DNA damage and the activation of the p53 pathway mediate alterations in metabolic and secretory functions of adipocytes

B Vergoni, PJ Cornejo, J Gilleron, M Djedaini… - Diabetes, 2016 - Am Diabetes Assoc
B Vergoni, PJ Cornejo, J Gilleron, M Djedaini, F Ceppo, A Jacquel, G Bouget, C Ginet…
Diabetes, 2016Am Diabetes Assoc
Activation of the p53 pathway in adipose tissue contributes to insulin resistance associated
with obesity. However, the mechanisms of p53 activation and the effect on adipocyte
functions are still elusive. Here we found a higher level of DNA oxidation and a reduction in
telomere length in adipose tissue of mice fed a high-fat diet and an increase in DNA damage
and activation of the p53 pathway in adipocytes. Interestingly, hallmarks of chronic DNA
damage are visible at the onset of obesity. Furthermore, injection of lean mice with …
Activation of the p53 pathway in adipose tissue contributes to insulin resistance associated with obesity. However, the mechanisms of p53 activation and the effect on adipocyte functions are still elusive. Here we found a higher level of DNA oxidation and a reduction in telomere length in adipose tissue of mice fed a high-fat diet and an increase in DNA damage and activation of the p53 pathway in adipocytes. Interestingly, hallmarks of chronic DNA damage are visible at the onset of obesity. Furthermore, injection of lean mice with doxorubicin, a DNA damage-inducing drug, increased the expression of chemokines in adipose tissue and promoted its infiltration by proinflammatory macrophages and neutrophils together with adipocyte insulin resistance. In vitro, DNA damage in adipocytes increased the expression of chemokines and triggered the production of chemotactic factors for macrophages and neutrophils. Insulin signaling and effect on glucose uptake and Glut4 translocation were decreased, and lipolysis was increased. These events were prevented by p53 inhibition, whereas its activation by nutlin-3 reproduced the DNA damage-induced adverse effects. This study reveals that DNA damage in obese adipocytes could trigger p53-dependent signals involved in alteration of adipocyte metabolism and secretory function leading to adipose tissue inflammation, adipocyte dysfunction, and insulin resistance.
Am Diabetes Assoc