利用低密度脂蛋白受体敲除仓鼠建立基于脑血管动脉粥样硬化的自发性脑卒中模型

Cerebral vascular obstruction caused by multiple factors can lead to ischemic stroke, which is closely related to disturbance of glucose and lipid metabolism, hypertension, hemodynamics, etc. However, at present, researchers can only obtain Ischemic cerebral animal models by blocking the cerebrovascular to investigate the repair of damaged brain tissue. The methods of developing ischemic cerebral animal models are thus very limited. In our previous research, we successfully constructed a low density lipoprotein receptor knockout (LDLR-/-) hamster, which mimicks the characteristics of lipid metabolism disorder in humans and has spontaneous formation of coronary atherosclerosis and of neurological symptoms. In order to establish a spontaneous animal model with cerebral artery atherosclerosis, which can mimic the mechanisms of human stroke, we intend to use the LDLR-/- hamsters to increase the incidence of stroke by giving them angiotensin sustained release pumps. In addition, we will explore the predisposing factors and pathological basis of cerebral stroke, as well as the difference between the spontaneous cerebral stroke model and middle cerebral artery occlusion model. Also, effects of age, sex, diet and metabolic diseases on stroke will be discussed. We will further explore the comprehensive effects and multitarget mechanisms of the extracts of Rosa rugose, a Xinjiang uygur medicine with lipid-lowering, anti-inflammation, anti-oxidation and inhibition of fibrosis activities, on cerebral stroke. The establishment of this model has great potential to be an ideal tool for the study of ischemic stroke.

缺血性脑卒中由多因素共同作用造成的脑血管阻塞引起的，其发生与糖脂代谢紊乱、高血压、血流动力学等因素密切相关。但目前脑卒中动物模型非常单一，只能通过人为阻塞大脑动脉造模后研究脑损伤的修复。我们团队前期研究建立了低密度脂蛋白受体敲除（LDLR-/-）仓鼠，该动物模型具有类人化的脂代谢紊乱、能够自发形成冠状动脉粥样硬化以及出现神经系统症状等特征。为了建立自发性的、具有脑动脉血管动脉粥样硬化病变基础的、能模拟人类脑卒中发生机制的动物模型，我们拟利用LDLR-/-的仓鼠，通过给予血管紧张素缓释泵增加脑卒中发生的诱发因素，观察脑卒中发生的条件和病理基础、自发性脑卒中与大脑中动脉梗死模型诱导的差异，并且探讨年龄、性别、饮食、代谢性疾病等对卒中的影响；同时探讨具有降脂、抗炎、抗氧化、抑制纤维化等作用的新疆地区维药玫瑰花的提取物对脑卒中的多靶点综合作用。该模型的建立有望为缺血性脑卒中研究提供理想的平台。

缺血性脑卒中是一种具有高发病率、高死亡率和高致残率的毁灭性疾病。然而，缺乏与人类相似的脑卒中动物模型是缺血性脑卒中治疗新药在临床试验中转化失败的重要原因。因此，建立具有脑动脉血管动脉粥样硬化病变基础的、能模拟人类脑卒中的动物模型可为缺血性脑卒中的研究和新型治疗策略的临床转化提供理想的平台。本课题采用低密度脂蛋白受体敲除（LDLR-/-）仓鼠和腺苷三磷酸转运盒结合子A1敲除(ABCA1-/-)仓鼠结合两肾一夹建立高血压模型及大脑中动脉阻塞（MCAO）建立仓鼠缺血性脑卒中模型。首先发现LDLR-/-和ABCA1-/-仓鼠不仅旨在脂代谢、血细胞成分、凝血功能、炎症反应等和脑卒中相关的全身性变化方面出现明显的病理性改变，而且在脑局部的血液循环、炎症反应、神经元细胞损害等方面出现明显的生理、病理和行为学改变。仓鼠c-MCAO手术后，相比于野生型仓鼠，LDLR和ABCA1敲除均可诱导更大的梗死体积，但经c-MCAO手术的ABCA1-/-仓鼠和LDLR-/-仓鼠在脑梗死体积上并无显著差异。同时通过对LDLR-/-仓鼠进行两肾一夹手术造成仓鼠高血脂叠加高血压危险因素，发现腹主动脉斑块明显增加，而脑组织炎症阳性细胞明显增加；而五月龄ABCA1-/-仓鼠自发发生冠状动脉粥样硬化，同时实验也证明ABCA1-/-的仓鼠脑组织IL-6、TNF-α、CD36等呈现高表达；ABCA1-/-的仓鼠凝血指标 PT、APTT均较野生型升高；而且新事物认知功能明显的受损，说明 ABCA1-/-仓鼠相较于LDLR-/-可能更有利于脑卒中的发生，提示基因修饰 ABCA1-/-仓鼠模型是研究脑卒中相关的遗传和环境因素的较好模型。