Altered levels of Ets-1 transcription factor and matrix metalloproteinases in melanocytes from patients with vitiligo

Emerging Role of Fibroblasts in Vitiligo: A Formerly Underestimated Rising Star

Vitiligo is a disfiguring depigmentation disorder characterized by loss of melanocytes. Although numerous studies have been conducted on the pathogenesis of vitiligo, the underlying mechanisms remain unclear. Although most studies have focused on melanocytes and keratinocytes, growing evidence suggests the involvement of dermal fibroblasts, residing deeper in the skin. This review aims to elucidate the role of fibroblasts in both the physiological regulation of skin pigmentation and their pathological contribution to depigmentation, with the goal of shedding light on the involvement of fibroblasts in vitiligo. The topics covered in this review include alterations in the secretome, premature senescence, autophagy dysfunction, abnormal extracellular matrix, autoimmunity, and metabolic changes.

The Keratinocyte in the Picture Cutaneous Melanoma Microenvironment

Melanoma progression is a multistep evolution from a common melanocytic nevus through a radial superficial growth phase, the invasive vertical growth phase finally leading to metastatic dissemination into distant organs. Melanoma aggressiveness largely depends on the propensity to metastasize, which means the capacity to escape from the physiological microenvironment since tissue damage due to primary melanoma lesions is generally modest. Physiologically, epidermal melanocytes are attached to the basement membrane, and their adhesion/migration is under the control of surrounding keratinocytes. Thus, the epidermal compartment represents the first microenvironment responsible for melanoma spread. This complex process involves cell-cell contact and a broad range of secreted bioactive molecules. Invasion, or at the beginning of the microinvasion, implies the breakdown of the dermo-epidermal basement membrane followed by the migration of neoplastic melanocytic cells in the superficial papillary dermis. Correspondingly, several experimental evidences documented the structural and functional rearrangement of the entire tissue surrounding neoplasm that in some way reflects the atypia of tumor cells. Lastly, the microenvironment must support the proliferation and survival of melanocytes outside the normal epidermal-melanin units. This task presumably is mostly delegated to fibroblasts and ultimately to the self-autonomous capacity of melanoma cells. This review will discuss remodeling that occurs in the epidermis during melanoma formation as well as skin changes that occur independently of melanocytic hyperproliferation having possible pro-tumoral features.

Management of the refractory vitiligo patient: current therapeutic strategies and future options

Vitiligo is an autoimmune disease that leads to disfiguring depigmented lesions of skin and mucosa. Although effective treatments are available for vitiligo, there are still some patients with poor responses to conventional treatment. Refractory vitiligo lesions are mostly located on exposed sites such as acral sites and lips, leading to significant life stress. Understanding the causes of refractory vitiligo and developing targeted treatments are essential to enhance vitiligo outcomes. In this review, we summarized recent treatment approaches and some potential methods for refractory vitiligo. Janus kinase inhibitors have shown efficacy in refractory vitiligo. A variety of surgical interventions and fractional carbon dioxide laser have been widely applied to combination therapies. Furthermore, melanocyte regeneration and activation therapies are potentially effective strategies. Patients with refractory vitiligo should be referred to psychological monitoring and interventions to reduce the potential pathogenic effects of chronic stress. Finally, methods for depigmentation and camouflage may be beneficial in achieving uniform skin color and improved quality of life. Our ultimate focus is to provide alternative options for refractory vitiligo and to bring inspiration to future research.

A triple combination of latanoprost, fractional CO2 laser, and platelet-rich plasma in localized vitiligo: A clinical and histopathologic study

BACKGROUND

Several treatment modalities are available for the treatment of vitiligo due to the lack of a uniformly effective therapy. Topical latanoprost 0.005% is an effective topical treatment. Fractional CO2 laser alone or combined with platelet-rich plasma (PRP) has been proposed as effective adjunctive therapies.

OBJECTIVES

We aimed to compare the efficacy of topical latanoprost 0.005% (Ioprost®, Orchidia, Egypt) combined with either add-on fractional CO2 laser or fractional CO2 -PRP versus topical latanoprost monotherapy in the treatment of localized stable vitiligo.

PATIENTS/METHODS

The study included 60 patients randomly assigned into three equal groups. Group A patients received topical latanoprost drops only. Group B patients received topical latanoprost drops and fractional CO2 laser sessions at 2-week interval for 3 months. Group C patients received topical latanoprost drops and fractional CO2 laser sessions combined with PRP at a 2-week interval for 3 months. The mean improvement score by the physician was calculated 4 months after the start of the study. Punch skin biopsies were obtained before treatment and 4 months from the beginning of the study and stained with H&E and HMB-45 antibody for evaluation of pigmentation.

RESULTS

Significant clinical improvement of vitiligo lesions with significant increase of re-pigmentation were reported in the three treated groups. Latanoprost in combination with fractional CO2 and PRP was associated with more significant therapeutic outcomes than either combined latanoprost and fractional CO2 or latanoprost alone.

CONCLUSION

Fractional CO2 laser-PRP enhances the therapeutic efficacy of latanoprost 0.005% in the treatment of localized stable vitiligo.

