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Generation of an Immortalized Murine Brain Microvascular Endothelial Cell Line as an In Vitro Blood Brain Barrier Model
Published on: August 29, 2012
ZO-1 expression is suppressed by GM-CSF via miR-96/ERG in brain microvascular endothelial cells
Hu Zhang1, Shuhong Zhang1, Jilin Zhang1
1Department of Developmental Cell Biology, Cell Biology Division, Key Laboratory of Cell Biology, Ministry of Public Health, Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, Liaoning Province, PR China.
Abstract:
The level of granulocyte-macrophage colony-stimulating factor (GM-CSF) increases in some disorders such as vascular dementia, Alzheimer's disease, and multiple sclerosis. We previously reported that in Alzheimer's disease patients, a high level of GM-CSF in the brain parenchyma downregulated expression of ZO-1, a blood-brain barrier tight junction protein, and facilitated the infiltration of peripheral monocytes across the blood-brain barrier. However, the molecular mechanism underlying regulation of ZO-1 expression by GM-CSF is unclear. Herein, we found that the erythroblast transformation-specific (ETS) transcription factor ERG cooperated with the proto-oncogene protein c-MYC in regulation of ZO-1 transcription in brain microvascular endothelial cells (BMECs). The ERG expression was suppressed by miR-96 which was increased by GM-CSF through the phosphoinositide-3 kinase (PI3K)/Akt pathway. Inhibition of miR-96 prevented ZO-1 down-regulation induced by GM-CSF both in vitro and in vivo. Our results revealed the mechanism of ZO-1 expression reduced by GM-CSF, and provided a potential target, miR-96, which could block ZO-1 down-regulation caused by GM-CSF in BMECs.
Insights
Granulocyte-macrophage colony-stimulating factor (GM-CSF) reduces ZO-1 expression in brain endothelial cells. Inhibiting miR-96 blocks this effect, offering a potential therapeutic target for neurological disorders.
Area of Science:
- Neuroscience
- Molecular Biology
- Immunology
Background:
- Elevated granulocyte-macrophage colony-stimulating factor (GM-CSF) is linked to neurological disorders like Alzheimer's disease.
- GM-CSF downregulates ZO-1, a key blood-brain barrier protein, facilitating monocyte infiltration.
- The precise molecular mechanism of GM-CSF's effect on ZO-1 remains elusive.
Purpose of the Study:
- To elucidate the molecular mechanism by which GM-CSF downregulates ZO-1 expression in brain microvascular endothelial cells (BMECs).
- To identify potential therapeutic targets for mitigating GM-CSF-induced blood-brain barrier dysfunction.
Main Methods:
- Investigated the roles of transcription factors ERG and c-MYC in ZO-1 regulation.
- Examined the involvement of microRNA-96 (miR-96) in the GM-CSF signaling pathway.
- Utilized in vitro and in vivo models to assess the effects of miR-96 inhibition.
Main Results:
- ERG and c-MYC were identified as key regulators of ZO-1 transcription in BMECs.
- GM-CSF increases miR-96 expression via the PI3K/Akt pathway, which in turn suppresses ERG.
- Inhibition of miR-96 successfully prevented GM-CSF-induced ZO-1 downregulation both in vitro and in vivo.
Conclusions:
- GM-CSF downregulates ZO-1 expression by increasing miR-96, which suppresses ERG transcription in BMECs.
- Targeting miR-96 presents a promising strategy to counteract GM-CSF-mediated blood-brain barrier disruption.
