Inhibitory effect of ulinastatin on osteoclast activation and the relationship of ulinastatin to matrix metalloproteinase-2 and matrix metalloproteinase-9:potential of preventing prosthetic osteolysis / 中国组织工程研究

ABSTRACT

BACKGROUND:It is presumed that urinary trypsin inhibitor could have protective effects on local and systemic tissues and could inhibit osteoclast proliferation and activation under long-term chronic inflammation conditions and in ischemic and anoxic environment which was induced by prosthetic wear. OBJECTIVE:To investigate the inhibitory effect of ulinastatin on receptor activator for nuclear factor-κb ligand-induced differentiation, proliferation and osteoclastogenesis of RAW264.7 cells and its effects on matrix metal oproteinase-2, matrix metal oproteinase-9 expression level and activity. METHODS:Mouse monocyte/macrophage cellline RAW264.7 was treated with different concentrations of urinary trypsin inhibitor (0, 500, 5 000 U/mL) for 24, 48 and 72 hours. Experiments were divided into four groupsthe blank group (RAW264.7 cells), receptor activator for nuclear factor-κb ligand-induced group (0 U/mL ulinastatin), 500 U/mL ulinastatin group and 5 000 U/mL ulinastatin group. RESULTS AND CONCLUSION:(1) MTT results indicated that there was no significant difference on the proliferation of RAW264.7 cells treated with urinary trypsin inhibitor at 0-5 000 U/mL (P>0.05) (2) Tartrate-resistant acid phosphatase staining results revealed that compared with receptor activator for nuclear factor-κb ligand-induced group, the number of tartrate-resistant acid phosphatase-positive cells was significantly less in the ulinastatin group (P<0.05), showing a time-dose dependent manner. (3) Immunohistochemisical results found that compared with receptor activator for nuclear factor-κb ligand-induced group, the percentage of matrix metal oproteinase-9-positive cells was apparently lower in the ulinastatin group. (4) Western blot assay results demonstrated that matrix metal oproteinase-9 expression was low in the RAW264.7 cells alone. At 48 hours after addition of receptor activator for nuclear factor-κb ligand, matrix metal oproteinase-9 protein expression was large. At 72 hours after culture in the 5 000 U/mL ulinastatin group, matrix metal oproteinase-9 protein expression was evidently reduced. (5) Gelatin zymography results showed that compared with the receptor activator for nuclear factor-κb ligand-induced group, matrix metal oproteinase-9 expression was significantly lower in the 5 000 U/mL ulinastatin group (P<0.05). Results suggested that urinary trypsin inhibitor inhibited receptor activator for nuclear factor-κb ligand-induced osteoclastogenesis and diminished matrix metal oproteinase-9 expression and activity.