Department of Biology and Biotechnology Charles Darwin, "Sapienza" University of Rome, 00185 Rome, Italy.
Department of Pharmacy, University of Naples Federico II, 80138 Naples, Italy.
Int J Mol Sci. 2021 May 23;22(11):5499. doi: 10.3390/ijms22115499.
Dorsal root ganglia (DRG) neurons synthesize acetylcholine (ACh), in addition to their peptidergic nature. They also release ACh and are cholinoceptive, as they express cholinergic receptors. During gangliogenesis, ACh plays an important role in neuronal differentiation, modulating neuritic outgrowth and neurospecific gene expression. Starting from these data, we studied the expression of choline acetyltransferase (ChAT) and vesicular ACh transporter (VAChT) expression in rat DRG neurons. ChAT and VAChT genes are arranged in a "cholinergic locus", and several splice variants have been described. Using selective primers, we characterized splice variants of these cholinergic markers, demonstrating that rat DRGs express R1, R2, M, and N variants for ChAT and V1, V2, R1, and R2 splice variants for VAChT. Moreover, by RT-PCR analysis, we observed a progressive decrease in ChAT and VAChT transcripts from the late embryonic developmental stage (E18) to postnatal P2 and P15 and in the adult DRG. Interestingly, Western blot analyses and activity assays demonstrated that ChAT levels significantly increased during DRG ontogenesis. The modulated expression of different ChAT and VAChT splice variants during development suggests a possible differential regulation of cholinergic marker expression in sensory neurons and confirms multiple roles for ACh in DRG neurons, both in the embryo stage and postnatally.
背根神经节 (DRG) 神经元除了具有肽能特性外，还合成乙酰胆碱 (ACh)。它们还释放 ACh，并且具有胆碱能受体，因此是胆碱能接受体。在神经节发生过程中，ACh 对于神经元分化起着重要作用，调节神经突的生长和神经特异性基因表达。基于这些数据，我们研究了大鼠 DRG 神经元中胆碱乙酰转移酶 (ChAT) 和囊泡乙酰胆碱转运体 (VAChT) 的表达。ChAT 和 VAChT 基因排列在“胆碱能基因座”中，并已描述了几种剪接变体。使用选择性引物，我们对这些胆碱能标记物的剪接变体进行了特征描述，证明大鼠 DRG 表达 ChAT 的 R1、R2、M 和 N 变体以及 VAChT 的 V1、V2、R1 和 R2 剪接变体。此外，通过 RT-PCR 分析，我们观察到从胚胎发育后期 (E18) 到出生后 P2 和 P15 以及成年 DRG 中，ChAT 和 VAChT 转录本逐渐减少。有趣的是，Western blot 分析和活性测定表明，ChAT 水平在 DRG 发生过程中显著增加。不同 ChAT 和 VAChT 剪接变体在发育过程中的表达变化表明，在感觉神经元中，胆碱能标记物的表达可能存在差异调节，并证实了 ACh 在 DRG 神经元中的多种作用，无论是在胚胎阶段还是出生后。
