Project description:Mutant and non-mutant footpad. McGowan et al. in press Keywords: Mutant vs. non-mutant The tissue (footpad epidermis) is from a conditional heterozygous null deletion of Rps6. One copy of Rps6 was deleted from keratinocytes in the skin using the K5.Cre transgene.
Project description:Mutant and non-mutant footpad. McGowan et al. in press Keywords: Mutant vs. non-mutant The tissue (footpad epidermis) is from a conditional heterozygous null deletion of Rps6. One copy of Rps6 was deleted from keratinocytes in the skin using the K5.Cre transgene. K5Cre x Rps6^loxP
Project description:Patients with tuberous sclerosis complex (TSC) develop hamartomas containing biallelic inactivating mutations in either TSC1 or TSC2, resulting in mammalian target of rapamycin (mTOR) activation. Hamartomas overgrow epithelial and mesenchymal cells in TSC skin. The pathogenetic mechanisms for these changes had not been investigated, and the existence or location of cells with biallelic mutations (âtwo-hitâ cells) that resulted in mTOR activation was unclear. We compared TSC skin hamartomas (facial angiofibromas and periungual fibromas) to normal-appearing skin of the same patient, and observed more proliferation and mTOR activation in hamartoma epidermis. âTwo-hitâ cells were not detected in the epidermis. Fibroblast-like cells in the dermis, however, exhibited allelic deletion of TSC2, in both touch preparations of fresh tumor samples and cells grown from TSC skin tumors, suggesting that increased epidermal proliferation and mTOR activation were not caused by second-hit mutations in the keratinocytes but by mesenchymal-epithelial interactions. Gene expression arrays, used to identify potential paracrine factors released by mesenchymal cells, revealed more epiregulin mRNA in fibroblast-like angiofibroma and periungual fibroma cells than in fibroblasts from normal-appearing skin of the same patient. Elevation of epiregulin mRNA was confirmed using real-time PCR, and increased amounts of epiregulin protein were demonstrated using immunoprecipitation and ELISA. Epiregulin stimulated keratinocyte proliferation and phosphorylation of ribosomal protein S6 in vitro. These results suggest that hamartomatous TSC skin tumors are induced by paracrine factors released by âtwo-hitâ cells in the dermis, and that proliferation with mTOR activation of the overlying epidermis is an effect of epiregulin. Experiment Overall Design: The study is of case/control design with biological replication. Tumor (case) and normal (control) fibroblast cells were isolated from each of four patients (biological replicates).
Project description:Patients with tuberous sclerosis complex (TSC) develop hamartomas containing biallelic inactivating mutations in either TSC1 or TSC2, resulting in mammalian target of rapamycin (mTOR) activation. Hamartomas overgrow epithelial and mesenchymal cells in TSC skin. The pathogenetic mechanisms for these changes had not been investigated, and the existence or location of cells with biallelic mutations (“two-hit” cells) that resulted in mTOR activation was unclear. We compared TSC skin hamartomas (facial angiofibromas and periungual fibromas) to normal-appearing skin of the same patient, and observed more proliferation and mTOR activation in hamartoma epidermis. “Two-hit” cells were not detected in the epidermis. Fibroblast-like cells in the dermis, however, exhibited allelic deletion of TSC2, in both touch preparations of fresh tumor samples and cells grown from TSC skin tumors, suggesting that increased epidermal proliferation and mTOR activation were not caused by second-hit mutations in the keratinocytes but by mesenchymal-epithelial interactions. Gene expression arrays, used to identify potential paracrine factors released by mesenchymal cells, revealed more epiregulin mRNA in fibroblast-like angiofibroma and periungual fibroma cells than in fibroblasts from normal-appearing skin of the same patient. Elevation of epiregulin mRNA was confirmed using real-time PCR, and increased amounts of epiregulin protein were demonstrated using immunoprecipitation and ELISA. Epiregulin stimulated keratinocyte proliferation and phosphorylation of ribosomal protein S6 in vitro. These results suggest that hamartomatous TSC skin tumors are induced by paracrine factors released by “two-hit” cells in the dermis, and that proliferation with mTOR activation of the overlying epidermis is an effect of epiregulin. Keywords: Disease state analysis
Project description:The type I intermediate filament keratin 16 (Krt16 gene; K16 protein) is constitutively expressed in ectoderm-derived appendages and volar palmar/plantar epidermis, and is otherwise inducibly expressed in non-volar epidermis when skin epithelia are under stress. Mutations at the (human) KRT16 locus can cause pachyonychia congenita (PC) and focal non-epidermolytic palmoplantar keratoderma (PPK), which each entail painful calluses on palmar and/or plantar skin. Krt16 null mice develop footpad lesions that mimic several aspects of PC-associated PPK and FNEPPK, including hypoactive Keap1-Nrf2 signaling and elevated expression of skin barrier homeostasis genes and Danger Associated Molecular Patterns (DAMPs). This provides a unique opportunity to understand the intricacies of PPK and devise effective therapies (see Lessard and Coulombe, J. Invest. Dermatol. 2012; Lessard et al. PNAS (USA) 2013; Kerns et al. J. Clin. Invest. 2016; Kerns et al., J. Invest. Dermatol. 2018; Zieman and Coulombe Exp. Dermatol. 2018). Here, we report on insight gained from a genome-wide analysis of gene expression in PPK-like lesions of Krt16 null mice. In this dataset, we include expression data obtained from Krt16 null paw skin lesions and WT littermate controls (C57Bl/6 strain background) at two months of age.
Project description:To determine if changes in Protein Disulfide Isomerase (PDIA1) expression in mice with a null Reelin allele were caused by accumulation of intracellular Reelin or were an effect of reduced Reelin protein, we examined expression of PDIA1 and other stress markers in heterozygous RELN +/- null allele mice. The levels of PDIA1 as well as PERK, BIP, phospho-eIF2alpha and total eIF2alpha were unchanged between wild-type and RELN +/- null allele mice. This suggested that there are phenotypic differences in the cerebella between mice that carry a RELN allele that fails to produce a protein (null allele) and those that make a protein that fails to be secreted (Orl allele). Each of the three major ER stress pathways ultimately leads to changes in gene transcription. Thus, we compared wild-type and heterozygous RELN Orl +/- mice cerebellum by RNAseq. Analysis was performed on 3 heterozygous (HET) and 3 wild-type (WT) cerebella, obtained from 6-week old male mice.