Increased expression of matrix metalloproteinases in the uterine cervix of postmenopausal women

OBJECTIVE.: To determine whether atrophy of the uterine cervix in menopausal women is associated with an increased expression of matrix metalloproteinases (MMP), a decrease in their counter regulatory proteins (tissue inhibitors of matrix metalloproteinase [TIMP]), and a decrease in type I collagen. MATERIALS AND METHODS.: A pilot study was performed on cervical stroma harvested from 10 premenopausal and 9 postmenopausal women undergoing a hysterectomy. The amount of pro-MMP-2 and pro-MMP-9 in protein extracts from the two groups was compared by gelatin zymography. The membrane-type (MT)1-MMP, TIMP-1, and TIMP-2 were quantitated by Western immunoblotting. Total collagen was estimated by measuring hydroxyproline content. A primary fibroblast culture was developed to study estrogen regulation of MMP expression in vitro. RESULTS.: Pro-MMP-2 and pro-MMP-9 were increased in postmenopausal extracts. No difference in the amount of MT1-MMP, TIMP-1, TIMP-2, or total collagen was detected. In primary cervical fibroblast cultures, only active MMP-2 was suppressed by estrogen. CONCLUSIONS.: The protein expression of pro-MMP-2 and pro-MMP-9 is increased in cervical stroma of postmenopausal women relative to premenopausal women.     

Metalloproteinase levels are decreased in symptomatic carotid plaques

BACKGROUND: Matrix metalloproteinase enzymes (MMP) have been identified in carotid atherosclerotic plaques, but their role in the development of clinical symptoms remains ill defined. We correlated the activity and levels of metalloproteinase enzymes and their inhibitors in human carotid plaques to ischemic neurologic events. METHODS: Carotid plaques were collected at the time of endarterectomy from 23 patients with carotid stenosis. Sixteen patients were asymptomatic and 7 patients had symptoms of stroke or transient ischemic attack within 6 weeks of surgery. Protein was extracted from the plaques, proteolytic activity was determined by gelatin zymography, and pro-MMP and tissue inhibitor of metalloproteinase (TIMP) enzyme content were measured by ELISA assay. Macrophage accumulation in the plaque was determined using immunohistochemistry. RESULTS: Plaques from symptomatic patients had decreased proteolytic activity on substrate gel zymography at the 62- and 92-kDa regions (corresponding to active MMP-2 and pro-MMP-9). A decrease in pro-MMP-9 (8.21 +/- 2.35 vs 17.42 +/- 3.14 ng, P < 0. 05) and an increase in TIMP-2 protein (12.62 +/- 0.58 vs 10.56 +/- 0. 77 ng, P < 0.05) were noted on ELISA in plaques from symptomatic patients. No difference was noted in macrophage accumulation in the plaques between the two groups. CONCLUSIONS: Plaques from patients who present with ischemic neurologic symptoms have decreased proteolytic activity associated with decreased pro-MMP-9 and increased TIMP-2 protein levels. These data suggest that metalloproteinase enzymes are not responsible for plaque instability in the carotid circulation and may in fact promote plaque stability.     

Presence of matrix metalloproteinases and tissue inhibitor of matrix metalloproteinase in human sperm

The matrix metalloproteinases (MMPs) are a family of proteolytic enzymes that degrade protein components of the extra-cellular matrix. The necessity of breakdown of physical barriers in the fertilization process suggests that MMPs, along with their tissue inhibitors (TIMPs), might be involved in this task. We have examined the presence of MMP and TIMP in normal and abnormal human sperm samples by gel zymography and Western blot analysis. Thirty-five normal sperm samples and 35 abnormal sperm samples were examined in this study. Gel zymography showed 92-, 72-, 62-, and 28-kd molecular-weight bands exhibiting gelatin-degrading activity in both normal and abnormal sperm samples. The 92-, 72-, and 62-kd bands with gelatinolytic activity are consistent with pro-MMP-9, pro-MMP-2, and active MMP-2, respectively (pro-MMP being the zymogen of MMP). Western blot analysis showed the presence of TIMP-1 in both normal and abnormal sperm samples. A higher 28-kd activity and a lower 92-kd MMP activity in normal sperm samples relative to abnormal samples were detected. No marked difference in TIMP-1, 72-kd, and 62-kd release was observed between normal and abnormal sperm samples. In conclusion, this is the first report of MMP activity in normal and abnormal human sperm samples and of TIMP presence in sperm samples. The data indicate a different MMP profile between normal and abnormal sperm samples, with a higher 28-kd activity and a lower 92-kd MMP activity in normal relative to abnormal samples.     

