Mitogenic bovine whey extract modulates matrix metalloproteinase-2, -9, and tissue inhibitor of matrix metalloproteinase-2 levels in chronic leg ulcers

Matrix metalloproteinases (MMPs) and their tissue inhibitors play important roles in the wound-healing process. An imbalance in the expression of these molecules is thought to contribute to the failure of chronic ulcers to heal. We investigated whether a mitogenic bovine whey extract enriched with growth factors modulated the expression and activity of MMP-2 and -9, and the tissue inhibitor of MMP-2 (TIMP-2) in chronic leg ulcers. Wound fluids and biopsies were collected from chronic leg ulcer patients whose ulcers were treated topically for 4 weeks with placebo or mitogenic bovine whey extract at concentrations of 2.5, 10, and 20 mg/mL. The levels of MMP-2 and -9 in wound fluid samples was assessed by gelatin zymography and showed a decrease in active MMP-2 in the 2.5 and 10.0 mg/mL mitogenic bovine whey extract-treated ulcers compared with placebo (p<0.05). Immunohistochemical analysis of ulcer biopsies for MMP-2, -9, and TIMP-2 expression showed a reduction in the number of MMP-2-positive dermal fibroblasts in the mitogenic bovine whey extract-treated ulcers compared with pretreatment biopsies (p<0.05) that persisted over the course of the study. In contrast, a transient increase in the number of MMP-9- and TIMP-2-positive cells was observed in mitogenic bovine whey extract treated ulcer biopsies compared with pretreatment levels (p<0.05). These results show that topical application of mitogenic bovine whey extract was able to modulate the expression of MMP-2, -9, and TIMP-2 in chronic leg ulcers and that its constituent growth factors may have the potential to redress the proteolytic imbalance observed in nonhealing chronic ulcers.     

神经慢性卡压后基质金属蛋白酶及其组织抑制物在神经中的表达

目的 观察大鼠坐骨神经慢性卡压后基质金属蛋白酶-9(MMP-9)和金属蛋白酶组织抑制剂( TIMP-1)在神经中的表达.方法 将90只雄性SD大鼠随机分为对照组和卡压组.根据Mackinnon法建立神经慢性卡压模型,采用逆转录-聚合酶链反应(RT-PCR)和免疫组织化学技术检测神经干内MMP-9和TIMP-1的表达.结果 神经慢性卡压2周时神经纤维脱髓鞘;4周时结缔组织增生;12周后神经内纤维分隔进行性增多,神经纤维化.早期,MMP-9和TIMP-1表达增加,MMP-9mRNA在2周达峰值0.0485,TIMP-1 10周达峰值0.1592,MMP-9/TIMP-1明显升高;后期,MMP-9显著降低,TIMP-1继续升高,MMP-9/TIMP-1显著降低.结论 周围神经慢性卡压后神经纤维化,其机制可能与神经中MMP-9/TIMP-1比值早期增高、晚期降低有关.     

基质金属蛋白酶1,9表达与下肢慢性静脉功能不全关系的研究

目的检测慢性静脉功能不全(CVI)患者大隐静脉组织中基质金属蛋白酶(MMP)1,9的表达,探讨MMP-1、MMP-9在CVI血管重塑中的作用。方法对80例CVI患者(其中轻度CVI22例,中度CVI28例,重度CVI30例)及20例对照组病例,采用免疫组织化学染色法测定MMP-1、MMP-9蛋白在大隐静脉标本中的表达,以逆转录-聚合酶链反应(RT-PCR)法检测MMP-1mRNA、MMP-9mRNA的表达。结果在轻、中、重CVI组中MMP-1蛋白及mRNA的表达水平高于正常对照组,差异有统计学意义(P0.05);在轻、中、重CVI组中MMP-9蛋白及mRNA表达水平高于正常对照组,差异有统计学意义(P0.05);在轻、中、重CVI三组内比较时,重度CVI组和轻、中度CVI组之间MMP-9mRNA表达,差异有统计学意义(P0.01)。结论 MMP-1、MMP-9可能参与下肢CVI血管重塑这个过程的调节;MMP-9表达水平随临床严重程度升高而升高,提示MMP-9可能作为评估临床严重程度的一个指标。     

