Differential expression of caveolin-3 in mouse smooth muscle cells in vivo.
Expression of caveolin-1 and -3 in mouse smooth muscle cells in vivo was examined by immunohistochemistry. Caveolin-1 was detected in almost all smooth muscles examined, except for the pupillary dilator muscle, whereas caveolin-3 was present only in smooth muscles of some specific tissues. In the eye, the pupillary sphincter muscle was intensely positive for caveolin-3, whereas the ciliary muscle and pupillary dilator muscle were negative. In the gastrointestinal tract, caveolin-3 was detected in the inner circular layer, but not in the outer longitudinal layer. Vascular smooth muscle cells of the resistance-sized artery in the uterus and corpus cavernosum were intensely positive for caveolin-3, whereas those of the aorta were only weakly positive and those of the vena cava were negative. Caveolin-3 was also detected in smooth muscle cells of the urinary bladder, ureter, prostatic vas deferens, and seminal vesicle. The different levels of caveolin-3 expression among various smooth muscle tissues were confirmed by Western blot analysis. Even within the same muscle, the relative expression levels of caveolin-1 and -3 were variable among neighboring cells, suggesting distinct fine regulation of expression of these two caveolins. Moreover, even in the same cell, caveolin-1 and -3 showed different distributions. These results indicate that the two caveolins form distinct caveolae in smooth muscles, and that caveolin-1 and -3 serve different functions. Their differential expression may therefore be related to the functional diversity of smooth muscles.
Kogo
Hiroshi
H
Department of Anatomy and Molecular Cell Biology, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, 466-8550, Japan. hkogo@fujita-hu.ac.jp
Ito
Shin-ya
SY
Moritoki
Yoshinobu
Y
Kurahashi
Hiroki
H
Fujimoto
Toyoshi
T
D000818:Animals; D015153:Blotting, Western; D051242:Caveolin 1 / Q000378:metabolism; D051244:Caveolin 3 / Q000378:metabolism*; D002460:Cell Line; D004064:Digestive System / Q000166:cytology / Q000378:metabolism; D005123:Eye / Q000166:cytology / Q000378:metabolism; D005260:Female; D005835:Genitalia / Q000166:cytology / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D014018:Tissue Distribution; D014551:Urinary Tract / Q000166:cytology / Q000378:metabolism
C495548:Cav3 protein, mouse; D051242:Caveolin 1; D051244:Caveolin 3