血管内皮生长因子调节小鼠系膜细胞基质金属蛋白酶及其组织抑制物的表达

目的：研究血管内皮生长因子（VEGF）对体外培养的小鼠系膜细胞表达基质金属蛋白酶（MMPs)和金属蛋白酶组织抑制物（TIMPs)的调节作用。方法：对体外培养的小鼠系膜细胞应用人重组VEGF孵育12h，应用蛋白质印迹法检测细胞培养液MMP2、MMP9、TIMP1、TIMP2的蛋白质水平；应用白明胶酶谱法检测MMP2、MMP9的活性；应用RT－PCR检测系膜细胞TIMP1、TIMP2 mRNA表达。结果：VEGF（10ng/ml)可提高小鼠系膜细胞MMP2和MMP9蛋白质释放（和对照组相比分别提高43％和34％，P＜0．05），MMP2和MMP9活性分别提高17％和26％（P＜0．05）。同时，VEGF可呈剂量依赖地下调小鼠系膜细胞TIMP1和TIMP2蛋白质和mRNA的表达，VEGF（25ng/ml)可减少小鼠系膜细胞TIMP1和TIMP2蛋白质释放分别为43％和67％（P＜0．05）；并抑制TIMP1和TIMP2 mRNA的表达（分别下降41％和59％，P＜0．01）。结论：VEGF使系膜细胞MMPs蛋白质表达增加、活性增强，同时下调TIMPs mRNA和蛋白质的表达，可能在增生性肾小球肾炎的发病机制中起一定的作用。     

Matrix metalloproteinases in the aneurysm wall of patients treated with low-dose doxycycline

The purpose of this study was to determine the effect of low-dose doxycycline on matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP)-1 expression in the wall of abdominal aortic aneurysms. A double-blind, randomized study was conducted of patients treated with doxycycline (100 mg/d orally) or placebo for 1 month prior to surgery. MMP-2, -3, and -9 (zymogen and activity); MMP-1, -2, -3, -7, -9, -11, -12, and -14; and TIMP-1 (messenger ribonucleic acid [mRNA]) were measured in the aneurysm wall. No differences were found between the treatment and placebo groups in zymogen levels of MMP-2, -3, or -9 or in the free or total activities of MMP-2 and -9. Treatment with doxycycline also had no effect on the concentration of any mRNA measured. No relationship was found between the number of tablets taken and MMP or TIMP protein, mRNA, or activity levels in the aneurysm wall. Low-dose doxycycline treatment does not alter the expression or activity of metalloproteinases or their inhibitor, TIMP-1, in the aneurysm wall.     

The no donor DETA-NONOate decreases MMP-9 expression and activity in abdominal aortic explants

