Silencing of Dicer enhances dacarbazine resistance in melanoma cells by inhibiting ADSL expression.

Dacarbazine (DTIC) is the primary first-line treatment for advanced-stage metastatic melanoma; thus, DTIC resistance is poses a major challenge. Therefore, investigating the mechanism underlying DTIC resistance must be investigated. Dicer, a type III cytoplasmic endoribonuclease, plays a pivotal role in the maturation of miRNAs. Aberrant Dicer expression may contribute to tumor progression, clinical aggressiveness, and poor prognosis in various tumors. Dicer inhibition led to a reduction in DTIC sensitivity and an augmentation in stemness in melanoma cells. Clinical analyses indicated a low Dicer expression level as a predictor of poor prognosis factor. Metabolic alterations in tumor cells may interfere with drug response. Adenylosuccinate lyase (ADSL) is a crucial enzyme in the purine metabolism pathway. An imbalance in ADSL may interfere with the therapeutic efficacy of drugs. We discovered that DTIC treatment enhanced ADSL expression and that Dicer silencing significantly reduced ADSL expression in melanoma cells. Furthermore, ADSL overexpression reversed Dicer silencing induced DTIC resistance and cancer stemness. These findings indicate that Dicer-mediated ADSL regulation influences DTIC sensitivity and stemness in melanoma cells.

Effectiveness and Safety of Immunosuppressants and Biological Therapy for Chronic Spontaneous Urticaria: A Network Meta-Analysis.

Chronic spontaneous urticaria (CSU) is the most common phenotype of chronic urticaria. We compared treatment effects and safety profiles of the medications in patients with CSU. We searched PubMed, MEDLINE, and Web of Science for randomized control trials (RCTs), from 1 January 2000 to 31 July 2021, which evaluated omalizumab and immunosuppressants. Network meta-analyses (NMAs) were performed with a frequentist approach. Outcome assessments considered the efficacy (Dermatology Life Quality Index (DLQI) and weekly urticaria activity score (UAS7)) and tolerability profiles with evaluations of study quality, inconsistencies, and heterogeneity. We identified 14 studies which we included in our direct and indirect quantitative analyses. Omalizumab demonstrated better efficacy in DLQI and UAS7 outcomes compared to a placebo, and UAS7 assessments also demonstrated better outcomes compared to cyclosporine. Alongside this, omalizumab demonstrated relatively lower incidences of safety concerns compared to the other immunosuppressants. Cyclosporin was also associated with higher odds of adverse events than other treatment options. Our findings indicate that omalizumab resulted in greater improvements in terms of the DLQI and UAS7 with good tolerability in CSU patients compared to the other immunosuppressants.

Laser-assisted nanoparticle delivery to promote skin absorption and penetration depth of retinoic acid with the aim for treating photoaging.

Retinoic acid (RA) is an approved treatment for skin photoaging induced by ultraviolet (UVA). Topically applied RA is mainly located in the stratum corneum (SC) with limited diffusion into the deeper strata. A delivery system capable of facilitating dermal delivery and cellular internalization for RA is critical for a successful photoaging therapy. Two delivery approaches, namely nanoparticles and laser ablation, were combined to improve RA's absorption efficacy and safety. The nanoparticle absorption enhancement by the lasers was compared between full-ablative (Er:YAG) and fractional (CO2) modalities. We fabricated poly-L-lactic acid (PLA) and PLA/poly(lactic-co-glycolic acid) (PLGA) nanoparticles by an emulsion-solvent evaporation technique. The mean size of PLA and PLA/PLGA nanocarriers was 237 and 222 nm, respectively. The RA encapsulation percentage in both nanosystems was > 96 %. PLA and PLA/PLGA nanocarriers promoted RA skin deposition by 5- and 3-fold compared to free control. The ablative lasers further enhanced the skin deposition of RA-loaded nanoparticles, with the full-ablative laser showing greater permeation enhancement than the fractional mode. The skin biodistribution assay evaluated by confocal and fluorescence microscopies demonstrated that the laser-assisted nanoparticle delivery achieved a significant dermis and follicular accumulation. The cell-based study indicated a facile uptake of the nanoparticles into the human dermal fibroblasts. The nanoparticulate RA increased type I collagen and elastin production in the UVA-treated fibroblasts. A reduction of matrix metalloproteinase (MMP)-1 was also highlighted in the photoaging cells. The calculation of therapeutic index (TI) by multiplying collagen/elastin elevation percentage and skin deposition predicted better anti-photoaging performance in Er:YAG laser-assisted nanoparticle delivery than CO2 laser. Nanoencapsulation of RA decreased the cytotoxicity against skin fibroblasts. In vivo skin tolerance test on a nude mouse showed less skin damage after topical application of the nanoparticles than free RA. Our results hypothesized that the laser-mediated nanoparticle delivery provided an efficient and safe use for treating photoaging.

