Effects of Oxidized Low-density Lipoprotein on Bone Marrow Stem Cell

氧化低密度脂蛋白对骨髓干细胞的影响

• 批准号: 8481572
• 负责人: ZHENGUO LIU
• 金额: $ 35.93万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8481572
• 关键词: 1-Phosphatidylinositol 3-Kinase; Adhesions; Adult; Animals; Area; Arterial Fatty Streak; Atherogenic Diet; Atherosclerosis; Beryllium; Blood Vessels; Bone Marrow; Bone Marrow Stem Cell; Bone Marrow Transplantation; C57BL/6 Mouse; Cardiovascular Diseases; Cardiovascular system; Cell Count; Cell Proliferation; Cell physiology; Cells; Collaborations; Complex; Data; Development; Electron Spin Resonance Spectroscopy; Functional disorder; Generations; Genes; Hyperlipidemia; In Vitro; Infusion procedures; Injury; Knock-out; Knowledge; Label; Low Density Lipoprotein Receptor; MAP Kinase Gene; MAPK3 gene; Marrow; Measures; Mitogen-Activated Protein Kinases; Modeling; Multipotent Stem Cells; Mus; Natural regeneration; Oxidation-Reduction; Oxidative Stress; Pathogenesis; Pathway interactions; Patients; Phosphorylation; Play; Population; Protein-Serine-Threonine Kinases; Research; Role; Signal Transduction; Stem cells; Testing; Tissues; Transfection; Wild Type Mouse; base; design; in vivo; injured; intravenous administration; low density lipoprotein inhibitor; male; migration; monolayer; neointima formation; novel; novel strategies; overexpression; oxidized low density lipoprotein; peripheral blood; prevent; public health relevance; repaired; research study; stem cell population; vector

DESCRIPTION (provided by applicant): Adult bone marrow multipotent progenitor cells (MAPCs) are one of well characterized bone marrow- derived stem cells. Our initial studies show that oxidized low-density lipoprotein (ox-LDL) significantly inhibits the proliferation of murine MAPCs and their endothelial differentiation in association with a selective and dramatic reduction of serine/threonine kinase Akt (Akt) phosphorylation. It is well known that the number and function of endothelial progenitor cells (EPCs) are markedly reduced in the patients with hyperlipidemia. The present study will test the hypothesis that ox-LDL reduces stem cell population within the bone marrow, and impairs their differentiation into EPCs due to interrupted Akt signaling. The specific aims are: 1). To evaluate the effect of ox-LDL on the population of stem cells within bone marrow and the underlying mechanisms; and 2). To investigate the role of ox-LDL in the differentiation of MAPCs into EPCs and the underlying mechanisms. Murine MAPCs will be isolated, cultured and quantitatively analyzed from both hyperlipidemic male LDL receptor knock out (LDLR-/-) mice (with atherogenic diet) and ox-LDL-infused wild-type (WT) normal C57BL/6 mice. The number of MAPCs within the bone marrow, Oct-4 expression, and their proliferation and differentiation into EPCs will be evaluated. To further test the hypothesis, bone marrow transplantation with eGFP- labeled MAPCs will be performed in LDLR(-/-) mice and ox-LDL-infused WT mice. The eGFP-positive EPCs will be isolated and quantitatively analyzed from the animals for EPC number and function. If the hypothesis is true, it is expected that the population and function of MAPCs within the bone marrow and EPCs in the bone marrow and peripheral blood will be significantly decreased in ox-LDL-infused animals and in hyperlipidemic LDLR(-/-) mice. It is also anticipated that Oct-4 expression, cell proliferation, and endothelial differentiation of the MAPCs isolated from the hyperlipidemic LDLR(-/-) mice and ox-LDL- infused WT mice will be significantly decreased along with a significant reduction in Akt phosphorylation in MAPCs. Conversely, the number and function of eGFP-positive MAPCs within the bone marrow and EPCs in the bone marrow and peripheral blood will increase significantly in the animals (both hyperlipidemic mice and ox-LDL-infused WT mice) that receive bone marrow transplantation with eGFP- positive MAPCs transfected with retroviral Akt1 vectors, and stably over-expressing active Akt. In addition, overexpression of active Akt will decrease atherosclerotic plaque formation in hyperlipidemic mice, and enhance vascular repair with reduced neointima formation in ox-LDL-infused mice. The data from this study will provide novel information on the mechanisms for the development of atherosclerosis in patients with hyperlipidemia, and help explore new approaches to preventing and treating cardiovascular diseases.

描述（由申请人提供）： 成体骨髓多能祖细胞（MAPC）是已充分表征的骨髓来源干细胞之一。我们的初步研究表明，氧化低密度脂蛋白 (ox-LDL) 显着抑制小鼠 MAPC 的增殖及其内皮分化，并与丝氨酸/苏氨酸激酶 Akt (Akt) 磷酸化的选择性和显着减少相关。众所周知，高脂血症患者的内皮祖细胞（EPC）数量和功能显着降低。本研究将检验这样的假设：ox-LDL 会减少骨髓内的干细胞数量，并由于 Akt 信号传导中断而损害其向 EPC 的分化。具体目标是：1）．评估ox-LDL对骨髓内干细胞群的影响及其潜在机制；和2）。探讨ox-LDL在MAPCs分化为EPCs中的作用及其机制。将从高脂血症雄性 LDL 受体敲除 (LDLR-/-) 小鼠（动脉粥样硬化饮食）和 ox-LDL 输注野生型 (WT) 正常 C57BL/6 小鼠中分离、培养和定量分析小鼠 MAPC。将评估骨髓内 MAPC 的数量、Oct-4 表达及其增殖和分化为 EPC 的情况。为了进一步检验这一假设，将在 LDLR(-/-) 小鼠和 ox-LDL 输注的 WT 小鼠中进行带有 eGFP 标记的 MAPC 的骨髓移植。将从动物中分离出 eGFP 阳性 EPC 并对其 EPC 数量和功能进行定量分析。如果该假设成立，则预计在输注 ox-LDL 的动物和高脂血症 LDLR(-/-) 小鼠中，骨髓内的 MAPC 以及骨髓和外周血中的 EPC 的数量和功能将显着减少。还预计从高脂血症 LDLR(-/-) 小鼠和 ox-LDL 输注的 WT 小鼠分离的 MAPC 的 Oct-4 表达、细胞增殖和内皮分化将显着降低，同时 Akt 磷酸化显着降低。在 MAPC 中。相反，在接受 eGFP 骨髓移植的动物（高脂血症小鼠和输注 ox-LDL 的 WT 小鼠）中，骨髓内 eGFP 阳性 MAPC 以及骨髓和外周血中 EPC 的数量和功能将显着增加- 用逆转录病毒 Akt1 载体转染的阳性 MAPC，并稳定过表达活性 Akt。此外，活性 Akt 的过度表达将减少高脂血症小鼠中动脉粥样硬化斑块的形成，并通过减少 ox-LDL 输注小鼠中的新内膜形成来增强血管修复。这项研究的数据将为高脂血症患者动脉粥样硬化的发生机制提供新的信息，并有助于探索预防和治疗心血管疾病的新方法。