心钠素在原代培养大鼠耳蜗螺旋神经元细胞中的表达

Expression of atrial natriuretic peptides in primary cultured spiral ganglion neurons from rat cochlea

目的观察心钠素(atrial natriuretic peptide,ANP)在原代培养大鼠耳蜗螺旋神经元细胞(spiralgan-glion neurons,SGN)中是否表达。方法应用细胞培养技术原代培养SGN,并进行鉴定、纯化,应用免疫细胞化学方法和逆转录—聚合酶链反应(RT-PCR)检测原代培养的SGN中ANP的表达情况。结果原代培养的SGN经免疫细胞化学检测,证实其神经元特异性核蛋白(neuron-specific nuclear protein,NeuN)表达阳性,并且发现近胞核周围的胞质存在ANP免疫反应阳性颗粒,免疫荧光染色检测证实了ANP、NeuN的共同表达,RT-PCR方法检测到ANP-mRNA的存在。结论本实验表明原代培养的SGN具有表达与合成ANP的能力,提示ANP可能作为内耳SGN神经调节的一种递质或调质,参与其生理活动和突触传递功能的调节。

Objective To study expression of atrial natriuretic peptides (ANP) in primary cultured spiral ganglion neurons (SGN)from the rat cochlea. Methods SGN were cultured, identified and purified in vitro. Immunocytochemistry and reverse-transcription polymerase chain reaction (RT-PCR) techniques were used to examine expression of ANP in cultured SGN. Results The neuron -specific nuclear protein (NeuN) was positive in cultured SGN, and ANP immunoreactive granules localized around the perinuclear cytoplasm of neurons. Co-expression of ANP and NeuN in SGN was confirmed by immunofluorescence staining, and expression of ANP -mRNA was also detected by RT -PCR. Conclusion The results suggest that primary cultured SGN can express and synthesize ANP, indicating that the ANP may play a role as a neurotransmitter or neuromodulator in modulating physiological activities and neurotransmission in SGN in the inner ear.