A potential role for N-cadherin in mediating endothelial cell-smooth muscle cell interactions in the rat vasculature.
BACKGROUND
The cadherins are a family of calcium-dependent cell adhesion molecules that play a critical role in morphogenetic cell interactions in the embryo. N-cadherin has been identified in neural and non-neural tissues, including developing muscle; however, there are few reports of N-cadherin expression in adult mammals. We attempted to identify N-cadherin in the rat vasculature and to ask whether it has a role in mediating vascular cell interactions.


METHODS
Vascular tissues were isolated from Fischer rats and analyzed immunohistochemically and by Western blotting using pan-cadherin and N-cadherin antibodies. Anti-N-cadherin antibodies were used in an in vitro cell adhesion assay to determine if N-cadherin mediates interactions between smooth muscle cells (SMC) and endothelial cells (EC).


RESULTS
Western blot analysis of vascular tissues reveals a 135 kilodalton (kd) band that is recognized by anti-N-cadherin antibodies. N-cadherin localizes in the rat aorta to the endothelium and to the smooth muscle cell layer beneath the internal elastic membrane. A cell adhesion assay demonstrates that rat SMCs and ECs adhere to each other in a Ca(2+)-dependent manner, and an anti-N-cadherin antibody inhibits approximately 25% of this adhesion.


CONCLUSIONS
Our data indicate that N-cadherin is expressed in large vessels of the rat and is capable of mediating EC-SMC adhesion in vitro. It is noteworthy that N-cadherin localizes to a population of SMCs in the rat aorta adjacent to ECs suggesting that N-cadherin may mediate EC-SMC interactions in vivo.
Gilbertson-Beadling
S K
SK
Upjohn Company, Kalamazoo, Michigan.
Fisher
C
C
D000818:Animals; D001011:Aorta / Q000166:cytology; D015153:Blotting, Western; D015820:Cadherins / Q000502:physiology*; D002448:Cell Adhesion; D002450:Cell Communication; D004730:Endothelium, Vascular / Q000166:cytology*; D007150:Immunohistochemistry; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D051381:Rats; D011916:Rats, Inbred F344
D015820:Cadherins