Progneaux, A;Evrard, C;De Glas, V;Fontaine, A;Dotreppe, C;De Vuyst, E;Nikkels, AF;García-González, V;Dumoutier, L;Lambert de Rouvroit, C;Poumay, Y;
PMID: 36645024 | DOI: 10.1111/exd.14749
Atopic dermatitis (AD) is a Th2-type inflammatory disease characterized by an alteration of epidermal barrier following the release of IL-4 and IL-13. These cytokines activate type II IL-4Rα/IL-13Rα1 receptors in the keratinocyte. Whilst IL-2Rγ, that forms type I receptor for IL-4, is only expressed in haematopoietic cells, recent studies suggest its induction in keratinocytes, which questions about its role. We studied expression of IL-2Rγ in keratinocytes and its role in alteration of keratinocyte function and epidermal barrier. IL-2Rγ expression in keratinocytes was studied using both reconstructed human epidermis (RHE) exposed to IL-4/IL-13 and AD skin. IL-2Rγ induction by type II receptor has been analyzed using JAK inhibitors and RHE knockout (KO) for IL13RA1. IL-2Rγ function was investigated in RHE KO for IL2RG. In RHE, IL-4/IL-13 induce expression of IL-2Rγ at the mRNA and protein levels. Its mRNA expression is also visualized in keratinocytes of lesional AD skin. IL-2Rγ expression is low in RHE treated with JAK inhibitors and absent in RHE KO for IL13RA1. Exposure to IL-4/IL-13 alters epidermal barrier, but this alteration is absent in RHE KO for IL2RG. A more important induction of IL-13Rα2 is reported in RHE KO for IL2RG than in not edited RHE. These results demonstrate IL-2Rγ induction in keratinocytes through activation of type II receptor. IL-2Rγ is involved in the alteration of the epidermal barrier and in the regulation of IL-13Rα2 expression. Observation of IL-2Rγ expression by keratinocytes inside AD lesional skin suggests a role for this receptor subunit in the disease.
Seeler, S;Moldovan, LI;Bertelsen, T;Hager, H;Iversen, L;Johansen, C;Kjems, J;Sommer Kristensen, L;
PMID: 36174034 | DOI: 10.1371/journal.pone.0275219
Psoriasis is a common chronic inflammatory skin disease accompanied by heterogenous clinical and histological features, including a characteristic keratinocyte hyperproliferation and dermal immunogenic profile. In addition, psoriasis is associated with widespread transcriptomic alterations including changes in microRNA (miRNA) and circular RNA (circRNA) abundance, which constitute non-coding RNA (ncRNA) classes with specific regulatory capacities in diverse physiological and pathological processes. However, the knowledge about the expression dynamics of ncRNA during psoriasis treatment is sparse. To elucidate the dynamics of miRNA and circRNA abundance during secukinumab (anti-IL-17A) treatment, we studied their expression patterns in skin biopsies from 14 patients with severe plaque-type psoriasis before and during an 84-day secukinumab therapy at day 0, 4, 14, 42, and 84 using NanoString nCounter technology. We found a comprehensive downregulation of the majority of investigated circRNAs and specific alterations in the miRNA profile, including an upregulation of miR-203a-3p, miR-93-5p, and miR-378i in lesional compared to non-lesional skin before treatment. During treatment, the circRNAs progressively returned to the expression levels observed in non-lesional skin and already four days after treatment initiation most circRNAs were significantly upregulated. In comparison, for miRNAs, the normalization to baseline during treatment was delayed and limited to a subset of miRNAs. Moreover, we observed a strong correlation between multiple circRNAs, including ciRS-7 and circPTPRA, and the psoriasis area and severity index (PASI). Similar pronounced correlations could, however, not be found for miRNAs. Finally, we did not observe any significant changes in circRNA expression in peripheral blood mononuclear cells during treatment. In conclusion, we uncovered a rapid shift in global circRNA abundance upon anti-IL-17A treatment, which predated clinical and histological improvements, and a strong correlation with PASI, indicating a biomarker potential of individual circRNAs.
