Chieh-Shan Wu

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

Abstract:  Narrow‐band ultraviolet‐B (UVB) radiation is an effective treatment for vitiligo vulgaris. However, the mechanisms of narrow‐band UVB in inducing repigmentation of vitiligo lesions are not thoroughly clarified. The purpose of our study was to investigate the effects of narrow‐band UVB irradiation on melanocyte proliferation and migration in vitro. Our results showed that the cell counts as well as [3H]thymidine uptake of melanocytes were significantly enhanced by narrow‐band UVB‐irradiated keratinocyte supernatants. In these supernatants, a significant increase in basic fibroblast growth factor (bFGF) and in endothelin‐1 (ET‐1) release was observed. bFGF is a natural mitogen for melanocytes, whereas ET‐1 can stimulate DNA synthesis in melanocytes. This stimulatory effect of melanocyte proliferation by supernatants derived from narrow‐band UVB‐irradiated keratinocytes was significantly reduced by a selective endothelin‐B (ET‐B) receptor antagonist (BQ788), suggesting an essential role of ET‐1 on melanocyte proliferation. Our results of time‐lapse microphotography revealed a stimulatory effect of narrow‐band UVB irradiation on melanocyte migration. Focal adhesion kinase (FAK) plays a pivotal role in cell migration. Phosphorylated FAK (p125FAK) expression on melanocyte was enhanced by narrow‐band UVB irradiation. In this study, narrow‐band UVB irradiation stimulated a significant increase in matrix metalloproteinase‐2 (MMP‐2) activity in melanocyte supernatants. Narrow‐band UVB‐irradiation‐induced migration of melanocytes was significantly annihilated by the addition of p125FAK inhibitor (herbimycin‐A) or MMP‐2 inhibitor (GM6001). These results suggest that p125FAK and MMP‐2 activity play important roles in narrow‐band UVB‐induced migration of melanocytes. Our results provide a theoretical basis for the effectiveness of narrow‐band UVB irradiation in treating vitiligo.

Cutaneous blood flow and adrenoceptor response increase in segmental-type vitiligo lesions

It has been proposed that two types of vitiligo exist from the physiological and clinical points of view. Nonsegmental-type vitiligo is associated with autoimmune diseases while segmental-type vitiligo results from the dysfunction of sympathetic nerves in the affected area. Using laser Doppler flowmetry and iontophoresis for cutaneous microcirculatory assessments, we evaluated these two types of vitiligo in regard to their physiological changes. Ten patients with facial stable stage segmental-type vitiligo and ten stable nonsegmental-type vitiligo patients were selected for this study. Our results revealed that a nearly threefold increase in cutaneous blood flow was noticed in segmental-type vitiligo as compared to contralateral normal skin. In contrast, a 1.4-1.5 times difference was found among nonsegmental-type vitiligo, lesion side clinically normal skin and contralateral normal skin. There was a significant increase in cutaneous alpha- and beta-adrenoceptor response in segmental-type vitiligo lesions. However, no change in plasma catecholamines or adrenoceptor densities on blood cells was noticed. Our findings suggest that a dysfunction of the sympathetic nerves exists in the affected skin and plays a role in the pathogenesis of segmental-type vitiligo.

Low-Energy Helium-Neon Laser Therapy Induces Repigmentation and Improves the Abnormalities of Cutaneous Microcirculation in Segmental-Type Vitiligo Lesions

Segmental vitiligo (SV) is a special form of vitiligo occurring in a dermatomal distribution, and an abnormality involving the sympathetic nerves supplying the affected dermatome is known to underlie this disorder. Previously, we have shown that SV is associated with an abnormal increase in cutaneous blood flow and adrenoceptor responses in the affected areas. Since SV is resistant to conventional forms of therapy, its management represents a challenge for dermatologists. Low energy helium‐neon lasers (He‐Ne laser, wavelength 632.8nm) have been employed as a therapeutic instrument in many clinical situations, including vitiligo management and repair of nerve injury. The purpose of this study was to evaluate the effectiveness and safety of He‐Ne lasers in treating SV, and determine their effects on the repair of sympathetic nerve dysfunction. Forty patients with stable‐stage SV on the head and/or neck were enrolled in this study. He‐Ne laser irradiation was administered locally at 3.0J/cm2 with point stimulation once or twice weekly. Cutaneous microcirculatory assessments in six SV patients were performed using a laser Doppler flowmeter. The sympathetic adrenoceptor response of cutaneous microcirculation was determined by measuring cutaneous blood flow before, during and after iontophoresis with sympathomimetic drugs (phenylephrine, clonidine and propranolol). All measurements of microcirculation obtained at SV lesions were simultaneously compared with contralateral normal skin, both before and after He‐Ne laser treatment. After an average of 17 treatment sessions, initial repigmentation was noticed in the majority of patients. Marked repigmentation (> 50%) was observed in 60% of patients with successive treatments. Cutaneous blood flow was significantly higher at SV lesions compared with contralateral skin, but this was normalized after He‐Ne laser treatment. In addition, the abnormal decrease in cutaneous blood flow in response to clonidine was improved by He‐Ne laser therapy. Our study showed that He‐Ne laser therapy is an effective treatment for SV by normalizing dysfunctions of cutaneous blood flow and adrenoceptor responses in SV patients. Thus, the beneficial effects of He‐Ne laser therapy may be mediated in part by a reparative effect on sympathetic nerve dysfunction.

