Mechanisms of Central Sensitization in an Animal Model of Interstitial Cystitis

间质性膀胱炎动物模型的中枢致敏机制

• 批准号: 7571243
• 负责人: Robert W Gereau
• 金额: $ 20.7万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-15 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7571243
• 关键词: Abdomen; Abdominal Muscles; Acute; Address; Animal Model; Animals; Behavior; Behavioral; Biochemical; Bladder; Bladder Diseases; Characteristics; Chronic; Cyclophosphamide; Dominant-Negative Mutation; Dose; Goals; Hyperalgesia; Hypersensitivity; Inflammation; Inflammatory; Injury; Interstitial Cystitis; Knock-out; Knockout Mice; Laboratories; Localized; MAPK1 gene; MAPK3 gene; MEKs; Measurement; Mediating; Methods; Mitogen-Activated Protein Kinase 3; Modeling; Molecular; Mus; Neuraxis; Nociception; Nociceptive Stimulus; Pain; Pain Disorder; Pain Research; Patients; Phosphorylation; Posterior Horn Cells; Potassium Channel; Process; Protein Isoforms; Research; Role; Signal Transduction; Spinal; Spinal Cord; Spinal cord posterior horn; Syndrome; Techniques; Testing; Time; Transgenic Animals; Visceral; Visceral pain; allodynia; central pain; central sensitization; dorsal horn; experience; frontier; inflammatory pain; mouse model; neuronal excitability; novel therapeutics; research study; response

The overall goal of the current proposal is to investigate the cellular and molecular mechanisms of central sensitization that underlies pain hypersensitivity in interstitial cystitis (1C). We previously demonstrated in a somatic pain model (hind paw inflammation) that activation of ERKs (extracellular signal-regulated kinases 1 and 2) and resultant modulation of their downstream target, the Kv4.2 potassium channel, alters neuronal excitability of spinal cord dorsal horn neurons and contributes to central sensitization leading to pain hypersensitivity in somatic pain. Preliminary results in a mouse model of 1C shows that noxious bladder distention in an inflamed bladder also evokes ERK activation in the spinal cord dorsal horn. We therefore hypothesize that pain hypersensitivity of 1C is mediated by dorsal horn pain sensitization involving activation of ERK and involvement of Kv4.2 potassium channels. In our mouse model, cyclophosphamide (CYP) will be used to induce bladder inflammation while phasic bladder distention will be used as a nociceptive stimulus to evoke visceral pain. In SPECIFIC AIM 1, we will test the hypothesis that dorsal horn ERK activation induced by bladder distention in CYP-treated animals is behaviorally relevant. We will perform experiments to test whether ERK activation evoked by bladder distention in CYP-treated mice is associated with nociceptive behaviors and increased abdominal muscle visceromotor response (VMR), an objective measurement of visceral pain. IN SPECIFIC AIM 2, we will test the hypothesis that central sensitization in a visceral pain model of 1C is mediated by activation of MEK-ERK2 signaling. IN SPECIFIC AIM 3, we will test the hypothesis that central sensitization in a visceral pain model of 1C requires the expression of Kv4.2 potassium channels, which are known phosphorylation targets of ERK1/2 in the dorsal horn. These studies will use a combination of molecular and behavioral techniques to elucidate mechanisms involved in spinal central sensitization leading to pain hypersensitivity in 1C. We have extensive experience in the biochemical and behavioral approaches and a unique set of knockout and transgenic animals (MEKdn, ERK1-/-, Kv4.2-/-) to carry out the proposed experiments. The spinal cord is a new frontier in 1C pain research. A better understanding of the mechanisms of pain sensitization in 1C may open up new therapeutic paradigms that target the central nervous system in a chronic visceral pain syndrome like 1C.

目前的建议的总体目标是研究中枢神经系统的细胞和分子机制， 间质性膀胱炎疼痛超敏反应的致敏作用（1C）。我们以前在一个 躯体疼痛模型（后爪炎症）ERK（细胞外信号调节激酶1）激活 和2）以及其下游靶点Kv4.2钾通道的调节，改变了神经元的 脊髓背角神经元的兴奋性，并有助于导致疼痛的中枢敏感化 躯体疼痛的超敏反应。小鼠1C模型的初步结果表明， 发炎膀胱中的膨胀也引起脊髓背角中的ERK激活。因此我们 假设1C疼痛超敏性是由涉及激活的背角疼痛敏化介导的 ERK和Kv4.2钾通道的参与。在我们的小鼠模型中， 而阶段性膀胱扩张将被用作伤害性刺激 引起内脏疼痛的刺激。在特定目的1中，我们将检验背角ERK CYP处理的动物中由膀胱膨胀诱导的激活与行为相关。我们将执行 在CYP处理的小鼠中，通过膀胱扩张诱发ERK激活来测试ERK激活是否与 与伤害性行为和增加腹部肌肉内脏反应（VMR），一个目标， 测量内脏疼痛。在具体目标2中，我们将检验一个假设，即中枢致敏作用在一个 1C内脏痛模型是由MEK-ERK 2信号转导激活介导的。在具体目标3中，我们将测试 假设在1C内脏痛模型中中枢敏化需要Kv4.2的表达 钾通道，已知是背角中ERK 1/2的磷酸化靶点。这些研究 将使用分子和行为技术相结合，以阐明涉及脊髓的机制， 中枢致敏导致1C疼痛超敏反应。我们在生物化学方面有丰富的经验， 和行为方法以及一组独特的敲除和转基因动物（MEKdn，ERK 1-/-，Kv4.2-/-） 来进行所提议的实验。脊髓是1C疼痛研究的新前沿。更好的 对1C疼痛敏感机制的理解可能会开辟新的治疗范例， 针对中枢神经系统的慢性内脏疼痛综合征，如1C。