Gas5参与电针调节手术创伤引起的下丘脑-垂体-肾上腺轴功能亢进的机制

Severe surgery or trauma can induce the Hypothalamus pituitary adrenal (HPA) axis hyperactivity, which may lead to adverse reaction, and previous study has showed that Electroacupuncture (EA) can improve surgical trauma induced HPA axis hyperactivity, and its mechanisms remain to be clarified. Long noncoding RNAs (LncRNAs) growth arrest specific 5 (Gas5) had significant difference between with and without surgery and the application of EA. The expression of hypothalamus glucocorticoid receptor (GR) can inhibit the overexpression of corticotrophin releasing hormone (CRH), which is the initial part of the HPA axis, and regulated by Gas5 expression in primary hypothalamus neurons.Gas5 has been reported to inhibit the function of GR binding to GRE via binding to its DNA-binding domain (DBD) and played a endogenous competition function via binding to miRNAs. Thus, we focus on the Gas5 involvement in the HPA axis regulation after surgery in a rat model of partial hepatectomy from the overall, cellular and molecular level on the basis of previous studies, and make a deep analysis of the mechanism of EA in alleviating the HPA axis hyperactivity after surgical trauma, to provide a theoretical basis on EA application.

手术或重大创伤刺激会引起HPA轴功能亢进进而导致机体功能损伤，而我们前期研究发现电针(EA)可以改善手术创伤诱导的HPA轴功能亢进，但其机制未明。长链非编码RNA Gas5水平在手术创伤及给予EA后存在差异，原代培养的下丘脑神经元表达Gas5且Gas5的高表达可以减弱糖皮质激素(GC)/糖皮质激素受体(GR)对HPA轴始动因子促肾上腺皮质激素释放激素(CRH)的抑制作用，而电针可以下调手术创伤导致的Gas5水平上调。考虑到Gas5可以与GR的DNA结合域结合而抑制GR与糖皮质激素反应元件结合，同时与miRNAs结合发挥内源性竞争抑制作用。因此，本研究拟在前期研究的基础上，采用部分肝切模型，从整体、细胞和分子水平探讨Gas5参与调控手术创伤后HPA轴功能的机制，深入分析Gas5参与EA缓解手术创伤诱导的HPA轴功能亢进的机理，为临床EA推广提供理论依据。

下丘脑-垂体-肾上腺 (HPA) 轴功能的调控对经历严重创伤应激患者意义重大。在前期研究的基础上采用部分肝脏切除手术创伤模型，以外周血促肾上腺皮质激素（ACTH）及皮质酮（CORT）评价HPA轴功能，发现创伤极早期可引起HPA轴功能亢进，电针(EA)能改善部分肝脏切除手术创伤模型大鼠HPA轴功能亢进。通过神经药理学方法发现，下丘脑促肾上腺皮质激素释放激素（CRH）及糖皮质激素受体（GR）均参与电针对手术创伤后HPA轴的功能调控。同时，手术创伤会引起下丘脑长链非编码RNA 生长停滞特异因子5（Gas5）的高表达，而电针能显著降低下丘脑Gas5的表达。采用腺相关病毒（pAAV-CMV-Gas5-BGHpolyA-EF1A-EGFP-3FLAG）高表达下丘脑室旁核Gas5水平后，可以抑制EA对创伤后HPA轴的调节作用。通过培养原代下丘脑神经元发现，下丘脑Gas5表达影响GR的核转位。进一步通过生物信息学分析与Gas5相关miRNAs，并筛选发现，抑制Gas5能显著增加下丘脑miR-674的表达。双荧光素酶报告基因检测进一步明确下丘脑SGK-1为miR-674的靶基因。电针能降低下丘脑Gas5的表达，进而增加下丘脑miR-674的表达水平，从而减弱下丘脑SGK-1的表达发挥对创伤后HPA轴的功能调控作用。