Differential CCR4 Expression and Function in Cutaneous T-Cell Lymphoma Cell Lines

Cutaneous T cell lymphoma (CTCL) is a clonal epidermotropic malignancy of memory T cells primarily involving the skin. However, the mechanisms governing migration of CTCL cells have not been fully clarified. It has been shown that certain chemokine receptors are upregulated in CTCL cells, but it remains unanswered whether these chemokine receptors play a critical role in the migration dynamics of CTCL. Using cell lines originally derived from patients with different subtypes of CTCL, we have shown higher CCR4 expression in the line derived from the mycosis fungoides (MJ), compared with the line derived from Sézary syndrome (Hut78). In specific responses to CCL22 (a CCR4 ligand) treatments, MJ cells showed significant chemotactic migration, enhanced activation and adhesion of certain integrins (CD49d and CD29) in vitro, while the control cells (Hut78, CD4+CD45RO+ memory T cells, and Jurkat cells) did not. Furthermore, compared with Hut78 cells, MJ cells manifested significantly more transendothelial migration in responses to treatments with either CCL22 or conditioned medium from dendritic cells in vitro. These results provide further dynamic evidence, in line with the multistep cascade paradigm for leukocyte transendothelial migration, to support a critical role for CCR4 in CTCL migration.

Silver-containing Hydrofiber Dressing is an Effective Adjunct in the Treatment of Pemphigus Vulgaris

Pemphigus vulgaris is a life‐threatening autoimmune bullous dermatosis and its management represents a major challenge to medical teams. The primary treatments for pemphigus vulgaris are oral steroids and immunosuppressants, but topical approaches also play a role in disease management. Here, we report a patient with pemphigus vulgaris involving 62% of the total body surface area, with initial poor clinical response to systemic steroids and topical silver sulfadiazine therapy. However, a marked improvement in wound healing and decreased patient discomfort were observed after application of silver‐containing hydrofiber dressings (Aquacel‐Ag®). Therefore, silver‐containing hydrofiber dressings may offer an effective adjunct in the treatment of patients with pemphigus vulgaris with extensive skin involvement. Our encouraging experience with these dressing patches may be extended to manage other large exudation wounds.

Phakomatosis cesioflammea with late-onset glaucoma and acquired nevus spilus-like lesion - 15 years of follow-up.

Phakomatosis pigmentovascularis is a very rare disease characterized by coexistence of a capillary malformation with various melanocytic lesions, including dermal melanocytosis (Mongolian spots), nevus spilus, and nevus of Ota. As of now about 200 cases have been reported, most are of Japanese origin and about half of reported cases are associated with various systemic involvement. We present a 15‐year‐old Taiwanese male with phakomatosis cesioflammea who developed, during adolescence, a nevus spilus‐like lesion and late‐onset open angle glaucoma, suggesting that long‐term ophthalmic follow‐up is necessary in this type of patient.

Various UVB doses affect change of raf kinase inhibitor protein, nitric oxide and proliferation in keratinocytes

UVB is a potent modulator of cell growth and differentiation in the skin. The UVB irradiation has been used in treating hyperproliferative dermatoses. Otherwise, UVB radiation is also the major risk factor for developing skin cancer. Nitric oxide (NO) has been suggested to be a physiological modulator of cell proliferation. Raf-1 kinase inhibitory protein (RKIP) was involved in cell growth, transformation, and differentiation. The purpose of this study was to search for the possible cause of UVB-inhibited hyperplasia and UVB-resulted hyperproliferation. We evaluated various UVB dose whether affect the expression of RKIP, iNOS, NO and proliferation in keratinocyte. Normal human keratinocytes were treated with UVB dose of 40mJ/cm2, 80mJ/cm2, 120mJ/cm2, 160mJ/cm2 and 0mJ/cm2 (control group) respectively. The results showed that RKIP, iNOS and NO of keratinocytes with doses of 40mJ/cm2 and 80mJ/cm2 UVB treatment significantly higher than control group (P<0.01). The proliferation of keratinocyte with doses of 40mJ/cm2 and 80mJ/cm2 UVB treatment was significantly lower than control group (P<0.01). However, RKIP, iNOS and NO of keratinocytes with doses of 120mJ/cm2 and 160mJ/cm2 UVB treatment significantly lower than control group (P<0.01). The proliferation of keratinocyte with doses of 120mJ/cm2 and 160mJ/cm2 UVB treatment was significantly higher than control group (P<0.01). In conclusion, these results showed that the different UVB dosages induced various alteration of RKIP, NO, iNOS and proliferation may provide important information on the therapeutic molecular mechanism of UVB-inhibited hyperplasia and UVB resulted hyperproliferation.

Chemokine receptor CCR3 is important for migration of mast cells in neurofibroma

Background Neurofibroma consists of abundant extracellular matrix and many types of cells, including Schwann cells (SCs), mast cells (MCs), fibroblasts and endothelial cells. As SCs have been found to be the cell of origin for neurofibroma, how MCs may migrate into the tumor has not been fully clarified. Given that chemokine receptor CCR3 is found predominantly expressed by differentiated MCs, we postulated that CCR3 may play a role in the homing of MCs to neurofibroma. The goal of this study is to investigate the possible involvement of chemokine receptor CCR3 in the migration of MCs to the neurofibroma. Methods Expressional and functional assays for CCR3 and its ligands were performed on MCs and SCs. Results By real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, we found one of the CCR3 ligand, CCL7 was highly expressed by murine SC cell line SW10, and also moderately expressed by MCs. In serial chemotaxis assays, MCs were found specifically responsive to CCL7 and also condition medium from SW10 cells, indicating SCs may attract MCs by CCR3-mediated cell migration. Conclusion The interaction of CCR3 and CCL7 may play important roles for MC migration toward SC in the neurofibroma.