Different types of hair follicles can be found in the skin of mice. It is believed that the signals that control hair follicle differentiation arise from cells in a structure called the dermal papilla. Understanding the nature of those signals is of interest for the biology of the normal tissue.
Sox2-positive dermal papilla cells specify hair follicle type in mammalian epidermis.
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View SamplesThe Wnt/alpha-catenin pathway plays a central role in epidermal homeostasis and regeneration but how it affects fibroblast fate decisions is unknown. Here, we investigated the effect of targeted alpha-catenin stabilization in dermal fibroblasts. Comparative gene expression profiling of Sca1- and Sca1+ neonatal fibroblasts, from upper and lower dermis respectively, confirmed that Sca1+ cells had a pre-adipocyte signature and revealed differential expression of Wnt/alphacatenin-associated genes. By targeting all fibroblasts or selectively targeting Dlk1+ lower dermal fibroblasts, we found that -catenin stabilization between E16.5 and P2 resulted in a reduction in the dermal adipocyte layer with a corresponding increase in dermal fibrosis and an altered hair cycle. The fibrotic phenotype correlated with a reduction in the potential of Sca1+ fibroblasts to undergo adipogenic differentiation ex vivo. Our findings indicate that Wnt/alpha-catenin signaling controls adipogenic cell fate within the lower dermis, which potentially contributes to the pathogenesis of fibrotic skin diseases.
β-Catenin Stabilization in Skin Fibroblasts Causes Fibrotic Lesions by Preventing Adipocyte Differentiation of the Reticular Dermis.
Specimen part
View SamplesWe performed gene expression profiling of P1 and P5 back and tail dermis to uncover potential explanations for the differences in HF formation at different ages and in different body sites.
Inhibition of β-catenin signalling in dermal fibroblasts enhances hair follicle regeneration during wound healing.
Specimen part, Time
View SamplesFibroblasts synthesize the extracellular matrix of connective tissue and play an essential role in maintaining tissue integrity. We have previously shown that mouse skin connective tissue, the dermis, is comprised of functionally distinct fibroblast lineages. However, the extent of fibroblast heterogeneity in human skin is unknown. Here, using a combination of spatial transcriptional profiling of human and mouse dermis and single cell transcriptional profiling of human dermal fibroblasts, we show that there are at least four distinct fibroblast populations in adult human skin. We define markers permitting prospective isolation of these cells and show that although marker expression is rapidly lost in culture, different fibroblast subpopulations retain distinct functionality in terms of Wnt signalling, T cell communication and the ability to support human epidermal reconstitution in organotypic culture. Furthermore, while some fibroblast subpopulations are spatially segregated, others are not. These findings have profound implications for normal wound healing and diseases characterized by excessive fibrosis, and suggest that ex vivo expansion or in vivo ablation of specific fibroblast subpopulations may have therapeutic applications. Overall design: Spatial RNA sequencing of human papillary versus reticular dermis for 3 individuals, and single cell RNA sequencing of dermal fibroblasts for a single individual.
Spatial and Single-Cell Transcriptional Profiling Identifies Functionally Distinct Human Dermal Fibroblast Subpopulations.
Specimen part, Subject
View SamplesExpression data from P2 mouse fibroblasts sorted for CD26, Sca1 and Dlk1. We have sorted mouse fibroblasts using the different lineages markers
Spatial and Single-Cell Transcriptional Profiling Identifies Functionally Distinct Human Dermal Fibroblast Subpopulations.
