Nephrin expression in human epidermal keratinocytes and its implication in poor wound closure.

Nephrin is a type-1 transmembrane protein and a component of the slit diaphragm renal-filtration barrier. It has several functions in actin remodeling and cell-cell adhesion. Nephrin is principally located in the kidney glomerulus, but several studies have reported that nephrin is found in the pancreas, brain, and placenta. However, nephrin expression and its role in human skin have not yet been reported. First, using single-cell RNA sequencing, immunohistochemistry, and immuno-electron microscopy, nephrin expression was confirmed in human-skin epidermal keratinocytes. Nephrin expression colocalized with the expression of zonula occludens-1 in keratinocytes and was closely related to keratinocyte cell density, proliferation, and migration. High glucose treatment decreased nephrin expression and compromised keratinocyte cell migration without yes-associated protein nuclear entry. This reduced cell migration under high glucose conditions was improved in nephrin-overexpressing keratinocytes. Nephrin was highly expressed on the margins of re-epithelized epidermis based on in vivo mice and ex vivo human skin wound models. The results demonstrate that nephrin is expressed in human-skin keratinocytes and functions in cell adhesion, proliferation, and migration. In conclusion, this study suggests that nephrin may have a variety of physiological roles in human skin.

Slow Mohs Micrographic Surgery for Acral Melanoma Treatment in Korean Patients.

BACKGROUND: Obtaining conventional wide surgical margins is challenging in melanomas occurring at anatomically complex sites (e.g., hands and feet). OBJECTIVE: We investigated the potential benefits of slow Mohs micrographic surgery (MMS) for acral melanomas. MATERIALS AND METHODS: This single-center retrospective study investigated 210 patients who underwent slow MMS (n = 66) or wide local excision (WLE, n = 144) for melanomas during 2005 to 2015. Slow MMS was used for melanomas in anatomically complex locations and for high-risk lesions. RESULTS: Acral melanoma (166/210) was the most common lesion observed in patients, in addition to head and neck (21/210) and trunk (23/210) melanomas. Slow MMS was more commonly performed for acral, and head and neck melanomas (32.5% and 52.4%, respectively) than for trunk melanomas (4.3%, p = .002). Local recurrence of acral melanomas occurred in 3.7% of patients after slow MMS and in 10.7% of patients after WLE. Multivariate analysis showed comparable prognostic outcomes between slow MMS and WLE used for acral melanomas. Compared with WLE, slow MMS resulted in a smaller postoperative defect after acral lesion excision (p < .001). CONCLUSION: Slow MMS is an effective alternative to WLE for acral melanomas in anatomically complex sites, as evidenced by superior outcomes and maximum tissue conservation.

Extraciliary roles of the ciliopathy protein JBTS17 in mitosis and neurogenesis.

OBJECTIVE: JBTS17 is a major gene mutated in ciliopathies such as Joubert syndrome and oral-facial-digital syndrome type VI. Most patients with loss of function mutations in JBTS17 exhibit cerebellar vermis hypoplasia and brainstem malformation. However, some patients with JBTS17 mutations show microcephaly and abnormal gyration. We examined potential roles of JBTS17 in neurogenesis to understand the pathological mechanism of JBTS17-related cortical abnormalities. METHODS: We examined subcellular localization and cell-cycle-dependent expression of JBTS17 proteins using anti-JBTS17 antibodies and JBTS17 expression vectors. We also performed knockdown experiments to determined roles of JBTS17 in human cells, and demonstrated mitotic functions of JBTS17 using immunostaining and live imaging. We examined the involvement of JBTS17 in cortical neurogenesis using a mouse in utero electroporation technique. RESULTS: We found that JBTS17 localizes to the kinetochore and the level of JBTS17 is regulated by cell-cycle-dependent proteolysis. Depletion of JBTS17 disrupts chromosome alignment and spindle pole orientation, resulting in mitotic delay. JBTS17 interacts with LIS1 and influences LIS1 localization. Depletion of Jbts17 in the developing mouse cortex interferes with the mitotic progression of neural progenitors and the migration of postmitotic neurons. INTERPRETATION: LIS1 is implicated in lissencephaly, but altered dosage of LIS1 has been also associated with microcephaly syndromes. Our results suggest that JBTS17 contributes to mitotic progression by interacting with LIS1, and abnormal mitosis is an underlying mechanism of the microcephaly phenotype in JBTS17-related ciliopathies. We propose that understanding extraciliary roles of ciliopathy proteins is important to elucidate pathological mechanisms underlying diverse ciliopathy phenotypes. ANN NEUROL 2019.

