哮喘小鼠HMGB1/TLR4/NF-κB信号通路及维生素D的作用

目的 观察哮喘小鼠肺组织高迁移率族蛋白B1(HMGB1)、Toll样受体4(TLR4)和核因子κB(NF-κB)m RNA和蛋白表达变化,以及维生素D的干预作用。方法 将48只BALB/c小鼠随机分为对照组、哮喘组和1,25-(OH)2D3干预组,每组16只。建立哮喘动物模型,干预组在每次雾化激发前给予腹腔注射1,25-(OH)2D3(4μg/kg)。分别在雾化激发1周和2周采集各组标本,常规苏木精-伊红(HE)染色测定气道壁厚度;免疫组化染色观察HMGB1、TLR4和NF-κB在肺组织中的表达;采用实时荧光定量PCR和Western blot分别从m RNA和蛋白质水平检测HMGB1、TLR4和NF-κB表达变化。结果 雾化激发1周和2周,哮喘组小鼠气道壁厚度较对照组明显增加,干预组较哮喘组明显减少(P0.05);哮喘组肺组织中HMGB1、TLR4和NF-κB的m RNA表达量均明显高于对照组,干预组TLR4和NF-κB的m RNA均明显低于哮喘组(P0.05)。雾化激发1周时干预组HMGB1 m RNA表达量与哮喘组比较差异无统计学意义(P0.05),但在雾化激发2周时则明显下降(P0.05)。雾化激发1周和2周,肺组织中HMGB1、TLR4和NF-κB的蛋白表达量均明显高于对照组,干预组均明显低于哮喘组(P0.05)。小鼠气道壁厚度与肺组织HMGB1、TLR4和NF-κB的m RNA的表达量均呈正相关性(r分别为0.804、0.895、0.834;P0.05)。结论 HMGB1/TLR4/NF-κB信号通路在哮喘发病中起重要作用,适量1,25-(OH)2D3可能通过对其的调控作用阻止哮喘的进展,有望成为哮喘治疗的新选择。

HMGB1/TLR4/NF-κB signaling pathway and role of vitamin D in asthmatic mice

Objective To investigate the changes in the mRNA and protein expression of high-mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR4), and nuclear factor-kappa B (NF-κB) in lung tissues of asthmatic mice and the interventional effect of vitamin D. Methods A total of 48 BALB/c mice were randomly divided into control group, asthma group, and 1,25-(OH)2D3 intervention group, with 16 mice in each group. An animal model of asthma was established, and lung tissue samples were taken in each group at weeks 1 and 2 of ovalbumin challenging. Conventional hematoxylin-eosin staining was used to measure airway wall thickness. Immunohistochemical staining was used to observe the expression of HMGB1, TLR4, and NF-κB in lung tissues. Quantitative real-time PCR and Western blot were used to investigate the changes in the mRNA and protein expression of HMGB1, TLR4, and NF-κB. Results At weeks 1 and 2 of ovalbumin challenging, compared with the control group, the asthma group had a signiifcant increase in airway wall thickness and the intervention group had a signiifcant reduction compared with the asthma group (P<0.05). The asthma group had signiifcantly higher mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had signiifcantly lower mRNA expression of TLR4 and NF-κB than the asthma group (P<0.05). At week 1 of ovalbumin challenging, there was no significant difference in the mRNA expression of HMGB1 between the intervention group and the asthma group (P>0.05). At week 2, the intervention group had a signiifcant reduction in the mRNA expression of HMGB1 compared with the asthma group (P<0.05). At weeks 1 and 2 of ovalbumin challenging, the asthma group had signiifcantly higher protein expression of HMGB1, TLR4, and NF-κB in lung tissues than the control group, and the intervention group had signiifcantly lower expression than the asthma group (P<0.05). Airway wall thickness was positively correlated with the mRNA expression of HMGB1, TLR4, and NF-κB in lung tissues (r=0.804, 0.895, and 0.834;P<0.05). Conclusions The HMGB1/TLR4/NF-κB signaling pathway plays an important role in the pathogenesis of asthma, and an appropriate amount of 1,25-(OH)2D3 has a regulatory effect on this pathway and may prevent the progression of asthma. Therefore, 1,25-(OH)2D3 is expected to become a new choice for the treatment of asthma.