Deep intronic founder mutations identified in the ERCC4/XPF gene are potential therapeutic targets for a high-frequency form of xeroderma pigmentosum.

Xeroderma pigmentosum (XP) is a genodermatosis defined by cutaneous photosensitivity with an increased risk of skin tumors because of DNA repair deficiency. The worldwide prevalence of XP is ~1 to 4 in million, with higher incidence in some countries and regions including Japan (1 in 22,000) and North Africa due to founder mutations and a high degree of consanguinity. Among XP, the complementation group F (XP-F), is a rare form (1% of worldwide XP); however, this is underdiagnosed, because the ERCC4/XPF gene is essential for fetal development and most of previously reported ERCC4/XPF pathogenic variants are hypomorphs causing relatively mild phenotypes. From the largest Japanese XP cohort study, we report 17 XP-F cases bearing two pathogenic variants, both identified in deep intronic regions of the ERCC4/XPF gene. The first variant, located in intron 1, is a Japanese founder mutation, which additionally accounts for ~10% of the entire Japanese XP cases (MAF = 0.00196), causing an aberrant pre-mRNA splicing due to a miss-binding of U1snRNA. The second mutation located in intron eight induces an alternative polyadenylation. Both mutations cause a reduction of the ERCC4/XPF gene expression, resulting in XP clinical manifestations. Most cases developed early-onset skin cancers, indicating that these variants need critical attention. We further demonstrate that antisense oligonucleotides designed for the mutations can restore the XPF protein expression and DNA repair capacity in the patients' cells. Collectively, these pathogenic variants can be potential therapeutic targets for XP.

Coexistence of keloids and pilomatricoma in a patient with Rubinstein-Taybi syndrome.

Rubinstein-Taybi syndrome (RTS) is an autosomaldominant hereditary disease, which contains many skeletal and organ anomalies as well as mental retardation. Although high incidence of keloids in RTS is known, it is difficult to find a detailed report on the clinical features of keloids. In the following letter, we report an RTS patient fulfilling diagnostic criteria whosuffered from both keloids and pilomatricoma. We also performed a literature search, which identified the possible involvement of the Wnt/ß-catenin signaling pathway in the pathogenesis of these two skin lesions.

Depletion of Epidermal Langerhans Cells in the Skin Lesions of Pellagra Patients.

Pellagra is a nutrient deficiency disease caused by insufficient niacin levels. Recent studies have shown that numbers of epidermal Langerhans cells decreased in other diseases caused by nutritional deficiencies, including necrolytic migratory erythema and acrodermatitis enteropathica. Epidermal Langerhans cells are capable of modulating or even halting the inflammatory reaction. The aim of this study was to examine changes in the number of Langerhans cells and other dendritic cells, and maturation of epidermal Langerhans cells in the lesional and adjacent non-lesional skin in pellagra patients. Seven pellagra patients and 10 healthy individuals who served as controls were included. The number and distribution of dendritic cells and other cutaneous cells were examined by immunohistochemistry. Epidermal Langerhans cells decreased considerably in the skin lesions of pellagra patients, whereas other dendritic cells did not change. The decrease in the number of Langerhans cells was positively correlated with the histological severity of skin lesions. As the number of Langerhans cells was not reduced in the undisturbed neighboring skin, the depletion of epidermal Langerhans cells did not precede skin damage but was a cause of prolonged severe inflammation.

Malfunction of nuclease ERCC1-XPF results in diverse clinical manifestations and causes Cockayne syndrome, xeroderma pigmentosum, and Fanconi anemia.

Cockayne syndrome (CS) is a genetic disorder characterized by developmental abnormalities and photodermatosis resulting from the lack of transcription-coupled nucleotide excision repair, which is responsible for the removal of photodamage from actively transcribed genes. To date, all identified causative mutations for CS have been in the two known CS-associated genes, ERCC8 (CSA) and ERCC6 (CSB). For the rare combined xeroderma pigmentosum (XP) and CS phenotype, all identified mutations are in three of the XP-associated genes, ERCC3 (XPB), ERCC2 (XPD), and ERCC5 (XPG). In a previous report, we identified several CS cases who did not have mutations in any of these genes. In this paper, we describe three CS individuals deficient in ERCC1 or ERCC4 (XPF). Remarkably, one of these individuals with XP complementation group F (XP-F) had clinical features of three different DNA-repair disorders--CS, XP, and Fanconi anemia (FA). Our results, together with those from Bogliolo et al., who describe XPF alterations resulting in FA alone, indicate a multifunctional role for XPF.

