ABSTRACT
BACKGROUND:Our preliminary findings have shown that stem cells have a certain effect on early formation of renal fibrosis and delay the occurrence of renal interstitial fibrosis.OBJECTIVE:To investigate the effect of exogenous adipose-derived stem cell transplantation on the formation of renal interstitial fibrosis in rats,and to explore the dose-effect relationship.METHODS:Fifty Sprague-Dawley rats were randomly divided into five groups.Rats in sham operation group were injected with PBS;and those in the other four groups were ligated to establish the model of renal fibrosis.After successful modeling,the model group was injected with PBS,while low dose group,middle dose group and high dose group were injected with 1 ×107/L,2x107/L,3x107/L adipose-derived stem cell suspension (0.1 mL),respectively.Rats were killed 14 days after injection.Hematoxylin-eosin staining and Masson staining were used to observe the degree of renal tubular interstitial injury and the relative area of the renal interstitium.Expression of alpha smooth muscle actin and transforming growth factor beta1 was detected by immunohistochemistry.RESULTS AND CONCLUSION:(1) Hematoxylin eosin staining:The model group showed typical glomerular and tubulointerstitial changes;the low,middle and high dose groups had a certain degree of glomerular and tubulointerstitial changes,but the severity of injury in these three groups,especially in the high dose group,was significantly milder than that in the model group.(2) Masson staining:In the model group,the renal interstitium was widened and the collagen fibers were deposited;in the low,middle and high dose groups,the degree of renal interstitial expansion was lower than that in the model group,and moreover,the degree of renal interstitial expansion in the middle and high dose groups was lower than that in the low dose group (P ＜ 0.05).(3) Immunohistochemical staining:Compared with the sham operation group,the expression of alpha smooth muscle actin and transforming growth factor beta1 in the model group was higher than that in the sham operation group (P ＜ 0.05).Compared with the model group,significantly decreased expression of alphasmooth muscle actin was found in the high dose group (P ＜ 0.05) and significantly reduced transforming growth factor beta1 expression was observed in the high,middle,and low dose groups (P ＜ 0.05),especially in the middle and high dose groups.To conclude,exogenous adipose-derived stem cell transplantation can delay the formation of early renal fibrosis in a dose-effect manner,which may be realized by changing the signal pathway state induced by transforming growth factor beta1.