Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Chicago, IL 60611, USA.
Circ Res. 2010 Oct 29;107(9):1083-93. doi: 10.1161/CIRCRESAHA.110.220970. Epub 2010 Sep 16.
The mobilization of bone marrow (BM) progenitor cells (PCs) is largely governed by interactions between stromal cell-derived factor (SDF)-1 and CXC chemokine receptor (CXCR)4. Ischemic injury disrupts the SDF-1-CXCR4 interaction and releases BM PCs into the peripheral circulation, where the mobilized cells are recruited to the injured tissue and contribute to vessel growth. BM PCs can also be mobilized by the pharmacological CXCR4 antagonist AMD3100, but the other components of the SDF-1-CXCR4 signaling pathway are largely unknown. c-kit, a membrane-bound tyrosine kinase and the receptor for stem cell factor, has also been shown to play a critical role in BM PC mobilization and ischemic tissue repair.
To investigate the functional interaction between SDF-1-CXCR4 signaling and c-kit activity in BM PC mobilization.
AMD3100 administration failed to mobilize BM PCs in mice defective in c-kit kinase activity or in mice transplanted with BM cells that expressed a constitutively active c-kit mutant. Furthermore, BM levels of phosphorylated (phospho)-c-kit declined after AMD3100 administration and after CXCR4 deletion. In cells adhering to culture plates coated with vascular cell adhesion molecule 1, SDF-1 and stem cell factor increased phospho-c-kit levels, and AMD3100 treatment suppressed SDF-1-induced, but not SCF-induced, c-kit phosphorylation. SDF-1-induced c-kit phosphorylation also required the activation of Src nonreceptor tyrosine kinase: pretreatment of cells with a selective Src inhibitor blocked both c-kit phosphorylation and the interaction between c-kit and phospho-Src.
These findings indicate that the regulation of BM PC trafficking by SDF-1 and CXCR4 is dependent on Src-mediated c-kit phosphorylation.
骨髓（BM）祖细胞（PC）的动员在很大程度上受基质细胞衍生因子（SDF）-1 和 CXC 趋化因子受体（CXCR）4 之间相互作用的控制。缺血性损伤破坏了 SDF-1-CXCR4 相互作用，将 BM PC 释放到外周循环中，动员的细胞被募集到损伤组织中，并有助于血管生长。BM PC 也可以被药理学 CXCR4 拮抗剂 AMD3100 动员，但 SDF-1-CXCR4 信号通路的其他成分在很大程度上尚不清楚。膜结合酪氨酸激酶和干细胞因子受体 c-kit 也已被证明在 BM PC 动员和缺血组织修复中发挥关键作用。
研究 SDF-1-CXCR4 信号和 c-kit 活性在 BM PC 动员中的功能相互作用。
在 c-kit 激酶活性缺陷的小鼠或表达组成性激活 c-kit 突变体的 BM 细胞移植的小鼠中，AMD3100 给药未能动员 BM PC。此外，AMD3100 给药后和 CXCR4 缺失后，BM 中磷酸化（磷酸化）c-kit 的水平下降。在黏附在涂有血管细胞黏附分子 1 的培养板上的细胞中，SDF-1 和干细胞因子增加了磷酸化 c-kit 的水平，而 AMD3100 处理抑制了 SDF-1 诱导的但不是 SCF 诱导的 c-kit 磷酸化。SDF-1 诱导的 c-kit 磷酸化也需要Src 非受体酪氨酸激酶的激活：细胞用选择性 Src 抑制剂预处理可阻断 c-kit 磷酸化和 c-kit 与磷酸化 Src 之间的相互作用。
这些发现表明，SDF-1 和 CXCR4 对 BM PC 迁移的调节依赖于Src 介导的 c-kit 磷酸化。
