Narrow-band ultraviolet-B stimulates proliferation and migration of cultured melanocytes

Bridging Molecular Mechanism and Clinical Practice in Vitiligo Treatment: An Updated Review

BACKGROUND

Treatment of vitiligo seeks to achieve three goals: cessation of disease progression, regeneration of pigmentation, and prevention of recurrence.

SUMMARY

Number of nonsurgical interventions are available that suppress the autoimmune response and regenerate the melanocytes from the reservoir: phototherapy including psoralen and ultraviolet A, narrowband ultraviolet B, and 308-nm excimer and 311-nm Titanium:Sapphire lasers; topical agents including topical calcineurin inhibitors, topical corticosteroids, and topical 5-fluorouracil; and systemic agents including corticosteorids, mycophenolate mofetil, cyclosporine, methotrexate, minocycline, afamelanotide, and antioxidants. In recent years, a great advance has been made in the understanding of pathogenesis of vitiligo, and JAK inhibitors are being investigated as a new treatment. Minimally invasive procedures such as fractional lasers or microneedling can help achieve the optimal treatment outcome when used properly.

KEY MESSAGES

Our review describes various treatment modalities for vitiligo based on their molecular mechanism of action. Bridging the gap between molecular mechanisms and therapeutic options would be a valuable reference for physicians in clinical practice.

Comparison of NB-UVB combination therapy regimens for vitiligo: A systematic review and network meta-analysis

BACKGROUND

Vitiligo was an autoimmune disease and some guidelines for the management of vitiligo encouraged the use of NB-UVB combination therapies to enhance repigmentation.

OBJECTIVES

To compare the effectiveness of current NB-UVB combination regimen at the improvement in repigmentation through a systematic review and network meta-analysis.

METHODS

We searched the electronic databases for randomized controlled trials related to NB-UVB combination therapy for vitiligo till October 2022. STATA15.0 software was applied to carrying out data analysis.

RESULTS

A total of 28 eligible studies involving 1194 participants were enrolled in the analysis. The NMA results revealed that compared with NB-UVB, carboxytherapy [OR = 32.35, 95% CI (1.79, 586.05)], Er: YAG laser+ topical 5% 5-FU [OR = 10.74, 95% CI (4.05, 28.49)], needling/micro-needling [OR = 3.42, 95% CI (1.18, 9.88)], betamethasone intramuscular injection [OR = 3.08, 95% CI (1.17, 8.13)], topical tacrolimus [OR = 2.54, 95% CI (1.30, 4.94)], and oral Chinese herbal medicine compound [OR = 2.51, 95% CI (1.40, 4.50)] integrated with NB-UVB were more efficacious in excellent to complete repigmentation response rate (≥75%). Besides, NB-UVB+ Er: YAG laser+ topical 5% 5-FU [OR = 0.17, 95% CI (0.04, 0.67)] and NB-UVB+ needling/micro-needling [OR = 0.24, 95% CI (0.06, 0.88)] were less likely evaluated as ineffective repigmentation response (≤25%).

CONCLUSIONS

All combination therapies ranked higher than NB-UVB monotherapy in inducing successful repigmentation and avoiding failed treatment in patients with vitiligo. Comprehensive consideration, NB-UVB+ Er: YAG laser+ topical 5% 5-FU and NB-UVB+ needling/microneedling would be the preferred therapeutic approaches.

An overview of the efficacy of phototherapy in oncodermatology

BACKGROUND

Cutaneous adverse events (AEs) following cancer immunotherapy, targeted therapy, and chemotherapy have been well-documented in the literature. A number of case reports have identified phototherapy, a form of light therapy that mimics sunlight exposure, as a noninvasive treatment modality for these cutaneous toxicities. By inducing local suppression of the immune system, phototherapy is a skin-directed treatment with minimal effect on tumor response. Phototherapy may therefore be a viable treatment option for cutaneous AEs from cancer therapies.

METHODS

We reviewed the literature for patients treated with phototherapy for cutaneous AEs following cancer immunotherapy, targeted therapy, or chemotherapy. We also included three previously unpublished cases from our own institution.

RESULTS

We identified 24 patients (80% male, mean age 67 years, range 49-75 years). Patients received the following phototherapy types: NB-UVB (n = 17), PUVA (n = 6), or PDT (n = 1). A topical steroid was used in conjunction with phototherapy in seven patients. At phototherapy onset, cancer treatment was either continued, temporarily discontinued, or discontinued (n = 9, 6, 7, respectively; in two cases, the cancer treatment course was unknown). Improvement of cutaneous AEs was observed in 96% of patients.

CONCLUSIONS

Phototherapy resulted in full or partial improvement in all but one patient. A topical steroid was used in nearly a third of patients, suggesting some oncodermatologists co-administer topicals to further boost response. Continuation of cancer therapy in the majority of patients highlights an additional advantage of phototherapy. We believe phototherapy may be an effective adjunctive treatment to topical steroids when treating these cutaneous toxicities.

The clinical and pathological effectiveness of microneedling and topical 5-fluorouracil in vitiligo treatment: An association with matrix metalloproteinase 2 immunohistochemical expression

BACKGROUND

The current therapies for vitiligo require long duration with often disappointing outcomes. 5-Fluorouracil (5-FU) is a chemotherapeutic agent approved for topical use in the treatment of several dermatologic conditions. Matrix metalloproteinase 2 (MMP2) is synthesized by keratinocytes during the epidermal remodeling process and has been found to help in melanocyte migration.

AIM

To investigate the efficacy and safety of flexible microneedling followed by application of 5-FU in vitiligo treatment and to evaluate the immunohistochemical expression of MMP2 in involved skin in vitiligo patients before and after treatment.

METHODS

Twenty patients presented with vitiligo were planned to receive one session every 2 weeks for 12 weeks of microneedling followed by 5-FU application. Clinical response to therapy was evaluated by VASI score. Pre- and post-treatment biopsies were taken from vitiliginous patches for MMP2 immunostaining.

