Roles of Glycoconjugates and Redox Signaling in Tumor Biology

糖缀合物和氧化还原信号在肿瘤生物学中的作用

基本信息

批准号：
8938402
负责人：
david d roberts
金额：
$ 44.04万
依托单位：
DIVISION OF CLINICAL SCIENCES - NCI
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/8938402
关键词：
Adverse effects Affinity Anabolism Angiogenesis Inhibitors Animal Model Autophagocytosis Autophagosome Binding Biological Process CD44 Antigens CD44 gene CD47 gene Cancer Patient Cancer cell line Carbon Monoxide Cardiovascular Physiology Cardiovascular system Cell Adhesion Molecules Cell membrane Cell physiology Cell surface Cells Confocal Microscopy Cystathionine beta-Synthase Cysteine Desulfhydrase Development Diagnostic Eating Electron Microscopy Endoplasmic Reticulum Enzymes Etiology Exhibits Extracellular Matrix FDA approved Family Fibronectins Flow Cytometry Glycoconjugates Glycolipids Glycoproteins Glycosaminoglycans Golgi Apparatus Hemostatic function Heparan Sulfate Proteoglycan Hyaluronan Hydrogen Sulfide Immunologic Surveillance Integrins Interleukin-2 Knockout Mice Label Ligands Lysosomes MEKs Mediating Mediator of activation protein Membrane Messenger RNA Metabolic Pathway Mitochondria Mitogen-Activated Protein Kinases Molecular Mus Mutant Strains Mice Neoplasm Metastasis Organelles Oxidation-Reduction Pathologic Neovascularization Pathway interactions Peptides Pharmaceutical Preparations Phosphorylation Play Polysaccharides Process Property Proteins Proteoglycan Recycling Relative (related person)Reporting Role Signal Transduction Source Splenocyte Staining method Stains Structure T-Cell Activation T-Cell Receptor T-Lymphocyte T-Lymphocyte Subsets Techniques Therapeutic Uses Thrombospondin 1 Thrombospondins Thymus Gland Tumor Angiogenesis Tumor Biology Tumor Tissue Vesicle Wild Type Mouse aged angiogenesis autocrine blood pressure regulation glycosylation inhibitor/antagonist neoplastic cell neovascularization novel parkin gene/protein prevent receptor response small molecule therapeutic angiogenesis therapeutic target thymocyte tissue culture

项目摘要

Thrombospondin-1 is a potent suppressor of T cell activation via its receptor CD47. However, the precise mechanism for this inhibition remains unclear. Because H2S is an endogenous potentiator of T cell activation and is necessary for full T cell activation, we hypothesized that thrombospondin-1 signaling through CD47 inhibits T cell activation by antagonizing H2S signaling. Primary T cells from thrombospondin-1 null mice were more sensitive to H2S-dependent activation assessed by proliferation and induction of interleukin-2 and CD69 mRNAs. Exogenous thrombospondin-1 inhibited H2S responses in wild type and thrombospondin-1 null T cells but enhanced the same responses in CD47 null T cells. Fibronectin, which shares integrin and glycosaminoglycan binding properties with thrombospondin-1 but not CD47 binding, did not inhibit H2S signaling. A CD47-binding peptide derived from thrombospondin-1 inhibited H2S-induced activation, whereas two other functional sequences from thrombospondin-1 enhanced H2S signaling. Therefore, engaging CD47 is necessary and sufficient for thrombospondin-1 to inhibit H2S-dependent T cell activation. H2S stimulated T cell activation by potentiating MEK-dependent ERK phosphorylation, and thrombospondin-1 inhibited this signaling in a CD47-dependent manner. Thrombospondin-1 also limited activation-dependent T cell expression of the H2S biosynthetic enzymes cystathionine beta-synthase and cystathionine gamma-lyase, thereby limiting the autocrine role of H2S in T cell activation. Thus, thrombospondin-1 signaling through CD47 is the first identified endogenous inhibitor of H2S signaling and constitutes a novel mechanism that negatively regulates T cell activation. Autophagy (macroautophagy), a cellular process of "self-eating", segregates damaged/aged organelles into vesicles, fuses with lysosomes, and enables recycling of the digested materials. The precise origin(s) of the autophagosome membrane is unclear and remains a critical but unanswered question. Endoplasmic reticulum, mitochondria, Golgi complex, and the plasma membrane have been proposed as the source of autophagosomal membranes. Using electron microscopy, immunogold labeling techniques, confocal microscopy, and flow cytometry we show that mitochondria can directly donate their membrane material to form autophagosomes. We expand upon earlier studies to show that mitochondria donate their membranes to form autophagosomes during basal and drug-induced autophagy. Moreover, electron microscopy and immunogold labeling studies show the first physical evidence of mitochondria forming continuous structures with LC3-labeled autophagosomes. The mitochondria forming these structures also stain positive for parkin, indicating that these mitochondrial-formed autophagosomes represent a novel mechanism of parkin-associated mitophagy. With the on-going debate regarding autophagosomal membrane origin, this report demonstrates that mitochondria can donate membrane materials to form autophagosomes. These structures may also represent a novel form of mitophagy where the mitochondria contribute to the formation of autophagosomes. This novel form of parkin-associated mitophagy may be a more efficient bio-energetic process compared with de novo biosynthesis of a new membrane, particularly if the membrane is obtained, at least partly, from the organelle being targeted for later degradation in the mature autolysosome.

