Project description:During epithelial tissue morphogenesis, developmental progenitor cells undergo dynamic adhesive and cytoskeletal remodeling to trigger proliferation and migration. Transcriptional mechanisms that restrict such mild form of epithelial plasticity to maintain lineage-restricted differentiation in committed epithelial tissues are poorly understood. Here we report that simultaneous ablation of transcriptional repressor-encoding Ovol1 and Ovol2 results in expansion and blocked terminal differentiation of embryonic epidermal progenitor cells. Conversely, mice overexpressing Ovol2 in their skin epithelia exhibit precocious differentiation accompanied by smaller progenitor cell compartments. We show that Ovol1/2-deficient epidermal cells fail to undertake alpha-catenin–driven actin cytoskeletal reorganization and adhesive maturation, and exhibit changes that resemble epithelial-to-mesenchymal transition (EMT). Remarkably, these alterations as well as defective terminal differentiation are reversed upon depletion of EMT-promoting transcriptional factor Zeb1. Collectively, our findings reveal Ovol-Zeb1-a-catenin sequential repression and highlight novel functions of Ovol as gatekeepers of epithelial adhesion and differentiation by inhibiting progenitor-like traits and epithelial plasticity. Isolated keratinocytes from control, Ovol1 knockout and Ovol1/2 double knockout were physically isolated for RNA extraction and hybridization on Affymetrix microarrays. In order to identify primary changes, we isolated the keratinocytes from mouse skin and allowed them to grow in culture for 2-5 days.
Project description:During epithelial tissue morphogenesis, developmental progenitor cells undergo dynamic adhesive and cytoskeletal remodeling to trigger proliferation and migration. Transcriptional mechanisms that restrict such mild form of epithelial plasticity to maintain lineage-restricted differentiation in committed epithelial tissues are poorly understood. Here we report that simultaneous ablation of transcriptional repressor-encoding Ovol1 and Ovol2 results in expansion and blocked terminal differentiation of embryonic epidermal progenitor cells. Conversely, mice overexpressing Ovol2 in their skin epithelia exhibit precocious differentiation accompanied by smaller progenitor cell compartments. We show that Ovol1/2-deficient epidermal cells fail to undertake alpha-catenin–driven actin cytoskeletal reorganization and adhesive maturation, and exhibit changes that resemble epithelial-to-mesenchymal transition (EMT). Remarkably, these alterations as well as defective terminal differentiation are reversed upon depletion of EMT-promoting transcriptional factor Zeb1. Collectively, our findings reveal Ovol-Zeb1-a-catenin sequential repression and highlight novel functions of Ovol as gatekeepers of epithelial adhesion and differentiation by inhibiting progenitor-like traits and epithelial plasticity. Isolated keratinocytes from control, Ovol1 knockout and Ovol1/2 double knockout were physically isolated for RNA extraction and hybridization on Affymetrix microarrays. In order to identify differentiation changes, we isolated the keratinocytes from mouse skin and allowed them to grow in culture for 2-5 days, then added calcium and allowed them to grow another 3-5 days.
Project description:During epithelial tissue morphogenesis, developmental progenitor cells undergo dynamic adhesive and cytoskeletal remodeling to trigger proliferation and migration. Transcriptional mechanisms that restrict such mild form of epithelial plasticity to maintain lineage-restricted differentiation in committed epithelial tissues are poorly understood. Here we report that simultaneous ablation of transcriptional repressor-encoding Ovol1 and Ovol2 results in expansion and blocked terminal differentiation of embryonic epidermal progenitor cells. Conversely, mice overexpressing Ovol2 in their skin epithelia exhibit precocious differentiation accompanied by smaller progenitor cell compartments. We show that Ovol1/2-deficient epidermal cells fail to undertake alpha-catenin–driven actin cytoskeletal reorganization and adhesive maturation, and exhibit changes that resemble epithelial-to-mesenchymal transition (EMT). Remarkably, these alterations as well as defective terminal differentiation are reversed upon depletion of EMT-promoting transcriptional factor Zeb1. Collectively, our findings reveal Ovol-Zeb1-a-catenin sequential repression and highlight novel functions of Ovol as gatekeepers of epithelial adhesion and differentiation by inhibiting progenitor-like traits and epithelial plasticity. Skin from control and Ovol2 overexpression (Ovol2 BT) were physically isolated for RNA extraction and hybridization on Affymetrix microarrays. In order to identify primary changes, we analyzed skin from E16.5 mice, when morphological differences between control and Ovol2 overexpression were still minimal.
Project description:During epithelial tissue morphogenesis, developmental progenitor cells undergo dynamic adhesive and cytoskeletal remodeling to trigger proliferation and migration. Transcriptional mechanisms that restrict such mild form of epithelial plasticity to maintain lineage-restricted differentiation in committed epithelial tissues are poorly understood. Here we report that simultaneous ablation of transcriptional repressor-encoding Ovol1 and Ovol2 results in expansion and blocked terminal differentiation of embryonic epidermal progenitor cells. Conversely, mice overexpressing Ovol2 in their skin epithelia exhibit precocious differentiation accompanied by smaller progenitor cell compartments. We show that Ovol1/2-deficient epidermal cells fail to undertake alpha-catenin–driven actin cytoskeletal reorganization and adhesive maturation, and exhibit changes that resemble epithelial-to-mesenchymal transition (EMT). Remarkably, these alterations as well as defective terminal differentiation are reversed upon depletion of EMT-promoting transcriptional factor Zeb1. Collectively, our findings reveal Ovol-Zeb1-a-catenin sequential repression and highlight novel functions of Ovol as gatekeepers of epithelial adhesion and differentiation by inhibiting progenitor-like traits and epithelial plasticity. Skin from control and Ovol2 overexpression (Ovol2 BT) were physically isolated for RNA extraction and hybridization on Affymetrix microarrays. In order to identify changes in differentiation of the epidermis, we analyzed skin from E17.5 mice, when differentiation of the epidermis was more advanced.
Project description:This paper shows, for the first time, a novel function of the OVO-like proteins (OVOL1and OVOL2) as critical inducers of mesenchymal to epithelial transition (MET) in human cancer. Examination of the effects of OVOL1 and OVOL2 overexpression in a prostate cancer model.
Project description:Skin constitutes the outer permeability barrier that protects the body from dehydration and a myriad of external assaults. Epidermal keratinocytes act as the first line of innate immune defense, and barrier defects underlie common inflammatory skin diseases. However, the molecular mechanisms that maintain barrier integrity when skin is under challenge to regulate the interplay between epidermal and immune cells are not fully understood. Here we report upregulated expression of transcriptional repressorencoding Ovol1 in epidermal cells of inflamed skin, and its functional importance in maintaining barrier integrity of physically or chemically challenged skin. Following stimulation with imiquimod, Ovol1-deficient mice exhibit significantly aggravated epidermal hyperplasia and psoriasis-like skin inflammation featuring persistent neutrophil accumulation. Using bulk and single-cell RNA-sequencing, we characterize molecular changes in epidermal, fibroblasts, and immune cells that reflect altered epidermal proliferation and differentiation and/or significantly enhanced inflammatory responses as consequences of Ovol1 deletion. We identify both proliferation/differentiation-regulating and neutrophil-attracting chemokine genes as candidate direct targets of Ovol1. Finally, we provide evidence for altered IL-1a signaling in the microenvironment of Ovol1- deficient inflamed skin that functionally contributes to neutrophil accumulation and epidermal hyperplasia. Collectively, our study demonstrates a protective role for an epidermally expressed, disease-linked transcription factor in coordinating robust barrier maintenance with suppression of skin inflammation.