Pediatric mycosis fungoides in Singapore: a series of 46 children.

Few studies have evaluated Asian children with mycosis fungoides (MF). We report a series of patients from a tertiary dermatologic institution in Singapore. A retrospective review was performed of patients younger than 16 years old diagnosed with MF between 2000 and 2008 at the National Skin Centre, Singapore. Forty-six patients were identified. At initial presentation, a provisional diagnosis of MF was made in 19 patients (41.3%), pityriasis lichenoides chronica (PLC) in 11 (23.9%) and postinflammatory hypopigmentation due to eczema or other causes in 11 (23.9%). After skin biopsy, the hypopigmented variant of MF was diagnosed in 42 patients (91.3%). There was one case each of PLC-like MF, pigmented purpuric dermatosis-like MF, classic MF, and solitary MF. Pityriasis lichenoides coexisted in three cases (6.5%). All except one patient presented with the early patch-plaque stage of disease (stage IA/B). The disease did not progress in any of our patients after a mean follow-up of 71.0 ± 52.5 months. Twenty-seven patients (58.7%) had complete disease clearance after a mean duration of 27.1 ± 28.1 months; 15 (49.7%) of 32 patients who received narrowband ultraviolet B treatment had complete clearance within an average of 8.9 ± 5.3 months, but 7 patients relapsed within 14.9 ± 14.8 months. One patient with solitary MF failed multiple treatment modalities before eventually achieving disease clearance with photodynamic therapy. Hypopigmented MF is the most common MF variant in Asian children. The diagnostic difficulty is in differentiating this from PLC, which may coexist with MF. Long-term prognosis is generally favorable.

Angiopoietin-like 4 interacts with matrix proteins to modulate wound healing.

A dynamic cell-matrix interaction is crucial for a rapid cellular response to changes in the environment. Appropriate cell behavior in response to the changing wound environment is required for efficient wound closure. However, the way in which wound keratinocytes modify the wound environment to coordinate with such cellular responses remains less studied. We demonstrated that angiopoietin-like 4 (ANGPTL4) produced by wound keratinocytes coordinates cell-matrix communication. ANGPTL4 interacts with vitronectin and fibronectin in the wound bed, delaying their proteolytic degradation by metalloproteinases. This interaction does not interfere with integrin-matrix protein recognition and directly affects cell-matrix communication by altering the availability of intact matrix proteins. These interactions stimulate integrin- focal adhesion kinase, 14-3-3, and PKC-mediated signaling pathways essential for effective wound healing. The deficiency of ANGPTL4 in mice delays wound re-epithelialization. Further analysis revealed that cell migration was impaired in the ANGPTL4-deficient keratinocytes. Altogether, the findings provide molecular insight into a novel control of wound healing via ANGPTL4-dependent regulation of cell-matrix communication. Given the known role of ANGPTL4 in glucose and lipid homeostasis, it is a prime therapeutic candidate for the treatment of diabetic wounds. It also underscores the importance of cell-matrix communication during angiogenesis and cancer metastasis.

Angiopoietin-like 4 interacts with integrins beta1 and beta5 to modulate keratinocyte migration.

Adipose tissue secretes adipocytokines for energy homeostasis, but recent evidence indicates that some adipocytokines also have a profound local impact on wound healing. Upon skin injury, keratinocytes use various signaling molecules to promote reepithelialization for efficient wound closure. In this study, we identify a novel function of adipocytokine angiopoietin-like 4 (ANGPTL4) in keratinocytes during wound healing through the control of both integrin-mediated signaling and internalization. Using two different in vivo models based on topical immuno-neutralization of ANGPTL4 as well as ablation of the ANGPTL4 gene, we show that ANGPTL4-deficient mice exhibit delayed wound reepithelialization with impaired keratinocyte migration. Human keratinocytes in which endogenous ANGPTL4 expression was suppressed by either siRNA or a neutralizing antibody show impaired migration associated with diminished integrin-mediated signaling. Importantly, we identify integrins ß1 and ß5, but not ß3, as novel binding partners of ANGPTL4. ANGPTL4-bound integrin ß1 activated the FAK-Src-PAK1 signaling pathway, which is important for cell migration. The findings presented herein reveal an unpredicted role of ANGPTL4 during wound healing and demonstrate how ANGPTL4 stimulates intracellular signaling mechanisms to coordinate cellular behavior. Our findings provide insight into a novel cell migration control mechanism and underscore the physiological importance of the modulation of integrin activity in cancer metastasis.

