Department of Respiratory Medicine, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
Chin Med J (Engl). 2013;126(17):3283-8.
Expression of murine calcium-activated chloride channel family member 3 (mCLCA3) has been reported to be increased in the airway epithelium of asthmatic mice challenged with ovalbumin (OVA). However, its role in asthmatic airway inflammation under no OVA exposure has not yet been clarified.
mCLCA3 plasmids were transfected into the airways of normal BALB/c mice. mCLCA3 expression and airway inflammation in mouse lung tissue were evaluated. Cell differentials and cytokines in bronchoalveolar lavage fluid (BALF) were analyzed. The expression of mCLCA3 protein and mucus protein mucin-5 subtype AC (MUC5AC) were analyzed by Western blotting. The mRNA levels of mCLCA3, MUC5AC and interleukin-13 (IL-13) were determined quantitatively.
mCLCA3 expression was not detected in the control group while strong immunoreactivity was detected in the OVA and mCLCA3 plasmid groups, and was strictly localized to the airway epithelium. The numbers of inflammatory cells in lung tissue and BALF were increased in both mCLCA3 plasmid and OVA groups. The protein and mRNA levels of mCLCA3 and MUC5AC in the lung tissue were significantly increased in the mCLCA3 plasmid and OVA groups compared to the control group. The level of IL-13, but not IL-4, IL-5, IFN-γ, CCL2, CCL5 or CCL11, was significantly increased compared with control group in BALF in the mCLCA3 plasmid and OVA groups. The level of IL-13 in the BALF in the mCLCA3 plasmid group was much higher than that in the OVA group (P < 0.05). The level of mCLCA3 mRNA in lung tissue was positively correlated with the levels of MUC5AC mRNA in lung tissue, IL-13 mRNA in lung tissue, the number of eosinophils in BALF, and the content of IL-13 protein in BALF. The level of IL-13 mRNA in lung tissue was positively correlated with the number of eosinophils in BALF and the level of MUC5AC mRNA in lung tissue.
These findings suggest that increased expression of a single-gene, mCLCA3, could simulate an asthma attack, and its mechanism may involve mCLCA3 overexpression up-regulating IL-13 expression.
据报道，在卵清蛋白（OVA）致敏的哮喘小鼠的气道上皮细胞中，鼠钙激活氯离子通道家族成员 3（mCLCA3）的表达增加。然而，在没有 OVA 暴露的情况下，它在哮喘气道炎症中的作用尚不清楚。
将 mCLCA3 质粒转染到正常 BALB/c 小鼠的气道中。评估小鼠肺组织中 mCLCA3 的表达和气道炎症。分析支气管肺泡灌洗液（BALF）中的细胞差异和细胞因子。通过 Western blot 分析 mCLCA3 蛋白和粘蛋白-5 亚型 AC（MUC5AC）的表达。定量测定 mCLCA3、MUC5AC 和白细胞介素-13（IL-13）的 mRNA 水平。
对照组未检测到 mCLCA3 表达，而 OVA 和 mCLCA3 质粒组均检测到强烈的免疫反应性，且严格定位于气道上皮。肺组织和 BALF 中的炎症细胞数量在 mCLCA3 质粒和 OVA 组均增加。与对照组相比，mCLCA3 质粒和 OVA 组肺组织中 mCLCA3 和 MUC5AC 的蛋白和 mRNA 水平均显著升高。与对照组相比，mCLCA3 质粒和 OVA 组 BALF 中 IL-13 水平显著升高，但 IL-4、IL-5、IFN-γ、CCL2、CCL5 或 CCL11 水平无明显升高。mCLCA3 质粒组 BALF 中的 IL-13 水平明显高于 OVA 组（P<0.05）。肺组织中 mCLCA3 mRNA 水平与肺组织中 MUC5AC mRNA 水平、肺组织中 IL-13 mRNA 水平、BALF 中嗜酸性粒细胞数和 BALF 中 IL-13 蛋白含量呈正相关。肺组织中 IL-13 mRNA 水平与 BALF 中嗜酸性粒细胞数和肺组织中 MUC5AC mRNA 水平呈正相关。
这些发现表明，单个基因 mCLCA3 的表达增加可以模拟哮喘发作，其机制可能涉及 mCLCA3 过表达上调 IL-13 的表达。