RESULTS

Fifteen patients (75%) responded to therapy with observed side effects such as pain, erythema, and hyperpigmentation of margins. The clinical response was more in young patients and those who have short disease duration. MMP2 was significantly increased in post-treatment biopsy compared with the pretreatment one.

CONCLUSIONS

5-Fluorouracil application after microneedling is effective in the treatment of vitiligo with 75% response, 60% patient satisfaction, and tolerable side effects. The improvement in vitiligo patients by microneedling and 5-fluorouracil could be due to upregulation of MMP2 in affected vitiligo specimens.

Topical Band-pass Filter Cream (TBFC)-assisted home-based NB-UVB: A must-know Alternative to artificial phototherapy

BACKGROUND

Treatment-refractory lesions of vitiligo and psoriasis are typically associated with significant psychological morbidity. Although narrowband-ultraviolet B (NB-UVB) phototherapy remains one of the safest and effective treatment modalities, the cost and logistics related to the access and high cost of therapy delivered artificially via devices/chambers become highly restrictive. The use of topical Photocil®, a novel topical band-pass filter cream (TBFC), that selectively filters solar radiation, biasing toward delivery of 311-313 nm (action spectrum of NB-UVB) to the treated lesions, following the exposure of TBFC-smeared lesions to natural sunlight offsets many aforementioned limitations of artificial phototherapy. The non-inferior efficacy of Photocil® as an alternative to artificial NB-UVB has recently been reported in patients with lighter skin phototypes (SPT) with non-segmental vitiligo and psoriasis.

OBJECTIVES

To demonstrate the high efficacy-cum-safety of the novel approach in repigmenting treatment-refractory segmental vitiligo (SV) in an adult man with SPT-V and discuss the essentials of successful administration of NB-UVB using this approach.

METHODS

The baseline clinical details and therapeutic outcome of 12-week protocol of TBFC-assisted NB-UVB (with details of step-by-step administration including precautions) in SV of the aforementioned patient are discussed.

RESULTS

Up to 75% repigmentation without any remarkable adverse effects was noted with persistent efficacy over the next 12 weeks.

CONCLUSION

The device-free home-based TBFC-assisted NB-UVB delivery using natural sunlight offers a viable, convenient, and cost-effective alternative to artificial phototherapy for successful treatment of vitiligo; with its utility proven even in SV that too in individual(s) with darker SPT.

Updates and new medical treatments for vitiligo (Review)

Vitiligo is a multifactorial disease characterized by the loss of skin pigment, which results in achromic macules and patches. There are currently several medical treatments available, which aim to arrest progression and induce skin repigmentation. These treatments alone or combined have exhibited varying degrees of pigmentation, and the majority are safe and effective. All therapies for vitiligo are limited, and no known treatment can consistently produce repigmentation in all patients. Individualized treatment is appropriate according to the location, clinical presentation and the presence of disease activity. The present review summarizes the medical treatments available for vitiligo: Systemic and topic pharmacological therapies, physical and depigmentation treatments. Several treatments are still underway and have not yet been approved. However, due to the promising preliminary results, these are also mentioned in the present review.

Stem Cell Therapy Offers a Possible Safe and Promising Alternative Approach for Treating Vitiligo: A Review

BACKGROUND

Normal skin pigmentation pattern is an extremely important component of the appearance of a person, as it can be a significant factor in the social context of any person. A condition known as vitiligo is caused by the death of melanocytes leading to pigmentation loss in the skin. This affects all races across the globe and sometimes leads to social avoidance as in some communities, it is stigmatized. Although there are different pathobiological processes suspected because of the different underlying causes of vitiligo, autoimmunity and oxidative stress are suspected to be the most probable ones.

OBJECTIVE

In this review, we present an overview of the underlying mechanisms causing and developing the disease. Also, some of the most successful treatments along with the clinical applications of Mesenchymal Stem Cells (MSCs) as a comprehensive approach for treating this condition will be covered.

RESULTS

Autoreactive CD8+ T-cells are the primary suspect considered to be responsible for the destruction of melanocytes. Therefore, topical use of autoimmune inhibitors including those derived from MSCs, thanks to their immune-modulatory properties, have been reported to be successful in the promotion of repigmentation. MSCs can suppress the proliferation of CD8+T via the NKG2D pathway while inducing T-cell apoptosis. The use of pharmacological agents for reducing cellular oxidative stress with the help of topical application of antioxidants and growth factors also have been in use. Intravenous administration of MSCs has been shown to regulate the level of reactive oxidative species (ROS) in a mice model. Growth factors derived from platelet-rich-plasma (PRP) or from MSCs caused rapid tissue regeneration.

CONCLUSIONS

Finally, MSC therapy also has been shown to stimulate the mobilization of healthy melanocytes, leading to successful repigmentation of skin lesions in vitiligo patients.

Monogenic Immune Diseases Provide Insights Into the Mechanisms and Treatment of Chronic Graft-Versus-Host Disease

Chronic graft-versus-host disease (GvHD) has become a leading cause of morbidity and mortality following allogeneic hematopoietic stem cell transplantation (HSCT) and can burden patients with devastating and lifelong health effects. Our understanding of the pathogenic mechanisms underlying chronic GvHD remains incomplete and this lack of understanding is reflected by lack of clear therapeutic approaches to steroid refractory disease. Observations predominantly from mouse models and human correlative studies currently support a three phase model for the initiation and development of chronic GvHD: 1) early inflammation and tissue damage triggers the innate immune system. This leads to inflammatory cytokine/chemokine patterns that recruit effector immune cell populations; 2) chronic inflammation causes the loss of central and peripheral tolerance mechanisms leading to emergence of pathogenic B and T cell populations that promote autoimmune and alloimmune reactions; 3) the dysregulated immunity causes altered macrophage polarization, aberrant tissue repair leading to scarring and end organ fibrosis. This model has led to the evaluation of many new therapies aimed at limiting inflammation, targeting dysregulated signaling pathways and restoring tolerance mechanisms. However, chronic GvHD is a multisystem disease with complex clinical phenotypes and it remains unclear as to which cluster of patients will respond best to specific therapeutic strategies. However, it is possible to gain novel insights from immune-related monogenic diseases. These diseases either share common clinical manifestations, replicate steps from the three phase chronic GvHD model or serve as surrogates for perfectly targeted drugs being investigated in chronic GvHD therapy. In this review, we will summarize the evidence from these monogenic immune related diseases that provide insight into pathogenic pathways in chronic GvHD, rationales for current therapies and novel directions for future drug discovery.