Melanocyte-keratinocyte cross-talk in vitiligo

Vitiligo is a common acquired pigmentary disorder that presents as progressive loss of melanocytes from the skin. Epidermal melanocytes and keratinocytes are in close proximity to each other, forming a functional and structural unit where keratinocytes play a pivotal role in supporting melanocyte homeostasis and melanogenesis. This intimate relationship suggests that keratinocytes might contribute to ongoing melanocyte loss and subsequent depigmentation. In fact, keratinocyte dysfunction is a documented phenomenon in vitiligo. Keratinocyte apoptosis can deprive melanocytes from growth factors including stem cell factor (SCF) and other melanogenic stimulating factors which are essential for melanocyte function. Additionally, keratinocytes control the mobility/stability phases of melanocytes via matrix metalloproteinases and basement membrane remodeling. Hence keratinocyte dysfunction may be implicated in detachment of melanocytes from the basement membrane and subsequent loss from the epidermis, also potentially interfering with repigmentation in patients with stable disease. Furthermore, keratinocytes contribute to the autoimmune insult in vitiligo. Keratinocytes express MHC II in perilesional skin and may present melanosomal antigens in the context of MHC class II after the pigmented organelles have been transferred from melanocytes. Moreover, keratinocytes secrete cytokines and chemokines including CXCL-9, CXCL-10, and IL-15 that amplify the inflammatory circuit within vitiligo skin and recruit melanocyte-specific, skin-resident memory T cells. In summary, keratinocytes can influence vitiligo development by a combination of failing to produce survival factors, limiting melanocyte adhesion in lesional skin, presenting melanocyte antigens and enhancing the recruitment of pathogenic T cells.

Treatment update for vitiligo based on autoimmune inhibition and melanocyte protection

INTRODUCTION

The treatment of vitiligo remains challenging due to the complexity of its pathogenesis, influenced by genetic factors, oxidative stress and abnormal cell adhesion that collectively impact melanocyte survival and trigger immune system attacks, resulting in melanocyte death. Melanocytes in vitiligo are believed to exhibit genetic susceptibility and defects in cellular mechanisms, such as defects in autophagy, that reduce their ability to resist oxidative stress, leading to increased expression of the pro-inflammatory protein HSP70. The low expression of adhesion molecules, such as DDR1 and E-cadherin, accelerates melanocyte damage and antigen exposure. Consequently, autoimmune attacks centered on IFN-γ-CXCR9/10-CXCR3-CD8⁺ T cells are initiated, causing vitiligo.

AREAS COVERED

This review discusses the latest knowledge on the pathogenesis of vitiligo and potential therapeutic targets from the perspective of suppressing autoimmune attacks and activating melanocytes functions.

EXPERT OPINION

Vitiligo is one of the most challenging dermatological diseases due to its complex pathogenesis with diverse therapeutic targets. Immune suppression, such as corticosteroids and emerging JAK inhibitors, has proven effective in disease progression. However, during the early stages of the disease, it is also important to optimize therapeutic strategies to activate melanocytes for alleviating oxidative stress and improving treatment outcomes.

Beneficial UVB phototherapy preceding a fractional CO2 laser-UVB protocol in refractory non-segmental vitiligo

OBJECTIVES

To explore the short- and long-term effects of UVB phototherapy preceding a fractional CO₂ laser-UVB protocol in patients with resistant nonsegmental vitiligo.

MATERIALS AND METHODS

This single-center, prospective, split-face/body, evaluator-blinded study included adult patients with stable vitiligo refractory to conventional treatments. Two symmetrical lesions were selected. Phototherapy was delivered with one side covered, until minimal erythema. Within 3 days, 31-month-apart sessions of laser were performed on both sides. After each laser session, phototherapy was resumed three times weekly, with all lesions uncovered, until 8 weeks after the last laser session. At baseline, at the end of treatment, and 5 years later, a Mean Improvement Score by Physician (MISP) and a patient satisfaction 10-point visual analog score (VAS) were recorded.

RESULTS

Ten patients (8 women and 2 men) were included; their mean age was 32.9 years; phototype III was predominant; the mean duration of vitiligo was 3 years. At the end of treatment and 5 years later, scores of lesions treated with UVB-CO₂ -UVB (mean MISP 3.0 and 2.9, mean ΔVAS 4.5 and 3.9, respectively), were higher than those of lesions treated only with CO₂ -UVB (mean MISP 2.5 and 2.4, mean ΔVAS 4.1 and 3.6, respectively). After 5 years, one patient lost his partial response and two patients developed light hyperpigmentation on both sides.

CONCLUSION

Exposure to UVB before CO₂ -UVB explains the higher scores as it was the only variable between the two sides. It may improve the response of resistant lesions with a constantly sustained result over 5 years.