Different mRNA and protein expression of matrix metalloproteinases 2 and 9 and tissue inhibitor of metalloproteinases 1 in benign and malignant prostate tissue

OBJECTIVE: The aim of this study was to assess the behavior of the matrix metalloproteinases (MMPs) 2 and 9 and the tissue inhibitor of metalloproteinases 1 (TIMP-1) in human prostate cancer. METHODS: mRNA and protein expression patterns of MMP-2, MMP-9, and TIMP-1 were studied in cancerous and noncancerous parts of 17 prostates removed by radical prostatectomy. Competitive RT-PCR, gelatin-substrate zymography, and ELISA techniques were used for quantification. RESULTS: On the mRNA level, MMP-2 expression was decreased and MMP-9, TIMP-1, the ratios of MMP-2 and MMP-9 to TIMP-1 were unchanged in cancerous tissue compared to the normal counterparts. On the protein level, expression of MMP-9 was significantly higher and TIMP-1 expression was significantly lower, MMP-2 was unchanged and the ratios of MMP-2 and MMP-9 to TIMP-1 were increased in tumor tissue. CONCLUSIONS: The higher concentration of MMP-9 as well as the increased ratios of MMP-2 and MMP-9 to TIMP-1 in malignant tissue prove the proteolytic dysbalance in prostate cancer, which does not seem to be associated with the stage and grade of the tumor. Comparison of mRNA and protein expression of MMP-2, MMP-9 and TIMP-1, respectively, did not show any significant relationships illustrating the necessity to study these components at both molecular levels.     

大鼠脑动脉瘤形成过程中基质金属蛋白酶2和9及其抑制物的表达变化

目的观察基质金属蛋白酶（MMP）-2和MMP-9及其抑制物的表达变化在脑动脉瘤形成过程中的作用。方法制作肾性高血压大鼠脑动脉瘤模型，系统动态观察脑动脉瘤形成过程中MMP-2、MMP-9及其特异性抑制物（TIMP-1）表达的变化。结果实验组在术后1周脑动脉壁即可见MMP-2、MMP-9、TIMP-1表达增加，随着血压的升高，其表达也迅速增加，术后1个月基本达最高峰并-直持续至4个月，其中MMP-9增加最为显著，约是正常状态的10倍，而MMP-2和TIMP-1的表达约是正常状态的2倍。对照组脑动脉壁MMP-2、MMP-9、TIMP-1也有微弱表达，且MMP-2表达较MMP-9略强。结论脑动脉壁MMP-2、MMP-9特别是MMP-9的过度表达是导致动脉瘤形成的主要原因之-     

血清基质金属蛋白酶2和抑制因子与绝经后骨质疏松症的相关性

目的探讨绝经后妇女血清基质金属蛋白酶2（MMP-2）和抑制因子（TIMP-2）水平及其与绝经骨质疏松症指标的关系。方法将202名48～65岁绝经后妇女分为正常组、低骨量组和骨质疏松组，用酶联免疫吸附试验（EIJSA）测定的血清MMP-2、TIMP-2以及骨保护蛋白（OPG）、骨保护蛋白配体（OPGL），计算MMP-2／TIMP-2和OPG／OPGL比值，用双能X线吸收法（DEXA）测定腰椎正位、股骨颈、华氏区和大粗隆的骨密度（BMD）。结果①骨质疏松组中血清MMP-2的数值（1392±121）μg／L高于正常组（1123±141）μg／L（P〈0．05），而TIMP-2的数值（44．3±36．2）ng/ml低于正常组（47．8±30．2）ng/ml。②骨质疏松组中血清MMP-2和MMP-2／TIMP-2比值与骨密度、血精OPGL数值存在明显负相关性（P〈0．05），和OPG和OPG／OPGL比值存在明显正相关性（P〈0．05），TIMP-2和华氏区骨密度和OPG存在明显正相关性（P〈0．05）。结论血清MMP-2和MMP-2／TIMP-2比值与绝经后骨质疏松症妇女骨密度和骨代谢指标OPG、OPGL和OPG／OPGL比值具有关联性。血清MMP-2水平升高和MMP-2／TIMP-2比值降低可能为绝经后骨质疏松症伴随骨代谢转换过程增快的表现。     

