Inhibition of intracellular ATP synthesis impairs the recruitment of homologous recombination factors after ionizing radiation

Ionizing radiation (IR)-induced double-strand breaks (DSBs) are primarily repaired by non-homologous end joining or homologous recombination (HR) in human cells. DSB repair requires adenosine-5'-triphosphate (ATP) for protein kinase activities in the multiple steps of DSB repair, such as DNA ligation, chromatin remodeling, and DNA damage signaling via protein kinase and ATPase activities. To investigate whether low ATP culture conditions affect the recruitment of repair proteins at DSB sites, IR-induced foci were examined in the presence of ATP synthesis inhibitors. We found that p53 binding protein 1 foci formation was modestly reduced under low ATP conditions after IR, although phosphorylated histone H2AX and mediator of DNA damage checkpoint 1 foci formation were not impaired. Next, we examined the foci formation of breast cancer susceptibility gene I (BRCA1), replication protein A (RPA) and radiation 51 (RAD51), which are HR factors, in G2 phase cells following IR. Interestingly, BRCA1 and RPA foci in the G2 phase were significantly reduced under low ATP conditions compared to that under normal culture conditions. Notably, RAD51 foci were drastically impaired under low ATP conditions. These results suggest that HR does not effectively progress under low ATP conditions; in particular, ATP shortages impair downstream steps in HR, such as RAD51 loading. Taken together, these results suggest that the maintenance of cellular ATP levels is critical for DNA damage response and HR progression after IR.

Prediction of m6A and m5C at single-molecule resolution reveals a transcriptome-wide co-occurrence of RNA modifications

The epitranscriptome embodies many new and largely unexplored functions of RNA. A significant roadblock hindering progress in epitranscriptomics is the identification of more than one modification in individual transcript molecules. We address this with CHEUI (CH3 (methylation) Estimation Using Ionic current). CHEUI predicts N6-methyladenosine (m6A) and 5-methylcytosine (m5C) in individual molecules from the same sample, the stoichiometry at transcript reference sites, and differential methylation between any two conditions. CHEUI processes observed and expected nanopore direct RNA sequencing signals to achieve high single-molecule, transcript-site, and stoichiometry accuracies in multiple tests using synthetic RNA standards and cell line data. CHEUI's capability to identify two modification types in the same sample reveals a co-occurrence of m6A and m5C in individual mRNAs in cell line and tissue transcriptomes. CHEUI provides new avenues to discover and study the function of the epitranscriptome.

Can dermatologists reach their full potential in teledermatology? A validation study of diagnostic performance of skin diseases in live video conferencing teledermatology

The diagnostic accuracy rate of live videoconferencing (LVC) teledermatology, by board-certified dermatologists compared to non-dermatologists has not yet been fully investigated. The aim of this study was to compare the diagnostic accuracy of board-certified dermatologists, dermatology specialty trainees, and board-certified internists in LVC teledermatology. We examined the diagnostic accuracy of clinicians from different specialties in diagnosing the same group of patients. The clinicians were isolated from each other during the diagnosis process. We enrolled 18 volunteer physicians (six board-certified dermatologists, six dermatology specialty trainees, and six board-certified internists) who reviewed the skin conditions of 18 patients via LVC teledermatology. The diagnostic accuracy of the participating physicians was evaluated using the final diagnosis as the reference standard. The diagnostic accuracy averages were compared according to the physicians' specialties and disease categories. The mean ± standard deviation diagnostic accuracy of the most detailed level diagnosis was 83.3% ± 3.5% (range, 77.8%-89.0%) for board-certified dermatologists, 53.7 ± 20.7% (range 27.8%-77.8%) for dermatology specialty trainees, and 27.8 ± 5.0% (range, 22.2%-33.3%) for board-certified internists. Board-certified dermatologists showed significantly higher diagnostic accuracy, not only against board-certified internists (p < 0.0001) but also against dermatology specialty trainees (p < 0.05). Disease categories with high accuracy rates (≥80%) only by board-certified dermatologists were inflammatory papulosquamous dermatoses (87.5%), compared to 58.3%, and 20.8% for dermatology specialty trainees and board-certified internists respectively). For inflammatory erythemas and other reactive inflammatory dermatoses the accuracy rates for board-certified dermatologists, dermatology specialty trainees, and board-certified internists were 83.3%, 33.3%, 8.3% respectively; for melanoma in situ neoplasms, 83.3%, 50.0%, 66.7% respectively), and for genetic disorders of keratinization 83.3%, 33.3%, and 0% respectively). Our findings showed that board-certified dermatologists may have high diagnostic accuracy with practical safety and effectiveness in LVC teledermatology.

