Mast cell infiltration is involved in renal interstitial fibrosis of rat models with protein overload nephropathy / 中华肾脏病杂志

ABSTRACT

Objective To investigate the correlation of infiltration of mast cells in kidney with renal interstitial fibrosis, expression of TGF-β1 and stem eel] factor (SCF) in rat models withprotein-overload nephropathy. Methods Sixty uninephrectomized SD rats were randomly divided into model group [intraperitoneal injections of bovine serum albumin (BSA)] and control group (intraperitoneal injections of equal volume of saline). Ten rats from both groups were sacrificed respectively at week 3, 7 and 11 after injection. 24 h urinary protein and serum biochemistry of these SD rats at the time of sacrifice were measured. The intensity of mast cell infiltration was examined by toluidine blue (TB) staining and immunohistochemistry using a monoclonal anti-MC chymase antibody. The expression of TGF-β1 and SCF was detected byimmunohistochemistry, using a monoclonal mouse anti-rat TGF-β1 antibody and a polyclonal rabbstanti-rat SCF antibody. Results Severe proteinuria was induced in the rats by BSA injectionpeaked at week 7 [(199.1±98.4) mg/d] after the BSA injection and gradually decreased until week11 [(133.7±67.8) mg/d]. Renal injury was accompanied with chymase-postitive and TB-postitive mast cell infiltration, in close proximity to areas of interstitial fibrosis. With aggravation oflesions degree, the number of mast cells increased,the difference between the modal rats and control rats was significant (P<0.05). Immunostainahle expression of SCIF and TGF-β1 was detected in tubular as well as interstitial cells, and increased with the BSA injection. The difference between the model rats and control rats was significant (P<0.05). Mast cells were positively correlated with interstitial fibrosis (r=0.772, P<0.01), expression of TGF-β1 (r=0.521, P<0.01) and SCF(r=0.916,P<0.01). Conclusions Increased infiltration of mast cells is involved in interstitial fibrosis of rats with protein-overload nephropathy. Proteinuria may attract mast cells to kidney by chemot actions of SCF,and mast cells may contribute to the development of renal fibrosis by secreting chymase and increasing expression of TGF-β1.