Melasma is a commonly acquired hyperpigmentary disorder of the face, but its pathogenesis is poorly understood and its treatment remains challenging. We conducted a comparative histological study on lesional and perilesional normal skin to clarify the histological nature of melasma. Significantly, higher amounts of melanin and of melanogenesis-associated proteins were observed in the epidermis of lesional skin, and the mRNA level of tyrosinase-related protein 1 was higher in lesional skin, indicating regulation at the mRNA level. However, melanocyte numbers were comparable between lesional and perilesional skin. A transcriptomic study was undertaken to identify genes involved in the pathology of melasma. A total of 279 genes were found to be differentially expressed in lesional and perilesional skin. As was expected, the mRNA levels of a number of known melanogenesis-associated genes, such as tyrosinase, were found to be elevated in lesional skin. Bioinformatics analysis revealed that the most lipid metabolism-associated genes were downregulated in lesional skin, and this finding was supported by an impaired barrier function in melasma. Interestingly, a subset of Wnt signaling modulators, including Wnt inhibitory factor 1, secreted frizzled-related protein 2, and Wnt5a, were also found to be upregulated in lesional skin. Immunohistochemistry confirmed the higher expression of these factors in melasma lesions.
Transcriptional profiling shows altered expression of wnt pathway- and lipid metabolism-related genes as well as melanogenesis-related genes in melasma.
Specimen part
View SamplesRosacea is a common chronic inflammatory skin disease of unknown etiology. Our knowledge about an involvement of the adaptive immune system is very limited. We performed detailed transcriptome analysis, qRT-PCR, and quantitative immunohistochemistry on facial biopsies of rosacea patients, classified according to their clinical subtype. As controls, we used samples from healthy controls. Our study shows significant activation of the immune system in all subtypes of rosacea, characterizing erythematotelangiectatic rosacea (ETR) already as a disease with significant influx of proinflammatory cells. The T cell response is dominated by Th1/Th17-polarized immune cells, as demonstrated by significant upregulation of IFN or IL-17, for example. Chemokine expression patterns support a Th1/Th17 polarization profile of the T cell response. Macrophages and mast cells are increased in all three subtypes of rosacea, while neutrophils reach a maximum in papulopustular rosacea. Our studies also provide evidence for activation of plasma cells with significant antibody production already in ETR, followed by a crescendo pattern towards phymatous rosacea. In sum, Th1/Th17 polarized inflammation and macrophage infiltration is an underestimated hallmark in all subtypes of rosacea. Therapies directly targeting the Th1/Th17 pathway are promising candidates in the future treatment of this skin disease.
Molecular and Morphological Characterization of Inflammatory Infiltrate in Rosacea Reveals Activation of Th1/Th17 Pathways.
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View SamplesVitiligo is an acquired depigmentation of the skin inducing a marked alteration of the quality of life of affected individuals. Halting the disease progression and repigmenting the lesional skin represent the two faces of the therapeutic challenge in vitiligo. So far, none of them has been successfully addressed. Oxidative stress and immune system in genetically predisposed individuaLesionalparticipate to the complex pathophysiology of vitiligo. We performed a transcriptome and proteomic analysis on lesional, perilesional and non-depigmented skin of vitiligo patients compared to matched skin controLesionalof healthy subjects. Our results show that the WNT pathway, implicated in melanocytes differentiation, was found to be altered in vitiligo skin. We demonstrated that the oxidative stress decreases WNT expression/activation in keratinocytes and in melanocytes. We developed an ex vivo skin model that remains functional up to 15 days. We then confirmed the decreased activation of the WNT pathway in human skin subjected to oxidative stress. Finally, using pharmacological agents that activate the WNT pathway, we treated the ex vivo depigmented skins from vitiligo patients and successfully induced the differentiation of resident stem celLesionalinto pre-melanocytes supporting further exploration of WNT activators to repigment vitiligo lesions.
Transcriptional Analysis of Vitiligo Skin Reveals the Alteration of WNT Pathway: A Promising Target for Repigmenting Vitiligo Patients.
Specimen part
View SamplesThe mechanisms of inflammation in acne are not well understood. This study performed in two separate patient populations focused on the activation of adaptive and innate immunity in early inflamed acne. Biopsies were collected from lesional and non-lesional skin of acne patients. Psoriasis patients and healthy volunteers were included in the study for comparison (not included in the records). Using Affymetrix Genechips, we observed significant elevation of the signature cytokines of the Th17 lineage in acne lesions compared to non-lesional skin. The increased expression of IL-17 was confirmed with real-time qPCR (RT-PCR) in two separate patient populations. Cytokines involved in Th17 lineage differentiation (IL-1beta, IL-6, TGF-beta; IL23p19) were remarkably induced at the RNA level. In addition, pro-inflammatory cytokines (IL-8, TNF-), Th1 markers (IL12p40, CXCR3, T-bet, IFN-gamma), T regulatory cell markers (Foxp3, IL-10, TGF-) and antimicrobial peptides (S100A7, S100A9, LNC2, hBD2, hBD3, hCAP18) were induced. Importantly, immunohistochemistry revealed significantly increased numbers of IL-17A positive T cells and CD83 dendritic cells in the acne lesions. In summary our results demonstrate the presence of IL17A positive T cells and the activation of Th17-related cytokines in acne lesions, indicating that the Th17 pathway may play a pivotal role in the disease process, offering new targets of therapy.
