ROLE OF ALDH2--TRANSGENIC MICE CARRYING ASIAN ALDH2-2 VARIANT ALLELE

线粒体乙醛脱氢酶 (ALDH2)是乙醛中主要的ALDH同工酶 新陈代谢。众所周知，一个单核苷酸 导致氨基酸变化的取代(G到A) (Glu487Lys)导致ALDH2活性显性失活。 我们的数据表明，重组人ALDH2变异体 蛋白与小鼠ALDH2蛋白相互作用 抑制小鼠的酶活性。基因 多态是观察到的刷新反应的原因 很多亚洲人都会饮酒。尽管 ALDH2-2等位基因已被证明具有保护作用 酒精中毒时，这种酶的生理作用仍不清楚。至 进一步研究ALDH2在体内的生理作用 酒精介导的组织损伤、饮酒行为和代谢 内源和外源底物，我们生产了转基因 携带人类ALDH2变体(Haldh2-2)的小鼠。目前，我们 已经建立了两个独立的Haldh2转基因小鼠品系。 人ALDH2蛋白在所检测的所有组织中均有表达 人ALDH2-2抑制小鼠ALDH2酶的表达 转基因小鼠体内的活性。我们还观察到FVB/N 背景应激小鼠表现出恐惧、回避和逃避 20%乙醇治疗3天后的行为但这些变化 在暴露于铅的转基因小鼠的行为中并不明显 乙醇(p&lt；0.001)。将明显的行为变化联系起来 与神经递质水平的关系，并研究ALDH2在脑出血中的作用 内生代谢，各种单胺的水平 神经递质正在用高效液相色谱法测定。我们的数据也 表明雄性和雌性转基因小鼠都表现出40%-50%的 肝脏中的乙醛水平高于FVB/N背景 小鼠(每组6只，p&lt；0.01)。我们正在确定 在两瓶选择范例中的饮酒偏好。我们的数据 到目前为止收集的数据表明携带Haldh2-2的转基因小鼠 可以成为研究ALDH在行为中的作用的有价值的模型， 神经递质代谢与饮酒偏好。为了 对ALDH2的生理作用有了明确的结果，我们有 我还准备了DNA载体来制备缺陷基因敲除小鼠 小鼠ALDH2基因的基因断裂法。

The mitochondrial aldehyde dehydrogenase (ALDH2) is the major ALDH isozyme involved in acetaldehyde metabolism. It is well established that a single nucleotide substitution (G to A) which results in the amino acid change (Glu487Lys) leads to dominant inactivation of ALDH2 activity. Our data indicated that the recombinant human ALDH2 variant protein interacted with the mouse ALDH2 protein and dominantly inhibited the activity of the mouse enzyme. The genetic polymorphism is the cause of the flushing response observed in many Asian people following alcohol intake. Although the ALDH2-2 allele has been shown to have a protective role against alcoholism, the physiological role of this enzyme is still unclear. To further examine the physiological role of ALDH2 in alcohol-mediated tissue damage, drinking behavior and metabolism of endogenous and exogenous substrates, we produced transgenic mice carrying the human ALDH2 variant (Haldh2-2). Currently, we have established two independent lines of Haldh2 transgenic mice. Human ALDH2 protein was expressed in all tissues examined and expression of human ALDH2-2 inhibited mouse ALDH2 enzyme activity in transgenic mice. We also observed that the FVB/N background strain mice showed fear, avoidance and escape behavior 3 days after treatment with 20% ethanol but these changes in behavior were not evident in the transgenic mice exposed to ethanol (p<0.001). To correlate the apparent behavioral change with levels of neurotransmitters and to study the role of ALDH2 in endobiotic metabolism, the levels of various monoamine neurotransmitters are being determined by HPLC. Our data also indicate that both male and female transgenic mice showed 40-50% higher acetaldehyde levels in the livers than the FVB/N background mice (n=6 for each group, p<0.01). We are determining the drinking preference in a two-bottle choice paradigm. Our data collected so far indicate that transgenic mice carrying the Haldh2-2 can be a valuable model to study the role of ALDH in behavior, neurotransmitter metabolism and drinking preference. In order to have clear results for the physiological roles of ALDH2, we have also prepared a DNA vector to prepare knock-out mice deficient of mouse ALDH2 gene by gene disruption method.