Repigmentation Of Skin Research Articles

The skin delivery of tofacitinib citrate using transethosomes and hybridized ethosomes/nanostructured lipid carriers for vitiligo therapy: Dermatopharmacokinetics and in vivo assays

Vitiligo is an autoimmune disease where its current treatment strategies are lengthy in course and do not guarantee complete cure. Tofacitinib citrate (JAK inhibitor) is a potential cure of vitiligo through halting JAK-STAT pathway preventing the destruction of melanocytes. The dermato-pharmacokinetics of the prepared transethosomes (Et) and the hybridized ethosomes/nanostructured lipid carriers (Eth/NLC), namely formulations; M.E-Cr and M.E-S.M, were evaluated. In addition, in vivo studies on C57/BL6 vitiligo mouse model were conducted to confirm effectiveness of Tofacitinib citrate delivery. The results unveiled that the transethosomes (359.46 ± 11.82 nm) were suitable for dermal delivery while M.E-Cr (179.64 ± 11.16 nm), a hybrid Eth/NLC formulation, was mostly suitable for transdermal delivery. Nevertheless, another hybrid formulation, M.E-S.M (253.60 ± 14.64 nm), was apt for both dermal and transdermal delivery. The histopathology confirmed re-pigmentation of mice skin where formulations Et and M.E-S.M showed severe pigmentation compared to the control healthy and induced mice. On the other hand, M.E-Cr showed mild pigmentation. Immunohistochemical assay was performed to evaluate infiltration of CD 8+T-lymphocytes where mild infiltration was observed. However, the systemic IFN-γ was significantly reduced in case of M.E-Cr and M.E-S.M. The present work proposed potential effective formulations to improve the treatment of vitiligo with potential reduction in the total therapeutic dose, drug’s side effects, and treatment costs.

Babchi unani marketed formulation effective in treatment of vitiligo: A case study

Bars (vitiligo) are defined in ancient unani classic as an idiopathic achromia in which skin looses its color. Due to melanocytes deficiency, white spots appeared on body. It may be localized or may spread and become generalized. The disease condition may be stable or some time spread over the body. leucotricha is also sometimes associated with Bars. The achievement of treating this condition in conventional medicines is limited and sometimes, treatment follows with side effects. Though a few case records are documented in the past about the success of various unani medicines. Numerous Unani drugs are well known for the regeneration of melanocytes. The current study was planned to highlight the use of Unani formulation to fight Vitiligo. A 11 year old male have chalky white patches with hypopigmentation without itching over hand, legs, stomach or on back for 1 year, gradually spreading over the chest. The patient was treated with unani oral medication (nobar tablet) and applied ointment, babchi oil locally. After treatment there was repigmentation of skin without any side effect. The treatment modility showed color changes of patches from chalky white to brown and it conclude that unani formulation effective in treatment of vitiligo.

Comparison of efficacy of noncultured hair follicle cell suspension and noncultured epidermal cell suspension in repigmentation of leukotrichia and skin patch in vitiligo: a randomized trial.

Vitiligo manifests as hypo- to de-pigmented macules, which are sometimes associated with leukotrichia. For complete cosmetic improvement, the repigmentation of leukotrichia is an important component. This randomized controlled trial included patients with stable vitiligo with leukotrichia. Two vitiligo patches in each patient were randomized to receive either of the two procedures. The patients were followed up for 9months posttransplantation. The efficacy of hair follicle cell suspension (HFCS) with epidermal cell suspension (ECS) in repigmentation of leukotrichia and skin in vitiligo was compared. A total of 20 patients underwent the procedure, and 19 completed the follow-up. The area of the vitiligo patch and the number of leukotrichia in the patches were comparable between the two groups. There was a significant difference in the mean±S.D. number of cells transplanted between the two groups (5.06×105 in HFCS vs. 39.8×105 in ECS, P<0.0001). The percentage viability of cells and proportion of melanocytes were comparable between the two groups. A total of 10 patients in HFCS and eight patients in ECS had repigmentation of leukotrichia. The mean±S.D. percentages of depigmented hair showing repigmentation at nine months were 7.42±11.62% in HFCS and 11.42±17.90% in ECS (P=0.4195), whereas the mean±S.D. percentage repigmentation of vitiligo patches was 61.58±42.68% in HFCS and 78.68±30.03% in ECS (P=0.1618). The mean number of cells transplanted in the HFCS group was about eight times less than those in ECS. ECS was better than HFCS in repigmentation of leukotrichia and vitiligo, although the difference was not statistically significant.

