Two Health Sciences Academics Present Research on Placentas in Paris

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Two studies conducted by academics in the College of Health Sciences’ Optics and Imaging (O&I) Unit were presented at a Conference held recently in Paris by the International Federation of Placenta Associations (IFPA) and European Placenta Group (EPG).

The UKZN researchers are Professor Anita Naicker, who heads the O&I Unit, and Ms Anushka Ajith, recipient of a YW Loke New Investigator Travel Award which results from the endowment of YW (Charlie) Loke, Emeritus Professor of Reproductive Immunology at the University of Cambridge and member of both the IFPA and EPG.

An expert in hypertension research, Naicker presented a study titled, “Placental Expression of Soluble Endoglin in HIV-associated Preeclampsia”. Preeclampsia is a placental disease related to increased maternal and neonatal morbidity and mortality. Naicker said that in South Africa, the majority of the 14% of maternal deaths arising from hypertension are attributed to pre-eclampsia.

‘Increased placental levels of the anti-angiogenic factors – sEng and sFlt-1 – are correlated with interrupted angiogenic balance in preeclampsia development. Inconsistent data exist on the impact of HIV infection on the incidence of preeclampsia. Furthermore, the effects of HIV infection on placental levels of sEng in both normotensive and preeclamptic pregnancies are unknown,’ she said.

The study examined the placental immunoexpression of sEng, in HIV-negative and positive normotensive (N- and N+ respectively) and preeclamptic (P- and P+ respectively) pregnancies at term using immunohistochemistry and immunoelectron microscopy. Findings revealed that increased placental sEng immunoexpression results in placental vascular maladaptation and the reduced blood flow and consequent hypoxia.

‘Subsequent discharge of trophoblastic/necrotic tissue and antiangiogenic molecules lead to abnormal placentation and endothelial dysfunction evident in preeclampsia.  However, irrespective of the HIV status, placental sEng1 remains high in preeclampsia compared to normotensive pregnancies,’ said Naicker. 

Ajith’s study was titled, “Immunoelectron Localisation of TGF-ß1 in the Placental Bed of Normotensive and Pre-eclamptic Pregnancies”. She said the transforming growth factor beta 1 (TGF-ß1) gene produced at the fetomaternal interface is believed to be a major factor regulating trophoblast invasion in the uterus. The trophoblastic is the outermost layer of cells of the blastocyst that attaches the fertilised ovum to the uterine wall and serves as a nutritive pathway for the embryo. 

‘Trophoblast invasion involves several molecular steps including proliferation, a switch in integrin expression and fibronectin production, and TGF-b₁ is known to regulate these processes.  However, the specific mechanisms by which TGF-b₁ isoforms exert their pleiotropic actions and the extent to which these events are regulated during trophoblast adhesion, migration and invasion remains to be determined.  The aim of this study is to subcellularly immunolocalise TGF-b₁ within the placental bed of normal and preeclamptic pregnancies.’

No observable difference in TGF-b₁ immunolocalisation was noted between the normotensive and preeclamptic groups in the study. Also, understanding TGF-b₁ immunolocalisation in the placental bed was deemed critical for understanding the ECM deposition effect of this peptide that invoked a control on trophoblast cell migration. 

Ajith said she was fortunate to be among the young investigators who received the YW Loke Award. In addition to the prestige of the award and its contribution to a growing CV, it also offset the recipient’s travel expenses to the Conference.

Lunga Memela