MT1-MMP、MMP-2和TIMP-2基因在去卵巢大鼠成骨细胞中的表达

目的　通过观察去卵巢 (OVX)骨质疏松模型大鼠成骨细胞膜型基质金属蛋白酶 1(MT1 MMP)基因的表达 ,探讨绝经后骨质疏松的发病机制。　方法　对OVX大鼠与假手术大鼠进行骨密度和骨组织形态计量学测定。股骨远端行原位杂交检测骨组织MT1 MMP、MMP 2和TIMP 2mRNA表达 ,免疫组化检测骨组织MT1 MMP、MMP 2和TIMP 2蛋白质表达。　结果　OVX大鼠第 3、4腰椎骨密度 (0 14 4± 0 0 11) g cm2 、(0 14 3± 0 0 15 ) g cm2 较对照组 (0 15 8± 0 0 18)g cm2 、(0 16 2± 0 0 17) g cm2 明显减少 ,OVX组骨小梁面积 (9 5 8± 3 39) %、厚度 (40 85± 8 0 4 ) μm和数目 (2 30± 0 4 8)个 mm分别较对照组 (2 0 6 3± 4 8) %、(44 73± 6 8) μm、(4 6± 0 7)个 mm明显下降 ,OVX组骨小梁间隔 (5 85 8± 115 1) μm较对照组 (2 5 4 6± 4 8 0 ) μm明显增宽 ;成骨细胞MT1 MMPmRNA与蛋白质表达下调 ,而MMP 2和TIMP 2之间表达无差异。　结论　雌激素不足可使成骨细胞MT1 MMP基因表达减少 ,可能为绝经后骨质疏松的发病机制之一。     

TIMP-2、MMP-2和MT1-MMP在活化肝星状细胞中的表达及对细胞外基质合成分泌的影响

目的 研究金属蛋白酶组织抑制剂-2(TIMP-2)、基质金属蛋白酶-2(MMP-2)和膜型基质金属蛋白酶-1(MT1-MMP)在活化肝星状细胞(HSCs)中的表达,观察其对细胞外基质(ECM)合成分泌的影响.方法 原代分离培养大鼠HSCs活化后,分别给予40～160 pmol化学合成经修饰抗TIMP-2 siRNA进行干预,检测培养细胞上清液透明质酸(HA)、Ⅲ型前胶原(PCⅢ)和羟脯氨酸(Hyp)的含量,采用荧光实时定量PCR法检测TIMP-2、MMP-2、MT1-MMP、MMP-13、COL Ⅰ和COL Ⅲ mRNA的表达,western印迹检测TIMP-2、MT1-MMP和MMP-13蛋白表达及明胶酶谱法检测MMP-2蛋白表达.结果 应用化学合成经修饰抗TIMP-2 siRNA后,TIMP-2、MMP-2、MT1-MMP、COL Ⅰ和COL Ⅲ的表达明显降低,而MMP-13的表达则明显增加,培养细胞上清液中HA、PCⅢ和Hyp的含量也明显减少.结论 TIMP-2通过MT1-MMP介导MMP-2的活化,抑制TIMP-2的表达,MT1-MMP和MMP-2的表达随之降低,而HSCs合成分泌ECM也相应减少.     

卵巢浆液性腺癌组织中MMP-2、MT1-MMP的表达变化及意义

目的观察卵巢浆液性腺癌中的基质金属蛋白酶-2（MMP-2）、膜型基质金属蛋白酶-1（MT1-MMP）的表达变化。方法采用免疫组化PV6000法检测50例卵巢浆液性腺癌、30例卵巢交界性浆液性腺瘤和30例卵巢良性浆液性腺瘤组织中的MMP-2、MT1-MMP。结果MMP-2和MT1-MMP在卵巢浆液性腺癌和交界性浆液性腺瘤中的表达阳性率高于良性浆液性腺瘤（P〈0．05）。卵巢良性浆液性腺瘤组织中的MMP-2、MT1-MMP与病理分级、淋巴结转移、临床分期和预后有关（P均〈0．0．5）。卵巢浆液性腺癌中MMP-2、MT1-MMP的表达呈正相关（L=0．61,P〈0．01）。结论卵巢浆液性腺癌中MMP-2、MT1-MMP表达上调。二者在卵巢浆液性腺癌的发生、浸润和转移中过程中协同发挥重要作用,可作为判断肿瘤恶性程度和预后的重要指标。     

Regulation of matrix metalloproteinase MT1-MMP/MMP-2 in cardiac fibroblasts by TGF-beta1 involves furin-convertase

