Institute for Environmental and Gender Specific Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Urayasu, Chiba 279-0021, Japan.
J Dermatol Sci. 2011 May;62(2):91-7. doi: 10.1016/j.jdermsci.2011.01.004. Epub 2011 Jan 15.
UV-based therapy has anti-pruritic effects in inflammatory skin diseases, such as atopic dermatitis and psoriasis. These anti-pruritic effects may be partly due to inhibition of intraepidermal nerve growth, but they have not been fully characterized.
This study was performed to characterize the anti-nerve growth effects of UV-based therapies in acetone-treated mice as an acute dry skin model.
Nerve fibers penetrate into the epidermis 24h after acetone treatment in mice, and nerve growth peaks 48h after acetone treatment. To investigate the effects of UV-based therapies on the epidermal nerve fibers, including combination treatment with corticosteroid ointment, the mice were treated with psoralen ultraviolet A (PUVA), PUVA and betamethasone valerate ointment (PUVA+BV), narrowband ultraviolet B (NB-UVB), or an excimer lamp. Each therapy was provided 24h after acetone treatment, and skin samples were taken 48h later. Nerve fiber densities and expression levels of nerve growth factor (NGF) and semaphorin 3A (Sema3A) in the epidermis were examined by immunohistochemistry.
Penetration of nerve fibers into the epidermis was observed in the acetone-treated mice, concomitant with increased NGF and decreased Sema3A levels in the epidermis. The acetone-induced intraepidermal nerve growth was significantly decreased by PUVA, PUVA+BV, NB-UVB, and excimer lamp treatments compared with controls. In addition, PUVA+BV and NB-UVB normalized the abnormal expression of NGF and Sema3A in the epidermis, but no such normalization was observed with excimer lamp treatment.
UV-based therapies, especially NB-UVB and excimer lamp treatments, may be effective therapeutic methods for pruritus involving epidermal hyperinnervation.
基于紫外线的疗法在特应性皮炎和银屑病等炎症性皮肤病中具有止痒作用。这些止痒作用可能部分归因于抑制表皮内神经生长，但尚未完全阐明。
本研究旨在通过丙酮处理的小鼠作为急性干燥皮肤模型来描述基于紫外线的疗法对神经生长的抑制作用。
在丙酮处理后 24 小时，神经纤维穿透到小鼠表皮，48 小时后神经生长达到峰值。为了研究基于紫外线的疗法对表皮神经纤维的影响，包括与皮质类固醇软膏的联合治疗，在丙酮处理后 24 小时给予补骨脂素紫外线 A（PUVA）、PUVA 和倍他米松戊酸酯软膏（PUVA+BV）、窄带紫外线 B（NB-UVB）或准分子灯治疗。每种治疗方法均在丙酮处理后 24 小时提供，并在 48 小时后采集皮肤样本。通过免疫组织化学检测表皮中神经纤维密度和神经生长因子（NGF）和 Sema3A 的表达水平。
在丙酮处理的小鼠中观察到神经纤维穿透表皮，同时表皮中 NGF 增加和 Sema3A 减少。与对照组相比，PUVA、PUVA+BV、NB-UVB 和准分子灯治疗明显减少了丙酮诱导的表皮内神经生长。此外，PUVA+BV 和 NB-UVB 使表皮中 NGF 和 Sema3A 的异常表达正常化，但准分子灯治疗则没有观察到这种正常化。
基于紫外线的疗法，特别是 NB-UVB 和准分子灯治疗，可能是治疗涉及表皮过度神经支配的瘙痒的有效方法。