Soluble Pearl Extract provides effective skin lightening by antagonizing endothelin

BACKGROUND

Incidence of skin pigmentation disorders has been on the rise globally. This calls for safer and more effective topical skin lightening and freckle-removing products. In this study, we hypothesized that Soluble Pearl Extract (SPE) may possess endothelin antagonizing compounds with good skin whitening effects.

OBJECTIVES

(a) To determine the effect and mechanisms of SPE on ET-1-treated B16 melanoma cells. (b) To explore the cytotoxic effects of SPE on B16 melanoma cells.

METHODS

CCK-8 assay was performed to determine how SPE and ET-1 affect the proliferation rate of B16 melanoma cells, the NaOH lysis assay was conducted to quantify the content of melanin while the tyrosinase activity was determined by DOPA oxidation test. The mRNA and protein expression levels of TYR and TRP-1 were determined by qRT-PCR assay and Western blot assay, respectively.

RESULTS

We found that SPE at 0.1 and 1 μg/mL concentrations has no effect on the proliferation of the cells and 10 nmol/L ET-1 promoted B16 melanoma cells proliferation. Notably, B16 melanoma cells treated with 10 nmol/L ET-1 exhibited significantly higher melanin synthesis, tyrosinase activity, TYR, and TRP-1 mRNA expression levels compared with untreated cells. Of note, the effects of 10 nmol/L ET-1 treatment were abolished with SPE in a dose-dependent manner.

CONCLUSIONS

SPE inhibits endothelin thereby safely and effectively lightening lightens the skin by antagonizing endothelin. Moreover, SPE is safe and effective.

A deep dive into UV-based phototherapy: Mechanisms of action and emerging molecular targets in inflammation and cancer

UV-based phototherapy (including psoralen plus UVA (PUVA), UVB and UVA1) has a long, successful history in the management of numerous cutaneous disorders. Photoresponsive diseases are etiologically diverse, but most involve disturbances in local (and occasionally systemic) inflammatory cells and/or abnormalities in keratinocytes that trigger inflammation. UV-based phototherapy works by regulating the inflammatory component and inducing apoptosis of pathogenic cells. This results in a fascinating and complex network of simultaneous events-immediate transcriptional changes in keratinocytes, immune cells, and pigment cells; the emergence of apoptotic bodies; and the trafficking of antigen-presenting cells in skin-that quickly transform the microenvironment of UV-exposed skin. Molecular elements in this system of UV recognition and response include chromophores, metabolic byproducts, innate immune receptors, neurotransmitters and mediators such as chemokines and cytokines, antimicrobial peptides, and platelet activating factor (PAF) and PAF-like molecules that simultaneously shape the immunomodulatory effects of UV and their interplay with the microbiota of the skin and beyond. Phototherapy's key effects-proapoptotic, immunomodulatory, antipruritic, antifibrotic, propigmentary, and pro-prebiotic-promote clinical improvement in various skin diseases such as psoriasis, atopic dermatitis (AD), graft-versus-host disease (GvHD), vitiligo, scleroderma, and cutaneous T-cell lymphoma (CTCL) as well as prevention of polymorphic light eruption (PLE). As understanding of phototherapy improves, new therapies (UV- and non-UV-based) are being developed that will modify regulatory T-cells (Treg), interact with (resident) memory T-cells and /or utilize agonists and antagonists as well as antibodies targeting soluble molecules such as cytokines and chemokines, transcription factors, and a variety of membrane-associated receptors.

How It Works: The Immunology Underlying Phototherapy

Phototherapeutic modalities induce apoptosis of keratinocytes and immune cells, impact cytokine production, downregulate the IL-23/Th17 axis, and induce regulatory T cells. As in anti-IL-17 or anti-IL-23 antibody treatment, the dual action of phototherapy on skin and the immune system is likely responsible for sustained resolution of lesions in diseases such as psoriasis. In cutaneous T cell lymphoma, phototherapy may function by causing tumor cell apoptosis and eliminating the neoplastic and inflammatory infiltrate. Further research on phototherapeutic mechanisms will help advance, optimize, and refine dermatologic treatments and may open up novel avenues for treatment strategies in dermatology and beyond.

The effects of UVB irradiance on vitiligo phototherapy and UVB-induced photocarcinogenesis

Phototherapy is the most commonly used modality for repigmenting vitiligo. Currently, UVB emitting devices, including narrow-band UVB (NBUVB) and excimer laser/light, are considered as the treatment of choice. While emitting wavelengths at close proximity, excimer lights emit higher irradiance (HI; W/m² ) compared to NBUVB. Clinical reports have shown that excimer light is more efficacious in treating vitiligo compared to NBUVB, and we demonstrated that irradiance plays a critical role in promoting melanoblasts differentiation. UVB radiation from the sun is closely associated with photocarcinogenesis of the skin. Sunscreens were used to protect the skin by reducing UVB irradiance (low irradiance (LI) UVB). Sunscreen use was associated with skin cancer reduction in clinical trials. Paradoxically, sunscreen use was associated with increased sunburn episodes in the real-world settings. It was shown that UVB-induced sunburn depends on fluence (J/m² ) but not irradiance of UVB radiation. We investigated the significance of irradiance in the context of UVB-induced carcinogenesis of the skin. For mice receiving equivalent fluence of UVB exposure, the LIUVB-treated mice showed earlier tumor development, larger tumor burden, and more epidermal keratinocytes harboring mutant p53 as compared to their HIUVB-treated counterparts. These results suggested that at equivalent fluence, LIUVB radiation has more photocarcinogenic potential on the skin compared to its HI counterpart. Since development of sunburn with or without sunscreen use indicates that certain threshold of UVB fluence has been received by the skin at LI and HI, respectively, sunburn episodes with sunscreen use (LIUVB) are more damaging to the skin compared to that without sunscreen (HIUVB) application. In summary, since irradiance plays an important role determining the biological effects of UVB radiation on the skin, future related studies should take this critical parameter into consideration.

