Signal Transduction in Depression

抑郁症中的信号转导

• 批准号: 7172949
• 负责人: Richard Charles Shelton
• 金额: $ 30.14万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-02-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7172949
• 关键词: Agonist; Autopsy; Binding; Biological; Bradykinin; Brain; Control Groups; Coupling; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cyclic AMP-Responsive DNA-Binding Protein; Data; Depressed mood; Disease; Enzymes; Fibroblasts; G alpha q Protein; Goals; Grant; HTR2A gene; Human; Hydrolysis; Immunoprecipitation; Investigation; Light; Link; Lysophospholipids; Major Depressive Disorder; Measures; Mediator of activation protein; Mental Depression; Messenger RNA; Modeling; Nature; Nuclear Translocation; Okadaic Acid; Patients; Persons; Phorbol; Phorbol Esters; Phorbols; Phosphatidylinositols; Phospholipase C; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Physiologic pulse; Population; Precipitation; Process; Protein Isoforms; Protein Kinase C; Protein phosphatase; Proteins; Pulse taking; Rate; Receptor Signaling; Relative (related person); Research; Research Personnel; Rolipram; Sampling; Serotonin; Serotonin Receptor 5-HT2A; Signal Transduction; Specimen; Stream; Testing; Tissue Sample; Tissues; attenuation; base; brain tissue; citrate carrier; comparative; depressive symptoms; dimethoxy-4-indophenyl-2-aminopropane; kemptide; lysophosphatidic acid; mRNA Expression; phosphodiesterase IV; polypeptide; programs; protein expression; radioligand; receptor; receptor coupling; research study; response; suicide victim

DESCRIPTION (provided by applicant): Major depression (MDD) is a common and serious disorder, but the biological basis remains elusive. Signal transduction mechanisms, including critical enzymes such as protein kinases A (PKA) and C (PKC), appear to be altered in MDD, particularly in the melancholic (MEL) subtype. Our preliminary data show: (1) A parallel reduction in the activity of both PKA and PKC in MDD, MEL subtype (but not in the non-melancholies [non- MEL]) relative to controls; (2) A concomitant decrease in [3H]cyclic AMP binding to PKA and [3H]PDBU binding to PKC; (3) Reduced levels of specific kinase protein isoforms. As well, we have recently demonstrated an apparent uncoupling of the PKC-linked serotonin 2A (5-HT2A) receptors from Gq proteins in this population. This project will evaluate potential causes and consequences of the findings. We have used a cultured human fibroblast (FB) model, but now can extend the investigation to post-mortem brain tissue (PMB) from well- characterized depressed suicide victims and normal controls (for which we also have preliminary data). We propose to compare in PMB from persons identified as MEL, non-MEL, and controls: (1) The level of CREB phosphorylation after PKA and PKC activation; (2) The binding of [3H] cyclic AMP to PKA and [3H]phorbol dibutyrate to PKC; and test (3) The possibility of a concomitant reduction of binding and activity of kinases. We also will contrast the following in the three study groups: (4) Protein and mRNA levels of PKA and PKC protein isoforms in PMB and FB; (5) Rates of degradation of PKA and PKC isoforms by pulse-chase immuno- precipitation in FB; (6) The comparative effects of key regulators of kinase activity by the inhibition of phosphodiesterase IV and protein phosphatase 2A and evaluating their mRNA and protein expression. We also will examine the apparent uncoupling of 5-HT2A receptors in MEL by contrasting between groups: (7) PI hydrolysis after a specific 5-HT2A agonist and alternative Gq-coupled receptor agonists in FB and PMB; (8) GTPyS incorporation following activation of 5-HT2A receptors in PMB; (9) Differential agonist and antagonist binding in PMB; (10) CREB-P formation after activation with a 5-HT2A agonist and alternative Gq-coupled receptor agonist in FB and PMB. These studies may shed light on important cellular mediators of depression and provide new targets for amelioration.

描述（由申请人提供）：严重抑郁症（MDD）是一种常见和严重的疾病，但生物学基础仍然难以捉摸。信号转导机制，包括临界酶，例如蛋白激酶A（PKA）和C（PKC），在MDD中似乎正在改变，特别是在忧郁症（MEL）亚型中。我们的初步数据表明：（1）相对于对照组，MEL亚型（但在非晶状体[non-mel]中）中PKA和PKC的活性平行降低； （2）[3H]循环AMP与PKA的结合和[3H] PDBU结合与PKC的结合； （3）降低了特异性激酶蛋白同工型的水平。同样，我们最近证明了该人群中GQ蛋白的PKC连接5-羟色胺2A（5-HT2A）受体的明显解偶。该项目将评估调查结果的潜在原因和后果。我们已经使用了培养的人成纤维细胞（FB）模型，但现在可以将研究扩展到验尸后脑组织（PMB），从良好表征的自杀受害者和正常对照（我们也具有初步数据）。我们建议与被称为MEL，非MEL和对照的人进行PMB进行比较：（1）PKA和PKC激活后CREB磷酸化的水平； （2）[3H]循环AMP与PKA和[3H] phorbol Dibutyrate与PKC的结合；和测试（3）激酶的结合和活性伴随的可能性。我们还将对以下三个研究组进行对比：（4）PMB和FB中PKA和PKC蛋白同工型的蛋白质和mRNA水平； （5）通过FB中的脉冲循环免疫沉淀，PKA和PKC同工型的降解速率； （6）通过抑制磷酸二酯酶IV和蛋白质磷酸酶2a并评估其mRNA和蛋白质表达，对激酶活性的关键调节剂的比较作用。我们还将通过对比两组之间的对比来检查MEL中5-HT2A受体的明显解耦合：（7）在FB和PMB中特定的5-HT2A激动剂和替代GQ耦合受体激动剂后PI水解； （8）在PMB中激活5-HT2A受体后的GTPY掺入； （9）PMB中的差异激动剂和拮抗剂结合； （10）用5-HT2A激动剂和FB和PMB中的替代GQ耦合受体激动剂激活后CREB-P形成。这些研究可能会阐明重要的抑郁症细胞介质，并为改善提供新的靶标。