Staphylococcus aureus Aggravates Atopic Dermatitis through Enhanced Bacterial Colonization
Ontology highlight
ABSTRACT:
ORGANISM(S): Staphylococcus Aureus
SUBMITTER: 
Qian Liu
PROVIDER: PXD070982 | iProX | Thu Nov 20 00:00:00 GMT 2025
REPOSITORIES: iProX
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Project description:Atopic dermatitis (AD) is the most common inflammatory skin disease. Stat3 mutation is a major cause of hyper IgE syndrome (HIES), which consistently represent AD like eczematous dermatitis. Based on multi-dimensional transcriptome analysis in pre- and post-flares skin, dermatitis phenotype was controlled by sequential two steps of Stat3 deficiency and environmental pathogenic stimuli. The Stat3 deficiency determined the barrier integrity that lowered threshold of inflammation, but this step was not sufficient to form pathogenicity. Transcriptome data indicated that emergence of dermatitis phenotype need to trigger robust activation of NFB pathway and TH2 cells. Continuous colonization of Staphylococcus aureus was an environmental stimulus to lower the activation threshold of TH2 inflammation in the skin.
2021-10-12 | GSE185340 | GEO
Project description:Atopic dermatitis (AD) is a common, chronic inflammatory skin disease that seriously affects quality of life and is a major cause of skin diseases worldwide. Staphylococcus aureus (S. aureus) colonization on the skin plays an important role in the pathogenesis of AD; however, the mechanism of how it modulates skin immunity to exacerbate AD remains unclear. MicroRNAs are short non-coding RNAs that act as post-transcriptional regulators of genes. They are involved in the pathogenesis of various inflammatory skin diseases. In this study, we established miRNA expression profiles for keratinocytes stimulated with heat-killed S. aureus (HKSA). We found that miR-939 was highly upregulated in HKSA-stimulated keratinocytes and AD lesions. In vitro studies revealed that miR-939 increased the expression of matrix metalloproteinase genes, including MMP1, MMP3, and MMP9, as well as the cell adhesion molecule ICAM1 in human primary keratinocytes. In vivo studies indicated that miR-939 increased the expression of matrix metalloproteinases to promote the colonization of S. aureus and exacerbated S. aureus-induced AD-like skin inflammation. Taken together, these findings suggest that miR-939 is an important regulator of skin inflammation in AD.
2023-12-11 | GSE249837 | GEO
Project description:EGFR targeted anti-cancer therapy induces severe skin toxicities, which affect life quality in patients. The lack of mechanistic details underlying these adverse events hampers their effective management. Here we identified EGFR as the epidermal master-regulator of the ERK pathway, which secures skin barrier integrity upon hair eruption. EGFR deficient epidermis displays a Th2-dominated expression signature and is permissive for excessive microbiota outgrowth. In the absence of EGFR, opening of the follicular ostia during hair eruption allows invasion of commensal microbiota aggravating barrier disruption and initiating an additional Th1 and Th17 response. Chronic folliculitis leads to Staphylococcus aureus dominated dysbiosis, further exacerbating inflammation and expanding barrier defects. Restoration of epidermal ERK signaling via therapeutic FGF7 treatment or transgenic SOS expression rescues skin barrier integrity in the absence of EGFR. These data reveal a gatekeeper function of the EGFR/ERK cascade in hair follicles securing the epidermal barrier around the erupting hair shaft.