Specimen part
View SamplesPurpose: The goals of this study were to identify the molecular alterations in the SCA1 inferior olive, and determine whether these changes are found in other affected tissues. Methods: mRNA profiling was conducted in two different SCA1 mouse models (Atxn1 154Q/2Q KI and ATXN1-82Q Tg), in two different affected tisues (inferior olive and cerebellum) during early disease initiation and progression (5 week and 12 week time-points). All analyses were conducted relative to appropriate wild-type controls. TopHat2 v2.1.0 was utilized to align reads to the mouse reference genome (mm10) before quantification and differential expression analysis with Cufflinks v2.2.1. Normalized expression values were generated using Cuffnorm. Results: Differentially regulated genes identified in the SCA1 inferior olive segregated into several enriched biological pathways, including the Defense Response at 12 weeks of age. Our study demonstrates that vulnerable tissues in SCA1 are not uniform in their gene expression changes, and express discrete and commonly enriched biological pathways. In addition, we found that brain region-specific differences occur early in disease initiation and progression at 5 weeks of age. Conclusions: The findings from this study suggest that different mechanisms of neurodegeneration are at work in the SCA1 inferior olive and cerebellum. Overall design: mRNA profiling was conducted on an Illumina HiSeq 2500. Three biological replicates were sequenced for each genotype (Atxn1 154Q/2Q KI mice and wild-type controls; ATXN1-82Q Tg mice and wild-type controls) in each brain region (inferior olive and cerebellum) at each time-point (5 weeks old and 12 weeks old), yielding a total of 48 biological samples.
Molecular pathway analysis towards understanding tissue vulnerability in spinocerebellar ataxia type 1.
Age, Specimen part, Cell line, Subject
View SamplesMotherhood involves a switch in natural rewards, whereby offspring become highly rewarding. Nucleus accumbens (NAC) is a key CNS region for natural rewards and addictions, but to date no study has evaluated on a large scale the events in NAC that underlie the maternal change in natural rewards. In this study we utilized microarray and bioinformatics approaches to evaluate postpartum NAC gene expression changes in mice. Modular Single-set Enrichment Test (MSET) indicated that postpartum (relative to virgin) NAC gene expression profile was significantly enriched for genes related to addiction and reward in 5 of 5 independently curated databases (e.g., Malacards, Phenopedia). Over 100 addiction/reward related genes were identified and these included: Per1, Per2, Arc, Homer2, Creb1, Grm3, Fosb, Gabrb3, Adra2a, Ntrk2, Cry1, Penk, Cartpt, Adcy1, Npy1r, Htr1a, Drd1a, Gria1, and Pdyn. ToppCluster analysis found maternal NAC expression profile to be significantly enriched for genes related to the drug action of nicotine, ketamine, and dronabinol. Pathway analysis indicated postpartum NAC as enriched for RNA processing, CNS development/differentiation, and transcriptional regulation. Weighted Gene Coexpression Network Analysis identified possible networks for transcription factors, including Nr1d1, Per2, Fosb, Egr1, and Nr4a1. The postpartum state involves increased risk for mental health disorders and MSET analysis indicated postpartum NAC to be enriched for genes related to depression, bipolar disorder, and schizophrenia. Mental health related genes included: Fabp7, Grm3, Penk, and Nr1d1. We confirmed via quantitative PCR Nr1d1, Per2, Grm3, Penk, Drd1a, and Pdyn. This study indicates for the first time that postpartum NAC involves large scale gene expression alterations linked to addiction and reward. Because the postpartum state also involves decreased response to drugs, the findings could provide insights into how to mitigate addictions.
Addiction and reward-related genes show altered expression in the postpartum nucleus accumbens.
