The effect of resveratrol on the expression of adiponectin receptors in intermittent high glucose-cultured rat mesangial cells

Abstract

Objective To study the effects and mechanisms of resveratrol (Resv) on the expression of adiponectin receptors ( AdipoR1 and AdipoR2 ) in rat mesangial cells (MCs) cultured in intermittent high glucose medium.Methods The MCs cultured in normal glucose ( 5.6 mmol/L) medium were transfected by the plasmid vector of the FoxO1 short hairpin RNAs ( FoxO1 shRNA ),and then cultured in intermittent high glucose medium (5.6mmol/L or 30 mmol/L,alternately every 8 hours ) and resveratrol ( Resv 20 μmol/L).The MCs cultured in normal glucose (5.6 mmol/L) medium served as normal glucose control group (NG),and the MCs exposed to iutermittent high glucose medium were divided into five groups:intermittent high glucose group (IHG),IHG+Resv group,IHG+FoxO1 shRNA group,IHG+ Resv + FoxO1 shRNA group,IHG + Negative control group ( shNC ),each group was cultured for 72 h.The level of reactive oxygen species (ROS) was assessed by Fluorescence microplate reader.The mRNA levels of Sirt1,Foxo1,AdipoR1,and AdipoR2 were assessed by RT-RCR.The protein levels of FoxO1,phosphorylation FoxO1 ( p-FoxO1 ),AdipoR1,and AdipoR2 were assessed by Western blotting.Results ( 1 )Compared with NG,intermittent high glucose significantly decreased the mRNA expression of Sirt1,but markedly increased the level of p-FoxO1.Furthermore,the mRNA and protein expression levels of AdipoR1 were obviously decreased while the level of ROS was enhanced in IHG ( all P＜0.05 ).(2) Compared with IHG,the mRNA and protein expression levels of FoxO1 and AdipoR1 were inhibited,but the level of ROS was enhanced in group IHG+FoxO1 shRNA ( all P＜0.05 ).( 3 ) Compared with IHG,after treating with Resv,the mRNA expression level of Sirtl was increased,whereas the level of p-FoxO1 was decreased.Moreover,the mRNA and protein levels of AdipoR1 was increased while the level of ROS was lowered in group IHG+Resv (all P＜0.05 ).(4) Compared with group IHG+Resv,the mRNA and protein levels of FoxO1 and AdipoR1 were inhibited,but the level of ROS was increased in group IHG+Resv+FoxO1 shRNA (all P＜O.05).(5) In addition,the mRNA and protein expression level of AdipoR2 showed no significant difference among these groups ( P＞0.05 ).Conclusion ( 1 ) Resveratrol significantly increases the expression of AdipoR1 in MCs induced by intermittent high glucose.( 2 ) FoxO1 plays an important role in regulating the expression of AdipoR1 by resveratrol. Key words: Resveratrol; Intermittent high glucose; Adiponectin receptor; Forkhead transcription factor O1