Oregon Hearing Research Center, Department of Otolaryngology, Head and Neck Surgery, Oregon Health & Science University, Portland, Oregon 97239-3098, USA.
Otol Neurotol. 2011 Apr;32(3):508-15. doi: 10.1097/MAO.0b013e31820e6de4.
Ion homeostasis genes are responsible for the movement of ions and water in the epithelium of the middle ear.
It is not well known to what extent disruption of ion homeostasis is a factor in the accumulation of middle ear fluid during otitis media.
Balb/c mice were transtympanically injected with heat-killed Hemophilus influenza bacteria. Untreated and saline-injected mice were used as controls. Mice were euthanized at 6, 24, and 72 hours and 1 week after injection, the bullae harvested, and total ribonucleic acid isolated from the middle ear tissues. Ion homeostasis genes were analyzed with real-time quantitative reverse transcription-polymerase chain reaction from the following gene families: Na,K-ATPase, claudins, K transport channels, epithelial Na channels, gap junctions, and aquaporins. Inflammatory genes also were analyzed to document inflammation.
All inflammatory genes analyzed were significantly upregulated, more at 6 hours than at 24 hours, with the exception of vascular endothelial growth factor and Mapk8. Most middle ear ion homeostasis genes experienced downregulation because of inflammation. This was most prominent in the aquaporin and Na,K-ATPase genes. Significant upregulation was seen in several genes in response to inflammation and saline independently.
The innate immune response to bacteria in the middle ear induces expression of several inflammatory genes. Coinciding with this inflammation is the downregulation of numerous ion homeostasis genes that are involved in ion and water transport and maintenance of tight junctions. This may explain the fluid accumulation within the middle ear seen with both acute and chronic otitis media.
离子动态平衡基因负责中耳上皮中离子和水的运动。
中耳积液的积聚在多大程度上与离子动态平衡的破坏有关，目前人们对此知之甚少。
Balb/c 小鼠经鼓室注射热灭活流感嗜血杆菌。未处理和盐水注射的小鼠作为对照。注射后 6、24、72 小时和 1 周处死小鼠，采集鼓室，从中耳组织中分离总核糖核酸。采用实时定量逆转录聚合酶链反应分析以下基因家族的离子动态平衡基因：Na，K-ATP 酶、紧密连接蛋白、K 转运通道、上皮 Na 通道、间隙连接和水通道蛋白。还分析了炎症基因以记录炎症。
所有分析的炎症基因均显著上调，6 小时时上调程度大于 24 小时，血管内皮生长因子和 Mapk8 除外。由于炎症，大多数中耳离子动态平衡基因下调。水通道蛋白和 Na，K-ATP 酶基因最为明显。几种基因对炎症和盐水的独立反应均呈显著上调。
中耳内细菌的先天免疫反应诱导了几个炎症基因的表达。与炎症同时发生的是许多参与离子和水转运以及紧密连接维持的离子动态平衡基因的下调。这可能解释了急性和慢性中耳炎中耳内积液的积聚。