Regulation of cell proliferation and migration by TAK1 via transcriptional control of von Hippel-Lindau tumor suppressor.

Skin maintenance and healing after wounding requires complex epithelial-mesenchymal interactions purportedly mediated by growth factors and cytokines. We show here that, for wound healing, transforming growth factor-beta-activated kinase 1 (TAK1) in keratinocytes activates von Hippel-Lindau tumor suppressor expression, which in turn represses the expression of platelet-derived growth factor-B (PDGF-B), integrin beta1, and integrin beta5 via inhibition of the Sp1-mediated signaling pathway in the keratinocytes. The reduced production of PDGF-B leads to a paracrine-decreased expression of hepatocyte growth factor in the underlying fibroblasts. This TAK1 regulation of the double paracrine PDGF/hepatocyte growth factor signaling can regulate keratinocyte cell proliferation and is required for proper wound healing. Strikingly, TAK1 deficiency enhances cell migration. TAK1-deficient keratinocytes displayed lamellipodia formation with distinct microspike protrusion, associated with an elevated expression of integrins beta1 and beta5 and sustained activation of cdc42, Rac1, and RhoA. Our findings provide evidence for a novel homeostatic control of keratinocyte proliferation and migration mediated via TAK1 regulation of von Hippel-Lindau tumor suppressor. Dysfunctional regulation of TAK1 may contribute to the pathology of non-healing chronic inflammatory wounds and psoriasis.

Fabrication and characterization of a novel crosslinked human keratin-alginate sponge.

Human hair keratins have been explored for biomedical applications because of their abundance, bioactivity and processability. However, pure keratin templates have poor mechanical properties, which limit their practical relevance. Herein, we described a novel composite sponge, consisting of human hair keratins chemically crosslinked with alginate using 1-ethyl-3-dimethylaminopropyl carbodiimide hydrochloride, with improved mechanical properties. Fourier transform infrared spectroscopy (FTIR) and free amine group quantification using ninhydrin revealed a maximum crosslinking index of 82.1 ± 1.3%. With increasing alginate proportions, the sponges exhibited increased tensile strength, tensile modulus and compression modulus at maximum values of 10.3 ± 1.92 kPa, 219.07 ± 52.39 kPa and 191.48 ± 32.89 kPa, respectively. The crosslinked sponges also demonstrated water vapour transmission rates comparable to commercial wound dressings. Meanwhile, sponges with higher proportions of keratin showed lower water uptake capacities and higher degradation rates by proteinase K, in comparison with sponges with higher proportions of alginate. Higher proportions of keratin on coated two-dimensional surfaces and in three-dimensional sponges resulted in more attachment and improved proliferation of L929 fibroblasts, verifying the bioactive role of keratin in the composites. In addition, subcutaneous implantation of the keratin-alginate sponges into C57BL/6NTac mice over 4 weeks showed no significant immunological reaction and minimal formation of fibrotic capsules. Furthermore, the sponges supported cellular infiltration, neo-tissue formation and vascularization in vivo. These findings demonstrated the feasibility of producing crosslinked human hair keratin-alginate sponges, with tuneable physical and mechanical properties, which are cell compliant in vitro and biocompatible in vivo, suggesting their potential for clinically relevant exploitations. Copyright © 2016 John Wiley & Sons, Ltd.

Comparison of the Simple Patient-Centric Atopic Dermatitis Scoring System PEST with SCORAD in Young Children Using a Ceramide Dominant Therapeutic Moisturizer.

