利用骨骼肌细胞高效表达人基质金属蛋白酶-9

为探讨利用培养的骨骼肌细胞表达人基质金属蛋白酶的可行性,利用PCR和DNA重组技术构建人mmp-9-myc-his/pcDNA3基因表达载体,转染成肌细胞QM-7,G418筛选阳性转染子.诱导细胞分化成肌管后,收集细胞培养上清.经Western印迹检测,表达产物分子量为93kD,与蛋白标准品对照推测表达量约10~15mg/L.利用Ni-NTA琼脂糖从1L培养上清中纯化到4~6mgMMP-9纯品,纯化效率约50%.经明胶酶谱检测,表达蛋白可以降解明胶.这些结果表明所表达的MMP-9具有生物活性,为以MMP-9为靶分子的特异拮抗剂和/或药物的筛选、MMP-9定量检测试剂盒的开发以及MMP-9的功能研究奠定了基础;以鹌鹑成肌细胞QM-7作为外源蛋白脊椎动物细胞表达体系具有表达量高、经济等优点,有可能进一步研究开发成为新的外源重组蛋白脊椎动物细胞表达体系.     

Matrix Metalloproteinase-9 Reduces Islet Amyloid Formation by Degrading Islet Amyloid Polypeptide

Deposition of islet amyloid polypeptide (IAPP) as amyloid is a pathological hallmark of the islet in type 2 diabetes, which is toxic to β-cells. We previously showed that the enzyme neprilysin reduces islet amyloid deposition and thereby reduces β-cell apoptosis, by inhibiting fibril formation. Two other enzymes, matrix metalloproteinase (MMP)-2 and MMP-9, are extracellular gelatinases capable of degrading another amyloidogenic peptide, Aβ, the constituent of amyloid deposits in Alzheimer disease. We therefore investigated whether MMP-2 and MMP-9 play a role in reducing islet amyloid deposition. MMP-2 and MMP-9 mRNA were present in mouse islets but only MMP-9 activity was detectable. In an islet culture model where human IAPP (hIAPP) transgenic mouse islets develop amyloid but nontransgenic islets do not, a broad spectrum MMP inhibitor (GM6001) and an MMP-2/9 inhibitor increased amyloid formation and the resultant β-cell apoptosis. In contrast, a specific MMP-2 inhibitor had no effect on either amyloid deposition or β-cell apoptosis. Mass spectrometry demonstrated that MMP-9 degraded amyloidogenic hIAPP but not nonamyloidogenic mouse IAPP. Thus, MMP-9 constitutes an endogenous islet protease that limits islet amyloid deposition and its toxic effects via degradation of hIAPP. Because islet MMP-9 mRNA levels are decreased in type 2 diabetic subjects, islet MMP-9 activity may also be decreased in human type 2 diabetes, thereby contributing to increased islet amyloid deposition and β-cell loss. Approaches to increase islet MMP-9 activity could reduce or prevent amyloid deposition and its toxic effects in type 2 diabetes.     

Interferon-Gamma Increases the Ratio of Matrix Metalloproteinase-9/Tissue Inhibitor of Metalloproteinase-1 in Peripheral Monocytes from Patients with Coronary Artery Disease

Acute coronary syndromes (ACS) may be triggered by acute infections. Systemic production of interferon gamma (IFN-γ) is induced during infection and regulates the production of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs), both important in plaque stability. This study evaluates the effect of IFN-γ on the MMPs/TIMP-1 ratio in cultured monocytes from 30 patients with stable coronary artery disease (CAD), 30 with unstable angina (UA) or non-ST-segment elevation myocardial infarction (NSTEMI), and 30 healthy blood donors. Supernatant concentrations of MMP-1, -2, -9, and TIMP-1 were measured by enzyme-linked immunoassays. Basal concentration of MMP-1 and TIMP-1 was similar between groups, while MMP-2 was higher in healthy individuals and MMP-9 in patients with UA/NSTEMI. Upon IFN-γ stimulation, MMP-9 secretion increased in all groups, while TIMP-1 decreased only in patients with CAD, which in turn result in a strikingly elevation in their mean MMP-9/TIMP-1 ratio. MMP-1/TIMP-1 and MMP-2/TIMP-1 ratios were <1.0 in basal conditions and after stimulation in all groups. Our results suggest that nonstimulated monocytes from patients with stable CAD show a similar behavior than those from healthy individuals. However, stimulation with IFN-γ induces an increase on the MMP-9/TIMP-1 ratio as high as that found in patients with ACS. Thus, it may bring biological plausibility to the association between acute infections and the development of ACS.     

