巨噬细胞极化异常对LMNA基因突变中耳炎小鼠预后和转归的影响及机制

Otitis media (OM) is a common and frequently occurring disease. Morbidity of OM varies up to 40%, which refers to the genetic background for the occurrence of the disease. In recent years, some foreign study groups has established mouse model of otitis media caused by gene mutation. Our study groups has investigated a mouse model of OM with spontaneous mutation of LMAN gene, which was called Dhe mutant mice. We found that all the heterozygotes developed OM after 12 days of birth, associated with eustachian tube and nasal pharynx dysplasia. Peritoneal macrophages were found to have higher expression of TNFα and TGFβ, which were crucial markers of polarized macrophages M1 and M2. M1 and M2 types of macrophages are essential for reaction of anti-inflammation and tissue remodeling. Here we hypothesize that if macrophage polarization is involved in the development OM. We purpose to investigate the macrophage polarization and M1/M2 ratio in the heterozygotes mice. Further study needs to be done to find the proper concentration of the interference factors to the polarization. After interfere the macrophages of heterozygotes mice in vivo, we have to investigated morphogenesis, genetics, and cytological features of OM of the mice, to elucidate if the gene mutation could lead to the abnormality of macrophage polarization, thus lead to the onset OM. Finally we put forward some suggestions of the genetic pathogenesis and signaling pathways of the disease. We hopefully provide theoretical basis of the treatment and the prevention of the disease.

中耳炎是耳鼻喉科的常见病、多发病。不同地域及同种族发病率差异可高达40%，提示出基因学背景的潜在作用。国外多通过基因突变中耳炎小鼠模型对发病机制进行研究。我们前期通过对一种最新发现的LMNADhe基因突变中耳炎小鼠的研究，发现全部杂合子Dhe/+小鼠均于生后出现中耳炎；颅底解剖发现鼻咽顶部及咽鼓管结构发育异常；腹腔巨噬细胞培养发现杂合子小鼠巨噬细胞TNFα及TGFβ高表达，两者分别为巨噬细胞极化为M1型及M2型的重要标志物，在抗炎及组织重塑中发挥重要作用。由此我们提出，是否由于巨噬细胞的极化异常导致了突变小鼠颅底及咽鼓管组织结构发生异常，进而导致了中耳炎。本研究拟对小鼠腹腔巨噬细胞进行体外极化鉴定及干预，之后通过巨噬细胞极化调节因子对杂合子小鼠进行体内干预，研究干预后中耳炎发生、发展及病理生理学改变。探究是否LMNA基因突变导致了巨噬细胞极化发生改变，干预极化信号通路能否成为可行治疗策略。

背景.中耳炎的病因研究发现先天性因素可导致该疾病发生，中耳炎基因突变小鼠对于此研究很有帮助。中耳炎疾病进一步进展，可引起内耳迷路炎，导致前庭功能下降。.主要研究内容.我们此次研究定位了新的基因突变小鼠，命名为zey基因突变小鼠。该小鼠除具有中耳炎表现外，还具有平衡功能差，体态不稳及头部易出现卷曲等前庭功能症状。我们进一步对于能够反映并检侧前庭功能障碍的检查方法—前庭诱发肌源性电位进行了进一步的临床研究。研究纳入了29例双侧大前庭导水管综合征的患者及35名正常人作为对照组，检测并分析了他们的眼肌及颈肌前庭诱发肌源性电位各参数。.结果及关键数据. 我们通过全基因组连锁扫描，定位于在104个N2子代小鼠的小杂交群体中Chr 10的中心区域，位于D10Mit130（31 cM）和D10Mit115（38 cM）之间。Zey小鼠生后逐渐出现听力下降，对生后23天，50天，生后3个月，7个月进行听力检测发现zey突变小鼠听性脑干反应（ABR）阈值升高。HE染色发现除中耳炎症细胞浸润外，还可造成内耳部分的炎性渗出，造成前庭功能障碍。大前庭导水管综合征患者的前庭诱发肌源性电位检查发现，在儿童组中，患者眼肌前庭诱发肌源性电位的引出率为93.47%，颈肌前庭诱发肌源性电位引出率为86.95%，与正常对照组相比无统计学差异。在成人组中，上述两者引出率分别为83.33%及75%，两者较正常对照组均为低，具有统计学差异。在对比其他参数中，儿童组患者与正常对照组各参数无统计学差异。在成人组参数中，患者眼肌前庭诱发肌源性电位的振幅较正常对照组高，颈肌前庭诱发肌源性电位振幅较正常对照组低，N1潜伏期延长，P1潜伏期缩短，比较均具有统计学差异。成人组其他参数比较无统计学差异。.科学意义.Zey基因突变小鼠为我们提供了一种很好的研究中耳炎及迷路炎的模型，它可能对人类该突变的同源个体提供很好的中耳炎及迷路炎的病理生理的研究模板。另外我们发现在研究前庭功能方面，在LVAS成年患者中，cVEMP较oVEMP的敏感性及特异性更好。.