M1-type microglia-derived exosomes contribute to blood-brain barrier damage
Wen Jiang1, Yan Wu2, Ailan Pang2
1Department of Neurology, the First Affiliated Hospital of Kunming Medical University, No.295 Xichang Road, Kunming 650032, Yunnan, China; The Yunnan Province Clinical Research Center for Neurological Diseases, No.295 Xichang Road, Kunming 650032, Yunnan, China.
Background:
As a key substance for intercellular communication, exosomes could be a potential strategy for stroke treatment. Activated microglia disrupt the integrity of blood-brain barrier (BBB) to facilitate the stroke process. Hence, this study was designed to investigate the effect of microglia-derived exosomes on BBB cell model injury and to explore the underlying molecular mechanisms.
Methods:
M1 polarization of BV2 cells was induced with LPS and their derived exosomes were isolated. Astrocytes were cultured in primary culture and constructed with End3 cells as a BBB cell model. After co-culture with exosomes, the BBB cell model was examined for changes in TEER, permeability, and expression of BBB-related proteins (Claudin-1, Occludin, ZO-1 and JAM). Resting and M1-type BV2 cell-derived exosomes perform small RNA sequences and differentially expressed miRNAs (DE-miRNAs) are identified by bioinformatics.
Results:
M1-type BV2 cell-derived exosomes decreased End3 cell viability, and increased their apoptotic ratio. Moreover, M1 type BV2 cell-derived exosomes dramatically enhanced the permeability of BBB cell model, and diminished the TEER and BBB-related protein (Claudin-1, Occludin, ZO-1) expression. Notably, resting BV2 cell-derived exosomes had no effect on the integrity of BBB cell model. Sequencing results indicated that 71 DE-miRNAs were present in M1 BV2 cell-derived exosomes, and their targets mediated neurological development and signaling pathways such as MAPK and cAMP. RT-qPCR confirmed the differential expression of mmu-miR-125a-5p, mmu-miR-122b-3p, mmu-miR-139-3p, mmu-miR-330-3p, mmu-miR-3057-5p and mmu-miR-342-3p consistent with the small RNA sequence. Furthermore, Creb1, Jun, Mtor, Frk, Pabpc1 and Sdc1 are the most well-connected proteins in the PPI network.
Conclusion:
M1-type microglia-derived exosomes contribute to the injury of BBB cell model, which has the involvement of miRNAs. Our findings provide new perspectives and potential mechanisms for future M1 microglia-derived exosomes as therapeutic targets in stroke.
Insights
Microglia-derived exosomes, particularly from M1-activated cells, damage the blood-brain barrier (BBB) model by altering cell viability and permeability. These exosomes contain microRNAs (miRNAs) that may mediate BBB injury, offering potential therapeutic targets for stroke.
Area of Science:
- Neuroscience
- Cell Biology
- Biochemistry
Background:
- Exosomes facilitate intercellular communication and hold potential for stroke treatment.
- Activated microglia exacerbate stroke by disrupting the blood-brain barrier (BBB) integrity.
Purpose of the Study:
- To investigate the impact of microglia-derived exosomes on a BBB cell model.
- To elucidate the molecular mechanisms underlying exosome-mediated BBB injury.
Main Methods:
- M1 polarization of BV2 cells induced by LPS; isolation of derived exosomes.
- Construction of a BBB cell model using astrocytes and End3 cells.
- Analysis of exosome effects on TEER, permeability, BBB protein expression, and miRNA sequencing.
Main Results:
- M1-type microglia exosomes decreased cell viability and increased apoptosis in the BBB model.
- M1-type microglia exosomes enhanced BBB permeability, reduced TEER, and diminished tight junction protein expression.
- Sequencing identified 71 differentially expressed miRNAs in M1 exosomes targeting neurological pathways.
Conclusions:
- M1-type microglia-derived exosomes contribute to BBB cell model injury via miRNA involvement.
- Findings suggest M1 microglia exosomes as potential therapeutic targets for stroke treatment.
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