The Journal of investigative dermatology
Luo, L;Pasquali, L;Srivastava, A;Freisenhausen, JC;Pivarcsi, A;Sonkoly, E;
PMID: 36641130 | DOI: 10.1016/j.jid.2022.12.011
Psoriasis is a common immune-mediated skin disease characterized by epidermal hyperproliferation and chronic skin inflammation. Long non-coding RNAs (lncRNAs) are >200 nucleotide long transcripts, which possess important regulatory functions. To date, little is known about the contribution of lncRNAs to psoriasis. Here, we identify LINC00958 as a lncRNA overexpressed in keratinocytes from psoriasis skin lesions, in a transcriptomic screen performed on keratinocytes sorted from psoriasis and healthy skin. Increased levels of LINC00958 in psoriasis keratinocytes were confirmed by RT-qPCR and single molecule in situ hybridization. Confocal microscopy and analysis of subcellular fractions showed that LINC00958 is mainly localized in the cytoplasm of keratinocytes. IL-17A, a key psoriasis cytokine, induced LINC00958 in keratinocytes through C/EBP-β and the p38 pathway. Inhibition of LINC00958 led to decreased proliferation as measured by Ki67 expression, IncuCyte imaging and EdU assays. Transcriptomic analysis of LINC00958-depleted keratinocytes revealed enrichment of proliferation and cell cycle-related genes among differentially expressed transcripts. Moreover, LINC00958-depletion led to decreased basal and IL-17A-induced phosphorylation of p38. Furthermore, IL-17A-induced keratinocyte proliferation was counteracted by the inhibition of LINC00958. In summary, our data support a role for the IL-17A-induced lncRNA, LINC00958, in the pathological circuits in psoriasis by reinforcing IL-17A-induced epidermal hyperproliferation.
Deletion of TNFAIP6 gene in human keratinocytes demonstrates a role for TSG-6 to retain hyaluronan inside epidermis
Evrard, C;Faway, E;De Vuyst, E;Svensek, O;De Glas, V;Bergerat, D;Salmon, M;De Backer, O;Flamion, B;Le-Buanec, H;Lambert de Rouvroit, C;Poumay, Y;
| DOI: 10.1016/j.xjidi.2021.100054
TNFα-stimulated gene 6 (TSG-6) is a soluble protein secreted in the extracellular matrix (ECM) by various cell types in response to inflammatory stimuli. TSG-6 interacts with ECM molecules, particularly hyaluronan (HA), and promotes cutaneous wound closure in mouse. Between epidermal cells, the discrete ECM contains HA and tiny amount of TSG-6. However, challenges imposed to keratinocytes in reconstructed human epidermis (RHE) revealed strong induction of TSG-6 expression, after exposure to Th2 cytokines to recapitulate the atopic dermatitis phenotype, or after fungal infection that causes secretion of cytokines and antimicrobial peptides. Following both types of challenge, enhanced release of TSG-6 happens simultaneously with increased HA production. TSG-6 deficiency in N/TERT keratinocytes was created by inactivating TNFAIP6 using CRISPR/Cas9. Some TSG-6-/- keratinocytes analyzed through scratch assays tend to migrate more slowly, but produce RHE that exhibit normal morphology and differentiation. Few significant alterations were noticed by transcriptomic analysis. Nevertheless, reduced HA content in TSG-6-/- RHE was observed, along with enhanced HA release into culture medium, and this phenotype was even more pronounced following challenging conditions. Reintroduction of cells producing TSG-6 in RHE reduced HA leakage. Our results demonstrate a role for TSG-6 in sequestering HA between epidermal cells in response to inflammation.
Atsumi, Y;Toriyama, M;Kato, H;Nakamura, M;Morita, A;Takaishi, M;Saito, K;Tanaka, M;Okada, F;Tominaga, M;Ishii, KJ;Fujita, F;
PMID: 36645854 | DOI: 10.4049/immunohorizons.2200100
The pathology of skin immune diseases such as atopic dermatitis is closely related to the overproduction of cytokines by macrophages. Although the pathological functions of macrophages in skin are known, mechanisms of how they detect the tissue environment remain unknown. TRPV4, a nonselective cation channel with high Ca2+ permeability, is activated at physiological temperatures from 27 to 35°C and involved in the functional control of macrophages. However, the relationship between TRPV4 function in macrophages and skin immune disease is unclear. In this study, we demonstrate that TRPV4 activation inhibits NF-κB signaling, resulting in the suppression of IL-1β production in both human primary monocytes and macrophages derived from human primary monocytes. A TRPV4 activator also inhibited the differentiation of human primary monocytes into GM-CSF M1 macrophages but not M-CSF M2 macrophages. We also observed a significant increase in the number of inducible NO synthase-positive/TRPV4-negative dermal macrophages in atopic dermatitis compared with healthy human skin specimens. Our findings provide insight into the physiological relevance of TRPV4 to the regulation of macrophages during homeostasis maintenance and raise the potential for TRPV4 to be an anti-inflammatory target.
