Role Of12-lipoxygenase On Rat Glomerular Ezh2Expression And Mechanism

Renal fibrosis is the common pathological characteristics of chronic kidneydisease (CKD), mainly for the extracellular matrix (extracellular matrix, ECM)composition accumulation, glomerular sclerosis and the formation of renal tubuleinterstitial fibrosis. With the development of renal fibrosis, glomerulosclerosis,tubulointerstitial fibrosis, inflammatory cell infiltration and the loss of renalparenchyma (includes tubular atrophy, capillary occlusion and podocyte depletion) areall involved in its onset and progression. Renal fibrosis is the common pathway fromchronic kidney disease to the end-stage renal disease. In order to guide the clinicaltreatment,understanding the formation mechanism and influencing factors of renalfibrosis are extremely important. Blocking its effect pathways which connected withrenal fibrosis may be an effective therapeutic target to prevent patients with ESRD.Recently researchs show that histone modification plays an significant role in thedevelopment of kidney disease, end stage renal disease and renal fibrosis.There is asynergistic effect in the formation and degradation of matrix between cytokines,chemokines and growth factors,which can lead to the imbalance ofECM.Eventually,glomerular sclerosis and interstitial fibrosis are occurred.12(S)HETE,the metabolite of12-lipoxygenase (12-lipoxygenase,12-LO),has an importanteffect on promoting proliferation and increasing inflammation factors in vascularendothelial cells and kidneys cells,12-LO can cause glomerular ECM through itsmetabolites accumulation which results in renal fibrosis. The relationships betweenthe expression of histone methyltransferase Ezh2with the occurrence of renal fibrosisand12-LO metabolic pathway on glomerular Ezh2expression with regulationon renal fibrosis are unclear.Methods： Mesangial cells culture is available and RT-PCR, Western blot and transfectionare applied in this experiment to investigate whether12-LO can lead to renal fibrosisthrough P38MAPK pathway which regulates the expression of Ezh2.Results:1、Inhibition of p38activity can effectively block12(S) HETE down-regulatngon p38activity and protein expression of Ezh2in mesangial cells (mesangialcells,MC), the difference was statistically significant (P <0.01),and up-regulatng onexpression of CTGF mRNA,the difference was statistically significant (P <0.05).2、Compared with mesangial cells in wild-type mouse (mouse mesangialcells,MMC),Ezh2protein levels in12-LO knockout mice mesangial cells (12lipoxygenase knockout mesangial cells,12-LOKO MC) were higher (P <0.01),andCTGF mRNA expressions were lower (P <0.05) in12-LOKO MC.3、Compared with RMCs transfected with NTC, the CTGF mRNA levelincreased in RMCs transfected with siEzh2, the difference was statistically significant(P <0.05).Conclusions:1、12-LO regulates Ezh2expression which regulates CTGF mRNAexpression through p38MAPK pathway.2、12-LO caused renal fibrosis by down-regulating Ezh2and up-regulatingCTGF.