Surgical procedures and innovative approaches for vitiligo regenerative treatment and melanocytorrhagy

Surgical treatments for vitiligo are a safe and effective treatment modality for select patients with vitiligo. Many techniques of vitiligo surgery exist, each with unique advantages and disadvantages. We reviewed the various surgical therapies and innovative approaches for vitiligo regenerative treatment reported in the literature. Surgical therapies can be subdivided into tissue grafting methods and cellular grafting methods. Tissue grafting methods mainly include mini punch grafts, suction blister roof grafts, and hair follicle grafts. Cellular grafting methods include cultured and non-cultured treatments. The efficacy needs to be improved largely due to the poor proliferation and quality of the autologous melanocytes. Rho-associated protein kinase inhibitor enhances primary melanocyte culture proliferation from vitiligo patients to prevent apoptosis. Innovative approaches using stem cell methods could prove invaluable in developing a novel cell therapy for patients suffering from vitiligo. We succeeded in inducing melanin pigmentation in mice skin in vivo using our human induced pluripotent stem cell-derived melanocytes. In addition, we reviewed melanocytorrhagy, detachment and transepidermal loss of melanocytes, and melanocyte-related adhesion molecules. These adhesion molecules include epithelial cadherin, discoidin domain receptor tyrosine kinase 1, glycoprotein non-metastatic melanoma protein B, macrophage migration inhibiting factor, 17β-hydroxysteroid dehydrogenase 1, and E26 transformation-specific 1.

H2 O2 -induced oxidative stress disrupts mitochondrial functions and impairs migratory potential of human epidermal melanocytes

Reactive oxygen species (ROS) have already been demonstrated to impede the migratory ability in non-melanocytic cell lines by depleting mitochondrial ATP production. Therefore, understanding the mitochondrial metabolic response to migration in the presence of ROS should be a key to understanding repigmentation in vitiligo. This study aimed to investigate the energy mechanism associated with the ROS-mediated attenuation of melanocyte migration. After melanocytes were pretreated with H₂ O₂ , their ATP production, migratory ability, ultrastructural changes and Mitochondrial Permeability Potential were analysed. The results showed that, in parallel with the decreased ATP production, the migratory ability of melanocytes was significantly inhibited by oxidative stress. Supplementation with exogenous ATP reversed the suppressed ATP-dependent migration of melanocytes. Melanocytes were then stressed with H₂ O₂ and Agilent Whole Human Genome microarray analysis identified 763 up-regulated mRNAs and 1117 down-regulated mRNAs. Among them, 11 of the encoded proteins were involved in mitochondrial ATP production and their expression levels were verified. The decreased expression of NADH dehydrogenase 2(ND₂₎ , cytochrome c oxidase 1(COX1) and cytochrome c oxidase 3(COX3) was shown to be involved in the depletion of mitochondrial ATP production, which was coupled with the impaired migratory potential. These results indicate that the migration of melanocytes relies heavily on an inexhaustible supply of ATP from mitochondria.

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.

Fractional versus full ablative CO2 laser in recipient site of non-cultured melanocytes and keratinocyte transplantation in treatment of vitiligo

BACKGROUND

Melanocyte-keratinocyte transplant procedure (MKTP) or non-cultured epidermal cell suspension transplantation is a very popular surgical modality for treating stable vitiligo. The recipient-site preparation is one potential determinant in the repigmentation outcomes.

AIM

To assess the efficacy of fractional CO₂ (FCO₂ ) laser in recipient-site preparation before MKTP and comparing it to the frequently used full surface laser ablation.

METHODS

This randomized comparative trial included 19 patients with 40 stable vitiligo lesions. In each patient, the treated sites were randomly categorized into two groups according to the recipient-site ablation (either fractional or full ablative CO₂ laser). Assessment of repigmentation was performed six months after the procedure.

RESULTS

Both modalities achieved successful repigmentation of a median of 80% and 77.5% for fractional and full ablation groups, respectively, with a non-statistically significant difference between them. The median of VASI change percent was -73% and -71% with fractional and full surface ablation, respectively.

CONCLUSIONS

FCO₂ laser ablation is effective for recipient-site preparation before cell suspension transplantation as well as the full ablative CO₂ laser.

A comparative study on the use of fractional CO2 laser with tacrolimus or calcipotriol or narrow band ultraviolet-B in treatment of stable nonsegmental vitiligo

Conventional methods of treatment for vitiligo are often unsatisfactory to the patients and time consuming, new treatment modalities are needed. This study was conducted to evaluate the efficacy and safety of fractional carbon dioxide (CO₂ ) laser therapy followed by narrow band ultraviolet-B (NB-UVB) phototherapy, topical tacrolimus or topical calcipotriol on stable nonsegmental vitiligo. Thirty patients with stable nonsegmental vitiligo were evaluated. All patients were subjected to three sessions of fractional CO₂ laser 1 month apart. Patients were divided into three groups (each group 10 patients). Group (A) treated with tacrolimus ointment twice daily for 3 months, group (B) treated with calcipotriol ointment twice daily for 3 months, and group (C) treated with NB-UVB twice weekly for 3 months. Outcomes were evaluated by calculating vitiligo area scoring index (VASI) score change, percentage of repigmentation, patient satisfaction, and adverse effects. There was a statistical significant decrease in VASI score after treatment in the three groups. The VASI change and % of regimentation was higher in group (C) treated by laser and NB-UVB and this was significantly higher than group (B) treated with laser and calcipotriol. Otherwise, there was no statistical significant difference between other treatment groups. In concluion, NB-UVB phototherapy, topical tacrolimus, or topical calcipotriol in combination with fractional CO₂ laser could be used effectively and safely as an alternative modality for treatment of vitiligo. The combination of fractional CO₂ laser and NB-UVB was found to be more effective.