Phototherapy for Vitiligo

Vitiligo is a common disorder with a severe impact on quality of life. The authors review recent advances in phototherapy for vitiligo focusing on narrowband ultraviolet B including mechanisms, treatment recommendations, and combination therapies. Phototherapy is the first-line treatment of choice for vitiligo with narrowband UVB preferred for widespread vitiligo and excimer used for localized lesions. However, unfamiliarity with prescribing phototherapy may be limiting clinicians from using it to its full potential. This article provides clinicians with the critical information needed to safely and effectively provide phototherapy for their patients with vitiligo.

Home phototherapy for patients with vitiligo: challenges and solutions

Vitiligo is a chronic autoimmune condition involving selective dysfunction and destruction of melanocytes in the skin, hair, or both. The typical presentation is well-demarcated depigmented skin patches. Given vitiligo is the most common cause of depigmentation worldwide and early disease responds best to treatment, prompt diagnosis and proactive management of vitiligo are critical. While a wide variety of treatments has demonstrated variable effectiveness in treating vitiligo, phototherapy remains standard of care because of its proven efficacy and favorable side effect profile. However, many patients with vitiligo are unable to access affordable, consistent, or convenient phototherapy. To address these issues, home-based phototherapy has emerged as a patient-centered alternative. The purpose of this review is to discuss management of vitiligo with a specific focus on access to home-based phototherapy (HBPT) for patients with this condition. Key challenges to HBPT include misperceptions around safety and efficacy, inadequate physician education and training, insurance and financial barriers, and appropriate patient selection. Solutions to these challenges are presented, such as approaches to improve physician education and increasing the evidence surrounding the effectiveness and safety of this treatment for vitiligo. In addition, various practical considerations are discussed to guide dermatologists on how to approach HBPT as a treatment option for patients with vitiligo.

Platelet-rich plasma versus combined fractional carbon dioxide laser with platelet-rich plasma in the treatment of vitiligo: a comparative study

Purpose

The aim of this study was to assess the efficacy of platelet-rich plasma (PRP) vs combined fractional CO₂ (Fr: CO₂) laser with PRP in the treatment of stable nonsegmental vitiligo (NSV) lesions.

Patients and methods

This prospective, randomized, intrapatient, comparative controlled study was conducted between June 2014 and June 2016 at National Institute of Laser Enhanced Sciences (NILES), Cairo University, Cairo, Egypt. Thirty NSV patients were treated with PRP, Fr: CO₂ laser, and combined Fr: CO₂ laser with PRP. Intrapatient lesions were divide randomly into four groups. Each group was treated by one modality. The fourth group served as a control.Patients received six treatment sessions with 2-week interval for 3 months and were followed up after 3 months.

Results

A highly significant reduction was demonstrated through vitiligo analysis by computer-assisted grid (VACAG) in the combined Fr: CO₂ laser with PRP and in the PRP only groups than other groups. These results were confirmed by mean improvement score by physician (MISP) and by VAS with no statistical difference between them. The combined Fr: CO₂ laser with PRP group showed minimal side effects. Regardless of the modalities, better improvement was seen in the trunk than the face, extremities, and acral lesions with significant reduction in all regions. Face showed maximum response with combined Fr: CO₂ laser with PRP. Trunk showed higher response with PRP. Upper limbs showed highest response with combined Fr: CO₂ laser with PRP. Lower limbs showed the highest improvement with Fr: CO₂ laser.

Conclusion

According to our study, combined Fr: CO₂ laser with PRP achieved superior repigmentation than intradermal (ID) PRP. However, Fr: CO₂ alone showed poor improvement. Combined ablative Fr: CO₂ laser and PRP therapy followed by sun exposure could be used effectively and safely to treat refractory NSV.

Phenotypic and lipidomic characterization of primary human epidermal keratinocytes exposed to simulated solar UV radiation

BACKGROUND

Ultraviolet (UV) radiation is known to be one of the most important environmental hazards acting on the skin. The most part of UV radiation is absorbed in the epidermis, where keratinocytes are the most abundant and exposed cell type. Lipids have an important role in skin biology, not only for their important contribution to the maintenance of the permeability barrier but also for the production and storage of energy, membrane organization and cell signalling functions. However, the effects on the lipid composition of keratinocytes under UV radiation are little explored.

OBJECTIVE

The present work aims to explore the effects on the phenotype and lipid content of primary human keratinocytes exposed to simulated solar UV radiation.

METHODS

Keratinocytes were exposed to a single (acute exposure) and repeated simulated solar UV irradiations for 4 weeks (chronic exposure). Cell viability and morphology were explored, as well as the production of reactive oxygen species. Then, lipid extracts were analysed through liquid chromatography coupled to mass spectrometry (LC-MS) and the data generated was processed using the ROIMCR chemometric methodology together with partial least squares discriminant analysis (PLS-DA), to finally reveal the most relevant lipid changes that occurred in keratinocytes upon UV irradiation. Also, the potential induction of keratinocyte differentiation was explored by measuring the increase of involucrin.

RESULTS

Under acute irradiation, cell viability and morphology were not altered. However, a general increase of phosphatidylcholines (PC) phosphatidylethanolamines (PE) and phosphatidylglycerol (PG) together with a slight sphingomyelin (SM) decrease were found in UV irradiated cells, among other changes. In addition, keratinocyte cultures did not present any differentiation hallmark. Contrary to acute-irradiated cells, in chronic exposures, cell viability was reduced and keratinocytes presented an altered morphology. Also, hallmarks of differentiation, such as the increase of involucrin protein and the autophagy induction were detected. Among the main lipid changes that accompanied this phenotype, the increase of long-chain ceramides, lysoPC and glycerolipid species were found.