Deep dermatophytosis caused by Trichophyton rubrum in an elderly patient with CARD9 deficiency: A case report and literature review

Deep dermatophytosis is an invasive and sometimes life-threatening fungal infection mainly reported in immunocompromised patients. However, a caspase recruitment domain-containing protein 9 (CARD9) deficiency has recently been reported to cause deep dermatophytosis. Herein, we report the first Japanese case of deep dermatophytosis associated with CARD9 deficiency. An 80-year-old Japanese man with tinea corporis presented with subcutaneous nodules on his left sole. Histopathological findings revealed marked epithelioid cell granulomas with filamentous fungal structures in the deep dermis and subcutis, and the patient was diagnosed with deep dermatophytosis. Despite antifungal therapy, the subcutaneous nodule on his left sole gradually enlarged, his left calcaneal bone was invaded, and the patient finally underwent amputation of his left leg. Genetic analysis revealed a homozygous CARD9 c.586 A > G (p. Lys196Glu) variant, suggesting a CARD9 deficiency. Here, we discuss the clinical features of CARD9 deficiency-associated deep dermatophytosis with a case report and review of the literature.

Possible relation of cathepsin C activity and seasonal fluctuation of skin lesions in Papillon-Lefèvre syndrome

Our patient with Papillon–Lefèvre syndrome with a novel p.G430V and recurrent p.G301S missense mutation showing aggravation of skin lesions in wintertime. A temperature-dependent cathepsin C enzymatic activity study indicates a possible association between seasonal fluctuations, minimal dental involvement and temperature.

Two cases of infancy associated eosinophilic pustular folliculitis (I-EPF) comparing the profile of infiltrating cells with classic EPF by immunohistochemical study

Infancy associated eosinophilic pustular folliculitis (I-EPF) is a clinical variant of EPF that develops in childhood. Previous studies have suggested that I-EPF exhibits clinical and histological differences distinct from other variants, including classic EPF. Herein, we report two patients with I-EPF treated with topical indomethacin. These two cases exhibited less perifollicular and more perivascular eosinophilic infiltration, which is different in distribution from that of classic EPF. Immunohistochemical study demonstrated that the infiltrating mononuclear cells were CD4-dominant T cells in classic EPF and I-EPF, whereas the number of CD68-positive cells was significantly higher in classic EPF than in I-EPF. Immunohistochemical staining was also performed for eosinophilic pustular folliculitis (HPGDS), which has been reported to induce eosinophils and is a therapeutic target of indomethacin in classic EPF. HPGDS-positive cells were also observed in I-EPF, which may explain the effectiveness of topical indomethacin. Although clinical and histopathological features of I-EPF are different from other variants, the arachidonic acid pathway could be involved in eosinophil infiltration, not only in classic EPF but also in I-EPF.

CCL21-Ser expression in melanoma cells recruits CCR7+ naïve T cells to tumor tissues and promotes tumor growth

CCL21-Ser, a chemokine encoded by the Ccl21a gene, is constitutively expressed in the thymic epithelial cells and stromal cells of secondary lymphoid organs. It regulates immune cell migration and survival through its receptor CCR7. Herein, using CCL21-Ser-expressing melanoma cells and the Ccl21a-deficient mice, we demonstrated the functional role of cancer cell-derived CCL21-Ser in melanoma growth in vivo. The B16-F10 tumor growth was significantly decreased in Ccl21a-deficient mice compared with that in wild-type mice, indicating that host-derived CCL21-Ser contributes to melanoma proliferation in vivo. In Ccl21a-deficient mice, tumor growth of melanoma cells expressing CCL21-Ser was significantly enhanced, suggesting that CCL21-Ser from melanoma cells promotes tumor growth in the absence of host-derived CCL21-Ser. The increase in tumor growth was associated with an increase in the CCR7+ CD62L+ T cell frequency in the tumor tissue but was inversely correlated with Treg frequency, suggesting that naïve T cells primarily promote tumor growth. Adoptive transfer experiments demonstrated that naïve T cells are preferentially recruited from the blood into tumors with melanoma cell-derived CCL21-Ser expression. These results suggest that CCL21-Ser from melanoma cells promotes the infiltration of CCR7+ naïve T cells into the tumor tissues and creates a tumor microenvironment favorable for melanoma growth.

