Project description:Gene expression analysis of the epidermis from Lexicon Genetics Abca12 knockout mouse model of Harlequin Ichythois compared with wild type embryos to search for pathways specifically altered in the condition. Results indicate a large immune and inflammatory response occurs in the sterile environment of the uterus. Total RNA isolated from E17.5 back skin epidermis from murine Harlequin Ichthyosis model compared with wild type embryos.
Project description:Autosomal recessive congenital ichthyoses (ARCI) are a group of non-syndromic congenital keratinization disorders including harlequin ichthyosis, lamellar ichthyosis, and congenital ichthyosiform erythroderma with a total prevalence of 1:200,000. Affected individuals who are often born as collodion babies present with generalized scaling of the skin. This reflects a physical compensation for the defective cutaneous permeability barrier underlying all ichthyoses. Inactivity of 12R-lipoxygenase (12R-LOX) is a frequent cause of ARCI. Epidermis-specific conditional knockout of Alox12b encoding 12R-LOX was established in mice using the Cre-Lox system. Tamoxifen-induced Alox12b inactivation in mouse skin caused an ichthyosis-like phenotype. We used microarray to compare the gene expression profile in the epidermis of mice after tamoxifen induced Alox12b inactivation with that of control animals. Inactivation of Alox12b was associated with the upregulation of genes involved in keratinization, cholesterol biosynthesis, and Fc-epsilon receptor signaling.
Project description:Gene expression analysis of the epidermis from Lexicon Genetics Abca12 knockout mouse model of Harlequin Ichthyosis compared with wild type embryos to search for pathways specifically altered in the condition. Results indicate a large immune and inflammatory response occurs in the sterile environment of the uterus.
Project description:The biology of Harlequin Ichthyosis (HI), a devastating skin disorder, caused by loss of function mutations in the gene ABCA12, is poorly understood and to date no satisfactory treatment has been developed. We sought to investigate pathomechanisms of Harlequin Ichthyosis which could lead to the identification of safe and effective treatments to improve patients' quality of life. RNA-Seq analysis using normal skin (n=5) and HI patient skin (n=4) were performed to define the effects of loss of ABCA12. Functional annotation clustering analysis showed changes in three common groups: epidermal differentiation, lipid metabolism and inflammation (innate immunity and IFNγ signalling). In HI patient skin, gene expression of STAT1, STAT3 and Interleukin 36 (IL-36) A and G cytokines was significantly upregulated compared to normal skin, whereas IL-37, an inhibitor of innate immunity, was downregulated. RNA-Seq and functional assays were performed to define the effects of loss of ABCA12, using an engineered CRISPR-Cas9 ABCA12 KO 3D model. Functional annotation clustering analysis showed changes in three common groups: epidermal differentiation, lipid metabolism and inflammation.
Project description:Autosomal recessive congenital ichthyoses are a group of non-syndromic congenital keratinization disorders including harlequin ichthyosis, lamellar ichthyosis, and congenital ichthyosiform erythroderma with a total prevalence of 1:200,000. Affected individuals who are often born as collodion babies present with generalized scaling of the skin. This reflects a physical compensation for the defective cutaneous permeability barrier underlying all ichthyoses. Inactivity of 12R-lipoxygenase (12R-LOX) is a frequent cause of ARCI. Mice with targeted inactivation of the 12R-LOX gene Alox12b were established .Heterozygous mutant mice (Alox12b+/−) were bred with 129S6, and their heterozygous offspring were intercrossed to obtain homozygous mutant mice. Homozygous Alox12b knockout mice died within 3 hours after birth owing to defective skin barrier function. We used microarray to compare the gene expression profile in the epidermis of Alox12b-null mice with that of wildtype animals. Inactivation of Alox12b was associated with the upregulation of genes involved in keratinization, cholesterol biosynthesis, and Fc-epsilon receptor signaling.
Project description:Transcription profiling of murine J1 embryonic stem cells undergoing a differentiation time course to study changes in transcription during stem cell differentiation
Project description:Transcription profiling of murine R1 embryonic stem cells differentiating into embryoid bodies over a time-course to study changes in transcription during stem cell differentiation
Project description:Transcription profiling of murine V6.5 embryonic stem cells differentiating into embryoid bodies over a time-course to study changes in transcription during stem cell differentiation
Project description:During skin development, ectoderm-derived cells undergo precisely coordinated proliferation, differentiation, and adhesion to yield stratified epidermis. Disruptions in these processes can result in congenital anomalies including ectodermal dysplasia and harlequin ichthyosis. Protein Arginine Methyl Transferase 5 (PRMT5)—an enzyme responsible for methylating arginine residues in histones and other proteins—maintains progenitor status in germ and limb bud cells. Similarly, in vitro evidence suggests that PRMT5 prevents differentiation of basal keratinocytes, leading us to hypothesize that PRMT5 preserves the stem-cell phenotype of keratinocytes in vivo. To test this possibility, we generated conditional knockout (cKO) mice lacking Prmt5 in early ectoderm (E7.5), impacting the entire epidermis. Prmt5 cKOs exhibited gross skin defects, compromised skin barrier function, and reduced postnatal viability. Histological analyses revealed significant defects in epidermal stratification, without alterations in apoptosis or proliferation. Single-cell RNA and ATAC-seq analysis identified an atypical population of basal keratinocyte-like cells in Prmt5 cKOs, that exhibited a senescence-like program, characterized by increased Cdkn1a (p21), elevated senescence-associated secretory phenotype (SASP) molecules (Igfbp2), and decreased developmental transcription factor (Trp63) expression. Our findings suggest that PRMT5 prevents basal keratinocyte senescence by repressing Cdkn1a, shedding light on the epigenetic regulation of basal keratinocyte maintenance and senescence in congenital skin disorders.
Project description:During skin development, ectoderm-derived cells undergo precisely coordinated proliferation, differentiation, and adhesion to yield stratified epidermis. Disruptions in these processes can result in congenital anomalies including ectodermal dysplasia and harlequin ichthyosis. Protein Arginine Methyl Transferase 5 (PRMT5)—an enzyme responsible for methylating arginine residues in histones and other proteins—maintains progenitor status in germ and limb bud cells. Similarly, in vitro evidence suggests that PRMT5 prevents differentiation of basal keratinocytes, leading us to hypothesize that PRMT5 preserves the stem-cell phenotype of keratinocytes in vivo. To test this possibility, we generated conditional knockout (cKO) mice lacking Prmt5 in early ectoderm (E7.5), impacting the entire epidermis. Prmt5 cKOs exhibited gross skin defects, compromised skin barrier function, and reduced postnatal viability. Histological analyses revealed significant defects in epidermal stratification, without alterations in apoptosis or proliferation. Single-cell RNA and ATAC-seq analysis identified an atypical population of basal keratinocyte-like cells in Prmt5 cKOs, that exhibited a senescence-like program, characterized by increased Cdkn1a (p21), elevated senescence-associated secretory phenotype (SASP) molecules (Igfbp2), and decreased developmental transcription factor (Trp63) expression. Our findings suggest that PRMT5 prevents basal keratinocyte senescence by repressing Cdkn1a, shedding light on the epigenetic regulation of basal keratinocyte maintenance and senescence in congenital skin disorders.