CONCLUSION

Important lipid changes were detected under acute and chronic UV irradiation. The lipid profile under chronic exposure may represent a lipid fingerprint of the keratinocyte differentiation phenotype.

The effects of phototherapy and melanocytes on keratinocytes

Phototherapy is widely used in the treatment of vitiligo. Previous studies have focused on the effects of ultraviolet (UV) radiation on melanocytes; however, the biological effects of phototherapy and melanocytes on keratinocytes remain to be elucidated. To investigate and assess the effects of clinically doses of broad band (BB)-UVA, narrow band (NB)-UVB and melanocytes on human keratinocytes in vitro, clinical doses of BB-UVA or NB-UVB radiation and human melanoma cell A375 co-culture were performed as stress divisors to HaCaT cells. Cell proliferation, expression of protease-activated receptor-2 (PAR-2) and nuclear factor E2-related factor 2 mRNA, lipid peroxidation and intracellular antioxidant level of keratinocytes were analyzed. It was demonstrated that UV radiation inhibited the proliferation of cells apart from following exposure to low dose (1 J/cm²) UVA. Medium dose (5 J/cm²) UVA radiation had no adverse effects on lipid peroxidation and increased antioxidant levels in HaCaT cells. Medium (200 mJ/cm²) and high (400 mJ/cm²) doses of UVB radiation induced cellular damage due to increased lipid peroxidation as indicated by levels of malondialdehyde. Furthermore, A375 co-culture treatment induced a similar effect on the lipid peroxidation of HaCaT as with low dose UVB radiation. Therefore, the results of the present study determined that clinical doses of BB-UVA and NB-UVB radiation had varying effects on proliferation and related protein levels in HaCaT cells. Co-culture with A375 had similar effects as those of low dose UVA and UVB radiation, in which the PAR-2 expression was significantly upregulated.

The early repigmentation pattern of vitiligo is related to the source of melanocytes and by the choice of therapy: a retrospective cohort study

BACKGROUND

Patients with vitiligo present with different repigmentation patterns in the early recovery stage.

OBJECTIVES

To analyze the relationships between early repigmentation patterns in vitiliginous patches, their clinical characteristics, and therapeutic choices.

METHODS

Patients with vitiligo seen in the Department of Dermatology, The First Affiliated Hospital of Nanjing Medical University from 2010 to 2015, were included, and their clinical records, especially photographs and medical treatments, were reviewed.

RESULTS

One hundred and sixteen patients were included in this study, and 326 lesions with different degrees of depigmentation, locations, stages, distributions, therapies, and repigmentation patterns were included and analyzed. Perifollicular repigmentation occurred more frequently in lesions with complete depigmentation (P = 0.005), in non-sun exposed areas (P < 0.001), a stable stage (P = 0.008), and lesions treated with narrow band ultraviolet B (NB-UVB) (P < 0.001, despite lesion distributions). Marginal repigmentation is more frequent in lesions with complete depigmentation (P = 0.016), lesions treated without NB-UVB (P = 0.002), and facial lesions treated with topical vitamin D analogs (TVDAs) monotherapy (P = 0.022). Diffuse repigmentation is the predominant pattern in lesions with incomplete depigmentation (P < 0.001), in sun-exposed areas (P < 0.001), progressive stage (P = 0.044), and truncal lesions treated with TVDAs (P < 0.001).

CONCLUSIONS

The different repigmentation patterns of vitiligo lesions depend on the different source and status of melanocytes and their abilities to produce melanin on the choice of therapy.

Untargeted lipidomic analysis of primary human epidermal melanocytes acutely and chronically exposed to UV radiation

Ultraviolet (UV) radiation present in sunlight has been related to harmful effects on skin such as premature aging and skin cancer.

[Systemic treatment of vitiligo : Balance and current developments]

Systemic drug treatment of vitiligo is currently limited to predominantly adjuvant measures for increasing the effectiveness of UV light therapy. We here present new approaches for the systemic treatment of vitiligo currently under clinical investigation. These include the α‑MSH-analogue afamelatonide and oral immunosuppressants such as the Janus kinase (JAK) inhibitors which target interferon-α-dependent autotoxic inflammatory reactions. In 2015 the first publications on the successful systemic use of Janus kinase (JAK) inhibitors in vitiligo appeared. The effectiveness was experimentally supported by animal models of vitiligo and by the characterization of new biomarkers in the serum of vitiligo patients. This may significantly expand the range of treatment options for vitiligo. Topical antiinflammatory and UV therapies are still the main components of vitiligo treatment, often in combination. The main outcome parameters include the extent and duration of repigmentation, cessation of spreading, avoidance of side effects and improvement in the quality of life of patients.

Phototherapy and Combination Therapies for Vitiligo

Vitiligo is a disease characterized by disappearance of melanocytes from the skin. It can negatively influence the physical appearance of affected individuals, and may profoundly affect a person's psychosocial function and quality of life. Therefore, vitiligo should not be considered as merely a condition that affects a patient's appearance, but needs to be actively treated in patients who seek medical help. Phototherapy has been used as the main treatment modality for patients with vitiligo. Different forms of phototherapy for vitiligo include broadband UVB, narrowband UVB, excimer light and excimer laser, and psoralen plus UVA.

Effect of combination of fractional CO2 laser and narrow-band ultraviolet B versus narrow-band ultraviolet B in the treatment of non-segmental vitiligo

The present study was designed to evaluate the effect of combining fractional CO₂ laser with narrow-band ultraviolet B (NB-UVB) versus NB-UVB in the treatment of non-segmental vitiligo. The study included 20 patients with non-segmental stable vitiligo. They were divided into two groups. Group I received a single session of fractional CO₂ laser therapy on the right side of the body followed by NB-UVB phototherapy twice per week for 8 weeks. Group II received a second session of fractional CO₂ laser therapy after 4 weeks from starting treatment with NB-UVB. The vitiligo lesions were assessed before treatment and after 8 weeks of treatment by VASI. At the end of the study period, the vitiligo area score index (VASI) in group I decreased insignificantly on both the right (-2.6%) and left (-16.4%) sides. In group II, VASI increased insignificantly on the right (+14.4%) and left (+2.5%) sides. Using Adobe Photoshop CS6 extended program to measure the area of vitiligo lesions, group I showed a decrease of -1.02 and -6.12% in the mean area percentage change of vitiligo lesions on the right and left sides, respectively. In group II the change was +9.84 and +9.13% on the right and left sides, respectively. In conclusion, combining fractional CO₂ laser with NB-UVB for the treatment of non-segmental vitiligo did not show any significant advantage over treatment with NB-UVB alone. Further study of this combination for longer durations in the treatment of vitiligo is recommended.

