为了探索组蛋白乙酰化对吗啡成瘾记忆相关分子表达调控机制,文章选取健康成年雄性SD大鼠34只,随机分为正常对照组(n = 6)及基底外侧杏仁核(Basolateral amygdala, BLA)颅内定位手术组(n =28)。在条件性位置偏爱(Conditioned place preference, CPP)训练阶段,大鼠BLA内给予组蛋白去乙酰化酶抑制剂曲古抑菌素A(Trichostafin A, TSA)并且腹腔注射吗啡溶液(10.0 mg/kg),对照组给予相同体积的10%二甲基亚砜(Dimethyl sulfoxide,DMSO)或盐水。应用蛋白质印记方法,检测吗啡诱导大鼠CPP建立后BLA内组蛋白H3K14乙酰化和脑源性神经营养因子(Brain-derived neurotrophic factor, BDNF)蛋白表达水平。结果显示,腹腔注射10 mg/kg吗啡能成功建立CPP。吗啡、TSA联合给药组大鼠比单纯吗啡给药组大鼠表现出更强烈的CPP(P<0.0001)。吗啡和TSA都能使BLA内的组蛋白H3乙酰化水平和BDNF的表达显著增高(P < 0.0001),同时二者之间具有协同作用。结果表明,大鼠BLA内组蛋白乙酰化水平与吗啡成瘾记忆形成有关,抑制BLA内组蛋白去乙酰化酶(Histone deacetylases, HDACs)的活性可强化吗啡诱导的线索记忆的形成;大鼠BLA内BDNF参与了吗啡诱导的线索记忆的形成并可能受到组蛋白乙酰化的调控。
To examine the regulatory effect of histone acetylation on memory related molecules, 34 healthy male SD rats were randomly divided into control and basolateral amygdala (BLA) intracranial positioning operation groups. In the process of conditioned place preference (CPP) training, Trichostafin A (TSA) was administrated by the route of BLA and morphine was injected into enterocoelia with dimethyl sulfoxide or saline as control. Expression levels of H3K14 acetylation and brain-derived neurotrophic factor (BDNF) in BLA were evaluated by Western blotting.The results showed that CPP could be established by intraperitoneal injection of morphine. Compared with control groups, a stronger place preference was established and expression of H3K14 acetylation and BDNF was significantly increased in the group treated with TSA and morphine. In addition, there was a synergistic effect between morphine and TSA. Our results suggested that the level of histone acetylation in BLA is associated with the formation of morphine memory in rats. Inhibition of the activity of histone deacetylases in BLA can promote the formation of cue-associated memory induced by morphine and the involvement of BDNF in BLA maybe was regulated by histone acetylation.
[1] Cami J, Farré M. Mechanisms of disease: drug addiction. N Engl J Med , 2003, 349(10): 975-986.
[2] Hyman SE, Malenka R C, Nestler EJ. Neural mechanisms of addiction: the role of reward-related learning and memory. Annu Rev Neurosci , 2006, 29: 565-598.
[3] Hu XL, Wang YP, Shen Q. Epigenetic control on cell fate choice in neural stem cells. Protein Cell , 2012, 3(4): 278-290.
[4] Hoshino M, Tagawa K, Okuda T, Murata M, Oyanagi K, Arai N, Mizutani T, Kanazawa I, Wanker EE, Okazawa H. Histone deacetylase activity is retained in primary neurons expressing mutant huntingtin protein. J Neurochem, 2003, 87(1): 257-267.
[5] Steffan JS, Bodai L, Pallos J, Poelman M, McCampbell A, Apostol BL, Kazantsev A, Schmidt E, Zhu YZ, Greenwald M, Kurokawa R, Housman DE, Jackson GR, Marsh JL, Thompson LM. Histone deacetylase inhibitors arrest polyglutamine-dependent neurodegeneration in Drosophila . Nature , 2001, 413(6857): 739-743.
[6] Etchegaray JP, Lee C, Wade PA, Reppert SM. Rhythmic histone acetylation underlies transcription in the mammalian circadian clock. Nature , 2003, 421(6919): 177-182.
[7] Huang Y, Doherty JJ, Dingledine R. Altered histone acetylation at glutamate receptor 2 and brain-derived neurotrophic factor genes is an early event triggered by status epilepticus. J Neurosci , 2002, 22(19): 8422-8428.
[8] Tsankova NM, Kumar A, Nestler EJ. Histone modifications at gene promoter regions in rat hippocampus after acute and chronic electroconvulsive seizures. J Neurosci , 2004, 24(24): 5603-5610.
[9] Guan JS, Haggarty SJ, Giacometti E, Dannenberg JH, Joseph N, Gao J, Nieland TJF, Zhou Y, Wang XY, Mazitschek R, Bradner JE, DePinho RA, Jaenisch R, Tsai LH. HDAC2 negatively regulates memory formation and synaptic plasticity. Nature , 2009, 459(7243): 55-60.
[10] Levenson JM, O'Riordan KJ, Brown KD, Trinh MA, Molfese DL, Sweatt JD. Regulation of histone acetylation during memory formation in the hippocampus. J Biol Chem , 2004, 279(39): 40545-40559.
[11] Kumar A, Choi KH, Renthal W, Tsankova NM, Theobald DEH, Truong HT, Russo SJ, Laplant Q, Sasaki TS, Whistler KN, Neve RL, Self DW, Nestler EJ. Chromatin remodeling is a key mechanism underlying cocaine-induced plasticity in striatum. Neuron , 2005, 48(2): 303-314.
[12] Andressoo JO, Saarma M. Signalling mechanisms underlying development and maintenance of dopamine neurons. Curr Opin Neurobiol , 2008, 18(3): 297-306.
[13] Paxinos G, Watson C. The Rat Brain, in Stereotaxic Coordinates, 2nd ed. Sydney: Elsevier Academic Press, 1986.
[14] Renthal W, Nestler EJ. Epigenetic mechanisms in drug addiction. Trends Mol Med , 2008, 14(8): 341-350
[15] Guan Z, Giustetto M, Lomvardas S, Kim JH, Miniaci MC, Schwartz JH, Thanos D, Kandel ER. Integration of long-term-memory-related synaptic plasticity involves bidirectional regulation of gene expression and chromatin structure. Cell , 2002, 111(4): 483-493.
