The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor involved in adaptive cell functions, and highly active in the epidermis. AhR-ligands can accelerate keratinocyte differentiation, but a precise role for AhR in the skin barrier is unknown. We here show that transepidermal water loss (TEWL), a parameter of skin barrier integrity, is high in AhR-deficient (AhR-KO) mice. Experiments with conditionally AhR-deficient mouse lines identified keratinocytes as the major responsible cell population for high TEWL. Electron microscopy showed weaker inter-cellular connectivity in the epidermis of keratinocytes in AhR-KO mice, and gene expression analysis identified many barrier-associated genes as AhR targets. Moreover, AhR-deficient mice had higher inter-individual differences in their microbiome. Interestingly, removing AhR-ligands from the diet of wild-type mice mimicked AhR-deficiency regarding the impaired barrier. Vice versa, re-addition of the plant-derived ligand indole-3-carbinol (I3C) rescued the barrier deficiency even in aged mice. Our results suggest that functional AhR expression is critical for skin barrier integrity and that AhR represents a molecular target for the development of novel therapeutic approaches for skin barrier diseases, including dietary intervention.
Aryl Hydrocarbon Receptor in Keratinocytes Is Essential for Murine Skin Barrier Integrity.
Sex, Specimen part, Treatment, Time
View SamplesThe murine model of Lyme disease provides a unique opportunity to study the localized host response to similar stimulus, B. burgdorferi, in the joints of mice destined to develop severe arthritis (C3H) or mild disease (C57BL/6). Pathways associated with the response to infection and the development of Lyme arthritis were identified by global gene expression patterns using oligonucleotide microarrays. A robust induction of IFN responsive genes was observed in severely arthritic C3H mice at one week of infection, which was absent from mildly arthritic C57BL/6 mice. In contrast, infected C57BL/6 mice displayed a novel expression profile characterized by genes involved in epidermal differentiation and wound repair, which were decreased in the joints of C3H mice. These expression patterns were associated with disease state rather than inherent differences between C3H and C57BL/6 mice, as C57BL/6-IL10-/- mice infected with B. burgdorferi develop more severe arthritis that C57BL/6 mice and displayed an early gene expression profile similar to C3H mice. Gene expression profiles at two and four weeks post infection revealed a common response of all strains that was likely to be important for the host defense to B. burgdorferi and mediated by NF-kB-dependent signaling. The gene expression profiles identified in this study add to the current understanding of the host response to B. burgdorferi and identify two novel pathways that may be involved in regulating the severity of Lyme arthritis.
Gene expression profiling reveals unique pathways associated with differential severity of lyme arthritis.
No sample metadata fields
View SamplesGene expression profile of joint tissue from C3H and interval specific congenic mouse lines (ISCL) following infection with Borrelia burgdorferi
Interval-specific congenic lines reveal quantitative trait Loci with penetrant lyme arthritis phenotypes on chromosomes 5, 11, and 12.
Specimen part
View SamplesT lymphocytes are essential contributors to the adaptive immune system and consist of multiple lineages that serve various effector and regulatory roles. As such, precise control of gene expression is essential to the proper development and function of these cells. Previously, we identified Snai2 and Snai3 as being essential regulators of immune tolerance partly due to the impaired function of CD4+ regulatory T cells in Snai2/3 conditional double knockout mice. Here we extend those previous findings using a bone marrow transplantation model to provide an environmentally unbiased view of the molecular changes imparted onto various T lymphocyte populations once Snai2 and Snai3 are deleted. The data presented here demonstrate that Snai2 and Snai3 transcriptionally regulate the cellular fitness and functionality of not only CD4+ regulatory T cells but effector CD8a+ and CD4+ conventional T cells as well. This is achieved through the modulation of gene sets unique to each cell type and includes transcriptional targets relevant to the survival and function of each T cell lineage. As such, Snai2 and Snai3 are essential regulators of T cell immunobiology. Overall design: GFP- CD3e+ CD8a+ CD4-, GFP- CD3e+ CD8a- CD4+ CD25- and GFP- CD3e+ CD8a- CD4+ CD25+ T cells were isolated from spleens of UBC-GFP mice transplanted with WT or cDKO lineage-depleted donor bone marrow following lethal irradiation of recipient mice. RNA-seq was performed on 3-4 biological replicates from each genotype for all T cell populations analyzed.
Snai2 and Snai3 transcriptionally regulate cellular fitness and functionality of T cell lineages through distinct gene programs.
Specimen part, Cell line, Subject
View SamplesMicroarray analysis of wild type plants and plants with reduced (ago1-27 and se-1) or increased miR156 levels (se-1 p35S:MIR156). Shoot apices were dissected from 20-day-old, short-day grown plants.
miR156-regulated SPL transcription factors define an endogenous flowering pathway in Arabidopsis thaliana.
Age, Specimen part
View SamplesBehavioral analysis confirmed that the 14-day social defeat sessions resulted in induction of depressive-like states measured in social interaction and light/dark tests. The combined data show that stress-induced depressive states are associated with molecular and structural changes that demyelinate the prefrontal cortex.
Chronic social defeat reduces myelination in the mouse medial prefrontal cortex.
Specimen part
View Samples4-day-old XW119 seedlings were treated with 2% Ethanol on MS agar plates under light, and samples were collected at 0, 1, 2, 4 hours.
STIMPY mediates cytokinin signaling during shoot meristem establishment in Arabidopsis seedlings.
Age, Compound, Time
View SamplesPU.1 is a key transcription factor for macrophage differentiation. Novel PU.1 target genes were identified by mRNA profiling of PU.1-deficient progenitor cells (PUER) before and after PU.1 activation. We used two different types of Affymetrix DNA-microarrays (430 2.0 arrays and ST 1.0 exon arrays) to characterize the global PU.1-regulated transcriptional program underlying the early processes of macrophage differentiation.
Transcriptomic profiling identifies a PU.1 regulatory network in macrophages.
No sample metadata fields
View SamplesWe were interested in determining what genes might be controlled by TFAP2C and/or TFAP2A, either directly or indirectly through regulation of ER-alpha and potentially other signaling pathways. We performed an microarray analysis in MCF7 cells with elimination of either TFAP2C or TFAP2A. The patterns of gene expression with alteration of TFAP2 activity were compared to changes in expression induced by estrogen exposure. Knock-down of TFAP2C in the presence of estrogen altered the pattern of several known ERalpha-regulated genes and a number of genes outside the estrogen-regulated pathways.
TFAP2C controls hormone response in breast cancer cells through multiple pathways of estrogen signaling.
Specimen part
View SamplesTissues of Arabidopsis plants overexpressing artificial microRNAs were compared to wild_type and respective target gene mutants (duplicate arrays)
Highly specific gene silencing by artificial microRNAs in Arabidopsis.
Specimen part
View Samples