Melatonin and its metabolites protect human melanocytes against UVB-induced damage: Involvement of NRF2-mediated pathways

Ultraviolet light (UV) is an inducer of reactive oxygen species (ROS) as well as 6-4-photoproducts and cyclobutane pyrimidine dimers (CPD) in the skin, which further cause damage to the skin cells. Irradiation of cultured human melanocytes with UVB stimulated ROS production, which was reduced in cells treated with melatonin or its metabolites: 6-hydroxymelatonin (6-OHM), N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK), N-acetylserotonin (NAS), and 5-methoxytryptamine (5-MT). Melatonin and its derivatives also stimulated the expression of NRF2 (nuclear factor erythroid 2 [NF-E2]-related factor 2) and its target enzymes and proteins that play an important role in cell protection from different damaging factors including UVB. Silencing of NRF2 using siRNA diminished the protective effects of melatonin, while the membrane melatonin receptors (MT1 or MT2) did not change the activities of either melatonin or its derivatives. Melatonin and its metabolites enhanced the DNA repair in melanocytes exposed to UVB and stimulated expression of p53 phosphorylated at Ser-15. In conclusion, melatonin and its metabolites protect melanocytes from UVB-induced DNA damage and oxidative stress through activation of NRF2-dependent pathways; these actions are independent of an effect on the classic membrane melatonin receptors. Thus, melatonin and its derivatives can serve as excellent protectors of melanocytes against UVB-induced pathology.

Successful Treatment of Stable Vitiligo by Low-Density Cultured Autologous Melanocyte Transplantation Combined With Narrowband Ultraviolet B Therapy

BACKGROUND

Cultured autologous melanocyte transplantation (CMT) is an effective treatment for stable vitiligo, but the current method is time consuming and expensive because of the requirement of a large number of melanocytes.

OBJECTIVE

To assess the clinical effect of low-density CMT combined with narrowband ultraviolet B (NB-UVB) in treating stable vitiligo.

MATERIALS AND METHODS

The authors treated 8 patients with CMT at a low cell density (less than 2.5 × 10 cells/cm). Among them, 6 patients underwent NB-UVB therapy after CMT.

RESULTS

All the 6 patients treated with low-density CMT combined with NB-UVB obtained more than 90% repigmentation at the 1-year follow-up.

CONCLUSION

The authors' data suggest that low-density CMT combined with NB-UVB can be an effective form of surgical treatment for stable vitiligo.

Impact of Ultraviolet Light on Vitiligo

Vitiligo is a disorder of the melanocytes that results in a dynamic spectrum of skin depigmentation. Its etiology is complex and multifactorial, with data supporting several different hypotheses. Given its prominent phenotype, vitiligo has a significant negative impact on quality of life. Coupled with the chronic and incurable nature of the disease, this presents a formidable treatment challenge. Several treatment modalities have been instituted over the years, with varying efficacy. This chapter focuses on the use of ultraviolet light in vitiligo as an established therapeutic option.

Trends in Regenerative Medicine: Repigmentation in Vitiligo Through Melanocyte Stem Cell Mobilization

Vitiligo is the most frequent human pigmentary disorder, characterized by progressive autoimmune destruction of mature epidermal melanocytes. Of the current treatments offering partial and temporary relief, ultraviolet (UV) light is the most effective, coordinating an intricate network of keratinocyte and melanocyte factors that control numerous cellular and molecular signaling pathways. This UV-activated process is a classic example of regenerative medicine, inducing functional melanocyte stem cell populations in the hair follicle to divide, migrate, and differentiate into mature melanocytes that regenerate the epidermis through a complex process involving melanocytes and other cell lineages in the skin. Using an in-depth correlative analysis of multiple experimental and clinical data sets, we generated a modern molecular research platform that can be used as a working model for further research of vitiligo repigmentation. Our analysis emphasizes the active participation of defined molecular pathways that regulate the balance between stemness and differentiation states of melanocytes and keratinocytes: p53 and its downstream effectors controlling melanogenesis; Wnt/β-catenin with proliferative, migratory, and differentiation roles in different pigmentation systems; integrins, cadherins, tetraspanins, and metalloproteinases, with promigratory effects on melanocytes; TGF-β and its effector PAX3, which control differentiation. Our long-term goal is to design pharmacological compounds that can specifically activate melanocyte precursors in the hair follicle in order to obtain faster, better, and durable repigmentation.

Repigmentation patterns induced by NB-UVB and their relationship with melanocytic migration and proliferation in vitiligo

BACKGROUND/PURPOSE

Vitiligo is the most commonly acquired depigmentation disorder of the skin and is characterized by the destruction of melanocytes. Ultraviolet phototherapy with narrow band (UVB-NB) induces proliferation, differentiation, maturation, and migration of melanocytes. The clinical repigmentation is featured by follicular, marginal, and diffuse patterns. The aim of this study was to observe the process involved in the melanocyte migration and proliferation among these patterns and the unresponsive lesions following UVB-NB phototherapy. The focal adhesion kinase (FAK) and c-KIT were used as markers of melanocyte migration and differentiation, respectively.

METHODS

A total of 17 vitiligo patients under UVB-NB therapy were selected. The patients expressed the three repigmentation patterns as well as unresponsive lesions at the conclusion of a 30-session cycle. Skin biopsies were evaluated by immunohistochemistry and qRT-PCR.

RESULTS

We found an increased expression of c-KIT in the follicular pattern compared to the diffuse pattern that was expressed predominantly of FAK. Marginal pattern expressed both proteins. The unresponsive achromic lesions showed poor expressions of both markers.

