Role And Mechanism Of NHE1 In Injury Of Human Renal Tubular Cell Induced By Postasphyxial-Serum In Neonates

Objective : To investigate the role of NHE1 in injury of human renal tubular cells(HK-2) induced by postasphyxial-serum in neonates.Methods (1)Human renal proximal tubular cell(HK-2)was used as the target cel1.(2) The serum of neonates in one day after asphyxia, whose concentration were 200ml/l (volume fraction),were applied as attacking factor .(3)The experiment was designed as control group,asphyxia group,which were used to research whether NHE1 play an important role in the injury of human renal tubular cell induced by postasphyxial- serum of neonate .(4)In the second experiment was designed as control group,asphyxia group,EIPA group,which were researched whether EIPA had the protective effect . (5) The following indicators were detectied : In the first experiment,the expression of NHE1 in the HK-2 were detected by immunohistochemical method.In the second experiment,the cell viability was measured by 3-(4,5-dimethy lthiazcl-2-y1)-2,5-diphenyl–tetazoliumbromide (MTT) methods.In the first experiment,the changes of morphology were observed under inverted microscope,and the cell viability was measureed by 3-(4,5-dimethy lthiazcl-2-y1)-2,5-diphenyl -tetazolium bromide(MTT) methods,and the leakage rate of lactate dehydrogenase(LDH) was determined by biochemical methods.(6) All parameters were expressed as the mean value±standard difference( x±S), statistical analysis were carried out by the use of the least significant difference.Difference was considered significance when the p.value was less than 0.05.The statistics work were finished by spss10.0 software.Results (1)Compared with control group,the expression of NHE1 in the HK-2 were increased significantly in asphyxia group.(2) Under inverted microscopy,HK-2 cells in control group were significantly increased,sticked to each other tightly and grew very quickly.Their adhesion were better,multyang applan,and refraction raised.The form and quantity of HK-2 cell was normal .Compared with control group,the changes in morphology of HK-2 were most serious and obvious in asphyxia group,the cells grew slowly,the mount decreased,form of the cells changed from typical multy-ang applan to off-normal round or ellipse.Refraction rate was decreased,and contour enhanced.The vacuolus,lipid droplet and granulation appeared in the kytoplasm.There was much cell debris in accrescent intercellular space.the cell viability (optical density,OD) were obviously decreased in the asphyxia group(P=0.000) ,the leakage rate of LDH were significantly increased in asphyxia group(P=0.000) ,statistical significance existed between control group and asphyxia group(P<0.05).But compared with asphyxia group, the changes in morphology of HK-2 were obviously improved in the EIPA groups ( 2μmol/l), the leakage rate of LDH were significantly decreased,statistical significance existed between EIPA group and asphyxia group(P<0.05); the cell viability were obviously increased,statistical significance existed between EIPA group and asphyxia group(P<0.05).Conclusion :The postasphyxial-serum could induced the increased the expression of NHE1,which could play an important role in injury of renal tubular cells induced by postasphyxial-serum in neonates.