Effect of miRNAs on barrier properties of brain endothelial cells
To date, little is known about the molecular mechanisms that disturb BBB function during neuroinflammatory diseases such as MS and stroke. Recently, partner 12 discovered that miRNAs, small regulators of gene transcription, are downregulated quite early in the brain vessels of MS patients. Importantly, overexpressing identified miRNAs in in vitro systems induced a stronger BBB, indicating that miRNAs have a crucial role in regulating early inflammatory events at the endothelial level. Through this approach partner 12 has now discovered a panel of miRNAs critical in functioning of the BBB.
These data suggest that miRNAs may provide targets to treat neuroinflammatory disorders at an early stage. Within this project partner 12 would like to delineate the downstream targets of identified miRNAs (in particular miR125a and miR30) critical in BBB functioning by proteomics and reveal whether selected miRNAs can limit cellular migration and the expression of adhesion molecules. Moreover, partner 12 has shown that ABC transporters play a role in the immune process and will identify new pathways regulating ABC transporter expression that are under the control of identified miRNAs. In addition, partner 12 will determine how these miRNAs are regulated due to immune cell interaction using co-culture systems of brain endothelial cells and different phenotypes of monocyte-derived macrophages and in animal models for neuroinflammation. To investigate whether these miRNAs constitute an innovative means of repairing an inflamed BBB, partner 12 will apply miRNAs to animals with neuroinflammation (EAE and stroke) and determine the level of cell infiltration into the CNS using intravital microscopy in cooperation with partner 5. Animals will be scored as regards improved mobility, BBB leakage, and neuroinflammation using MRI in cooperation with partner 8.
- Kooij G, Mizee M, van Horssen J, Drexhage J, van der Pol SMA, van het Hof AJ, Scheffer G, Scheper R, Dijkstra CD, van der Valk P, de Vries HE (2011) ATP-binding cassette transporters mediate chemokine (C-C motif) ligand 2 secretion from reactive astrocytes: relevance to multiple sclerosis pathogenesis. Brain 134: 555-570
- Smits M, Wurdinger T, van het Hof B, Drexhage JA, Geerts D, Wesseling P, Noske DP, Vandertop WP, de Vries HE, Reijerkerk A.Myc-associated zinc finger protein (MAZ) is regulated by miR-125b and mediates VEGF-induced angiogenesis in glioblastoma. FASEB J. 2012 Jun;26(6):2639-47
Tasks and methodology
- EAE models
- MRI investigations of BBB integrity
- Intravital detection of cell infiltration into the CNS
- in vitro co-culture of brain endothelial cells and different phenotypes of monocyte-derived macrophages
University of Bern, In vivo tracking of cells, 7 month