The efficacy of fractional carbon dioxide laser combined with narrow-band ultraviolet B phototherapy for non-segmental vitiligo: a systematic review and meta-analysis

Fractional carbon dioxide (CO₂) laser has been used with conventional treatments for vitiligo, demonstrating more effectiveness compared with conventional treatments alone. Especially, fractional CO₂ laser combined with narrow-band ultraviolet B (NB-UVB) was shown to induce more improvement compared with NB-UVB monotherapy for treating stable non-segmental vitiligo. However, the effectiveness of fractional CO₂ laser plus NB-UVB for the treatment of non-segmental vitiligo remains controversial. Therefore, this study aimed to confirm the safety and efficacy of fractional CO₂ laser combined with NB-UVB compared with NB-UVB monotherapy in stable non-segmental vitiligo. We searched the data from different databases, including Cochrane, Embase, and PubMed up to January 2020. Four randomized controlled trials (RCTs) for comparison between fractional CO₂ laser plus NB-UVB and NB-UVB monotherapy in patients with stable non-segmental vitiligo were included. We performed meta-analyses for repigmentation improvement and patient satisfaction as well as subgroup analyses based on acral or non-acral vitiligo, according to the PRISMA guidelines. The combination treatment showed more superior results than NB-UVB monotherapy (≥ 75% repigmentation, RR 4.60, 95% CI 1.19-17.74; ≥ 50% repigmentation, RR 2.24, 95% CI 0.45-11.17; < 25% repigmentation, RR 0.81, 95% CI 0.60-1.08). Also, fractional CO₂ laser plus NB-UVB significantly improved acral and non-acral vitiligo compared with NB-UVB monotherapy (standard mean difference (SMD) 1.24, 95% CI 0.66-1.82; SMD 1.14, 95% CI 0.67-1.60, respectively), while it increased markedly patient satisfaction compared with NB-UVB monotherapy (SMD 1.12, 95% CI 0.66-1.58). Collectively, this meta-analysis suggested that fractional CO₂ laser combined with NB-UVB might be more effective for treating non-segmental vitiligo than NB-UVB monotherapy.

Type-1 cytokines regulate MMP-9 production and E-cadherin disruption to promote melanocyte loss in vitiligo

Loss of melanocytes is the pathological hallmark of vitiligo, a chronic inflammatory skin depigmenting disorder induced by exaggerated immune response, including autoreactive CD8 T cells producing high levels of type 1 cytokines. However, the interplay between this inflammatory response and melanocyte disappearance remains to be fully characterized. Here, we demonstrate that vitiligo skin contains a significant proportion of suprabasal melanocytes, associated with disruption of E-cadherin expression, a major protein involved in melanocyte adhesion. This phenomenon is also observed in lesional psoriatic skin. Importantly, apoptotic melanocytes were mainly observed once cells were detached from the basal layer of the epidermis, suggesting that additional mechanism(s) could be involved in melanocyte loss. The type 1 cytokines IFN-γ and TNF-α induce melanocyte detachment through E-cadherin disruption and the release of its soluble form, partly due to MMP-9. The levels of MMP-9 are increased in the skin and sera of patients with vitiligo, and MMP-9 is produced by keratinocytes in response to IFN-γ and TNF-α. Inhibition of MMP-9 or the JAK/STAT signaling pathway prevents melanocyte detachment in vitro and in vivo. Therefore, stabilization of melanocytes in the basal layer of the epidermis by preventing E-cadherin disruption appears promising for the prevention of depigmentation occurring in vitiligo and during chronic skin inflammation.

Aberrant ETS-1 signalling impedes the expression of cell adhesion molecules and matrix metalloproteinases in non-segmental vitiligo

Cell adhesion is a complex process that involves multiple molecules on the cell surface (ie cell adhesion molecules [CAMs]), surrounding cells and extracellular matrix (ECM). Repigmentation in vitiligo is dependent on the ECM remodelling and cellular migration, primarily attributed to the transcriptional activation of matrix metalloproteinases (MMPs). In this study, we aimed to demonstrate the role of ETS-1 signalling in the regulation of MMPs and CAMs. Therefore, we studied the expression of ETS-1, MMPs (MMP-2, MMP-9) and CAMs including E-cadherin, ITGA-1 and ICAM-1 in vitiligo (both active and stable) ex vivo. Further, we compared melanocyte morphology and their adhesion towards collagen IV and laminin between control and vitiligo groups in vitro. Also, we silenced ETS-1 in melanocytes cultured from control skin and observed post-silencing effect on above-mentioned MMPs and CAMs. We perceived absent ETS-1 and significantly reduced CAMs and MMPs in vitiligo compared with normal skin. Scanning electron microscopy (SEM) revealed a translucent material surrounding individual melanocytes in stable vitiligo and controls, whereas active vitiligo melanocytes demonstrated loss of this extracellular substance. Adhesion assays revealed significantly decreased binding of cultured melanocytes to collagen IV and laminin V plates in both stable and active vitiligo. Importantly, ETS-1 silencing resulted in significantly reduced expression of CAMs and MMPs. In conclusion, absent ETS-1 expression in both stable and active non-segmental vitiligo seems to impede the expression of CAMs, apart from MMPs, probably leading to progressive depigmentation in active disease and absence of spontaneous repigmentation in stable disease.

