Neurovascular Research Laboratory, Vall d'Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain.
J Cell Mol Med. 2013 Dec;17(12):1543-53. doi: 10.1111/jcmm.12116. Epub 2013 Aug 15.
The enhancement of endogenous angiogenesis after stroke will be critical in neurorepair therapies where endothelial progenitor cells (EPCs) might be key players. Our aim was to determine the influence of cerebral ischaemia and the role of matrix metalloproteinase-9 (MMP-9) on the angiogenic function of EPCs. Permanent focal cerebral ischaemia was induced by middle cerebral artery (MCA) occlusion in MMP-9/knockout (MMP-9/KO) and wild-type (WT) mice. EPCs were obtained for cell counting after ischaemia (6 and 24 hrs) and in control animals. Matrigel(™) assays and time-lapse imaging were conducted to monitor angiogenic function of WT and MMP9-deficient EPCs or after treatment with MMP-9 inhibitors. Focal cerebral ischaemia increased the number of early EPCs, while MMP-9 deficiency decreased their number in non-ischaemic mice and delayed their release after ischaemia. Late outgrowth endothelial cells (OECs) from ischaemic mice shaped more vessel structures than controls, while MMP-9 deficiency reduced the angiogenic abilities of OECs to form vascular networks, in vitro. Treatment with the MMP inhibitor GM6001 and the specific MMP-9 inhibitor I also decreased the number of vessel structures shaped by both human and mouse WT OECs, while exogenous MMP-9 could not revert the impaired angiogenic function in MMP-9/KO OECs. Finally, time-lapse imaging showed that the extension of vascular networks was influenced by cerebral ischaemia and MMP-9 deficiency early during the vascular network formation followed by a dynamic vessel remodelling. We conclude that focal cerebral ischaemia triggers the angiogenic responses of EPCs, while MMP-9 plays a key role in the formation of vascular networks by EPCs.
中风后内源性血管生成的增强将在神经修复治疗中至关重要，其中内皮祖细胞（EPCs）可能是关键因素。我们的目的是确定脑缺血对 EPC 血管生成功能的影响以及基质金属蛋白酶-9（MMP-9）的作用。通过大脑中动脉（MCA）闭塞在 MMP-9/敲除（MMP-9/KO）和野生型（WT）小鼠中诱导永久性局灶性脑缺血。在缺血后（6 和 24 小时）和对照动物中获得 EPC 进行细胞计数。进行 Matrigel（™）测定和延时成像，以监测 WT 和 MMP9 缺陷的 EPC 的血管生成功能，或在 MMP-9 抑制剂处理后。局灶性脑缺血增加了早期 EPC 的数量，而 MMP-9 缺乏减少了非缺血小鼠中的数量，并延迟了其在缺血后的释放。来自缺血小鼠的晚期外生内皮细胞（OECs）形成的血管结构比对照多，而 MMP-9 缺乏减少了 OECs 形成血管网络的血管生成能力，在体外。用 MMP 抑制剂 GM6001 和特异性 MMP-9 抑制剂 I 处理也减少了由人 WT 和鼠 WT OEC 形成的血管结构的数量，而外源性 MMP-9 不能恢复 MMP-9/KO OECs 受损的血管生成功能。最后，延时成像显示血管网络的延伸受到脑缺血和 MMP-9 缺乏的影响，在血管网络形成早期影响血管网络的延伸，随后是动态的血管重塑。我们得出结论，局灶性脑缺血触发 EPC 的血管生成反应，而 MMP-9 在 EPC 形成血管网络中起关键作用。
