Muscarinic receptor-dependent activation of phospholipase C in human fetal central nervous system organotypic tissue culture.
Muscarinic receptor-dependent activation of phospholipase C in human fetal central nervous system organotypic tissue culture.
复制标题
人胎儿中枢神经系统器官组织培养中磷脂酶 C 的毒蕈碱受体依赖性激活。
DOI：
10.1016/0006-8993(95)00986-3
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发表时间：
1995
期刊：
影响因子：
2.9
通讯作者：
Lyman,WD
中科院分区：
文献类型：
--
作者：
Larocca,JN;Rodriguez-Gabin,AG;Rashbaum,WK;Weidenheim,KM;Lyman,WD
肌碱胆碱能受体（mAchR）与磷脂酶C （PLC）第二信使系统的偶联已在许多动物的中枢神经系统（CNS）组织中得到证实。然而，关于这种关联在发育中的人类中枢神经系统中存在的信息很少。由于乙酰胆碱在调节神经细胞的发育和分化中的作用，在人类胎儿发育过程中这些关系的知识获得了独特的重要性。因此，我们检测了PLC在人胎儿中枢神经系统器官型组织培养中的胆碱能刺激。在锂离子存在的情况下，对培养物进行激动剂处理，导致肌醇磷酸盐形成增加4 - 6倍。这种增加主要是由磷酸肌醇（IP）的形成引起的。然而，动力学研究表明，刺激后IP2、ip3和ip4水平也迅速上升，达到IT前的最高水平。这些结果支持了毒蕈碱受体激活导致PIP2水解增加的假设。肌醇磷酸的形成依赖于激动剂的浓度。羧酸乙酯的ec50值为57±15 μM，乙酰胆碱的ec50值为8±2 μM，氧tremorine的ec50值为49±15 μM。肌醇磷酸依赖于激动剂的形成被毒蕈碱类拮抗剂阿托品和匹伦齐平抑制。吡伦齐平具有高亲和力（Ki= 2.90±1.15 nM）抑制碳碱刺激，表明PLC激活是毒蕈碱受体m1亚型激活的结果。百日咳毒素处理培养没有导致抑制激动剂依赖的PLC激活。这一结果表明m1毒蕈碱受体通过Gq与PLC偶联。
The coupling of muscarinic-cholinergic receptors (mAchR) with the phospholipase C (PLC) second messenger system has been demonstrated in central nervous system (CNS) tissue of many animal species. However, little information exists regarding this association in the developing human CNS. Due to the suggested role of acetylcholine in the regulation of development and differentiation of neural cells, the knowledge of these relationships during human fetal development acquires singular importance. Because of this, we examined the cholinergic stimulation of PLC in human fetal CNS organotypic tissue cultures. Agonist treatment of cultures, in the presence of lithium, resulted in a 4–6-fold increase in inositol phosphates formation. This increase was caused principally by the formation of inositol phosphate (IP). However, kinetic studies demonstrated that the levels of IP2, IP3and IP4also increased rapidly after stimulation reaching maximum levels before IT. These results support the hypothesis that muscarinic receptor activation results in an increase in the hydrolysis of PIP2. The inositol phosphate formation was dependent on agonist concentration. The obtained EC50values were approximately 57 ± 15 μM for carbachol, 8 ± 2 μM for acetylcholine and 49 ± 15 μM for oxotremorine. The agonist-dependent formation of inositol phosphates was inhibited by the muscarinic antagonists atropine and pirenzepine. Pirenzepine inhibited carbachol stimulation with high affinity (Ki= 2.90 ± 1.15 nM), indicating that PLC activation is the result of activation of the m1 subtype of muscarinic receptors. Treatment of cultures with pertussis toxin did not result in inhibition of agonist-dependent activation of PLC. This result suggests that the m1 muscarinic receptor is coupled to PLC through Gq.