Expression of matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in different bacterial colonization diabetic wound tissues

Abstract

Objective To observe the expression levels of matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 in different bacterial colonization diabetic wound. Methods Included patients were divided into four groups: group A, 19 patients with diabetic foot wound, including group A1, 7 patients with bacterial growth on the wound, and group A2, 12 patients without bacterial growth on the wound; group B, 6 diabetic patients; group C, 7 normal controls. Skin tissues in all four groups were taken surigically. Bacterial culture and counting were done in group A. The MMP-9 and TIMP-1 gene expression in skin tissue was detected by real-time fluorescent quantitative polymerase chain reaction (FQ-PCR), and Western blotting was used to detect the expression of MMP-9 and TIMP-1 proteins. Results The relative expression of MMP-9 in groups A1, A2, B and C was 1.136±0.116, 0.601±0.080, 0.391±0.088 and 0.134±0.057 respectively (P=0.000 for all). The relative expression levels of TIMP-1 in groups A1, A2, B and C were 1.013±0.086, 2.570±0.845, 4.878±0.829 and 7.294±1.551 respectively (P=0.000 for all). The results from Western blotting were consistent with those from RT-PCR. Conclusion Hyperglycemia altered the expression of MMP-9 and TIMP-1 in the skin tissue. Heavy bacterial colonization in diabetic wound increased the expression of MMP-9, and decreased the TIMP-1 expression, which may disturb the balance of MMP-9/TIMP-1, affecting wound healing. Key words: Diabetes; Wound; Bacteria; Matrix metalloproteinase; Tissue inhibitorof metalloproteinase