Mousa Shaaban A, Dehe Lukas, Aboryag Noureddin, Shaqura Mohammed, Beyer Antje, Schäfer Michael, Treskatsch Sascha
Department of Anaesthesiology and Intensive Care Medicine, Charité - University Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin Institute of Health, Campus Benjamin Franklin, Berlin, Germany.
Department of Anaesthesiology, Ludwig-Maximilians-University Munich, Munich, Germany.
Front Neuroanat. 2022 Sep 23;16:902738. doi: 10.3389/fnana.2022.902738. eCollection 2022.
Emerging evidences indicate that glucocorticoid receptors (GR) play a regulatory role in cardiac function, particularly with regard to the autonomic nervous system. Therefore, this study aimed to demonstrate the expression and the precise anatomical location of GR in relation to the parasympathetic and sympathetic innervations of the heart.
The present study used tissue samples from rat heart atria to perform conventional reverse-transcriptase polymerase chain reaction (RT-PCR), Western blot, and double immunofluorescence confocal analysis of GR with the neuronal markers vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP) as well as the mineralocorticoid receptor (MR).
Double immunofluorescence labeling revealed that GRs were co-expressed with VAChT in parasympathetic principal neuronal somata and nerve terminals innervating atrium. Also, GR colocalized with the sympathetic neuronal marker TH in a cluster of small intensely fluorescent (SIF) cells, on intracardiac nerve terminals and in the atrial myocardium. GR immunoreactivity was scarcely identified on CGRP-immunoreactive sensory nerve terminals. Approximately 20% of GR immunoreactive neuronal somata co-localized with MR. Finally, conventional RT-PCR and Western blot confirmed the presence of GR and MR in rat heart atria.
This study provides evidence for the existence of GR predominantly on cardiac parasympathetic neurons and TH-immunoreactive SIF cells suggesting a functional role of cardiac GR on cardiovascular function by modulation of the cardiac autonomic nervous system.
新出现的证据表明，糖皮质激素受体（GR）在心脏功能中发挥调节作用，特别是在自主神经系统方面。因此，本研究旨在证明GR在心脏副交感神经和交感神经支配方面的表达及精确解剖位置。
本研究使用大鼠心房组织样本进行常规逆转录聚合酶链反应（RT-PCR）、蛋白质免疫印迹法，以及GR与神经元标志物囊泡乙酰胆碱转运体（VAChT）、酪氨酸羟化酶（TH）、降钙素基因相关肽（CGRP）和盐皮质激素受体（MR）的双重免疫荧光共聚焦分析。
双重免疫荧光标记显示，GR与VAChT在支配心房的副交感神经主要神经元胞体和神经末梢中共表达。此外，GR与交感神经神经元标志物TH在一群小而强荧光（SIF）细胞、心内神经末梢和心房心肌中共定位。在CGRP免疫反应性感觉神经末梢上几乎未发现GR免疫反应性。约20%的GR免疫反应性神经元胞体与MR共定位。最后，常规RT-PCR和蛋白质免疫印迹法证实大鼠心房中存在GR和MR。
本研究为GR主要存在于心脏副交感神经元和TH免疫反应性SIF细胞上提供了证据，提示心脏GR通过调节心脏自主神经系统对心血管功能发挥作用。
