Imaging screen of bioactive compounds repurposes the BRAF inhibitor dabrafenib against vascular lesions in cerebral cavernous malformation models
- An image-based screen of about 5,200 bioactive compounds in CCM3-deficient mouse endothelial cells nominated dabrafenib, an approved BRAF inhibitor, for restoring cell junctions and barrier function.
- In acute and chronic CCM mouse models, treatment lowered brain lesion burden and leakiness, and corrected retinal vessel abnormalities.
- In human brain endothelial cells, the drug affected ERK5-KLF2/4 signaling and actin stress fibers; the BRAF-independent framing indicates BRAF is not the key mediator.
💡 Points
A junction-and-barrier imaging readout in mouse CCM3-null endothelium is a reasonable phenotypic filter, but it leaves the target unassigned: if BRAF is not the mediator, ERK5-KLF2/4 engagement by dabrafenib could be off-target polypharmacology, and the safety margin cannot be judged without knowing it. Before extending this, I would want brain-endothelial exposure at the effective dose and a target-deconvolution result, since lesion reduction alone gives nothing to optimize against.