CONCLUSION

Proliferation was prominent in the follicular pattern, but migration was prominent in the diffuse pattern. For the marginal pattern, both dynamics were present. The absence of these markers in vitiligo lesions suggests a lack of response to UVB-NB.

Vitiligo - The story from within: A transmission electron microscopic study before and after narrow-band ultraviolet B

Melanocyte loss is the main feature of vitiligo, but evidence refers to pathological multiplayers. Transmission electron microscopy was utilized to further explore vitiligo before and after narrow-band ultraviolet B (NB-UVB) therapy. Skin biopsies were retrieved from lesional and perilesional skin and compared to normal control skin. Sections were examined for melanocytes and keratinocytes and the number of melanosomes and thickness of basal lamina were measured. In lesional skin, keratinocytes revealed two types of degeneration with a significant increase in the mean thickness of basal lamina and decrease in the number of melanosomes. After treatment, lesional and perilesional skin showed variable ultrastructural features.

The role of systemic steroids and phototherapy in the treatment of stable vitiligo: a randomized controlled trial

Pathogenesis of vitiligo is believed to be multifactorial disease with a wide variety of therapeutic modalities. The aim of this work is to assess the efficacy of oral mini-pulse steroids (OMP) plus Nb-U.V.B in comparison to OMP alone and Nb-U.V.B alone in treating stable vitiligo. A prospective randomized controlled study including 45 patients categorized into three groups receiving therapy for 3 months; Group A received Nb-U.V.B plus OMP, Group B received OMP alone while Group C received Nb-U.V.B alone. Clinical assessment and PCR evaluation of bFGF, ICAM1, and ELISA for AMA were done. Patients receiving Nb-U.V.B plus OMP and using Nb-U.V.B alone gave statistically significant clinical response than those treated with OMP alone. Statistically significant rise of BFGF was noticed after treatment with Nb-U.V.B plus OMP and with Nb-U.V.B alone. Patients treated with OMP alone and with Nb-U.V.B alone showed statistically significant drop of ICAM-1 after therapy. NB-U.V.B plus OMP and Nb-U.V.B alone were found to be clinically superior over OMP alone in treating stable vitiligo patients, hence suggesting that adding OMP to Nb-U.V.B can maintain clinical and laboratory success for a longer period of time and with less relapse.

Phototherapy: The vitiligo management pillar

Phototherapy has been the mainstay of vitiligo therapy for several decades. A variety of wavelengths and modalities are available, but narrowband ultraviolet B remains the safest and most commonly used treatment. Acting on multiple steps in vitiligo pathogenesis, narrowband ultraviolet B is one of the few therapies that can effectively induce stabilization and stimulate repigmentation. Achievement of optimal results involves using a combination of appropriate treatment protocols, careful patient selection, and patient education to set expectations. Individual patient characteristics, including disease activity, vitiligo phenotype, lesion location, and skin phototype, should all be considered, along with combination therapies.

FK506 positively regulates the migratory potential of melanocyte-derived cells by enhancing syndecan-2 expression

Although topical tacrolimus (FK506) is known to promote repigmentation by increasing the pigmentation and migration of melanocytes, the mechanism through which FK506 regulates cell migration remains unclear. Here, we report that FK506 treatment enhanced cell spreading on laminin-332 and increased migration in both melanocytes and melanoma cells. Interestingly, FK506 also increased the expression of syndecan-2, a transmembrane heparan sulfate proteoglycan through c-jun terminal kinase activation. Moreover, siRNA-mediated reduction of syndecan-2 expression decreased FK506-mediated cell spreading and migration in melanoma cells and decreased focal adhesion kinase phosphorylation in both melanocytes and melanoma cells. Consistent with these effects on syndecan-2 expression, FK506 enhanced the membrane and melanosome localizations of PKCβII, a regulator of tyrosinase activity. This suggests that FK506 may play a dual regulatory role by affecting both melanogenesis and migration in melanocyte-derived cells. Interestingly, however, FK506 failed to show any synergistic effect on the migration of UVB-treated melanocyte-derived cells. Taken together, these data indicate that FK506 regulates cell migration by enhancing syndecan-2 expression, further suggesting that syndecan-2 could be a potential target for the treatment of patients with vitiligo.

Epithelial expression of cytokeratins 15 and 19 in vitiligo

BACKGROUND

Cytokeratins (CK) belong to the family of intermediate filament proteins, and among them specific epithelial keratins are considered markers for stem cells activation.

OBJECTIVES

This study aims to investigate the expression of CK15 and CK19 as possible stem cell markers in vitiligo during phototherapy.

METHODS

The study was conducted on vitiligo patients receiving narrow-band ultraviolet therapy. Immunohistochemical staining for CK15 and CK19 was carried out, and clinical follow-up continued for 4 weeks.

RESULTS

Of 28 patients, CK15 expression was demonstrated in 17 cases (61%) while CK19 expression was demonstrated in 11 cases (39%). Cells expressing positive staining were demonstrated in follicular and interfollicular epithelium. Expression was clearly demonstrated in patients younger than 20 years old, with shorter disease duration, with disease stability, and with normally pigmented hairs. Expression of cytokeratins was significantly correlated to improvement of vitiligo lesions.

CONCLUSION

CK15 and CK19 are expressed in vitiligo during UV repigmentation in the follicular and interfollicular epithelium. This expression of cytokeratins was significantly correlated to improvement and can be considered valuable tool to monitor stem cells stimulation for the sake of the repigmentation process in vitiligo.

