Background

: Depression is a prevalent emotion disorder which thought to be due to neuronal structural alterations and/or functional impairment within specific brain regions. Several studies have shown that microRNAs are involved in the pathogenesis of depression. As a Chinese herbal formula, Xiaoyaosan (XYS) could have antidepressive effects, although the mechanisms associated with microRNAs are poorly understood.

Purpose

: In this study, we investigated whether inhibition of the miR-200a/b-3p/NR3C1 pathway in the prefrontal cortex is involved in the anti-neuronal apoptosis and anti-stress effects of XYS and then further delineated the underlying mechanism.

Methods

: To evaluate the efficacy of XYS in relieving stress behaviors and altering the expression of miRNAs involved in the regulation of these behaviors in vivo, a chronic unpredictable mild stress (CUMS) rodent model and RNA-seq were performed. Primary cortical neurons were used to evaluate the molecular function of miR-200a/b-3p and detect the in vitro neuroprotective function of paeoniflorin, which is one of the main components of XYS. To investigate the function of miR-200a/b-3p in stress behaviors, stereotactic microinjection of AAV2/9-Syn-miR-200a/b-3p was performed to deliver the treatment to the rat mPFC.

Results

: XYS reduced the anxiety and depression-like behaviors associated with chronic stress and reduced the expression of miR-200a/b-3p and neuronal apoptosis in the prefrontal cortex (PFC). The overexpression of miR-200a/b-3p in primary cortical neurons reduced the expression of the target gene NR3C1, increased the protein expression of cleaved caspase-3 and Bax, and decreased the anti-apoptotic protein Bcl-2. One of the active ingredients of XYS, paeoniflorin, can inhibit miR-200a/b-3p-mediated apoptosis of primary neurons and abnormal expression of apoptosis-related proteins. After overexpressing miR-200a/b-3p in vivo (vmPFC), the rats eventually showed significant anxiety-like behaviors similar to those caused by chronic stress.

Conclusion

: Our findings indicate that XYS can inhibit the CUMS-induced expression of miR-200a/b-3p, regulate miR-200a/b-3p/NR3C1 signaling in the PFC caused by chronic stress, and reduce neuronal apoptosis and stress-related behaviors.

中文翻译：

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逍遥散通过调节慢性应激大鼠前额叶皮层 miR-200/NR3C1 信号通路抑制神经元凋亡

背景

: 抑郁症是一种普遍的情绪障碍，被认为是由于特定大脑区域内的神经元结构改变和/或功能障碍所致。多项研究表明，microRNA 参与了抑郁症的发病机制。作为一种中草药配方，逍遥散 (XYS) 可能具有抗抑郁作用，尽管与 microRNA 相关的机制知之甚少。

目的

：在这项研究中，我们研究了前额叶皮层 miR-200a/b-3p/NR3C1 通路的抑制是否与 XYS 的抗神经元凋亡和抗应激作用有关，然后进一步阐明了潜在的机制。

方法

：为了评估 XYS 在缓解压力行为和改变体内参与调节这些行为的 miRNA 表达方面的功效，进行了慢性不可预测的轻度压力 (CUMS) 啮齿动物模型和 RNA-seq。原代皮层神经元用于评估 miR-200a/b-3p 的分子功能，并检测芍药苷的体外神经保护功能，芍药苷是 XYS 的主要成分之一。为研究 miR-200a/b-3p 在应激行为中的作用，采用立体定向显微注射 AAV2/9-Syn-miR-200a/b-3p 对大鼠 mPFC 进行治疗。

结果

：XYS 减少了与慢性压力相关的焦虑和抑郁样行为，并减少了前额叶皮层 (PFC) 中 miR-200a/b-3p 和神经元凋亡的表达。miR-200a/b-3p在原代皮层神经元中的过表达降低了靶基因NR3C1的表达，增加了cleaved caspase-3和Bax的蛋白表达，降低了抗凋亡蛋白Bcl-2。XYS的活性成分之一芍药苷可抑制miR-200a/b-3p介导的原代神经元凋亡和凋亡相关蛋白的异常表达。在体内过表达 miR-200a/b-3p (vmPFC) 后，大鼠最终表现出明显的焦虑样行为，类似于慢性压力引起的行为。

结论

: 我们的研究结果表明，XYS 可以抑制 CUMS 诱导的 miR-200a/b-3p 表达，调节慢性应激引起的 PFC 中的 miR-200a/b-3p/NR3C1 信号传导，并减少神经元凋亡和应激相关行为.