Value of silicone gel in prevention of cobblestoning following punch minigrafting in vitiligo

Background: Cobblestoning is the most common complication of minipunch grafting.Objective: To assess the value of silicone gel application following minipunch grafting and the histopathological and immunohistochemical changes in cases with cobblestoning.Methods: Minipunch grafting was performed in two similar vitiligo lesions in 27 cases with stable vitiligo. After healing, silicone gel was applied twice daily on one lesion while zinc oxide ointment was applied to the other lesion serving as a control. Four biopsies were taken from each case; normal, vitiliginous skin before treatment and the two treated lesions 3 months after therapy, for histopathology and immunohistochemical staining for MMP9 & tenascin-C.Results: Repigmentation occurred in 19 cases (70.7%). The number of lesions showing excellent and good response was significantly higher on the silicone gel side (p < .001). In 20 cases, cobblestoning either occurred or was absent on both sides. Histopathologically, cobblestoning was similar to hypertrophic scarring. Both markers were elevated after therapy on both sides with no significant difference in percentage change between lesions showing positive and negative cobblestoning.Conclusion: Silicone gel application after minigrating improved the final response with no significant effect on the occurrence of cobblestoning. Cobblestoning resembled hypertrophic scarring histopathologically.

Role of the p53‑TRPM1/miR‑211‑MMP9 axis in UVB‑induced human melanocyte migration and its potential in repigmentation

Clinical studies have proven that ultraviolet B (UVB) based phototherapy can induce perifollicular and marginal repigmentation patterns in the skin of vitiligo patients. It is, however, difficult to conceive how melanocytes can easily exit from their tightly interconnected epidermal microenvironment to re‑enter a different location in the skin to establish a new network with neighboring keratinocytes. While it is known that matrix metalloprotease 9 (MMP9) is involved in the degradation of the extracellular matrix in physiological or pathological processes, little is known about whether MMP9 affects melanocyte migration in vitiligo repigmentation. To investigate the effects of the p53‑ transient receptor potential cation channel subfamily M member 1 (TRPM1)/microRNA (miR/miRNA)‑211‑MMP9 axis to regulate melanocyte migration following exposure to UVB, the expression profile of MMP9 in cultured human melanocytes transfected with or without the miR‑211‑mimic and p53‑GFP lentiviral vector, respectively were determined. Quantitative polymerase chain reaction and western blotting were used to examine p53, TRPM1 and MMP9 mRNA and protein levels in UVB‑exposed and unexposed cells. The capacity of melanocytes to migrate on collagen IV substrate was estimated using a Transwell migration assay. Interestingly, the upregulation of p53 and MMP9 at the mRNA and protein levels was evident in melanocytes treated with single or repeat exposures to UVB, whereas levels of TRPM1 and miR‑211 were significantly suppressed in UVB‑exposed melanocytes compared with the UVB‑unexposed control cells. These results indicate that the p53‑TRPM1/miR‑211‑MMP9 axis is significantly activated in melanocytes exposed to UVB. Notably, the ability of melanocyte migration was altered by the overexpression of p53 using a lentiviral vector and by the upregulation of miR‑211 using an miRNA mimic. That altered migration could be neutralized by co‑treatment with GM6001 (a broad‑spectrum MMP inhibitor). Overall, these results show that the MMP9‑mediated migration of melanocytes is regulated by a novel mechanism driven by the p53‑TRPM1/miR‑211‑MMP9 axis. Activation of the p53‑TRPM1/miR‑211‑MMP9 axis potentially represents an attractive therapeutic target to improve repigmentation outcomes in vitiligo patients.

Premature cell senescence in human skin: Dual face in chronic acquired pigmentary disorders

