Novel cholineacetyltransferase variants (pChAT) in the brain of human and monkey

虽然大多数ChAT抗体清楚地染色中枢性胆碱能神经元，但很难揭示外周胆碱能系统。这一困难表明，周围组织中可能存在不同形式的Chat。为了验证这一假设，我们研究了大鼠翼腭神经节，它是一个含有许多胆碱能神经元的结构，将它们的轴突外周发送到脑血管。从实验中，我们发现ChAT mRNA的一个剪接变体在翼腭部而不是在大脑中表达。根据ChAT的基因组结构，该变异体缺少外显子6、7、8和9。该序列没有移码，并保留了ChAT蛋白的催化功能所必需的区域。由于该变体在外周组织中优先表达，我们将其命名为pChAT(外周型ChAT)。在这项研究中，我们研究了人和猴子的cChAT和pChAT的结构。我们从人和猴的胎盘中克隆了cChAT和pChAT的cDNA。在实验的第二步，我们制备了针对cChAT和pChAT的抗血清。利用这些抗血清，我们研究了cChAT和pChAT蛋白在大鼠、猴子和人脑中的定位。我们已经在国际期刊的11篇论文上发表了这一结果(列表见下一页)。PChAT的发现将有助于研究中枢和外周神经系统的胆碱能机制。

Although most ChAT antibodies clearly stain central cholinergic neurons, it is difficult to reveal peripheral cholinergic system. The difficulty suggests that different forms of ChAT may exist in peripheral tissues. To test the hypothesis, we investigated the rat pterygopalatine ganglion, which is a structure that contains many cholinergic neurons sending their axons peripherally to cerebral vessels. From the experiments, we found a splice variant of ChAT mRNA expressed, not in the brain, but in the pterygopalatine. According to the genomic structure of ChAT, the variant lacks exons 6, 7, 8 and 9. The cDNA sequence has no frame shift and preserves regions of the ChAT protein which are essential for its catalytic function. Since the variant is expressed preferentially in peripheral tissues, we termed the form as pChAT(peripheral type of ChAT). And we termed the known ChAT as cChAT (common type of ChAT).In this study, we investigated the structure of cChAT ad pChAT of human and monkey. We cloned cDNAs of cChAT and pChAT from the placenta of human and monkey. In the second step of our experiments, we produced antisera specific to cChAT and pChAT. Using these antisera, we investigated localizations of cChAT and pChAT proteins in the brain of rat, monkey and human. We have published the results in eleven papers of international journals (List in the next page). Findings of pChAT should facilitate investigations of cholinergic mechanism in the central and peripheral nervous system.