Endogenous CCL21-Ser deficiency reduces B16-F10 melanoma growth by enhanced antitumor immunity

The chemokine CCL21 regulates immune and cancer cell migration through its receptor CCR7. The Ccl21a gene encodes the isoform CCL21-Ser, predominantly expressed in the thymic medulla and the secondary lymphoid tissues. This study examined the roles of CCL21-Ser in the antitumor immune response in Ccl21a-knockout (KO) mice. The Ccl21a-KO mice showed significantly decreased growth of B16-F10 and YUMM1.7 melanomas and increased growth of MC38 colon cancer, despite no significant difference in LLC lung cancer and EO771 breast cancer. The B16-F10 tumor in Ccl21a-KO mice showed melanoma-specific activated CD8+ T cell and NK cell infiltration and higher Treg counts than wild-type mice. B16-F10 tumors in Ccl21a-KO mice showed a reduction in the positive correlation between the ratio of regulatory T cells (Tregs) to activated CD8+ T cells and tumor weight. In Ccl21a-KO tumor, the intratumoral Tregs showed lower co-inhibitory receptors TIM-3 and TIGIT. Taken together, these results suggest that endogenous CCL21-Ser supports melanoma growth in vivo by maintaining Treg function and suppressing antitumor immunity by CD8+ T cells.

Different degree of loss-of-function among four missense mutations in the EDAR gene responsible for autosomal recessive hypohidrotic ectodermal dysplasia may be associated with the phenotypic severity

Hypohidrotic ectodermal dysplasia is a rare condition characterized by hypohidrosis, hypodontia, and hypotrichosis. The disease can show X-linked recessive, autosomal dominant or autosomal recessive inheritance trait. Of these, the autosomal forms are caused by mutations in either EDAR or EDARADD. To date, the underlying pathomechanisms or genotype-phenotype correlations for autosomal forms have not completely been disclosed. In this study, we performed a series of in vitro studies for four missense mutations in the death domain of EDAR protein: p.R358Q, p.G382S, p.I388T, and p.T403M. The results revealed that p.R358Q- and p.T403M-mutant EDAR showed different expression patterns from wild-type EDAR in both western blots and immunostainings. NF-κB reporter assays demonstrated that all the mutant EDAR showed reduced activation of NF-κB, but the reduction by p.G382S- and p.I388T-mutant EDAR was moderate. Co-immunoprecipitation assays showed that p.R358Q- and p.T403M-mutant EDAR did not bind with EDARADD at all, whereas p.G382S- and p.I388T-mutant EDAR maintained the affinity to some extent. Furthermore, we demonstrated that all the mutant EDAR proteins analyzed aberrantly bound with TRAF6. Sum of the data suggest that the degree of loss-of-function is different among the mutant EDAR proteins, which may be associated with the severity of the disease.

Interleukin-18 as a severity marker and novel potential therapeutic target for epidermolytic ichthyosis

BACKGROUND

Epidermolytic ichthyosis (EI) is a major form of nonsyndromic inherited ichthyosis, characterized by erythroderma, marked hyperkeratosis and scale, bulla and erosion at birth, associated with KRT1/KRT10 mutations. The cytokine and chemokine profiles in EI are poorly understood, and specific treatment options have not been established.

AIM

To explore novel biomarkers and therapeutic targets in patients with EI.

METHODS

We analysed cytokine levels in serum and skin samples from 10 patients with inherited ichthyosis, including seven patients with EI. Wild-type and mutant KRT1 constructs were established and transfected into HaCaT cells, an immortalized keratinocyte cell line, for in vitro immunoblotting and immunocytochemistry analyses.