Laser-assisted nanocarrier delivery to achieve cutaneous siRNA targeting for attenuating psoriasiform dermatitis.

Psoriasis is an autoimmune skin disorder presenting the excessive expression of interleukin (IL)-6. The topical use of small interfering RNA (siRNA) has been increasingly discovered for treating skin diseases. A delivery system capable of protecting siRNA while facilitating both skin targeting and cellular entrance is critical for the successful medication of topically-applied siRNA. Herein, we developed a delivery system for siRNA based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles and combined this system with an ablative laser to promote skin absorption for topical psoriasis therapy. The siRNA absorption enhancement was compared by two laser modalities: a fractional CO2 laser and a fully-ablative Er:YAG laser. We characterized the effect of the delivery system by the cellular uptake, IL-6 silencing, in vitro skin absorption, cutaneous biodistribution, and in vivo psoriasiform dermatitis in mice. The nanocarriers showed minimal cytotoxicity and facile cellular uptake to knock down the IL-6 expression. The nanoformulation containing a cationic surfactant (Forestall) for ion pairing with siRNA achieved a 66% and 77% IL-6 knockdown efficiency toward keratinocytes and macrophages, respectively. In the Franz cell absorption, the lasers increased the naked siRNA penetration to the receptor compartment by 3.7-5.0-fold but remarkably reduced skin deposition using imiquimod (IMQ)-treated psoriasiform skin as the barrier. The fractional laser facilitated nanoparticle-associated siRNA skin deposition up to 3.3-fold, whereas the transport of the nanocarriers to the receptor was negligible. Qualitatively, the lasers increased nanoparticle delivery in the epidermis with limited effect to elevate the penetration depth. The fractional-mediated nanocarrier delivery dramatically attenuated the erythema and scaly lesions of psoriasiform dermatitis. The histological examination displayed a reduction of epidermal hyperplasia and macrophage infiltration by the combination of laser and nanosystem. The passive and laser-assisted naked siRNA delivery was less effective in mitigating dermatitis. The topical delivery of fractional laser-assisted nanoparticles on mice resulted in a 56% IL-6 knockdown. Our results manifested the benefit of cutaneous siRNA targeting using ablative lasers to deliver nanocarriers for treating psoriatic inflammation.

Cutaneous Delivery of Cosmeceutical Peptides Enhanced by Picosecond- and Nanosecond-Domain Nd:YAG Lasers with Quick Recovery of the Skin Barrier Function: Comparison with Microsecond-Domain Ablative Lasers.