基质金属蛋白酶－9、细胞金属蛋白酶抑制因子－1在胃癌中的表达

目的：探讨基质金属蛋白酶－9（MMP－9）,组织金属蛋白酶抑制因子－1（TIMP－1）在胃癌中表达的意义。方法：采用免疫组化S－P法对47例胃癌组织进行MMP－9及TIMP－1的检测。结果：MMP－9,TIMP－1主要表达于癌周基质细胞,癌细胞少量表达,MMP－9,TIMP－1表达与胃癌患淋巴结转移（P＜0．01）,浆膜浸润相关（P＜0．01）;TIMP－1的表达与胃癌TNM分期相关（P＜0．05）,而MMP－9的表达与胃癌TNM分期无相关性（P＞0．05）。结论：MMP－9及TIMP－1可作为判断胃癌恶性行为的重要生物学标记物。     

结肠直肠癌病人血浆金属蛋白酶及其组织抑制物的表达及意义

目的：探讨结肠直肠癌病人血浆中基质金属蛋白酶-9（MMP-9）及其组织抑制因子-1（TIMP-1）的表达与结肠直肠癌浸润、转移及预后的关系,以及手术、化疗对其表达的影响,以期在分子水平上更准确地判断结肠直肠癌的预后。方法：选取结肠直肠癌病人50例,于手术前、术后10d、6次化疗后2周,分别抽取病人4mL外周静脉血,采用酶联免疫分析法检测MMP-9、TIMP-1血浆浓度的变化。结果：低分化结肠直肠癌病人血浆MMP-9及TIMP-1水平高于高、中分化者（P〈0．01、P〈0．05）;TNMⅢ、Ⅳ期病人高于TNMⅠ、Ⅱ期者（P〈0．01）。手术后血浆MMP-9、TIMP-1水平显著下降,有统计学意义（P〈0．01、P〈0．05）,化疗后其浓度变化无显著性差异（P〉0．05）。结论：MMP-9和TIMP-1与肿瘤恶性程度有关;术前检测外周血MMP-9和TIMP-1浓度有可能成为结肠直肠癌辅助诊断及病情评估的较好血清学标志。MMP-9可能与肿瘤复发或转移存在一定关系,术后动态检测外周血MMP-9浓度可反映肿瘤负荷。从而对监测肿瘤复发提供一定帮助。     

The impact of differential expression of extracellular matrix metalloproteinase inducer, matrix metalloproteinase-2, tissue inhibitor of matrix metalloproteinase-2 and PDGF-AA on the chronicity of venous leg ulcers.

INTRODUCTION: Alteration in the expression of extracellular matrix metalloproteinase inducer (EMMPRIN), matrix metalloproteinase-2 (MMP-2), tissue inhibitors of matrix metalloproteinases (TIMP-2) and platelet derived growth factor (PDGF-AA) may contribute to poor healing in venous leg ulcers. AIM: The aim of this study is to determine the expression of EMMPRIN, MMP-2, TIMP-2 and PDGF-AA in the ulcer exudates and perivascular tissue of healing and non-healing chronic venous ulcers. PATIENTS, MATERIALS AND METHODS: Forty patients with chronic venous ulcers were included in this study, with a mean age of 60 years. Eleven patients were males and 29 were females. All patients had normal ankle brachial index and a venous ulcer of at least 8 weeks duration. Immuno-histochemistry using monoclonal antibodies to PDGF-AA, MMP-2, TIMP-2 and EMMPRIN was carried out on paraffin embedded punch biopsy skin specimens from the ulcer edge. Enzyme linked immunosorbent assay for PDGF, MMP-2 and TIMP-2 were carried out on wound fluids collected from patients. The ulcer size and character at the initial assessment and after 8 weeks were assessed to determine the status of ulcer healing. RESULTS: No significant difference was seen in the expression of TIMP-2, MMP-2 and EMMPRIN between the two groups. However, in the non-healing group high levels of MMP-2 and low levels of TIMP-2 in the wound fluid suggest a strong correlation of these two markers in the state of healing. Analysis of wound fluid by ELISA demonstrated high PDGF-AA in the healing group (p = 0.021). Significantly increased levels of PDGF-AA (p<0001) was noted in the perivascular area on immuno-histochemistry of healing ulcers. These data suggest that PDGF-AA plays an important role in healing of venous ulcers. CONCLUSION: Non-healing venous ulcers are associated with greater activity MMP-2 activity. The ratio of MMPs to their inhibitors TIMPs, dictate the rate of healing of the ulcers. PDGF-AA activity is associated with ulcer healing, though the mechanism is unclear. EMMPRIN expression in chronic venous ulcers probably parallels the chronicity of the condition rather than propagate it. However, further studies with larger samples are needed.     

