Aix-Marseille Université, Vascular Research Center of Marseille (VRCM), INSERM UMR-S 1076, Faculté de Pharmacie, 27 Bd Jean Moulin, 13385 Marseille Cedex 05, France.
Institut des Maladies Métaboliques et Cardiovasculaires, INSERM U1048, Université de Toulouse III, 1 Av Jean Poulhès, BP 84225, 31432 Toulouse Cedex 4, France.
Cardiovasc Res. 2014 Jul 1;103(1):121-30. doi: 10.1093/cvr/cvu104. Epub 2014 Apr 17.
Cell therapy based on endothelial colony-forming cells (ECFCs) is a promising option for ischaemic cardiovascular diseases. A better understanding of the mechanisms by which these cells promote revascularization remains a critical challenge to improving their therapeutic potential. We aimed to identify the critical mechanisms involved in the revascularization activity of ECFCs by using the paracrine properties of mesenchymal stem cells (MSC).
Conditioned medium from human bone marrow-derived MSCs (MSC-CM) increased the angiogenic activity of cord blood ECFCs in vitro (proliferation, migration, and pseudo-tube formation), the survival of ECFCs in mice (Matrigel Plug assay), and the capacity of ECFCs to promote the recovery of blood perfusion in mice with hindlimb ischaemia. Furthermore, the capillary density in ischaemic gastrocnemius muscle was significantly increased in mice transplanted with the ECFCs pre-treated with the MSC-CM. The enhancement of ECFCs activity involved the up-regulation of sphingosine kinase 1 (SphK1) expression and activity. The inhibition of SphK1 in ECFCs by using an inhibitor or a siRNA knockdown of SphK1 prevented the stimulation of the ECFCs induced by the MSC-CM. The improvement of ECFC activity by MSC-CM also involved the up-regulation of sphingosine-1-phosphate receptor 1 (S1P1) and a S1P/S1P1/3-dependent mechanism. Finally, we showed that the stimulation of ECFCs with exogenous S1P increased angiogenesis and promoted blood perfusion in hindlimb ischaemia.
The up-regulation of SphK1 and S1P-dependent pathways is critical for the angiogenic/vasculogenic activity of ECFCs. The identification of this pathway provides attractive targets to optimize cell-based therapy for revascularization in ischaemic diseases.
基于内皮祖细胞（ECFCs）的细胞治疗是缺血性心血管疾病的一种很有前途的选择。更好地了解这些细胞促进血管生成的机制仍然是提高其治疗潜力的关键挑战。我们旨在通过间充质干细胞（MSC）的旁分泌特性来确定与 ECFC 血管生成活性相关的关键机制。
人骨髓来源的 MSC 的条件培养基（MSC-CM）增加了脐带血 ECFC 的体外血管生成活性（增殖、迁移和假管形成）、ECFC 在小鼠中的存活（Matrigel Plug 测定）以及 ECFC 促进小鼠后肢缺血血灌注恢复的能力。此外，与用 MSC-CM 预处理的 ECFC 移植的小鼠的缺血性比目鱼肌中的毛细血管密度显著增加。ECFC 活性的增强涉及鞘氨醇激酶 1（SphK1）表达和活性的上调。使用抑制剂或 SphK1 的 siRNA 敲低抑制 ECFC 中的 SphK1 可阻止 MSC-CM 诱导的 ECFC 刺激。MSC-CM 对 ECFC 活性的改善还涉及鞘氨醇-1-磷酸受体 1（S1P1）和 S1P/S1P1/3 依赖性机制的上调。最后，我们表明，外源性 S1P 刺激 ECFC 增加血管生成并促进后肢缺血的血灌注。
SphK1 和 S1P 依赖性途径的上调对 ECFC 的血管生成/血管生成活性至关重要。该途径的鉴定为优化缺血性疾病血管再通的基于细胞的治疗提供了有吸引力的靶点。
