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IL-33 is a dual-functional molecule; it acts as a cytokine to enhance type 2 inflammation, and as a nuclear factor. The roles of nuclear IL-33 are not yet fully understood.We aimed to investigate the role of IL-33 in normal human epidermal keratinocytes (NHEKs).We utilized RNA interference to knock down cellular IL-33.The IL-33-knockdown (KD) cells showed decreased BrdU incorporation and decreasing tendency in RhoA activity and decreased ECT2 oncogene expression, compared to the controls. Supplementation of IL-33 expression utilizing adenovirus vector recovered the BrdU incorporation in IL-33-KD cells. Increased number of G2/M phase cells and binucleated cells were observed among the KD cells. Overtime observation revealed that IL-33-KD cells could not divide properly, formed binucleated cells, and were less motile than control cells.IL-33 KD in NHEKs affected the division and motility, probably by slightly decreasing the RhoA activity by attenuating ECT2 expression.

Objectives The aim of this study was to evaluate the expression of GCDFP15 and GATA‐binding protein 3 (GATA‐3) in extramammary Paget's disease (EMPD) skin and serum samples and to assess their availability as tumor markers for the diagnosis and assessment of disease severity in primary EMPD. Methods Skin samples and serum samples were obtained from 16 patients with primary EMPD (10 cases from male, six cases from female; stage IA six cases, stage IB seven cases, stage III one case, stage IV two cases). By immunohistochemistry, the expression of GCDFP15 and GATA3 was examined in skin specimens. The serum levels of GCDFP15 and GATA3 were quantified by ELISA. Results In our study, eight out of 16 patients showed positive staining for GCDFP15. In contrast, all 16 patients showed positive staining for GATA‐3. Immunohistochemical staining of EMPD skin samples showed that GATA‐3 had a higher positivity rate than GCDFP15. However, there was no correlation between serum levels of GCDFP15 or GATA‐3 and the disease stage. Conclusion Our results indicate that GCDFP15 and GATA‐3 are useful for the diagnosis of primary EMPD, but not for monitoring disease progression, and suggest that GATA‐3 is a more reliable marker than GCDFP15 for the diagnosis of primary EMPD.

Pinyadapat Vacharanukrauh,1 Jitlada Meephansan,1 Pattarin Tangtanatakul,2 Wipasiri Soonthornchai,3 Jongkonnee Wongpiyabovorn,4 Onsiri Serirat,5 Mayumi Komine6 1Division of Dermatology, Chulabhorn International College of Medicine, Thammasat University, Pathum Thani, 12120, Thailand; 2Department of Transfusion Medicine and Clinical Microbiology, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330, Thailand; 3Demonstration School, University of Phayao, Phayao, 56000, Thailand; 4Division of Immunology, Department of Microbiology, Faculty of Medicine, Center of Excellence in Immunology and Immune Mediated Diseases, Chulalongkorn University, Bangkok, 10330, Thailand; 5Division of Dermatology, Department of Medicine, Rajavithi Hospital, Ministry of Public Health, Bangkok, 10400, Thailand; 6Department of Dermatology, Jichi Medical University, Tochigi, JapanCorrespondence: Jitlada MeephansanDivision of Dermatology, Chulabhorn International College of Medicine, Thammasat University, Rangsit Campus, Klong Luang, Pathum Thani, 12120, ThailandTel +662564-4444, ext.1535Fax +662564-4440, ext.7594Email kae_mdcu@yahoo.comObjective: To identify the narrowband ultraviolet B (NB-UVB)-induced molecular mechanisms that may account for their anti-inflammatory efficacy, gene expression and transcriptome profiling, which were performed using advanced molecular techniques.Methods: This research was conducted on patients with moderate-to-severe plaque-type psoriasis who received NB-UVB treatment. RNA sequencing (RNA-Seq) was conducted to assay the transcriptomes and identify the differentially expressed transcripts that had been enriched during the major pathway analysis.Results: Clinical improvement of psoriasis by NB-UVB therapy is linked to the suppression of the “immunological signaling pathways” and “cell cycle regulatory, growth and proliferation pathways” which are critical to the pathogenesis of the disease. In addition, these results were further substantiated by demonstrating that NB-UVB therapy has a significant effect on keratinocyte differentiation and affects the regulation of genes and inflammatory mediators that are related to cell proliferation and apoptosis. Moreover, NB-UVB phototherapy is also involved with the downregulation of toll-like receptors signaling in lesional psoriasis.Conclusion: NB-UVB is an effective treatment for psoriasis. Our study supports the conclusion that the clinical effectiveness of NB-UVB therapy is based on the suppression of a broad range of inflammatory signaling pathways, gene expression of inflammatory cytokines and increased expressions of anti-inflammatory signaling pathways in psoriatic skin. This is the first study that applied advanced molecular techniques to investigate phototherapy as a new key to unlock genetic knowledge and create novel information. Ultimately, the goal is to increase medical knowledge and improve the patient care of psoriasis.Keywords: psoriasis, pathogenesis, inflammation, NB-UVB, high-throughput RNA-sequencing, Inflammation, gene, translational study, chronic skin disease, UVB irradiation