IL-17/Th17 pathway is activated in acne lesions.
Specimen part
View SamplesOne of the most common genetic alterations in acute myeloid leukemia is the internal tandem duplication (ITD) in the FLT3 receptor for cytokine FLT3 ligand (FLT3L). The constitutively active FLT3-ITD promotes the expansion of transformed progenitors, but also has pleiotropic effects on normal hematopoiesis. We analyzed the effect of FLT3-ITD on dendritic cells (DCs), which express FLT3 and can be expanded by FLT3L administration. We report that young pre-leukemic mice with the Flt3ITD knock-in allele manifest an expansion of all DCs including classical (cDCs) and plasmacytoid (pDCs). The expansion originated in DC progenitors, occurred in a cell-intrinsic manner and was further enhanced in Flt3ITD/ITD mice. The mutation caused the downregulation of Flt3 on the surface of DCs and reduced their responsiveness to Flt3L. Flt3ITD mice showed enhanced capacity to support T cell proliferation, including a cell-extrinsic expansion of regulatory T cells (Tregs). Accordingly, these mice restricted alloreactive T cell responses during graft-versus-host reaction, but failed to control autoimmunity in the absence of Tregs. Thus, the FLT3-ITD mutation directly affects DC development, thereby indirectly modulating T cell homeostasis and supporting Treg expansion. This effect of FLT3-ITD may subvert immunosurveillance and promote leukemogenesis in a cell-extrinsic manner. Overall design: Sorted splenic dendritic cell subsets from either Flt3+/+ or Flt3ITD/+ mice were sequenced for mRNA profiling. For each subset per genotype contains 2-3 replicates, all from independent experiments.
Leukemia-associated activating mutation of Flt3 expands dendritic cells and alters T cell responses.
Specimen part, Cell line, Subject
View SamplesGene expression in placenta from 5 smoking and 5 non-smoking mothers analyzed by Affymetrix Hg133_plus2 microarrays.
Microarray analysis of the global alterations in the gene expression in the placentas from cigarette-smoking mothers.
No sample metadata fields
View SamplesPrecise spatiotemporal regulation of genetic programs, driven by cellspecific super-enhancers, is paramount for the function of cell lineages. Studies have suggested that insulated neighborhoods, formed by the zincfinger protein CTCF, sequester genes and their associated enhancers thus preventing them from trespassing on off-target genes. Although this could explain the enhancer-gene-specificity conundrum, there is limited genetic evidence that the search space of cell-specific super-enhancers is constrained by CTCF. We have addressed this question in the Wap locus with its exceptional mammary-specific super-enhancer, which is separated by five CTCF sites from neighboring genes. Three of these sites are positioned between the Wap super-enhancer and the widely expressed Ramp3. Enhancer deletions demonstrated that the Wap super-enhancer controls Ramp3 expression despite the presence of three parting CTCF sites. Individual and combinatorial deletions of these CTCF sites revealed cell-specific functions of the conserved anchor site. Although unable to block super-enhancer activity, it muffled its impact on Ramp3 in mammary tissue. Unexpectedly, this CTCF site was obligatory for Ramp3 expression in cerebellum, suggesting the coinciding presence of regulatory elements. While our results suggest a surprisingly limited in vivo role for a CTCF anchor in blocking a mammary-specific super-enhancer, they also implicate this site in cerebellum-specific gene activation. Our study illustrates additional complexities of CTCF sites supporting tissue-specific functions. Overall design: Total RNA-seq was done for mammary tissue at pregnancy day 18.
Facultative CTCF sites moderate mammary super-enhancer activity and regulate juxtaposed gene in non-mammary cells.
Specimen part, Cell line, Subject
View SamplesIn the diploid genome, genes come in two copies, which can have different DNA sequence and where one is maternal and one is paternal. In a particular cell, a gene could potentially be expressed from both copies (biallelic expression) or only one (monoallelic). We performed RNA-Sequencing on individual cells, from zygote to the cells of the late blastocyst, and also individual cells from the adult liver. Using first generation crosses between two distantly related mouse strains, CAST/Ei and C57BL/6, we determined the expression separately from the maternal and paternal alleles. We found that half of the genes were expressed by only one allele, randomly so that some cells would express the paternal allele, some the maternal and a few cell both alleles. We also observed the spread of the progressive inactivation of the paternal X chromosome. Overall design: First generation mouse strain crosses were used to study monoallelic expression on the single cell level
Single-cell RNA-seq reveals dynamic, random monoallelic gene expression in mammalian cells.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Promoter DNA methylation patterns of differentiated cells are largely programmed at the progenitor stage.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic priming of inflammatory response genes by high glucose in adipose progenitor cells.
Specimen part
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