Colocalization between caveolin isoforms in the intestinal smooth muscle and interstitial cells of Cajal of the Cav1+/+ and Cav1-/- mouse

Confocal microscopic images were obtained from the immunohistochemical sections of jejeunum to determine the localization/colocalization between caveolin-1, caveolin-2 and caveolin-3 in intestinal smooth muscle cells (SMCs) and interstitial cells of Cajal (ICC) of Cav1(+/+) and Cav1(-/-) mouse. Intestinal regions were segmented [inner circular muscle (icm), outer circular muscle (ocm), myenteric plexus region (mp), and longitudinal muscle (lm)] by LSM 5 and analyzed by ImageJ to show Pearson's correlation (r (p)) and overlap coefficient (r) of colocalization. In the intestine of Cav1(+/+), caveolin-1 (cav1) was colocalized with caveolin-2 (cav2) and caveolin-3 (cav3). Cav2 also was well colocalized with cav3. In the intestine of Cav1(-/-), cav1 and cav2 were absent in all images, but reduced cav3 was expressed in ocm. Caveolae were present in cell types with cav1 in Cav1(+/+), and present with cav3 in ocm of Cav1(-/-). C-kit occurred in deep muscular plexus (ICC-DMP) and myenteric plexus (ICC-MP), in both Cav1(+/+) and Cav1(-/-), and colocalized with cav1 and cav2 in the intestine of Cav1(+/+). Cav3 was absent/present at low immunoreactivity in ICC-DMP and ICC-MP of the intestines of Cav1(+/+) and Cav1(-/-). To conclude, cav1 is necessary for the expression of cav2 in SMC and ICC of intestine and facilitates, but is not necessary for the expression of cav3.