Internship: Development of a zebrafish model for the pathological breakdown of the blood-brain barrier

Loss of the proper function of the neuroprotective blood-brain barrier (BBB) is a critical and chronic event in numerous neurological disorders. Leakage of plasma proteins can lead to vasogenic edema and significant clinical problems such as neuronal morbidity and mortality. More research is needed to get more insight into the molecular and cellular processes in the pathological breakdown of the BBB.

The aim of our study is to develop a zebrafish model that can be employed to study pathological breakdown of the BBB. No such model presently exists. Two reporter lines with fluorescent labeled blood vessels, Tg(Fli1:EGFP) and Tg(Kdrl:RFP), are in our possession and can be used in combination with fluorescently labeled tracer molecules to study vascular permeability. Breakdown of the BBB will be induced by several pathological conditions, including hypoxia, high VEGF, and high glucose that will be administered by addition to the embryo medium in which the larvae are maintained. After different time points fluorescent tracers will be injected intracardially, embryos will be mounted in 1% low-melting agarose and vascular leakage will be assessed by using time-lapse confocal microscopy. In addition, if time permits, reporter lines will be cross-bred with mutant lines to study essential genes that are involved in BBB breakdown or maintenance of an intact BBB. 

We will study this in great detail, not only using time-lapse confocal imaging, but also transmission electron microscopy to study ultrastructural cell components as tight junctions and caveolar vesicles.

Contact
Dr. Ingeborg Klaassen: i.klaassen @ amsterdamumc.nl