Developmental programming of obesity by maternal exposure to concentrated ambient PM_2.5 is maternally transmitted...

Obesity is an uncontrolled global epidemic and one of the leading global public health challenges. Maternal exposure to ambient fine particulate matter (PM_2.5) may adversely program offspring's adiposity, suggesting a specialized role of PM_2.5 pollution in the global obesity epidemic. However, the vulnerable window for this adverse programming and how it is cross-generationally transmitted have not been determined. Therefore, in the present study, female C57Bl/6 J mice were exposed to filtered air (FA) or concentrated ambient PM_2.5 (CAP) during different periods, and the development and adulthood adiposity of their four-generational offspring were assessed.

Our data show that the pre-conceptional but not gestational exposure to CAP was sufficient to cause male but not female offspring's low birth weight, accelerated postnatal weight gain, and increased adulthood adiposity. These adverse developmental traits were transmitted into the F₂ offspring born by the female but not male F₁ offspring of CAP-exposed dams. In contrast, no adverse development was noted in the F₃ offspring.

The present study identified a pre-conceptional window for the adverse programming of adiposity by maternal exposure to PM_2.5, and showed that it was maternally transmitted into the third generation. These data not only call special attention to the protection of women from exposure to PM_2.5, but also may facilitate the development of intervention to prevent this adverse programming.