Irina Meln, Gretchen Wolff, Thomas Gajek, Johanna Koddebusch, Sarah Lerch, Liza Harbrecht, Wujun Hong, Irem Bayindir-Buchhalter, Damir Krunic, Hellmut G. Augustin, Alexandros Vegiopoulos
The quantity and anatomical distribution of adipose tissue are key drivers of the metabolic syndrome. Obesity and abdominal visceral adiposity in particular are major risk factors for type 2 diabetes and cardiovascular disorders. Accumulating evidence suggests that childhood and adolescence are critical periods for shaping adipose tissue properties. However, the control of adipose progenitor proliferation and hyperplasia by dietary components are poorly understood. Meln, Wolff, et al. have investigated the role of excess calories and dietary lipids in adipose tissue proliferative growth in juvenile mice and found that both differentially and synergistically drive adipose tissue proliferative growth and the programming of the metabolic syndrome in childhood.
Objective: The susceptibility to abdominal obesity and the metabolic syndrome is determined to a substantial extent during childhood and adolescence, when key adipose tissue characteristics are established. Although the general impact of postnatal nutrition is well known, it is not clear how specific dietary components drive adipose tissue growth and how this relates to the risk of metabolic dysfunction in adulthood.
Methods: Adipose tissue growth including cell proliferation was analyzed in juvenile mice upon dietary manipulation with in vivo nucleotide labeling. The proliferative response of progenitors to specific fatty acids was assayed in primary cultures. Long-term metabolic consequences were assessed through transient dietary manipulation post-weaning with a second obesogenic challenge in adulthood.
Results: Dietary lipids stimulated adipose tissue progenitor cell proliferation in juvenile mice independently of excess caloric intake and calorie-dependent adipocyte hypertrophy. Excess calories increased mitogenic IGF-1 levels systemically, whereas palmitoleic acid was able to enhance the sensitivity of progenitors to IGF-1, resulting in synergistic stimulation of proliferation. Early transient consumption of excess lipids promoted hyperplastic adipose tissue expansion in response to a second dietary challenge in adulthood and this correlated with abdominal obesity and hyperinsulinemia.
Conclusions: Dietary lipids and calories differentially and synergistically drive adipose tissue proliferative growth and the programming of the metabolic syndrome in childhood.