摘要目的 探讨水通道蛋白3(aquaporin 3,AQP3)、半胱氨酸蛋白酶14(Caspase 14)、博来霉素水解酶(bleomycin hydrolase,BH)在慢性湿疹患者皮肤屏障中的作用以及窄谱中波紫外线(NB-UVB)治疗慢性湿疹的部分作用机制.方法 多功能皮肤测试仪测定30例慢性湿疹患者皮损及非皮损处皮肤含水量及经皮水分丢失(TEWL).免疫组化方法检测AQP3、Caspasel4、BH在慢性湿疹患者皮损及非皮损处的表达.400、800、1200 mJ/cm2三组不同剂量NB-UVB照射培养的角质形成细胞,免疫印迹方法检测AQP3、Caspase14及BH蛋白表达变化.结果 慢性湿疹患者皮损部位皮肤含水量显著减少,约为11.32±5.25,经皮水分丢失明显增加,约为86.28±16.35,与非皮损处比较,差异有统计学意义(P＜0.05).慢性湿疹患者皮损处AQP3及Caspase 14表达显著增高,分别为非皮损处的5.3倍及4.2倍.BH表达显著下降,约为非皮损处的1/3.皮损处与非皮损处比较差异有统计学意义(P＜0.05).400、800、1200 mJ/cm2 NB-UVB照射角质形成细胞后,AOP3及BH蛋白表达均明显下降,分别为对照组的0.48、0.23、0.16;0.82、0.78、0.22.而Caspase 14表达只有在1200 mJ/cm2较高剂量NB-UVB照射后才显著下降,为对照组的0.34.与对照组相比,差异有统计学意义(P＜0.05).结论 慢性湿疹患者皮肤屏障功能受损可能与BH表达减少,Caspase 14及AQP3表达增加有关,NB-UVB治疗慢性湿疹的部分作用机制可能与下调AQP3、Caspasel4及BH的表达有关.

abstractsObjective To study the roles of aquaporin 3 (AQP3),Caspase 14 and bleomycin hydrolase (BH) in skin barrier in patients with chronic eczema and to tackle the mechanisms underlying the therapeutic effect of narrow-band ultraviolet B (NB-UVB) on eczema.Methods Transepidermal water loss (TEWL)and water content of skin were detected by a muhi-functional skin tester in lesions and non-lesional skin of 30 patients with chronic eczema.The protein expressions of AQP3,Caspase 14 and BH were detected by immunohistochemistry in tissue specimens from lesioual and non-lesional skin of these patients.Cultured keratinocytes were irradiated with 3 different doses (400,800,1200 mJ/cm2) of UVB,and Western blot was performed to quantify the protein expressions of AQP3,Caspase 14 and BH at 24 hours after the irradiation.Results There was a significant decrease in water content of skin (11.32 ± 5.25 vs.49.68 ± 8.62) but an increase in TEWL (86.28 ± 16.35 vs.14.62 ± 6.68) in lesional skin compared with non-lesional skin from the patients with chronic eczema (both P ＜ 0.05).The protein expression levels of AQP3,Caspase 14 and BH in lesional skin were 5.3 times,4.2 times and one-third of,those in non-lesional skin from the patients,respectively,and significant differences existed between the lesional and non-lesional skin in the 3 parameters (all P ＜ 0.05 ).After irradiation with NB-UVB at 400,800 and 1200 mJ/cm2,the expression level of AQP3 in keratinocytes was decreased by 52％,77％ and 84％,respectively,and that of Caspase 14 was decreased by 18％,22％ and 78％,respectively,compared with unirradiated keratinocytes (all P ＜ 0.05).A marked decrease (by 66％) was also observed in the expression of Caspase 14 in keratinocytes after irradiation with NB-UVB at 1200 mJ/cm2 (P ＜ 0.05).Conclusions The impairment of skin barrier function in chronic eczema may be related to the downregulated expression of BH and upregulated expression of Caspase 14 and AQP3.The therapeutic effect of NB-UVB on chronic eczema may be partly attributed to the diminished expression of AQP3,Caspase 14 and BH.