Export of membrane proteins from the Golgi complex to the primary cilium requires the kinesin motor, KIFC1.

Microtubule-based motors contribute to the efficiency and selectivity of Golgi exit and post-Golgi transport of membrane proteins that are targeted to distinct compartments. Cytoplasmic dynein moves post-Golgi vesicles that carry rhodopsin toward the base of the connecting cilium in photoreceptor cells; however, the identity of the motors that are involved in the vesicular trafficking of ciliary membrane proteins in nonphotoreceptor cells remains unclear. Here, we demonstrate that the minus end-directed kinesin KIFC1 (kinesin family member C1) is required for both ciliary membrane protein transport and serum starvation-induced ciliogenesis in retinal pigmented epithelial 1 cells. Although KIFC1 is known as a mitotic motor that is sequestered in the nucleus during interphase, KIFC1 immunoreactivity appeared in the Golgi region after serum starvation. Knockdown of KIFC1 inhibited the export of ciliary receptors from the Golgi complex. KIFC1 overexpression affected the Golgi localization of GMAP210 (Golgi microtubule-associated protein 210) and IFT20 (intraflagellar transport 20), which are involved in membrane protein transport to cilia. Moreover, KIFC1 physically interacted with ASAP1 (ADP-ribosylation factor GTPase-activating protein with SH3 domain, ankyrin repeat and PH domain 1), which regulates the budding of rhodopsin transport carriers from the Golgi complex, and KIFC1 depletion caused Golgi accumulation of ASAP1. A decrease in the centrosomal levels of IFT20 and TTBK2 (τ-tubulin kinase 2) was associated with ciliogenesis defects in KIFC1-depleted cells. Our results suggest that KIFC1 plays roles in the Golgi exit of ciliary receptors and in the recruitment of ciliogenesis regulators.-Lee, S.-H., Joo, K., Jung, E. J., Hong, H., Seo, J., Kim, J. Export of membrane proteins from the Golgi complex to the primary cilium requires the kinesin motor, KIFC1.

Increased Serum Antibody Titer against HPV-16 Antigen in Patients with Behçet's Disease.

Quadrivalent human papillomavirus (HPV) vaccine has been reported to be significantly associated with Behçet's disease (BD). However, no reports have described HPV infection as a possible cause for the development of BD. The objective of this study was to evaluate whether anti-HPV immunoglobulin G (IgG) antibody titer is increased in BD. Serum samples from 93 Korean BD patients, who fulfilled the diagnostic criteria of the International Study Group for BD, were used in an enzyme-linked immunosorbent assay (ELISA). The clinical activity of BD was evaluated at the time of blood sampling. HPV-16 L1 virus-like particle (VLP) antigen was used in this study for the ELISA. Patients with BD had significantly higher antibody titers against HPV-16 (optical density [OD], 0.210-3.675; mean 0.992) than that of healthy controls (OD, 0.248-0.762; mean 0.517; P < 0.001). Using a receiver operating characteristic (ROC) analysis, a cut-off value of 0.578 OD for the anti-HPV antibody titer was determined that differentiated BD patients from healthy controls. When we compared the clinical features of BD between the 2 groups, articular involvement of BD was more likely in patients with an anti-HPV-16 antibody titer < 0.578 OD (P = 0.035). In addition, patients with an anti-HPV-16 antibody titer < 0.578 were significantly younger than those with a titer ≥ 0.578 OD. HPV itself may be a possible extrinsic triggering infectious agent causing the development of BD.

Gut microbiota modulation and gold nanoparticle-mediated photothermal therapy for treatment of recalcitrant acne.

Recent studies highlight that gut dysbiosis, an imbalanced state of intestinal microbiota, exacerbates skin inflammation. Here, we showed the presence of gut microbiota alterations in two patients with recalcitrant acne and investigated the impact of its therapeutic modulation together with gold nanoshell-mediated photothermal therapy (gold PTT).

Weight-bearing activity impairs nuclear membrane and genome integrity via YAP activation in plantar melanoma.

Acral melanoma commonly occurs in areas that are not exposed to much sunlight, such as the sole of the foot. Little is known about risk factors and mutational processes of plantar acral melanoma. Nuclear envelope rupture during interphase contributes to genome instability in cancer. Here, we show that the nuclear and micronuclear membranes of melanoma cells are frequently ruptured by macroscopic mechanical stress on the plantar surface due to weight-bearing activities. The marginal region of plantar melanoma nodules exhibits increased nuclear morphological abnormalities and collagen accumulations, and is more susceptible to mechanical stress than the tumor center. An increase in DNA damage coincides with nuclear membrane rupture in the tumor margin. Nuclear envelope integrity is compromised by the mechanosensitive transcriptional cofactor YAP activated in the tumor margin. Our results suggest a mutagenesis mechanism in melanoma and explain why plantar acral melanoma is frequent at higher mechanical stress points.

