Tryptophan metabolism and its role in fibroid pathogenesis

色氨酸代谢及其在肌瘤发病机制中的作用

• 批准号: 10504393
• 负责人: OMID A. KHORRAM
• 金额: $ 38.53万
• 依托单位: LUNDQUIST INSTITUTE FOR BIOMEDICAL INNOVATION AT HARBOR-UCLA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-30 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10504393
• 关键词: African American population; Aryl Hydrocarbon Receptor; Binding; CYP1B1 gene; Catabolism; Caucasians; Cell Cycle Proteins; Cell Proliferation; Collagen; Data; Development; Diet; Dietary Factors; Endocrine Disruptors; Environmental Risk Factor; Enzymes; Epigenetic Process; Exposure to; Extracellular Matrix; Fibroid Tumor; Gene Expression; Genes; Goals; Gonadal Steroid Hormones; Growth; Hispanic Populations; Hormonal; Hydrocortisone; In Vitro; Inflammation; Kynurenine; Leiomyoma; Lentivirus; Link; Messenger RNA; Metabolic; Metabolic Pathway; Mutation; NF-kappa B; Pathogenesis; Pharmacology; Quantitative Reverse Transcriptase PCR; Race; Reaction; Receptor Signaling; Reporting; Response Elements; Risk Factors; Role; Sampling; Smooth Muscle Myocytes; Specimen; Stress; Testing; Tetrachlorodibenzodioxin; Tissues; Tryptophan; Tryptophan 2,3 Dioxygenase; Tryptophan Metabolism Pathway; Tryptophanase; Untranslated RNA; Ursidae Family; Western Blotting; Xenobiotics; aryl hydrocarbon receptor ligand; base; cell growth; design; enzyme activity; in vivo; inhibitor; innovation; knock-down; mRNA Expression; mouse model; myometrium; novel; novel therapeutics; overexpression; protein expression; small hairpin RNA; transcription factor; transforming growth factor beta3; translational potential; trend; tumor

Abstract In the course of our profiling for non-coding RNAs in fibroids we discovered highly aberrant overexpression of Tryptophan 2,3 dioxygenase (TDO2) and Indoleamine 2,3-dioxygenase (IDO1) in fibroids. We confirmed this finding by both qRT-PCR and Western blot analysis, and found a consistently elevated expression of TDO2 and more variable overexpression of IDO1 in our tissue specimens. The increment in TDO2 expression in fibroids was higher as compared to IDO1, and the expression of IDO2 was barely detected. Relevant to the pathogenesis of fibroids was that the increment in TDO2 but not IDO1 was race dependent, with the increment being significantly higher in African Americans as compared with Caucasians. Furthermore, the expression of TDO2 was significantly increased in MED12 mutation bearing leiomyomas, and its inhibition by pharmacologic blockade in vitro led to decreased proliferation and expression of genes related to extracellular matrix, inflammation and cell growth in leiomyoma smooth muscle cells (LSMC) spheroids. Aberrant expression of these enzymes in fibroids resulted in increased levels of kynurenine (Kyn), a metabolic byproduct of tryptophan degradation and a known endogenous ligand for Aryl hydrocarbon receptor (AhR). Based on this preliminary data we hypothesized that dysregulation of Trp metabolism as characterized by marked overexpression of TDO2 is fundamental to the pathogenesis of fibroids and correction of Trp metabolic dysregulation by inhibition of TDO2 and normalization of kynurenine levels will inhibit fibroid growth and progression and potentially tumor establishment. We propose to this hypothesis in 3 aims. In aim1 we will characterize Trp metabolism in myometrium and fibroid tumors and explants, and determine the mechanism(s) underlying the marked overexpression of TDO2 in fibroids using an in vitro approach. In Aim 2 we will examine the impact of kynurenine and its activation of AhR on downstream genes regulating extracellular matrix (ECM), inflammation and cell proliferation. Aim 3 is designed to determine the utility of a pharmacological inhibitor of TDO2 and with lentivirus bearing shRNA to knock down TDO2 on fibroid establishment and progression in in vivo mouse models of fibroids. This novel metabolic mechanism for fibroid pathogenesis has great translational significance as it opens the way for novel therapies aimed at correction of tryptophan metabolism in fibroids.

抽象的 在肌瘤中非编码RNA的分析过程中，我们发现了高度异常的过表达 色氨酸2,3二加氧酶（TDO2）和吲哚胺2,3-二氧酶（IDO1）中的肌瘤中。我们确认了这一点 通过QRT-PCR和Western印迹分析的发现，发现TDO2和 在我们的组织样品中IDO1的更可变的过表达。肌瘤中TDO2表达的增加 与IDO1相比，较高，几乎没有检测到IDO2的表达。与发病机理有关 肌瘤的是TDO2但不是IDO1的增量是依赖种族的，而增量为 与高加索人相比，非洲裔美国人的高度更高。此外，TDO2的表达 在轴承平滑肌瘤的Med12突变中显着增加，并通过药物阻滞抑制 体外导致与细胞外基质，炎症和 平滑肌平滑肌细胞（LSMC）球体的细胞生长。这些酶在异常表达 肌瘤导致Kynurenine（Kyn）水平升高，Throppophan降解的代谢副产品和A 已知的内源配体用于芳基烃受体（AHR）。基于此初步数据，我们假设 TTO2明显过表达为特征的TRP代谢的失调是 通过抑制作用肌瘤的发病机理和TRP代谢失调的基础 TDO2和Kynurenine水平的归一化将抑制肌瘤的生长和进展 潜在的肿瘤建立。我们在3个目标中提出了这一假设。在AIM1中，我们将描述TRP 肌层和肌瘤肿瘤和外植体中的代谢，并确定机制 使用体外方法在肌瘤中标记了TDO2的过表达。在AIM 2中，我们将研究 Kynurenine及其在调节细胞外基质（ECM）的下游基因上的AHR激活，炎症 和细胞增殖。 AIM 3旨在确定TDO2药理抑制剂的实用性以及 慢病毒轴承shRNA在体内小鼠模型中击倒肌瘤建立和进展的TDO2 肌瘤。这种新型肌瘤发病机理的代谢机制具有很大的翻译意义 为旨在纠正色氨酸代谢的新型疗法打开道路。