A study in the journal Nature Cell Biology has uncovered information about a key stage that human embryonic cells must pass through just before an embryo implants. The research, led by UCLA biologist Amander Clark, could help explain certain causes of infertility and spontaneous miscarriage.
A team led by Clark, a UCLA professor of molecular cell and developmental biology, set out to find how epigenomic changes — non-genetic influences on gene expression — in human embryonic stem cells could explain why some embryos are not viable. They started by analyzing cells within the early embryo; these cells are pluripotent, meaning that they can turn into any cell within the human body.
After a human embryo is fertilized and before it implants in the uterine lining, cells in the embryo are in a very immature state of pluripotency called the “naive” state. Little is known about the naive state, but scientists believe that if embryonic cells cannot first enter this state, the embryo is not viable and a miscarriage would occur. The findings, Clark said, provide “new information about a time in the lifecycle that we know little about. Fundamental knowledge like this could help better predict infertility or embryo quality.”
The study also could lead to important advances in an area of medicine that historically has been underfunded and underappreciated — in part because the subject of infertility is sometimes seen as taboo and because it doesn’t attract the attention of deadly diseases like cancer.
“People who experience infertility and miscarriage may tell close friends or family, but too often, these issues are not discussed,” Clark said. “But infertility is a significant health concern. It deserves our attention, and we as a society need to be more open about it.”