INTRODUCTION: Patient eczema severity time (PEST) is a new atopic dermatitis (AD) scoring system based on patients' own perception of their disease. Conventional scales such as SCORing of atopic dermatitis (SCORAD) reflect the clinician's observations during the clinic visit. Instead, the PEST score captures eczema severity, relapse and recovery as experienced by the patient or caregiver on a daily basis, promoting patient engagement, compliance with treatment and improved outcomes. This study aims to determine the correlation between carer-assessed PEST and clinician-assessed SCORAD in paediatric AD patients after 12 weeks of treatment using a ceramide-dominant therapeutic moisturizer. METHODS: Prospective, open-label, observational, multi-centre study in which children with AD aged 6 months to 6 years were treated with a ceramide dominant therapeutic moisturizer twice daily for 12 weeks; 58 children with mild-to-moderate AD were included. Correlation between the 7-day averaged PEST and SCORAD scores for assessment of AD severity was measured within a general linear model. PEST and SCORAD were compared in week 4 and week 12. RESULTS: At week 12, a moderate correlation was found between the SCORAD and PEST scores (r = 0.51). The mean change in SCORAD and PEST scores from baseline to week 12 was -11.46 [95% confidence interval (CI) -14.99 to -7.92, p < 0.0001] and -1.33 (95% CI -0.71 to -0.10, p < 0.0001) respectively. PEST demonstrated greater responsiveness to change (33.3% of scale) compared to SCORAD (13.8% of scale). CONCLUSION: The PEST score correlates well with the SCORAD score and may have improved sensitivity when detecting changes in the severity of AD. The ceramide-dominant therapeutic moisturizer used was safe and effective in the management of AD in young children. FUNDING: Hyphens Pharma Pte Ltd. TRIAL REGISTRATION: clinicaltrials.gov identifier, NCT02073591.

Whole metagenome profiling reveals skin microbiome-dependent susceptibility to atopic dermatitis flare.

Whole metagenome analysis has the potential to reveal functional triggers of skin diseases, but issues of cost, robustness and sampling efficacy have limited its application. Here, we have established an alternative, clinically practical and robust metagenomic analysis protocol and applied it to 80 skin microbiome samples epidemiologically stratified for atopic dermatitis (AD). We have identified distinct non-flare, baseline skin microbiome signatures enriched for Streptococcus and Gemella but depleted for Dermacoccus in AD-prone versus normal healthy skin. Bacterial challenge assays using keratinocytes and monocyte-derived dendritic cells established distinct IL-1-mediated, innate and Th1-mediated adaptive immune responses with Staphylococcus aureus and Staphylococcus epidermidis. Bacterial differences were complemented by perturbations in the eukaryotic community and functional shifts in the microbiome-wide gene repertoire, which could exacerbate a dry and alkaline phenotype primed for pathogen growth and inflammation in AD-susceptible skin. These findings provide insights into how the skin microbial community, skin surface microenvironment and immune system cross-modulate each other, escalating the destructive feedback cycle between them that leads to AD flare.

Early controlled release of peroxisome proliferator-activated receptor ß/δ agonist GW501516 improves diabetic wound healing through redox modulation of wound microenvironment.

Diabetic wounds are imbued with an early excessive and protracted reactive oxygen species production. Despite the studies supporting PPARß/δ as a valuable pharmacologic wound-healing target, the therapeutic potential of PPARß/δ agonist GW501516 (GW) as a wound healing drug was never investigated. Using topical application of polymer-encapsulated GW, we revealed that different drug release profiles can significantly influence the therapeutic efficacy of GW and consequently diabetic wound closure. We showed that double-layer encapsulated GW microparticles (PLLA:PLGA:GW) provided an earlier and sustained dose of GW to the wound and reduced the oxidative wound microenvironment to accelerate healing, in contrast to single-layered PLLA:GW microparticles. The underlying mechanism involved an early GW-mediated activation of PPARß/δ that stimulated GPx1 and catalase expression in fibroblasts. GPx1 and catalase scavenged excessive H2O2 accumulation in diabetic wound beds, prevented H2O2-induced ECM modification and facilitated keratinocyte migration. The microparticles with early and sustained rate of GW release had better therapeutic wound healing activity. The present study underscores the importance of drug release kinetics on the therapeutic efficacy of the drug and warrants investigations to better appreciate the full potential of controlled drug release.

Evaluation of a Pseudoceramide Moisturizer in Patients with Mild-to-Moderate Atopic Dermatitis.