The enigma and challenges of vitiligo pathophysiology and treatment.

Vitiligo is the most common acquired pigmentary disorder, which afflicts 0.5%-1% of the world population, and is characterized by depigmented skin patches resulting from melanocyte loss. Vitiligo has a complex etiology and varies in its manifestations, progression, and response to treatment. It presents as an autoimmune disease, evidenced by circulating melanocyte-specific antibodies, and association with other autoimmune diseases. However, autoimmunity may be secondary to the high oxidative stress in vitiligo skin and to intrinsic defects in melanocytes and their microenvironment, which contribute to aberrant stress response, neo-antigenicity, and susceptibility of melanocytes to immune attack and apoptosis. There is also a genetic predisposition to vitiligo, which sensitizes melanocytes to environmental agents, such as phenolic compounds. Currently, there are different treatment modalities for re-pigmenting vitiligo skin. However, when repigmentation is achieved, the major challenge is maintaining the pigmentation, which is lost in 40% of cases. In this review, we present an overview of the clinical aspects of vitiligo, its pathophysiology, the intrinsic defects in melanocytes and their microenvironment, and treatment strategies. Based on lessons from the biology of human melanocytes, we present our perspective of how repigmentation of vitiligo skin can be achieved and sustained.

Efficiency of Ayurveda modalities in the management of Switra (Vitiligo): A case report

Beauty and attraction of an individual depend on skin condition. However, there are certain pathologies which wipe out this beauty and attraction by altering skin health. Vitiligo is a condition, which means “to have white skin.” In Ayurveda, it is referred as Switra or Kilasa and cited under the category of Kushta rogas (~skin diseases). It is caused by the imbalance of all the three Doshas (~three regulatory functional factors of the body) vitiating Rakta (~blood tissue), Mamsa (~muscle tissue), and Medas (~fat tissue). A 32-year-old male came to the outpatient department with complaints of chalky white patches with hypo-pigmented border without itching over the chest and face for two years, gradually spreading over the chest. The patient was treated with Ayurvedic oral medications and Virechana karma (~therapeutic purgation) along with the instructions of Pathya (~wholesome diet and lifestyle) and Apathya (~unwholesome diet and lifestyle). After treatment, there was repigmentation of skin without any side effects. The treatment modalities showed color changes of patches from chalky white to pinkish inferring that Ayurveda has treatment approaches to manage condition like Switra (~vitiligo).

&lt;p&gt;Vitiligo – New Treatment Approach&lt;/p&gt;

IntroductionVitiligo is one of the most common hypomelanoses. Current treatments include ultraviolet, topical corticosteroids, calcineurin inhibitors. Orally administered vitamins, acting as anti-oxidants and in combination with ultraviolet light have also demonstrated skin re-pigmentation. In our pilot study of seven patients, we injected skin affected with vitiligo intra-dermally with a complex of vitamins and minerals and assessed the outcome.AimThe aim of this study was to evaluate a novel treatment modality for vitiligo.MethodsWe present a pilot study of seven patients; each having been diagnosed with generalized progressive vitiligo. In all cases, multiple therapies had been previously attempted. All patients were subjected to intradermal injections of biorevitalizant NCTF 135 (3 mls) in the hypo-pigmented areas of skin, once a week for 5 weeks. A 30Gx13 mm needle was used for the 0.025 mls intradermal injections to create micro-papules with a 1 cm distance between the injection sites. The results were assessed at 2 weeks and 5 weeks and were considered successful if partial or complete repigmentation was achieved.ResultsPartial or complete skin re-pigmentation post-treatment was observed in vitiligo macules of all patients (100%). No significant side effects, or exacerbation of vitiligo were observed during or after treatment with NCTF 135 in the following 6 months (five patients) and 12 months (two patients).DiscussionIncreasing the armamentarium of new treatments of vitiligo is important. Previous studies showed the effectiveness of oral and intramuscularly injected multivitamins in the treatment of vitiligo, explaining the results by the antioxidative qualities of the above. Our study demonstrated that intradermal mesotherapy injections of NCTF135, rich with vitamins and other antioxidants are well tolerated and effective in achieving significant re-pigmentation of de-pigmented skin in all patients studied, including five who had been resistant to previous standard therapies.

