The expression and significance of renal connective tissue growth factor in lupus nephritis

Objective To investigate the expression of connective tissue growth factor (CTGF) in kidney tissues and its relationship with kidney fibrosis in lupus nephritis (LN).Methods CTGF of 36 specimens from LN kidneys and 15 from normal controls were detected by immunohistochemistry and hybridization in situ in order to find out the relationship of CTGF expression with fibrosis of kidney interstitium.Results CTGF distributed not only on tubular epithelial cells and interstitial cells,but also on glomerular epithelial cells and mesangial cells in LN.There was no or only a little renal CTGF mRNA and protein expression in normal controls.Renal CTGF mRNA and protein expression was significantly higher than normal controls(CTGF mRNA: 8.22±3.13 to 1.12±0.23; CTGF protein: 8.74±3.24 to 1.21±0.22,P0.001);Renal CTGF expression in LN was positively related with tubulointerstitial fibrosis(r=0.863,P0.01).Renal CTGF expression in type Ⅳ LN was significantly higher than in other LN(CTGF mRNA: 10.73±3.61 to 4.78±1.82,CTGF protein: 11.03±1.12 to 5.02±1.31 P0.01).Renal CTGF protein expression was also positively related with TGF-β1,FN and ColIII(r=0.704?r=0.783 and r=0.756,P0.01) in LN.Conclusion The level of renal CTGF mRNA and protein expression is gradually increased with the degree of tubulointerstitial fibrosis.As the downstream factor of TGF-β,CTGF may promote the expansion of extra-matrix such as Fn and ColIII,and enhance the glomerular and tubulointerstitial fibrosis in LN.