CXCR4 and ckit signaling in BM progenitor cell recruitment in the ischemic heart

CXCR4 和 ckit 信号传导在缺血心脏中 BM 祖细胞募集中的作用

• 批准号: 8448213
• 负责人: Gangjian Qin
• 金额: $ 36.77万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8448213
• 关键词: Area; Blood capillaries; Bone Marrow; Bone Marrow Cells; CXC Chemokines; Cardiac; Cardiovascular system; Cause of Death; Cell Therapy; Cells; Code; Disease; Effectiveness; Engineering; Event; Family; Gel; Genetic; Goals; Health; Heart; Injury; Label; Laboratories; Lentivirus Vector; Link; Mass Spectrum Analysis; Mediating; Mus; Myocardial Infarction; Myocardial Ischemia; Myocardial tissue; Pathway interactions; Perfusion; Phosphorylation; Protein Tyrosine Kinase; Proteins; Proto-Oncogene Protein c-kit; Publications; Publishing; Receptor Protein-Tyrosine Kinases; Recruitment Activity; Role; Saline; Series; Signal Transduction; Signaling Molecule; Site; Stem Cell Factor; Stem cells; Stromal Cell-Derived Factor 1; Surface; Techniques; Tissues; Transactivation; Transgenic Mice; Tyrosine; Vascular blood supply; Work; capillary; cardiac repair; chemokine receptor; density; improved; insight; migration; mutant; neovascularization; novel; novel therapeutic intervention; overexpression; peripheral blood; repaired; research study; tissue regeneration; vector; vector control

DESCRIPTION (provided by applicant): Cell therapy trials suggest that bone marrow (BM)-derived progenitor cells (PCs) could be a promising new option for treating ischemic heart disease, but the efficacy of this approach has been modest. Some of the barriers to successful cell therapy include poor recruitment of cells from the BM to the site of injury and the low proportion of recruited cells that are retained and survive in the ischemic region. Both the release (i.e., mobilization) of PCs from the BM to the peripheral blood and the recruitment and retention of PCs in ischemic tissue are regulated by interactions between stromal cell-derived factor-1 (SDF-1) and CXC chemokine receptor 4 (CXCR4), and a recent publication from our laboratory shows that in the BM, SDF-1/CXCR4 signaling is linked to c-kit activity. C-kit is a type III receptor tyrosine kinase and is expressed on the surface of many types of PCs, where it functions as a receptor for stem cell factor (SCF) and is crucial for BM PC- mediated cardiac repair. Our published observations indicate that SDF-1/CXCR4 signaling induces c-kit phosphorylation (transactivation), which retains PCs, in the BM, and that the antagonism or genetic deletion of CXCR4 mobilizes PCs by downregulating SDF-1-mediated (but not SCF-mediated) c-kit activity. We also showed that SDF-1-induced c-kit phosphorylation requires activation of the Src family of non-receptor tyrosine kinases (SFKs)-SFK inhibition blocked both c-kit phosphorylation and the interaction between c-kit and phosphorylated Src in BM PCs-and our ongoing experiments indicate that c-kit-deficiencies impair the migration of BM PCs toward SDF-1 and significantly reduce BM PC recruitment to the ischemic myocardium. The goal of this application is to establish the role of SDF-1/CXCR4-c-kit signaling in BM PC recruitment, and to determine whether techniques that target this pathway could enhance the effectiveness of cell therapy. Our central hypothesis is that SDF-1/CXCR4 signaling activates (i.e., phosphorylates) c-kit, and that c-kit activation subsequently leads to the recruitment and retention of PCs in the ischemic region; thus, treatments that enhance c-kit activity in circulating PCs will improve PC recruitment and PC-mediated cardiac repair by increasing the sensitivity of PCs to SDF-1/CXCR4 signaling. We will accomplish our objective by evaluating our central hypothesis with a series of experiments grouped under three specific aims: Aim 1) to characterize the molecules and mechanisms involved in SDF-1/CXCR4-c-kit signaling; Aim 2) to identify the role of SDF- 1/CXCR4-c-kit signaling in BM PC recruitment; and Aim 3) to determine whether PC recruitment and cardiac repair after MI can be improved by increasing c-kit activity in BM PCs. We anticipate that the work proposed in this project will provide novel insights into the mechanism by which the SDF-1/CXCR4-c-kit pathway regulates BM PC recruitment and retention in ischemic tissue, thereby identifying new therapeutic approaches and targets that could enhance the effectiveness of cell therapy for treatment of ischemic heart disease.

描述（由申请人提供）：细胞治疗试验表明，骨髓（BM）来源的祖细胞（PC）可能是治疗缺血性心脏病的一种有前途的新选择，但这种方法的疗效有限。成功的细胞治疗的一些障碍包括从BM到损伤部位的细胞募集不良以及在缺血区域中保留和存活的募集细胞的比例低。两者的释放（即，PC从BM到外周血的动员）以及PC在缺血组织中的募集和保留是由基质细胞衍生因子-1（SDF-1）和CXC趋化因子受体4（CXCR 4）之间的相互作用调节的，并且我们实验室最近的出版物表明，在BM中，SDF-1/CXCR 4信号传导与c-kit活性相关。C-kit是一种类型 III受体酪氨酸激酶，表达于许多类型PC的表面，其功能是干细胞因子（SCF）的受体，对于BM PC介导的心脏修复至关重要。我们发表的观察结果表明，SDF-1/CXCR 4信号转导诱导c-kit磷酸化（反式激活），这保留了PC，在BM中，和CXCR 4的拮抗作用或基因缺失动员PC通过下调SDF-1介导的（但不是SCF介导的）c-kit活性。我们还发现，SDF-1诱导的c-kit磷酸化需要激活Src家族的非受体酪氨酸激酶（SFK）-SFK抑制阻断c-kit磷酸化和c-kit与BM PC中磷酸化Src之间的相互作用-我们正在进行的实验表明，c-kit缺陷损害BM PC向SDF-1的迁移，并显着减少BM PC向缺血心肌的募集。本申请的目的是确定SDF-1/CXCR 4-c-kit信号传导在BM PC募集中的作用，并确定靶向该途径的技术是否可以增强细胞治疗的有效性。我们的中心假设是SDF-1/CXCR 4信号转导激活（即，因此，增强循环PC中c-kit活性的治疗将通过增加PC对SDF-1/CXCR 4信号传导的敏感性来改善PC募集和PC介导的心脏修复。我们将通过一系列实验来评估我们的中心假设，以实现我们的目标，这些实验分为三个具体目标：目的1）表征SDF-1/CXCR 4-c-kit信号转导的分子和机制;目的2）鉴定SDF- 1/CXCR 4-c-kit信号转导在BM PC募集中的作用;目的3）确定是否可以通过增加BM PC中的c-kit活性来改善MI后PC的募集和心脏修复。我们预计，该项目中提出的工作将为SDF-1/CXCR 4-c-kit途径调节缺血组织中BM PC募集和保留的机制提供新的见解，从而确定新的治疗方法和靶点，可以提高细胞疗法治疗缺血性心脏病的有效性。