RESULTS

Multiplex cytokine/chemokine analysis revealed that 10 cytokines/chemokines [interleukin (IL)-1β, IL-4, IL-17A, IL-16, IL-18, IL-1 receptor-α, macrophage colony-stimulating factor, interferon-α2, basic fibroblast growth factor and monocyte chemotactic protein-3] were significantly increased in patients with EI. Furthermore, IL-18 levels were significantly higher in patients with EI [n = 7; 2714.1 (1438.0) pg mL-1] than in healthy controls [n = 11; 218.4 (28.4) pg mL-1, P < 0.01]. Immunohistochemical analyses showed that IL-18 expression was elevated in skin samples from patients with EI. Serum IL-18 levels correlated with the severity of ichthyosis, as measured by the Ichthyosis Scoring System. Immunoblotting analysis revealed that mature IL-18 levels were increased in the supernatant of mutant KRT1 expressing HaCaT cells. Additionally, these cells showed NLRP3 aggregation in the cytoplasm and ASC clustered around mutant keratin aggregations. These findings suggest that mutant keratin might promote the activation of the NLRP3 inflammasome and its downstream caspase-1-mediated IL-18 release in keratinocytes from patients with EI.

CONCLUSIONS

Our results suggest that serum IL-18 is a severity marker released from the skin of patients with EI. Blockade of IL-18 may be a useful novel therapeutic option for patients with EI.

Jumping to conclusions correlates with negative symptoms, poor response inhibition, and impaired functioning in individuals diagnosed with schizophrenia

BACKGROUND

The jumping to conclusions (JTC) bias is the tendency to make immediate decisions based on little information. There are few studies that have investigated the relationship between JTC and frontal lobe function. We examined the association between JTC and the Brief Psychiatric Rating Scale (BPRS), Frontal Assessment Battery (FAB), and Global Assessment of Functioning (GAF) scale in individuals with schizophrenia.

METHODS

In total, 50 individuals diagnosed with schizophrenia and 50 healthy control individuals were administered the beads task. Individuals diagnosed with schizophrenia were assessed using the FAB, BPRS, and GAF.

RESULTS

There was a significant negative correlation between JTC and the negative symptoms of the BPRS (rs=-.368, p = .008). There was a significant positive correlation between JTC and the Go/No-Go task of the FAB (rs=.319, p = .026), and the GAF (rs=.433, p = .002).

CONCLUSION

JTC in individuals with schizophrenia may be categorized according to several causes, including negative symptoms and poor response inhibition.

Engineering human skin model innervated with itch sensory neuron-like cells differentiated from induced pluripotent stem cells

Atopic dermatitis (AD), driven by interleukins (IL-4/IL-13), is a chronic inflammatory skin disease characterized by intensive pruritus. However, it is unclear how immune signaling and sensory response pathways cross talk with each other. We differentiated itch sensory neuron-like cells (ISNLCs) from iPSC lines. These ISNLCs displayed neural markers and action potentials and responded specifically to itch-specific stimuli. These ISNLCs expressed receptors specific for IL-4/IL-13 and were activated directly by the two cytokines. We successfully innervated these ISNLCs into full thickness human skin constructs. These innervated skin grafts can be used in clinical applications such as wound healing. Moreover, the availability of such innervated skin models will be valuable to develop drugs to treat skin diseases such as AD.

An epidemiological survey of anhidrotic/hypohidrotic ectodermal dysplasia in Japan: High prevalence of allergic diseases

Anhidrotic/hypohidrotic ectodermal dysplasia (A/HED) is a congenital disorder characterized by anhidrosis/hypohidrosis and inadequate hair and dental dysplasia. Large-scale case studies of patients with A/HED have already been conducted overseas, while there has been no large-scale study, but only a few case reports in Japan. Furthermore, an epidemiological study of this disease has not been conducted in Japan to date. The purpose of this study was to investigate the clinical characteristics of A/HED patients, the status of genetic aberrations and complications of A/HED in Japan. Initially, we conducted a physician-initiated questionnaire survey of A/HED patients who visited medical institutions across Japan to investigate their backgrounds, clinical symptoms, genotypes, diagnostic methods and complications of A/HED. We also investigated the presence or absence of various allergic diseases (atopic dermatitis-like skin manifestations, bronchial asthma and food allergies). Questionnaires were also obtained from 26 patients with ectodermal dysplasia (ED) who visited four medical institutions. We compared the incidence of allergic diseases in healthy controls in a similar study to that of patients. Twenty-four of those patients were considered to have A/HED, of which 18 had a confirmed genetic diagnosis and were genotyped. All patients had anhidrosis or hypohidrosis, hair and dental dysplasia, and unique facial appearance; 23 patients had several cutaneous manifestations and seven patients had periorbital pigmentation. In addition, there was a significantly higher incidence of atopic dermatitis-like cutaneous manifestations, bronchial asthma and food allergies in the A/HED patients than in healthy controls. We report the results from a questionnaire survey of 24 patients with A/HED. This is the first report of a large number of A/HED patients in Japan. This study clarifies the status of clinical diagnosis and genetic testing of A/HED patients in Japan, as well as the characteristics of their skin symptoms and allergic complications.

