The Role Of Circulating Fibrocytes In The Process Of Chronic Progression Of IgA Nephropathy In Rats

ObjectiveIgA nephropathy is a group of clinicopathological syndrome mainly based on glomerular mesangial area Ig A or main IgA deposition.The prevalence of children in recent years has increased significantly.About 25%-30% of patients can develop into end-stage renal disease in 20-25 years,which seriously threatens human health.The pathological grade of kidney determines the prognosis of IgA nephropathy.The current assessment methods of renal injury mainly includes urine analysis,renal function,imaging diagnosis and pathological diagnosis,the kidney pathological examination is the gold standard to evaluate the pathological grade of IgA nephropathy.Because of the existence of traumatic,renal biopsy cannot be a clinical follow-up index.Clinical follow-up was assessed on the basis of renal function and urine protein content,but the renal pathological changes and progress could not be evaluated very well.Circulating fibroblast is origin from bone marrow,a small amount of which in blood in the physiological state.When the body is damaged,it can be recruited to the injured part under the action of chemokines,and differentiate into the active myofibroblast,secrete the extracellular matrix and promote the development of fibrosis.Many studies have confirmed that circulating fibrocytes involved in the genesis and development of renal interstitial fibrosis,renal artery stenosis and acute kidney injury to the chronic kidney disease transformation and other diseases,but there is still no report about the circulating fibrocytes on the occurrence and development of IgA nephropathy.“BSA+LPS+CCl4” method is currently recognized as one of the models of IgA nephropathy.In this study,we investigate the changes of circulating fibroblasts in the progression of IgA nephropathy,and to find the association between circulating fibroblasts with the progression of IgA nephropathy,to providing a clinical basis for clinical treatment and long-term prognosis.Methods1.42 rats of 2-4 weeks were enrolled in this study,control group(n=21),IgA nephropathy model group(n=21);using “BSA+LPS+CCl4” method to establish the model of IgA nephropathy.2.The rats in each group began to make the model after collecting the urine for 24 hours.After the sixth week,eighth week and tenth week after modeling,two groups of 24 hour urine were collected and divided into groups(7 rats in each group).After anesthesia,blood was taken through the right ventricle and the left kidney was cut.The renal tissue was fixed in 10% formalin and treated with HE staining,PAS staining and immunofluorescence staining.3.Samples of anticoagulant specimens were taken and flow cytometry was used to detect the level of circulating fibrous cells in peripheral blood.4.The results were analyzed by SPSS21.0.Means±standard deviation is used to express continuous data.The data of homogeneity between each two groups were analyzed by independent-samplesT test.Three groups and multiple groups of data were analyzed by one-way ANOVA.Further comparisons between each two group were conducted by LSD method.Spearman correlation coefficient is used to analyze correlation between variables.When the P value is < 0.05,there is statistically significant.Result1.24 hours of urine protein quantitative: The urinary protein quantitative had no significant difference between the control group and the IgA nephropathy model group in the first week(t=0.67,P>0.05).The urine protein of IgA nephropathy model group was higher than that the same age of control group in the sixth week,eighth week and tenth week,and has significante difference between them(P<0.05).There were significant differences between the sixth week,eighth week,tenth week with the first week of IgA nephropathy group(P<0.05),but there was no significant difference between the each two group of the sixth week,the eighth week and the tenth week(P>0.05).There was no significantly difference between the each two group in the control group.2.The level of circulating fibrocytes in peripheral blood: Compared with the same week age of control group,there was significante difference between them(P<0.05).In the IgA nephropathy model group,there was significant difference between each two groups(F=104.54,P < 0.05).It had no significant difference between each two groups in the control group(F=0.61,P=0.55).3.Renal histological changes: HE staining and PAS staining showed that the control group of glomerular and tubular structure were normal,no obvious hyperplasia of mesangial cells and mesangial matrix normal;IgA nephropathy model group glomerular mesangial cells have different degrees of hyperplasia,and the proliferation gradually increased with the prolongation of model making.4.IgA staining: Compared with the same week age of control group,IgA deposition intensity has statistically significant IgA deposition between them(P<0.05).There was no significante difference between each two groups in the control group(F=1.047,P>0.05).The IgA deposition intensity was gradually increased in the IgA nephropathy model group,and there was significante difference between each two groups(F=45.894,P<0.05).5.The expression of circulating fibrocytes in renal tissues: Compared with the same age of control group,the expression level of circulating fibrocytes in the IgA nephropathy model group was significantly higher,and there was significante difference between each two groups(P<0.05).With the prolongation of modeling time,the expression level of circulating fibrocytes in the IgA nephropathy model group increased,and there was significant differences between each two groups(F=60.422,P<0.05),but there was no statistical difference between each two groups of the control group(F=0.817,P>0.05).6.The correlation between the level of circulating fibrocytes in peripheral blood and 24 hours urine protein,IgA deposition intensity in renal tissue,the expression of circulating fibrocytes in kidney tissue: there was no significant correlation between circulating fibrocytes in peripheral blood with the urine protein of 24 hours in the IgA nephropathy model group(r=0.018,P=0.939),but was positively correlated with the deposition intensity of IgA,the expression of circulating fibrocytes in kidney tissue in renal tissues,the correlation coefficients were respectively 0.974 and 0.982(P < 0.05).7.The correlation between the intensity of IgA deposition and the expression of circulating fibrocytes in renal tissue in the IgA nephropathy model group: There was a significant positive correlation between the two groups(r=0.936,P < 0.05).Conclusion1.Circulating fibrocytes were involved in the occurrence and development of IgA nephropathy in rats.2.The dynamic changes of circulating fibrocytes in peripheral blood and kidney tissue reflect the severity of renal pathology of IgA nephropathy in rats to some extent.