Although senescence was originally described as an in vitro acquired cellular characteristic, it was recently recognized that senescence is physiologically and pathologically involved in aging and age-related diseases in vivo. The definition of cellular senescence has expanded to include the growth arrest caused by various cellular stresses, including DNA damage, inadequate mitochondria function, activated oncogene or tumor suppressor genes and oxidative stress. While senescence in normal aging involves various tissues over time and contributes to a decline in tissue function even with healthy aging, disease-induced premature senescence may be restricted to one or a few organs triggering a prolonged and more intense rate of accumulation of senescent cells than in normal aging. Organ-specific high senescence rate could lead to chronic diseases, especially in post-mitotic rich tissue. Recently, two opposite acquired pathological conditions related to skin pigmentation were described to be associated with premature senescence: vitiligo and melasma. In both cases, it was demonstrated that pathological dysfunctions are not restricted to melanocytes, the cell type responsible for melanin production and transport to surrounding keratinocytes. Similar to physiological melanogenesis, dermal and epidermal cells contribute directly and indirectly to deregulate skin pigmentation as a result of complex intercellular communication. Thus, despite senescence usually being reported as a uniform phenotype sharing the expression of characteristic markers, skin senescence involving mainly the dermal compartment and its paracrine function could be associated with the disappearance of melanocytes in vitiligo lesions and with the exacerbated activity of melanocytes in the hyperpigmentation spots of melasma. This suggests that the difference may arise in melanocyte intrinsic differences and/or in highly defined microenvironment peculiarities poorly explored at the current state of the art. A similar dualistic phenotype has been attributed to intratumoral stromal cells as cancer-associated fibroblasts presenting a senescent-like phenotype which influence the behavior of neoplastic cells in either a tumor-promoting or tumor-inhibiting manner. Here, we present a framework dissecting senescent-related molecular alterations shared by vitiligo and melasma patients and we also discuss disease-specific differences representing new challenges for treatment.

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.

Fractional CO2 laser contributes to the treatment of non-segmental vitiligo as an adjunct therapy: a systemic review and meta-analysis

The treatment of stable non-segmental vitiligo is often challenging, which new therapies are being searched. Multiple clinical trials have proposed the benefits and safety of using fractional carbon dioxide (CO2) laser as an adjunct therapy to conventional treatments. This study aimed to evaluate the safety and efficacy of fractional carbon dioxide laser as a combination therapy to conventional treatments in patients with stable non-segmental vitiligo. A literature search using PubMed, EMBASE, and the Cochrane Library was performed for comparative studies among vitiligo patients treated with additional fractional CO2 laser. Clinical outcomes in the selected studies were compared, and a meta-analysis was performed via Review Manager version 5.3, according to the PRISMA guidelines. Six studies with a total of 184 patches/patients were included in the present meta-analysis. The combination therapy group had significantly superior results than that of the control group (≥ 75% re-pigmentation, risk ratio [RR] 2.80, 95% confidence interval [CI] 1.29-6.07; ≥ 50% re-pigmentation, RR 2.26, 95% CI 1.23-5.9; < 25% re-pigmentation, RR 0.57, 95% CI 0.43-0.75). Limitations of the study included the small number of studies and sample size, inadequate blinding of participants, and variation between therapy protocols. Meta-analysis revealed that using fractional CO2 laser in combination with conventional treatments is efficient and safe, and may be considered as an adjunct therapeutic option for patients with refractive non-segmental vitiligo.

Clinical and Molecular Aspects of Vitiligo Treatments

Vitiligo is an asymptomatic but cosmetically disfiguring disorder that results in the formation of depigmented patches on skin and/or mucosae. Vitiligo can be segmental or non-segmental depending upon the morphology of the clinical involvement. It can also be classified as progressing or stable based on the activity of the disease. Further, the extent of involvement can be limited (localized disease) or extensive (generalized disease). The treatment of vitiligo therefore depends on the clinical classification/characteristics of the disease and usually comprises of 2 strategies. The first involves arresting the progression of active disease (to provide stability) in order to limit the area involved by depigmentation. The second strategy aims at repigmentation of the depigmented area. It is also important to maintain the disease in a stable phase and to prevent relapse. Accordingly, a holistic treatment approach for vitiligo should be individualistic and should take care of all these considerations. In this review, we shall discuss the vitiligo treatments and their important clinical and molecular aspects.

Effect of Dickkopf1 on the senescence of melanocytes: in vitro study

Fibroblasts secrete several growth factors which are important for the regulation of skin pigmentation. Dickkopf1 (DKK1) is also secreted by fibroblasts which inhibit the growth and function of melanocytes. Therefore, the study was designed to check the role of DKK1 in vitiligo pathogenesis. This study confirmed the higher expression of DKK1 in lesional skin of vitiligo patients. In vitro effect of DKK1 on cultured melanocytes revealed decrease in the melanocytes proliferation and pigmentation. In vitro effect of DKK1 was then checked on the melanocytes senescence and found that DKK1 induced senescence in the treated melanocytes. Expression of senescence markers was significantly higher in DKK1 treated melanocytes. This study suggests that higher expression of DKK1 in the dermis induced senescence in melanocytes that may lead to hypopigmentation and play role in vitiligo pathogenesis.

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.

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.

Effect of different types of therapeutic trauma on vitiligo lesions

New treatment modalities for vitiligo acting by changing certain cytokines and metalloproteinases are newly emerging. The aim of this work is to To assess the efficacy of trichloroacetic acid (TCA) chemical peel, dermapen, and fractional CO₂ laser in treatment of stable non-segmental vitiligo and to detect their effects on IL-17 and MMP-9 levels. Thirty patients with stable vitiligo were recruited in a randomized controlled study. They were randomly categorized into three equal groups. Group 1: TCA peel, Group 2: dermapen machine, and Group 3: Fractional CO₂ laser. Skin biopsies were taken from treated areas and from control areas for which MMP-9 and IL-17 tissue levels were measured using ELISA. The 30 vitiligo patients had low basal tissue MMP-9 levels and high baseline IL-17 tissue levels. As regards the three different used modalities, all of them caused rise in MMP-9 as well as IL-17 levels and almost their levels were much more elevated with repetition of the previously mentioned traumatic procedures. TCA 25% peel proved to be the most effective modality both clinically and laboratory and it can be used prior or with other conventional therapies in the treatment of vitiligo.

