The Research On The Mechanism Of Renal Epithelial Cell Hurt Caused By Proton Pump Inhibitors(PPIs)

BackgroundWith the wide use of proton pump inhibitors in clinical practice,the adverse reactions of acute interstitial nephritis and chronic kidney disease by PPIs have been increasingly reported in recent years,and have drawn the attention of experts.However,the mechanism of renal hurt caused by PPIs remains unrevealed.This study focus on whether PPIs can induce Ca²⁺overload in NRK-52E through inhibiting the activity of Na⁺,K⁺-ATPase and Ca²⁺-ATPase in membrane and endoplasmic reticulum,which will lead to cell damage.MethodsCCK-8 method was utilized to measure the cell viability with different concentration of PPIs after 24 h.The Ca²⁺concentration was calculated by flow cytometer and laser scanning confocal microscope.Western blot was used to detect relative protein expression of Na⁺,K⁺-ATPase,Ca²⁺-ATPase,P38 MAPK and Caspase3 in NRK-52E.RT-PCR was used to detect mRNA expression levels of Na⁺,K⁺-ATPase and Ca²⁺-ATPase in NRK-52E.The relative protein expression of Na⁺,K⁺-ATPase was detected by Elisa kit.ResultsCCK-8 showed the viability of Hek-293 and NRK-52E was decreased with the increasing of PPIs concentration.Flow cytometry showed that the Ca²⁺concentration in NRK-52E increased with the increasing of lansoprazole and ilaprazole concentration.However,the differences of Ca²⁺concentration in NRK-52E among different concenteration levels was decreased after adding 10μmol/L KB-R7943before administration.The consequece between flow cytometer and laser scanning confocal microscope was similar.Western blot showed the relative protein expression of Na⁺,K⁺-ATPase was decreased with the increasing of lansoprazole and ilaprazole concentration.The relative protein expression of Ca²⁺-ATPase in membrane and endoplasmic reticulum was decreased in concentration of 50 and 100μmol/L,but this change was not abvious in other concentration points.The consequece between western blot and Real Time-PCR was similar.It turned out that the relative protein expression of Na⁺,K⁺-ATPase was decreased with the increasing of lansoprazole concentration through Elisa.Western blot indicated that relative protein expression of P38 MAPK and Caspase 3 were decreased with the increasing of lansoprazole concentration.ConclusionsOur results confirmed that PPIs can increase the Ca²⁺concentration in NRK-52E.The mechanism was that PPIs could inhibit the activity of Na⁺,K⁺-ATPase,and lead to the increasing of Na⁺,then the Ca²⁺concentration was increased by NCX.Ca²⁺overload can activate the expression of P38 MAPK and Caspase 3 and result in cell damage.However,the relationship between PPIs and Ca²⁺-ATPase in membrane and endoplasmic reticulum still need further research.