mRNA expression in lung tissue. mRNA expression in lung tissue

Previous studies have reported sex differences in the incidence, prognosis and control of respiratory diseases and lung immunity. However, the role of sex hormones in the inflammatory response, and the mechanisms involved are unknown. Here, we explored whether variations in circulating hormone levels in the mouse estrous cycle could alter the inflammatory response to air pollutants such as ozone. To test this, female mice of the C57BL/6 background were exposed to 2ppm of ozone or filtered air (control) for 3 hours at different stages of the estrous cycle. Following exposure, lungs were harvested and total RNA was extracted. We used Inflammatory Response and Autoimmunity PCR Arrays to study differences in gene expression across the estrous cycle. Our results identified differentially expressed mRNA signatures in the lungs of females exposed to ozone at different stages of the estrous cycle. In addition, in silico pathway analyses discovered differences in mRNA expression and predicted regulatory networks in females exposed to ozone at different estrous cycle stages. These results indicate that the effects of ozone exposure in the female lung are affected by hormonal status. Overall design: Female C57BL/6 mice of 8 weeks of age were exposed to 2ppm ozone (O3) or filtered air (FA) for 3 hours at different stages of the estrous cycle: Metestrus (M), Diestrus (D), proestrus (P), estrus (E). Total RNA was extracted from whole lung homogenates and PCR arrays were used to determine the expression of 84 mRNAs associated with inflammation and immunity (3-6 animals per group).

既往研究已报道呼吸道疾病的发病率、预后及防控水平，以及肺部免疫功能存在性别差异。然而，性激素在炎症应答中的作用及其相关调控机制仍未明确。本研究旨在探究小鼠动情周期中循环激素水平的变化，是否会改变机体对臭氧等空气污染物的炎症应答反应。

为验证这一研究假设，我们将C57BL/6背景的雌性小鼠在动情周期的不同阶段暴露于2ppm臭氧或过滤空气（对照组）中，持续3小时。暴露结束后，采集肺部组织并提取总RNA。我们采用炎症反应与自身免疫PCR芯片阵列（Inflammatory Response and Autoimmunity PCR Arrays）分析不同动情周期阶段的基因表达差异。

研究结果显示，在动情周期不同阶段暴露于臭氧的雌性小鼠肺部，存在差异表达的mRNA特征谱。此外，通过计算机模拟（in silico）通路分析，我们发现不同动情周期阶段的臭氧暴露雌性小鼠，其mRNA表达模式及预测调控网络均存在显著差异。上述结果表明，雌性小鼠肺部暴露于臭氧后的生物学效应，受到其自身激素状态的影响。

实验设计概述：本实验选用8周龄C57BL/6背景雌性小鼠，在动情周期的四个阶段——动情后期（Metestrus, M）、间情期（Diestrus, D）、动情前期（Proestrus, P）及动情期（Estrus, E）——分别暴露于2ppm臭氧（O₃）或过滤空气（Filtered Air, FA），持续3小时。从全肺组织匀浆中提取总RNA，并采用PCR芯片阵列检测84种与炎症及免疫相关的mRNA表达水平，每组设置3-6只实验动物。