Figure 5.

TSP1 derivative, 3TSR, prevents CCMs and retinal vascular lesions in Krit1^ECKO mice. (A) Experimental protocol: vehicle or 3TSR (1.6 mg/Kg) was administered by retroorbital plexus injection at P5 and P6, and brains and retinas were analyzed at P7. (B) Prominent lesions are present in the cerebellum of Krit1^ECKO mice, whereas administration of 3TSR suppressed lesion formation. (C) Hematoxylin and eosin staining of cerebellar sections from Krit1^ECKO mice after treatment with 3TSR or vehicle (n = 4 mice in each group). (D) Representative image of whole-mount P7 retinal vasculature at the angiogenic growth front. The marked area in Krit1^ECKO whole-mount retina shows decreased areas of condensed vascular plexus in Krit1^ECKO treated with 3TSR compared with vehicle-treated Krit1^ECKO littermates (SEM, n = 8 mice in each group). (E) Quantification of lesion coverage in Krit1^ECKO mice treated with 3TSR or Vehicle (SEM, n = 8 mice in each group). (F) Administered 3TSR is present in CCM. 3TSR was injected retroorbitally into a Krit1^ECKO;Thbs1^−/− mouse. After 30 min, the mouse was killed, and its cerebellar cortex was stained for 3TSR (red, using anti-TSP1 antibodies) and endothelial marker PECAM1 (green); DAPI staining (blue) was used to reveal nuclei. 3TSR is observed in CCM. (G) Higher-magnification images of boxed areas in F. (F and G) Asterisks, vascular lumen of CCM. Bars: (B) 1 mm; (C and F) 100 µm; (D) 200 µm; (G) 50 µm. ***, P < 0.001 versus vehicle-treated Krit1^ECKO mice; determined by Student’s t test.