This is the English version of Japanese guidance for use of biologics for psoriasis (the 2022 version). As the first biologics for psoriasis in Japan, infliximab and adalimumab, anti-tumor necrosis factor-α antibodies, became available in the field of dermatology in 2010, followed by ustekinumab, an anti-interleukin (IL)-12/IL-23p40 antibody, which was launched in Japan in 2011. Moreover, after 2015, three IL-17 inhibitors, the IL-17A antibody preparations secukinumab and ixekizumab, and an anti-IL-17 receptor antibody preparation brodalumab were marketed. Furthermore, after 2018, the anti-IL23p19 antibody preparations guselkumab and risankizumab, the TNF inhibitor certolizumab pegol, the IL-23 inhibitor tildrakizumab, and the anti-IL-17A/F antibody bimekizumab were marketed. It is important for physicians to select appropriate biologic therapy for each psoriatic patient after due consideration of disease factors, treatment factors, and patient background factors, sharing such information with patients. The followings can be listed as points to be considered for the selection of biologics: drug effects (e.g., strength of effectiveness, time to onset of effectiveness, effectiveness against arthritis, primary failure, secondary failure), safety (e.g., infections, administration-related reactions, and relationships with other comorbidities), convenience for patients (e.g., hospital visit intervals, self-injection, maintenance therapy at clinics, feasibility of drug discontinuation/re-administration), and payment (medical costs) borne by patients. This guidance has been prepared with the aim of allowing dermatologists experienced in the treatment of psoriasis to use biologics appropriately according to the circumstances of individual patients after consideration of the above-mentioned factors.

SLC29A3, also known as ENT3, is a lysosomal transmembrane protein that transports nucleosides from the lysosomes to the cytoplasm1. Loss-of-function mutations inSLC29A3cause lysosomal nucleoside storage and histiocytosis: phagocyte accumulation in multiple organs2,3. However, little is known about the mechanism through which lysosomal nucleoside storage drives histiocytosis. Herein, histiocytosis inSlc29a3−/−mice was demonstrated to depend on TLR7, which senses a combination of nucleosides and oligoribonucleotides4,5. TLR7 responded to lysosomal nucleoside storage and enhanced proliferation of Ly6ChiCX3CR1lowimmature monocytes and their maturation into Ly6Clowphagocytes inSlc29a3−/−mice. Because accumulated nucleosides primarily originated from cell corpse phagocytosis, TLR7 in immature monocytes recognized nucleoside storage as lysosomal stress and increased phagocyte numbers. This non-inflammatory compensatory response is referred to as the TLR7 stress response where Syk, GSK3β, β-catenin, and mTORC1 serve as downstream signalling molecules. In SLC29A3 disorders, histiocytosis accompanies inflammation6,7. Nucleoside storage failed to induce pro-inflammatory cytokine production inSlc29a3−/−mice, but enhanced ssRNA-dependent pro-inflammatory cytokine production in Ly6Chiclassical monocytes and peripheral macrophages, not proliferating immature monocytes. Patient-derived monocytes harbouring G208RSLC29A3mutation showed higher survival and proliferation in the presence of M-CSF and produced larger amounts of IL-6 upon ssRNA stimulation than did those derived from healthy subjects. A TLR8 antagonist inhibited the survival/proliferation of patient-derived macrophages. These results demonstrated that TLR7/8 responses to lysosomal nucleoside stress drive SLC29A3 disorders.

