Abstract: Objective To investigate the effect of peroxisome proliferator-activated receptors γ (PPARγ) on insulin receptor
substrate-4 (IRS-4) gene expression in the brain. Methods Primarily cultured cortical neurons from E17-18 Sprague Dawley
rats, after 1 week of plating, were exposed to 10 μmol/L PPARγ agonist rosiglitazone for 0, 1, 4 or 24 h. Adult C57BL/6J mice or
conditional brain PPARγ knock-out mice (B-PPARγ-KO, BKO) received an intraperitoneal injection of rosiglitazone in 10%
DMSO at 12 mg/kg or injection of the same volume of saline containing 10% DMSO. The effect of rosiglitazone on the survival
of the neurons was examined by MTT assay. The expression of IRS-4 mRNA was analyzed by real-time quantitative PCR.
Results The survival of the cortical neurons showed no significant difference between the agonist groups and the control
group. The expression of IRS-4 mRNA was significantly up-regulated in the cortical tissues and neurons of the agonist groups
compared with the control groups (P<0.05), but in BKO mice without treatment, IRS-4 mRNA expression was significantly
down-regulated (P<0.05). Conclusion PPARγ can enhance the expression of IRS-4 mRNAin the brain.