Picosecond or nanosecond-domain non-ablative lasers generate faster photothermal effects and cause less injury than microsecond lasers. In this study, we investigated the enhancing effect of 1064 nm picosecond- and nanosecond-domain neodymium (Nd):yttrium-aluminum-garnet (YAG) lasers on the cutaneous delivery of cosmeceutical peptides. Microsecond-domain fractional ablative CO2 and fully ablative erbium (Er):YAG lasers were also used for comparison. In the Franz diffusion cell study, pig or mouse skin was treated with a laser before exposure to palmitoyl tripeptide (PT)-1, PT-38, and copper tripeptide (CT)-1 at a concentration of 150 µM. Psoriasiform, atopic dermatitis (AD)-like, and photoaged skins were also developed as permeation barriers. The non-ablative laser elicited the ultrastructural disruption of the stratum corneum and epidermal vacuolation. All laser modalities significantly increased the skin permeation of peptides in vitro. The non-ablative laser chiefly enhanced peptide delivery to the receptor compartment, whereas the ablative laser mainly increased the intracutaneous peptide deposition. The picosecond- and nanosecond-domain Nd:YAG lasers elevated the amount of PT-1 in the receptor up to 40- and 22-fold compared with untreated skin, respectively. Laser treatment promoted peptide delivery in barrier-deficient and inflamed skins, although this enhancement effect was less than that observed in healthy skin. Fluorescence microscopy indicated the capability of the non-ablative laser to deliver peptides to deeper skin strata. The ablative laser confined the peptide distribution in the epidermis. Confocal microscopy showed that peptides penetrated the skin along the microdots created by the fractional Nd:YAG and CO2 lasers. The skin barrier function determined by transepidermal water loss suggested quick recovery when using a nanosecond-domain laser (within 4 h). A longer period was needed for the skin treated with the fully ablative Er:YAG laser (76-84 h). Nanosecond non-ablative laser-facilitated peptide delivery may become an efficient and safe approach for cosmeceutical applications.

Vitiligo: An Autoimmune Skin Disease and its Immunomodulatory Therapeutic Intervention.

Vitiligo is a chronic autoimmune depigmenting skin disorder characterized by patches of the skin losing functional melanocytes. Multiple combinatorial factors are involved in disease development, among which immune T cells play a prominent role. The immune cells implicated in melanocyte destruction through adaptive immunity include CD8+ cytotoxic T cells and regulatory T cells, and aberrantly activated skin-resident memory T cells also play a role in melanocyte destruction. Over the past several years, major progress in understanding vitiligo pathogenesis has led to the development of targeted therapies. Janus kinase (JAK) inhibitors, which share the similar mechanism that autoactivates CD8+ T cells in chronic inflammatory diseases, have been reported to have therapeutic significance in vitiligo. Recently, immunomodulatory therapeutic interventions in vitiligo have been emerging. Mesenchymal stem cells (MSCs) regulate cytokine secretion and the balance of T-cell subsets, which makes them a promising cell-based treatment option for autoimmune diseases. The induction of MSC-mediated immunomodulation is complicated and occurs by contact-dependent mechanisms and soluble extracellular vesicle (EV) mediators. EVs released from MSCs contain various growth factors and cytokines with anti-inflammatory effects in the skin immune response. Here, we summarize and discuss the progress to date in targeted therapies that immunomodulate the niche environment of vitiligo, from the clinical trial of JAK inhibitors to the potential of MSCs and MSC-EVs. The available information was collected to highlight the need for further research into the treatment of vitiligo.

Activation of Deoxyribonuclease I by Nicotinamide as a New Strategy to Attenuate Tetracycline-Resistant Biofilms of Cutibacterium acnes.

Biofilms of Cutibacterium (C.) acnes (formerly Propionibacterium acnes) are responsible for the persistence and antibiotic resistance of acne vulgaris. In addition to the standard treatments for acne vulgaris, a common adjunctive treatment is the topical administration of nicotinamide (NAM). However, the effects of NAM on biofilms of C. acnes have never been explored. This study comprehensively investigates the effects of NAM against biofilms of C. acnes using in vitro and in vivo approaches. The results showed that NAM potentiated the efficacy of suboptimal dosing of tetracycline against C. acnes. Moreover, NAM alone decreased the formation and increased the degradation of biofilms in C. acnes. The antibiofilm effect of NAM against C. acnes was further enhanced in combination with deoxyribonuclease (DNase) I, an enzyme with known antibiofilm properties. The computational molecular docking, surface plasmon resonance analysis, and enzymatic kinetic assay demonstrated that NAM binds to DNase I and accelerated its reaction. In conclusion, NAM activates DNase I to attenuate biofilms of C. acnes. This offers valuable insights into the strategies against biofilms that are worth elaborating on in other biofilm-related chronic cutaneous infections in the future.

