Project description:The pathogenesis of acne has been linked to multiple factors such as increased sebum production, inflammation, follicular hyperkeratinization, and the action of Propionibacterium acnes within the follicle. In an attempt to understand the specific genes involved in inflammatory acne, we performed gene expression profiling in acne patients. Skin biopsies were obtained from an inflammatory papule and from normal skin in six patients with acne. Biopsies were also taken from normal skin of six subjects without acne. Gene array expression profiling was conducted using Affymetrix HG-U133A 2.0 arrays comparing lesional to nonlesional skin in acne patients and comparing nonlesional skin from acne patients to skin from normal subjects. Within the acne patients, 211 genes are upregulated in lesional skin compared to nonlesional skin. A significant proportion of these genes are involved in pathways that regulate inflammation and extracellular matrix remodeling, and they include matrix metalloproteinases 1 and 3, IL-8, human beta-defensin 4, and granzyme B. These data indicate a prominent role of matrix metalloproteinases, inflammatory cytokines, and antimicrobial peptides in acne lesions. These studies are the first describing the comprehensive changes in gene expression in inflammatory acne lesions and are valuable in identifying potential therapeutic targets in inflammatory acne. Experiment Overall Design: total 18 chips. 6 for acne lesion samples, 6 for normal skin samples, 6 for non-acne patient normal skin samples
Project description:During the COVID-19 pandemic, facemasks have played a pivotal role in preventing person-person droplet transmission of viral particles. However, prolonged facemask wearing causes skin irritations colloquially referred to as ‘maskne’ (mask + acne), which manifests as acne and contact dermatitis and is mostly caused by pathogenic skin microbes. Previous studies revealed that the putative causal microbes were anaerobic bacteria, but the pathogenesis of facemask-associated skin conditions remains poorly defined. We therefore characterized the role of the facemask-associated skin microbiota in the development of maskne using culture-dependent and -independent methodologies. Metagenomic analysis revealed that the majority of the facemask microbiota were anaerobic bacteria that originated from the skin rather than saliva. Previous work demonstrated direct interaction between pathogenic bacteria and antagonistic strains in the microbiome. We expanded this analysis to include indirect interaction between pathogenic bacteria and other indigenous bacteria classified as either ‘pathogen helper (PH)’ or ‘pathogen inhibitor (PIn)’ strains. In vitro screening of bacteria isolated from facemasks identified both strains that antagonized and promoted pathogen growth. These data were validated using a mouse skin infection model, where we observed attenuation of symptoms following pathogen infection. Moreover, the inhibitor of pathogen helper (IPH) strain, which did not directly attenuate pathogen growth in vitro and in vivo, functioned to suppress symptom development and pathogen growth indirectly through PH inhibitory antibacterial products such as phenyl lactic acid. Taken together, our study defines a mechanism by which indirect microbiota interactions under facemasks control symptoms of maskne by suppressing a skin pathogen for the first time.
Project description:The pathogenesis of acne has been linked to multiple factors such as increased sebum production, inflammation, follicular hyperkeratinization, and the action of Propionibacterium acnes within the follicle. In an attempt to understand the specific genes involved in inflammatory acne, we performed gene expression profiling in acne patients. Skin biopsies were obtained from an inflammatory papule and from normal skin in six patients with acne. Biopsies were also taken from normal skin of six subjects without acne. Gene array expression profiling was conducted using Affymetrix HG-U133A 2.0 arrays comparing lesional to nonlesional skin in acne patients and comparing nonlesional skin from acne patients to skin from normal subjects. Within the acne patients, 211 genes are upregulated in lesional skin compared to nonlesional skin. A significant proportion of these genes are involved in pathways that regulate inflammation and extracellular matrix remodeling, and they include matrix metalloproteinases 1 and 3, IL-8, human beta-defensin 4, and granzyme B. These data indicate a prominent role of matrix metalloproteinases, inflammatory cytokines, and antimicrobial peptides in acne lesions. These studies are the first describing the comprehensive changes in gene expression in inflammatory acne lesions and are valuable in identifying potential therapeutic targets in inflammatory acne. Keywords: acne lesion, normal skin
Project description:The 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-α), Th1 markers (IL12p40, CXCR3, T-bet, IFN-gamma), T regulatory cell markers (Foxp3, IL-10, TGF-β) 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. Total of 24 chips. 12 patients : 2 biospies per patient: 1 lesional and 1 non lesional.
