白介素－2对海马神经细胞的功能调控

Modulation of Hippocampal Neuronal Activities by rhIL-2

采用形态学、电生理学和生物化学等方法，研究了重组人白介素－２（ｒｈＩＬ－２）对新生大鼠海马培养神经元生长发育、平均蛋白总量、膜电活动以及细胞内游离钙离子浓度的影响。结果显示，ｒｈＩＬ－２对海马培养神经元的突起生长、胞体发育以及发育过程中神经元的蛋白质合成具有明显的促进作用，并且在提高海马培养神经元存活、延长存活时间方面有较为显著的效应。细胞内记录结果显示，ｒｈＩＬ－２可改变海马神经元的膜兴奋性，该作用可被纳洛酮减弱。提示阿片受体可能参与介导ｒｈＩＬ－２的作用过程。另外，采用ｆｕｒａ－２荧光探针标记法发现，ｒｈＩＬ－２能够通过胞外钙离子的流入和胞内钙库的释放提高海马神经元胞浆内游离钙离子的浓度。上述研究结果初步表明，细胞因子ｒｈＩＬ－２能够调控海马神经元的功能活动。

The effects of recombinant human interleukin-2(rhIL-2)on the growth and electrophysiological functions of hippocamnpal neurons were studied by using morphological、biochemical and physiological methods.Results from image analysis and flow cytometry showed that cytokine rhIL-2 can promote neurite outgrowth、soma development and protein synthesis during neuronal growth,as well as support the survival of hippocampal neurons in culture.The results of intracellular recordings from the neonatal rat hippocampal neurons in culture showed that a depolarization can be induced by rhIL-2 while naloxone can influence this effect of rhIL-2 by reducing the firing rate.It suggests a possible involvement of opiate receptor in the event. Intracellular free calcium concentration([Ca2+]i)of neonatal rat hippocampal neurons was determined with the fluorescent indicator Fura-2.rhIL-2 causes an increase of 43.7±15.8 nmol/L(n=5)[Ca2+]i with the Hank's solution free of extracellular calcium or an increase of 94.5±27.4 nmol/L(n=5) with the presence of 1.3 mmo1/L extracellular calcium respectively.This indicated that rhIL-2 can enhance the[Ca2+]i of hippocampal neurons by inducing Ca[2+]6 influx and stimulating the release of calcium from intracellular calcium stores.Therefore,we suppose that Ca[2+] may play an important role in mediating the effect of rhIL-2.In summary,rhIL-2 can modulate the activity of hippocampal neurons.