PPARγ-mediated advanced glycation end products regulate neural stem cell proliferation but not neural differentiation through the BDNF-CREB pathway

AimsTo investigate the roles of PPARγ in advanced glycation end product (AGE)-mediated characteristics of neural stem cells (NSCs) and the molecular mechanisms of action.MethodsWe prepared pLentiLox3.7 lentiviral vectors expressing short hairpin RNA (shRNA) against PPARγ and transduced NSCs. MTT absorbance and cell counts were used to assay cell growth, and cell differentiation was analysed by confocal laser-scanning and western blots for the expression of MAP2/nestin. The protein and gene expression of the BDNF-CREB pathway components were examined by western blotting and real-time PCR.ResultsImmunoblot analysis indicated that shRNA delivered by lentiviral vectors silenced PPARγ expression in NSCs. The proliferation of NSCs and expression of BDNF pathway components dropped in AGE-BSA culture medium (400 mg/L and 200 mg/L) on Day 3 and Day 7, respectively (all P < 0.001). PPARγ-silenced NSCs exhibited a significant increase in cell growth and expression of BDNF pathway components compared with NSCs incubated with AGE-BSA (all P < 0.001). Immunocytochemistry and western blotting analysis showed that AGE-BSA (400 mg/L) induced a significant decrease in the expression of MAP2 both in NSCs and PPARγ-silenced NSCs, as standardised by nestin. There was no significant difference between NSCs and PPARγ-silenced NSCs in the presence of AGE-BSA.ConclusionsPPARγ plays roles in the AGE-mediated regulation of NSC proliferation but not neural differentiation through the BDNF-CREB pathway.

► pLL3.7 lentiviral vector expressing short hairpin RNA against PPARγ was designed. ► AGE can inhibit the proliferation, differentiation and BDNF pathway of NSCs. ► PPARγ-RNAi attenuated the effect of AGE on cell growth of NSCs and expression of BDNF. ► PPARγ-RNAi was independent of the effect of AGE on cell differentiation of NSCs.