Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, USA.
University of the Incarnate Word School of Medicine, San Antonio, Texas, USA.
Anat Rec (Hoboken). 2024 Mar;307(3):592-599. doi: 10.1002/ar.25298. Epub 2023 Jul 29.
Osteogenesis imperfecta (OI) is known to cause hearing loss in ~60% of the affected human population. While OI-related pathologies have been studied in the middle ear, the development of cochlear pathologies is less well understood. In this study, we examine OI-related pathologies of the cochlea in a mouse model of OI to (1) document variation between OI and unaffected mice, and (2) assess the intrusion of the otic capsule onto the cochlea by analyzing differences in duct volumes. Juvenile and adult OIM C57BL/6mice were compared to unaffected wildtype (WT) mice using three-dimensional models of the cochlea generated from high resolution micro-CT scans. Two-tailed Mann-Whitney U tests were then used to investigate duct volume differences both within and between the OI and WT samples. Areas of higher ossification were observed at the cochlear base in the OI sample. OI mice also had significant intraindividual differences in duct volume between right and left ears (4%-15%), an effect not observed in WT mice. WT and OI duct volumes showed a large degree of overlap, although the OIM volumes were more variable. Our findings indicate that OIM mice are likely to exhibit more asymmetry and variation in cochlear volume despite minor differences in sample cochlear volumes, possibly due to bony capsule intrusion. This suggests a potential mechanism of hearing loss, and a high potential for cochlear and otic capsule alteration in OIM mice.
成骨不全症（OI）已知会导致受影响人群中约 60%的人出现听力损失。虽然中耳的 OI 相关病理学已得到研究，但耳蜗病理学的发展还不太清楚。在这项研究中，我们在 OI 小鼠模型中检查了耳蜗的 OI 相关病理学，以（1）记录 OI 和未受影响的小鼠之间的差异，（2）通过分析管腔体积的差异来评估耳囊对耳蜗的侵入。使用来自高分辨率微 CT 扫描的耳蜗三维模型，将幼年和成年 OIM C57BL/6 小鼠与未受影响的野生型（WT）小鼠进行比较。然后使用双尾曼-惠特尼 U 检验来研究 OI 和 WT 样本内和样本间的管腔体积差异。在 OI 样本中，在耳蜗基底处观察到更高的骨化区域。OI 小鼠的左右耳之间的管腔体积也存在显著的个体内差异（4%-15%），WT 小鼠则没有观察到这种差异。WT 和 OI 管腔体积有很大的重叠，尽管 OIM 体积的变化更大。我们的发现表明，尽管样本耳蜗体积存在微小差异，但 OIM 小鼠的耳蜗体积可能表现出更大的不对称性和变异性，这可能是由于骨囊侵入所致。这提示了一种听力损失的潜在机制，以及 OIM 小鼠耳蜗和耳囊改变的高潜力。
