PELI1 Selectively Targets Kinase-Active RIP3 for Ubiquitylation-Dependent Proteasomal Degradation.

Receptor-interacting protein kinase-3 (RIP3 or RIPK3) is a central protein in necroptosis, but posttranslational processes that regulate RIP3 activity and stability remain poorly understood. Here, we identify pellino E3 ubiquitin protein ligase 1 (PELI1) as an E3 ligase that targets RIP3 for proteasome-dependent degradation. Phosphorylation of RIP3 on T182 leads to interaction with the forkhead-associated (FHA) domain of PELI1 and PELI1-mediated K48-linked polyubiquitylation of RIP3 on K363. This same phosphorylation event is also important for RIP3 kinase activity; thus, PELI1 preferentially targets kinase-active RIP3 for degradation. PELI1-mediated RIP3 degradation effectively prevents cell death triggered by RIP3 hyperactivation. Importantly, upregulated RIP3 expression in keratinocytes from toxic epidermal necrolysis (TEN) patients is correlated with low expression of PELI1, suggesting that loss of PELI1 may play a role in the pathogenesis of TEN. We propose that PELI1 may function to control inadvertent activation of RIP3, thus preventing aberrant cell death and maintaining cellular homeostasis.

Toll-like receptors and antimicrobial peptides expressions of psoriasis: correlation with serum vitamin D level.

To evaluate the association of Toll-like receptors (TLRs), antimicrobial peptides (AMPs) and vitamin D receptors (VDRs) in psoriasis, lesional (PP) and perilesional skin (PN) from psoriasis, atopic dermatitis (AD) patients and healthy controls (NN) were studied by immunohistochemistry. Compared with PN, AD and NN skin, dysregulated expression of TLRs, AMPs and VDR was detected in PP skin. Noteworthy, our results showed altered correlation between TLR2 and VDR expression in PP and PN skin. Human beta defensin 2 (HBD2) and cathelicidin (LL-37) expressions in the PP skin were higher in serum vitamin D sufficient (VDS) groups than serum vitamin D deficient (VDD) groups. Negative correlation was found between TLR2 and VDR expression in the PP skin of VDD groups. However, positive correlation was noted in the PP skin of VDS groups. Based on the present results, therapies targeting the activity of TLRs, AMPs and vitamin D, including modulation of the TLR-VDR pathways, might provide new therapeutic approaches to the psoriasis and other inflammatory skin diseases.

Primary Merkel cell carcinoma of the earlobe in a young healthy man.

Merkel cell carcinoma (MCC) is an uncommon neuroendocrine cutaneous tumor with poor prognosis. It has the high rate of recurrence, mortality, regional nodal involvement, and distant metastases. It is difficult to diagnose MCC because of its non-specific clinical findings. It usually occurs on sun-exposed areas of the skin, mostly at head and neck. There is a difference in the incidence and prognosis according to site in the head and neck. However, there is no consented site-specific diagnosis, treatment or follow-up protocol for MCC at the head and neck. We herein report a case of MCC arising in the right earlobe of an otherwise healthy young man who has been diagnosed early, thereby successfully treated. With our closed follow-up, there was no tumor recurrence or complication at 33 months after diagnosis.

Metastatic Blue Nevus-Like Melanoma Detected by Liquid-Based Catheterized Urine Cytology.

Primary or metastatic malignant melanoma can mimic benign blue nevus in rare cases, making the diagnosis challenging. Herein, we report an exceptionally rare case of blue nevus-like melanoma and its blue nevus-like metastasis which was detected by catheterized urine cytology. The patient presented with blue-colored papuloplaques on his temple which were diagnosed as blue nevus-like melanoma on punch biopsies. While he was admitted for administration of chemotherapy, hematuria was detected. Catheterized urine cytology revealed singly scattered oval to spindle-shaped pigmented cells with a moderate degree of variation in shape and size. Many of them had small nuclei with indiscernible to inconspicuous nucleoli while only a few cells showed nuclear enlargement and nuclear hyperchromasia, which could be diagnostic pitfalls. Most of the cells on the smear were positive for HMB45 immunostaining, which confirmed the diagnosis of metastatic blue nevus-like melanoma. To the best of our knowledge, the present case is the first report describing cytomorphologic findings of blue nevus-like metastasis of melanoma in the urine specimen.

Photodynamic therapy inhibits melanogenesis through paracrine effects by keratinocytes and fibroblasts.

