Elucidation of inflammatory cell dynamics in the inner ear

1)将锁孔帽贝血青素（KLH）接种于豚鼠中耳膜，经该抗原全身致敏后诱导实验性迷路炎。对动物模型内耳进行组织学观察。鼓室鳞片、螺旋模窦静脉（SMY）及其聚集小静脉（CV）均可见炎性细胞，部分细胞含有KLH。SMV、螺旋韧带和螺旋缘弥漫性IgG和白蛋白阳性，但很少检出IgG阳性浆细胞。内淋巴囊免疫活性细胞数量未见明显增加。我们之前报道了细胞间粘附分子-1 （ICAM-1）不仅在SMVand CVs上表达，而且在螺旋韧带上表达。综上所述，动物模型中耳蜗的炎症细胞主要是由血管外渗而非内淋巴囊浸润引起的。螺旋韧带上皮细胞对连接蛋白26和三磷酸腺苷钠钾的免疫反应性降低。提示螺旋韧带纤维细胞损伤可引起耳蜗功能障碍。2)用白细胞介素(IL)-1b或肿瘤坏死因子(TNF)-a刺激小鼠螺旋韧带纤维细胞培养物，用酶联免疫吸附法测定各种介质的分泌。促炎因子刺激后，IL-6、TNF-a、单核细胞趋化蛋白-1、KC、巨噬细胞炎性蛋白-2、可溶性ICAM-1和血管内皮生长因子水平升高。这些趋化因子和其他介质的分泌可诱导炎症、细胞运动，从而延长炎症反应，导致纤维细胞损伤。螺旋韧带纤维细胞可能在耳蜗液和离子稳态中起作用，这种纤维细胞的破坏可能导致耳蜗功能障碍。3)研究中耳炎对耳蜗的影响，以确定引起耳蜗功能障碍的损伤区域。采用活菌肺炎链球菌注射中耳腔诱导BALB/c小鼠中耳炎，进行免疫组化分析。有些动物的耳蜗内有炎性细胞。免疫组化结果显示，纤维蛋白原主要分布于耳蜗螺旋韧带下部和螺旋缘。螺旋韧带中连接蛋白26免疫染色降低，纤维蛋白原染色明显。耳蜗中纤维蛋白原的存在提示中耳炎症引起血迷宫屏障的破坏。连接蛋白26染色的变化提示螺旋韧带可能是导致耳蜗功能障碍的区域之一。少

1) Experimental labyrinthitis was induced in guinea pigs by inocultation of keyhole limpet hemocyanin (KLH) into the scala tympani after sysytemic sensitization of the same antigen. The inner ears in the animal models were investigated histologically. Inflammatory cells, some of which contained KLH, were observed in the scala tympani, spiral modiolar vein (SMY) and its collecting venule (CV). SMV, spiral ligament and spiral limbus were diffusely positive for IgG and albumin, although lgG-positive plasma cells were hardly detected. The endolymphatic sac showed no increase in number of immunocompetent cells. We previously reported the expression of intercellular adhesion molecule-1 (ICAM-1) not only on the SMVand CVs but also on the spiral ligament. These data, take together, suggest that the inflammatory cells seen in the cochlea in this animal model were mainly due to extravasation from blood vessels rather than infiltration from the endolymphatie sac. In addition, immunoreactivity for … More connexin 26 and sodium-potassium adenosine triphosphate was decreased in the fobrocytes of the spiral ligament. The results suggest that fibrocyte damage in the spiral ligament could cause cochlear dysfunction.2) Cultures from murine spiral ligament fibrocytes were stimulated by interleukin (IL)-1b or tumor necrosis factor (TNF)-a, and secretion of various mediators was measured by enzyme-linked immunosorbent assay. After stimulation with the proinflammatory cytokines, IL-6, TNF-a, monocyte chemoattractant protein-1, KC, macrophage inflammatory protein-2, soluble ICAM-1, and vascular endothelial growth factor levels were elevated. Secretion of these chemokines and other mediators could induce inflammatory, cell movement, which wound prolong the inflammatory response, leading to fibrocyte damage. Given that spiral ligament fibrocytes may play a role in cochlear fluid and ion homeostasis, such fibrocyte disruption could cause cochlear malfunction.3) The cochlear influence of otitis media was investigated in order to identify damaged regions causing cochlear malfunction. Otitis media in BALB/c mice was induced by injection of viable Streptococcus pneumoniae into the middle ear cavity for immunohistochemical analysis. Some animals showed inflammatory cells in the cochlea. Immunohistochemistry showed the presence of fibrinogen in the cochlea, mainly in the lower portion of the spiral ligament and in the spiral limbus. Immunostaining for connexin 26 was decreased in the spiral ligament, accompanied by remarkable fibrinogen staining. The presence of fibrinogen in the cochlea suggests disruption of the blood-labyrinth barrier caused by the middle ear inflammation. Changes in connexin 26 staining suggest the possibility that the spiral ligament could be among the regions responsible for the cochlear malfunction. Less