Mesenchymal stem cells injected into carotid artery to target focal brain injury home to perivascular space
Mesenchymal stem cells injected into carotid artery to target focal brain injury home to perivascular space
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DOI：
10.7150/thno.43169
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发表时间：
2020-01-01
期刊：
影响因子：
12.4
通讯作者：
Janowski, Miroslaw
中科院分区：
文献类型：
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作者：
Andrzejewska, Anna;Dabrowska, Sylwia;Janowski, Miroslaw
基本原理：间充质干细胞（MSC）的突破性发现及其多方面的益处导致其在实验医学（包括神经病学）中的广泛应用。有效地将MSC递送到中枢神经系统的受损区域可能是决定结果的关键因素。由ITGA 4和ITGB 1基因编码的整合素VLA-4（α 4 β 1）是由白细胞表达的粘附分子，其负责通过细胞对接至表达VCAM 1受体的发炎血管壁来启动它们的渗出。VLA-4的这一功能在神经干细胞和神经胶质祖细胞中重现。因此，将该工具作为驱动MSC外渗的工具进行研究是谨慎的。由于MSC天然表达ITGB 1亚基，我们决定仅用ITGA 4补充它们。方法：将ITGA 4基因转染的MSCs和未转染的MSCs分别注射到局灶性脑损伤大鼠的右侧颈内动脉内。在接下来的三天里，通过磁共振成像导航动物脑中MSC的存在。死后用免疫组织化学方法分析移植细胞相对于脑血管的位置和宿主的免疫反应。此外，在体外transwell migration assay.Results：无论是幼稚和ITGA 4过表达细胞的趋化性的修改和幼稚MSC检查在IA输液后的头两天内仍然在血管腔内。在第三天，39%的mRNA-ITGA 4修饰的MSC和51%的幼稚MSC归巢到损伤区域中的血管周围空间（p=NS）。观察到大鼠脑中幼稚和mRNA-ITGA 4转染的hBM-MSC的逐渐减少。mRNA-ITGA 4转染的MSC似乎比幼稚细胞更容易被吞噬。此外，在体外研究表明，匀浆从受伤的大脑排斥迁移的间充质干细胞，证实了观察到的不完全extravasation invivo.Conclusions：总之，IA移植的间充质干细胞能够归巢到血管周围的空间，一个组成部分的神经血管单位，这可能有助于更换受伤的周细胞，促进恢复中枢神经系统功能的一个关键因素。mRNA-ITGA 4转染改善了细胞与血管的对接，但这种净效益在接下来的两天内消失，因为大多数移植细胞从脑血管中快速清除，无论其工程状态如何。mRNA-ITGA 4转染的缺点在移植后第3天变得明显，因为存活率较低且对宿主免疫攻击的脆弱性较高。
Rationale: The groundbreaking discovery of mesenchymal stem cells (MSCs) with their multifaceted benefits led to their widespread application in experimental medicine, including neurology. Efficient delivery of MSCs to damaged regions of the central nervous system may be a critical factor in determining outcome. Integrin VLA-4 (alpha 4 beta 1) coded by ITGA4 and ITGB1 genes is an adhesion molecule expressed by leukocytes, which is responsible for initiation of their diapedesis through cell docking to the inflamed vessel wall expressing VCAM1 receptor. This function of VLA-4 has been recapitulated in neural stem cells and glial progenitors. Thus, it was prudent to investigate this tool as a vehicle driving extravasation of MSCs. Since MSCs naturally express ITGB1 subunit, we decided to supplement them with ITGA4 only. The purpose of our current study is to investigate the eventual fate of IA delivered ITGA4 engineered and naive MSCs.Methods: mRNA-ITGA4 transfected and naive MSCs were injected to right internal carotid artery of rats with focal brain injury. Through next three days MSC presence in animals' brain was navigated by magnetic resonance imaging. Transplanted cell location relative to the brain blood vessels and host immunological reaction were analyzed post-mortem by immunohistochemistry. The chemotaxis of modified and naive MSCs was additionally examined in in vitro transwell migration assay.Results: Both naive and ITGA4-overexpressing cells remained inside the vascular lumen over the first two days after IA infusion. On the third day, 39% of mRNA-ITGA4 modified and 51% naive MSCs homed to perivascular space in the injury region (p=NS). The gradual decrease of both naive and mRNA-ITGA4 transfected hBM-MSCs in the rat brain was observed. mRNA-ITGA4 transfected MSCs appeared to be more vulnerable to phagocytosis than naive cells. Moreover, in vitro study revealed that homogenate from the injured brain repels migration of MSCs, corroborating the incomplete extravasation observed in vivo.Conclusions: In summary, IA transplanted MSCs are capable of homing to the perivascular space, an integral part of neurovascular unit, which might contribute to the replacement of injured pericytes, a critical element facilitating restoration of CNS function. The mRNA-ITGA4 transfection improves cell docking to vessel but this net benefit vanishes over the next two days due to fast clearance from cerebral vessels of the majority of transplanted cells, regardless of their engineering status. The drawbacks of mRNA-ITGA4 transfection become apparent on day 3 post transplantation due to the lower survival and higher vulnerability to host immune attack.