The Role Of ERK1/2-GSK3?-NF?B Signaling Pathway In The Pathogenesis Of Early Stage Of Chronic Renal Allograft Dysfunction Promoted By IR

ObjectiveTo explore the role of ERK1/2-GSK3?-NF-?B signaling pathway in the mechanism of insuline resistance(IR)promoting chronic renal allograft dysfunction(CRAD)in early stage.MethodOn the basis of internationally accepted model of CRAD in the past years,We split the successful transplantation rats into two groups:high fat diet group and normal diet group.Meanwhile,uninephrectomized rats were fed by normal diet as controls.After feed for 8 weeks,the body weight were measured in each group.We collected blood samples via vein blood sampling angular vein to measue triglyceride(TG)?total cholesterol(TC)?fasting blood-glucose(FBG)?fasting serum lisulin(FINS),and then HOMA-IR was calculated.Oral glucose tolerance test(OGTT)and Insulin tolerance test(ITT)test were also implemented,and the area under curve were calculated to evaluate the degree of insulin resistance.After the model of CRAD+IR building,we randomly assigned them into three groups:renal transplantation with insulin resistance(CRAD+IR)group,rosiglitazone group(5mg/kg/d,gavage)and TDZD8(GSK3? blockers)group(lmg/kg/wk,tail vein injection).After 4 weeks of intervention,the blood samples,urine samples were collected.At week 12,all rats were killed 3%anesthetized with pentobarbital.We observed the pathological changes of renal tissue of the model by pathological staining,immunohistochemical staining and western blot were used to detect the expression of ERK1/2-GSK3?-NF?B signaling protein and the downstream of the inflammation factor.Results1.High fat diets for 8 weeks can successfully induce insulin resistance model:Compared with CRAD group and uninephrectomized group,CRAD+IR group showed higher body weight increase?higher levels of FINS?FBG and HOMA-IR.The results of OGTT test and ITT test showed that,compared with CRAD group and uninephrectomized group,CRAD+IR showed higher level of blood glucose at 0 minutes,30 minutes,60 minutes,90 minutes and 120 minutes.OGTT-AUC and ITT-AUC were both increased(p<0.05).CRAD+IR group also had higher levels of TG and TC,but only the TG level had statistical significance compared with CRAD group.It was suggested that rat models of insulin resistance were successfully established by high fat feed.2.After drug intervention for 4 weeks,the change of every index was observed.(1)The results of blood biochemical and urine testAt week 12,there was no statistical difference in the levels of FINS?FBG?OGTT-AUC and ITT-AUC between uninephrectomized group and CRAD group,but serum creatinine and 24-hour urinary protein excretion were increased(P<0.05).Compared to CRAD group,CRAD+IR group showed higher body weight increase?higher level of FINS?FBG?HOMA-IR?OGTT-AUC?ITT?serum creatinine and 24-hour urinary protein excretion(p<0.05).After the the intervention of rosiglitazone,the above indicators were decreased compared with CRAD+IR group(P<0.05).No significant changes in the above indicators between CRAD+IR group and TDZD8 group(P>0.05).(2)The renal pathological changes in each group.At week 12,the kidney sections of the uninephrectomized group did not exhibit marked histological changes.The kidney sections of the CRAD group exhibited renal interstitial inflammatory cell infiltration,vacuolar degeneration emerged in the epithelial cell of renal tubule,glomerular mesangial cell proliferation,intimal thickening and mild interstitial fibrosiss.The changes was obviously in the CRAD+IR group.After the the intervention of rosiglitazone and TDZD8,the development of these lesions and tissue damage were significantly attenuated.(3)The expression of ERK1/2-GSK3P-NF?B signaling protein in each groupCompared with uninephrectomized group,the expression of P-ERK1/2?P-GSK3? and P-P65 were increased in CRAD group;Compared with CRAD group,the levels of the phosphorylated proteins mentioned above were increased in CRAD+IR group.MCP-1 and ICAM-1 protein expression were also higher.After the the intervention of rosiglitazone and TDZD8,the above mentioned protein were significantly decreased.Conclusions1.ERK1/2-GSK3?-NF?B signal pathway participates in regulating the interstitial inflammatory cell infiltration at the early stage of IR-mediated CRAD,and promote the development of chronic renal allograft dysfunction;2.Rosiglitazone improve interstitial inflammatory cell infiltration at the early stage of IR-mediated CRAD via blocking of the ERK1/2-GSK3?-NF?B signaling pathway.