Distribution of Angiotensin-(1-7) and ACE2 in Human Placentas of Normal and Pathological Pregnancies

• Published in: Placenta (Eastbourne) Vol. 27; no. 2; pp. 200 - 207
• Main Authors: Valdés, G., Neves, L.A.A., Anton, L., Corthorn, J., Chacón, C., Germain, A.M., Merrill, D.C., Ferrario, C.M., Sarao, R., Penninger, J., Brosnihan, K.B.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.02.2006; Elsevier
• Subjects: Angiotensin converting enzyme 2; Angiotensin I - analysis; Angiotensin I - metabolism; Angiotensin-(1-7); Biological and medical sciences; Carboxypeptidases - analysis; Carboxypeptidases - metabolism; Embryology: invertebrates and vertebrates. Teratology; Female; Fundamental and applied biological sciences. Psychology; Humans; Hypertension; Immunohistochemistry; Peptide Fragments - analysis; Peptide Fragments - metabolism; Peptidyl-Dipeptidase A; Placenta - chemistry; Placenta - enzymology; Placenta - metabolism; Pre-Eclampsia - metabolism; Preeclampsia; Pregnancy; Pregnancy - metabolism; Pregnancy Complications - enzymology; Pregnancy Complications - metabolism; Renin angiotensin system; Hypertension; Pregnancy; Renin angiotensin system; Angiotensin converting enzyme 2; Angiotensin-(1-7); Preeclampsia; Human; Vertebrata; Mammalia; Placenta; Fetal membrane; Angiotensin; Distribution; Normal
• ISSN: 0143-4004; 1532-3102
• DOI: 10.1016/j.placenta.2005.02.015

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.