Direct Transplant of Melanocytes from Normal Donor Area into Vitiligenous Recipient Area by Intralesional Injection of Melanocytes Using Spade Like Needle Technique

Background: Vitiligo is a common autoimmune inflammatory skin disease, where there are different surgical techniques for treatment of stable patches of vitiligo .Objective: To find non-costly, minimally invasive, simple technique by direct melanocytes transplant by spade needle technique in treatment of vitiligo. Patients and Methods: This interventional, therapeutic, comparative study was done in Department of Dermatology, Baghdad Teaching Hospital, Baghdad, Iraq from April 2014-March 2015. Twenty patients with localized, generalized and segmental vitiligo were included. Full history and examination for each patient was done with 4 (20%) males and 16 (80%) females and their ages ranged from 9 - 40 (23.15 ± 11.44) years. Forty one patches in 20 patients treated by spade grafting technique and the donor and recipient sites were demarcated and anesthesia done by xylocaine 2% with adrenalin 1:100,000. Transplantation was started by using disposable needle gauge 18 (the sharp end of needle was cut by a scissor to make it a spade like) with medical syringe 5 ml supplied with normal saline. The micro-pieces were taken from donor site and transplanted directly, easily and rapidly into dermis of recipient site and followed by pushing normal saline and the procedure was repeated to cover all recipient sites with 5 mm distance between injection points. The surface area of the lesions was calculated and the reduction rate was estimated every month till the end of the 4th month period of the treatment. Results: Including 41 patches in 20 patients with the surface area of the patches ranged from 1.5 - 90 cm2 (13.78 ± 17.57) cm2. The mean ±SD of surface area of lesions was decreased from 13.78 ± 17.57 cm2 at baseline visit to 13.61 ± 17.48 cm2 at the second visit (after 2 weeks ) which was statistically significant (p value ≤ 0.001). The mean surface area continued to be reduced till reaching 12.20 ± 15.68 cm2 at the third visit and 12.01 ± 15.55 cm2 at the fourth visit. All were statistically significant when compared to baseline visit. There was reduction in surface area 1.1% at two weeks, 9.93%, and 12.5% at the 2nd, 4th months respectively. Conclusions: Intradermal injection of melanocytes in patients with vitiligo by spade like needle was very quick and simple non-costly technique, and gave 12.5% reduction which could be repeated at different times until satisfactory re-pigmentation of vitiligenous skin is achieved.

Efficacy of single-hair follicular unit transplantation in the treatment of vitiligo in hair-bearing areas

Objective To evaluate the efficacy of single-hair follicular unit transplantation in the treatment of vitiligo in hair-bearing areas, and to estimate the performance of dermoscopy in efficacy evaluation. Methods Eighty-nine patients with vitiligo in hair-bearing areas were divided into two groups: a treatment group (38 patients with 46 vitiligo lesions) receiving single-hair follicular unit transplantation, a control group (51 patients with 67 vitiligo lesions) treated with topical drugs. Follow up visits were scheduled every 4 weeks for 24 weeks. The growth of epidermal melanocytes and degree of repigmentation were evaluated by both dermoscopy and naked eyes at every visit. Results A better outcome was achieved in the treatment group compared with the control group. Of the 46 vitiligo lesions receiving transplantation, 12 achieved complete repigmentation of white hairs and skin around transplanted hair follicles, with a marked response rate of 54.3% . Perifollicular repigmentation was seen by dermoscopy as early as 4 weeks after the transplantation, and gradually expanded and coalesced thereafter. The average time required for the appearance of repigmentation was 9.8 weeks by dermoscopy, markedly shorter than that by naked eyes (14.5 weeks). After transplantation, microcirculation in vitiligo lesions was improved obviously, skin was softened, and skin texture became clear, but no correlation was observed with the appearance of perifollicular pigmentation islands. No complications such as scarring or infection occurred at incision sites after the operation. Conclusion Single-hair follicular unit transplantation is safe, simple to operate, and effective for the treatment of vitiligo in hair-bearing areas. Key words: Vitiligo; Hair; Hair follicle; Transplantation; Dermoscopy