Photodynamic therapy (PDT) is a treatment option for skin cancer and premalignant skin diseases and exhibits rejuvenation effects, including reducing fine wrinkles and whitening, on aged skin. In this study, we investigated the mechanism underlying the whitening effects of PDT on melanocytes (MCs) in vitro and in vivo. Exposure of MCs to PDT in vitro reduced their melanin content and tyrosinase activity without, however, affecting cell survival. Interestingly, melanogenesis was also inhibited by exposing MCs to conditioned media of PDT-treated keratinocytes or dermal fibroblasts. This paracrine effect was likely due to a decreased release of melanocyte-stimulating cytokines such as Kit ligand and hepatocyte growth factor from these cells. Furthermore, we observed that PDT reduced mottled hyperpigmentation of photoaged patient skin in vivo, highlighting the clinical importance of skin whitening by PDT.

Low-Level Light Therapy with 410 nm Light Emitting Diode Suppresses Collagen Synthesis in Human Keloid Fibroblasts: An In Vitro Study.

BACKGROUND: Keloids are characterized by excessive collagen deposition in the dermis, in which transforming growth factor ß (TGF-ß)/Smad signaling plays an important role. Low-level light therapy (LLLT) is reported as effective in preventing keloids in clinical reports, recently. To date, studies investigating the effect of LLLT on keloid fibroblasts are extremely rare. OBJECTIVE: We investigated the effect of LLLT with blue (410 nm), red (630 nm), and infrared (830 nm) light on the collagen synthesis in keloid fibroblasts. METHODS: Keloid fibroblasts were isolated from keloid-revision surgery samples and irradiated using 410-, 630-, 830-nm light emitting diode twice, with a 24-hour interval at 10 J/cm2. After irradiation, cells were incubated for 24 and 48 hours and real-time quantitative reverse transcription polymerase chain reaction was performed. Western blot analysis was also performed in 48 hours after last irradiation. The genes and proteins of collagen type I, TGF-ß1, Smad3, and Smad7 were analyzed. RESULTS: We observed no statistically significant change in the viability of keloid fibroblasts after irradiation. Collagen type I was the only gene whose expression significantly decreased after irradiation at 410 nm when compared to the non-irradiated control. Western blot analysis showed that LLLT at 410 nm lowered the protein levels of collagen type I compared to the control. CONCLUSION: LLLT at 410 nm decreased the expression of collagen type I in keloid fibroblasts and might be effective in preventing keloid formation in their initial stage.

Epithelial-mesenchymal interaction during photodynamic therapy-induced photorejuvenation.

Recently, several clinical studies reported that the photodynamic therapy (PDT) has photorejuvenation effects on the aged skin. Previously, our group introduced evidence of direct effect of PDT on cultured fibroblast (FB). PDT directly stimulated FBs and induced collagen synthesis through activation of extracellular signal-regulated kinase. In this study, we investigated indirect effect of PDT on the human dermal FB during photorejuvenation focused on the epithelial-mesenchymal interaction between keratinocyte (KC) and FB. The "low-level PDT" condition was used for PDT therapy to the cultured KC. Various kinds of cytokines in the supernatants of KC were evaluated by enzyme-linked immunosorbent assay. FBs were stimulated with the KC-conditioned medium (KCM) taken after PDT. The mRNA level of matrix metalloproteinases (MMPs), transforming growth factor (TGF)-ß and collagen type Iα in the FB, was determined by real-time polymerase chain reaction. Clinical phtorejuvenation effect was also evaluated from nine patients who had PDT to treat actinic keratoses. Among the FB-stimulating cytokines, a significant elevation of interleukin (IL)-1α, IL-6, and tumor necrosis factor-α level in KCM was noted after PDT compared with controls. After stimulating FB with KCM, the mRNA of MMP-1 was decreased and the mRNA of collagen type Iα was increased compare to control. Clinically, fine wrinkles significantly reduced after PDT. However, coarse wrinkles were not recovered significantly. In conclusion, increased collagen synthesis may be mediated not only by direct effect of PDT on FB but also by indirect effect of PDT on FB through cytokines from KC, such as IL-1α, IL-6, and tumor necrosis factor-α.

Photodynamic therapy in Bowen disease of the first web space of the hand.