Multiplexed analysis of matrix metalloproteinases in leg ulcer tissue of patients with chronic venous insufficiency before and after compression therapy

Elevated matrix metalloproteinases (MMP) levels have been implicated in the pathogenesis of chronic venous insufficiency ulcers. Quantitative measurements of a broad range of MMP proteins in human tissue treated with compression bandaging have not been reported. The goal of this study was to determine the expression of a wide range of proteases in untreated venous leg ulcer tissue and the changes in these levels after 4 weeks of high‐strength compression therapy. Twenty‐nine limbs with new or untreated chronic venous insufficiency and leg ulceration received therapy for 4 weeks with sustained high compression bandaging. Biopsies were obtained from healthy tissue and from ulcerated tissue before and after therapy. A novel multiplexed protein assay was used to measure multiple MMPs in a single sample. MMP protein activity, TIMP protein levels, and gene expression levels were also addressed. MMP1, 2, 3, 8, 9, 12, and 13 protein levels were elevated in ulcer tissue compared with healthy tissue. MMP8 and 9 were highly expressed in ulcer tissue. MMP3, 8, and 9 significantly decreased following treatment. Reduction in the levels of MMP1, 2, and 3 was associated with significantly higher rates of ulcer healing at 4 weeks. We conclude that compression therapy results in a reduction of the pro‐inflammatory environment characterizing chronic venous ulcers, and ulcer healing is associated with resolution of specific elevated levels of protease expression.     

基质金属蛋白酶和组织金属蛋白酶抑制剂在大肠癌中的表达

目的　研究基质金属蛋白酶 (MMPs)及组织金属蛋白酶抑制剂 (TIMPs)在大肠癌中的表达特点 ,与肿瘤发生发展的关系 ,以及在肿瘤治疗中的应用前景。　方法　采用RT PCR方法测定 2 8例大肠癌患者肿瘤组织和周围正常粘膜的基质金属蛋白酶 2 (MMP 2 )、膜型 1 基质金属蛋白酶 (MT1 MMP)、基质溶素 (MMP 7)、组织金属蛋白酶抑制剂 2 (TIMP 2 )、组织金属蛋白酶抑制剂 3(TIMP 3)的mRNA表达状况 ,并将其结果与临床及病理学资料进行统计学分析。　结果　 (1) 2 7例患者肿瘤组织中MMP 7mRNA表达阳性 ,MMP 2、MT1 MMP、TIMP 2和TIMP 3在肿瘤组织和正常粘膜中均有高表达 ;(2 )肿瘤组织中MMP 7mRNA的表达水平与大肠癌患者的Dukes′分期相关 (P <0 0 1) ;(3)淋巴结阳性患者的肿瘤组织TIMP 2表达水平为 (1 2 5± 0 46 )明显高于淋巴结阴性患者的 (0 75± 0 41) ,差异有显著性意义 (P <0 0 1) ;(4)大肠癌患者癌周正常粘膜TIMP 3mRNA表达随患者Duke′s分期的进展和肿瘤浸润深度的增加而降低 (P <0 0 1) ;(5 )TIMPs与MMPs之间无明显相关关系 (P >0 1)。　结论　MMP 7可望成为诊断大肠癌的敏感指标 ;人工诱导TIMP 2、TIMP 3或阻断MMP 7、MMP 2、MT1 MMP的表达可能抑制肿瘤的浸润和转移 ,成为肿瘤治疗的新途径。     

