JAK inhibitors for the treatment of vitiligo.

Vitiligo is an autoimmune disease involving melanocyte-targeting T cells initiated by environmental and genetic factors. Steroids and tacrolimus have been used as topical treatments. Recently, novel topical agents targeting Janus kinase (JAK), a family of tyrosine kinases that regulates cytokine signaling, have emerged. Ruxolitinib is the first approved in vitiligo therapy. Furthermore, ritlecitinib is currently under clinical trials for oral treatment of active vitiligo. In this review, we discuss the possibility of topical JAK inhibitors as promising options for the treatment of vitiligo with regard to their mechanism of action, efficacy and safety.

Lysophospholipase D from Thermocrispum limits psoriatic inflammation by hydrolyzing epidermal lysoplasmalogen produced by group IIF secreted phospholipase A2.

Epidermal lipids play important roles in skin homeostasis and diseases. Psoriasis is an inflammatory disease characterized by keratinocyte hyperproliferation and Th17 immune responses. We previously reported that ethanolamine-type lysoplasmalogen (P-LPE), preferentially produced by group IIF secreted PLA2 (sPLA2-IIF/PLA2G2F) that is expressed in the suprabasal epidermis, promotes epidermal hyperplasia in psoriatic inflammation. Herein, we show that forcible degradation of epidermal P-LPE by topical application of recombinant lysophospholipase D (LyPls-PLD) from Thermocrispum, a lysoplasmalogen-specific hydrolase, attenuated epidermal hyperplasia and inflammation in imiquimod-induced and K5.Stat3C-transgenic mouse psoriasis models. In humans, P-LPE levels were elevated in the tape-stripped stratum corneum of patients with psoriasis. Moreover, in primary cultured human epidermal keratinocytes, aberrant cell proliferation and activation by psoriatic cytokines were sPLA2-IIF/P-LPE-dependent and were suppressed by the addition of LyPls-PLD with a decrease in P-LPE. These findings confirm that the sPLA2-IIF/P-LPE axis in the epidermis indeed regulates psoriasis, that P-LPE is a lipid biomarker that predicts the severity of psoriasis, and that pharmacological removal of this bioactive lipid is useful to prevent the disease. Thus, our study may lead to the development of drug discovery and diagnostic techniques based on this pathway.

Efficacy and Safety of Apremilast for the Treatment of Japanese Patients with Palmoplantar Pustulosis: Results from a Phase 2, Randomized, Placebo-Controlled Study.

BACKGROUND: Palmoplantar pustulosis (PPP) is a pruritic, painful, recurrent, and chronic dermatitis with limited therapeutic options. OBJECTIVE: To evaluate the efficacy and safety of apremilast for the treatment of Japanese patients with PPP and inadequate response to topical treatment. METHODS: This phase 2, randomized, double-blind, placebo-controlled study enrolled patients with Palmoplantar Pustulosis Area and Severity Index (PPPASI) total score ≥ 12 and moderate or severe pustules/vesicles on the palm or sole (PPPASI pustule/vesicle severity score ≥ 2) at screening and baseline with an inadequate response to topical treatment. Patients were randomized (1:1) to apremilast 30 mg twice daily or placebo for 16 weeks, followed by a 16-week extension phase during which all patients received apremilast. The primary endpoint was achievement of PPPASI-50 response (≥ 50% improvement from baseline in PPPASI). Key secondary endpoints included change from baseline in PPPASI total score, Palmoplantar Pustulosis Severity Index (PPSI), and patient's visual analog scale (VAS) for PPP symptoms (pruritus and discomfort/pain). RESULTS: A total of 90 patients were randomized (apremilast: 46; placebo: 44). A significantly greater proportion of patients achieved PPPASI-50 at week 16 with apremilast versus placebo (P = 0.0003). Patients receiving apremilast showed greater improvement in PPPASI at week 16 versus placebo (nominal P = 0.0013), as well as PPSI and patient-reported pruritus and discomfort/pain (nominal P ≤ 0.001 for all). Improvements were sustained through week 32 with apremilast treatment. The most common treatment-emergent adverse events included diarrhea, abdominal discomfort, headache, and nausea. CONCLUSIONS: Apremilast treatment demonstrated greater improvements in disease severity and patient-reported symptoms versus placebo at week 16 in Japanese patients with PPP with sustained improvements through week 32. No new safety signals were observed. CLINICALTRIALS: GOV: NCT04057937.

A case of persistent, confluent maculopapular erythema following a COVID-19 mRNA vaccination is possibly associated with the intralesional spike protein expressed by vascular endothelial cells and eccrine glands in the deep dermis.

Here, we report an 86-year-old Japanese woman presenting with confluent maculopapular erythema, which developed following the second dose of COVID-19 Messenger RNA (mRNA) vaccine (BNT162b2). Her skin lesions spread over time and persisted for more than 3 months. Surprisingly, immunohistochemical staining of the lesion 100 days after the disease onset revealed the COVID-19 spike protein expressed by vascular endothelial cells and eccrine glands in the deep dermis. As she had no episode of COVID-19 infection, it is highly likely that the spike protein was derived from the mRNA vaccine and it might be the cause of the development and persistence of her skin lesions. Her symptoms were prolonged and intractable until oral prednisolone was given.

Keratinocyte Regnase-1, a Downregulator of Skin Inflammation, Contributes to Protection against Tumor Promotion by Limiting Cyclooxygenase-2 Expression.