Matrix Metalloproteinase-9 Protects Islets from Amyloid-induced Toxicity

Deposition of human islet amyloid polypeptide (hIAPP, also known as amylin) as islet amyloid is a characteristic feature of the pancreas in type 2 diabetes, contributing to increased β-cell apoptosis and reduced β-cell mass. Matrix metalloproteinase-9 (MMP-9) is active in islets and cleaves hIAPP. We investigated whether hIAPP fragments arising from MMP-9 cleavage retain the potential to aggregate and cause toxicity, and whether overexpressing MMP-9 in amyloid-prone islets reduces amyloid burden and the resulting β-cell toxicity. Synthetic hIAPP was incubated with MMP-9 and the major hIAPP fragments observed by MS comprised residues 1–15, 1–25, 16–37, 16–25, and 26–37. The fragments 1–15, 1–25, and 26–37 did not form amyloid fibrils in vitro and they were not cytotoxic when incubated with β cells. Mixtures of these fragments with full-length hIAPP did not modulate the kinetics of fibril formation by full-length hIAPP. In contrast, the 16–37 fragment formed fibrils more rapidly than full-length hIAPP but was less cytotoxic. Co-incubation of MMP-9 and fragment 16–37 ablated amyloidogenicity, suggesting that MMP-9 cleaves hIAPP 16–37 into non-amyloidogenic fragments. Consistent with MMP-9 cleavage resulting in largely non-amyloidogenic degradation products, adenoviral overexpression of MMP-9 in amyloid-prone islets reduced amyloid deposition and β-cell apoptosis. These findings suggest that increasing islet MMP-9 activity might be a strategy to limit β-cell loss in type 2 diabetes.     

Role of Matrix Metalloproteinase-9 Dimers in Cell Migration: DESIGN OF INHIBITORY PEPTIDES*

Non-proteolytic activities of matrix metalloproteinases (MMPs) have recently been shown to impact cell migration, but the precise mechanism remains to be understood. We previously demonstrated that the hemopexin (PEX) domain of MMP-9 is a prerequisite for enhanced cell migration. Using a biochemical approach, we now report that dimerization of MMP-9 through the PEX domain appears necessary for MMP-9-enhanced cell migration. Following a series of substitution mutations within the MMP-9 PEX domain, blade IV was shown to be critical for homodimerization, whereas blade I was required for heterodimerization with CD44. Blade I and IV mutants showed diminished enhancement of cell migration compared with wild type MMP-9-transfected cells. Peptides mimicking motifs in the outermost strands of the first and fourth blades of the MMP-9 PEX domain were designed. These peptides efficiently blocked MMP-9 dimer formation and inhibited motility of COS-1 cells overexpressing MMP-9, HT-1080, and MDA-MB-435 cells. Using a shRNA approach, CD44 was found to be a critical molecule in MMP-9-mediated cell migration. Furthermore, an axis involving a MMP-9-CD44-EGFR signaling pathway in cell migration was identified using antibody array and specific receptor tyrosine kinase inhibitors. In conclusion, we dissected the mechanism of pro-MMP-9-enhanced cell migration and developed structure-based inhibitory peptides targeting MMP-9-mediated cell migration.     