Wound fixation for pressure ulcers: a new therapeutic concept based on the physical properties of wounds.

A pressure ulcer is defined as damage to skin and other tissues over a bony prominence caused by excess pressure. Deep pressure ulcers that develop over specific bony prominences often exhibit wound deformity, defined as a change in the 3-dimensional shape of the wound. Subsequently, the wound deformity can result in undermining formation, which is a characteristic of deep pressure ulcers. However, to date, a concept with respect to alleviating wound deformity has yet to be defined and described. To clarify the issue, we propose a new concept called "wound fixation" based on the physical properties of deep pressure ulcers with wound deformity. Wound fixation is defined here as the alleviation of wound deformity by exogenous materials. The wound fixation methods are classified as traction, anchor, and insertion based on the relation between the wound and action point by the exogenous materials. A retrospective survey of a case series showed that wound fixation was preferentially used for deep pressure ulcers at specific locations such as the sacrum, coccyx, and greater trochanter. Moreover, the methods of wound fixation were dependent on the pressure ulcer location. In conclusion, our new concept of wound fixation will be useful for the practical treatment and care of pressure ulcers. Further discussion and validation by other experts will be required to establish this concept.

[Serum Levels of Regulatory T Cell in the Yusho Patients].

Dioxin and dioxin-like compounds receptor (Ahr) mainly expressed on the surface of regulatory T (Treg) cell and Th17 cell could regulate immunological functions in the Yusho patients. We prospectively analyzed data obtained in a total of 56 cases of Yusho, which include patients identified ('Nintei' ) or non-identified ( 'Minintei') or identified as a family member, at the annual health check in 2014. The number of Treg cell showed lower among identified patients compared with non-identified group or family identified group (p = 0.4184 and p = 0.291, respectively). There was also a strong correlation between serum levels of neutral fat and the number of Treg cells (p = 0.0313). These results suggest that Treg cell plays a principal role in the immune response among Yusho patients.

Molecular interplays involved in the cellular uptake of octaarginine on cell surfaces and the importance of syndecan-4 cytoplasmic V domain for the activation of protein kinase Cα.

Arginine-rich cell-penetrating peptides (CPPs) are promising carriers for the intracellular delivery of various bioactive molecules. However, many ambiguities remain about the molecular interplays on cell surfaces that ultimately lead to endocytic uptake of CPPs. By treatment of cells with octaarginine (R8), enhanced clustering of syndecan-4 on plasma membranes and binding of protein kinase Cα (PKCα) to the cytoplasmic domain of syndecan-4 were observed; these events potentially lead to the macropinocytic uptake of R8. The cytoplasmic V domain of syndecan-4 made a significant contribution to the cellular uptake of R8, whereas the cytoplasmic C1 and C2 domains were not involved in the process.

[Current state and prospect of pseudoxanthoma elasticum (PXE)].

Pseudoxanthoma elasticum (PXE; OMIM 264800) is a rare, recessively-inherited disorder, which is characterized by progressive calcification and fragmentation of the elastic fibers in the skin, eyes, and cardiovascular system. We have collected clinical information from more than 200 Japanese PXE patients by sending mail to -1,000 hospitals in Japan. In those data, PXE is found to be accompanied by reduced visual acuity in the -30% patients. The incidences of ischemic disorders of the brain and heart in the PXE have been proved to be significantly higher than those in over 50 Japanese as control. Genetic analysis with 70 PXE cases revealed new mutations of ABCC6 that are different from those of Caucasian cases, which showed no genotype-phenotype relationship.

Definitions of the physical properties of pressure ulcers and characterisation of their regional variance.

A pressure ulcer is a localised injury of the skin and underlying tissue that usually develops over a bony prominence. A decrease in the pressure over the bony prominence effectively prevents pressure ulcers; however, no studies have systematically assessed the physical properties of existing pressure ulcers. To characterise pressure ulcers, we established new terminology that clarifies the physical properties of pressure ulcers: wound mobility was defined as movement using the bony prominence as a predefined specific marker, and wound deformity was defined as a change in the three-dimensional shape of the wound. Observational studies using this terminology showed that the distinct physical properties of pressure ulcers depend on the site of development and the wound depth according to the National Pressure Ulcer Advisory Panel criteria. Most grade IV sacrum pressure ulcers exhibited mobility and deformity. Superficial sacrum pressure ulcers below grade II showed only mobility. In contrast, foot pressure ulcers did not exhibit mobility or deformity. We propose a new concept, 'wound physical property', for understanding the unique pathogenesis of pressure ulcers.

