ABSTRACT
BACKGROUND: Disorder of the extracellular matrix has been suggested to play a role in the development of diabetic nephropathy. The aim of the present study was to examine the expression of matrix metalloproteinase-9 (MMP-9) in the kidney of Kkay mice, a type 2 diabetic model. METHODS: Eight Kkay control mice (KA) and eight Kkay diabetic mice (KB) were fed with the same diets for 4 months and sacrificed after glucose levels and weight were measured. The renal pathological changes were examined by periodic acid-Schiff and periodic acid-silver methenamine staining, and the glomerulosclerosis indexes (GIs) were calculated. The levels of MMP-9 protein in the kidney tissue were assessed by immunohistochemistry. The gene expression of MMP-9 was measured by reverse transcription polymerase chain reaction. RESULTS: The diabetic group had morphological findings of diabetic nephropathy, and their GI (240.0+/-17.3) was much higher than that of the control group (118.4+/-15.1) (P<.01). The mean positive area of MMP-9 protein in the glomeruli of Kkay mice in the KB group was higher than that in the KA group. The expression of MMP-9 messenger RNA level in the diabetic KB group was up-regulated when compared with the KA group. CONCLUSION: The expression of MMP-9 in the kidney of mice with diabetic nephropathy was enhanced, and MMP-9 might be involved in the development of diabetic nephropathy.