Specimen part
View SamplesThe transition from the non-maternal to the maternal state is characterized by a variety of CNS alterations that support the care of offspring. The septum (including lateral and medial portions) is a brain region previously linked to various emotional and motivational processes, including maternal care. In this study, we used microarrays (PLIER algorithm) to examine gene expression changes in the septum of postpartum mice and employed gene set enrichment analysis (GSEA) to identify possible regulators of altered gene expression. Genes of interest identified as differentially regulated with microarray analysis were validated with quantitative real-time PCR. We found that fatty acid binding protein 7 (Fabp7) and galanin (Gal) were downregulated, whereas insulin-like growth factor binding protein 3 (Igfbp3) was upregulated in postpartum mice compared to virgin females. These genes were previously found to be differentially regulated in other brain regions during lactation. We also identified altered expression of novel genes not previously linked to maternal behavior, but that could play a role in postpartum processes, including glutamate-ammonia ligase (Glul) and somatostatin receptor 1 (Sstr1) (both upregulated in postpartum). Genes implicated in metabolism, cell differentiation, or proliferation also exhibited altered expression. Unexpectedly, enrichment analysis revealed a high number of microRNAs, transcription factors, or conserved binding sites (177 with corrected P-value <0.05) that were significantly linked to maternal upregulated genes, while none were linked to downregulated genes. MicroRNAs have been linked to placenta and mammary gland development, but this is the first indication they may also play a key role in sculpting the maternal brain. Together, this study provides new insights into genes (along with possible mechanisms for their regulation) that are involved in septum-mediated adaptations during the postpartum period.
Gene expression changes in the septum: possible implications for microRNAs in sculpting the maternal brain.
Specimen part
View SamplesCoordinated gene expression changes across the CNS help to produce the mammalian maternal phenotype. Lateral septum (LS) is a brain region critically involved with aspects of maternal care, and we recently examined gene expression of whole septum (LS and medial septum) in selectively bred maternal mice. Here, we expand on the prior study by 1) conducting microarray analysis solely on LS in virgin and postpartum mice, 2) using outbred mice, and 3) evaluating the role of sensory input on gene expression changes. Large scale changes in genes related to neuronal signaling were identified, including nine GABAA receptor subunits (p<0.05). Subunits 4 and were downregulated in maternal LS, likely reflecting a reduction in the extrasynaptic, neurosteroid-sensitive 4/ containing receptor subtype. Conversely, subunits and were increased in maternal LS. Sixteen K+ channel related genes showed altered expression, as did dopamine receptors Drd1a and Drd2 (both downregulated), hypocretin receptor 1 (Hcrtr1), kappa opioid receptor 1 (Oprk1), and transient receptor potential channel 4 (Trpc4). Expression of a large number of genes linked to developmental processes or cell differentiation were also altered in postpartum LS, including chemokine (C-X-C) motif ligand 12 (Cxcl12), fatty acid binding protein 7 (Fabp7), plasma membrane proteolipid (Pllp), and suppressor of cytokine signaling 2 (Socs2). Additional genes that are linked to anxiety, such as glutathione reductase (Gsr), exhibited altered expression. Pathway analysis also identified changes in genes related to cyclic nucleotide metabolism, chromatin structure, and the Ras gene family. The sensory presence of pups was found to contribute to the altered expression of a subset of genes across all categories. This study suggests that both large changes in neuronal signaling and the possible terminal differentiation of neuronal and/or glial cells play important roles in producing the maternal state.
Large scale expression changes of genes related to neuronal signaling and developmental processes found in lateral septum of postpartum outbred mice.
Specimen part
View SamplesPTEN is thought to play a critical role in T cell activation by negatively regulating the PI3K signaling pathway important for cellular activation, growth, and proliferation. T cells from mice in which PTEN was conditionally deleted in the thymus were reported to display CD28-independent IL-2 production and relative resistance to anergy induction. However, such observations could have stemmed from alterations in T cell development due to early deletion in thymocytes. To directly eliminate PTEN in post-thymic T cells, we utilized CAR Tg x PTENflox/flox mice which enabled gene deletion using a Cre adenovirus in vitro. Gene expression profiling revealed a small subset of induced genes that were augmented upon PTEN deletion and T cell stimulation. Our results indicate that deletion of PTEN can augment the activation of post-thymic T cells. Nonetheless, PTEN inhibition may be a viable target for immune potentiation due to increased cytokine production by activated CD4+ cells.
Conditional deletion of PTEN in peripheral T cells augments TCR-mediated activation but does not abrogate CD28 dependency or prevent anergy induction.
Specimen part
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