Low-fluence laser-facilitated platelet-rich plasma permeation for treating MRSA-infected wound and photoaging of the skin.

Platelet-rich plasma (PRP) is rich in cytokines and growth factors and is a novel approach for tissue regeneration. It can be used for skin rejuvenation but the large molecular size of the actives limits its topical application. In this study, low-fluence laser-facilitated PRP was delivered to evaluate its effect on absorption through the skin, infection-induced wound, and photoaging. The PRP permeation enhancement was compared for two ablative lasers: fractional (CO2) laser and fully-ablative (Er:YAG) laser. In the Franz cell experiment, pig skin was treated with lasers with superficial ablation followed by the application of recombinant cytokines, growth factors, or PRP. The transport of interferon (IFN)-γ and tumor necrosis factor (TNF)-α was negligible in intact skin and stratum corneum (SC)-stripped skin. Both lasers significantly elevated skin deposition of IFN-γ and TNF-α from PRP, and fully-ablative laser showed a higher penetration enhancement. A similar tendency was found for vascular endothelial growth factor and epidermal growth factor. Er:YAG laser-exposed skin displayed 1.8- and 3.9-fold higher skin deposition of platelet-derived growth factor (PDGF)-BB and transforming growth factor (TGF)-ß1 from PRP, respectively. According to the confocal images, both laser interventions led to an extensive and deep distribution of IFN-γ and PDGF-BB in the skin. In the in vivo methicillin-resistant Staphylococcus aureus (MRSA) infection model, CO2 laser- and Er:YAG laser-assisted PRP delivery reduced bacterial load from 1.8 × 106 to 5.9 × 105 and 1.4 × 104 colony-forming units, respectively. The open wound induced by MRSA was closed by the laser-assisted PRP penetration. In the mouse photoaging model, elastin and collagen deposition were fully restored by combined PRP and full-ablative laser but not by PRP alone and PRP combined with fractional laser. Laser-facilitated PRP delivery even with a low fluence setting can be considered a promising strategy for treating some dermatological disorders.

Recommendations for psoriatic arthritis management: A joint position paper of the Taiwan Rheumatology Association and the Taiwanese Association for Psoriasis and Skin Immunology.

In Taiwan, the incidence and prevalence of psoriatic arthritis (PsA) have risen significantly in recent years. Moreover, data from the Taiwan National Health Insurance Research Database (NHIRD) show that more than 85% of PsA patients are treated with just non-steroidal anti-inflammatory drugs (NSAIDs) and/or conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs). Taiwanese clinicians have also expressed concerns regarding uncertainties in the diagnosis of PsA and the delayed, interrupted, and/or tapered use of biologics, as well as differences in therapeutic preferences between and within dermatologists and rheumatologists. To address these issues, the Taiwan Rheumatology Association and the Taiwanese Association for Psoriasis and Skin Immunology jointly convened a committee of 28 clinicians from the fields of rheumatology, dermatology, orthopedics, and rehabilitation, to develop evidence-based consensus recommendations for the practical management of PsA in Taiwan. A total of six overarching principles and 13 recommendations were developed and approved, as well as a treatment algorithm with four separate tracks for axial PsA, peripheral PsA, enthesitis, and dactylitis. Psoriasis (PsO) management was not discussed here, as the Taiwanese Dermatological Association has recently published a comprehensive consensus statement on the management of PsO. Together, these recommendations provide an up-to-date, evidence-based framework for PsA care in Taiwan.

Durvalumab-induced de novo annular psoriasiform drug eruption successfully treated with a combination of narrowband ultraviolet B phototherapy and topical treatment.

Immune checkpoint inhibitors, including anti-programmed death 1 and anti-programmed death ligand 1, have become prominent treatment options for various types of cancers. However, immune checkpoint inhibitors are associated with various cutaneous adverse events, one of which is psoriasiform drug eruption. Some cases of psoriasiform drug eruption can only be controlled through the cessation of immune checkpoint inhibitors and administration of systemic immunosuppressants, such as corticosteroids and methotrexate. However, no clear guideline is available on the management of this specific rash, and the use of systemic immunosuppressants is contraindicated in selected conditions. In this article, we report a case of annular psoriasiform drug eruption induced by an anti-programmed death ligand 1 monoclonal antibody, durvalumab. The patient responded well to the combination of phototherapy and topical treatment, which allowed continuation of durvalumab treatment without concomitant systemic immunosuppressants in a 2-year follow up.