INTRODUCTION: To evaluate the efficacy and safety of a pseudoceramide-containing moisturizer as maintenance therapy in patients with mild-to-moderate atopic dermatitis (AD). METHODS: This was a prospective, single-arm, open-label clinical trial of a twice-daily application of a pseudoceramide-containing moisturizer for 4 weeks as maintenance therapy in 40 patients with stable, mild-to-moderate AD in a tropical climate. Clinical and skin barrier assessment was done at week 0, week 2 and week 4. Any adverse effects were also recorded during the study period. RESULTS: The objective scoring atopic dermatitis decreased from 29.1 [interquartile range (IQR) 21.9-33.7] at week 0 to 22.0 (IQR 21.2-27.8) at week 4 (p < 0.001). There was no detectable difference in transepidermal water loss after 4 weeks; however, stratum corneum (SC) hydration was significantly increased from 39.7 (IQR 35.3-46.4) at week 0 to 49.2 (IQR 41.2-54.6) after 4 weeks (p < 0.001). Both Dermatology Life Quality Index and patient-oriented eczema measure showed significant improvement at week 4 (p < 0.001). The moisturizer was well tolerated with no serious adverse events recorded. CONCLUSION: After 4 weeks of barrier maintenance therapy with a pseudoceramide moisturizer, there was a significant improvement in disease severity, SC hydration and quality of life in both pediatric and adult patients with mild-to-moderate AD.

Isotretinoin is safe and efficacious in Asians with acne vulgaris.

BACKGROUND: Oral isotretinoin is effective for acne vulgaris but concerns remain regarding its adverse effects. OBJECTIVES: This study aims to evaluate the safety and efficacy of isotretinoin for acne vulgaris in Asian patients. METHODS: We conducted a 4-year retrospective study on all patients with acne vulgaris treated with isotretinoin, between January 2005 and December 2008 at the National Skin Centre in Singapore. Medical records were reviewed for information on patient demographics, acne severity, isotretinoin dose, duration, adverse effects and outcome. RESULTS: There were 2,255 patients, with a mean age of 22.5 years, male:female ratio of 2.5:1 and 82.3% being Chinese. The mean starting dose of isotretinoin was 0.4 mg/kg and on average, patients received 7.8 months of treatment at a mean dose of 0.5 mg/kg. Mean total cumulative dose was 95.6 mg/kg. Vast majority (93.9%) achieved complete remission or substantial improvement. Thirty-eight (2.2%) and 24 patients (2.7%) developed elevated serum levels of alanine and aspartate aminotransferases subsequent to treatment. There were 194 (12.1%) and 80 (4.8%) patients who developed hyperlipidaemia and hypertriglyceridaemia respectively. Isotretinoin was generally well-tolerated, with 6.4% (n = 145) discontinuing due to side-effects. CONCLUSIONS: This study reaffirms the overall safety and efficacy of oral isotretinoin in Asian patients with acne vulgaris.

Livedoid vasculopathy and its association with factor V Leiden mutation.

Livedoid vasculopathy is a rare chronic relapsing disorder characterised by recurrent painful thrombotic and vasculitic ulcers on the legs. We present the cases of two Indian women with livedoid vasculopathy that were found to be associated with an underlying factor V Leiden heterozygous mutation. There were no other thrombotic manifestations, and livedoid vasculopathy was the sole presenting feature of the factor V Leiden mutation, although this could also be coincidental. Initial treatment with high-dose immunosuppressive therapy was suboptimal, and the addition of pentoxifylline and antiplatelet therapy was crucial in achieving disease control and remission. These cases highlight the possible association with an underlying prothrombotic disorder, such as factor V Leiden mutation, in patients with livedoid vasculopathy. Although this association is relatively uncommon, it is more relevant to Indian patients, as the presence of factor V Leiden mutation is highest in this ethnicity as compared to the local Malay and Chinese populations.

Hailey-Hailey disease: effective treatment with topical cadexomer iodine.

Hailey-Hailey disease (HHD) or familial benign pemphigus is known to have a chronic relapsing-remitting course. Conventional treatment with topical steroids and antibiotics often yield unsatisfactory results. We report a case of HHD treated successfully with topical cadexomer iodine powder. Cadexomer iodine may be a useful therapy for recalcitrant cases of HHD.