A case of cutaneous syncytial myoepithelioma with extensive adipocytic metaplasia: Usefulness of EWSR1-PBX3 gene fusion analysis

Cutaneous syncytial myoepithelioma (CSM) is a recently recognized variant of myoepithelial neoplasms. CSM is characterized by an intradermal syncytial proliferation of spindled, ovoid, and histiocytoid cells. Immunohistochemically, tumor cells usually show strong positivity for S-100 and EMA. Here, we report a case of CSM in the thigh of a 51-year-old Japanese woman. Histopathological findings showed a sheet-like growth of ovoid cells and histiocytoid cells with an eosinophilic syncytial cytoplasm, and adipocytic metaplasia was widely observed in the tumor. Immunohistochemical staining revealed a diffuse strong pattern for EMA, smooth muscle actin (SMA), and HHF35 and variable positivity for S-100 protein and p63 in ovoid and histiocytoid cells without significant mitotic figures or pleomorphism. In addition, EWSR1-PBX3 gene fusion, which is characteristic of CSM, was observed in the tumor. Based on these findings, we diagnosed the patient as having CSM. Our case suggests that CSM could show extensive adipocytic metaplasia, which could make its histopathological diagnosis challenging. This article is protected by copyright. All rights reserved.

Update of recent findings in genetic hair disorders

Genetic hair disorders, although unusual, are not very rare, and dermatologists often have opportunities to see patients. Significant advances in molecular genetics have led to identifying many causative genes for genetic hair disorders, including the recently identified causative genes, such as LSS and C3ORF52. Many patients have been detected with autosomal recessive woolly hair/hypotrichosis in the Japanese population caused by founder mutations in the LIPH gene. Additionally, many patients with genetic hair disorders caused by other genes have been reported in East Asia including Japan. Understanding genetic hair disorders is essential for dermatologists, and the findings obtained from analyzing these diseases will contribute to revealing the mechanisms of hair follicle morphogenesis and development in humans.

Past Biodiversity: Japanese Historical Monographs Document the Epibiotic Barnacles and Cold-Stunning Event of the Hawksbill Turtle Eretmochelys imbricata

The historical monographs called “Honzou Gaku” present the first record of cold-stunning of a hawksbill turtle Eretmochelys imbricata (Linnaeus, 1766) in the Echigo region of Japan during the Edo period (1600–1868), and the barnacles attached to the turtle were identified as Platylepas hexastylos (Fabricius, 1798). Analysis of this finding adds substantial knowledge to our understanding of the life history of the hawksbill turtles along the coast of Japan. As reported in this study, literature on the historical heritage of other animals or plants can also provide information about their past biodiversity.

Only plantar lesion of punctate palmoplantar keratoderma with a novel missense mutation in the AAGAB gene: Two Japanese familial case reports and review of reported mutations

