MicroRNA-153在长期脑低灌注大鼠基底前脑-海马胆碱能神经环路损伤中的作用及分子机制

Impairment of basal forebrain – hippocampus cholinergical circuit is an important clinical feature of senile dementia at the early stage, while the molecular mechanism is unknown. Our previous studies have been demonstrated that rats suffering from chronic brain hypoperfusion (CBH) induced by bilateral common carotid artery occlusion (2VO) could promote Aβ cascade response through inhibiting the expression of miR-195. As a preclinical stage, how CBH afftect basal forebrain – hippocampus cholinergical circuit and what is the molecular mechanism is largely unknown. Research contents: 1. To evaluate the electrophysiological characteristics of neurons of MS and hippocampus, mitochondrial function and mitochondrial biogenesis and fission related protein expression, as well as miR-153 level; 2. To investigate the regulation of miR-153 on targets genes; 3. By employing the cutting edge technologies of anteriograde and retrograde monosynaptic and cholinergic neuron –specific labels and electrophysiology, we will study whether miR-153 could regulates impairment of basal forebrain – hippocampus cholinergical circuit by affecting mitochondrial function of basal forebrain using miR-153 transgenic mice and 2VO rats with stereotaxic injection of the lentiviral vectors containing pre-AMO-miR-153. This study is the further study based on our previous published results. Our aim is to disclose the microRNAs mechanism involvement of dementia induced by CBH and provide the research evidence for future clinical drug discovery.

基底前脑-海马胆碱能神经（MS-CA1）环路损伤是老年痴呆患者早期重要的病理生理特征，但分子机制不清。我们前期研究证明大鼠双侧颈总动脉结扎（2VO）引起长期脑低灌注（CBH）可抑制miR-195表达促进Aβ级联反应过程。CBH是否可引起MS-CA1环路损伤未见报道。研究内容：1. 评价2VO大鼠MS和海马胆碱能神经元电生理特征、MS线粒体功能及相关蛋白和miR-153的水平；2. 阐明miR-153对目的蛋白靶向调控作用；3. 采用miR-153基因编辑小鼠和2VO大鼠局部海马注射含AMO-miR-153慢病毒载体，联合使用正向和逆向单突触追踪，特异性胆碱能神经元标记等技术探讨miR-153是否通过抑制基底前脑线粒体功能调节CBH诱导的MS-CA1环路的损伤过程。本研究是课题组前期原创性研究的系列研究，旨在系统阐明miRNAs在CBH诱导痴呆发生中的分子机制，为临床药物研发提供实验依据。

基底前脑-海马胆碱能神经（MS-CA1）环路损伤是老年痴呆患者早期重要的病理生理特征，但分子机制尚未完全阐明。在课体组前期研究基础上，本研究联合使用网络数据库、慢病毒转染、miR-masking、光遗传学、正向和逆向突触追踪技术以及电生理和相关分子生物学技术探讨在实验性CBH大鼠模型和OVX小鼠痴呆痴呆模型中MS-CA1环路的损伤特征、环路机制及miR-153对线粒体的调节作用及其机制。研究发现：1. CBH损伤MS-dCA1神经环路的胆碱能神经元投射、胆碱能神经元突触前释放功能和突触后nAChR功能；2. CBH 可以上调MS区miR-153表达，引起线粒体空泡化，ROS 升高和线粒体膜电位下降。 MiR-153转录后抑制Nrf-2的表达抑制线粒体的功能。（3）揭示了MS内PV+神经元的肠道感应特性。发现高脂饮食协同雌激素缺乏损伤肠道菌群（普雷沃氏菌）-MSA（PV阳性神经元）-dCA1环路触发小鼠认知功能损伤。