Coronavirus disease 2019 (COVID‐19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2). The ongoing COVID‐19 pandemic has affected both daily life and medical care; therefore, the aim of this study was to analyze the use of biologics for inflammatory skin diseases during the COVID‐19 pandemic in our hospital. The observation period was between 1 January 2020 and 23 February 2021. In this study, we enrolled 227 patients with psoriasis, six patients with palmoplantar pustulosis (PPP), 69 patients with atopic dermatitis (AD), and five patients with hidradenitis suppurativa (HS). Bioswitch was performed in 25 patients with psoriasis (11.0%). Biologics were discontinued in 14 patients with psoriasis (6.2%), 10 patients with AD (14.5%), and four patients with HS (80.0%); they were not discontinued in patients with PPP. The introduction of biologics was observed in 27 patients with psoriasis (11.9%), four patients with PPP (66.7%), 33 patients with AD (47.8%), and two patients with HS (40.0%). The use of telephone consultations was observed in four patients with psoriasis and two patients with AD. One patient, who received adalimumab for the treatment of psoriatic arthritis, suffered from COVID‐19 and recovered after a mild course. In conclusion, we report our experience regarding the use of biologic drugs for inflammatory skin diseases. The use of biologics seemed safe for use amidst COVID‐19 infection during the observation period; however, further observation on a larger number of patients is required to confirm the risks and benefits of biologic use in the COVID‐19 era.

Skin pigmentation is a specific and complex mechanism that occurs as a result of the quantity and quality of melanin produced, as well as the size, number, composition, mode of transfer, distribution, and degradation of the melanosomes inside keratinocytes and the handling of the melanin product by the keratinocyte consumer. Melanocyte numbers typically remain relatively constant. Melanin synthesis, melanosome maturation, and melanoblast translocation are considered to be responsible for hereditary pigmentary disorders. Keratinocytes play a significant role in regulating the adhesion, proliferation, survival, and morphology of melanocytes. In the epidermis, each melanocyte is surrounded by 30–40 keratinocytes through dendrites and transfers mature melanosomes into the cytoplasm of keratinocytes, which are then digested. Melanocytes are believed to transfer melanosomes to neighboring keratinocytes via exocytosis-endocytosis, microvesicle shedding, phagocytosis, or the fusion of the plasma membrane, protecting skin cells against ultraviolet (UV) damage by creating a physical barrier (cap structure) over the nucleus. An understanding of the factors of melanocytes and keratinocytes that induce pigmentation and the transfer mechanism of melanosomes to keratinocytes and how genetic abnormalities in keratinocytes affect pigmentary skin disorders will help us to elucidate hereditary pigmentary disorders more transparently and provide a conceptual framework for the importance of keratinocytes in the case of pigmentary disorders.

Keratinocytes are the major structural component of the epidermis. They differentiate from the basal through spinous to granular layers, and abrupt loss of nucleus pushes them to differentiate into cornified layers, which exfoliates as scales. Differentiation process is tightly controlled by the organized expression of transcription factors and other regulators, which sustains the physiological function of the skin barrier. The genetic abnormality of the molecules expressed in this pathway causes hereditary skin disorders and defects in barrier function. Ichthyosis is caused by keratins, enzymes, and structural proteins involved in lipid metabolism and cornified envelope formation. Atopic dermatitis seemed to be an immune-oriented disease, but the recent finding revealed filaggrin as a causative factor. Keratinocytes respond to acute injury by releasing alarmins. IL-33 is one of such alarmins, which provoke Th2-type inflammation. IL-33 works as a cytokine and, at the same time, as nuclear protein. IL-33 has double-faced nature, with pro- and anti-inflammatory functions. Epidermis, covering the entire body, should stay silent at minor insults, while it should provoke inflammatory signals at emergency. IL-33 and other double-faced molecules may play a role in fine tuning the complexed function of epidermal keratinocytes to maintain the homeostasis of human body.