基质金属蛋白酶2,9及金属蛋白酶组织抑制剂1在肾盂移行细胞癌中的表达及意义

目的 探讨基质金属蛋白酶2（MMP-2），9（MMP-9）及金属蛋白酶组织抑制剂1（TIMP-1）表达与肾盂移行细胞癌分级、分期及预后的关系。方法 采用免疫组化SP法检测117例肾盂移行细胞癌标本MMP-2，MMP-9发TIMP-1表达水平。患者中男97例，女20例。平均年龄59岁。肿瘤病理分级：G123例、G273例、G321例；TNM病理分期：Ta22例、T127例、T221例、T325例、T422例。结果 肾盂癌组织MMP-2表达阳性率81．2％（95例），MMP-9表达阳性率72．6％（85例），TIMP1表达阳性率72．6％（85例），阳性表达强度和阳性细胞分布不均匀，主要位于肿瘤细胞的胞质，随肿瘤分级、分期增加，MMP-2、MMP-9阳性表达率呈递增趋势，FL与预后相关，差异有统计学意义（P〈0．05）。TIMP-1阳性表达率随分级、分期增加呈递减趋势，但其差异无统计学意义（P〉0．05），TIMP-1表达强度与患者的生存时间无明显相关性。单因素方差分析发现MMP-9／TIMP-1比值与肿瘤临床病理分级、分期密切相关，随着分级、分期增加呈递增趋势（P〈0．05）。结论 MMP-2及MMP-9检测在肾盂癌病理分级、分期中有重要价值。MMP-2、MMP-9及MMP-9／TIMP-1比值在肾盂癌的预后判断中有重要意义。     

Expression of matrix metalloproteinase-7 and tissue inhibitor of metalloproteinase-2 in human endometrial carcinoma

<正>Objective:To investigate the expression of matrix metalloproteinase-7(MMP-7) and its tissue inhibitor (TIMP-2) in endometrial carcinoma and analyze their significance in endometrial cancer's invasion and metastasis. Methods:Endometrial tissues were collected from 64 patients with endometrial carcinoma,20 patients with endometrial hyperplasia and 20 normal women.The expressions of MMP-7,TIMP-2 in endometrium were measured by immuohistochemistry. Results;Expressions of MMP-7,TIMP-2 in endometrium of patients with endometrial carcinoma were significantly higher than those in normal endometrium(P0.05).MMP-7 expression increased with surgical-pathological staging,depth of myometrial invasion,histologic grades and lymph node metastasis(P0.05),while TIMP-2 expression was related to lymph node metastasis(P0.05).TIMP-2 expression in endometrial cancer was significantly higher than that in hyperplastic endometrium(P0.05).Expressions of TIMP-2 and MMP-7 in endometrium of patients with endometrial carcinoma were positively correlated(r=0.654,P0.001). Conclusion:Highly expressed MMP-7 and TIMP-2 in endometrium may be related to development,invasion and metastasis of endometrial cancers.     

Matrix metalloproteinase activity and immunohistochemical profile of matrix metalloproteinase-2 and -9 and tissue inhibitor of metalloproteinase-1 during human dermal wound healing

Proteolytic activity is required for the turnover of the extracellular matrix during wound healing. Matrix metalloproteinases can collectively cleave all components of the extracellular matrix, with the endogenous tissue inhibitor of metalloproteinase-1 regulating their activity. Breast tissue taken at varying postoperative times (n= 92) or during surgery (controls, n= 17), was used to investigate the temporal and spatial activity of matrix metalloproteinase-2 and -9 and tissue inhibitor of metalloproteinase-1 during human wound healing. Matrix metalloproteinase activity, determined using a quenched fluorescence substrate assay, increased during early healing (3-8 weeks) compared to controls, and then decreased between 24 and 36 weeks after surgery (p < 0.05 until 24 weeks, Mann-Whitney U-test). Immunohistochemistry scores for matrix metalloproteinase-9 expression were significantly elevated compared to controls in scar endothelial cells and fibroblasts from 2 until 12 and 20 weeks, respectively. Matrix metalloproteinase-2 staining was observed exclusively in fibroblasts, reaching maximum levels 8-12 weeks after surgery, decreasing by 1.5 years but remaining significantly increased. Tissue inhibitor of metalloproteinase-1 staining was relatively sparse but was significantly increased until 8 weeks after surgery. These results show that matrix metalloproteinases are present at elevated levels during early wound healing, when angiogenesis occurs, and suggest that matrix metalloproteinase-9 may play a significant role. The later expression of matrix metalloproteinase-2 and -9 in fibroblasts suggests a role in extracellular matrix remodeling.     

