Sphingolipid Signaling

鞘脂信号转导

基本信息

批准号：
7735100
负责人：
SHELDON MILSTIEN
金额：
$ 23.29万
依托单位：
NATIONAL INSTITUTE OF MENTAL HEALTH
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/7735100
关键词：
Accounting Actins Allergic Anaphylaxis Animal Model Animals Antigens Apoptosis Apoptosis Promoter Apoptotic Asthma Attention Autophagocytosis Biological Process Brain CCL2 gene Cardiovascular Diseases Cardiovascular system Cell Death Cell Death Process Cell Line Cell Proliferation Cell Surface Receptors Cell physiology Cells Ceramides Cessation of life Chemotaxis Collaborations Condition Data Development Disease Doxorubicin EGF gene Enzymes Epidermal Growth Factor Receptor Etiology Extrinsic asthma G-Protein-Coupled Receptors Glioblastoma Glioma Goals Growth Hearing Heart Human IgE Immune system In Vitro Induction of Apoptosis Inflammation Interleukin-6 Isoenzymes Knowledge Lead Ligands Link Lipids Location Lysophospholipids Malignant Neoplasms Mediating Membrane Metabolism Multiple Sclerosis Mus Names Necrosis Nervous system structure Neuraxis Neurons Patients Peripheral Blood Mononuclear Cell Personal Satisfaction Pharmaceutical Preparations Physiological Processes Physiology Plasminogen Activator Inhibitor 1 Play Production Proteins Regulation Role SRC gene Signal Transduction Signaling Molecule Sphingolipids Sphingosine Sphingosine-1-Phosphate Receptor Structure Sum Therapeutic Thinking Time Tissues Translating Tumor Necrosis Factor-alpha Umbilical Cord Blood Universities Virginia analog autocrine cancer cell cell growth cell motility chemokine cytokine edg-1 Protein filamin human TNF protein human disease inhibitor/antagonist leukemia lipid mediator lysophosphatidic acid macrophage malignant stomach neoplasm mast cell medical schools migration monocyte neuronal survival novel therapeutics outcome forecast paracrine plasminogen receptor prevent protein crosslink receptor response sphingosine 1-phosphate sphingosine kinase therapeutic target tumor progression tumor xenograft vzg-1 Receptor