Topical delivery of clobetasol propionate loaded microemulsion based gel for effective treatment of vitiligo – Part II: Rheological characterization and in vivo assessment through dermatopharmacokinetic and pilot clinical studies

Vitiligo is a non contagious acquired pigmentation disorder with limited treatment possibilities. Clobetasol propionate (CP) is the drug-of-choice for vitiligo which suppresses the immune system by reducing immunoglobulin action and causes the restoration of melanocytes leading to repigmentation of skin. However, despite being effective, its low and variable bioavailability prompt for development of novel carrier that could effectively target CP to site of action without producing undesirable side-effects. Low solubility of CP in subsequent poor in vivo bioavailability was overcome by formulating microemulsion based gel of CP (MBC) which would enhance the percutaneous transport of CP into and across the skin barrier. Comprehensive characterization of MBC was carried out for viscosity, gel strength and rheological behavior. In vitro studies revealed much higher drug release, skin penetration and enhanced skin accumulation as compared to control (Cream of CP). In vitro and in vivo occlusion studies demonstrated similar occlusiveness for MBC and control. MBC exhibited 3.16 times higher stratum corneum CP levels compared to control. Visualization of cutaneous uptake in vivo using laser scanning microscopy confirmed targeting of CP to epidermis and dermis. Dermatopharmacokinetic studies of MBC showed enhanced drug deposition of CP in skin layers. MBC was assessed for in vivo efficacy by single blind randomized pilot clinical study. The efficacy was assessed by vitiligo area scoring index (VASI) method. After completion of trial, repigmentation of vitiligo patches in patients were evaluated and scored. MBC was superior in terms of faster repigmentation and efficacy when compared with control (p value<0.5). Hence, it was concluded that CP loaded MBC possess enhanced skin localization as well as therapeutic activity in vitiligo patients.

Repigmentation of vitiligo-associated leukotrichia after autologous, non-cultured melanocyte-keratinocyte transplantation

Many cases of leukotrichia are associated with vitiligo. Hair follicles are believed to be the source of melanocytes for skin repigmentation using standard medical therapy for vitiligo. Vitiliginous areas with overlying leukotrichia usually fail to achieve repigmentation by conventional medical treatments as a result of a deficient melanocyte reservoir. Even after the successful repigmentation of vitiliginous skin by medical therapies, leukotrichia hairs may remain depigmented, causing a major psychological impact to the patient. In such cases, surgical treatments may help to achieve the repigmentation of leukotrichia hairs. Reports of successful repigmentation in leukotrichia using different surgical treatments for vitiligo are few. This study reports the benefit of autologous non-cultured melanocyte-keratinocyte transplantation (MKT) in patients with vitiligo-associated leukotrichia. We report four cases of vitiligo-associated leukotrichia treated with MKT. All four patients showed significant repigmentation in vitiligo-associated leukotrichia after MKT. Melanocyte-keratinocyte transplantation may represent a good therapeutic option for the repigmentation of vitiligo-associated leukotrichia. This series includes only four responsive cases. Larger prospective studies are needed to determine the true response rate and mechanism of repigmentation.