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.

Liver X Receptor-α polymorphisms (rs11039155 and rs2279238) are associated with susceptibility to vitiligo

Vitiligo is a complex genetic skin depigmentation disorder caused by the destruction of melanocyte from the lesional site. Liver X Receptor-α (LXR-α) expression is upregulated in the melanocytes from perilesional skin as compared to the normal skin of vitiligo patient suggesting its involvement in vitiligo pathogenesis. Polymorphisms in LXR-α have been associated with several diseases including cardiovascular disease, polycystic ovary syndrome, cancer, inflammatory bowel disease and diabetes. In this study, for the first time, we have investigated the association of LXR-α gene polymorphisms and risk of vitiligo. Sixty six vitiligo patients and 75 matched healthy control subjects who did not have any history of vitiligo or any other autoimmune disorder were recruited. The DNA isolated from patients and healthy controls was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) for both rs11039155 (- 6 G > A) and rs2279238 (+ 1257 C > T) variants. Our data suggest significant association between the LXR-α gene polymorphisms and vitiligo susceptibility (rs11039155: odds ratio (OR) = 1.99, 95% CI = 1.07-3.71, p = 0.03; rs2279238: OR = 1.70, 95% CI = 1.06-2.73, p = 0.027). Our results provide an evidence that the LXR-α - 6A and + 1257T alleles contribute to risk of vitiligo in North Indian population and highlight the importance of this gene in the vitiligo pathogenesis.

Effects of a preceding fractional carbon dioxide laser on the outcome of combined local narrowband ultraviolet B and topical steroids in patients with vitiligo in difficult-to-treat areas

BACKGROUND AND OBJECTIVE

Conventional treatment of vitiligo on hands and feet often produces an unsatisfactory result. Various ablative treatment methods were tried with favorable results in facial, neck, and truncal areas. The aim of this study is to evaluate the efficacy and safety of combined fractional CO2 laser, narrowband UVB (NB-UVB) phototherapy, and topical clobetasol propionate in managing stable vitiligo in difficult-to-treat areas.

STUDY DESIGN

A prospective randomized-intraindividual study was conducted on 27 patients with 27 pair-lesions of non-segmental vitiligo on both hands. The lesions were randomized to receive treatment with fractional CO2 laser, NB-UVB phototherapy, and 0.05% clobetasol propionate cream (Group A) or NB-UVB phototherapy and 0.05% clobetasol propionate cream (Group B). Fractional CO2 laser was performed at 1-week interval for 10 sessions. NB-UVB phototherapy was administered twice weekly for 20 sessions. Patients were evaluated 12 weeks after the last treatment. Outcome was evaluated objectively based on standard digital photographs, patient satisfaction, and adverse events.

RESULTS

Twenty-six patients completed the study. Six vitiligious lesions (23.1%) in group A achieved good to excellent repigmentation compared with one lesion (3.9%) in group B (P = 0.065). The overall mean improvement score was 1.35 (± 1.38) in group A and 0.50 (± 0.95) in group B (P = 0.0004). Patients' satisfaction score was significantly higher for the lesions in group A than group B. Lesions on the dorsum of the hand showed a higher response rate than those on the fingers. No serious side-effects were noted.

CONCLUSION

This study demonstrates that adding fractional CO2 laser treatment to NB-UVB phototherapy and topical steroids improves the repigmentation rate of vitiliginous lesions on hands in some patients. This technique may be offered to vitiligo patients who are unresponsive to other treatments.

Human pigmentation: A side effect adapted from a primitive organism's survival. Part 2: The melanocyte as mentor of the keratinocye

Pigmentation featured millions of years ago and perhaps began with an amoeba frightening off a predator with some agent such as dopamine to prevent its attachment for phagocytosis by an enemy. This paper suggests that the environmental forces of grip and stick, rather than pure chemical influences, deserve greater emphasis, and that the influence of the mechanical forces involved in grip and stick or release from attachment, all point to control of proteases as a function underlying pigmentation. How and why pigmentation varies with temperature and sunlight is discussed. The toxicity of melanin, pH, transepidermal water loss, and the influence of endocrine factors are also addressed.

Fractional laser for vitiligo treated by 10,600 nm ablative fractional carbon dioxide laser followed by sun exposure

BACKGROUND

Vitiligo is an acquired disorder of the skin and mucous membranes. Many patients with vitiligo remain in the refractory state despite the availability of numerous potential treatments. To the best of our knowledge, only one trial considers ablative fractional CO2 laser in the treatment of vitiligo.

OBJECTIVE

To investigate the effects of fractional CO2 laser followed by systemic sun exposure on non-segmental vitiligo (NSV).

