It rears its head around tax time and lunges at you when your experiments fail. It can be good for you, but usually stinks….STRESS. It goes without saying that stress in any form is best avoided. This is especially true if you happen to be an expecting mother who’s currently eating for two, as the impact of stress on the development of offspring in animals is well documented. Mounting evidence suggests that prenatal maternal stress (PNMS) is associated with childhood obesity and other metabolic related complications in humans. Sources of prenatal stress are vast, and may include rare extreme environmental conditions, such as the Canadian 1998 Ice Storm.
Remember “Project Ice Storm”? Well, in case you have forgotten here’s a refresher. A team of Scientists from Canada’s McGill University studied a cohort of women who were pregnant during the “greatest natural disaster in Canadian history”— the 1998 Ice Storm.
Last year the group reported that the ice storm, which left many people without power and other amenities for a long time, created extremely stressful conditions for the pregnant women. Additionally, the environmentally induced stress was found to be associated with DNA methylation at numerous CpG sites, affecting genes involved in immunity and other important biological functions.
This time around Cao-Lei and colleagues decided to extend their study to children born to women affected by the 1998 ice storm.
To accomplish this, the team examined the impact of prenatal “objective exposure and subjective distress” on the BMI and central adiposity (waist-to-height ratio) of children at age 13.5. The team also wanted to determine the role of DNA methylation on mediating prenatal maternal stress and its concomitant impact on growth.
The team discovered that:
- Objective and subjective PNMS correlated with central adiposity, but only objective PNMS predicted BMI.
- DNA methylation minimizes the impact of objective PNMS on both central adiposity and BMI by regulating key immune genes (LTA, NFKBIA, and PIK3CD), and type-1 and -2 diabetes mellitus pathways.
The authors conclude that “DNA methylation is a potential mechanism involved in the long-term adaptation and programming of the genome in response to early adverse environmental factors”.
Get protected at Epigenetics, June 2015.