Review of narrowband ultraviolet B radiation in vitiligo

Vitiligo is a common, acquired pigmentary disorder of unknown etiology with great impact on patient’s appearance and quality of life. It presents a therapeutic challenge to many dermatologists. Photochemotherapy using psoralen and ultraviolet A (UVA) therapy, topical and oral immunosuppresants, as well as cosmetic camouflage are also commonly employed with varying clinical efficacy. Phototherapy is a popular treatment option, which includes both of the generalized ultraviolet B (UVB) therapies, broadband UVB and narrowband UVB (NB-UVB). It has been used favorably, both alone as well as in combination with other agents like topical calcineurin inhibitors, vitamin-D analogs. Combination therapies are useful and may provide quicker regimentation and treat vitiligo with an additive mechanism of action than UVB phototherapy. Advances in technology may lead to the continuing use of UVB phototherapy as a treatment for vitiligo through the development of sophisticated devices and delivery systems as well as innovative application methods. These will provide increased therapeutic options for all vitiligo patients, particularly those with refractory disease. In this article, I have reviewed the available data pertaining to efficacy and safety issues for NB-UVB as monotherapy, its comparison with psoralen plus UVA and other modes of phototherapy, combination regimens that have been tried and future prospects of NB-UVB in vitiligo.

[Treatment of vitiligo]

The range of treatment options for vitiligo has significantly expanded in the last 10 years and we can offer our patients more effective treatment strategies supported by European guidelines and consensus findings. Topical and UV therapy are-often in combination-the main components of vitiligo treatment. The main outcome parameters include extent and maintenance of gained repigmentation, cessation of spreading, avoidance of side effects and the influence of the treatment on the quality of life. The efficacy of the currently available treatments is often limited. New options include antioxidative or melanocyte-stimulating adjuvant therapies in combination with UV or laser light as well as a topical maintenance treatment to reduce the risk of recurrences. In many cases, psychological support is indicated.

Effect of ultra violet irradiation on the interplay between Th1 and Th2 lymphocytes

Although ultraviolet (UV) radiation is used to treat several types of diseases, including rickets, psoriasis, eczema, and jaundice, the prolonged exposure to its radiation may result in acute and chronic health effects particularly on the skin, eyes, and the immune system.

AIM

This study was carried out to show the effect of UV on both of the lymphoproliferative response and their capacity to produce IL-12 and IL-10 in mice.

METHODS

Mice were exposed to whole body UVB and tested for the effect of recovery times on lymphocyte proliferation and cytokine production. In addition, direct irradiation of spleens and lymphocyte suspension was carried out. Basal and mitogens-stimulated lymphocyte proliferation was assessed by MTT assay while IL-10 and IL-12 were measured using ELISA.

RESULTS

There was a significant suppression in lymphocyte proliferation in comparison with control. IL-12 level was significantly reduced while the level of IL-10 was increased. Con A and PWM mitogens had no significant changes in IL-10 while Con A caused a highly significant increase in IL-12 at day 6 of recovery in UVB body irradiation.

CONCLUSION

Exposure to UVB radiation could cause a state of immune suppression and shifts Th1/Th2 cell response. This effect is closely associated with the reduction of Th1 cytokines' expression and increase in Th2 cytokines' levels.

Adipose-derived stem cells improve efficacy of melanocyte transplantation in animal skin

Vitiligo is a pigmentary disorder induced by a loss of melanocytes. In addition to replacement of pure melanocytes, cocultures of melanocytes with keratinocytes have been used to improve the repigmentation outcome in vitiligo treatment. We previously identified by in vitro studies, that adipose-derived stem cells (ADSCs) could be a potential substitute for keratinocytes in cocultures with melanocytes. In this study, the efficacy of pigmentation including durability of grafted melanocytes and short-term safety was examined in the nude mouse and Sprague-Dawley rat after grafting of primary cultured human melanocytes, with or without different ratios of primary cultured human ADSCs. Simultaneous grafting of melanocytes and ADSCs, which were separately cultured and mixed on grafting at the ratios of 1:1, 1:2, or 1:3, showed better efficacy than that of pure melanocytes. Grafting of melanocytes cocultured with ADSCs resulted in a similar outcome as the grafting of cell mixtures. Skin pigmentation by melanocytes : ADSCs at the ratios of 1:1 and 1:2 was better than at 1:3. No significant difference was observed between the 1-week and 2-week durations in coculturing. Time-course microscopic examination showed that the grafted melanocytes remained a little longer than 6-week post-grafting. No inflammatory cell infiltration was observed in the grafted skin and no melanocytes were detectable in other organs. Collectively, grafting of melanocytes and ADSCs was equally safe and more effective than grafting of melanocytes alone. Despite the absence of significant differences in efficacy between the group of 1:1 and that of 1:2 ratio, 1:2 ratio for 1-week coculturing may be better for clinical use from the cost-benefit viewpoint.

Human melanocytes form a PAX3-expressing melanocyte cluster on Matrigel by the cell migration process

BACKGROUND

The interactions between human epidermal melanocytes and their cellular microenvironment are important in the regulation of human melanocyte functions or in their malignant transformation into melanoma. Although the basement membrane extracellular matrix (BM-ECM) is one of major melanocyte microenvironments, the effects of BM-ECM on the human melanocyte functions are not fully explained at a molecular level.

OBJECTIVE

This study was aimed to characterize the molecular and cellular interactions between normal human melanocytes (NHMs) and BM-ECM.

METHODS

We investigated cell culture models of normal human melanocytes or melanoma cells on three-dimensional (3D) Matrigel to understand the roles of the basement membrane microenvironment in human melanocyte functions. Melanogenesis and melanobast biomarker expression in both primary human melanocytes and melanoma cells on 3D Matrigel were evaluated.

RESULTS

We found that NHMs migrated and formed reversible paired box 3 (PAX3) expressing cell clusters on three-dimensional (3D) Matrigel. The melanogenesis was significantly decreased in the PAX3 expressing cell cluster. The expression profile of PAX3, SOX10, and MITF in the melanocyte cluster on 3D Matrigel was similar to that of melanoblasts. Interestingly, PAX3 and SOX10 showed an inverse expression profile in NHMs, whereas the inverse expression pattern of PAX3 and SOX10 was disrupted in melanoma MNT1 and WM266-4 cells.

CONCLUSION

The human melanocyte culture on 3D Matrigel provides an alternative model system to study functions of human melanoblasts. In addition, this system will contribute to the elucidation of PAX3-related tumorigenic mechanisms to understand human melanoma.