Abstract Body (Do not enter title and authors here): Cardiovascular disease is the leading cause of death in the United States and stress is a significant risk factor in its pathogenesis. Exposure to stress during critical windows of development, such as pregnancy (i.e. maternal stress), may also affect offspring cardiovascular health. Previous studies and preliminary data from our lab have shown that maternal exercise improves the metabolic and cardiovascular health of adult offspring, including negating the detrimental effects of maternal distress such as high-fat diet and psychosocial stress. However, the underlying mechanisms remain unclear. This study aimed to determine the effects of maternal stress and exercise on adult offspring cardiac function in vivo and in vitro.
To investigate this, six-week-old C57BL/6 virgin female mice were divided into sedentary (static cages) or exercised-trained (cages with running wheels, -Ex) for two weeks before and throughout gestation. During pregnancy, dams were further subdivided into a group that was exposed to concentrated air particulate matter (PM_2.5; 6 h/day, 5 days/week) as a model of psychosocial stress (MatExpo and MatExpo-Ex groups) or to filtered air (MatFA and MatFA-Ex groups). All male and female offspring were sedentary and assessed throughout life. Body composition, glucose metabolism, and cardiovascular health were evaluated at 8, 16, 24, 36, and 52 weeks of age.
Our exciting preliminary data show that at 16 weeks, male offspring of stressed dams had impaired body composition, with increased fat mass and decreased lean mass (MatExpo vs. MatFA, P<0.05); these effects persisted into later life (52 weeks). Maternal exercise negated these detrimental changes. Additionally, maternal psychosocial stress impaired glucose tolerance in male offspring at 52 weeks (MatExpo vs MatFA, P<0.05). No significant effects were observed in female offspring. At 12 weeks, male offspring of exercised dams had increased left ventricular mass (MatFA and MatExpo vs MatExpo-Ex, P<0.05), and female offspring of exercised dams showed a trend toward improved cardiac health, as indicated by preserved ejection fraction and fractional shortening (MatExpo vs. MatExpo-Ex, P=0.08).
In summary, maternal psychosocial stress negatively impacted body composition throughout life and impaired metabolic health in male offspring, while maternal exercise protected offspring from these effects. Maternal exercise may also positively affect early-life cardiac health in males and female offspring.