Bowen disease (BD), or intraepithelial squamous cell carcinoma (SCC), may progress to an invasive SCC. Although surgery is preferred because of the low recurrence rate, it can result in hypertrophic scarringor contracture, particularly in lesions on the hands. We report a case of BD in the first web space of the hand, which was treated with ablative fractional laser-assisted photodynamic therapy (AFXL-assisted PDT). After multiple AFXL-assisted PDT sessions, the lesion showed no clinical or pathological abnormalities. Thus, we believe that PDT can be an alternative treatment for BD occurring in the web space of the hand.

Upregulated RIP3 Expression Potentiates MLKL Phosphorylation-Mediated Programmed Necrosis in Toxic Epidermal Necrolysis.

Toxic epidermal necrolysis (TEN) is a severe adverse drug reaction involving extensive keratinocyte death in the epidermis. Histologically, the skin from TEN patients exhibits separation at the dermo-epidermal junction and accompanying necrosis of epidermal keratinocytes. Receptor-interacting protein kinase-3 (RIP3 or RIPK3) is an essential part of the cellular machinery that executes "programmed", or "regulated", necrosis and has a key role in spontaneous cell death and inflammation in keratinocytes under certain conditions. Here we show that RIP3 expression is highly upregulated in skin sections from TEN patients and may therefore contribute to the pathological damage in TEN through activation of programmed necrotic cell death. The expression level of mixed lineage kinase domain-like protein (MLKL), a key downstream component of RIP3, was not significantly different in skin lesions of TEN. However, elevated MLKL phosphorylation was observed in the skin from TEN patients, indicating the presence of RIP3-dependent programmed necrosis. Importantly, in an in vitro model of TEN, dabrafenib, an inhibitor of RIP3, prevented RIP3-mediated MLKL phosphorylation and decreased cell death. Results from this study suggest that the high expression of RIP3 in keratinocytes from TEN patients potentiates MLKL phosphorylation/activation and necrotic cell death. Thus, RIP3 represents a potential target for treatment of TEN.

Comparison between Malassezia Folliculitis and Non-Malassezia Folliculitis.

BACKGROUND: Among the various types of folliculitis, differentiation of Malassezia folliculitis (MF) from other forms of folliculitis is important because it is usually treated with antifungal agents. OBJECTIVE: We attempted to find a method to enhance the detection rate of MF, and examined the differences in the clinical manifestation between MF and non-MF (NMF). METHODS: We performed a retrospective study involving patients with folliculitis who were previously diagnosed with MF or NMF on the basis of serial tissue sectioning and diastase-Periodic acid-Schiff (d-PAS) staining findings. The clinical features of MF and NMF were compared. RESULTS: Among a total of 100 folliculitis patients, 20 were diagnosed with MF and 80 with NMF. Tissues from the 80 patients with NMF were sectioned serially into 10 slices and stained with hematoxylin and eosin stain; among these, 10 had many round-to-oval yeast organisms in the hair follicles that confirmed MF. Finally, d-PAS staining was used to detect the presence of yeast in the NMF slides. Notably, among the 70 d-PAS-stained samples, yeast organisms were found in 6 samples, confirming MF. As a result, the diagnosis of 16 patients changed from NMF to MF. Compared with NMF, MF showed major involvement of the trunk and low involvement of the face and legs as well as male predilection. CONCLUSION: Physicians should consider serial sectioning and/or d-PAS staining of folliculitis lesions, particularly of those on the trunk of male patients, even if no yeast organisms are detected initially.

Photodynamic therapy with ablative carbon dioxide fractional laser for treating Bowen disease.

BACKGROUND: Topical photodynamic therapy (PDT) has been increasingly used to treat malignant skin tumors including the Bowen disease. However, patients could be displeased with the long incubation time required for conventional PDT. OBJECTIVE: We evaluated the efficacy and safety of PDT with a short incubation time of ablative CO2 fractional laser pretreatment for treating Bowen disease. METHODS: Ten patients were included. Just before applying the topical photosensitizer, all lesions were treated with ablative CO2 fractional laser, following the application of methyl aminolevulinate and irradiation with red light (Aktilite CL 128). Histological confirmation, rebiopsy, and clinical assessments were performed. Adverse events were also recorded. RESULTS: Five of the ten (50%) lesions showed a complete response (CR) within three PDT sessions. After four treatment sessions, all lesions except one penile shaft lesion (90%) achieved clinical and histological CR or clinical CR only. The average number of treatments to CR was 3.70±1.70. The treatments showed favorable cosmetic outcomes and no serious adverse events. CONCLUSION: The results suggest that pretreatment with an ablative fractional CO2 laser before PDT has similar treatment efficacy and requires a shorter photosensitizer incubation time compared with the conventional PDT method.