METHODS

Ten patients presenting refractory NSV were enrolled in this study. The patients underwent three sessions, one month apart, of fractional CO2 laser therapy on the affected areas of the skin (L-group). Five days after each laser treatment, patients were asked to expose themselves to the sun for 2 hours on a daily basis. Objective and subjective clinical assessments were performed at the beginning and at the end of the treatment. The L-group was then compared to a control group (C-group) that consisted of vitiligo lesions in the same patients but with sun exposure as the exclusive therapy.

RESULTS

Compared to the C-group, the L-group showed better improvement in both objective and subjective assessments. There were no noticeable adverse events in terms of scarring and Koebner phenomenon among others.

CONCLUSIONS

All patients treated with both, laser sessions and sun exposure, improved their chronic NSV lesions. Improvement was less significant in patients who exhibited vitiligo lesions over articular surfaces such as elbows and underarms. The best results were observed in vitiligo plaques located on the face, neck and legs. Consequently, fractional CO2 laser followed by sun exposure could be considered as an alternative modality for the treatment of refractory vitiligo, especially in sunny regions.

Novel genes and pathways modulated by syndecan-1: implications for the proliferation and cell-cycle regulation of malignant mesothelioma cells

Malignant pleural mesothelioma is a highly malignant tumor, originating from mesothelial cells of the serous cavities. In mesothelioma the expression of syndecan-1 correlates to epithelioid morphology and inhibition of growth and migration. Our previous data suggest a complex role of syndecan-1 in mesothelioma cell proliferation although the exact underlying molecular mechanisms are not completely elucidated. The aim of this study is therefore to disclose critical genes and pathways affected by syndecan-1 in mesothelioma; in order to better understand its importance for tumor cell growth and proliferation. We modulated the expression of syndecan-1 in a human mesothelioma cell line via both overexpression and silencing, and followed the transcriptomic responses with microarray analysis. To project the transcriptome analysis on the full-dimensional picture of cellular regulation, we applied pathway analysis using Ingenuity Pathway Analysis (IPA) and a novel method of network enrichment analysis (NEA) which elucidated signaling relations between differentially expressed genes and pathways acting via various molecular mechanisms. Syndecan-1 overexpression had profound effects on genes involved in regulation of cell growth, cell cycle progression, adhesion, migration and extracellular matrix organization. In particular, expression of several growth factors, interleukins, and enzymes of importance for heparan sulfate sulfation pattern, extracellular matrix proteins and proteoglycans were significantly altered. Syndecan-1 silencing had less powerful effect on the transcriptome compared to overexpression, which can be explained by the already low initial syndecan-1 level of these cells. Nevertheless, 14 genes showed response to both up- and downregulation of syndecan-1. The "cytokine - cytokine-receptor interaction", the TGF-β, EGF, VEGF and ERK/MAPK pathways were enriched in both experimental settings. Most strikingly, nearly all analyzed pathways related to cell cycle were enriched after syndecan-1 silencing and depleted after syndecan-1 overexpression. Syndecan-1 regulates proliferation in a highly complex way, although the exact contribution of the altered pathways necessitates further functional studies.

Novel genes and pathways modulated by syndecan-1: implications for the proliferation and cell-cycle regulation of malignant mesothelioma cells

Malignant pleural mesothelioma is a highly malignant tumor, originating from mesothelial cells of the serous cavities. In mesothelioma the expression of syndecan-1 correlates to epithelioid morphology and inhibition of growth and migration. Our previous data suggest a complex role of syndecan-1 in mesothelioma cell proliferation although the exact underlying molecular mechanisms are not completely elucidated. The aim of this study is therefore to disclose critical genes and pathways affected by syndecan-1 in mesothelioma; in order to better understand its importance for tumor cell growth and proliferation. We modulated the expression of syndecan-1 in a human mesothelioma cell line via both overexpression and silencing, and followed the transcriptomic responses with microarray analysis. To project the transcriptome analysis on the full-dimensional picture of cellular regulation, we applied pathway analysis using Ingenuity Pathway Analysis (IPA) and a novel method of network enrichment analysis (NEA) which elucidated signaling relations between differentially expressed genes and pathways acting via various molecular mechanisms. Syndecan-1 overexpression had profound effects on genes involved in regulation of cell growth, cell cycle progression, adhesion, migration and extracellular matrix organization. In particular, expression of several growth factors, interleukins, and enzymes of importance for heparan sulfate sulfation pattern, extracellular matrix proteins and proteoglycans were significantly altered. Syndecan-1 silencing had less powerful effect on the transcriptome compared to overexpression, which can be explained by the already low initial syndecan-1 level of these cells. Nevertheless, 14 genes showed response to both up- and downregulation of syndecan-1. The "cytokine - cytokine-receptor interaction", the TGF-β, EGF, VEGF and ERK/MAPK pathways were enriched in both experimental settings. Most strikingly, nearly all analyzed pathways related to cell cycle were enriched after syndecan-1 silencing and depleted after syndecan-1 overexpression. Syndecan-1 regulates proliferation in a highly complex way, although the exact contribution of the altered pathways necessitates further functional studies.