Objective By using primary cultured mouse renal tubular epithelial cells (TECs) to develop an in vitro model of simulated ischemia-reperfusion (IR) injury.Methods The outer medulla of C57BL/6J mouse kidney was flushed and primary cultured after digestion in type Ⅰ collagenase,and then immunocytochemical staining was used to verify TECs.Primary cultured TECs were immersed in mineral oil to simulate the ischemic process,and 60 min later the whole culture medium was added to simulate reperfusion process.The cells were collected and RAN was extracted at indicated time points after medium replacement.The expression of TNF-α,IL-1β and IL-6 was detected by using real-time fluorescence quantitative RT-PCR. The culture supernatants were collected at 24 h after medium replacement for detection of the expression of cytokine protein by using ELISA.Results Primary cultured TECs were identified by cobblestone-shaped morphology and then verified by cytokeratin 18 (CK18) staining.In TECs of IR group after medium replacement the mRNA expression of TNF-α,IL-1β and IL-6 was higher than in control group.The expression of TNF-α after medium replacement was increased to a peak level at 0.5 h,about (24.45 ±6.51) times (P＜0.01 ) higher than the control group,and gradually declined thereafter.The mRNA expression of IL-1β after medium replacement kept an increasing tendency,about ( 15.27 ± 4.29) times (P＜0.05) higher than the control group at 6 h,and that of IL-6 after medium replacement was increased to a peak level at 3 h,about ( 11.19 ±4.55) times (P＜0.01) higher than the control group. In the IR group at 24 h after medium replacement,the protein expression of NF-α,IL-1β and IL-6 in the supernatants was significantly higher than in the control group.Conclusion High purity of primary cultured TECs was achieved from the outer medulla of mouse kidney by separation and digestion.The in vitro model of simulated IR in primary cultured mouse renal TECs was successfully created using paraffin oil.

ObjectiveTo investigate the effect and underling mechanism of water-soluble CO-releasing molecules (CORM-3)on the alleviation of allograft rejectionafter mouse kidney transplantation.Methods A mice kidney transplantation model was established using C.FVB-Tg (Itgax-DTR/GFP)57Lan/J or C57BL/6J (H-2Kb) mice as donors,and Balb/c (H-2Kd) mice as recipients.After donor nephrectomy,kidney was preserved in UW solution which contained CORM-3 or iCORM (inactive CO-releasing molecules) for 24 h in 4℃.Recipient survival after removal of both na? ve kidneys,serum creatinine as well as graft histology was observed.In the C.FVB-Tg(ItgaxDTR/GFP) 57Lan/J donors,rDCs were acquired in vitro and selected by magnetic cell sorting (MACS) after graft nephrectomy.The expression of activation markers,CD80 and CD86,on rDC was assessed by using flow cytometry.ResultsThe graft medium survival time was 40.5 days in the iCORM group and 70 days in the CORM-3 group respectively (P＜0.05).CORM-3 preserved the graft function as shown by significantly lower serum creatinine (P＜0.05; or P＜0.01) and alleviated graft pathology injury.Diffuse infiltration of mononuclear cells in the interstitial tissues,moderate tubulitis and partial glomerular sclerosis were found in the iCORM graft kidney,while the CORM-3 graft kidney displayed almost normal histology.Meanwhile,CORM-3 suppressed the expression of CD80 and CD86 in donor-derived rDC.ConclusionCORM-3 can alleviate allograft rejection,prolong the graft survival,and improve kidney function in mouse kidney transplantation,probably via inhibiting rDC activation.

ObjectiveTo investigate the role of aldehyde dehydrogenase 2 (ALDH2) in the protection against tubular epithelial cells (TEC) ischemia/reperfusion (IR)injury induced by pretreatment with ethanol.Methods Mouse primary cultured TECs were pretreated with 50 mM ethanol 3 h before simulation of in vitro IR.Lactate dehydrogenase (LDH) release was assessed to evaluate the protection of ethanol pretreatment on IR injury.Thereafter,TECs were transfected with a negative control siRNA (NC) or an ALDH2-siRNA. The ALDH2 protein levels and ALDH enzymatic activities were assessed 48 h after transfection.Ethanol pretreatment and in vitro IR were performed on those transfected TECs.LDH release was assessed to evaluate the role of ALDH2 in the ethanol pretreatment-induced protection against IR injury.ResultsEthanol pretreatment significantly reduced the LDH release in TECs upon IR insult.As compared with NC group and INTERFERin group,the ALDH2 protein levels were decreased by 82.1％,ALDH enzymatic activities were decreased hy 67.3％,and the protective effect induced by ethanol pretreatment was almost completely abrogated in ALDH2-siRNA group.ConclusionEthanol pretreatment protects TECs against IR injury through ALDH2 dependent pathways.