Fractional Laser-Mediated siRNA Delivery for Mitigating Psoriasis-like Lesions via IL-6 Silencing.

The poor permeability of topically applied macromolecules such as small interfering RNA (siRNA) has inhibited the translation to clinical application. In this study, the fractional CO2 laser-assisted approach was developed to describe siRNA permeation enhancement mediated by the created microchannels for silencing the gene to treat psoriasiform lesions. In vitro permeation using Franz cell and in vivo interleukin (IL)-6 silencing using psoriasis-like plaque in mice were evaluated to verify the impact of the laser irradiation. Low-fluence laser exposure enabled a significant increase in skin transport of siRNA, peptide, and 5-fluorouracil (5-FU). The laser treatment resulted in the enhancement of siRNA flux by 33- and 14-fold as compared to the control in nude mouse and pig skin, respectively. The laser exposure also promoted siRNA penetration across psoriatic and photoaging skins with the deficient barrier, although the enhancement level was minor compared to that of intact skin. The 3D images of confocal microscopy revealed a diffusion of macromolecules into the laser-created microchannels; the radial and vertical distribution to the surrounding and deep tissues followed this. A single laser treatment and the following topical siRNA administration were able to reduce IL-6 expression by 64% in the psoriatic skin model. Laser assistance led to the marked improvement in the plaque and the reduction of specific cytokine expression, keratinocyte proliferation, and neutrophil infiltration. Our data support the use of the fractional laser for delivery of functional nucleic acid into the skin and the target cells.

The α9 Nicotinic Acetylcholine Receptor Mediates Nicotine-Induced PD-L1 Expression and Regulates Melanoma Cell Proliferation and Migration.

Cigarette smoking is associated with an increased risk of melanoma metastasis. Smokers show higher PD-L1 expression and better responses to PD-1/PD-L1 inhibitors than nonsmokers. Here, we investigate whether nicotine, a primary constituent of tobacco, induces PD-L1 expression and promotes melanoma cell proliferation and migration, which is mediated by the α9 nicotinic acetylcholine receptor (α9-nAChR). α9-nAChR overexpression in melanoma using melanoma cell lines, human melanoma tissues, and assessment of publicly available databases. α9-nAChR expression was significantly correlated with PD-L1 expression, clinical stage, lymph node status, and overall survival (OS). Overexpressing or knocking down α9-nAChR in melanoma cells up- or downregulated PD-L1 expression, respectively, and affected melanoma cell proliferation and migration. Nicotine-induced α9-nAChR activity promoted melanoma cell proliferation through stimulation of the α9-nAChR-mediated AKT and ERK signaling pathways. In addition, nicotine-induced α9-nAchR activity promoted melanoma cell migration via activation of epithelial-mesenchymal transition (EMT). Moreover, PD-L1 expression was upregulated in melanoma cells after nicotine treatment via the transcription factor STAT3 binding to the PD-L1 promoter. These results highlight that nicotine-induced α9-nAChR activity promotes melanoma cell proliferation, migration, and PD-L1 upregulation. This study may reveal important insights into the mechanisms underlying nicotine-induced melanoma growth and metastasis through α9-nAChR-mediated carcinogenic signals and PD-L1 expression.

Post-irradiation recovery time strongly influences fractional laser-facilitated skin absorption.