Gender-Dependent Differences in Plasma Matrix Metalloproteinase-8 Elevated in Pulmonary Tuberculosis

Tuberculosis (TB) remains a global health pandemic and greater understanding of underlying pathogenesis is required to develop novel therapeutic and diagnostic approaches. Matrix metalloproteinases (MMPs) are emerging as key effectors of tissue destruction in TB but have not been comprehensively studied in plasma, nor have gender differences been investigated. We measured the plasma concentrations of MMPs in a carefully characterised, prospectively recruited clinical cohort of 380 individuals. The collagenases, MMP-1 and MMP-8, were elevated in plasma of patients with pulmonary TB relative to healthy controls, and MMP-7 (matrilysin) and MMP-9 (gelatinase B) were also increased. MMP-8 was TB-specific (p<0.001), not being elevated in symptomatic controls (symptoms suspicious of TB but active disease excluded). Plasma MMP-8 concentrations inversely correlated with body mass index. Plasma MMP-8 concentration was 1.51-fold higher in males than females with TB (p<0.05) and this difference was not due to greater disease severity in men. Gender-specific analysis of MMPs demonstrated consistent increase in MMP-1 and -8 in TB, but MMP-8 was a better discriminator for TB in men. Plasma collagenases are elevated in pulmonary TB and differ between men and women. Gender must be considered in investigation of TB immunopathology and development of novel diagnostic markers.     

Neutrophil Infiltration and Matrix Metalloproteinase-9 in Lacunar Infarction

We use the modified pial vessel disruption rat model to elucidate the cellular and molecular mechanisms of cavitation as it plays a role in lacunar infarction. Here we discuss the similarities between the genesis of pulmonary cavitation in various animal models and lacunar infarction in the cerebral cortex of rats. Both pathological processes involve the creation of a cavity surrounded by fibroblasts or reactive astrocytes. A crucial step in both, the lung and the cerebral cortex, appears to be the migration of neutrophils across the endothelial barrier into the parenchyma. In the lung and cerebral cortex this involves release of matrix metalloproteinase-9 (MMP-9). Inside the parenchyma neutrophils continue to release MMP-9. In both situations batimastat (BB-94) and minocycline reduce release of MMP-9 and prevent cavitation. In the cerebral cortex MMP-9 release by resident microglia plays an additional role. We therefore advance the hypothesis that cavitation in both tissues is driven by MMP-9 originating from invading neutrophils. Therapeutic intervention has to focus on these blood-borne intruder cells and specific MMP actions. Batimastat and its derivatives (marimastat, BB-1101, mCGS-27023-A, ilomastat, GM6001, CTK8G1150) are already in clinical or experimental use in humans for anti-cancer treatment, and these clinically relevant drugs could be repurposed to act as anti-inflammatory to counter neutrophil contribution to lung or cerebral cortex cavitation.     

基质金属蛋白酶- 9, 组织抑制因子- 1 在进展期 胃癌中的表达与意义

目的：研究基质金属蛋白酶-9（matrix metalloproteinase-9,MMP-9）及其组织抑制因子-1（tissue inhibitor of metallopmteinase—1,TMP-1）在进展期胃癌中的表达情况,探讨二者的表达与胃癌侵袭转移闻的关系及二者间的联系。方法：应用免疫组化方法检测70例进展期胃癌标本中MMP-9,TIMP-1的表达,并进行回顾性随访。结果：馒反肌层以上者MMP-9的阳性表达（66．67％）明显高于肿瘤局限于粘膜、粘膜下者（20％P〈0.01）。MMP-9阳性表达与胃癌的淋巴转移与肝转移有相关性（P〈0．01）。TIMP-1的表达随胃癌浸润深度增加而减少,当肿瘤突破浆膜时TIMP-1的表达呈现陡降趋势（P〈0．01）。结论：MMP-9的过阳性表达和TIMP-1的表达失衡可能与胃癌转移行为有关。TIMP-1可能抑制胃癌的浸润转移。     