血小板传播1是通过其受体CD47激活T细胞激活的有效抑制剂。但是，这种抑制的确切机制尚不清楚。由于H2S是T细胞激活的内源性增强剂，对于全T细胞激活是必要的，因此我们假设通过CD47的血小板传播信号传导通过拮抗H2S信号传导抑制T细胞激活。来自血小板蛋白-1 NULL小鼠的原代T细胞对通过增殖和诱导白介素-2和CD69 mRNA评估的H2S依赖性激活更敏感。外源性血小板素1抑制了野生型和血小板蛋白-1 null T细胞中的H2S反应，但增强了CD47 null T细胞中相同的反应。纤连蛋白共享整合素和糖胺聚糖的结合特性与血小板传播1但不抑制H2S信号传导。源自血小板素-1的CD47结合肽抑制了H2S诱导的激活，而血小板传播1增强的H2S信号传导的其他两个功能序列。因此，参与CD47是必需的，足以使血小板传播1抑制H2S依赖性T细胞激活。 H2S通过增强MEK依赖性ERK磷酸化而刺激T细胞的激活，而血小板传播1则以CD47依赖性方式抑制了该信号传导。血小板传播1还限制了H2S生物合成酶的活化依赖性T细胞表达，Cystathionineβ-合成酶和胱淀粉γ-溶解酶，从而限制了H2S在T细胞活化中的自身分泌作用。因此，通过CD47通过CD47信号传导是H2S信号传导的第一个鉴定的内源性抑制剂，构成了一种负面调节T细胞激活的新机制。自噬（大量自噬）是一种“自食”的细胞过程，将受损/老化的细胞器分离为囊泡，与溶酶体的融合，并可以回收消化材料。自噬体膜的确切起源尚不清楚，并且仍然是一个关键但未解决的问题。已经提出了内质网，线粒体，高尔基体复合物和质膜作为自噬体膜的来源。使用电子显微镜，免疫元标记技术，共聚焦显微镜和流式细胞仪，我们表明线粒体可以直接捐赠其膜材料以形成自噬体。我们根据早期的研究扩展，以表明线粒体在基础和药物诱导的自噬过程中捐赠其膜形成自噬体。此外，电子显微镜和免疫金标记研究表明，用LC3标记的自噬体形成线粒体连续结构的第一个物理证据。形成这些结构的线粒体也对帕金染色阳性，表明这些线粒体形成的自噬体代表了与帕金相关的线粒体的新机制。随着关于自噬体膜起源的持续辩论，该报告表明线粒体可以捐赠膜材料以形成自噬体。这些结构也可能代表一种新型的线粒体形式，线粒体有助于自噬体的形成。与新膜的从头生物合成相比，这种新型的帕金相关线形形式可能是一种更有效的生物能源过程，尤其是如果至少部分从细胞器获得的膜被靶向的膜被靶向，以便在成熟体内体中以后的降级。