Huge Bowen's disease: a pitfall of topical photodynamic therapy.

Bowen's disease (BD) is one of the major histological types of nonmelanoma skin cancer. With challengeable "multiple and large" patches of BD, topical photodynamic therapy (PDT) has been considered as a first-line effective modality for decades. However, there was no general consensus among authors about the definition of "large BD". Herein, we have experienced two cases of huge BD which has over 10 cm in diameter with resistance to topical PDT. Our cases suggest that topical PDT is likely to show a much less satisfactory effect for huge BD than we have expected, and the previously specified indication of topical PDT ("multiple, larger lesion") seems the fallacy of hasty generalization. Therefore, it is required that further cut-off value of size for suitable candidate for topical PDT would be clarified.

Orofacial granulomatosis associated with Crohn's disease.

Orofacial granulomatosis (OFG) is a term used to describe swelling of the orofacial area, mainly in the lips, secondary to an underlying granulomatous inflammatory process. OFG has been reported in association with systemic conditions such as sarcoidosis and Crohn's disease (CD). OFG may precede gastrointestinal disease, such as CD, by several years and may be the only obvious focus of the disease. Herein, we report a patient with OFG and non-symptomatic ulcerations of the ileocecal valve. The patient received intralesional triamcinolone injections every 2 weeks. After 6 weeks, all oral lesions showed marked improvement. The favourable treatment response of this patient suggests that intralesional triamcinolone can be used as a treatment option for patients with CD that have oral lesions. In addition, patients presenting with OFG should be carefully evaluated for gastrointestinal signs and symptoms.

Clinical comparison of psoriasis in Korean adults and children: correlation with serum anti-streptolysin O titers.

Psoriasis is a relatively common disorder in children and can be triggered by an upper respiratory tract infection. The aim of this study was to compare the clinical features of psoriasis in children and adult. In addition, we evaluated the relationship between anti-streptolysin O (ASO) titers and the clinical features of psoriasis. A total of 30 childhood psoriasis patients and 30 adult psoriasis patients were evaluated. Childhood psoriasis had a facial predominance when compared with the adult psoriasis. The childhood psoriasis patients with high ASO titers had guttate psoriasis more frequently than patients with normal ASO titers. In children with plaque-type psoriasis, psoriasis area and severity index score was increased in the high ASO titer group than normal ASO titer group. In conclusion, if the children with psoriasis show increased ASO titer, the physician should pay attention to the worsening of the psoriasis. Furthermore, early treatment of streptococcal infections might be beneficial in childhood psoriasis.

Comprehensive understanding of idiopathic guttate hypomelanosis: clinical and histopathological correlation.

BACKGROUND: The histological findings associated with idiopathic guttate hypomelanosis (IGH) are hyperkeratosis, an atrophic epidermis, and flattened rete ridges. In addition, a decreased melanin content and reduced numbers of melanocytes are reported features. However, there are few recent studies that have been published on the histopathology of IGH and no comparative studies are available on the skin lesions and perilesional skin of patients with IGH. OBJECTIVES: The goals of this study were to identify the clinical and histopathological features of IGH and determine their correlation. We evaluated the clinical features and the histopathological differences between the skin lesions and the perilesional skin in patients with IGH. METHODS: A clinical survey was carried out on 47 patients with IGH. Specimens from skin lesions and perilesional skin were stained with hematoxylin-eosin, Fontana-Masson, MART-1, and NKI/beteb. We also studied the ultrastructure of four cases. RESULTS: About 30% of the patients had their initial lesions prior to 20 years of age. The arm was the most commonly affected site (53%). Histologically, we found hyperkeratosis in 18 cases (38.3%), but epidermal atrophy was present in only five cases (10.6%), and flattened rete ridges in seven cases (14.9%) compared to the normal skin. Epidermal atrophy was more frequently found at nonsun-exposed areas. The IGH lesions demonstrated decreased melanin pigment and reduced numbers of melanocytes by NKI/beteb and MART-1. The ultrastructural evaluation showed degenerative melanocytes and decreased melanosomes. One specimen had normal melanocytes with decreased melanosomes. CONCLUSIONS: Idiopathic guttate hypomelanosis is a disorder with multifactorial etiology; its pathogenesis may depend on various factors such as patient age and sun-exposure. Histopathologically, hyperkeratosis was frequently found; however, the other characteristic findings such as epidermal atrophy and flattened rete ridges were relatively rare.