The role of trace metals and T-channels in pain

微量金属和 T 通道在疼痛中的作用

基本信息

批准号：
8633031
负责人：
Slobodan M. Todorovic
金额：
$ 19.75万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-04-01 至 2015-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8633031
关键词：
Acute Pain Adverse effects Afferent Neurons Affinity Alzheimer&apos s Disease Amino Acids Calcium Channel Cations Cells Chelating Agents Chronic Clinical Cysteine Data Development Diabetic Neuropathies Dialysis procedure Disease Drug Targeting Drug abuse Drug usage Esthesia Exclusion Fibromyalgia Funding Goals Hepatolenticular Degeneration High Pressure Liquid Chromatography Histidine Human Hyperalgesia In Vitro Injection of therapeutic agent Intestines Intractable Pain Ion Channel Lead Measures Menkes Kinky Hair Syndrome Metals Methods Modeling Molecular Molecular Weight Names Narcotics Neuronal Injury Neurons Neurosciences Nociception Nociceptors Opioid Outcome Pain Pain Disorder Pain management Pathway interactions Patients Peptides Peripheral Phase Physiological Physiological Processes Play Population Posterior Horn Cells Protein Isoforms Quality of life Rattus Recombinants Regulation Regulatory Pathway Research Research Design Research Project Grants Resources Risk Role Sedation procedure Serum Solutions Spinal Ganglia Spinal cord posterior horn Staging Symptoms Synaptic Transmission Syndrome T-Type Calcium Channels Testing Thermal Hyperalgesias Trace metal Transition Elements Work addiction allodynia animal pain base cellular targeting chronic neuropathic pain chronic pain clinical effect cohort disability dorsal horn effective therapy experience extracellular gabapentin in vivo inflammatory neuropathic pain innovation liquid chromatography mass spectrometry metal chelator mutant neuronal excitability novel painful neuropathy patch clamp patient population pregabalin public health relevance research study transmission process voltage

项目摘要

DESCRIPTION (provided by applicant): Intractable pain has significant adverse effects on quality of life measures, and none of the available treatments can completely reverse these symptoms. Recent studies have established that CaV3.2 T- type voltage-gated calcium channels (T-channels) play a key role in control of cellular excitability of peripheral nociceptors and thus represent promising new cellular targets for development of pain therapies. In our previous work, we identified several endogenous metal chelators, including amino acids such as L-histidine and L-cysteine, which can selectively modulate function of the CaV3.2 isoform of T-channels and consequently influence neuronal excitability of nociceptive sensory neurons of dorsal root ganglia (DRG). Importantly, our Preliminary Data reveal a new role of CaV3.2 T-channels in supporting spontaneous excitatory synaptic transmission in nociceptive neurons of superficial lamina of the spinal cord dorsal horn (DH). Furthermore, we discovered a novel endogenous serum factor, tentatively named "Substance T" that is about 100-fold more potent a modulator of native and recombinant CaV3.2 T-currents than previously described compounds known to modulate function of these channels. Based on size exclusion dialysis, known sensitivity of Cav3.2 channels to metal chelators via H191, and loss of the "Substance T" effect in H191Q mutants, we hypothesize that "Substance T" is a low molecular weight peptide that can act as a chelator of trace metals that can increase cellular excitability of nociceptive DRG and DH neurons and consequently modulate pain sensation by potentiating function of CaV3.2 channels. We plan to test our central hypothesis and accomplish the objective of this application by pursuing the following specific aims: Aim 1: To identify the putative serum factor that functions as an endogenous modulator of CaV3.2 currents. Specific experiments will focus initially on the identification of this molecule using immobilized metal-affinity columns, reverse-phase high performance liquid chromatography (HPLC), mass spectrometry and patch-clamp recordings of recombinant CaV3.2 T-currents. Aim 2: To investigate the role of endogenous trace metals in modulation of pain transmission in the dorsal horn of the spinal cord and in dorsal root ganglion. We will use patch-clamp recordings from native DH and DRG neurons and in vivo pain studies designed to examine the physiological roles of "Substance T", trace metals and metal chelators in regulating cellular excitability and pain transmission in these neurons. The proposed work is innovative in that a new mechanism for channel regulation will be characterized. It is medically significant because understanding the details of this regulatory pathway will facilitate development of novel pain therapies targeting steps in this pathway that could be useful for treatment of intractable neuropathic pain.

描述（由申请人提供）：顽固性疼痛对生活质量措施产生重大不利影响，并且没有任何可用的治疗方法可以完全扭转这些症状。最近的研究表明，CAV3.2 T型电压门控钙通道（T通道）在控制外周伤害感受器的细胞兴奋性方面起着关键作用因此，代表了有希望的新细胞靶标，用于开发疼痛疗法。在我们先前的工作中，我们确定了几种内源性金属螯合剂，包括氨基酸，例如L-齐替丁和L-半胱氨酸，它们可以选择性地调节T通道的CAV3.2同工型的功能，从而影响背部神经神经节（DRG）伤害性神经元的神经元素兴奋性。重要的是，我们的初步数据揭示了CAV3.2 T通道在支持脊髓背角表层层层（DH）的伤害性神经元中自发兴奋性突触传播中的新作用。此外，我们发现了一种新型的内源血清因子，暂定称为“物质t”，比以前所述调节这些通道功能的化合物的天然和重组CAV3.2 T-货币的调节剂高约100倍。根据尺寸排除透析，CAV3.2通道对金属螯合剂的已知敏感性通过H191以及H191Q突变体中“物质t”效应的丧失，我们假设“物质T”是一种低分子量肽，可以增加痕量的狭o氏症的螯合剂，可以增加感觉良好的耐药性和DHINCITED NINURINTIED DRG DRG DRG DRG DRG DRG DRG DRG，DHINUR NIN GREG和DHINUR的脑含量CAV3.2通道的功能。我们计划通过追求以下特定目的来检验我们的中心假设，并实现该应用的目标：目标1：确定在Cav3.2电流的内源性调节剂中起作用的假定血清因子。特定的实验最初将专注于使用固定的金属亲和力柱，反相高性能液相色谱（HPLC），质谱法和重组CAV3.2 T-T-电流的斑块夹记录的鉴定。目标2：研究内源痕量金属在脊髓背角和背根神经节中疼痛传播调节中的作用。我们将使用来自天然DH和DRG神经元的斑块钳记录以及旨在检查“物质T”，痕量金属和金属螯合剂在调节这些神经元中细胞兴奋性和疼痛传播中的生理作用的体内疼痛研究。拟议的工作是创新的，因为将要表征一种新的通道调节机制。这具有医学意义，因为了解这种调节途径的细节将有助于在该途径中靶向步骤的新型疼痛疗法的发展，这对于治疗棘手的神经性疼痛可能有用。