Quantitative measurement of changes in amyloid-β(40) in the rat brain and cerebrospinal fluid following treatment with the γ-secretase inhibitor LY-411575 [N2-[(2S)-2-(3,5-difluorophenyl)-2-hydroxyethanoyl]-N1-[(7S)-5-methyl-6-oxo-6,7-dihydro-5H-dibenzo[b,d]azepin-7-yl]-L-alaninamide]
Quantitative measurement of changes in amyloid-β(40) in the rat brain and cerebrospinal fluid following treatment with the γ-secretase inhibitor LY-411575 [N2-[(2S)-2-(3,5-difluorophenyl)-2-hydroxyethanoyl]-N1-[(7S)-5-methyl-6-oxo-6,7-dihydro-5H-dibenzo[b,d]azepin-7-yl]-L-alaninamide]
复制标题
DOI：
10.1124/jpet.104.081174
复制
发表时间：
2005-05-01
影响因子：
3.5
通讯作者：
Atack, JR
中科院分区：
文献类型：
--
作者：
Best, JD;Jay, MT;Atack, JR
迄今为止，γ-分泌酶抑制剂的体内功效通常在表达增加水平的淀粉样蛋白-β（A β）肽的转基因小鼠模型中进行评估，从而允许检测A β产生的变化。然而，目前尚不清楚γ-分泌酶抑制剂的体内效力是否与淀粉样前体蛋白表达水平无关。换句话说，γ-分泌酶抑制剂在非转基因生理动物和转基因过表达动物中是否具有相同的作用？在本研究中，已经开发了一种免疫测定法，可以检测大鼠大脑中的A β（40），其中浓度远低于转基因小鼠如Tg 2576（c. 0.7和25 nM）和脑脊液（CSF，c. 0.3 nM）。使用这种免疫测定法，γ-分泌酶抑制剂LY-411575 [N-2-[（2S）-2（3，5-二氟苯基）-2-羟基乙酰基]-N-1-[（7S）-5-甲基-6-氧代-6，7-二氢-5H-二苯并[B，d]氮杂环庚三烯-7-基]-L-丙氨酰胺]进行了评估，并在大鼠脑和CSF A β中出现了稳健的剂量依赖性降低（40）观察到脑和CSF的ID 50值均为1.3 mg/kg。这些值与转基因小鼠中LY-411575的计算值相当。使用LY-411575进行的时间过程实验表明，大鼠大脑和CSF A β的时间减少相当（40），进一步表明这两种A β池相关。因此，当剂量-反应曲线和时间过程的所有数据相关时，在脑和CSF A β（40）水平之间观察到强相关性。这些数据证明了大鼠作为评估γ-分泌酶抑制剂对体内中枢神经系统A β（40）水平影响的新方法的实用性。
The efficacy of gamma-secretase inhibitors in vivo has, to date, been generally assessed in transgenic mouse models expressing increased levels of amyloid-beta (A beta) peptide thereby allowing the detection of changes in A beta production. However, it is not clear whether the in vivo potency of gamma-secretase inhibitors is independent of the level of amyloid precursor protein expression. In other words, does a gamma-secretase inhibitor have the same effect in nontransgenic physiological animals versus transgenic overexpressing animals? In the present study, an immunoassay has been developed which can detect A beta(40) in the rat brain, where concentrations are much lower than those seen in transgenic mice such as Tg2576 (c. 0.7 and 25 nM, respectively) and in cerebrospinal fluid (CSF, c. 0.3 nM). Using this immunoassay, the effects of the gamma-secretase inhibitor LY-411575 [N-2-[(2S)-2(3,5-difluorophenyl)-2-hydroxyethanoyl]-N-1-[(7S)-5-methyl-6- oxo-6,7-dihydro-5H-dibenzo[b,d]azepin-7-yl]-L-alaninamide] were assessed and robust dose-dependent reductions in rat brain and CSF A beta(40) levels were observed with ID50 values of 1.3 mg/kg for both brain and CSF. These values were comparable with those calculated for LY-411575 in transgenic mice. Time course experiments using LY-411575 demonstrated comparable temporal reductions in rat brain and CSF A beta(40), further suggesting these two pools of A beta are related. Accordingly, when all the data for the dose-response curve and time course were correlated, a strong association was observed between the brain and CSF A beta(40) levels. These data demonstrate the utility of the rat as a novel approach for assessing the effects of gamma-secretase inhibitors on central nervous system A beta(40) levels in vivo.