokine C-X-C motif ligand family Cxcl1, Cxcl9, Cxcl16; beta-defensins Defb4, Defb6, Defb14; and others. Many of them have been associated with cancerous transformation. Among the upregulated genes we also discovered genes coding for proteins specific for mast cells multiple C2 domains, transmembrane 1, Mctp4 and protease, serine, 22 . This prompted us to assess the number of immune cells infiltrating the skin. In the skin from Grhl12/2 mice we detected increased count of toluidine blue stained cells, that are recognized as mast cells. These are known to support the development of SCC. The described gene signature and infiltration with immune cells agree with the notion that the Grhl12/2 mice exhibit mild skin barrier impairments. Recent research showed that mice with subacute skin barrier defects may be more prone to chemically-induced skin tumor development. The authors suggested that the underlying mechanism is general and is dependent on development of tumorpromoting chronic inflammatory microenvironment in the skin. Here we MedChemExpress Luteolin 7-glucoside present data concerning the role of GRHL1 transcription factor in development of skin cancers. The Grhl1-null mice PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19637192 do not develop spontaneous tumors, even in old age, and their life span is the same as that of their Grhl1+/+ littermates. The Grhl12/2 mice develop more carcinomas but fewer p