The Expression Of IL-1β,TIM-1,E-cadherin In Urinary Exosomes Of Diabetic Kidney Disease

BackgroundDiabetic kidney disease(DKD)is a microvascular complication with a high mortality rate of diabetes,and is also the main cause of chronic kidney disease(CKD).The pathogenesis involved in the disease process is very complicated.With the progress of research in recent years,the role of immune inflammation has become increasingly prominentAt present,increased urinary protein excretion is an important clinical indicator for the diagnosis of DKD.However,this indicator is low in sensitivity and lagging.Considering that patients with DKD become progressively worse in the later stages of the disease and the trend of progresses to end-stage renal disease(ESRD)is hard to reverse,the early diagnosis of DKD is particularly importantExosomes are extracellular vesicles that can be secreted by almost all types of cells.They carry a wealth of information molecules such as protein,lipid,and nucleic acid from the source cells.Exosomes have diagnostic and therapeutic significance for various diseases.Various types of kidney cells can release exosomes.Through the biological information carried by urinary exosomes,we can understand the physiological and pathological changes of the kidney,and it is expected to identify early DKD.Interleukin-1 β(IL-1β)is an important pro-inflammatory cytokine.When cells recognize a danger signal,IL-1β can be activated in a large number of ways and produce pathological effects.Studies have shown that it plays a role in the pathogenesis of diabetes.T cell immunoglobulin and mucin domain-1(TIM-1)is mainly expressed on Th2 cells,which can stimulate Th2 cells to proliferate and differentiate.Then the Th2 cells will secrete a variety of inflammatory factors to play a pro-inflammatory role.TIM-1 can be detected in urine when kidney tissue is damaged E-cadherin is an important cell adhesion molecule.Tubulointerstitial fibrosis occurs during the progression of CKDs.Many studies have shown that E-cadherin will be down-regulated and lost during this process.In this study,we detected the changes of the expression of these protein molecules in urinary exosomes during the progression of DKD to explore the relationship between them and DKDObjectiveThe expression levels of IL-1β,TIM-1 and E-cadherin in urinary exosomes of healthy adults and patients with DKD were measured to investigate their correlation with DKD.MethodsIn this study,97 diabetic patients were collected.According to the urinary albumin/creatinine ratio(UACR),the patients were divided into normoalbuminuria group(DM,n=46,UACR<30mg/g);microalbuminuria group(DN1,n=32,30mg/g≤UACR<300mg/g)and macroalbuminuria group(DN2,n=19,UACR≥300mg/g).At the same time,31 healthy adults were collected as controls.Collecting the ordinary materials and the clinical data of all selected subjects.Urine exosomes were extracted by filtra-ultracentrifugation and specific monoclonal antibodies.We use transmission electron microscope(TEM)and western blot to identify exosome.The expression of IL-1β,TIM-1,E-cadherin in urinary exosomes were detected by ELISA.All the data are statistically analyzed with SPSS 21.0,p<0.05 is considered statistically significantResults1.There were no significant differences in age,gender,body mass index,systolic blood pressure,diastolic blood pressure,creatinine,urea nitrogen,cholesterol,triglycerides,and HDL-C among the four groups.Compared with the control group,the levels of UACR in the DM,DN1,and DN2 groups were significantly increased,and the differences between the three groups were statistically significant(p<0.05)2.Urinary exosomes showed a double-concave disc-shaped vesicles under TEM,with a double-layer membrane structure.In the western blot experiment,exosome marker proteins TSG101 and CD63 were positive3.Western blot results indicated that the expression levels of IL-1β and E-cadherin were significantly increased in DN2 group.ELISA results indicated that the expression level of IL-1β in urinary exosomes was significantly lower in the healthy control group than in the DM,DN1,and DN2 group.The differences between these groups were statistically significant(p<0.05).The expression level of E-cadherin in urinary exosomes in the DM,DN1 and DN2 groups was significantly lower than that in the control group(p<0.05),but there was no significant difference between the DM,DN1 and DN2 groups(p>0.05).There was no significant difference in the expression of TIM-1 in urinary exosomes between the four groups(p>0.05).The expression level of IL-1β in urinary exosomes was positively correlated with urinary UACR,glycated hemoglobin,low-density lipoprotein cholesterol,and cholesterol.Stepwise multiple linear regression analysis showed that UACR and glycated hemoglobin were independent risk factors for IL-1β in urinary exosomes(p<0.05)Conclusions1.The expression level of IL-1β in urinary exosomes increases with the severity of DKD,suggesting that the expression level of IL-1β in urinary exosomes has certain significance for the diagnosis of DKD.The expression levels of IL-1β in urinary exosomes are positively correlated with UACR,HbAlc,LDL-C and CH;UACR and HbA1c are independent risk factors for IL-1β in urinary exosomes2.The expression level of E-cadherin in urinary exosome in patients with DKD is significantly lower than that in healthy adults,but it does not increase with the aggravation of the patient’s condition.In future studies,it is needed to expand the sample size.3.The expression level of TIM-1 in urinary exosomes has no significant difference between healthy adults and patients with DKD,and its correlation with the incidence of DKD remains to be studied.