Fractional CO2 laser treatment has been used in some clinical trials to promote topical drug delivery. Currently, there is no standard for laser settings to achieve a feasible therapy. The cutaneous recovery following laser treatment and its influence on drug absorption have not been well explored. This study evaluated the kinetics of laser-treated skin-barrier restoration and drug permeation in nude mice. The skin recovery and observation of the process were characterized by transdermal water loss (TEWL), erythema measurement, gross appearance, optical microscopy, and scanning electron microscopy (SEM). The skin absorption of a lipophilic small permeant (tretinoin), a hydrophilic small permeant (acyclovir), and a large molecule (fluorescein isothiocyanate dextran 4 kDa, FD4) was examined in vitro using Franz cell. TEWL suggested that the laser-treated skin restored its barrier function at 16 h after irradiation. The fractional laser produced microchannels of about 150 µm in diameter and 25 µm in depth that were surrounded with thermal coagulation. The bright-field imaging indicated that the micropores were progressively closed during the recovery period but had not completely closed even after a 16-h recovery. The laser treatment led to a rapid tretinoin penetration across the skin immediately after irradiation, with a 5-fold enhancement compared to intact skin. This enhancement was gradually reduced following the increase of recovery time. Conversely, the acyclovir and FD4 permeation peaked at 1-2 h post-irradiation. The FD4 flux was even elevated as the recovery time increased. The reasons for this could have been the subsequent inflammation after laser exposure and the deficient tight junction (TJ) barrier. The confocal imaging demonstrated the perpendicular diffusion of rhodamine B and FD4 through microchannels immediately after laser exposure. The lateral diffusion from the microchannels was observed at 2 h post-irradiation. Our results revealed a time-dependent recovery of skin permeation. The time frame for applying the drugs after laser irradiation was dependent upon the permeants and their various physicochemical properties.

Folic acid inhibits colorectal cancer cell migration.

We recently showed that folic acid (FA) could decrease the proliferation rate of colorectal cancer cells in vitro and reduce the volume of COLO-205 tumor in vivo. Since cancer cell proliferation and migration are two major events during cancer development, we further examined whether FA could also affect the migration of colorectal cancer cells. Transwell invasion assays demonstrated that FA reduced the invasion ability of colorectal cancer cell lines, COLO-205, LoVo and HT-29. Using COLO-205 as a cell model, we further delineated the molecular mechanism underlying FA-inhibited colorectal cancer cell invasion. Western blot analyses showed that FA (10 µM) activated cSrc, ERK1/2, NFκB, and p27 at serine 10 (Ser10), and up-regulated p53, p27, and KIS protein. Subcellular fractionation illustrated that FA treatment increased cytosolic translocation of p27, formation of the p27-RhoA complex, and RhoA degradation. The FA-induced migration inhibition in COLO-205 was abolished by blockade of the cSrc or ERK1/2 activity, knockdown of p27 or KIS using the siRNA technique, or over-expression of a constitutive active RhoA cDNA. Our results suggest that FA up-regulated p27 through increasing the cSrc/ERK1/2/NFκB/p53-mediated pathway. In the nucleus, FA up-regulated KIS, which in turn increased p27 phosphorylation at serine 10 (Ser10), subsequently resulting in cytosolic translocation of p27 and forming the p27-RhoA complex, thereby causing RhoA degradation, and eventually inhibited COLO-205 cell migration. Together with our previous findings suggest that FA reduced colorectal cancer development through inhibiting colorectal cancer cell proliferation and migration.

Hypoxia Stimulates the Epithelial-to-Mesenchymal Transition in Lung Cancer Cells Through Accumulation of Nuclear ß-Catenin.

BACKGROUND/AIM: Recent studies implied a significant role of hypoxia-inducible factor-1α (HIF1α) in cell transformation. This study aimed to assess the effects of HIF1α on the epithelial-to-mesenchymal transition (EMT) and tumorigenesis of lung adenocarcinoma cells. MATERIALS AND METHODS: Invasion, migration and colony formation assays were used to evaluate cell transformation. Expression of EMT-related markers were analyzed by western blot, reverse-transcription polymerase chain reaction or zymography. A luciferase assay was carried out to access the transcriptional activity of ß-catenin. RESULTS: Hypoxia enhanced migration, invasion and transformation of A549 lung adenocarcinoma cells. Hypoxic stimulation promoted the expression of EMT-related markers in lung cancer cells. The expression of HIF1α was found to be involved in hypoxia-mediated modulation of expression of snail family transcriptional repressors 1 (SNAI1) and 2 (SLUG). Hypoxia enhanced nuclear accumulation and transcriptional activity of ß-catenin. CONCLUSION: ß-Catenin promotes expression of EMT-related genes and eventually contributes to the metastatic process.

