Extracellular Vesicles Maintain Blood-Brain Barrier Integrity by the Suppression of Caveolin-1/CD147/VEGFR2/MMP Pathway After Ischemic Stroke

Abstract

Background

Ischemic stroke (IS) causes tragic death and disability worldwide. However, effective therapeutic interventions are finite. After IS, blood–brain barrier (BBB) integrity is disrupted, resulting in deteriorating neurological function. As a novel therapeutic, extracellular vesicles (EVs) have shown ideal restorative effects on BBB integrity post-stroke; however, the definite mechanisms remain ambiguous. In the present study, we investigated the curative effects and the mechanisms of EVs derived from bone marrow mesenchymal stem cells and brain endothelial cells (BMSC-EVs and BEC-EVs) on BBB integrity after acute IS.

Methods

EVs were isolated from BMSCs and BECs, and we investigated the therapeutic effect in vitro oxygen-glucose deprivation (OGD) insulted BECs model and in vivo rat middle cerebral artery occlusion (MCAo) model. The cell monolayer leakage, tight junction expression, and metalloproteinase (MMP) activity were evaluated, and rat brain infarct volume and neurological function were also analyzed.

Results

The administration of two kinds of EVs not only enhanced ZO-1 and Occludin expressions but also reduced the permeability and the activity of MMP-2/9 in OGD-insulted BECs. The amelioration of the cerebral infarction, BBB leakage, neurological function deficits, and the increasing ZO-1 and Occludin levels, as well as MMP activity inhibition was observed in MCAo rats. Additionally, the increased levels of Caveolin-1, CD147, vascular endothelial growth factor receptor 2 (VEGFR2), and vascular endothelial growth factor A (VEGFA) in isolated brain microvessels were downregulated after EVs treatment. In vitro, the employment of Caveolin-1 and CD147 siRNA partly suppressed the expressions of VEGFR2, VEGFA and MMP-2/9 activity and reduced the leakage of OGD insulted BECs and enhanced ZO-1 and Occludin expressions.

Conclusion

Our study firstly demonstrates that BEC and BMSC-EVs administrations maintain BBB integrity via the suppression of Caveolin-1/CD147/VEGFR2/MMP pathway after IS, and the efficacy of BMSC-EVs is superior to that of BEC-EVs.

Graphical Abstract

Keywords:

• extracellular vesicles
• ischemic stroke
• Caveolin-1
• CD147
• matrix metalloproteinase
• VEGFR2
• blood-brain barrier

Data Sharing Statement

All datasets that support the study are available from the corresponding author on reasonable request.

Ethics Approval

All animal experiments were approved and supervised by the Ethics Committee of the University of Macau. Animal welfare was ensured according to the Guide for the Care and Use of Laboratory Animals.

Acknowledgments

We thank Faculty of Health Sciences of University of Macau for their animal offering in this work. Additionally, we thank Fan Zhang for drawing work of graphic abstract, and we appreciate group members from Dr. Jiahong LU and Dr. Ying Zheng’s group for their kind technical assistance.

Disclosure

The authors declare no competing interests in this work.

Additional information

Funding

This work is funded by the University of Macau (MYRG2022-00221-ICMS, MYRG-CRG2022-00011-ICMS), Guangdong Natural Science Fund (General Programme, no. 2023A1515010034), and the National Natural Science Foundation of China (NSFC No. 82074051).