title: Distribution of angiotensin-(1-7) and ACE2 in human placentas of normal and pathological pregnancies.
abstract: This work was designed to study the expression of the vasodilator peptide angiotensin-(1-7) [Ang-(1-7)] and its generating enzyme (ACE2) in the uteroplacental interface. Placentas were obtained from 11 early pregnancy failures (5 miscarriages and 6 ectopic pregnancies), 15 normotensive, and 10 preeclamptic gestations. In placental villi, the main sites of immunocytochemical expression of Ang-(1-7) and ACE2 were the syncytiotrophoblast, cytotrophoblast, endothelium and vascular smooth muscle of primary and secondary villi. Syncitial Ang-(1-7) expression in samples obtained from miscarriages and ectopic pregnancies was increased compared to normal term pregnancy [2.0 (2.0-2.25 for the 25 and 75% interquartile range) vs 1.3 (1.0-1.9), p<0.01]. In the maternal stroma, Ang-(1-7) and ACE2 were expressed in the invading and intravascular trophoblast and in decidual cells in all 3 groups. Ang-(1-7) and ACE2 staining was also found in arterial and venous endothelium and smooth muscle of the umbilical cord. The expression of Ang-(1-7) and ACE2 was similar in samples obtained from normal term or preeclamptic pregnancies, except for increased expression of ACE2 in umbilical arterial endothelium in preeclampsia [0.5 (0.5-0.8) vs 0.0 (0.0-0.0), p<0.01]. The uteroplacental location of Ang-(1-7) and ACE2 in pregnancy suggests an autocrine function of Ang-(1-7) in the vasoactive regulation that characterizes placentation and established pregnancy.
authors.affiliation: Departamento Nefrología, Facultad Medicina Universidad Católica Santiago, Chile.
authors.forename: G
authors.initials: G
authors.lastname: Valdés
authors.forename: L A A
authors.initials: LA
authors.lastname: Neves
authors.forename: L
authors.initials: L
authors.lastname: Anton
authors.forename: J
authors.initials: J
authors.lastname: Corthorn
authors.forename: C
authors.initials: C
authors.lastname: Chacón
authors.forename: A M
authors.initials: AM
authors.lastname: Germain
authors.forename: D C
authors.initials: DC
authors.lastname: Merrill
authors.forename: C M
authors.initials: CM
authors.lastname: Ferrario
authors.forename: R
authors.initials: R
authors.lastname: Sarao
authors.forename: J
authors.initials: J
authors.lastname: Penninger
authors.forename: K B
authors.initials: KB
authors.lastname: Brosnihan
mesh_terms: D000803:Angiotensin I / Q000032:analysis* / Q000378:metabolism; D000085962:Angiotensin-Converting Enzyme 2; D002268:Carboxypeptidases / Q000032:analysis* / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D010446:Peptide Fragments / Q000032:analysis* / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A; D010920:Placenta / Q000737:chemistry* / Q000201:enzymology / Q000378:metabolism; D011225:Pre-Eclampsia / Q000378:metabolism; D011247:Pregnancy / Q000378:metabolism*; D011248:Pregnancy Complications / Q000201:enzymology / Q000378:metabolism*
chemical_list: D010446:Peptide Fragments; D000803:Angiotensin I; D002268:Carboxypeptidases; D007703:Peptidyl-Dipeptidase A; C000705307:ACE2 protein, human; D000085962:Angiotensin-Converting Enzyme 2; C118790:angiotensin I (1-7)