Angiopoietin-like 4 regulates epidermal differentiation.

The nuclear hormone receptor PPARß/δ is integral to efficient wound re-epithelialization and implicated in epidermal maturation. However, the mechanism underlying the latter process of epidermal differentiation remains unclear. We showed that ligand-activated PPARß/δ indirectly stimulated keratinocyte differentiation, requiring de novo gene transcription and protein translation. Using organotypic skin cultures constructed from PPARß/δ- and angiopoietin-like 4 (ANGPTL4)-knockdown human keratinocytes, we showed that the expression of ANGPTL4, a PPARß/δ target gene, is essential for the receptor mediated epidermal differentiation. The pro-differentiation effect of PPARß/δ agonist GW501516 was also abolished when keratinocytes were co-treated with PPARß/δ antagonist GSK0660 and similarly in organotypic skin culture incubated with blocking ANGPTL4 monoclonal antibody targeted against the C-terminal fibrinogen-like domain. Our focused real-time PCR gene expression analysis comparing the skin biopsies from wildtype and ANGPTL4-knockout mice confirmed a consistent down-regulation of numerous genes involved in epidermal differentiation and proliferation in the ANGPTL4-knockout skin. We further showed that the deficiency of ANGPTL4 in human keratinocytes and mice skin have diminished expression of various protein kinase C isotypes and phosphorylated transcriptional factor activator protein-1, which are well-established for their roles in keratinocyte differentiation. Chromatin immunoprecipitation confirmed that ANGPTL4 stimulated the activation and binding of JUNB and c-JUN to the promoter region of human involucrin and transglutaminase type 1 genes, respectively. Taken together, we showed that PPARß/δ regulates epidermal maturation via ANGPTL4-mediated signalling pathway.

Contact sensitization in patients with chronic venous leg ulcers in Singapore.

Contact sensitization rates are high in patients with chronic venous leg ulcers. Allergic contact dermatitis poses a significant hindrance to the healing of the wounds. There are no published studies examining the rate of contact sensitization in Asian patients. Our objective was to determine the rate of contact sensitization in patients with chronic venous leg ulcer in Singapore and the variation in the common allergens based on local practices in comparison with Western countries. 44 patients were patch tested to the National Skin Centre standard series, steroid series, medicaments, topical Chinese medicaments, and to modern wound dressings used. The overall rate of contact sensitization was 61.4%. The common allergen groups were topical antibiotics (18.2%) and topical traditional Chinese medicaments (TTCM) (15.9%). Individually, colophony (11.3%), Saw Hong Choon skin ointment (Kam Bo Med, Hong Kong, Hong Kong) (11.3%), Balsam of Peru (9.1%), and povidone iodine (9.1%) were among the most frequent allergens. The sensitization rate among users of TTCM was notably high (41%). A high rate of contact sensitization was found in our study, similar to previous reports from the West. TTCM play a major role as possible allergens in our patients. In Asian patients, a history of its usage should be elicited, and patch testing should include the commonly used TTCM where possible.

Retrospective 5-year review of 131 patients with mycosis fungoides and Sézary syndrome seen at the National Skin Centre, Singapore.

A total of 131 new cases of mycosis fungoides and Sézary syndrome were diagnosed clinically and histopathologically at our centre over a 5-year period. There were 87 males and 44 females with a mean age of 36.3 years (range 3-87 years) and no racial predilection. Of the 62 patients (47.3%) with classical mycosis fungoides, the majority were male (male : female = 4.2:1). There was one patient with Sézary syndrome. Patients aged older than 50 years were more likely to present with a longer duration of symptoms and advanced disease. In contrast to classical mycosis fungoides, the 47 patients diagnosed with hypopigmented mycosis fungoides had early stage disease, were younger, and no gender predilection was noted. The mean duration of follow up was 19.7 months (range 0.2-54.8 months). Complete remission was achieved in 24.7% and 53.8% of patients followed up at 1 and 3 years, respectively, using skin-directed and systemic treatment modalities appropriate for the stage of disease. There were five patients with progressive disease and three patients with advanced disease who died from disease-related complications. The most significant prognostic factors for 1-year and 3-year outcomes were the patient's duration of symptoms and stage of disease at presentation.