目的 探讨维生素D对特应性皮炎小鼠的保护作用及其作用机制.方法 将清洁级的50只BALB/c雄性小鼠随机分为空白组、模型组、对照组和低、高剂量实验组,每组10只.除空白组外,其余组小鼠用2,4-二硝基氟苯(DNCB)进行建模,低、高剂量实验组小鼠建模后分别每天背部均匀涂抹5、10 μg·kg-1的1,25(OH)2D3,对照组每天均匀涂抹氢化可的松溶液(1 mg·cm-2),每天2次,连续给药10 d,空白组和模型组小鼠每天涂抹等量的0.9％NaCl.给药结束后对皮肤病变状况进行评估,眼眶采血并收集小鼠背部皮肤组织备用.以苏木精-伊红染色观察皮肤表皮厚度,以甲苯胺蓝染色法检测肥大细胞数量,以酶联免疫吸附测定(ELISA)法检测血清免疫球蛋白E(IgE)、白细胞介素(IL)-13、IL-4、IL-17表达水平,以流式细胞术检测血清Th1、Th2细胞比例,以免疫组化法检测背部皮肤组织组胺1型受体(HIR)、蛋白酶激活受体2(PAR2)、瞬时受体电位香草素1(TRPV1)表达情况.结果 空白组、模型组、低剂量实验组、高剂量实验组和对照组小鼠的皮炎症状评分分别为0、(8.50±1.12)、(6.34±0.54)、(3.91±0.29)和(3.79±0.53)分,背部皮肤表皮厚度分别为(42.05±4.14)、(77.65±7.02)、(61.12±5.02)、(55.34±4.13)和(52.19±3.08)μm,背部组织肥大细胞数量分别为(4.67±0.27)、(32.16±2.49)、(25.23±2.07)、(18.13±1.46)和(15.37±1.29)number·mm-2,Th1/Th2 细胞比值分别为 2.76±0.28、0.36±0.06、1.02±0.18、2.05±0.14 和 2.07±0.29,HIR 表达水平分别为 0.05±0.00、0.21±0.02、0.16±0.02、0.10±0.01 和 0.08±0.01,PAR2 表达水平分别为 0.05±0.01、0.19±0.01、0.12±0.01、0.09±0.01 和 0.07±0.01,TRPV1 表达水平分别为0.05±0.01、0.25±0.03、0.15±0.01、0.10±0.01 和 0.09±0.00;以上指标,低剂量实验组、高剂量实验组、对照组分别与模型组比较,高剂量实验组和低剂量实验组比较,在统计学上差异均有统计学意义(均P＜0.05).结论 维生素D可通过调节Th1/Th2细胞平衡,减轻DNCB诱导的特应性皮炎,可能与HIR、PAR2介导的TRPV1痒信号通路有关.
Objective To investigate the protective effect of vitamin D on atopic dermatitis mice,and its mechanism.Methods Fifty male BALB/c mice in clean grade were randomly divided into blank group,model group,control group and experimental-L group,experimental-H group,10 rats in each group.Except for the blank group,mice in the other groups were modeled with 2,4-dinitrofluorobenzene(DNCB).After modeling,mice in experimental-L and experimental-H groups were evenly smeared with 5 and 10 μg·kg-11,25(OH)2D3 on their backs every day,respectively;control group were evenly coated with hydrocortisone solution(1 mg·cm-2)twice a day for 10 days,and the mice in blank group and model group were coated with the same amount of 0.9％NaCl every day.After the administration,the skin lesions were evaluated,and orbital blood was collected and the back skin tissues were collected for use.The epidermal thickness was observed by hematoxylin-eosin staining,and the number of mast cells was detected by toluidine blue staining.The expression levels of serum immunoglobulin E(IgE),interleukin(IL)-13,IL-4,IL-17 were detected by enzyme-linked immunosorbent assay(ELISA),and the proportion of serum Th1 and Th2 cells were detected by flow cytometry.The expression of histamine type 1 receptor(HIR),protease activating receptor 2(PAR2),transient receptor potential vanillin 1(TRPV1)in back skin was detected by immunohistochemistry.Results The symptom scores of mice in blank group,model group,experimental-L group,experimental-H group and control group were 0,(8.50±1.12),(6.34±0.54),(3.91±0.29)and(3.79±0.53)points;the epidermal thickness of the back skin were(42.05±4.14),(77.65±7.02),(61.12±5.02),(55.34±4.13)and(52.19±3.08)μm;the number of mast cells in back tissue were(4.67±0.27),(32.16±2.49),(25.23±2.07),(18.13±1.46)and(15.37±1.29)number·mm-2;Th1/Th2 cell ratios were 2.76±0.28,0.36±0.06,1.02±0.18,2.05±0.14 and 2.07±0.29,respectively;HIR expression levels were 0.05±0.00,0.21±0.02,0.16±0.02,0.10±0.01 and 0.08±0.01;the expression levels of PAR2 were 0.05±0.01,0.19±0.01,0.12±0.01,0.09±0.01 and 0.07±0.01;the expression levels of TRPV1 were 0.05±0.01,0.25±0.03,0.15±0.01,0.10±0.01 and 0.09±0.00,respectively.The above indicators,experimental-L group,experimental-H group and control group were compared with model group;experimental-H group compared with experimental-L group,the differences were all statistically significant(all P＜0.05).Conclusion Vitamin D can reduce DNCB induced atopic dermatitis by regulating Th1/Th2 cell balance,which may be related to the TRPV1 oxygen signaling pathway mediated by HIR and PAR2.
丁张军;吴志鹏;陈晓栋
南通大学 附属医院皮肤科,江苏南通 226001||东台市人民医院皮肤科,江苏盐城 224200东台市人民医院皮肤科,江苏盐城 224200南通大学 附属医院皮肤科,江苏南通 226001
药学
维生素D;特应性皮炎;Th1/Th2平衡;肥大细胞;作用机制
vitamin D;atopic dermatitis;Th1/Th2 balance;mast cells;mechanism of action
《中国临床药理学杂志》 2024 (006)
884-888 / 5
10.13699/j.cnki.1001-6821.2024.06.021
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