项目摘要

Sphingosine-1-phosphate (S1P) is a potent lipid mediator that regulates many vital biological processes, including cell growth, death, and differentiation. S1P has been shown to play important roles in normal and patho-physiological processes, including cancer, asthma, allergic responses, hearing, and development of the cardiovascular and nervous systems. In a continuing and highly successful collaboration with Dr. Sarah Spiegel at Virginia Commonwealth University School of Medicine, we are elucidating the mechanisms by which S1P is produced by two sphingosine kinases (SphK1 and SphK2), how its levels are regulated, and how it mediates such diverse actions. S1P is a ligand for five specific G protein-coupled receptors (named S1Psub(1-5)) that regulate many vital cellular processes and account for the pleiotropic effects of S1P. In fact, no cell in the body has been found that does not express as least one S1P receptor. Although they were long considered to be merely structural components of membranes, in the last decades it has become apparent that sphingolipids have other important functions. More recently, S1P and its precursors, sphingosine and ceramide, have been implicated in the regulation of many aspects of neuronal proliferation, differentiation, survival and apoptosis. Sphingolipids, such as S1P, are highly enriched in the CNS and recent data has substantiated their importance in development and functions of the brain. We recently reviewed current knowledge of regulation of SphK1 and SphK2 on both transcriptional and post-translational levels and the functions of these isozymes and their product S1P and its receptors in the central nervous system. In this regard, we recently examined the role of S1P in glioblastoma cells. Patients with gliomas expressing high levels of epidermal growth factor receptor (EGFR) and plasminogen activator inhibitor-1 (PAI-1) have a shorter overall survival prognosis. Although multiple signaling cascades are activated by EGF in glioma cells, we showed for the first time that EGF enhances expression of PAI-1 via sequential activation of c-Src, PKCdelta, and SphK1, the enzyme that produces S1P, which have all been implicated in regulating motility and invasion of glioma cells. We previously found that SphK1 was important for cell growth and survival and SphK2 seemed to inhibit proliferation and promote cell death. SphK1 and SphK2 have different cellular localizations and have opposing roles in the regulation of sphingolipid metabolism suggesting that the location of S1P production in the cell dictates its functions. We have now identified filamin A (FLNa), an actin crosslinking protein involved in cell movement, as a SphK1-interacting protein and showed that FLNa links SphK1 and the S1P1 receptor to locally influence the dynamics of actin cytoskeletal structures by orchestrating the concerted actions of the triumvirate of SphK1, FLNa, and PAK1, at lamellipodia to promote cell movement. Lysophosphatidic acid (LPA), like S1P, mediates similar diverse cellular processes important for cancer progression. We recently found that LPA markedly enhanced SphK1 expression and S1P formation in gastric cancer cells and in other human cancer cells that express the LPA1 receptor. Our results suggest that SphK1 is a convergence point of multiple cell surface receptors for three different ligands, LPA, EGF, and S1P, which have all been implicated in regulation of motility and invasiveness of cancer cells. We have been developing specific SphK1 inhibitors as potential therapeutic agenst. A sphingosine analogue we called SK1-I decreased growth and survival of human leukemia cell lines and primary leukemia cells from patients, while sparing normal peripheral blood mononuclear cells. Importantly, SK1-I markedly reduced growth of xenograft tumors. Our results suggest that specific inhibitors of SphK1 warrant attention as potential additions to the therapeutic armamentarium in leukemia. We also made the unexpected finding that treatment of leukemia cells with a non-specific SphK inhibitor caused a large increase in expression of SphK1 concomitant with induction of apoptosis. The chemotherapeutic drug doxorubicin, a potent inducer of apoptosis in these cells, also stimulated SphK1 expression and activity and promoted S1P secretion. We found that secreted S1P potently stimulated chemotaxis of leukemia cells and primary monocytes and macrophages and suggested that apoptotic cells may up-regulate SphK1 to produce and secrete S1P (inside-out signaling) that serves as a "come-and-get-me" signal for scavenger cells to engulf them in order to prevent necrosis. In two invited reviews, we discussed how inside-out signaling of S1P could be a therapeutic target and wju targeting SphK1 could become a new strategy against cancer. Mast cells are tissue-dwelling pivotal early effectors of allergic responses, which produce and secrete S1P, that acts in an autocrine or paracrine manner to influence many facets of the immune system. The relevance of mast cells in the etiology of allergic disorders, asthma and anaphylaxis is well established. In contrast to its weak effect on degranulation of murine mast cells, we found that S1P potently induced degranulation of a human mast-cell line and of cord blood-derived human mast cells (hMCs). S1P also stimulated production and secretion of cytokines, TNF-alpha and IL-6, and markedly enhanced secretion of a chemokine, CCL2/MCP-1, important modulators of inflammation. Production of S1P by SphK1 but not SphK2 was critical for IgE/Ag-induced degranulation, migration toward antigen, and CCL2 secretion from hMCs, although both isoenzymes were required for TNF-alpha secretion. In sum, our data suggest that differential formation of S1P by SphK1 and SphK2 has distinct and important actions in hMCs.