Ratios of activated matrix metalloproteinase-9 to tissue inhibitor of matrix metalloproteinase-1 in wound fluids are inversely correlated with healing of pressure ulcers

Previous analyses of fluids collected from chronic, nonhealing wounds found elevated levels of inflammatory cytokines, elevated levels of proteinases, and low levels of growth factor activity compared with fluids collected from acute, healing wounds. This led to the general hypothesis that chronic inflammation in acute wounds produces elevated levels of proteinases that destroy essential growth factors, receptors, and extracellular matrix proteins, which ultimately prevent wounds from healing. To test this hypothesis further, pro- and activated matrix metalloproteinases (MMP-2 and MMP-9), tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2), and the ratios of MMPs/TIMPs were assayed in fluids and biopsies collected from 56 patients with chronic pressure ulcers. Specimens included ulcers treated for 0, 10, and 36 days with conventional therapy or with exogenous cytokine therapies. Quantitative assay data were correlated with the amount of healing. The average MMP-9/TIMP-1 ratio in fluids from 56 ulcers decreased significantly as the chronic pressure ulcers healed. Furthermore, the average MMP-9/TIMP-1 ratio was significantly lower for fluids collected on day 0 from wounds that ultimately healed well (> or =85% reduction in initial wound volume) compared with wounds that healed poorly (< 50% wound volume reduction). These data show that the ratio of MMP-9/TIMP-1 levels is a predictor of healing in pressure ulcers and they provide additional support for the hypothesis that high levels of MMP activity and low levels of MMP inhibitor impair wound healing in chronic pressure ulcers.     

An imbalance between matrix metalloproteinase-2 and tissue inhibitor of matrix metalloproteinase-2 contributes to the development of early diabetic nephropathy.

BACKGROUND: High glucose and angiotensin-II (Ang-II) levels are the known important mediators of diabetic nephropathy. However, the effects of these mediators on matrix metalloproteinase-2 (MMP-2) and on tissue inhibitor of metalloproteinase-2 (TIMP-2) in proximal tubule cells have yet to be fully examined within the context of early stage diabetic nephropathy. METHODS: In this study, we attempted to characterize changes in MMP-2 and TIMP-2 in streptozotocin-induced diabetic rats. To further examine the molecular mechanisms involved, we evaluated the effects of high glucose (30 mM) or Ang-II on MMP-2, TIMP-2 and collagen synthesis in proximal tubule cells, and investigated whether MMP-2 and TIMP-2 are regulated via the TGF-beta1 pathway. RESULTS: In streptozotocin-induced diabetic rats, TIMP-2 mRNA and protein levels were significantly higher than in controls. Urinary protein excretion also showed a significant positive correlation with glomerular and tubular TIMP-2 protein expressions, and a negative correlation with MMP-2 expression. In cultured cells, both high glucose and Ang-II induced significant increases in TGF-beta1, TIMP-2, and in collagen synthesis, and significant decreases in MMP-2 gene expression and activity, and thus disrupted the balance between MMP-2 and TIMP-2. Moreover, treatment with a selective angiotensin type 1 (AT1) receptor antagonist significantly inhibited Ang-II mediated changes in TGF-beta1, MMP-2, TIMP-2, and in collagen production, suggesting the role of the AT1 receptor. The addition of exogenous TGF-beta1 produced an effect similar to those of high glucose and Ang-II. Furthermore, the inhibition of TGF-beta1 protein prevented Ang-II-induced MMP-2 and TIMP-2 alterations, suggesting the involvement of a TGF-beta1 pathway. CONCLUSIONS: High glucose or Ang-II treatment induce alterations in MMP-2 and TIMP-2 balance, which favour TIMP-2 over-activity. Moreover, Ang-II-mediated changes in the productions of MMP-2 and TIMP-2 occur via AT1 receptors and a TGF-beta1-dependent mechanism. These results suggest that an imbalance between the MMP-2 and TIMP-2, caused primarily by an increase in TIMP-2 activity, contributes to the pathogenesis of diabetic nephropathy.     

