Oral psoralen with UV-A therapy releases circulating growth factor(s) that stimulates cell proliferation

Abdel-Naser, Mohamed Badawy

doi:10.1001/archderm.133.12.1530

Cited by 15 publications

(6 citation statements)

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“…As bFGF, SCF and HGF are the documented factors that stimulate the growth of MCs, 34,35 our result corroborated the previous study from Abdel‐Naser et al. , 36 showing that sera from patients with vitiligo could promote MC growth. Although PUVA did not induce release of MC mitogens from cultured KCs, the possible explanations for the increase seen in our in vivo results include (i) fibroblasts, another natural cellular neighbour of MCs in vivo , that may release these mitogens after phototherapy; 37–39 and (ii) because at least 20–40 PUVA treatments are generally required before repigmentation occurs in patients, 7 short‐term PUVA treatment may not be adequate to stimulate the release of growth factors by KCs or fibroblasts in vitro .…”

Section: Discussionsupporting

confidence: 90%

Effects of psoralen plus ultraviolet A irradiation on cultured epidermal cells in vitro and patients with vitiligo in vivo

Lan

Chen

et al. 2007

Br J Dermatol

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Our results indicate that in addition to immune suppression, PUVA treatment creates a favourable milieu for promoting the growth of MCs in patients with vitiligo instead of directly stimulating the regrowth of MCs. Based on our results, we propose that in the active stage of vitiligo, PUVA treatment is the therapy of choice to slow down the destruction of MCs and to create a favourable environment for MCs to survive. In the stable stage of vitiligo, NB-UVB irradiation should be used to stimulate the proliferation and migration of MCs directly.

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Section: Discussionsupporting

confidence: 90%

Effects of psoralen plus ultraviolet A irradiation on cultured epidermal cells in vitro and patients with vitiligo in vivo

Lan

Chen

et al. 2007

Br J Dermatol

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“…Pure HMel grown in 12‐ O ‐tetradecanoyl‐phorbol‐13‐acetate (TPA) and serum‐free medium appear as bipolar spindle‐shaped or fibroblast‐like cells 9 ,. 10 , 15 Keratinocytes have been shown to release several factors that induce and increase dendrite formation by melanocytes in vitro 4 ,. 16 The present study failed to show any morphological changes in melanocytes when inoculated with M‐CM, low or high Ca 2+ K‐CM.…”

Section: Discussionmentioning

confidence: 99%

Differential effects on melanocyte growth and melanization of low vs. high calcium keratinocyte-conditioned medium

Abdel-Naser

1999

British Journal of Dermatology

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Epidermal keratinocytes secrete several growth factors that stimulate melanocyte proliferation and melanin pigment synthesis in vitro. As the epidermis is formed of two distinct layers, i.e. basal cell layer and suprabasal cell layers, and both are functionally and biologically different compartments, it was interesting to investigate which type of epidermal keratinocytes modulate melanocyte proliferation and function most. Normal human epidermal melanocytes (HMel) were incubated with melanocyte-conditioned medium (M-CM) and low Ca2+ and high Ca2+ keratinocyte-conditioned medium (K-CM) obtained from the same skin source of melanocytes. The morphology, proliferation rate and melanin synthesis were evaluated at days 3, 6 and 12 of incubation. The results showed no evidence of major morphological changes in the epidermal melanocytes with any of the conditioned media, although marked dendrite formation was observed in coculture of melanocytes and differentiated keratinocytes. On the other hand, low Ca2+ K-CM induced a mild but statistically significant stimulation of melanocyte growth in a time-dependent manner. The significant percentage increase was evident on day 6 (124.6%, P < 0.05) and on day 12 (138.1%, P < 0.01) of incubation. In contrast, high Ca2+ K-CM showed no significant effect on melanocyte proliferation (P > 0.05). Both low Ca2+ and high Ca2+ K-CM stimulated melanin synthesis, although synthesis induced by low Ca2+ K-CM was higher than that of high Ca2+ K-CM. The significant percentage increase induced by low Ca2+ K-CM was evident on day 6 (117.9%, P < 0.05) and on day 12 (127.8%, P < 0.05) of incubation, whereas it was evident with high Ca2+ K-CM only on day 12 (119.7%, P < 0.05) of incubation. It is concluded from the above data that keratinocytes grown at a low Ca2+ level release factors that stimulate melanocyte proliferation as well as melanin synthesis, whereas keratinocytes grown at a high Ca2+ level release factors that only stimulate melanin synthesis. This may provide an explanation of the anatomical position of melanocytes and may play a part in the pigmentary changes following injury to epidermal cells.

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“…PUVA induces re-pigmentation by one of the following mechanisms: increase in the number of the active melanocytes or their hypertrophy, activation of melanosomes, stimulation of tyrosinase activity, migration of activated melanocytes from skin appendages, activation of interleukin-1 followed by increased expression of melanocyte stimulating hormone receptor (MSHR), formation of growth factors which stimulate melanocyte proliferation. 7,8 The results from the local KUVA and systemic PUVA therapy were compared with regard to their clinical efficacy. To our knowledge no such comparison of the two regimens has been performed until now.…”

Section: Reportmentioning

confidence: 99%

Treatment of vitiligo with local khellin and UVA: comparison with systemic PUVA

2004

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Vitiligo is an idiopathic leukoderma often with a progressive course causing destruction of melanocytes. The best methods for achieving cosmetically acceptable re-pigmentation of affected skin appear to be both local and systemic PUVA. They may, however, cause serious side effects, which is an argument for conducting research into new, equally effective photo-chemotherapeutic agents. One of these agents is khellin. We conducted a pilot study in 33 patients to evaluate the effectiveness of local KUVA and systemic PUVA therapy for vitiligo and to compare them in terms of the degree of re-pigmentation, duration of treatment, number of procedures, total UVA dose and side effects. Local KUVA required longer duration of treatment and higher UVA doses. KUVA-induced re-pigmentation depended on the age of the patients (r = -0.61, P = 0.001), and better results were achieved with younger individuals [% re-pigmentation = 81.76 - (1.48 x age in years)]. No side effects were observed in cases of local KUVA treatment. Erythema, itching and gastro-intestinal disturbances occurred with some patients treated with PUVA. The results demonstrate that local KUVA may effectively induce re-pigmentation of vitiligo-affected skin areas to a degree comparable to that achieved when using systemic PUVA, provided that treatment duration is long enough.

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Oral psoralen with UV-A therapy releases circulating growth factor(s) that stimulates cell proliferation

Cited by 15 publications

References 0 publications

Effects of psoralen plus ultraviolet A irradiation on cultured epidermal cells in vitro and patients with vitiligo in vivo

Effects of psoralen plus ultraviolet A irradiation on cultured epidermal cells in vitro and patients with vitiligo in vivo

Differential effects on melanocyte growth and melanization of low vs. high calcium keratinocyte-conditioned medium

Treatment of vitiligo with local khellin and UVA: comparison with systemic PUVA

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