[Serum levels of IL-21 and TGF-beta in the Yusho patients].

Aryl hydrocarbon receptor (AhR), recognized as a dioxin receptor, is expressed on the surface of helper T (Th) 17 cells. As PCBs and PCDFs are still detected in the sera of the Yusho patients, we hypothesized dysregulation of Th17 cells in the Yusho patients. In the present study, we measured IL-21 and TGF-beta in the Yusho patients which induce differentiation from Th0 to Th17 cells. Serum levels of IL-21 were lower than those of controls (p < 0.05). Meanwhile, serum levels of TGF-beta were decreased relative to controls, but not significant. These results may imply differentiation from Th0 cells to Th17 cells is not induced in the Yusho patients.

[Serum levels of IL-10 and IL-35 in Yusho patients].

We thought that dioxin and dioxin-like compound receptor AhR expressed on the surface of regulatory T (Treg) cells and Th17 cells could regulate immunological functions in the Yusho patients. In the present study, we measured Treg cell related cytokines IL-10 and IL-35 in the Yusho patients. Serum levels of IL-10 were higher, but not significant (p = 0.06), and serum levels of IL-35 were increased (p = 0.006) in comparison with healthy controls. These results imply Treg cell activation in the Yusho patients.

Attenuation of an adult T-cell leukemia skin lesion after treatment of a concomitant herpes simplex infection: a case study.

We report the development and treatment of eczema herpeticum in a 51-year-old male suffering from adult T-cell leukemia (ATL). Lesions of eczema herpeticum coexisted with the skin lesions of ATL. Treatment of eczema herpeticum resulted in a concomitant improvement in the symptoms of ATL, including a reduction in the size of the ATL plaques, for over 2 months before relapse.

Fibulin-4 Accelerates Amyloid Formation by Binding with a Keratin 5 Peptide Fragment.

Keratins are the major amyloid fibril component in localized cutaneous amyloidosis. We analyzed the amyloid components in the skin of patients with localized cutaneous amyloidosis by immunohistochemical staining using antisera against extracellular matrix proteins and keratin 5 (K5). Fibulin-4 and K5 colocalized in the amyloid deposits. Using 14 synthetic peptides, we screened for amyloidogenic sequences in the C-terminal region of K5, including the α-helical rod domain and the tail domain. Two peptides stained with thioflavin T possessed a ß-sheet structure and formed amyloid-like fibrils. Among the amyloidogenic peptides, a peptide KT5-6 (YQELMNTKLALDVEIATYRKLLEGE) derived from the α-helical rod domain of K5 specifically bound to fibulin-4. In addition, amyloid formation of KT5-6 was accelerated by fibulin-4. These results suggest that degraded fragments of K5 containing the KT5-6 sequence form amyloid fibrils with fibulin-4. The data further suggest that degraded fragments of K5 and fibulin-4 have the potential to initiate cutaneous amyloidosis.

Clinical practice guidelines for pseudoxanthoma elasticum (2017): Clinical Practice Guidelines for Pseudoxanthoma Elasticum Drafting Committee

Pseudoxanthoma elasticum (PXE) is a progressive hereditary disease that affects tissues such as the skin, retina, blood vessels, and gastrointestinal tracts. Therefore, comprehensive medical care across clinical departments specialized in specific organs is needed to provide the best clinical practices to PXE patients. The Japanese version of clinical guidelines developed by the Japanese Dermatological Association was published in 2017, and aimed to promote equal accessibility of PXE-related medical care. Here, the English version of Japanese guideline is reported, and is intended to be worldwide reference for medical care of PXE.

Heparanase deglycanation of syndecan-1 is required for binding of the epithelial-restricted prosecretory mitogen lacritin.

Cell surface heparan sulfate (HS) proteoglycans are carbohydrate-rich regulators of cell migratory, mitogenic, secretory, and inflammatory activity that bind and present soluble heparin-binding growth factors (e.g., fibroblast growth factor, Wnt, Hh, transforming growth factor beta, amphiregulin, and hepatocyte growth factor) to their respective signaling receptors. We demonstrate that the deglycanated core protein of syndecan-1 (SDC1) and not HS chains nor SDC2 or -4, appears to target the epithelial selective prosecretory mitogen lacritin. An important and novel step in this mechanism is that binding necessitates prior partial or complete removal of HS chains by endogenous heparanase. This limits lacritin activity to sites where heparanase appears to predominate, such as sites of exocrine cell migration, secretion, renewal, and inflammation. Binding is mutually specified by lacritin's C-terminal mitogenic domain and SDC1's N terminus. Heparanase modification of the latter transforms a widely expressed HS proteoglycan into a highly selective surface-binding protein. This novel example of cell specification through extracellular modification of an HS proteoglycan has broad implications in development, homeostasis, and disease.

