Microarray Studies of Anti-Apoptotic, BAG-1 in BPD

BPD 中抗凋亡 BAG-1 的微阵列研究

• 批准号: 6982750
• 负责人: HUSSEINI K MANJI
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6982750
• 关键词: BCL2 gene /protein; RNA interference; apoptosis; biotechnology; bipolar depression; brain mapping; cell growth regulation; cell proliferation; corticosteroid receptors; drug administration rate /duration; drug interactions; glucocorticoids; hippocampus; hormone regulation /control mechanism; human tissue; laboratory rat; lithium; mental disorder chemotherapy; microarray technology; mitogen activated protein kinase; protein quantitation /detection; psychopharmacology; receptor expression; small interfering RNA; stimulant /agonist; transfection; valproate

The mood stabilizers lithium and valproate are both effective in the treatment of bipolar disorder(BD); however, their therapeutic mechanisms remain unclear. Because of the delayed onset of clinical efficacy (days to weeks), it has been proposed that adaptive changes in gene expression, rather than their initial pharmacological actions, may be directly responsible. To investigate the strategic regulation of signaling pathways and gene expression in critical neuronal circuits likely involved in the long term treatment of bipolar disorder, we used microarray methodologies to identify novel targets of therapeutic relevance with validating criteria including the following: (1) dose and time frame consistent with clinical therapeutic effects; (2) observed with structurally highly dissimilar but clinically efficacious agents; (3) specific to brain regions implicated in the disorder (4) specific for mood stabilizers (5) validated at a protein level. Using these stringent criteria, our recent microarray studies have revealed a novel target for the long-term actions of the mood stabilizers lithium and valproate. Chronic administration of both agents at therapeutic doses increased the expression of BAG-1 (bcl-2 associated athanogene) in rat hippocampus. Furthermore, these findings were validated in the hippocampus at the protein level, the effects were seen in a time frame consistent with therapeutic effects, and were specific for mood stabilizers. BAG -1 is an important chaperone of bcl-2 (B-cell CLL/lymphoma 2), and enhances bcl-2?s anti-apoptotic functions; furthermore, through interaction with raf (v-raf-1 murine leukemia viral oncogene homolog 1), BAG-1 is able to activate ERK(extracellular signal-regulated protein kinase) MAP (mitogen-activated protein) kinases. Consistent with this, we found that lithium and valproate activate ERK MAP kinases and exert anti-apoptotic effects. Bag-1 also inhibits GR(glucocorticoid receptor) activation, which may counteract the deleterious effects of hypercortisolemia seen in BD. Anti-GR antibody immunostaining plus double staining with DAPI (4',6-Diamidino-2-phenylindole) showed either lithium or VPA, at therapeutically relevant levels, inhibited dexamethasone induced GR nuclear translocation. In addition, glucocorticoid response element (GRE) transfection assay showed lithium, at therapeutically relevant levels, inhibited GR activity in SH-SY5Y cells. Evaluated through siRNA (short interference RNA) silencing of BAG-1, the inhibition of mood stabilizers to GR nuclear translocation and to GR activity is mediated, at least in part, by BAG-1. The effect that BAG-1 inhibits glucocorticoid activation suggests mood stabilizers may counteract the deleterious effects of hypercortisolemia seen in BD by up-regulating BAG-1. Together, the data suggests that BAG-1 may represent a novel, highly therapeutically relevant target in the long-term treatment of bipolar disorder. Complementary human studies have shown that chronic lithium significantly increases gray matter content in a regionally selective manner, suggesting a reversal of illness-related atrophy and an increase in the volume of the neuropil. Interestingly, the gray matter changes are seen in a regionally-specific manner, and are only observed in treatment-responders. The growing body of preclinical/clinical data suggests that for many refractory patients, optimal treatment may only be attained by providing both trophic and neurochemical support; the trophic support would be envisioned as enhancing and maintaining normal synaptic connectivity, thereby allowing the chemical signal to reinstate the optimal functioning of critical circuits necessary for normal affective functioning.

情绪稳定器锂和丙戊酸均可以有效地治疗躁郁症（BD）。但是，它们的治疗机制尚不清楚。由于临床疗效的发作延迟（天到几周），因此有人提出，基因表达的适应性变化，而不是其初始的药理作用，可能是直接造成的。为了研究可能参与双相情感障碍长期治疗的关键神经元回路中信号通路和基因表达的战略调节，我们使用微阵列方法来识别具有验证标准的新型治疗性相关目标，包括以下几点：（1）剂量和与临床治疗效应一致的剂量和时间框架； （2）在结构上高度不同但临床上有效的药物中观察到； （3）针对疾病的脑部区域（4）特定于蛋白质水平验证的疾病（4）。使用这些严格的标准，我们最近的微阵列研究揭示了对情绪稳定器锂和丙戊酸的长期作用的新目标。长期以治疗剂量施用两种药物，增加了大鼠海马中BAG-1（BCl-2相关的雌激素）的表达。此外，这些发现在蛋白质水平的海马中得到了验证，在与治疗效果一致的时间范围内看到了这些作用，并且特定于情绪稳定剂。 Bag -1是Bcl-2（B细胞CLL/淋巴瘤2）的重要伴侣，并且可以增强Bcl-2的抗凋亡功能。此外，通过与RAF（V-RAF-1鼠白血病病毒癌基因同源物1）的相互作用，Bag-1能够激活ERK（细胞外信号调节蛋白激酶）图（有丝分裂原激活的蛋白）激酶。与此一致，我们发现锂和丙戊酸激活ERK MAP激酶并发挥抗凋亡作用。 BAG-1还抑制GR（糖皮质激素受体）激活，这可能抵消BD中观察到的高皮质血症的有害作用。抗GR抗体免疫染色加上DAPI（4'，6-二胺-2-苯基吲哚）的双重染色显示在治疗相关水平下，锂或VPA抑制了地塞米松诱导的GR核易位。此外，糖皮质激素反应元件（GRE）转染测定法显示在治疗相关水平下锂抑制了SH-SY5Y细胞中的GR活性。通过BAG-1的siRNA（短干扰RNA）沉默评估，抑制情绪稳定剂对GR核易位和GR活性的抑制作用至少部分由BAG-1介导。 BAG-1抑制糖皮质激活的作用表明，情绪稳定剂可能会通过上调Bag-1来抵消BD中高皮质血症的有害作用。总之，数据表明，BAG-1可能代表了长期治疗双相情感障碍的新型，高度治疗相关的靶标。互补的人类研究表明，慢性锂会以区域选择性的方式显着增加灰质含量，表明与疾病相关的萎缩逆转和神经皮质体积的增加。有趣的是，灰质的变化以特定区域的方式观察到，仅在治疗反应者中观察到。临床前/临床数据的不断增长表明，对于许多难治性患者而言，只能通过提供营养和神经化学支持才能获得最佳治疗。营养支持将被设想为增强和维持正常的突触连通性，从而允许化学信号恢复正常情感功能所必需的关键电路的最佳功能。