Basic evidence for epidermal H 2 O 2 /ONOO – ‐mediated oxidation/nitration in segmental vitiligo is supported by repigmentation of skin and eyelashes after reduction of epidermal H 2 O 2 with topical NB‐UVB‐activated pseudocatalase PC‐KUS

Nonsegmental vitiligo (NSV) is characterized by loss of inherited skin color. The cause of the disease is still unknown despite accumulating in vivo and in vitro evidence of massive epidermal oxidative stress via H2O2 and peroxynitrite (ONOO(-)) in affected individuals. The most favored hypothesis is based on autoimmune mechanisms. Strictly segmental vitiligo (SSV) with dermatomal distribution is a rare entity, often associated with stable outcome. Recently, it was documented that this form can be associated with NSV (mixed vitiligo). We here asked the question whether ROS and possibly ONOO(-) could be players in the pathogenesis of SSV. Our in situ results demonstrate for the first time epidermal biopterin accumulation together with significantly decreased epidermal catalase, thioredoxin/thioreoxin reductase, and MSRA/MSRB expression. Moreover, we show epidermal ONOO(-) accumulation. In vivo FT-Raman spectroscopy reveals the presence of H2O2, methionine sulfoxide, and tryptophan metabolites; i.e., N-formylkynurenine and kynurenine, implying Fenton chemistry in the cascade (n=10). Validation of the basic data stems from successful repigmentation of skin and eyelashes in affected individuals, regardless of SSV or segmental vitiligo in association with NSV after reduction of epidermal H2O2 (n=5). Taken together, our contribution strongly supports H2O2/ONOO-mediated stress in the pathogenesis of SSV. Our findings offer new treatment intervention for lost skin and hair color.

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

Vitiligo is characterized by the loss of functional melanocytes from the epidermis. Repigmentation in vitiligo is initiated by activation, proliferation and migration of melanoblasts from the outer root sheath of hair follicles, or melanocytes from the border area of vitiligo lesions, into the depigmented epidermis. Cell migration plays a crucial role during repigmentation in vitiligo. To investigate the role of matrix metalloproteinases (MMPs) and their transcription factor Ets-1 in vitiligo. Skin biopsies were taken from 15 patients with vitiligo and six controls to culture melanocytes from clinically active perilesional and normal skin. Expression of MMP-1, MMP-2, MMP-9 and Ets-1 was examined by reverse transcriptase-polymerase chain reaction analysis. Expression of Ets-1 was also confirmed with Western blot analysis. Activity of MMP-2 and MMP-9 was assessed using gelatin zymography. The activity of MMP-2 and MMP-9 was significantly lower in patients with vitiligo compared with the controls. The expression of MMP-2 and MMP-9 was also significantly lower in patients with vitiligo. There was no expression of Ets-1 transcription factor at either the transcriptional or translational level in melanocytes cultured from patients with vitiligo. The absence of a basal level of expression of Ets-1 significantly decreases the expression and activity of MMP-2 and MMP-9. Significant decreases in MMP-2 and MMP-9 activity could possibly reduce the migration of melanocyte precursors (melanoblasts) from the outer root sheath of hair follicles or migration of melanocytes from the border of vitiligo lesions into clinically depigmented epidermis which is crucial to the repigmentation of vitiliginous skin.

Highlighting Tacrolimus and Vitiligo

In vitiligo, narrowband ultraviolet B (NB-UVB) spectrum radiation induces repigmentation of the depigmented skin, but treatments require frequent trips

Repigmentation of skin and hairs in stable vitiligo by transplantation of autologous melanocytes in fibrin suspension

Repigmentation of skin and hairs in stable vitiligo by transplantation of autologous melanocytes in fibrin suspension

Endothelin-1 combined with extracellular matrix proteins promotes the adhesion and chemotaxis of amelanotic melanocytes from human hair follicles in vitro