ATP-P2X7-Induced Inflammasome Activation Contributes to Melanocyte Death and CD8+ T-Cell Trafficking to the Skin in Vitiligo.

Extracellular adenosine 5'-triphosphate (ATP) is a well-known inflammasome-activating signal. Emerging evidence demonstrates a critical role for inflammasome activation in vitiligo pathogenesis. However, the specific molecular mechanism of inflammasome-dependent melanocyte degeneration in vitiligo is still not clear. This study presents how extracellular ATP, released from keratinocytes by oxidative stress, affects melanocyte survival in vitiligo skin. H2O2-induced oxidative injury increased ATP release from keratinocytes and skin tissues. The high concentration of extracellular ATP induced both ROS production and cell death in melanocytes. Treatment with ATP caused the activation of caspase-1 as well as the production of active forms of IL-1ß and IL-18 via P2X7 receptor in keratinocytes and melanocytes. Lesional and perilesional skin of vitiligo showed higher levels of ATP as well as upregulation of active caspase-1 compared with nonlesional skin, suggesting its possible role in inflammasome activation in vitiligo. Moreover, the elevated expression of CXCL9 in keratinocytes, mediated through ATP/P2X7 receptor-dependent inflammasome activation, was responsible for CLA+CD8+ T-cell chemotaxis into the skin. These results demonstrate that extracellular ATP as a danger signal activates the inflammasome pathway and increases cutaneous chemotaxis of CD8+ T cells via CXCL9 in vitiligo. Therefore, targeting ATP-P2X7 signaling may be a potential strategy for vitiligo treatment.

MK5 Regulates YAP Stability and Is a Molecular Target in YAP-Driven Cancers.

Transcriptional regulator YAP is activated in multiple human cancers and plays critical roles in tumor initiation, progression, metastasis, and drug resistance. However, therapeutic targeting of the Hippo-YAP pathway has been challenging due to its low druggability and limited knowledge of YAP regulation in cancer. Here we present a functional screen and identify a novel therapeutic target for YAP-driven tumorigenesis. RNAi screening using an oncogenic YAP activation model identified the serine/threonine kinase MK5 as a positive regulator of YAP. MK5 physically interacted with YAP and counteracted CK1δ/ε-mediated YAP ubiquitination and degradation independent of LATS1/2. MK5 kinase activity was essential for protecting YAP from ubiquitin-mediated degradation and cytoplasmic retention. Downregulating MK5 expression inhibited the survival of YAP-activated cancer cell lines and mouse xenograft models. MK5 upregulation was associated with high levels of YAP expression and poor prognosis in clinical tumor samples, confirming its important role for YAP activity in human cancer. These results uncover MK5 as a novel factor that regulates YAP stability, and targeting the YAP degradation pathway controlled by MK5 is a potential strategy for suppressing YAP activity in cancer. SIGNIFICANCE: These findings reveal MK5 is a novel kinase that regulates YAP in a LATS-independent manner and can be targeted for cancer therapy.

Regulation of Hippo signaling by actin remodeling.

The Hippo signaling pathway controls nuclear accumulation and stability of the transcriptional coregulator YAP and its paralog TAZ. The activity of Hippo-YAP signaling is influenced not only by biochemical signals, but also by cell shape and mechanical tension transmitted through cell-cell junctions and cell-matrix adhesions. Data accumulated thus far indicates that the actin cytoskeleton is a key mediator of the regulation of Hippo-YAP signaling by means of a variety of biochemical and mechanical cues. In this review, we have outlined the role of actin dynamics and actin-associated proteins in the regulation of Hippo-YAP signaling. In addition, we discuss actinmediated regulation of YAP/TAZ activity independent of the core Hippo kinases MST and LATS. Although our understanding of the link between Hippo-YAP signaling and the actin cytoskeleton is progressing rapidly, many open questions remain. [BMB Reports 2018; 51(3): 151-156].

Thiopurine S-Methyltransferase Polymorphisms in Korean Dermatologic Patients.