OBJECTIVE: Heart failure is characterized by an imbalance of matrix synthesis/turnover, finally resulting in fibrosis. Cardiac myocytes and fibroblasts play a pivotal role in the remodeling process. Cardiac remodeling involves the expression of TGF-beta1 and matrix metalloproteinases (MMPs) in cardiac fibroblasts (CFBs). Furin, a subtilisin/kexin-like proprotein convertase (PC), activates TGF-beta1 and membrane-bound MT1-MMP, which facilitates pro-gelatinase A (MMP-2) activation. Even though several reports identified TGF-beta1 as a pro-fibrotic cytokine in the heart, it increases MMP-activity and cell migration/invasion in several cell types. The present study was done to investigate the contribution of TGF-beta1 and furin to CFBs MMP-activity and motility. METHODS AND RESULTS: Stimulation of CFBs from adult Sprague-Dawley rats with TGF-beta1 (20 ng/ml) induced furin, but had no effect on the closely related PC5. Inhibition of furin inhibited angiotensin II-induced TGF-beta1 activation, indicating that TGF-beta1 amplifies its activating convertase in CFBs. Pretreatment of CFBs with TGF-beta1 (20 ng/ml, 24 h) increased their migration by about two-fold (p<0.05), which was accompanied by an enhanced expression and activity of MT1-MMP and MMP-2. Brefeldin A (BFA), a Golgi-disturbing agent, inhibited MT1-MMP activation, indicating that it occurs in the trans-Golgi network (TGN), where furin is concentrated and colocalized with MT1-MMP. Inhibition of furin significantly inhibited TGF-beta1-induced MT1-MMP/MMP-2 activation. Furthermore, inhibition of furin attenuated TGF-beta1-enhanced migration on gelatin-coated membranes (p<0.05). This was comparable to the effects of the MMP-inhibitor GM6001, pointing out that MMPs are major mediators of TGF-beta1-enhanced CFB motility. CONCLUSION: We demonstrate that TGF-beta1 induces MMP-activity in CFBs, thereby facilitating CFBs motility. Furthermore, TGF-beta1 amplifies its activating convertase furin, which is also required for MT1-MMP/MMP-2 activation in CFBs. Thus, furin is central for TGF-beta1 and MT1-MMP activation and might be a novel target in cardiac remodeling.     

Catechins prevent vascular smooth muscle cell invasion by inhibiting MT1-MMP activity and MMP-2 expression

OBJECTIVE: Regular consumption of green tea is associated with a reduced risk of mortality due to coronary diseases and cancer. The present study examined whether a green tea extract (GTE) inhibits activation of matrix metalloproteinase-2 (MMP-2), a major collagenase involved in vascular remodeling of atherosclerotic plaques, in vascular smooth muscle cells (VSMCs). METHODS AND RESULTS: The expression of MMP-2 was assessed by Northern and Western blot analyses in human aortic VSMCs. MMP-2 activity was evaluated by zymography, membrane-type1-MMP (MT1-MMP, MMP-14) activity by an enzymatic assay, and cell invasion by a modified Boyden chamber assay. The thrombin-induced activation of secreted MMP-2 was abolished by GTE and the green tea polyphenols (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG). GTE reduced the expression of MMP-2 mRNA and protein. GTE, EGCG and ECG directly inhibited cell-associated MT1-MMP activity, the physiological activator of MMP-2, in a reversible manner. Thrombin-stimulated VSMCs invasion was abolished by EGCG and ECG, and reduced by GTE. CONCLUSIONS: GTE inhibits thrombin-induced VSMCs invasion most likely by preventing MMP-2 expression and its activation by a direct inhibition of MT1-MMP. The ability of green tea to prevent cell invasion and matrix degradation might contribute to its protective effect on atherosclerosis and cancer.     

MT1-MMP对人肝癌细胞株HepG2生物学行为的影响

目的 观察膜型基质金属蛋白酶-1(MT1-MMP)对人肝癌细胞株HepG2生物学行为的影响.方法 将稳定表达MT1-MMP基因转染至HepG2细胞中,应用RT-PCR、Ⅰ型胶原黏附和Matrigel侵袭小室实验,检测细胞MT1-MMP mRNA水平,体外黏附、侵袭和迁移能力的变化.结果 重组质粒转染株MT1-MMP mRNA表达水平明显高于空质粒组和对照组(P<0.01).MT1-MMP明显提高细胞Ⅰ型胶原黏附、迁移和Matrigel侵袭能力(P<0.01).结论 MT1-MMP过表达可促进HepG2细胞体外侵袭和转移,提示其可作为人肝癌抗侵袭治疗的分子靶点.     

