Effect Of PPAR Gamma On Hypoxia Induced RTEC Necrotic Apoptosis

Objective:By establishing a necrotic apoptosis model of hypoxic damaged renal tubular epithelial cells（RTEC）,agonist rosiglitazone was used to up regulate the expression of peroxisome proliferator activated receptor gamma（PPARγ）,and to study the role of PPARγin hypoxia induced RTEC necrotic apoptosis.Method:Rat RTEC（NRK-52E）in vitro,after cultured and passaged,was randomly divided into normal control group,hypoxia model group and rosiglitazone group.The normal control group was cultured under normal conditions without any treatment.In the rosiglitazone group,rosiglitazone was added（15μmol/L）.The hypoxia model group and rosiglitazone group were put into the small hypoxic box（filled with 95%N₂and 5%CO₂）for 48 hours to establish RTEC hypoxic injury model.The morphological changes of RTEC in each group were observed by optical microscope.The morphology of the cells in each group was observed by transmission electron microscopy,and the necrotic apoptosis was observed.The expression of PPARγ,receptor interaction protein（RIP）1 and RIP3 was detected by RT-PCR.Western blotting was used to detect the protein expression of PPARγ,RIP1 and RIP3.Results:1.Under the optical microscope,RTEC in the normal group were fusiform,with full body,orderly arrangement and moderate cell gap;compared with the normal control group,the cell density in the hypoxia model group and the rosiglitazone group were reduced,with narrow and long cells,slender body,atrophic morphology,widened and deepened cell gap and increased cell fragments.Compared with the hypoxia model group,RTEC in the rosiglitazone group the density was higher and the cell fragment was decreased.2.Compared with the normal control group,the hypoxia model group and rosiglitazone group showed necrosis apoptosis under transmission electron microscope;compared with the hypoxia model group,rosiglitazone group showed less necrosis apoptosis.3.Compared with the normal control group,the m RNA expression of PPARγin the hypoxic model group and rosiglitazone group decreased significantly（P<0.05）.Compared with the hypoxic model group,the m RNA expression of PPARγin rosiglitazone group increased significantly（P<0.05）.Compared with the normal control group,the m RNA expression of RIP1 and RIP3 in hypoxia model group and rosiglitazone group was significantly increased（P<0.05）.Compared with hypoxia model group,the m RNA expression of RIP1 and RIP3 in rosiglitazone group was significantly decreased（P<0.05）.4.Compared with the normal control group,the protein expression of PPARγin hypoxia model group and rosiglitazone group significantly decreased（P<0.05）.Compared with hypoxia model group,the protein expression of PPARγin rosiglitazone group significantly increased（P<0.05）.Compared with the normal control group,the expression of RIP1 and RIP3 in hypoxia model group and rosiglitazone group significantly increased（P<0.05）.Compared with hypoxia model group,the expression of RIP1 and RIP3 in rosiglitazone group significantly decreased（P<0.05）.5.Correlation analysis:The m RNA expression of PPARγwas negatively correlated with RIP1 and RIP3 protein expression in hypoxia induced necrotic apoptosis of RTEC.The protein expression of PPARγwas negatively correlated with that of RIP1 and RIP3（r=-0.608,-0.317,P<0.05）.Conclusion:Rosiglitazone may up regulate the expression of PPARγprotein in RTEC.Up regulation of PPARγmay reduce the ne-crotic apoptosis of RETC under hypoxia.