Table 1. Quantification of morphological changes caused by myc-SH3A expression in cultured ECs.

Fifty electron micrographs (30,000 × magnification) per experimental condition, containing ECs profiles of control and myc-SH3A transfected ECs were used to count the number of i) abnormal caveolae clusters open to the apical side of the endothelial PM, ii) apparently normal caveolae, omega-shaped, connected to the PM either directly or through short necks, iii) caveolae with their neck surrounded by staining dense collars and iv) caveolae with elongated necks (less than ½ of caveolar diameter). Quantification of these morphological characteristics and the measurement of the length PM on the electron micrograph used were performed as described previously [10, 28]. The data were normalized per 100 μm length PM and are averages ± SD of three independent experiments.

experimental condition	abnormal caveolae clusters open to the apical side of EC	apparently normal - omega shaped caveolae	single caveolae with staining dense rings around the neck	caveolae with elongated necks
control ECs	3 ± 0.4	82 ± 8	2 ± 0.3	8 ± 0.9
myc-SH3A transfected ECs	30 ± 5.3	15 ± 6.1	38 ± 4.2	34± 2.5