皮炎小鼠胸腺基质淋巴细胞生成素的表达未受膳食硒水平的影响

目的 了解不同膳食硒水平下皮炎小鼠胸腺基质淋巴细胞生成素（thymic stromal lymphopoietin,TSLP）的表达情况。 方法 40只BALB/c小鼠随机分为4组（n=10）,3个致敏组分别以低硒（0.01 mg/kg）、中量硒（0.25 mg/kg,正常水平）和高量硒（3.00 mg/kg）饲料喂养,对照组以中量硒（正常水平）饲料喂养。饲养8周后致敏组采用1-氯2 ,4二硝基苯（1-Chloro 2,4-dinitrobenzene,DNCB）激发特应性皮炎样症状。激发期间监测皮炎症状。激发3周后采样进行皮肤组织病理观察,血浆总IgE检测,组织硒含量测定,TSLPmRNA丰度和TSLP蛋白表达分析。 结果 激发小鼠均出现典型的皮炎症状和皮炎病理改变,皮炎症状评分、挠痒计数和血浆总IgE显著高于对照组（P<0.05）。与对照组（标化为1）相比,除缺硒组（2.51±0.43）皮肤组织外（P<0.05）,激发小鼠皮肤（中、高硒组：1.83±0.79,2.26±0.75）、脾脏（低、中、高硒组：1.33±0.17,1.06±0.13,0.99±0.45）、肾脏（低、中、高硒组：1.16±0.42,1.10±0.40,1.53±0.40）和肝脏（低、中、高硒组：0.95±0.30,0.90±0.31,1.11±0.43）组织TSLP mRNA相对表达量与对照组比较,差异均无统计学意义（P>0.05）,激发小鼠4种组织中TSLPmRNA的相对表达量在三个硒水平组之间差异无统计学意义（P>0.05）;线性回归分析发现,3个硒水平组激发小鼠皮肤组织中TSLP mRNA相对表达量与皮肤组织中硒水平无相关性（R²=0.006,P>0.05）。蛋白分析发现,致敏组TSLP蛋白在低中高三个硒水平致敏组小鼠皮肤组织中的表达差异无统计学意义;在致敏组小鼠肝脏、脾脏和肾脏中均未见明显表达条带。 结论 DNCB激发特应性皮炎样皮炎小鼠皮肤、肝脏、脾脏和肾脏组织中TSLP的表达不受膳食硒水平的影响,这可能与TSLP的亚型和表达时机有关。

Affection of dietary selenium levels on expression of TSLP in dermatitis mice

Objective To investigate the affection of dietary selenium levels on the expression of thymic stromal lymphopoietin (TSLP) in atopic dermatitis mice. Methods Forty BALB/c mice were randomly divided into 4 groups (n = 10). The three sensitized groups were treated with low selenium (0.01 mg/kg), medium selenium (0.25 mg/kg, normal level) and high selenium (3.00 mg /kg) diets, and the control group was fed with a medium selenium diet. After the induction for 8 weeks, the sensitized groups were treated with 1-chloro 2, 4-dinitrobenzene (DNCB) to induce atopic dermatitis. The dermatitis was monitored during the sensitization period. Three weeks after the sensitization, the skin histopathological observation was performed, the plasma total IgE was detected, the selenium content in tissues was determined, and the TSLP mRNA abundance and TSLP protein expression in the skin, liver, spleen and kidney were analyzed. Results The typical dermatitis symptoms and dermatitis pathological changes were found in all the sensitized mice. Compared with the control group, the dermatitis symptom score, tickling count and plasma total IgE were significantly increased (P<0.05). Compared with the control group (standardized as 1), there was no significant difference (P> 0.05) in the relative expression of TSLP mRNA between/among the skin (medium and high selenium groups: 1.83 ± 0.97, 2.26 ± 0.75), spleen (low, medium and high selenium groups: 1.33 ± 0.17, 1.06 ± 0.10, 0.99 ± 0.45), kidney (low, medium and high selenium groups: 1.16 ± 0.42, 1.10 ± 0.10, 1.53 ± 0.4) and liver (low, medium and high selenium groups: 0.95 ± 0.30, 0. 0.90 ± 0.31, 1.11 ± 0.43) tissues of the sensitized mice except the skin group (P<0.05). The relative expression of TSLP mRNA in the four tissues of the sensitized mice was also not significantly different among the three selenium groups (P> 0.05). The linear regression analysis showed that the relative expression of TSLP mRNA in the skin tissues of the mice of the three selenium-sensitive groups was not correlated with the selenium levels in the skin tissues (R²=0.006, P>0.05). There was no significant difference among the expressions of TSLP proteins in the skin tissues of the mice with low, medium and high levels of selenium, and no obvious expression bands were found in the liver, spleen and kidney of the sensitized mice. Conclusion The expression of TSLP in the skin, liver, spleen and kidney tissues of the mice induced by DNCB sensitization is not affected by the dietary selenium levels, which may be related to the subtype and expression timing of TSLP.