BACKGROUND This study investigated the
therapeutic effects of the
peroxisome proliferator-activated receptor-γ (PPARγ) agonist
pioglitazone in ob/ob mice with
obesity-related glomerulopathy (ORG). MATERIAL AND METHODS A total of 24 mice were divided into 3 groups: wild-type C57BL/6 mice (n=8), ob/ob mice (n=8), and ob/ob mice receiving
pioglitazone treatment (n=8). Body mass,
blood glucose, serum
adiponectin (
ADP), and urine microalbumin (mALB) levels were determined. Renal histology was examined using light and electron microscopy.
Wilms tumor 1 (WT1), Zonula occludens-1 (ZO-1),
AMP activated protein kinase (AMPK), and
NADPH oxidase-4 (NOX-4) expression were evaluated by immunohistochemistry and Western blot. RESULTS Serum
ADP did not alter between weeks 0 and 12 in the control group, while the ob/ob mice showed a time-dependent decrease that was prevented by
pioglitazone. Urinary mALB did not alter between week 0 and 12 in the control group, but was higher in week 0 and week 12 in the ob/ob group.
Pioglitazone prevented the rise in urinary mALB in week 12. Histology revealed glomerulomegaly, mesangial proliferation,
focal segmental glomerulosclerosis, and foot processes fusion in the ob/ob group, which were ameliorated by
pioglitazone treatment. Compared to the control group, ob/ob mice had a higher kidney index and glomerular diameter, which were reduced by
pioglitazone treatment. Immunohistochemical and Western blot experiments revealed lower expression levels of WT1, ZO-1, and AMPK and higher NOX-4 expression level in the ob/ob group, which was prevented by
pioglitazone treatment. CONCLUSIONS
Pioglitazone, a PPARγ agonist, can prevent ORG, probably by reducing oxidative stress.