人基质金属蛋白酶-9在酵母Pichia pastoris中的表达

基质金属蛋白酶 - 9( MMP- 9)可促进恶性肿瘤的侵袭、转移 ,并在组织重建、胚胎发育以及伤口愈合等生理过程中发挥重要作用 .为研究这一蛋白的性质 ,并以之为靶标筛选抗肿瘤转移药物 ,在酵母 Pichia pastoris中实现了重组人 MMP- 9蛋白的高效、高活性、分泌表达 .首先用 PCR扩增了 MMP- 9基因编码区 (不含信号肽序列 ) ,经测序证实后 ,将其插入 p PIC9质粒中 ,构建表达载体 .用 Li C1 - PEG法转化酵母后 ,采用明胶 -酶谱法筛选获得 5株高效分泌表达 MMP- 9的克隆 ,经PCR证实 MMP- 9基因整合在阳性克隆的染色体中 .重组蛋白分子量为 93k D,表达量为 1 0 mg/L.重组蛋白可水解明胶及 型胶原 ,并可经有机汞 APMA诱导发生自剪切 ,转换成 85k D的激活形式 ,表明重组蛋白具有与天然人 MMP- 9蛋白相似的底物水解活性和自剪切激活特性 .     

Omega-3 and Omega-6 Fatty Acids Act as Inhibitors of the Matrix Metalloproteinase-2 and Matrix Metalloproteinase-9 Activity

Polyunsaturated fatty acids have been reported to play a protective role in a wide range of diseases characterized by an increased metalloproteinases (MMPs) activity. The recent finding that omega-3 and omega-6 fatty acids exert an anti-inflammatory effect in periodontal diseases has stimulated the present study, designed to determine whether such properties derive from a direct inhibitory action of these compounds on the activity of MMPs. To this issue, we investigated the effect exerted by omega-3 and omega-6 fatty acids on the activity of MMP-2 and MMP-9, two enzymes that actively participate to the destruction of the organic matrix of dentin following demineralization operated by bacteria acids. Data obtained (both in vitro and on ex-vivo teeth) reveal that omega-3 and omega-6 fatty acids inhibit the proteolytic activity of MMP-2 and MMP-9, two enzymes present in dentin. This observation is of interest since it assigns to these compounds a key role as MMPs inhibitors, and stimulates further study to better define their therapeutic potentialities in carious decay.     

基质金属蛋白酶-9及金属蛋白酶组织抑制剂-1在孕鼠胎盘形成中期的表达模式

目的探讨基质金属蛋白酶-9(MMP-9)及金属蛋白酶组织抑制剂-1(TIMP-1)在孕鼠胎盘形成中期的表达模式。方法 HE染色观察孕鼠第9天至第14天(D9~D14)胎盘形态结构的变化,同时免疫组织化学法检测相应天数胎盘中MMP-9和TIMP-1的表达情况。结果 HE染色结果显示孕鼠D11时胎盘的3层结构开始形成,包括蜕膜区(Dec)、海绵滋养细胞层(Sp)和迷路区(Lab);随着妊娠天数的增加,Dec区域逐渐缩小,Sp和Lab区域增大;免疫组化表明,MMP-9和TIMP-1均表达于细胞浆和细胞核中,MMP-9强表达于D9和D10胎盘的外胎盘锥中,D10~D13的Dec、Sp和D11~D13的滋养巨细胞中。MMP-9在D11的Lab,D12的Dec和Lab,D13的Dec、Sp、Lab区域中的阳性细胞的积分光密度值与D14胎盘中对应值比较,差异有统计学意义(P0.05);TIMP-1在D9~D12的Dec区域中的阳性细胞的积分光密度值与D14胎盘中对应值比较,差异有统计学意义(P0.05);MMP-9/TIMP-1在D9、D11的Dec及D12的Lab区域中的比值与D14胎盘中对应值比较,差异有统计学意义(P0.05),在D10、D12的Dec和D13的Lab区域中的比值与D14胎盘中对应值比较,差异有高度统计学意义(P0.01)。结论 MMP-9和TIMP-1在孕鼠胎盘中的协同表达可能参与调节胎盘的形成。     

Serum Matrix Metalloproteinase-9 Levels in the Diagnosis of Functioning Adrena Tumors

