Mesothelium expression of integrins in vivo and in vitro.
OBJECTIVE
To characterize the expression of alpha subunits of integrin adhesion molecules in peritoneal tissue in vivo and in vitro.


METHODS
Peritoneum from the anterior abdominal wall (n = 22) and the serosa of the posterior uterus (n = 11) was obtained from women of reproductive age without endometriosis who were undergoing surgery for benign conditions. Immunohistochemical studies were performed on serial sections of peritoneum from the anterior abdominal wall, the uterine serosa, mesothelial monolayer cultures, and peritoneum explants from the abdominal wall using monoclonal antibodies to alpha subunits of integrin adhesion molecules. Electron microscopy was performed to localize these adhesion molecules in the mesothelium.


RESULTS
The mesothelial expression of alpha integrin subunits was identical in the anterior peritoneum and uterine serosa. In vivo the mesothelium strongly expressed alpha 2 and alpha 3 and variably expressed alpha 6. In the monolayer cultures there was moderate/strong staining for alpha 2, alpha 3, and alpha 5; there was minimal expression of alpha v. In the explants there was moderate/strong expression of alpha 2, alpha 3, alpha 5, and alpha v; alpha 6 was variably expressed. The ultrastructure of the mesothelium was unique in the anterior peritoneum, uterine serosa, and the monolayer cultures. The integrin subunits were distributed throughout the cytoplasm, were expressed in the plasma membrane, and were present on the surface (i.e., towards the peritoneal cavity) of the mesothelium.


CONCLUSIONS
Integrins are expressed by the mesothelium of the peritoneum. The mesothelium expression of integrins in vivo differs from that of the mesothelium integrin expression in monolayer culture and explant culture.
Witz
C A
CA
Department of Obstetrics and Gynecology, University of Texas Health Science Center at San Antonio 78284-7836, USA.
Montoya-Rodriguez
I A
IA
Miller
D M
DM
Schneider
B G
BG
Schenken
R S
RS
D015703:Antigens, CD / Q000032:analysis; D002478:Cells, Cultured; D004848:Epithelium / Q000737:chemistry / Q000648:ultrastructure; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D039423:Integrin alpha1; D039421:Integrin alpha2; D039422:Integrin alpha3; D039441:Integrin alpha4; D039482:Integrin alpha5; D039503:Integrin alpha6; D039564:Integrin alphaV; D016023:Integrins / Q000032:analysis*; D016253:Microscopy, Immunoelectron; D010537:Peritoneum / Q000737:chemistry*; D014599:Uterus / Q000737:chemistry*
D015703:Antigens, CD; D039423:Integrin alpha1; D039421:Integrin alpha2; D039422:Integrin alpha3; D039482:Integrin alpha5; D039503:Integrin alpha6; D039564:Integrin alphaV; D016023:Integrins; D039441:Integrin alpha4