Cocoa procyanidins inhibit expression and activation of MMP-2 in vascular smooth muscle cells by direct inhibition of MEK and MT1-MMP activities

AIMS: Expression and activation of matrix metalloproteinase (MMP)-2 play pivotal roles in the migration and invasion of human aortic vascular smooth muscle cells (VSMC) originating from normal human tissue, which is strongly linked to atherosclerosis. The present study investigated the possible inhibitory effects of cocoa procyanidin on thrombin-induced expression and activation of MMP-2 in VSMC. METHODS AND RESULTS: Cocoa procyanidin fraction (CPF) and procyanidin B2, one of major procyanidins in cocoa (3 microg/mL and 5 microM, respectively), strongly inhibited thrombin-induced activation and expression of pro-MMP-2 in VSMC, as determined by zymography. The thrombin-induced invasion and migration of VSMC were inhibited by CPF or procyanidin B2 (P < 0.05), as assessed by a modified Boyden chamber and wound healing assays, respectively. An enzymatic assay data demonstrated that CPF and procyanidin B2 directly inhibited membrane type-1 (MT1)-MMP activity (P < 0.05), and this inhibition of CPF was greater than those of red wine polyphenols. Western blot data showed that CPF and procyanidin B2 inhibited thrombin-induced phosphorylation of extracellular signal-regulated protein kinase but not mitogen-activated protein kinase kinase (MEK) in VSMC. Kinase and pull-down data revealed that CPF and procyanidin B2 inhibited MEK1 activity and directly bound with glutathione-S-transferase-MEK1. In addition, the thrombin-induced invasion and migration and the activation and expression of pro-MMP-2 in VSMC were attenuated by U0126 (a well-known inhibitor of MEK1). CONCLUSION: Cocoa procyanidins are potent inhibitors of MEK and MT1-MMP, and subsequently inhibit the expression and activation of pro-MMP-2, and also the invasion and migration of VSMC, which may in part explain the molecular action of antiatherosclerotic effects of cocoa.     

MT1-MMP对人肝癌细胞浸润能力的影响

目的 观察膜型基质金属蛋白酶-1(MT1-MMP)对人肝癌细胞株浸润能力的影响,并初步探讨其作用机制.方法 将稳定表达MT1-MMP基因转染至HepG2细胞中,应用Western印迹法检测MT1-MMP蛋白表达;明胶酶谱分析法检测MMP-2酶原活性;体外侵袭实验检测细胞株浸润能力.结果 重组质粒转染株MT1-MMP蛋白表达水平明显高于空质粒组和未转染组(P＜0.01).明胶酶谱分析实验发现,MT1-MMP组同时检测到72000酶原形式和64000活性形式的MMP-2,另两组只检测到72000酶原形式的MMP-2.体外侵袭实验结果显示,MT1-MMP组细胞穿过基质胶(Matrigel)的细胞数目明显多于其他两组(P＜0.01).结论 MT1-MMP能显著增强肝癌细胞株的浸润能力,其机制主要是通过激活MMP-2-酶原,降解肿瘤周围的基质成分实现的.     

法尼酯衍生物X受体活化对肝星状细胞TIMP-1、TIMP-2及MMP-2表达的调节作用

目的研究法尼酯衍生物X受体（FXR）对肝星状细胞基质金属蛋白酶组织抑制因子-1（TIMP-1）和基质金属蛋白酶组织抑制因子-2（TIMP-2）及基质金属蛋白酶-2（MMP-2）表达的影响。方法应用FXR人工合成配体GW4064（0.01、0.1、1μmol/L）处理大鼠肝星状细胞株HSC-T6后,应用实时荧光定量PCR法检测FXR、TIMP-1、TIMP-2及MMP-2 mRNA表达变化,应用Western Blot法检测TIMP-1、TIMP-2及MMP-2蛋白表达的变化。结果 GW4064处理HSC-T6后,FXR mRNA相对表达量明显增加（P=0.000）,TIMP-1及TIMP-2 mRNA及蛋白相对表达量明显减少（P〈0.01）,GW4064浓度在1μmol/L时MMP-2mRNA及蛋白相对表达量则明显增加（P=0.000）。结论 GW4064通过激活FXR下调TIMP-1和TIMP-2表达及上调MMP-2的表达来调控细胞外基质的合成和降解的平衡,提示FXR配体可能可以治疗肝纤维化。     