ObjectiveTo investigate whether serum matrix metalloproteinase-9 (MMP-9) levels can be used as a diagnostic tool in determining the functioning status of benign adrenal tumors.MethodsIn this case-control study, medical records of patients with adrenal tumors who consecutively presented to an endocrinology clinic between August 2005 and October 2008 were evaluated. Operation was recommended when the incidentaloma was larger than 4 cm or when a hypersecreting tumor was suspected. A control group of healthy persons matched for age, body mass index, and sex was also enrolled. Patients underwent routine endocrinologic examinations. MMP-9 levels were compared preoperatively and postoperatively. Findings were compared among patients with functioning adrenal tumors, patients with nonfunctioning adrenal tumors, and control participants.ResultsOf 370 patients with adrenal tumors, 50 with adrenal incidentaloma met the inclusion criteria. Twenty- five healthy individuals were enrolled as controls. Group 1 included 20 patients with functioning adrenal tumors (14 with Cushing syndrome and 6 with pheochromocytoma), and Group 2 included 30 patients with nonfunctioning adrenal tumors. MMP-9 levels were higher in patients with nonfunctioning adrenal tumors and functioning adrenal tumors than in control participants (P < .001). MMP-9 levels in patients with functioning adrenal tumors were significantly higher than those in patients with nonfunctioning adrenal tumors (P = .002). After operation, levels decreased significantly in patients with Cushing syndrome and in those with pheochromocytoma; however, patients with Cushing syndrome and pheochromocytoma had similar MMP-9 levels preoperatively and postoperatively. No significant linear correlation existed between tumor volume and MMP-9 levels. A significant positive correlation was determined between preoperative MMP-9 concentrations and 24-hour urinary fractionated metanephrine and epinephrine (r = 0.938, P = .006; r = 0.965, P = .002, respectively), between MMP-9 levels and baseline cortisol levels (r = 0.402, P = .003), and between MMP-9 levels and cortisol levels obtained after dexamethasone suppression testing (r = 0.357, P = .006).ConclusionOur data suggest that serum MMP-9 levels may be useful in differentiating benign subclinical functioning adrenal tumors from benign nonfunctioning adrenal tumors. (Endocr Pract. 2010;16:419-427)     

Elevation of Matrix Metalloproteinase-9 Level in Cerebrospinal Fluid of Tick-Borne Encephalitis Patients Is Associated with IgG Extravassation and Disease Severity

Background

Tick-borne encephalitis (TBE), caused by tick-borne encephalitis virus (TBEV), is an infectious disease involving the central nervous system (CNS). The pathogenesis of CNS injury has not been clearly demonstrated. Matrix metalloproteinase-9 (MMP-9) and some cytokines, such as interleukin 6 (IL-6), may play important roles in the disruption of the blood-brain barrier (BBB) and the pathogenesis of TBE.

Methods

72 cerebrospinal fluid (CSF) samples were collected from TBE patients in north eastern China. IgG levels in CSF and serum were compared and MMP-9 and IL-6 levels were evaluated by ELISA. The correlation between the elevated MMP-9 levels and IgG extravasation, disease severity, and neuroinflammation was analyzed.

Results

Increased concentration of MMP-9 was detected in some of the CSF samples, and the elevation was found to be closely related to CSF TBEV IgG extravasation and enhancement of IL-6 expression. Moreover, elevated levels of MMP-9 were found to be correlated with IL-6 enhancement. Four of the 72 patients, the ones who died, presented with high CSF MMP-9 levels.

Conclusions

In TBE patients, elevated CSF MMP-9 levels were associated with brain inflammatory reaction, disruption of the blood-brain barrier, and disease severity.     

Decreased Expression of Matrix Metalloproteinase-9 and Increased Expression of Tissue Inhibitors of Matrix Metalloproteinase-1 in Paratuberculosis-Infected Cattle in the ELISA-Negative Subclinical Stage

We investigated the gene expression of matrix metalloproteinases-9 (MMP-9) and tissue inhibitors of matrix metalloproteinases-1 (TIMP-1) in peripheral blood cells from infected cattle with Mycobacterium avium subsp. paratuberculosis (Map) in the ELISA-negative subclinical stage compared with uninfected control cattle. Significant decreased MMP-9 expression and increased TIMP-1 expression were found in peripheral blood cells from Map-infected cattle after stimulation with Map lysate and Map purified protein derivative (PPD) than in control cattle by real-time RT-PCR analysis. In contrast to the uninfected controls, the activity of MMP-9 was also decreased in peripheral blood cell culture supernatants from Map-infected cattle at 24 hr after Map lysate and MapPPD stimulation by gelatin zymography analysis. As a result, the MMP-9 may play an important role in the development of Mycobacterium avium subsp. paratuberculosis disease.     