BACKGROUND: Thiopurine S-methyltransferase (TPMT) is an important enzyme in the metabolism of thiopurines including azathioprine (AZA), 6-mercaptopurine, and 6-thioguanine. TPMT genotyping is widely used for screening of AZA-related toxicity during routine clinical practice in Korea. However, the data of TPMT genotypes and its AZA-related toxicity have not been studied in the field of dermatology. OBJECTIVE: The aim of this study was to evaluate the genetic basis of TPMT polymorphism in Korean dermatologic patients and subsequently to investigate the relationship between mutant TPMT and adverse responses to AZA treatment. METHODS: This study was retrospective, single-center study. One hundred forty-nine Korean dermatologic patients who underwent TPMT screening test were included. Each patient's medical records, the result of TPMT screening test, dose and treatment period of AZA, and side effects, were reviewed. Laboratory tests were assessed at each visit in order to monitor adverse drug reactions. Leukopenia grading was used in accordance with the common terminology criteria for adverse events (CTCAE) ver. 4.03. RESULTS: Behçet's disease was the leading disorder among the patients. The frequency of TPMT mutation was 4.0% (6/149) among the participants in this study. Four of the six patients with genetic alterations were treated with a low-dose AZA regimen, but no AZA-related adverse events were observed. CONCLUSION: Our results suggest that 1) TPMT polymorphisms in Korean dermatologic patients are similar to those previously reported in Asian patients with the most common mutant allele being TPMT*3C and 2) AZA can be used in the patients with these polymorphisms under a careful dosing regimen.

Intramuscular triamcinolone acetonide: An undervalued option for refractory alopecia areata.

Severe alopecia areata (AA) can have an unpredictable clinical course and become refractory to contact immunotherapy. Novel treatment options include low-dose interleukin-2 and Janus kinase inhibitors; however, these treatments are still under investigation. Therefore, we evaluated the efficacy and safety of intramuscular (i.m.) triamcinolone acetonide (TAC) as a rescue therapy for refractory AA. We retrospectively analysed efficacy, adverse effects and relapse rate of i.m. TAC monthly in 27 patients with refractory AA. We defined AA as refractory if the patient showed an unsatisfactory response to both systemic treatment (not i.m. TAC) and the consecutive diphenylcyclopropenone immunotherapy. The initial systemic treatment of other forms of corticosteroids and/or cyclosporin was used to control extensive AA involving more than 25% of the scalp. Administration of i.m. TAC for 3-6 months resulted in a 63.0% response rate, and all patients showed inactive disease after treatment. Final hair regrowth negatively correlated with initial scalp involvement (Spearman r = -0.595, P = 0.001). All patients showed complete recovery of adrenocortical reserve within 3 months after the last injection. Adverse effects of systemic steroid therapy were observed only in female patients (dysmenorrhea and osteoporosis). i.m. TAC may provide a valuable therapeutic option to manage active hair loss and facilitate hair regrowth in refractory AA, especially in male patients.

Paraneoplastic Pemphigus Associated with a Malignant Thymoma: A Case of Persistent and Refractory Oral Ulcerations Following Thymectomy.

Paraneoplastic pemphigus is a rare, life-threatening autoimmune mucocutaneous blistering disease associated with underlying neoplasia, commonly lymphoproliferative tumors. Herein we report a case of paraneoplastic pemphigus with a unique autoantibody profile associated with a malignant thymoma. A 56-year-old female patient presented with relapsing oral ulcerations accompanied by erythematous papules and patches on her extremities for 2 months. Skin and mucosal biopsies identified interface dermatitis with lichenoid lymphocytic infiltration in the upper dermis. Immunoblotting and enzyme-linked immunosorbent assays revealed that the patient had multiple autoantibodies against desmoglein 1, desmocollin 1, 2, 3, laminin gamma-1, envoplakin, and periplakin. The skin lesions completely healed following thymectomy and systemic corticosteroid therapy, but the oral ulcerations persisted through a follow-up period of over 2 years.

Reconstruction of large wounds using a combination of negative pressure wound therapy and punch grafting after excision of acral lentiginous melanoma on the foot.

Melanoma in darker-pigmented individuals often develops in an acral lentiginous fashion on the foot. After surgical removal of a tumor at this site, repair of the wound can be challenging. This is because there is an insufficient local skin pool and lack of mobility of the skin in this area. Moreover, functional aspects such as walking and weight bearing should be considered. We performed a combination treatment of negative pressure wound therapy (NPWT) and punch grafting on 15 patients, after wide excision of acral lentiginous melanomas on the foot, and compared these to 26 patients who underwent either secondary intention healing (SIH, n = 13) or NPWT (n = 13) alone. The punch grafting with NPWT group showed significantly shorter healing times than those of the other two groups. Evaluation of completely healed wounds using the Vancouver Burn Scar Assessment Scale revealed that the punch grafting group had mean values better, or comparable, to the SIH or NPWT group in four of the five scales (except pigmentation). As for complications, only one patient developed a wound infection after punch grafting. Further, by utilizing NPWT for fixation of punch grafts, it was possible to treat all subjects as outpatients after punch grafting. These results show that a combination treatment of NPWT and punch grafting is an excellent therapeutic option for post-wide excision wounds on the feet, with significantly shortened healing times and favorable cosmetic outcomes.

