’Hyperglycaemic Memory’ In Human Mesangial Cells Mediated By Local Aldosterone System

Objective: To investigate the effect of reversal of high glucose tonormal glucose on local aldosterone system, reactive oxygen species (ROS)and expression of oncofetal fibronectin (oncofetal FN) mRNA in Humanmesangial cells（HMCs），and explore the relationships of local aldosteronesystem with ROS production and expression of oncofetal FN mRNA.Methods: HMCs were divided into following groups：normal glucosegroup（NG,5mmol/L D-glucose for2days），high glucose group (HG,25mmol/L D-glucose for2days), memory group (M,25mmol/L D-glucose for2daysâ†'5mmol/L D-glucose for4days)，memory+eplerenone group（MY，25mmol/LD-glucose for2daysâ†'5mmol/LD-glucose+10μmol/L eplerenone for4days），normal glucose+eplerenone group（NY，5mmol/L D-glucose for2daysâ†'5mmol/L D-glucose+10μmol/L eplerenone for4days），stable normal glucose group (SN,5mmol/L D-glucose for6days).The mRNA expression of Aldosterone synthase （CYP11B2），11β-hydroxysteroid dehydrogenase type2（11βHSD2）and oncofetal FNwere detected by RT-PCR. CYP11B2protein expression was detected by Western-blot. Aldosterone level in cells culture supernatant was detected byradioimmunoassay. The expression and translocation of Mineralocorticoidreceptor(MR) protein was observed by laser scanning confocalmiccopy（L SCM）. ROS levels were tested by fluorescence miccopy andfluorescence microplate reader.Results:（1）CYP11B2mRNA and protein expression in group HGand in group M all increased, with3.45,2.09and3.14,2.06folds of groupNG, respectively (all P<0.05). The aldosterone level of HMCs culturesupernatant in group HG and in group M was also increased，being2.01,1.81folds of those in group NG (P<0.05)， MR was activated andtranslocated from cytosol to nucleus in group HG and in group M.Quantitative analysis showed the ratio of cytosol/nucleus fluorescenceintensity in group HG and in group M was decreased，with30%and21%ofgroup NG (P<0.05).（2）Oncofetal FN mRNA expression and ROS levelsin group HG and in group M were increased，with2.23,1.99and2.16,1.90folds of group NG, respectively (P<0.05). Compared with group M,oncofetal FN mRNA expression and ROS levels in group MY wassignificantly decreased，with35%and51%of group M.Conclusion: The effect of reversal of high glucose to normal glucoseleads to injury of HMCs via activation of local aldosterone system.