瘦素及其受体在哮喘BALB/c小鼠肺组织中的表达及布地奈德的干预作用

Expression of leptin and its receptor in lungs of asthmatic BALB/c mice and effect of budesonide on their expression

摘要:

目的 探讨不同严重程度哮喘小鼠及布地奈德干预后肺组织中瘦素及其受体表达的变化规律。方法 将40 只Balb/c 小鼠随机分成对照组、诱喘3 d 组、诱喘7 d 组和布地奈德干预组, 每组10 只。采用卵清蛋白(OVA)致敏后分别激发3 d 和7 d 建立小鼠哮喘模型;布地奈德干预组于激发前1 h 雾化吸入布地奈德混悬液干预;对照组不予任何处理。苏木精- 伊红染色观察各组小鼠气道炎症情况;免疫组化、Western blot 和Real-time PCR 方法检测肺组织中的瘦素及其受体蛋白和mRNA 的表达。结果 哮喘组气道病理学改变较对照组、布地奈德干预组明显, 而哮喘组中, 诱喘7 d 组改变较诱喘3 d 组明显。肺组织中瘦素蛋白及mRNA 表达在诱喘3 d 组较对照组显著增高(P<0.01), 诱喘7 d 组较3 d 组显著增高(P<0.01);瘦素受体蛋白表达在诱喘3 d组较对照组显著降低(P<0.01), 布地奈德干预组较诱喘7 d 组明显增高(P<0.01);瘦素受体mRNA 表达在4组间比较差异无统计学意义(P>0.05)。结论 哮喘肺组织中瘦素呈高表达, 而瘦素受体呈低表达;布地奈德可以上调瘦素受体的表达, 而对瘦素表达无明显影响。

Abstract:

Objective To determine the changes in the expression of leptin and its receptor in the lungs of mice with varying degrees of asthma before and after budesonide treatment. Methods Forty Balb/c mice were randomly assigned into 4 groups with 10 animals in each. One group received no treatment (control group) and the other groups were challenged with either nebulized ovalbumin (OVA) for three days (3-day group) or seven days (7-day group), or with nebulized ovalbumin followed by budesonide administration (treatment group). Changes in airway inflammation were observed using hematoxylin-eosin staining. The protein and mRNA levels of leptin and its receptor in lung tissues were determined using immunohistochemistry/Western blot and real-time PCR, respectively. Results The two asthmatic groups showed more significant pathological changes in the airway than the control and the treatment groups. Mice that were challenged by OVA for seven days showed more marked pathological changes in the airway compared with mice challenged by OVA for three days. The protein and mRNA levels of leptin in the lung tissues of the 3-day group were significantly higher than those of the control group (P<0.01), but significantly lower than those of the 7-day group (P<0.01). The protein levels of leptin receptor in the lung tissues of the 3-day group were significantly lower than those of the control group (P<0.01). The treatment group showed increased protein levels of leptin receptor compared with the 7-day group (P<0.01). No significant difference was noted between the four groups with respect to the mRNA levels of leptin receptor in the lung tissues. Conclusions Leptin is highly expressed whereas its receptor is lowly expressed in the lung tissues of asthmatic mice. Budesonide can increase the expression of leptin receptor, but has no significant impact on the expression of leptin.