Estrogen and TMJ Pain

雌激素和颞下颌关节疼痛

• 批准号: 8531207
• 负责人: PHILLIP R KRAMER
• 金额: $ 35.28万
• 依托单位: TEXAS A&M UNIVERSITY HEALTH SCIENCE CTR
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8531207
• 关键词: Acute; Address; Adrenergic Receptor; Affect; Animals; Arthralgia; Axon; Binding; Binding Sites; Biological Assay; Cells; Cervical; Chemicals; Chronic; Clinical Trials; Collaborations; DNA; Diestrus; Electrophoretic Mobility Shift Assay; Estradiol; Estrogen Receptors; Estrogens; Estrous Cycle; Feeding behaviors; Female; Filament; Future; GABA-A Receptor; Gene Expression; Genes; Glycine; Glycine Receptors; Goals; Gonadal Hormones; Hypersensitivity; Individual; Injection of therapeutic agent; Ligation; Ligature; Luciferases; Masseter Muscle; Measures; Mediating; Menstruation; Methodology; Modeling; Neuroglia; Neurons; Nociception; Orofacial Pain; Pain; Patients; Peripheral; Phase; Physiological; Proestrus; Rattus; Reporter; Reporting; Role; Secure; Signal Transduction; Simplexvirus; Simulate; Site; Small Interfering RNA; Staging; Staining method; Stains; Structure of trigeminal ganglion; Sympathomimetic Amines; Symptoms; Temporomandibular Joint; Temporomandibular joint disorder pain; Tendon structure; Testosterone; Tissues; Trigeminal subnucleus caudalis; United States; Woman; base; beta-2 Adrenergic Receptors; chromatin immunoprecipitation; extracellular; gamma-Aminobutyric Acid; ganglion cell; knock-down; male; nociceptive response; novel; orofacial; receptor; response; transcription factor

DESCRIPTION (provided by applicant): Women report greater temporomandibular joint (TMJ) pain when the concentration of estrogen is diminishing. Consistent with these results, estrogen reduces TMJ hypersensitivity in proestrus rats, when estrogen concentrations are highest. In our lab, a large gene array study (>10,000 genes) indicated that gene expression in the rat trigeminal ganglia (TG) was significantly affected by increased estrogen. High proestrus versus low diestrus levels of 17ß-estradiol resulted in a 16 to 34 fold increase in the GABAA receptor subunit α6 (Gabrα6), the glycine receptor subunit α2 (Glrα2) and the beta-adrenergic receptor subunit ß1 (Adrß1). This significant increase occurred in the TG of naïve rats and in rats with ligature of the masseter tendon, a model of chronic (>6 months) myogenic TMJ hypersensitivity. Since GABA, glycine and sympathomimetic amines can inhibit hypersensitivity the knock-down of Gabrα6, Glrα2 and Adrß1 expression would be expected to increase hypersensitivity. In preliminary studies siRNA knock-down of Gabrα6 expression in the TG increased hypersensitivity, increased the level of phosphorylated-ERK (p-ERK) in TG neurons and increased neuronal electrical activity. A homology search for estrogen receptor α and ß (ER α and ERß) binding sites 10kb of the transcriptional start site for these three genes showed that at least one potential binding site was present but the mechanism regulating the estrogen response of these genes is unknown. Based on this information we hypothesize that 17 ß-estradiol decreased TMJ hypersensitivity at proestrus by increasing Gabrα6, Glrα2 and Adrß1 expression in the TG and that this estrogen effect was due to interaction with the estrogen receptor and sequence proximal of the transcriptional start site. To address this hypothesis we propose two specific aims, in Aim #1 we will determine in the TG the role of Gabrα6, Glrα2 and Adrß1 in modulating TMJ hypersensitivity/cellular activity in both males and females. To complete aim #1 a ligature will be placed on the masseter tendon and TG expression of Gabrα6, Glrα2, and Adrß1 will be reduced through antagonists or siRNA. Hypersensitivity/cellular activity will be assessed at an acute stage (7 days post-ligature) and at a chronic stage (6 months post-ligature) using von Frey filaments, meal duration, electrophysiological recordings and by quantitating p-ERK levels. The goal of Aim #2 will be to characterize the role of ERα and ERß in controlling Gabrα6, Glrα2, and Adrß1 expression using chromatin immunoprecipitation, electrophoretic mobility shift assays and luciferase reporter constructs. We expect to show that an altered expression of these three genes can affect the TMJ nociceptive response and that these genes are responsible, in part, for the decrease in hypersensitivity observed in proestrus rats. We also expect to determine the mechanism by which estrogen modulates expression of these genes in TG cells.

描述（由申请人提供）：当雌激素浓度降低时，女性报告颞下颌关节（TMJ）疼痛更大，与这些结果一致，当雌激素浓度最高时，发情前期大鼠的雌激素颞下颌关节过敏。研究（>10,000 个基因）表明，与低雌激素水平相比，大鼠三叉神经节（TG）中的基因表达受到高雌激素水平的显着影响。发情间期水平 17β-雌二醇导致 GABAA 受体亚基 α6 (Gabrα6)、甘氨酸受体亚基 α2 (Glrα2) 和 β-肾上腺素受体亚基 ß1 (Adrß1) 增加 16 至 34 倍，这种显着增加发生在初始试验中。大鼠和咬肌腱结扎大鼠，慢性（> 6 个月）肌源性肌腱炎模型由于 GABA、甘氨酸和拟交感胺可以抑制超敏反应，因此敲低 Gabrα6、Glrα2 和 Adrß1 表达预计会增加超敏反应。在初步研究中，siRNA 敲低 TG 中的 Gabrα6 表达会增加超敏反应，从而增加超敏反应水平。 TG 神经元中的磷酸化 ERK (p-ERK) 并增加神经元电活动。对这三个基因转录起始位点 10kb 处雌激素受体 α 和 β（ER α 和 ERß）结合位点的同源性搜索表明，至少存在一个潜在的结合位点，但调节这些基因雌激素反应的机制尚不清楚。基于这些信息，我们认为 17β-雌二醇通过增加 TG 中 Gabrα6、Glrα2 和 Adrß1 的表达来降低发情前期的 TMJ 过敏，并且这种雌激素效应是由于与雌激素受体和转录起始位点近端序列的相互作用所致。为了解决这一假设，我们提出了两个具体目标，在目标#1中，我们将确定 TG 中 Gabrα6、Glrα2 和 Adrß1 在调节 TMJ 过敏中的作用。为了完成目标#1，将在咬肌腱上进行结扎，并表达 Gabrα6、Glrα2 和 TG。 Adrß1 将通过拮抗剂或 siRNA 减少，在急性阶段（结扎后 7 天）和慢性阶段（结扎后 6 个月）将使用 von Frey 细丝、进餐时间、电生理记录和评估来评估超敏反应/细胞活性。通过定量 p-ERK 水平，目标#2 是表征 ERα 和 ERß 在控制 Gabrα6、Glrα2 和使用染色质免疫沉淀、电泳迁移率变动分析和荧光素酶报告构建体进行 Adrß1 表达，我们希望证明这三个基因的表达改变可以影响 TMJ 伤害性反应，并且这些基因在一定程度上负责观察到的超敏反应的减少。我们还希望确定雌激素调节 TG 细胞中这些基因表达的机制。