Mechanisms of Altered Gastrointestinal Dysfunction

胃肠功能障碍的改变机制

基本信息

批准号：
9136101
负责人：
George Nicholas Verne
金额：
$ 32.73万
依托单位：
TULANE UNIVERSITY OF LOUISIANA
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：
2013-09-15 至 2018-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9136101
关键词：
Abdominal Pain Biological Biological Factors Colon Constipation Development Diarrhea Disease Down-Regulation Figs - dietary Fluorescent in Situ Hybridization Functional disorder Gene Targeting Genes Glutamate Receptor Glutamates Goals Health Hypersensitivity Intestines Intrathecal Injections Irritable Bowel Syndrome Knowledge Lead Methods MicroRNAs Modeling N-Methyl-D-Aspartate Receptors Neurotransmitters Nociception Nociceptive Stimulus Oligonucleotide Probes Oligonucleotides Opioid Opioid Receptor Pain Pathway interactions Patients Pharmaceutical Preparations Process Property Rattus Receptor Signaling Role Signal Pathway Signal Transduction Stimulus Stream Symptoms Technology Testing Therapeutic Tissues United States National Institutes of Health Up-Regulation Visceral base chronic abdominal pain chronic pain epigenetic regulation follow-up gastrointestinal glutamatergic signaling glutamine receptor in vivo inhibitor/antagonist innovation locked nucleic acid novel therapeutic intervention novel therapeutics receptor receptor expression relating to nervous system translational study

项目摘要

DESCRIPTION (provided by applicant): Patients with irritable bowel syndrome (IBS) suffer from chronic abdominal pain and associated GI symptoms - diarrhea, constipation, bloating & urgency. Those with severe symptoms may also have visceral hypersensitivity to nociceptive stimuli, suggesting aberrant neural pain processing mechanisms. Indeed, we found a significant subset (~35%) of IBS patients with visceral hypersensitivity to noxious experimental stimuli (e.g., colonic distension); but the mechanism was unclear. We found a clue to that mechanism during our previous NIH-supported study (R01NS053090); we identified unique microRNAs (miRNAs) in colon tissues of this subset. Here we will follow up on that clue by testing the following hypothesis: Aberrant expression of key miRNAs dysregulates expression of downstream miRNA targets (opioid receptors; NMDA receptors) which contributes to visceral hypersensitivity in IBS patients. To determine the intra- and inter-cellular roles of unique miRNAs in the epigenetic regulation of down- stream receptor target genes, our lab has developed innovative methods. These methods combine unique miRNA recognition properties of locked nucleic acid (LNA) modified oligonucleotide probes with fluorescence in situ hybridization (FISH) using tyramide signal amplification (TSA) technology. We will use in vivo intrathecal injection of miRNA inhibitors (LNAs) or miRNA mimics (precursors) to experimentally regulate expression of specific miRNAs that target opioid (Aim 1) and glutamate (Aim 2) receptors in our validated rat model of visceral hypersensitivity (Zhou et al., Pain, 2008). Thus, we will use a combination of strategies to develop a comprehensive high-confidence model of miRNA targeting networks for opioid and glutamine receptors. In Aim 1 we will determine whether increased miR-29a/b cluster and miR-29b-1-5p expression enhances visceral hypersensitivity via downregulation of opioid signaling pathways. In Aim 2, we will determine whether decreased miR-23a/b cluster and 125b-1-3p expression facilitates visceral hypersensitivity via upregulation of glutamate signaling mechanisms. Our proposed studies should identify critical contributions of aberrantly expressed miRNAs that target downstream opioid and glutamate receptors in intestinal tissues of IBS patients with visceral hypersensitivity This will bridge an important gap in our knowledge of the underlying mechanisms of dysregulation of nociceptive pathways that lead to chronic pain and altered visceral nociception in patients who suffer from common functional GI disorders. More importantly, the results should lead to the development of innovative therapeutic strategies via development of synthesized oligonucleotides that inhibit or mimic specific miRNAs that modulate epigenetic regulation of down-stream target genes (e.g. opioid or glutamate receptors) that drive visceral nociception. The ultimate goal of the proposed translational studies is to develop new therapies for treating our patients with IBS and other functional GI disorders.

描述（由申请人提供）：肠易激综合征（IBS）患者患有慢性腹痛和相关的胃肠道症状 - 腹泻，便秘，腹胀和紧迫性。患有严重症状的人也可能对伤害性刺激具有内在性超敏反应，这表明神经疼痛处理机制异常。实际上，我们发现对有害实验性刺激的内脏性超敏反应（例如结肠延伸）的IBS患者有明显的子集（约35％）。但是该机制尚不清楚。我们在先前的NIH支持研究（R01NS053090）中找到了该机制的线索；我们在该子集的结肠组织中鉴定了独特的microRNA（miRNA）。在这里，我们将通过检验以下假设来跟进该线索：关键miRNA的异常表达失调会导致下游miRNA靶标（阿片受体； NMDA受体）的表达，这有助于IBS患者内脏性高敏性。为了确定独特的miRNA在向下流受体靶基因的表观遗传调节中的细胞内和细胞间作用，我们的实验室开发了创新的方法。这些方法结合了锁定的核酸（LNA）修饰的寡核苷酸探针的独特miRNA识别特性，并使用泰米酰胺信号扩增（TSA）技术结合了原位杂交（FISH）的荧光原位杂交（FISH）。我们将在体内鞘内注射miRNA抑制剂（LNA）或miRNA Mimics（前体）来实验调节靶向阿片类阿片类药物（AIM 1）和谷氨酸（AIM 2）受体的特定miRNA的表达等，痛苦，2008）。因此，我们将使用各种策略组合来开发用于阿片类药物和谷氨酰胺受体网络的miRNA靶向网络的全面高信模型。在AIM 1中，我们将确定增加的miR-29a/b簇和miR-29b-1-5p表达是否通过下调阿片类药物信号通路来增强内脏超敏反应。在AIM 2中，我们将确定miR-23a/b簇减少和125b-1-3p表达是否通过上调谷氨酸信号传导机制来促进内脏超敏反应。我们提出的研究应确定异常表达的miRNA的关键贡献，这些miRNA靶向下游阿片类药物和谷氨酸受体在肠道组织的内脏性超敏反应的患者的肠道组织中，这将弥合我们了解导致慢性疼痛失调途径的潜在机制的重要差距并改变患有常见功能性胃肠道疾病的患者的内脏伤害感受。更重要的是，结果应通过开发合成的寡核苷酸来发展创新的治疗策略，从而抑制或模拟特定的miRNA，从而调节下游靶基因（例如阿片类或谷氨酸受体）的表观遗传学调节，从而驱动内脏摄入膜。拟议的翻译研究的最终目标是开发用于治疗IBS和其他功能性GI疾病患者的新疗法。