We previously showed that the ribonuclease Regnase-1 (Reg1) in keratinocytes plays a role in mitigating skin inflammation by downregulating proinflammatory cytokines. In this study, we explored whether Reg1 also has a protective role against skin carcinogenesis. The chemically induced two-stage carcinogenesis protocol revealed that epidermis-specific Reg1-deficient (Reg1-knockout [Reg1-cKO]) mice developed skin tumors with shorter latency and more multiplicity than control mice. In addition, repeated UVB irradiation readily provoked solar keratosis-like lesions in Reg1-cKO mice. Increased levels of cyclooxygenase 2, whose mRNA (Ptgs2) is reportedly a target of Reg1, have been known to be associated with the development of squamous cell carcinomas. Indeed, Ptgs2 mRNA levels were upregulated in the skin of Reg1-cKO mice after treatment with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate. The level of prostaglandin E2 was higher in 12-O-tetradecanoylphorbol-13-acetate‒treated Reg1-cKO mouse skin than in control mice skin. Moreover, in vivo inhibition of cyclooxygenase 2 attenuated the 12-O-tetradecanoylphorbol-13-acetate‒induced epidermal thickening in Reg1-cKO mice. Finally, REG1 knockdown in human squamous cell carcinomas lines enhanced PTGS2 mRNA levels after 12-O-tetradecanoylphorbol-13-acetate treatment. In conclusion, epidermal Reg1 plays a regulatory role not only in skin inflammation but also in tumor promotion through the downregulation of cyclooxygenase 2. Therefore, forced expression of Reg1 under inflammatory conditions may be relevant to preventing skin cancer.

English version of Japanese guidance for use of biologics for psoriasis (the 2022 version).

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.

Loss of epidermal Langerhans cells in psoriasiform lesions of de novo induced or worsened pre-existing psoriasis following uses of immune checkpoint inhibitors.

Immune checkpoint inhibitors (ICI), including monoclonal antibodies to programmed death 1, programmed death ligand 1, and cytotoxic T lymphocyte-associated antigen 4, have provided great therapeutic benefits for cancer patients at advanced stages. However, the introduction of ICI frequently results in the development of immune-related adverse events (irAE) through activation of autoreactive T cells. Here, we present three cases of cancer patients with cutaneous irAE, including development of de novo psoriasis and exacerbation of pre-existing psoriasis. Interestingly, these patients shared an altered histological feature characterized by loss of epidermal CD1a+ cells, namely Langerhans cells (LC), in the psoriasiform lesions in contrast to "conventional psoriasis" exhibiting unchanged or activated LC. A possible underlying mechanism was that ICI-mediated hyperactivation of effector T cells contributed to aggravation or establishment of psoriasis phenotype, which might be associated with direct cytotoxicity or expulsion of LC from the epidermis.

A familial case of periodontal Ehlers-Danlos syndrome lacking skin extensibility and joint hypermobility with a missense mutation in C1R.

Periodontal Ehlers-Danlos syndrome (pEDS) is an autosomal-dominant disorder first described by Stewart in 1977 that is characterized by severe gingival recession and periodontitis that triggers premature loss of permanent teeth and alveolar bone absorption. It was recently shown that pEDS is caused by a heterozygous missense mutation in C1R or C1S, which encode complement 1 proteases. Here, we report a familial case of pEDS with a novel heterozygous missense mutation, c.674G>C (p.R225P), in C1R (NM_001733.4). The case exhibited pretibial hyperpigmentation and extended periodontitis but neither skin extensibility nor joint hypermobility, suggesting that this mutation will expand the definition of pEDS.

Knockout of Zeb2 ameliorates progression of renal tubulointerstitial fibrosis in a mouse model of renal ischemia-reperfusion injury.

BACKGROUND: Zeb2, a zinc finger E-box-binding homeobox transcription factor, regulates transforming growth factor (TGF)-ß signaling pathway. However, its role in the pathogenesis of acute kidney injury (AKI) and AKI-to-chronic kidney disease (CKD) transition is unclear. METHODS: We evaluated Zeb2 function in a bilateral renal ischemia-reperfusion injury (IRI)-induced AKI model using proximal tubule-specific Zeb2 conditional knockout (Zeb2-cKO) and wild-type (WT) mice, and in renal biopsy samples. RESULTS: In Zeb2-cKO mice, the levels of plasma creatinine and blood urea nitrogen post-IRI were significantly lower than that in WT mice. Immunohistological analysis revealed mild tubular injury, reduced neutrophil infiltration, fewer fibrotic changes and reduced expression of fibrotic proteins [collagen type IV, α-smooth muscle actin (α-SMA), fibronectin and connective tissue growth factor (CTGF)], at 3-14 days post-IRI. Zeb2 expression was upregulated in proximal tubular cells post-IRI in WT mice. Zeb2 siRNA transfection reduced TGF-ß-stimulated mRNA and protein expression of collagen type IV, α-SMA, fibronectin and CTGF in cultured renal tubular cells. Patients with AKI-to-CKD transition exhibited high Zeb2 expression in renal tubules, as revealed by renal biopsy. Hypoxia and CoCl2-treatment upregulated Zeb2 promoter activity and mRNA and protein expression in cultured renal tubular epithelial cells, suggesting a regulatory role for hypoxia. CONCLUSIONS: Zeb2 was upregulated in renal tissues in both mice and humans with AKI. Zeb2 regulates fibrotic pathways in the pathogenesis of AKI and AKI-to-CKD transition. Therefore, inhibition of Zeb2 could be a potential therapeutic strategy for AKI.