Cutaneous Serratia marcescens infections in Korea: A retrospective analysis of 13 patients.

Serratia marcescens is a Gram-negative bacillus belonging to the Enterobacteriaceae family. Because of increasing reports of antimicrobial resistance, this bacterium has received considerable attention and has emerged as an important pathogen. In order to reveal clinical and microbiological characteristics of S. marcescens cutaneous infection and to suggest appropriate antibiotic treatment, we retrospectively analyzed 17 strains isolated from wound swabs of Korean patients between November 2005 and March 2014. A total of 13 patients (five men and eight women) were included in our study, with a mean age of 46.3 years (range, 21-82). Based on medical history, seven patients were classified as immunocompromised. Prior predisposing factors for infections were noted in 12 patients, including pre-existing leg ulcers or dermatitis (5/13), preceding cancer surgeries (2/13), plastic surgeries and filler injection (2/13), traumas (2/13) and medical procedures following cutaneous abscess (1/13). Cutaneous infections showed various clinical presentations, including spontaneous dermal abscess, fingernail change, painful nodules and papular erosions. We found that third- and fourth-generation cephalosporins, gentamicin, levofloxacin and meropenem appeared active against all 17 strains in vitro. Clinically, all patients treated with empirical first-generation cephalosporin showed treatment resistance, and oral quinolone monotherapy was the most preferred antibiotic regimen without treatment failure, with an average treatment duration of 25 days (range, 14-42). This study demonstrates the various clinical presentations and treatment responses for cutaneous S. marcescens infection. Moreover, we suggest that initial antibiotic coverage should be broad enough to account for multidrug resistance in this rare pathogen.

Multiple milia formation induced by dovitinib.

Dovitinib is a novel multi-target tyrosine kinase inhibitor that inhibits vascular endothelial growth factor receptor-1-3, platelet-derived growth factor receptor-ß, Fms-like tyrosine kinase 3, c-Kit and fibroblast growth factor receptor-1-3. This compound is currently being assessed clinically for treatment of various malignancies. In phase I and II clinical trials of dovitinib treatment for renal cell carcinoma, 20% of patients experienced cutaneous adverse events, although the specific type of skin rash was not documented. Here, we report two cases of multiple milia formation induced by dovitinib. We believe our cases are the first report mainly showing non-inflammatory cystic structure.

Predictive value of bone scintigraphy for the detection of joint involvement in Behçet's disease: Dermatologists' perspectives.

BACKGROUND: Behçet's disease (BD) is a multisystemic inflammatory disease with articular involvement. Non-specific arthralgia without objective signs of arthritis, such as swelling or effusion, is common in such patients. Thus, an accurate diagnosis of joint involvement may be challenging for dermatologists. OBJECTIVES: To evaluate the validity of (99m)Tc-methylene diphosphonate (Tc-99m-MDP) bone scintigraphy for joint involvement assessment in patients with BD. MATERIALS AND METHODS: In 211 patients with BD who had scintigraphic evaluations due to joint symptoms, agreement between bone scintigraphy findings and clinically evaluated joint complaints was retrospectively assessed using Cohen's kappa (κ) statistic. A patient subset (n = 104) showing agreement between joint complaints and scintigraphy results was re-evaluated by a rheumatologist to determine the level of diagnostic specificity attained by combining bone scintigraphy with clinical examinations of dermatologists. RESULTS: The total kappa value (211 patients) was 0.604, indicating fair agreement between joint complaints and scintigraphy results. Individual analysis of eleven joint categories revealed statistically significant correlations for wrist (κ = 0.677), shoulder (κ = 0.661), and foot joints (κ = 0.618). Of the 104 referrals to a rheumatologist, 95 (91.34%) were confirmed as having BD-associated articular involvement. Joint acral areas (e.g., foot, hand, wrist and shoulder) that had the highest kappa value correlations also ranked highest in diagnostic specificity. CONCLUSION: Bone scintigraphy presents a simple and useful option for dermatologists to assess joint involvement in BD patients, especially for specific anatomic sites.