Matrix metalloproteinases in ascending aortic aneurysms: bicuspid versus trileaflet aortic valves

BACKGROUND: Abnormal matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) expression contributes to the development of abdominal aortic aneurysms. Recent data suggest that MMP-2 and MMP-9 may also play a role in thoracic aortic disease. We sought to determine (1) whether ascending aortic aneurysms are associated with increased MMP expression and (2) whether aortic inflammation and MMP expression differ between patients with congenital bicuspid aortic valves (BAVs) and those with trileaflet aortic valves (TAVs). MATERIALS AND METHODS: Samples of ascending aortic aneurysms were obtained from 29 patients; 14 patients had BAVs and 15 had TAVs. Control ascending aorta was obtained from 14 organ donors or heart transplant recipients. Aortic histology and immunohistochemistry were performed to evaluate elastin degradation, inflammatory changes, and MMP-2 and MMP-9 expression. Aortic levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 were measured using ELISA. RESULTS: Aneurysms in the TAV patients exhibited marked inflammation, high CD68 expression, diminished elastin content, increased MMP-9 expression, and normal MMP-2 levels. In contrast, BAV aneurysms were characterized by a relative lack of inflammation, preservation of elastin content, normal MMP-9 levels, and elevated MMP-2 expression. TIMP-1 and TIMP-2 levels were not significantly different among the three groups. CONCLUSIONS: Ascending aortic aneurysms exhibited increased MMP expression. The pattern of MMP expression and the degree of inflammation, however, differed between aneurysms associated with BAVs and those with TAVs. Variations in the molecular mechanisms underlying different types of thoracic aortic aneurysms warrant further investigation.     

大鼠牙齿移动牙周组织中Ⅰ型胶原和MMP-1及TIMP-1的表达

目的：观察大鼠正畸牙齿移动过程中I型胶原和MMP-i、TIMP-1在上颌第-磨牙牙周组织中的表达和变化。方法：建立大鼠正畸磨牙移动模型，分为对照组和术后1、3、5、7、10、14天组，用免疫组织化学方法观察各组中Ⅰ型胶原和MMP-1、TIMP-1表达的变化。结果：I型胶原和MMP-1、TIMP-1在大鼠正畸牙周组织中的阳性表达明显强于对照组，且有时间依赖性。结论：Ⅰ型胶原在牙周组织改建中具有重要的作用，MMP-1、TIMP-1参与了正畸牙周组织细胞外基质的代谢过程。     

Role of ADAMTS1 and ADAMTS5 in male infertility

The aim of this study was to investigate the relationship of infertility with metalloproteinases ADAMTS1 and ADAMTS5, which are known to be responsible for the degradation of extracellular matrix (ECM) proteins associated with many diseases. ECM is the noncellular component that provides structural and biochemical support to the surrounding cells required for tissue morphogenesis, differentiation and homoeostasis. Sixty infertile individuals and 10 healthy semen donors were included in this study. The infertile individuals were classified as normozoospermia (NS; n = 20), oligozoospermia (OS; n = 20), azoospermia (AS; n = 20) groups. ADAMTS1 and ADAMTS5 protein levels in semen were analysed by Western blot. ADAMTS1 protein level was 3.0‐, 3.3‐ and 1.6‐fold lower in the OS, AS and NS groups, respectively, than in the control group (P < 0.001). ADAMTS5 protein level was 3.2‐, 2.7‐ and 1.4‐fold lower in the OS, AS and NS groups, respectively, than in the control group (P < 0.001). Sperm count and sperm motility showed a negative correlation with the levels of ADAMTS1 and ADAMTS5 protein expression: r = ?0.477, r = ?0.470; and r = ?0.332, r = ?0.275 respectively (P < 0.001). In conclusion, ADAMTS1 and ADAMTS5 protein expressions in semen are significantly related with sperm production. It is very important to understand molecular function and organisation of ADAMTSs which will be significant in enlightening the process of spermatogenesis in male infertility.     

The Effects of Platelet‐Rich Plasma on Halting the Progression in Porcine Intervertebral Disc Degeneration

Disc degeneration and the subsequent herniation and/or rupture of the intervertebral disc (IVD) are due to a failure of the extracellular matrix of the annulus to contain the contents of the nucleus. This results from inadequate maintenance of the matrix components as well as the proteolytic activity of matrix metalloproteinases (MMPs) that degrade matrix molecules. Arresting progression of disc degeneration in the annulus holds greater clinical potential at this point than prevention of its onset in the nucleus. Therefore, in this study, we have therapeutic aims that would decrease levels of the cytokines and growth factors that indirectly lead to disc degeneration via stimulating MMP and increase levels of several beneficial growth factors, such as transforming growth factor‐β, with the addition of platelet‐rich plasma (PRP) that would stimulate cell growth and matrix synthesis. For this study, we attempted to address these imbalances of metabolism by using tumor necrosis factor‐α treated annulus fibrosus cells isolated from porcine IVD tissue and incubating the cells in a growth factor rich environment with PRP. These results indicate that the PRP in vitro increased the production of the major matrix components (type II collagen and aggrecan) and decreased the inhibitory collagenase MMP‐1. This application will address a therapeutic approach for intervening early in the degenerative process.     