Objective: The goal of this project is to examine the role of an exogenous NO donor, DETA-NONOate (DETA), on MMP-9, MMP-2, and TIMP-1 expression and activity in interleukin-1β (IL-1β) induced rat aortic explants (RAE). Methods: RAEs were incubated with IL-1β (2 ng/ml) and increasing concentrations of DETA (0, 5.0, 50, 100, and 500 μM) (n = 3 per group). Messenger RNA (mRNA) was extracted from cells after 24 hours and analyzed for MMP-9, MMP-2, and TIMP-1 expression levels by real time RT-PCR. Media at 48 hours was collected and assayed for NO₂ and NO₃ (NO_x) by the Saville Assay, MMP-9 and MMP-2 activity by gelatin zymography, and TIMP-1 activity by reverse zymography. All statistical analyses were performed by ANOVA and Pearson correlation. Results: DETA administration resulted in a dose-dependent increase in media NO_x concentration (0.001 +/- 0.0003 ng NO_x / mg protein to 0.062 +/- 0.004 ng NO_x / mg protein, p < 0.01). In RAE, MMP-9 expression and activity decreased significantly in a dose dependent fashion with increasing DETA concentrations (p < 0.01). At the maximal dose of 500 μM DETA, a 78% decrease in MMP-9 expression (p < 0.05) and a 72% decrease in pro-MMP-9 activity (p < 0.05) was demonstrated compared to RAE treated with IL-1β alone (0 μM DETA). There were no significant differences seen in MMP-2 and TIMP-1 expression or activity in response to DETA exposure. Conclusion: The NO donor DETA-NONOate decreased IL-1β induced MMP-9 expression and activity in RAE in a dose dependent fashion. These data suggest that NO donors may be beneficial in decreasing MMP-9 levels, an enzyme believed to be critical in vessel wall remodeling, and therefore may serve to inhibit MMP-9 dependent vessel wall degradation seen during AAA formation.     

Metalloproteinases and their inhibitors: influence on tumor invasiveness and metastasis formation in head and neck squamous cell carcinomas

BACKGROUND: Matrix metalloproteinases (MMPs) play an important role in tumor invasiveness. This study investigates the expression status of MMPs and tissue inhibitors of metalloproteinases (TIMPs) in head and neck squamous cell carcinomas (HNSCC). METHODS: Of 48 laryngeal squamous cell carcinoma (LSCC) biopsies and 10 HNSCC cell lines, mRNA was isolated, reversely transcribed, and subjected to polymerase chain reaction (PCR) amplifying MMP-1, MMP-2, MMP-9, MMP-10, TIMP-1, and TIMP-2. Silver nitrate-stained gel electrophoresis demonstrated MMP and TIMP expression status. Exemplary immunohistochemistry and zymography confirmed translation and enzyme activity. RESULTS: Densitometric analysis revealed MMP-2 expression and lymph node metastases to be positively and TIMP-1 and TIMP-2 to be negatively correlated with lymph node metastases. TIMP-2 expression and tumor size were negatively correlated. MMP-1, MMP-9, and MMP-10 expression were not correlated to metastasis formation or tumor size. CONCLUSIONS: Our results suggest that MMP-2 expression enhances, whereas TIMP-1 and TIMP-2 both suppress, cancer spread in LSCC.     

Systemic dilation diathesis in patients with abdominal aortic aneurysms: a role for matrix metalloproteinase-9?

INTRODUCTION: Accumulating evidence suggests that patients with abdominal aortic aneurysm (AAA) suffer from a systemic dilating condition affecting all arteries. Matrix metalloproteinases (MMPs) and their natural inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), appear to be involved in aneurysm formation, as evidenced by increased aortic tissue MMP activity and plasma MMP levels in patients with AAA. Hypothesizing that an imbalance in plasma MMP/TIMP level might be associated with a systemic dilation diathesis, we studied mechanical vessel wall properties of non-affected arteries of patients with either AAA or aorto-iliac obstructive lesions in association with plasma MMP-9 and TIMP-1 levels. METHODS: Twenty-two patients with AAA and 12 with aorto-iliac occlusive disease (AOD) were included. Diastolic diameter (d) and distension (Deltad) were measured at the level of the common carotid artery (CCA) and suprarenal aorta (SA) using ultrasonography. Distensibility (DC) and compliance (CC) were calculated from d, Deltad and brachial pulse pressure. Plasma MMP-9 and TIMP-1 were determined with specific immunoassays. RESULTS: The average (+/-SD) age was 72.3+/-5.6 and 65.0+/-8.2 years for the AAA and AOD patients, respectively, (P=0.005). CCA diameter was 9.1+/-1.3mm in AAA patients and AOD 7.8+/-1.4mm in AOD patients, P=0.009. This difference persisted after correction for age. Plasma MMP-9 and TIMP-1 did not differ significantly between AAA and AOD patients. In the total 34 patients, the MMP-9/TIMP-1 ratio was correlated inversely with distensibility (r=-0.74, P=0.002) and to compliance (r=-0.58, P=0.024) of the suprarenal aorta. CONCLUSIONS: The CCA diameter was larger in AAA patients compared to AOD patients. MMP-9/TIMP-1 ratio was associated with decreased distensibility and compliance of the suprarenal aorta. These data support the idea that AAA patients exhibit a systemic dilation diathesis, which might be attributable to MMP/TIMP imbalances.     

