Modulation of neurodegeneration and neuroinflamation by the liver X receptor (LXR) in Alzheimer`s disease

来自第一个资助期的体外证据表明，星形胶质细胞LXRa和ApoE表达对于引导小胶质细胞ApoE摄取至关重要。这一发现现在将在体内得到验证。因此，将通过甲氧基-X 04在体内标记Ablad 3，随后分离小胶质细胞以通过FACS定量甲氧基-X 04标记的Ablad 3吞噬细胞。此外，还将使用双光子生命显微镜研究Aesthetic吞噬作用。由于LXR介导的ApoE脂化也可能影响ApoE的聚集，因此将在体外研究LXR刺激后ApoE脂化的变化影响ApoE与ApoE的结合，从而影响ApoE聚集，并在体内证实。我们还打算研究ApoE 3和ApoE 4对LXR刺激改变APP/PSI小鼠病理学和行为的能力的影响。我们预期ApoE 4将损害在响应LXR刺激中观察到的积极作用，从而进一步阐明ApoE 4作为AD风险因素的作用。为了确定星形胶质细胞表达的LXRa对于AAP 13吞噬作用的作用，将星形胶质细胞特异性条件性LXRa敲除小鼠与APP/PS1小鼠杂交。在所有相关小鼠品系中，将通过qPCR定量炎性介质和AAF清除蛋白，以获得AAF吞噬作用中促炎或抗炎作用的证据。

In vitro evidence from the first funding period suggests that astroglial LXRa and ApoE expression are critical to guide microglial Aß uptake. This finding will now be validated in vivo. Therefore, Aß will be labelled in vivo by methoxy-X04 and subsequently microglia isolated to quantify methoxy- X04-labelled Aß phagocytois by FACS. In addition, Aß phagocytosis will be studied using 2- photon life microscopy. Since LXR mediated lipidation of ApoE may also affect aggregation of Aß, changes of ApoE lipidation upon LXR stimulation affecting the binding of Aß to ApoE and thereby Aß aggregation will be studied in vitro and confirmed in vivo. We further intend to study the effect of ApoE3 and ApoE4 on the ability of LXR stimulation to alter pathology and behaviour in APP/PSI mice. We expect that ApoE4 will impair the positive effects observed in response to LXR stimulation and thereby further elucidating the role of ApoE4 as an AD risk factor. To define a role of astrocyte-expressed LXRa for Aß phagocytosis, astrocyte specific conditional LXRa knockout mice will cross-bred with APP/PS1 mice. In all relevant mouse strains, inflammatory mediators and Aß scavenging proteins will be quantified by qPCR to obtain evidence for a pro- or anti-inflammatory contribution in the phagocytosis of Aß.