Expression of chemokine by human coronary-artery and umbilical-vein endothelial cells and its regulation by inflammatory cytokines

BACKGROUND: Activation of the endothelium is a critical event in the process of inflammation and is associated with the production of chemokines. OBJECTIVE: To evaluate the proinflammatory cytokine-induced chemokine repertoire of human coronary-artery endothelial cells (HCAEC) both at the messenger RNA (mRNA) level and at protein level in direct comparison with that of human umbilical-vein endothelial cells (HUVEC). METHODS: Human coronary-artery and human umbilical-vein endothelial cells were obtained commercially and experimental data were derived from cell cultures between passage levels 3 through 6. Supernatant fluids from cytokine [tumor necrosis factor-alpha (TNF-alpha), interleukin-1-alpha, and anti-TNF R55] stimulated endothelial cell cultures were used to study chemokine release. Sandwiched ELISA assays, obtained commercially, were used to estimate cell culture supernatant fluid levels of the selected chemokines: monocytic chemotactic protein-1, regulated upon activated normal T cells expressed and secreted, interleukin-8, transforming growth factor-beta-2 (TGF-beta2), and gamma interferon protein-10. Expression of messenger RNA was determined using selected labeled riboprobes (32P UTP) in a ribonuclease protection assay using total cellular mRNA. RESULTS: Upon in-vitro stimulation with TNF-alpha and interleukin-1-alpha, production of regulated-upon-activated-normal-T-cells expressed and secreted (RANTES) protein by HCAEC was significantly increased relative to that by HUVEC, the greatest effect being found with interleukin-1-alpha. The opposite effect, however, was noted for levels of monocytic-chemotactic-protein-1 protein, which were detected in HUVEC at significantly higher levels than they were in HCAEC challenged by those cytokines. Production of gamma interferon-inducible protein-10 (gammaIP-10) by HUVEC was induced by TNF-alpha and interleukin-1-alpha, whereas only a modest induction by interleukin-1-alpha was seen in HCAEC. TGF-beta-2 protein was constitutively expressed in HCAEC but not in HUVEC. Expression of mRNA was analyzed by the ribonuclease-protectionassay. RANTES mRNA was expressed in HCAEC from 3 h through 48 h after treatment with TNF-alpha, whereas only a modest induction of RANTES was expressed in HUVEC 24 h and 48 h after treatment with TNF-alpha. Monocytic-chemotactic-protein-1 mRNA was constitutively expressed by both types of cell, but the basal levels in HCAEC was significantly higher than in HUVEC. HCAEC constitutively expressed both TGF-beta-1 and TGF-beta-2 mRNA, whereas HUVEC constitutively expressed TGF-beta-1 only. CONCLUSION: Our data indicate that HCAEC and HUVEC express chemokines differently, which could contribute to or influence site-specific recruitment of subsets of leukocytes.     

Evidence that MMP-2 and TIMP-2 are at play in the FSH-induced changes in Sertoli cells

FSH has been shown to elicit in vitro changes in the Sertoli cell cytoskeleton through involving proteases, and cytochalasin-D mimics FSH. Testis extracts were screened (RT-PCR) for various metalloproteinases (MMPs), 20-day-old rat Sertoli cells were purified, cultured and treated with FSH, cytochalasin D and TNFalpha (to antagonize FSH action). Cell shape (phase-contrast microscopy) and levels for MMP-2 (gelatin zymography) and its inhibitor TIMP-2 (Northern and Western blot) were monitored. TNFalpha-treated cells spread readily and grew larger than FSH-treated cells. Cytochalasin-D mimicked FSH, and MMP-2 production and TIMP-2 gene expression were augmented. Interestingly, TNFalpha reversed FSH- and cytochalasin D-induced effects both on cell shape and on MMP-2 and TIMP-2. These effects occurred during the first 48 h of culture, when Sertoli cells migrated from the freshly dispersed aggregates, but not once cells were organized in monolayers. MMP-2 and TIMP-2 are likely involved in the FSH-induced changes in Sertoli cells.     