2019-12-31 | GSE119376 | GEO
Project description:Background: Atopic dermatitis (AD) is a common inflammatory skin disease exhibiting a predominantly Th2/"T22" immune activation and a defective epidermal barrier. Narrow-band UVB (NB-UVB) is considered an efficient treatment for moderate to severe AD. In psoriasis, NB-UVB has been found to suppress the Th1/Th17 immune polarization with subsequent reversal of epidermal hyperplasia. The immunomodulatory effects of this treatment are largely unknown in AD. Our study evaluates the effects of NB-UVB on immune and barrier abnormalities in AD, aiming to establish reversibility of disease and biomarkers of therapeutic response. Methods: 12 moderate-to-severe chronic AD patients received NB-UVB phototherapy 3 times weekly for up to 12 weeks. Lesional and non-lesional skin biopsies were obtained before and after treatment and evaluated by gene-expression and immunohistochemistry studies. Results: All patients had at least a 50% reduction in SCORing of AD (SCORAD) index with NB-UVB phototherapy. The Th2, T22, and Th1 immune pathways were suppressed and measures of epidermal hyperplasia and differentiation also normalized after phototherapy. The reversal of disease activity was associated with elimination of inflammatory leukocytes, Th2/"T22"-associated cytokines and chemokines, and normalized expression of barrier proteins. Conclusions: Our study shows reversal of both the epidermal defects and underlying immune activation in AD. By determining the correlation of variables with therapeutic response, we have defined a set of biomarkers of disease response that associate resolved Th2 and T22 inflammation with reversal of barrier pathology. This data supports the "inside-out" hypothesis of AD, suggesting that it is a disease primarily driven by an immune stimulus. genomic profiling of treatment effect of NB-UVB in AD in both lesional and non-lesional AD skin from 10 patients. Treatment effect, disease state analysis
2011-07-01 | E-GEOD-27887 | biostudies-arrayexpress
Project description:Background: Atopic dermatitis (AD) is a common inflammatory skin disease with a TH2 immune polarity and is often colonized with Staphylococcus aureus. Despite recent advances in understanding Staphylococcus species infection and the impact of polar TH cytokines on the skin, the interactions between these factors in AD pathology are poorly understood. Methods: AD-related key immune biomarkers were measured by quantitative real-time PCR in human keratinocytes exposed heat-killed S. epidermidis or S. aureus with/without polar T-cell derived cytokines such as IFN-γ (TH1), IL-4/IL-13 (TH2), and IL-22 (TH22). Further analysis was performed by RNA-sequencing to define broader responses in both Staphylococcus species and polar cytokines. The similarity of gene expression patterns in AD skin lesions and stimulated keratinocytes was evaluated by gene-set variation analysis (GSVA). Results: Gene expression analysis exhibited distinct immune responses in keratinocytes depending on individual bacterial or polar cytokine exposure. Besides, numerous genes were synergistically upregulated by the combination exposure of bacteria and polar TH cytokines. Moreover, GSVA revealed that combined exposure of S. aureus and IL-4 + IL-13 exhibited significantly higher correlations with a genomic signature of AD skin lesions than their single exposure or combinations of other polar TH cytokines. Conclusions: Our findings provide novel insights into AD-related transcriptional activation and illustrate a potentially novel pathogenic function of S. aureus and IL-4/IL-13 interactions in AD.
2021-12-31 | GSE173902 | GEO
Project description:Atopic dermatitis (AD) is characterized by dysregulated T cell immunity and skin microbiome dysbiosis with predominance of Staphylococcus aureus (S. aureus). Emerging evidence suggests a role for S. aureus in exacerbating AD skin inflammation. Interestingly, specific glycosylation of S. aureus cell wall structures amplifies skin inflammation through interaction with Langerhans cells (LCs). However, the role of LCs in AD remains poorly characterized. Here, we performed single cell RNA-sequencing of primary epidermal LCs and dermal T cells isolated from skin biopsies of AD patients and healthy controls, alongside specific glycoanalysis of S. aureus strains isolated from the AD lesions. Our findings reveal four LC subpopulations, including two steady-state clusters (LC1 and LC1H) and two pro-inflammatory/matured subsets (LC2 and migratory LCs). The latter two subsets were enriched in AD skin. AD LCs showed enhanced expression of C-type lectin receptors, the high-affinity IgE receptor (FcεR1), and activation of prostaglandin and leukotrienes biosynthesis pathways, as well as upregulated transcriptional signatures related to T cell activation pathways and increased expression of CCL17 (specifically LC2) compared to healthy LCs. Correspondingly, T helper 2 and regulatory T cell populations were increased in AD lesions. Our study provides proof-of-concept for an active role of LCs in connecting the S. aureus-T cell axis in the AD inflammatory cycle.
