Microglial activation in the cochlear nucleus after early hearing loss in rats.
Microglial activation in the cochlear nucleus after early hearing loss in rats.
复制标题
DOI：
10.1016/j.anl.2019.02.006
复制
发表时间：
2019-10
期刊：
影响因子：
--
通讯作者：
M. Noda;M. Hatano;T. Hattori;Mika Takarada-Iemata;T. Shinozaki;H. Sugimoto;Makoto Ito;T. Yoshizaki;O. Hori
中科院分区：
文献类型：
--
作者：
M. Noda;M. Hatano;T. Hattori;Mika Takarada-Iemata;T. Shinozaki;H. Sugimoto;Makoto Ito;T. Yoshizaki;O. Hori
小胶质细胞是中枢神经系统中高度特化的组织巨噬细胞。他们在听觉系统中的激活已在成人听力损失模型中报道，但他们在发育中的听觉系统中的地位却知之甚少。因此，我们调查小胶质细胞的状态在耳蜗核（CN）在正常发育期间和暴露后，大鼠阿米卡星，一个强大的耳毒素，周围的时间听力onset.MethodsTo开发的耳聋模型，大鼠每天腹腔注射阿米卡星（500 mg/kg）从出生后第7天（P7）至P15。为了评估离子钙结合衔接分子1（Iba 1）的表达，我们进行了免疫组织化学分析，从P10-60大鼠大脑。为了比较小胶质细胞相关基因的表达，逆转录定量聚合酶链反应（RT-qPCR）分析performed. ResultsImmunohistochemistry分析显示，在正常条件下，小胶质细胞有相对较大的细胞体与几个延伸的突起，周围的其他细胞在P10，而这些细胞的大小和数量逐渐减少。相比之下，当阿米卡星从P7到P15给药时，小胶质细胞在P15和P21都保持具有相对较短突起的大细胞体。此外，RT-qPCR分析显示，包括阿米卡星administration.ConclusionThese结果表明，小胶质细胞被激活的CN后，吞噬和抗炎标志物的基因上调，他们可能有助于组织重塑后，早期听力损失的发展中的听觉系统。
ObjectiveMicroglia are highly specialized tissue macrophages in the central nervous system. Their activation in the auditory system has been reported in adult hearing loss models, but their status in the developing auditory system is less understood. Therefore, we investigated microglial status in the cochlear nucleus (CN) during normal developing periods and after exposing rats to amikacin, a potent ototoxin, around the time of hearing onset.MethodsTo develop the deafness model, rats were administered with a daily intraperitoneal injection of amikacin (500 mg/kg) from postnatal day 7 (P7) to P15. To evaluate the expression of ionized calcium binding adaptor molecule 1 (Iba1), we performed immunohistochemical analysis using rat brains from P10–60. To compare the expression of microglia-related gene, reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis were performed.ResultsImmunohistochemical analysis revealed that, under normal conditions, microglia had relatively large cell bodies with several extended processes that surrounded other cells at P10, while the sizes and number of these cells gradually decreased afterward. In contrast, when amikacin was administered from P7 to P15, microglia maintained large cell bodies with relatively shorter processes at both P15 and P21. Furthermore, RT-qPCR analysis revealed upregulation of genes including phagocytotic and anti-inflammatory markers after amikacin administration.ConclusionThese results suggest that microglia are activated in the CN, and they may contribute to tissue remodeling after early hearing loss in the developing auditory system.