Silencing dopamine D3-receptors in the nucleus accumbens shell in vivo induces changes in cocaine-induced hyperlocomotion
Silencing dopamine D3-receptors in the nucleus accumbens shell in vivo induces changes in cocaine-induced hyperlocomotion
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DOI：
10.1111/j.1460-9568.2005.04157.x
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发表时间：
2005-06-01
影响因子：
3.4
通讯作者：
Dreyer, JL
中科院分区：
文献类型：
--
作者：
Bahi, A;Boyer, F;Dreyer, JL
多巴胺D-3受体(D3R)因其在精神疾病和药物依赖中的潜在作用而成为重要的药物治疗靶点。为了进一步探讨其在大鼠体内的功能，构建了一个携带大鼠D3R基因的可调控慢病毒Lenti-D3，以及三种非可调节慢病毒Lenti-D3-siRNA1、Lenti-D3-siRNA2和Lenti-D3-siRNA3，它们表达小发夹RNA，目的是沉默D3R的表达，并针对D3R mRNA的不同区域进行特异性靶向。在体外，Lenti-D3表达D3R，并能被Lenti-D3-SILs有效阻断。这些病毒被立体定向注射到伏隔核(NAcc)的壳部，并评估了被动可卡因注射对运动活动的影响。与对照治疗相比，操纵D3R水平导致可卡因的运动刺激效应发生变化。用Lenti-D3-SILs局部敲除NAcc中的多巴胺(DA)D3R可增加运动兴奋效应，而Lenti-D3过表达则显著降低运动兴奋效应。当给动物喂多西环素时，后一种效应可以被逆转，从而阻止慢病毒介导的DA D3R在NAcc中的过度表达。定量RT-PCR的基因表达检测证实，Lenti-D3-SILs治疗的动物体内非常有效的基因敲除(>；93%的D3R基因沉默)。因此，D3R的表达极大地促进了与慢性可卡因输送相关的行为改变。
The dopamine D-3 receptor (D3R) is an important pharmacotherapeutic target for its potential role in psychiatric disorders and drug dependence. To further explore its function in rats, a regulatable lentivirus, Lenti-D3, holding the rat D3R cDNA, has been constructed as well as three nonregulatable lentiviruses, Lenti-D3-siRNA1, Lenti-D3-siRNA2 and Lenti-D3-siRNA3, expressing small hairpin RNAs, aimed at silencing D3R expression and specifically targeted against different regions of the D3R mRNA. In vitro, Lenti-D3 expressed D3R and could efficiently be blocked with Lenti-D3-Sils. These viruses were stereotaxically injected into the shell part of the nucleus accumbens (NAcc) and effects of passive cocaine delivery on locomotor activity were assessed. Manipulations of D3R levels induced changes in the locomotor stimulant effects of cocaine as compared to control treatment. Suppression of dopamine (DA) D3R in the NAcc by means of local knockdown (with Lenti-D3-Sils) increased locomotor stimulant effects, whereas its overexpression with Lenti-D3 drastically reduced them. The latter effects could be reversed when animals were fed doxycycline, which prevented lentiviral-mediated DA D3R overexpression in the NAcc. Gene expression assessed by quantitative RT-PCR confirmed very efficient gene knockdown in vivo in animals treated with Lenti-D3-Sils (> 93% silencing of D3R gene). Thus D3R expression significantly contributes to behavioural changes associated with chronic cocaine delivery.