Project description:To investigate skin aging is an important driver of experimental osteoarthritis(OA) progression in mice via enhanced IL-36 receptor (IL-36R) signaling. The supernatants from the co-culture of UV-aged mouse primary keratinocytes with synovial fibroblasts were collected to induce mouse primary articular chondrocytes (CCs) to become aging SNL CCs. On this basis, Spesolimab (100ng/ml) was added to culture aging SNL CCs to study the drug's effect on OA. We then performed gene expression profiling analysis using data obtained from RNA-seq of 3 groups: control CCs, aging SNL CCs, aging SNL CCs+Spesolimab.
Project description:To investigate skin aging is an important driver of experimental osteoarthritis(OA) progression in mice via enhanced IL-36 receptor (IL-36R) signaling. we generated epidermis keratinocyte conditional knockout mice (IL-36Ra-cKO) with topical administration of capsid-mutant Adeno-associated virus 2 (AAV2) vector23 encoding Cre recombinase (AAV2-Cre) to IL-36Rafl/fl mice. Subsequently, epidermal skin tissues were collected from IL-36Rafl/fl and IL-36Ra-cKO mice for RNA sequencing analysis.
Project description:Skin aging is characterized by structural and functional changes that lead to slower wound healing and higher rate of infections, which contribute to age-associated frailty. This likely depends on synergy between alterations in the local microenvironment and stem cell–intrinsic changes, underscored by pro-inflammatory microenvironments that drive pleotropic changes. To date, little is known about the precise nature and origin of the proposed age-associated inflammatory cues, or how they affect different tissue resident cell types. Based on deep single-cell RNA-sequencing of the entire dermal compartment, we now provide a comprehensive understanding of the age-associated changes in all skin cell types. We show a previously unreported skew towards an IL-17–expressing phenotype of Th cells, γδ T cells and innate lymphoid cells in aged skin. Aberrant IL-17 signaling is common to many autoimmune (e.g., rheumatoid arthritis and psoriasis) and chronic inflammatory diseases. Importantly, in vivo blockade of IL-17–triggered signaling during the aging process reduces the pro-inflammatory state by affecting immune and non-immune skin cells of both dermis and epidermis. Strikingly, IL-17 neutralization significantly delays the appearance of age-related traits, such as decreased epidermal thickness, increased cornified layer thickness and ameliorated hair follicle stem cell activation and hair shaft regeneration. Our results indicate that the aged skin shows chronic and persistent signs of inflammation, and that age-associated increased IL-17 signaling could be targeted as a strategy to prevent age-associated skin ailments in elderly.
Project description:Mammalian skin wounds heal by forming fibrotic scars. We report that reindeer antler velvet exhibits regenerative wound healing, whereas identical injury to back skin forms scar. This regenerative capacity was retained following ectopic transplantation of velvet to scar-forming sites. Single-cell mRNA/ATAC-Sequencing revealed that while uninjured velvet fibroblasts resembled human fetal fibroblasts, back skin fibroblasts were enriched in pro-inflammatory features resembling adult human fibroblasts. Injury elicited site-specific immune polarization; back skin fibroblasts amplified the immune response, whereas velvet fibroblasts adopted an immunosuppressive state leading to restrained myeloid maturation and hastened immune resolution ultimately enabling myofibroblast reversion to a regeneration-competent state. Finally, regeneration was blunted following application of back skin associated immunostimulatory signals or inhibition of pro-regenerative factors secreted exclusive to velvet fibroblasts. This study highlights a unique model to interrogate mechanisms underlying divergent healing outcomes and nominates both decoupling of stromal-immune crosstalk and reinforcement of pro-regenerative fibroblast programs to mitigate scar.
Project description:Skin barrier dysfunction initiates or deteriorates various cutaneous problems, such as atopic dermatitis (AD). In high concentrations, the nonreducing disaccharide α-d-glucopyranosyl α-d-glucopyranoside (trehalose) can induce transient senescence-like state in fibroblasts and promote wound repair. Here we have investigated the direct effect of a high concentration of trehalose on primary human keratinocytes (KCs) and demonstrated its specific role in the skin barrier. RNA-seq analysis revealed that trehalose regulates many skin-barrier-associated genes in T helper 2 (Th2) cytokines interleukin (IL)-4/IL-13-treated and -untreated KCs. Using monolayer-cultured post-confluent normal human KCs and living skin equivalent (LSE), we identified IL-4/IL-13-downregulated differentiation markers and various epidermal antimicrobial proteins, all of which were significantly upregulated or restored by trehalose (60 mg/mL). Trehalose inhibited IL-33 expression and reduced nuclear IL-33 by activating MEK5- extracellular signal-regulated kinase (ERK)-5 and suppressing MEK1/2-ERK pathways. It also increased nuclear factor erythroid 2-related factor 2 (Nrf2)-heme oxygenase 1 (HMOX1) activation via c-Jun N-terminal kinase (JNK), thus, neutralizing IL-4/IL-13-mediated oxidative stress. Trehalose prevented IL-4/IL-13-mediated signal transducer and activator of transcription (STAT)3 and STAT6 activation and restored various skin barrier molecules reduced by IL-4/IL-13 via IL-33 downregulation and Nrf2-HMOX1 activation. This study demonstrates that trehalose might play salubrious roles as skin barrier repair in AD.
Project description:Interleukin-31 (IL-31), a T cells derived cytokine which is mainly produced by CD4+ T cells skewed towards Th2 phenotypes. It signals via a heterodimeric receptors composed of IL-31RA and OSMR that is expressed constitutively in epithelial cells and keratinocytes. IL-31 is shown to play a pathogenic role in allergic and inflammatory diseases. Transgenic mice overexpressing IL-31 have a phenotype similar to atopic dermatitis. Here, we studied the role of IL-31 in skin damage by intradermal administration of recombinant IL-31. Notably, IL-31 was sufficient to increase epidermal basal cell proliferation and thickening of the epidermal layer of skin in mice. Analysis of skin transcriptome indicates a significant increase in the transcripts involved in epidermal cell proliferation and pathological skin remodeling. Thus, our study revealed an important role of IL-31 signaling in activating transcriptional programs involved in the pathophysiology of skin diseases.