Obesity exacerbates
aging-induced
adipose tissue dysfunction. This study aimed to investigate the effects of long-term
exercise on inguinal
white adipose tissue (iWAT) and interscapular
brown adipose tissue (iBAT) of
aged obese mice. Two-month-old
female mice received a
high-fat diet for 4 months. Then, six-month-old
diet-induced obese
animals were allocated to sedentarism (DIO) or to a long-term treadmill
training (DIOEX) up to 18 months of age. In exercised
mice, iWAT depot revealed more adaptability, with an increase in the expression of
fatty acid oxidation genes (Cpt1a, Acox1), and an amelioration of the inflammatory status, with a favorable modulation of pro/antiinflammatory
genes and lower
macrophage infiltration. Additionally, iWAT of trained
animals showed an increment in the expression of
mitochondrial biogenesis (Pgc1a, Tfam, Nrf1),
thermogenesis (Ucp1), and
beige adipocytes genes (Cd137, Tbx1). In contrast, iBAT of
aged obese mice was less responsive to
exercise. Indeed, although an increase in functional
brown adipocytes genes and
proteins (Pgc1a, Prdm16 and UCP1) was observed, few changes were found on
inflammation-related and
fatty acid metabolism genes. The
remodeling of iWAT and iBAT depots occurred along with an improvement in the HOMA index for
insulin resistance and in
glucose tolerance. In conclusion, long-term
exercise effectively prevented the loss of iWAT and iBAT thermogenic properties during
aging and
obesity. In iWAT, the long-term
exercise program also reduced the inflammatory status and stimulated a fat-oxidative
gene profile. These
exercise-induced
adipose tissue adaptations could contribute to the beneficial effects on
glucose homeostasis in
aged obese mice. (AU)