The prolactin receptor is expressed in macrophages within human carotid atherosclerotic plaques: a role for prolactin in atherogenesis?
Atherosclerotic vascular disease is the consequence of a chronic inflammatory process, and prolactin has been shown to be a component of the inflammatory response. Additionally, recent studies indicate that prolactin contributes to an atherogenic phenotype. We hypothesized that this may be the result of a direct effect of prolactin on atherogenesis through activation of the prolactin receptor. Human carotid atherosclerotic plaques were obtained from patients by endarteriectomies. The mRNA of prolactin receptor, but not of prolactin, was detected in these atherosclerotic plaques by quantitative real-time PCR. In situ hybridization confirmed the expression of the prolactin receptor in mononuclear cells. Analysis at the protein level using immunohistochemistry and immunoelectron microscopy revealed that the prolactin receptor was abundantly present in macrophages near the lipid core and shoulder regions of the plaques. Our findings demonstrate that the prolactin receptor is present in macrophages of the atherosclerotic plaque at sites of most prominent inflammation. We therefore propose that prolactin receptor signaling contributes to the local inflammatory response within the atherosclerotic plaque and thus to atherogenesis.
Department of Vascular Medicine, Academic Medical Center, 1105 AZ Amsterdam, The Netherlands. a.q.reuwer@amc.uva.nl
Anne Q
AQ
Reuwer
Marco
M
van Eijk
Felicia M
FM
Houttuijn-Bloemendaal
Chris M
CM
van der Loos
Nike
N
Claessen
Peter
P
Teeling
John J P
JJ
Kastelein
Jörg
J
Hamann
Vincent
V
Goffin
Jan H
JH
von der Thüsen
Marcel Th B
MT
Twickler
Jan
J
Aten
D050197:Atherosclerosis / Q000209:etiology*; D002340:Carotid Artery Diseases / Q000378:metabolism* / Q000473:pathology*; D016893:Carotid Stenosis / Q000378:metabolism*; D003199:Computer Systems; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007249:Inflammation / Q000209:etiology; D018836:Inflammation Mediators / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism*; D008297:Male; D016253:Microscopy, Immunoelectron; D016133:Polymerase Chain Reaction; D011388:Prolactin / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D011981:Receptors, Prolactin / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014018:Tissue Distribution
D018836:Inflammation Mediators; D012333:RNA, Messenger; D011981:Receptors, Prolactin; D011388:Prolactin