Nitric oxide modulates expression of matrix metalloproteinase-9 in rat mesangial cells

Nitric oxide modulates expression of matrix metalloproteinase-9 in rat mesangial cells. BACKGROUND: High-output levels of nitric oxide (NO) are produced by rat mesangial cells (MCs) in response to proinflammatory cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) by the inducible isoform of NO synthase (iNOS). We tested modulatory effects of NO on the expression and activities of matrix metalloproteinases-9 and -2 (MMP-9 and MMP-2), respectively. Temporal and spatial expression of these MMPs and their specific inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), seems to be critical in the extensive extracellular matrix (ECM) remodeling that accompanies sclerotic processes of the mesangium. Methods and Results. Using the NO donors S-Nitroso-N-acetyl-D,L-penicillamine (SNAP) and DETA-NONOate, we found strong inhibitory effects of NO mainly on the IL-1beta-induced MMP-9 mRNA levels. NO on its own had only weak effects on the expression of MMP-9 and MMP-2. The addition of the NOS inhibitor NG-monomethyl L-arginine (L-NMMA) dose dependently increased steady-state mRNA levels of cytokine-induced MMP-9, suggesting that endogenously produced NO exerts tonic inhibition of MMP-9 expression. MMP-9 activity in conditioned media from MCs costimulated with IL-1beta and NO donor contained less gelatinolytic activity than media of cells treated with IL-1beta alone. Exogenously added NO did not alter gelatinolytic activity of MMP-9 in cell-free zymographs. The expression levels of TIMP-1 were affected by NO similarly to the expression of MMP-9. CONCLUSION: We conclude that NO modulates cytokine-mediated expression of MMP-9 and TIMP-1 in rat MCs in culture. Our results provide evidence that NO-mediated attenuation of MMP-9 gelatinolytic activity is primarily due to a reduced expression of MMP-9 mRNA, and not the result of direct inhibition of enzymatic activity.     

Differential regulation of matrix metalloproteinase activities in abdominal aortic aneurysms

BACKGROUND: The increased synthesis of matrix metalloproteinases (MMPs) by aortic smooth muscle cells (SMCs) is thought to be involved in the etiopathogenesis of abdominal aortic aneurysms (AAAs), but the functional regulation and the activation states of these MMPs remain unclear. In this study, we assessed the expression levels and the functional regulation of several MMPs in the pathogenesis of AAAs. METHODS: Human healthy aorta and AAA specimens were homogenized, and the proteolytic activities of MMP-2 and MMP-9 and of the macrophage metalloelastase (MMP-12) were assessed with zymography. Protein expression of MMP-1, MMP-12, membrane-type 1 MMP (MT1-MMP), tissue inhibitor of MMP 1 (TIMP-1), TIMP-2, TIMP-3, alpha-actin, and beta-actin was analyzed with electrophoresis on sodium dodecyl sulfate gels and immunoblotting. RESULTS: MMP-1, MMP-9, and MMP-12 zymogen levels and proteolytic activities were increased in AAAs when compared with healthy aorta. A severe reduction in alpha-actin--positive vascular SMCs was observed in all the AAA specimens and was correlated with an increase in TIMP-3 but not TIMP-1 or TIMP-2 potential activities. Although pro--MMP-2 activity was decreased, the extent of activated MMP-2 remained unaffected in the AAAs. In accordance with this result, a highly activated MT1-MMP form was also observed in AAAs. CONCLUSION: These data suggest that chronic aortic wall inflammation is mediated by macrophage infiltration, which may account for the destruction of medial elastin, as reflected by SMC down regulation, through increased levels of active MMP-1 and MMP-12. Moreover, altered MT1-MMP proteolytic turnover and differential regulation of TIMP expression in AAAs suggest that tight regulatory mechanisms are involved in the molecular regulation of MMP activation processes in the pathogenesis of AAAs.     

