Effect of CD40 siRNA on lupus nephritis of MRL/Lpr mice / 中国免疫学杂志

ABSTRACT

Objective:To observe the effect of CD40 siRNA on the changes in kidney,urinary protein and complement C3 of MRL/Lpr mice and explore its therapy on lupus nephritis.Methods: 16 female MRL/Lpr mice were randomly divided into control group,empty vector group,CD40-siRNA1 group and CD40-siRNA2 group.The vectors expressing siRNA against CD40 were injected by tail veil into MRL/Lpr mice,while MRL/Lpr mice in control group and empty vector group were injected with the same dose of PBS and pGFP-V-RS vector respectively.There were six times injection and every one day.The 24 hours urine output was gathered 24 hours before mice were killed.Fourteen days following administration,these mice were killed,tissue sections of kidney were observed if the signal of siRNA were expressed in kidney.The expression levels of CD40 mRNA and protein in kidney tissue of MRL/Lpr mice were detected by RT-PCR and immunohistochemistry methods respectively.At the same time,the pathological changes of the kidney were observed by haematoxylin-eosin ( HE) staining method.The 24 h urinary protein content was detected using the method of coomassie brilliant blue and the expression levels of complement C3 in serum were detected by Immunoturbidimetric assays.Results:The vector of CD40-siRNA was expressed in kidney of MRL/Lpr.The expression levels of CD40 mRNA and protein in kidney were lower in CD40-siRNA1 group and CD40-siRNA2 group than control group and empty vector group on the 14th day after last injection ( P<0.05).The inflammatory cells infiltration of kidney and some glomerular volume were significantly reduced in CD40-siRNA1 group and CD40-siRNA2 group than control group and empty vector group.The renal tubular swelling was alleviated in CD40-siRNA1 group and CD40-siRNA2 group than control group and empty vector group.The levels of 24 hours urinary protein were lower and the levels of complement C3 were higher in CD40-siRNA1 group and CD40-siRNA2 group than control group and empty vector group ( P<0.05). Conclusion:CD-40 siRNA can suppress the expression levels of CD40 mRNA and protein and decrease inflammatory cells infiltration in kidney of MRL/Lpr.Meanwhile after suppressing expression of CD40 mRNA and protein, it can reduce the content of 24 hours urinary protein and elevate the level of complement C3 in serum,which CD-40 siRNA can delay progress of the disease and protect kidney,so that it has therapy effect on lupus nephritis.