Vorstandlechner V, Laggner M, Kalinina P, Haslik W, Radtke C, Shaw L, Lichtenberger BM, Tschachler E, Ankersmit HJ, Mildner M
PMID: 31930613 | DOI: 10.1096/fj.201902001RR
Though skin fibroblasts (FB) are the main cell population within the dermis, the different skin FB subsets are not well characterized and the traditional classification into reticular and papillary FBs has little functional relevance. To fill the gap of knowledge on FB diversity in human skin, we performed single-cell RNA sequencing. Investigation of marker genes for the different skin cell subtypes revealed a heterogeneous picture of FBs. When mapping reticular and papillary FB markers, we could not detect cluster specificity, suggesting that these two populations show a higher transcriptional heterogeneity than expected. This finding was further confirmed by in situ hybridization, showing that DPP4 was expressed in both dermal layers. Our analysis identified six FB clusters with distinct transcriptional signatures. Importantly, we could demonstrate that in human skin DPP4+ FBs are the main producers of factors involved in extracellular matrix (ECM) assembly. In conclusion, we provide evidence that hitherto considered FB markers are not ideal to characterize skin FB subpopulations in single-cell sequencing analyses. The identification of DPP4+ FBs as the main ECM-producing cells in human skin will foster the development of anti-fibrotic treatments for the skin and other organs
Tanaka, T;Okuda, H;Isonishi, A;Terada, Y;Kitabatake, M;Shinjo, T;Nishimura, K;Takemura, S;Furue, H;Ito, T;Tatsumi, K;Wanaka, A;
PMID: 36703006 | DOI: 10.1038/s41590-022-01418-5
Cross-talk between peripheral neurons and immune cells is important in pain sensation. We identified Snx25 as a pain-modulating gene in a transgenic mouse line with reduced pain sensitivity. Conditional deletion of Snx25 in monocytes and macrophages, but not in peripheral sensory neurons, in mice (Snx25cKO mice) reduced pain responses in both normal and neuropathic conditions. Bone marrow transplantation using Snx25cKO and wild-type mice indicated that macrophages modulated pain sensitivity. Expression of sorting nexin (SNX)25 in dermal macrophages enhanced expression of the neurotrophic factor NGF through the inhibition of ubiquitin-mediated degradation of Nrf2, a transcription factor that activates transcription of Ngf. As such, dermal macrophages set the threshold for pain sensitivity through the production and secretion of NGF into the dermis, and they may cooperate with dorsal root ganglion macrophages in pain perception.
The Journal of investigative dermatology
Mortlock, RD;Ma, EC;Cohen, JM;Damsky, W;
PMID: 37341663 | DOI: 10.1016/j.jid.2023.04.005
Immunologically targeted therapies have revolutionized the treatment of inflammatory dermatoses, including atopic dermatitis and psoriasis. Although immunologic biomarkers hold great promise for personalized classification of skin disease and tailored therapy selection, there are no approved or widely used approaches for this in dermatology. This review summarizes the translational immunologic approaches to measuring treatment-relevant biomarkers in inflammatory skin conditions. Tape strip profiling, microneedle-based biomarker patches, molecular profiling from epidermal curettage, RNA in situ hybridization tissue staining, and single-cell RNA sequencing have been described. We discuss the advantages and limitations of each and open questions for the future of personalized medicine in inflammatory skin disease.
Zhang, X;Li, X;Wang, Y;Chen, Y;Hu, Y;Guo, C;Yu, Z;Xu, P;Ding, Y;Mi, QS;Wu, J;Gu, J;Shi, Y;
PMID: 35801590 | DOI: 10.1172/jci.insight.150223
Psoriasis is a chronic, inflammatory skin disease, frequently associated with dyslipidemia. Lipid disturbance in psoriasis affects both circulatory system and cutaneous tissue. Epidermal Langerhans cells (LCs) are tissue-resident DCs that maintain skin immune surveillance and mediate various cutaneous disorders, including psoriasis. However, the role of LCs in psoriasis development and their lipid metabolic alternation remains unclear. Here, we demonstrate that epidermal LCs of psoriasis patients enlarge with longer dendrites and possess elevated IL-23p19 mRNA and a higher level of neutral lipids when compared with normal LCs of healthy individuals. Accordantly, epidermal LCs from imiquimod-induced psoriasis-like dermatitis in mice display overmaturation, enhanced phagocytosis, and excessive secretion of IL-23. Remarkably, these altered immune properties in lesional LCs are tightly correlated with elevated neutral lipid levels. Moreover, the increased lipid content of psoriatic LCs might result from impaired autophagy of lipids. Bulk RNA-Seq analysis identifies dysregulated genes involved in lipid metabolism, autophagy, and immunofunctions in murine LCs. Overall, our data suggest that dysregulated lipid metabolism influences LC immunofunction, which contributes to the development of psoriasis, and therapeutic manipulation of this metabolic process might provide an effective measurement for psoriasis.
