Chiu H-C, Lu Y-T, Chin Y-T, Tu H-P, Chiang C-Y, Gau C-H, Nieh S, Fu E
Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, China.
J Periodontal Res. 2009 Jun;44(3):338-47. doi: 10.1111/j.1600-0765.2008.01126.x. Epub 2009 Feb 6.
Membrane type-I matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase-2 (TIMP-2) regulate the activation of MMP-2; however, their roles in the activation of MMP-2 in gingiva during treatment with cyclosporine A are still unknown. Therefore, the expressions of membrane type-I MMP and TIMP-2, as well as MMP-2, in gingivae upon treatment with cyclosporine A were examined in vivo and in vitro.
Thirty-four rats were divided into two groups after edentulous ridges were established. The experimental group received 30 mg/kg/d of cyclosporine A and the control group received vehicle. At the end of the experimental period, the rats were killed, the gingivae were obtained and the expression of mRNA and protein of membrane type-I MMP, TIMP-2 and MMP-2 in gingiva were examined using real-time polymerase chain reaction and immunohistochemistry. In human gingival fibroblasts, the activity of MMP-2 and the expression of MMP-2, membrane type-I MMP and TIMP-2 mRNAs were examined (using zymography and reverse transcription-polymerase chain reaction, respectively) after treatment with cyclosporine A.
In gingivae of rats, cyclosporine A significantly decreased the expression of mRNA and protein of membrane type-I MMP, but not of TIMP-2. The expression of MMP-2 mRNA was unaffected but the expression of MMP-2 protein showed a significant decrease upon treatment with cyclosporine A. In fibroblast culture medium, the presence of cyclosporine A induced a decrease in MMP-2 activity in a dose-dependent manner. The expression of MMP-2, membrane type-I MMP and TIMP-2 mRNAs in fibroblasts was not significantly affected by cyclosporine A; however, in fibroblasts the ratio of mRNA expression of membrane type-I MMP to that of TIMP-2 decreased as the cyclosporine A dose was increased.
Cyclosporine A inhibits the expression of membrane type-I MMP in gingiva and it may further reduce the activation of MMP-2.
膜型-I基质金属蛋白酶（MMP）和金属蛋白酶组织抑制剂-2（TIMP-2）调节MMP-2的激活；然而，它们在环孢素A治疗期间牙龈中MMP-2激活过程中的作用仍不清楚。因此，在体内和体外研究了环孢素A治疗后牙龈中膜型-I MMP、TIMP-2以及MMP-2的表达。
建立无牙嵴后，将34只大鼠分为两组。实验组给予30mg/kg/d的环孢素A，对照组给予赋形剂。实验期末，处死大鼠，获取牙龈，采用实时聚合酶链反应和免疫组织化学检测牙龈中膜型-I MMP、TIMP-2和MMP-2的mRNA和蛋白表达。在人牙龈成纤维细胞中，用环孢素A处理后，分别采用酶谱法和逆转录-聚合酶链反应检测MMP-2的活性以及MMP-2、膜型-I MMP和TIMP-2 mRNA的表达。
在大鼠牙龈中，环孢素A显著降低膜型-I MMP的mRNA和蛋白表达，但不影响TIMP-2。环孢素A处理后，MMP-2 mRNA的表达未受影响，但MMP-2蛋白表达显著降低。在成纤维细胞培养基中，环孢素A的存在以剂量依赖方式诱导MMP-2活性降低。环孢素A对成纤维细胞中MMP-2、膜型-I MMP和TIMP-2 mRNA的表达无显著影响；然而，在成纤维细胞中，随着环孢素A剂量增加，膜型-I MMP与TIMP-2的mRNA表达比值降低。
环孢素A抑制牙龈中膜型-I MMP的表达，可能进一步降低MMP-2的激活。