Bullous dermatosis associated with IgG antibodies specific for desmocollins.

We describe a 53-year-old man with a two-year history of bullous disease. He had also had stage IV gastric cancer for 3 years. He presented with cutaneous erythemas and blisters, showing an annular arrangement. Histopathological examination revealed intraepidermal pustules of eosinophils and neutrophils without apparent acantholysis. Indirect immunofluorescence (IIF) analysis showed IgG anti-keratinocyte cell surface antibodies. The result of IIF on rat bladder was positive. IgG enzyme-linked immunosorbent assays failed to detect antibodies to either anti-desmoglein-1 (Dsg1), Dsg3, or BP180. Immunoblot analysis with normal human epidermal extract revealed IgG reactivity with 120, 110, and 100 kDa species. Immunofluorescence analysis using COS-7 cells that expressed desmocollin (Dsc) 1, 2, and 3 demonstrated that IgG autoantibodies in the patient's serum reacted with all Dsc1-3. A heterogeneous autoantibody profile including IgG reactivity against Dsc1-3 implicated association with cancer-related pemphigoid, although the findings did not fulfill the diagnostic criteria of paraneoplastic pemphigus. A review of the literature revealed that rare autoantibodies to Dsc, most of which were IgA class, were detected in 7 reported bullous diseases. In 5 out of 7 cases, they were combined with autoantibodies to bullous pemphigoid or pemphigus vulgaris. This is the first case that has IgG autoantibodies to all Dsc1~3.

Fibroblast growth factor 2 accelerates the epithelial-mesenchymal transition in keratinocytes during wound healing process.

In the wound healing process, the morphology of keratinocytes at the wound edge temporarily changes to a spindle morphology, which is thought to occur due to an epithelial-mesenchymal transition (EMT). Fibroblast growth factor (FGF) 2, also called basic FGF, has the potential to accelerate wound closure by activating vascular endothelial cells and fibroblasts. We examined the effects of FGF2 on keratinocyte morphology and EMT in wounded skin. Histological examination of murine wounds treated with FGF2 revealed that wound edge keratinocytes formed thickened and multilayered epithelia. In addition, we detected wound edge keratinocytes migrating individually toward the wound center. These migrating keratinocytes exhibited not only spindle morphology but also down-regulated E-cadherin and up-regulated vimentin expression, which is characteristic of EMT. In FGF2-treated wounds, a PCR array revealed the upregulation of genes related to EMT, including transforming growth factor (TGF) signaling. Further, FGF2-treated wound edge keratinocytes expressed EMT-associated transcription factors, including Snai2, and showed translocation of ß-catenin from the cell membrane to the cytoplasm/nucleus. However, in vitro examination of keratinocytes revealed that FGF2 alone did not activate EMT in keratinocytes, but that FGF2 might promote EMT in combination with TGFß1. These findings suggest that FGF2 treatment of wounds could promote keratinocyte EMT, accelerating wound closure.

Elastic fiber assembly is disrupted by excessive accumulation of chondroitin sulfate in the human dermal fibrotic disease, keloid.

Keloid is a fibrotic disease characterized by abnormal accumulation of extracellular matrix in the dermis. The keloid matrix contains excess collagen and glycosaminoglycans (GAGs), but lacks elastic fiber. However, the roles of these matrix components in the pathogenesis of keloid are largely unknown. Here, we show that elastin and DANCE (also known as fibulin-5), a protein required for elastic fiber formation, are not deposited in the extracellular matrix of keloids, due to excess accumulation of chondoitin sulfate (CS), although the expression of elastin and DANCE is not affected. Amount of CS accumulated in the keloid legion was 6.9-fold higher than in normal skin. Fibrillin-1, a scaffold protein for elastic fiber assembly, was abnormally distributed in the keloid matrix. Addition of purified CS to keloid fibroblast culture resulted in abnormal deposition of fibrillin-1, concomitant with significantly decreased accumulation of elastin and DANCE in the extracellular matrix. We propose that CS plays a crucial role in the development of keloid lesions through inhibition of elastic fiber assembly.