Nilotinib induction of melanogenesis via reactive oxygen species-dependent JNK activation in B16F0 mouse melanoma cells.

Nilotinib (AMN), a second-generation tyrosine kinase inhibitor, induces apoptosis in various cancer cells, and our recent study showed that AMN effectively reduced the viability of human ovarian cancer cells via mitochondrion-dependent apoptosis. The effect of AMN in the melanogenesis of melanoma cells is still unclear. In the present study, we found that the addition of AMN but not imatinib (STI) significantly increased the darkness of B16F0 melanoma cells, and the absorptive value increased with the concentration of AMN. A decrease in the viability of B16F0 cells by AMN was detected in a concentration-dependent manner, accompanied by increased DNA ladders, hypodiploid cells and cleavage of the caspase-3 protein. An in vitro tyrosinase (TYR) activity assay showed that increased TYR activity by AMN was detected in a concentration-dependent manner; however, induction of TYR activity by STI at a concentration of 40 µmol/L was observed. Increased intracellular peroxide by AMN was detected in B16F0 cells, and application of the antioxidant, N-acetylcysteine (NAC), significantly reduced AMN-induced peroxide production which also reduced the darkness of B16F0 cells. Additionally, AMN induced c-Jun N-terminal kinase (JNK) protein phosphorylation in B16F0 cells, which was inhibited by the addition of NAC. AMN-induced melanogenesis of B16F0 cells was significantly inhibited by the addition of NAC and the JNK inhibitor, SP600125 (SP). Data of Western blotting showed that increased protein levels of melanogenesis-related enzymes of tyrosinase-related protein-1 (TRP1), TRP2 and TYR were observed in AMN-treated B16F0 cells which were inhibited by the addition of NAC and SP. Evidence is provided supporting AMN effectively inducing the melanogenesis of B16F0 melanoma cells via reactive oxygen species-dependent JNK activation.

Is the Fractional Laser Still Effective in Assisting Cutaneous Macromolecule Delivery in Barrier-Deficient Skin? Psoriasis and Atopic Dermatitis as the Disease Models.

PURPOSE: Most of the investigations into laser-assisted skin permeation have used the intact skin as the permeation barrier. Whether the laser is effective in improving cutaneous delivery via barrier-defective skin is still unclear. METHODS: In this study, ablative (Er:YAG) and non-ablative (Er:glass) lasers were examined for the penetration of peptide and siRNA upon topical application on in vitro skin with a healthy or disrupted barrier. RESULTS: An enhanced peptide flux (6.9 fold) was detected after tape stripping of the pig stratum corneum (SC). A further increase of flux to 11.7 fold was obtained after Er:YAG laser irradiation of the SC-stripped skin. However, the application of Er:glass modality did not further raise the flux via the SC-stripped skin. A similar trend was observed in the case of psoriasiform skin. Conversely, the flux was enhanced 3.7 and 2.6 fold after treatment with the Er:YAG and the Er:glass laser on the atopic dermatitis (AD)-like skin. The 3-D skin structure captured by confocal microscopy proved the distribution of peptide and siRNA through the microchannels and into the surrounding tissue. CONCLUSIONS: The fractional laser was valid for ameliorating macromolecule permeation into barrier-disrupted skin although the enhancement level was lower than that of normal skin.

Utility of Gram staining for diagnosis of Malassezia folliculitis.

Malassezia folliculitis (MalF) mimics acne vulgaris and bacterial folliculitis in clinical presentations. The role of Gram staining in rapid diagnosis of MalF has not been well studied. In our study, 32 patients were included to investigate the utility of Gram staining for MalF diagnosis. The final diagnoses of MalF were determined according to clinical presentation, pathological result and treatment response to antifungal agents. Our results show that the sensitivity and specificity of Gram staining are 84.6% and 100%, respectively. In conclusion, Gram staining is a rapid, non-invasive, sensitive and specific method for MalF diagnosis.