During the repigmentation of vitiliginous skin, amelanotic melanocytes (AMMCs) migrate from the outer root sheath (ORS) of the hair follicles into depigmented skin. It has been shown that endothelin-1 (ET-1) is an important cytokine in the migration of epidermal melanocytes, produced by keratinocytes particularly after irradiation with ultraviolet B (UVB). To further examine the role of ET-1 on the migration of AMMCs, we investigated the effects of ET-1 to the adhesion and chemotaxis of human AMMCs combined with extracellular matrix proteins (ECMP) and observed the effects on the actin and tubulin cytoskeleton of AMMC by ET-1. Human AMMCs were treated with different concentrations of ET-1 (0.1-100 nM) to observe adhesion on culture dishes coated with fibronectin (FN), laminin (LN) and collagen IV (CIV). In addition, chemotaxis on FN, LN and CIV coated micropore filters, with various concentrations of ET-1 as attractants, was investigated using a Boyden chemotaxis chamber. Cellular microfilaments and microtubules were immunostained with Rhodamine labeled actin and FITC labeled beta-tubulin. The effects of ET-1 on cytoskeleton were observed with laser confocal microscopy. The study demonstrated that ET-1 increases human AMMCs adhesion on FN in a dose-dependent manner, but minor increases are found on the coated surface with LN and CIV. ET-1 also induces chemotaxis of AMMCs on CIV, LN and FN in a dose-dependent manner. The greatest effect was seen with CIV. Minor chemotactic effects were observed with non-coated surfaces. A concentration of >or=10nM ET-1 induced an apparent increase in stress fibers underneath the cell membrane, but no effects were found on tubulin. ET-1 has various effects on the adhesion and chemotaxis of AMMCs on various ECMP, which could be partly due to a modulation and reorganization of the actin cytoskeleton.

In vitro migration of melanoblasts requires matrix metalloproteinase-2: implications to vitiligo therapy by photochemotherapy.

It is known that the migration of melanocyte precursors (melanoblasts) from the outer root sheath of hair follicles into clinically depigmented epidermis is crucial to the repigmentation of vitiliginous skin treated with photochemotherapy (PUVA), but such migratory cells must penetrate extracellular matrix tissue barriers in vivo. To test the hypothesis that matrix metalloproteinases (MMPs) are required for this process, we determined whether cultured melb-a cells, an immortal line of melanoblasts isolated from neonatal mouse epidermis, express and secrete MMPs and whether a synthetic metalloproteinase inhibitor, GM6001 (Galardin), inhibits their migratory behavior in vitro. Reverse transcriptase-polymerase chain reaction and Western blotting were used to determine the patterns of MMP expression by melanoblasts at the mRNA and protein levels, respectively. The proteolytic activities of MMPs secreted into the culture medium were assessed by gelatin zymography. The capacity of melanoblasts to migrate on fibronectin, laminin or laminin-5 substrates was estimated using Transwell migration assays. The results show that MMP2, MMP9 and MT1-MMP transcripts are expressed by these melanoblasts, but only MMP2 is secreted and activated in the extracellular environment. Although the therapeutic efficacy of PUVA in stimulating repigmentation of vitiliginous skin might derive from direct effects of UVA and/or 8-methoxypsoralen (8MOP), recent studies have shown that keratinocyte-derived factors induced by ultraviolet radiation, especially alpha-melanocyte stimulating hormone (alpha MSH), play a major role in regulating melanocyte function. Therefore, we also examined whether 8MOP and/or alphaMSH are involved in the up-regulation of MMP2 expression in melanoblasts. Western blotting and zymographic analyses revealed that MMP2 synthesis and secretion were induced by 8MOP and/or by alpha MSH. This induction of MMP2 resulted in significant increases of migration by melanoblasts on laminin or on laminin-5 substrates, while concomitant treatment with GM6001 blocked that induced migration. Taken together, these results suggest the importance of MMP2 in melanoblast migration and in the response to PUVA therapy.

Treatment of Vitiligo With UV-B Radiation vs Topical Psoralen Plus UV-A

To compare the efficacy and safety of 2 treatment modalities, topical psoralen plus UV-A (PUVA) with unsubstituted psoralen and 311-nm UV-B radiation, in patients with vitiligo. This intervention study was designed as a before-and-after trial with 2 arms, in which patients were consecutively included. Male (n = 99) and female (n = 182) patients, who predominantly had skin type III, with extensive, generalized vitiligo of more than 3 months' duration. Two patient groups were investigated. The first group of patients was treated for 4 months with either topical PUVA (n = 28) or 311-nm UV-B radiation (n = 78). The second group of patients, treated twice weekly with 311-nm UV-B radiation, was followed up for 3 (n = 60), 6 (n = 27), 9 (n = 37), or 12 months (n = 51). Thirteen (46%) patients in the first group treated with topical PUVA showed repigmentation after 4 months. Fifty-two patients (67%) in the 311-nm UV-B treatment group showed repigmentation after 4 months. After 3 months, 5 patients (8%) in the second group showed more than 75% repigmentation of lesional skin compared with 32 patients (63%) after 12 months. As in other treatment modalities, the face showed good repigmentation, whereas hands and feet responded poorly. No adverse effects were encountered with treatment with narrowband UV-B radiation, contrary to those seen with topical PUVA treatment. The cumulative UV-B dose was very small compared with that of the topical PUVA treatment. According to our results, the treatment of patients with vitiligo with 311-nm UV-B radiation is as efficient as with topical PUVA and has fewer adverse effects.