Connective tissue growth factor increases matrix metalloproteinase-2 and suppresses tissue inhibitor of matrix metalloproteinase-2 production by cultured renal interstitial fibroblasts

The involvement of gelatinase (matrix metalloproteinase-2 [MMP-2] and MMP-9) in the matrix remodeling and development of tubulointerstitial fibrosis has been studied recently, but relatively little is known about the regulators and the mechanisms controlling the activation and expression of gelatinase in renal fibroblasts. In these studies, the production and underlying signaling pathway for gelatinase by exogenous connective tissue growth factor (CTGF) treatment were investigated. Here, we show that CTGF acts as a potent promoter of the activation and expression of MMP-2, but not MMP-9 in normal rat kidney fibroblasts cell line (NRK-49F). We found that CTGF significantly increased the activity of MMP-2, as well as MMP-2 protein in conditioned medium and MMP-2 mRNA levels in cells. In studies to address the mechanisms involved in the regulation of MMP-2 activity, we found that the tissue inhibitor of matrix metalloproteinase-2 (TIMP-2), the inhibitor of MMP-2, decreased significantly when cells were treated with CTGF. Further studies showed that extracellular signal-regulated kinase (ERK) signaling is responsible for most of the CTGF-induced MMP-2 expression and TIMP-2 suppression. When NRK-49F fibroblasts were incubated with CTGF, activation of ERK1/2 signaling was observed. Suppression of ERK1/2 activation with nontoxic concentrations of PD98059, a specific inhibitor of ERK activation, was associated with a reduction of CTGF-stimulated MMP-2 activity and protein expression. In addition, the CTGF-mediated reduction of TIMP-2 activity and protein expression was prevented when ERK1/2 activation was inhibited by PD98059. These results provide evidence that CTGF augments activation of MMP-2 through an effect on MMP-2 protein expression and TIMP-2 suppression, and that these effects are dependent on the activation of the ERK1/2 pathway.     

绝经后妇女血清基质金属蛋白酶-9和基质金属蛋白酶抑制因子-1与骨密度的关系

目的 探讨绝经后妇女血清基质金属蛋白酶-9(MMP-9)和基质金属蛋白酶抑制因子-1(TIMP-1)与骨密度(BMD)之间的关系.通过观察绝经后妇女不同骨密度条件下MMP-19、TIMP-1浓度的变化,探讨两者在骨质疏松症(OP)中的作用,为临床OP诊断与干预治疗提供依据.方法 选择绝经后妇女80例.采用Challenge双能x线骨密度仪(DXA)测量腰椎(L2-L4)侧位和左侧髋部(股骨颈、大转子、Ward三角区)6个骨骼区域的骨密度(BMD).分为正常对照组(骨密度正常组,21例)、低骨量组(20例)、骨质疏松组(23例)和严重骨质疏松组(骨质疏松骨折组,16例),对各组进行身高、体重等常规检查并用酶联免疫吸附试验(ELISA法)测定各组血清MMP-9和TIMP-1的浓度.结果 绝经后女性血清MMP-9水平随骨密度的降低呈现升高趋势.以骨质疏松骨折组为著;低骨量组、骨质疏松组TIMP-1水平与对照组比较没有统计学意义;正常对照组、低骨量组、骨质疏松组MMP-9与TIMP-1的比率依次升高,致使MMP-9与TIMP-1的比率失调.结论 绝经后妇女血清MMP-9水平升高及MMP-9与,TIMP-1的比率失调可能为绝经后骨质疏松症发生的重要影响因素.