Effects of 17beta-estradiol on the expression of membrane type 1 matrix metalloproteinase (MT1-MMP) and MMP-2 in human osteoblastic MG-63 cell cultures

Estrogens are important regulators of bone cell function. Osteoblast-derived membrane type 1 matrix metalloproteinses (MT1-MMP) have recently been implied to play an important role in the process of bone resorption by proteolytically activating latent matrix metalloproteinase-2 (proMMP-2) at the cell surface and degrading tumor necrosis factor-alpha (TNF-alpha). In the present study, we observed the effects of 17beta-estradiol (E2) on MT1-MMP production and subsequent activation of latent matrix proMMP-2, and also proMMP-2 secretion in cultures of human osteoblastic MG-63 cells. Western immunoblot analysis showed that treatment with increasing doses of E2 in MG-63 cells caused a dose-dependent increase in expression of MT1-MMP protein. Confocal immunohistochemistry analysis also confirmed that E2 induced MT1-MMP synthesis in MG-63 cells. We found unexpectedly that although MT1-MMP synthesis was up-regulated by E2 in cultures of MG-63 cells, activation of proMMP-2 was unchanged, which can be attributed partly to the undetectable tissue inhibitor of metalloproteinase-2 (TIMP-2) protein in MG-63 cells by Western immunoblotting. ProMMP-2 production was also not influenced by E2. In conclusion, E2 induces MT1-MMP protein expression in MG-63 cells while it is not followed by proMMP-2 activation, E2 may suppress bone resorption by accentuated degradation of TNF-alpha which mediated through increasingly MT1 -MMP production in osteoblastic cells.     

Cloning of human Bcl-2 homologue: inflammatory cytokines induce human A1 in cultured endothelial cells

Bcl-2 is an intracellular membrane-associated protein that functions to block programmed cell death. Despite recurrent exposure to cellular toxins from the circulation and tissue, endothelial cells are remarkably resistant to cell death. Because Bcl-2 protein levels are low or undetectable in endothelial cells, we postulated that other members of the growing Bcl-2 family would be present in endothelial cells to provide protection against apoptosis. Degenerate primers to two conserved regions of the Bcl-2 family were used to amplify potential homologues in endothelial cells. This strategy resulted in the isolation of a human Bcl-2 homologue related to murine Al, a recently identified member of this family. We show here that, in endothelial cells, human Al is rapidly inducible by phorbol ester and the inflammatory cytokines, tumor necrosis factor-alpha and interleukin- 1beta, but not by the growth factors, basic fibroblast growth factor or vascular endothelial growth factor. Al is the only known Bcl-2 family member that is inducible by inflammatory cytokines, suggesting that it may play a protective role during inflammation. Additionally, vascular smooth muscle cells and various nonhematopoietic tissues express human Al, indicating that human Al is a widely expressed Bcl-2 homologue.     

Expression of MMP—2,TIMP—2 protein and the ratio of MMP—2／TIMP—2 in gallbladder carcinoma and their significance

AIM: To study the correlation between expression of MMP-2, TIMP-2 protein and the ratio of MMP-2/TIMP-2 and clinicalpathological parameters of patients with gallbladder carcinoma.METHODS: Carcinomas (n=45) and polypoid lesions (n=15) of the gallbladder were studied for the expression of MMP-2 and TIMP-2 protein by immunohistochemical avidin-biotin-complex method and image analysis. Clinicalpathological data of patients with gallbladder carcinoma such as histological type, grade of differentiation, level of infiltration, liver invasion and lymph node involvement, etc, were recorded.RESULTS: There was significant difference between the average level (1.123±0.108 VS 1.030±0.054, P=0.002) of MMP-2, the ratio (1.050±0.013 VS0.937±0.078, P=0.003) of MMP-2/TIMP-2 in gallbladder carcinomas and in polypoid lesions of the gallbladder. Significant difference was found between the expression of MMP-2 in early stage and advanced tumors, but there was no correlation between MMP-2 protein expression and histological type, differentiation degree, infiltration level, lymph node involvement or liver invasion. Although no difference was observed between TIMP-2 expression and histological type or differentiation degree, signific ant difference was found between TIMP-2 expression and different Nevin stage, infiltration level, local lymph node involvement or liver invasion (1.168±0.067 VS1.048±0.075, 1.170±0.062 vs 1.039±0.06g, 1.039±0.076 VS1.147±0.083, 1.048±0.074 vs 1.103±0.095, P＜0.05). MMP-2/TIMP-2 ratio did not correlate with histological type, grade of differentiation and liver invasion, but significant differences were found between MMP-2/TIMP-2 ratio and different Nevin stage, infiltration level and lymph node involvement in patients with carcinoma of gallbladder.CONCLUSION: TIMP-2 and MMP-2/TIMP-2 ratio could reflect more accurately biological characteristic of gallbladder carcinoma and MMP-2/TIMP-2 ratio might be a new significant marker in early diagnosis, in the judgment of invasion or metastasis and the estimate of prognosis in patients with gallbladder carcinomas.