SC COBRE: HUMAN ALKALINE PHYTOCERAMIDASE REGULATION OF ANGIOGENESIS

SC COBRE：人体碱性植物神经酰胺酶对血管生成的调节

• 批准号: 7381850
• 负责人: CUNGUI MAO
• 金额: $ 7.13万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7381850
• 关键词: SC; COBRE; HUMAN; ALKALINE; PHYTOCERAMIDASE

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Angiogenesis, the process of formation of new capillaries from preexisting blood vessels, is essential for the proper organ development and tissue repair. However, uncontrollable angiogenesis may lead to pathologies such as chronic inflammation, rheumatoid arthritis, and solid-tumor growth. Our long-term goals are to define the role of human alkaline phytoceramidase (haPHC) in regulating angiogenesis and to develop this concept into a new strategy to treat angiogenesis-related diseases by targeting this enzyme. haPHC, a novel enzyme which the PI identified recently, cleaves hydroxylceramide, one type of ceramides, to generate sphingosine, which is in turn phosphorylated to generate sphingosine-1-phosphate (S1P) through the action of sphingosine kinases. S1P mediates angiogenesis and vascular genesis. Our studies demonstrate that 1) haPHC mRNA is highly expressed in placenta in which angiogenesis and vascular genesis occur actively; and 2) haPHC and its homologous ceramidases co-regulate the levels of S1P. These results support the hypothesis that haPHC regulates angiogenesis by regulating the levels of S1P. To test this hypothesis, we proposed three specific aims: Aim 1: to determine the role of haPHC in growth and survival of human umbilical vein endothelial cells (HUVEC). We will determine whether haPHC up-regulation elevates the levels of S1P in HUVEC and results in cell proliferation whereas haPHC down-regulation has the opposite effects; and whether growth inhibition induced by haPHC down-regulation is alleviated or suppressed by exogenous S1P. Aim 2: to determine mechanism of the human alkaline phytoceramidase action. We will express haPHC in HaCaT cells and determine its substrate specificity, effects of cations and lipids on its activity, its cellular localization, and tissue specific expression. Aim 3: to determine the role of the alkaline phytoceramidase in angiogenesis. We will generate alkaline phytoceramidase (maPHC) knockout mice and analyze developmental angiogenesis and vascular genesis in maPHC null versus wild type mice.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子弹和调查员（PI）可能已经从其他NIH来源获得了主要资金，因此可以在其他清晰的条目中代表。列出的机构适用于该中心，这不一定是调查员的机构。血管生成是由先前存在的血管形成新毛细血管的过程，对于适当的器官发育和组织修复至关重要。然而，无法控制的血管生成可能导致病理，例如慢性炎症，类风湿关节炎和固体肿瘤生长。我们的长期目标是定义人类碱性植物氨基酰胺酶（HAPHC）在调节血管生成中的作用，并将这种概念发展为一种新的策略，以通过靶向这种酶来治疗与血管生成有关的疾病。 HAPHC是一种新型的酶，PI最近鉴定出，一种切氧胺（一种类型的神经酰胺）生成鞘氨醇，而鞘氨酸又被磷酸化以通过鞘氨醇激酶的作用产生鞘氨醇1-磷酸盐（S1P）。 S1P介导血管生成和血管生成。我们的研究表明，1）HAPHC mRNA在血管生成和血管生成的胎盘中高度表达； 2）HAPHC及其同源性神经酶共同调节S1P的水平。这些结果支持以下假设：HAPHC通过调节S1P的水平来调节血管生成。为了检验这一假设，我们提出了三个具体目的：目标1：确定HAPHC在人脐静脉内皮细胞（HUVEC）中的生长和存活中的作用。我们将确定HAPHC上调是否会提高HUVEC中的S1P水平，并导致细胞增殖，而HAPHC下调的影响相反。外源S1P是否可以减轻或抑制HAPHC下调引起的生长抑制作用。目标2：确定人类碱性植物氨基酰胺酶作用的机理。我们将在HACAT细胞中表达HAPHC，并确定其底物特异性，阳离子和脂质对其活性，其细胞定位和组织特异性表达的影响。目标3：确定碱性植物陶瓷酶在血管生成中的作用。我们将产生碱性植物陶瓷酶（MAPHC）基因敲除小鼠，并分析MAPHC NULL与野生型小鼠的发育血管生成和血管生成。