For Dr. Jennifer Adibi, a good day in the laboratory is one in which her trophoblasts are thriving. The cells, which are the first to differentiate from a fertilized egg (they later develop into the placenta) require as much care, feeding and nurturing as a slew of laboratory animals.
As every mother knows, parenting involves unceasing communication between parent and child. What few realize is that the conversation begins long before birth, as the placenta supplies a developing fetus with oxygen, food and up-to-the minute news of the environment outside the womb.
So when something goes wrong with placental development, that conversation can go awry and influence health across the lifespan. This potential is what Adibi is trying to decode in her laboratory: whether phthalates — a group of industrial chemicals used to make plastics more flexible — change the hormonal development of infants in utero.
Adibi’s path to trophoblast housekeeping began in Russia. As a young post-graduate there in the early 1990s, she met scientists studying the impacts that years of chemical and weapons manufacturing along the Volga, Europe’s longest river, had left on the people who lived along it. Until that point, Adibi, a Russian studies major, thought her life’s work would be translating Russian. Instead she went to Columbia and Harvard to study the relationship between humans and the chemicals around them.
Adibi began her advanced studies in the fields of environmental health and epidemiology. The research methods she learned ranged from laboratory work to asking groups of people with and without a disease the same questions, to see if any differences in their answers might point to why some got sick and others did not.
A class in molecular epidemiology sparked her interest in how trophoblasts, cells that arise shortly after a sperm fertilizes an egg, can serve as “medical records” of sorts. By taking samples of the placenta at the time of delivery, scientists can learn about what might have happened during pregnancy. Excited about the potential to decipher medical history using a microscope instead of a health survey, Adibi began to look for molecular clues to find out how chemicals affect fetal development.
Specifically, Adibi now looks for clues about phthalates. A recent study by another group of UCSF scientists found that virtually every pregnant woman in the United States has phthalates in her body.
We know that phthalates in a mother’s body can reach the developing embryo and fetus. Studies on animals have demonstrated that developmental exposure to phthalates leaves a mark on the reproductive system, resulting in abnormal genitalia, poor sperm quality and testicular cancer later in life.
How to prove or disprove that the same is true of humans? Phthalates are so ubiquitous in our culture that every young child will come into continual contact with them as it grows and develops.
Few have looked at the placenta as a place where the fate of these exposures may be written. It’s more typical to conduct animal studies, or to use surveys to collect data about possible exposures before birth. Trophoblast research is difficult and expensive, but it would be groundbreaking to not only show that certain chemicals have an early impact on fetal development, but how that impact actually occurs.
Typically, to understand prenatal exposure and health impacts, scientists use animal models or collect and analyze human data about preconception and prenatal exposures via surveys or other means and see what happens to children. Adibi looks at in utero exposures to see not if but how chemicals change the developing fetus.
We know enough about phthalates right now to advise preventing exposure by avoiding drinking out of squishy water bottles, staying away from scented products, and avoiding eating food packaged in plastic containers. In the future,Adibi’s research findings could have an effect on how phthalates are regulated.
It’s the potential for these kinds of groundbreaking results that keeps Adibi in the lab, carrying out tedious “trophoblast housekeeping.” Stay tuned to this column to see how her research develops.
Photograph courtesy of Premasagar.