Peripheral edge (PE) of plaques contains inflammatory molecules and has potential to initiate plaque formation, while the center (CE) of plaques has regression trends.To elucidate the chronological molecular events by comparing the gene profiles in PE skin to those in CE skin.Biopsied PE, CE, and uninvolved (UN) skin samples were analyzed by next-generation sequencing. Three groups of differentially expressed genes (DEGs) were analyzed, PE/UN-, CE/UN-, and PE/CE-skin-derived DEGs.PE skin contained inflammation-priming molecules, such as S100A7 and S100A15, and inflammatory drivers, such as interleukin (IL)-36α. IL-6 signaling was more active in PE than in CE skin. IL-8, S100A7, S100A8, S100A9, and human β-defensin-2 were all regulated with the similar pattern in both areas. However, PE skin created a more active inflammatory network and downstream functions, including chemotaxis and angiogenesis, were more prominent than in CE skin. Conversely, CE skin, where epidermal growth factor and hepatocyte growth factor increased their activity, was found to be more stable.This is the first RNA-seq-based report to determine the chronological molecular events in plaque formation. In the early phase, inflammation might be initiated through molecules, such as IL-36α, S100A7, and S100A15, as observed in PE skin. The inflammation state in PE skin progresses to the more stable state found in CE skin. In CE skin, the growth factor activities are increased, which might lead to attenuation of initial inflammation and initiation of the regression phase. These molecular events may accelerate research towards developing novel therapies for psoriasis.

Background A wide gender gap exists in many fields in Japan, including the academic society of dermatology. Women are substantially underrepresented in the highest academic ranks. Objective We aimed to clarify the possible factors contributing to the current gender gap in the field of academic dermatology and to recommend necessary measures to decrease the gender gap. Methods We performed a cross-sectional study of faculty members’ academic productivity at the dermatology departments of all the educational institutions in Japan in 2019. Results Women had significantly lower academic productivity than men. A significant gender difference in academic productivity was found in lecturers and assistant professors but not in associate professor and professor positions. This gender difference was still significant after normalizing the productivity for career length. Conclusion Our findings suggest the need to encourage women lecturers and assistant professors to improve their academic achievement to decrease the gender gap in academic dermatology.

Elucidating transcriptome in the peripheral edge of the lesional (PE) skin could provide a better understanding of the molecules or signalings that intensify inflammation in the PE skin. Full-thickness biopsies of PE skin and uninvolved (UN) skin were obtained from psoriasis patients for RNA-seq. Several potential differentially expressed genes (DEGs) in the PE skin compared to those in the UN skin were identified. These DEGs enhanced functions such as angiogenesis, growth of epithelial tissue, chemotaxis and homing of cells, growth of connective tissues, and degranulation of myeloid cells beneath the PE skin. Moreover, the canonical pathways of IL-17A, IL-6, and IL-22 signaling were enriched by the DEGs. Finally, we proposed that inflammation in the PE skin might be driven by the IL-36/TLR9 axis or IL-6/Th17 axis and potentiated by IL-36α, IL-36γ, IL-17C, IL-8, S100A7, S100A8, S100A9, S100A15, SERPINB4, and hBD-2. Along with IL-36α, IL-17C, and IκBζ, ROCK2 could be an equally important factor in the pathogenesis of psoriasis, which may involve self-sustaining circuits between innate and adaptive immune responses via regulation of IL-36α and IL-36γ expression. Our finding provides new insight into signaling pathways in PE skin, which could lead to the discovery of new psoriasis targets.

As the first biologics for psoriasis in Japan, infliximab and adalimumab, anti-tumor necrosis factor-α antibodies, became available in the field of dermatology in 2010, followed by ustekinumab, an anti-interleukin (IL)-12/IL-23p40 antibody, which was launched in Japan in 2011. Since 2015, three IL-17 inhibitors of secukinumab and ixekizumab, anti-IL-17A antibodies, and brodalumab, an anti-IL-17 receptor antibody, and two anti-IL-23p19 antibodies of guselkumab and risankizumab, have also been launched. It is important for physicians to select appropriate biologic therapy for each psoriatic patient after due consideration of disease factors, treatment factors and patient background factors, sharing such information with patients. The following can be listed as points to be considered for the selection of biologics: drug effects (e.g. strength of effectiveness, time to onset of effectiveness, effectiveness against arthritis, primary failure, secondary failure), safety (e.g. infections, administration-related reactions and relationships with other comorbidities), convenience for patients (e.g. hospital visit intervals, self-injection, maintenance therapy at clinics, feasibility of drug discontinuation/re-administration) and payment (medical costs) borne by patients. This guidance has been prepared with the aim of allowing dermatologists experienced in the treatment of psoriasis to use biologics appropriately according to the circumstances of individual patients after consideration of the above-mentioned factors.