A Novel Role of Matrix Metalloproteinase-8 in Macrophage Differentiation and Polarization

Matrix metalloproteinase-8 (MMP8) has been shown to influence various cellular functions. As monocytes and macrophages (Mφ) express MMP8, we investigated if MMP8 played a role in macrophage differentiation and polarization. MMP8 expression was significantly increased during monocyte differentiation into Mφ. Monocyte-derived Mφ from MMP8-deficient mice expressed higher levels of M1-Mφ markers but lower levels of M2-Mφ markers than monocyte-derived Mφ from wild-type mice. Although Mφ from either MMP8-deficient or wild-type mice were inducible by interferon-γ into M1-Mφ, only wild-type Mφ but not MMP8-deficient Mφ could be induced into M2-Mφ by interleukin-4. However, MMP8-deficient Mφ exposed to conditioned culture media of wild-type Mφ developed a M2-Mφ phenotype. Compared with conditioned culture media of wild-type Mφ, conditioned culture media of MMP8-deficient Mφ contained a lower concentration of active transforming growth factor-β (TGF-β), an M2-Mφ inducer. Moreover, evidence also showed that the degradation of the TGF-β sequester, fibromodulin, was modulated by MMP8. The data indicate a previously unknown role of MMP8 in M2-Mφ polarization by cleaving fibromodulin and therefore increasing the bioavailability of the M2-Mφ inducer TGF-β.     

Downregulation of CD9 in Keratinocyte Contributes to Cell Migration via Upregulation of Matrix Metalloproteinase-9

Tetraspanin CD9 has been implicated in various cellular and physiological processes, including cell migration. In our previous study, we found that wound repair is delayed in CD9-null mice, suggesting that CD9 is critical for cutaneous wound healing. However, many cell types, including immune cells, endothelial cells, keratinocytes and fibroblasts undergo marked changes in gene expression and phenotype, leading to cell proliferation, migration and differentiation during wound repair, whether CD9 regulates kerationcytes migration directly remains unclear. In this study, we showed that the expression of CD9 was downregulated in migrating keratinocytes during wound repair in vivo and in vitro. Recombinant adenovirus vector for CD9 silencing or overexpressing was constructed and used to infect HaCaT cells. Using cell scratch wound assay and cell migration assay, we have also demonstrated that downregulation of CD9 promoted keratinocyte migration in vitro, whereas CD9 overexpression inhibited cell migration. Moreover, CD9 inversely regulated the activity and expression of MMP-9 in keratinocytes, which was involved in CD9-regulated keratinocyte migration. Importantly, CD9 silencing-activated JNK signaling was accompanied by the upregulation of MMP-9 activity and expression. Coincidentally, we found that SP600125, a JNK pathway inhibitor, decreased the activity and expression of MMP-9 of CD9-silenced HaCaT cells. Thus, our results suggest that CD9 is downregulated in migrating keratinocytes in vivo and in vitro, and a low level of CD9 promotes keratinocyte migration in vitro, in which the regulation of MMP-9 through the JNK pathway plays an important role.     

基质金属蛋白酶-9、微量元素与胎膜早破的关系

胎膜早破的确切病因尚不清楚,近年来的研究更大程度上提示其发生与胎膜本身结构变化存在密切的联系.众多试验提示基质金属蛋白酶-9时胎膜结构的稳定性、完整性的维持起重要作用.铜、锌等微量元素缺乏或含量不足可导致胶原纤维合成受阻或不足,可使胎膜变脆、变薄而易发生胎膜破裂.