The kidney expression of matrix metalloproteinase-9 in the diabetic nephropathy of Kkay mice.
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.


CONCLUSIONS
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.
Qing-Hua
Guo
G
Department of Endocrinology, Chinese PLA General Hospital, Beijing 100853, China. gqh301@gmail.com.cn
Ju-Ming
Lu
L
Chang-Yu
Pan
P
Zhao-Hui
Lu
L
Xiao-Man
Zou
Z
Yi-Ming
Mu
M
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000201:enzymology*; D003928:Diabetic Nephropathies / Q000201:enzymology* / Q000473:pathology; D015870:Gene Expression; D007150:Immunohistochemistry; D007668:Kidney / Q000737:chemistry / Q000378:metabolism* / Q000473:pathology; D007678:Kidney Glomerulus / Q000201:enzymology / Q000473:pathology; D020780:Matrix Metalloproteinase 9 / Q000032:analysis / Q000235:genetics*; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D001786:Blood Glucose; D012333:RNA, Messenger; D020780:Matrix Metalloproteinase 9