Activation of signal transducer and activator of transcription (STAT)3 has been reported in many cancers. It is also well known that STAT3 is activated in skin lesions of psoriasis, a chronic skin disease. In this study, to ascertain whether patients with psoriasis have a predisposition to STAT3 activation, we examined phosphorylated STAT3 in cancer cells of psoriasis patients via immunohistochemistry. We selected patients with psoriasis who visited the Department of Dermatology, Jichi Medical University Hospital, from January 2000 to May 2015, and had a history of cancer. We performed immunostaining for phosphorylated STAT3 in tumor cells of five, four, and six cases of gastric, lung, and head and neck cancer, respectively. The results showed that there was no significant difference in STAT3 activation in any of the three cancer types between the psoriasis and control groups. Although this study presents limitations in its sample size and inconsistency in the histology and differentiation of the cancers, results suggest that psoriasis patients do not have a predisposition to STAT3 activation. Instead, STAT3 activation is intricately regulated by each disorder or cellular microenvironment in both cancer and psoriasis.

NKIRAS1 and NKIRAS2 (also called as κB-Ras) were identified as members of the atypical RAS family that suppress the transcription factor NF-κB. However, their function in carcinogenesis is still controversial. To clarify how NKIRAS acts on cellular transformation, we generated transgenic mice in which NKIRAS2 was forcibly expressed using a cytokeratin 15 (K15) promoter, which is mainly activated in follicle bulge cells. The ectopic expression of NKIRAS2 was mainly detected in follicle bulges of transgenic mice with NKIRAS2 but not in wild type mice. K15 promoter-driven expression of NKIRAS2 failed to affect the development of epidermis, which was evaluated using the expression of K10, K14, K15 and filaggrin. However, K15 promoter-driven expression of NKIRAS2 effectively suppressed the development of skin tumors induced by treatment with 7,12-dimethylbenz(a)anthracene (DMBA)/12-O-tetradecanoylphorbol 13-acetate (TPA). This observation suggested that NKIRAS seemed to function as a tumor suppressor in follicle bulges. However, in the case of oncogenic HRAS-driven cellular transformation of murine fibroblasts, knockdown of NKIRAS2 expression drastically suppressed HRAS-mutant-provoked cellular transformation, suggesting that NKIRAS2 was required for the cellular transformation of murine fibroblasts. Furthermore, moderate enforced expression of NKIRAS2 augmented oncogenic HRAS-provoked cellular transformation, whereas an excess NKIRAS2 expression converted its functional role into a tumor suppressive phenotype, suggesting that NKIRAS seemed to exhibit a biphasic bell-shaped enhancing effect on HRAS-mutant-provoked oncogenic activity. Taken together, the functional role of NKIRAS in carcinogenesis is most likely determined by not only cellular context but also its expression level.

COVID-19 is a recently emerged viral infection worldwide. SARS-CoV-2, the causative virus, is believed to have emerged from bat coronaviruses, probably through host conversion. The bat coronavirus which has the highest gene homology to SARS-CoV-2 specifically infects deep forest bats in China whose habitat extends through the Middle East to Southern Europe. Host conversion might have occurred due to the deforestation by humans exposing wild bats to the environment they had never encountered before. SARS-CoV-2 infects cells through two mechanisms: through its receptor ACE2 with the help of enzyme TMPRSS and through membrane fusion with the help of elastases in the inflammatory condition. Obesity, hypertension, diabetes mellitus, and pulmonary diseases cause poor prognosis of COVID-19. Aging is another factor promoting poor prognosis. These diseases and aging cause low-level and persistent inflammation in humans, which can promote poor prognosis of COVID-19. Psoriasis and atopic dermatitis are the major inflammatory skin diseases. These inflammatory skin conditions, however, do not seem to cause poor prognosis for COVID-19 based on the epidemiological data accumulated so far. These mechanisms need to be elucidated.