Project description:Innate immune defense against deep tissue infection by Staphylococcus aureus is orchestrated by fibroblasts that become antimicrobial when triggered to differentiate into adipocytes. However, the role of this process in non-infectious human diseases is unknown. To investigate the potential role of adipogenesis by dermal fibroblasts in acne, a disorder triggered by Cutibacterium acnes (C. acnes), single-cell RNA-sequencing was performed on human acne lesions and mouse skin challenged by C. acnes. A transcriptome consistent with adipogenesis was observed within specific fibroblast subsets from human acne and mouse skin lesions infected with C. acnes. Perifollicular dermal preadipocytes in human acne and mouse skin lesions showed colocalization of PREF1, an early marker of adipogenesis, and cathelicidin (Camp), an antimicrobial peptide. This capacity of C. acnes to trigger production of cathelicidin in preadipocytes was dependent on TLR2. Treatment of wild-type mice with retinoic acid (RA) suppressed the capacity of C. acnes to form acne-like lesions, inhibited adipogenesis and enhanced cathelicidin expression in preadipocytes, but lesions were unresponsive in Camp-/- mice, despite the anti-adipogenic action of RA. Analysis of inflamed skin of acne patients after retinoid treatment also showed enhanced induction of cathelicidin, a previously unknown beneficial effect of retinoids in difficult-to-treat acne. Overall, these data provide evidence that adipogenic fibroblasts are a critical component of the pathogenesis of acne and represent a potential target for future therapy.
Project description:The 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-α), Th1 markers (IL12p40, CXCR3, T-bet, IFN-gamma), T regulatory cell markers (Foxp3, IL-10, TGF-β) 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.
Project description:Cutibacterium acnes (C. acnes) is a ubiquitous skin commensal bacterium that is generally well tolerated by the immune system. Different strain-types of C. acnes have been reported to be enriched on patients with acne. To understand if these strain-types contribute to skin inflammation, we generated a library of over 200 C. acnes isolates from skin swabs of healthy and acne subjects and assessed their strain-level identity and inflammatory potential. Phylotype II K-type strains were more frequent on healthy and acne non-lesional skin compared to lesional. Phylotype IA-1 C-type strains were dominant on acne lesional skin but absent from healthy. Measurement of host cytokine responses from C. acnes supernatant revealed neither strain-type nor skin-type association predicted inflammatory potential. However, differential proinflammatory responses were induced from identical strain-types, but these differences were not attributable to protease, short chain fatty acid or porphyrin production. Instead, whole genome sequencing revealed the presence of a linear plasmid in high inflammatory strain-types. Intradermal injection of C. acnes in mouse skin revealed a plasmid-associated inflammatory response in dermal fibroblasts, revealed by single-cell RNA sequencing. We conclude that C. acnes strain-type is not sufficient to predict inflammation but other virulence factors including a plasmid may contribute to disease.
Project description:<p>Studies have emphasized the importance of disease-associated microorganisms in perturbed communities, however, the protective roles of commensals are largely under recognized and poorly understood. Using acne as a model disease, we investigated the determinants of the overall virulence property of the skin microbiota when disease- and health-associated organisms coexist in the community. By ultra-deep metagenomic shotgun sequencing, we revealed higher relative abundances of propionibacteria and Propionibacterium acnes phage in healthy skin. In acne patients, the microbiome composition at the species level and at P. acnes strain level was more diverse than in healthy individuals, with enriched virulence-associated factors and reduced abundance of metabolic synthesis genes. Based on the abundance profiles of the metagenomic elements, we constructed a quantitative prediction model, which classified the clinical states of the host skin with high accuracy in both our study cohort (85%) and an independent sample set (86%). Our results suggest that the balance between metagenomic elements, not the mere presence of disease-associated strains, shapes the overall virulence property of the skin microbiota. This study provides new insights into the microbial mechanism of acne pathogenesis and suggests probiotic and phage therapies as potential acne treatments to modulate the skin microbiota and to maintain skin health.</p>