New research sheds light on the intricate link between maternal obesity, offspring health, and the role of exercise during pregnancy. A study published in the open-access journal PLOS Biology by Laura Dearden and Susan Ozanne from the MRC Metabolic Diseases Unit, Institute of Metabolic Science, University of Cambridge, UK, along with colleagues, reveals how maternal obesity affects offspring eating behaviors through the overexpression of the microRNA miR-505-5p in the hypothalamus.
Understanding the Impact of Maternal Obesity
Studies have consistently shown that offspring born to obese mothers face a heightened risk of obesity and type 2 diabetes. While genetic and environmental factors play pivotal roles in this association, emerging evidence suggests that maternal obesity can disrupt the hypothalamus, a brain region crucial for regulating nutrition sensing and energy balance.
Insights from Animal Models
Mice born to obese mothers exhibited elevated levels of miR-505-5p in their hypothalamus from fetal stages through adulthood. This heightened expression correlated with increased food intake and a preference for high-fat diets. Remarkably, the study found that maternal exercise during pregnancy mitigated the impact of obesity on both miR-505-5p levels and eating behaviors in offspring.
Unraveling Molecular Mechanisms
Cell culture experiments revealed that exposing hypothalamic neurons to long-chain fatty acids and insulin, common in pregnancies complicated by obesity, induced miR-505-5p expression. The microRNA was identified as a key regulator of pathways involved in fatty acid uptake and metabolism, thereby impairing the brain’s ability to sense high-fat food consumption.
Implications and Preventative Measures
Several genes regulated by miR-505-5p have been linked to high body mass index in human genetic studies, highlighting the clinical relevance of these findings. The study underscores the critical role of prenatal factors in shaping offspring health and emphasizes the potential of maternal exercise as a preventive measure against offspring obesity.
Concluding Remarks
The authors stress the significance of their findings, emphasizing that obesity during pregnancy induces changes in the offspring’s brain that predispose them to increased high-fat food consumption and obesity risk. Importantly, the study demonstrates that moderate exercise during pregnancy, independent of weight loss, can counteract these adverse effects, providing valuable insights into interventions to mitigate the intergenerational cycle of obesity.