Keren, A;Bertolini, M;Keren, Y;Ullmann, Y;Paus, R;Gilhar, A;
PMID: 35749494 | DOI: 10.1126/sciadv.abm6756
Transplanting aged human skin onto young SCID/beige mice morphologically rejuvenates the xenotransplants. This is accompanied by angiogenesis, epidermal repigmentation, and substantial improvements in key aging-associated biomarkers, including ß-galactosidase, p16ink4a, SIRT1, PGC1α, collagen 17A, and MMP1. Angiogenesis- and hypoxia-related pathways, namely, vascular endothelial growth factor A (VEGF-A) and HIF1A, are most up-regulated in rejuvenated human skin. This rejuvenation cascade, which can be prevented by VEGF-A-neutralizing antibodies, appears to be initiated by murine VEGF-A, which then up-regulates VEGF-A expression/secretion within aged human skin. While intradermally injected VEGF-loaded nanoparticles suffice to induce a molecular rejuvenation signature in aged human skin on old mice, VEGF-A treatment improves key aging parameters also in isolated, organ-cultured aged human skin, i.e., in the absence of functional skin vasculature, neural, or murine host inputs. This identifies VEGF-A as the first pharmacologically pliable master pathway for human organ rejuvenation in vivo and demonstrates the potential of our humanized mouse model for clinically relevant aging research.
The polyamine regulator AMD1 up-regulates spermine levels to drive epidermal differentiation
The Journal of investigative dermatology
Rahim, AB;Lim, HK;Ru Tan, CY;Jia, L;Leo, VI;Uemura, T;Hardman-Smart, J;Common, JEA;Lim, TC;Bellanger, S;Paus, R;Igarashi, K;Yang, H;Vardy, LA;
PMID: 33984347 | DOI: 10.1016/j.jid.2021.01.039
Maintaining tissue homeostasis depends on a balance of cell proliferation, differentiation and apoptosis. Within the epidermis the levels of the polyamines putrescine, spermidine and spermine are altered in many different skin conditions yet their role in epidermal tissue homeostasis is poorly understood. We identify the polyamine regulator, AMD1, as a crucial regulator of keratinocyte differentiation. AMD1 protein is upregulated on differentiation and highly expressed in the suprabasal layers of the human epidermis. During keratinocyte differentiation, elevated AMD1 promotes decreased putrescine and increased spermine levels. Knockdown/inhibition of AMD1 results in reduced spermine levels and inhibition of keratinocyte differentiation. Supplementing AMD1-knockdown keratinocytes with exogenous spermidine/spermine rescued aberrant differentiation. We show that the polyamine shift is critical for the regulation of key transcription factors and signalling proteins that drive keratinocyte differentiation including KLF4 and ZNF750. These findings demonstrate that human keratinocytes use controlled changes in polyamine levels to modulate gene expression to drive cellular behaviour changes. Modulation of polyamine levels during epidermal differentiation could impact skin barrier formation or be used in the treatment of hyper-proliferative skin disorders.
Archives of dermatological research
Murphy, MJ;Leasure, AC;Damsky, W;Cohen, JM;
PMID: 36436011 | DOI: 10.1007/s00403-022-02488-z
Psoriasis and sarcoidosis are inflammatory skin and systemic diseases that may share a similar immunopathogenesis involving a Th1 and/or Th17 polarized immune response. Although the coexistence of sarcoidosis and psoriasis in the same individuals has been reported, the potential association between these diseases at a population-level in the United States has not been evaluated. To evaluate this association, we performed a matched cross-sectional study in the All of Us research program database. In the multivariable analysis of 4932 psoriasis cases and 19,728 controls, sarcoidosis was found to be significantly associated with psoriasis (OR 2.37 [95% CI 1.73-3.23], p < 0.001). The relative strength of this association between psoriasis and sarcoidosis may be, in part, explained by overlapping immunopathogenesis and common genetic susceptibility of these diseases. Taken together, these observations underscore the need for screening psoriasis patients for development of new cardiopulmonary symptoms. Further research into the mechanism of this relationship and its implications is warranted.