Matrix metalloproteinases, their tissue inhibitors and colorectal cancer staging

BACKGROUND: Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are important in tumour invasion and metastasis. The levels of MMPs, TIMPs and total MMP activity were compared in paired colorectal tumour (n = 50) and normal tissue (n = 49) samples and correlated with clinical and pathological staging. METHODS: Gelatin zymography (MMP-2 and MMP-9), enzyme-linked immunosorbent assays (MMP-1, MMP-3, TIMP-1 and TIMP-2) and quenched fluorescent substrate hydrolysis (total MMP activity) were employed in resection specimens from 50 patients, four with adenomas and 46 with colorectal cancer. RESULTS: The levels of active MMP-2 and MMP-9 and total MMP-1, MMP-3 and TIMP-1 were significantly greater in tumour tissue than in normal colon (e.g. TIMP-1 tumour median 72 (range 25-351) versus normal 26 (4-107) ng per mg total protein content; P<0.05); however, TIMP-2 levels were significantly greater in normal tissue (P<0.05). Total MMP activity was significantly greater in tumour than in normal tissue (15 025 (1750-174 400) versus 7250 (750-354 650) pmol l-1 min-1 mg protein-1; P<0.05). Correlations were found between both MMP and TIMP levels and pathological tumour staging. MMP-1 appeared to be most important as its concentration correlated positively with Dukes staging, tumour differentiation and lymphatic invasion. CONCLUSION: The levels of the studied MMPs and total MMP activity were upregulated in colorectal tumours. MMP-1 is important in colorectal cancer progression.     

Fibrosis and matrix metalloproteinases in rat renal allografts

The temporal activity and gene expression of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinase (TIMP) were investigated in a rat model of chronic allograft nephropathy. Gelatinolytic activity of MMP-2 and -9 were demonstrated by zymography, and MMP-2,-9 and TIMP-3 mRNA by in situ hybridization. The generation of fibrosis was determined as total collagen content/DNA. Significantly more latent and active MMP-2, as well as latent MMP-9, were seen in allografts than in autografts. Intense MMP-2 mRNA expression was demonstrated in the allografts during the first 20 days after transplantation, located mainly in the interstitium of the kidney. In addition, some tubular cells expressed MMP-2 mRNA. After day 20, MMP-2 gene expression was faint. MMP-9 mRNA expression in allografts was located mainly in the glomerulus. TIMP-3 mRNA expression was downregulated in allografts. MMP-2, MMP-9 and TIMP-3 seem to play a critical role in the development of fibrosis in the renal allograft.     

Circulating levels of matrix metalloproteinases and tissue inhibitors of metalloproteinases in patients with incisional hernia

Incisional hernia formation is a common complication to laparotomy and possibly associated with alterations in connective tissue metabolism. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are closely involved in the metabolism of the extracellular matrix. Our aim was to study serum levels of multiple MMPs and TIMPs in patients with and without incisional hernia. Out of 305 patients who underwent laparotomy, 79 (25.9%) developed incisional hernia over a median follow‐up period of 3.7 years. Pooled sera from a subset (n = 72) of these patients were screened for MMP‐1, MMP‐2, MMP‐3, MMP‐7, MMP‐8, MMP‐9, MMP‐10, MMP‐12, MMP‐13, TIMP‐1, TIMP‐2, and TIMP‐4 using a multiplex sandwich fluorescent immunoassay supplemented with gelatin zymography. The screening indicated differences in serum MMP‐9 and TIMP‐1 levels. Consequently, MMP‐9 and TIMP‐1 levels were measured in serum in the whole patient cohort with enzyme‐linked immunosorbent assay. There were no significant differences in either MMP‐9 (p = 0.411) or TIMP‐1 (p = 0.679) levels between hernia and hernia‐free patients. MMP‐9 was significantly increased in smokers compared with nonsmokers (p = 0.016). In conclusion, a possible involvement of MMPs and TIMPs in the pathogenesis of incisional hernia formation was not reflected systemically.