中国神经再生研究(英文版) ›› 2025, Vol. 20 ›› Issue (1): 224-233.doi: 10.4103/NRR.NRR-D-22-01292

• 原著:脑损伤修复保护与再生 • 上一篇    下一篇

miR-27a升高的脑内皮细胞源性小细胞外囊泡可促进缺血性脑卒中恢复

  


  • 出版日期:2025-01-15 发布日期:2025-01-15
  • 基金资助:
    美国国立卫生研究院(NIH)R01 NS111801和美国心脏协会(American Heart Association)资助

Small extracellular vesicles derived from cerebral endothelial cells with elevated microRNA 27a promote ischemic stroke recovery

Yi Zhang1, *, Zhongwu Liu1, Michael Chopp1, 2, Michael Millman1, Yanfeng Li1, Pasquale Cepparulo1, †, Amy Kemper3, Chao Li1, Li Zhang1, Zheng Gang Zhang1, *   

  1. 1Department of Neurology, Henry Ford Hospital, Detroit, MI, USA; 2Department of Physics, Oakland University, Rochester, MI, USA; 3Department of Pathology, Henry Ford Hospital, Detroit, MI, USA
  • Online:2025-01-15 Published:2025-01-15
  • Contact: Yi Zhang, PhD, yzhang3@hfhs.org; Zheng Gang Zhang, MD, PhD, zzhang1@hfhs.org.
  • Supported by:
    This work was supported by the NIH grants, R01 NS111801 (to ZGZ) and American Heart Association 16SDG29860003 (to YZ).

摘要:

轴突重塑是缺血性脑修复过程的一个重要方面,有助于自发性功能恢复。作者既往的体外研究表明,从缺血性大脑内皮细胞(CEC-sEVs)中分离出的外泌体/小细胞外囊泡(sEVs)能促进胚胎皮质神经元的轴突生长,而且缺血性 CEC-sEVs 中的 miR-27a 水平升高。为了解与非工程CEC-sEVs治疗相比,富含miR-27a水平的正常CEC-sEVs(27a-sEVs)是否能进一步促进轴突生长,并改善缺血性脑卒中后的神经功能预后。实验从转染了慢病毒 miR-27a 表达载体的健康小鼠 CEC 的条件培养基中分离出27a-sEVs。以转染了干扰载体(Scra-sEVs)的CECs中分离出的小Evs作为对照。成年雄性小鼠接受永久性大脑中动脉阻塞,然后随机接受27a-sEVs或Scra-sEVs治疗。与Scra-sEVs治疗的脑缺血小鼠相比,使用27a-sEVs治疗可显著增强梗死周围区和去神经支配侧脊髓灰质的皮质脊髓束中的轴突和棘突,并显著改善神经功能预后。体外研究显示,携带miR-27a水平下降的 CEC-sEV 会抑制 27a-sEV 增强的轴突生长。超微结构分析显示,系统给药的27a-sEV优先定位于突触前活性区,而定量反转录聚合酶链反应和Western印迹分析显示,梗死周围区miR-27a升高,轴突抑制蛋白Semaphorin 6A和Ras同源家族成员A水平减少。Clathrin依赖性内吞途径的阻断大大减少了27a-sEVs的神经元内化。 以上证据表明,脑内皮细胞源性小细胞外囊泡中的27a-sEVs可促进缺血性脑卒中轴突重塑和改善神经功能预后。抑制轴突抑制蛋白(如 Semaphorin 6A)可能有助于 27a-sEVs 对轴突重塑的有益作用。

https://orcid.org/0000-0001-8373-017X (Yi Zhang); https://orcid.org/0000-0002-9018-7723 (Zheng Gang Zhang)

Abstract: Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery. Our previous in vitro study demonstrated that exosomes/small extracellular vesicles (sEVs) isolated from cerebral endothelial cells (CEC-sEVs) of ischemic brain promote axonal growth of embryonic cortical neurons and that microRNA 27a (miR-27a) is an elevated miRNA in ischemic CEC-sEVs. In the present study, we investigated whether normal CEC-sEVs engineered to enrich their levels of miR-27a (27a-sEVs) further enhance axonal growth and improve neurological outcomes after ischemic stroke when compared with treatment with non-engineered CEC-sEVs. 27a-sEVs were isolated from the conditioned medium of healthy mouse CECs transfected with a lentiviral miR-27a expression vector. Small EVs isolated from CECs transfected with a scramble vector (Scra-sEVs) were used as a control. Adult male mice were subjected to permanent middle cerebral artery occlusion and then were randomly treated with 27a-sEVs or Scra-sEVs. An array of behavior assays was used to measure neurological function. Compared with treatment of ischemic stroke with Scra-sEVs, treatment with 27a-sEVs significantly augmented axons and spines in the peri-infarct zone and in the corticospinal tract of the spinal grey matter of the denervated side, and significantly improved neurological outcomes. In vitro studies demonstrated that CEC-sEVs carrying reduced miR-27a abolished 27a-sEV-augmented axonal growth. Ultrastructural analysis revealed that 27a-sEVs systemically administered preferentially localized to the pre-synaptic active zone, while quantitative reverse transcription-polymerase chain reaction and Western Blot analysis showed elevated miR-27a, and reduced axonal inhibitory proteins Semaphorin 6A and Ras Homolog Family Member A in the peri-infarct zone. Blockage of the Clathrin-dependent endocytosis pathway substantially reduced neuronal internalization of 27a-sEVs. Our data provide evidence that 27a-sEVs have a therapeutic effect on stroke recovery by promoting axonal remodeling and improving neurological outcomes. Our findings also suggest that suppression of axonal inhibitory proteins such as Semaphorin 6A may contribute to the beneficial effect of 27a-sEVs on axonal remodeling.

Key words: axonal remodeling, cerebral endothelial cells, exosomes, miR-27a, mitochondria, Semaphorin 6A, small extracellular vesicles, stroke