鞘氨醇1-磷酸盐（S1P）是一种有效的脂质介质，可调节许多重要的生物学过程，包括细胞生长，死亡和分化。 S1P已被证明在正常和病态生理过程中起着重要作用，包括癌症，哮喘，过敏反应，听力和心血管和神经系统的发展。在与弗吉尼亚联邦大学医学院的莎拉·斯皮格尔（Sarah Spiegel）博士进行的持续和非常成功的合作中，我们正在阐明由两个鞘氨醇激酶（SPHK1和SPHK2）生产的S1P的机制，如何调节其水平以及如何调节这种不同的行动。 S1P是一种适用于五个特定G蛋白偶联受体（称为S1PSUB（1-5））的配体，可调节许多重要的细胞过程，并解释了S1P的多效效应。实际上，没有发现体内至少一个S1P受体的细胞。尽管它们长期以来被认为仅仅是膜的结构成分，但在过去的几十年中，显然鞘脂具有其他重要功能。最近，S1P及其前体，鞘氨酸和神经酰胺，与神经元增殖，分化，生存和凋亡的许多方面有关。鞘脂（例如S1P）在中枢神经系统中高度富集，并且最近的数据证实了它们在大脑的发育和功能中的重要性。我们最近回顾了当前对转录和翻译后水平的SPHK1和SPHK2调控知识，这些同工酶及其产物S1P及其受体在中枢神经系统中的功能。在这方面，我们最近检查了S1P在胶质母细胞瘤细胞中的作用。表达高水平表皮生长因子受体（EGFR）和纤溶酶原激活剂抑制剂1（PAI-1）的胶质瘤患者的总生存率较短。尽管多种信号传导级联在神经胶质瘤细胞中被EGF激活，但我们首次表明EGF通过顺序激活C-SRC，PKCDELTA和SPHK1增强了PAI-1的表达，S1P的酶是产生S1P的酶，这些酶都与调节胶质瘤细胞的运动性和入侵有关。我们先前发现SPHK1对于细胞生长和生存很重要，而SPHK2似乎抑制了增殖并促进细胞死亡。 SPHK1和SPHK2具有不同的细胞定位，并且在调节鞘脂代谢的调节中具有相反的作用，这表明S1P产生在细胞中的位置决定了其功能。 We have now identified filamin A (FLNa), an actin crosslinking protein involved in cell movement, as a SphK1-interacting protein and showed that FLNa links SphK1 and the S1P1 receptor to locally influence the dynamics of actin cytoskeletal structures by orchestrating the concerted actions of the triumvirate of SphK1, FLNa, and PAK1, at lamellipodia to promote cell movement. 溶血磷脂酸（LPA）像S1P一样，介导相似的各种细胞过程，对癌症进展很重要。我们最近发现，LPA在胃癌细胞和表达LPA1受体的其他人类癌细胞中显着增强了SPHK1表达和S1P形成。我们的结果表明，SPHK1是三种不同的配体LPA，EGF和S1P的多个细胞表面受体的收敛点，它们都与调节癌细胞的运动性和侵入性有关。我们一直在开发特定的SPHK1抑制剂作为潜在的治疗AGENST。我们称SK1-1的鞘氨酸类似物降低了患者人类白血病细胞系和原发性白血病细胞的生长和存活，同时避免了正常的外周血单核细胞。重要的是，SK1-I显着降低了异种移植肿瘤的生长。我们的结果表明，特定的SPHK1抑制剂值得关注，这是对白血病治疗性武术的潜在增加。我们还出乎意料地发现，用非特异性SPHK抑制剂治疗白血病细胞导致SPHK1表达与诱导凋亡的同时大大增加。化学治疗药物阿霉素是这些细胞中凋亡的有效诱导剂，也刺激了SPHK1表达和活性，并促进了S1P分泌。我们发现，分泌的S1P有效刺激白血病细胞和原发性单核细胞和巨噬细胞的趋化性，并建议凋亡细胞可以上调SPHK1以产生并分泌S1P（内而外信号），这些S1P（内而外信号）用作“ cose-Get-me”信号，以防止它们吞噬它们，以防止其吞噬Necrosis。在两次邀请的评论中，我们讨论了S1P的内而外信号如何成为治疗目标，而WJU靶向SPHK1可能会成为针对癌症的新策略。肥大细胞是产生和分泌S1P的过敏反应的组织居住的关键早期效应子，它们以自分泌或旁分泌方式作用，以影响免疫系统的许多方面。肥大细胞在过敏性疾病，哮喘和过敏反应的病因中的相关性已得到很好的确定。与其对鼠肥大细胞脱粒的影响相反，我们发现S1P有效诱导了人类肥大细胞系和脐带血的人类肥大细胞（HMC）的脱粒。 S1P还刺激了细胞因子TNF-Alpha和IL-6的产生和分泌，并显着增强了趋化因子，CCL2/MCP-1的分泌，即炎症的重要调节剂。 SPHK1而非SPHK2的S1P对IgE/Ag诱导的脱粒，向抗原迁移和HMC的CCL2分泌至关重要，尽管这两个同工酶都需要TNF-Alpha分泌。总而言之，我们的数据表明，SPHK1和SPHK2对S1P的差异形成在HMC中具有独特而重要的作用。