Secretomics uncovers blood-brain barrier mystery

Mystery of blood-brain barrier unraveled: researchers find substrates with high importance for the barrier. During neuroinflammation, immune cells such as leukocytes cross the blood-brain barrier. One key to this is the gelatinases matrix metalloproteinase (MMP)-2 and -9. Until now, the substrates of these enzymes involved in the process were unknown. Now, using a sensitive mass spectrometry-based secretome approach, researchers at the University of Münster and Bonn University Hospital (UKB) have succeeded in identifying hundreds of such molecules that are cleaved from the cell surface of astrocytes. In doing so, they have generated a unique database of MMP-2/-9 substrates specific to the formation and maintenance of the barrier as well as communication between astrocytes and neurons. The results have now been published in the journal ,,Science Advances".