Punctate palmoplantar keratoderma type 1 (PPPK1) is a rare autosomal dominant disorder characterized by hyperkeratotic papules on the palms and soles. In 2012, heterozygous loss-of-function mutations in the AAGAB gene were identified as the cause of this disorder. To date, 51 AAGAB mutations have been reported in families with PPPK1, but clear genotype-phenotype correlations have not been established yet. In this report, we identified four Japanese patients with PPPK1 from two families with an identical novel heterozygous AAGAB mutation. All patients showed hyperkeratotic papules only on the soles. Direct sequencing analysis of the AAGAB gene using peripheral blood-derived genomic DNA samples revealed that all of the patients carried a heterozygous 1-bp substitution (c.844G>A, p.Glu282Lys) in exon 9, leading to a missense change. Since all patients with the same missense mutation showed a mild phenotype limited to the soles, there is thought to be a genotype-phenotype correlation regarding this mutation. The c.844G>A mutation is a known single-nucleotide polymorphism with a minor allele frequency of 0.000012. Because of its mild symptoms, individuals with this mutation can be misdiagnosed with clavus or verruca vulgaris; this suggests that there may be a high incidence of mild symptoms of skin lesions found only on the soles in patients with PPPK1. Therefore, it is necessary to consider this disease when keratotic papules are found on the soles.

Facilitative Exercise for Surface Myoelectric Activity Using Robot Arm Control System – Training Scheme with Gradually Increasing Difficulty Level –

Various control systems for robot arms using surface myoelectric signals have been developed. Abundant pattern-recognition techniques have been proposed to predict human motion intent based on these signals. However, it is laborious for users to train the voluntary control of myoelectric signals using those systems. In this research, we aim to develop a rehabilitation support system for hemiplegic upper limbs with a robot arm controlled by surface myoelectric signals. In this study, we construct a simple one-link robot arm that is controlled by estimating the wrist motion from the surface myoelectric signals on the forearm. We propose a training scheme with gradually increasing difficulty level for robot arm manipulation to evoke surface myoelectric signals. Subsequently, we investigate the possibility of facilitative exercise for the voluntary surface myoelectric activity of the desired muscles through trial experiments.

Characterization of EDARADD gene mutations responsible for hypohidrotic ectodermal dysplasia

Hypohidrotic ectodermal dysplasia (HED) is a genetic disorder characterized by hypohidrosis, hypodontia, and hypotrichosis. Autosomal forms of the disease are caused by mutations in either EDAR or EDARADD. To date, the underlying pathomechanisms for HED resulting from EDARADD mutations have not fully been disclosed. In this study, we performed detailed in vitro analyses in order to characterize three dominantly inherited missense mutations, p.D120Y, p.L122R, and p.D123N, and one recessively inherited missense mutation, p.E152K, in the EDARADD gene. Nuclear factor (NF)-κB reporter assays demonstrated that all the mutant EDARADD showed reduction in activation of NF-κB. Importantly, p.D120Y-, p.L122R-, and p.D123N-mutant EDARADD slightly reduced the NF-κB activity induced by wild-type EDARADD in a dominant negative manner. Co-immunoprecipitation assays showed that all of the mutant EDARADD were capable of binding to EDAR and wild-type EDARADD. Additional co-immunoprecipitation assays revealed that p.D120Y-, p.L122R-, and p.D123N-mutant EDARADD markedly prevented the interaction between EDAR and wild-type EDARADD, which further indicated a dominant negative effect by these mutations. Finally, we found that p.D120Y-, p.L122R-, and p.D123N-mutant EDARADD completely lost the ability to bind with TRAF6, while p.E152K-mutant EDARADD showed a mild reduction in the affinity. Our findings will provide crucial information toward unraveling the molecular mechanisms how EDARADD gene mutations cause the disease.

Evidence for a dominant-negative effect of a missense mutation in the SERPING1 gene responsible for hereditary angioedema type I

Hereditary angioedema (HAE) is a rare condition characterized by episodic local edema involving various organs, which can be life-threatening in some cases. Among the three subtypes of the disease, HAE types I and II are known to be caused by heterozygous mutations in the SERPING1 gene encoding C1 inhibitor (C1INH). Although a number of mutations in the SERPING1 gene have been identified to date, the mechanisms how these mutations cause HAE are not completely understood. We herein performed detailed in vitro studies for a missense SERPING1 gene mutation p.S150F which we recently identified in a Japanese patient with HAE type I. We showed that the p.S150F-mutant C1INH was stably expressed within the cultured cells, while it was not secreted into the medium at all. Furthermore, we demonstrated that the mutant C1INH significantly prevented secretion of wild-type C1INH. Finally, the results suggested that the wild-type protein was not only retained but also degraded within the cytoplasm through interacting with the mutant protein. Our study clearly revealed a dominant-negative effect of the p.S150F-mutant C1INH against the wild-type C1INH.