A critical role for collagen II in cartilage matrix degradation: Collagen II induces pro‐inflammatory cytokines and MMPs in primary human chondrocytes

We report a process that results in the acceleration of matrix degradation in human articular cartilage, a phenomenon commonly observed in osteoarthritis (OA). The study was conducted by (1) examining the potential of collagen II in modulating the gene expression profile of primary human chondrocytes (PHCs), and (2) investigating the involvement of pro‐inflammatory signaling cascades. We first tested the collagen II‐dependent induction of pro‐inflammatory cytokines and matrix metalloproteinases (MMPs) in PHCs. PHCs were incubated with or without monomeric (i.e., nonfibrillar) collagen II. Cells were then analyzed by RT‐PCR for the expression of MMP1, MMP3, MMP13, MMP14, and IL‐1β. ELISA was used to quantify IL‐6 and IL‐8 release. To examine the influence of collagen II signaling, specifically the role of MAPK p38, a p38‐inhibitor was added prior to collagen treatment. Changes in IκB concentration were monitored by immunoblot analysis to detect NFκB signaling. Results indicated that incubation of PHCs with collagen II did produce a dose‐dependent induction of MMP1, MMP3, MMP13, MMP14, as well as cytokines IL‐1β, IL‐6, and IL‐8. At the same time, inhibition of p38 and IκB degradation revealed that collagen II‐dependent gene induction also involves MAPK p38 and NFκB signaling. Thus, we provide evidence for a collagen II‐dependent feed‐forward mechanism whereby collagen II induces first MMPs and pro‐inflammatory cytokines and then release of collagen II fragments from mature collagen II fibers. This, in turn, induces more pro‐inflammatory cytokines and MMPs, and the process is repeated, which results in the acceleration and perpetuation of cartilage matrix degradation. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:65–70, 2009     

基质金属蛋白酶9、3和金属蛋白酶组织抑制物1在原发性膜性肾病肾小球内的表达及意义

目的探讨基质金属蛋白酶9（MMP-9）、基质金属蛋白酶3（MMP-3）和金属蛋白酶组织抑制物1（TIMP-1）在原发性膜性肾病（IMN）患者肾小球内的表达变化及其与蛋白尿、Scr的关系。方法用免疫组织化学技术分别检测44例IMN患者（IMN组）与6例正常对照者（对照组）肾小球内MMP-9、MMP-3和TIMP-1的表达。结果MMP-9及MMP-3在对照组正常肾组织的肾小管上皮细胞、肾间质和肾小球足细胞有少量表达；在IMN组肾小球足细胞、系膜细胞、肾小球基底膜及肾小管上皮细胞有表达。IMN组肾小球内MMP-9及MMP-3的表达均较对照组显著增强（P〈0．05）。TIMP-1在对照组正常肾组织的肾小管上皮细胞有少量表达，肾小球内无表达；在IMN组肾小球足细胞、肾小管上皮细胞有表达。IMN组肾小球内TIMP-1的表达较对照组显著增强（P〈0．01）。IMN组24h尿蛋白定量显著高于对照组（P〈0．01）。Ⅱ期MN组肾小球MMP-9／TIMP-1及MMP-3／TIMP-1比值较Ⅰ期MN组明显下降（P〈0．01）。IMN组肾小球内MMP-9的表达与Scr呈负相关（r=-0．02，P〈0．05）；TIMP-1的表达与Scr呈正相关（r=0．34，P〈0．05）。结论MMP-9与TIMP-1从正反两方面影响IMN患者肾功能的改变。MMP-9、MMP-3的异常表达与IMN患者蛋白尿之间可能相关；IMN患者肾小球MMP／TIMP比值失衡可能与IMN患者肾小球基底膜增厚相关。     

Plasma matrix metalloproteinase 9 as biomarker of prostate cancer progression in Dunning (Copenhagen) rats

