Differential expression of angiopoietin-1, angiopoietin-2, and Tie receptors in placentas from pregnancies complicated by placenta accreta.

Abstract

OBJECTIVE:

The purpose of this study was to investigate the differential expression of angiopoietin-1, angiopoietin-2, and Tie receptors (Tie-1 and Tie-2) in placentas from pregnancies complicated by placenta accreta.

STUDY DESIGN:

Paraffin sections of 46 placental specimens with (cases) and 46 without (controls) placenta accreta were studied immunohistochemically for the expression of Tie receptors and angiopoietin-2 in trophoblast populations. Protein levels of Tie receptors and angiopoietins were also examined by Western blot analysis and/or enzyme-linked immunosorbent assay. Controls were matched for gestational age in this case-control study.

RESULTS:

In both second and third trimesters, the percentage of intermediate/strong immunoreactivity of Tie-2 in the syncytiotrophoblast was significantly lower in cases than controls (P = .015 and .025, respectively). However, Tie-2 expression in the cytotrophoblastic and extravillous trophoblastic cells and Tie-1 in all trophoblast subpopulations were not significantly different between cases and controls (P > .05). The majority of Tie-2 expression, as demonstrated by Western blots, was consistent with the trends of immunohistochemical findings in the syncytiotrophoblast. Enzyme-linked immunosorbent assay in the placental lysates showed that women with placenta accreta demonstrated significantly higher angiopoietin-2 and lower Tie-2 concentrations than did women with normal pregnancies (P = .026 and .003, respectively). Placental angiopoietin-1 levels did not have any significance (P > .05). Also, angiopoietin-2 immunoreactivity in the syncytiotrophoblast was compatible with the finding demonstrated by enzyme-linked immunosorbent assay (P = .005 and .012, respectively).

CONCLUSION:

These observations suggest that the participation of up-regulated angiopoietin-2 and down-regulated Tie-2 in the placental tissues may indicate a role for these angiogenic factors in the development of placenta accreta.

• Authors: Jenn J Tseng, Shih L Hsu, Esther Shih C Ho, Yun T Hsieh, Mei C Wen, Min M Chou
• Journal: American journal of obstetrics and gynecology (Am J Obstet Gynecol) Vol. 194 Issue 2 Pg. 564-71 (Feb 2006) ISSN: 1097-6868 [Electronic] United States
• PMID: 16458662 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Angiopoietin-1
• Angiopoietin-2
• Receptor, TIE-1
• Receptor, TIE-2

Topics

• Angiopoietin-1 (metabolism)
• Angiopoietin-2 (metabolism)
• Blotting, Western
• Case-Control Studies
• Enzyme-Linked Immunosorbent Assay
• Female
• Gestational Age
• Humans
• Immunohistochemistry
• Placenta (metabolism)
• Placenta Accreta (metabolism)
• Pregnancy
• Pregnancy Trimester, Second (metabolism)
• Pregnancy Trimester, Third (metabolism)
• Receptor, TIE-1 (metabolism)
• Receptor, TIE-2 (metabolism)
• Trophoblasts (metabolism)