2024-05-03 | GSE266239 | GEO
Project description:<p>The NIH Intramural Skin Microbiome Consortium (NISMC) is a collaboration of investigators with primary expertise in genomics, bioinformatics, large-scale DNA sequencing, dermatology, immunology, allergy, infectious disease, and clinical microbiology. Atopic dermatitis (AD, "eczema") is a chronic relapsing skin disorder that affects ~15% of U.S. children and is associated with $1 billion of medical costs annually. AD is characterized by dry, itchy skin, infiltrated with immune cells. Colonization by Staphylococcus aureus (S. aureus) is ten-fold more common in AD patients and is associated with disease flares. We hypothesize that, in addition to S. aureus, AD may also be associated with additional novel microbes and/or selective shifts of commensal microbes that are relevant to disease progression. The NISMC seeks to define the microbiota that resides in and on the skin and nares of three patient groups, all of whom have eczematous lesions and are currently seen at the NIH Clinical Center: (1) AD patients; (2) Wiskott-Aldrich syndrome (WAS) patients; and (3) Hyper IgE syndrome (HIES) syndrome patients. Examination of the microbiome of patients with WAS or HIES syndromes, both rare immunodeficiencies, will advance our understanding of how an individual's immune system shapes their cutaneous microbial community. We are performing a prospective longitudinal study that follows these groups of patient thorough the cycles of eczema flares, ascertaining clinical data and samples at each stage.</p>
| phs000266 | dbGaP
Project description:Background: Atopic dermatitis (AD) is a common inflammatory skin disease exhibiting a predominantly Th2/“T22” immune activation and a defective epidermal barrier. Narrow-band UVB (NB-UVB) is considered an efficient treatment for moderate to severe AD. In psoriasis, NB-UVB has been found to suppress the Th1/Th17 immune polarization with subsequent reversal of epidermal hyperplasia. The immunomodulatory effects of this treatment are largely unknown in AD. Our study evaluates the effects of NB-UVB on immune and barrier abnormalities in AD, aiming to establish reversibility of disease and biomarkers of therapeutic response. Methods: 12 moderate-to-severe chronic AD patients received NB-UVB phototherapy 3 times weekly for up to 12 weeks. Lesional and non-lesional skin biopsies were obtained before and after treatment and evaluated by gene-expression and immunohistochemistry studies. Results: All patients had at least a 50% reduction in SCORing of AD (SCORAD) index with NB-UVB phototherapy. The Th2, T22, and Th1 immune pathways were suppressed and measures of epidermal hyperplasia and differentiation also normalized after phototherapy. The reversal of disease activity was associated with elimination of inflammatory leukocytes, Th2/“T22”-associated cytokines and chemokines, and normalized expression of barrier proteins. Conclusions: Our study shows reversal of both the epidermal defects and underlying immune activation in AD. By determining the correlation of variables with therapeutic response, we have defined a set of biomarkers of disease response that associate resolved Th2 and T22 inflammation with reversal of barrier pathology. This data supports the “inside-out” hypothesis of AD, suggesting that it is a disease primarily driven by an immune stimulus.
2011-07-01 | GSE27887 | GEO
Project description:Atopic dermatitis (AD) is a chronic pruritic inflammatory skin disease. We recently described an animal model in which repeated epicutaneous applications of a house dust mite extract and Staphylococcal enterotoxin B induced eczematous skin lesions. In this study we showed that global gene expression patterns are very similar between human AD skin and allergen/staphylococcal enterotoxin B–induced mouse skin lesions, particularly in the expression of genes related to epidermal growth/differentiation, skin barrier, lipid/energy metabolism, immune response, or extracellular matrix. In this model, mast cells and T cells, but not B cells or eosinophils, were shown to be required for the full expression of dermatitis, as revealed by reduced skin inflammation and reduced serum IgE levels in mice lacking mast cells or T cells (TCRb-/- or Rag1-/-). The clinical severity of dermatitis correlated with the numbers of mast cells, but not eosinophils. Consistent with the idea that T helper type 2 (Th2) cells play a predominant role in allergic diseases, the receptor for the Th2-promoting cytokine thymic stromal lymphopoietin and the high-affinity IgE receptor, FceRI, were required to attain maximal clinical scores. Therefore, this clinically relevant model provides mechanistic insights into the pathogenic mechanism of human AD. A total of six samples were analyzed. Back skin samples from healthy or AD-induced C57BL/6, PLC-beta 3 KO (C57BL/6 background), and NC/Nga mice were collected for total RNA extraction. Pooled RNA from 2-4 mice per condition were used for analysis.
2013-12-10 | E-GEOD-53132 | biostudies-arrayexpress
Project description:Staphylococcus aureus is a common human and animal opportunistic pathogen. In humans nasal carriage of S. aureus is a risk factor for various infections. Methicillin-resistant S. aureus ST398 is highly prevalent in pigs in Europe and North America. The mechanism of successful pig colonization by MRSA ST398 is poorly understood. Previously, we developed a nasal colonization model of porcine nasal mucosa explants to identify molecular traits involved in nasal MRSA colonization of pigs. Here, we report the analysis of the transcriptome of MRSA ST398 strain S0462 during colonization on the explant epithelium. Major regulated genes were encoding metabolic processes and regulation of these genes represents metabolic adaptation to nasal mucosa explants. Colonization was not accompanied by significant changes in transcripts of main virulence associated genes or known human colonization factors. Here, we document regulation of two genes which have potential influence on S. aureus colonization; cysteine extracellular proteinase (scpA) and von Willebrand factor-binding protein (vwbp, located on SaPIbov5). Colonization with isogenic-deletion strains (Î?vwbp and Î?scpA) did not alter the nasal S. aureus colonization compared to wild type. Our results suggest that nasal colonization with MRSA ST398 is a complex event that is accompanied with changes in bacterial gene expression regulation and metabolic adaptation. Number of the samples: 5 (timepoint 0 min, 30 min, 60 min, 90 min and 180 min) in 4 replicates. 4 control samples
2015-12-31 | E-GEOD-47910 | biostudies-arrayexpress