John’s Master degree work on DNA methylation changes in preeclampsia has come out in two publications. The first study demonstrates how many changes in DNA methylation there are in placentas with preeclampsia—Thousands! So many its hard to know what to say except –wow! How does the placenta support the baby at all when so much has changed? Of course, such placentas tend to show obvious pathology and what we are seeing may be a reflection of that altered cellular composition and behaviour–but the placenta is so complex, it is difficult to sort out what is really going on. Regardless of the why, we think this could be very useful for identifying new clinical markers of preeclampsia, as well as understanding how the placenta adapts and changes to different situations.
- Widespread DNA hypomethylation at gene enhancer regions in placentas associated with early-onset pre-eclampsia. Blair JD, Yuen RK, Lim BK, McFadden DE, von Dadelszen P, Robinson WP. Mol Hum Reprod. 2013 Oct;19(10):697-708.
This second follow-up paper was fun as we were able to connect our newer work on preeclampsia with our older work on confined placental mosaicism (CPM). Paul Yong (former PhD student) had published back in 2006 that pregnancies associated with CPM for trisomy 16 were at high risk of preeclampsia. So we decided to go back and compare methylation changes in these placentas with those from chromosomally normal preeclampsia. Many similarities were found, though as expected, CPM16 had even more methylation changes! These changes seem largely to arise later in development rather than being set in the first trimester.
- Overlapping DNA methylation profile between placentas with trisomy 16 and early-onset preeclampsia. Blair JD, Langlois S, McFadden DE, Robinson WP. Placenta. 2014 Mar;35(3):216-22.