BACKGROUND: Matrix metalloproteinases (MMPs) play an important role in invasion and metastatic spread of cancer cells. The objective of this study was to assess MMPs in plasma of Dunning tumor rats as indicators of the progression of prostate cancer and follow-up parameters after treatment. METHODS: Prostate cancer was induced in male Copenhagen rats by either subcutaneous or orthotopic implantation of R3327-MatLyLu cells. During the development of the tumor, plasma MMP-2, and MMP-9 were measured by gelatin-substrate zymography and Western blot technique with densitometry in untreated animals, rats treated with laser-induced hyperthermia, or with the new synthetic MMP inhibitor RO 28-2653. RESULTS: Normal prostatic tissue of the Copenhagen rats predominantly expressed proMMP-2 but not proMMP-9 whereas MMP-9 was only found in cancerous tissue. Elevated plasma MMP-9 values were demonstrated in rats with subcutaneous or orthotopic tumors. Animals with tumors and treated with the MMP inhibitor RO 28-2653 had both a lower tumor volume and a lower plasma MMP-9 concentration compared with controls. CONCLUSIONS: The determination of plasma MMP-9 in Dunning tumor rats is a useful tool to monitor the progression of prostate cancer and to assess the efficacy of drugs like MMP inhibitors or other treatment protocols.     

Metalloproteinase inhibition reduces lung injury and improves survival after cecal ligation and puncture in rats

BACKGROUND: Neutrophil activation with concomitant matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) release has been implicated in the development of sepsis-induced acute lung injury. We hypothesized that COL-3, a chemically modified tetracycline known to inhibit MMP-2 and MMP-9, would reduce lung injury and improve survival in rats following cecal ligation and puncture (CLP). METHODS: Sprague-Dawley rats were separated into five groups: 1) sham CLP+ carboxymethylcellulose (CMC; vehicle for COL-3, n = 6); 2) sham CLP + COL-3 (n = 6); 3) CLP + CMC (n = 10); 4) CLP + single-dose (SD) COL-3 administered concomitant with CLP (n = 9); and 5) CLP + multiple-dose (MD) COL-3 administered concomitant with CLP and at 24 h after CLP (n = 15). Rats were sacrificed at 168 h (7 days) or immediately after death, with survival defined as hours after CLP. Histological lung assessment was made based on neutrophil infiltration, alveolar wall thickening, and intraalveolar edema fluid. Lung MMP-2 and MMP-9 levels were assessed by immunohistochemistry. MMP-2 and MMP-9 levels were correlated with survival by simple regression analysis. RESULTS: The mortality of rats in the cecal ligation and puncture without treatment group (CLP + CMC) was 70% at 168 h. A single dose of COL-3 in the CLP + COL-3 (SD) group significantly reduced mortality to 54%. Furthermore, with a repeat dose of COL-3 at 24 h after CLP, mortality was significantly reduced to 33%. Pathologic lung changes seen histologically in the CLP + CMC group were significantly reduced by COL-3. A significant reduction in lung tissue levels of MMP-2 and MMP-9 was noted in both groups treated with COL-3. Reduction of MMP-2 and MMP-9 levels correlated with improved survival. CONCLUSION: Inhibition of MMP-2 and MMP-9 by COL-3 in a clinically relevant model of sepsis-induced acute lung injury reduces pulmonary injury and improves survival in a dose-dependent fashion. Our results suggest that prophylactic treatment with COL-3 in high-risk patients may reduce the morbidity and mortality associated with sepsis-induced acute respiratory distress syndrome.     

基质金属蛋白酶-2,9及其抑制因子在增生性瘢痕中的表达特征及意义

 目的 探讨3种不同的基质金属蛋白酶-2, 9(MMP-2, 9)及其抑制因子(TIMP-2)在不同形成时期的增生性瘢痕中的基因表达和蛋白含量的变化.方法 用病理学技术检测增生性瘢痕和正常皮肤的结构特征后,分别用RT-PCR和Western blot方法检测这3种基因在16例不同发生时期的增生性瘢痕和8例正常皮肤组织中的基因表达和蛋白含量的变化规律.结果 在正常皮肤组织内,MMP-2, 9和TIMP-2的基因表达较弱,蛋白含量较低;而在增殖期的增生性瘢痕中这2种MMPs和TIMP2基因表达水平和蛋白含量都显著升高(P＜0.05),在成熟期的瘢痕中,MMP-2, 9基因表达量降低至正常皮肤水平,但蛋白含量仍保持较高水平,明显高于正常皮肤(P＜0.05),TIMP-2的mRNA水平和蛋白含量则降低至正常皮肤相近的水平.结论 MMP-2, 9和TIMP-2表达增强可能是增生性瘢痕形成的机制之一,而MMP-2, 9蛋白含量的增多,TIMP-2蛋白含量减少可能与增生性瘢痕达到相对稳定的成熟期有关.