| Objective:To study the effects of glomerular endothelial cells injury and repair on renal function and structure in rats with IgA nephropathy and its possible mechanism.Methods:The rats were randomly divided into 4 groups: control group,IMD group,IgAN group and IgAN + IMD group,with 9 rats in each group.The IgAN rat model was constructed by BSA and other reagents.At the end of 12 weeks,3 rats in each group were randomly selected to detect the modeling effect.After successful modeling,IMD was continuously given subcutaneously for intervention,and urine,blood and renal tissue samples were taken.The changes of urinary protein were detected by automatic specific protein analyzer,the changes of blood creatinine and urea nitrogen were detected by automatic biochemical analyzer.The pathological changes of glomerulus were observed by HE and PAS staining,IgA deposition in glomerular mesangial area was observed by immunofluorescence staining,the electron density deposition and ultrastructural changes in mesangial area were observed by electron microscope.The expressions of endothelial cell markers CD31,CD34,JG-l2 and VEGF,VEGFR2,VE-cadherin in glomerulus were detected by immunohistochemistry,and the expressions of VEGF,VEGFR2 and VE-cadherin m RNA in renal tissue were detected by real-time quantitative PCR.Results:(1)Changes of urinary protein: before modeling,the urinary protein level of rats in each group was low and there was no difference.At the 12 th week after modeling,compared with the control group,urinary protein in IgAN group and IgAN + IMD group was significantly higher(P < 0.05).After IMD intervention at the 16 th week,compared with IgAN group and control group,urinary protein in IgAN + IMD group decreased,but it was still higher than the normal level(P < 0.05).(2)Changes of renal function: the level of SCr in IgAN group was higher than that in control group(P < 0.05);The level of SCr in IgAN + IMD group was lower than that in IgAN group(P < 0.05).BUN was no difference between each groups.(3)Histological changes of kidney: HE and PAS staining showed glomerular mesangial cell proliferation,mesangial matrix increase,renal tubular expansion and lymphocyte infiltration in varying degrees,and renal tubular atrophy or glomerular segmental sclerosis in some rats in IgAN group.After IMD intervention,the proliferation of mesangial cells and matrix decreased,the interstitial lesions decreased,and there was no obvious inflammatory change.(4)Immunofluorescence and electron microscopic changes:compared with the control group,a large amount of IgA fluorescence deposition can be seen in the glomerular mesangial area of IgAN group;Compared with IgAN group,the intervention of IMD can significantly reduce glomerular IgA deposition.Electron microscopic observation showed that electron density deposition in glomerular mesangial area and podocyte protrusion fusion even disappearance were observed in IgAN group;After IMD intervention,the electron density in mesangial area decreased and the podocyte protrusion injury decreased.(5)Glomerular microvascular changes: immunohistochemical results showed that the expressions of CD31,CD34 and JG12 in IgAN group were lower than those in control group(P < 0.05).After IMD intervention,the expressions of CD31,CD34 and JG12 in IgAN + IMD group were higher than those in IgAN group(P < 0.05).(6)Changes of protein and m RNA expression levels of VEGF,VEGFR2 and VE-cadherin:immunohistochemical and PCR results showed that the protein and m RNA expression of VEGF,VEGFR2 and VE-cadherin in IgAN group were lower than that in control group(P< 0.05).After IMD intervention,the protein and m RNA expressions of VEGF,VEGFR2 and VE-cadherin in IgAN + IMD group were higher than those in IgAN group(P < 0.05).Conclusion:There is endothelial cells injury in IgAN rat model,IMD may repair endothelial cells and microvasculars through VEGF-VEGFR2 pathway and further improve the structure and function of IgAN rat kidney,in which VE-cadherin plays certain role. |
PDF Full Text Request