Melanocyte Movement In Vitro: Role of Matrix Proteins and Integrin Receptors

During the repigmentation of vitiliginous skin, melanocytes migrate from the outer root sheath of the hair follicle into the depigmented skin. We hypothesize that this requires changes in the local microenvironment that are conductive to melanocyte migration. One important change in the microenvironment could be the localized production of matrix proteins. We have previously employed time-lapse photography to evaluate the effect of inflammatory mediators and cytokines on melanocyte movement. We have adapted this system to study the effect of matrix proteins on melanocyte movement in vitro. Type IV collagen significantly increases melanocyte migration, whereas laminin and fibronectin have no effect. Cell/matrix interactions are in part controlled by cell-surface integrins. Integrins have been demonstrated to be important in controlling the migration of many cell types. We demonstrate that melanocytes express cell-membrane alpha 2, alpha 3, and alpha 5 integrins and that the enhanced melanocyte migration on type IV collagen is inhibited by specific function-blocking antibodies to integrins alpha 2 and alpha 3, but not to alpha 5 integrins.

Vitiligo and idiopathic guttate hypomelanosis. Repigmentation of skin following engraftment onto nude mice

Several diseases are included in the category of hypomelanosis. Their clinical course as well as the pathogenesis are diverse and in many cases poorly understood. The aim of the present study is to use the nude mice model to determine whether the primary defect in various pigmentary skin disorders is inherent to the tissue itself or is secondary to systemic factors. Split-thickness skin grafts obtained from patients with vitiligo, acquired hypomelanosis guttata, and tyrosinase-negative albinism were grafted onto nude mice. Histologic examination and dopa staining were performed prior to and following the engraftment. The dopa staining was performed on the epidermal sheet following separation from the dermis. The depigmented area of the vitiligo became completely pigmented 6 to 10 weeks after skin transplantation. The dopa reaction that was negative prior to skin engraftment became completely positive after the transplantation. The number of melanocytes (expressed per square millimeter of skin surface) 8 weeks after transplantation was 197 +/- 73 mm2. Dopa reaction in acquired hypomelanosis guttata showed reduction of the number of melanocytes in the depigmented macula as compared with the surrounding area (55.25 +/- 18.00 mm2 vs 220 +/- 28.28 mm2. Twenty days after skin transplantation, repigmentation of the area was observed. The number of melanocytes increased significantly (388.75 +/- 213 mm2). The grafted skin obtained from patients with tyrosinase-negative albinism showed persistence of the depigmentation after skin transplantation. Dopa reaction was negative prior to and 8 weeks after transplantation. The results of the present study suggest that systemic factors may play a role in the pathogenesis of vitiligo and acquired hypomelanosis guttata.

Repigmentation of Vitiliginous Skin by Cultured Cells

Epidermal cells from pigmented areas of a patient with vitiligo were cultured in MCDB-153 medium, which supports the clonal growth of undifferentiated keratinocytes and melanocytes. The cells were grown on collagen-coated substrata. After the cells reached semiconfluence, the composite of substratum and cells was emplaced onto dermabraded vitiliginous areas as a graft. Re-epithelialization of the grafted areas was complete after 2 weeks. Repigmentation was evident after 1 month and continued over the observation period of several months. There was complete and normal differentiation of the graft, including a normal distribution of melanocytes in the basal layer. Ultrastructural studies showed a normal distribution of melanosomes in the melanocytes and showed keratinocytes that were indistinguishable from the uninvolved skin.